diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_1.txt b/notes/A K Khurana - Comprehensive Ophthalmology_1.txt new file mode 100644 index 0000000000000000000000000000000000000000..5daaf7593fcd29ddc9c031608dbc17d3913b79fb --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_1.txt @@ -0,0 +1,1599 @@ + + + + +Comprehensive Ophthalmology +S I X t h E d I t I O n + + + +Comprehensive OphthalmOlOgy + + + + + +aK Khurana ms faico cto (London) +Senior Professor and Head Regional Institute of Ophthalmology +Postgraduate Institute of Medical Sciences Rohtak, India + +aruj K Khurana +dnb (Sankara Nethralaya, Chennai) fico +Department of Ophthalmology Himalayan Institute of Medical Sciences Jolly Grant, Dehradun (UK), India + +Bhawna Khurana ms dnb fico +Department of Ophthalmology +All India Institute of Medical Sciences (AIIMS) Rishikesh (UK), India + + + + + + + + + + +The Health Sciences Publisher New Delhi | London | Philadelphia | Panama + + +Jaypee Brothers Medical Publishers (P) Ltd + + + + +Headquarters +Jaypee Brothers Medical Publishers (P) Ltd 4838/24, Ansari Road, Daryaganj +New Delhi 110 002, India Phone: +91-11-43574357 Fax: +91-11-43574314 +Email: jaypee@jaypeebrothers.com + + +Overseas Offices +J.P. Medical Ltd +83, Victoria Street, London SW1H 0HW (UK) +Phone: +44 20 3170 8910 Fax: +44 (0)20 3008 6180 Email: info@jpmedpub.com + +Jaypee Brothers Medical Publishers (P) Ltd 17/1-B Babar Road, Block-B, Shaymali Mohammadpur, Dhaka-1207 +Bangladesh +Mobile: +08801912003485 Email: jaypeedhaka@gmail.com + + +Jaypee-Highlights Medical Publishers Inc City of Knowledge, Bld. 237, Clayton Panama City, Panama +Phone: + 1 507-301-0496 Fax: + 1 507-301-0499 +Email: cservice@jphmedical.com + +Jaypee Brothers Medical Publishers (P) Ltd Bhotahity, Kathmandu +Nepal +Phone: +977-9741283608 +Email: kathmandu@jaypeebrothers.com + + +Jaypee Medical Inc The Bourse +111 South Independence Mall East Suite 835, Philadelphia, PA 19106, USA Phone: + 1 267-519-9789 +Email: jpmed.us@gmail.com + + + + +Website: www.jaypeebrothers.com Website: www.jaypeedigital.com + +© 2015, AK Khurana + +The views and opinions expressed in this book are solely those of the original contributor(s)/author(s) and do not necessarily represent those of editor(s) of the book. + +All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission in writing of the publishers. + +All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. + +Medical knowledge and practice change constantly. This book is designed to provide accurate, authoritative information about the subject matter in question. However, readers are advised to check the most current information available on procedures included and check information from the manufacturer of each product to be administered, to verify the recommended dose, formula, method and duration of administration, adverse effects and contraindications. It is the responsibility of the practitioner to take all appropriate safety precautions. Neither the publisher nor the author(s)/editor(s) assume any liability for any injury and/or damage to persons or property arising from or related to use of material in this book. + +This book is sold on the understanding that the publisher is not engaged in providing professional medical services. If such advice or services are required, the services of a competent medical professional should be sought. + +Every effort has been made where necessary to contact holders of copyright to obtain permission to reproduce copyright material. If any have been inadvertently overlooked, the publisher will be pleased to make the necessary arrangements at the first opportunity. + +Inquiries for bulk sales may be solicited at: jaypee@jaypeebrothers.com + +Comprehensive Ophthalmology + +First Edition: 1996 Sixth Edition: 2015 +ISBN 978-93-5152-657-5 + +Printed at + + + + + + + + + + + + + + + + + + + + + + +Dedicated + +To my parents and teachers for their blessings To my students for their encouragement To my children for their patience To my wife for her understanding + +Preface + + + + + + +Journey of Comprehensive Ophthalmology, beginning from January 1996, has been satisfying, as it has succeeded in serving the needs of the students at large. Thoroughly revised and updated sixth edition of the book retains its well accepted style of presenting the text. However, to make it more user-friendly its layout has been re-organized into six sections as against two sections in the fifth edition. +Section 1: Anatomy and Physiology of Eye includes two chapters. First chapter is devoted to essential aspects of Anatomy and Development of the Eye, and second chapter covers Physiological aspects of various ocular structures including Physiology of Vision in a concise manner. +Section II: Optics and Refraction. Out of two chapters of this section one is devoted to Elementary and Physiological Optics and the other describes Errors of Refraction and Accommodation in depth. +Section III: Diseases of Eye. This section covers important diseases of various structure components of the eyeball, ocular adnexa and visual pathway in fourteen chapters. +Section IV: Ocular Therapeutics. This section comprises two chapters one each on Ocular Pharmacology, and Lasers and Cryotherapy in Ophthalmology. +Section V: Systemic and Community Ophthalmology includes two chapters one on each topic. +Section VI: Practical Ophthalmology. This section includes chapters on Clinical Methods in Ophthalmology and different other aspects essential to the practical examinations such as Ophthalmic Cases, Darkroom Procedures, and Ophthalmic Instruments. +Review of Ophthalmology. This companion to the textbook provides an in depth revision of the subject at a glance and an opportunity for self-assessment, and thus makes it the book of choice for preparing for various postgraduate entrance examinations. + +Salient Features of the Book +ƒEach chapter begins with a brief overview highlighting the topics covered followed by relevant applied anatomy and physiology. The text is then organized in such a way that the students can easily understand, retain and reproduce it. Various levels of headings, subheadings, bold face and italics given in the text will be helpful for a quick revision of the subject. +ƒText is complete and up-to-date with recent advances. To be true, some part of the text is in more detail than the requirement of undergraduate students. But this very feature of the book makes it a useful handbook for the postgraduate students as well. +ƒText is illustrated with plenty of diagrams, comprising clinical photographs and clear-line diagrams which provide vivid and lucid details. +ƒOperative steps of important surgical techniques have been given in the relevant chapters. ƒWherever possible important information has been given in the form of tables and flow charts. +Sixth Edition of the book has been possible as a result of active criticism, suggestions and generous help of many teachers and students. Surely, I owe sincere thanks to them all. Those who need special mention are Prof. R.C. Nagpal, Prof. Harsh Bahadur and Prof. Renu Dhasmana from HIMS, Jolly Grant, Dehradun; Prof. G.S. Bajwa, DMC, Ludhiana; Prof. R.N. Bhatnagar, Gian Sagar Medical College, Rajpura; Prof. P.S. Sandhu, Faridkot; Prof. S.S. Shergill, Amritsar; Prof. Dharamveer, Patiala; Prof. S.M. Bhati and Prof. Nitin Batra from CMC, Ludhiana; Prof. V.P. Gupta, UCMS, New Delhi; Prof. K.P. Chaudhary, GMC, Shimla; Prof. Atul Kumar, and Prof. Tanuj Dada from Dr. R.P. Centre for Ophthalmic Sciences, AIIMS, New Delhi; Prof. Vishnu Gupta and Prof. B.P. Guliani from VMMC, New Delhi; Prof. Amod Gupta, Prof. Jagat Ram and Prof. M.R. Dogra from PGIMER, Chandigarh and Dr.Mahipal S. Sachdev, Medical Director, Centre for Sight, New Delhi. +viii Comprehensive Ophthalmology + +I acknowledge the special help rendered by Prof. S. Sood from GMC, Chandigarh by contributing fundus photographs and OCT pictures; Dr. Santosh Honavar from CFS, Hyderabad for some figures of orbital tumours and Dr. Shweta Goel for her sincere help in updating this edition. I am grateful to Dr. C.S. Dhull, Director, PGIMS and Dr. S.S. Sangwan, Vice-Chancellor, University of Health Sciences, Rohtak for providing an academic atmosphere conducive to such a venture. I acknowledge with humble thanks, the respect, affection and cooperation of faculty members of Regional Institute of Ophthalmology (RIO), PGIMS, Rohtak namely Dr. S.V. Singh, Dr. J.P. Chugh, Dr. V.K. Dhull, Dr. R.S. Chauhan, Dr. Manisha Rathi, Dr. Neebha Anand, Dr. Manisha Nada, Dr. Urmil Chawla, Dr. Ashok Rathi, Dr. Sumit Sachdeva, Dr. Sumeet Khanduja, Dr. Reena Gupta and Dr. Jitender Phogat. +The love and moral support, in addition to the editorial help, rendered by my daughter Dr. Arushi, University of Connecticut, USA, and my wife Dr. Indu Khurana, Senior Professor, Physiology made my task untiring. +The enthusiastic cooperation received from Shri Jitendar P Vij (Group Chairman), Mr Ankit Vij (Group President), Mr Tarun Duneja (Director–Publishing), Ms. Sunita Katla (Publishing Manager), Mr. Rajesh Sharma (Author Coordinator), and Mr. Sumit Kumar (Graphic Designer), Ms. Seema Dogra (Cover Designer), Ms. Geeta Srivastava and Geeta Barik (Proof Readers) and Mr. Kapil Dev Sharma (DTP Operator) of Jaypee Brothers Medical Publishers (P) Ltd., New Delhi, needs special acknowledgement. +Sincere efforts have been made to verify the correctness of the text. However, in spite of best efforts, ventures of this kind are not likely to be free from human errors, some inaccuracies, ambiguities and typographic mistakes. Users are therefore requested to send their feedback and suggestions. The importance of such views in improving the future editions of the book cannot be overemphasized. Feedbacks received will be highly appreciated and duly acknowledged. + +A K Khurana + +Contents + + + + + +Preface vii + +Section I Anatomy and Physiology of Eye + +1. Anatomy and Development of Eye 3 2. Physiology of Eye and Vision 14 + +Section II Optics and Refraction + +3. Elementary and Physiological Optics 23 4. Errors of Refraction and Accommodation 34 + +Section III Diseases of Eye + +5. Diseases of Conjunctiva 59 6. Diseases of Cornea 95 7. Diseases of Sclera 140 8. Diseases of Uveal Tract 146 9. Diseases of Lens 179 10. Glaucoma 219 11. Diseases of Vitreous 257 12. Diseases of Retina 263 13. Neuro-ophthalmology 310 14. Disorders of Ocular Motility 336 15. Disorders of Eyelids 362 16. Diseases of Lacrimal Apparatus 386 17. Diseases of Orbit 401 18. Ocular Injuries 426 + +Section IV Ocular Therapeutics + +19. Ocular Pharmacology 443 20. Lasers and Cryotherapy in Ophthalmology 461 + +Section V Systemic and Community Ophthalmology + +21. Systemic Ophthalmology 467 22. Community Ophthalmology 475 +x Comprehensive Ophthalmology + +Section VI Practical Ophthalmology + +23. Clinical Methods in Ophthalmology 493 24. Clinical Ophthalmic Cases 528 25. Darkroom Procedures 566 26. Ophthalmic Instruments and Operative Ophthalmology 591 + +Index 611 +Section I + + + +Anatomy and Physiology of Eye + + + + + + +Section Outline + +1. Anatomy and Development of Eye 2. Physiology of Eye and Vision +1 +Anatomy and Development of Eye + + +Chapter Outline + +ANATOMY OF EYE Eyeball +Visual pathway +• +• +• +• +Orbit, extraocular muscles and appendages of the eye Blood vessels and nerves +DEVELOPMENT OF EYE +• +Formation of optic vesicle and optic stalk + + + +ANATOMY OF EYE + +This chapter gives only a brief account of the anatomy of eyeball and its related structures. The detailed anatomy of different structures is described in the relevant chapters. +EyEball +Each eyeball (Fig. 1.1) is a cystic structure kept distended by the pressure inside it. +• Shape. Although, generally referred to as a globe, the eyeball is not a sphere but an oblate spheroid. +• Poles. The central point on the maximal convexities of the anterior and posterior curvatures of the eyeball is called the anterior and posterior pole, respectively. +• Equator of the eyeball lies at the mid plane between the two poles (Fig. 1.2). +Dimensions of an adult eyeball +• Anteroposterior diameter 24 mm +• Horizontal diameter 23.5 mm • Vertical diameter 23 mm +• Circumference 75 mm • Volume 6.5 ml • Weight 7 gm +Coats of the eyeball +The eyeball comprises three coats: outer (fibrous coat), middle (vascular coat) and inner (nervous coat). 1. Fibrous coat. It is a dense strong wall which protects the intraocular contents. Anterior 1/6th of + +• Formation of lens vesicle • Formation of optic cup +• Changes in the associated mesenchyme • Development of various ocular structures +• Structures derived from the embryonic layers +• Important milestones in the development of eye + + + +this fibrous coat is transparent and is called cornea. Posterior 5/6th opaque part is called sclera. Cornea is set into the sclera like a watch glass. Junction of the cornea and sclera is called limbus. Conjunctiva is firmly attached at the limbus. +2. Vascular coat (uveal tissue). It supplies nutrition to the various structures of the eyeball. It consists of three parts, from anterior to posterior, which are: iris, ciliary body and choroid. +3. Nervous coat (retina). It is concerned with visual functions and projects to visual cortex through the visual pathway. +Segments and chambers of the eyeball +The eyeball can be divided into two segments: anterior and posterior. +1.Anterior segment.It includes crystalline lens (which is suspended from the ciliary body by zonules), and structures anterior to it, viz., iris, cornea and two aqueous humour-filled spaces : anterior and posterior chambers. +■Anterior chamber. It is bounded anteriorly by the back of cornea, and posteriorly by the anterior surface of iris and part of ciliary body. The anterior chamber is about 2.5 mm deep in the centre in normal adults. It is slightly shallower in hypermetropes and deeper in myopes, but is almost equal in the two eyes of the same individual. It contains about 0.25 ml of the aqueous humour. It communicates with posterior chamber through the pupil. +4 Section i Anatomy and Physiology of Eye + + + + + + + + + + + + + + + + + + + + + +Fig. 1.1 Gross anatomy of the eyeball + + + + + + + + + + + + + + +Fig. 1.2 Poles and equators of the eyeball + + +■Posteriorchamber.It is a triangular space containing 0.06 ml of aqueous humour. It is bounded anteriorly by the posterior surface of iris and part of ciliary body, posteriorly by the crystalline lens and its zonules, and laterally by the ciliary body. +2. Posterior segment. It includes the structures posterior to lens, viz., vitreous humour (a gel-like material which fills the space behind the lens), retina, choroid and optic disc. + +ViSual Pathway +Each eyeball acts as a camera; it perceives the images and relays the sensations to the brain (occipital cortex) via visual pathway which comprises optic nerves, optic chiasma, optic tracts, geniculate bodies +and optic radiations (Fig. 1.3). + +Orbit, ExtraOCular MuSClES anD aPPEnDagES Of thE EyE +Each eyeball is suspended by extraocular muscles and fascial sheaths in a quadrilateral pyramid-shaped bony cavity called orbit (Fig. 1.4). Each eyeball is located in the anterior orbit, nearer to the roof and lateral wall than to the floor and medial wall. Each eye is protected anteriorly by two shutters called the eyelids.The anterior part of the sclera and posterior surface of lids are lined by a thin membrane called conjunctiva. For smooth functioning, the cornea and conjunctiva are to be kept moist by tears which are produced by lacrimal gland and drained by the lacrimal passages. These structures (eyelids, eyebrows, conjunctiva and lacrimal apparatus) are collectively called ‘the appendages of the eye’. + + + + + + + + + + + + + + + +Fig. 1.3 Gross anatomy of the visual pathway +Chapter 1 Anatomy and Development of Eye 5 + + + + + + + + + + +Fig. 1.4 Section of the orbital cavity to demonstrate eyeball and its accessory structures + +blOOD VESSElS anD nErVES Arteries +Ophthalmic artery, a branch of internal carotid artery, constitutes the main source of blood supply for the eyeball and other orbital structures. Blood supply of each ocular structure is described in the relevant chapters. +• Branchesofophthalmicartery are shown in Fig. 1.5. • Arterialsupplyofeyeballis depicted in Fig. 1.6. +Veins +Veins draining blood from the eyeball include (Figs. 1.6 and 1.7): +• Central retinal vein which drains blood from the retina; and +• Anterior ciliary veins, short posterior ciliary veins and venae verticosae which drain blood from the uveal tissue. +Main venous channels which ultimately get tributaries from various orbital structures include (Fig. 1.7): +• Superior ophthalmic vein, • Inferior ophthalmic vein, • Middle ophthalmic vein, • Medial ophthalmic vein, +• Angular vein, and • Cavernous sinus. +Nerves Sensory nerves Ophthalmic nerve +Ophthalmic nerve, smallest of the three divisions of trigeminal (5th cranial) nerve, supplies the various ocular structures through its three branches (Fig. 1.8): 1. Lacrimal nerve. It lies in the lateral part of the orbit and supplies lacrimal gland, conjunctiva and lateral part of upper eyelid. +2. Frontal nerve. It divides into two branches in the middle of orbit: +■Supratrochlear nerve supplies the conjunctiva, middle part of upper eyelid, and skin of the forehead above the root of nose. +■Supraorbitalnerve supplies the conjunctiva, central part of upper eyelid, and part of the skin of forehead and scalp. + + + + + + +Fig.1.5 Ophthalmic artery and its branches + +3. Nasociliary nerve. It has following branches: ■Longciliarynerves,two in number, pierce the sclera on either side of optic nerve, run forward between sclera and choroid and supply sensory nerves to the ciliary body, iris and cornea. ■Communicatingbranchestociliaryganglion form its sensory root and their fibres pass along the short ciliary nerves, to supply the ciliary body, iris and cornea. ■Posterior ethmoidal nerve supplies the ethmoidal and sphenoidal air sinuses. +■Anterior ethmoidal nerve is a terminal branch of nasociliary nerve which leaves the orbit through the anterior ethmoidal foramen. +■Infratrochlearnerve is the other terminal branch of nasociliary nerve. It runs forward and supplies the conjunctiva, lacrimal sac, caruncle, and medial part of the eyelids. + + + + + + + + + + + + + + + + + + + + + +Fig. 1.6 Blood supply of eyeball +6 Section i Anatomy and Physiology of Eye + + + + + + + + + + + + + + + + + + +Fig.1.7 Schematic drawing showing orbital veins draining blood from the ocular tissues + + +Motor nerves +• 3rd, 4th and 6th cranial nerves supply the extraocular muscles, and +• 7th cranial nerve branches supply the orbicularis oculi muscle of the eyelids. +autonomic nerves Parasympathetic nerves +Edinger-Westphal nucleus, located in midbrain (Fig. 1.9), sends preganglionic fibres through the third cranial nerve to ciliary ganglion and accessory ganglion. Postganglionic nerve fibres from ciliary ganglion travel along the short ciliary nerves to supply the sphincter pupillae muscle and postganglionic fibres from the accessory ganglion supply the ciliary muscle. + +Salivatory nucleus, located in pons (Fig. 1.10), sends preganglionic fibres through facial nerve to the sphenopalatine ganglion. Postganglionic secretomotor fibres finally reach the lacrimal gland through the lacrimal nerve. + +Ciliary ganglion +Ciliary ganglion is a peripheral parasympathetic ganglion placed in the course of oculomotor nerve near the apex of orbit (Fig. 1.9). +Roots of ciliary ganglion include: +■Sensory root, as described above, comes from the nasociliary nerve. +■Sympathetic root of ciliary ganglion comes from internal carotid plexus. These fibres also do not relay + + + + + + + + + + + + + + + + + + + + +Fig.1.8 Ophthalmic nerve and its branches +Chapter 1 Anatomy and Development of Eye 7 + + + + + + + + + + + + + + + + + + + +Fig.1.9 Course of parasympathetic nerve supply from Edinger-Westphal nucleus to ciliary muscle and sphincter pupillae muscle + +here and pass along the short ciliary nerves to supply the blood vessels of the eyeball. +■Parasympathetic root of ciliary ganglion arises from the nerve to inferior oblique muscle and carries the preganglionic fibres from the Edinger–Westphal nucleus. These fibres relay here and postganglionic fibres pass through the short ciliary nerves and supply the sphincter pupillae and ciliary muscle. +Short ciliary nerves, branches of ciliary ganglion, about 10 in number, pierce the sclera around the optic nerve and run forward between the sclera and choroid and reach the ciliary muscles where the sensory fibres form a plexus and supply it. + + +Sympathetic nerves +Preganglionic fibres arise from the ciliospinal center of Budge (located in inferio mediolateral cell column of spinal cord at C8, T1 and T2 level) and go to cervical sympathetic chain to relay in the superior cervical ganglion (Fig. 1.11). +Postganglionic fibres from the superior cervical ganglion enter the skull with the internal carotid plexuses and supply following structures: +■Orbital arteries receive vasomotor fibres through the plexuses around ophthalmic artery. +■Dilator pupillae muscle is supplied by the sympathetic fibres from the carotid plexuses which + + + + + + + + + + + + + + + + + + + +Fig.1.10 Course of parasympathetic nerve supply from lacrimatory nucleus to the lacrimal gland +8 Section i Anatomy and Physiology of Eye + + + + + + + + + + + + + + + + + + + + +Fig.1.11 Course of ocular sympathetic nerves + + +enter the Gasserian ganglion of 5th cranial nerve and ultimately reach the dilator pupillae muscle along with long ciliary branches of nasociliary nerve (branch of ophthalmic division of 5th nerve). ■Blood vessels inside the eyeball are supplied by the fibres from the internal carotid plexuses which join the ciliary ganglion as its sympathetic root and without relaying here these fibres enter inside the eyeball along the short ciliary nerves. These fibres may also supply the dilator pupillae muscle when it is not supplied by the usual course via the nasociliary nerve. ■Palpebral(Muller’s)muscleoftheeyelid is supplied by the postganglionic fibres forming cavernous plexuses reaching the muscle through the branches of oculomotor (3rd cranial) nerve. + + + + + + + + + + + + + + + +Fig.1.12 Lymphatic drainage of eyelids, conjunctiva and orbital tissues + +Lymphatic drainage +Lymphatics draining the eyelids, conjunctiva and orbital tissues are arranged in two groups (Fig. 1.12): • Medial group of lymphatics drain into the sub- +mandibular lymph nodes, and +• Lateral group of lymphatics drain into the sub-auricular lymph nodes. + +DEVELOPMENT OF EYE +Development of eyeball can be considered to commence around day 22 when the embryo has eight pairs of somites and is around 2 mm in length. Eyeball and its related structures are derived from the following primordia: +• Optic vesicle, an outgrowth from prosencephalon (a neuroectodermal structure), +• Lens placode, a specialized area of surface ectoderm, and the surrounding surface ectoderm, +• Mesenchyme surrounding the optic vesicle, and • Visceral mesoderm of maxillary processes. +Before going into the development of individual structure, it will be helpful to understand the formation of optic vesicle, lens placode, optic cup and changes in the surrounding mesenchyme, which play a major role in the development of the eye and its related structures. +fOrMatiOn Of OPtiC VESiClE anD OPtiC Stalk +The area of neural plate (Fig. 1.13A) which forms the prosencephalon develops a linear thickened area on either side (Fig. 1.13B), which soon becomes depressed to form the optic sulcus (Fig. 1.13C). Meanwhile +Chapter 1 Anatomy and Development of Eye 9 + +overlying the optic vesicle becomes thickened to form the lens placode (Fig. 1.14A) which sinks below the surface and is converted into the lens vesicle (Figs. 1.14B and C). It is soon separated from the surface ectoderm at 33rd day of gestation (Fig. 1.14D). +fOrMatiOn Of OPtiC CuP +The optic vesicle is converted into a double-layered optic cup. It appears from Fig. 1.15 that this has happened because the developing lens has invaginated itself into the optic vesicle. In fact conversion of the optic vesicle to the optic cup is due to differential growth of the walls of the vesicle. The margins of optic cup grow over the upper and lateral sides of the lens to enclose it. However, such a growth does not take place over the inferior part of the lens, and therefore, the walls of the cup show deficiency in this part. This deficiency extends to some distance along the inferior surface of the optic stalk and is called the choroidal or fetal fissure (Fig. 1.15). + +ChangES in thE aSSOCiatED MESEnChyME The developing neural tube (from which central nervous system develops) is surrounded by mesenchyme, which subsequently condenses to + + + + + + + +Fig. 1.13 Formation of the optic vesicle and optic stalk +the neural plate gets converted into prosencephalic vesicle. As the optic sulcus deepens, the walls of the prosencephalon overlying the sulcus bulge out to form the optic vesicle (Figs. 1.13D, E and F). The proximal part of the optic vesicle becomes constricted and elongated to form the opticstalk (Figs. 1.13G and H). + +fOrMatiOn Of lEnS VESiClE +The optic vesicle grows laterally and comes in contact with the surface ectoderm. The surface ectoderm, + + + + + + + + + + + +Fig. 1.15 Optic cup and stalk seen from below to show the choroidal fissure + + + + + + + + + + + +Fig. 1.14 Formation of lens vesicle and optic cup +10 Section i Anatomy and Physiology of Eye + + + + + + + + + + + + + +Fig. 1.16 Developing optic cup surrounded by mesenchyme + +form meninges. An extension of this mesenchyme also covers the optic vesicle. Later, this mesenchyme differentiates to form a superficial fibrous layer (corresponding to dura) and a deeper vascular layer (corresponding to pia-arachnoid) (Fig. 1.16). With the formation of optic cup, part of the inner vascular layer of mesenchyme is carried into the cup through the choroidal fissure. With the closure of this fissure, the portion of mesenchyme which has made its way into the eye is cut off from the surrounding mesenchyme and gives rise to the hyaloid system of +the vessels (Fig. 1.17). +The fibrous layer of mesenchyme surrounding the anterior part of optic cup forms the cornea. The corresponding vascular layer of mesenchyme becomes the iridopupillary membrane, which in the peripheral region attaches to the anterior part of the optic cup to form the iris. The central part of this lamina is pupillary membrane which also forms the tunica vasculosa lentis (Fig. 1.17). +In the posterior part of optic cup the surrounding fibrous mesenchyme forms sclera and extraocular muscles, while the vascular layer forms the choroid and ciliary body. + + + + + + + + + + + + + + +Fig. 1.17 Derivation of various structures of the eyeball + +DEVElOPMEnt Of VariOuS OCular StruCturES +retina +Retina is developed from the two walls of the optic cup, namely: +• Nervous retina from the inner wall, and Pigment epithelium from the outer wall (Fig. 1.18). +Nervous retina. The inner wall of the optic cup is a single-layered epithelium. It divides into several layers of cells which differentiate into the following three layers (as also occurs in neural tube): +• Matrix cell layer. Cells of this layer form the rods and cones. +• Mantle layer. Cells of this layer form the bipolar cells, ganglion cells, other neurons of retina and the supporting tissue. +• Marginallayer. This layer forms the ganglion cells, axons of which form the nerve fibre layer. +Pigment epithelial layer. Cells of the outer wall of the optic cup become pigmented. Its posterior part forms the pigmented epithelium of retina and the anterior part continues forward in ciliary body and iris as their anterior pigmented epithelium. + + + + + + + + + + + + + +Fig. 1.18 Development of the retina + +Optic nerve +Optic nerve develops in the framework of optic stalk as below: +■Optic nerve fibres develop from the nerve fibre layer of retina which grow into the optic stalk by passing through the choroidal fissure (by 6th week of gestation) and pass posteriorly to the brain. ■Glial system of the nerve develops from the neuro-ectodermal cells forming the outer wall of the optic stalk. Glial septa surrounding the nerve bundles are composed of astroglia that differentiate from the cells of the inner wall of the optic stalk. ■Sheathsofopticnerve are formed from the layers of mesenchyme like meninges of other parts of central nervous system. +Chapter 1 Anatomy and Development of Eye 11 + + +■Myelination of nerve fibres takes place from brain distally and reaches the lamina cribrosa just before birth and stops there. In some cases, this extends up to around the optic disc and presents as congenital opaque nerve fibres. These develop after birth. +Crystalline lens +The crystalline lens is developed from the surface ectoderm as below: +Lens placode and lens vesicle formation (see page 9 and Fig. 1.14). +Primary lens fibres. The cells of posterior wall of lens vesicle elongate rapidly to form the primary lens fibres which obliterate the cavity of lens vesicle. The primary lens fibres are formed upto 3rd month of gestation and are preserved as the compact core of lens, known as embryonic nucleus (Fig. 1.19). Secondary lens fibres are formed from equatorial cells of anterior epithelium which remain active throughout life. Since the secondary lens fibres are laid down concentrically, the lens on section has a laminated appearance. Depending upon the period of development, the secondary lens fibres are named as below: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 1.19 Development of the crystalline lens + +• Fetal nucleus (3rd to 8th month), +• Infantilenucleus (last weeks of fetal life to puberty), • Adult nucleus (after puberty), and +• Cortex (superficial lens fibres of adult lens). +Lens capsule isa true basement membrane produced by the lens epithelium on its external aspect. +Cornea +1. Epithelium is formed from the surface ectoderm. 2. Other layers viz. endothelium, Descemet’s mem-brane, pre-Descemet’s membrane, stroma and Bowman’s layer are derived from the fibrous layer of mesenchyme lying anterior to the optic cup (Fig. 1.17). +Sclera +Sclera is developed from the fibrous layer of mesenchyme surrounding the optic cup (corres-ponding to dura of CNS) (Fig. 1.17). +Choroid +Choroid is derived from the inner vascular layer of mesenchyme that surrounds the optic cup (Fig. 1.17). +Ciliary body +■Thetwolayersofepithelium of ciliary body develop from the anterior part of the two layers of optic cup (neuroectodermal). +■Stroma of ciliary body, ciliary muscle and blood vessels are developed from the vascular layer of mesenchyme surrounding the optic cup (Fig. 1.17). +iris +• Both layers of epithelium are derived from the marginal region of optic cup (neuroectodermal) (Fig. 1.17). +• Sphincteranddilatorpupillae muscles are derived from the anterior epithelium (neuroectodermal). +• Stroma and blood vessels of the iris develop from the vascular mesenchyme present anterior to the optic cup. +Vitreous +1. Primary or primitive vitreous is mesenchymal in origin and is a vascular structure having the hyaloid system of vessels. +2. Secondary or definitive or vitreous proper is secreted by neuroectoderm of optic cup. This is an avascular structure. When this vitreous fills the cavity, primitive vitreous with hyaloid vessels is pushed anteriorly and ultimately disappears. +3. Tertiaryvitreous is developed from neuroectoderm in the ciliary region and is represented by the ciliary zonules. +Eyelids +Eyelids are formed by reduplication of surface ectoderm above and below the cornea (Fig. 1.20). +12 Section i Anatomy and Physiology of Eye + + +The folds enlarge and their margins meet and fuse with each other. The lids cut off a space called the conjunctival sac. The folds thus formed contain some mesoderm which would form the muscles of the lid and the tarsal plate. The lids separate after the seventh month of intrauterine life. +• Tarsal glands are formed by ingrowth of a regular row of solid columns of ectodermal cells from the lid margins. +• Cilia develop as epithelial buds from lid margins. + +Conjunctiva +Conjunctiva develops from the ectoderm lining the lids and covering the globe (Fig. 1.20). ■Conjunctivalglandsdevelop as growth of the basal cells of upper conjunctival fornix. Fewer glands develop from the lower fornix. +the lacrimal apparatus +■Lacrimal gland develops from about 8 cuneiform epithelial buds which grow by the end of 2nd month of fetal life from the superolateral side of the conjunctival sac (Fig. 1.20). +■Lacrimal sac, nasolacrimal duct and canaliculi develop from the ectoderm of nasolacrimal furrow which extends from the medial angle of eye to + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 1.20 Development of the eyelids, conjunctiva and lacrimal gland + +the region of developing mouth. The ectoderm gets buried to form a solid cord which is later canalized. The upper part forms the lacrimal sac. The nasolacrimal duct is derived from the lower part as it forms a secondary connection with the nasal cavity. The ectodermal buds arise from the medial margins of eyelids which are later canalized to form the canaliculi. +Extraocular muscles +All the extraocular muscles develop in a closely associated manner by mesodermally derived mesenchymal condensation. This probably corresponds to preotic myotomes, hence the triple nerve supply (III, IV and VI cranial nerves). +StruCturES DEriVED frOM thE EMbryOniC layErS +Based on the above description, the various structures derived from the embryonic layers are given below: +1. Surface ectoderm • The crystalline lens +• Epithelium of the cornea +• Epithelium of the conjunctiva • Lacrimal gland +• Epithelium of eyelids and its derivatives viz., cilia, tarsal glands and conjunctival glands +• Epithelium lining the lacrimal apparatus. + +2. neural ectoderm +• Retina with its pigment epithelium • Epithelial layers of ciliary body +• Epithelial layers of iris +• Sphincter and dilator pupillae muscles +• Optic nerve (neuroglia and nervous elements only) • Melanocytes +• Secondary vitreous +• Ciliary zonules (tertiary vitreous). + +3. associated paraxial mesenchyme +• Blood vessels of choroid, iris, ciliary vessels, central retinal artery, other vessels +• Primary vitreous +• Substantia propria, Descemet’s membrane and endothelium of cornea +• The sclera +• Stroma of iris • Ciliary muscle +• Sheaths of optic nerve • Extraocular muscles +• Fat, ligaments and other connective tissue structures of the orbit +Chapter 1 Anatomy and Development of Eye 13 + + +• Upper and medial walls of the orbit +• Connective tissue of the upper eyelid. + +Contd... +membrane and hyaloid vessels + + + +4. Visceral mesoderm of maxillary process below the eye +• Lower and lateral walls of orbit +• Connective tissue of the lower eyelid. + +iMPOrtant MilEStOnES in thE DEVElOPMEnt Of EyE +Embryonic and fetal period +Stage of growth Development +2.6 mm (3 weeks) Optic pits appear on either side of cephalic end of forebrain. +3.5 mm (4 weeks) Primary optic vesicle invaginates. 5.5 to 6 mm Development of embryonic fissure. 10 mm (6 weeks) Retinal layers differentiate, lens +vesicle formed. +20 mm (9 weeks) Sclera, cornea and extra ocular muscles differentiate. +25 mm (10 weeks) Lumen of optic nerve obliterated. 50 mm (3 months) Optic tracts completed, pars ciliaris +retina grows forwards, pars iridica retina grows forward and lid folds develop. +60 mm (4 months) Hyaloid vessels atrophy, iris +sphincter, dilator and ciliary + +disappear. Medulation of optic nerve reaches lamina cribrosa. + +Eye at birth +• Anteroposterior diameter of the eyeball is about 16.5 mm (70% of adult size which is attained by 7-8 years). +• Corneal diameter is about 10 mm. Adult size (11.7 mm) is attained by 2 years of age. +• Anterior chamber is shallow and angle is narrow. • Pupil is small and does not dilate fully. +• Lens is spherical at birth. Infantile nucleus is present. +• Retina. Apart from macular area the retina is fully differentiated. Macula differentiates 4–6 months after birth. +• Myelination of optic nerve fibres has reached the lamina cribrosa. +• Refractive status. Newborn is usually hyper-metropic by +2 to +3 D. +• Orbit is more divergent (50°) as compared to adult (45°). +• Lacrimal gland is still underdeveloped and tears are not secreted. + + + + +230-265 mm (8th month) + + +265-300 mm (9th month) + +muscles develop. +Fetal nucleus of lens is complete, all layers of retina nearly developed and macula starts differentiation. +Except macula, retina is fully developed, infantile nucleus of lens begins to appear, pupillary +Contd... + + +Postnatal period +• Fixation starts developing in first month and is completed in 6 months. +• Macula is fully developed by 4–6 months. +• Fusional reflexes, stereopsis and accommodation are well developed by 4–6 months. +• Cornea attains normal adult diameter by 2 years of age. +• Lens grows throughout life. +2 +Physiology of Eye and Vision + + +Chapter Outline + + +INTRODUCTION +MAINTENANCE OF CLEAR OCULAR MEDIA Physiology of tears +• +• +• +• +Physiology of cornea Physiology of crystalline lens +Physiology of aqueous humour and maintenance of intraocular pressure +PHYSIOLOGY OF VISION Phototransduction +• +• +Processing and transmission of visual impulse + + + +INTRODUCTION + +Sense of vision is a complex function of the two eyes and their central connections. The physiological activities involved in the normal functioning of the eyes are: +• Maintenance of clear ocular media, +• Maintenance of normal intraocular pressure, • The image forming mechanism, +• Physiology of vision, +• Physiology of pupil (see page 315), • Physiology of binocular vision, and • Physiology of ocular motility. + +MAINTENANCE OF CLEAR OCULAR MEDIA +The main prerequisite for visual function is the maintenance of clear refractive media of the eye. The major factor responsible for transparency of the ocular media is their avascularity. The structures forming refractive media of the eye from anterior to posterior are: +• Tear film, • Cornea, +• Aqueous humour, +• Crystalline lens, and • Vitreous humour. + +• Visual perception Electrophysiological Tests +Electroretinography Electrooculography Visual evoked potential +• +• +• +PHYSIOLOGY OF OCULAR MOTILITY AND BINOCULAR +VISION +• Physiology of ocular motility Physiology of binocular single vision +• + + + +Physiology of tears +Tear film plays a vital role in maintaining the transparency of cornea. The physiological aspects of the tears and tear film are described in the chapter 16: diseases of the lacrimal Apparatus (see page 387). +Physiology of cornea +The cornea forms the main refractive medium of the eye. Physiological aspects in relation to cornea include: +• Transparency of cornea, +• Nutrition and metabolism of cornea, • Permeability of cornea, and +• Corneal wound healing. (For details see page 96). +Physiology of crystalline lens +The crystalline lens is a transparent structure playing main role in the focussing mechanism for vision. Its physiological aspects include: +• lens transparency (see page 181), +• Metabolic activities of the lens (see page 181), and • Accommodation (see page 45). +Physiology of aqueous humour and maintenance of intraocular pressure +The aqueous humour is a clear watery fluid filling the anterior chamber (0.25 ml) and the posterior chamber +Chapter 2 Physiology of Eye and Vision 15 + + +(0.06 ml) of the eyeball. In addition to its role in maintaining a proper intraocular pressure it also plays an important metabolic role by providing substrates and removing metabolites from the avascular cornea and the crystalline lens. For detailsseepages 221-224. + +PHYSIOLOGY OF VISION + +Physiology of vision is a complex phenomenon which is still poorly understood. The main mechanisms involved in physiology of vision are: +• Initiation of vision (Phototransduction), a function of photoreceptors (rods and cones), +• Processing and transmission of visual sensation, a function of image processing cells of retina and visual pathway, and +• Visual perception, a function of visual cortex and related areas of cerebral cortex. +Phototransduction +The rods and cones serve as sensory nerve endings for visual sensation. light falling upon the retina causes photochemical changes which in turn trigger a cascade of biochemical reactions that result in generation of electrical changes. Photochemical changes occurring in the rods and cones are essentially similar but the changes in rod pigment (rhodopsin or visual purple) have been studied in more detail. This whole phenomenon of conversion of light energy into nerve impulse is known as phototransduction. +Photochemical changes +The photochemical changes include: +Rhodopsin bleaching. Rhodopsin refers to the visual pigment present in the rods—the receptors for night (scotopic) vision. Its maximum absorption spectrum is around 500 nm. Rhodopsin consists of a colourless protein called opsin coupled with a carotenoid called retinine (Vitamin A aldehyde or 11-cis-retinal). light falling on the rods converts 11-cis-retinalcomponent of rhodopsin into 11-cis-retinal through various stages (Fig. 2.1). The all-trans-retinal so formed is soon separated from the opsin (Fig. 2.2). This process of separation is called photodecomposition and the rhodopsin is said to be bleached by the action of light. Rhodopsin regeneration. The 11-cis-retinal is regenerated from the alt-trans-retinal separated from the opsin (as described above) and vitamin-A (retinal) supplied from the blood. The 11-cis-retinal then reunites with opsin in the rod outer segment to form the rhodopsin. This whole process is called rhodopsin regeneration (Fig. 2.1). Thus, the bleaching of the rhodopsin occurs under the influence of light, whereas the regeneration process + + + + + + + + + + + + + + + + + + + +Fig. 2.1 Light-induced changes in rhodopsin + +is independent of light, proceeding equally well in light and darkness. +Visual cycle. In the retina of living animals, under constant light stimulation, a steady state must exist under which the rate at which the photochemicals are bleached is equal to the rate at which they are regenerated. This equilibrium between the photodecomposition and regeneration of visual pigments is referred to as visual cycle (Fig. 2.2). + +Electrical changes +The activated rhodopsin, following exposure to light, triggers a cascade of complex biochemical reactions which ultimately result in the generation of receptor potential in the photoreceptors. In this way, the light energy is converted into electrical energy which is further processed and transmitted via visual pathway. + +ProcEssing and transmission of Visual imPulsE +The receptor potential generated in the photoreceptors is transmitted by electrotonic conduction (i.e. direct flow of electric current, and not as action potential) to other cells of the retina viz. horizontal cells, amacrine cells, and ganglion cells. However, the ganglion cells transmit the visual signals by means of action potential to the neurons of lateral geniculate body and the later to the primary visual cortex. +The phenomenon of processing of visual impulse is very complicated. It is now clear that visual image is deciphered and analysed in both serial and parallel fashion. +16 Section i Anatomy and Physiology of Eye + +Table 2.1 Differences in the sensitivity of M and P cells to stimulus features + +Stimulus feature +M cell Colour contrast No Luminance contrast Higher Spatial frequency Lower +Temporal frequency Higher + +Sensitivity P cell Yes +Lower Higher +Lower + + + +Fig. 2.2 Visual cycle + +Serial processing. The successive cells in the visual pathway starting from the photoreceptors to the cells of lateral geniculate body are involved in increasingly complex analysis of image. This is called sequential or serial processing of visual information. +Parallel processing. Two kinds of cells can be distinguished in the visual pathway starting from the ganglion cells of retina including neurons of the lateral geniculate body, striate cortex, and extrastriate cortex. These are large cells (magno or M cells) and small cells (parvo or P cells). There are striking differences between the sensitivity of M and P cells to stimulus features (Table 2.1). +The visual pathway is now being considered to be made of two lanes: one made of the large cells is called magnocellular pathway and the other of small cells is called parvocellular pathway. These can be compared to two-lanes of a road. The M pathway and P pathway are involved in the parallel processing of the image, i.e., analysis of different features of the image. +Visual PErcEPtion +It is a complex integration of light sense, form sense, sense of contrast and colour sense. The receptive field organisation of the retina and cortex are used to encode this information about a visual image. +1. light sense +It is awareness of the light. The minimum brightness required to evoke a sensation of light is called the light minimum.It should be measured when the eye is dark adapted for at least 20-30 minutes. +The human eye in its ordinary use throughout the day is capable of functioning normally over an exceedingly wide range of illumination by a highly complex phenomenon termed as the visual adaptation. The process of visual adaptation primarily involves +• dark adaptation (adjustment in dim illumination), and +• light adaptation (adjustment to bright illumination). + + +Dark adaptation +It is the ability of the eye to adapt itself to decreasing illumination. When one goes from bright sunshine into a dimly-lit room, one cannot perceive the objects in the room until some time has elapsed. during this period, eye is adapting to low illumination. The time taken to see in dim illumination is called ‘dark adaptation time’. +The rods are much more sensitive to low illumination than the cones. Therefore, rods are used more in dim light (scotopic vision) and cones in bright light (photopic vision). +Dark adaptation curve (Fig. 2.3) plotted with illumination of test object in vertical axis and duration of dark adaptation along the horizontal axis shows that visual threshold falls progressively in the darkened room for about half an hour until a relative constant value is reached. Further, the dark adaptation curve consists of two parts: the initial small curve represents the adaptation of cones and the remainder of the curve represents the adaptation of rods. + + + + + + + + + + + + + + + + + +Fig. 2.3 Dark adaptation curve plotted with illumination of test object in vertical axis and duration of dark adaptation along the horizontal axis +Chapter 2 Physiology of Eye and Vision 17 + + +■When fully dark adapted, the retina is about one lakh times more sensitive to light than when bleached. +■Delayed dark adaptation occurs in diseases of rods, e.g. retinitis pigmentosa and vitamin A deficiency. +Light adaptation +When one passes suddenly from a dim to a brightly lighted environment, the light seems intensely and even uncomfortably bright until the eyes adapt to the increased illumination and the visual threshold rises. The process by means of which retina adapts itself to bright light is called light adaptation. Unlike dark adaptation, the process of light adaptation is very quick and occurs over a period of 5 minutes. Strictly speaking, light adaptation is merely the disappearance of dark adaptation. +2. form sense +It is the ability to discriminate between the shapes of the objects. Cones play a major role in this faculty. Therefore, form sense is most acute at the fovea, where there are maximum number of cones and decreases very rapidly towards the periphery (Fig. 2.4). Visual acuity recorded by Snellen’s test chart is a measure of the form sense. +Components of visual acuity. In clinical practice, measurement of the threshold of discrimination of two spatially separated targets (a function of the fovea centralis) is termed visual acuity. However, in theory, visual acuity is a highly complex function that consists of the following components. +Minimum visible. It is the ability to determine whether an object is present or not. + + + + + + + + + + + + + + + + +Fig. 2.4 Visual acuity (form sense) in relation to the regions of the retina: N, nasal retina; B, blind spot; F, foveal region; and T, temporal retina + +Resolution (ordinary visual acuity). discrimination of two spatially separated targets is termed resolution. The minimum separation between the two points, which can be discriminated as two, is known as minimum resolvable. Measurement of the threshold of discrimination is essentially an assessment of the function of the fovea centralis and is termed ordinary visual acuity. Histologically, the diameter of a cone in the foveal region is 0.004 mm and this, therefore, represents the smallest distance between two cones. It is reported that in order to produce an image of minimum size of 0.004 mm (resolving power of the eye) the object must subtend a visual angle of 1 minute at the nodal point of the eye. It is called the minimum angle of resolution (MAR). +The clinical tests determining visual acuity measure the form sense or reading ability of the eye. Thus, broadly, resolution refers to the ability to identify the spatial characteristics of a test figure. The test targets in these tests may either consist of letters (Snellen’s chart) or broken circle (landolt’s ring). More complex targets include gratings and checker board patterns. Recognition. It is that faculty by virtue of which an individual not only discriminates the spatial characteristics of the test pattern but also identifies the patterns with which he has had some experience. Recognition is thus a task involving cognitive components in addition to spatial resolution. For recognition, the individual should be familiar with the set of test figures employed in addition to being able to resolve them. The most common example of recognition phenomenon is identification of faces. The average adult can recognise thousands of faces. +Thus, the form sense is not purely a retinal function, as the perception of its composite form (e.g. letters) is largely psychological. +Minimum discriminable refers to spatial distinction by an observer when the threshold is much lower than the ordinary acuity. The best example of minimum discriminable is vernier acuity, which refers to the ability to determine whether or not two parallel and straight lines are aligned in the frontal plane. +3. sense of contrast +It is the ability of the eye to perceive slight changes in the luminance between regions which are not separated by definite borders. loss of contrast sensitivity results in mild fogginess of the vision +Contrast sensitivity is affected by various factors like age, refractive errors, glaucoma, amblyopia, diabetes, optic nerve diseases and lenticular changes. +18 Section i Anatomy and Physiology of Eye + + +Further, contrast sensitivity may be impaired even in the presence of normal visual acuity. +Measurement of contrast sensitivity. In clinical practice the contrast sensitivity can be measured by using any of the following charts with letters or stripes represented in various shades of grey: +• Arden gratings, +• Cambridge low-contrast gratings, +• Pelli-Robson contrast sensitivity chart which consists of triplets 1 low contrast letters with same size (Fig. 2.5), +• Visitach chart, and +• Functional acuity contrast test (FACT). + +4. colour sense +It is the ability of the eye to discriminate between different colours excited by light of different wavelengths. Colour vision is a function of the cones and thus better appreciated in photopic vision. In dim light (scotopic vision), all colours are seen grey and this phenomenon is called Purkinje shift. +Theories of colour vision +The process of colour analysis begins in the retina and is not entirely a function of brain. Many theories have been put forward to explain the colour perception, but two have been particularly influential: +1. Trichromatic theory.The trichromacy of colour vision was originally suggested by Young and subsequently modified by Helmholtz. Hence it is called Young-Helmholtz theory. It postulates the existence of three kinds of cones, each containing a different photopigment which is maximally sensitive to one of the three primary colours viz. red, green and blue. The sensation of any given colour is determined by the relative frequency of the impulse from each of the three cone systems. In other words, a given colour consists of admixture of the three primary colours in different proportions. The correctness of the Young-Helmholtz’s trichromacy theory of colour vision has now been demonstrated by the identification and chemical characterisation of each of the three pigments by recombinant dNA technique, each having different absorption spectrum as below (Fig. 2.6): +Red sensitive cone pigment, also known as erythrolabe or long wavelength sensitive (lWS) cone pigment, absorbs maximally in a yellow portion with a peak at 565 nm. But its spectrum extends far enough into the long wavelength to sense red. +Green sensitive cone pigment, also known as chlorolabe or medium wavelength sensitive (MWS) cone pigment, absorbs maximally in the green portion with a peak at 535 nm. + + + + + + + + + + + + + +A + + + + + + + + + + + + + + + +B + +Fig. 2.5 Pelli-Robson contrast sensitivity chart (A) and log contrast sensitivity score of each triplet (B) + +Blue sensitive cone pigment, also known as cyanolabe or short wavelength sensitive (SWS) cone pigment, absorbs maximally in the blueviolet portion of the spectrum with a peak at 440 nm. +Thus, the Young-Helmholtz theory concludes that blue, green and red are primary colours, but the cones with their maximal sensitivity in the yellow portion of the spectrum are at a lower threshold than green. It has been studied that the gene for human rhodopsin is located on chromosome 3, and the gene for the blue-sensitive cone is located on chromosome. The genes for the red and green sensitive cones are arranged in tandem array on the q arm of the X +chromosomes. +2. Opponent colour theory of Hering. The opponent colour theory of Hering points out that some colours appear to be ‘mutually exclusive’. There is no such colour as ‘reddish-green’, and such phenomenon can be difficult to explain on the basis of trichromatic theory alone. In fact, it seems that both theories are useful in that: +Chapter 2 Physiology of Eye and Vision 19 + +cones, which is contrasted with the output from blue cones within the receptive field. +Colour vision tests See page 330 + + + + + + + + + + + +Fig. 2.6 Absorption spectrum of three cone pigments + +■Colour vision is trichromatic at the level of photo-receptors, and +■Colour opponency occurs at ganglion cell onwards. According to opponent colour theory, there are two main types of colour opponent ganglion cells: +■Red-green opponent colour cells use signals from red and green cones to detect red/green contrast within their receptive field. +■Blue-yellow opponent colour cells obtain a yellow signal from the summed output of red and green + +ELECTROPHYSIOLOGICAL TESTS + +Electrophysiological tests have been evolved to assess the function of rods–cone system and visual pathway. These include: +• Electroretinography (ERG) to assess the response of retinal cell to a flash of light. +• Electrooculography (EOG) to study the function of retinal pigment epithelium (RPE) and interaction between photoreceptor–RPE junction. +• Visual evoked potential (VEP) to access the function of visual pathway. +Note. For details of ERG, EOG and VEP see page 518. + +PHYSIOLOGY OF OCULAR MOTILITY AND BINOCULAR VISION + +Physiology of ocular motility See page 338. +Physiology of binocular singlE Vision See page 341. +Section II Optics and Refraction + + + + + + + + +Section Outline + +3. Elementary and Physiological Optics +4. Errors of Refraction and Accommodation +3 +Elementary and Physiological optics + + +Chapter Outline + +ELEMENTARY OPTICS Light +PhYSICAL OPTICS Wave optics Quantum optics +• +• +• +GEOMETRICAL OPTICS Reflection of light +• +• +Laws of reflection Mirrors +Refraction of light + + + +ELEMENTARY OPTICS + +Light +Light is a form of energy whose interaction with retina gives the sensation of sight. It is visible portion of the electromagnetic radiation spectrum. It lies between ultraviolet and infrared portions, from 400 nm at the violet end of the spectrum to 700 nm at the red end (Fig. 3.1). The white light consists of seven colours denoted by VIBGYOR (violet, indigo, blue, green, yellow, orange and red). +Nature of light +Various theories have been put forward from time to time to explain the nature of light. At present, it is universally accepted that like matter, light also + +• Laws of refraction Total internal reflection Prism +Lenses +• +• +• +PhYSIOLOGICAL OPTICS (OPTICS OF ThE EYE) Eye as an optical instrument +• +• +• +• +• +Schematic eye: cardinal points Reduced eye +Axes and visual angles of the eye Optical aberrations of the normal eye + + + +has dual nature, i.e., it possesses the characteristics of both the wave and the particle (photon or quantum). The two characters of its dual nature are complementary. +Properties of light +• Propagated as electromagnetic wave, i.e., it does not require medium for its propagation. +• Speed of light in free space (vacuum) is 3 × 108 m/s (186,000 miles/s). Speed in a medium is less than in the vacuum. +• Transversein nature, so can be polarized. +• Monochromatic light refers to light of a single wavelength. White light is heterochromatic. +• Not deflected by electric and magnetic field. + + + + + + + + + + + + + + +Fig. 3.1 Spectrum of electromagnetic radiation. Note the very small portion occupied by visible light +24 Section ii optics and Refraction + + +Visible light and the eye +• Media of the eye are uniformly permeable to the visible rays between 600 nm and 390 nm. +• Cornea absorbs rays shorter than 295 nm. Therefore, rays between 600 nm and 295 nm only can reach the lens. +• Lensabsorbsrays shorter than 350 nm. Therefore, rays between 600 nm and 350 nm can reach the retina in phakic eyes; and those between 600 nm and 295 nm in aphakic eyes. +• Eye is most sensitive to yellow-green light (wave length 550 nm). The sensitivity decreases on both sides of this wavelength, so it is minimum for violet and red light (Fig. 3.2). + + + + + + + + + + + + + + +Fig. 3.2 Sensitivity of eye to visible spectrum of light + + +PhYSICAL OPTICS + +Physical optics takes into consideration the basic dual nature of light, the waveform and the particle (photon or quantum) form, and thus includes: ■Wave optics, and +■Quantum optics. + +WaVe OPtics +In its waveform, the light is treated as a wave with following characteristics (Fig. 3.3): +Wavelength (L) of a light wave is defined as the distance between two symmetrical parts of the wave motion. + + + + + + + + +Fig. 3.3 Light as a waveform depicting basic characteristics + + +Amplitude (A)of light wave is maximum displacement of an imaginary particle on the wave from the base line. Phase. One complete oscillation of light is called a wave. Any portion of the cycle is called a phase. Phenomena based on wave optics are: +• Interference, +• Diffraction, and • Polarization. +QuaNtum OPtics +Quantum optics treats light as a particle (localized energy pocket) called photon. +Phenomena based on quantum optics are: • Transmission and absorption of light, +• Scattering of light, +• Photoelectric effect, +• LASER (Light amplification of stimulated emission of radiation), and +• Fluorescence. + +GEOMETRICAL OPTICS + +The behaviour of light rays is determined by ray optics. A ray of light is the straight line path followed by light in going from one point to another. The ray optics, therefore, uses the geometry of straight lines to account for the macroscopic phenomena like rectilinear propagation, reflection and refraction. That is why the ray optics is also called geometrical optics. +The knowledge of geometrical optics is essential to understand the optics of eye, errors of refraction and their correction. Therefore, some of its important aspects are described in the following text. + +REfLECTION Of LIGhT + +Reflection of light is a phenomenon of change in the path of light rays without any change in the medium (Fig. 3.4). The light rays falling on a reflecting surface are called incident rays and those reflected by it are reflected rays. A line drawn at right angle to the surface is called the normal. +LaWs Of refLectiON Laws of reflection are (Fig. 3.4): +1.The incident ray, the reflected ray and the normal at the point of incident, all lie in the same plane. +2.The angle of incidence (i) is equal to the angle of reflection (r). +mirrOrs +A smooth and well-polished surface which reflects regularly most of the light falling on it is called a mirror. +Chapter 3 Elementary and Physiological optics 25 + + + + + + + + + + + +Fig. 3.6 Cardinal points of a spherical mirror + + + + + +Fig. 3.4 Laws of reflection + +types of mirrors +Mirrors can be plane or spherical. +1. Plane mirror +The features of an image formed by a plane mirror (Fig. 3.5) are: (i) it is of the same size as the object; (ii) it lies at the same distance behind the mirror as the object is in front; (iii) it is laterally inverted; and (iv) virtual in nature. +2. Spherical mirror +A spherical mirror (Fig. 3.6) is a part of a hollow sphere whose one side is silvered and the other side is polished. The two types of spherical mirrors are : concave mirror (whose reflecting surface is towards the centre of the sphere) and convex mirror (whose reflecting surface is away from the centre of the sphere). +Cardinal data of a spherical mirror include (Fig. 3.6): • Centre of curvature (C) and radius of curvature (R) of a spherical mirror are the centre and radius, respectively, of the sphere of which the mirror +forms a part. +• Normal to the spherical mirror at any point is the line joining that point to the centre of curvature (C) of the mirror. + + + + + + + + + + + + +Fig. 3.5 Image formation with a plane mirror + +• Poleofthemirror(P) is the centre of the reflecting surface. +• Principal axis of the mirror is the straight line joining the pole and centre of curvature of spherical mirror and extended on both sides. +• Principal focus (F) of a spherical mirror is a point on the principal axis of the mirror at which, ray incident on the mirror in a direction parallel to the principal axis actually meet (in concave mirror) or appear to diverge (as in convex mirror) after reflection from the mirror. +• Focal length (f) of the mirror is the distance of principal focus (F) from the pole of the spherical mirror (P). +images formed by mirrors +Images formed by plane mirrors +Features of an image formed by a plane mirror (Fig. 3.5) are: +• Size of the image is same as that of object. +• Same distance behind the mirror as the object is in front. +• Laterally inverted. • Virtual in nature. +Images formed by concave mirror +As a summary, Table 3.1 gives the position, size and nature of images formed by a concave mirror for different positions of the object and Fig. 3.7 illustrates various situations. +Image formed by convex mirror +The image formed by convex mirror, irrespective of the place of object, is always (Fig. 3.8): +• Virtual, +• Erect, and +• Diminished in size. + +REfRACTION Of LIGhT + +Refraction of light is the phenomenon of change in the path of light, when it goes from one medium to another. The basic cause of refraction is change in the velocity of light in going from one medium to the other. +26 Section ii optics and Refraction + + +Table 3.1 Images formed by a concave mirror for different positions of object + + +No. Position of the object +1. At infinity +2. Beyond the centre of curvature (C) +3. At C +4. Between F & C +5. At F +6. Between pole of the mirror (P) and focus (F) + +Position of the image +At the principal focus (F) +Between F & C + +At C +Beyond C +At infinity +Behind the mirror + +Nature and size of the image +Real, very small and inverted +Real, diminished in size, and inverted + +Real, same size as object and inverted +Real, enlarged and inverted +Real, very large and inverted +Virtual, enlarged and erect + +Ray diagram +Fig. 3.7 (a) +Fig. 3.7 (b) + +Fig. 3.7 (c) +Fig. 3.7 (d) +Fig. 3.7 (e) +Fig. 3.7 (f) + + + + + + + + + + +a d + + + + + + + +b e + + + + + + + +c f +Fig. 3.7 Images formed by a concave mirror for different positions of the object : (a) at infinity; (b) beyond the centre of curvature; (c) at C; (d) between C and F; (e) at F; (f) between F and P + + + + + + + + + +Fig. 3.8 Image formed by a convex mirror + +LaWs Of refractiON + +Laws of refraction are (Fig. 3.9): +1. The incident (i) and refracted (r) rays are on opposite sides of the normal (N) and all the three are in the same plane. +2. The ratio of sine of angle of incidence (i) to the sine of angle of refraction (r) is constant for the part of media in contact. This constant is denoted by the letter m and is called ‘refractiveindex’ of the medium +Chapter 3 Elementary and Physiological optics 27 + + + + + + + + + + + + + + +Fig. 3.10 Refraction of light (1-1’); path of refracted ray at critical angle, c (2-2’); and total internal reflection (3-3’) + + + + + + +Fig. 3.9 Laws of refraction. N1 and N2 (normals); I (incident ray); i (angle of incidence); R (refracted ray, bent +towards normal); r (angle of refraction); E (emergent ray, bent from the normal) +2. In which the refracted ray lies with respect to medium 1 (in which the incident ray sin i lies), i.e. +sin r = m2. When the medium 1 is air (or vaccum), then n is called the refractive index of the medium +2. This law is also called Snell’slawofrefraction. + +tOtaL iNterNaL refLectiON +When a ray of light travelling from an optically-denser medium to an optically-rarer medium is incident at an angle greater than the critical angle of the pair of media in contact, the ray is totally reflected back into the denser medium (Fig. 3.10). This phenomenon is called total internal reflection. Critical angle refers to the angle of incidence in the denser medium, corresponding to which angle of refraction in the rare medium is 90°. It is represented by C and its value depends on the nature of media in contact. +Application.The principle of total internal reflection is utilized in many optical equipments; such as fibroptic lights, applanation tonometer, and gonioscope. +Prism +A prism (Fig. 3.11) is a refracting medium, having two plane surfaces, inclined at an angle. +■Apical angle (refracting angle) of a prism is the angle between two surfaces (x in Fig. 3.11). The greater the angle formed by two surfaces at the apex, the stronger is the prismatic effect. +■Axis of the prism refers to the line bisecting the optical angle. + +■Base of prism refers to the surface opposite to the apical angle. When prescribing a prism, the orientation is indicated by the position of the base, e.g., ‘base-in’ or ‘base-out’ or ‘base-up’. ■Refractionthroughtheprism produces displacement of the objects seen through it towards apex (away from the base) (Fig. 3.11). +■Powerofaprism is measured in prism dioptres. One prism dioptre (D) produces displacement of an object by one cm when kept at a distance of one metre. Two prism dioptres of displacement is approximately equal to one degree of arc. +■Image formed by a prism is virtual, erect and displaced towards its apex. +uses in ophthalmology +1. Diagnostic uses include: +• Objective measurement of angle of deviation (Prism bar cover test, Krimsky test). +• Measurement of fusional reserve. • Diagnosis of microtropia. +2. Prisms are also used in many ophthalmic equipments such as gonioscope, keratometer and applanation tonometer. + + + + + + + + + + + + +Fig. 3.11 Refraction through a prism +28 Section ii optics and Refraction + + + + + + + + +Fig. 3.12 Cardinal points of a convex lens: optical centre (O); principal focus (F); centre of curvature (C); and principal axis (AB) + +3. Therapeutic uses of prisms are: +• Torelievediplopia in patients with decompensated phorias and small tropias. +• For exercises to develop fusional reserve. + +LeNses +A lens is a transparent refracting medium, bounded by two surfaces which form a part of a sphere (spherical lens) or a cylinder (cylindrical or toric lens). +cardinal data of a lens +Cardinal data of a lens include (Fig. 3.12): +1. Centre of curvature (C) of the spherical lens is the centre of the sphere of which the refracting lens surface is a part. +2. Radius of curvature of the spherical lens is the radius of the sphere of which the refracting surface is a part. +3. Principal axis (AB) of the lens is the line joining the centres of curvatures of its surfaces. +4. Optical centre (O) of the lens corresponds to the nodal point of a thick lens. It is a point on the principal axis in the lens, the rays passing from where do not undergo deviation. In meniscus lenses, the optical centre lies outside the lens. +5. Principal focus (F) of a lens is that point on the principal axis where parallel rays of light, after passing through the lens, converge (in convex lens) or appear to diverge (in concave lens). +6. Focal length (f) of a lens is the distance between the optical centre and the principal focus. + + + +Fig. 3.13 Basic forms of a convex lens: (A) biconvex; (B) plano-convex; (C) concavo-convex + +7. Power of a lens (P) is defined as the ability of the lens to converge a beam of light falling on the lens. For a converging (convex) lens the power is taken as positive and for a diverging (concave) lens power is taken as negative. It is measured as reciprocal of the focal length in metres, i.e., P = 1/f. The unit of power is dioptre (D). One dioptre is the power of a lens of focal length one metre. +types of lenses +Lenses are of two types: the spherical and cylindrical (toric or astigmatic). +1. Spherical lenses +Spherical lenses are bounded by two spherical surfaces and are mainly of two types convex and concave. Convex lens or plus lens is a converging lens. It may be of biconvex, plano-convex or concavo-convex (meniscus) type (Fig. 3.13). +■ Identification of a convex lens. (i) The convex lens is thick in the centre and thin at the periphery, (ii) An object held close to the lens, appears magnified, (iii) When a convex lens is moved, the object seen through it moves in the opposite direction to the lens. ■ Uses of convex lens. It is used (i) for correction of hypermetropia, aphakia and presbyopia; (ii) in oblique illumination (loupe and lens) examination, in indirect ophthalmoscopy, as a magnifying lens and in many other equipments. ■Imageformationbyaconvexlens. Table 3.2 and Fig. 3.14 provide details about the position, size and the nature of the image formed by a convex lens. + + +Table 3.2 Images formed by a convex lens for various positions of object + + +No. Position of the object 1. At infinity +2. Beyond 2F1 3. At 2F1 +4. Between F1 and 2F1 5. At focus F1 +6. oBepttwicealecneFn1tarenodftthhee lens + +Position of the image +At focus (F2) Between F2 and 2F2 At 2F2 +Beyond 2F2 At infinity +On the same side of lens + +Nature and size of the image Real, very small and inverted Real, diminished and inverted Real, same size and inverted Real, enlarged and inverted Real, very large and inverted +Virtual, enlarged and erect + +Ray diagram Fig. 3.14 (a) Fig. 3.14 (b) Fig. 3.14 (c) Fig. 3.14 (d) Fig. 3.14 (e) +Fig. 3.14 (f) +Chapter 3 Elementary and Physiological optics 29 + + + + + + +a d + + + + + + + +b e + + + + + + + +c f +Fig. 3.14 Images formed by a convex lens for different positions of the object, (a) at infinity ; +(b) beyond 2F1 ; (c) at 2F1; (d) between F1 and 2F1; (e) at F1; (f) between F1 and optical centre of lens + + +Concave lens or minus lens is a diverging lens. It is of three types: biconcave, plano-concave and convexo-concave (meniscus) (Fig. 3.15). +■ Identification of concave lens. (i) It is thin at the centre and thick at the periphery. (ii) An object seen through it appears minified. (iii) When the lens is moved, the object seen through it moves in the same direction as the lens. +■ Uses of concave lens. It is used (i) for correction of myopia; (ii) as Hruby lens for fundus examination with slit-lamp. +■ Imageformationbyaconcavelens. A concave lens always produces a virtual, erect image of an object (Fig. 3.16). +2. Cylindrical lens +A cylindrical lens acts only in one axis, i.e., power is incorporated in one axis, the other axis having zero + + + + + + + + + + +Fig. 3.15 Basic forms of a concave lens: (A) biconcave (B) plano-concave; and (C) convexo-concave + + + + + + + + + +Fig. 3.16 Image formation by a concave lens + +power. A cylindrical lens may be convex (plus) or concave (minus). +• Convex cylindrical lens is a segment of a cylinder of glass cut parallel to its axis (Fig. 3.17) refers to a lens cast in a convex cylindrical mould. +• Concave cylindrical lens (Fig. 3.17). +• Axis of a cylindrical lens is parallel to that of the cylinder of which it is a segment. +• Power in a cylindrical lens is present only in the direction at right angle to the axis. Therefore, the parallel rays of light after passing through a cylindrical lens do not come to a point focus but form a focal line (Fig. 3.18). +Identification of a cylindrical lens +• When the cylindrical lens is rotated around its optical axis, the object seen through it becomes distorted. +• The cylindrical lens acts in only one axis, so when it is moved up and down or sideways, the objects will move with the lens (in concave cylinder) or opposite to the lens (in convex cylinder) only in one direction. +30 Section ii optics and Refraction + + + + + + + + + \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_10.txt b/notes/A K Khurana - Comprehensive Ophthalmology_10.txt new file mode 100644 index 0000000000000000000000000000000000000000..72aba0c82810b66ef4fed26ab49a7c488d526452 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_10.txt @@ -0,0 +1,1599 @@ +II. Proliferative diabetic retinopathy (PDR) III. Diabetic maculopathy +IV. Advanced diabetic eye disease (ADED) + +I. Non-proliferative diabetic retinopathy (NPDR) Ophthalmoscopic features of NPDR include: +• Microaneurysms are seen in the macular area (the earliest detectable lesion) and elsewhere in relation to area of capillary nonperfusion. These are formed due to focal dilation (out pouching) of capillary wall following loss of pericytes. These appear as red dots and leak fluid, proteins, lipids and also fluorescein dye on FFA. +• Retinal haemorrhages. Both deep (dot and blot haemorrhages which are more common) and superficial haemorrhages (flame-shaped), occur from capillary leakage. +• Retinal oedema characterized by retinal thickening is caused by capillary leakage. +• Hard exudates—yellowish-white waxy-looking patches are arranged in clumps or in circinate pattern. These are commonly seen in the macular area. These occur due to chronic localised oedema and are composed of leaked lipoproteins and lipid filled macrophages. +• Cotton-wool spots, are small whitish fluffy superficial lesions. These represent areas of nerve fibre infarcts. + +• Venous abnormalities (beading, looping and dilatation) occur adjacent to area of capillary non-perfusion. +• Intraretinal microvascular abnormalities (IRMA) seen as fine irregular red lines connecting arterioles with venules, represent arteriovenular shunts. +• Dark-blot haemorrhages representing haemor-rhagic retinal infarcts. +ETDRS study classification: On the basis of severity of the above findings the NPDR has been further clas-sified as under: +1. Mild NPDR (Fig. 12.14A). +• At least one microaneurysm must be present. 2. Moderate NPDR (Fig. 12.14B) +• Microaneurysms/intraretinal haemorrhage in 2 or 3 quadrants. +• Early mild IRMA. +• Hard/soft exudates may or may not present. +3. Severe NPDR. Any one of the following (4–2–1 Rule) (Fig. 12.14C): +• Four quadrants of microaneurysms and extensive intraretinal haemorrhages. +• Two quadrants of venous beading. • One quadrant of IRMA changes. +4. Very severe NPDR. Any two of the following (4–2–1 Rule) (Fig. 12.14D): +• Four quadrants of microaneurysms and extensive intraretinal haemorrhages. +• Two quadrants of venous beading. • One quadrant of IRMA changes. +Risk factors for progression to PDR,observed in ETDRS include presence of: +• IRMAs, +• Multiple increasing intraretinal haemorrhages, • Venous beading and loops, and +• Wide spread capillary non-perfusion (CNP) areas. +Note. Interestingly cotton wool spots were not found to be significant predictors. +II. Proliferative diabetic retinopathy (PDR) Proliferative diabetic retinopathy (Figs. 12.14E and F) develops in more than 50% of cases after about 25 years of the onset of disease. Therefore, it is more common in patients with juvenile onset diabetes. ■Occurrence of neovascularization over the changes of very severe non-proliferative diabetic retinopathy is hallmark of PDR. It is characterised by proliferation of new vessels from the capillaries, in the form of neovascularization at the optic disc (NVD) and/or elsewhere (NVE) in the fundus, usually along the course of the major temporal retinal vessels. These +Chapter 12 Diseases of Retina 279 + + + + + + + + + + + + +A B + + + + + + + + + +C D + + + + + + + + + + +E F G +Fig. 12.14 Diabetic retinopathy: A, mild NPDR; B, moderate NPDR; C, severe NPDR; D, very severe NPDR; E, early PDR; F, high­risk PDR; G, focal exudative diabetic maculopathy + + +new vessels may proliferate in the plane of retina or spread into the vitreous as vascular fronds. Later on results in formation of: +• Fibrovascular epiretinal membrane formed due to condensation of connective tissue around the new vessels. +• Vitreous detachment and vitreous haemorrhage may occur in this stage. +Types.On the basis of high-risk characteristics (HRCs) described by diabetic retinopathy study (DRS) group, the PDR can be further classified as below: +1. Early NVD or NVE PDR without HRCs (Early PDR) (Fig. 12.14E), and +2. PDR with HRCs. High-risk characteristics (HRC) of PDR are as follows (Fig. 12.14F): + +• NVD 1/4 to 1/3 of disc area with or without vitreous haemorrhage (VH) or preretinal haemorrhage (PRH) +• NVD <1/4 disc area with VH or PRH • NVE >1/2 disc area with VH or PRH +III. Diabetic maculopathy +Changes in macular region need special mention, due to their effect on vision. These changes may be associated with non-proliferative diabetic retinopathy (NPDR) or proliferative diabetic retinopathy (PDR). The diabetic macular oedema (DME) occurs due to increased permeability of the retinal capillaries. +Clinically significant macular oedema (CSME) +CSME is the term coined during early treatment diabetic retinopathy study (ETDRS). It is diagnosed +280 Section 3 Diseases of Eye + + + +if one of the following three criteria are present on slit-lamp examination with 90D lens: +• Thickening of the retina at or within 500 micron of the centre of the fovea. +• Hard exudates at or within 500 micron of the centre of fovea associated with adjacent retinal thickening. +• Development of a zone of retinal thickening one disc diameter or larger in size, at least a part of which is within one disc diameter of the foveal centre. +Clinico-angiographic classification of diabetic maculopathy +1. Focal exudative maculopathy (Fig. 12.14G). It is characterised by microaneurysms, haemorrhages, well-circumscribed macular oedema and hard exudates which are usually arranged in a circinate pattern. Fluorescein angiography reveals focal leakage with adequate macular perfusion. +2. Diffuse exudative maculopathy. It is characterised by diffuse retinal oedema and thickening throughout the posterior pole, with relatively few hard exudates. Fluorescein angiography reveals diffuse leakage at the posterior pole. +3. Ischaemic maculopathy. It occurs due to microvascular blockage. Clinically, it is characterised by marked visual loss with microaneurysms, haemorrhages, mild or no macular oedema and a few hard exudates. Fluorescein angiography shows areas of non-perfusion which in early cases are in the form of enlargement of foveal avascular zone (FAZ), later on areas of capillary dropouts are seen and in advanced cases precapillary arterioles are blocked. +4. Mixed maculopathy. In it combined features of ischaemic and exudative maculopathy are present. +OCT classification of diabetic macular oedema. +On the basis of OCT examination the diabetic macular oedema (DME) has been classified as below: 1. Non-tractional DME. It may be of following types: a. Spongy thickness of macula (>250 µ), +b. Cystoid macular oedema (CME), and +c. Neurosensory detachment with or without (a) or (b) above. +2. Tractional DME. It may be of following types: a. Vitreo-foveal traction (VFT), and +b. Taut/thickened posterior hyaloid membrane. +Note. The OCT classification has a bearing on the management since non-tractional DME is treated conservatively whereas tractional DME is purely treated by pars-plana vitrectomy (PPV) with removal of posterior hyaloid. + +IV. Advanced diabetic eye disease +It is the end result of uncontrolled proliferative diabetic retinopathy. It is marked by complications such as: +• Persistent vitreous haemorrhage, +• Tractional retinal detachment, and • Neovascular glaucoma. + +Management +Management of diabetic retinopathy includes its screening investigation and treatment. +A. Screening for diabetic retinopathy +To prevent visual loss occurring from diabetic retinopathy a periodic follow-up is very important for a timely intervention. The recommendations for periodic fundus examination are as follows: +• First examination, 5 years after diagnosis of type 1 DM and at the time of diagnosis in type 2 DM. +• Every year, till there is no diabetic retinopathy or there is mild NPDR. +• Every 6 months, in moderate NPDR. • Every 3 months, in severe NPDR. +• Every 2 months, in PDR with no high-risk chara-cteristics. +B. Investigations in a case of DR include: • Urine examination +• Blood sugar estimation • 24 hour urinary protein • Renal function tests +• Lipid profile • Haemogram +• Glycosylated haemoglobin (HbA1C) +• Fundus fluorescein angiography should be carried out to elucidate areas of neovascularization, leakage and capillary nonperfusion. +• Optical coherence tomography (OCT) to study detailed structural changes in diabetic maculopathy. +C. Treatment of diabetic retinopathy +Treatment modalities for diabetic retinopathy include metabolic control of DM and associated risk factors, intravitreal anti-VEGF drugs, intravitreal steroids, laser therapy, and pars plana vitrectomy. I. Metabolic control of diabetes mellitus and associated risk factors. It is of first and foremost importance to stabilize DM metabolically. Not only the blood glucose levels be in the normal range but other biochemical parameters should also be normal. In case these are deranged consultation from an internist/endocrinologist should be sought. The normal values as under should be targeted: +Chapter 12 Diseases of Retina 281 + + + +• Control of glycaemia. Target blood glucose level: fasting <120 mg%, post-prandial <180 mg%, and HbA1c (glycosylated haemoglobin) <7%. +• Control of dyslipidaemia. Target lipid profile (fasting): Cholesterol <200 mg%, Triglycerides <150 mg%, HDL >50 mg%, and LDL <150 mg%. +• Renal function tests. Target level are serum creatinine 1.0 mg%, blood urea 20–40 mg%, and 24-hour urinary protein <200 mg%. +• Control of associated anaemia. Target hemoglobin >10 mg%. +• Control of associated hypertension. Target blood pressure levels:130/80 mm Hg. +• Life style changes. Patients should be counselled toprohibit smoking and alcohol consumption, and take regular exercises. +II. Intravitreal anti-VEGF drugs. Vascular endothelial growth factor (VEGF) plays a pivotal role in the etiopathogenesis of diabetic maculopathy and retinopathy. Anti-VEGFs, e.g., Bevacizumab (1.25 mg) and Ranibizumab (0.5 mg) when given intravitrealy in 0.1 ml vehicle lead to improvement in vision in >40% cases and stabilize vision in another >40% cases. These drugs should be preferred over laser therapy particularly in patients with: +• Focal CME involving centre of fovea, • Diffuse DME, +• Diabetic CME, and +• DME with neurosensory detachment +• Anti-VEGFs are also recommended before pan-retinal photocoagulation (PRP) in patients with PDR and diffuse DME. +Note. Effects of the anti-VEGFs last for 4–6 weeks and frequent injections are warranted. In addition the cost factor and risk of endophthalmitis are the deterrent of anti-VEGF therapy. +III. Intravitreal steroids. Intravitreal triamcinolone acetonide (IVTA) (20 mg) is another drug which is being tried. It restores inner retinal barrier and has some anti-VEGF effects as well. However, risk of glaucoma, steroid induced cataract, and increased vulnerability to endophthalmitis restrict its use. Hence, anti-VEGFs are preferred over IVTA these days. However, in recalcitrant cases IVTA may be given along with anti-VEGFs. +IV. Laser therapy. ETDRS had recommended focal laser for focal DME and grid laser for diffuse DME. Laser helps possibly by stimulating the RPE pump mechanism and by inhibiting VEGF release. Till recently laser therapy, which only stabilizes the vision, was the mainstay in the treatment of DME. + +However, with the introduction of anti-VEGF drugs, which also improve vision, the role of laser therapy has become limited. Laser therapy is performed using double frequency YAG laser 532 nm or argon green laser, or diode laser. Protocols for laser therapy as far now are as below: +i. Macular photocoagulation. It is of two types: +• Focal photocoagulation (Fig. 12.15A). It is the treatment of choice for focal DME not involving the centre of fovea. +• Grid photocoagulation (Fig. 12.15B). It is no more the treatment of choice for diffuse DME. It may be considered only for recalcitrant cases not responding to anti-VEGFs and intravitreal steroids. Note. Macular photocoagulation is contraindicated +in ischemic maculopathy and tractional DME. +ii. Panretinal photocoagulation (PRP) or scatter laser consists of 1200–1600 spots, each 500 mm in size and 0.1 sec duration. Laser burns are applied outside the temporal arcades and on nasal side one disc diameter from the disc upto the equator. The burns should be one burn width apart (Fig. 12.15C). +In PRP inferior quadrant of retina is first coagulated. PRP produces destruction of hypoxic retina which is responsible for the production of vasoformative factors. + +Indications for PRP are: +■PDR with HRCs, ■Neovascularization of iris (NVI), ■Severe NPDR associated with: +• Poor compliance for follow-up, +• Before cataract surgery/YAG capsulotomy, • Renal failure, +■One eyed patient, and ■Pregnancy. +Note. A shot of anti-VEGF drug intravitrealy given before PRP may protect the macula as well as reduce the risk of vitreous haemorrhage. Further, intravitreal triamcinolone may be considered as an adjunct to PRP. +V. Surgical treatment is indicated in following cases: • Tractional DME with NPDR. Treatment of choice +is pars plana vitrectomy (PPV) with removal of posterior hyaloid. +• Advanced PDR with dense vitreous haemorrhage. PPV along with removal of opaque vitreous gel and endophotocoagulation should be done at an early stage. +• Advanced PDR with extensive fibrovascular epiretinal membrane should be treated by PPV +282 Section 3 Diseases of Eye + + + + + + + + + + + +A B C +Fig. 12.15 Protocols of laser application in diabetic retinopathy: A, focal treatment; B, grid treatment and; C, panretinal photocoagulation + + + +along with removal of fibrovascular epiretinal membrane and endophotocoagulation. +• Advanced PDR with tractional retinal detachment should be treated by PPV with endopho-tocoagulation and reattachment of detached retina along with other methods like scleral buckling and internal tamponade using intravitreal silicone +oil or gases like sulphur hexafluoride (SF6) or +perfluoropropane (C3F8). +RETINOPATHIES OF BLOOD DISORDERS These are seen in patients suffering from sickel cell anaemias, leukaemias and polycythemias. + +Sickle-cell Retinopathy +Retinal changes in patients suffering from sickle cell haemoglobinopathies (abnormal haemoglobins) are primarily caused by retinal hypoxia; which results from blockage of small blood vessels by the abnormal-shaped rigid red blood cells. +Clinical features +Sickle-cell retinopathy can be divided into five self-explanatory stages as follows: +1. Stage of peripheral arteriolar occlusion and ischaemia. +2. Stage of peripheral arteriovenous anastomoses. 3. Stage of neovascularization. +4. Stage of vitreous haemorrhage. +5. Stage of vitreoretinal traction bands and tractional retinal detachment. +Treatment +• Panretinal photocoagulation (PRP) is effective in regressing the neovascularization. +• Pars plana vitrectomy is required for vitreoretinal tractional bands. It should be followed by repair of the retinal detachment, when present. + +Anaemic Retinopathy +In anaemia, retinal changes are liable to occur when haemoglobin level falls by 50% and are consistently present when it is below 35% (5 gm%). Duration and type of anaemia do not influence the occurrence of retinopathy. +Pathogenesis involves factors like anoxia, venous stasis, angiospasm, increased capillary permeability, and thrombocytopenia. +Characteristc features of anaemic retinopathy are as below: +• Fundus background becomes pale • Retinal arterioles are also pale +• Retinal veins are tortuous and dilated +• Retinal haemorrhages, superficial flame shaped and preretinal (subhyaloid) may be seen in the posterior half of fundus +• Roth spots, i.e., haemorrhages with white center and platelet-fibrin emboli constitute the white centre +• Cotton wool spots may also be seen especially in patients with coexisting thrombocytopenia in aplastic anaemia. + +Management includes: +• Treatment of anemia, which leads to reversal of retinopathy in most cases. +• Intervention for a large subhyaloid haemorrhage, which does not resolve spontaneously, in the form of intravitreal tissue plasminogen activator (tPA), or YAG posterior hyaloidotomy, or pars plana vitrectomy, may be required. + +Leukaemic Retinopathy +Ocular involvement is more common with acute than chronic leukaemia. +Chapter 12 Diseases of Retina 283 + + + +Characteristic features of leukaemic retinopathy include: +• Fundus background is pale and orangish • Retinal veins are tortuous and dilated +• Retinal arterioles become pale and narrow +• Perivascular leukaemic infiltrates, seen as grayish white lines along the course of veins, are seen in latter stages +• Roth spots, i.e., retinal haemorrhages with typical white centre are very common +• Subhyaloid haemorrhage i.e., large preretinal haemorrhages may also be seen. + +Other ocular changes in leukaemia include: +• Orbital infiltration, particularly in children presenting as proptosis +• Ocular haemorrhages in the form of subconj-unctival haemorrhage and hyphaema (bleeding in anterior chamber) +• Iris changes in the form of iris thickening and iritis • Pseudohypopyon, i.e., collection of white cells in +the anterior chamber. + +RETINOPATHY OF PREMATURITY +Retinopathy of prematurity (ROP) is a bilateral proliferative retinopathy, occurring in premature infants with low birth weight who often have been exposed to high concentration of oxygen. Earlier this disease was known as retrolental fibroplasia. +Etiopathogenesis +Primary risk factors include: +• Low gestation age, especially <32 weeks +• Low birth weight (<1500 g, especially <1250 g), • Supplemental oxygen therapy, and +Other risk factors reported include light, vitamin E deficiency, respiratory distress syndrome, asphyxia, shock, and acidosis. +Pathogenesis In the normal development of retina, the vessels reach the nasal periphery after 8 months of gestation and temporal periphery about 1 month after delivery, by the effect of VEGF. +In premature birth, the production of VEGF is downregulated and vessel migration is halted. However, with growing age, because of increased metabolic demands, the oxygen regulated vasculo-endothelial growth factors (VEGFs) and non-oxygen regulated insulin like growth factors (IGF-1) are produced in excess resulting in neovascularization and fibrous proliferation progressively resulting in different stages of retinopathy of prematurity described below. + +Clinical features +The condition has been divided into active ROP and cicatricial ROP. International classification of ROP (ICROP) is based on the stage, zone and extent of ROP. +Staging of ROP +Clinically, the evolution of ROP has been divided into five stages (Fig. 12.16): +• Stage 1. Demarcation line formation at the edge of vessels, dividing the vascular from the avascular retina. +• Stage 2. The line structure of stage 1 acquires a volume to form a ridge with height and width. +• Stage 3. Ridge with extraretinal fibrovascular proliferation into the vitreous. This stage is further subdivided into mild, moderate and severe, depending on the amount of fibrovascular proliferation. +• Stage 4a. Subtotal retinal detachment not involving the macula is a feature of this stage. It occurs as a result of exudation from incompetent blood vessels or traction from the fibrous (cicatricial) tissue. +• Stage 4b. Subtotal retinal detachment involving the macula occur in this stage. +• Stage 5. Total retinal detachment which is always funnel-shaped. +Zones of ROP +The retina is divided into three zones. The centre of the retinal map for ROP is the optic disc not the macula as in other retinal charts (Fig. 12.17). +Diseases of the retina +Zone I +A circle drawn on the posterior pole, with the optic disc as the centre and twice the distance from the centre of disc to fovea as the radius, constitutes zone I. Any ROP in this zone is usually very severe because of a large peripheral area of avascular retina. +Zone II +A circle is drawn with the optic disc as the centre and the distance from the centre of disc to nasal ora serrata as the radius. The area between zone I and this boundary constitutes zone II. +Zone III +The temporal arc of retina left beyond the radius of zone II is zone III. +Extent of involvement +Extent of involvement is denoted by the clock hours of retinal involvement in the particular zone (Fig. 12.17). +284 Section 3 Diseases of Eye + + + + + + + + + + + + +A B C + + + + + + + + + + + + +D E +Fig. 12.16 Stages of retinopathy of prematurity (ROP):A, stage 1—demarcation line; B, stage 2—demarcation ridge; C, stage 3—extraretinal neovascularization and proliferation; D, stage 4b—subtotal retinal detachment involving macula: E. stage 5—total retinal detachment + + +Other features +Plus disease refers to presence of engorged veins and tortuous arteries in at least two quadrants at posterior pole with any stage of ROP. +Associated with it is the engorgment and dilatation of iris vessels, which result in poor pharmacological dilatation of pupil. Plus diseases signifies a tendency to progression and is notated by adding plus sign (+) after the number of stage of ROP (e.g., stage 2+) +Pre-plus disease is labelled when venous dilation and arterial tortuosity is more than normal but insufficient to be defined as plus disease. +Aggressive posterior ROP (AP-ROP), also called Rush-disease, refers to the ROP located in zone I with plus disease out of proportion to the peripheral retinopathy or ROP in posterior zone II with severe plus disease. APROP requires immediate treatment. It may progress rapidly to stage 5 ROP without passing through the other stages. +Threshold disease refers to stage 3 +ROP with plus disease located in zone I or II and involving 5 continuous or 8 discontinuous clock hours. This stage needs laser therapy in less than 72 hours. + + + + + + + + + + + + + + + + + + +Fig. 12.17 Division of retina into zones (I, II, III) and clock hour positions to depict involvement in retinopathy of prematurity. + +Prethreshold disease. Early treatment of retinopathy of prematurity (ETROP) group has classified prethreshold disease into two types: +Chapter 12 Diseases of Retina 285 + + + +Type I or high-risk prethreshold disease, which needs laser photocoagulation. It includes: +• Zone I Plus disease, any stage, +• Zone I: Non–plus disease, stage 3, and • Zone II: Plus disease, stage 2, and 3. +Type 2 or low-risk prethreshold disease which requires weekly follow-up. It includes: +• Zone I: Non-plus disease, stage 1, and 2, and • Zone II: Non-plus disease stage 3. +Differential diagnosis +• Active ROP needs to be differentiated from familial exudative vitreoretinopathy (FEVR) and incontinentia pigmenti in girls and persistent fetal vasculature. +• Advanced retrolental fibroplasia needs to be differentiated from other causes of leukocoria (see page 306). +Management +Treatment of well-established disease is unsatisf-actory. Prophylaxis is thus very important. To reduce high-risk ROP, the premature newborns should not +be placed in incubator with an O2 concentration of +more than 30% and efforts should be made to avoid infections and attacks of apnoea.Early diagnosis and treatment is essential to prevent blindness in high-risk cases. Therefore, a regular screening and timely intervention is recommended. +Screening protocol +All premature babies born at less than or equal to 32 weeks of gestational age and those weighing 1500 g or less (for Indian scenario <35 weeks and < 2800 g) should be screened for ROP. +■First examination by indirect ophthalmosocpy should be done between 4 to 6 weeks postnatal age or 34 weeks postconceptual age (whichever is earlier). Further line of action will depend upon the status of retina. +• Immature retina is labelled when the vessels are short of one disc diameter of the nasal or temporal ora but ROP is not developed yet. +• ROP, when present should be classified as its stage, zone, and extent of involvement. +Subsequent follow-up examination. Spontaneous regression of disease occurs in about 80% of the cases. So following patients should be examined as below till regression occurs or disease reaches treatment stage: +• Immature retina but no ROP-bi-weekly +• Stage 1 & 2 (Zone I & II ROP), weekly and • Stage 3 (Zone II ROP) also weekly. + + +Treatment protocol +Treatment options include laser therapy or cryotherapy. ETROP group has recommended use of laser over the cryotherapy. +Laser treatment. Laser photocoagulation using diode laser 810 nm or frequency doubled Nd: YAG (532 nm) with LIO (laser indirect ophthalmoscope) delivery should be carried out in all patients with high-risk pre-threshold, threshold, and aggressive posterior ROP. Post-laser treatment and follow-up. Antibiotic and steroid eye drops should be prescribed for a week. Post-laser treatment follow-up should be done weekly for 3 weeks and if required retreatment should be done. Subsequent follow-up examination should be continued at 3, 6 and 12 weeks after treatment. Long-term follow-up is must for timely management of complications if any. +Surgical treatment. Patients with stage IV a, IV b, and V require lens sparing vitrectomy along with endolaser photocoagulation, and retinal reattachment measures. +PRIMARY RETINAL TELANGIECTASIA +Primary retinal telangiectasia refer to idiopathic congenital or acquired retinal vascular malfor-mations. Characterized by irregular dilation of capillary bed and segmental dilation of neighbouring venules and arterioles. Primary retinal telangiectasia include: +• Idiopathic juxtafoveolar retinal telangiectasia, • Coats’ disease, and +• Leber’s miliary aneurysm. + +Idiopathic juxtafoveolar retinal telangiectasia Idiopathic juxtafoveolar retinal telangiectasia also known as ‘idiopathic macular telangiectasia’ is a rare condition presenting with mild decrease in visual acuity due to exudation from the juxtafoveal telangiectatic retinal capillaries. This condition has been divided into three groups: 1, 2 and 3, (each group is subdivided into A and B) depending on the characteristics of lesion. +Coats’ disease +Coats’ disease, also known as exudative retinopathy of Coats, is a severe form of retinal telangiectasia (idiopathic congenital vascular malformation). Characteristic features of Coats’ disease are: +• Typically affects one eye of boys in their first decade of life. +• In early stages it is characterised by large areas of intra and subretinal yellowish exudates and haemorrhages associated with overlying dilated +286 Section 3 Diseases of Eye + + + +and tortuous retinal blood vessels and a number of small aneurysms near the posterior pole and around the disc. +• It may present with visual loss, strabismus or leukocoria (whitish pupillary reflex) and thus needs to be differentiated from retinoblastoma. +• Condition usually progresses to produce exudative retinal detachment and a retrolental mass. In late stages complicated cataract, uveitis and secondary glaucoma occur, which eventually end in phthisis bulbi. +• FFA highlights abnormal vessels, leakage and areas of capillary drop out. +Treatment is as below: +• Photocoagulation or cryotherapy may check progression of the disease if applied in the early stage. +• However, once the retina is detached the treatment becomes increasingly difficult and success rate declines to 33%. +Leber’s miliary aneurysms +• Leber’s miliary aneurysm is essentially a localised less severe form of Coats’ disease presenting in adults with decreased vision. +• Characterized by a local area of fusiform and saccular aneurysmic dilation of venules and arterioles with associated local exudation. +• Treatment consists of direct photocoagulation of the abnormal vessels. +OCULAR ISCHAEMIC SYNDROME +Etiology. Ocular ischaemic syndrome refers to a rare condition resulting from chronic ocular hypoperfusion secondary to >90% stenosis of carotid artery. Carotid stenosis refers to atherosclerotic occlusive carotid artery disease often associated with ulceration at the bifurcation of common carotid artery. +Risk factorsfor carotid stenosis include male gender, old age (60–90 years), smoking, hypertension, diabetes mellitus and hyperlipidaemia. Manifestations of carotid occlusive disease include: • Amaurosis fugax (transient retinal ischaemic +attack), +• Retinal artery occlusion (due to embolus), +• Transient cerebral ischaemic attacks (TIA), and • Stroke. +Clinical features. Ocular ischaemic syndrome is usually unilateral (80%), affecting elder males more commonly than females (2:1). + +Symptoms include: +■Loss of vision, which usually progresses gradually over several weeks or months. +■Transient black outs (amaurosis fugax) may be noted by some patients. +■Pain, ocular or periorbital, may be complained by some patients. +■Delayed dark adaptation may be noted by few patients. + +Signs include: +■Cornea may show oedema and striae. +■Anterior chamber may reveal faint aqueous flare with few, if any, cells (ischaemic pseudoiritis). +■Pupil may be mid dilated and poorly reacting. ■Iris shows rubeosis iridis (in 66% cases) and +atrophic patches. +■Cataract may occur as a complication in advanced cases. +■Neovascular glaucoma is a frequent sequelae to anterior segment neovascularization. +■Fundus examination may reveal: +• Venousdilatation with irregular calibre but no or only mild tortuosity. +• Retinal arterial narrowing is present. +• Retina shows midperipheral dot and blot haemorrhages, microaneurysms and cotton wool spots. +• Retinal neovascularization is noted in 37% cases, which may be in the form of NVD and occasionally NVE. +• Macular oedema is a common complication. Differential diagnosis. Ocular ischaemic syndrome needs to be differentiated from non-ischaemic CRVO, diabetic retinopathy, hypertensive retinopathy and aortic arch disease caused by Takayasu arteritis, aortoarteritis, atherosclerosis and syphilis (Table 12.1). +Investigations. In suspected cases the carotid stenosis can be confirmed by Doppler ultrasound and magnetic resonance angiography. +Treatment of ocular ischaemic syndrome includes: • Treatment of neovascular glaucoma (see page 250). • Treatment of proliferative retinopathyby panretinal +photocoagulation (PRP) (see page 281). +• Treatment of pseudoiritis with topical steroid eye drops. +• Treatment of carotid stenosis is medical (antiplatelet therapy, oral anticoagulants) and surgical (carotid endarterectomy). +Chapter 12 Diseases of Retina 287 + + +Table 12.1 Differential diagnosis of ocular ischaemic syndrome + + +Condition +1. Nonischaemic CRVO + + +2. Diabetic retinopathy + +3. Hypertensive retinopathy +4. Aortic arch disease + +Similarities +Unilateral retinal haemorrhages, venous dilatation and cotton wool spots + + +Microaneurysms, dot and blot haemorrhages, venous dilatation, NVD and NVE, cotton wool spots +Arteriolar narrowing and focal constriction, retinal haemorrhages and cotton wool spots +Arteriolar narrowing, retinal haemorrhages, cotton wool spots, NVD and NVE + +Differences +Veins are more tortuous, haemorrhages are more numerous, normal retinal arteriolar perfusion, disc oedema, and sometimes opticociliary shunt vessels can be seen on the disc. +Usually bilateral, with characteristic hard exudates + + +Usually bilateral, no marked venous changes, and NVD and NVE. +Usually bilateral, absent arm and neck pulses, cold hands, and spasm of arm muscles with excercise. + + + + +DYSTROPHIES AND DEGENERATIONS OF RETINA + +RETINAL DYSTROPHIES + +Hereditary retinal dystrophies primarily affect the outer retina (RPE and photoreceptors). Common retinal dystrophies can be classified as below: +A. Generalised photoreceptor dystrophies +These involve the entire retina (peripheral retina more than macula) and include: +• Typical retinitis pigmentosa and its variants, • Progressive cone dystrophy, +• Leber congenital amaurosis, +• Congenital stationary night blindness, and +• Congenital monochromatism (achromatopsia). +B. Macular dystrophies +These primarily involve the macular area and a few common macular dystrophies are: +• Juvenile best macular dystrophy, • Stargardt’s disease, and +• Vitelliform dystrophy. +Note. Only the most important retinal dystrophy, the retinitis pigmentosa and its varients, are described here. +RETINITIS PIGMENTOSA +Retinitis pigmentosa, primary pigmentary retinal dystrophy is a hereditary disorder predominantly affecting the rods more than the cones. +Inheritance +Retinitis pigmentosa (RP) may occur as: +1. Sporadic disorder, isolated without family history due to mutation of multiple gene (>50%) including rhodopsin gene (40%), or + +2. Inherited disorder as: +• Autosomal recessive (AR), most common (25%), intermediate severity +• Autosomal dominant (AD), next common (25%), least severe +• X-linked (XL), least common (10%), most severe. +Prevalence and demography +• Prevalence. It occurs in 1 person per 5,000 of the world population. +• Age. It appears in the childhood and progresses slowly, often resulting in blindness in advanced middle age. +• Race. No race is known to be exempt or prone to it. • Sex. Males are more commonly affected than +females in a ratio of 3:2. +• Laterality. Disease is almost invariably bilateral and both eyes are equally affected. +Pathogenesis +As a group majority of retinitis pigmentosa conditions are characterized bydeath of rod photoreceptors. The molecular mechanism by which the genetic mutation eventuallycausesrod celldeathare unclear, although ample evidence indicates that apoptosis is involved in the final pathway of cell death. That the cone photoreceptors ultimately die from a disease that begins with rod-cell disease remains a puzzle. + +Clinical features +Typical retinitis pigmentosa, i.e., rod-cone dystrophy, in which rods are degenerated early and cones are involved late, is characterized by following features: +A. Visual symptoms +1. Night blindness. It is the characteristic and earliest feature and may present several years before the visible changes in the retina appear. It occurs due to degeneration of the rods. +288 Section 3 Diseases of Eye + + + +2. Dark adaptation. Light threshold of the peripheral retina is increased; though the process of dark adaptation itself is not affected until very late. +3. Tubular vision, i.e., loss of peripheral vision with preservation of central vision occurs in advanced cases. +4. Central vision is also lost ultimately after many years. +B. Fundus changes (Fig. 12.18) +1. Retinal pigmentary changes. These are typically perivascular (around veins) and jet black spots resembling bone corpuscles in shape. Initially, these changes are found in the equatorial region only and later spread both anteriorly and posteriorly. +2. Retinal arterioles are attenuated (narrowed) and may become thread-like in late stages. +3. Thinning and atrophy of retinal pigment epithelium (RPE) is seen in mid and far peripheral retina with relative sparing of RPE at the macula. +4. Optic disc becomes pale and waxy in later stages and ultimately consecutive optic atrophy occurs (Fig. 12.18). +5. Other associated changes which may be seen are colloid bodies, choroidal sclerosis, cystoid macular oedema, atrophic or cellophane maculopathy. +C. Visual field changes +Annular or ring-shaped scotoma (Fig. 12.19) is a typical feature which corresponds to the degenerated + + + + + + + + + + + + + + + + + + + + +Fig. 12.18 Fundus picture of retinitis pigmentosa with +consecutive optic atrophy + +equatorial zone of retina. As the disease progresses, scotoma increases anteriorly and posteriorly and ultimately only central vision is left (tubular vision). Eventually, even this is also lost and the patient becomes blind. +D. Electrophysiological changes +Typical electrophysiological changes appear early in the disease before the subjective symptoms or the objective signs (fundus changes) appear. +1. Electroretinogram (ERG) is initially subnormal (scotopic affected before photopic; b-wave affected before a wave) and eventually extinguished. +2. Electro-oculogram (EOG) is subnormal with an absence of light peak. +Associations of retinitis pigmentosa +I. Ocular associations. These include myopia, primary open-angle glaucoma, microphthalmos, conical cornea (keratoconus) and posterior subcapsular cataract. +II. Systemic associations. Most cases of retinitis pigmentosa (RP) are isolated (i.e., with no systemic features), but about 25% have associated systemic diseases. A number of specific syndromes are described: 1. Laurence-Moon-Biedl syndrome. It is characterised by retinitis pigmentosa, obesity, hypogenitalism, +polydactyly and mental deficiency. +2. Cockayne’s syndrome. It comprises retinitis pigmentosa, progressive infantile deafness, dwarfism, mental retardation, nystagmus and, ataxia. + + + + + + + + + + + + + + + + + + + + +Fig. 12.19 Field changes in retinitis pigmentosa +Chapter 12 Diseases of Retina 289 + + + +3. Refsum’s syndrome. It is characterised by retinitis pigmentosa, peripheral neuropathy and cerebellar ataxia. +4. Usher’s syndrome. It includes retinitis pigmentosa and labyrinthine deafness. +5. Hallgren’s syndrome. It comprises retinitis pigmentosa,vestibulocerebellarataxia,congenital deafness and mental deficiency. +6. Other associated syndromes include Bussen– Koranzweig syndrome (Abetalipoproteinaemia), Kearns-Sayer syndrome, Friedreich’s ataxia, Bardet-Biedle syndrome, NARP (neuropathy, ataxia, and retinitis pigmentosa), neuronal ceroid lipofuscinosis, and olivopontocerebellar degeneration. +Atypical forms of retinitis pigmentosa +1. Cone-rod dystrophy. In this condition, cones are degenerated earlier and more severely than the rods. +Symptoms include: +• Central vision is reduced, • Colour vison is defective, +• Defective vision in bright light +Fundus examination shows macular lesions with or without peripheral changes. +2. Retinitis pigmentosa sine pigmento. It is characterised by all the clinical features of typical retinitis pigmentosa, except that there are no visible pigmentary changes in the fundus. +3. Sectorial retinitis pigmentosa. It is characterized by involvement of only one sector of the retina. +4. Pericentric retinitis pigmentosa. In this condition, all the clinical features are similar to typical retinitis pigmentosa except that pigmentary changes are confined to an area, immediately around the macula. +5. Retinitis punctata albescens. It is characterised by the presence of innumerable discrete white dots scattered over the fundus without pigmentary changes. Other features are narrowing of arterioles, night blindness and constriction of visual fields. +Treatment +It is most unsatisfactory; rather we can say that till date there is no effective treatment for the disease. 1. Measures to stop progression, which have +been tried from time to time, without any breakthrough include: vasodilators, placental extracts, transplantation of rectus muscles into + +suprachoroidal space, light exclusion therapy, ultrasonic therapy and acupuncture therapy. Recently vitamin A (15000 IU, PO, qd of palmitate form) has been recommended to check its progression. +2. Correct any refractive error, prescribe glasses. +3. Systemic acetazolamide (500mg po) for associated cystoid macular oedema. +4. Low vision aids (LVA) in the form of ‘magnifying glasses’ and ‘night vision device’ may be of some help. +5. Rehabilitation of the patient should be earned out as per his socioeconomic background. +6. Prophylaxis.Genetic counselling for no consan-guinous marriages may help to reduce the inci-dence of disease. Further, affected individuals should be advised not to produce children. + +RETINAL DEGENERATIONS + +Retinal degenerations are acquired disorders of retina characterized by degenerative changes. These can be classified as below: +■Peripheral retinal degenerations, ■Vitreoretinal degenerations, and ■Macular degenerations, e.g., +• Age-related degeneration (see page 295), and • Myopic macular degeneration (see page 41). +PERIPHERAL RETINAL DEGENERATIONS +1. Lattice degeneration. It is the most important degeneration associated with retinal detachment. Incidence is 6 to 10% in general population and 15 to 20% in myopic patients. +Characteristic feature includes: +• White arborizing lines arranged in a lattice pattern along with areas of retinal thinning and abnormal pigmentation (Fig. 12.20A). +• Small round retinal holes are frequently present in it. +• Typical lesion is spindle-shaped, located between the ora serrata and the equator with its long axis being circumferentially oriented. +• Involves more frequently the temporal than the nasal, and is superior than the inferior halves of the fundus. +2. Snail tract degeneration. It is a variant of lattice degeneration in which white lines are replaced by snow-flake areas which give the retina a white frost-like appearance (Fig. 12.20 B). +290 Section 3 Diseases of Eye + + + + + + + + + + + + + + + + + + +Fig. 12.20 Peripheral retinal degenerations: A, lattice degeneration; B, snail track degeneration; C, acquired retinoschisis; D, white­with­pressure; E, focal pigment clumps; F, diffuse chorioretinal degeneration; and G, peripheral cystoid degeneration + +3. Acquired retinoschisis. The term retinoschisis refers to splitting of the sensory retina into two layers at the level of the inner nuclear and outer plexiform layers. It occurs in two forms—the congenital and acquired. +Acquired retinoschisis is also called as senile retinoschisis, may rarely act as predisposing factor for primary retinal detachment. It is characterised by thin, transparent, immobile, shallow elevation of the inner retinal layers (Fig. 12.20C) which typically produces absolute field detects—the fact which helps in differentiating it from the shallow retinal detachment which produces a relative scotoma. The condition is frequently bilateral and usually involves the lower temporal quadrants, anterior to the equator. +4. White-with-pressure and white-without pressure. These are not uncommonly associated with retinal detachment. +• ‘White-with-pressure’ lesions are characterised by greyish translucent appearance of retina seen on scleral indentation (Fig. 12.20D). +• ‘White-without-pressure’ lesions are located in the peripheral retina and may be associated with lattice degeneration. +5. Focal pigment clumps. These are small, localised areas of irregular pigmentation, usually seen in the equatorial region (Fig. 12.20E). These may be associated with posterior vitreous detachment and/ or retinal tear. + +6.Diffuse chorioretinal degeneration.It is characterised by diffuse areas of retinal thinning and depigmentation of underlying choroid (Fig. 12.20F). It commonly involves equatorial region of highly myopic eyes. +7. Peripheral cystoid retinal degeneration. It is a common degeneration (Fig. 12.20G) seen in the eyes of old people. It may predispose to retinal detachment in some very old people. +VITREORETINAL DEGENERATIONS Vitreoretinal degenerations or vitreoretinopathies include: +• Wagner’s syndrome, • Stickler syndrome, +• Favre-Goldmann syndrome, +• Familial exudative vitreoretinopathy, • Erosive vitreoretinopathy, +• Dominant neovascular inflammatory vitreoretino-pathy, and +• Dominant vitreoretinochoroidopathy. +Note. Characteristic features of some conditions are mentioned here. +Wagner’s syndrome +Wagner’s syndrome has an autosomal dominant (AD) inheritance with following features: +• Vitreous is liquified with condensed membranes. • Retina shows narrow and sheathed vessels, and +pigmented spots in the periphery. • Choroid may be atrophied. +• Cataract may develop as late complication. + +Stickler syndrome +Stickler syndrome, also known as hereditary arthro-ophthalmopathy, is an autosomal dominant connective tissue disorder characterized by following features: +Ocular features are as below: +Vitreous is liquified and shows syneresis giving appearance of an optically-empty vitreous cavity. Progressive myopia is very common. +Radial lattice like degeneration associated with pigmentary changes and vascular sheathing. Bilateral retinal detachment may occur in 30% cases (commonest inherited cause of retinal detachment in children). +Ectopia lentis is occasionally associated. Pre-senile cataract occurs in 50% cases. +Orofacial abnormalities include flattened nasal bridge, maxillary hypoplasia, cleft palate and high arched palate. +Chapter 12 Diseases of Retina 291 + + + +Arthropathy is characterized by stiff, painful, prominent and hyperextensible large joints. +Other features include deafness and mitral valve prolapse. +Favre-Goldmann syndrome +It is an autosomal recessive condition presenting in childhood with nyctalopia. Characteristic features are: +• Vitreous shows syneresis but the cavity is not optically empty. +• Retinoschisis, both central (affecting macula) and peripheral, is present, although macular findings are more subtle. +• Pigmentary changes similar to retinitis pigmentosa are marked. +• ERG is subnormal. + +MACULAR DISORDERS + +Macula, being concerned with vision, has attracted the attention of many retina specialists. Consequently, many disorders have been defined and variously classified. A simple, etiological classification for a broad overview of the macular lesions is as follows: A. Congenital anomalies. These include aplasia, hypoplasia and coloboma. +B. Hereditary dystrophies. These include Best’s disease, Stargardt’s disease, butterfly-shaped dystrophy, bull’s eye dystrophy and central areolar dystrophy. +C. Acquired maculopathies include: +1. Traumatic lesions. These include traumatic macular oedema, traumatic macular degeneration, macular haemorrhage and macular hole (see page 431). +2. Inflammations, i.e., central chorioretinitis (see page 162). +3. Solar retinopathy, i.e., photoretinitis. +4. Degenerations. Important conditions are age-related macular degeneration (ARMD), and myopic degeneration. +5. Metabolic disorders include: diabetic maculopathy and sphingolipidosis. +6. Toxic maculopathies. These are chloroquine and phenothiazine-induced maculopathy. +7. Miscellaneous acquired maculopathies. A few common conditions are: +• Central serous chorioretinopathy (CSCR), • Cystoid macular oedema (CME), +• Macular hole, +• Macular epiretinal membrane, + +• Vitreomacular traction syndrome, and +• Idiopathic choroidal neovascularization. Note. Only a few macular disorders are described. +HEREDITARY MACULAR DYSTROPHIES Best’s disease +Inheritence: Autosomal dominant +Clinical picture can be divided into five stages: +• Pre-vitelliform stage. Normal fundus, but EOG is abnormal. +• Vitelliform stage. Egg yolk lesion at macula. +• Pseudohypopyon stage. Partially absorbed egg yolk lesion. +• Vitelli eruptive stage. A scrambled egg appearance of macula. +• Stage of scarring. Hypertrophic or atrophic vascu-larized scar at macula. +Stargardt’s disease +Clinical presentation is with decreased vision in first or second decade of life. +Fundus examinationshows ‘beaten-bronze’ or ‘snail-slime reflex’ in macular area. +SOLAR RETINOPATHY +Solar retinopathy also known as photoretinitis, or eclipse retinopathy, refers to retinal injury induced by direct or indirect sun viewing. Solar retinopathy is associated with religious sun gazing, solar eclipse observing, telescopic solar viewing, sun bathing and sun watching in psychiatric disorders. +Causes of photic retinopathy, other than solar retinopathy, are: +• Welding arc exposure, +• Lightening retinopathy, and +• Retinal phototoxicity from ophthalmic instruments like operating microscope. +Pathogenesis +Solar radiations damage the retina through: ■Photochemical effects produced by UV and visible +blue light, and +■Thermal effects may enhance the photochemical effects. The long visible wavelength and infrared rays from the sun are absorbed by the pigment epithelium producing a thermal effect. Therefore, severity of lesion varies directly with the degree of pigmentation of the fundus, duration of exposure and the climatic conditions during exposure. +Clinical features Symptoms. These include: +• Persistence of negative after-image of the sun, progressing later into a positive scotoma and metamorphopsia. +292 Section 3 Diseases of Eye + + + +• Decreased vision (6/12–6/60) (unilateral or bilateral) which develops within 1 to 4 hours after solar exposure, usually improves to 6/6–6/12 within six months. +Signs. Initially, the fundus may appear normal. Shortly after exposure a small yellow spot with grey margin may be noted in the foveolar and parafoveolar region. The typical lesion, which appears later, consists of a central burnt-out hole in the pigment epithelium surrounded by aggregation of mottled pigment. Ophthalmoscopically, it appears as a bean- or kidney-shaped pigmented spot with yellowish white centre in the foveal region. In worst cases, typical macular hole may appear. +Treatment +There is no effective treatment for photoretinitis, so emphasis should be on prevention. Eclipse viewing should be discouraged unless there is proper use of protective eye wear filters (which absorb UV and infrared wavelengths). +Prognosis is guarded, since some scotoma and loss in visual acuity by one or two lines mostly persists. +CENTRAL SEROUS CHORIORETINOPATHY Central serous chorioretinopathy (CSCR) is characterised by spontaneous serous detachment of neurosensory retina in the macular region, with or without retinal pigment epithelium detachment. +Etiopathogenesis Risk factors include: +• Age and sex. The disease affects typically young adult (20–50 years), males more than females, +• Personality. Type A personality individuals are more prone, +• Steroid intake is an important risk factor, • Emotional stress, + + + + + + + + + + + + + +Fig. 12.21 Best disease: vitelliform disease (egg yolk lesion at macula) + +• Hypertension, +• Pregnancy (usually 3rd trimester), and +• Cushing’s disease are also reported as risk factors. Pathogenesis is not known exactly. Various theories have been postulated. Presently, the most accepted theory is of ‘choroidal vascular hyperpermeability’. This theory correlates the clinical findings with indocyanine green (ICG) angiography findings. It proposes that sympathetic drive, sympathomimetics and corticosteroids alter the choroidal vascular permeability either directly or indirectly by affecting its autoregulation. This, in turn, increases the tissue hydrostatic pressure in the choroid causing pigment epithelial defect (PED) resulting in a breach in the outer blood retinal barrier. Leakage of fluid across this area results in development of localized serous detachment of neurosensory retina. +Clinical features +Symptoms. Patient may present with: +• Sudden painless loss of vision (6/9–6/24) associated with +• Relative positive scotoma, micropsia and metamorphopsia. +Signs. Biomicroscopic fundus examination reveals: • Mild elevation of macular area, demarcated by a +circular ring reflex. +• Small yellow grey elevations may be seen due to RPE detachment. +• Foveal reflex is absent or distorted (Fig. 12.22). • Subretinal deposists may be seen. +• Multifocal pigmentary changes suggest chronicity. + +Clinical course +CSR is usually self-limiting but often recurrent. Three patterns are known: + + + + + + + + + + + + + + + +Fig. 12.22 Fundus photograph showing central serous retinopathy +Chapter 12 Diseases of Retina 293 + + + +Acute classic CSCR is characterized by short clinical course with spontaneous resolution within 3–6 months with near normal visual recovery. Recurrences are known in 30–50% of all the cases. Chronic CSCR, also termed as diffuse retinal pigment epitheliopathy (DRPE), is seen in few cases. It is characterized by a chronic course lasting more than 12 months, typically affecting individuals above 50 years of age. Such cases may have permanent visual impairment due to progressive RPE atrophy and photoreceptor degeneration. +Bullous CSCR is rare presentation characterized by larger and more numerous areas of serous retinal and RPE detachments often confused with bullous retinal detachment. +Investigations +1.Fundus fluorescein angiography helps in confirming the diagnosis. Two patterns of progressive leakage and pooling from one or more points seen are: +• Ink-blot pattern. It consists of small hyperfluorescent spot which gradually increases in size (Fig. 12.23A). +• Smoke-stack pattern. It consists of a small hyperfluorescent spot which ascends vertically like a smoke-stack and gradually spreads laterally to take a mushroom or umbrella configuration (Fig. 12.23B). +2.ICGshows multiple areas of hyperfluorescence due to choroidal hyperpermeability. +3. OCT shows neurosensory retinal detachment and accompanying small detachments of the RPE (Fig. 12.23C). +Differential diagnosis +Differential diagnosis of CSR includes other entities which may produce serous detachment of sensory retina in macular area. These include optic pit, idiopathic polypoidal choroidal vasculopathy, macular hole with serous detachment, choroidal tumors and pigment epithelial defect (PED). +Treatment +1. Conservative measures. Reassurance is the only treatment required in majority of the cases, since CSR undergoes spontaneous resolution in 80 to 90% cases. Visual acuity returns to normal or near normal within 3 to 6 months. +• Discontinuation of steroids, if possible, should be done at the earliest. +• Life style changes to reduces stress in life, should be adopted. +2. Laser photocoagulation is indicated in following cases: + + + + + + + + + + + + + +A + + + + + + + + + + + + + +B + + + + + + + +C +Fig. 12.23 Fundus fluorescein angiogram showing ink­blot pattern (A) and smoke­stack pattern (B) of hyperfluorescence in central serous retinopathy and (C) OCT picture of CSR + +• Long-standing cases (more than 6 months). +• Patients having recurrent CSR with visual loss. +• Patients having permanent loss of vision in the other eye due to this condition. Contraindications include the cases having leak near or within the FAZ. +3. Photodynamic therapy (PDT) may be beneficial for those with severe disease not amenable to conventional laser treatment, e.g., with sub-foveal leaks and chronic cases. +4. Anti-VEGF can be considered if CNV develops. +294 Section 3 Diseases of Eye + + + +CYSTOID MACULAR OEDEMA (CME) +It refers to collection of fluid in the outer plexiform (Henle’s layer) and inner nuclear layer of the retina, centred around the foveola. +Etiology +It is associated with a number of disorders. A few common causes are as follows: +1. Complication of ocular treatment such as: +• Ocular surgery, e.g., cataract extraction (Irvine-Gass syndrome), penetrating keratoplasty, glaucoma filteration surgery and retinal detachment surgery. +• Ocular laser therapy, e.g., panretinal photoco-agulation (PRP), and Nd:YAG laser capsulotomy. +• Topical ocular therapy with eye drops like epinephrine, dipivefrine and prostaglandin analogues, especially in patients who have undergone cataract surgery. +2. Retinal vascular disorders e.g., diabetic retinopathy and central retinal vein occlusion (CRVO), branch retinal vein occlusion (BRVO), retinal telangiectasia (e.g., Coats’ disease), periphlebitis retinae (Eales disease), and hypertensive retinopathy. +3. Intraocular inflammations, e.g., pars planitis, posterior uveitis and anterior uveitis. +4. Retinal dystrophies, e.g., retinitis pigmentosa. +5. Vitreomacular traction as seen in macular epiretinal membrane (ERM) and vitreo macular traction (VMT) syndrome. +6. Systemic diseases such as leukaemia, chronic renal failure and multiple myeloma. +7. Miscellaneous causes include intraocular tumours, choroidal neovascularization (CNV) and collagen vascular diseases. +Pathogenesis +CME develops due to leakage of fluid following breakdown of inner blood-retinal barrier (i.e., leakage from the retinal capillaries) and accumulating in the outer plexiform and inner nuclear layer of retina with the formation of cyst-like changes as depicted on OCT macular scan (Fig. 12.25B). +Clinical features +1. Visual loss. Initially there is minimal to moderate loss of vision, unassociated with other symptoms. If oedema persists, there may occur permanent decrease in vision. +2. Ophthalmoscopy reveals loss of foveal contour, retinal thickening, a yellow spot at the center of fovea and in clinically established cases a typical ‘Honey-comb appearance’ of macula (due to multiple cystoid + + + + + + + + + + + + + + +Fig. 12.24 Fundus photograph showing honey­comb appearance in cystoid macular oedema (CME) + +oval spaces) (Fig. 12.24). CME is best examined with a fundus contact lens on slit-lamp or +90D lens. Associated features depend on the underlying cause, e.g., CRVO, etc. +3. Fundus fluorescein angiography demonstrates leakage and accumulation of dye in the macular region which in a well-established case presents a ‘flower petal appearance’ in late frames (Fig. 12.25A). +4. Optical coherence tomography (OCT) reveals loss of foveal depression, intraretinal area of decreased reflectivity with round optically clear regions (cystoid spaces) and over all retinal thicknening (Fig. 12.25B). Detection rate on OCT is similar to FFA. It can also detect associated specific pathology, e.g., vitreomacular traction. +Complications +Long-standing CME may end in lamellar macular hole. +Treatment +1. Treatment of the causative factor,e.g., photocoagula-tion for diabetic CSME; cessation of causative topical 2% adrenaline eye drops and soon. +2. Topical antiprostaglandin (NSAID) drops like ketorolac, diclofenac or profenac when used pre-and postoperatively, prevent the occurrence of CME associated with intraocular surgery. These are also useful in the treatment of most CMEs when given for 3 to 4 months. +3. Topical and systemic steroids may be of some use in established cases. +4. Systemic carbonic anhydrase inhibitors (CAIs), e.g., oral acetazolamide may be beneficial in some cases of CME, e.g., in retinitis pigmentosa. +Chapter 12 Diseases of Retina 295 + + + + + + + + + + + + + + + +A + + + + + + + + + + +B +Fig. 12.25 Cystoid macular oedema: A, Fundus fluorescein angiogram showing flower petal appearance and B, OCT picture showing cystoid spaces + +AGE-RELATED MACULAR DEGENERATION Age-related macular degeneration (ARMD), also called senile macular degeneration, is a bilateral disease of persons over 50 years of age. It is a leading cause of blindness in developed countries, in population above the age of 65 years. It is of two types non-exudative and exudative. +Etiopathogenesis +ARMD is an age-related disease of worldwide prevalence. Certain risk factors which may affect the age of onset and/or progression include heredity, nutrition, smoking, hypertension, exposure to sun light, hyperopia, blue eyes and cataract particularly nuclear opacity. The disease is most prevalent in Caucasians. +Clinical types +1. Non-exudative or atrophic ARMD +It is also called dry or geographic ARMD and is responsible for 90% cases. +Symptoms. It typically causes mild to moderate, gradual loss of vision. Patients may complain of distorted vision and difficulty in reading due to central shadowing. + +Signs. Ophthalmoscopically, lesions of non exudative ARMD can be described into three stages (Fig. 12.26A): +Early stage cases are characterized by occurrence of macular drusens, focal hyperpigmentation and pale area of retinal pigment atrophy (RPE atrophy). Macular drusens are well defined, yellowish white, slightly-elevated spots. In early cases less than 20 small to medium sized (60–125 mm) drusens are seen. +Intermediate stagecasesshow sharply circumscribed circular areas of RPE atrophy with variable loss of choriocapillaries along with drusens [1 large drusen >125mm and/or >20 medium drusens (60–125 mm)]. Large drusens are soft drusens with less sharply defined edges, tend to enlarge or coalesce. Advanced stage cases show enlargement of atrophic areas within which the larger choroidal vessels may become visible and pre-existing drusen disappear (Geographical atrophy). +2. Exudative ARMD +It is also called wet or neovascular ARMD. It is responsible for only 10% cases of ARMD but is associated with comparatively rapidly progressive marked loss of vision. +Typical lesions of exudative ARMD seen in chro-nological order are as below: +• Drusens with retinal pigment epithelial detachment (PED) seen as sharply circumscribed dome-shaped elevation. +• Choroidal neovascularization (CNV) proliferating in sub-RPE space (type 1) is seen as greyish green or pinkish yellow raised lesion (Fig 12.26B). The CNV proliferating in sub-retinal space (type 2) is seen as sub-retinal halo or pigment plaque. +• Haemorrhagic pigment epithelial detachment (PED). It appears as dark elevated mount. +• Haemorrhagic detachment of neurosensory retina which assumes diffuse outline and a lighter red colour around and adjacent to the PED. +• Disciform sub-retinal scarring in the macular region may result from gradual organization of blood with further fibrovascular ingrowth. +Diagnosis +Clinical diagnosis is made from the typical signs described above, which are best elucidated on examination of the macula by slit-lamp biomicroscopy with a +90D/+78D non-contact lens or Mainster contact lens. +296 Section 3 Diseases of Eye + + + +Fundus fluorescein angiography and indocyanine green angiography help in detecting choroidal neovascularization (CNV) in relation to foveal avascular zone. CNV may be classical or occult: +• Classical CNVM is seen as lacy hyperfluorescence with progressive leakage (Fig. 12.26 C). It may be subfoveal, juxtafoveal or extrafoveal in location. +• Occult CNVM isseen as stippled hyperfluorescence (type I) or as late leakage of undetermined source. (type II). +■Optical coherence tomography (OCT) reveals subretinal fluid, intraretinal thickening, choroidal neovascularization and haemorrhages in exudative ARMD (Fig. 12.26 D). +Treatment +Treatment of non-exudative ARMD. Currently, there is no effective treatment that stop progression of dry AMD. Measures to be tried include: +• Dietary supplements and antioxidants. The age-related eye disease study (AREDS) has suggested that use of certain specific antioxidants, vitamins and minerals [vitamin C (500 mg) and vitamin E (400 IU), beta carotene (15 mg), zinc oxide (80 mg) and cupric oxide (2 mg)] could possibly prevent or delay the progression of ARMD. +• Smoking cessation may slow down the progress. +• Amsler grid used regularly allows the patients to detect new or progressive metamorphopsia prompting them to seek ophthalmic advice. +• Refraction with increased near add may be helpful in early cases. +• Low vision aid may be needed in advanced cases of geographical atrophy. +Treatment modalities available for exudative (neovas-cular) ARMD : +Intravitreal anti-VEGF therapy has become the treatment of first choice for all CNV lesions. Anti-VEGFs are injected intravitreally. These include: +• Bevacizumab (Avastin), dose: 1.25 mg, or +• Ranibizumab (Lucentis), dose: 0.5 mg/0.05 ml, or • Pegaptanib (Macugen), dose: 0.3 mg in 90 ml (For +detail see page 458). +Results of anti-VEGF are encouraging in the sense that they improve the vision in 30–40% of cases and stabilize the vision in rest of the cases. However, the effect is short lasting and repeated injections are required at an interval of 1–3 months. VEGF-trap-eye (afibercept), a fusion protein, is reported to be equally effective as standard therapy, but requires fewer injections into the eyes. + + + + + + + + + + + +A + + + + + + + + + + +B + + + + + + + + + + +C + + + + + + + + +D +Fig. 12.26 Age­related macular degeneration: A, non­ exudative; B, exudative; C, FFA showing leakage and lacy pattern in CNVM; D, OCT picture of CNVM + +Note. Although anti-VEGF therapy is the preferred strategy for the treatment of CNV, some patients may choose not to undergo an intravitreal procedure. In these cases, options include PDT, TPT, argon laser photocoagulation. +Chapter 12 Diseases of Retina 297 + + + +Photodynamic therapy (PDT) is the treatment of choice after anti-VEGF injections for subfoveal and juxtafoveal classic CNVM. In PDT, vertiporfin, a photosensitizer or light activated dye is injected intravenously. The area of CNVM is then exposed to light from a diode laser source at a wavelength (689 nm) that corresponds to absorption peak of the dye. The light-activated dye then causes disruption of cellular structures and occlusion of CNVM with minimum damage to the adjacent RPE, photoreceptors and capillaries. +Transpupillary thermotherapy (TTT) with a diode laser (810 nm) may be considered for subfoveal occult CNVM. PDT is definitely better than TTT but is very expensive. +Double frequency and YAG 532 nm photocoagulation may be used for extrafoveal choroidal neovascular membrane (CNVM). +Surgical treatment. Submacular surgery to remove CNVM and macular translocation surgery are being evaluated. +MACULAR HOLE +Macular hole refers to a partial thickness of full thickness hole in the neurosensory retina in the foveal region. +Causes +1. Senile or idiopathic (83%), more common in females aged 60–80 years than males (F:M, 3:1). +2. Traumatic macular hole account for (5%) cases. 3. Other causes of macular hole include: cystoid +macular oedema, vitreomacular traction, post-surgical, myopia, post-laser treatment, epiretinal membrane traction and post-inflammatory. +Pathogenesis: Senile macular holes are caused by tractional forces associated with early PVD. +Clinical features +Symptoms include: +• Decreased vision, typically around 6/60 level for a full thickness hole and better for a partial hole. +• Metamorphopsia or distortion of vision may be there. +• Central scotoma may be reported by some patients. +Signs. Based on the fundus appearance (best examined with 78/90D slit-lamp examination), the macular hole can be classified into four stages (Fig.12.27): +Stage 1 or impending hole. It is characterized by absent foveal reflex and a yellow spot (Stage 1A, Fig. 12.27A) or a yellow ring (Stage 1B) in the foveal + + +region. OCT examination reveals a pseudocyst with a vitreous detachment in stage 1 A (Fig. 12.27B), and progression of the pseudocyst with a break in the outer foveal layer in stage 1B. +Stage 2. A small full thickness hole (Fig. 12.27C) is seen either in the centre of the ring (central) or at the margin of the ring (eccentric). OCTexamination shows a full thickness hole less than 400 mm in size (Fig. 12.27D). +Stage 3. A full thickness hole is seen as round reddish spot surrounded by a grey halo [cuff of sub-retinal fluid (SRF)], but no PVD (Fig. 12.27E). OCT examination shows a full thickness macular hole more than 400 mm in size with partial vitreomacular adhesion/traction (Fig. 12.27F). +Stage 4. Full thickness hole with SRF cuff and complete PVD, i.e., posterior vitreous detachment (seen as Weiss ring) (Fig. 12.27G). OCTexamination confirms a large full thickness hole with posterior vitreous detached from the disc and macula. (Fig. 12.27H). +Management +Differential diagnosis of fundus appearance include: +• Macular pucker (epiretinal membrane) with pseudohole, +• Solar retinopathy, +• Intraretinal cyst (e.g., chronic CME with prominent central cyst) and +• Vitreomacular traction syndrome. +Investigations +1. Fundus fluorescein angiography reveals early foveal hyperfluorescence without leak in the late phase in patients with stage 2 to 4 macular holes. +2. Optical coherence tomography (OCT) (Fig. 12.27) is useful for: +• Differentiating true holes from the lamellar holes and cysts, +• Staging of the macular hole, +• Determining the degree of traction from the epiretinal membrane, and +• Planning the surgery. +Treatment +■Stage 1. Treatment is not recommended as spontaneous hole closure can occur. But close follow-up and observation is required as 50% cases do progress. +■Stage 2 to 4 holes of recent onset (<1 year) with reduced visual acuity (<6/24) should be treated with pars plana vitrectomy with posterior hyaloid +298 Section 3 Diseases of Eye + + + +removal, internal limiting membrane (ILM) peeling and gas or silicon oil tamponade with strict postoperative face down position for 7–14 days. +Prognosis. Anatomical closure is reported in 60–85% of cases. Visual improvement is reported in 70% cases with recent onset holes. +Complications of surgery. A comparatively common complication is occurrence or progression of cataract. Other reported complications include: retinal breaks, retinal detachment, late reopening of the hole, RPE loss under the hole, phototoxicity and endophthalmitis. + + + + + + + + + + + +A + + + + + + +B + + + + + + + + + + + +C + + + + + + + +D + + +RETINAL DETACHMENT + +Retinal detachment is the separation of neurosensory retina proper from the pigment epithelium. Normally, these two layers are loosely attached to each other with a potential space in between. Hence, actually speaking the term retinal detachment is a misnomer and it should be retinal separation. + +Classification +Clinico-etiologically retinal detachment can be classified into three types: + + + + + + + + + + + +E + + + + + + +F + + + + + + + + + + + +G + + + + + + + +H + +Fig. 12.27 Macular hole stages 1, 2, 3, 4: Fundus appearance (A, C, E, G) and OCT pictures (B, D, F, H), respectively +Chapter 12 Diseases of Retina 299 + + + +1. Rhegmatogenous or primary retinal detachment, 2. Tractional retinal detachment, and +3. Exudative retinal detachment. + +RHEGMATOGENOUS OR PRIMARY RETINAL DETACHMENT +Rhegmatogenous retinal detachment usually associated with a retinal break (hole or tear) through which subretinal fluid (SRF) seeps and separates the sensory retina from the pigmentary epithelium. This is the commonest type of retinal detachment. +Etiology +It is still not clear exactly. The predisposing factors and the proposed pathogenesis is as follows: +A. Predisposing factors include: +1. Age. The condition is most common in 40–60 years. However, age is no bar. +2. Sex. More common in males (M:F—3:2). +3. Myopia. About 40% cases of rhegmatogenous retinal detachment are myopic. +4. Aphakia and pseudophakia. The condition is more common in aphakes and pseudophake than phakes. +5. Retinal degenerations predisposed to retinal detachment are as follows: +• Lattice degeneration, +• Snail track degeneration, +• White-with-pressure and white-without-or occult pressure, +• Acquired or retinoschisis, and • Focal pigment clumps. +6. Trauma. It may also act as a predisposing factor. 7. Senile posterior vitreous detachment (PVD). It is +associated with retinal detachment in about 10% cases. +B. Pathogenesis +Pathogenesis of rhegmatogenous retinal detachment (RRD) is summarized in Fig. 12.28. The retinal breaks responsible for RRD are caused by the interplay between the dynamic vitreoretinal traction and predisposing degeneration in the peripheral retina. Dynamic vitreoretinal traction is induced by rapid eye movements especially in the presence of PVD, vitreous syneresis, aphakia and myopia. Once the retinal break is formed, the liquified vitreous may seep through it separating the sensory retina from the pigment epithelium. As the subretinal fluid (SRF) accumulates, it tends to gravitate downwards. The final shape and position of RD is determined + + + + + + + + + + + + + +Fig. 12.28 Flowchart depicting pathogenesis of rhegmatogenous retinal detachment + +by location of retinal break (Lincoff’s rule) and the anatomical limits of optic disc and ora serrata. +The degenerated fluid vitreous seeps through the retinal break and collects as subretinal fluid (SRF) between the sensory retina and pigmentary epithelium. +Clinical features +Prodromal symptoms include: +• Dark spots (floaters) in front of the eye (due to rapid vitreous degeneration), and +• Photopsia, i.e., sensation of flashes of light (due to irritation of retina by vitreous movements). +Symptoms of detached retina are as follows: +1. Localised relative loss in the field of vision (of detached retina) is noticed by the patient in early stage which progresses to a total loss when peripheral detachment proceeds gradually towards the macular area. +2. Sudden appearance of a dark cloud or veil in front of the eye is complained by the patients when the detachment extends posterior to equator. +3. Sudden painless loss of vision occurs when the detachment is large and central. +Signs. These are elicited on following examinations: +1. External examination, eye is usually normal. +2. Intraocular pressure is usually slightly lower or may be normal. +3. Marcus Gunn pupil (relative afferent pupillary defect) is present in eyes with extensive RD. +4. Plane mirror examination or Distant Direct ophthalmoscopy reveals an altered red reflex in the pupillary area (i.e., greyish reflex in the quadrant of detached retina). +300 Section 3 Diseases of Eye + + + +5. Ophthalmoscopy should be carried out both direct and indirect techniques. Retinal detachment, is best examined by indirect ophthalmoscopy using scleral indentation (to enhance visualization of the peripheral retina anterior to equator). +• Freshly-detached retina gives grey reflex instead of normal pink reflex and is raised anteriorly (convex configuration). It is thrown into folds which oscillate with the movements of the eye. These may be small or may assume the shape of balloons in large bullous retinal detachment. In total detachment retina becomes funnel-shaped, being attached only at the disc and ora serrata. Retinal vessels appear as dark tortuous cords oscillating with the movement of detached retina. +• Retinal breaks associated with rhegmatogenous detachment are located with difficulty. These look reddish in colour and vary in shape. These may be round, horse-shoe shaped, slit-like or in the form of a large anterior dialysis (Fig. 12.29). Retinal breaks are most frequently found in the periphery (commonest in the upper temporal quadrant). Associated retinal degenerations, pigmentation and haemorrhages may be discovered. +• Vitreous pigments may be seen in the anterior vitreous (tobacco dusting or Shaffer sign), with posterior vitreous detachment. +• Old retinal detachment is characterized by retinal thinning (due to atrophy), formation of subretinal demarcation line (high water marks) due to proliferation of RPE cells at the junction of flat detachment and formation of secondary intraretinal cysts (in very old RD). +6. Visual field charting reveals scotomas corres-ponding to the area of detached retina, which are relative to begin with but become absolute in long-standing cases. +7. Electroretinography (ERG)is subnormal or absent. + +8. Ultrasonography confirms the diagnosis. It is of particular value in patients with hazy media especially in the presence of dense cataracts and vitreous haemorrhage. +Complications +Complications usually occur in long-standing cases and include proliferative vitreoretinopathy (PVR), complicated cataract, uveitis and phthisis bulbi. +Treatment +Basic principles and steps of RD surgery are sealing of retinal breaks, reducing the vitreous traction on the retina, and flattening of retina by draining of subretinal fluid and external or internal tamponade. +1. Sealing of retinal breaks. All the retinal breaks should be detected, accurately localised and sealed by producing aseptic chorioretinitis, with cryocoagulation, or photocoagulation or diathermy. Cryocoagulation is more frequently utilised (Fig. 12.30). +2. Drainage of SRF. It allows immediate apposition between sensory retina and RPE. SRF drainage is done very carefully by inserting a fine needle through the sclera and choroid into the subretinal space and allowing SRF to drain away. SRF drainage may not be required in some cases. +3. Maintenance of chorioretinal apposition is required for at least a couple of weeks. This can be accomplished by either of the following procedures depending upon the clinical condition of the eye: +i. Scleral buckling i.e., inward indentation of sclera to provide external tamponade is still widely used to achieve the above mentioned goal successfully in simple cases of primary RD. Scleral buckling is achieved by inserting an explant (silicone sponge or solid silicone band) with the help of mattress type sutures applied in the sclera (Fig. 12.31). + + + + + + + + + + + +A B C +Fig. 12.29 Retinal detachment associated with: A, horse­shoe tear; B, round retinal hole; C, anterior dialysis +Chapter 12 Diseases of Retina 301 + + + + + + + + + + + + + + + + + +Fig. 12.30 Cryocoagulation of the retinal hole area under direct vision with indirect ophthalmoscopy + + + + + + + + + + + + + + + + +Fig. 12.31 Diagram depicting scleral buckling and subretinal fluid (SRF) drainage + +Radially-oriented explant is most effective in sealing an isolated hole, and circumferential explant (encirclage) is indicated in breaks involving three or more quadrants. +ii. Pneumatic retinopexy is a simple out-patient procedure which can be used to fix a fresh superior RD with one or two small holes extending over less than two clock hour area in the upper two-thirds of peripheral retina. In this technique after sealing the breaks with cryopaxy, an expanding gas bubble +(SF6 or C3 F8) is injected in the vitreous. Then proper +positioning of the patient is done so that the break is uppermost and the gas bubble remains in contact with the tear for 5–7 days. +iii. Pars plana vitrectomy, endolaser photocoagulation and internal tamponade. This procedure is indicated in: + +• All complicated primary RDs, and • All tractional RDs. +• Presently, even in uncomplicated primary RDs (where scleral buckling is successful), the primary vitrectomy is being used with increasing frequency by the experts in a bid to provide better results. +Main steps of this procedure are: +• Pars plana, 3-port vitrectomy (see page 261) is done to remove all membranes and vitreous and to clean the edges of retinal breaks. +• Internal drainage of SRF through existing retinal breaks using a fine needle or through a posterior retinotomy is done. +• Flattening of the retina is done by injecting silicone oil or perfluorocarbon liquid. +• Endolaser is then applied around the area of posterior retinotomy, retinal tears, and holes to create chorioretinal adhesions. +• To tamponade the retina internally either silicone oil is left inside or is exchanged with some long-acting gas (gas-silicone oil exchange). Gases commonly used to tamponade the retina are +sulphur hexafluoride (SF6) or perfluoropropane +(C3 F8) (see page 262). +Prophylaxis +Occurrence of primary retinal detachment can be prevented by timely application of laser photo-coagulation or cryotherapy in the areas of retinal breaks and/or predisposing lesions like lattice degeneration. Prophylactic measures are particularly indicated in patients having associated high-risk factors like myopia, aphakia, retinal detachment in the fellow eye or history of retinal detachment in the family. +EXUDATIVE OR SOLID RETINAL DETACHMENT Exudative (serous) retinal detachment occurs due to the retina being pushed away by a neoplasm or accumulation of fluid beneath the retina following inflammatory or vascular lesions. +Etiology +Common causes of exudative retinal detachment can be grouped as under: +1. Systemic diseases. These include: toxaemia of pregnancy, renal hypertension, blood dyscrasias and polyarteritis nodosa. +2. Ocular diseases. These include: +i. Congenital abnormalities such as nanophthalmos, optic pit, choroidal coloboma and familial exudative vitreoretinopathy (FEVR); +ii. Inflammations such as Harada’s disease, +302 Section 3 Diseases of Eye + + + +sympathetic ophthalmia, posterior scleritis, and orbital cellulitis; +iii.Vascular diseases such as central serous retinopathy and exudative retinopathy of Coats; +iv. Neoplasms, e.g., malignant melanoma of choroid retinoblastoma (exophytic type), haemangioma, and metastatic tumours of choroid; +v. Sudden hypotony due to perforation of globe and intraocular operations. +vi. Uveal effusion syndrome is characterised by bilateral detachment of the peripheral choroid, ciliary body and retina. +vii. Choroidal neovascularization may also cause exudative retinal detachment. +Clinical features +Exudative retinal detachment can be differentiated from a simple primary detachment by: +• Absence of photopsia, holes/tears, folds and undulations. +• The exudative retinal detachment is smooth and convex (Fig. 12.32). At the summit of a tumour it is usually rounded and fixed and may show pigmentary disturbances. +• Pattern of retinal vessels may be disturbed occasionally, due to presence of neovascularization on the tumour summit. +• Shifting fluid characterised by changing position of the detached area with gravity is the hallmark of exudative retinal detachment. +• On transillumination test a simple detachment appears transparent while solid detachment is opaque. +Investigations +1. Ocular and systemic examination should be carried out thoroughly. + + + + + + + + + + + + + +Fig. 12.32 Exudative retinal detachment in a patient with malignant melanoma of choroid + +2. B-scan ultrasonography may help delineate the underlying cause. +3. FFA may show source of fluid. +4. CT scanand/or MRI is useful, specially in cases of intraocular tumours. +Treatment +Treatmentof the causeis required in most of the cases, as the exudative retinal detachment due to transudate, exudate and haemorrhage may undergo spontaneous regression following absorption of the fluid. Thus, the treatment should be for the causative disease. +• Enucleation is usually required in the presence of intraocular tumours. +TRACTIONAL RETINAL DETACHMENT +Tractional retinal detachment (TRD) occurs due to retina being mechanically pulled away from its bed by the contraction of fibrous tissue in the vitreous (vitreoretinal tractional bands). +Etiology +TRD is associated with the following conditions: +• Post-traumatic retraction of scar tissue especially following penetrating injury, +• Proliferative diabetic retinopathy, +• Post-haemorrhagic retinitis proliferans, • Retinopathy of prematurity, +• Plastic cyclitis, +• Sickle cell retinopathy, +• Proliferative retinopathy in Eales’ disease, • Vitreomacular traction syndrome, +• Incontinentia pigmenti, • Retinal dysplasia, and +• Toxocariasis. + +Clinical features +Photopsia and floaters are not complained. Tractional retinal detachment (Fig. 12.33) is characterised by: • Presence of vitreoretinal bands with lesions of the +causative disease. +• Retinal breaks are usually absent and configuration of the detached area is concave. +• Highest elevation of the retina occurs at sites of vitreoretinal traction. +• Retinal mobility is severely reduced and shifting fluid is absent. +Treatment +• Surgery is difficult and requires pars plana vitrectomy to cut the vitreoretinal tractional bands and internal tamponade with either a long-acting gas or silicon oil. +• Prognosis in such cases is usually not so good. +Chapter 12 Diseases of Retina 303 + + + + + + + + + + + + + + + + +Fig. 12.33 Tractional retinal detachment in a patient with advanced diabetic retinopathy + +TUMOURS OF RETINA + +Tumours of retina have become a subject of increasing interest to clinical ophthalmologists as well as ocular pathologists. Classification of retinal tumours is given below and only a few, which are commonly seen are described. +Classification +A. Primary tumours +1. Neuroblastic tumours. These arise from sensory retina (retinoblastoma and astrocytoma) and pigment epithelium (benign epithelioma and melanotic malignant tumours). +2. Mesodermal angiomata, e.g., cavernous haemangioma. +3. Phakomatoses. These include: angiomatosis retinae (von Hippel-Lindau disease), tuberous sclerosis (Bourneville’s disease), neurofibromatosis (von Recklinghausen’s disease and encephalo-trigeminal angiomatosis (Sturge-Weber syndrome). +B. Secondary tumours +1. Direct extension, e.g., from malignant melanoma of the choroid. +2. Metastatic carcinomas from the gastrointestinal tract, genitourinary tract, lungs, and pancreas. +3. Metastatic sarcomas. +4. Metastatic malignant melanoma from the skin. +RETINOBLASTOMA +Retinoblastoma is a common malignant tumour arising from the neurosensory retina in one or both eyes. +Demographic data +1. Prevalence. It is the most common intraocular tumour of childhood occurring 1 in 15,000 to 20,000 live births. + +2. Age. Retinoblsatoma is confined to infancy and very young children usually seen between 1 and 2 years of age. +3. Sex. There is no sex predisposition. +4. Race. It is rarer in Negroes than Whites. +5. Bilaterality. In 25–30% cases, there is bilateral involvement, although one eye is affected more extensively and earlier than the other. +Genetics and heredity +Retinoblastoma (RB) gene has been identified as 14 band on the long arm of chromosome 13 (13q 14) and is a ‘cancer suppressor’ or ‘antioncogenic’ gene. Deletion or inactivation of both the normal allels of this protective gene by two mutations (Knudson’s two hit hypothesis, 1971) results in occurrence of retinoblastoma. +Some facts about occurrence of retinoblastoma are as below: +■Of all cases, only 10% are familial (inherited by autosomal dominant mode) and the rest about 90% occur sporadically. +■Of sporadic cases, about two-third (i.e., 60% of all cases) occur by somatic mutation and one-third (i.e., 30% of all cases) occur by germline mutation. ■Thus, the retinoblastoma either occurs as heritable (germline) cases (40%) or non-heritable somatic +cases (60%). +1. Heritable or germline cases. In such cases first hit (mutation) occurs in one of the two alleles of retinoblastoma gene on the germ cells (gametes), before fertilization. This occurs in 40% of all cases either due to inheritence from the affected parent (10% cases) or sporadically in one of the gametes (30% cases). This means mutation will occur in all the somatic cells (predisposing to develop even nonocular tumours such as osteosarcoma). Second hit (mutation) occurs late in the postzygote phase and affects second allele of one or more retinal cells, resulting in multifocal and usually bilateral tumour formation. About 15% of heritable cases are unilateral. Some heritable cases have trilateral retinoblastoma (i.e., having associated pinealoblastoma). Heritable case can transmit the disease by autosomal dominant way to 50% of offsprings. However, due to variable penetrance only 40% are affected. +2. Non-heritable or somatic cases. About 60% of retinoblastoma cases occur sporadically by both hits (mutations) occurring in the same retinal cell in the embryo after fertilization. These mutations +304 Section 3 Diseases of Eye + + + +generally result in unifocal and unilateral tumours which cannot be passed on to the offsprings. Such patients are not predisposed for nonocular tumours. +Pathology +Origin. Retinoblastoma arises as malignant proliferation of the immature retinal neural cells which are small round cells with large nuclei, i.e., it is a tumour of a group called small round blue cell tumour. Histopathology. The tumour chiefly consists of small round cells with large nuclei, resembling the cells of the nuclear layer of retina. These cells may present as a highly undifferentiated or well-differentiated tumour. Microscopic features of a well-differentiated tumour include Flexner-Wintersteiner rosettes, (highly specific of retinoblastoma), Homer-Wright rosettes, pseudorosettes and fleurettes formation (Fig. 12.34). Other histologic features are presence of areas of necrosis and calcification. +Clinical features +Common presenting features of retinoblastoma are listed in Table 12.2. These can be described stage-wise as below: +I. Intraocular stage of retinoblastoma +Presentation of this stage can be divided into two subgroups: quiescent presentations and painful red eye presentations. +a. Quiescent presentations include: +1. Leukocoria or yellowish-white pupillary reflex (also called as amaurotic cat’s eye appearance) is the commonest presenting feature (60%) (Fig. 12.35). + + + + + + + + + + + + + + + + + + + +Fig. 12.34 Histopathological picture of retinoblastoma + +Table 12.2 Presenting features of retinoblastoma + +Presenting features Percentages Leucocoria 60% Strabismus 20% +Painful red eye 07% Poor vision 05% Asymptomatic 03% Orbital cellulitis 03% Unilateral mydriasis 02% Heterochormia iridis 01% Hyphema 01% + + + + + + + + + + + + + + +Fig. 12.35 Leukocoria right eye in a patient with retinoblastoma + +2. Squint, usually convergent, is the second commonest mode of presentation. +3. Nystagmus is a rare feature, noticed in bilateral cases. +4. Defective vision. Very rarely, when the tumour arises late (3–5 years of age), the child may complain of defective vision. +5. Ophthalmoscopic features of the tumour. In the early stages, before the appearance of leukocoria, fundus examination after full mydriasis performed in children presenting with strabismus, poor vision, or other quiescent features may reveal the growth. Ophthalmoscopic signs in three types of retinoblastoma are as follows: +i. Endophytic retinoblastoma (Fig. 12.36A): It grows inwards from the retina into the vitreous cavity. On ophthalmoscopic examination, the tumour looks like a well-circumscribed polypoidal mass of white or pearly pink colour (Fig. 12.36B). Fine blood vessels and sometimes a haemorrhage may be present on its surface. In the presence of +Chapter 12 Diseases of Retina 305 + + + + + + + + + + + + + + +A D + + + + + + + + + + + + + +B E + + + + + + + + + + + +C F +Fig. 12.36 Diagrammatic depiction (A&D); Fundus photographs (B&E); CT scan/MRI scan (C&F) of endophytic and exophytic retinoblastoma, respectively + + +calcification, it gives the typical ‘cottage cheese’ appearance. There may be multiple growths projecting into the vitreous. +ii. Exophytic retinoblastoma (Fig. 12.36D). It grows outwards and separates the retina from the choroid. On fundus examination it gives appearance of exudative retinal detachment (Fig. 12.36E, also see page 301). + +iii.Diffuse infiltrating tumours show just a placoid thickness of retina and not a mass. Such cases are usually diagnosed late. +b. Painful red eye presentations.When retinoblastoma is left untreated during the quiescent stage, some patients may present with severe pain, redness, and watering. These symptoms occur either due to acute secondary glaucoma or apparent intraocular inflammation or orbital cellulitis. +306 Section 3 Diseases of Eye + + + +■Acute secondary glaucoma may occur either due to tumour pushing the lens-iris diaphragm forward or tumour cells clogging the trabecular meshwork. In this stage, eyeball is enlarged (buphthalmos) with apparent proptosis, conjunctiva is congested, cornea become hazy, intraocular pressure is raised. ■Apparent intraocular inflammation.Occasionally, picture simulating severe, acute uveitis usually associated with pseudohypopyon and/or hyphaema may be the presenting mode (retinoblastoma +masquerading as iridocyclitis). +■Orbital cellulitis like presentation occurs with necrotic tumours. It does not imply extraocular extension and the exact mechanism is not known. +Classifications of retinoblastoma +i. Reese-Ellsworth classification, which was of prognostic significance for the control of local disease has become irrelevant with the availability of newer chemotherapeutic agents and modes of therapy, and so not described here. +ii.International classification of retinoblastoma(ICRB), which is presently being followed worldwide to decide the treatment modality, is given below: Group A (very low risk): includes all small tumours <3 mm in greatest dimension, confined to retina, located >3 mm from fovea and >1.5 mm from the optic disc. +Group B (low risk): includes large tumours >3 mm in dimension, and any size tumours located <3 mm from fovea, and <1.5 mm from the optic disc margin. +Group C (moderate risk): includes retinoblastoma with focal seeds characterized by subretinal and or vitreous seeds ≤ 3 mm from the retinoblastoma. Group D (high risk): includes retinoblastoma with diffuse seeds characterized by subretinal and or vitreous >3 mm seeds from the retinoblastoma. Group E (very high risk): includes extensive retinoblastoma characterized by any of the following: tumour touching the lens, neovascular glaucoma, tumour anterior to anterior vitreous face involving ciliary body and anterior segment, diffuse infiltrating tumour, opaque media with haemorrhage, tumour necrosis with aseptic orbital cellulitis, invasion of postlaminar optic nerve, choroid, sclera, orbit, and anterior chamber, or phthisis bulbi. +II. Stage of extraocular extension +Due to progressive enlargement of tumour, the globe bursts through the sclera, usually near the limbus or near the optic disc. It is followed by rapid fungation + +and involvement of extraocular tissues resulting in marked proptosis (Fig. 12.37). +III. Stage of distant metastasis +It is characterised by the involvement of distant structures as follows: +1. Lymphatic spread first occurs in the preauricular and neighbouring lymph nodes. +2. Direct extension by continuity to the optic nerve and brain is common. +Differential diagnosis +1. Differential diagnosis of leukocoria. Various conditions other than retinoblastoma, which present as leukocoria are collectively called as ‘pseudoglioma’. A few common conditions are congenital cataract, inflammatory deposits in vitreous following a plastic cyclitis or choroiditis, coloboma of the choroid, the retrolental fibroplasia (retinopathy of prematurity), persistent hyperplastic primary vitreous, toxocara endophthalmitis and exudative retinopathy of Coats. +2. Endophytic retinoblastoma discovered on fundus examination should be differentiated from retinal tumours in tuberous sclerosis and neurofibromatosis, astrocytoma and a patch of exudative choroiditis. 3. Exophytic retinoblastoma should be differentiated from other causes of exudative retinal detachment in children such as: Coats’ disease (see pages 285 and 301). +Diagnosis +1. Examination under anaesthesia: It should be performed in all clinically suspected cases. It should include fundus examination of both eyes after full + + + + + + + + + + + + + + + + + +Fig. 12.37 Fungating retinoblastoma involving the orbit +Chapter 12 Diseases of Retina 307 + + + +mydriasis with atropine (direct as well as indirect ophthalmoscopy), measurement of intraocular pressure and corneal diameter. +2. Plain X-rays of orbit may show calcification which occurs in 75% cases of retinoblastoma. +3. Lactic dehydrogenase (LDH) level is raised in aqueous humour. +4. Ultrasonography and CT/MRI scanning are very useful in the diagnosis. CT/MRI also demonstrate extension to optic nerve, orbit and CNS, if any (Fig. 12.36C and F). However, CT should be used sparingly because of potential risk of radiation sarcomas. +Treatment +A.Conservativetumour destructive therapyto salvage eyeball is indicated when tumour is diagnosed at an early stage I, i.e., when tumour involves less than half of retina and optic nerve is not involved (usually in the second eye of bilateral cases). Present recommendations for the treatment are primary systemic chemotherapy (for chemoreduction) followed by focal therapy (for consolidation). Chemotherpy. Dose in mg/kg body weight for chemoreduction of retinoblastoma are as below: ■Standard dose CVE regimen, recommended for group A, B, and, C patients, consists of 3-weekly, 6 cycles of carboplatin (18.6 mg) on day 1, vincristine (0.05 mg) on day 1, and etoposide (5 mg) on day 1 and 2. +■High dose CVE regimen, recommended for group D patients, consists of 3 weekly, 6–12 cycles of carboplatin (28 mg) on day 1, vincristine (0.25 mg) on day 1 and etoposide (12 mg) on day 1 and 2. Focal therapy. Depending upon the location and size of the tumour, focal therapy can be chosen from the following modalities: +• Cryotherapy is indicated for a small tumour located anterior to equator. +• Laser photocoagulation is used for a small tumour located posterior to equator. +• Thermotherapy with diode laser is used for a small tumour located posterior to equator away from macula. +• Plaque radiotherapy is very effective against localised viterous disease and for the elevated tumours when laser is ineffective. +• External beam radiotherapy (EBR), once the mainstay of treatment, is now reserved for diffuse disease in the only remaining eye. +Note. If the above modalities are not available, the eyeball should be enucleated without hesitation. + +B. Enucleation. It is the treatment of choice for group E tumors and when: +• Tumour involves more than half of the retina. • Optic nerve is involved. +• Glaucoma is present and anterior chamber is involved. +Eyeball should be enucleated along with maximum length of the optic nerve taking special care not to perforate the eyeball. If optic nerve shows invasion, postoperative treatment should include: +• External beam radiotherapy (5,000 rads) should be applied to the orbital apex. +• Chemotherapy, consisting of vincristine, carboplatin, and etoposide which may be combined with cyclosporin should be supplemented. +C. Palliative therapy isgiven in following cases where prognosis for life is dismal in spite of aggressive treatment: +• Retinoblastoma with orbital extension, +• Retinoblastoma with intracranial extension, and • Retinoblastoma with distant metastasis. +Palliative therapy should include combination of: • Chemoradiation (CVE regimen), +• Surgical debulking of the orbit or orbital exentration, and +• External beam radiotherapy (EBRT) +Note. Exenteration of the orbit (a mutilating surgery commonly performed in the past) is now not preferred by many surgeons. +Prognosis +If untreated the prognosis is almost always bad and the patient invariably dies. Rarely spontaneous regression with resultant cure and shrinkage of the eyeball may occur due to necrosis followed by calcification; suggesting role of some immunological phenomenon. +If the eyeball is enucleated before the occurrence of extraocular extension, prognosis is fair (survival rate 70–85%). +Poor prognostic factors are: Optic nerve involvement, undifferentiated tumour cells and massive choroidal invasion. +ENUCLEATION +Enucleation refers to excision of the eyeball. It can be performed under local anaesthesia in adults and under general anaesthesia in children. +Indications +1. Absolute indications are retinoblastoma and malignant melanoma. +308 Section 3 Diseases of Eye + + + +2. Relative indications are painful blind eye, non-responsive to conservative measure mutilating ocular injuries, anterior staphyloma and phthisis bulbi. +3. Indication for eye donation from cadaver is presently the most common indication for enucleation. +Surgical technique +1. Separation of conjunctiva and Tenon’s capsule (Fig. 12.38A): Conjunctiva is incised all around the limbus with the help of spring scissors. Undermining of the conjunctiva and Tenon’s capsule is done combinedly, all around up to the equator, using blunt-tipped curved scissors. This manoeuvre exposes the extraocular muscles. +2. Separation of extraocular muscles (Fig. 12.38B): The rectus muscles are pulled out one by one with the help of a muscle hook and a 3–0 silk suture is passed near the insertion of each muscle. The muscle is then cut with the help of tenotomy scissors leaving behind a small stump carrying the suture. The inferior and superior oblique muscles are hooked out and cut near the globe. +3. Cutting of optic nerve (Fig. 12.38C): The eyeball is prolapsed out by stretching and pushing down the eye speculum. The eyeball is pulled out with the help of sutures passed through the muscle stumps. The enucleation scissors is then introduced along the medial wall up to the posterior aspect of the eyeball. + + + + + + + + +A + +Optic nerve is felt and then cut with the scissors while maintaining a constant pull on the eyeball. +4. Removal of eyeball. The eyeball is pulled out of the orbit by incising the remaining tissue adherent to it and haemostasis is achieved by packing the orbital cavity with a wet pack and pressing it back. +5. Inserting an orbital implant (Fig. 12.38D): Preferably an orbital implant (made up of PMMA Medpor or hydroxyapatite) of appropriate size should be inserted into the orbit and sutured with the rectus muscles. 6. Closure of conjunctiva and Tenon’s capsule is done separately. Tenon’s capsule is sutured horizontally with 6-0 vicryl or chromic catgut. Conjunctiva is sutured vertically so that conjunctival fornices are retained deep with 6–0 silk sutures (Fig. 12.38E) which are removed after 8–10 days. After completion +of surgery, antibiotic ointment is applied, lids are closed and dressing is done with firm pressure using sterile eye pads and a bandage. +Fitting of artificial prosthetic eye +Conformer may be used postoperatively so that the conjuctival fornices are retained deep. A proper sized prosthetic eye can be inserted for good cosmetic appearance (Fig. 12.39) after 6 weeks when healing of the enucleated socket is complete. \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_11.txt b/notes/A K Khurana - Comprehensive Ophthalmology_11.txt new file mode 100644 index 0000000000000000000000000000000000000000..f257cea1837ca481e0d6008bfc66218dfb2c498f --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_11.txt @@ -0,0 +1,1599 @@ +PHACOMATOSES +Phacomatoses or neurocutaneous syndromes refer to a group of familial conditions (having autosomal + + + + + + + + +B + + + + + + + + + +C D E + +Fig. 12.38 Surgical steps of enucleation operation: A, separation of conjunctiva and Tenon’s capsule; B, separation of extraocular muscles; C, cutting of optic nerve and removal of eyeball; D, insertion of an orbital implant; and E, closure of the conjunctiva +Chapter 12 Diseases of Retina 309 + + + + + + + + + + + + +A + + + + + + + + + +B +Fig. 12.39 Photographs of a patient: A, without artificial eye and B, with artificial eye +dominant transmission) which are characterised by development of neoplasms in eye, skin and central nervous system. Phacomatoses includes the following conditions: +1.Angiomatosis retinae (Von Hippel Lindau’s syndrome). This is a rare condition affecting males more often than females, in the third and fourth decade of life. ■Angiomatosis involves retina, brain, spinal cord, +kidneys and adrenals. +■Clinical course of angiomatosis retinae comprises vascular dilatation, tortuosity and formation of aneurysms which vary from small and miliary to + +balloon-like angiomas, followed by appearance of haemorrhages and exudates, resembling eventually the exudative retinopathy of Coats. Massive exudation is frequently complicated by retinal detachment which may be prevented by an early destruction of angiomas with cryopexy or photocoagulation. +2. Tuberous sclerosis (Bourneville disease). It is characterised by a classic diagnostic triad of adenoma sebaceum, mental retardation and epilepsy associated with hamartomas of the brain, retina and viscera. The name tuberous sclerosis is derived from the potato-like appearance of the tumours in the cerebrum and other organs. Two types of hamartomas found in the retina are: (1) relatively flat and soft appearing white or grey lesions usually seen in the posterior pole; and (2) large nodular tumours having predilection for the region of the optic disc. +3. Neurofibromatosis (von Recklinghausen’s disease). It is characterised by multiple tumours in the skin, nervous system and other organs. +■Cutaneous manifestations are very characteristic and vary from cafe-au-lait spots to neurofibromata. ■Ocular manifestations include neurofibromas of the lids and orbit, glioma of optic nerve and congenital glaucoma. +4. Encephalofacial angiomatosis (Sturge-Weber syndrome). It is characterised by angiomatosis in the form of port-wine stain (naevus flammeus), involving one side of the face which may be associated with choroidal haemangioma, leptomeningeal angioma and congenital glaucoma on the affected side. +13 + +Neuro-ophthalmology + + + +Chapter Outline + +ANATOMY AND PHYSIOLOGY Anatomy of the visual pathway +Pathway of visual sensations versus somatic sensations LESIONS OF THE VISUAL PATHWAY +• +• +PUPILLARY REFLEXES AND THEIR ABNORMALITIES DISEASES OF OPTIC NERVE +• +• +• +• +• +• +• +Congenital anomalies Optic neuritis +Toxic/nutritional optic neuropathy Anterior ischaemic optic neuropathy Papilloedema +Optic atrophy Tumours +SYMPTOMATIC DISTURBANCES OF THE VISION Night blindness (Nyctalopial) +• +• +Day blindness (Hamarlopia) + + + +ANATOMY AND PHYSIOLOGY +AnAtomy of the VisuAl PAthwAy Components of visual pathway +The visual pathway starting from retina consists of optic nerves, optic chiasma, optic tracts, lateral geniculate bodies, optic radiations and the visual cortex (Fig. 13.1). +optic nerve +Each optic nerve (second cranial nerve) starts from the optic disc and extends up to optic chiasma, where the two nerves meet. It is the backward continuation of the nerve fibre layer of the retina, which consists of the axons originating from the ganglion cells (second order neuron). It also contains the afferent fibres of the pupillary light reflex. +Morphologically and embryologically, the optic nerve is comparable to a sensory tract: +■Unlike peripheral nerves it is not covered by neurilemma (so it does not regenerate when cut). ■The fibres of optic nerve, numbering about a million, are very fine (2–10 mm in diameter as compared to 20 mm of sensory nerves). + +• Colour blindness Amaurosis Amblyopia Cortical blindness Malingering +Hysterical blindness +• +• +• +• +• +• +Disorders of higher visual functions +OCULAR MANIFESTATIONS OF DISEASES OF CENTRAL NERVOUS SYSTEM +• +• +• +• +• +• +Intracranial infections Intracranial aneurysms Intracranial haemorrhages +Intracranial space-occupying lesions (ICSOLs) Demyelinating diseases +Ocular signs in head injury + + + +■Like other parts of CNS, the optic nerve is also covered by meningial sheaths. +Parts of optic nerve.The optic nerve is about 47–50 mm in length, and can be divided into 4 parts: intraocular (1 mm), intraorbital (30 mm), intracanalicular (6-9 mm) and intracranial (10 mm). +1. Intraocular part starts from the optic disc (see page 263), pierces the choroid and sclera (converting it into a sieve-like structure the lamina cribrosa). At the back of eyeball it becomes continuous with the intraorbital part. +2. Intraorbital part extends from back of the eyeball to the optic foramina. This part is slightly sinuous to give play for the eye movements. Posteriorly, near the optic foramina, it is closely surrounded by the annulus of Zinn and the origin of the four rectus muscles. Some fibres of superior rectus muscle are adherent to its sheath here, and accounts for the painful ocular movements seen in retrobulbar neuritis. Anteriorly, the nerve is separated from the ocular muscles by the orbital fat. +3. Intracanalicular part is closely related to the ophthalmic artery which lies inferolateral to it and +Chapter 13 Neuro-ophthalmology 311 + + +crosses obliquely over it, as it enters the orbit, to lie on its medial side. Sphenoid and posterior ethmoidal sinuses lie medial to it and are separated by a thin bony lamina. This relation accounts for retrobulbar neuritis following infection of the sinuses. +4. Intracranial part of the optic nerve lies above the cavernous sinus and converges with its fellow (over the diaphragma sellae) to form the optic chiasma. +Meningeal sheaths. Pia mater, arachnoid and dura covering the brain are continuous over the optic nerves. In the optic canal, the dura is firmly adherent with the surrounding bone. The subarachnoid and subdural spaces around the optic nerve are also continuous with those of the brain. +optic chiasma +It is a flattened structure measuring 12 mm (horizontally) and 8 mm (anterioposteriorly). It lies over the tuberculum and diaphragma sellae and, therefore, presence of visual field defects in a patient with pituitary tumor indicates suprasellar extension. Fibres originating from the nasal halves of the +retina decussate at the chiasma (Fig. 13.1). + +optic tracts +These are cylindrical bundles of nerve fibres running outwards and backwards from the posterolateral aspect of the optic chiasma. Each optic tract consists of fibres from the temporal half of the retina of the same eye and the nasal half of the opposite eye. Posteriorly, each optic tract ends in the lateral geniculate body (Fig. 13.1). The pupillary reflex fibres pass on to pretectal nucleus in the midbrain through the superior brachium. Some fibres terminate in the superior colliculus (see Fig. 13.6). + + + + + + + + + + + + + + + + + + +Fig. 13.1 Components of the visual pathway + +lateral geniculate bodies +These are oval structures situated at the posterior termination of the optic tracts. Each geniculate body consists of six layers of neurons (grey matter) alternating with white matter (formed by optic fibres). The fibres of second-order neurons coming via optic tracts relay in these third-order neurons. +optic radiations +These extend from the lateral geniculate bodies to the visual cortex and consist of the axons of third-order neurons of visual pathway (Fig. 13.1). +Visual cortex +It is located on the medial aspect of the occipital lobe, above and below the calcarine fissure. It is subdivided into the visuosensory area (striate area 17) that receives the fibres of the radiations, and the surrounding visuopsychic area (peristriate area 18 and parastriate area 19). + +Blood supply of the visual pathway +The visual pathway is mainly supplied by pial network of vessels except the orbital part of optic nerve which is also supplied by an axial system derived from the central artery of retina. The pial plexus around different parts of the visual pathway gets contribution from different arteries as shown in Fig. 13.2. +Blood supply of the optic nerve head needs special mention (Fig. 13.3): +• Surface layer of the optic disc is supplied by capillaries derived from the retinal arterioles. +• Prelaminar region is mainly supplied by centripetal branches of the peripapillary choroid with some contribution from the vessels of lamina cribrosa. + + + + + + + + + + + + + + + + + + +Fig. 13.2 Blood supply of posterior visual pathway +312 Section iii Diseases of Eye + + + + + + + + + + + + + + + + + +Fig. 13.3 Blood supply of the optic nerve + + + +• Lamina cribrosa is supplied by branches from the posterior ciliary arteries and arterial circle ofZinn. +• Retrolaminar part of the optic nerve is supplied by centrifugal branches from central retinal artery and centripetal branches from pial plexus formed by branches from the choroidal arteries, circle of Zinn, central retinal artery and ophthalmic artery. +PAthwAy of VisuAl sensAtions Versus somAtic sensAtions +The pathway of somatic as well as visual sensations consists of three neurons (Fig. 13.4). The corresponding parts of the pathway of these sensations are shown in Table 13.1. + +LeSIONS Of THe vISuAL PATHwAY + +Salient features and important causes of lesions of the visual pathway at different levels (Fig. 13.5) are as follows: +Table 13.1 Somatic vs. visual sensations + +Fig. 13.4 Pathway of visual sensations (B) versus somatic sensations (A) + + +oPtic nerVe lesions +1. lesions of the distal optic nerve +Salient features are: +• Marked loss of vision or complete blindness on the affected side associated with +• Abolition of the direct light reflex on the ipsilateral side and consensual on the contralateral side (Fig. 13.5A). +• Near (accommodation) reflex is present. Common causes of optic nerve lesions are: optic atrophy, traumatic avulsion of the optic nerve, indirect optic neuropathy, ischemic optic neuropathy and acute optic neuritis. +2. lesions through proximal part of the optic nerve. Salient features of such lesions are: +• Ipsilateral blindness, +• Contralateral hemianopia, +• Abolition of direct light reflex on the affected side and consensual on the contralateral side, and +• Near reflex is intact. + + + + +Feature +1. Sensory end organ +2. Neurons of first order +3. Neurons of second order +4. Neurons of third order + + +Somatic sensation Visual sensation +Nerve endings in Rods and cones the skin +Lie in posterior Lie in bipolar cell root ganglion layer of the retina +Lie in nucleus Lie in ganglion gracilis or cells of the retina cuneatus +Lie in thalamus Lie in geniculate body + +chiAsmAl lesions +causes of chiasmal lesions +1. Intrinsic causes, i.e., which produce thickening of chiasma itself include gliomas, and multiple sclerosis. +2. Extrinsic causes include compressive lesions such as pituitary adenoma (most common cause), craniopharyngiomas, and meningioma. +3. Other causes of chiasmal syndrome include metabolic, toxic, traumatic, and inflammatory conditions (lymphoid hypophysitis and sarcoidosis). +Chapter 13 Neuro-ophthalmology 313 + + +features of chiasmal lesions Chiasmal syndrome +Chiasmal syndrome refers to the set of signs and symptoms associated with lesions of optic chiasma. Chiasmal syndrome has been classified into three types: +1. Anterior chiasmal syndrome is produced by lesions that affect the ipsilateral optic nerve fibres and the contralateral inferonasal fibres located in the Willebrand knee; typically producing the so-called junctional scotoma, i.e., a combination of central scotoma in one eye and temporal hemianopia defect in the other eye. (Fig. 13.5B) +2. Middle chiasmal syndrome is produced by lesions involving the decussating fibres in the body of chiasma typically producing bitemporal hemianopia (Fig. 13.5C) and bitemporal hemianopic paralysis of pupillary reflexes. Rarely, the middle lesions can affect the uncrossed temporal fibres and produce nasal or binasal hemianopia. +3.Posterior chiasmal syndrome is produced by lesions affecting the caudal fibres in chiasma. Characteristic features are as below: +• Paracentral bitemporalfield defects occur because the macular fibres which cross more posteriorly in the chiasma are damaged in the posterior chiasmal lesions. +• Visual acuity and colour vision may be preserved as temporal macular fibres are not, damaged. +• Homonymous hemianopia on the contralateral side may occur when posterior chiasmal lesions involve the optic tract (Fig. 13.5E). +Lateral chiasmal lesions +Salient features of such lesions are: +• Binasal hemianopia (Fig. 13.5D) associated with • Binasal hemianopic paralysis of the pupillary +reflexes. These usually lead to partial descending optic atrophy. +Common causes of such lesions are: +• Distension of third ventricle causing pressure on each side of the chiasma and +• Atheroma of the carotids or posterior communicating arteries. + +retrochiasmal lesions +Retrochiasmal lesions include lesions of optic tract, lateral geniculate nucleus, optic radiations and occipital lobe. +Contralateral homonymous hemianopia of different forms such as incomplete (congruous or uncongruous) or complete, depending upon the site of lesion is the predominant field defect of all retrochiasmal lesions. + + +Lesions of optic tract +Causes of optic tract lesions include: +• Intrinsic lesions include demyelinating diseases and infarction. Such lesions produce optic tract syndrome type II. +• Extrinsic, i.e., compressive lesions include pituitary adenomas (most common cause), craniopharyngioma (common), tumours of optic thalamus, and large aneurysm of superior cerebellar or posterior cerebral arteries. +• Other causes include syphilitic meningitis, gumma and tubercular meningitis. +Characteristic features include: +• Incongruous homonymous hemianopia, i.e., asymmetrical field defect involving either right halves of visual field of both eyes (right homonymous hemianopia (Fig. 13.5E) in left optic tract lesions) or left halves of visual fields of both eyes (left homonymous hemianopia due to lesions of right optic tract). This is explained anatomically by the fact that each optic tract contains fibres from the ipsilateral temporal half of retina and contralateral nasal half of retina. +• Contralateral hemianopic pupillary responses, i.e., Wernicke’s reaction. +• Optic disc changes. Optic tract lesions produce descending type of partial optic atrophy characterized by temporal pallor on the side of lesion and bow–tie atrophy on the contralateral side. +• Visual acuity is usually intact in the intrinsic lesions of optic tract. +• Ipsilateral third nerve palsy and ipsilateral hemiplegia may be associated with optic tract lesions in some cases. +lesions of lateral geniculate nucleus +Characteristic features of lateral geniculate nucleus (LGN) lesions are as below: +■Homonymous hemianopia produced is usually incongruous (Fig. 13.5E). +■Pupillary reflexes are normal, as fibres for pupillary reflexes from the optic tract are diverted to pretectal nucleus and do not reach the LGN. +■Optic disc pallor may occur due to partial descending atrophy. +lesions of optic radiations +Common lesions of optic radiations include: • Vascular occlusions, +• Tumours (primary or secondary), • Trauma, and +• Temporal lobectomy for seizures +314 Section iii Diseases of Eye + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 13.5 Lesions of the visual pathways at the level of: 1. optic nerve; 2. proximal part of optic nerve; 3. central chiasma; 4. lateral chiasma (both sides); 5. optic tract; 6. geniculate body; 7. part of optic radiations in temporal lobe; 8. part of optic radiations in parietal lobe; 9. optic radiations; 10. visual cortex sparing the macula; 11. visual cortex, only macula; 12. bilateral visual cortex only macula + + +Characteristic features include: +1. Visual field defects in the lesions of optic radiations vary depending upon the site of lesion as below: +• Superior quadrantic hemianopia (pie in the sky) (Fig. 13.5E) is produced when inferior fibres are involved in temporal lobe lesions. Anatomically, it is explained by the fact that inferior fibres of optic radiations contain fibres from ipsilateral lower temporal retina and contralateral lower nasal retina. Inferior most fibres of optic radiation form the so called Meyer’s loop. +• Inferior quadrantic hemianopia (pie on the floor) (Fig. 13.5G) is produced when superior fibres are involved in parietal lobe lesions. This is explained anatomically by the fact that superior fibres of optic radiations contain fibres from ipsilateral + +upper temporal retina and contralateral upper nasal retina. +• Complete homonymous hemianopia, (Fig. 13.5H) is produced when total fibres of optic radiations, are involved sometimes with sparing of macula (as macular fibres lie in the central part of optic radiations). +2. Pupillary reflexes are spared in lesions of optic radiations. +3. Optic disc atrophy does not occur in lesions of optic radiations, as the second order neurons synapse in the lateral geniculate nucleus (LGN). +lesions of visual cortex +Characteristic features of visual cortex lesions can be described as visual field defects and other manifestations. +Chapter 13 Neuro-ophthalmology 315 + + +I. Visual field defects in occipital lobe lesionsinclude: • Congruous homonymous hemianopia (Fig. 13.5I) (usually sparing the macula) is a feature of occlusion of posterior cerebral artery supplying +the anterior part of visual cortex. +• Congruous homonymous macular defects (Fig. 13.5J) occur in lesions of the tip of occipital cortex following head injury or gun shot injuries. +• Bilateral homonymous hemianopia with macula sparing producing a picture of ring scotoma is seen in bilateral occipital lobe lesions. +• Bilateral homonymous macular defects, presenting like bilateral central scotoma (Fig. 13.5K) occur in bilateral lesions of occipital cortex. +Note. Pupillary light reflexes are normal and optic atrophy does not occur following visual cortex lesions. +II. Other manifestations of occipital lobe lesions include: • Cortical blindness can occur in bilateral occipital +lobe lesions. +• Dyschromatopsia, i.e., acquired colour blindness. • Visual hallucinations occurring in occipital lobe lesions are unformed, while in temporal lobe +lesions the visual hallucinations are formed. +• Palinopsia, i.e., persistent or recurrent perception of a visual image, may occur. +• Visual anesthesia, i.e., transpositioning of visual stimuli from one hemifield to another. +• Polyopsia, i.e., multiple images of a single object, seen in occipital lobe lesions, does not disappear on closing of eye. + +PuPILLARY RefLeXeS AND THeIR ABNORMALITIeS + +PuPillAry reflexes +light reflex +When light is shone in one eye, both the pupils constrict. Constriction of the pupil to which light is shone is calleddirect light reflexand that of the other pupil is called consensual (indirect) light reflex. Light reflex is initiated by rods and cones. +Pathway of light reflex include (Fig. 13.6): +1. Afferent fibres extend from retina to the pretectal nucleus in the midbrain. These travel along the optic nerve to the optic chiasma where fibres from the nasal retina decussate and travel along the opposite optic tract to terminate in the contralateral pretectal nucleus. While the fibres from the temporal retina remain uncrossed and travel along the optic tract of the same side to terminate in the ipsilateral pretectal nucleus. + + + + + + + + + + + + +Fig. 13.6 Pathway of the light reflex + +2. Internuncial fibres connect each pretectal nucleus with Edinger-Westphal nuclei of both sides. This connection forms the basis of consensual light reflex. 3. Efferent pathway consists of the parasympathetic fibres which arise from the Edinger-Westphal nucleus in the midbrain and travel along the third (oculomotor) cranial nerve. The preganglionic fibres enter the inferior division of the third nerve and via the nerve to the inferior oblique reach the ciliary ganglion to relay. Post-ganglionic fibres travel along the short ciliary nerves to innervate the sphincter pupillae. +near reflex +Near reflex occurs on looking at a near object. It consists of two components: (a) convergence reflex, i.e., contraction of pupil on convergence; and (b) accommodation reflex, i.e., contraction of pupil associated with accommodation. +Pathway of convergence reflex (Fig. 13.7). Its afferent pathway is still not elucidated. It is assumed that the afferents from the medial recti travel centrally via the third nerve to the mesencephalic nucleus of the fifth nerve, to a presumptive convergence centre in the tectal or pretectal region. From this the impulse is relayed to the Edinger-Westphal nucleus and the subsequent efferent pathway of near reflex is along the 3rd nerve. The efferent fibres relay in the accessory ganglion before reaching the sphincter pupillae. Pathway of accommodation reflex (Fig. 13.7). The afferent impulses extend from the retina to the parastriate cortex via the optic nerve, chiasma, optic tract, lateral geniculate body, optic radiations, and striate cortex. From the parastriate cortex, the impulses are relayed to the Edinger-Westphal nucleus of both sides via the occipitomesencephalic tract and the pontine centre. From the Edinger-Westphal nucleus the efferent impulses travel along the 3rd nerve and reach the sphincter pupillae and ciliary muscle after relaying in the accessory and ciliary ganglions. +316 Section iii Diseases of Eye + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 13.7 Pathway of the near reflex + + +Psychosensory reflex +It refers to dilatation of the pupil in response to sensory and psychic stimuli. It is very complex and its mechanism is still not elucidated. +exAminAtion of PuPillAry reflexes See page 505. + +AbnormAlities of PuPillAry reActions 1. Amaurotic light reflex. It refers to the absence of direct light reflex on the affected side (say right eye) and absence of consensual light reflex on the normal side (i.e., left eye). This indicates lesions of the optic nerve or retina on the affected side (i.e., right eye), leading to complete blindness. In diffuse illumination both pupils are of equal size. +2. Efferent pathway defect. Absence of both direct and consensual light reflex on the affected side (say right eye) and presence of both direct and consensual Q light reflex on the normal side (i.e., left eye) indicates efferent pathway defect + +(sphincter paralysis). Near reflex is also absent on the affected side. Its causes include: effect of parasympatholytic drugs (e.g., atropine, homatropine), internal ophthalmoplegia, and third nerve paralysis. +3. Wernicke’s hemianopic pupil. It indicates lesion of the optic tract. In this condition, light reflex (ipsilateral direct and contralateral consensual) is absent when light is thrown on the temporal half of the retina of the affected side and nasal half of the opposite side; while it is present when the light is thrown on the nasal half of the affected side and temporal half of the opposite side. +4. Marcus Gunn pupil. It is the paradoxical response of a pupil to light in the presence of a relative afferent pathway defect (RAPD).Causes of Marcus Gunn pupil include incomplete optic nerve lesions and severe retinal diseases. +Tests. It is tested by swinging flash light test (For details see page 505). +Chapter 13 Neuro-ophthalmology 317 + + +Note. Marcus Gunn pupil is the earliest indication of optic nerve disease even in the presence of normal visual acuity in the affected eye. +5. Argyll Robertson pupil (ARP). Here the both pupils are slightly small in size and reaction to near reflex is present but light reflex (both direct and consensual) is absent, i.e., there is light near dissociation (to remember, the acronym ARP may stand for ‘accommodation reflex present’). Both pupils are involved and dilate poorly with mydriatics. It is caused by a lesion (usually neurosyphilis) in the region of tectum. +6.Adie’s tonic pupil. In this condition, reaction to light is absent and to near reflex is very slow and tonic. The affected pupil is larger (anisocoria). It is caused by post ganglionic parasympathetic pupillomotor damage. It is usually unilateral, associated with absent knee jerk and occurs more often in young women. Adie’s pupil constricts with weak pilocarpine (0.125%) drops, while normal pupil does not, because the denervated iris sphincter is supersensitive to topical parasympathomimetics. +AnisocoriA +Normal size of pupil varies between 3 to 4 mm depending upon the room illumination. Difference between the size of two pupils is called anisocoria. +causes +Anisocoria may be physiological or pathological. Physiological anisocoria is usually minimal, both pupils react well to light and there is no dilation lag. Pathological anisocoriais usually a difference of 2 mm or more and may either be due to abnormal miosis or mydriasis of one pupil. +• Causes of miosis (see page 504) +• Causes of mydriasis (see page 504) +Note. Anisocoria is not caused by optic nerve lesions or other afferent pupil pathway defects. Assuming the sphincter and dilator pupillae muscles are structurally normal, anisocoria is a sign of autonomic (sympathetic or parasympathetic) dysfunction. +evaluation of anisocoria +1. Pupil size in dim and bright illumination should be noted first. +• Anisocoria same in dark and bright illumination is usually physiological. +• Anisocoria greater in dim illumination is suggestive of sympathetic palsy (i.e., Horner’s syndrome) and the smaller pupil is normal. Physiological anisocoria also sometimes behaves in this manner. 2. Pupillary light reflex should be tested after noting +the pupil size. + +• Poor light reaction indicates defect in parasym-pathetic system (3rd nerve palsy, tonic pupil, anticholinergic drugs). +• Normal light reaction (constriction) followed by dilation lag indicates Horner’s syndrome (in physiological anisocoria there is no dilation lag). +3. Pharmacological tests are conducted after noting the pupillary light reaction. +i. Pharmacological tests for suspected parasympathetic palsy. Pilocarpine test is used to determine if a dilated pupil is due to 3rd nerve palsy, pharmacological mydriasis, or tonic pupil. +• Pupil constricts to low concentration of pilocarpine (0.125%): Adies tonic pupil. +• Pupil constricts to usual concentration of pilocarpine (1 to 2%): 3rd nerve palsy. +• Pupil does not constrict with pilocarpine: Mydriasis due to parasympathetic drugs, other conditions where dilated pupil does not constrict with pilocarpine are traumatic mydriasis and fixed pupil in irits. +ii. Pharmacological tests for suspected sympathetic palsy include: +• Cocaine test ( 2 to 4%). Small pupil fails to dilate in Horner’s syndrome. +• Hydroxyamphetamine test (1%). Small pupil dilates in central and pre-ganglionic and does not dilate in post-ganglionic Horner’s syndrome. + +DISeASeS Of OPTIC NeRve + +Diseases of the optic nerve include: +■ Congenital anomalies (see page 266). ■ Traumatic lesions (see page 323) +■ Inflammatory lesions • Optic neuritis +• Toxic/nutritional optic neuropathy ■ Vascular disturbances include: +• Anterior ischaemic neuropathy • Papilloedema +■ Degenerations: • Optic atrophy +■Tumours (see page 419) + +oPtic neuritis +Optic neuritis includes inflammatory and demyelinating disorders of the optic nerve. +etiology +1. Idiopathic. In a large proportion of cases the underlying cause is unidentifiable. +2. Hereditary optic neuritis (Leber’s disease). +3. Demyelinating disorders are by far the most common cause of optic neuritis. These include +318 Section iii Diseases of Eye + + +multiple sclerosis, neuromyelitis optica (Devic’s disease) and diffuse periaxial encephalitis of Schilder. About 70% cases of established multiple sclerosis may develop optic neuritis. +4. Parainfectious optic neuritis is associated with various viral infections such as measles, mumps, chickenpox, whooping cough and glandular fever. It may also occur following immunization. +5. Infectious optic neuritis may be sinus related (with acute ethmoiditis) or associated with cat scratch fever, syphilis (during primary or secondary stage), tuberculosis, lyme disease and cryptococcal meningitis in patients with AIDS. +6. Autoimmune disorders associated with optic neuritis include sarcoidosis, systemic lupus erythematosus, polyarteritis nodosa, Guillain-Barre syndrome and Wegener’s granulomatosis. +7. Toxic optic neuritis (see toxic amblyopias, page 320). +clinical Profile +Anatomical types +Optic neuritis can be classified into three anatomical types: +• Papillitis. It refers to involvement of the optic disc in inflammatory and demyelinating disorders. This condition is usually unilateral but sometimes may be bilateral. +• Neuroretinitis refers to combined involvement of optic disc and surrounding retina in the macular area. +• Retrobulbar neuritis is characterized by involvement of optic nerve behind the eyeball. Clinical features of acute retrobulbar neuritis are essentially similar to that of acute papillitis except for the fundus changes and ocular changes described below. +Typical versus atypical optic neuritis +Traditionally, the term typical optic neuritis refers to the one associated with demyelination, particularly multiple sclerosis and the term atypical neuritis is labeled for the one associated with causes other than demyelination disorders. +Clinical features +Symptoms. Optic neuritis may be asymptomatic or may be associated with following symptoms: +• Visual loss. Monocular sudden, progressive and profound visual loss is the hallmark of acute optic neuritis. +• Dark adaptation may be lowered. +• Visual obscuration in bright light is a typical symptom of acute optic neuritis. + +• Impairment of colour vision is always present in optic neuritis. Typically, the patients observe reduced vividness of saturated colours. +• Movement phosphenes and sound induced phosphenes may be perceived by patients with optic neuritis. Phosphenes refer to glowing sensations produced by nonphotic or the so called inadequate stimuli. +• Episodic transient obscuration of vision on exertion and on exposure to heat, which recovers on resting or moving away from the heat (Uhthoff’s symptom) occurs in patient with isolated optic neuritis. +• Depth perception, particularly for the moving object may be impaired (Pulfrich’s phenomenon). +• Pain.Patients may complain of mild dull eyeache. It is more marked in patients with retrobulbar neuritis than with papillitis. Pain is usually aggravated by ocular movements, especially in upward or downward directions due to attachment of some fibres of superior rectus to the dura mater. +Signs are as follows: +1. Visual acuity is usually reduced markedly. +2. Colour vision is often severely impaired (typically red desaturation). +3. Pupil shows ill-sustained constriction to light. Marcus Gunn pupil which indicates relative afferent pupillary defect (RAPD) is a diagnostic sign. It is detected by the swinging flash light test (see page 505). +4. Ophthalmoscopic features (Fig 13.8). Papillitis is characterised by hyperaemia of the disc and blurring of the margins. Disc becomes oedematous + + + + + + + + + + + + + + + + + + + +Fig. 13.8 Fundus photograph showing papillitis +Chapter 13 Neuro-ophthalmology 319 + + +and physiological cup is obliterated (in papillitis disc oedema rarely exceeds 2–3 D, while in papilloedema it become 3–6 D). Retinal veins are congested and tortuous. Splinter haemorrhages and fine exudates may be seen on the disc. Slit-lamp examination may reveal inflammatory cells in the vitreous. Inflammatory signs may also be present in the surrounding retina when papillitis is associated with macular star formation and the condition is labelled as ‘neuroretinitis.’In majority of the cases with retrobulbar neuritis fundus appears normal and the condition is typically defined as a disease where neither the ophthalmologist nor the patient sees anything. Occasionally, temporal pallor of the disc may be seen. +5. Visual field changes. The most common field defect in optic neuritis is a relative central or centrocaecal scotoma. Other field defects noted rarely include: paracentral nerve fibre bundle defect, a nerve fibre bundle defect extending up to periphery and a nerve fibre bundle defect involving fixation point and periphery. The field defects are more marked to red colour than the white. +6. Contrast sensitivity is impaired. +7. Visually evoked response (VER) shows reduced amplitude and delay in the transmission time. +8. Fundus fluorescein angiography reveals mild to moderate leak in early phase which increases with the time. +Differential diagnosis +• Papillitis should be differentiated from papilloedema, ischaemic optic neuropathy, anterior orbital compressive neuropathy and pseudopapilloedema (see Table 13.2). +• Acute retrobulbar neuritis. It must be differentiated from malingering, hysterical blindness, cortical blindness and indirect optic neuropathy. +evolution, recovery and complications +Evolution. In optic neuritis, typically, the visual acuity and colour vision is lost progressively over 2–5 days. Recovery. The rate of visual recovery is slower than the rate of visual loss and usually starts within 2 weeks and takes between 4 and 6 weeks. About 75 to 90% cases get good visual recovery. Complications. Recurrent attacks of acute retrobulbar neuritis are followed by primary optic atrophy and recurrent attack of papillitis are followed by postneuritic optic atrophy leading to complete blindness. +treatment +1. Treatment of the causes. Efforts should be made to find out and treat the underlying cause. There is no + +effective treatment for idiopathic and hereditary optic neuritis and that associated with demyelinating disorders. +2. Corticosteroid therapy may shorten the period of visual loss, but will not influence the ultimate level of visual recovery in patients with optic neuritis. Optic neuritis treatment trial (ONTT) group has made following recommendations for the use of corticosteroids: +• Oral prednisolone therapy alone is contraindicated in the treatment of acute optic neuritis, since, it did not improve visual outcome and was associated with a significant increase in the risk of new attacks of optic neuritis. +• Intravenous methylprednisolone. A patient presenting with acute optic neuritis should have brain MRI scan. If the brain shows lesions supportive of multiple sclerosis (MS), regardless of the severity of visual loss, each patient should receive immediate intravenous methylprednisolone (1 gm daily) for 3 days followed by oral prednisolone (1 mg/kg/day) for 11 days. Then taper prednisolone over 4 days. This therapy will delay conversion to clinical MS over the next 2 years. +Note. Intravenous dexamethasone has been reported to be as effective as methylprednisolone in many studies. +■Indications for intravenous methylprednisolone in acute optic neuritis patients with a normal brain MRI scan are: +• Visual loss in both eyes simultaneously or subsequently within hours or days of each other. +• When the only good eye is affected. +• When the slow progressive visual loss continues to occur. +3. Interferon therapy has been reported to reduce recurrences in patients with multiple sclerosis. However, the treatment is very expensive and with unknown long term benefits. +leber’s hereDitAry oPtic neuroPAthy Leber’s hereditary optic neuropathy (LHON) is characterized by sequential subacute optic neuropathy in males aged 11-30 years. The underlying genetic abnormality is a point mutation in mitochondrial DNA. Since, mitochondrial DNA is exclusively derived from mother, males do not transmit the disease. It is transmitted by carrier females. Males are four times more likely than the females to be affected. +Presenting symptoms +• Visual acuity. Affected individuals are usually entirely asymptomatic in early phase until they +320 Section iii Diseases of Eye + + +develop blurring affecting the central visual field of one eye. Bilateral, painless, subacute visual failure usually develops during young adult life. Thus, ultimately, patients generally have bilateral impairment of visual acuity. +• Visual fields show centrocecal scotoma that begins nasal to the blind spot and extends to involve fixation of both sides of the vertical meridian. +• Pupillary reactions are often normal. +• Ophthalmoscopic examination shows fundus abnormalities in acute phase like swelling of disc, and peripapillary retinal telangiectasia. But, characteristically there is no leak from the optic disc during fluorescein angiography. Later the disc becomes atrophic and pale. +toxic/nutritionAl oPtic neuroPAthy Toxic/nutritional optic neuropathy, also known as toxic amblyopia, is basically chronic retrobulbar neuritis. Wherein visual loss results from damage to the optic nerve fibres due to the effects of exogenous (commonly) or endogenous (rarely) poisons. It is frequently bilateral and has a chronic course with permanent visual deterioration. The toxic agents involved may be: tobacco, ethyl alcohol, methyl alcohol, ethylene glycol, lead, arsenic, cannabis, indica, carbon di-sulphide, various drugs like quinine, chloroquine, ethambutol, isoniazid, streptomycin, digitalis (digoxion), amiodaron, NSAIDs, vigabatrin and disulfiram. +Varieties of toxic amblyopia described here include: • Tobacco amblyopia, +• Ethyl alcohol amblyopia, +• Methyl alcohol amblyopia, • Quinine amblyopia, and +• Ethambutol amblyopia. + +Tobacco amblyopia +Tobacco amblyopia typically occurs in men who are generally pipe smokers, heavy drinkers and have a diet deficient in proteins and vitamin B complex; and hence also labelled as ‘tobacco-alcohol-amblyopia’. Pathogenesis. It is caused by excessive use of tabacco by smoking and chewing. The toxic agent involved is cyanide found in tobacco. The pathogenesis is summarised in Fig. 13.9. +Clinical features.The condition usually occurs in men between 40 and 60 years and is characterised by: Impairment of central vision, which is bilateral and gradually progressive. Patients usually complain of fogginess and difficulty in doing near work. +• Visual field examination reveals bilateral centrocaecal scotomas with diffuse margins which + + + + + + + + + + + + + + + +Fig. 13.9 Flow chart depicting pathogenesis of tobacco amblyopia +are not easily defined. The defect is greater for rest than for the white colour. +• Fundus examination is essentially normal or there may be slight temporal pallor of the disc. +Treatment. It consists of: +• Complete cessation of tobacco and alcohol +consumption +• Hydroxocobalamin 1000 mg intramuscular injections weekly for 10 weeks +• Care of general health and nutrition +• Vasodilators have also been tried. +Prognosis. It is good, if complete abstinence from tobacco and alcohol is maintained. Visual recovery is slow and may take several weeks to months. +Ethyl alcohol amblyopia +It usually occurs in association with tobacco amblyopia. However, it may also occur in non-smokers, who are heavy drinkers suffering from chronic gastritis. The optic neuritis occurs along with the peripheral neuritis of chronic and debilitated alcoholics. +Clinical feature and treatment is similar to tobacco amblyopia, but the prognosis is not so good. +Methyl alcohol amblyopia +Unlike ethyl alcohol (which produces chronic amblyopia), poisoning by methyl alcohol (methanol) is typically acute, usually resulting in optic atrophy and permanent blindness. +Etiology. It usually occurs due to intake of wood alcohol or methylated spirit in cheap adulterated or fortified beverages. Sometimes, it may also be absorbed by inhalation of fumes in industries, where methyl alcohol is used as a solvent. Rarely, it may also be absorbed from the skin following prolonged daily use of liniments. +Chapter 13 Neuro-ophthalmology 321 + + +Pathogenesis. Methyl alcohol is metabolised very slowly and thus stays for a longer period in the body. It is oxidised into formic acid and formaldehyde in the tissues. These toxic agents cause oedema followed by degeneration of the ganglion cells of the retina, resulting in complete blindness due to optic atrophy. +Clinical features include: +General symptoms of acute poisoning are headache, dizziness, nausea, vomiting, abdominal pain, delirium, stupor and even death. Presence of a characteristic odour due to excretion of formaldehyde in the breath or sweat is a helpful diagnostic sign. +Ocular features. Patients are usually brought with almost complete blindness, which is noticed after 2–3 days, when stupor weans off. Fundus examination in cases reveals mild disc oedema and markedly narrowed blood vessels. Finally bilateral primary optic atrophy ensues. +Treatment includes: +1. Gastric lavage to wash away the methyl alcohol should be carried out immediately and at intervals during the first few days, as the alcohol in the system is continuously returned to stomach. +2. Administration of alkali to overcome acidosis should be done in early stages. Soda bicarb may be given orally or intravenously (500 ml of 5% solution). +3. Ethyl alcohol. It should also be given in early stages. It competes with the methyl alcohol for the enzyme alcohol dehydrogenase, thus preventing the oxidation of methanol to formaldehyde. It should be given in small frequent doses, 90 cc every 3 hours for 3 days. +4. Eliminative treatment by diaphoresis in the form of peritoneal dialysis is also helpful by washing the alcohol and formaldehyde from the system. +5. Prognosis is usually poor; death may occur due to acute poisoning. Blindness often occurs in those who survive. +Quinine amblyopia +It may occur even with small doses of the drug in susceptible individuals. +Clinical features. Patient may develop near total blindness. Deafness and tinnitus may be associated. The pupils are fixed and dilated. Fundus examination reveals retinal oedema, marked pallor of the disc and extreme attenuation of retinal vessels. Visual fields are markedly contracted. + +Ethambutol amblyopia +Ethambutol is a frequently used antitubercular drug. It is used in the doses of 15 mg/kg per day. Sometimes, it may cause toxic optic neuropathy. + +Ethambutol toxicity usually occurs in patients who have associated alcoholism and diabetes. +Clinical features. There may occur optic neuritis with typical central scotoma. Involvement of optic chiasma may result in a true bitemporal hemianopia. Patients usually complain of reduced vision or impairment of colour vision during the course of antitubercular treatment. Fundus examination may reveal signs of papillitis. In most of the cases, recovery occurs following cessation of the intake of drug. +Anterior ischAemic oPtic neuroPAthy (Aion) +Anterior Ischaemic Optic Neuropathy (AION)refers to ischaemic damage to the optic nerve head from occlusion of the short posterior ciliary arteries. It is of two types: +• Arteritic anterior ischaemic optic neuropathy (AAION), and +• Non-arteritic anterior ischaemic optic neuropathy (NAAION). +Arteritic anterior ischaemic optic neuropathy +Etiology +Arteritic anterior ischaemic optic neuropathy (AAION), results from inflammatory and thrombic occlusion of short posterior ciliary arteries caused by Giant Cell Arteritis (GCA). It usually occurs in older patients (mean age 70 years) and accounts for only 5–10% cases of AION. +Clinical features +Systemic and/or other ocular features of Giant Cell Arteritis (GCA) may also be associated with AAION. Systemic features of GCA include: +• Headache and tenderness of the temporal arteries and scalp. +• Jaw claudication, characterized by pain on speaking or chewing, is pathognomonic of GCA. It is caused by ischaemia of masseter muscle. +• Other symptoms include fever, malaise, anorexia, weight loss, night sweats and joint and muscle pain. +Ocular presentations of GCA, other than AAION include: +• Transient Ischaemic Attacks (TIA), i.e., amaurosis fugax, may precede AAION by several weeks. +• Central retinal artery occlusion (CRAO), or cilioretinal artery occlusion may sometimes be associated with AAION. +• Ocular Ischaemic Syndrome (see page 286) due to involvement of ophthalmic artery, is comparatively rare association of AAION. +• Diplopia may occur due to ischaemic paresis of extraocular muscles. +322 Section iii Diseases of Eye + + +Features of AAION are as follows: +• Visual loss is usually marked (visual acuity < 6/60) and sudden, may be preceded by TIA and general features of GCA. +• RAPD is present. +• Optic disc oedema in AAION is typically pale as compared to NAION and may be associated with cotton wool spots and splinter haemorrhages. +• Peripapillary pallor and oedema deep to retina may occur due to accompanying choroidal ischaemia. +• Temporal arteries loose pulsation and become tender. +Investigations +• Fundus fluorescein angiography reveals delayed choroidal filling, an important differentiating sign of AAION from NAION. +• Visual fields show typical altitudinal hemianopia involving the inferior (commonly) or superior half (Fig. 13.10). +• ESR and C-reactive protein levels are raised in patients with giant cell arteritis. +• Temporal artery biopsy is required for confirmation of diagnosis. +Treatment +Goal of treatment is to prevent visual loss in the fellow eye, apart from avoiding systemic vascular complications. +Corticosteroids, started immediately, as follows, constitute the main treatment. +• Methylprednisolone 1 gm/day, intravenously for 3–5 days followed by +• Prednisolone per oral 80 mg/day to be tapered every week by 10 mg. Daily maintenance therapy of 10 mg may have to be continued for 1–2 years. + + + + + + + + + + + + + + + + + + +Fig. 13.10 Altitudinal hemianopia in AION + +Note. Since treatment lasts long, special care has to be taken for side effects of steroids. +non-arteritic anterior ischaemic neuropathy +Non-arteritic anterior ischaemic optic neuropathy (NAION) accounts for 90–95% cases of AION. +Etiology +Exact etiology of occlusion of posterior ciliary arteries causing infarction of the retrolaminar portion of the disc in this condition is not known. +Risk factors associated with NAION may be ocular or systemic. +• Ocular risk factors are: disc at risk (structural crowding of the disc with a small cup) cataract surgery, and neglected acute primary angle closure. +• Systemic risk factors include hypertension, diabetes (particularly in young patients), smoking, hyperlipidemia, collagen vascular disease, hyperhomocystinemia, severe anemia and sudden hypotensive events (e.g., massive hemorrhage). +• Drugs, such as sildenafil (Viagra), presumably because of its hypotensive effect, may be associated with NAION. +Clinical features +Clinical features of NAION vis-a-vis AAION can be summarized as below: +• Age of presentation is slightly younger, i.e., mean age is 60 years as compared to 70 years in AAION. +• Sex. NAION is equally common in males and females while AAION is more common in females than males. +• Associated symptoms such as headache, scalp tenderness, jaw claudication and amaurosis fugax seen with AAION and absent in NAION. +• Visual loss with NAION is comparatively less marked. +• Optic disc oedema is hyperaemic as compared to pale oedema noted with AAION +• ESR as compared to AAION (mean 70 mm after 1st hour) is less raised in NAION (mean 20–40 mm after 1st hour). +• C-reactive proteins are normal in NAION, while they are raised in AAION. +• FFA reveals only disc delay in NAION, while in AAION both disc delay and choroidal delay are noted. +Differential diagnosis +NAION also need to be differentiated from optic neuritis, infiltrative optic neuropathy, anterior orbital compressive optic neuropathy and other forms of optic disc oedema including diabetic papillopathy. +Chapter 13 Neuro-ophthalmology 323 + + +Treatment +• No proven benefit of any treatment measures including steroids is reported. +• Addressing the systemic risk factors may probably reduce the incidence. +• Aspirin has a proven effect in reducing the incidence of stroke in patients at risk, but its role in reducing involvement of other eye is not clear. +trAumAtic oPtic neuroPAthy +Traumatic optic neuropathy is of two types direct and indirect: +■Direct traumatic optic neuropathy is less common and involves direct anatomical disruption of the optic nerve in cranio-orbital trauma. +■Indirect traumatic optic neuropathy occurs in closed head injury due to shearing or avulsion of nutrient vessels or by the pressure transmitted along the bone to the optic canal. +Characteristic features of traumatic optic neuropathy are: +• Loss of vision/or decreased visual acuity. • Dilation of pupil is noted. +• Pupillary light reflex. There occurs loss of direct light reflex on the affected side with preservation of ipsilateral consensual light reflex and loss of consensual light reflex on the contralateral side with preservation of contralateral direct light reflex. +• Relative afferent pupillary defect (RAPD) or Marcus Gunn pupil is the first sign. +• Preservation of near reflex (convergence and accommodation reflex) as optic nerve is not involved in the pathway of near reflex. +• Light brightness sensitivity and contrast sensitivity are diminished. +• Subjective red colour saturation and light intensity are the two best tests for overall optic nerve function. +• Visual fieldtestingin an awake and fully cooperative patients can be more revealing than visual acuity determination. Visual field testing is done by perimetry. Visual fields show central or centrocecal scotoma. +• Visual evoked potential (VEP) shows reduced amplitude. +• Imaging. High resolution CT scan is the diagnostic procedure of choice for determining the site of trauma. MRI is the investigation of choice for visualization of optic nerve. +Treatment includes steroids, surgical decompression or combination of both. + +PAPilloeDemA +The terms papilloedema and disc oedema look alike and per se mean swelling of the optic disc. However, arbitrarily the term ‘papilloedema’ has been reserved for the passive disc swelling associated with increased intracranial pressure which is almost always bilateral although it may be asymmetrical. The term ‘disc oedema or disc swelling’ includes all causes of active or passive oedematous swelling of the optic disc other than the causes of papilloedema. +causes of disc oedema +1. Inflammations such as papillitis, neuroretinitis, papillophlebitis, and uveitis. +2. Ocular hypotony due to any cause. +3. Vascular causes include CRVO, diabetic papillopathy, uremia, anterior ischaemic optic neuropathy (AION). +4. Orbital causes are: tumours, Graves’ orbitopathy, and orbital cellulitis. +5. Infiltrative condition include leukaemias, and lymphomas. +etiopathogenesis of papilloedema +Causes. As discussed above, papilloedema is a non-inflammatory oedema of optic disc which occurs secondary to raised intracranial pressure associated with following conditions: +1. Congenital conditions include aqueductal stenosis and craniosynostosis. +2. Intracranial space-occupying lesions (ICSOLs). These include brain tumours, abscess, tuberculoma, gumma, subdural haematoma and aneurysms. The ICSOLs in any position excepting medulla oblongata may induce papilloedema. Papilloedema is most frequently associated with tumours arising in posterior fossa, which obstruct aqueduct of Sylvius and least with pituitary tumours. Thus, the ICSOLs of cerebellum, midbrain and parieto-occipital region produce papilloedema more rapidly than the mass lesions of other areas. Further, the fast progressing lesions produce papilloedema more frequently and acutely than the slow growing lesions. +3. Intracranial infections such as meningitis and encephalitis may be associated with papilloedema. 4. Intracranial haemorrhages. Cerebral as well as subarachnoid haemorrhage can give rise to papilloedema which is frequent and considerable in extent. +5. Obstruction of CSF absorption via arachnoid villi which have been damaged previously. +6. Tumours of spinal cord occasionally give rise to papilloedema. +324 Section iii Diseases of Eye + + +7. Idiopathic intracranial hypertension (IIH) also known as pseudotumour cerebri, is an important cause of raised intracranial pressure. It is a poorly understood condition, usually found in young obese women. It is characterised by chronic headache and bilateral papilloedema without any ICSOLs or enlargement of the ventricles due to hydrocephalus. 8. Systemic conditions include malignant hypertension, pregnancy induced hypertension (PIH), cardiopulmonary insufficiency, blood dyscrasias and nephritis. +9. Diffuse cerebral oedema from blunt head trauma may causes papilloedema. +10. Cerebral venous sinus thrombosis may also cause papilloedema. +Unilateral versus bilateral papilloedema. Disc swelling due to ocular and orbital lesions is usually unilateral. In majority of the cases with raised intracranial pressure, papilloedema is bilateral. However, unilateral cases as well as of unequal change do occur with raised intracranial pressure. A few such conditions are as follows: +1. Foster-Kennedy syndrome. It is associated with olfactory or sphenoidal meningiomata and frontal lobe tumours. In this condition, there occurs pressure optic atrophy on the side of lesion and papilloedema on the other side (due to raised intracranial pressure). +2. Pseudo-Foster-Kennedy syndrome. It is characterised by occurrence of unilateral papilloedema associated with raised intracranial pressure (due to any cause) and a pre-existing optic atrophy (due to any cause) on the other side. +Pathogenesis. Till date, Hayreh’s theory is the most accepted one. It states that, `papilloedema develops as a result of stasis of axoplasm in the prelaminar region of optic disc, due to an alteration in the pressure gradient across the lamina cribrosa.’ +Increased intracranial pressure, malignant hypertension and orbital lesions produce disturbance in the pressure gradient by increasing the tissue pressure within the retrolaminar region. While, ocular hypotony alters it by lowering the tissue pressure within the prelaminar area. +Thus, the axonal swelling due to axoplasmic stasis in prelaminar region is the initial structural alteration, which in turn produces venous congestion and ultimately the extracellular oedema. This theory discards the old view that the papilloedema results due to compression of the central retinal vein by the raised cerebrospinal fluid pressure around the optic nerve. + + +Evolution and recovery. Papilloedema usually develops quickly, appearing within 1–5 days of raised intracranial pressure. +In cases with acute subarachnoid haemorrhage it may develop even more rapidly (within 2–8 hours). However, recovery from fully developed papilloedema is rather slow. It takes about 6–8 weeks to subside after the intracranial pressure is normalised. +clinical features +A. General features +Patients usually present to general physicians with general features of raised intracranial pressure. These include headache, nausea, projectile vomiting and diplopia. Focal neurological deficit may be associated. +b. Ocular features +Patients may give history of recurrent attacks of transient blackout of vision (amaurosis fugax).Visual acuity and pupillary reactions usually remain fairly normal until the late stages of diseases when optic atrophy sets in, so, loss of vision is not a common feature of papilloedema. +Clinical features of papilloedema can be described under four stages: early, fully developed, chronic and atrophic. + +1. Early (incipient) papilloedema +Symptoms are usually absent and visual acuity is normal. +Pupillary reactions are normal. +Ophthalmoscopic features of early papilloedema are (Fig. 13.11A): +• Obscuration of the disc margins (nasal margins are involved first followed by the superior, interior and temporal). +• Blurring of peripapillary nerve fibre layer. +• Absence of spontaneous venous pulsation at the disc (appreciated in 80% of the normal individuals). +• Mild hyperaemia of the disc. +• Splinter haemorrhages in the peripapillary region may be present. +Visual fields are fairly normal. + +2. Established (fully developed) papilloedema +Symptoms. Patient may give history of transient visual obscurations in one or both eyes, lasting a few seconds, after standing. Visual acuity is usually normal. +Pupillary reaction remain fairly normal. +Chapter 13 Neuro-ophthalmology 325 + + +Ophthalmoscopic features (Fig. 13.11B): +• Apparent optic disc oedema is seen as its forward elevation above the plane of retina; usually up to 1–2 mm (1 mm elevation is equivalent to +3 dioptres). +• Physiological cup of the optic disc is obliterated. • Disc becomes markedly hyperaemic and blurring +of the margin is present all around. +• Multiple cotton wool spots and superficial haemorrhages may be seen near the disc. +• Veins become tortuous and engorged. In advanced cases, the disc appears to be enlarged and elevated (mushroom or dome shaped) so that vessels bend sharply over its margins. There occurs difference of 2–6 D between the vessels at the top of dome and those on the retina. By indirect ophthalmoscopy, a definitive parallax can be elicited. +• Paton’s lines i.e., circumferential greyish white folds may develop due to separation of nerve fibres by the oedema. +• Rarely, hard exudates may radiate from the fovea in the form of an incomplete star (macular star or macular fan). +• Visual fields show enlargement of blind spot. + +3. Chronic or long-standing (vintage) papilloedema +Symptoms. Visual acuity is variably reduced depending upon the duration of the papilloedema. +Pupillary reactions are usually normal. Ophthalmoscopic features (Fig. 13.11C). In this stage: +• Acute haemorrhages and cotton wool spots resolve, and peripapillary oedema is resorbed. +• The optic disc gives appearance of the dome of a champagne cork. The central cup remains obliterated. Small drusen like crystalline deposits (corpora amylacea) may appear on the disc surface. +• Visual fields. Blind spot is enlarged and the visual fields begin to constrict. + +4. atrophic papilloedema +Symptoms. Atrophic papilloedema develops after 6–9 months of chronic papilloedema and is characterized by severely impaired visual acuity. +Pupillary reaction. Light reflex is impaired. Ophthalmoscopicfeaturesof the so called postneuritic optic atrophy are as below (Fig. 13.11D): +• There occur greyish white discolouration and pallor of the disc due to atrophy of the neurons and associated gliosis. +• Prominence of the disc decreases in spite of persistent raised intracranial pressure. + +• Retinal arterioles are narrowed and veins become less congested. Whitish sheathing develops around the vessels. +Visual felds. Concentric contraction of peripheral fields becomes apparent as atrophy sets in. +Differential diagnosis +Papilloedema should be differentiated from pseudopapilloedema and papillitis. Pseudop-apilloedema is a non-specific term used to describe elevation of the disc similar to papilloedema, in conditions such as optic disc drusen, hypermetropia, and persistent hyaloid tissue. The differentiating points between papilloedema, papillitis and pseudopapilloedema (pseudopapillitis) due to hypermetropia are enumerated in Table 13.2. +treatment and prognosis +Papilloedema is a neurological emergency and requires immediate hospitalisation. Urgent neuroimaging (CT scan or preferably MR1 with a gadolinium enhancement) may reveal primary pathology. As a rule unless the causative disease is treatable or cerebral decompression is done, the course of papilloedema is chronic and ultimate visual prognosis is bad. +oPtic AtroPhy +Optic atrophy refers to degeneration of the optic nerve, which occurs as an end result of any pathologic process that damages axons in the anterior visual system, i.e., from retinal ganglion cells to the lateral geniculate body. +classification +a. Primary versus secondary optic atrophy. It is customary to divide the optic atrophy into primary and secondary. +■Primary optic atrophy refers to the simple degeneration of the nerve fibres without any complicating process within the eye, e.g., syphilitic optic atrophy of tabes dorsalis. +■Secondary optic atrophy occurs following any pathologic process which produces optic neuritis or papilloedema. +Recently, most of the authors have discarded the use of this time-honoured but noninformative classification. Further, such a classification is misleading since identical lesion at disc (e.g., papillitis in multiple sclerosis) will produce secondary optic atrophy and when involving optic nerve a little distance up (e.g., retrobulbar neuritis in multiple sclerosis) will produce an apparently primary optic atrophy. +326 Section iii Diseases of Eye + + + + + + + + + + + + + + + + +A B + + + + + + + + + + + + +C D + +Fig. 13.11 Fundus photograph showing papilloedema: A, early; B, established; C, chronic; D, atrophic + + + +B. Ophthalmoscopic classification. It is more useful to classify optic atrophy based on its ophthalmoscopic appearance. Common types are as follows: +1. Primary (simple) optic atrophy 2. Consecutive optic atrophy +3. Glaucomatous optic atrophy 4. Post-neuritic optic atrophy +5. Vascular (ischaemic) optic atrophy. +The etiology and salient features of each type will be considered separately. +C. Ascending versus descending optic atrophy. ■Ascending or autograde optic atrophy (Wallerian degeneration)follows damage to ganglion cells or nerve fibre layer due to diseases of the retina or optic disc. In it the nerve fibre degeneration progresses (ascends) from the eyeball towards the geniculate body. ■Descending or retrograde optic atrophy proceeds from the region of the optic tract, chiasma or posterior portion of the optic nerve towards the optic disc. Damage beyond lateral geniculate nucleus (LGN), i.e., optic radiations and occipital cortex does + +not cause optic atrophy as the second order neurons (axons of ganglion cells) synapse in LGN. +Pathological features +Degeneration of the optic nerve fibres is associated with attempted but unsuccessful regeneration which is characterised by proliferation of astrocytes and glial tissue. Ophthalmoscopic appearance of the atrophic optic disc depends upon the degree of loss of nerve tissue vis-vis gliosis. Following three situations may occur: +1. Degeneration of the nerve fibres may be associated with excessive gliosis. These changes are pathological features of the consecutive and postneuritic optic atrophy. +2. Degeneration and gliosis may be orderly and the proliferating astrocytes arrange themselves in longitudinal columns replacing the nerve fibres (columnar gliosis). Such pathological features are seen in primary optic atrophy. +3. Degeneration of the nerve fibres may be associated with negligible gliosis. It occurs due to progressive +Chapter 13 Neuro-ophthalmology 327 + +Table 13.2: Differentiating features of papilloedema, papillitis and pseudopapillitis + + +Feature +1. Laterality 2. Symptoms +• Visual acuity + + + +• Painandtenderness + +3. Fundus examination • Media + +• Disc-colour + +Disc-margins Disc-swelling + + +• Peripapillary oedema +• Venous engorgement +• Retinal haemorrhages +• Retinal exudates • Macula + +4. Fields + +5. Fluorescein angiography + +Papilloedema Usually bilateral + +Transient attacks of blurred vision +Later vision decreases due to optic atrophy +Absent + + +Clear + +Red and juicy appearance Blurred +2-6 dioptres + + +Present + +More marked + +Marked + +More marked +Macular star may be present + +Enlarged blind spot + +Vertical oval pool of dye due to leakage + +Papillitis +Usually unilateral + +Marked loss of vision of sudden onset + + +May be present with ocular movements + +Posterior vitreous haze is common +Marked hyperaemia Blurred Usually not more than 3 dioptres +Present + +Less marked + +Usually not present + +Less marked +Macular fan may be present +Central scotoma more for colours +Minimal leakage of dye + +Pseudopapillitis +May be unilateral or bilateral + +Defective vision depending upon the degree of refractive error + +Absent + + +Clear + +Reddish + +Not well defined +Depending upon the degree of hypermetropia + +Absent + +Not present + +Not present + +Absent Absent + +No defect + +No leakage of dye + + + + +decrease in blood supply. Such pathological changes are labelled as cavernous (schnabel’s) optic atrophy and are features of glaucomatous and ischaemic (vascular) optic atrophy. + +etiology +1. Primary (simple) optic atrophy. It results from the lesions proximal to the optic disc without antecedent papilloedema. Its common causes are: multiple sclerosis, retrobulbar neuritis (idiopathic), Leber’s and other hereditary optic atrophies, intracranial tumours pressing directly on the anterior visual pathway (e.g., pituitary tumour), traumatic severance or avulsion of the optic nerve, toxic amblyopias (chronic retrobulbar neuritis) and tabes dorsalis. + +2. Consecutive optic atrophy. It occurs following destruction of ganglion cells secondary to degenerative or inflammatory lesions of the choroid and/or retina. Its common causes are: diffuse chorioretinitis, retinal pigmentary dystrophies such as retinitis pigmentosa, pathological myopia and occlusion of central retinal artery. +3. Post-neuritic optic atrophy. It is secondary optic atrophy which develops as a sequelae to long-standing papilloedema or papillitis. +4. Glaucomatous optic atrophy. It results from the effect of long-standing raised intraocular pressure. 5. Vascular (ischaemic) optic atrophy. It results from the conditions (other than glaucoma) producing disc ischaemia. These include: giant cell arteritis, severe haemorrhage, severe anaemia and quinine poisoning. +328 Section iii Diseases of Eye + + +clinical features of optic atrophy +1. Loss of vision, may be of sudden or gradual onset (depending upon the cause of optic atrophy) and partial or total (depending upon the degree of atrophy). It is important to note that ophthalmoscopic signs cannot be correlated with the amount of vision. 2. Pupil is semidilated and direct light reflex is very sluggish or absent. Swinging flash light test depicts Marcus Gunn pupil (RAPD). +3. Visual field loss will vary with the distribution of the fibres that have been damaged. In general, the field loss is peripheral in systemic infections, central in focal optic neuritis and eccentric when the nerve or tracts are compressed. +4. Ophthalmoscopic appearance of the disc will vary with tape of optic atrophy. However, ophthalmoscopic features of optic atrophy in general are pallor of the disc and decrease in the number of small blood vessels (Kastenbaum index). The pallor is not due to atrophy of the nerve fibres but to loss of vasculature. Ophthalmoscopic features of different types of optic atrophy are as described below: +i. Primary optic atrophy (Fig. 13.12A). Colour of the + + + + + + + + + + + + + + + +A + + + + + + + + + + + + +C + + +disc is chalky white or white with bluish hue. Its edges (margins) are sharply outlined. Slight recession of the entire optic disc occurs in total atrophy. Lamina cribrosa is clearly seen at the bottom of the physiological cup. Major retinal vessels and surrounding retina are normal. +ii. Consecutive optic atrophy (Fig. 13.12B). Disc appears yellow waxy. Its edges are not so sharply defined as in primary optic atrophy. Retinal vessels are attenuated. +iii. Post-neuritic optic atrophy (also labeled as secondary optic atrophy) (Fig. 13.12C). Optic disc looks dirty white in colour. Due to gliosis, its edges are blurred, physiological cup is obliterated and lamina cribrosa is not visible. Retinal vessels are attenuated and perivascular sheathing is often present. +iv. Glaucomatous optic atrophy. Itis characterised by deep and wide cupping of the optic disc and nasal shift of the blood vessels (for details see page 232 and Fig. 10.11). v.Ischaemicopticatrophy.Ophthalmoscopic features are pallor of the optic disc associated with marked attenuation of the vessels (Fig. 13.12D). + + + + + + + + + + + + + + + +B + + + + + + + + + + + + +D + +Fig. 13.12 Optic atrophy : A, primary; B, consecutive (in a patient with retinitis pigmentosa); C, postneuritic; D, ischaemic +Chapter 13 Neuro-ophthalmology 329 + + +Differential diagnosis +1. Primary versus secondary and consecutive optic atrophy. Differences are summarised in Table 13.3. 2. Optic atrophy versus other causes of pale optic disc. Pallor of optic disc seen in partial optic atrophy must be differentiated from other causes of pallor disc which may be non-pathological and pathological. +i. Non-pathological pallor of optic discis seen in: axial myopia, infants, and elderly people with sclerotic changes. Temporal pallor is associated with large physiological cup. +ii. Pathological causes of pallor disc (other than optic atrophy) include hypoplasia, congenital pit, and coloboma. +treatment +Treatment of underlying cause may help in preserving some vision in patients with partial optic atrophy. However, once complete atrophy has set in, the vision cannot be recovered. + +SYMPTOMATIC DISTuRBANCeS Of THe vISION + +night blinDness (nyctAloPiA) +Night blindness may occur in patients with rod dysfunction and also in patients having media opacities and advanced POAG. +rod dysfunction +Night (scotopic) vision is a function of rods. Therefore, the conditions in which functioning of these nerve endings is deranged will result in night blindness. These include: +• Vitamin A deficiency, tapetoretinal degenerations (e.g., retinitis pigmentosa), +• Congenital high myopia, +• Familial congenital night blindness, and • Oguchi’s disease. + +Table 13.3 Primary versus secondary and consecutive +optic atrophy + +media opacities +Night blindness may also develop in conditions of the ocular media interfering with the light rays in dim light (i.e., with dilated pupils). These include: +• Paracentral lenticular, and • Corneal opacities. +Advanced PoAg +In advanced cases of primary open angle glaucoma, dark adaptation may be so much delayed that patient gives history of night blindness. +DAy blinDness (hAmArloPiA) +It is a symptomatic disturbance of the vision, in which the patient is able to see better in dim light as compared to bright light of the day. Its causes are: +• Congenital deficiency of cones +• Central lenticular opacities (polar cataracts) • Central corneal opacities. +colour blinDness +An individual with normal colour vision is known as trichromate. This is because the normal human eye can appreciate three primary colours (red, green and blue) due to presence of three different types of cones, i.e., red sensitive, green sensitive and blue sensitive. All colours of the spectrum can be perceived by fusion of these three primary colours in varying proportions. (Young-Helmholtz trichromatic theory of colour vision.) In colour blindness, mechanism to appreciate one or more primary colours is either defective (anomalous) or absent (anopia). It may be congenital or acquired. +A. congenital colour blindness +It is a hereditary condition affecting males more (3-4%) than females (0.4%). It may be of the following types: +• Dyschromatopsia • Achromatopsia. +1. Dyschromatopsia +Dyschromatopsia, literally means colour confusion due to deficiency of mechanism to perceive colours. + + + +Feature APPeARAnce + +MARgiNS +LAMiNA CRiBRoSA +Vessels + +SURRoUNDiNg RETiNA + + +Primary Chalky white + +Well defined Well seen + +Normal + +Healthy + + +Secondary +Dirty grey white +ill defined obscured + +Peripapillary sheathing +Hyaline bodies/ drusen + + +Consecutive Waxy pallor + +Well defined Well seen + +Allenuation + +Pathology seen + +It can be classified into: +• Anomalous trichromacy • Dichromacy +• Blue cone monochromatism +a. Anomalous trichromatic colour vision. Here, the mechanism to appreciate all the three primary colours is present but is defective for one or two of them. It may be of following types: ■Protanomalous. It refers to defective red colour appreciation. +■Deuteranomalous. It means defective green colour appreciation. +330 Section iii Diseases of Eye + + +■Tritanomalous. It implies defective blue colour appreciation. +b.Dichromatic colour vision. In this conditon faculty to perceive one of the three primary colours is completely absent. Such individuals are called dichromates and may have one of the following types of defects: +• Protanopia, i.e., complete red colour defect. +• Deuteranopia, i.e., complete defect for green colour. • Tritanopia, i.e., absence of blue colour appreciation. +Red-green deficiency (protanomalous, protanopia, deuteranomalous and deuteranopia) is more common. Such a defect is a source of danger in certain occupations such as drivers, sailors and traffic police. Blue deficiency (tritanomalous and tritanopia) is comparatively rare. +c. Blue cone monochromatism (BCM). It is a condition of complete absence of red and green cone function. It is characterised by: +• Poor day vision but normal night vision, +• Colour vision severely limited, only differences in blue hues are detectable, +• Reduced visual acuity (6/24 to 6/6), • Small amplitude nystagmus, and +• Photosensitivity. +2. Achromatopsia +It is an extremely rare condition presenting as rod monochromatism. +Rod monochromatismmay be complete or incomplete. It is inherited as an autosomal recessive trait affecting both sexes equally. It is characterized by: +• Total colour blindness, +• Day blindness (visual acuity is about 6/60), • Nystagmus, and +• Fundus is usually normal. +b. Acquired colour blindness +It may follow damage to macula or optic nerve, Usually, it is associated with a central scotoma or decreased visual acuity. +■Blue-yellow impairment is seen in retinal lesions such as CSR, macular oedema and shallow retinal detachment. +■Red-green deficiency is seen in optic nerve lesions such as optic neuritis, Leber’s optic atrophy and compression of the optic nerve. +■Acquired blue colour defect (blue blindness) may occur in old age due to increased sclerosis of the crystalline lens. It is owing to the physical absorption of the blue rays by the increased amber coloured pigment in the nucleus. +tests for colour vision +These tests are designed for: (1) Screening defective colour vision from normal; (2) Qualitative + + + + + + + + + + + + + + + + + +Fig. 13.13 Ishihara’s pseudoisochromatic chart + +classification of colour blindness i.e., protons, deuteran and tritan; and (3) Quantitative analysis of degree of deficiency, i.e., mild, moderate or marked. +Commonly employed colour vision tests are as follows: +1.Pseudoisochromatic charts. It is the most commonly employed test using Ishihara’s plates (Fig. 13.13). In this there are patterns of coloured and grey dots which reveal one pattern to the normal individuals and another to the colour deficients. It is a quick method to screen Congenital proton and deuteron (i.e., red-green defects). Another test based on the same principle are: +Hardy-Rand-Rittler plates (HRR) (more sensitive than Ishihara since it can detect all the three congenital defects). +American optical colour plate test. +2. Edridge-Green lantern test. In this test the subject has to name the various colours shown to him by a lantern and the judgement is made by the mistake he makes. +3. Farnsworth-Munsell 100 hue test. It is a spectroscopic test in which subject has to arrange the coloured chips in ascending order. The colour vision is judged by the error score, i.e., greater the score poorer the colour vision. It is the most sensitive test for both congenital and acquired colour vision defects. It consists of 85 hue caps (not 100) and colour vision is judged by error score (higher score means poorer colour vision). +4. Farnsworth D15 hue discrimination test is similar test but utilizes only 15 hue caps. +5. City university colour vision test. It is also a spectroscopic test where a central coloured plate is to +Chapter 13 Neuro-ophthalmology 331 + + +be matched to its closest hue from four surrounding colour in each of 10 plates. +6. Nagel’s anomaloscope. In this test, the observer is asked to mix red and green colour in such a proportion that the mixture should match the given yellow coloured disc. The judgement about the defect is made from the relative amount of red and green colours and the brightness setting used by the observer. +7. Holmgren’s wools test. In this, the subject is asked to make a series of colour-matches from a selection of skeins of coloured wools. +Note. Currently, there is no treatment for the color blindness. +AmAurosis +It implies complete loss of sight in one or both eyes, in the absence of ophthalmoscopic or other marked objective signs. +1. Amaurosis fugax +It refers to a sudden, temporary and painless monocular visual loss occurring due to a transient failure of retinal circulation. +Common causes of amaurosis fugax are: carotid transient ischaemic attacks (TIA), embolization of retinal circulation, papilloedema, giant cell arteritis, Raynaud’s disease, migraine, as a prodromal symptom of central retinal artery or carotid artery occlusion, hypertensive retinopathy, and venous stasis retinopathy. +Clinical characteristics. An attack of amaurosis fugax is typically described by the patients as a curtain that descends from above or ascends from below to occupy the upper or lower halves of their visual fields. +The attack lasts for two to five minutes and resolves in the reverse pattern of progression, leaving no residual deficit. Due to brief duration of the attack, it is rarely possible to observe the fundus. When observed shortly after an attack, the fundus may either be normal or reveal signs of retinal ischaemia such as retinal oedema and small superficial haemorrhages. In some cases, retinal emboli in the form of white plugs (fibrin-platelet aggregates) may be seen. +2. uraemic amaurosis +It is a sudden, bilateral, complete loss of sight occurring probably due to the effect of certain toxic materials upon the cells of the visual centre in patients suffering from acute nephritis, eclampsia of pregnancy and renal failure. The visual loss is associated with dilated pupils which generally react to light. The fundi are usually normal except for the coincidental findings of hypertensive retinopathy, + + +when associated. Usually, the vision recovers in 12–48 hours. + +AmblyoPiA +It implies a partial loss of sight in one or both eyes, in the absence of ophthalmoscopic or other marked objective signs. It may be either congenital or acquired. Acquired amblyopia may be organic (toxic amblyopia; page 320) or functional. +Functional amblyopia results from the psychical suppression of the retinal image. It may be anisometropic, strabismic or due to stimulus deprivation (amblyopia ex anopsia) (see page 342). +corticAl blinDness +Cortical blindness (visual cortex disease) is produced by bilateral occipital lobe lesions. Unilateral occipital lobe lesions typically produce contralateral macular sparing congruous homonymous hemianopia. +Causes of cortical blindness include: +• Vascular lesions producing bilateral occipital infarction are the commonest cause of cortical blindness (e.g., embolisation of posterior cerebral arteries). +• Head injury involving bilateral occipital lobes is the second common cause. +• Tumours, primary (e.g., falcotentorial meningiomas, bilateral gliomas) or metastatic are rare causes. +• Other rare causes of cortical blindness are migraine, hypoxic encephalopathy, Schilder’s disease and other leukodystrophies. +Clinical features. Cortical blindness is characterized by: • Bilateral loss of vision, +• Normal pupillary light reflexes, +• Visual imagination and visual imagery in dream are preserved, +• Anton syndrome, i.e., denial of blindness by the patients who obviously cannot see, +• Riddoch phenomenon, i.e., ability to perceive kinetic but not static targets. +Management. A thorough neurological and cardiovascular investigative workup including MRI and MRI angiography should be carried out. Treatment depends upon the underlying cause. Partial or complete recovery may occur in patients with stroke progressing from cortical blindness through visual agnosia, and partially impaired perceptual function to recovery. +mAlingering +In malingering a person poses to be visually defective, while he is not. The person may do so to gain some undue advantage or compensation. Usually, one eye is said to be blind which does not +332 Section iii Diseases of Eye + + +show any objective sign. Rarely, a person pretends to be completely blind. In such cases, a constant watch over the behaviour may settle the issue. +Differential diagnosis +Before diagnosing malingering following conditions (which produce visual loss with apparently normal anterior segment and a normal fundus) should be ruled out: +1. Amblyopia. Many a time an individual may suddenly notice poor vision in one eye though the onset is usually in early childhood. It is important to identify an amblyogenic factor (see page 342). +2. Cortical blindness must be ruled out from its characteristic features (see page 331). +3. Retrobulbar neuritis a common cause of visual loss with normal fundus. Presence of a definite or relative afferent pupillary defect (RAPD) and VER are diagnostic. +4. Cone rod dystrophy is characterized by a positive family history, photophobia in bright light, abnormal dark adaptation and abnormal cone dystrophy electroretinogram. +5. Chiasmal tumours may sometimes present with visual loss and normal fundus (before the onset of optic atrophy). Sluggish pupillary reactions to light with characteristic visual field defects may be noted. +tests for malingering +1. Convexlens test. Place a low convex or concave lens (0.25 D) before the blind eye and a high convex lens (+10 D) before the good eye. If the patient can read distant words, malingering is proved. +2. Prism base down test. Place a prism with its base downwards before the good eye and tell the person to look at a light source. If the patient admits seeing two lights, it confines malingering. +3. Prism base out test. Ask the patient to look at a light source. Then a prism of 10 D is placed before the alleged blind eye with its base outwards. If the eye moves inwards (to eliminate diplopia) malingering is proved. +4. Snellen’s coloured types test. It has letters printed in red and green. Place a red glass before the good eye. If the person can read all the letters, it confines malingering because, normally one can see only red letters through red glass. +hysterical blindness +It is a form of psychoneurosis, commonly seen in attention-seeking personalities, especially females. + +Characteristic features include: +• Sudden bilateral loss of vision (c.f. malingering). The patient otherwise shows little concern for + +the symptoms and negotiates well with the surroundings (c.f. malingering). +• Blepharospasmand lacrimation may be associated. • Pupillary responses are essentially normal and so +is the blink response. +• Optokinetic nystagmus is intact. +• Visual fields are concentrically contracted. One can commonly find spiral fields as the target moves closer to the fixation point. +Treatment includes psychological support and reassurance. Placebo tablets may also be helpful. A psychiatrist’s help should be sought for, if these fail. +DisorDers of higher VisuAl functions +Visual agnosia +Definition. Visual agnosia refers to a rare disorder in which ability to recognise the objects by sight (despite adequate visual acuity) is impaired while the ability to recognise by touch, smell or sound is retained. +Types of visual agnosia include: +• Prosopagnosia. In this patient cannot recognize familiar faces. +• Object agnosia. In this patient is not able to name and indicate the use of a seen object by spoken or written words or by gestures. +Site of lesion in visual agnosia is bilateral inferior (ventromedial) occipitotemporal junction. + +Associated features include: +• Bilateral homonymous hemianopia. +• Dyschromatopsia (disturbance of colour vision). + +Visual hallucinations +Visual hallucinations refer to the conditions in which patient alleges of seeing something that is not evident to others in the same environment. +Types. Visual hallucinations are of two types: +• Elementary (unformed) hallucinations include flashes of light, colours, luminous points, stars, multiple lights and geometric forms. They may be stationary or moving. +• Complex (formed) hallucinations include objects, persons or animals. +Causes of visual hallucinations include: +• Occipital and temporal lobe lesions. Elementary hallucinations are considered to have their origin in the occipital cortex and complex ones in the temporal cortex. +• Drug induced. Many drugs acting on the CNS in high doses are hallucinogenic. +• Bilateral visual loss in elderly individuals may be associated with formed hallucinations (Charles Bonnet syndrome). +Chapter 13 Neuro-ophthalmology 333 + + +• Migraine is a common cause of unformed hallucinations. +• Optic nerve diseases and vitreous traction are reported to produce unformed hallucinations. +• Psychiatric disorders are not the causes of isolated visual hallucinations. +Alexia and agraphia +Alexia means the inability to read (despite good vision). It is commonly associated with agraphia (inability to write). +Causes. Alexia associated with agraphia is produced by lesions of the angulate gyrus of the dominant hemisphere. +■Alexia without agraphia is usually caused by lesions that destroy the visual pathway in the left occipital lobe and also interrupt the association fibres from the right occipital lobe that have crossed in the splenium of corpus callosum. +Visual illusions +In visual illusions patients perceive distortions in form, size, movement or colour of the objects seen. Some of the visual illusions are: +• Palinopsia (visual perservation) is an illusion whereby the patient continues to perceive an image after the actual object is no longer in view. +• Optic anaesthesia refers to false orientation of objects in space. +• Cerebral dyschromatopsia may occur as dis-appearance of colour (achromatopsia) or illusional colouring (e.g., erythropsia). +• Cerebral diplopia or polyopia are also reported to occur as rare symptoms of central nervous system disease. +Causes. Visual illusions are reported to occur in lesions of the occipital, occipitoparietal or occipitotemporal regions, and right hemisphere appears to be involved more often than the left. + +OCuLAR MANIfeSTATIONS Of DISeASeS Of CeNTRAL NeRvOuS SYSTeM +Ocular involvement in diseases of the central nervous system is not infrequent. A few common ocular lesions of these diseases are mentioned here. +intrAcrAniAl infections +These include meningitis, encephalitis, brain abscess and neurosyphilis. +1. Meningitis. It may be complicated by papillitis, and paralysis of third, fourth and sixth cranial nerves. Chronic chiasmal arachnoiditis may produce + + +bilateral optic atrophy. Tuberculous meningitis may be associated with choroidal tubercles. +2. Encephalitis. It may be complicated by papillitis and/or papilloedema. Cranial nerve palsies are usually incomplete. Diplopia and ptosis are often present. +3. Brain abscess. It is frequently associated with papilloedema. Focal signs depend upon the site of the abscess, and are thus similar to tumours. +4. Neurosyphilis. Ocular involvement is quite frequent. Gummatous meningitis may be associated with papillitis, papilloedema or postneuritic optic atrophy and cranial nerve palsies. Third nerve is paralysed in nearly 30% cases, less frequently the fifth and sixth, and least frequently the fourth. Tabes dorsalis and generalised paralysis of insane may be associated with primary optic atrophy, Argyll Robertson pupil, and internal and/or external ophthalmoplegia. +intrAcrAniAl Aneurysms +Intracranial aneurysms associated with ocular manifestations are located around the circle of Willis. Intracranial aneurysms may produce complications by following mechanisms: +1. Pressure effects are as follows: +i. Aneurysms of circle of Willis and internal carotid artery (supraclenoid, infraclenoid, i.e., intracavernous, and anterior communicating artery) may produce following pressure effects: +• Central and peripheral visual loss due to pressure on intracranial part of optic nerve and chiasma. +• Slowly progressive ophthalmoplegia, due to pressure, on motor nerves in the cavernous sinus. +• Facial pain and paraesthesia associated with corneal anaesthesia due to pressure on the branches of trigeminal nerve. +• Horner’s syndrome due to pressure on sympathetic fibres along the carotid artery. +ii. Posterior communicating artery aneurysm typically presents with isolated painful third nerve palsy. +iii. Vertebrobasilar artery aneurysms may also be associated with third nerve palsy. +2. Production of arteriolar venous fistula. Carotid-cavernous fistula may be produced by rupture of a giant aneurysm of the intracavernous part of the internal carotid artery. Pulsating exophthalmos is a typical presentation of carotid-cavernous fistula. +3. Subarachnoid haemorrhage. Subarachnoid haemorrhage is a life-threatening complication associated with sudden rupture of aneurysm of the circle of Willis. It is characterized by: +334 Section iii Diseases of Eye + + +• Sudden violent headache. +• Third nerve palsy with pupillary dilatation. +• Photophobia, signs of meningeal irritation, vomiting and unconsiousness. +• Terson syndrome refers to the combination of bilateral intraocular haemorrhages (intraretinal, subhyaloid and vitreous haemorrhage) and subarachnoid haemorrhage due to aneurysmal rupture. +intrAcrAniAl hAemorrhAges Ophthalmic signs of intracerebral haemorrhage are tonic conjugate and dysconjugate deviations. Subarachnoid haemorrhage may produce retinal haemorrhages (especially subhyaloid haemorrhage of the posterior pole), papilloedema, and ocular palsies. +intrAcrAniAl sPAce-occuPying lesions (icsols) +These include primary and secondary brain tumours, haematomas, granulomatous inflammations and parasitic cysts. Clinical features of the ICSOLs may be described under three heads: +i. General effects of raised intracranial pressure +These include headache, vomiting, papilloedema, drowsiness, giddiness, slowing of pulse rate and rise in blood pressure. +ii. False localising signs +These occur due to the effect of raised intracranial pressure and displacement or distortion of the brain tissue. False localising signs of ophthalmological interest are as follows: +1. Diplopia: It occurs due to pressure palsy of the sixth nerve. +2. Sluggish pupillary reflexes and unilateral mydriasis may occur due to pressure on the 3rd nerve. +3. Bitemporal hemianopia: It results from downward pressure of the distended third ventricle on the chiasma. +4. Homonymous hemianopia: It may result from occipital herniation through the tentorium cerebelli with compression of the posterior cerebral artery. +iii. Focal signs of intracranial mass lesions +These depend upon the site of the lesion.Focal signs of ophthalmological interest are as follows: +1. Prefrontal tumours, particularly meningioma of the olfactory groove, are associated with a pressure atrophy of the optic nerve on the side of lesion and papilloedema on the other side due to raised intracranial pressure (Foster-Kennedy syndrome). 2. Temporal lobe tumours. These may produce incongruous crossed upper quadrantanopia due to pressure on the optic radiations. Visual + +hallucinations may occur owing to irritation of the visuo-psychic area. Third and fifth cranial nerves may be involved due to downward pressure. Impairment of convergence and of superior conjugate movements may occur in late stages due to prolapse of the uncus through the tentorium cerebelli into the posterior fossa, with resulting distortion of the ventral part of midbrain. +3. Parietal lobe tumours. These are associated with crossed lower homonymous quadrantanopia due to involvement of the upper fibres of the optic radiations. Other lesions include visual and auditory hallucinations, conjugate deviations of the eyes and optokinetic nystagmus. +4. Occipital lobe tumours. These may produce crossed homonymous quadrantic or hemianopic defect involving the fixation point. Visual agnosia may also be associated. +5. Midbrain tumours. These may be associated with homonymous hemianopia due to pressure on the optic tracts. Other signs depending upon the site of involvement are as follows: +i. Tumours of the upper part produce spasmodic contraction of the upper lid followed by ptosis and loss of upward conjugate movements. In about 25% cases, an upper motor neuron facial paralysis and ipsilateral hemiplegia may also develop. +ii. Tumours of the intermediate level may be associated with the following syndromes: (i)Weber’s syndrome. It is characterised by ipsilateral third nerve palsy, contralateral hemiplegia and facial palsy of upper motor neuron type. (ii) Benedikt’s syndrome. It is characterised by ipsilateral third nerve palsy associated with tremors and jerky movements of the contralateral side which occur due to involvement of the red nucleus. +6. Tumours of the pons. Lesions in the upper part are characterised by ipsilateral third nerve palsy, contralateral hemiplegia and upper motor neuron type facial palsy. While the lesions in the lower part of the pons produce Millard-Gubler syndrome which consists of ipsilateral sixth nerve palsy, contralateral hemiplegia and ipsilateral facial palsy; or Foville’s syndrome in which sixth nerve paralysis is replaced by a loss of conjugate movements to the same side. +7. Cerebellar tumours. Those arising from the cerebellopontineangle produce corneal anaesthesia due to involvement of fifth nerve, early deafness and tinnitis of one side, sixth and seventh cranial nerve paralysis, cerebellar symptoms such as ataxia and vertigo, marked papilloedema and nystagmus. +Chapter 13 Neuro-ophthalmology 335 + + +8. Chiasmal and pituitary tumours. These include: pituitary adenomas, craniopharyngiomas and suprasellar meningiomas. These tumours typically produce chiasmal syndrome which is characterised by bitemporal visual field defects, optic atrophy and sometimes endocrinal disturbances. +DemyelinAting DiseAses +These include multiple sclerosis, neuromyelitis optica and diffuse sclerosis. Ocular involvement may occur in all these conditions. Their salient features are as follows: +multiple sclerosis +It is a demyelinating disorder of unknown etiology, affecting women more often than men, usually in the 15–50 years age group. Pathologically, the condition is characterised by a patchy destruction of the myelin sheaths throughout the central nervous system. Clinical course of the condition is marked by remissions and relapses. In this condition, optic neuritis is usually unilateral (see page 317). Other ocular lesions include internuclear ophthalmoplegia and vestibular or cerebellar nystagmus. +neuromyelitis optica (Devic’s disease) +It is characterised by bilateral optic neuritis associated with ascending myelitis, entailing a progressive quadriplegia and anaesthesia. Unlike multiple sclerosis, this condition is not characterised by remissions and is not associated with ocular palsies and nystagmus. +Diffuse sclerosis (schilder’s disease) +It typically affects children and adolescents and is characterised by progressive demyelination of the entire white matter of the cerebral hemispheres. Ocular lesions include: optic neuritis (papillitis or retrobulbar neuritis), cortical blindness (due to destruction of the visual centres and optic radiations), ophthalmoplegia and nystagmus. +oculAr signs in heAD injury +Ocular signs related only to the intracranial damage are described here. However, direct trauma to the eyeball and/or orbit is frequently associated with the head + + +injury. Lesions of direct ocular trauma are described in the chapter on ocular injuries (see pages 426-440). +A. concussion injuries to the brain +These are usually associated with subdural haemorrhage and unconsciousness which may produce the following ocular signs: +1. Hutchinson’s pupil. It is characterised by initial ipsilateral miosis followed by dilatation with no light reflex due to raised intracranial pressure. If the pressure rises still further, similar changes occur in the contralateral pupil. Therefore, presence of bilateral fixed and dilated pupils is an indication of immediate cerebral decompression. +2. Papilloedema. When it appears within 48 hours of the trauma, it indicates extra or intracerebral haemorrhage and is an indication for immediate surgical measures. While the papilloedema appearing after a week of head injury is usually due to cerebral oedema. + +b. fractures of the base of skull Associated ocular signs are as follows: +1. Cranial nerve palsies. These are often seen with fractures of the base of the skull; most common being the ipsilateral facial paralysis of the lower motor neuron type. Extraocular muscle palsies due to involvement of sixth, third and fourth cranial nerves may also be seen. +2. Optic nerve injury. It may be injured directly, indirectly or compressed by the haemorrhage. Primary optic atrophy may appear in 2–4 weeks following injury. Presence of papilloedema suggests haemorrhage into the nerve sheath. +3. Subconjunctival haemorrhage. It may be seen when fracture of the base of skull is associated with fractures of the orbital roof. The subconjunctival haemorrhage is usually more marked in the upper quadrant and its posterior limit cannot be reached. 4.Pupillary signs. These are inconsistent and thus not pathognomonic. However, usually pupil is dilated on the affected side. +14 + +Disorders of Ocular Motility + + + +CHAPTER OUTLINE + +ANATOMY AND PHYSIOLOGY OF OCULAR MOTILITY SYSTEM +Extraocular muscles Ocular motility +• +• +• +Supranuclear control of eye movements BINOCULAR SINGLE VISION +• +• +• +• +Definition +Development of binocular single vision Grades of binocular single vision Anomalies of binocular vision +STRABISMUS +• +Definition and classification + + + +ANATOMY AND PHYSIOLOGY OF OCULAR MOTILITY SYSTEM + +EXTRAOCULAR MUSCLES +A set of six extraocular muscles (4 recti and 2 obliques) control the movements of each eye (Fig. 14. 1). Rectus muscles are superior (SR), inferior (IR), medial (MR) and lateral (LR). The oblique muscles include superior (SO) and inferior (IO). +Origin and insertion +Rectus muscles originate from a common tendinous ring (the annulus of Zinn), which is attached at the apex of the orbit, encircling the optic foramina and medial part of the superior orbital fissure (Fig. 14.2). Medial rectus arises from the medial part of the ring, superior rectus from the superior part and also the adjoining dura covering the optic nerve, inferior rectus from the inferior part and lateral rectus from the lateral part by two heads which join in a ‘V’ form. +All the four recti run forward around the eyeball and are inserted into the sclera, by flat tendons (about 10 mm broad) at different distances from the limbus as under (Fig. 14.3): +• Medial rectus : 5.5 mm • Inferior rectus : 6.5 mm + +• Pseudostrabismus Heterophoria +Concomitant strabismus Incomitant strabismus Strabismus surgery +• +• +• +• +NYSTAGMUS +• +• +Definition and features Pathogenesis and classification – Physiological nystagmus +– Pathological nystagmus +NYSTAGMOID MOVEMENTS + + + +• Lateral rectus : 6.9 mm • Superior rectus : 7.7 mm +Superior oblique muscle arises from the bone above and medial to the optic foramina. It runs forward and turns around a pulley—‘the trochlea’ (present in the anterior part of the superomedial angle of the orbit) and is inserted in the upper and outer part of the sclera behind the equator (Fig. 14.3C). +Inferior oblique muscle arises by a rounded tendon from the orbital plate of maxilla just lateral to the orifice of the nasolacrimal duct. It passes laterally and backward to be inserted into the lower and outer part of the sclera behind the equator (Fig. 14.3C). +Nerve Supply +The extraocular muscles are supplied by third, fourth and sixth cranial nerves. +• Third cranial nerve (oculomotor) supplies the superior, medial and inferior recti and inferior oblique muscles. +• Fourth cranial nerve (trochlear) supplies the superior oblique, and +• Sixth nerve (abducent) supplies the lateral rectus muscle. +Actions +The extraocular muscles rotate the eyeball around vertical, horizontal and anteroposterior axes. Medial +Chapter 14 Disorders of Ocular Motility 337 + + + + + + + + + + + + + + + + + +Fig. 14.1 Extraocular muscles + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 14.2 Origin of the rectus muscles and the superior oblique muscle + + + + +and lateral rectus muscles are almost parallel to the optical axis of the eyeball; so they have got only the main action. While superior and inferior rectus muscles make an angle of 23° (Fig. 14.4) and reflected tendons of the superior and inferior oblique muscles of 51° (Fig. 14.5) with the optical axis in the primary position; so they have subsidiary actions in addition to the main action. Actions of each muscle (Fig. 14.6) +are shown in Table 14.1. + +OCULAR MOTILITY +Types of ocular movements +A. Unilateral movements are called ‘ductions’ and include the following: +1. Adduction. It is inward movement (medial rotation) along the vertical axis. +2. Abduction. It is outward movement (lateral rotation) along the vertical axis. +338 Section III Diseases of Eye + + + + + + + + + + +A + + + + + + + +Fig. 14.5 Relation of the superior and inferior oblique muscles with the optical axis in primary position + + +B + + + + + + + + + + + +C +Fig. 14.3 Insertion lines of the extraocular muscles on the sclera as seen from: A, front; B, above; C, behind. SR, superior rectus; MR, medial rectus; IR, inferior rectus; LR, lateral rectus; SO. superior oblique; IO, inferior oblique + + + + + + + + + +Fig. 14.6 Action of the extraocular muscles + + + + + + +Fig. 14.4 Relation of the superior and inferior rectus muscles with the optical axis in primary position + +3. Supraduction. It is upward movement (elevation) along the horizontal axis. +4. Infraduction. It is downward movement (depression) along the horizontal axis. +5. Incycloduction (intorsion). It is a rotatory movement along the anteroposterior axis in which +Chapter 14 Disorders of Ocular Motility 339 + + +Table 14.1 Actions of extraocular muscles + +Muscle Primary Secondary Tertiary action action action +LR Abduction — — +SR Elevation Intorsion Adduction IR Depression Extorsion Adduction SO Intorsion Depression Abduction IO Extorsion Elevation Abduction + +superior pole of the cornea (12 O’clock point) moves medially (internal rotation). +6. Excycloduction (extorsion). It is a rotatory movement along the anteroposterior axis in which superior pole of the cornea (12 O’clock point) moves laterally (external rotation). +B. Binocular movements. These are of two types: versions and vergences. +a. Versions, also known as conjugate movements, are synchronous (simultaneous) symmetric movements of both eyes in the same direction. These include: 1. Dextroversion. It is the movement of both +eyes to the right (Fig. 14.7D). It results due to simultaneous contraction of right lateral rectus and left medial rectus. +2. Levoversion. It refers to movement of both eyes to the left (Fig. 14.7F). It is produced by simultaneous contraction of left lateral rectus and right medial rectus. +3. Supraversion. It is upward movement of both eyes in primary position (Fig. 14.7B). It results due to simultaneous contraction of bilateral superior recti and inferior obliques. +4. Infraversion. It is downward movement of both eyes in primary position (Fig. 14.7H). It results due to simultaneous contraction of bilateral inferior recti and superior obliques. +5. Dextroelevation. It is movement to the right and up side (Fig. 14.7A). It is caused by simultaneous action of right superior rectus and left inferior oblique. +6. Dextrodepression. It is movement to the right and down side (Fig. 14.7G). It is caused by simultaneous action of right inferior rectus and left superior oblique. +7. Levoelevation. It is movement to the left and up side (Fig. 14.7C). It is caused by simultaneous action of left superior rectus and right inferior oblique. +8. Levodepression. It is movement to the left and down side (Fig. 14.7I). It is caused by simultaneous action of left inferior rectus and right superior oblique. + +9. Dextrocycloversion. It is rotational movement around the anteroposterior axis, in which superior pole of cornea of both the eyes tilts towards the right. 10. Levocycloversion. It is just the reverse of dextrocycloversion. In this superior pole of cornea +of both the eyes tilts towards the left. +b. Vergences, also called disconjugate movements, are synchronous and symmetric movements of both eyes in opposite directions e.g.: +1. Convergence. It is simultaneous inward movement of both eyes which results from contraction of the medial recti. +2. Divergence. It is simultaneous outward movement of both eyes produced by contraction of the lateral recti. + +Synergists, antagonists and yoke muscles +1. Synergists. If refer to the muscles having similar primary action in the same eye; e.g., superior rectus and inferior oblique of the same eye act as synergistic elevators. +2. Antagonists.These are the muscles having opposite actions in the same eye. For example, medial and lateral recti, superior and inferior recti and superior and inferior obliques are antagonists to each other in the same eye. +3. Yoke muscles (contralateral synergists). These refers to the pair of muscles (one from each eye) which contract simultaneously during version movements. For example, right lateral rectus and left medial rectus act as yoke muscles for dextroversion movements. Other pairs of yoke muscles are: right MR and left LR, right LR and left MR, right SR and left IO, right IR and left SO, right SO and left IR and right IO and left SR. 4. Contralateral antagonists. These are a pair of muscles (one from each eye) having opposite action; for example, right LR and left LR, right MR and left MR. +Laws governing ocular movements +1. Hering’s law of equal innervation. According to law an equal and simultaneous innervation flows from the brain to a pair of muscles which contract simultaneously (yoke muscles) in different binocular movements, e.g.: +i. During dextroversion: right lateral rectus and left medial rectus muscles receive an equal and simultaneous flow of innervation. +ii. During convergence, both medial recti get equal innervation. +iii.During dextroelevation, right superior rectus and left inferior oblique receive equal and simultaneous innervation. +340 Section III Diseases of Eye + + + + + + + + + \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_12.txt b/notes/A K Khurana - Comprehensive Ophthalmology_12.txt new file mode 100644 index 0000000000000000000000000000000000000000..af4c8106fdc76314dbbf92288c0617384500162e --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_12.txt @@ -0,0 +1,1599 @@ + + + + + + + + + + + + + + + + + + + +Fig. 14.7 Diagnostic positions of gaze: primary position (E); secondary positions (B, D, F, H); tertiary positions (A, C, G, I); cardinal positions (A, C, D, F, G, I) + + +2. Sherrington’s law of reciprocal innervation. According to it, during ocular motility increased flow of innervation to the contracting muscle is accompanied by decreased flow of innervation to the relaxing antagonist muscle. For example, during dextroversion, an increased innervation flow to the right LR and left MR is accompanied by decreased flow to the right MR and left LR muscles. +Diagnostic positions of gaze +There are nine diagnostic positions of gaze (Fig. 14.7). These include one primary, four secondary and four tertiary positions. +1. Primary position of gaze. It is the position assumed by the eyes when fixating a distant object (straight ahead) with the erect position of head (Fig. 14.7E). 2. Secondary positionsof gaze. These are the positions assumed by the eyes while looking straight up, straight down, to the right and to the left (Figs. 14.7B, D, F and H). +3. Tertiary positions of gaze. These describe the positions assumed by the eyes when combination of vertical and horizontal movements occur. These include position of eyes in dextroelevation, + +dextrodepression, levoelevation and levodepression (Figs. 14.7A, C, G and I). +4. Cardinal positions of gaze. These are the positions which allow examination of each of the 12extraocular muscles in their main field of action. There are six cardinal positions of gaze, viz, dextroversion, levoversion, dextroelevation, levoelevation, dextrodepression and levodepression (Figs. 14.7 A, C, D, F, G and I). +SUPRANUCLEAR CONTROL OF EYE MOVEMENTS +There exists a highly accurate, still not fully elucidated, supranuclear control of eye movements which keeps the two eyes yoked together so that the image of the object of interest is simultaneously held on both fovea despite movement of the perceived object or the observer’s head and/or body. +Supranuclear eye movement systems include: 1. Saccadic system +2. Smooth pursuit system 3. Vergence system +4. Vestibular system +Chapter 14 Disorders of Ocular Motility 341 + + +5. Optokinetic system +6. Position maintenance system +All these systems perform specific functions and each one is controlled by a different neural system but share the same final common path the motor neurons that supply the extraocular muscles. 1.Saccadic system.Saccades are sudden, jerky conjugate eye movements, that occur as the gaze shifts from one object to another. Thus, they are performed to bring the image of an object quickly on the fovea. Though normally voluntary, saccades may be involuntarily aroused by peripheral, visual or auditory stimuli. +2. Smooth pursuit eye movement system. Smooth pursuit movements are tracking movements of the eye as they follow moving objects. These occur voluntarily when the eyes track moving objects but take place involuntarily if a repetitive visual pattern is displayed continuously. When the velocity of the moving object is more, the smooth pursuit movement is replaced by small saccades (catchup saccades), voluntary saccades serve to bring new objects of interest on the fovea centralis. +3. Vergence movement system. Vergence movements allow focussing of an object which moves away from or towards the observer or when visual fixation shifts from one object to another at a different distance. Vergence movements are very slow disconjugate movements. 4. Vestibular eye movement system. Vestibular movements are usually effective in compensating for the effects of head movements in disturbing visual fixation. These movements operate through the vestibular system and constitute the vestibulo ocular reflex (VOR). +5. Optokinetic system. The system helps to hold the images of the seen world steady on the retinae during sustained head rotation. This system becomes operative, when the vestibulo-ocular reflex (VOR) gets fatigued after 30 seconds. It consists of a smooth pur suit movement following the moving scene, succeeded by a rapid saccade in the opposite direction (Optokinetic nystagmus). +6. Position maintenance system. This system helps to maintain a specific gaze position by means of rapid micromovements called ‘flicks’ and slow micromovements called ‘drifts’. This system co-ordinates with other systems. Neural pathway for this system is believed to be the same as for saccades and smooth pursuits. + +BINOCULAR SINGLE VISION + +DEFINITION +When a normal individual fixes his visual attention on an object of regard, the image is formed on the + +fovea of both the eyes separately; but the individual perceives a single image. This state is called binocular single vision. In other words, binocular single vision is the coordinated use of both eyes so as to produce a single mental impression. +DEVELOPMENT OF BINOCULAR SINGLE VISION +Binocular single vision is a conditioned reflex which is not present since birth but is acquired during first 6 months and is completed during first few years. +The process of its development is complex and partially understood. +Important milestones in the visual development are: • At birth there is no central fixation and the eyes +move randomly. +• By the first month of life fixation reflex starts developing and becomes established by 6 months. +• By6 months,the macular stereopsis and accommo-dation reflex is fully developed. +• By 6 years of age full visual acuity (6/6) is attained and binocular single vision is well developed. +Prerequisites for development of binocular single vision +1. Straight eyes starting from the neonatal period, with precise coordination for all directions of gaze (motor mechanism). +2. Reasonably clear visionin both eyes so that similar images are presented to each retina (sensory mechanism). +3. Ability of visual cortexto promote binocular single vision (mental process). +Therefore, pathologic states disturbing any of the above mechanisms during the first few years of life will hinder the development of binocular single vision and may cause squint. + +GRADES OF BINOCULAR SINGLE VISION Worth has described three grades of binocular single vision, which are best tested with the help of a synoptophore. +Grade I—Simultaneous perception. It is the power to see two dissimilar objects simultaneously. It is tested by projecting two dissimilar objects (which can be joined or superimposed to form a complete picture) in front of the two eyes. For example, when a picture of a bird is projected onto the right eye and that of a cage on to the left eye, an individual with presence of simultaneous perception will see the bird in the cage (Fig. 14.8A). +Grade II—Fusion. It consists of the power to superimpose two incomplete but similar images to form one complete image (Fig. 14.8B). +342 Section III Diseases of Eye + + + + + + + + + + + + + + + + +Fig. 14.8 Slides for testing three grades of binocular vision : A, simultaneous perception; B, fusion; C, stereopsis + + + +The ability of the subject to continue to see one complete picture when his eyes are made to converge or diverge a few degrees, gives the positive and negative fusion range, respectively. +Grade III—Stereopsis. It consists of the ability to perceive the third dimension (depth perception). It can be tested with stereopsis slides in synoptophore (Fig. 14.8C). +ANOMALIES OF BINOCULAR VISION Anomalies of binocular vision include suppression, amblyopia, abnormal retinal correspondence (ARC), confusion and diplopia. +Suppression +It is a temporary active cortical inhibition of the image of an object formed on the retina of the squinting eye. This phenomenon occurs only during binocular vision (with both eyes open). However, when the fixating eye is covered, the squinting eye fixes (i.e., suppression disappears). +Tests to detect suppression include Worth’s 4-dot test, four dioptre base out prism test, red glass test and synoptophore test (see page 352). +Amblyopia +Definition.Amblyopia, by definition, refers to a partial reversible loss of vision in one or both eyes, for which no cause can be found by physical examination of the eye, i.e., there is absence of any organic disease of ocular media, retina and visual pathway. Pathogenesis. Amblyopia is produced by certain amblyogenic factors operating during the critical period of visual development (birth to 6-7 years of age). During this period, the visual pathway continues to develop and brain learns to interpret the signals that come from the eye. If, for any reason, a young child + +cannot use one or both eyes normally, then the vision is not developed completely and the condition is called amblyopia. The most sensitive period for development of amblyopia is first six months of life and it usually does not develop after the age of 6-7 years. +Amblyogenic factors include: +• Visual (form sense) deprivation as occurs in anisometropia, +• Light deprivation e.g., due to congenital cataract, and +• Abnormal binocular interaction e.g., in strabismus. Types. Depending upon the cause, amblyopia is of following types: +1. Strabismic amblyopia results from prolonged uniocular suppression in children with unilateral constant squint who fixate with normal eye. Squint is the most common cause of amblyopia. +2. Stimulus deprivation amblyopia (old term: amblyopia ex anopsia) develops when one eye is totally excluded from seeing early in life as, in congenital or traumatic cataract, complete ptosis and dense central corneal opacity. +3. Anisometropic amblyopia occurs in an eye having higher degree of refractive error than the fellow eye. It is more common in anisohypermetropic than the anisomyopic children. Even 1-2 D hypermetropic anisometropia may cause amblyopia while upto 3 D myopic anisometropia usually does not cause amblyopia. +4. Isoametropic amblyopia is bilateral amblyopia occurring in children with bilateral uncorrected high refractive error. +5. Meridional amblyopia occurs in children with uncorrected astigmatic refractive error. It is a selective amblyopia for a specific visual meridian. +Chapter 14 Disorders of Ocular Motility 343 + + +Clinical characteristics of an amblyopic eye are: +1. Visual acuity is reduced. Recognition acuity is more affected than resolution acuity. +2. Effect of neutral density filter. Visual acuity when tested through neutral density filter improves by one or two lines in amblyopia and decreases in patients with organic lesions. +3. Crowding phenomenon is present in amblyopics i.e., visual acuity is less when tested with multiple letter charts (e.g., Snellen’s chart) than when tested with single charts (optotype). +4. Fixation pattern may be central or eccentric. Degree of amblyopia in eccentric fixation is proportionate to the distance of the eccentric point from the fovea. +5. Colour vision is usually normal, may be affected in deep amblyopia with vision below 6/36. +Treatment of amblyopia should be started as early as possible (younger the child, better the prognosis). Amblyopia therapy works best when initiated in young children under 3 years of age. +1. Occlusion therapy i.e., occlusion of the sound (normal) eye to force use of amblyopic eye is the main stay in the treatment of amblyopia. However, before the occlusion therapy is started, it should be ensured that: +• Opacity in the media (e.g., cataract), if any, should be removed first, and +• Refractive error, if any, should be fully corrected. Simplified schedule for occlusion therapy depending on the age is as below: +• Upto 2 years, the occlusion should be done in 2:1, i.e., 2 days in sound eye and one day in amblyopic eye. +• At the age of 3 years, 3:1, • At the age of 4 years, 4:1, +• At the age of 5 years, 5:1, and • After the age of 6 years, 6:1. +Duration of occlusion should be until the visual acuity develops fully, or there is no further improvement of vision for 3 months. +2.Penalization, i.e., blurring of vision of normal eye either by using atropine (atropine penalization) or by using over plus lenses in spectacles (optical penalization) can be used as alternative when occlusion is not possible. 3. Pleoptic exercises were recommended in the past to re-establish foveal fixation especially in young children. +4. Pharmacologic manipulation using levodopa/ carbidopa has been studied as an adjunct to occlusion therapy. +5. Perceptual learning is also suggested as an adjunct to occlusion therapy. + +6. Computerized vision therapy using specially designed software has come into vogue for the treatment of amblyopia with controversial results. Vision therapy works on the concept of operant conditioning (a form of psychological learning). Computerized Home Vision Therapy (CHVT) can be prescribed as supplementary treatment to the occlusion therapy. +Abnormal retinal correspondence (ARC) +In a state of normal binocular single vision, there exists a precise physiological relationship between the corresponding points of the two retinae. Thus, the foveae of two eyes act as corresponding points and have the same visual direction. This adjustment is called normal retinal correspondence (NRC). When squint develops, patient may experience either diplopia or confusion. To avoid these, sometimes (especially in children with small degree of esotropia), there occurs an active cortical adjustment in the directional values of the two retinae. In this state fovea of the normal eye and an extrafoveal point on the retina of the squinting eye acquire a common visual direction i.e., become corresponding points. This condition is called abnormal retinal correspondence (ARC) and the child gets a crude type of binocular single vision. +Tests to detect abnormal retinal correspondence include Worth’s four-dot test, litmus stereo test, Bagolini striated glass tests, after image tests and synoptophore tests (see pages 351-352). + +Diplopia +Diplopia refers to simultaneous perception of two images of a single object. Diplopia may be binocular or uniocular. +Binocular diplopia +Occurs due to formation of image on dissimilar points of the two retinae (see page 354, Fig. 14.24). Causes of binocular diplopia are: +■Paralysis or paresis of the extraocular muscles (commonest cause) +■Displacement of one eyeball as occurs in space occupying lesion in the orbit, and fractures of the orbital wall, +■Mechanical restriction of ocular movements as caused by thick pterygium, symblepharon and thyroid ophthalmopathy +■Deviation of ray of light in one eye as caused by decentred spectacles +■Anisometropia i.e., disparity of image size between two eyes as occurs in acquired high anisometropia (e.g., uniocular aphakia with spectacle correction). +344 Section III Diseases of Eye + + +Types. Binocular diplopia may be crossed or uncrossed. +■Uncrossed diplopia. In uncrossed (harmonious) diplopia the false image is on the same side as deviation. It occurs in convergent squint as in lateral rectus paralysis. +■Crossed diplopia. In crossed (unharmonious) diplopia the false image is seen on the opposite side. It occurs in divergent squint as in medial rectus paralysis. +Uniocular diplopia +Though not an anomaly of binocular vision, but it will not be out of place to describe uniocular diplopia along with binocular diplopia. In uniocular diplopia an object appears double from the affected eye even when the normal eye is closed. +Causes of uniocular diplopia are: +• Subluxated clear lens (pupillary area is partially phakic and partially aphakic). +• Subluxated intraocular lens (pupillary area is partially aphakic and partially pseudophakic). +• Double pupil due to congenital anomaly, or large peripheral iridectomy or iridodialysis. +• Incipient cataract.Usually polyopia i.e., multiple images may be seen due to multiple water clefts within the lens. +• Keratoconus.Diplopia occurs due to changed refractive power of the cornea in different parts. +Treatment of diplopia +Treat the causative disease. Temporary relief from annoying diplopia can be obtained by occluding the affected eye. + +STRABISMUS + +DEFINITION AND CLASSIFICATION +Definition +Normally, visual axis of the two eyes are parallel to each other in the ‘primary position of gaze’ and this alignment is maintained in all positions of gaze. +A misalignment of the visual axes of the two eyes is called squint or strabismus. +Classification of strabismus +Broadly, strabismus can be classified as below: i. Apparent squint or pseudostrabismus. +ii. Latent squint (Heterophoria) iii.Manifest squint (Heterotropia) +1. Concomitant squint 2. Incomitant squint. +PSEUDOSTRABISMUS +In pseudostrabismus (apparent squint), the visual axes are in fact parallel, but the eyes seem to have a squint: + +1. Pseudoesotropia or apparent convergent squint may be associated with: +• Prominent epicanthal fold (which covers the normally visible nasal aspect of the globe and gives a false impression of esotropia). +• Negative angle kappa. +2. Pseudoexotropiaor apparent divergent squint may be associated with: +• Hypertelorism, a condition of wide separation of the two eyes (i.e., wide IPD), and +• Positive angle kappa. + +HETEROPHORIA + +Heterophoria also known as ‘latent strabismus’, is a condition in which the tendency of the eyes to deviate is kept latent by fusion. Therefore, when the influence of fusion is removed the visual axis of one eye deviates away. Orthophoria is a condition of perfect alignment of the two eyes which is maintained even after the removal of influence of fusion. However, orthophoria is a theoretical ideal. Practically, a small amount of heterophoria is of universal occurrence and is known as ‘physiological heterophoria’. +Types of heterophoria +1. Esophoria or latent convergent squint refers to tendency of the eyeballs to deviate inward. +It may be: +i. Convergence excess type (esophoria greater for near than distance). +ii. Divergence weakness type (esophoria greater for distance than near). +iii.Non-specific type (esophoria which does not vary significantly in degree for any distance). +2. Exophoria or latent divergent squint refers to tendency of the eyeballs to deviate outwards.It may be: i. Convergence weakness type (exophoria greater for +near than distance). +ii. Divergence excess type (exophoria greater on distant fixation than the near). +iii.Non-specific type (exophoria which does not vary significantly in degree for any distance). +3. Hyperphoria is a tendency of the eyeball to deviate upwards, while hypophoria is a tendency to deviate downwards. However, in practice it is customary to use the term right or left hyperphoria depending on the eye which remains up as compared to the other. +4. Cyclophoria or torsional deviation is a tendency of the eyeball to rotate around the anteroposterior axis. When the 12 O’clock meridian of cornea rotates nasally, it is called incyclophoria and when it rotates temporally it is called encyclophoria. +Chapter 14 Disorders of Ocular Motility 345 + + +Etiology +A. Anatomical factors +Anatomical factors responsible for development of heterophoria include: +1. Orbital asymmetry. +2. Abnormal interpupillary distance (IPD). A wide IPD is associated with exophoria and small with esophoria. +3. Faulty insertion of extraocular muscle. +4. A mild degree of extraocular muscle weakness. 5. Anomalous central distribution of the tonic +innervation of the two eyes. +6. Anatomical variation in the position of the macula in relation to the optical axis of the eye. +B. Physiological factors +1. Age. Esophoria is more common in younger age group as compared to exophoria which is more often seen in elderly. +2. Role of accommodation. Increased accom-modation is associated with esophoria (as seen in hypermetropes and individuals doing excessive near work) and decreased accommodation with exophoria (as seen in simple myopes). +3. Role of convergence. Excessive use of convergence may cause esophoria (as occurs in bilateral congenital myopes) while decreased use of convergence is often associated with exophoria (as seen in presbyopes). +4. Dissociation factor such as prolonged constant use of one eye may result in exophoria (as occurs in individuals using uniocular microscope and watch makers using uniocular magnifying glass). + +Factors predisposing to decompensation +• Inadequacy of fusional reserve, +• General debility and lowered vitality, +• Psychosis, neurosis, and mental stress, • Precision of job, and +• Advancing age. + +Symptoms +Depending upon the symptoms heterophoria can be divided into compensated and decompensated. Compensated heterophoria. It is associated with no subjective symptoms. Compensation of heterophoria depends upon the reserve neuro-muscular power to overcome the muscular imbalance and individual’s desire for maintenance of binocular vision. +Decompensated heterophoria. It is associated with multiple symptoms which may be grouped as under: + + +1. Symptoms of muscular fatigue. These result due to continuous use of the reserve neuromuscular power. These include: +• Headache and eyeacheafter prolonged use of eyes, which is relieved when the eyes are closed. +• Difficulty in changing the focus from near to distant objects of fixation or vice versa. +• Photophobia due to muscular fatigue is not relieved by using dark glasses, but relieved by closing one eye. +2. Symptoms of failure to maintain binocular single vision are: +• Blurring or crowding of words while reading, +• Intermittent diplopia due to temporary manifest deviation under conditions of fatigue, and +• Intermittent squint (without diplopia) which is usually noticed by the patient’s close relations or friends. +3. Symptoms of defective postural sensations cause problems in judging distances and positions especially of the moving objects. This difficulty may be experienced by cricketers, tennis players and pilots during landing. +Examination of a case of heterophoria +1. Testing for vision and refractive error. It is most important, because a refractive error may be responsible for the symptoms of the patient or for the deviation itself. Preferably, refraction should be performed under full cycloplegia, especially in children. +2. Cover-uncover test. It tells about the presence and type of heterophoria. To perform it, one eye is covered with an occluder and the other is made to fix an object. In the presence of heterophoria, the eye under cover will deviate. After a few seconds, the cover is quickly removed and the movement of the eye (which was under cover) is observed. Direction of movement of the eyeball tells the type of heterophoria (e.g., the eye will move outward in the presence of esophoria) and the speed of movement tells whether recovery is slow or rapid. +3. Prism cover test. (see page 351). +4. Maddox rod test. Patient is asked to fix on a point light in the centre of Maddox tangent scale (Fig. 14.9) at a distance of 6 metres. A Maddox rod (which consists of many glass rods of red colour set together in a metallic disc) (Fig. 14.10) is placed in front of one eye with axis of the rod parallel to the axis of deviation (Fig. 14.11). +The Maddox rod converts the point light image into a line. Thus, the patient will see a point light with one eye and a red line with the other. Due to +346 Section III Diseases of Eye + + + + + + + + + + + + + +Fig. 14.9 Maddox tangent scale + + + + + + + + + + + + + + + + + +Fig. 14.10 Maddox rod + + + + + + + + + + + + + + + + + + + + + +A + +dissimilar images of the two eyes, fusion is broken and heterophoria becomes manifest. The number on Maddox tangent scale where the red line falls will be the amount of heterophoria in degrees. In the absence of Maddox tangent scale, the dissociation between the point light and red line is measured by the superimposition of the two images by means of prisms placed in front of one eye with apex towards the phoria. +5. Maddox wing test. Maddox wing is an instrument (Fig. 14.12) by which the amount of phoria for near (at a distance of 33 cm) can be measured. It is also based on the basic principle of dissociation of fusion by dissimilar objects. +The instrument is designed in such a way that, through its two slits, right eye sees a vertical white arrow and a horizontal red arrow and the left eye sees a vertical and a horizontal line of numbers. The patient is asked to tell the number on the horizontal line which the vertical white arrow is pointing (this will give amount of horizontal phoria) and the number on the vertical line at which the red arrow is pointing (this will measure the vertical phoria). The cyclophoria is measured by asking the patient to align the red arrow with the horizontal line of numbers (Fig. 14.13). +6. Measurement of convergence and accommodation is important in planning the management of heterophorias. +• Near point of convergence (NPC) can be measured with the help of a RAF rule or the Livingstone + + + + + + + + + + + + + + + + + + + + +B + + +Fig. 14.11 Maddox rod test for horizontal (A) and vertical (B) heterophorias +Chapter 14 Disorders of Ocular Motility 347 + +1.Correction of refractive error when detected, is most important. It may correct the phoria and/or relieve the symptoms. +2. Orthoptic treatment. It is indicated in patients with heterophoria without refractive error and in those where heterophoria and/or symptoms are not corrected by glasses. Aim of orthoptic treatment is to improve convergence insufficiency and the fusional reserve. Orthoptic exercises can be done with synoptophore. Simple exercises to be carried out at home should also be taught to the patient. +3. Prescription of prism in glasses. It may be tried in selected cases of hyperphoria and in troublesome cases of esophoria and exophoria. Prism is prescribed +Fig. 14.12 Maddox wing with apex towards the direction of phoria to correct only half or at the most two-thirds of heterophoria. 4. Surgical treatment. It is undertaken in patients with marked symptoms which are not relieved by other measures. Aim of the surgical management is to strengthen the weak muscle or weaken the strong muscle. + +CONCOMITANT STRABISMUS + + + + + + + + + + + +Fig. 14.13 Maddox wing test + +binocular gauge. The normal NPC is considered to be around 70 mm. +• Near point of accommodation (NPA) should be measured after the NPC. NPA can be measured with the help of a RAF or Prince’srule. Normal NPA varies with the age of patient (see page 47). +7.Measurement of fusional reserve. It can be done with the help of a synoptophore or prism bar. The normal values of fusional reserve are as follows: +• Vertical fusional reserve: 1.5°–2.5° +• Horizontal negative fusional reserve (abduction range): 3°–5 ° +• Horizontal positive fusional reserve (adduction range) : 20°–40°. +Treatment +Treatment described below, is indicated mainly in patients with decompensated heterophoria (i.e., symptomatic cases). + +It is a type of manifest squint in which the amount of deviation in the squinting eye remains constant (unaltered) in all the directions of gaze; and there is no associated limitation of ocular movements. + +Etiology +It is not clearly defined. The causative factors differ in individual cases. As we know, the binocular vision and coordination of ocular movements are not present since birth but are acquired in the early childhood. The process starts by the age of 3–6 months and is completed up to 5–6 years. Therefore, any obstacle to the development of these processes may result in concomitant squint. These obstacles can be arranged into three groups, namely: sensory, motor and central. +1. Sensory obstacles. These are the factors which hinder the formation of a clear image in one eye. These include: +• Refractive errors, +• Prolonged use of incorrect spectacles, • Anisometropia, +• Corneal opacities, +• Lenticular opacities, +• Diseases of macula (e.g., central chorioretinitis), • Optic atrophy, and +• Obstruction in the pupillary area due to congenital ptosis. +348 Section III Diseases of Eye + + +2. Motor obstacles. These factors hinder the maintenance of the two eyes in the correct positional relationship in primary gaze and/or during different ocular movements. A few such factors are: +• Congenital abnormalities of the shape and size of the orbit, +• Abnormalities of extraocular muscles such as faulty insertion, faulty innervation and mild paresis, +• Abnormalities of accommodation, convergence and AC/A ratio. +3. Central obstacles. These may be in the form of: • Deficient development of fusion faculty, or +• Abnormalities of cortical control of ocular movements as occurs in mental trauma, and hyperexcitability of the central nervous system during teething. +Clinical features of concomitant strabismus (in general) +The cardinal features of different clinico-etiological types of concomitant strabismus are described separately. However, the clinical features of con-comitant strabismus (in general) are as below: 1.Ocular deviation.Characteristics of ocular deviation are: +• Unilateral (monocular squint) or alternating (alternate squint). +• Inward deviation (esotropia) or outward deviation (exotropia) or vertical deviation (hypertropia). +• Primary deviation (of squinting eye) is equal to secondary deviation (deviation of normal eye under cover when patient fixes with squinting eye). +• Ocular deviation is equal in all the directions of gaze. +2. Ocular movements are not limited in any direction. 3. Refractive error may or may not be associated. +4. Suppression and amblyopia may develop as sensory adaptation to strabismus. Suppression may be monocular (in monocular squint) and alternating (in alternating strabismus). Amblyopia develops in monocular strabismus only and is responsible for poor visual acuity. +5. A-V patterns may be observed in horizontal strabismus. When A-V patterns are associated, the horizontal concomitant strabismus becomes vertically incomitant (see page 357). +Types of concomitant squint +Three common types of concomitant squint are: 1. Convergent squint (esotropia), +2. Divergent squint (exotropia), and 3. Vertical squint (hypertropia). + + +CONVERGENT SQUINT +Concomitant convergent squint or esotropia denotes inward deviation of one eye (Fig. 14.14) and is the most common type of squint in children. It can be unilateral (the same eye always deviates inwards and the second normal eye takes fixation) or alternating (either of the eyes deviates inwards and the other eye takes up fixation, alternately). +Clinico-etiological types +Depending upon the clinico-etiological features convergent concomitant squint can be further classified into following types: +1. Infantile esotropia +Clinical features.Infantile esotropia, previously called as congenital esotropia, is characterised by following features (Fig. 14.14): +• Age of onset, is usually 1–2 months of age, but may occur any time in first 6 months of life. +• Angle of deviation is usually constant and fairly large (>30°). +• Fixation pattern. Binocular vision does not develop and there is alternate fixation in primary gaze and cross fixation in the lateral gaze. +• Amblyopia develops in 25–40% cases. +• Associations include inferior oblique overaction (usually developing after 1 year of age),dissociated vertical deviation (DVD) in about 70–90% cases, and latent horizontal nystagmus. +Treatment. Surgery is the treatment of choice. +• Amblyopia treatment by patching the normal eye should always be done before performing the surgery. +• Recession of both medial recti is preferred over unilateral recess-resect procedure. +• Time of surgery. Surgery should be done between 6 months to 2 years (preferably before 1 year of age). + + + + + + + + + + + + + +Fig. 14.14 Concomitant convergent squint (infantile esotropia) +Chapter 14 Disorders of Ocular Motility 349 + + +2. Accommodative esotropia +It occurs due to overaction of convergence associated with accommodation reflex. Accommodative esotropia is the most common type of squint in children (previously it was believed that congenital esotropia was most common). When esotropia develops around 2–3 years of age, it is most likely accommodative. It is of three types: refractive, nonrefractive and mixed. +i. Refractive accommodative esotropia: It usually develops at the age of 2 to 3 years and is associated with high hypermetropia (+4 to +7 D). Mostly it is for near and distance (marginally more for near) and fully correctable by use of spectacles (Fig. 14.15). +ii. Non-refractive accommodative esotropia: It is caused by abnormal AC/A (accommodative convergence/accommodation) ratio. This may occur even in patients with no refractive error. Esotropia is greater for near than that for distance (minimal or no deviation for distance). It is fully corrected by bifocal glasses with add +3 DS for near vision. Miotics may be useful in younger children not suitable for bifocals. Miotics facilitate accommodation and thus reduce the accommodative convergence. +iii. Mixed accommodative esotropia: It is caused by combination of hypermetropia and high AC/A ratio. Esotropia for distance is corrected by correction of hypermetropia; and the residual esotropia for near is corrected by an addition of +3 DS lens. + + + + + + + + + + +A + +3. Acquired Non-accommodative esotropias +This group includes all those acquired primary esodeviations in which amount of deviation is not affected by the state of accommodation. It includes: i. Essential acquired or late onset esotropia, acute concomitant esotropia, cyclic esotropia, nystagmus blockage syndrome, esotropia in myopia and microtropia. +ii. Essential acquired or late onset esotropia. It is a common variety of concomitant convergent squint. It typically occurs during first few years of life any time after six months of age. It is of three types: +• Basic type. In it the deviation is usually equal at distance and near. +• Convergence excess type. In it the deviation is large for near and small or no deviation for distance. +• Divergence insufficiency type. It is characterised by a greater deviation for distance than near. +Treatment includes early surgery after correction of the associated refractive error and amblyopia. +4. Sensory esotropia +It results from monocular lesions (in childhood) which either prevent the development of normal binocular vision or interfere with its maintenance. Examples of such lesions are: cataract, severe congenital ptosis, aphakia, anisometropia, optic atrophy, retinoblastoma, central chorioretinits, and so on. +5. Consecutive esotropia +It results from surgical overcorrection of exotropia. +DIVERGENT SQUINT +Concomitant divergent squint (exotropia) is characterised by outward deviation of one eye while the other eye fixates. +Clinico-etiological types +It can be classified into following clinico-etiological types: +1. Congenital exotropia +It is rare and almost always present at birth. It is characterised by a fairly large angle of squint, usually alternate with homonymous fixation in lateral gaze, and no amblyopia. + + + + + + + + + +B +Fig. 14.15 (A) Accommodative esotropia, (B) fully corrected by spectacles + +2. Primary exotropia +It may be unilateral or alternating and may present as intermittent or constant exotropia. +Intermittent exotropia. It is the most common type of exodeviation with following features: +• Age of onset is usually early between 2 to 5 years. • Deviation becomes manifest at times and latent at +others. Precipitating factors include bright light, fatigue, ill health and day dreaming. +350 Section III Diseases of Eye + + +• Sensory testing usually reveals good fusion, stereopsis and no amblyopia. +Constant exotropia. If not treated in time the intermittent exotropia may decompensate to become constant exotropia (Fig. 14.16). +Types. Primary exotropia may be of following three types: +• Convergence insufficiency type of exotropia is greater for near than distance, +• Divergence excess type of exotropia is greater for distance than near, or +• Basic non-specific type exotropia is equal for near and distance. +3. Secondary (sensory deprivation) exotropia +It is a constant unilateral deviation which results from long-standing monocular lesions (in adults), associated with low vision in the affected eye. Common causes include: traumatic cataract, corneal opacity, optic atrophy, anisometropic amblyopia, retinal detachment and organic macular lesions. +4. Consecutive exotropia +It is a constant unilateral exotropia which results either due to surgical overcorrection of esotropia, or spontaneous conversion of small degree esotropia with amblyopia into exotropia. +EVALUATION OF A CASE OF CONCOMITANT STRABISMUS +I. History +A meticulous history is very important. It should include: age of onset, duration, mode of onset (sudden or gradual), any illness preceding squint (fever, trauma, infections, etc.), intermittent or constant, unilateral or alternating, history of diplopia, family history of squint, history of head tilt or turn and so on. +II. Examination +1. Inspection. Large degree squint (convergent or divergent) is obvious on inspection. +2. Ocular movements. Both uniocular as well as binocular movements should be tested in all the cardinal positions of gaze. + + + + + + + + + + +Fig. 14.16 A patient with primary exotropia + +3. Pupillary reactions. These may be abnormal in patients with secondary deviations due to diseases of retina and optic nerve. +4. Media and fundus examination. It may reveal associated disease of ocular media, retina or optic nerve. +5. Testing of vision and refractive error. It is most important, because a refractive error may be responsible for the symptoms of the patient or for the deviation itself. Preferably, refraction should be performed under full cycloplegia, especially in children. +6. Cover tests +i. Direct cover test (Fig. 14.17). It confirms the presence of manifest squint. To perform it, the patient is asked to fixate on a point light. Then, the normal looking eye is covered while observing the movement of the uncovered eye. In the presence of squint, the uncovered eye will move in opposite direction to take fixation, while in apparent squint there will be no movement. This test should be performed for near fixation (i.e., at 33 cm) as well as distance fixation (i.e., at 6 metres). +ii. Alternate cover test. It reveals whether the squint is unilateral or alternate and also differentiates concomitant squint from paralytic squint (where secondary deviation is greater than primary). +7. Estimation of angle of deviation +i. Hirschberg corneal reflex test. It is a rough but handy method to estimate the angle of manifest squint. In it the patient is asked to fixate at point + + + + + + + + + + + + + + + + + + + + +Fig. 14.17 Direct cover test depicting left exotropia +Chapter 14 Disorders of Ocular Motility 351 + + +light held at a distance of 33 cm and the deviation of the corneal light reflex from the centre of pupil is noted in the squinting eye. Roughly, the angle of squint is 15° and 45° when the corneal light reflex falls on the border of pupil and limbus, respectively (Fig. 14.18). +ii. The prism and cover test (prism bar cover test i.e., PBCT). Prisms of increasing strength with apex towards the deviation are placed in front of one eye and the patient is asked to fixate an object with the other. The cover-uncover test is performed till there is no recovery movement of the eye under cover. This will tell the amount of deviation in prism dioptres. Both heterophoria as well as heterotropia can be measured by this test. +iii. Krimsky corneal reflex test.In this test, the patient is asked to fixate on a point light and prisms of increasing power (with apex towards the direction of manifest squint) are placed in front of the normal fixating eye till the corneal light reflex is centred in the squinting eye. The power of prism required to centre the light reflex in the squinting eye equals the amount of squint in prism dioptres. +iv. Measurement of deviation with synoptophore. All types of heterophorias and heterotropias (both objective and subjective angle of squint) can be measured accurately with it. In addition, many other tests can also be performed with this instrument (for details see page 352). +8.Tests for grade of binocular vision and sensory functions. Normal binocular single vision consists of three grades. Sensory anomalies include disturbances of binocular vision, eccentric fixation, suppression, amblyopia, abnormal retinal correspondence and diplopia. A few common tests for sensory functions are as follows: +i. Worth’s four-dot test. For this test, patient wears goggles with red lens in front of the right and green lens in front of the left eye and views a box with four lights—one red, two green and one white (Fig. 14.19). + + + + + + + + + + + + +Fig. 14.18 Hirschberg corneal reflex test + + +Interpretation +• In normal binocular single vision, the patient sees all the four lights in the absence of manifest squint (Fig. 14.19A). +• Inabnormal retinal correspondence (ARC) patient sees four lights even in the presence of a manifest squint (Fig. 14.19B). +• In left suppression the patient sees only two red lights, (Fig. 14.19C). +• In right suppression the patient sees only three green lights, (Fig. 14.19D). +• In alternating suppression the patient sees three green lights and two red lights, alternately. +• In diplopia the patient sees five lights (2 red and 3 green) (Fig. 14.19E). +ii. Tests for fixation. It can be tested with the help of a visuoscope or fixation star of the ophthalmoscope. Patient is asked to cover one eye and fix the star with the other eye. Fixation may be centric (normal on the fovea) or eccentric (which may be unsteady, parafoveal, macular, paramacular, or peripheral (Fig. 14.20). +iii. After-image test. In this test the right fovea is stimulated with a vertical and left with a horizontal bright light and the patient is asked to draw the position of after-images. +Interpretation +• A patient with normal retinal correspondence will draw a cross (Fig. 14.21A). +• An esotropic patient with abnormal retinal correspondence (ARC) will draw vertical image to the left of horizontal (Fig. 14.21B). + + + + + + + + + + + + + + + + + + + + + + +Fig. 14.19 Worth’s four-dot test +352 Section III Diseases of Eye + + + + + + + + + + + + + + + +Fig. 14.20 Types of fixation Fig. 14.22 Synoptophore + + + + + + + + +Fig. 14.21 After-image test: A, normal retinal corres-pondence; B, esotropia with ARC; C, exotropia with ARC + + +• An exotropic patient with ARC will draw vertical image to the right of horizontal (Fig. 14.21C). +iv. Sensory function tests with synoptophore. Synoptophore (major amblyoscope) consists of two tubes, having a right-angled bend, mounted on a base (Fig. 14.22). Each tube contains a light source for illumination of slides and a slide carrier at the outer end, a reflecting mirror at the right-angled bend and an eyepiece of +6.5 D at the inner end (Fig. 14.23). The two tubes can be moved separately or together by means of knobs around a semicircular scale. Synoptophore is used for many diagnostic and therapeutic indications in orthoptics. Synoptophore tests for sensory functions include: ■Estimation of grades of binocular vision (see page 341). ■Detection of normal/abnormal retinal corres-pondence (ARC).It is done by determining the subjective and objective angles of the squint. In normal retinal correspondence, these two angles are equal. In ARC, objective angle is greater than the subjective angle and the difference between these is called the angle of anomaly. When the angle of anomaly is equal to the objective angle, the ARC is harmonious. In unharmonious ARC angle of anomaly is smaller than the objective angle. +v. Neutral density filter test. In this test, visual acuity is measured without and with neutral density filter placed in front of the eye. In cases with functional + + + + + + + + +Fig. 14.23 Optical principle of synoptophore + + + +amblyopia visual acuity slightly improves while in organic amblyopia it is markedly reduced when seen through the filter. +TREATMENT OF CONCOMITANT STRABISMUS Goals of treatment are: +• To achieve good cosmetic correction, • To improve visual acuity, and +• To maintain binocular single vision. +However, many time it is not possible to achieve all the goals in every case. + +Treatment modalities. These include the following: +1. Spectacles with full correction of refractive error should be prescribed in every case. It will improve the visual acuity and at times may correct the squint partially or completely (as in accommodative squint). +Chapter 14 Disorders of Ocular Motility 353 + + +2. Occlusion therapy. It is indicated in the presence of amblyopia. After correcting the refractive error, the normal eye is occluded and the patient is advised to use the squinting eye. Regular follow-ups are done in squint clinic. Occlusion helps to improve the vision in children below the age of 10 years. (For occlusion regimen see page 343). +3. Preoperative orthoptic exercises. These are given after the correction of amblyopia to overcome suppression. +4. Squint surgery. It is required in most of the cases to correct the deviation. However, it should always be instituted after the correction of refractive error, treatment of amblyopia and orthoptic exercises. ■Basic principles of squint surgery.These are to weaken the strong muscle by recession (shifting the insertion posteriorly) or to strengthen the weak muscle by resection (shortening the muscle). ■Type and amount of muscle surgery. It depends upon the type and angle of squint, age of patient, duration of the squint and the visual status. Therefore, degree of correction versus amount of extraocular muscle manipulation required cannot be mathematically determined. However, roughly 1 mm resection of medial rectus (MR) will correct about 1°–1.5° and 1 mm recession will correct about 2°–2.5°. While l mm resection and recession of lateral rectus (LR) muscle will correct 1°–2°. The maximum limit allowed for MR resection is 8 mm and recession is 5.5 mm. The corresponding figures for LR muscle are 10 mm and 8 mm, respectively. +5. Postoperative orthoptic exercises. These are required to improve fusional range and maintain binocular single vision. + +INCOMITANT SQUINT + +It is a type of heterotropia (manifest squint) in which the amount of deviation varies in different directions of gaze. It includes following conditions: +1. Paralytic squint, +2. ‘A’ and ‘V’ pattern heterotropias, and 3. Restrictive squint. +PARALYTIC STRABISMUS +It refers to ocular deviation resulting from complete or incomplete paralysis of one or more extraocular muscles. +Etiology +The lesions may be neurogenic, myogenic or at the level of neuromuscular junction. + + +I. Neurogenic lesions +Neurogenic lesions may occur at the level of nerve nucleus, nerve root, or any part of the nerve in its course. Nuclear ophthalmoplegia refers to paralysis of extraocular muscles due to lesions of 3rd cranial nerve. They are more often bilateral. +Common causes of neurogenic lesions are: +1. Congenital. Hypoplasia or absence of nucleus is a known cause of third and sixth cranial nerve palsies. Birth injuries may mimic congenital lesions. +2. Inflammatory lesions. These may be in the form of encephalitis, meningitis, neurosyphilis or peripheral neuritis (commonly viral). Nerve trunks may also be involved in the infectious lesions of cavernous sinus and orbit. +3. Neoplastic lesions. These include brain tumours involving nuclei, nerve roots or intracranial part of the nerves; and intraorbital tumours involving peripheral parts of the nerves. +4. Vascular lesions. These are known in patients with hypertension, diabetes mellitus and athero-sclerosis.These may be in the form of haemorrhage, thrombosis, embolism, aneurysms or vascular occlusions. Cerebrovascular accidents are more common in elderly people. Ophthalmoplegic migraine or episodic ophthalmoplegia is a well known vascular condition characterized by recurrent attacks of headache associated with paralysis of 3rd (most common), 4th or 6th cranial nerve. The condition is often unilateral, persists for days or weeks and even tends to become permanent, in some cases. +5. Traumatic lesions. These include head injury and direct or indirect trauma to the nerve trunks. Head injury is common cause of 6th nerve palsy. +6. Toxic lesions. These include carbon monoxide poisoning, effects of diphtheria toxins (rarely), alcoholic and lead neuropathy. +7. Demyelinating lesions. Ocular palsy may occur in multiple sclerosis and diffuse sclerosis. +II. Myogenic lesions +1. Congenital lesions. These include absence, hypoplasia, malinsertion, weakness and musculo-facial anomalies. +2. Traumatic lesions. These may be in the form of laceration, disinsertion, haemorrhage into the muscle substance or sheath and incarceration of muscles in blow out fractures of the orbital walls (floor or medial wall). +354 Section III Diseases of Eye + + +3. Inflammatory lesions. Myositis is usually viral in origin and may occur in influenza, measles and other viral fevers. +4. Myopathies. These include thyroid myopathy, carcinomatous myopathy and that associated with certain drugs. Chronic progressive ophth-almoplegia (CPO) is a bilateral myopathy of extraocular muscles; which may be sporadic or inherited as an autosomal dominant disorder. It is the most common (75% cases) type of mitochondrial myopathy. It is characterised by: +• Bilateral ptosis with slowly progressive ophth-almoplegia is typical presentation. +• Diplopia is usually not a complaint since all eye movements are reduced equally. +• Other associated symptoms of CPO include exercise intolerance, hearing loss, ataxia, sensory axonal neuropathy, parkinsonism, and clinical depression. + +III. Neuromuscular junction lesion +It includes myasthenia gravis. The disease is characterised primarily by fatigue of muscle groups, usually starting with the small extraocular muscles, before involving other large muscles. +Clinical features +Symptoms +1. Diplopia. It is the main symptom of paralytic squint. It is more marked in the field of action of paralysed muscle. It may be crossed (in divergent squint) or uncrossed (in convergent squint). It may be horizontal, vertical or oblique depending on the muscle paralysed. Diplopia occurs due to formation of image on dissimilar points of the two retinae (Fig. 14.24). The false image (seen by the squinting eye) is less distinct than the true image (seen by the other eye). +2. Confusion. It occurs due to formation of image of two different objects on the corresponding points of two retinae. +3. Nausea and vertigo. These result from diplopia and confusion and may cause vomiting also. +4. Ocular deviation is typically a sudden onset. +Signs +1. Primary deviation. It is deviation of the affected eye and is away from the action of paralysed muscle, e.g., if lateral rectus is paralysed the eye is converged. Angle of deviation varies in different directions of gaze (incomitant). +2. Secondary deviation. It is deviation of the normal eye seen under cover, when the patient is made to fix with the squinting eye. It is greater than the primary deviation. This is due to the fact that the strong + + + + + + + + + + + + + + + + + + + + +Fig. 14.24 Diplopia + + +impulse of innervation required to enable the eye with paralysed muscle to fix is also transmitted to the yoke muscle of the sound eye resulting in a greater amount of deviation. This is based on Hering’s law of equal innervation of yoke muscles. +3. Restriction of ocular movement. It occurs in the direction of the action of paralysed muscles. +4. Compensatory head posture. It is adopted to avoid diplopia and confusion. Head is turned towards the direction of action of the paralysed muscle, e.g., if the right lateral rectus is paralysed, patient will keep the head turned towards right. Ocular torticollis refers to tilting of head and chin depression occurring to compensate for the vertical diplopia. It needs to be differentiated from the true torticollis occurring due to undue contracture of sternocleidomastoid muscle. 5. False projection or orientation. It is due to increased innervational impulse conveyed to the paralysed muscle. It can be demonstratedby asking the patient to close the sound eye and then to fix an object placed on the side of paralysed muscle. Patient will locate it further away in the same direction. For example, a patient with paralysis of right lateral rectus will point towards right more than the object actually is. +Note. Visual acuity is normal and there is no amblyopia as usually the paralytic squint develops in adults when visual acuity has already developed. However, if it occurs in children below 6 years than amblyopia can occur. +Pathological sequelae of an extraocular muscle palsy In all cases of extraocular muscle palsy, certain sequelae take place after some time. These occur +Chapter 14 Disorders of Ocular Motility 355 + + +more in paralysis due to lesions of the nerves than the lesions of muscles. These include: +1. Overaction of the contralateral synergistic muscle. 2. Contracture of the direct antagonist muscle. +3. Secondary inhibitional palsy of the contralateral antagonist muscle. +For example, in paralysis of the right lateral rectus muscle there occurs (Fig 14.25): +■Overaction of the left medial rectus, ■Contracture of the right medial rectus and ■Inhibitional palsy of the left lateral rectus muscle. +Clinical varieties of ocular palsies +1. Isolated muscle paralysis. Lateral rectus and superior oblique are the most common muscles to be paralysed singly, as they have separate nerve supply. Isolated paralysis of the remaining four muscles is less common, except in congenital lesions. +2. Paralysis of the third cranial nerve. It is of common occurrence. It may be congenital or acquired. Clinical features of third nerve palsy (Figs. 14.26A and B) include: +• Ptosis due to paralysis of the LPS muscle. +• Deviation. Eyeball is turned down, out and slightly intorted due to actions of the lateral rectus and superior oblique muscles. +• Ocular movements are restricted in all the directions except outward. +• Pupil is fixed and dilated due to paralysis of the sphincter pupillae muscle. +• Accommodation is completely lost due to paralysis of the ciliary muscle. +• Crossed diplopia is elicited on raising the eyelid. • Head posture may be changed if pupillary area +remains uncovered. +3. Double elevator palsy, also known as monocular elevation deficiency is a congenital condition caused by third nerve nuclear lesion. It is characterised by paresis of the superior rectus and the inferior oblique muscle of the involved eye. + + + + + + + + + + + +Fig. 14.25 Pathological sequelae of the right lateral rectus muscle paralysis + + + + + + + + + + + +A + + + + + + + + + + + +B +Fig. 14.26 A patient with third cranial nerve paralysis showing: A, ptosis; B, divergent squint + +4. Total ophthalmoplegia. In this condition, all extraocular muscles including LPS and intraocular muscles, viz., sphincter pupillae, and ciliary muscle are paralysed. It results from combined paralysis of third, fourth and sixth cranial nerves. It is a common feature of orbital apex syndrome and cavernous sinus thrombosis. +5. External ophthalmoplegia. In this condition, all extraocular muscles are paralysed, sparing the intraocular muscles. It results from lesions at the level of motor nuclei sparing the Edinger-Westphal nucleus. +6. Internuclear ophthalmoplegia. In this condition, there is lesion of the medial longitudinal fasciculus (MLF). It is the pathway by which various ocular motor nuclei are linked. Internuclear ophthalmoplegia is characterised by: defective action of medial rectus on the side of lesion, horizontal nystagmus of the opposite convergence is normal, as the pathway of convergence runs directly into the midbrain without involving the MLF. +Investigations of a case of paralytic squint +A. Evaluation for squint +Every case of squint should be evaluated utilising the tests described on page 350-352. Additional tests required for a case of paralytic squint are: +356 Section III Diseases of Eye + + +1. Diplopia charting. It is indicated in patients complaining of confusion or double vision. In it patient is asked to wear red and green diplopia charting glasses. Red glass being in front of the right eye and green in front of the left. Then in a semi-dark room, he is shown a fine linear light from a distance of 4 ft. and asked to comment on the images in primary position and in other positions of gaze. Patient tells about the position and the separation of the two images in different fields. Fig. 14.27 shows diplopia charting in a patient with right lateral rectus palsy. 2. Hess screen test. Hess screen/Lees screen (Fig. 14.28) test tells about the paralysed muscles and + + + + + + + + + + + + + + + + + + +Fig. 14.27 Diplopia chart of a patient with right lateral rectus palsy + + + + + + + + + + + + + + + + + + + + +Fig. 14.28 Hess screen + + + + + + + + + + +Fig. 14.29 Hess chart in right lateral rectus palsy + + +the pathological sequelae of the paralysis, viz., overaction, contracture and secondary inhibitional palsy. The two charts are compared. The smaller chart belongs to the eye with paretic muscle and the larger to the eye with overacting muscle (Fig. 14.29). 3. Field of binocular fixation. It should be tested in patients with paralytic squint where applicable, i.e., if patient has some field of single vision. This test is performed on the perimeter using a central chin rest. 4. Forced duction test (FDT). It is performed to differentiate between the incomitant squint due to paralysis of extraocular muscle and that due to mechanical restriction of the ocular movements. FDT is positive (resistance encountered during passive rotation) in cases of incomitant squint due to mechanical restriction and negative in cases of extraocular muscle palsy. +B. Investigations to find out the cause of paralysis These include orbital ultrasonography, orbital and skull computerised tomography scanning and neurological investigations. +Paralytic vs. Non-paralytic squint +Differences between paralytic and non-paralytic squint are depicted in Table 14.2. +Management +1. Treatment of the cause. An exhaustive investigative work-up should be done to find out the cause and, if possible, treat it. +2. Conservative measures. These include: wait and watch for self-improvement to occur for a period of 6 months, vitamin B-complex as neurotonic; and systemic steroids for non-specific inflammations. +3. Treatment of annoying diplopia. It includes use of occluder on the affected eye, with intermittent use of both eyes with changed headposture to avoid suppression amblyopia. +4. Chemodenervation of the contralateral muscle with botulinum toxin may be useful during the recovery period. +Chapter 14 Disorders of Ocular Motility 357 + +Table 14.2: Differences between paralytic and non-paralytic squint + + +Features 1. Onset +2. Diplopia +3. Ocular movements 4. False projection + + +5. Head posture + +6. Nausea and vertigo 7. Secondary deviation + +8. In old cases pathological sequelae in the muscles + +Paralytic squint Usually sudden Usually present +Limited in the direction of action of paralysed muscle +It is positive i.e., patient cannot correctly locate the object in space when asked to see in the direction of paralysed muscle in early stages. +A particular head posture depending upon the muscle paralysed may be present. +Present +More than the primary deviation + +Present + +Nonparalytic squint Usually slow +Usually absent Full +False projection is negative + +Normal + +Absent +Equal to primary deviation +Absent + + + + +5. Surgical treatment. It should be carried out in case the recovery does not occur in 6 months. Aim of treatment is to provide a comfortable field of binocular fixation, i.e., in central field and lower quadrants. The principles of surgical treatment involve strengthening of the paralysed muscle by resection; weakening of the overacting muscle by recession, and transplantation of normal muscle tendon at or near the insertion of paralysed muscle. +‘A’ AND‘V’ PATTERN HETEROTROPIA + +Terminology +The terms ‘A’ or ‘V’ pattern squint are labeled when the amount of deviation in squinting eye varies by more than 10° and 15°, respectively, between upward and downward gaze. +‘A’ and ‘V’ esotropia. In ‘A’ esotropia the amount of deviation increases in upward gaze and decreases in downward gaze. The reverse occurs in ‘V’ esotropia. ‘A’ and ‘V’ exotropia. In ‘A’ exotropia the amount of deviation decreases in upward gaze and increases in downward gaze. The reverse occurs in ‘V’ exotropia. +Etiology +■Oblique muscle dysfunction is the commonest cause of AV pattern. +■Other causes include horizontal rectus muscle dysfunction, vertical muscle dysfunction and certain orbital factors. +Clinical presentations +A and V pattern heterotropia essentially refers to vertically incomitant horizontal strabismus. Thus, the horizontally comitant esotropias and exotropias + +(described on page 347-350) may be associated with A or V patterns. +Treatment +Surgical treatment consists of correction of horizontal deviation along with: +• Weakening of overacting oblique muscle, inferior oblique for V pattern and superior oblique for A pattern. +• Transpositioning of horizontal rectus muscles is to be considered when there is no associated overaction of the oblique muscle. As shown in Fig. 14.29, Medial recti are transposed toward Apex of A or V (pattern) and Lateral recti toward Empty space (to remember mnemonic is MALE). +RESTRICTIVE SQUINT +In restrictive squint, the extraocular muscle is not paralysed but its movement is mechanically restricted. +Characteristic features of restrictive squints are: +• Smaller ocular deviation in primary position in proportion to the limitation of movement and +• Positive forced duction test (i.e., a restriction is encountered on passive rotation) (see page 356). +Common causes of restrictive squint are: • Duane’s retraction syndrome, +• Brown’s superior oblique tendon sheath syndrome, • Strabismus fixus, +• Dysthyroid ophthalmopathy (see page 414), and • Incarceration of extraocular muscle in blow-out +fracture of the orbit (see page 422). + +1. Duane’s retraction syndrome +Duane’s retraction syndrome is a congenital ocular motility defect occurring due to paradoxical +358 Section III Diseases of Eye + + +innervation of lateral or medial or both rectus muscles. +Characteristics features are: +• Limitation of abduction (type I DRS) or adduction (type II DRS) or both (type III DRS). +• Retraction of the globe and narrowing of the palpebral fissure on attempted adduction and widening of the palpebral fissure on attempted abduction. +• Eye in the primary position may be orthotropic, esotropic or exotropic. +2. Brown’s superior oblique tendon sheath syndrome +It is a congenital ocular motility defect due to fibrous tightening of the superior oblique tendon. It is characterized by limitation of elevation of the eye in adduction (normal elevation in abduction), usually straight eyes in primary position and positive forced duction test on attempts to elevate eye in adduction. +3. Strabismus fixus +It is a rare condition characterised by bilateral fixation of eyes in convergent position due to fibrous tightening of the medial recti. +STRABISMUS SURGERY +Surgical techniques +1. Muscle weakening procedures include recession, marginal myotomy and myectomy. +2. Muscle strengthening procedures are resection, tucking and advancement. +3. Procedures that change direction of muscle action. These include: +• Vertical transposition of horizontal recti to correct ‘A’ and ‘V’ patterns, +• Posterior fixation suture (Faden operation) to correct dissociated vertical deviation, and +• Transplantation of muscles in paralytic squints. + +Steps of recession (Fig. 14.30) +1. Muscle is exposed by reflecting a flap of overlying conjunctiva and Tenon’s capsule. +2. Two vicryl sutures are passed through the outer quarters of the muscle tendon near the insertion. +3. The muscle tendon is disinserted from the sclera with the help of tenotomy scissors. +4. The amount of recession is measured with the callipers and marked on the sclera. +5. The muscle tendon is sutured with the sclera at the marked site posterior to original insertion. +6. Conjunctival flap is sutured back. + + + + + + + + + + + + + + + + + + +Fig. 14.30 Technique of recession + +Steps of resection (Fig. 14.31) +1. Muscle is exposed as for recession and the amount to be resected is measured with callipers and marked. +2. Two absorbable sutures are passed through the outer quarters of the muscles at the marked site. +3. The muscle tendon is disinserted from the sclera and the portion of the muscle anterior to sutures is excised. +4. The muscle stump is sutured with the sclera at the original insertion site. +5. Conjunctival flap is sutured back. + +NYSTAGMUS + +DEFINITION AND FEATURES +Nystagmus is defined as regular and rhythmic to-and-fro involuntary oscillatory movements of the + + + + + + + + + + + + + + + + + +Fig. 14.31 Technique of resection +Chapter 14 Disorders of Ocular Motility 359 + + +eyes. It may be characterised by any of the following features: +1. It may be pendular or jerk nystagmus. In pendularnystagmus movements are of equal velocity in each direction. It may be horizontal, vertical or rotatory. In jerk nystagmus, the move-ments have a slow component in one direction and a fast component in the other direction. The direction of jerk nystagmus is defined by direction of the fast component (phase). It may be right, left, up, down or rotatory. +2. Nystagmus movements may be rapid or slow. 3. The movements may be fine or coarse. +4. Nystagmus may be latent or manifest. + +PATHOGENESIS AND CLASSIFICATION Nystagmus occurs due to disturbance of the factors responsible for maintaining normal ocular posture. These include disorders of sensory visual pathway, vestibular apparatus, semicircular canals, midbrain and cerebellum. +Many classifications are in vogue for nystagmus. A simple classification modified from “Classification of Eye Movements Abnormalities and Strabismus (CEMAS)” is as below: +Physiological nystagmus • Optokinetic nystagmus • Endpoint nystagmus +• Physiological vestibular nystagmus. + +Pathological nystagmus Nystagmus of infancy +• Infantile nystagmus syndrome (INS) +• Fusion maldevelopment nystagmus syndrome (FMNS) +• Spasmus nutans syndrome (SNS) Acquired nystagmus +• Nystagmus due to disorders of visual fixation • Nystagmus caused by vestibular imbalance +• Acquired pendular nystagmus. + +A. Physiological Nystagmus +Physiological nystagmus occurs normally in a variety of situations including optokinetic nystagmus (OKN), end gaze nystagmus (EGN) and physiological vestibular nystagmus (vestibulo-ocular reflex i.e., VOR) +1. Optokinetic nystagmus. It is a physiological jerk nystagmus induced by presenting to gaze the objects moving serially in one direction, such as strips of a spinning optokinetic drum. The eyes will follow a fixed strip momentarily and then jerk back to reposition centrally to fix up a new strip. Similar condition occurs while looking at outside things from a moving train. + +2. End-gaze nystagmus. It is a fine jerk horizontal nystagmus seen in normal persons on extreme right or left gaze. +3. Physiological vestibular nystagmus(vestibulo-ocular reflex i.e., VOR). It is a jerk nystagmus which can be elicited by stimulating the tympanic membrane with hot or cold water. It forms the basis of caloric test. If cold water is poured into right ear the patient develops left jerk nystagmus (rapid phase towards left), while the reverse happens with warm water, i.e., patient develops right jerk nystagmus. It can be remembered by the mnemonic ‘COWS’ (Cold-Opposite, Warm-Same). + +B. Pathological Nystagmus +I. Nystagmus of infancy +Three most common forms of nystagmus seen in childhood begin in infancy and therefore, are not congenital as believed earlier. These include: +• Infantile nystagmus syndrome, +• Fusion maldevelopment nystagmus syndrome, and • Spasmus nutans syndrome. +1. Infantile nystagmus syndrome is the new name given in the CEMAS system for the old congenital, motor and sensory nystagmus. +Etiology. It may be (I) Idiopathic or (II) Associated with sensory deprivation due to any of the following causes: +• Ocular albinism, • Aniridia, and +• Leber’s congenital amaurosis. +• Other causes include, bilateral congenital cataract, achromatopsia, congenital stationary night blindness, bilateral optic nerve hypoplasia, bilateral congenital toxoplasmosis and bilateral macular hypoplasia. +Characteristic features. It is characterized by erratic waveform with or without roving eye movements associated with reduced visual acuity due to above mentioned conditions. +CEMAS criteria for INS includes: • Infantile onset, +• Ocular motor recordings show accelerating slow phases (diagnostic) +• Wave forms may change in early infancy, +• Head posture usually evident by 4 years of age. +• Vision prognosis dependent on integrity of sensory system. +Common associated findings: +• Progression from pendular to jerk, • Family history often positive, +• Null and neutral zones present, and +360 Section III Diseases of Eye + + +• May decrease with induced convergence, increased fusion, extraocular muscle surgery, contact lenses, and sedation. +2. Fusion maldevelopment nystagmus syndrome (FMNS) is the new name for the old term-‘latent/ latent manifest nystagmus’ as described in CEMAS. +Characteristic features are: • Infantile onset +• Associated strabismus. May be associated with congenital esotropia and dissociated vertical deviation (DVD). +• Intensity decrease with age +• Nystagmus is not present, when both eyes are open. It appears when one eye is covered. Becomes manifest under monocular viewing conditions, i.e., in the presence of decreased vision in one eye as in anisometropic amblyopia, strabismic amblyopia, etc. +• It is a jerk nystagmus with rapid phase towards the uncovered eye. Low–amplitude pendular nystagmus (dual-jerk waveform), jerk in direction of fixing eye. +Note. While testing visual acuity in such patients, one eye should be fogged (by adding plus lenses in front) rather than occluding to minimize induction of latent nystagmus. +3. Spasmus Nutans syndrome (SNS) is the 3rd most common nystagmus seen in infancy. +Characteristic features include: • Infantile onset +• Abnormal head posture and head oscillation which improve (disappears) during childhood. Usually spontaneously remits clinically in 2 to 8 years, remains present with eye movement recordings. +• Normal MRI/CT scan of visual pathways. +• Ocular motility recordings-high-frequency (>10 Hz), asymmetric, variable conjugacy, pendular oscillations, small-frequency, low-amplitude oscillation. +II. Acquired nystagmus +Late onset or acquired nystagmus is usually characterized by oscillopsia, and is often associated with other neurological abnormalities. Acquired nystagmus includes: +i. Nystagmus due to disorders of visual fixation. Also called as ‘Vision loss nystagmus’ may occur due to diseases affecting any part of the visual system from retina to visual cortex or conditions interrupting visual projection to the pons and cerebellum as below: +• Nystagmus in diseases of the retina. +• Nystagmus in diseases of the optic nerve. + +• Nystagmus in diseases affecting the optic chiasma. • Nystagmus in diseases affecting the postchiasmal +visual system. +ii. Nystagmus caused by vestibular imbalance + +a. Peripheral vestibular nystagmus +Features. Conjugate horizontal jerk nystagmus with fast phase away from the side of lesion. Nystagmus improves with fixation and worsens with gaze towards fast phase. +Causes. It is associated with destructive lesions of vestibular system such as labyrinthitis and vestibular neuritis. +b. Central vestibular nystagmus It may be of the following types: +1. Up beat nystagmus. In primary position of gaze, the fast component is upward. It is usually seen in lesions of central tegmentum of brainstem. +2. Down beat nystagmus. In primary position of gaze the fast component is downward. It is usually associated with posterior fossa diseases and is typical of compression at the level of foramen magnum. It is a common feature of cerebellar lesions and Arnold Chiari syndrome. +Causes. It is usually associated with brainstem and cerebellar diseases. +3. See-saw nystagmus +Features. In it, one eye rises up and intorts, while other shifts down and extorts. +Causes.It is usually associated with upper brainstem lesions. +4. Periodic alternating nystagmus +Features. Conjugate, horizontal jerk nystagmus present in the primary gaze characterized by spontaneous direction changes every 60–90 seconds, with 10-15 second gap or null period, i.e., period of no nystagmus. +Causes. It occurs usually due to vestibulo-cerebellar diseases such as demyelination and Arnold Chiari malformation. It may also be associated with cervicomedullary junction lesions. +iii. Nystagmus due to disorders of gaze holding +1. Gaze-evoked nystagmus +Features. Slow, conjugate horizontal jerk nystagmus in the direction of gaze (no nystagmus in primary gaze). It occurs at smaller angles than physiological end-gaze nystagmus, i.e., around 45° movement. Causes. It may occur due to: +• Neurological lesions of brainstem and posterior fossa, and +• CNS depression caused by certain drugs such as alcohol, anticonvulsants, and barbiturates. +Chapter 14 Disorders of Ocular Motility 361 + + +2. Dissociated or disconjugate nystagmus (Ataxic nystagmus) +Features. It is special type of pathologic gaze evoked nystagmus which is unilateral or asymmetric nystagmus usually of the abducting and occasionally of the adducting eye. +Causes. It commonly occurs with internuclear ophthalmoplegia (INO) +3. Convergence retraction syndrome +Features. It is a jerk nystagmus with bilateral fast component towards the medial side. It is associated with retraction of the globe in convergence. +Causes. Classically associated with pinealoma, but may also occur with other neoplasms, stroke, trauma or multiple sclerosis. +4. Brun’s nystagmus. +Tumours in the cerebello-pontine angle, produce a low-frequency, large amplitude nystagmus, when the patient looks towards the side of the lesion, and a high-frequency, small-amplitude nystagmus, when the patient looks toward the side opposite to the lesion. The nystagmus that occurs on gaze towards the side of the lesion is gaze-evoked nystagmus caused by defective gaze holding, whereas the nystagmus that occurs during gaze towards the side opposite the lesion is caused by vestibular imbalance. This is called Brun’s nystagmus. +5. Centripetal and rebound nystagmus. +If a patient with gaze-evoked nystagmus attempts to look eccentrically for a sustained period, the nystagmus begins to decrease in amplitude and may even reverse the direction, this is called centripetal nystagmus. If the eyes are then returned to the central position, a short-lived nystagmus with slow drifts in + +the direction of the prior eccentric gaze occurs. This is called rebound nystagmus. Both centripetal and rebound nystagmus reflect an attempt by brainstem or cerebellar mechanisms to correct for the drift of gaze-evoked nystagmus. +Causes of rebound nystagmus include: • Cerebellar diseases, +• Lateral medullary infarction, and +• Tumours confined to the flocculus. +iv. Acquired pendular nystagmus +• Usually disconjugate with horizontal, vertical and torsional components. +• May be associated with involuntary, repetitive movements of palate, pharynx and face (oculopalatal myoclonus). + +NYSTAGMOID MOVEMENTS +These are ocular movements which mimic nystagmus. These include: +1. Ocular flutter occurs due to interruption of cerebellar connection to brainstem. It is characterized by horizontal oscillation and inability to fixate after change of gaze. +2. Opsoclonus refers to combined horizontal, vertical and/or torsional oscillations associated with myoclonic movement of face, arms and legs. It is seen in patients with encephalitis. +3. Superior oblique myokymia is characterized by monocular, rapid, intermittent, torsional and vertical movements (which are best seen on slit-lamp examination). +4. Ocular bobbingrefers to rapid downward deviation of the eyes with slow updrift. It occurs due to pontine dysfunctions. +15 + +Disorders of Eyelids + + + +CHAPTER OUTLINE + +APPLIED ANATOMY Gross anatomy Structure +Glands of eyelids Blood supply Nerve supply +• +• +• +• +• +CONGENITAL ANOMALIES OEDEMA OF EYELIDS +INFLAMMATORY DISORDERS OF EYELIDS Blepharitis +• +• +• +• +• +External hordeolum (stye) Chalazion +Internal hordeolum Molluscum contagiosum +EYELASH DISORDERS Trichiasis +• + + + +APPLIED ANATOMY +GROSS ANATOMY +The eyelids are mobile tissue curtains placed in front of the eyeballs (Fig. 15.1). These act as shutters protecting the eyes from injuries and excessive light. These also perform an important function of spreading the tear film over the cornea and conjunctiva and also help in drainage of tears by lacrimal pump system. +Parts of eyelid. Each eyelid is divided by a horizontal furrow (sulcus) into an orbital and tarsal part. Position of lids. When the eye is open, the upper lid covers about one-sixth of the cornea and the lower lid just touches the limbus. +Canthi. The two lids meet each other at medial and lateral angles (or outer and inner canthi). In Caucasians with the lids open, the lateral canthus is about 2 mm higher than the medial canthus. Palpebral aperture. It is the elliptical space between the upper and the lower lid. When the eyes are open it measures about 10–11 mm vertically in the centre and about 28–30 mm horizontally. + +• Distichiasis Madarosis +ANOMALIES IN THE POSITION OF LID MARGINS Entropion +• +• +• +• +• +• +• +• +• +• +Ectropion Symblepharon Ankyloblepharon Blepharophimosis Lagophthalmos Blepharospasm Ptosis +Lid retraction TUMOURS OF EYELIDS +• +• +• +Benign tumours Premalignant tumours +Malignant tumours + + + + + + + + + + + + + + +Fig. 15.1 Gross anatomy of the eyelid + + +Lid margin. It is about 2 mm broad and is divided into two parts by the punctum. The medial, lacrimal portion is rounded and devoid of lashes or glands. +The lateral, ciliary portion consists of a rounded anterior border, a sharp posterior border (placed against the globe) and an intermarginal strip (between the two borders). The grey line (which marks junction of skin and conjunctiva) divides the intermarginal strip into an anterior strip bearing +Chapter 15 Disorders of Eyelids 363 + + +2–3 rows of lashes and a posterior strip on which openings of meibomian glands are arranged in a row. The splitting of the eyelids when required in operations is done at the level of grey line. +STRUCTURE +Each eyelid consists (from anterior to posterior) of the following layers (Fig. 15.2): +1. Skin. It is elastic having a fine texture and is the thinnest in the body. +2. Subcutaneous areolar tissue. It is very loose and contains no fat. It is thus readily distended by oedema or blood. +3. Layer of striated muscle. It consists of orbicularis muscle which forms an oval sheet across the eyelids. It comprises three portions: the orbital, palpebral (pretarsal and preseptal parts) and lacrimal. It closes the eyelids and is supplied by zygomatic branch of the facial nerve. Therefore, in paralysis of facial nerve there occurs lagophthalmos which may be complicated by exposure keratitis. +In addition, the upper lid also contains levator palpebrae superioris muscle (LPS). It arises from the apex of the orbit and is inserted by three parts on the skin of lid, anterior surface of the tarsal plate and conjunctiva of superior fornix. It raises the upper lid. It is supplied by a branch of oculomotor nerve. 4. Submuscular areolar tissue. It is a layer of loose connective tissue. The nerves and vessels lie in this layer. Therefore, to anaesthetise lids, injection is given in this plane. +5. Fibrous layer. It is the framework of the lids and consists of two parts: the central tarsal plate and the peripheral septum orbitale (Fig. 15.3). +i. Tarsal plate. There are two plates of dense connective tissue, one for each lid, which give shape + + + + + + + + + + + + + + + + + +Fig. 15.2 Structure of the upper eyelid + + + + + + + + + + + + +Fig. 15.3 Tarsal plates and septum orbitale + +and firmness to the lids. The upper and lower tarsal plates join with each other at medial and lateral canthi; and are attached to the orbital margins through medial and lateral palpebral ligaments. In the substance of the tarsal plates lie meibomian glands in parallel rows. +ii. Septum orbitale (palpebral fascia). It is a thin membrane of connective tissue attached centrally to the tarsal plates and peripherally to periosteum of the orbital margin. It is perforated by nerves, vessels and levator palpebrae superioris (LPS) muscle, which enter the lids from the orbit. +6. Layer of non-striated muscle fibres. It consists of the palpebral muscle of Muller which lies deep to the septum orbitale in both the lids. In the upper lid it arises from the fibres of LPS muscle and in the lower lid from prolongation of the inferior rectus muscle; and is inserted on the peripheral margins of the tarsal plate. It is supplied by sympathetic fibres. +7. Conjunctiva. The part which lines the lids is called palpebral conjunctiva. It consists of three parts: marginal, tarsal and orbital. (For structures of conjunctiva see page 60). +GLANDS OF EYELIDS (FIG. 15.4) +1. Meibomian glands. These are also known as tarsal glands and are present in the stroma of tarsal plate arranged vertically. They are about 30–40 in the upper lid and about 20–30 in the lower lid. They are modified sebaceous glands. Their ducts open at the lid margin. Their secretion constitutes the oily layer of tear film. +2. Glands of Zeis. These are also sebaceous glands which open into the follicles of eyelashes. +3. Glands of Moll. These are modified sweat glands situated near the hair follicle. They open into the hair follicles or into the ducts of Zeis glands. They do not open directly onto the skin surface as elsewhere. 4. Accessory lacrimal glands of Wolfring. These are present near the upper border of the tarsal plate. +364 Section II Diseases of Eye + + + + + + + + + + + + + + + + + + + +Fig. 15.4 Glands of eyelids + +BLOOD SUPPLY +Arteries of the lids (medial and lateral palpebral) form marginal arterial arcades which lie in the submuscular plane in front of the tarsal plate, 2 mm away from the lid margin, in the upper lid and about 4 mm away in the lower lid. In the upper lid another arcade (superior arterial arcade) is formed which lies near the upper border of the tarsal plate. Branches go forward and backward from these arches to supply various structures. +Veins. These are arranged in two plexuses: a post-tarsal which drains into ophthalmic veins and a pre-tarsal opening into subcutaneous veins. Lymphatics. These are also arranged in two sets: the pre-tarsal and the post-tarsal. Those from lateral half of the lids drain into preauricular lymph nodes and those from the medial half of the eyelids drain into submandibular lymph nodes. +NERVE SUPPLY +Motor nerves are facial (which supplies orbicularis muscle), oculomotor (which supplies LPS muscle) and sympathetic fibres (which supply the Muller’s muscle). +Sensory nerve supply is derived from branches of the trigeminal nerve such as lacrimal, supraorbital and supratrochlear nerves for upper lid; and the infraorbital nerve with infratrochlear branch for lower lid. + +CONGENITAL ANOMALIES + +1. Congenital ptosis. It is a common congenital anomaly. It is described in detail in the section of ptosis on page 379. + +2. Congenital coloboma. It is a rare condition characterised by a full thickness triangular gap in the tissues of the lids (Fig. 15.5). The anomaly usually occurs near the nasal side and involves the upper lid more frequently than the lower lid. Treatment consists of plastic repair of the defect. +3. Epicanthus. It is a semicircular fold of skin which covers the medial canthus. It is a bilateral condition and may disappear with the development of nose. It is a normal facial feature in Mongolian races. It is the most common congenital anomaly of the lids. Treatment consists of plastic repair of the deformity. 4. Distichiasis. (see page 371) +5.Cryptophthalmos. It is a very rare anomaly in which lids fail to develop and the skin passes continuously from the eyebrow to the cheek hiding the eyeball (Fig. 15.6). +6. Microblepharon. In this condition, eyelids are abnormally small. It is usually associated with microphthalmos or anophthalmos. Occasionally, the lids may be very small or virtually absent and the condition is called ablepharon. +7. Epiblepharon refers to a congenital anomaly in which a horizontal fold of tissue rides above the lower eyelid margin. It usually disappears with the growth of face and needs no surgical correction. +8. Euryblepharon refers to unilateral or bilateral horizontal widening of palpebral fissure. It is usually associated with lateral canthal malposition and lateral ectropion. Congenital euryblepharon usually involves the lateral portion of lower eyelids. + +OEDEMA OF EYELIDS + +Owing to the looseness of the tissues, oedema of the lids is of common occurrence. It may be classified as inflammatory, solid and passive oedema. + + + + + + + + + + + + + + + +Fig. 15.5 Congenital coloboma upper eyelid +Chapter 15 Disorders of Eyelids 365 + + + + + + + + + + + + + + + + + +Fig. 15.6 Cryptophthalmos + +I. Inflammatory oedema. It is seen in the following conditions. +1. Inflammations of the lid itself, which include dermatitis, stye, hordeolum internum, insect bites, cellulitis and lid abscess. +2. Inflammations of the conjunctiva, such as acute purulent, membranous and pseudomembranous conjunctivitis. +3. Inflammations of the lacrimal sac, i.e., acute dacryocystitis and lacrimal abscess. +4. Inflammations of the lacrimal gland, i.e., acute dacryoadenitis. +5. Inflammations of the eyeball, such as acute irido-cyclitis, endophthalmitis and panophthalmitis. +6. Inflammations of the orbit, which include orbital cellulitis, orbital abscess and pseudotumour. +7. Inflammations of the paranasal sinuses, e.g., maxillary sinusitis. +II. Solid oedema of the lids. It is chronic thickening of the lids, which usually follows recurrent attacks of erysipelas. It resembles inflammatory oedema of the lids but is harder in consistency. +III. Passive oedema of the lids. It may occur due to local or general causes. +1. Local causes are: cavernous sinus thrombosis, head injury and angioneurotic oedema. +2. General causes are congestive heart failure, renal failure, hypoproteinaemia and severe anaemia. + +INFLAMMATORY DISORDERS OF EYELIDS +BLEPHARITIS +Blepharitis is a subacute or chronic inflammation of the lid margins. It is an extremely common disease which can be divided into following clinical types: + +• Bacterial blepharitis, +• Seborrhoeic or squamous blepharitis, +• Mixed staphylococcal with seborrhoeic blepharitis, • Posterior blepharitis or meibomitis, and +• Parasitic blepharitis. + +Bacterial Blepharitis +Bacterial blepharitis, also known as chronic anterior blepharitis, or staphylococcal blepharitis or ulcerative blepharitis, is a chronic infection of the anterior part of the lid margin. It is a common cause of ocular discomfort and irritation. The disorder usually starts in childhood and may continue throughout life. +Etiology +Causative organisms, most commonly involved are coagulase positive Staphylococci. Rarely, Streptococci, Propionibacterium acnes, and Moraxella may be involved. +Predisposing factors, usually none, may rarely include chronic conjunctivitis and dacryocystitis. +Clinical features +Symptoms include chronic irritation, itching, mild lacrimation, gluing of cilia, and mild photophobia. The symptoms are characteristically worse in the morning. Remissions and exacerbations in symptoms are quite common. +Signs (Fig. 15.7) are as below: +• Yellow crusts are seen at the root of cilia which glue them together. +• Small ulcers, which bleed easily, are seen on removing the crusts. +• Red, thickened lid margins are seen with dilated blood vessels (rosettes). +• Mild papillary conjunctivitis and conjunctival hyperemia are common associations. +Complications and sequelae of long standing bacterial blepharitis include: +• Lash abnormalities such as madarosis (sparseness or absence of cilia), trichiasis (misdirected cilia), and poliosis (graying of lashes). + + + + + + + + + + + + +Fig. 15.7 Bacterial blepharitis +366 Section II Diseases of Eye + + +• Tylosis, i.e., thickening and scarring of lid margin. • Eversion of punctum leading to epiphora. +• Eczema of skin and ectropion may develop due to prolonged watering. +• Recurrent styes (external hordeola) are a common complication. +• Marginal keratitis, and occasionally phlyctenulosis may develop. +• Tear film instability, and dry eye may result. +• Secondary inflammatory and mechanical changes in the conjunctiva and cornea are common because of intimate relationship between the lid margins and ocular surface. +Treatment +Bacterial blepharitis should be treated promptly, as below, to avoid complications and sequelae: +1. Lid hygiene is essential at least twice daily and should include: +• Warm compresses for 5–10 minutes to soften the crusts, +• Crust removal and lid margin cleaning with the help of cotton buds dipped in the dilute baby shampoo or solution of 3% sodium bicarbonate. +• Avoid rubbing of the eyes or fingering of the lids. 2. Antibiotic should be used as below: +• Eye ointment should be applied at the lid margin, immediately after removal of the crusts. +• Antibiotic eye dropsshould be used 3–4 times a day. • Oral antibiotics such as erythromycin or doxycycline may be useful in unresponsive patients and those complicated by external hordeola and abscess of +lash follicle. +3. Topial steroids (weak) such as fluoromethalon may be required in patients with papillary conjunctivitis, marginal keratitis and phlyctenulosis. +4. Ocular lubricants, i.e., artificial tear drops, are required for associated tear film instability and dry eye. + +Seborrhoeic or Squamous Blepharitis Seborrhoeic blepharitis is primarily anterior blepharitis with some spill over posteriorly. It is of common occurrence. +Etiology. It is usually associated with seborrhoea of scalp (dandruff). Some constitutional and metabolic factors play a part in its etiology. In it, glands of Zeis secrete abnormal excessive neutral lipids which are split by Corynebacterium acne into irritating free fatty acids. +Symptoms. Patients usually complain of deposition of whitish material (soft scales) at the lid margin associated with mild discomfort, irritation, occasional watering and a history of falling of eyelashes. + +Signs include: +• Accumulation of white dandruff-like scales is seen on the lid margin, among the lashes (Fig. 15.8). On removing these scales underlying surface is found to be hyperaemic and greasy (no ulcers). +• The lashes fall out easily but are usually replaced quickly without distortion. +• Lid margin is thickened and the sharp posterior border tends to be rounded leading to epiphora, in long standing cases. +• Signs of bacterial blepharitis, as described above, may be superadded in patients with mixed seborrhoeic and bacterial blepharitis. +Complications are similar to bacterial blepharitis with comparatively lesser frequency (see page 365). Treatment includes: +• General measures include improvement of health and balanced diet. +• Associated seborrhoea of the scalp should be adequately treated. +• Local measures include removal of scales from the lid margin with the help of lukewarm solution of 3% soda bicarb or baby shampoo and frequent application of combined antibiotic and steroid eye ointment at the lid margin. +• Antibiotics, as described above in bacterial blepharitis, may be required in patients with mixed seborrhoeic and bacterial blepharitis. + +Posterior Blepharitis (Meibomitis) Meibomitis, i.e., inflammation of Meibomian glands occurs in chronic and acute forms. +1. Chronic meibomitis +Chronic meibomitis is a commonly occurring meibomian gland dysfunction, seen more commonly in middle aged persons, especially those with acne rosacea and/or seborrhoeic dermatitis. Bacterial lipases are being blamed to play main role in the pathogenesis of chronic meibomitis. + + + + + + + + + + + + + +Fig. 15.8 Seborrhoeic blepharitis +Chapter 15 Disorders of Eyelids 367 + + +Clinical features +Symptoms include chronic irritation, burning, itching, grittiness, mild lacrimation with remissions and exacerbations intermittently. Symptoms are characteristically worse in the morning. +Signs include (Fig. 15.9): +• White frothy (foam like) secretions are frequently seen on the eyelid margins and canthi (meibomian seborrhoea). +• Opening of meibomian glands become prominent with thick secretions which can be expressed out by pressure on the lids giving toothpaste appearance. Meibomian gland orifices may also show capping with oil globules, pouting, recession, or plugging. +• Vertical yellowish streaks shining through conjunctiva can be seen on eversion of the lids. These represent the meibomian ducts filled with thick secretion. +• Hyperemia and telangiectasia of posterior lid margin around the orifices of meibomian glands can be seen frequently. +• Oily and foamy tear film with accumulation of froth on the lid margins or inner canthus. +• Secondary changes in the form of papillary conjunctivitis, and inferior corneal punctate epithelial erosions may be seen. +2. Acute meibomitis +Acute meibomitis occurs due to staphylococcal infection. It is characterized by painful swelling around the involved gland. Pressure on it results in expression of pus bead followed by serosanguinous discharge. +Treatment of meibomitis +1. Lid hygiene is essential at least once a day and should include: +• Warm compresses for several minutes. +• Expression of accumulated secretions by repeated vertical massage of lids in the form of milking. + + + + + + + + + + + + +Fig. 15.9 Chronic meibomitis + +2. Topical antibiotics in the form of eye ointment should be rubbed at the lid margin immediately after massage, and +• Eye drops may be used 3–4 times a day. +3. Systemic tetracyclines, e.g., doxycycline 100 mg b.d. for 1 week and then o.d. for 6–12 weeks, remain the mainstay of treatment of posterior blepharitis because of their ability to block staphylococcal lipase production. Erythromycin may be used where tetracyclines are contraindicated. +4. Ocular lubricants i.e., artificial tear drops are required for associated tear film instability and dry eye disease. +5. Topical steroids(weak) such as fluoromethalon may be required in patients with papillary conjunctivitis. + +Parasitic Blepharitis (Lash Infestation) +Etiology +Blepharitis associated with infestation of lashes by lice is not uncommon in persons living in poor hygienic conditions. The lice infestations include the following: +• Phthiriasis palpebrum refers to the infestation by phthirus pubis (crab louse). It is most commonly seen in adults in whom it is usually acquired as a sexually transmitted infection. +• Pediculosis refers to the infestation by pediculus humanus corporis or capitis(head louse). If heavily infested the lice may spread to involve lashes. +Clinical features +Infestation of lashes with lice causes chronic blepharitis and chronic follicular conjunctivitis. Symptoms includechronicirritation,itching,burning, and mild lacrimation. +Signs are as below (Fig. 15.10): +• Lid margins are red and inflamed. +• Lice anchoring the lashes with their claws may be seen on slit-lamp examination. +• Nits (eggs) may be seen as opalescent pearls adherent to the base of cilia. +• Conjunctival congestion and follicles may be seen in long standing cases. +Treatment +• Mechanical removal of the lices and nits with forceps. +• Application of antibiotic ointment and yellow mercuric oxide 1% to the lid margins and lashes. +• Delousing of the patient, family members, clothing and bedding is important to prevent recurrences. +EXTERNAL HORDEOLUM (STYE) +It is an acute suppurative inflammation of lash follicle and its associated glands of Zeis or Moll. +368 Section II Diseases of Eye + + + + + + + + + + + + + + +Fig. 15.10 Phthiriasis palpebrum + +Etiology +1. Predisposing factors are as below: +• Age. It is more common in children and young adults (though no age is bar) and in patients with eye strain due to muscle imbalance or refractive errors. +• Habitual rubbing of the eyes or fingering of the lids and nose, chronic blepharitis and diabetes mellitus are usually associated with recurrent styes. +• Metabolic factors, chronic debility, excessive intake of carbohydrates and alcohol also act as predisposing factors. +2. Causative organism commonly involved is staphylococcus aureus. +Clinical features +Symptoms include acute pain associated with swelling of lid, mild watering and photophobia. Signs are as follows: +• Stage of cellulitis is characterised by localised, firm, red, tender swelling at the lid margin associated with marked oedema (Fig. 15.11). Usually, there is one stye, but occasionally, these may be multiple. +• Stage of abscess formation is characterised by a visible pus point on the lid margin in relation to the affected cilia. +Treatment +• Hot compresses 2–3 times a day are very useful especially in cellulitis stage. +• Evacuation of the pus should be done by epilating the involved cilia, when the pus point is formed. +• Surgical incision is required rarely for a large abscess. +• Antibiotic eye drops (3–4 times a day) and eye ointment (at bed time) should be applied to control the infection. +• Systemic anti-inflammatory and analgesics relieve pain and reduce oedema. +• Systemic antibiotics should be used for early control of infection. + +Fig. 15.11 Hordeolum externum (stye) upper eyelid + +• In recurrent styes, try to find out and treat the associated predisposing condition. +CHALAZION +Chalazion, also called a tarsal or meibomian cyst, is a chronic non-infective (non-suppurative) lipogranulomatous inflammation of the meibomian gland. This is the commonest of all lid lumps. +Etiology +1. Predisposing factors are similar to hordeolum externum. +2. Pathogenesis. Usually, first there occurs mild grade infection of the meibomian gland by organisms of very low virulence. As a result, there occurs proliferation of the epithelium and infiltration of the wallsofthe ducts, which are blocked. Consequently, there occurs retention of secretions (sebum) in the gland, causing its enlargement. The pent-up and extravasated secretions (fatty in nature) act like an irritant and excite non-infective lipogranulomatous inflammation of the blocked meibomian glands and surrounding tissue. +Clinical features Symptoms include: +• Painless swelling in the eyelid, gradually increasing in size is the main presenting symptom. +• Mild heaviness in the lid may be felt with moderately large chalazion. +• Blurred vision may occur occasionally due to induced astigmatism by a very large chalazion pressing on the cornea. +• Watering (epiphora) may occur sometimes due to eversion of lower punctum caused by a large chalazion of the lower eyelid. +Signs include: +• Nodule is noted slightly away from the lid margin (Fig. 15.12) which is firm to hard and non-tender on palpation. Upper lid is involved more commonly than the lower lid probably because of +Chapter 15 + + + + + + + + + + + + + +Fig. 15.12 Chalazion upper eyelid + +Disorders of Eyelids 369 + + + + + + + + + + + + + +Fig. 15.13 Incision and curettage of chalazion from the conjunctival side + + + +the fact that upper lid contains more meibomian glands than the lower lid. Frequently multiple chalazia may be seen. +• Reddish purple area, where the chalazion usually points, is seen on the palpebral conjunctiva after eversion of the lid. +• Projection of the main bulk of the swelling on the skin side may be seen rarely instead of conjunctival side. +• Marginal chalazion, occurring occasionally, may present as small reddish grey nodule on the lid margin. +Clinical course and complications +• Complete spontaneous resolution may occur rarely. • Slow increase in size is often seen and eventually +it may become very large. +• Fungating mass of granulation tissue may be formed occasionally when the lesion bursts on the conjunctival side. +• Secondary infection may lead to formation of hordeolum internum. +• Calcification may occur, though very rarely. +• Malignant change into meibomian gland adenocarcinoma (sebaceous cell carcinoma) may be seen occasionally in elderly people. +Treatment +1. Conservative treatment. In a small, soft and recent chalazion, self-resolution may be helped by conservative treatment in the form of hot fomentation, topical antibiotic eyedrops and oral anti-inflammatory drugs. +2. Intralesional injection of long-acting steroid (triamcinolone) is reported to cause resolution in about 50% cases, especially in small and soft chalazia of recent onset, located near the puncta, where incision and curettage may cause damage. 3.Incision and curettage(Fig. 15.13) is the conventional and effective treatment for chalazion. + +• Surface anaesthesia is obtained by instillation of xylocaine drops in the eye and the lid in the region of the chalazion is infiltrated with 2% xylocaine solution. +• Incision is made with a sharp blade, which should be vertical on the conjunctival side (to avoid injury to other meibomian ducts) and horizontal on skin side (to have an invisible scar). +• Contents are curetted out with the help of a chalazion scoop. +• Carbolic acid cautery followed by neutralization with methylated spirit should be preformed in the cavity to avoid recurrence. +• Patching of eye should be done, after instilling antibiotic eye ointment, for about 6 to 12 hours. +• Postoperative treatment, to decrease discomfort and prevent infection, should be given in the form of hot fomentation, antibiotic eyedrops, oral anti-inflammatory, analgesics and oral antibiotics for 4-5 days. +4. Diathermy. A marginal chalazion is better treated by diathermy. +5. Oral tetracycline should be given as prophylaxis in recurrent chalazia, especially if associated with acne rosacea or seborrhoeic dermatitis. +Note. In recurrent chalazion malignancy should be ruled out. +INTERNAL HORDEOLUM +It is a suppurative inflammation of the meibomian gland associated with blockage of the duct. +Etiology +Predisposing factors are similar to hordeolum externum (see page 368). +Causative mechanism. Hordeolum internum may occur as: +• Primary Staphylococcal infectionof the meibomian gland or due to +370 Section II Diseases of Eye + + +• Secondary infection in a chalazion (infected chalazion). +Clinical features +Symptoms include acute pain associated with swelling of the lid, mild watering and photophobia. Thus, the symptoms are similar to hordeolum externum, except that pain is more intense, due to the swelling being embedded deeply in the dense fibrous tissue. +Signs include a localized, firm, red, tender swelling of the lid associated with marked oedema. On examination, hordeolum internum can be differentiated from hordeolum externum by the fact that in it, the point of maximum tenderness and swelling is away from the lid margin and that pus usually points on the tarsal conjunctiva (seen as yellowish area on everting the lid) and not on the root of cilia (Fig. 15.14). Sometimes, pus point may be seen at the opening of involved meibomian gland or rarely on the skin. +Treatment +It is similar to hordeolum externum (see page 368), except that, when pus is formed, it should be drained by a vertical incision from the tarsal conjunctiva. +MOLLUSCUM CONTAGIOSUM \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_13.txt b/notes/A K Khurana - Comprehensive Ophthalmology_13.txt new file mode 100644 index 0000000000000000000000000000000000000000..b3313346af40bf100f487675bf7c53a29c87d61a --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_13.txt @@ -0,0 +1,1599 @@ +Etiology. It is a viral infection of the lids, commonly affecting children. It is caused by a large poxvirus. Clinical features. Its typical lesions are multiple, pale, waxy, umbilicated swellings scattered over the skin near the lid margin (Fig. 15.15). +Complications include chronic follicular conjunctivitis and superficial keratitis. +Treatment. The skin lesions should be incised and the interior cauterised with tincture of iodine or pure carbolic acid. + + + + + + + + + + + + + + + +Fig. 15.14 Hordeolum internum lower eyelid + + + + + + + + + + + + + + +Fig. 15.15 Molluscum contagiosum of the lids + +EYELASH DISORDERS + +TRICHIASIS +It refers to inward misdirection of cilia (which rub against the eyeball) with normal position of the lid margin (Fig. 15.16). +Pseudotrichiasis. The inward turning of lashes along with the lid margin (seen in entropion) is called pseudotrichiasis. +Etiology +Common causes of trichiasis are: cicatrising trachoma, ulcerative blepharitis, healed mem-branous conjunctivitis, hordeolum externum, mechanical injuries, burns, and operative scar on the lid margin. +Clinical features +Symptoms. These include foreign body sensation and photophobia. Patient may feel troublesome irritation, pain and lacrimation. +Signs. Examination reveals: +• Misdirected cilia one or more touching the cornea. • Reflex blepharospasm and photophobia occur +when cornea is abraded. +• Conjunctiva may be congested. +• Signs of causative disease viz. trachoma, blepharitis, etc. may be present. +Complications. These include recurrent corneal abrasions, superficial corneal opacities, corneal vascularisation (Fig. 15.16B) and non-healing corneal ulcer. +Treatment +A few misdirected cilia may be treated by any of the following methods: +1. Epilation (mechanical removal with forceps). It is a temporary measure, as recurrence occurs within 3–4 weeks. +2. Electrolysis. It is a method of destroying the lash follicle by electric current. In this technique, +Chapter 15 Disorders of Eyelids 371 + + + + + + + + + + + + + + + +A + + + + + + + + + + + +B +Fig. 15.16 Trichiasis; A, diagrammatic depiction; B, clinical photograph + +infiltration anaesthesia is given to the lid and a current of 2 mA is passed for 10 seconds through a fine needle inserted into the lash root. The loosened cilia with destroyed follicles are then removed with epilation forceps. +3. Cryoepilation. It is also an effective method of treating trichiasis. After infiltration anaesthesia, the cryoprobe (–20°C) is applied for 20–25 seconds to the external lid margin by double freeze-thaw technique. Its main disadvantage is depigmentation of the skin. 4. Surgical correction.When many cilia are misdirected operative treatment similar to cicatricial entropion should be employed. +DISTICHIASIS +Congenital distichiasis (Fig. 15.17) is a rare anomaly in which an extra row of cilia occupies the position of Meibomian glands which open into their follicles as ordinary sebaceous glands. These cilia are usually directed backwards and when rubbing the cornea, should be electroepilated or cryoepilated. Acquired distichiasis (metaplastic lashes) occurs when due to metaplasia and differentiation, the meibomian glands are transformed into hair follicles. The most important cause is late stage of cicatrizing + + +Fig. 15.17 Distichiasis + +conjunctivitis associated with chemical injury, Stevens-Johnson syndrome and ocular cicatricial pemphigoid. +MADAROSIS +Madarosis refers to partial or complete loss of eyelashes. +Causes can be local or systemic. +■Local causes of madarosis include chronic blepheriris, cicatrizing conjunctivitis, and complication of cryotherapy, radiotherapy or surgery done for any eyelid lesion. +■Systemic causes of madarosis are alopecia (patchy, totalis/universalis), psoriasis, hypothyroidism and leprosy. + +ANOMALIES IN THE POSITION OF LID MARGINS +ENTROPION +Entropion refers to inward rolling and rotation of the lid margin toward globe. +Etiological types +1. Congenital entropion. It is a rare condition seen since birth. Seen more commonly in lower than upper eyelid. +■Lower eyelid congenital entropion is caused by improper development of the lower lid retractors. ■Upper eyelid congenital entropion is usually secondary to mechanical effects of microphthalmos. 2. Cicatricial entropion (Fig. 15.18). It is a common variety usually involving the upper lid. It is caused by cicatricial contraction of the palpebral conjunctiva, with or without associated distortion of the tarsal plate. +Common causes are trachoma, membranous conjunctivitis, chemical burns, pemphigus and Stevens-Johnson syndrome. +372 Section II Diseases of Eye + + + + + + + + + + + + + + + +Fig. 15.18 Cicatricial entropion + +3. Senile (involutional) entropion. It is common occurrence and affects only the lower lid in elder people (Fig. 15.19). +Etiological factors which contribute for its development are: +• Horizontal laxity of the lid due to weakening of orbicularis muscle. +• Vertical lid instability due to weakening or dehiscence of capsulopalpebral fascia (lower lid retractor). +• Over-riding of pretarsal orbicularis. Degeneration of palpebral connective tissue separates the orbicularis muscle fibres and thus allowes preseptal fibres to over-ride the pretarsal fibres and thus tipping the lid margin inwards. +• Laxity of orbital septum along with prolapse of orbital fat into the lower lid also contribute to inward rolling of lid margin. +4.Mechanical entropion.It occurs due to lack of support provided by the globe to the lids. Therefore, it may occur in patients with phthisis bulbi, enophthalmos and after enucleation or evisceration operation. +Clinical features +Symptoms occur due to rubbing of cilia against the cornea and conjunctiva and are thus similar to + + + + + + + + + + + +Fig. 15.19 Senile entropion right lower eyelid + +trichiasis. These include foreign body sensation, irritation, lacrimation and photophobia. +Signs are as follows: +1.Inturning of lid margins. On examination, lid margin is found inturned. Depending upon the degree of inturning, it can be divided into three grades: +• Grade I entropion, only the posterior lid border is inrolled, +• Grade II entropion, includes inturning up to the inter-marginal strip, and +• Grade III entropion, in which the whole lid margin including the anterior border is inturned. +2. Signs of causative disease, e.g., scarring of palpebral conjunctiva in cicatricial entropion, and horizontal lid laxity in involutional entropion may be seen. +3. Signs of complications include recurrent corneal abrasions, superficial corneal opacities, corneal vascularization and even corneal ulceration. +Treatment +1.Congenital entropionmay resolve with time without need of any intervention or may require excision of a strip of skin and muscle with plastic reconstruction of the lid crease (Hotz procedure). +2. Cicatricial entropion. It is treated by a plastic operation, which is based on any of the following basic principles: +• Altering the direction of lashes, or • Transplanting the lashes, or +• Straightening the distorted tarsus. +Surgical techniquesemployed for correcting cicatricial entropion are as follows: +i. Anterior lamellar resection. It is the simplest operation employed to correct mild degree of entropion. In this operation, an elliptical strip of skin and orbicularis muscle is resected 3 mm away from the lid margin. +ii. Tarsal wedge resection. It corrects moderate degree of entropion associated with atrophic tarsus. In this operation, in addition to the elliptical resection of skin and muscle, a wedge of tarsal plate is also removed (Fig. 15.20). +iii.Transposition oftarsoconjunctival wedge.(Modified Ketssey’s operation) (Fig. 15.21): This is indicated to treat mild to moderate amount of cicatricial entropion. It basically involves tarsal fracture and eversion of distal tarsus. A horizontal incision is made along the whole length of sulcus subtarsalis (2–3 mm above the lid margin) involving conjunctiva and tarsal plate (Fig. 15.21A). The lower piece of tarsal plate is undermined up to lid margin. Mattress sutures are then passed from the upper cut end of the tarsal plate to emerge on the skin 1 mm above +Chapter 15 Disorders of Eyelids 373 + + +the lid margin (Fig. 15.21B). When sutures are tied the entropion is corrected by transposition of tarsoconjunctival wedge (Fig. 15.21C). +iv. Posterior lamellar graft. Indications of this operation include severe entropion with upper eyelid retraction. In this operation, the deficient or keratinized conjunctiva and the scarred and contracted tarsus are replaced by a composite posterior lamellar graft. Tarsus may be replaced by preserved sclera or ear cartilage or hard palate alongwith conjunctival or mucous membrane graph. 3. Senile entropion. Surgical techniques are as below: i. Transverse everting suture. These offer temporary cure (upto 18 months) and are thus indicated in very old patients. The transverse sutures are applied through full thickness of the lids (Fig. 15.22) to prevent over-riding of the preseptal muscles. +ii. Wies operation (Transverse lid split and everting sutures). This operation is indicated for long term cure in patients with little horizontal laxity. In this operation, an incision involving skin, orbicularis and tarsal plate is given 3 mm below the lid margin, along the whole length of the eyelid. Mattress sutures are then passed through the lower cut end of the tarsus to emerge on the skin, 1 mm below the lid margin and are tied firmly (Fig. 15.23). The entropion is corrected by prevention of over-riding of preseptal muscle by the horizontal fibrous scar tissue barrier and transferring of the pull of lid retractors to the upper border of tarsus by the everting sutures. +iii. Plication of lower lid retractors (Jones operation). It is performed in severe cases or when recurrence occurs after the above described operations. In this + + + + + + + + + +A + + + + + + + + +B + + + + + + +C + +Fig. 15.21 Transposition of tarsoconjunctival wedge + + + +A + + + + + + + + + +B + +Fig. 15.22 Transverse lid everting sutures. A, diagrammatic section; and B, frontal view to show the position of sutures + +operation, the lower lid retractors are exposed via horizontal skin incision at the lower border of the +Fig. 15.20 Tarsal wedge resection tarsal plate, shortened and the sutures are used to +374 Section II Diseases of Eye + + + + + + + + + + + + + + + + + + + + + +Fig. 15.23 Wies operation + +create a barrier to prevent over-riding of the preseptal muscle. (Fig. 15.24). +iv. Quickert procedure. This is indicated in patients having associated marked horizontal lid laxity. This operation consists of transverse lid split to create barrier for over-riding of preseptal muscle, everting + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 15.24 Plication of lower lid retractors: A, front view; B, cut section + +sutures to transfer pull of lower lid retractors to upper border of tarsus and horizontal lid shortening to correct the laxity (Fig. 15.25). Thus Quickert procedure basically combines horizontal lid shortening with Weis procedure. +ECTROPION +Out rolling or outward turning of the lid margin is called ectropion. +Etiological types +1. Congenital ectropion. This is very rare, but may be seen in Down syndrome and blepharophimosis syndrome. It may occur in both the upper and lower lids and is due to a congenital shortage of the skin. +2. Involutional ectropion. It is the commonest variety and involves only the lower lids (Fig. 15.26A). It occurs due to following age-related changes: +• Horizontal laxity of eyelid, +• Medial canthal tendon laxity, +• Lateral canthal tendon laxity, and • Disinsertion of lower lid retractors. +3. Cicatricial ectropion. It occurs due to scarring of the skin and can involve both the lids (Fig. 15.26B). Common causes of skin scarring are: thermal burns, chemical burns, lacerating injuries and skin ulcers. +4. Paralytic ectropion. It results due to paralysis of the seventh nerve. It mainly occurs in the lower lids. Common causes of facial nerve palsy are: Bell’s palsy, head injury, infections of the middle ear and operations on parotid gland. +5.Mechanical ectropion. It occurs in conditions where either the lower lid is pulled down (as in tumours) or pushed out and down (as in proptosis and marked chemosis of the conjunctiva). +Clinical features +Symptoms +• Epiphora is the main symptom in ectropion of the lower lid. +• Symptoms due to associated chronic conjunct-ivitis include: irritation, discomfort and mild photophobia. +Signs +1.Lid margin is outrolled. Depending upon the degree of outrolling, ectropion can be divided into three grades: +• Grade I: In it only punctum is everted. +• Grade II: Lid margin is everted and palpebral conjunctiva is visible. +• Grade III: The fornix is also visible. +2. Signs of the etiological condition such as: +Chapter 15 Disorders of Eyelids 375 + + + + + + + + + + +A + +A + + + + + + + + + + + + +B + + + + + + + + + + + +C +Fig. 15.25 Quickert procedure: A, two vertical incisions for horizontal lid shortening and horizontal slit incision; B, passage of lid everting suture after completion of horizontal lid resection and C, final position of the sutures + +• Skin scars in cicatricial ectropion and +• Seventh nerve palsy in paralytic ectropion may also be seen. +3. In involutional ectropion one or more of the following signs can be elicited: +• Horizontal lid laxity can be demonstrated by positive snap test, i.e., lid can be easily pulled away from the globe but fails to snap back to the normal position on release. +• Medial canthal tendon laxity. Normally on pulling the lid laterally the inferior punctum moves by 1–2 mm only; while it can the moved upto limbus + +B +Fig. 15.26 A. Involutional ectropion, B. Cicatricial ectropion lower eyelid + +in mild and upto pupil in severe degree of medial tendon laxity. +• Lateral canthal tendon laxity is evidenced by rounded appearance of the lateral canthus and its more than 2 mm movement on pulling the lid medially. +Complications +• Dryness and thickening of conjunctiva and corneal ulceration (exposure keratitis) may occur due to prolonged exposure. +• Eczema and dermatitis of the lower lid skin may occur due to prolonged epiphora. +Treatment +1.Congenital ectropion. Mild ectropion often requires no treatment. Moderate or severe ectropion is treated like cicatricial ectropion with horizontal lid tightening and full thickness skin graft to vertically lengthen anterior lamella. +2. Involutional ectropion. Depending upon the severity, following three operations are commonly performed: +i. Medial conjunctivoplasty. It is useful in mild cases of ectropion involving punctal area. It consists of excising a spindle-shaped piece of conjunctiva and subconjunctival tissue from below the punctal area (Fig. 15.27). +376 Section II Diseases of Eye + + + + + + + + + + + + + + + + + + +Fig. 15.27 Medial conjunctivoplasty + +ii. Horizontal lid shortening. It is performed by a full thickness pentagonal excision in patients with moderate degree of ectropion (Fig. 15.28). +iii.Byron Smith’s modified Kuhnt-Szymanowski operation. It is performed for severe degree of ectropion which is more marked over the lateral half of the lid. In it, a base up pentagonal full thickness excision from the lateral third of the eyelid is combined with triangular excision of the skin from the area just lateral to lateral canthus to elevate the lid (Fig. 15.29). +iv. Lateral tarsal strip technique is very useful for generalized ectropion associated with horizontal lid laxity. +3. Paralytic ectropion. Paralytic ectropion often resolves spontaneously within 6 months especially when due to Bells palsy. Therefore, temporary measures are taken initially. Permanent surgical treatment is required only in non-resolving cases. +Temporary measures include: • Topical lubricants, + + + + + + + + + + + + + +Fig. 15.28 Horizontal lid shortening + +Fig. 15.29 Modified Kuhnt-Szymanowski operation + +• Taping temporal side of eyelid, and • Suture tarsorrhaphy. +Permanent measures include: +• Horizontal lid tightening with or without middle lamellar buttress such as ear cartilage or +• Palpebral sling operation, in which a fascia lata sling is passed in the subcutaneous layer all around the lid margins. +4. Cicatricial ectropion. Depending upon the degree it can be corrected by any of the following plastic operations: +i. V-Y operation. It is indicated in mild degree ectropion. In it a V-shaped incision is given, skin is undermined and sutured in a Y-shaped pattern (Fig. 15.30). +ii. Z-plasty (Elschnig’s operation). It is useful in mild to moderate degree of ectropion. +iii.Excision of scar tissue and full thickness skin grafting. It is performed in severe cases. Skin graft may be taken from the upper lid, behind the ear, or inner side of upper arm. +5. Mechanical ectropion. It is corrected by treating underlying mechanical force causing ectropion. +SYMBLEPHARON +In this condition, lids become adherent with the eyeball as a result of adhesions between the palpebral and bulbar conjunctiva. + + + + + + + + + + +Fig. 15.30 V-Y operation +Chapter 15 Disorders of Eyelids 377 + + +Etiology +It results from healing of the kissing raw surfaces upon the palpebral and bulbar conjunctiva. Common causes are thermal or chemical burns, membranous conjunctivitis, injuries, conjunctival ulcerations, ocular pemphigus and Stevens-Johnson syndrome. +Clinical features +Clinical features of symblepharon are: +• Ocular movements become restricted, +• Diplopia may be experienced due to restricted ocular motility, +• Lagophthalmos, i.e., inability to close the lids may occur due to adhesions. +• Cosmetic disfigurement is a common complaint. Types of symblepharon, depending upon the extent of adhesions, are as below: +• Anterior symblepharon—adhesions present only in the anterior part (Fig. 15.31A and D). +• Posterior symblepharon—adhesions presentin the fornices (Fig. 15.31B and E). +• Total symblepharon—adhesions involving whole of the lid (Fig. 15.31C). +Complications +These include dryness, thickening and keratinisation of conjunctiva due to prolonged exposure and corneal ulceration (exposure keratitis). + +Treatment +1. Prophylaxis. During the stage of raw surfaces, the adhesions may be prevented by: . +• Sweeping a glass rod coated with lubricant around the fornices several times a day. +• Therapeutic soft contact lens of large size, also helps in preventing the adhesions. +2. Curative treatment consists of symblepharectomy. The raw area created may be covered by: +• Mobilising the surrounding conjunctiva in mild cases. +• Conjunctival or buccal mucosal graft is required in severe cases. +• Amniotic membrane transplantation (AMT), also gives good results. + +ANKYLOBLEPHARON +It refers to the adhesions between margins of the upper and lower lids. +Etiology. Ankyloblepharon may occur as: • Congenital anomaly and +• Acquired adhesions after healing of chemical burns, thermal burns, ulcers and traumatic wounds of the lid margins. +Clinically ankyloblepharon may be complete or incomplete. It is usually associated with symblepharon. + + + + + + + + + + + +A B C + + + + + + + + + + + + +D E +Fig. 15.31 Symblepharon: Diagrammatic depiction of anterior (A), posterior (B) and total symblepharon (C), clinical photographs of anterior (D) and posterior (E) symblepharon +378 Section II Diseases of Eye + + +Treatment. Lids should be separated by excision of adhesions between the lid margins and kept apart during healing process. When adhesions extend to the angles, epithelial grafts should be given to prevent recurrences. +BLEPHAROPHIMOSIS +In this condition the extent of the palpebral fissure is decreased. It appears contracted at the outer canthus. +Etiology. It may be congenital (see page 379) or acquired, due to formation of a vertical skin fold at the lateral canthus (epicanthus lateralis) following eczematous contractions. +Treatment. Usually no treatment is required. In marked cases, canthoplasty operation is performed. +LAGOPHTHALMOS +This condition is characterised by inability to close the eyelids voluntarily. +Etiology. It occurs in patients with paralysis of orbicularis oculi muscle, cicatricial contraction of the lids, symblepharon, severe ectropion, proptosis, following over-resection of the levator muscle for ptosis, and in comatosed patients. Physiologically some people sleep with their eyes open (nocturnal lagophthalmos). +Clinical features. It is characterised by incomplete closure of the palpebral aperture associated with features of the causative disease. +Complications include conjunctival and corneal xerosis and exposure keratitis. +Treatment is as below: +1. Measures to prevent exposure keratitis +• Artificial tear drops should be instilled frequently and the open palpebral fissure should be filled with an antibiotic eye ointment during sleep and in comatosed patients. +• Soft bandage contact lens may be used to prevent exposure keratitis. +• Tarsorrhaphy may be performed to cover the exposed cornea when indicated. +2. Measures to treat the cause of lagophthalmos, wherever possible should be taken. + +Tarsorrhaphy +In this operation, adhesions are created between a part of the lid margins with the aim to narrow down or almost close the palpebral aperture. It is of two types: temporary and permanent. +1. Temporary tarsorrhaphy +Indications. (i) To protect the cornea when seventh nerve palsy is expected to recover. (ii) To assist healing of an indolent corneal ulcer. (iii) To assist + +in healing of skin-grafts of the lids in the correct position. +Surgical technique. This can be carried out as median or paramedian tarsorrhaphy (Fig. 15.32). +i. Incision. For paramedian tarsorrhaphy, about 5 mm long incision site is marked on the corresponding parts of the upper and lower lid margins, 3 mm on either side of the midline. An incision 2 mm deep is made in the grey line on the marked site and the marginal epithelium is then excised taking care not to damage the ciliary line anteriorly and the sharp lid border posteriorly. +ii. Suturing. The raw surfaces thus created on the opposing parts of the lid margins are then sutured with double-armed 6–0 silk sutures passed through a rubber bolster. +2. Permanent tarsorrhaphy +Indications. (i) Established cases of VII nerve palsy where there is no chance of recovery; and (ii) established cases of neuroparalytic keratitis with severe loss of corneal sensations. +Technique. It is performed at the lateral canthus to create permanent adhesions. The eyelids are overlapped after excising a triangular flap of skin and orbicularis from the lower lid and corre-sponding triangular tarsoconjunctival flap from the upper lid. +BLEPHAROSPASM +It refers to the involuntary, sustained and forceful closure of the eyelids. +Etiology +Blepharospasm occurs in two forms: +1. Essential (spontaneous) blepharospasm. It is a rare idiopathic condition involving patients between 45 and 65 years of age. +2. Reflex blepharospasm. It usually occurs due to reflex sensory stimulation through branches of fifth nerve, in + + + + + + + + + + + + + + +Fig. 15.32 Surgical technique of paramedian tarsorrhaphy +Chapter 15 Disorders of Eyelids 379 + + +conditions such as: phlyctenular keratitis, interstitial keratitis, corneal foreign body, corneal ulcers and iridocyclitis. It is also seen in excessive stimulation of retina by dazzling light, stimulation of facial nerve due to central causes and in some hysterical patients. +Clinical features +• Persistent epiphora may occur due to spasmodic closure of the canaliculi which may lead to eczema of the lower lid. +• Oedema of the lids is of frequent occurrence. +• Spastic entropion (in elderly people) and spastic ectropion (in children and young adults) may develop in long-standing cases. +• Blepharophimosis may result due to contraction of the skin folds following eczema. + +Treatment +Treatment of essential blepharospasm: +• Botulinum toxin, injected subcutaneously over the orbicularis muscle, blocks the neuromuscular junction and relieves the spasm. +• Facial denervation mayberequiredinseverecases. +Treatment of reflex blepharospasm: +• Causative disease should be treated to prevent recurrences. +• Associated complications should also be treated. + +PTOSIS +Abnormal drooping of the upper eyelid is called ptosis. Normally, upper lid covers about upper one-sixth of the cornea, i.e., about 2 mm. Therefore, in ptosis it covers more than 2 mm. + +Clinic-etiological Types I. Congenital ptosis +Etiology. It is associated with congenital weakness (maldevelopment) of the levator palpebrae superioris (LPS). +Characteristic features of congenital ptosis are: +• Drooping of one or both upper lids more often since birth of variable severity (mild, moderate or severe). +• Lid crease is either diminished or absent. +• Lid lag on downgaze (i.e., ptotic lid is higher than the normal) due to tethering effect of abnormal LPS muscle. This is in contrast to acquired ptosis in which ptotic lid is lower than the normal in downgaze also. +• LPS function may be poor, fair or good depending upon the degree of weakness. + +1. Simple congenital ptosis (not associated with any other anomaly) (Fig. 15.33A). +2. Congenital ptosis with associated weakness of superior rectus muscle. +3. Blepharophimosis syndrome, which comprises congenital ptosis, blepharophimosis, telecanthus and epicanthus inversus (Fig. 15.33B). +4. Congenital synkinetic ptosis (Marcus Gunn jaw-winking ptosis). In this condition, there occurs retraction of the ptotic lid with jaw movements, i.e., with stimulation of ipsilateral pterygoid muscle. +II. Acquired ptosis +Depending upon the cause it can be neurogenic. myogenic, aponeurotic or mechanical. +1. Neurogenic ptosis. It is caused by innervational defects such as: +• Third nerve palsy (see page 355), • Horner’s syndrome, +• Ophthalmoplegic migraine, and • Multiple sclerosis. +Horner’s syndrome, occurring due to oculo-symp-athetic paresis, is characterised by classic triad of: +• Mild ptosis (due to paralysis of Muller’s muscles), • Miosis (due to paralysis of dilator pupillae), and • Reduced ipsilateral sweating (anhydrosis), + + + + + + + + + + + + + +A + + + +Associated features. Based on the absence or presence B of other associated features, the congenital ptosis +may occur in following forms: + + +Fig. 15.33 Congenital ptosis: A, simple: B, blepharophimosis syndrome +380 Section II Diseases of Eye + + +• Other features include mild enophthalmos , loss of cilio-spinal reflex, heterochromia, i.e., ipsilateral iris is lighter in color, pupil is slow to dilate, and there occurs slight elevation of the lower eyelid. +Note. Also see page 317 +2. Acquired myogenic ptosis. It occurs due to acquired disorders of the LPS muscle or of the myoneural junction. It may be seen in patients with myasthenia gravis, dystrophia myotonica, ocular myopathy, oculopharyngeal muscular dystrophy and following trauma to the LPS, muscle thyrotoxicosis, and Lambert-Eaton myasthenia syndrome. +3. Aponeurotic ptosis. It develops due to defects of the levator aponeurosis in the presence of a normal functioning muscle. It includes: +• Involutional (senile) ptosis, +• Postoperative ptosis (which is rarely observed after cataract and retinal detachment surgery), +• Ptosis due to aponeurotic weakness associated with blepharochalasis, and +• Traumatic dehiscence or disinsertion of the aponeurosis. +4. Mechanical ptosis. It may result due to excessive weight on the upper lid as seen in patients with lid tumours, multiple chalazia and lid oedema. It may also occur due to scarring (cicatricial ptosis) as seen in patients with ocular pemphigoid and trachoma. + +Clinical evaluation +Following scheme may be adopted for work up of a ptosis patient: +I. History +It should include age of onset, family history, history of trauma, eye surgery and variability in degree of the ptosis. +II. Examination +1. Exclude pseudoptosis (simulated ptosis) on inspection. Its common causes are: +• Ipsilateral conditions such a microphthalmos, phthisis bulbi, enophthalmos, prosthesis, brow ptosis, dermatochalasis, and hypotropia. +• Contralateral conditions include: eyelid retraction, high myopia, and proptosis. +2. Observe the following points in each case: +• Whether ptosis is unilateral or bilateral. Causes of bilateral ptosis include congenital ptosis, myasthenia gravis, myotonic dystrophy, Kearns-Sayre syndrome, Lambert-Eaton myasthenic syndrome, and chronic progressive external ophthalmoplegia. +• Function of orbicularis oculi muscle. • Eyelid crease is present or absent. + +• Jaw-winking phenomenon is present or not. +• Associated weakness of any extraocular muscle. • Bell’s phenomenon (up and outrolling of the +eyeball during forceful closure) is present or absent. +3. Measurement of amount (degree) of ptosis. +• In unilateral cases, difference between the vertical height of the palpebral fissures of the two sides indicates the degree of ptosis (Fig. 15.34). +• In bilateral cases it can be determined by measuring the amount of cornea covered by the upper lid and then subtracting 2 mm.Ptosis is graded depending upon its amount as: +• Mild ptosis : 2 mm • Moderate ptosis : 3 mm • Severe ptosis : 4 mm +4. Margin reflex distance (MRD) refers to the distance between the upper lid margins and corneal light reflex (of a pen torch held in front, on which patient is looking). Normal value of MRD is 4–5 mm. +5. Assessment of levator function. It is determined by the lid excursion caused by LPS muscle (Burke’s method). Patient is asked to look down, and thumb of one hand is placed firmly against the eyebrow of the patient (to block the action of frontalis muscle) by the examiner. Then the patient is asked to look up and the amount of upper lid excursion is measured with a ruler (Fig. 15.35) held in the other hand by the examiner. Levator function is graded as follows: +• Normal : 15 mm +• Good : 8 mm or more • Fair: : 5–7 mm +• Poor : 4 mm or less +6. Special investigations. Those required in patients with acquired ptosis are as follows: + + + + + + + + + + + + + + + +Fig. 15.34 Measurement of degree of ptosis in millimeters +Chapter 15 Disorders of Eyelids 381 + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 15.35 Assessment of levator function: A, looking down: B, looking up + +i. Tensilon test is performed when myasthenia is suspected. There occurs improvement of ptosis with intravenous injection of edrophonium (Tensilon) in myasthenia. +ii. Phenylephrine test is carried out in patients suspected of Horner’s syndrome. +iii.Neurological investigations may be required to find out the cause in patient with neurogenic ptosis. +7. Photographic record of the patient should be maintained for comparison. Photographs should be taken in primary position as well as in up and down gazes. + +Treatment +I. Treatment of Congenital ptosis +It almost always needs surgical correction. In severe ptosis, surgery should be performed at the earliest to prevent stimulus deprivation amblyopia. However, in mild and moderate ptosis, surgery should be delayed until the age of 34 years, when accurate measurements are possible. Congenital ptosis can be treated by any of the following operations: +1. Tarso-conjunctivo-Mullerectomy (Fasanella-Servat operation).It is performed in cases having mild ptosis (1.5–2 mm) and good levator function. In it, upper + +lid is everted and the upper tarsal border along with its attached Muller’s muscle and conjunctiva are resected (Fig. 15.36). +2. Levator resection. It is a very commonly performed operation for moderate and severe grades of ptosis. It is contraindicated in patients having severe ptosis with poor levator function. +Amount of levator resection required: Most of the surgeons find it out by adjusting the lid margin in relation to cornea during operation on the table in individual case. However, a rough estimate in different grades of ptosis can be made: +■Moderate ptosis. Depending on the level of LPS function the amount of LPS to be resected is as below: +• Good function : 16–17 mm (minimal) • Fair function : 18–22 mm (moderate) +• Poor function : 23–24 mm (maximum) ■Severe ptosis. Fair levator function: 23–24 mm +(maximum LPS resection). +Techniques. Levator muscle may be resected by either conjunctival or skin approach. +i. Conjunctival approach (Blaskowics’ operation): This technique is comparatively easy but not suitable for large amount of resection. In it LPS muscle is exposed by an incision made through the conjunctiva near the upper tarsal border, after the upper lid is doubly everted over a Desmarre’s lid retractor (Fig. 15.37). +ii. Skin approach (Everbusch’s operation): It is a more frequently employed technique. It allows comparatively better exposure of the LPS muscle through a skin incision along the line of future lid crease (Fig. 15.38). +3. Frontalis sling operation (Brow suspension). This is performed in patients having severe ptosis with no levator function. In this operation, lid is anchored to the frontalis muscle via a sling (Fig. 15.39). Fascia lata (best material) or some non-absorbable material + + + + + + + + + + + + + +Fig. 15.36 Fasanella-Servat operation +382 Section II Diseases of Eye + + + + + + + + + + + + + + + + + + + +Fig. 15.37 Conjunctival approach for levator resection + + + + + + + + + + + + + + + + +Fig. 15.38 Skin approach for levator resection + + + + + + + + + + + + + + + + + + +Fig. 15.39 Frontalis sling operation + +(e.g., supramide suture, silicon rod) may be used as sling. +II. Treatment of acquired ptosis +• Treat the underlying cause wherever possible. +• Conservative treatment should be carried out and surgery deferred at least for 6 months in neurogenic ptosis. +• Surgical procedures (when required) for acquired ptosis are essentially the same as described for congenital ptosis. However, the amount of levator resection required is always less than the congenital ptosis of the same degree. Further, in most cases the simple Fasanella-Servat procedure is adequate. +LID RETRACTION +Normally, the upper eyelid covers 1/6th of the cornea (about 2 mm). Lid retraction is labelled when the lid margin is either at or above the level of superior limbus. Causes of lid retraction are as below: +1. Congenital. The lid retraction may occur isolated or in association with Duane’s retraction syndrome and Down’s syndrome. +2. Thyroid eye disease is the more common cause. 3. Mechanical causes of lid retraction are: +• Surgical overcorrection of ptosis, and +• Scarring of the upper eyelid skin after burns, trauma or infection. +4. Neurogenic causes include: +• Facial palsy (due to unopposed levator action), • Third nerve misdirection, +• Marcus-Gunn jaw winking syndrome • Parinaud syndrome, and +• Effect of sympathomimetic eyedrops 5. Systemic causes: +• Uraemia. + +TUMOURS OF EYELIDS + +Almost all types of tumours arising from the skin, connective tissue, glandular tissue, blood vessels, nerves and muscles can involve the eyelids. A few common tumours are listed and only the important ones are described here. +Classification +1. Benign tumours. These include; simple papilloma, naevus, angioma, haemangioma, neurofibroma and sebaceous adenoma. +2. Pre-cancerous conditions. These are solar keratosis, carcinoma in situ and xeroderma pigmentosa. +3. Malignant tumours. Commonly observed tumours include squamous cell carcinoma, basal cell carcinoma, malignant melanoma and sebaceous gland adenocarcinoma. +Chapter 15 Disorders of Eyelids 383 + + +BENIGN TUMOURS 1. Papillomas +Papillomas are the most common benign tumours arising from the surface epithelium. These occur in two forms: squamous papillomas and seborrhoeic keratosis. +i. Squamous papillomas derived from squamous cells occur in adults, as very slow growing or stationary, raspberry-like growths or as a pedunculated lesion, usually involving the lid margin. These may be nonspecific or related to human papilloma virus (viral wart or verruca vulgaris). Its treatment consists of simple excision. +ii. Seborrhoeic keratosis (basal cell papilloma), derived from basal cells occurs in middle-aged and older persons. Their surface is friable, verrucous and slightly pigmented. +2. Xanthelasma +These are creamy-yellow plaque-like lesions which frequently involve the skin of upper and lower lids near the inner canthus (Fig. 15.40). Xanthelasma occurs more commonly in middle-aged women. Xanthelasma represents lipid deposits in histiocytes in the dermis of the lid. These may be associated with diabetes mellitus or high cholesterol levels. ■Treatment: Excision may be advised for cosmetic reasons; but recurrences are common. + +3. Haemangioma +Haemangiomas of the lids are common tumours. These occur in three forms: +i. Capillary haemangioma (Fig. 15.41) is the most common variety which occurs at or shortly after birth, often grows rapidly and in many cases resolves spontaneously by the age of 7 years. These may be superficial and bright red in colour (strawberry naevus) or deep bluish or violet in colour. They consist of proliferating capillaries and endothelial cells. ■Treatment. Unless the tumour is very large it may be left untouched until the age of 7 years (as in many + + + + + + + + + + + + +Fig. 15.40 Xanthelasma + + + + + + + + + + + + +Fig. 15.41 Capillary haemangioma + +cases it resolves spontaneously). The treatment modalities include: +• Excision: It is performed in small tumours. +• Intralesional steroid (triamcinolone) injection is effective in small to medium size tumours. +• High dose oral steroid therapy, alternate day regimen is recommended for large diffuse tumours. +• Superficial radiotherapy may also be given for large tumours. +ii. Naevus flammeus (port wine stain). It may occur pari passu or more commonly as a part of Sturge-Weber syndrome. It consists of dilated vascular channels and does not grow or regress like the capillary haemangioma. +iii. Cavernous haemangiomas are developmental venous anomaly and usually occur after first decade of life. It consists of large endothelium-lined vascular channels and usually does not show any regression. Treatment is similar to capillary haemangiomas. +4. Neurofibroma +Lids and orbits are commonly affected in neurofibromatosis (von Recklinghausen’s disease). The tumour is usually of plexiform type (Fig. 15.42). +5. Keratoacanthomas +Keratoacanthomas occur as nonpigmented protrusions with a keratin filled central crater. + + + + + + + + + + + + +Fig. 15.42 Neurofibroma upper eyelid +384 Section II Diseases of Eye + + +These are comparatively uncommon tumours that grow rapidly for 2 to 6 weeks and then spontaneously involute over a few months. +■Differential diagnosis need to be made sometimes from the squamous cell carcinoma. +■Treatment consists of complete excision and biopsy. Incomplete specimen may be indistinguishable from a squamous cell carcinoma on histopathological examination. +6. Naevi +Naevi are common cutaneous lesions that arise from the arrested epidermal melanocytes . +Types. Depending upon the depth of involvement, naevi are of three types: +• Junctional naevi,located at the epidermis/dermis. • Junctional naevi, are flat, brown in appearance +(Fig. 15.43). +• Dermal naevi, located within the dermis, are elevated lesions which may not be visibly pigmented. +• Compound naevi, are slightly elevated and share features of junctional and dermal naevi. + +PREMALIGNANT TUMOURS Actinic (solar) keratosis +Actinic keratosis, though a common lesion of sun exposed skin is relatively uncommon on the eyelids. ■Clinical features include a flat, scaly lesion with +hyperkeratosis with or without keratin horn. ■Histologically, it is characterized by parakeratosis +and cellular atypia but no invasion. + +Xeroderma pigmentosa +Characteristic features of this autosomal recessive (AR) disease are: +• Progressive cutaneous pigmentation resulting from damage on exposure to natural sunlight. +• Bird-like facies is typical of this condition. +• Predisposition to develop lid tumours (basal + + + + + + + + + + + + + + +Fig. 15.43 Divided naevi of eyelids + + +cell carcinoma, squamous cell carcinoma and melanoma) and conjunctival malignancies. +MALIGNANT TUMOURS +1. Basal cell carcinoma +As per western literature it is the commonest malignant tumour of the lids (90%) usually seen in elderly people. It is locally malignant and involves most commonly lower lid (50%) followed by medial canthus (25%), upper lid (10–15%) and outer canthus (5–10%). Predisposing factors include increasing age, white skin, sun exposure, xeroderma pigmentosa and basal cell naevus syndrome. +Clinical features. It may present in four forms: • Non-ulcerated nodular form +} +• Sclerosing or morphea type rare presentation, • Pigmented basal cell carcinoma. +• Noduloulcerative basal cell carcinoma is the most common presentation. It starts as a small nodule which undergoes central ulceration with pearly rolled margins. The tumour grows by burrowing and destroying the tissues locally like a rodent and hence the name rodent ulcer (Fig. 15.44). +Histological features. The most common pattern is solid basal cell carcinoma in which the dermis is invaded by irregular masses of basaloid cells with characteristic peripheral palisading appearance. +Treatment includes: +• Surgery. Local surgical excision of the tumour along with a 3 mm surrounding area of normal skin with primary repair is the treatment of choice. Mohs’ microsurgical technique or frozen section biopsy should be adopted for complete removal. +• Radiotherapy and cryotherapy should be given only in inoperable cases for palliation. +2. Squamous cell carcinoma +It forms the second commonest malignant tumour of the lid. Its incidence (5%) is much less than the + + + + + + + + + + + + + + +Fig. 15.44 Basal cell carcinoma lower eyelid +Chapter 15 Disorders of Eyelids 385 + +basal cell carcinoma. It commonly arises from the lid margin (mucocutaneous junction) in elderly patients de novo or from pre-existing lesion such as actinic keratosis, Bowen’s disease and radiation dermatosis. It affects lower lids more frequently. +Risk factors include sun exposure, radiation, fair skin, injury or other irritative insults. There is a male predilection. +Clinical features. It may present in two forms: +• Ulcerated, scaly, erythematous plaque like growth with elevated and indurated margins is the common presentation (Fig. 15.45). +• Fungating or polypoid verrucous lesion without +ulceration, is a rare presentation. Fig. 15.46 Meibomian gland carcinoma lower eyelid + +4. Malignant melanoma (Melanocarcinoma) Malignant melanoma (Fig. 15.47) is a rare tumour of the lid (less than 1% of all eyelid lesions). It may arise from a pre-existing naevus, but usually arises de novo from the melanocytes present in the skin. + + + + + + + +Fig. 15.45 Squamous cell carcinoma of upper lid + + +Metastasis. It is metastasized in preauricular and submandibular lymph nodes. +Histological features. It is characterised by an irregular downward proliferation of epidermal cells into the dermis. In well-differentiated form, the malignant cells have a whorled arrangement forming epithelial pearls which may contain laminated keratin material in the centre. +Treatment is on the lines of basal cell carcinoma. +3. Sebaceous gland carcinoma +It is a rare tumour arising from the meibomian glands (western literature). However, Indian literature reports the sebaceous gland carcinoma being the commonest malignancy of eyelid followed by basal cell and squamous cell carcinoma. +Clinical features. It usually presents initially as a nodule (which may be mistaken for a chalazion), more frequently on the upper eyelid. Which then grows to form a big growth (Fig. 15.46). Rarely, a diffuse tumour along the lid margin may be mistaken as chronic blepharitis. +Treatment. Surgical excision with reconstruction of the lids is the treatment of choice. Recurrences are common. + + + + + + +Fig. 15.47 Malignant melanoma + +Clinical features. It may present in three forms: +• Lentigo maligna type is characterized initially by a flat, pigmented, well-defined lesion which later on becomes elevated as it invades the dermis. +• Superficial spreading type is characterized by mildly elevated, pigmented lesion with irregular margins. +• Nodular type is characterized by a rapidly growing lesion (may not be visibly pigmented), which ulcerates and bleeds frequently. +Metastasis. The tumour spreads locally as well as to distant sites by lymphatics and bloodstream. Treatment. It is a radio-resistant tumour. Therefore, surgical excision with 10 mm margins (confirmed on frozen section) with reconstruction of the lid is the treatment of choice. +16 +Diseases of Lacrimal Apparatus + + + +Chapter Outline + +APPLIED ANATOMY Main lacrimal gland +Accessory lacrimal glands Lacrimal passages +• +• +• +TEAR FILM Structure Functions Secretion of tears Elimination of tears +• +• +• +• +THE DRY EYE Sjogren’s syndrome +• +THE WATERING EYE Etiology +• + + + +Applied AnAtomy + +The lacrimal apparatus comprises • Lacrimal glands, and +• Lacrimal passages, which include: puncta, canaliculi, lacrimal sac and nasolacrimal duct (NLD) (Fig. 16.1) + +Lacrimal glands +Lacrimal glands includes main and accessory. + +Main lacrimal gland +It consists of an upper orbital and a lower palpebral part. + +1. Orbital part +Orbital part is larger, about the size and shape of a small almond, and is situated in the fossa for lacrimal gland at the outer part of the orbital plate of frontal bone. It has got two surfaces—superior and inferior. The superior surface is convex and lies in contact with the bone. The inferior surface is concave and lies on the levator palpebrae superioris muscle. + +2. Palpebral part +Palpebral part is small and consists of only one or two lobules. It is situated upon the course of the + +• Clinical evaluation +DACRYOCYSTITIS +• Congenital dacryocystitis Adult dacryocystitis +• +• +Surgical technique of DCR and DCT +SWELLINGS OF LACRIMAL GLAND +• Dacryoadenitis Mikulicz’s syndrome Dacryopes +• +• +• +Tumours + + + + + + + + + + + + + + +Fig. 16.1 The lacrimal apparatus +ducts of orbital part from which it is separated by LPS muscle. Posteriorly, it is continuous with the orbital part. +Ducts of lacrimal gland +Approximately 10–12 ducts pass downward from the main gland to open in the lateral part of superior fornix. One or two ducts also open in the lateral part of inferior fornix. +Accessory lacrimal glands +1. Glands of Krause. These are microscopic glands lying beneath the palpebral conjunctiva between fornix and the edge of tarsus. These are about 42 in the upper fornix and 6–8 in the lower fornix (see Fig. 15.4). +Chapter 16 Diseases of Lacrimal Apparatus 387 + + +2. Glands of Wolfring. These are present near the upper border, of the superior tarsal plate and along the lower border of inferior tarsus (see Fig. 15.4). +Structure, blood supply and nerve supply Structure.All lacrimal glands are serous acini, similar in structure to the salivary glands. Microscopically these consist of glandular tissue (acini and ducts), connective tissue and puncta. +Blood supply. Main lacrimal gland is supplied by lacrimal artery which is a branch of ophthalmic artery. +Nerve supply includes: +1. Sensory supply comes from lacrimal nerve, a branch of the ophthalmic division of the fifth nerve. +2. Sympathetic supplycomes from the carotid plexus of the cervical sympathetic chain. +3. Secretomotor fibres are derived from the superior salivary nucleus (pons) greater petrosal nerve +synapse at pterygopalatine ganglion zygomatic nerve lacrimal nerve lacrimal gland. + +Lacrimal passages +1. Lacrimal puncta +These are two small, rounded or oval openings on upper and lower lids, about 6 and 6.5 mm, respectively, temporal to the inner canthus. Each punctum is situated upon a slight elevation called lacrimal papilla which becomes prominent in old age. Normally, the puncta dip into the lacus lacrimalis (collection of tear fluid in the inner canthus). +2. Lacrimal canaliculi +Superior and inferior canaliculi join the puncta to the lacrimal sac. Each canaliculus has two parts: vertical (1–2 mm) and horizontal (6–8mm) which lie at right angle to each other. The horizontal part converges towards inner canthus to open in the sac. The two canaliculi may open separately or may join to form common canaliculus which opens immediately into the outer wall of lacrimal sac. Afold of mucosa at this point forms the valve of Rosenmuller which prevents reflux of tears. +3. Lacrimal sac +Location: It lies in the lacrimal fossa located in the anterior part of medial orbital wall. The lacrimal fossa is formed by lacrimal bone and frontal process of maxilla. It is bounded by anterior and posterior lacrimal crests. Lacrimal fascia, which encloses the lacimal sac, is formed by periorbita. The periorbita splits at the posterior lacrimal crest into two layers + +which enclose the sac and again fuse at the anterior lacrimal crest. Between the lacrimal sac and the fascia lies alveolar tissue and venous plexus which becomes continuous around the nasolacrimal duct. Size: When distended, lacrimal sac is about 12–15 mm in length and 5–6 mm in breadth with a volume of about 2 cc. +Parts: It has got three parts: fundus (portion above the opening of canaliculi), body (middle part) and the neck (lower small part which is narrow and continuous with the nasolacrimal duct). +4. Nasolacrimal duct (NLD) +Dimensions and location. It extends from neck of the lacrimal sac to inferior meatus of the nose. It is about 15–18 mm long and lies in a bony canal formed by the maxilla and the inferior turbinate. +Direction of the NLD is downwards, backwards and laterally. Externally, its location is represented by a line joining inner canthus to the ala of nose. The upper end of the NLD is the narrowest part. Numerous membranousvalves are present in the NLD, the most important is the valve of Hasner, which is present at the lower end of the duct and prevents reflux from the nose. + +teAR Film +Structure of tear film +Wolff was the first to describe the detailed structure of the fluid covering the cornea and called it precorneal film. He described this film to consist of three layers, which from posterior to anterior are mucus layer, aqueous layer and lipid or oily layer (Fig. 16.2). +1. Mucus layer. It is the innermost and about 0.2 mm thick stratum of the tear film. It consists of mucin secreted by conjunctival goblet cells and glands of Manz. It converts the hydrophobic corneal surface into hydrophilic one. +2. Aqueous layer. The bulk of tear film (7.0 mm) is formed by this intermediate layer which consists of +tears secreted by the main and accessory lacrimal glands. The tears mainly comprise of water and small quantities of solutes such as sodium chloride, sugar, urea and proteins. Therefore, it is alkaline and salty in taste. It also contains antibacterial substances like lysozyme, betalysin and lactoferrin. +3. Lipid or oily layer. This is the outermost and thinnest (0.1mm) layer of tear film formed at air-tear interface from the secretions of meibomian, zeis, and moll glands. This layer prevents the overflow of tears, retards their evaporation and lubricates the eyelids as they slide over the surface of the globe. +388 Section iii Diseases of Eye + + + + + + + + + + + + + + + + + + +Fig. 16.2 Structure of the tear film + + +Functions of tear film +1. Keeps moist the cornea and conjunctiva. 2. Provides oxygen to the corneal epithelium. 3. Washes away debris and noxious irritants. +4. Prevents infection due to presence of anti-bacterial substances. +5. Facilitates movements of the lids over the globe. + +Secretion of tears +Tears are continuously secreted throughout the day by accessory (basal secretion) and main (reflex secretion) lacrimal glands. Reflex secretion is in response to sensations from the cornea and conjunctiva, probably produced by evaporation and breakup of tear film. Hyperlacrimation occurs due to irritative sensations from the cornea and conjunctiva. Afferent pathway of this secretion is formed by fifth nerve and efferent by parasympathetic (secretomotor) supply of lacrimal gland. + +Elimination of tears +From the lacrimal gland, the tears flow downwards and laterally across the ocular surface. A variable + +amount of tears is lost by evaporation from the ocular surface. The remainder of tears flow along the superior and inferior marginal strips and collects as lacus lacrimalis in the inner canthus (Fig. 16.3A), from where it is drained by the lacrimal passage into the nasal cavity. About 70% tears is drained via inferior canaliculus and 30% via the superior canaliculus by an active lacrimal pump mechanism constituted by the fibres of orbicularis as below: When the eyelids close with each blink there occurs: • Contraction of pretarsal orbicularis oculi which +compresses the ampulla and shortens the canaliculi. This movement propels the tear fluid present in the ampulla and horizontal part of canaliculi towards the lacrimal sac. +• Contraction of preseptal fibers of orbicularis distends the lacrimal sac and creates therein a negative pressure which draws the tear fluid from canaliculi into the lacrimal sac (Fig. 16.3B). +When the eyelids open following events occur: +• Relaxation of pretarsal orbicularis allows the canaliculi and ampulla to expand and reopen, and + + + + + + + + + + + + +A B C +Fig. 16.3 Elimination of tears by lacrimal pump mechanism +Chapter 16 Diseases of Lacrimal Apparatus 389 + + +to draw the tear fluid from the lacus lacrimalis and marginal tear strips. +• Relaxation of preseptal fibres (Horner’s muscle) results in collapse of sac, as a consequence a positive pressure is created which forces the tears down the nasolacrimal duct (NLD) into the nose (Fig. 16.3C). Gravity also helps in downward flow of tears along the NLD. +Note. In atonia of sac, tears are not drained through the lacrimal passages, in spite of anatomical patency; resulting in epiphora. + +tHe dRy eye + +The dry eye per se is not a disease entity, but a symptom complex occurring as a sequelae to deficiency or abnormalities of the tear film. +Etiology +According to International Dry Eye Workshop report (DEWS report 2007), the causes of dry eye can be classified as below: +I. Aqueous deficiency dry eye +Aqueous deficiency dry eye also known as keratoconjunctivitis sicca (KCS). Its causes include: a. Sjogren’s syndrome (Primary keratoconjunctivitis sicca). +b. Non-Sjogren’s keratoconjunctivitis sicca. Causes can be grouped as below: +1. Primary age-related hyposecretion is the most common cause. +2. Lacrimal gland deficiencies as seen in congenital alacrima, infiltrations of lacrimal gland, e.g., in sarcoidosis, tumours, post-radiation fibrosis of lacrimal gland and surgical removal. +3. Lacrimal gland duct obstruction as seen in old trachoma, chemical burns, cicatricial pemphigoid and Stevens-Johnson syndrome. +4. Reflex hyposecretion (neurogenic causes) as seen in Familial dysautonomia (Riley-Day syndrome), Parkinson disease, reflex sensory block, reflex motor blade, 7th cranial nerve damage, reduced corneal sensations after refractive surgery and corneal lens wear. +II. Evaporative dry eye +It is caused by the conditions which decrease tear film stability and thus increase evaporation. +Causes can be grouped as: +1. Meibomian gland dysfunction as seen in chronic posterior blepharitis, rosacea, and congenital absence of meibomian glands. +2. Lagophthalmos as seen in facial nerve palsy, severe proptosis, symblepharon and eyelid scarring. + +3. Defective blinking such as low blink rate as seen in prolonged computer users and other causes. +4. Vitamin A deficiency and other factors affecting ocular surface, e.g., topical drugs, preservatives, contact lens wear, ocular surface allergic disease and scarring disorders. +Clinical features +Symptoms suggestive of dry eye include irritation, foreign body (sandy) sensation, feeling of dryness, itching, nonspecific ocular discomfort and chronically sore eyes not responding to a variety of drops instilled earlier. +Signs of dry eye are as below: +• Tear film signs. It may show presence of stingy mucous and particulate matter. Marginal tear strip is reduced or absent (normal height is 1 mm). Froth in the tears along the lid margin is a sign of meibomian gland dysfunction. +• Conjunctival signs. It becomes lustureless, mildly congested, conjunctival xerosis and keratinization may occur. Rose Bengal or Lisamin green staining may be positive (details given in tear film tests). +• Corneal signs. It may show punctate epithelial erosions, filaments and mucus plaques. Cornea may loose lusture. Vital stains, fluorescein, Rose Bengal or Lisamin green may delineate the above lesions. +• Signs of causative disease such as posterior blepharitis, conjunctival scarring diseases (trachoma, Stevens-Johnson syndrome, chemical burns, ocular pemphigoid) and lagophthalmos may be depicted. +Tear film tests +These include tear film break-up time (BUT), Schirmer-I test, vital staining with Rose Bengal, tear levels of lysozyme and lactoferrin, tear osmolarity and conjunctival impression cytology. Out of these BUT, Schirmer-I test and Rose Bengal staining are most important and when any two of these are positive, diagnosis of dry eye syndrome is confirmed. 1. Tear film break-up (BUT). It is the interval between a complete blink and appearance of first randomly distributed dry spot on the cornea. It is noted after instilling a drop of fluorescein and examining in a cobalt-blue light of a slit-lamp. BUT is an indicator of adequacy of mucin component of tears. Its normal values range from 15 to 35 seconds. Values less than 10 seconds imply an unstable tear film. +2. Schirmer-I test. It measures total tear secretions. It is performed with the help of a 5 × 35 mm strip of Whatman-41 filter paper which is folded 5 mm from one end and kept in the lower fornix at the junction of lateral one-third and medial two-thirds. The patient is asked to look up and not to blink or +390 Section iii Diseases of Eye + + +close the eyes (Fig. 16.4). After 5 minutes wetting of the filter paper strip from the bent end is measured. Normal values of Schirmer-I test are more than 15 mm. Values of 5–10 mm are suggestive of moderate to mild keratoconjunctivitis sicca (KCS) and less than 5 mm of severe KCS. +3. Rose Bengal staining. It is a very useful test for detecting even mild cases of KCS. Depending upon the severity of KCS three staining patterns A, B and C have been described: ‘C’ pattern represents mild or early cases with fine punctate stains in the interpalpebral area; ‘B’ the moderate cases with extensive staining; and ‘A’ the severe cases with confluent staining of conjunctiva and cornea. +Grading of dry eye severity +Various criteria have been proposed to grade severity of dry eye. Recently accepted system based on severity of signs and tear film tests recommended by Dry Eye Workshop (DEWS) Report (2007) grades the severity of dry eye into 4 levels: +• Level 1 (mild dry eye), +• Level 2 (moderate dry eye), • Level 3 (severe dry eye), and • Level 4 (very severe dry eye). +Treatment +At present, there is no cure for dry eye. The following treatment modalities have been tried with variable results: +1. Supplementation with tear substitutes. Artificial tears remains the mainstay in the treatment of dry eye. These are available as drops, ointments and slow-release inserts. Mostly available artificial tear drops contain either cellulose derivatives (e.g., 0.25 to 0.7% methyl cellulose and 0.3% hypromellose) or polyvinyl alcohol (1.4%). +2. Topical cyclosporine (0.05%, 0.1%) is reported to be very effective drug for dry eye in many recent studies. + + + + + + + + + + + + + + + +Fig. 16.4 Schirmer test + + +It helps by reducing the cell-mediated inflammation of the lacrimal tissue. +3. Mucolytics, such as 5% acetylcystine used 4 times a day helps by dispersing the mucus threads and decreasing tear viscosity. +4.Preservation of existing tears by reducing evaporation and decreasing drainage. +• Evaporation can be reduced by decreasing room temperature, use of moist chambers and protective glasses. +• Punctal occlusion to decrease drainage can be carried out by collagen implants, cynoacrylate tissue adhesives, electrocauterisation, argon laser occlusion and surgical occlusion to decrease the drainage of tears in patients with very severe dry eye. +• Permanent lateral tarsorrhaphy may be required in very severe cases. +5. Treatment of the causative disease of dry eye when discovered is very useful e.g.: +• Systemic tetracyclines and lid hygiene in patients with chronic posterior blepharitis +• Vitamin A supplement for the deficiency • Treat the cause of lagophthalmos. +SjOGrEN’S SyNDrOME +Etiology: It is an autoimmune chronic inflammatory disease with multisystem involvement. It typically occurs in women between 40 and 50 years of age. Characteristic feature is an aqueous deficiency dry eye—the keratoconjunctivitis sicca (KCS). +• In primary Sjogren’s syndrome patients present with sicca complex—a combination of KCS and xerostomia (dryness of mouth). +• In secondary Sjogren’s syndrome dry eye and/or dry mouth are associated with an autoimmune disease, commonly rheumatoid arthritis. +Pathological features include focal accumulation and infiltration by lymphocytes and plasma cells with destruction of lacrimal and salivary glandular tissue. + +tHe WAteRinG eye + +It is characterised by overflow of tears from the conjunctival sac. The condition may occur either due to excessive secretion of tears (hyperlacrimation) or may result from inadequate drainage (outflow) of normally secreted tears (epiphora). +Etiology +A. Causes of hyperlacrimation +1. Primary hyperlacrimation. It is a rare condition which occurs due to direct stimulation of the lacrimal gland. It may occur in early stages of lacrimal gland +Chapter 16 Diseases of Lacrimal Apparatus 391 + + +tumours and cysts and due to the effect of strong parasympathomimetic drugs. +2. Reflex hyperlacrimation. It results from stimulation of sensory branches of fifth nerve due to irritation of cornea or conjunctiva. It may occur in multitude of conditions which include: +• Affections of the lids: Stye, hordeolum internum, acute meibomitis, trichiasis, concretions and entropion. +• Affections of the conjunctiva: Conjunctivitis which may be infective, allergic, toxic, irritative or traumatic. +• Affections of the cornea: These include, corneal abrasions, corneal ulcers and non-ulcerative keratitis. +• Affections of the sclera: Episcleritis and scleritis. +• Affections of uveal tissue: Iritis, cyclitis, iridocyclitis. • Acute glaucomas. +• Endophthalmitis and panophthalmitis. • Orbital cellulitis. +3. Central lacrimation (psychical lacrimation). The exact area concerned with central lacrimation is still not known. It is seen in emotional states, voluntary lacrimation and hysterical lacrimation. +B. Causes of epiphora +Inadequate drainage of tears may occur due to physiological or anatomical (mechanical) causes. +I. Physiological cause is ‘lacrimal pump’ failure due to lower lid laxity or weakness of orbicularis muscle. II. Mechanical obstruction in lacrimal passages may lie at the level of punctum, canaliculus, lacrimal sac or nasolacrimal duct. +1. Punctal causes include: +• Eversion of lower punctum: It is commonly seen in old age due to laxity of the lids. It may also occur following chronic conjunctivitis, chronic blepharitis and due to any cause of ectropion. +• Punctal obstruction: There may be congenital absence of puncta or cicatricial closure following injuries, burns or infections. Rarely, a small foreign body, concretion or cilia may also block the punctum. Prolonged use of drugs like idoxuridine and pilocarpine is also associated with punctal stenosis. +2. Causes in the canaliculi. Canalicular obstruction may be congenital or acquired due to foreign body, trauma, idiopathic fibrosis and canaliculitis. Commonest cause of canaliculitis is actinomyces. 3. Causes in the lacrimal sac. These include congenital mucous membrane folds, traumatic strictures, dacryocystitis, specific infections like tuberculosis and syphilis, dacryolithiasis and tumours (Atonia of the sac is a physiological cause). + +4. Causes in the nasolacrimal duct. Congenital lesions include noncanalization, partial canalization or imperforated membranous valves. Acquired causes of obstruction are traumatic strictures, inflammatory strictures, idiopathic stenosis, tumours and diseases of the surrounding bones. +Clinical evaluation of a case of `watering eye’ +1. Ocular examination with diffuse illumination using magnificationshould be carried to rule out any cause of reflex hypersecretion located in lids, conjunctiva, cornea, sclera, anterior chamber, uveal tract and so on. This examination should also exclude punctal causes of epiphora and any swelling in the sac area. 2. Regurgitation test. A steady pressure with index finger is applied over the lacrimal sac area above the medial palpebral ligament. Reflux of mucopurulent discharge indicates chronic dacryocystitis with obstruction at lower end of the sac or the nasolacrimal duct. +3. Fluorescein dye disappearance test (FDDT). In this test 2 drops of fluorescein dye are instilled in both the conjunctival sacs and observations are made after 2 minutes. Normally, no dye is seen in the conjunctival sac. A prolonged retention of dye in conjunctival sac indicates inadequate drainage which may be due to atonia of sac or mechanical obstruction. +4. Lacrimal syringing test.It is performed after topical anaesthesia with 4% xylocaine (Fig. 16.5). Normal saline is pushed into the lacrimal sac from lower punctum with the help of a syringe and lacrimal cannula. +• A free passage of saline through lacrimal passages into the nose rules out any mechanical obstruction. + + + + + + + + + + + + + + + + + + + +Fig. 16.5 Technique of lacrimal syringing +392 Section iii Diseases of Eye + + +• In the presence of partial obstruction, saline passes with considerable pressure on the syringe. +• In the presence of obstruction no fluid passes into nose and it may reflux through same punctum (indicating obstruction in the same or common canaliculus) or through opposite punctum (indicating obstruction in the lower sac or nasolacrimal duct). +5. Jones dye tests. These are performed when partial obstruction is suspected. Jones dye tests are of no value in the presence of total obstruction. +i. Jones primary test (Jones test I). It is performed to differentiate between watering due to partial obstruction of the lacrimal passages from that due to primary hypersecretion of tears. Two drops of 2% fluorescein dye are instilled in the conjunctival sac and a cotton bud dipped in 1% xylocaine is placed in the inferior meatus at the opening of nasolacrimal duct. After 5 minutes the cotton bud is removed and inspected. A dye-stained cotton bud indicates adequate drainage through the lacrimal passages and the cause of watering is primary hypersecretion (further investigations should aim at finding the cause of primary hypersecretion). While the unstained cotton bud (negative test) indicates either a partial obstruction or failure of lacrimal pump mechanism. To differentiate between these conditions, Jones dye test-II is performed. +ii. Jones secondary test (Jones test II). When primary test is negative, the cotton bud is again placed in the inferior meatus and lacrimal syringing is performed. A positive test suggests that dye was present in the sac but could not reach the nose due to partial obstruction. A negative test indicates presence of lacrimal pump failure. +6. Dacryocystography. It is valuable in patients with mechanical obstruction. It tells the exact site, nature and extent of block (Fig. 16.6). In addition, it also gives + + +information about mucosa of the sac, presence of any fistulae, diverticulae, stone, or tumour in the sac. To perform it a radiopaque material such as lipiodol, pentopaque, dianosil or condray-280 is pushed in the sac with the help of a lacrimal cannula and X-rays are taken after 5 minutes and 30 minutes to visualize the entire passage. For better anatomical visualization the modified technique known as subtraction macrodacryocystography with +canalicular catheterisation should be preferred. +7. Radionucleotide dacryocystography (lacrimal scintillography). It is a noninvasive technique to assess the functional efficiency of lacrimal drainage apparatus. A radioactive tracer (sulphur colloid or technetium) is instilled into the conjunctival sac and its passage through the lacrimal drainage system is visualised with an Anger gamma camera (Fig. 16.7). + +dACRyoCyStitiS + +Inflammation of the lacrimal sac is not an uncommon condition. It may occur in two forms: congenital and adult dacryocystitis. +CONGENITAL DACryOCySTITIS +It is an inflammation of the lacrimal sac occurring in newborn infants; and thus also known as dacryocystitis neonatorum. +Etiology +It follows stasis of secretions in the lacrimal sac due to congenital blockage in the nasolacrimal duct. It is of very common occurrence. As many as 30% of newborn infants are believed to have closure of nasolacrimal duct at birth. +• Membranous occlusion’ at its lower end, near the valve of Hasner is the commonest cause. +• Other causes of congenital NLD block are: presence of epithelial debris, membranous occlusion at its upper end near lacrimal sac, complete noncanalisation and rarely bony occlusion. +• Common bacteria associated with congenital dacryocystitis areStaphylococci, Pneumococci and Streptococci. + + + + + + + + +A B +Fig. 16.7 Lacrimal scintillography showing: A, normal lacrimal excretory system on right side; B, obstruction at +Fig. 16.6 Normal dacryocystogram the junction of lacrimal sac and nasolacrimal on left side +Chapter 16 Diseases of Lacrimal Apparatus 393 + + +Clinical features +Congenital dacryocystitis usually presents as a mild grade chronic inflammation. It is characterised by: 1. Epiphora, usually developing after seven days of birth. It is followed by copious mucopurulent discharge from the eyes. +2. Regurgitation test is usually positive, i.e., when pressure is applied over the lacrimal sac area, purulent discharge regurgitates from the lower punctum. +3. Swelling on the sac area may appear eventually. + +Differential diagnosis +Congenital dacryocystitis needs to be differentiated from other causes of watering in early childhood especially: +■Ophthalmia neonatorum and ■Congenital glaucoma. +Complications +When not treated in time it may be complicated by recurrent conjunctivitis, acute or chronic dacryocystitis, lacrimal abscess and fistulae formation. +Treatment +It depends upon the age at which the child is brought. The treatment modalities employed are as follows: 1. Massage over the lacrimal sac area and topical antibiotics constitute the mainstay of treatment of congenital NLD block. Massage increases the hydrostatic pressure in the sac and helps to open up the membranous occlusions. It should be carried out at least 4 times a day to be followed by instillation of antibiotic drops. This conservative treatment coupled with spontaneous recanalization cure obstruction in about 90% of the infants upto 6-9 months. +2. Lacrimal syringing (irrigation) with normal saline and antibiotic solution. It should be added to the conservative treatment if the condition is not cured up to the age of 3 months. Lacrimal irrigation helps to open the membranous occlusion by exerting hydraulic pressure. Syringing may be carried out once a week or once in two weeks. +3. Probing of NLD with Bowman’s probe. It should be performed in case the condition is not cured by the age of 6 months. Some surgeons prefer to wait till the age of 9–12 months. It is usually performed under general anaesthesia. While performing probing, care must be taken not to injure the canaliculus. In most instances, a single probing will relieve the obstruction. In case of failure, it may be repeated after an interval of 3–4 weeks. + +4. Balloon catheter dilation, with the help of a probe carrying inflatable balloon, may be carried out in children where repeated probing is failure or directly in cases where the obstruction seems to be due to scarring or constriction rather than merely by a distal membrane. +5. Intubation with silicone tube may be performed if repeated probings and balloon catheter dilation are failure. The silicone tube should be kept in the NLD for about six months. +6. Dacryocystorhinostomy (DCR) operation: When the child is brought very late or repeated probing, balloon catheter dilation and intubation are a failure, then conservative treatment by massaging, topical antibiotics and intermittent lacrimal syringing should be continued till the age of 4 years. After this, DCR operation should be performed. + +ADuLT DACryOCySTITIS +Adult dacryocystitis may occur in an acute or a chronic form. + +Chronic Dacryocystitis +Chronic dacryocystitis is more common than the acute dacryocystitis. + +Etiology +The etiology of chronic dacryocystitis is multifactorial. The well-established fact is a vicious cycle of stasis and mild infection of long duration. The etiological factors can be grouped as under: +A. Predisposing factors +1. Age. It is more common between 40 and 60 years of age. +2. Sex.The disease is predominantly seen in females (80%) probably due to comparatively narrow lumen of the bony canal. +3. Race. It is rarer among Negroes than in Whites; as in the former NLD is shorter, wider and less sinuous. +4. Heredity. It plays an indirect role. It affects the facial configuration and so also the length and width of the bony canal. +5. Socio-economic status. It is more common in low socio-economic group. +6. Poor personal hygiene. It is also an important predisposing factor. +B. Factors responsible for stasis of tears in lacrimal sac 1. Anatomical factors,which retard drainage of tears +include: comparatively narrow bony canal, partial canalization of membranous NLD and excessive membranous folds in NLD. +394 Section iii Diseases of Eye + + +2. Foreign bodies in the sac may block opening of NLD. +3. Excessive lacrimation, primary or reflex, causes stagnation of tears in the sac. +4. Mild grade inflammation of lacrimal sac due to associated recurrent conjunctivitis may block the NLD by epithelial debris and mucus plugs. +5. Obstruction of lower end of the NLD by nasal diseases such as polyps, hypertrophied inferior concha, marked degree of deviated nasal septum, tumours and atrophic rhinitis causing stenosis may also cause stagnation of tears in the lacrimal sac. +C. Source of infection +Lacrimal sac may get infected from the conjunctiva, nasal cavity (retrograde spread), or paranasal sinuses. +D. Causative organisms +These include: Staphylococci, Pneumococci, Streptococci and Pseudomonas pyocyanea. Rarely chronic granulomatous infections like tuberculosis, syphilis, leprosy and occasionally rhinosporiodosis may also cause dacryocystitis. +Clinical features +Clinical features of chronic dacryocystitis may be divided into four stages: +1. Stage of chronic catarrhal dacryocystitis. It is characterised by mild inflammation of the lacrimal sac associated with blockage of NLD. +• Watering eye is the only symptom in this stage and sometimes mild redness in the inner canthus. +• On syringing the lacrimal sac, either clear fluid or few fibrinous mucoid flakes regurgitate. +• Dacryocystography reveals block in NLD, a normal-sized lacrimal sac with healthy mucosa. +2. Stage of lacrimal mucocele. It follows chronic stagnation causing distension of lacrimal sac. +• Characteristic features include constant epiphora associated with a swelling just below the inner canthus (Fig. 16.8). + + + + + + + + + + + + + +Fig. 16.8 Lacrimal mucocele + +• Regurgitation test.Milky or gelatinous mucoid fluid regurgitates from the lower punctum on pressing the swelling. +• Dacryocystography at this stage reveals a distended sac with blockage somewhere in the NLD. +• Encysted mucocele. Sometimes due to continued chronic infection, opening of both the canaliculi into the sac are blocked and a large fluctuant swelling is seen at the inner canthus with a negative regurgitation test. This is called encysted mucocele. +3. Stage of chronic suppurative dacryocystitis. Due to pyogenic infection, the mucoid discharge becomes purulent, converting the mucocele into ‘pyocoele’. • The condition is characterised by epiphora, +associated recurrent conjunctivitis and swelling at the inner canthus with mild erythema of the overlying skin. +• On regurgitation a frank purulent discharge flows from the lower punctum. +• If openings of canaliculi are blocked at this stage the so called encysted pyocoele results. +4. Stage of chronic fibrotic sac. Low grade repeated infections for a prolonged period ultimately result in a small fibrotic sac due to thickening of mucosa, which is often associated with persistent epiphora and discharge. +• Dacryocystography at this stage reveals a very small sac with irregular folds in the mucosa. +Complications +• Chronic intractable conjunctivitis, acute or chronic dacryocystitis. +• Ectropion of lower lid, maceration and eczema of lower lid skin due to prolonged watering. +• Chances of corneal ulceration are those as simple corneal abrasions may become infected. +• High risk of developing endophthalmitis is always there if an intraocular surgery is performed in the presence of dacryocystitis. Because of this, syringing of lacrimal sac is always done in suspected cases before attempting any intraocular surgery. +Treatment +1. Conservative treatment by probing and lacrimal syringing may be useful in recent cases only. Long-standing cases are almost always associated with blockage of NLD which usually does not open up with probing. +2. Balloon catheter dilation also known as balloon dacryocystoplasty can be tried in patient with partial nasolacrimal duct obstruction. Success rate reported in adults is about 50%. +Chapter 16 Diseases of Lacrimal Apparatus 395 + + +3. Dacryocystorhinostomy (DCR). It should be the operation of choice as it re-establishes the lacrimal drainage. However, before performing surgery, the infection especially in pyocoele should be controlled by topical antibiotics and repeated lacrimal syringings. +4. Dacryocystectomy (DCT). It should be performed only when DCR is contraindicated. Indications of DCT include: (i) Too young (less than 4 years) or too old (more than 60 years) patient. (ii) Markedly shrunken and fibrosed sac. (iii) Tuberculosis, syphilis, leprosy or mycotic infections of sac. (iv) Tumours of sac. (v) Gross nasal diseases like atrophic rhinitis. (vi) An unskilled surgeon, because it is said that, a good ‘DCT’ is always better than a badly done ‘DCR’. (for surgical procedure see page 396). +5. Conjunctivodacryocystorhinostomy (CDCR). It is performed in the presence of blocked canaliculi. + +Acute Dacryocystitis +Acute dacryocystitis is an acute suppurative inflammation of the lacrimal sac, characterised by presence of a painful swelling in the region of sac. +Etiology +It may develop in two ways: +1. As an acute exacerbation of chronic dacryocystitis. 2. As an acute peridacryocystitis due to direct involv-ement from the neighbouring infected structuressuch as: paranasal sinuses, surrounding bones and dental abscess or caries teeth in the upper jaw. ■Causative organisms. Commonly involved are Streptococcus haemolyticus, Pneumococcus and Staphylococcus. +Clinical features +Clinical features of acute dacryocystitis can be divided into 3 stages: +1. Stage of cellulitis. It is characterised by a painful swelling in the region of lacrimal sac associated with epiphora and constitutional symptoms such as fever and malaise. The swelling is red, hot, firm and tender. Redness and oedema also spread to the lids and cheek. When treated resolution may occur at this stage. However, if untreated, self-resolution is rare. 2. Stage of lacrimal abscess. Continued inflammation causes occlusion of the canaliculi due to oedema. The sac is filled with pus, distends and its anterior wall ruptures forming a pericystic swelling. In this way, a large fluctuant swelling the lacrimal abscess is formed. It usually points below and to the outer side of the sac, owing to gravitation of pus and presence of medial palpebral ligament in the upper part (Fig. 16.9). 3. Stage of fistula formation.When the lacrimal abscess is left unattended, it discharges spontaneously, + + + + + + + + + + + + + + +Fig. 16.9 Acute dacryocystitis: Stage of lacrimal abscess + + + + + + + + + + + + + +Fig. 16.10 Acute dacryocystitis: Stage of external lacrimal fistula + +leaving an external fistula below the medial palpebral ligament (Fig. 16.10). Rarely, the abscess may open up into the nasal cavity forming an internal fistula. +Complications These include: +• Acute conjunctivitis, +• Corneal abrasion which may be converted to corneal ulceration, +• Lid abscess, +• Osteomyelitis of lacrimal bone, • Orbital cellulitis, +• Facial cellulitis and acute ethmoiditis. +• Rarely cavernous sinus thrombosis and very rarely generalized septicaemia may also develop. +Treatment +1. During cellulitis stage. It consists of systemic and topical antibiotics to control infection; and systemic anti-inflammatory analgesic drugs and hot fomentation to relieve pain and swelling. +2. During stage of lacrimal abscess. In addition to the above treatment when pus starts pointing on the skin, it should be drained with a small incision. +396 Section iii Diseases of Eye + + +The pus should be gently squeezed out, the dressing done with betadine soaked roll gauze. +Later on depending upon condition of the lacrimal sac either DCT or DCR operation should be carried out, otherwise recurrence will occur. +3. Treatment of external lacrimal fistula. After controlling the acute infection with systemic antibiotics, fistulectomy along with DCT or DCR operation should be performed. + +SurGICAL TEChNIquE OF DACryOCySTOrhINOSTOMy +Dacryocystorhinostomy (DCR) operation can be performed by following techniques: +• Conventional external approach, DCR and • Endonasal (surgical or laser)DCR +• Endocanalicular laser DCR. + +Conventional external approach DCr (Fig. 16.11) +1. Anaesthesia. General anaesthesia is preferred, however, it may be performed with local infiltration anaesthesia in adults. +2. Skin incision. Either a curved incision along the anterior lacrimal crest or a straight incision 8 mm medial to the medial canthus is made. + + +3. Exposure of medial palpebral ligament (MPL) and anterior lacrimal crest. MPL is exposed by blunt dissection and cut with scissors to expose the anterior lacrimal crest. +4. Dissection of lacrimal sac. Periosteum is separated from the anterior lacrimal crest and alongwith the lacrimal sac is reflected laterally with blunt dissection exposing the lacrimal fossa. +5. Exposure of nasal mucosa. A 15 mm × 10 mm bony osteum is made by removing the anterior lacrimal crest and the bones forming lacrimal fossa, exposing the thick pinkish white nasal mucosa. +6. Preparation of flaps of sac. A probe is introduced into the sac through lower canaliculus and the sac is incised vertically. To prepare anterior and posterior flaps, this incision is converted into H shape. +7. Fashioning of nasal mucosal flaps is also done by vertical incision converted into H shape. +8. Suturing of flaps. Posterior flap of the nasal mucosa is sutured with posterior flap of the sac using 6–0 vicryl or chromic cat gut sutures. It is followed by suturing of the anterior flaps. +9. Closure. MPL is sutured to periosteum, orbicularis muscle is sutured with 6–0 vicryl and skin is closed with 6–0 silk sutures. + + + + + + + + + + + + + +A B C + + + + + + + + + + + +d e F + +Fig. 16.11 Surgical steps of external dacryocystorhinostomy: A, skin incision; B, exposure of bony lacrimal fossa; C, preparation of bony osteum and exposure of nasal mucosa; D, preparation of flaps of the nasal mucosa and lacrimal sac; E, suturing of posterior flaps: F, suturing of anterior flaps +Chapter 16 Diseases of Lacrimal Apparatus 397 + + +Endonasal DCr +Presently many eye surgeons, alone or in collaboration with the ENT surgeons, are preferring endonasal DCR over conventional external approach DCR because of its advantages (described below). +Surgical steps of endonasal DCR are (Fig. 16.12): 1. Preparation and anaesthesia. Nasal mucosa is prepared for 15–30 minutes before operation with nasal decongestant drops and local anaesthetic agent. Conjunctival sac is anaesthetised with topically instilled 2% lignocaine. Then 3 ml of lignocaine 2% with 1 in 2 lac adrenaline is injected into the medial parts of upper and lower eyelids and + + + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + + + + + + + +C + + +via subcaruncular injection to the lacrimal fossa region. +2. Identification of sac area. A 20-gauge light pipe is inserted via the upper canaliculi into the sac. With the help of endoscope, the sac area which is transilluminated by the light pipe is identified (Fig. 16.12A) and a further injection of lignocaine with adrenaline is made below the nasal mucosa in this area. 3. Creation of opening in the nasal mucosa, bones +forming the lacrimal fossa and posteromedial wall of sac can be accomplished by two techniques: +i. By cutting the tissues with appropriate instruments or + + + + + + + + + + + + + + + + + + + +B + + + + + + + + + + + + + + + + + +d + +Fig. 16.12 Surgical steps of endonasal DCR: A. endoscopic identification of sac area in the middle meatus; B,C, opening created in the middle meatus; D, stenting of rhinostomy opening with fine silicone tubes +398 Section iii Diseases of Eye + + +ii. By ablating with Holmium YAG laser (endoscopic laser-assisted DCR). +Note. The size of opening is about 12 mm × 10 mm (Fig. 16.12B). +4. Stenting of rhinostomy opening. The outflow system is then stinted using fine silicone tubes passed via the superior and inferior canaliculi into the rhinostomy and secured with a process of knotting (Fig. 16.12C). Nasal packing and dressing is done. +5. Postoperative care and removal of sialistic lacrimal stents. After 24 hours of operation nasal packs are removed and patient is advised to use decongestent, antibiotic and steroid nasal drops for 3–4 weeks. The sialistic lacrimal stents are removed 8–12 weeks after surgery and the nasal drops are continued further for 2–3 weeks. +Advantages and disadvantages of endonasal DCr vis-a-vis external DCr +Advantages and disadvantages of endoscopic DCR vis-a-vis external DCR are summerized in Table 16.1. +Table 16.1 Advantages and disadvantages of endonasal DCR vis-a-vis external DCR + +Endonasal DCR External DCR + +Endocanalicular Laser DCr +In this technique, laser probe is passed through a canaliculus upto the medial wall of sac. An opening is created by ablating the posteriomedial wall of the sac, bone forming the lacrimal fossa and adjacent nasal mucosa. It is performed with a Holmium YAG or KTP laser. This is a quick procedure and can be carried out under local anaesthesia. It is particularly useful for the elderly patients. Success rate is only 70%. Failure can be tackled by endonasal DCR or conventional external DCR. +SurGICAL TEChNIquE OF DACryOCySTECTOMy (DCT) +1 to 4 steps are same as for external DCR operation. 5. Removal of lacrimal sac. After exposing the sac, it is separated from the surrounding structures by blunt dissection followed by cutting its connections from the lacrimal canaliculi. It is then held with artery forceps and twisted 3-4 times to tear it away from the nasolacrimal duct (NLD). \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_14.txt b/notes/A K Khurana - Comprehensive Ophthalmology_14.txt new file mode 100644 index 0000000000000000000000000000000000000000..387bb57f53a08d4658a0f28c8243b4e38ee594e0 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_14.txt @@ -0,0 +1,1599 @@ +6. Curettage of bony NLD. It is done with the help of a lacrimal curette to remove the infected parts of membranous NLD. +7. Closure. It is done as for external DCR (Step 9). + + + +Advantages +• No external scar +• Relatively blood less surgery +• Better visualisation of nasal pathology +• Less chances of injury to ethmoidal vessels and cribri form plate +• Less time consuming (15–30 mins) since nasal mucosal flaps and sac wall flaps are not made. +• No postoperative morbidity +Disadvantages +• Less success rate (70-90%) +• Requires skilled ophthalmologist and/or rhinologist. +• Expensive equipment + +• Requires reasonable access to middle meatus and familiarity with endoscopic anatomy + +Disadvantages +• Cutaneous scar +• Relatively more bleeding during surgery + + +• Potential injury to adjacent medial canthus structures +• More operating time (45-60 minutes) + + +• Significant postoperative morbidity +Advantages +• More success rate (95%) +• Easily performed by ophthalmologists + +• Cheap (expensive equipment not required) +• Does not require familiarity with endoscopic anatomy + + +SWellinGS oF lACRimAl GlAnd + +DACryOADENITIS +Dacryoadenitis may be acute or chronic. + +I. Acute dacryoadenitis +Etiology. It may develop as a primary inflammation of the gland or secondary to some local or systemic infection. Dacryoadenitis secondary to local infections occurs in trauma, erysipelas of the face, conjunctivitis (especially gonococcal and staphylococcal) and orbital cellulitis. Dacryoadenitis secondary to systemic infections is associated with mumps, influenza, infectious mononucleosis and measles. +Clinical features. Acute inflammation of the palpebral part is characterised by a painful swelling in the lateral part of the upper lid. The lid becomes red and swollen with a typical S-shaped curve of its margin (Fig. 16.13). Acute orbital dacryoadenitis produces some painful proptosis in which the eyeball moves down and in. A fistula in the upper and lateral quadrant of the upper lid may develop as a complication of suppurative dacryoadenitis. Treatment. It consists of a course of appropriate systemic antibiotic, analgesic and anti-inflammatory drugs along with hot fomentation. When pus is formed, incision and drainage should be carried out. +Chapter 16 Diseases of Lacrimal Apparatus 399 + + + + + + + + + + + + +Fig. 16.13 A patient with bilateral dacryoadenitis: note, 5-shaped curve of upper eyelid + +II. Chronic dacryoadenitis +It is characterised by engorgement and simple hypertrophy of the gland. +Etiology. Chronic dacryoadenitis may occur: • As sequelae to acute inflammation; +• In association with chronic inflammations of conjunctiva and; +• Due to systemic diseases such as tuberculosis, syphilis and sarcoidosis. +Clinical features. These include (i) a painless swelling in upper and outer part of lid associated with ptosis; (ii) eyeball may be displaced down and in; and (iii) diplopia may occur in up and out gaze. +On palpation, a firm lobulated mobile mass may be felt under the upper and outer rim of the orbit. Differential diagnosis from other causes of lacrimal gland swellings is best made after fine needle aspiration biopsy or incisional biopsy. +Treatment consists of treating the cause. +MIkuLICz’S SyNDrOME +It is characterised by bilaterally symmetrical enlargement of the lacrimal and salivary glands associated with a variety of systemic diseases. These include: leukaemias, lymphosarcomas, benign lymphoid hyperplasia, Hodgkin’s disease, sarcoidosis and tuberculosis. + +DACryOPES +It is a cystic swelling, which occurs due to retention of lacrimal secretions following blockage of the lacrimal ducts. +TuMOurS OF ThE LACrIMAL GLAND +These are not so common and in a simplified way can be classified as below: +I. Epithelial tumours of lacrimal gland.These account for 50% tumourous swellings of lacrimal gland and include: +1. Benign epithelial tumours. These include ‘benign mixed tumour’ which accounts for 50% of epithelial tumours and 25% of all tumours of lacrimal gland. 2. Malignantepithelialtumours.These also constitute 25% of all cases and 50% of epithelial tumours and include: malignant mixed tumour, adenoid cystic carcinoma, mucoepidermoid carcinoma and adenocarcinoma. +II. Non-epithelial tumours of lacrimal gland. Constitute approximately 50% of all cases. These include: +1. Lymphoproliferative tumours (see page 421) and 2. Inflammatory conditions such as idiopathic +orbital inflammatory disease (see page 412), sarcoidosis, and Mikulicz’s syndrome. +Epithelial tumours of lacrimal gland +Pleomorphic adenoma +Also known as benign mixed tumour, is the commonest benign lacrimal gland tumour and occurs predominantly in young adult males. Clinically, it presents as a slowly progressive painless swelling in the upper-outer quadrant of the orbit displacing the eyeball downwards and inwards (Fig. 16.14). It is locally invasive and may infiltrate its own pseudocapsule to involve the adjacent periosteum. Histologically, it is characterised by presence of pleomorphic myxomatous tissue, just like benign mixed tumour of salivary gland. + + + + + + + + + + + +A B C +Fig. 16.14 A, Down and in displacement of left eyeball in a patient with benign mixed tumour; B, CT scan coronal view showing well defined mass in superotemporal quadrant; C, Well circumscribed benign mixed tumour removed by lateral orbitotomy +400 Section iii Diseases of Eye + + +Treatment consists of complete surgical removal with the capsule. Recurrences are very common following incomplete removal. +Lacrimal gland carcinoma +Lacrimal gland malignancies, occurring in 4th–5th decade of life are comparatively rare but have a high mortality. In order of the frequency, the main histological types are: +• Adenoid cystic carcinoma, +• Pleomorphic adenocarcinoma, + +• Mucoepidermoid carcinoma, and • Squamous cell carcinoma. +Clinical features.Lacrimal gland malignancies present as a painful mass of short duration in superotemporal quadrant of the orbit causing inferonasal dystopia. There may be associated sensory loss and paraesthesia in the region supplied by lacrimal nerve. +CT scanoften shows an infilterative tumour moulding the globe. +Treatment includes complete macroscopic excision and high-dose radiotherapy to the orbit. +17 + +Diseases of Orbit + + + +CHAPTER OUTLINE + +APPLIED ANATOMY Bony orbit +Orbital fascia Contents of orbit +• +• +• +• +Surgical spaces in orbit PROPTOSIS +• +• +• +Classification Etiology Investigations +Enophthalmos DEVELOPMENTAL ANOMALIES OF THE ORBIT +ORBITAL INFECTIONS AND INFLAMMATIONS Classification +Orbital infection Preseptal cellulitis +• +• +• +Orbital cellulitis and intraorbital abscess Orbital mucormycosis + + +APPLIED ANATOMY + +BONY ORBIT +The bony orbits are quadrangular truncated pyramids situated between the anterior cranial fossa above and the maxillary sinuses below (Fig. 17.1). Each orbit is about 40 mm in height, width and depth and is formed by portions of seven bones: (1) frontal, (2) maxilla, (3) Zygomatic, (4) sphenoid, (5) palatine, (6) ethmoid and (7) lacrimal. It has four walls (medial, lateral, superior and inferior), base and an apex. Medial wallsof the two orbits are parallel to each other and, being thinnest, are frequently fractured during injuries as well as during orbitotomy operations and, also accounts for ethmoiditis being the commonest cause of orbital cellulitis. +Inferior orbital wall (floor) is triangular in shape and being quite thin is commonly involved in blow-out fractures and is easily invaded by tumours from the maxillary antrum. +Lateral wall of the orbit is triangular in shape. It covers only posterior half of the eyeball. Therefore, palpation of the retrobulbar tumours is easier from + +• Cavernous sinus thrombosis +Non-infective orbital inflammations +• +• +Idiopathic orbital inflammatory disease (pseudotumour) Tolosa- Hunt syndrome +Thyroid eye disease Etiopathogenesis Clinical profile Management +• +• +• +CAROTID-CAVERNOUS FISTULA ORBITAL TUMOURS +• +• +• +Primary orbital tumours Secondary orbital tumours Metastatic orbital tumours +ORBITAL BLOW-OUT FRACTURES ORBITAL SURGERY +• +• +Orbitotomy Exenteration + + +this side. Because of its advantageous anatomical position, a surgical approach to the orbit by lateral orbitotomy is popular. +Roof of the orbit is triangular in shape and is formed mainly by the orbital plate of frontal bone. +Base of the orbit is the anterior open end of the orbit. It is bounded by thick orbital margins. +Orbital apex (Fig. 17.2). It is the posterior end of orbit where the four orbital walls converge. It has two orifices, the optic canal which transmits optic nerve and ophthalmic artery and the superior orbital fissure which transmits a number of nerves, arteries and veins (see Fig. 14.2). +ORBITAL FASCIA +It is a thin connective tissue membrane lining various intraorbital structures. Though, it is one continuous tissue, but for the descriptive convenience it has been divided into fascia bulbi, muscular sheaths, intermuscular septa, membranous expansions of the extraocular muscles and ligament of Lockwood. Fascia bulbi (Tenon’s capsule) envelops the globe from the margins of cornea to the optic nerve. Its lower part is thickened to form a sling or hammock +402 Section III Diseases of Eye + + + + + + + + + + + + + + + + + + + + + +Fig. 17.1 Schematic coronal section through the orbits and nasal cavity + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 17.2 A schematic view of the orbital cavity and orbital rim + + + +on which the globe rests; this is called ‘suspensory ligament of Lockwood.’ + +CONTENTS OF ORBIT +The volume of each orbit is about 30 cc. Approximately +one-fifth of it is occupied by the eyeball. Other + +contents of the orbit include: part of optic nerve, extraocular muscles, lacrimal gland, lacrimal sac, ophthalmic artery and its branches, third, fourth and sixth cranial nerves and ophthalmic and maxillary divisions of the fifth cranial nerve, sympathetic nerve, orbital fat and fascia. +Chapter 17 Diseases of Orbit 403 + + +SURGICAL SPACES IN ORBIT +These are of importance as most orbital pathologies tend to remain in the space in which they are formed. Therefore, their knowledge helps the surgeon in choosing the most direct surgical approach. Each orbit is divisible into four surgical spaces (Fig. 17.3). 1. Subperiosteal space. This is a potential space between the bone and the periorbita (periosteum). 2. Peripheral space. It is bounded peripherally by the periorbita and internally by the four recti with thin intermuscular septa. Tumours present here produce eccentric proptosis and can usually be palpated. For peribulbar anaesthesia, injection is made in this space. 3. Central space. It is also called muscular cone or retrobulbar space. 1t is bounded anteriorly by the Tenon’s capsule lining back of the eyeball and + + +peripherally by the four recti muscles and their intermuscular septa in the anterior part. In the posterior part, it becomes continuous with the peripheral space. Tumours lying here usually produce axial proptosis. Retrobulbar injections are made in this space. +4. Tenon’s space. It is a potential space around the eyeball between the sclera and Tenon’s capsule. + +PROPTOSIS + +Proptosis is defined as forward displacement of the eyeball beyond the orbital margins. Though the word exophthalmos (out eye) is synonymous with it; but somehow it has become customary to use the term exophthalmos for the displacement associated with thyroid eye disease. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +A B C +Fig. 17.3 Schematic sections of the orbital cavity to demonstrate surgical spaces of the orbit. Above sagittal section; below coronal sections at levels A, B, C (1. subperiosteal space; 2. peripheral space; 3. central space; 4. Tenon’s space; 5. peripheral and central spaces merged with each other at the orbital apex) +404 Section III Diseases of Eye + + +CLASSIFICATION +Proptosis can be divided into following clinical groups: +• Unilateral proptosis • Bilateral proptosis +• Acute proptosis +• Intermittent proptosis • Pulsating proptosis +ETIOLOGY +Important causes of proptosis in each clinical group are listed here: +A. Causes of unilateral proptosis +1. Congenital conditions. These include: dermoid cyst, congenital cystic eyeball, and orbital teratoma. +2. Traumatic lesions. These are: orbital haemorrhage, retained intraorbital foreign body, traumatic aneurysm and emphysema of the orbit. +3. Inflammatory lesions. Acute inflammations are orbital cellulitis, abscess, thrombophlebitis, panophthalmitis, and cavernous sinus thrombosis (proptosis is initially unilateral but ultimately becomes bilateral). Chronic inflammatory lesions include: pseudotumours, tuberculoma, gumma and sarcoidosis. +4. Circulatory disturbances and vascular lesions. These are: angioneurotic oedema, orbital varix and aneurysms. +5. Cysts of orbit. These include: haematic cyst, implantation cyst and parasitic cyst (hydatid cyst and cysticercus cellulosae). +6. Tumours of the orbit. These can be primary, secondary or metastatic (see page 417). +7. Mucoceles of paranasal sinuses, especially frontal (most common), ethmoidal and maxillary sinus are common causes of unilateral proptosis. +Note. Most common cause of unilateral proptosis in children is orbital cellulitis and in adults is thyroid ophthalmopathy. +B. Causes of bilateral proptosis +1. Developmental anomalies of the skull: Craniofacial dysostosis, e.g., oxycephaly (tower skull). +2. Osteopathies: Osteitis deformans, rickets and acromegaly. +3. Inflammatory conditions: Mikulicz’s syndrome and late stage of cavernous sinus thrombosis. +4. Endocrinal exophthalmos: It may be thyrotoxic or thyrotropic. +5. Tumours: These include symmetrical lymp-homa or lymphosarcoma, secondaries from neuroblastoma, nephroblastoma, Ewing’s sarcoma and leukaemic infiltration. + + +6. Systemic diseases: Histiocytosis, systemic amyloidosis, xanthomatosis and Wegener’s granulomatosis. +Note. Most common cause of bilateral proptosis in children is neuroblastoma and leukemia (chloroma) and in adults is thyroid ophthalmopathy. +C. Causes of acute proptosis +It develops with extreme rapidity (sudden onset). Its common causes are: orbital emphysema, fracture of the medial orbital wall, orbital haemorrhage and rupture of ethmoidal mucocele. +D. Causes of intermittent proptosis +This type of proptosis appears and disappears of its own. Its common causes are: orbital varix, periodic orbital oedema, recurrent orbital haemorrhage and highly vascular tumours. Most important cause of intermittent proptosis is orbital varix, in which proptosis develops intermittently and rapidly in one eye when venous stasis is induced by forward bending or lowering of the head, turning the head forcefully, hyperextension of the neck, coughing, forced expiration with or without compression of the nostrils, or pressure on the jugular veins. +E. Causes of pulsatile proptosis +It is caused by pulsating vascular lesions such as caroticocavernous fistula and saccular aneurysm of ophthalmic artery. Pulsatile proptosis also occurs due to transmitted cerebral pulsations in conditions associated with deficient orbital roof. These include congenital meningocele or meningoencephalocele, neurofibromatosis and traumatic or operative hiatus. +INVESTIGATIONS +I. Clinical evaluation +A. History +It should include: age of onset, nature of onset, duration, progression, chronology of orbital signs and symptoms, and associated symptoms. +B. Local examination +It should be carried out as follows: 1. Inspection should be performed: +• To differentiate proptosis from pseudoproptosis. Pseudoproptosis is a condition in which the eyeball appears to be proptosed but actually there is no forward displacement. Causes of pseudoproptosis are buphthalmos, axial high myopia, retraction of upper lid and enophthalmos of the opposite eye, paralysis of extraocular muscles, stimulation of Muller’s muscle by cocaine and shallow orbits as in craniofacial dysostosis. +Chapter 17 Diseases of Orbit 405 + + +• To ascertain whether the proptosis is unilateral or bilateral, +• To note the shape of the skull, +• To observe whether proptosis is axial or eccentric, • Axial proptosis is a feature of intraconal masses +and thyroid ophthalmopathy. +• Eccentric proptosis is produced by extraconal masses as below: +i. Medially placed masses, e.g., ethmoidal sinus mucocele/tumours and subperiostal collection, will produce lateral eccentricity. +ii. Laterally placed masses, e.g., lacrimal gland enlargement, will push the eyeball down and medially. +iii.Superiorly located masses, e.g., frontal sinus mucocele, encephalocoele, lacrimal gland mass, sphenoid wing meningioma, orbital roof fracture and nerve sheath tumours will produce inferior displacement of the eyeball. +iv. Inferiorly located masses, e.g., maxillary sinus tumours, and lymphoproliferative disorders, will produce superior displacement of the eyeball. +2. Palpation. It should be carried out for retrodisplacement of globe to know compressibility of the tumour, for orbital thrill, for any swelling around the eyeball, regional lymph nodes and orbital rim. +3. Auscultation. It is primarily of value in searching for abnormal vascular communications that generate a bruit, such as caroticocavernous fistula. +4. Transillumination. It is helpful in evaluating anterior orbital lesions. +5. Visual acuity. Orbital lesions may reduce visual acuity by three mechanisms: refractive changes due to pressure on back of the eyeball, optic nerve compression and exposure keratopathy. +6. Pupil reactions. The presence of Marcus Gunn pupil is suggestive of optic nerve compression. +7. Fundoscopy. It may reveal venous engorgement, haemorrhage, disc oedema and optic atrophy. Choroidal folds and opticociliary shunts may be seen in patients with meningiomas. +8. Ocular motility. It is restricted in thyroid ophthalmopathy, extensive tumour growths and neurological deficit. +9. Exophthalmometry. It measures protrusion of the apex of cornea from the outer orbital margin (with the eyes looking straight ahead). Normal values vary between 10 and 21 mm and are symmetrical in both eyes. A difference of more than 2 mm between the two eyes is considered significant. The simplest instrument to measure proptosis is Luedde’s + +exophthalmometer (Fig. 17.4). However, the Hertel’s exophthalmometer (Fig. 17.5) is the most commonly used instrument. Its advantage is that it measures the two eyes simultaneously. +10. Perimetry is useful for assessing optic nerve function and temporal change. +C. Systemic examination +A thorough examination should be conducted to rule out systemic causes of proptosis such as thyrotoxicosis, histiocytosis, and primary tumours elsewhere in the body (secondaries in orbits). Otorhinolaryngological examination is necessary when the paranasal sinus or a nasopharyngeal mass appears to be a possible etiological factor. +II. Laboratory Investigations These should include: +• Thyroid function tests, +• Haematological studies (TLC, DLC, ESR, VDRL test), +• Casoni’s test (to rule out hydatid cyst), +• Stool examination for cysts and ova, and +• Urine analysis for Bence Jones proteins for multiple myeloma. + + + + + + + + + + + + + + + +Fig. 17.4 Luedde’s exophthalmometer + + + + + + + + + + + + + +Fig. 17.5 Hertel’s exophthalmometer +406 Section III Diseases of Eye + + +III. Imaging techniques +A. Non-invasive techniques +1. Plain X-rays. Though with the availability of CT scan the plain X-rays have little value, but it is still the most frequently used initial radiological investigation. Commonly required exposures are in the Caldwell view, the Water’s view, a lateral view and the Rhese view (for optic foramina). X-ray signs of orbital diseases include enlargement of orbital cavity, enlargement of optic foramina, calcification and hyperostosis. +2. Computed tomography scanning. Presently, CT is the first line imaging modality for orbital diseases. It is very useful for determining the location and size of an orbital mass. A combination of axial (CAT) and coronal (CCT) cut enables a three-dimensional visualisation. CT scan is capable of visualising various structures like globe, extraocular muscles and optic nerves. Further, this technique is also useful in examining areas adjacent to the orbits such as orbital walls, cranial cavity, paranasal sinuses and nasal cavity. 3-D reconstructions are especially useful in trauma cases. +Disadvantage is the inability to distinguish between pathologically soft tissue masses which are radiologically isodense, radiation exposure, and reactions to contrast medium. +3. Ultrasonography. It is a non-radiational non-invasive, completely safe and extremely valuable initial scanning procedure for orbital lesions. In the diagnosis of orbital lesions, it is superior to CT scanning in actual tissue diagnosis and can usually differentiate between solid, cystic, infiltrative and spongy masses. Doppler flow studies may help in diagnosing and monitoring vascular lesions such as capillary haemangioma. +4. Magnetic resonance imaging (MRI). It is a major advance in the imaging techniques. It is very sensitive for detecting differences between normal and abnormal tissues and has excellent image resolution. The technique produces tomographic images which are superficially very similar to CT scan but rely on entirely different physical principles for their production. MRI is mainly indicated for diseases located at the orbitocranial junction, e.g. optic sheath tumours. Orbital MRI requires fat-suppression to allow delineation of the soft tissue structures. +MR angiography is useful in vascular lesions of the orbit. +B. Invasive procedures +Before the advent of CT and MR angiography, the invasive investigations were needed for vascular lesions as below: + + +■Orbital venography for the suspected orbital varix, ■Carotid angiography for suspected arteriovenous malformations, aneurysm and arteriovneous fistulas. ■Radioisotope arteriography in proptosis of vascular +lesions. +However, because of the availability of non-invasive techniques of CT and MR angiography, most of the vascular lesions can now be easily evaluated without the need of potentially dangerous above mentioned invasive procedures. +IV. Histopathological studies +The exact diagnosis of many orbital lesions cannot be made without the help of histopathological studies which can be accomplished by following techniques: 1.Fine-needle aspiration biopsy (FNAB). It is a reliable, accurate (95%), quick and easy technique for cytodiagnosis in orbital tumours. The biopsy aspirate is obtained under direct vision in an obvious mass and under CT scan or ultrasonographic guidance in retrobulbar mass using a 23-gauge needle. +Note. In general, it is preferable to obtain tissue by open biopsy (incisional or excisional) rather than FNAB, as histology gives better structural representation than cytology. Further, with biopsy tissue many specialized strains and immunohistopathological studies are also possible. 2. Incisional biopsy. Undoubtedly, for accurate tissue diagnosis a proper biopsy specimen at least 5 to 10 mm in length is required. Incisional biopsy in the diagnosis of orbital tumours may be undertaken along with frozen tissue study in infiltrative lesions which remain undiagnosed. +3. Excisional biopsy. It should always be preferred over incisional biopsy in orbital masses which are well encapsulated or circumscribed. It is performed by anterior orbitotomy for a mass in the anterior part of orbit and by lateral orbitotomy for a retrobulbar mass. +ENOPHTHALMOS +It is the inward displacement of the eyeball. About 50% cases of mild enophthalmos are mis-diagnosed as having ipsilateral ptosis or cont-ralateral proptosis. +Common causes are: +1. Congenital. Microphthalmos and maxillary hypoplasia. +2. Traumatic. Blow out fractures of floor of the orbit. 3. Post-inflammatory. Cicatrization of extraocular +muscles as in the pseudotumour syndromes. +4. Paralytic enophthalmos. It is seen in Horner’s syndrome (due to paralysis of cervical sympathetics). +Chapter 17 Diseases of Orbit 407 + + +5. Atrophy of orbital contents. Senile atrophy of orbital fat, atrophy due to irradiation of malignant tumours, following cicatrizing metastatic carcinoma and due to scleroderma. + +DEVELOPMENTAL ANOMALIES OF THE ORBIT +Developmental anomalies of the orbit are commonly associated with abnormalities of skull and facial bones. They are frequently hereditary (autosomal dominant) in origin. +Details of such anomalies are beyond the scope of the book. However, a few salient features of some anomalies are mentioned below: +Craniosynostosis +Craniosynostosis results from premature closure of one or more cranial sutures. Depending upon the suture involved craniosynostosis may be of following types: +Anomaly Suture closed prematurely +• Brachycephaly Coronal sutures (clover-leaf skull) +• Oxycephaly Coronal suture (tower-shaped skull) +• Scophocephaly Sagittal suture (boat-shaped skull) +• Trigonocephaly Frontal suture (egg-shaped skull) +• Acrocephaly Multiple cranial suture +Craniofacial dysostosis +Craniofacial dysostosis (Crouzon syndrome) refers to premature closure of coronal and sagittal sutures (brachycephaly) associated with maxillary hypoplasia. Inheritance is autosomal dominant, but 25% of cases occurs as fresh mutation. +Ocular features include: +• Proptosis due to shallow orbits, +• V-pattern exotropia and hypertropia, +• Hypertelorism i.e., widely separated eyeballs (increased interpupillary distance), and +• Optic atrophy may occur due to compression at optic foraman. +Ocular associationsinclude blue sclera, megalocornea, aniridia, glaucoma, cataract, ectopia lentis and optic nerve hypoplasia. +Systemic features are: • Mental retardation, +• High-arched palate, +• Irregular dentition, and +• Hooked (parrot beak) nose. + +Mandibulofacial dysostosis +Mandibulofacial dysostosis (Treacher-Collin syndrome) refers to a condition resulting from hypoplasia of zygoma and mandible. + +Ocular features include: +• Indistinct inferior orbital margin, • Coloboma of the lower eyelid, and • Anti-mongoloid slant. + +Systemic features are: +• Macrostomia with high-arched palate, • External ear deformity, and +• Bird-like face. + +Median facial cleft syndrome +Main ocular features of this anomaly are: • Hypertelorism, +• Telecanthus, and • Divergent squint. + +Main systemic features include: +• Cleft-nose, lip and palate; and +• V-shaped frontal hairline (widow’s peak). + +Acrocephaly-Syndactyly (Apert Syndrome) +It is the most severe of craniosynostosis in which all the cranial sutures may be involved. + +Systemic features include: +• Tower skull with flat occiput, • Mental retardation, +• Ventricular septal defect, • High arched palate, and +• Syndactyly of the fingers and toes. + +Ocular features are: +• Hypertelorism—increased IPD, +• Bilateral proptosis due to shallow orbits, • Congenital ptosis, +• Antimongoloid slant, and • Divergent squint. +Ocular associations include keratoconus, congenital glaucoma and ectopia lentis. +Hypertelorism +It is a condition of widely separated eyeballs resulting from widely separated orbits and broad nasal bridge. +Hypertelorism may occur de novo or as a part of various syndromes such as Apert syndrome, Crouzons syndrome and median facial cleft syndrome. Ocular features of hypertelorism are: +• Increased interpupillary distance (IPD)—may be 85 mm (normally average IPD in an adult is 60 mm), +408 Section III Diseases of Eye + + +• Telecanthus, +• Divergent squint, +• Antimongoloid slant, and +• Optic atrophy may be associated in some cases due to narrow optic canal. + +ORBITAL INFECTIONS AND INFLAMMATIONS + +CLASSIFICATION +A. Orbital infections +I. Acute orbital and related infections +1. Preseptal cellulitis +2. Orbital cellulitis and intraorbital abscess 3. Orbital osteoperiostitis +4. Orbital thrombophlebitis 5. Tenonitis +6. Cavernous sinus thrombosis. + +lI. Chronic orbital infections +1. Tuberculosis 2. Syphilis +3. Actinomycosis +4. Mycotic infections, e.g. mucormycosis 5. Parasitic infestations. +B. Non-infective orbital inflammations I. Isolated orbital inflammations +a. Diffuse +• Idiopathic orbital inflammatory disease (IOID) • Idiopathic sclerosing inflammation of the orbit b. Focal +• Myositis +• Dacryoadenitis +• Tolosa-Hunt syndrome. + +II. Systemic inflammations +• Thyroid eye disease, +• Wegner’s granulomatosis, and • Sarcoidosis. +Salient features of some infections and inflammations of the orbit are described here. + +A. ORBITAL INFECTIONS + +PRESEPTAL CELLULITIS +Preseptal (or periorbital) cellulitis refers to infection of the subcutaneous tissues anterior to the orbital septum. Strictly speaking it is not an orbital disease but is included here under because the facial veins are valveless and preseptal cellulitis may spread posteriorly to produce orbital cellulitis. + +Etiology +Causative organisms are usually Staphylococcus aureus or Sreptococcus pyogenes and occasionally Haemophilus influenzae. +Modes of infection. The organisms may invade the preseptal tissue by any of the following modes. +1. Exogenous infection may result following skin lacerations, insect bites and eyelid operations. +2. Extension from local infections such as from an acute hordeolum or acute dacryocystitis. +3. Endogenous infection may occur by haema-togenous spread from remote infection of the middle ear or upper respiratory tract. +Clinical features +Preseptal cellulitis presents as inflammatory oedema of the eyelids and periorbital skin with no involvement of the orbit. + +Characteristic features are (Fig. 17.6): +• Painful acute periorbital swelling, +• Erythema and hyperaemia of the lids, +• Fever and leukocytosis may be associated, • Proptosis is absent, +• Ocular movements are normal, +• Conjunctiva is usually not congested, and • Visual acuity is normal. +Treatment +Systemic antibiotics, form the mainstay of treatment. • Mild to moderate cases may be given oral co-amoxiclav 500/125 mg tds or flucloxacillin 500 +mg QID for about 10 days. +• Severe cases need hospitalization for intravenous ceftriaxone, 1–2 g/day in divided doses, for 4–5 days. Then treat as mild cases. +Systemic analgesics and anti-inflammatory drugs help in reducing pain and swelling. + + + + + + + + + + + + + +Fig. 17.6 Preseptal cellulitis +Chapter 17 Diseases of Orbit 409 + + +Warm compresses, 2–3 times a day, have a soothing effect. +Surgical exploration and debridement is required in the presence of a fluctuant mass or abscess, or when retained foreign body is suspected. +ORBITAL CELLULITIS AND INTRAORBITAL ABSCESS +Orbital cellulitis refers to an acute infection of the soft tissues of the orbit behind the orbital septum. Orbital cellulitis may or may not progress to a subperiosteal abscess or orbital abscess. +Etiology +Modes of infection +1. Exogenous infection. It may result from penetrating injury especially when associated with retention of intraorbital foreign body, and following operations like evisceration, enucleation, dacryocystectomy and orbitotomy. +2. Extensionofinfectionfromneighbouringstructures. These include paranasal sinuses, teeth, face, lids, intracranial cavity and intraorbital structures. It is the commonest mode of orbital infections. +3. Endogenous infection. It may rarely develop as metastatic infection from breast abscess, puerperal sepsis, thrombophlebitis of legs and septicaemia. +Causative organisms +Those commonly involved are: Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes and Haemophilus influenzae. + +Pathology +Pathological features of orbital cellulitis are similar to suppurative inflammations of the body in general, except for the following special features: ■Infection establishes early due to absence of lymphatics in the orbit. +■Rapid spread with extensive necrosis is common since in most cases infection spreads as thrombophebitis from the surrounding structures. +■Damage produced is rapid and extensive as orbital infection is associated with raised intraorbital pressure due to the tight compartment. +Clinical features Symptoms include: +• Swelling and severe pain (which is increased by movements of the eyeball or pressure) are main symptoms. +• Associated general symptoms include fever, nausea, vomiting and prostrations. +• Vision loss and/or diplopia may be complained by patients with moderate to advanced disease. + +Signs of orbital cellulitis (Fig. 17.7) are: +• Swelling of lids, characterised by woody hardness and redness, is usually marked. +• Chemosis of conjunctiva, which may protrude and become desiccated or necrotic. +• Axial proptosis of varying degree is present. +• Restriction of ocular movements, mild to severe, is frequently present. +• RAPD may occur due to complications in the form of optic neuropathy or central retinal artery occlusion. +• Fundus examination may show congestion of retinal veins and signs of papillitis or papilloedema. +Complications +These are quite common if not treated promptly. +1. Ocular complications are usually blinding and include exposure keratopathy, optic neuritis and central retinal artery occlusion. +2. Orbital complications are progression of orbital cellulitis into subperiosteal abscess and/or orbital abscess: +i. Subperiosteal abscess is collection of purulent material between the orbital bony wall and periosteum, most frequently located along the medial orbital wall. Clinically, subperiosteal abscess is suspected when clinical features of orbital cellulitis are associated with eccentric proptosis; but the diagnosis is confirmed by CT scan. +ii. Orbital abscess is collection of pus within the orbital soft tissue. Clinically, it is suspected by signs of severe proptosis, marked chemosis, complete ophthalmoplegia, and pus points below the conjunctiva, but is confirmed by CT scan. + + + + + + + + + + + + + + + + +Fig. 17.7 Orbital cellulitis in a three-year-old female child +410 Section III Diseases of Eye + + +3. Temporal or parotid abscesses may occur due to spread of infection around the orbit. +4. Intracranial complications include cavernous sinus thrombosis, meningitis and brain abscesses. +5. General septicemia or pyaemiamay occur eventually in few cases. +Investigations +1. Bacterial cultures should be performed from nasal and conjunctival swabs and blood samples. +2. Complete haemogram may reveal leukocytosis. 3. X-ray PNS to identify associated sinusitis. +4. Orbital ultrasonography to detect intraorbital abscess. +5. CT scan and MRI are useful: +• In differentiating preseptal and postseptal cellulitis; +• In detecting subperiosteal abscesses; • Orbital abscesses, +• In detecting intracranial extension; and +• In deciding when and from where to drain an orbital abscess. +Treatment +Orbital cellulitis is an emergency and so the patient should be hospitalised for aggressive management. 1. Intensive antibiotic therapy should be initiated to overcome the infection. After obtaining nasal, conjunctival and blood culture samples, intravenous antibiotics should be administered: +• For Staphylococcal infections high doses of penicillinase-resistant antibiotic (e.g., oxacillin) combined with ampicillin should be given. +• Cefotaxime, ciprofloxacin or vancomycin may be used alternative to oxacillin and penicillin combination. +• To cover H. influenzae especially in children, chloramphenicol or clavulanic acid should also be added. +• To cover anaerobes oral metronidazole 500 mg every 8 hours. should be added. +2. Analgesic and anti-inflammatory drugs are helpful in controlling pain and fever. +3. Topical antibiotic eye ointment, QID, for corneal exposure and chemosis when there is severe proptosis. +4. Nasal decongestant drops should be started. +5. Revaluation, at least twice to thrice daily in the hospital, is required to monitor the response and modify the treatment accordingly. +6. Surgical intervention. Its indications include unresponsiveness to antibiotics, decreasing vision and presence of an orbital or subperiosteal abscess. Surgical intervention may be required as follows: + +• Immediate canthotomy/cantholysis may be needed, if the orbit is tight, an optic neuropathy is present, or the IOP is severely elevated. +• A free incision into the abscess should be made when it points under the skin or conjunctiva. +• Subperiosteal abscess is drained by a 2–3 cm curved incision in the upper medial aspect. +• In most cases, it is necessary to drain both the orbit as well as the infected paranasal sinuses. +ORBITAL MUCORMYCOSIS Etiology.Mucormycosis, also known as phacomycosis, is a severe fungal infection of the orbit. The most common fungal genera causing are Mucor (mucormycosis) and Rhizopus. Infection usually begins in the sinuses and erodes into the orbital cavity. The organisms have a tendency to invade vessels and cause ischemic necrosis. A necrotizing reaction destroys muscles, bone and soft tissue, frequently without causing signs of orbital cellulitis. Clinical features. Mostly patients prone to such infections are either diabetics or immuno-compromised such as those with renal failure, malignant tumours and those on antimetabolite or steroid therapy; so most of the patients are seriously ill and present with: +• Pain and proptosis, and +• Necrotic areas with black eschar formation may be seen on the mucosa of palate, turbinates and nasal septum and skin of eyelids (Fig. 17.8). +Complications. If not treated energetically, patient may develop meningitis, brain abscess and die within days to weeks. +Diagnosis is made clinically and confirmed by biopsy of the involved area and finding of nonseptate broad branching hyphae. + + + + + + + + + + + + + + + +Fig. 17.8 Areas of black-eschar and necrosis on the eyelids in a patient with rhino-orbital mucormycosis +Chapter 17 Diseases of Orbit 411 + + +Treatmentis often difficult and inadequate. Therefore, recurrences are common. Treatment includes: +• Correction of underlying disease (e.g., diabetic ketoacidosis) if possible; +• Surgical excision of the involved tissue; and +• Intravenous amphotericin B or other appropriate antifungal drug. +• Exenteration may be required in severe unres-ponsive cases. +CAVERNOUS SINUS THROMBOSIS +Septic thrombosis of the cavernous sinus is a disastrous sequela, resulting from spread of sepsis travelling along its tributaries from the infected sinuses, teeth, ears, nose, and skin of the face. Very rarely cavernous sinus thrombosis may also occur after trauma (head injury). +Note. Cavernous sinus thrombosis is described along with infections of the orbit as it also manifests as acute inflammatory type of proptosis. +Communications of cavernous sinus and sources of infection (Fig. 17.9A and B) +1. Anteriorly, the superior and inferior ophthalmic veins drain in the sinus. These veins receive blood + +from face, nose, paranasal sinuses and orbits. Therefore, infection to cavernous sinus may spread from infected facial wounds, erysipelas, squeezing of stye, furuncles, orbital cellulitis and sinusitis. +2. Posteriorly, the superior and inferior petrosal sinuses leave it to join the lateral sinus. Labyrinthine veins opening into the inferior petrosal sinuses bring infections from the middle ear. Mastoid emissary veins may spread infection from the mastoid air cells. 3. Superiorly, the cavernous sinus communicates with veins of the cerebrum and may be infected from meningitis and cerebral abscesses. +4. Inferiorly, the sinus communicates with pterygoid venous plexus. +5. Medially, the two cavernous sinuses are connected with each other by transverse sinuses which account for transfer of infection from one side to the other. +Clinical features +Cavernous sinus thrombosis starts initially as a unilateral condition, which soon becomes bilateral in more than 50% of cases due to intercavernous communication. The condition is characterised by general and ocular features. + + + + + + + + + + + + + + + + + +A + + + + + + + + + +B + +Fig. 17.9 Tributaries of the cavernous sinus: (A) lateral view; (B) superior view +412 Section III Diseases of Eye + + +General features. Mostly patient is seriously ill having high grade fever with chills and rigors, vomiting and headache. +Ocular features include: +• Severe pain in the eye and forehead on the affected side. +• Conjunctiva is swollen and congested. • Proptosis develops rapidly. +• Ipsilateral ophthalmoplegia, causing diplopia, may occur due to palsy of 3rd, 4th and 6th cranial nerves. Ophthalmoplegia is sequential with 6th nerve palsy occurring first of all as it passes through the cavernosus sinus, 3rd and 4th nerves are involved later as they are related to the lateral wall of cavernous sinus. +• Ipsilateral ptosis, dilated pupil, and absence of direct as well as consensual pupillary light reflex are signs of 3rd nerve palsy. +• Corneal anaesthesia, i.e., loss of corneal reflex, may occur due to involvement of the ophthalmic division of 5th cranial nerve. +• Oedema in mastoid region is a pathognomic sign. It is due to back pressure in the mastoid emissary vein. +• Fundus may be normal with unimpaired vision in early cases. In advanced cases, retinal veins show congestion and there may appear papilloedema. +Investigations +• CT scan head and orbit may show involvement of cavernous sinuses and proptosis. +• Magnetic resonance venography (angiography) is the investigation of choice which shows an absence of flow void in thrombosed sinuses. +• Blood culture is recommended for sepsis. + + +Complications +At any stage, hyperpyrexia and signs of meningitis or pulmonary infarction may precede death. +Differential diagnosis +The rapidly developing, acute inflammatory type of proptosis seen in cavernous sinus thrombosis needs to be differentiated from orbital cellulitis and panophthalmitis as summarised in Table 17.1. +Treatment +1. Antibiotics are the sheet anchor of treatment. Massive doses of modern potent broad spectrum antibiotics should be injected intravenously. +2. Analgesics and anti-inflammatory drugs control pain and fever. +3. Anticoagulants’ role is controversial. + +B. NON-INFECTIVE ORBITAL INFLAMMATIONS + +IDIOPATHIC ORBITAL INFLAMMATORY DISEASE (PSEUDOTUMOUR) +The term ‘pseudotumour’ was coined for those conditions of the orbit which clinically presented as tumours but histopathologically proved to be chronic inflammations. However, recently, the use of this term has been restricted for an idiopathic localized inflammatory disease consisting principally of a lymphocytic infiltration associated with a polymorphonuclear cellular response and a fibrovascular tissue reaction that has a variable but self-limiting course. Presently, idiopathic orbital inflammatory disease (IOID) is a term being preferred to denote this condition. + + +Table 17.1 Differential diagnosis of acute inflammatory proptosis + + +Clinical features 1. Laterality + +2. Degree of proptosis 3. Vision + +4. Cornea and anterior chamber + +5. Ocular movements +6. Oedema in mastoid region +7. General symptoms with fever, and prostrations + +Cavernous sinus thrombosis +Initially unilateral, but soon becomes bilateral +Moderate +Not affected in early stage + +Clear in early stages + + +Complete limitation to palsy Present + +Marked + +Orbital cellulitis Unilateral + +Marked +Not affected in early stage + +Clear in early stages + + +Marked limitation Absent + +Mild + +Panophthalmitis Unilateral + +Moderate +Complete loss of vision from the beginning +Hazy due to corneal oedema. Pus in the anterior chamber +Painful and limited Absent + +Mild +Chapter 17 Diseases of Orbit 413 + + +Clinical features +IOID (Fig. 17.10) can occur throughout the orbit from the region of lacrimal gland to the orbital apex and thus produce varied clinical presentations. The most commonly noted features are: +• Age. The condition typically affects individuals between 40 and 50 years; however, age is no bar. +• Laterality.Most cases are unilateral, although both sides may be involved occasionally. +• Presenting ocular features are swelling or puffiness of the eyelids, congestive proptosis, orbital pain, restricted ocular movements, diplopia, chemosis and redness. +• Optic nerve dysfunction may occur when inflammation involves the posterior orbit. +• Spontaneous remissions. After few weeks, are known in IOID. +• Recurrences are also common. +• Severe prolonged inflammation in some patients may cause progressive fibrosis of the orbital tissues leading to a frozen orbit with visual impairment. +Diagnosis +• Clinically, IOID is suspected only by exclusion of the known conditions. +• Ultrasonic and CT scanning show a diffuse infiltrative lesion with irregular ill-defined margins, and variable density. +• MRIshows hypointense lesion c.f. muscle on T1 and hyperintense lesion c.f. muscle on T2. There occurs moderate enhancement with gadolinium. Fine-needle aspiration biopsy may give histological clue. +• Incisional biopsy may be needed to confirm the diagnosis in persistent cases. +Treatment +• NSAIDs are effective in some cases and should be tried before the steroid therapy. + + + + + + + + + + + + + + + +Fig. 17.10 Pseudotumour involving the right orbit + +• Systemic steroidsshould preferably be administered after the diagnostic biopsy, as they may mask other pathologies such as infections and Wegner granulomatosis. Oral prednisolone 60–80 mg of prednisolone per day for 2 weeks, initially and then to be tapered gradually forms the mainstay of treatment. Usually, more than half of the patients show a positive response. +• Radiotherapy is usually effective in patients nonresponsive to steroid therapy. +• Cytotoxic agents. Such as methotrexate or mycophenolate mofetil may be required in patients resistant to steroid and radiation therapy. +• Tumour necrosis factor inhibitor, e.g., systemic infiximab, may be required in recurrent and recalcitrant cases despite full conventional therapy. +TOLOSA–HUNT SYNDROME +Tolosa–Hunt syndrome refers to idiopathic non-specific granulomatous inflammation involving the superior orbital fissure, and/or orbital apex and/or cavernous sinsus. +Clinical features +Clinically, it manifests as painful ophthalmoplegia and depending upon the extent of involvement may present as superior orbital fissure syndrome or orbital apex syndrome. +Superior orbital fissure syndrome refers to the symptom complex produced by involvement of the structures passing through the superior orbital fissure. It is characterized by: +• Pain, typically labeled as retro–orbital ache, +• Sensory loss/disturbances in the distribution of ophthalmic division of 5th cranial nerve. +• Ipsilateral ophthalmoplegia due to 3rd, 4th, and 6th cranial nerve involvement. +• Ptosis due to 3rd nerve paralysis. +Orbital apex syndrome refers to the symptom complex produced by involvement of structures present at the apex of orbit, i.e., structures passing through the superior orbital fissure and the optic canal, So the features of orbital apex syndrome include: +• Features of superior orbital fissure described above, and +• Features of optic nerve involvement, i.e., early visual loss and afferent pupillary defect. +Note. In addition to Tolosa-Hunt syndrome other conditions which can involve the orbital apex such as infections, non-infective inflammations, neoplasms or trauma can also present with similar symptom complex. +414 Section III Diseases of Eye + + +Treatment +• Systemic steroidsremain the mainstay of treatment of Tolosa- Hunt syndrome. +• Radiotherapy may be effective in cases non– responsive to steroid therapy. +THYROID EYE DISEASE +The term thyroid eye disease denotes typical ocular changes which include lid retraction, lid lag, and proptosis. These changes have also been labelled as: endocrine exophthalmos, malignant exophthalmos, dysthyroid ophthalmopathy, ocular Graves’ disease (OGD), Graves’ ophthalmopathy, and thyroid associated ophthalmopathy (TAO). +Etiopathogenesis +Thyroid eye disease may be associated with hyperthyroidism (in 90% cases), hypothyroidism (4%) or even euthyroidism (6%). +Risk factors +• Female sex (4–6 times more common than males). • Smoking (Risk is directly related to the number of +cigarettes smoked per day). +• Middle age. Most cases occur in middle age. • Autoimmune thyroid disease. +• HLA-DR3 and HLA-B8. +Pathogenesis +Thyroid eye disease is being considered an autoimmune disease with orbital fibroblasts as the primary target of inflammatory attack and extraocular muscles being secondarily involved. It is probable that the target antigen is shared between the thyroid follicular cells and orbital fibroblasts. The activated T-cells probably act on the fibroblast-adipocyte lineage within the orbit and stimulate adipogenesis, fibroblast proliferation, and glycosaminoglycan synthesis. As a consequence, the extraocular muscles are enlarged due to edema and infiltration with round cells. The orbital soft tissue shows increased amounts of acid mucopolysaccharide and infiltration with lymphocytes, plasma cells, macrophages and mast cells. +Clinical profile +Clinical features (Fig. 17.11) 1. Lid signs. These are: +• Retraction of the upper lids producing the characteristic staring and frightened appearance (Dalrymple’s sign); is the most common clinical features (90% of cases). +• Lid lag (von Graefe’s sign). i.e., when globe is moved downward, the upper lid lags behind (50% cases). + + + + + + + + + + + + + +Fig. 17.11 A patient with Graves’ ophthalmopathy having bilateral exophthalmos and lid retraction +• Fullness of eyelids due to puffy oedematous swelling (Enroth’s sign); +• Difficulty in eversion of upper lid (Gifford’s sign). • Infrequent blinking (Stellwag’s sign). +2. Conjunctival signs. These include ‘deep injection’ and ‘chemosis’. +3. Pupillary signs. These are of less importance and may be evident as inequality of dilatation of pupils. 4. Ocular motility defects. These range from convergence weakness (Mobius’s sign) to partial or complete immobility of one or all of the extrinsic ocular muscles (40% of cases). The most common ocular motility defect is a unilateral elevator palsy caused by an involvement of the inferior rectus muscle followed by failure of abduction due to involvement of medial rectus muscle. +5. Exophthalmos. It is a common (60%) and classical sign of the disease. As a rule both eyes are symmetrically affected; but it is frequent to find one eye being more prominent than the other. +• Even unilateral proptosis is not uncommon. In majority of cases it is self-limiting. +6. Exposure keratitis and symptoms of ocular surface discomfort. These include sandy or gritty sensation, lacrimation and photophobia. Corneal exposure has been attributed to upper lid retraction, exophthalmos, lagophthalmos, inability to elevate the eyes and a decreased blink rate. +7. Optic neuropathy. It occurs in about 60% of cases due to direct compression of the nerve or its blood supply by the enlarged rectus muscles at the orbital apex. It may manifest as papilloedema or optic atrophy with associated slowly progressive impairment of vision. +Classification +American Thyroid Association (ATA) has classified Graves’ ophthalmopathy, irrespective of the hormonal status into following classes, characterised by the acronym ‘NOSPECS’. +Chapter 17 Diseases of Orbit 415 + + +Class 0 : N : No signs and symptoms. +Class 1 :O : Only signs, no symptoms (signs are limited to lid retraction, with or without lid lag and mild proptosis). +Class 2 : S : Soft tissue involvement with signs (as described in Class1) and symptoms including lacrimation, photophobia, lid or conjunctival swelling. +Class 3 : P : Proptosis is well established. +Class 4 : E : Extraocularmuscleinvolvement(limita-tion of movement and diplopia). +Class 5 : C : Corneal involvement (exposure keratitis). +Class 6 : S : Sight loss due to optic nerve involvement with disc pallor or papilloedema and visual field defects. +Clinical course +Thyroid eye disease (TED) is a self-limiting disease that lasts from 1–5 years (longer in smokers as compared to non-smokers). Its clinical course is divided into two phases: +1. Congestive or Active phase of increasing severity is characterized by active inflammation with marked lid oedema, conjunctival chemosis and congestion and increasing exophthalmos. Within 2 to 3 years, in majority of cases, there starts regression and most of the signs slowly settle down. +2. Fibrotic or Inactive phase, also known as quiescent burnt-out phase, ensues after the regression phase. In this phase eyes are white, however, a painless motility defect may be present. +Diagnosis Clinical diagnosis +Clinical diagnosis is not difficult in advanced cases of Graves’ ophthalmopathy with bilateral proptosis. However, early cases having unilateral proptosis need to be differentiated from other causes of unilateral proptosis of adulthood onset (see page 403). +Investigations +1. Thyroid function tests. These should include: serum T3, T4, TSH and estimation of radioactive iodine uptake. +2. Thyroid autoantibody assay may include anti TSH receptors, anti–thyroid peroxidase, anti-thyroglobulin, and thyroid stimulating antibodies. Some of these have poor sensitivity and specificity. 3. Ultrasonography. It can detect changes in extraocular muscles even in class 0 and class 1 cases and thus helps in early diagnosis. In addition to the increase in muscle thickness, erosion of temporal wall of orbit, accentuation of retrobulbar fat and + +perineural inflammation of optic nerve can also be demonstrated in some early cases. +4. Computerised tomographic scanning. It may show proptosis, muscle thickness, thickening of optic nerve and anterior prolapse of the orbital septum (due to excessive orbital fat and/or muscle swelling). 5. MRI (T2-weighted and STIR) gives better soft tissue resolution and identifies active disease. +Management +Management of thyroid eye disease (TED), described below, it is in addition to and independent of the therapy for the associated thyroid dysfunction; as the latter usually does not alter the course of ophthalmic features. Management of TED includes: +• Periodic clinical work up, +• Non-surgical measures, and • Surgical management. +A. Periodic clinical work up +It is essential to document the clinical course of the disease periodically to decide the treatment required and to monitor the effect of therapy. +Clinical activity score has been described to measure the activity of disease at a given time. Total score is noted by giving a score of 1 for each of the following 10 features: +Pain: 1. Retrobulbar pain, +2. Pain on ocular movement, Redness: 3. Redness of lids, +4. Redness (congestion) of conjunctiva, +Swelling: 5. Swelling of lids, +6. Swelling (chemosis) of conjunctiva, +7. Swelling of caruncle, +8. Proptosis (≥ 2 mm increase in proptosis over 1–3 months, +Loss of function: 9. Decrease in eye movement by ± 5° over 1–3 months, +10. Decreased vision by ≥ 1 Snellen line over 1–3 months, +Ocular motility work up. In addition to eye movements, the ocular motility workup should also include: +• Field of binocular single vision. • Field of uniocular fixation, and +• Hess/Lees charting to decide the intervention required. +B. Non-surgical management +1. Smoking cessation should be insisted with the patients as it may markedly influence the course of disease. +2. Head elevation at night andcold compresses in the morning help in reducing periorbital oedema. +416 Section III Diseases of Eye + + +3. Lubricating artificial tear drops instilled frequently in the day time and ointment at bed time are useful for relief of foreign body sensation and other symptoms of dry ocular surface. +4. Eyelid taping at night prevents complication of exposure. +5. Guanethidine 5% eyedrops may decrease the lid retraction caused by overaction of Muller’s muscle. +6. Prisms may be prescribed to alleviate annoying diplopia till the quiescent phase is reached. +7. Systemic steroids may be indicated in acutely inflamed orbit with rapidly progressive chemosis and proptosis with or without optic neuropathy. +8. Radiotherapy. 2000 rads given over 10 days period may help in reducing orbital oedema in patients where steroids are contraindicated. However, radiotherapy may transiently worsen the disease. +9. Combined therapy with low dose steroids, azathioprine and irradiation is reported to be more effective than steroids or radiotherapy alone. +C. Surgical management +■During active phase, orbital decompression may be required for an acutely progressive optic neuropathy and/or exposure keratitis, in patients who do not respond to energetic steroid therapy. +■During quiescent burn-out phase the surgical management is required to improve function and cosmesis. +■A stepwise surgical approach, starting with orbital decompression (if required to restore normal globe position) followed by extraocular muscle surgery (for diplopia if still persisting) followed by eyelid surgery is recommended. Alteration of this sequence may lead to unpredictable results. +1. Orbital decompression may be carried out by an external or endoscopic approach and may involve 2, 3 or 4 walls: +• Two-wall decompression, in which part of the orbital floor and medial wall are removed, allows 36 mm of replacement of the globe. +• Three-wall decompression involves removal of parts of the floor, medial wall and lateral wall, and allows about 6–10 mm of retroplacement of the globe. +• Four-wall decompression involves removal of lateral half of roof and large portion of sphenoid at the apex, in addition to three-wall removal as above. This allows 10–16 mm of retroplacement of the globe and is indicated very rarely in patients with severe proptosis. + +2.Extraocular muscle surgeryshould always be carried out after the orbital decompression, since the latter may alter extraocular motility. Extraocular muscle surgery in the form of recession is required to achieve binocular single vision in the primary gaze and reading position. Inferior rectus recession is the most commonly performed surgery. 3.Eyelidsurgery,when required, should be undertaken last, as the extraocular muscle surgery may affect eyelid retraction. As temporary measures, before the definitive surgical correction, the botulinum toxin injection aimed at Muller’s muscle and LPS muscle may be used, if so desired by the patient. Eyelid surgery for definitive correction may include: +• Mullerotomy, i.e., disinsertion of Muller’s muscle is required for mild lid retraction. +• Levator recession/disinsertion may be required for moderate to severe upper eyelid retraction. +• Scleral grafts with LPS recession may be required in very severe cases. +• Recession of lower eyelid retractors may be required to correct more than 2 mm retraction of lower eyelid. +• Blepharoplasty. It may be performed by removal of excess fatty tissue and redundant skin from around the eyelids. + +CAROTID-CAVERNOUS FISTULA + +Carotid-cavernous fistula is an acquired abnormal communication between the carotid arterial system and the venous cavernous sinus. +Clinical types +There are two type of carotid-cavernous fistula: High-flow fistula: These are secondary to trauma or iatrogenic and present acutely with pain, proptosis (often pulsatile exophthalmos). Chemosis, congestion, bruit, ophthalmoplegia (III-VI nerve palsies), headache, and objective pulsatile tinnitus. The classical triad of presentation is proptosis, chemosis, and bruit. It presents within days or weeks following trauma. +Low-flow fistula: These develop spontaneously in elder women, during pregnancy or in those with hyperplastic tissue. These typically present slowly with less pronounced symptoms. +Differential diagnosis +Common causes of proptosis after trauma are: • Carotid-cavernous fistula +• Retro-orbital haematoma +• Superior orbital fissure syndrome • Orbital apex syndrome. +Chapter 17 Diseases of Orbit 417 + + +Note. The differentiating feature of CCF from other conditions is the presence of conjunctival congestion and chemosis. +Investigations +• Selective carotid angiography using digital subtraction technique is the investigation of choice and essential if the treatment is contemplated. +• Magnetic resonance angiography (MRA) are also used commonly. +Treatment +A carotid-cavernous fistula requires a definitive treatment, which currently involves endovascular technique.The fistula can usually be occluded with a balloon or coil without sacrifice of the carotid artery. + +ORBITAL TUMOURS + +Orbital tumours include primary, secondary and metastatic tumours. +(A) Primary tumours. Those arising from the various orbital structures are as follows: +1. Developmental tumours: Dermoid, epidermoid, lipodermoid and teratoma. +2. Vascular tumours: Capillary and cavernous haemangioma, haemangiopericytoma and lymphangioma. +3. Adipose tissue tumours: Liposarcoma +4. Fibrous tissue tumours: Fibroma, fibrosarcoma and fibromatosis. +5. Osseous and cartilaginous tumours: Osteoma, chondroma, osteoblastoma, osteogenic sarcoma after irradiation, fibrous dysplasia of bone, and Ewing’s sarcoma. +6. Mesenchymal tumours: Rhabdomyoma and fibrous histiocytoma. +7. Neural tumours: Optic nerve glioma, optic nerve sheath meningioma, neurofibroma, neurofibromatosis and schwannoma. +8. Tumours of lacrimal gland include: Epithelial tumours (benign and malignant mixed tumours and adenocarcinoma) and non-epithelial tumours. +9. Lymphoproliferative disorders include: Benign reactive lymphoid hyperplasia, malignant orbital lymphomas, langerhan cell histiocytosis, plasma cell tumours and, xanthogranuloma. +(B) Secondary tumours, spreading from surrounding structures. Include squamous cell carcinoma (most common), malignant melanoma, adenocarcinoma, retinoblastoma. +(C) Metastatic tumours,from distant primary tumours. + +A. PRIMARY ORBITAL TUMOURS I. Developmental tumours +1. Dermoids +These are common developmental tumours which arise from an embryonic displacement of the epidermis to a subcutaneous location. The cystic component is lined with keratinizing epithelium and may contain one or more dermal adnexal structures such as hair follicles and sebaceous glands. Dermoids are of two types: +a. Superficial dermoid. It is seen in infancy. Appears as a firm, round, localised lesion in the upper temporal or upper nasal aspect of the orbit. These do not extend deep into the orbit and are not associated with bony defects. Displacement of globe is also not seen as these are located anterior to the orbital septum (Fig. 17.12). +b. Deep dermoids. These are present in adolescence with proptosis or a mass lesion having indistinct posterior margins (as they arise from deeper sites). They may be associated with bony defects. Treatment of dermoids issurgical excision. Care should be taken not to leave behind the contents of cyst which are potentially irritating. +2. Epidermoid +It is composed of epidermis without any epidermal appendages in the wall of the cyst. These are almost always cystic. The cyst wall contains keratin debris. Treatment is surgical excision. +3. Lipodermoids +These are solid tumours usually seen beneath the conjunctiva. These are mostly located adjacent to the superior temporal quadrant of the globe (Fig. 17.13). These do not require any surgical intervention unless they enlarge significantly. (Also see page 93). + + + + + + + + + + + + + +Fig. 17.12 Dermoid right orbit +418 Section III Diseases of Eye + + + + + + + + + + + + + + + + +Fig. 17.13 Lipodermoid + +4. Teratomas +These (Fig. 17.14) are composed of ectoderm, mesoderm and endoderm. These may be solid, cystic or a mixture of both. The cystic form is more prevalent. Most of these are benign but some solid tumours in newborns are malignant. Exenteration is usually performed for solid tumours to effect a permanent cure. Cystic tumours may be excised without removing the eyeball. +II. Vascular tumours +These are the most common primary benign tumours of the orbit. These can be either haemangiomas or lymphangiomas. Haemangiomas are further divided into two types—capillary and cavernous. +1. Capillary haemangioma +It is commonly seen at birth or during the first month. It appears as periocular swelling in the anterior part of the orbit. It tends to increase in size on straining or crying. This tumour may initially grow in size followed by stabilization and then regression and disappearance. + + + + + + + + + + + + + +Fig. 17.14 Congenital teratoma + +Treatment. These tumours usually do not require any treatment. +■Indications for treatment are: optic nerve com-pression, exposure keratitis, ocular dysfunction or cosmetic blemish. +■Modes of therapy are: +• Systemic and/or intralesional steroids, • Low-dose superficial radiations, +• Surgery and cryotherapy. +• Systemic beta blocker (propranolol) constitutes a new and very promising treatment modality. +2. Cavernous haemangioma +It is the commonest benign orbital tumour among adults with female preponderance (70%). The tumour is usually located in the retrobulbar muscle cone. So, it presents as a slowly progressing unilateral axial proptosis in the second to fourth decade. It may occasionally compress the optic nerve without causing proptosis. +Treatment. Surgical excision of the tumour is undertaken via lateral orbitotomy approach. Since the tumour is well encapsulated, complete removal is generally possible. +3. Lymphangioma +It is an uncommon tumour presenting with slowly progressive proptosis in a young person. It often enlarges because of spontaneous bleed within the vascular spaces, leading to formation of ‘chocolate cysts’ which may regress spontaneously. +III. Mesenchymal tumours +Rhabdomyosarcoma +It is a highly malignant tumour of the orbit arising from the pluripotent mesenchymal cells which have the potential to differentiate into striated muscles. It is the most common primary orbital tumour among children, usually occurring below the age of 15 years (90%), slightly more common in males. Histopathologically rhabdomyosarcoma may be of three types: +• Embryonal sarcoma, (commonest), followed by, • Alveolar sarcoma, and +• Pleomorphic sarcoma (least common). +Clinical features. It classically presents as rapidly progressive proptosis of sudden onset in a child of 7–8 years (Fig. 17.15). The clinical presentation mimics an acute inflammatory process. The tumour commonly involves the superonasal quadrant; but may invade any part of the orbit. +Diagnosis. The clinical suspicion is supported by X-rays showing bone destruction and CT/MRI scan +Chapter 17 Diseases of Orbit 419 + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 17.15 Rhabdomyosarcoma in inferior quadrant: A, clinical photograph; B, CT scan shows inferior orbital mass + +demonstrating irregular but well-defined tumour with adjacent bone destruction. Diagnosis is confirmed by biopsy. +Treatment includes: +• Surgical excision biopsy is possible only for a well circumscribed localised tumour. +• Chemotherapy regime consists of Vincristine 2 mg/m2 on day 1 and 5, actinomycin-D 0.015 mg/ kg IV once a day for 5 days and cyclophosphamide 10 mg/kg once a day for 3 days; to be repeated every 4 weeks for a period of 2 years. Chemotherapy generally results in a good prognosis in embryonal sarcomas but not in alveolar sarcomas (most malignant). +• Radiation therapy in high dose (5000 rads in 5 weeks) combined with systemic chemotherapy is very effective. +• Exenteration is required in a few unresponsive patients. +IV. Neural tumours +1. Optic nerve glioma +It is a slow growing tumour arising from the astrocytes. It usually occurs in first decade of life. It may present either as a solitary tumour or as a part + +of von Recklinghausen’s neurofibromatosis (30%). Optic nerve alone is affected in 28% of cases, 72% involve the optic chiasma, often with mid-brain and hypothalamic involvement. +Clinical features. It is characterised by gradual visual loss associated with a gradual, painless, unilateral axial proptosis occurring in a child usually between 4 and 8 years of age (Fig. 17.16A). Fundus examination may show optic atrophy (more common) or papilloedema and venous engorgement. Intracranial extension of the glioma through optic canal is not uncommon. +Diagnosis. Clinical diagnosis is well supported by X-rays showing uniform regular rounded enlargement of optic foramen in 90% of cases (Fig. 17.16 B) and CT scan and ultrasonography depicting a fusiform growth in relation to optic nerve (Fig. 17.16 C and D). Treatment includes: +• Observation, without any treatment, is recommended for patients having stationary tumour, with good vision, and non-disfiguring proptosis. +• Surgical excision of the tumour mass with preservation of the eyeball, by lateral orbitotomy when the cosmetically unacceptable proptosis is present in a blind eye (due to optic atrophy). Tumours with intracranial extensions are dealt with the neurosurgeons. +• Radiotherapy should be given in unoperable cases. +2. Meningiomas +These are invasive tumours arising from the arachnoidal villi. Meningiomas invading the orbit are of two types: primary and secondary. +(a) Primary intraorbital meningiomas, also known as ‘optic nerve sheath meningiomas’, is a rare benign tumour of meningothelial cells of the meninges that usually occur in mid-age and has slight female preponderance. There is an assocation with neuro-fibromatosis-2. This tumour usually presents with early visual loss associated with limitation of ocular movements, optic disc oedema or atrophy, and a slowly progressive unilateral proptosis (Fig. 17.17A). During the intradural stage, it is clinically indistinguishable from optic nerve glioma. However, the presence of opticociliary shunt is pathognomic of an optic nerve sheath meningioma. CT scan (Fig. 17.17B) is diagnostic. +Treatment is as below: +• Observation is recommended if visual acuity is good. • Surgical excision is recommended for severe proptosis with blind eye, or threat to the chiasma. +• Prognosis for life is good. +420 Section III Diseases of Eye + + + + + + + + + +C + + +A + + + + + + + + + + + + + +B D +Fig. 17.16 Optic nerve glioma : A, Clinical photograph; B, X-rays optic foramina; C, CT scan; D, Ultrasonography B scan. + + + + + + + + + + + +A + + + + + + + + + + + +B +Fig. 17.17 Optic nerve sheath meningioma: A, Clinical photograph showing axial proptosis; B, CT scan orbit +showing typical triple sign + +(b)Secondary orbital meningiomas.Those intracranial meningiomas which secondarily invade the orbit either arise from the sphenoid bone or involve it enroute to the orbit. Orbital invasion may occur through: floor of anterior cranial fossa, superior orbital fissure and optic canal. Meningioma enplaque, affecting the greater and lesser wings of sphenoid and taking origin in the region of pterion, is the most common variety affecting the orbit secondarily. These tumours typically occur in middle-aged women. +Clinical features. These are characterised by greater proptosis and lesser visual impairment than the primary intraorbital meningiomas. Other characteristic features of these tumours are boggy eyelid swelling and an ipsilateral swelling in the temporal region of the face, especially when the intracranial tumour arises from the lateral part of sphenoid ridge (Fig. 17.18A). In such cases, proptosis is due to hyperostosis on the lateral wall and roof of the orbit. CT scan is very useful in assessing the extent of tumour (Figs. 17.18B and C). +Management of secondary orbital (sphenoid wing) meningiomas is as below: +Chapter 17 Diseases of Orbit 421 + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B + + + + + + + + + + + +C +Fig. 17.18 Secondary orbital involvement in a patient with sphenoidal ridge meningioma, (A) clinical photograph; B & C, CT scan, coronal and axial section, respectively + +• Observation is recommended till they produce functional consequences. +• Subtotal resection through a combined approach to the intracranial and orbital component, in collaboration with neurosurgeon, is recommended when they produce profound proptosis, compressive optic neuropathy, motility impairment or cerebral oedema. +• Postoperative radiotherapy is advocated to reduce the risk of recurrences of the residual tumour. + +V. Lymphoproliferative tumours +World Health Organization (WHO) consensus classification of lymphoproliferative tumours is as below: +• Benign reactive lymphoid hyperplasia • Malignant orbital lymphomas +• Langerhan’s cell histiocytosis. +Benign reactive lymphoid hyperplasia (BRLH) +Benign reactive lymphoid hyperplasia is an uncommon polyclonal proliferation of lymphoid tissue, usually occurring in the anterior part of superolateral orbit with a predilection for lacrimal gland. + +Clinical features include: +■Proptosis, which is painless, progressive with medial displacement of the globe. +■Firm rubbery mass is often palpable beneath superolateral orbital rim. +■Pink subconjunctival infiltrate (salmon patch) may also be seen. +Treatment includes systemic steroids and local radiotherapy. Some patients may require cytotoxic drugs. Progression to systemic lymphomas occurs in about 25% cases by 5 years. +Atypical lymphoid hyperplasia +Atypical lymphoid hyperplasia (ALH) is an inter-mediate between BRLH and malignant lymphoma. +Features are similar to BRLH except that: • May involve other systemic organs, and • Usually does not respond to steroids. +Malignant orbital lymphomas +Orbit is mainly (90%) involved by malignant non-Hodgkin B-cell lymphomas. Hodgkin’s lymphoma seldom involves the orbit. According to ‘Revised European American Lymphoma (REAL)’ classification, the non-Hodgkin B-cell lymphomas involving orbit are as follows: +1. Mucosa Associated Lymphoid Tissue (MALT) +lymphoma +• Accounts for 40–70% of all orbital lymphomas. +• Usually unilateral, but bilateral involvement may occur in 25% cases. +• Present with gradual proptosis and/or palpable firm rubbery masses. +• Systemic involvement occurs in 50% of cases. Treatment includes radiotherapy or chemotherapy depending upon the grade and spread of tumour. 2. Chronic lymphocytic lymphoma (CLL). It also represents a low-grade lesion of small mature appearing lymphocytes. +422 Section III Diseases of Eye + + +3. Follicular center lymphoma. It represents a low-grade lesion with follicular centers. +4. High-grade lymphomas involving orbit include large cell lymphoma, lymphoblastic lymphoma and Burkitt’s lymphoma. +Langerhan’s cell histiocytosis +Langerhan’s cell histiocytosis, formerly known as histiocytosis X, is a group of diseases characterised by an idiopathic abnormal proliferation of histiocytes with granuloma formation. These diseases primarily affect children with an orbital involvement in 20% of cases. This group includes following three diseases: 1. Hand-Schuller-Christian disease. It is a chronic disseminated form of histiocytosis involving both soft tissues and bones in older children of either sex. It is characterised by a triad of proptosis, diabetes insipidus and bony defects in the skull. +2. Letterer-Siwe disease. Now termed as ‘diffuse soft tissue histiocytosis’ is a systemic form of histiocytosis characterised by widespread soft tissue and visceral involvement with or without bony changes. The disease has a slight male preponderance and often occurs in the first three years of life. Orbital involvement is comparatively rare. +3. Unifocal or multifocal eosinophilic granuloma is characterised by a solitary or multiple granulomas involving the bones. The disease occurs in elder children and frequently involves the orbital bones. +B. SECONDARY ORBITAL TUMOURS These may arise from the following structures: +1. Tumours of eyeball: Retinoblastoma (see Fig. 12.37 and 12.36) and malignant melanoma (see Fig. 8.24). +2. Tumours of the eyelids: Squamous cell carcinoma and basal cell carcinoma. +3. Tumours of nose and paranasal sinuses: These tumours very commonly involve the orbit (50%). These include: carcinomas, sarcomas and osteomas. +4. Tumours of nasopharnyx. Carcinoma of nasopharynx is the commonest tumour involving the orbit. 38% cases with this tumour show ophthalmoneurological symptoms which include proptosis and involvement of fifth and sixth cranial nerves. Rarely, third, fourth and second cranial nerves are also involved. +5. Tumours of cranial cavity invading orbit are glioma and meningioma. +C. METASTATIC ORBITAL TUMOURS +These involve the orbit by haematogenous spread from a distant primary focus and include the following: + + +I. Metastatic tumours in children +1. Neuroblastoma—from adrenals and sympathetic chain (most common). +2. Nephroblastoma—from kidneys. 3. Ewing’s sarcoma—from the bones. 4. Leukaemia infiltration. +5. Testicular embryonal sarcoma and ovarian sarcoma. +II. Metastatic tumours in adults +1. Carcinoma—from lungs (most common in males), breast (most common in females), prostate, thyroid and rectum. +2. Malignant melanoma—from skin. + +Note. Most common orbital tumours are as below: + +Tumour Children Adult Primary benign Dermoid cyst Cavernous +haemangioma Primary Rhabdomyosarcoma Lymphoma malignant +Secondary Retinoblastoma Squamous cell tumour carcinoma Metastatic Neuroblastoma Carcinoma tumour breast (females) +and carcinoma lungs (males) + +ORBITAL BLOW-OUT FRACTURES + +Blow-out fractures are isolated comminuted fractures which occur when the orbital walls are pressed indirectly. These mainly involve orbital floor and medial wall. +Etiology +Blow-out orbital fractures generally result from trauma to the orbit by a relatively large, often rounded object, such as tennis ball, cricket ball, human fist (Fig. 17.19) or part of an automobile. The force of the blow causes a backward displacement of the eyeball and an increase in the intraorbital pressure; with a resultant fracture at the weakest point of the orbital wall. Usually this point is the orbital floor, but this may be the medial wall also. +Classification +1. Pure blow-out fractures: These are not associated with involvement of the orbital rim. +2. Impure blow-out fractures: These are associated with other fractures about the middle third of the facial skeleton. +Clinical features +1. Periorbital oedema and blood extravasation in and around the orbit (such as subconjunctival +Chapter 17 Diseases of Orbit 423 + + + + + + + + + + + + + + +Fig. 17.19 Mechanism of blow-out fracture of the orbital floor + + +ecchymosis) occur immediately. This may mask certain signs and symptoms seen later. +2. Emphysema of the eyelids occurs more frequently with medial wall than floor fractures. It may be made worse by blowing of the nose. +3. Paraesthesia and anaesthesia in the distribution of infraorbital nerve (lower lid, cheek, side of nose, upper lip and upper teeth) are very common. +4. Ipsilateral epistaxis as a result of bleeding from maxillary sinus into the nose is frequently noted in early stages. +5. Proptosis of variable degree may also be present initially because of the associated orbital oedema and haemorrhage. +6. Enophthalmos and mechanical ptosis. After about 10 days, as the oedema decreases, the eyeball sinks backward and somewhat inferiorly resulting in enophthalmos and mechanical ptosis (Fig. 17.20). Three factors responsible for producing enophthalmos are: + + + + + + + + + + + + + + + +Fig. 17.20 Enophthalmos and mechanical ptosis in a patient with blow-out fracture of orbit + +• escape of orbital fat into the maxillary sinus; +• backward traction on the globe by entrapped inferior rectus muscle; and +• enlargement of the orbital cavity from displacement of fragments. +7. Diplopia also becomes evident after the decrease in oedema. It typically occurs in both up and down gaze (double diplopia) due to entrapment of soft tissue structures in the area of the blowout fracture. The presence of muscle restriction can be confirmed by a positive ‘forced duction test’. +8. Severe ocular damage associated with blow-out fracture is rare. This is because a ‘blow-out fracture’ is nature’s way of protecting the globe from injury. Nevertheless, the eye should be carefully examined to exclude the possibility of intraocular damage. +Orbital imaging +1. Plain X-rays. The most useful projection for detecting an orbital floor fracture is a nose-chin (Water’s) view. The common Roentgen findings are: fragmentation and irregularity of the orbital floor; depression of bony fragments and ‘hanging drop’ opacity of the superior maxillary antrum from orbital contents herniating through the floor (Fig. 17.21). 2. Computerised tomography scanning and magnetic resonance imaging (MRI). These are of greater value for detailed visualisation of soft tissues. Coronal sections (Fig. 17.22) are particularly useful in evaluating the extent of the fracture and herniation of contents into maxillary antrum (hanging drop or tear drop sign). +Management +I. General measures and medical treatment +1. Avoid nose blowing should be advised to each + + + + + + + + + + + + + + + +Fig. 17.21 Plain X-ray orbit (AP view) showing herniated orbital contents (arrow) with blow-out fracture of the orbital floor +424 Section III Diseases of Eye + + + + + + + + + + + + + + + +Fig. 17.22 CT scan coronal section of orbit showing fracture floor with herniation of orbital contents + +patient, as the nose blowing may contribute to surgical emphysema and herniation of soft tissue. +2. Systemic antibiotics should be given to prevent secondary infection from the maxillary sinus. +3. Analgesics and anti-inflammatory drugs to decrease pain and swelling. +4. Cold compresses, immediately following trauma may decrease swelling by causing vasoconstriction. +II. Surgical management +Surgical repair to restore continuity of the orbital floor may be made with or without implants. It may not be required in many cases. The optimal time for surgery when indicated, is after 10–14 days of injury. +Indications of surgical intervention include: +1. Diplopia not resolving significantly in the early days after trauma. +2. A fracture with a large herniation of tissues into the antrum. +3. Incarceration of tissues in the fracture resulting, in globe retraction and increased applanation tension on attempted upward gaze. +4. Enophthalmos greater than 3 mm. +Any of these factors, alone or combinedly could indicate that early orbital repair is necessary. + +ORBITAL SURGERY + +ORBITOTOMY +Orbitotomy operation refers to surgical approach for an orbital mass lesion. There are four surgical approaches to the orbit: +1. Anterior orbitotomy. It is indicated only when the lesion is readily palpable through the eyelids and is judged to be mainly in front of the equator of eyeball. Depending upon the location of the lesion the anterior orbitotomy can be performed by any of the following approaches: + +i. Superior approach is used for the lesions located in the superoanterior part of the orbit. It can be performed through: +• Transcutaneous route (Fig. 17.23A) or • Transconjunctival route. +ii. Inferior approach is suitable for the lesions located in the inferoanterior part of the orbit. It can be performed through: +• Transcutaneous route (Fig. 17.23B) or • Transconjunctival route. +iii. Medial approach can be performed through: • Transcutaneous route (Fig. 17.23C) +• Transconjunctival route, or • Transcaruncular route. +iv. Lateral approach is performed through a lateral canthotomy incision (Fig. 17.23D). +2. Lateral orbitotomy. In this approach, lateral half of the supraorbital margin with the quadrilateral piece of bone forming the lateral orbital wall is temporarily removed. This approach provides an adequate exposure to the orbital contents and is particularly valuable for the retrobulbar lesions. The classical technique of lateral orbitotomy using S-shaped brow skin incision (Fig. 17.23E) is called Kronlein’s operation. This incision allows good exposure but leaves noticeable scar. Therefore, presently the preferred incisions are: +• Upper eyelid crease incision (Fig. 17.23F), or • Lateral canthotomy incision (Fig. 17.23G). +3. Transfrontal orbitotomy. In this technique, orbit is opened through its roof and thus, mainly is the domain of neurosurgeons. Transfrontal orbitotomy is used to decompress the roof of the optic canal and to explore and remove when possible tumours of the sphenoidal ridge involving the superior orbital fissure. + + + + + + + + + + + +Fig. 17.23 Incision site for: Anterior orbitotomy (A, superior approach, upper eyelid crease incision; B, inferior approach, subciliary incision; C, medial i.e. frontoethmoidal approach; D, lateral approach by lateral canthotomy) and Lateral orbitotomy; (E, S-shaped brow skin incision; F, upper eyelid crease incision, and G, lateral canthotomy incision) +Chapter 17 Diseases of Orbit 425 + + + + + + + + + + + + + +A B C +Fig. 17.24 Exenteration of the orbit : A, skin incision; B, periosteal reflection and C, amputation of the orbital contents + + + +4. Temporofrontal orbitotomy. This approach provides an access to the orbit (through its roof) and anterior and middle cranial fossa simultaneously. +EXENTERATION +It is a mutilating surgery in which all the contents of the orbits along with the periorbita are removed + +through an incision made along the orbital margins (Fig. 17.24). Exenteration is indicated for malignant tumours arising from the orbital structures or spreading from the eyeball. Nowadays, debulking of the orbit is preferred over exenteration. +18 + +Ocular Injuries + + + +Chapter Outline + + +MECHANICAL INJURIES Ocular trauma terminologies Extraocular foreign bodies Blunt trauma +Open-globe injuries Sympathetic ophthalmitis +• +• +• +• +• +CHEMICAL INJURIES Alkali burns +• +• +Acid burns + + + +MECHANICAL INJURIES + +OCULAR tRAUMA tERMINOLOgIES + +In this era of high speed traffic and industrialisation, the incidence of injuries is increasing in general. Like any other part of the body, eyes are also not exempted from these injuries; in spite of the fact that they are well protected by the lids, projected margins of the orbit, the nose and a cushion of fat from behind. +Before going into details of the mechanical injuries, it will be worthwhile to become familiar with the new ocular trauma terminology system proposed by the ‘Birmingham Eye Trauma Terminology’ (BETT). The term eyewall has been restricted for the outer fibrous coat (cornea and sclera) of the eyeball. The definitions proposed by the BETT and as such adopted by ‘American Ocular Trauma Society’ (AOTS) for mechanical ocular injuries are as follows: 1. Closed-globe injury is the one in which eyewall (sclera and cornea) does not have a full thickness wound but there is intraocular damage. It includes contusion and lamellar laceration. +• Contusion refers to the closed-globe injury resulting from blunt trauma. Damage may occur at the site of impact or at a distant site. +• Lamellar laceration is a closed-globe injury characterized by a partial thickness wound of the eyewall caused by a sharp object or blunt trauma. + +NoN-MECHANICAL INJURIES Thermal Injuries +Electrical Injuries +Radiational Injuries +• Ultraviolet radiations • Infrared radiations +• Ionizing radiational injuries + + + + +2.Open-globe injuryis associated with a full-thickness wound of the sclera or cornea or both. It includes rupture and laceration of eyewall. +i. Rupture refers to a full-thickness wound of eyewall caused by the impact of blunt trauma. The wound occurs due to markedly raised intraocular pressure by an inside-out injury mechanism. +ii. Laceration refers to a full-thickness wound of eyewall caused by a sharp object. The wound occurs at the impact site by an outside-in mechanism. It includes penetrating and perforating injuries. +• Penetrating injury refers to a single laceration of eyewall caused by a sharp object which traverses the coats only once. +• Perforating injury refers to two full thickness lacerations (one entry and one exit) of the eyewall caused by a sharp object or missile. The two wounds must have been caused by the same agent (earlier known as double perforation). +• lntraocular foreign body injury is technically a penetrating injury associated with retained intraocular foreign body. However, it is grouped separately because of different clinical implications. +Note. In view of the above, mechanical ocular injuries can be discussed under following headings: • Extraocular foreign bodies, +• Blunt trauma, +• Open globe injuries, and +• Sympathetic ophthalmitis. +Chapter 18 Ocular Injuries 427 + + +ExtRAOCULAR FOREIgN BOdIES + +Extraocular foreign bodies are quite common in industrial and agricultural workers. Even in day-to-day life, these are not uncommon. +Common sites and types +Common sites. A foreign body may be impacted in the conjunctiva or cornea (Fig. 18.1). +• On the conjunctiva, it may be lodged in the sulcus subtarsalis, fornices or bulbar conjunctiva. +• In the cornea, it is usually embedded in the epithelium, or superficial stroma and rarely into the deep stroma. +Common types. The usual foreign bodies: +• In industrial workers are particles of iron (especially in lathe and hammer-chisel workers), emery and coal. +• In agriculture workers, these are husk of paddy and wings of insects. +• Other common foreign bodies are particles of dust, sand, steel, glass, wood and small insects (mosquitoes). +Clinical features +Symptoms. A foreign body produces immediate: +• Discomfort, profusewatering and redness in the eye. • Pain and photophobia are more marked in corneal +foreign body than the conjunctiva. +• Defective vision occurs when it is lodged in the centre of cornea. +Signs. Examination reveals marked blepharospasm and conjunctival congestion. A foreign body can be localized on the conjunctiva or cornea by oblique illumination. Slit-lamp examination after fluorescein staining is the best method to discover corneal foreign body. Double eversion of the upper lid is required to discover a foreign body in the superior fornix. +Complications include: +• Acute bacterial conjunctivitis may occur from infected foreign bodies or due to rubbing with infected hands. + + + + + + + + + + + + + +Fig. 18.1 Foreign body on the cornea + + +• Corneal ulceration may occur as a complication of corneal foreign body. +• Pigmentation and/or opacity may be left behind by an iron or emery particles embedded in the cornea. +Treatment +Extraocular foreign bodies should be removed as early as possible. +1.Removal of conjunctival foreign body.A foreign body lying loose in the lower fornix, sulcus subtarsalis or in the canthi may be removed with a swab stick or clean handkerchief even without anaesthesia. Foreign bodies impacted in the bulbar conjunctiva need to be removed with the help of a hypodermic needle after topical anaesthesia. +2.Removal of corneal foreign body.Eye is anaesthetised with topical instillation of 2 to 4% xylocaine and the patient is made to lie supine on an examination table. Lids are separated with universal eye speculum, the patient is asked to look straight upward and light is focused on the cornea. First of all, an attempt is made to remove the foreign body with the help of a wet cotton swap stick. If it fails then foreign body spud or hypodermic needle is used. Extra care is taken while removing a deep corneal foreign body, as it may enter the anterior chamber during manoeuvring. If such a foreign body happens to be magnetic, it is removed with a hand-held magnet. After removal of foreign body, patching with antibiotic eye ointment is applied for 24to 48 hours. Antibiotic eyedrops are instilled 3–4 times a day for about a week. +Prophylaxis +• Industrial and agricultural workers should be advised to use special protective glasses. +• Cyclists and scooterists should be advised to use protective plain glasses or tinted goggles. +• Special guards should be put on grinding machines and use of tools with overhanging margins should be banned. +• Eye health care education should be imparted, especially to the industrial andagricultural workers. + +BLUNt tRAUMA + +Causes and PaThogenesis of damage +modes of trauma +Blunt trauma may occur following: +• Direct blow to the eyeball by fist, a tennis or cricket or another ball or blunt instruments like sticks, and big stones. +• Accidental blunt trauma to eyeball may also occur in roadside accidents, automobile accidents, injuries by agricultural and industrial instruments/ +428 Section iii Diseases of Eye + + +machines and fall upon the projecting blunt objects. +mechanics of forces of blunt trauma +Blunt trauma of eyeball produces damage by different forces as described below: +1. Direct impact on the globe. It produces maximum damage at the point where the blow is received (Fig. 18.2A). +2. Compression wave force. It is transmitted through the fluid contents in all the directions and strikes the angle of anterior chamber, pushes the iris-lens diaphragm posteriorly, and also strikes the retina and choroid (Fig. 18.2B). This may cause considerable damage. Sometimes, the compression wave may be so explosive, that maximum damage may be produced at a point distant from the actual place of impact. This is called contre-coup damage. +3. Reflected compression wave force. After striking the outer coats, the compression waves are reflected towards the posterior pole and may cause foveal damage (Fig. 18.2C). +4. Rebound compression wave force. After striking the posterior wall of the globe, the compression waves rebound back anteriorly. This force damages the retina and choroid by forward pull and lens-iris diaphragm by forward thrust from the back (Fig. 18.2D). +5. Indirect force. Ocular damage may also be caused by the indirect forces from the bony walls and elastic contents of the orbit, when globe suddenly strikes against these structures. +mechanisms of damage +The different forces of the blunt trauma described above may cause damage to the structures of the globe by one or more of the following modes: 1.Mechanical tearing of the tissues of eyeball. 2.Damage to the tissue cells sufficient to cause +disruption of their physiological activity. 3.Vascular damage leading to ischaemia, oedema +and haemorrhages. +4.Trophic changes due to disturbances of the nerve supply. + +5.Delayed complications of blunt trauma such as secondary glaucoma, haemophthalmitis, late rosette cataract and retinal detachment. +TraumaTiC lesions of blunT Trauma Traumatic lesions produced by blunt trauma can be grouped as follows: +• Closed-globe injury, • Globe rupture, and • Extraocular lesions. + +A. Closed-globe injury +Either there is no corneal or scleral wound at all (contusion) or it is only of partial thickness (lamellar laceration). Contusional injuries may vary in severity from a simple corneal abrasion to an extensive intraocular damage. Lesions seen in closed-globe injury are briefly enumerated here. +i. Cornea +1. Simple abrasions. These are very painful and diagnosed by fluorescein staining. These usually heal up within 24 hours with patching applied after instilling antibiotic ointment. +2. Recurrent corneal erosions (recurrent keractalgia). These may sometimes follow simple abrasions, especially those caused by finger nail trauma. Patient usually gets recurrent attacks of acute pain and lacrimation on opening the eye in the morning. This occurs due to abnormally loose attachment of epithelium to the underlying Bowman’s membrane. Treatment. Loosely attached epithelium should be removed by debridement and ‘pad and bandage’ applied for 48 hours, so that firm healing is established. 3. Partial corneal tears (lamellar corneal laceration). These may also follow a blunt trauma and are treated by topical antibiotics and patching. +4. Tears in Descemet’s membrane are known to occur in birth trauma. These are usually vertical. +5. Acute corneal oedemamay occur following traumatic dysfunction of endothelial cells. It may be associated with Descemet’s folds and stromal thickening. It, usually, clears up spontaneously; rarely a deep corneal opacity may be the sequelae. + + + + + + + + + + +Fig. 18.2 Mechanics of blunt trauma to eyeball: A, direct impact; B, compression wave force: C, reflected compression wave; D, rebound compression wave +Chapter 18 Ocular Injuries 429 + + +6. Blood staining of cornea. It may occur occasionally from the associated hyphaema and raised intraocular pressure. Cornea becomes reddish brown (Fig. 18.3) or greenish in colour and in later stages simulates dislocation of the clear lens into the anterior chamber. It clears very slowly from the periphery towards the centre, the whole process may take even more than two years. +ii. Sclera +Partial thickness scleral wounds (lamellar scleral lacerations) may occur alone or in association with other lesions of closed-globe injury. +iii. Anterior chamber +1. Traumatic hyphaema (blood in the anterior chamber). It occurs due to injury to the iris or ciliary body vessels (Fig. 18.4). +■Treatment includes: +• Conservative treatment is aimed at prevention of rise in IOP and occurrence of secondary haemorrhage (re-bleed). +• Surgical treatment. A small hyphaema usually clears up with conservative treatment. A large non-resolving hyphaema causing raised IOP should be drained to avoid blood staining of the cornea. +2. Exudates. These may collect in the anterior chamber following traumatic uveitis. +iV. iris, pupil and ciliary body \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_15.txt b/notes/A K Khurana - Comprehensive Ophthalmology_15.txt new file mode 100644 index 0000000000000000000000000000000000000000..baeed327818c094067af69fe154ad87df6074441 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_15.txt @@ -0,0 +1,1599 @@ +1. Traumatic miosis. It occurs initially due to irritation of ciliary nerves. It may be associated with spasm of accommodation. +2. Traumatic mydriasis (Iridoplegia). It is usually permanent and may be associated with traumatic cycloplegia. +3. Rupture of the pupillary margin is a common occurrence in closed-globe injury. + + + + + + + + + + + + + + + +Fig. 18.3 Blood staining of cornea + + + + + + + + + + + + +Fig. 18.4 Photograph of a patient with hyphaema + + +4. Radiating tears in the iris stroma, sometimes reaching up to ciliary body, may occur occasionally. 5. Iridodialysis, i.e., detachment of iris from its root at the ciliary body occurs frequently. It results in a D-shaped pupil and a black biconvex area seen at the periphery (Fig. 18.5). +6. Antiflexion of the iris. It refers to rotation of the detached portion of iris, in which its posterior surface faces anteriorly. It occurs following extensive iridodialysis. +7. Retroflexion of the iris. This term is used when whole of the iris is doubled back into the ciliary region and becomes invisible. +8. Traumatic aniridia or iridemia. In this condition, the completely torn iris (from ciliary body) sinks to the bottom of anterior chamber in the form of a minute ball. +9. Angle recession refers to the tear between longitudinal and circular muscle fibres of the ciliary body. It is characterized by deepening of the anterior chamber and widening of the ciliary body band on gonioscopy. Later on, it is complicated by glaucoma. + + + + + + + + + + + + + + + +Fig. 18.5 Traumatic cataract and iridodialysis following contusional injury +430 Section iii Diseases of Eye + + +10. Inflammatory changes. These include traumatic iridocyclitis, haemophthalmitis, post-traumatic iris atrophy and pigmentary changes. +■Treatment. It consists of atropine, antibiotics and steroids. In the presence of ruptures of pupillary margins and subluxation of lens, atropine is contraindicated. +V. Lens +It may show following changes: +1. Vossius ring. It is a circular ring of brown pigment seen on the anterior capsule. It occurs due to striking of the contracted pupillary margin against the crystalline lens. It is always smaller than the size of the pupil. +2. Concussion cataract. It occurs mainly due to imbibition of aqueous and partly due to direct mechanical effects of the injury on lens fibres. It may assume any of the following shapes: +• Discrete subepithelial opacities are of most common occurrence. +• Early rosette cataract(punctate). It is the most typical form of concussion cataract. It appears as feathery lines of opacities along the star-shaped suture lines; usually in the posterior cortex (Fig. 18.6). +• Late rosette cataract. It develops in the posterior cortex 1 to 2 years after the injury. Its sutural extensions are shorter and more compact than the early rosette cataract. +• Traumatic zonular cataract. It may also occur in some cases, though rarely. +• Diffuse (total) concussion cataract. It is of frequent occurrence. +• Early maturation of senile cataract may follow blunt trauma. +Treatment of traumatic cataract is on general lines (see pages 195-210). +3. Traumatic absorption of the lens. It may occur sometimes in young children resulting in aphakia. 4. Subluxation of the lens(Figs. 9.38 and 9.40A). It may occur due to partial tear of zonules. The subluxated + + + + + + + + + + + + + +Fig. 18.6 Rosette-shaped cataract following blunt trauma + +lens is slightly displaced but still present in the pupillary area. On dilatation of the pupil its edge may be seen. Depending upon the site of zonular tear subluxation may be vertical (upward or downward), or lateral (nasal or temporal). Subluxated lens may cause trembling of the iris (iridodonesis) and/or trembling of lens (phacodonesis). +5. Dislocation of the lens. It occurs when rupture of the zonules is complete. It may be intraocular (commonly) or extraocular (sometimes). Intraocular dislocation may be anterior (into the anterior chamber, see Fig. 9.40B) or posterior (into the vitreous, see Fig. 9.40C). Extraocular dislocation may be in the subconjunctival space (phacocele) or it may fall outside the eye. +■For treatment and detailed features of the subluxated or dislocated lens see page 215. +Vi. Vitreous +1. Liquefaction and appearance of clouds of fine pigmentary opacities (a most common change). +2. Detachment of the vitreous either anteriorly at the base or posterior (PVD) may occur. +3. Vitreous haemorrhage. It is of common occurrence (for details see page 260). +4. Vitreous herniation in the anterior chamber may occur with subluxation or dislocation of the lens. +Vii. Choroid +1. Rupture of the choroid. The rupture of choroid is concentric to the optic disc and situated temporal to it. Rupture may be single or multiple. On fundus examination, the choroidal rupture looks like a whitish crescent (due to underlying sclera) with fine pigmentation at its margins. Retinal vessels pass over it (Fig. 18.7). + + + + + + + + + + + + + + + + + + +Fig. 18.7 Choroidal rupture following blunt trauma +Chapter 18 Ocular Injuries 431 + + +2. Choroidal haemorrhage may occur under the retina (subretinal) or may even enter the vitreous if retina is also torn. +3. Choroidal detachment is also known to occur following blunt trauma. +4. Traumatic choroiditis may be seen on fundus examination as patches of pigmentation and discoloration after the eye becomes silent. +Viii. Retina +1. Commotio retinae (Berlin’s oedema). It is of common occurrence following a blow on the eye. It manifests as milky white cloudiness involving a considerable area of the posterior pole with a ‘cherry-red spot’ in the foveal region (Fig. 18.8). It may disappear after some days or may be followed by pigmentary changes. +2. Retinal haemorrhages. These are quite common following concussion trauma. Multiple haemorrhages including flame-shaped and pre-retinal D-shaped (subhyaloid) haemorrhage may be associated with traumatic retinopathy. +3. Retinal tears. These may follow a contusion, particularly in the peripheral region, especially in eyes already suffering from myopia or senile degenerations. +4. Traumatic proliferative retinopathy (Retinitis proliferans). It may occur secondary to vitreous haemorrhage, forming tractional bands. +5. Retinal detachment. It may follow retinal tears or vitreo-retinal tractional bands. +6. Concussion changes at macula. Traumatic macular oedema is usually followed by pigmentary degeneration. Sometimes, a macular cyst is formed, which on rupture may be converted into a lamellar or full thickness macular hole. +iX. intraocular pressure changes in closed-globe injury +1. Traumatic glaucoma. It may occur due to multiple factors, which are described in detail on page 251. + + + + + + + + + + + + + +Fig. 18.8 Commotio retinae following blunt trauma + +2. Traumatic hypotony. It may follow temporary damage to the ciliary body (ciliary shock) or there may occur permanent damage to the ciliary body which may even result in phthisis bulbi. +X. Traumatic changes in the refraction +1. Myopia may follow ciliary spasm or rupture of zonules or anterior shift of the lens. +2. Hypermetropia and loss of accommodation may result from damage to the ciliary body (cycloplegia). + +B. globe Rupture +Globe rupture is a full-thickness wound of the eyewall (sclera, cornea or both) caused by a blunt object. +Types of globe rupture +Globe rupture may occur in two ways: +1. Direct rupture may occur, though rarely, at the site of injury. +2. Indirect rupture is more common and occurs because of the compression force. The impact results in momentary increase in the intraocular pressure and an inside-out injury at the weakest part of eyewall, i.e., in the vicinity of canal of Schlemm concentric to the limbus. The superonasal limbus is the most common site of globe rupture (contrecoup effect—the lower temporal quadrant being most exposed to trauma). +Clinical features +Rupture of the globe may be associated with: Prolapse of uveal tissue, vitreous loss, intraocular haemorrhage and dislocation of the lens. +• Intraocular pressure may be raised initially, but ultimately it is decreased. +• Accompanying signs include irregular pupil, hyphaema, commotio retinae, choroidal rupture, and retinal tears. +Treatment +• Repair of tear in the eyewall should be done meticulously under general anaesthesia to save the eyeball whenever possible. +• Postoperativetreatment should include antibiotics, steroids and atropine. +• Enucleation may be required in a badly damaged eye where salvation is not possible. + +C. Extraocular Lesions +Extraocular lesions caused by blunt trauma are as follows: +1. Conjunctival lesions include: +• Subconjunctival haemorrhage occurs very commonly. It appears as a bright red spot. +• Chemosis and lacerating wounds of conjunctiva (tears) are also not uncommon. +432 Section iii Diseases of Eye + + +2. Eyelid lesion include: +• Ecchymosis of eyelids is of frequent occurrence. Because of loose subcutaneous tissue, blood collects easily into the lids and produces ‘black-eye.’ Ecchymosis of the eyelids may characteristically appear as bilateral ring haematomas (panda eye) in patients with basal skull fracture. +• Laceration and avulsion of the lids. +• Traumatic ptosis may follow damage to the levator muscle. +3. Lacrimal apparatus lesions include: • Dislocation of lacrimal gland, and +• Lacerations of lacrimal passages especially the canaliculi. +4. Optic nerve injuries. These are commonly associated with fractures of the base of skull. These may be in the form of traumatic papillitis, lacerations of optic nerve, optic nerve sheath haemorrhage and avulsion of the optic nerve from back of the eye. For details of traumatic optic neuropathy see page 323. +5. Orbital injury. There may occur fractures of the orbital walls; commonest being the ‘blow-out fracture’ of the orbital floor (see page 422). Orbital haemorrhage may produce sudden proptosis. Orbital emphysema may occur following ethmoidal sinus rupture. + +OpEN-gLOBE INJURIES + +Open-globe injury is defined as a full thickness wound of the eyewall (sclera or/and cornea). It includes: +1. Globe rupture, i.e. full thickness wound of the eye-wall caused by blunt trauma. It is covered with blunt trauma, see page 431. +2. Globe laceration refers to full-thickness wound of eyewall caused by sharp objects. It includes: +i. Penetrating injury, +ii. Perforating injury, and +iii. Intraocular foreign bodies. + +PeneTraTing and PerforaTing injuries As mentioned earlier, penetrating injury is defined as a single full-thickness wound of the eyewall caused by a sharp object. While perforating injury refers to two full-thickness wounds (one entry and one exit) of the eyewall caused by a sharp object or missile. +These can cause severe damage to the eye and so should be treated as serious emergencies. + +modes of injury +1.Trauma by sharp and pointed instruments like needles, knives, nails, arrows, screw-drivers, pens, pencils, compasses, glass pieces and so on. + +2.Trauma by foreign bodies travelling at very high speed such as bullet injuries and iron foreign bodies in lathe workers. +mechanisms of damage +Damage to the ocular structures may occur by following effects: +1.Mechanical effects of the trauma or physical changes. These are discussed later in detail. +2.Introduction of infection. Sometimes, pyogenic organisms enter the eye during open globe injuries, multiply there and can cause varying degree of infection depending upon the virulence and host defence mechanism. These include: ring abscess of the cornea, sloughing of the cornea, purulent iridocyclitis, endophthalmitis or panophthalmitis (see pages 170-172). Rarely tetanus and infection by gas-forming organisms (Clostridium welchii) may also occur. +3.Post-traumatic iridocyclitis. It is of frequent occurrence and if not treated properly can cause devastating damage, a rare but most dangerous complication of a perforating injury. It is described separately (see page 430). +Traumatic lesions with management +Mechanical effects of penetrating/perforating trauma on the different ocular structures with their management are enumerated here briefly. +1. Wounds of the conjunctiva. These are common and usually associated with subconjunctival haemorrhage. A wound of more than 3 mm should be sutured. +2. Wounds of the cornea. These can be divided into uncomplicated and complicated wounds. i.Uncomplicated corneal wounds. These are not associated with prolapse of intraocular contents. Margins of such wounds swell up and lead to automatic sealing and restoration of the anterior chamber. ■Treatment. A small central wound does not need stitching. The only treatment required is pad and bandage with atropine and antibiotic ointments. +A large corneal wound (more than 2 mm) should always be sutured. +ii. Complicated corneal wounds. These are associated with prolapse of iris (Fig. 18.9), sometimes lens matter and even vitreous. +■Treatment.Corneal wounds with iris prolapse should be sutured meticulously after abscising the iris. The prolapsed iris should never be reposited; since it may cause infection. When associated with lens injury and vitreous loss, lensectomy and anterior vitrectomy may be performed along with repair of the corneal wound. +Chapter 18 Ocular Injuries 433 + + + + + + + + + + + + + + +Fig. 18.9 Corneal tear with iris prolapse + +3. Wounds of the sclera. These are usually associated with corneal wounds and should be managed as above. In corneo-scleral tear, first suture should be applied at the limbus. +4. Wounds of the lens. Extensive lens ruptures with vitreous loss should be managed as above. Small wounds in the anterior capsule may seal and lead on to traumatic cataract; which may be in the form of a localised stationary cataract, early or late rosette cataract, or complete (total) cataract. These should be treated on general lines (see pages 195-210). +5.A badly (severely) wounded eye. It refers to extensive corneo-scleral tears associated with prolapse of the uveal tissue, lens rupture, vitreous loss and injury to the retina and choroid. Usually there seems to be no chance of getting useful vision in such cases. So, preferably such eyes should be excised. +inTraoCular foreign bodies Penetrating injuries with foreign bodies are not infrequent. Seriousness of such injuries is compounded by the retention of intraocular foreign bodies (IOFB). +Common foreign bodies responsible for such injuries include: chips of iron and steel (90%), particles of glass, stone, lead pellets, copper percussion caps, aluminium, plastic and wood. It is important to note that during chopping a stone with an iron chisel, it is commonly a chip of the chisel and not of the stone which enters the eye. + +Modes of damage and Lesions +A penetrating/perforating injury with retained foreign body may damage the ocular structures by the following modes: +A. Mechanical effects. +B. Introduction of infection. C. Reaction of foreign bodies. D. Post-traumatic iridocyclitis. +E. Sympathetic ophthalmitis (see page 437). + +a. mechanical effects +Mechanical effects depend upon the size, velocity and type of the foreign body. Foreign bodies greater than 2 mm in size cause extensive damage. The lesions caused also depend upon the route of entry and the site up to which a foreign body has travelled. Traumatic lesions produced by intraocular foreign bodies include: +• Corneal or/and scleral perforation, hyphaema, iris hole, +• Rupture of the lens and traumatic cataract, +• Vitreous haemorrhage and/or degeneration, +• Choroidal perforation, haemorrhage and inflammation, +• Retinal hole, haemorrhages, oedema and detachment. +Locations of IOFB. Having entered the eye through the cornea or sclera a foreign body may be retained at any of the following sites (Fig. 18.10): +1.Anterior chamber. In the anterior chamber, the IOFB usually sinks at the bottom. A tiny foreign body may be concealed in the angle of anterior chamber, and visualised only on gonioscopy. +2.Iris. Here the foreign body is usually entangled in the stroma. +3.Posterior chamber. Rarely, a foreign body may sink behind the iris after entering through pupil or after making a hole in the iris. +4.Lens. Foreign body may be present on the anterior surface or inside the lens. Either an opaque track may be seen in the lens or the lens may become completely cataractous. +5.Vitreous cavity. A foreign body may reach here through various routes, which are depicted in Fig. 18.11. + + + + + + + + + + + + + + + + +Fig. 18.10 Common sites for retention of an intraocular foreign body: 1, anterior chamber; 2, iris; 3, lens; 4, vitreous; 5, retina; 6, choroid; 7, sclera; 8, orbital cavity +434 Section iii Diseases of Eye + + + + + + + + + + + + + + +I + + + + + + + + + + + + +II + +Fig. 18.11 Logarithmic (I) and diagrammatic (II) depiction of routes of access of a foreign body in the vitreous, through: A, cornea, pupil, lens; B, cornea, iris, lens; C, cornea, iris, zonules; D, sclera, choroid, retina + +6.Retina, choroid and sclera. A foreign body may obtain access to these structures through corneal route or directly from scleral perforation. +7.Orbital cavity. A foreign body piercing the eyeball may occasionally cause double perforation and come to rest in the orbital tissues. +b. introduction of infection +Intraocular infection is the real danger to the eyeball. Fortunately, small flying metallic foreign bodies are usually sterile due to the heat generated on their commission. However, pieces of the wood and stones carry a great chance of infection. Unfortunately, once intraocular infection is established it usually ends in endophthalmitis or even panophthalmitis. +C. reactions of the foreign body +i. Reactions of Inorganic foreign body +Depending upon its chemical nature following 4 types of reactions are noted in the ocular tissues: 1.No reaction is produced by the inert substances +which include glass, plastic, porcelain, gold, silver and platinum. + +2.Local irritative reaction leading to encapsulation of the foreign body occurs with lead and aluminium particles. +3.Suppurative reaction is excited by pure copper, zinc, nickel and mercury particles. +4.Specific reactions are produced by iron (Siderosis bulbi) and copper alloys (Chalcosis). +Siderosis bulbi +It refers to the ocular degenerative changes produced by an iron foreign body. Siderosis bulbi usually occurs after 2 months to 2 years of the injury. However, earliest changes have been reported after 9 days of trauma. +Mechanism.The iron particle undergoes electrolytic dissociation by the current of rest and its ions are disseminated throughout the eye. These ions combine with the intracellular proteins and produce degenerative changes. In this process, the epithelial structures of the eye are most affected. +Clinical manifestations include: +1. Anterior epithelium and capsule of the lens are involved first of all. Here, the rusty deposits are arranged radially in a ring. Eventually, the lens becomes cataractous. +2.Iris. It is first stained greenish and later on turns reddish brown (heterochromia iridis). +3.Retina develops pigmentary degeneration which resembles retinitis pigmentosa. Electroretinography (ERG) shows progressive attenuation of the b-wave over time. +4.Secondary open angle glaucoma may occur due to degenerative changes in the trabecular meshwork. +Chalcosis +It refers to the specific changes produced by the alloy of copper in the eye. +Mechanism of chalcosis. Copper ions from the alloy are dissociated electrolytically and deposited under the membranous structures of the eye. Unlike iron ions these do not enter into a chemical combination with the proteins of the cells and thus produce no degenerative changes. +Clinical features include: +1. Kayser-Fleischer ring. It is a golden brown ring which occurs due to deposition of copper under peripheral parts of the Descemet’s membrane of the cornea. +2.Sunflower cataract. It is produced by deposition of copper under the posterior capsule of the lens. +It is brilliant golden green in colour and arranged like the petals of a sunflower. +3.Retina. It may show deposition of golden plaques at the posterior pole which reflect the light with a metallic sheen. +Chapter 18 Ocular Injuries 435 + + +ii. Reaction of organic foreign bodies +The organic foreign bodies such as wood and other vegetative materials produce a proliferative reaction characterised by the formation of giant cell. Caterpillar hair produces ophthalmia nodosum, which is characterised by a severe granulomatous iridocyclitis with nodule formation. + +Management of Retained intraocular foreign Bodies (iOfB) +diagnosis +It is a matter of extreme importance particularly as the patient is often unaware that a particle has entered the eye. To come to a correct diagnosis following steps should be taken: +1. History. A careful history about the mode of injury may give a clue about the type of IOFB. +2.Ocular examination.A thorough ocular examination with slit-lamp including gonioscopy should be carried out. The signs which may give some indication about IOFB are: subconjunctival haemorrhage, corneal scar, holes in the iris, and opaque track through the lens. With clear media, sometimes IOFB may be seen on ophthalmoscopy in the vitreous (Fig. 18.12) or on the retina. IOFB lodged in the angle of anterior chamber may be visualised by gonioscopy. +3. Plain X-rays orbit. Anteroposterior and lateral views are still being recommended for the location of IOFB, as most foreign bodies are radio opaque. However, many workers feel there is no use of plain film radiology (PFR), as CT images are required for suspected IOFB, even if PFR is negative. +4. Localization of iOfB. Once IOFB is suspected clinically and later confirmed, on fundus examination and/or X-rays, its exact localization is mandatory to plan the proper removal. Following techniques may be used: + + + + + + + + + + + + + + +Fig. 18.12 Fundus photograph depicting intravitreal foreign body + +Radiographic localization. Before the advent of ultrasonography and CT scan, different specialized radiographic techniques were used to localize IOFBs; which are now obsolete. However, a simple limbal ring method which is still used (most centers have discarded it) is described below: +■Limbal ring method. It is the most simple but nowadays, sparingly employed technique. A metallic ring of the corneal diameter (Fig. 18.13) is stitched at the limbus and X-rays are taken. One exposure is taken in the anteroposterior view. In the lateral view three exposures are made one each while the patient is looking straight, upwards and downwards, respectively. The position of the foreign body is estimated from its relationship with the metallic ring in different positions (Fig. 18.14). Ultrasonographic localization. It is being used increasingly these days. It can tell the position of even non-radioopaque foreign bodies. +CT scan. With axial and coronal cuts, CT scan is presently the best method of IOFB localization. It + + + + + + + + + + + + + + +Fig. 18.13 Limbal ring used for localization of an intraocular foreign body seen in anteroposterior view of X-ray + + + + + + + + + + + + + + +Fig. 18.14 Limbal ring method of radiographic localization of IOFB: Lateral view with eyeball in straight position +436 Section iii Diseases of Eye + + +provides cross-sectional images with a sensitivity and specificity that are superior to plain radiography and ultrasonography. +Magnetic resonance imaging (MRI) is not recommended as a general screening tool, since it can cause further damage by producing movement of a magnetic IO foreign body. However, after the CT has excluded the presence of a metallic IO foreign body; MRI has a special role in localizing small plastic or wooden IO foreign bodies. +Treatment +IOFB should always be removed, except when it is inert and probably sterile or when little damage has been done to the vision and the process of removal may be risky and destroy sight (e.g., minute FB in the retina). +Removal of magnetic IOFB is easier than the removal of non-magnetic FB. Usually a hand-held electromagnet (Fig. 18.15) is used for the removal of magnetic foreign body. Method of removal depends upon the site (location) of the IOFB as follows: +1. foreign body in the anterior chamber. It is removed through a corresponding corneal incision directed straight towards the foreign body. It should be 3 mm internal to the limbus and in the quadrant of the cornea lying over the foreign body (Fig. 18.16). • Magnetic foreign body is removed with a hand- +held magnet. It may come out with a gush of aqueous. +• Non-magnetic foreign body is picked up with toothless forceps. + + + + + + + + + + + + + + + + + + + + + +Fig. 18.15 Hand-held magnet + + + + + + + + + + +Fig. 18.16 Removal of a magnetic intraocular foreign body from the anterior chamber: A, the wrong incision; B, correct incision + +2. foreign body entangled in the iris tissue (magnetic as well as non-magnetic) is removed by performing sector iridectomy of the part containing foreign body. 3.foreign body in the lens.Magnet extraction is usually difficult for intralenticular foreign bodies. Therefore, magnetic foreign body should also be treated as non-magnetic foreign body. An extracapsular cataract extraction (ECCE) with intraocular lens implantation should be performed. The foreign body may be evacuated itself along with the lens matter or may be removed with the help of forceps. +4.foreign body in the vitreous and the retina isremoved by the posterior route as follows: +i.Magnetic removal. This technique is used to remove a magnetic foreign body that can be well localized and removed safely with a powerful magnet without causing much damage to the intraocular structures. ■An intravitreal foreign body is preferably removed through a pars plana sclerotomy (5 mm from the limbus) (Fig. 18.17 position ‘A’). At the site chosen + + + + + + + + + + + + + + + + + + + +Fig. 18.17 Removal of a magnetic intraocular foreign body from posterior segment +Chapter 18 Ocular Injuries 437 + + +for incision, conjunctiva is reflected and the incision is given in the sclera concentric to the limbus. A preplaced suture is passed and lips of the wound are retracted. A nick is given in the underlying pars plana part of the ciliary body. And the foreign body is removed with the help of a powerful hand-held electromagnet. Preplaced suture is tied to close the scleral wound. Conjunctiva is stitched with one or two interrupted sutures. +■For an intraretinal foreign body, the site of incision should be as close to the foreign body as possible (Fig. 18.17 position ‘B’). A trapdoor scleral flap is created, the choroidal bed is treated with diathermy, choroid is incised and foreign body is removed with either forceps or external magnet. +ii. Forceps removal with pars plana vitrectomy. This technique is used to remove all non-magnetic foreign bodies and those magnetic foreign bodies that cannot be safely removed with a magnet. In this technique, the foreign body is removed with vitreous forceps after performing three-pore pars plana vitrectomy under direct visualization using an operating microscope (Fig. 18.18). + +SyMpAtHEtIC OpHtHALMItIS + +Sympathetic ophthalmitis is a serious bilateral granulomatous panuveitis which follows a penetrating ocular trauma. The injured eye is called exciting eye and the fellow eye which also develops uveitis is called sympathizing eye. Very rarely, sympathetic ophthalmitis can also occur following an intraocular surgery. + + + + + + + + + + + + + + + + + + +Fig. 18.18 Removal of a non-magnetic foreign body through pars plana + +incidence +Incidence of sympathetic ophthalmitis has markedly decreased in the recent years due to meticulous repair of the injured eye utilizing microsurgical techniques and use of the potent steroids. +etiology +Etiology of sympathetic ophthalmitis is still not known exactly. However, the facts related with its occurrence are as follows: +a. Predisposing factors +1. It almost always follows a penetrating injury. +2. Wounds in the ciliary region (the so-called dangerous zone) are more prone to it. +3. Wounds with incarceration of the iris, ciliary body or lens capsule are more vulnerable. +4. It is more common in children than in adults. +5. It does not occur when actual suppuration develops in the injured eye. +b. Pathogenesis +Various theories have been put forward. Most accepted one is allergic theory, which postulates that the uveal pigment acts as an allergen and excites plastic uveitis in the sound eye. +Pathology +It is characteristic of granulomatous uveitis, i.e., there is: +• Nodular aggregation of lymphocytes, plasma cells, epitheloid cells and giant cells scattered throughout the uveal tract. +• Dalen-Fuchs’ nodules are formed due to proliferation of the pigment epithelium (of the iris, ciliary body and choroid) associated with invasion by the lymphocytes and epitheloid cells. +• Sympathetic perivasculitis. Retina shows perivascular cellular infiltration. +Clinical features +i. Exciting (injured) eye. It shows clinical features of persistent low grade plastic uveitis, which include ciliary congestion, lacrimation and tenderness. Keratic precipitates may be present at the back of cornea (dangerous sign). +ll. Sympathizing (sound) eye. It is usually involved after 4–8 weeks of injury in the other eye. Earliest reported case is after 9 days of injury. Most of the cases occur within the first year. However, delayed and very late cases are also reported. Sympathetic ophthalmitis, almost always, manifests as acute plastic iridocyclitis. Rarely it may manifest as neuroretinitis or choroiditis. Clinical feature of the iridocyclitis in sympathizing eye can be divided into two stages: +438 Section iii Diseases of Eye + + +1. Prodromal stage. +■Symptoms. Sensitivity to light (photophobia) and transient indistinctness of near objects (due to weakening of accommodation) are the earliest symptoms. +■Signs. In this stage, the first sign may be presence of retrolental flare and cells or the presence of a few keratic precipitates (KPs) on back of cornea. Other signs includes mild ciliary congestion, slight tenderness of the globe, fine vitreous haze and disc oedema which is seen occasionally. +2. Fully-developed stage. It is clinically characterised by typical signs and symptoms consistent with acute plastic iridocyclitis (see page 153). +Treatment +a. Prophylaxis +i. Early excision of the injured eye. It is the best prophylaxis when there is no chance of saving useful vision. + +ii. When there is hope of saving useful vision, following steps should be taken: +1.A meticulous repair of the wound using microsurgical technique should be carried out, taking great care that uveal tissue is not incarcerated in the wound. +2.Immediate expectant treatment with topical as well as systemic steroids and antibiotics along with topical atropine should be started. +3.When the uveitis is not controlled after 2 weeks of expectant treatment, i.e., lacrimation, photophobia and ciliary congestion persist and if KPs appear, this injured eye should be excised immediately. +b. Treatment when sympathetic ophthalmitis has already supervened +I. Early excision (enucleation) should be done when the case is seen shortly after the onset of inflammation (i.e., during prodromal stage) in the sympathizing eye, and the injured eye has no useful vision, this useless eye should be excised at once. II.Conservative treatment of sympatheticophthalmitis on the lines of iridocyclitis should be started immediately, as follows: +1. Corticosteroids should be administered by all routes, i.e., systemic, periocular injections and frequent instillation of topical drops. +2. Immunosuppressant drugs should be started in severe cases, without delay. +3. Atropine should be instilled three times a day in all cases. +Note. The treatment should be continued for a long time. + + + + + + + + + + + + + + +Fig. 18.19 A patient with chemical injury face including eye + + +Prognosis. If sympathetic ophthalmitis is diagnosed early (during prodromal stage) and immediate treatment with steroids is started, a useful vision may be obtained. However, in advanced cases, prognosis is very poor, even after the best treatment. + +CHEMICAL INJURIES + +Chemical injuries (Fig. 18.19) are by no means uncommon. These vary in severity from a trivial and transient irritation of little significance to complete and sudden loss of vision. +modes of chemical injury +These usually occur due to external contact with chemicals under following circumstances: 1.Domestic accidents, e.g., with ammonia, solvents, +detergents and cosmetics. +2.Agricultural accidents, e.g., due to fertilizers, insecticides, toxins of vegetable and animal origin. 3.Chemical laboratory accidents, with acids and +alkalies. +4.Deliberate chemical attacks, especially with acids to disfigure the face. +5.Chemical warfare injuries. +6.Self-inflicted chemical injuries are seen in malingerers and psychopaths. +Types of chemical injuries +In general, the serious chemical burns mainly comprise alkali and acid burns. +a. Alkali burns +Alkali burns are among the most severe chemical injuries known to the ophthalmologists. Common alkalies responsible for burns are: lime, caustic potash or caustic soda and liquid ammonia (most harmful). +Chapter 18 Ocular Injuries 439 + + +Mechanisms of damage produced by alkalies includes: +1.Alkalies dissociate and saponify fatty acids of the cell membrane and, therefore, destroy the structure of cell membrane of the tissues. +2.Being hygroscopic, they extract water from the cells, a factor which contributes to the total necrosis. +3.They combine with lipids of cells to form soluble compounds, which produce a condition of softening and gelatinisation. +The above effects result in an increased deep penetration of the alkalies into the tissues. Alkali burns, therefore, spread widely, their action continues for some days and their effects are difficult to circumscribe. Hence, prognosis in such cases must always be guarded. +Clinical feature can be divided into three stages: 1. Stage of acute ischaemic necrosis. In this stage: +• Conjunctiva shows marked oedema, congestion, widespread necrosis and a copious purulent discharge. +• Cornea develops widespread sloughing of the epithelium, oedema and opalescence of the stroma. +• Iris becomes violently inflamed and in severe cases both iris and ciliary body are replaced by granulation tissue. +2. Stage of reparation. In this stage, conjunctival and corneal epithelium regenerate, there occurs corneal vascularization and inflammation of the iris subsides. +3. Stage of complications. This is characterised by development of symblepharon, recurrent corneal ulceration and development of complicated cataract and secondary glaucoma. +b. Acid burns +Acid burns are less serious than alkali burns. Common acids responsible for burns are: sulphuric acid, hydrochloric acid and nitric acid. +Chemical effects.Strong acids cause instant coagulation of all the proteins which then act as a barrier and prevent deeper penetration of the acids into the tissues. Thus, the lesions become sharply demarcated. +Ocular lesions include: +1. Conjunctiva. There occurs immediate necrosis followed by sloughing. Later on, symblepharon is formed due to fibrosis. +2. Cornea. It is also necrosed and sloughed out. The extent of damage depends upon the concentration of acid and the duration of contact. +• In mild to moderate degree of corneal burns end result is corneal opacification of varying degree. + +• In severe cases, the whole cornea may slough out followed by staphyloma formation. +grading of chemical burns +Depending upon the severity of damage caused to the limbus and cornea, the extent of chemical burns may be graded in Roper-Hall classification as follows (Table 18.1): +Table18.1 Grades of chemical burns (Roper-Hall classification) +Grade Corneal Limbal Visual appearance ischaemia prognosis +I Clear cornea Nil Excellent +II Hazy but iris < 1/3 Good details visible +III Opaque 1/3 to 1/2 Doubtful/ cornea. Guarded Iris details +obscured +IV Opaque, no > 1/2 Poor view of the +iris and pupil + + +Treatment of chemical burns +1. Prevent further damage by following measures: +• Immediate and thorough irrigation with the available clean water or saline delivered through an IV tubing. Deliver minimum of 2 L of water in 20–30 minutes or until pH is restored. +Note.Do not waste time on history and examination of the patient; it should be done after the irrigation. +• Mechanical removal of contaminant. If any particles are left behind, particularly in the case of lime, these should be removed carefully with a swab stick. +• Removal of contaminated and necrotic tissue. Necrosed conjunctiva should be excised. Contaminated and necrosed corneal epithelium should be removed with a cotton swab stick. +2. Maintenance of favourable conditions for rapid and uncomplicated healing by following measures: +• Topical antibiotic drops, e.g., moxifloxacin 4–6 times a day to prevent infection. +• Steroid eye drops to reduce inflammation, neutrophil infiltration, and address anterior uveitis. Cautious use is recommended after 2 weeks, as steroids may interfere with collagen synthesis. +• Cycloplegics, e.g., atropine, may improve the comfort. +• Ascorbic acid, in the form of 10% sodium ascorbate eyedrops (4–5 times), along with systemic use +440 Section iii Diseases of Eye + + +(1–2 gm orally/day) improves wound healing and promotes synthesis of the mature collagen by corneal fibroblasts. +• Lubricant eyedrops (preservative free) should be used in abundance to promote the healing. +• Autologous serum, instilled as eyedrops, provides growth factors, collagenase inhibitors, retinoic acid, fibrinogen activator and promotes epithelial healing. +• Sodium citrate, used as 10% topical eyedrops stabilizes neutrophils and reduces collagenase release. +• Doxycycline, 100 mg BD, chelates zinc which is necessary for collagenase. +3. Prevention of symblepharon can be done by using a glass shell or sweeping a glass rod in the fornices twice daily. +4. Treatment of complications, as below: +• Secondary glaucoma should be treated by topical 0.5% timolol, instilled twice a day along with oral acetazolamide 250 mg 3–4 times a day. +• Poor corneal healing with limbal stem cell deficiency may be treated by amniotic membrane transplantation with or without limbal stem cell transplantation. +• Pseudopterygium, when formed, should be excised together with conjunctival autograft (if adequate host conjunctiva) or amniotic membrane facilitated by antimitotic drugs (e.g., mitomycin C). +• Symblepharon needs surgical treatment (see page 376). +• Corneal opacity may be treated by keratoplasty if adequate tear film and stem cell population available. +• Keratoprosthesis remains a surgical option in severely damaged eyes where keratoplasty is not possible. + + +NON-MECHANICAL INJURIES + +Thermal injuries +Thermal injuries are usually caused by fire, or hot fluids. The main brunt of such injuries lies on the lids. Conjunctiva and cornea may be affected in severe cases. +Treatment for burns of lids is on general lines. When cornea is affected, it should be treated with atropine, steroids, antibiotics and lubricants. +eleCTriCal injuries +The passage of strong electric current from the area of eyes may cause following lesions: +1.Conjunctiva becomes congested. +2.Cornea develops punctate or diffuse interstitial opacities. +3.Iris and ciliary body are inflamed. +4.Lens may develop ‘electric cataract’ after 2–4 months of accident. +5.Retina may show multiple haemorrhages. 6.Optic nerve may develop neuritis. +radiaTional injuries +1. Ultraviolet radiations. These may cause (i) photo-ophthalmia (see page 119) and (ii) may be responsible for senile cataract. +2. Infrared radiations. These may cause solar macular burns (see page 291). +3. Ionizing radiational injuries. These are caused following radiotherapy to the tumours in the vicinity of the eyes. The common ocular lesions include: +• Radiation keratoconjunctivitis, • Radiation dermatitis of lids, +• Radiation cataract, and • Radiation retinopathy. +Section IV Ocular Therapeutics + + + + + + + + +Section Outline + +19. Ocular Pharmacology +20. Lasers and Cryotherapy in Ophthalmology +19 + +Ocular Pharmacology + + + +Chapter Outline + +MODES OF ADMINISTRATION Topical instillation +Periocular injections Intraocular injections Systemic administration +• +• +• +• +COMMON PHARMACOLOGICAL AGENTS USED IN OPHTHALMOLOGY +• +Anti-infective agents + + + +MODES OF ADMINISTRATION + +Ocular pharmacotherapeutics can be delivered by four methods: topical instillation into the conjunctival sac, periocular injections, intraocular injections and systemic administration. +I. Topical instillation into the conjunctival sac +This is the most commonly employed mode of administration for ocular therapeutics. The drugs can be administered topically in the form of eyedrops, ointments, gels, ocuserts and with the help of soft contact lenses. +1. Eyedrops (gutta). This is the simplest and most convenient method of topical application, especially for daytime use. Eyedrops may be in the form of aqueous solutions (drug totally dissolved) or aqueous suspensions (drug is present as small particles kept suspended in the aqueous medium) or oily solutions. Application in the form of eyedrops makes the drug available for immediate action but it is quickly diluted by tears within about a minute. 2. Eye ointment (oculenta or ung). Topical application in the form of an eye ointment increases the bioavailability of the drug by increasing tissue contact time and by preventing dilution and quick absorption. However, the drug is not available for immediate use and ointments blur the vision. These are best for bedtime application or when ocular bandage is to be applied. + +• Anti-glaucoma drugs +Anti-inflammatory and immunosuppressive agent Anti-allergic and vasoconstrictor drugs Lubricating agent and artificial tear +• +• +• +• +• +• +• +Intraocular and irrigating solutions Viscoelastic substances +Anti-VEGFs agents +Dyes used in ophthalmology + + + +3. Gels. These have prolonged contact time like ointments and do not cause much blurring of vision. However, they are costly and difficult to prepare. +4. Ocuserts. These form a system of drug delivery through a membrane. These can be placed in the upper or lower fornix up to a week and allow a drug to be released at a relatively constant rate. Pilocarpine ocuserts have been found very useful in patients with primary open-angle glaucoma; by efficiently controlling intraocular pressure with comparatively fewer side-effects. +5. Soft contact lenses. These are very good for delivering higher concentrations of drugs in emergency treatment. A pre-soaked soft contact lens in 1% pilocarpine has been found as effective as 4% pilocarpine eyedrops in patients with acute angle-closure glaucoma. Soft contact lenses are also used to deliver antibiotics and antiviral drugs in patients with corneal ulcers. +Intraocular penetration of topically instilled drugs Topically instilled medications largely penetrate intraocularly through the cornea. The main barrier through cornea is its epithelium, which is lipophilic, and crossed readily by nonpolar drugs. Stroma being hydrophilic allows rapid passage of the drug through endothelium into the anterior chamber. So following features will allow better penetration of drugs through the cornea: +444 Section iV Ocular Therapeutics + + + +• Drugs which are soluble both in water and fats. +• Prodrug forms are lipophilic and after absorption through epithelium are converted into proper drugs which can easily pass through stroma. +• Agents that reduce surface tension increase corneal wetting and therefore present more drug for absorption. Benzalkonium chloride used as preservative also acts as a wetting agent and thus increases the drug absorption. +II. Periocular injections +These are not infrequently employed to deliver drugs. These include subconjunctival, sub-Tenon, retrobulbar and peribulbar injections. +1. Subconjunctival injections. These are used to achieve higher concentration of drugs. Further, the drugs which cannot penetrate the cornea owing to large-sized molecules can easily pass through the sclera. +2. Sub-Tenon injections. These are preferred over subconjunctival injections. +• Anterior sub-Tenon injections are used mainly to administer steroids in the treatment of severe or resistant anterior uveitis. +• Posterior sub-Tenon injections are indicated in patients with intermediate and posterior uveitis. +3. Retrobulbar injections. Nowadays, these are sparingly used to deliver drugs for optic neuritis, papillitis, posterior uveitis and also for administering retrobulbar block anaesthesia. +4. Peribulbar injections. These are now frequently used for injecting anaesthetic agents. Peribulbar anaesthesia has almost replaced the retrobulbar and facial block anaesthesia. +III. Intraocular injections and implants +Such injections are made in desperate cases (e.g., endophthalmitis) to deliver the drugs in maximum concentration at the target tissue. Intraocular injections include: +• Intracameral injection (into the anterior chamber), and +• Intravitreal injection (into the vitreous cavity). Intravitreal drug implants are inserted in the vitreous cavity through pars plana for sustained and slow release, e.g.: +• Steroid implants of fluocinolone and dexamethsone are available for use in patients with posterior uveitis and diabetic macular oedema. +• Gancyclovir implants are available for use in cytomegalovirus (CMV) retinitis. + +IV. Systemic administration +The systemic routes include oral intake, intramuscular and intravenous injections. The intraocular penetration of systemically administered drugs mainly depends upon the blood-aqueous barrier. The passage through blood-aqueous barrier in turn is influenced by the molecular weight and the lipid solubility of the drug. +Only low molecular weight drugs can cross this blood-aqueous barrier. No passage is allowed to large-sized molecules, such as penicillin. Out of the borderline molecular weight drugs, those with high lipid solubility can pass easily, e.g., sulphonamides have the same molecular weight as sucrose but are 16 times more permeable due to their lipid solubility. Similarly, chloramphenicol being lipid soluble also enters the eye easily. + +COMMON PHARMACOLOGICAL AGENTS USED IN OPHTHALMOLOGY +Common pharmacological agents used in ophthalmology include: +1. Anti-infective agents • Antibacterial agents • Antiviral drugs +• Antifungal agents +2. Mydriatics and cycloplegics agents (see page 572) 3. Anti-glaucoma drugs +4. Anti-inflammatory and immunosuppressive agents +• Corticosteroid +• Nonsteroidal anti-inflammatory drugs +• Immunosuppressive and antimitotic drugs 5. Anti-allergic and vasoconstrictor drug +6. Lubricating agent and artificial tear 7. Intraocular and irrigating solutions 8. Viscoelastic substances +9. Anti-VEGFs agents +10. Dyes used in ophthalmology + +ANTI-INFECTIVE AGENTS + +AnTIbAcTerIAl AgenTS +Antimicrobial drugs are the greatest contribution of the present century to therapeutics. As there are a wide range of microorganisms, there are also specific antibiotics for almost each organism. Depending on the type of action, these can be either bacteriostatic or bactericidal. A few common antimicrobials described here are grouped on the basis of their chemical structure. +Chapter 19 Ocular Pharmacology 445 + + + +Sulphonamides +These are bacteriostatic agents that act by competing with PABA (para-aminobenzoic acid) which is essential for the bacterial cell nutrition. Thus, they prevent susceptible microorganisms from synthesizing folic acid. +In ophthalmic practice, these are used topically and systemically in the treatment of chlamydial infections, viz., trachoma and inclusion conjunctivitis. They are also helpful as an adjunct to pyrimethamine in the treatment of toxoplasmosis. +beta-lactam antibiotics +These antibiotics have a beta-lactam ring. The two important groups are penicillins, and cephalosporins. All beta-lactam antibiotics act by interfering with the synthesis of bacterial cell wall. +A. Penicillins. These are produced by growing one of the penicillium moulds in deep tanks. These may be categorised as: natural penicillins and semisynthetic penicillins. +In deep-seated inflammations of the orbit or lids, penicillin is given parenterally. In superficial inflammations of the conjunctiva and cornea it is administered locally as drops or ointments. In intraocular infections it is given as subconjunctival injections. Commonly used preparations are as follows: +1. Benzyl penicillin. A dose of 500,000 units twice daily is sufficient for sensitive infections and produces high levels in all tissues except CNS and eye. +2. Procaine penicillin. This is an intramuscular depot preparation which provides tissue levels up to 24 hours. +3. Methicillin, cloxacillin and flucloxacillin. These penicillins are not affected by penicillinase and are, therefore, used for staphylococcal infections which are resistant to other penicillins. +4. Carbenicillin. It is resistant to the penicillinase produced by some strains of Proteus, Pseudomonas and coliform organisms. It is ineffective by mouth. 5. Ampicillin. It is a broad-spectrum penicillinase-sensitive penicillin. It is acid resistant and usually administered orally. +Its dosage is 0.25–2 g oral/IM/IV depending upon the severity of infection every 6 hours. Paediatric dose is 25–50 mg/kg/day. +6. Amoxicillin. Its spectrum is similar to ampicillin except that it is less effective against Shigella and H. influenzae. Its oral absorption is better than ampicillin and thus higher and more sustained + + +blood levels are produced. Incidence of diarrhoea is less with it than with ampicillin and is thus better tolerated orally. +B. Cephalosporins. These drugs have a similar structure and mode of action as penicillin. All the cephalosporins have a bactericidal action against a wide range of organisms. By convention these have been categorised into three generations of broadly similar antibacterial and pharmacokinetic properties: +1. First-generation (narrow spectrum) cephalosporins. These are very active against Gram-positive cocci and thus have useful antistaphylococcal activity. These include cefazolin, cephradine, cephalexin and cephadroxyl. +2. Second-generation (intermediate spectrum) cephalosporins. These have anti-staphylococcal activity and are also effective against certain Gram-negative organisms. They comprise cefuroxime, cefamandole and cefoxitin. +3. Third-generation (wide spectrum) cephalosporins. These are mainly effective against Gram-negative organisms but not against Staphylococci. These include: cefotaxime, cefixime and cefotetan. +Side-effects. Cephalosporins have a low frequency of adverse effects in comparison to antimicrobials in general. The most usual are allergic reactions of the penicillin type. If these are continued for more than 2 weeks, thrombocytopenia, neutropenia, interstitial nephritis or abnormal liver function tests may occur. These resolve on stopping the drug. +Aminoglycosides +These are bactericidal and act primarily against Gram-negative bacilli. These are not absorbed orally, distributed mainly extracellularly and are excreted unchanged in the urine. These are ototoxic and nephrotoxic. Certain aminoglycosides are too toxic for systemic use and hence used only topically. Commonly used preparations are as follows: +1. Streptomycin. It is used mainly in tuberculosis. +2. Gentamicin. It has become the most commonly used aminoglycoside for acute infections. It has a broader spectrum of action and is effective against Pseudomonas aeruginosa. It is nephrotoxic, therefore, its dose must be precisely calculated according to body weight and renal function. For an average adult with normal renal function, the dose is 1–1.5 mg/kg intramuscularly, 8 hourly. Topically, it is used as 0.3% eyedrops. +446 Section iV Ocular Therapeutics + + + +3. Tobramycin. It is 2–4 times more active against Pseudomonas aeruginosa and Proteus as compared to gentamicin. Topically, it is used as 1% eyedrops. 4. Amikacin. It is recommended as a reserve drug for hospital-acquired infections with Gram-negative bacilli, where gentamicin resistance is increasing. 5. Neomycin. It is a widespectrum aminoglycoside, active against most Gram-negative bacilli and some Gram-positive cocci. However, Pseudomonas and Streptococcus pyogenes are not sensitive to it. It is highly toxic to internal ear and kidney and hence used only topically (0.3–0.5%). +6. Framycetin. It is very similar to neomycin. It is also too toxic for systemic use and hence used only topically. It is available as 1% skin cream; 0.5% eye ointment and eyedrops. +Tetracyclines +These are broad-spectrum bacteriostatic agents with a considerable action against both Gram-positive and Gram-negative organisms as well as some fungi, Rickettsiae and Chlamydiae. This group includes tetracycline, chlortetracycline and oxytetracycline. +chloramphenicol +It is also a broad-spectrum antibiotic, primarily bacteriostatic, effective against Gram-positive as well as Gram-negative bacteria, Rickettsiae, Chlamydiae and Mycoplasma. +Its molecule is relatively small and lipid soluble. Therefore, on systemic administration, it enters the eye in therapeutic concentration. Topically, it is used as 0.5% eyedrops. +Polypeptides +These are powerful bactericidal agents, but rarely used systemically due to toxicity. Clinically used polypeptides are polymyxin B, bacitracin, colistin and tyrothricin. +1. Polymyxin B and colistin. These are active against most Gram-negative bacteria, notably Pseudomonas. 2. Neosporin (neomycin-polymyxin-bacitracin). It is an effective broad-spectrum antimicrobial but suffers the disadvantage of a high incidence (68%) of sensitivity due to neomycin. +Fluoroquinolones +Fluoroquinolones are potent synthetic agents having broad spectrum of activity against Gram-positive and Gram-negative organisms. +Mechanism of action.Fluoroquinolones are bactericidal drugs. They inhibit the bacterial DNA synthesis. + + +Preparations. Fluoroquinolones by convention have been grouped into four generations (Table 19.1). +AnTIVIrAl drugS +These are more often used locally in the eye. Currently available antiviral agents are virostatic. They are active against DNA viruses; especially herpes simplex virus. Antiviral drugs used in ophthalmology can be grouped as below: +For herpes simplex virus infection • Idoxuridine +• Vidarabine • Trifluridine • Acyclovir +• Famiciclovir +For herpes zoster virus infection • Acyclovir +• Famiciclovir • Valaciclovir • Vidarabine • Sorvudine + + +Table 19.1 Commonly used fluoroquinolones + +Generation Preparation and doses and drug +Topical Systemic First generation +• Ciprofloxacin 0.3% 500 mg orally 12 hrly. 200 1 to 4 hrly mg I/V 12 hrly +• Norfloxacin 0.3% 400 mg orally 12 hrly 1 to 4 hrly +Second generation +• Ofloxacin 0.3% 200–400 mg orally 12 hrly 1 to 4 hrly 200 mg I/V 12 hrly +• Lomefloxacin 0.3%, 400 mg orally OD 1 to 4 hrly +• Pefloxacin 0.3% 400 mg orally or I/V 1 to 4 hrly 12 hrly +Third generation +• Sparfloxacin 0.3% 400 mg orally on day 1 1 to 4 hrly followed by 200 mg OD +Fourth generation +• Gatifloxacin 0.3% 400 mg OD 1 to 4 hrly +• Moxifloxacin 0.5% 400 mg OD 1 to 4 hrly +Chapter 19 Ocular Pharmacology 447 + + + +For CMV retinitis • Ganciclovir +• Foscarnet +• Zidovudine +Nonselective • Interferons +• Immunoglobulins +Some of the antiviral drugs are described in brief. 1. Idoxuridine (IDU, 5-iodo-2 deoxyuridine). It is a halogenated pyrimidine resembling thymidine. Mechanism of action. It inhibits viral metabolism by substituting for thymidine in DNA synthesis and thus prevents replication of virus. +Topically, it is used as 0.1% eyedrops. +Preparations. It is available as 0.1% eye drops and 0.5% eye ointment. +Indications and doses: Since, the intraocular penetration of topically applied IDU is very poor, it is not of much value in the treatment of chronic stromal herpetic keratitis. It is mainly used in acute epithelial herpetic keratitis. IDU drops are used one hourly during day and two hourly during night and has to be continued till microscopic staining disappears. Side-effects include follicular conjunctivitis, lacrimal punctal stenosis and irritation with photophobia. Contraindications. It is known to inhibit corneal stromal healing, hence its use is not advisable during first few weeks after keratoplasty. +2.Adenine arabinoside (Ara-A, Vidarabine).It is a purine nucleoside. It has antiviral activity against herpes simplex, cytomegalo, vaccinia and zoster viruses. It is more potent and less toxic than IDU and is also effective in IDU resistant cases. It has no cross allergenicity with +IDU or TF3 and thus can be used with IDU. +Mechanism of action: It is metabolized to triphosphate form which inhibits DNA polymerase and thus the growth of viral DNA is arrested. +Preparations: It is available as 3% ophthalmic ointment. +Dose: It is used 5 times a day till epithelialization occurs and then reduced to once or twice daily for 4–5 days to prevent recurrences. +Side-effects are superficial punctate keratitis and irritation on prolonged application. +3. Cytosine-Arabinoside (Cytarabine). It is a purine nucleoside. +Mechanism of action: It blocks nucleic acid synthesis by preventing conversion of cytosine ribose to cytosine deoxyribose. +Preparation: It is not commercially available at present. 5% solution used as drops has been found + +experimentally effective for treatment of herpes simplex keratitis. +■Side-effects. It causes profound corneal epithelial toxicity with superficial punctate keratitis and iritis. So, it is not recommended for clinical use. +4. Trifluorothymidine (TF3). It is a pyrimidine nucleoside. It has the advantage over IDU of higher +solubility, greater potency, lack of toxicity and allergic reactions. It is also effective in IDU-resistant cases. +Mechanism of action: It is a DNA inhibitor with same mechanism as IDU. +Preparation: It is available as 1% eyedrops. Dose:One drop is instilled 4 hourly. If no improvement occurs in 14 days, it is better to change to some other antiviral drug. +Toxicity: It is least toxic. It may cause mild superficial punctate keratitis on prolonged use. +5. Acyclovir (Acycloguanosine). It has proved to be an extremely safe and effective agent and is effective in most forms of herpes simplex and herpes zoster infections. +Mechanism of action: It inhibits viral DNA, preferentially entering the infected cells, with little effect on normal cells. It penetrates into deeper layers and thus is very effective in stromal keratitis. Preparation. It is available as 3% ophthalmic ointment and also as tablet for oral use and injection for intravenous use. +Indications and doses: (a) Topical 3% ointment is used 5 times a day for epithelial as well as stromal herpes simplex keratitis. (b) Oral acyclovir four tablets of 200 mg each, 5 times a day for 5–7 days, may be considered in following situations: (i) After penetrating keratoplasty in patients suffering from herpes simplex keratitis. (ii) Recalcitrant stromal or uveal disease caused by HSV. (iii) To reduce ocular complications of keratitis and uveitis in herpes zoster ophthalmicus. Side-effects: A few cases show slight punctate epithelial keratopathy which ceases once the drug is stopped. +6.Valaciclovir. It is used for treatment of herpes zoster ophthalmicus in a dose of 500–700 mg tds for 7 days. It is as effective as acyclovir in acute disease and is more effective in reducing late neuralgia. +7. Famiciclovir. Its use, dose and effectivity is similar to valaciclovir. +8. Interferons. These are nontoxic, species-specific proteins possessing broad-spectrum antiviral activity. However, it is still not available for commercial use. +448 Section iV Ocular Therapeutics + + + +9. Immunoglobulins. These preparations may be useful in the treatment or prophylaxis of certain viral diseases especially in patients with immune deficiencies. +10. Ganciclovir. It is used for the treatment of CMV retinitis in immunocompromised individuals. Dose: 5 mg/kg body weight every 12 hours for 2–3 weeks, followed by a permanent maintenance dose of 5 mg/ kg once daily for 5 out of 7 days. +11. Foscarnet (Phosphonoformic acid; PFA). It is as effective as ganciclovir in the treatment of CMV retinitis in AIDS patients. +12. Zidovudine (Azidothymidine; AZT). It has been recently recommended for selected AIDS patients with non-vision threatening retinitis who have no evidence of systemic CMV infection. +AnTIFungAl AgenTS +A number of antifungal agents have become available in the recent years. These can be broadly classified on the basis of their chemical structure into polyene antibiotics, imidazole derivatives, pyrimidines and silver compounds. +I. Polyene antifungals +These have been the mainstay of antifungal therapy. These are isolated from various species of Streptomyces and consist of a large, conjugated, double-bond system in a lactose ring linked to an amino acid sugar. +Mechanism of action. They work by binding to the sterol groups in fungal cell membranes, rendering them permeable. This occurrence leads to lethal imbalances in cell contents. Polyenes do not penetrate well into the cornea and are not beneficial in deep stromal keratitis. +Preparations. This group includes following drugs: 1. Nystatin. It is fungistatic and is well tolerated in the eye as 3.5% ointment. It has a medium level of activity in ocular infections caused by Candida or Aspergillus isolates. Because of its narrow spectrum and poor intraocular penetration its use is restricted. +2. Amphotericin B (Fungizone). This antibiotic may act as fungistatic or fungicidal depending upon the concentration of the drug and sensitivity of the fungus. Topically, it is effective in superficial infections of the eye in the concentration of 0.075 to 0.3% drops. Subconjunctival injections are quite painful and more than 300 mg is poorly tolerated. +Amphotericin B may be given intravitreally or/and intravenously for treatment of intraocular infections + + +caused by Candida, Histoplasma, Cryptococcus and some strains of Aspergillus and others. For intravenous administration, a solution of 0.1 mg/ml in 5% dextrose with heparin is used. +3. Natamycin (Pimaricin). It is a broad-spectrum antifungal drug having activity against Candida, Aspergillus, Fusarium and Cephalosporium. Topical application of 5% pimaricin suspension produces effective concentrations within the corneal stroma but not in intraocular fluid. It is the drug of choice for Fusarium solani keratitis. It adheres well to the surface of the ulcer, making the contact time of the antifungal agent with the eye greater. It is not recommended for injection. +II. Imidazole antifungal drugs +Various imidazole derivatives available for use in ocular fungal infections include: miconazole, clotrimazole, ketoconazole, econazole and itraconazole. +1. Miconazole. It possesses a broad antifungal spectrum and is fungicidal to various species of Candida, Aspergillus, Fusarium, Cryptococcus, Cladosporium, Trichophyton and many others. Topical (1%) and subconjunctival (10 mg) application of miconazole produces high levels of drug in the cornea which is more dramatic in the presence of epithelial defect. +2. Clotrimazole. It is fungistatic and is effective againstCandida, Aspergillus and many others. Its 1% suspension is effective topically and is the treatment of choice in Aspergillus infections of the eye. +3. Econazole. It also has broadspectrum antifungal activity and is used topically as 1% econazole nitrate ointment. Because of its poor intraocular penetration, it is effective only in superficial infections of the eye. +4. Ketoconazole. It is effective after oral administration and possesses activity against common fungi. It is given as single oral dose of 200–400 mg daily up to at least one week after the symptoms have disappeared. It is an adjunctive systemic antifungal agent in fungal keratitis complicated by endophthalmitis. +5. Fluconazole. It is fungistatic drug active against Candida, Aspergillus and Cryptococcus. It is available for oral use (50–100 mg tablets) and also for topical use (0.2% eyedrops). +6. Itraconazole. It is prescribed for treatment of fungal infections caused primarily by Aspergillus, Histoplasmosis, Blastomycosis. It has moderate effect against Candida and Fusarium infections. It +Chapter 19 Ocular Pharmacology 449 + + + +is available for oral and topical use. Oral dose is 200 mg twice daily for a week. Topically, it is used as 1% eye drops. +III. Pyridine +This group includes flucystosine, which is a fluorinated salt of pyrimidine. Its mechanism of action is not clear. The drug is very effective against Candida species and yeasts. It is used as 1.5% aqueous drops hourly. It can also be given orally or intravenously in doses of 200 mg/kg/day. +IV. Silver compounds +Combination of silver with sulfonamides and with other anti-microbial compounds significantly increases the activity against bacterial and fungal infections. In this context several silver compounds have been synthesized. Most frequently used is silver sulphadiazine which is reported to be highly effective against Aspergillus and Fusarium species. + +ANTI-GLAUCOMA DRUGS + +clASSIFIcATIon +A. Parasympathomimetic drugs (Miotics) +B. Sympathomimetic drugs (Adrenergic agonists) C. Betablockers +D. Carbonic anhydrase inhibitors E. Hyperosmotic agents +F. Prostaglandins +G. Calcium channel blockers + +A. PArASymPAThomImeTIc drugS (mIoTIcS) Parasympathomimetics, also called as cholinergic drugs, either imitate or potentiate the effects of acetylcholine. +classification +Depending upon the mode of action, these can be classified as follows: +1. Direct-acting or agonists, e.g., pilocarpine. +2. Indirect-acting parasympathomimetics or cholinesterase inhibitors: As the name indicates these drugs act indirectly by destroying the enzyme cholinesterase; thereby sparing the naturally acting acetylcholine for its actions. These drugs have been divided into two subgroups, designated as reversible (e.g., physostigmine) and irreversible (e.g., echothiophate iodide, demecarium and diisopropyl- +fluorophosphate, DFP3) anti-cholinesterases. +3. Dual-action parasympathomimetics, i.e., which act as both a muscarinic agonist as well as a weak cholinesterase inhibitor, e.g., carbachol. + +mechanism of action +1. In primary open-angle glaucoma the miotics reduce the intraocular pressure (IOP) by enhancing the aqueous outflow facility. This is achieved by changes in the trabecular meshwork produced by a pull exerted on the scleral spur by contraction of the longitudinal fibres of ciliary muscle. +2. In primary angle-closure glaucoma these reduce the IOP due to their miotic effect by opening the angle. The mechanical contraction of the pupil moves the iris away from the trabecular meshwork. +Side-effects +1. Systemic side-effects noted are: bradycardia, increased sweating, diarrhoea, excessive salivation and anxiety. The only serious complication noted with irreversible cholinesterase inhibitors is ‘scoline apnoea,’i.e., inability of the patient to resume normal respiration after termination of general anaesthesia. 2. Local side-effects are encountered more frequently with long acting miotics (i.e., irreversible cholinesterase inhibitors). These include problems due to miosis itself (e.g., reduced visual acuity in the presence of polar cataracts, impairment of night vision and generalized contraction of visual fields), spasm of accommodation which may cause myopia and frontal headache, retinal detachment, lenticular opacities, iris cyst formation, mild iritis, lacrimation and follicular conjunctivitis. +Preparations +1. Pilocarpine. It is a direct-acting parasympatho-mimetic drug. Earlier, it was the most commonly used and the most extensively studied miotic. However, presently, due to availability of many better drugs, it is not being preferred as the option for treatment in POAG. Even in PNAG, many glaucoma experts are discouraging its use. Indications: (i) Primary open-angle glaucoma; (ii) Acute angle-closure glaucoma; (iii) Chronic synechial angle-closure glaucoma. Contraindications: inflammatory glaucoma, malignant glaucoma and known allergy. Available preparations and dosage are: (a) Eye drops are available in 1%, 2% and 4% strengths. Except in very darkly pigmented irides maximum effect is obtained with a 4 percent solution. In POAG, therapy is usually initiated with 1 percent concentration. The onset of action occurs in 20 minutes, peak in 2 hours and duration of effect is 4–6 hours. Therefore, the eye drops are usually prescribed every 6 or 8 hourly. (b) Ocuserts are available as pilo-20 and pilo-40. These are changed once in a week. Pilo-20 +450 Section iV Ocular Therapeutics + + + +is generally used in patients controlled with 2% or less concentration of eye drops; and pilo-40 in those requiring higher concentration of eye drops. (c) Pilocarpine gel (4%) is a bedtime adjunct to the daytime medication. +2. Carbachol. It is a dual-action (agonist as well as weak cholinesterase inhibitor) miotic. Indications: It is a very good alternative to pilocarpine in resistant or intolerant cases. Preparations: It is available as 0.75% and 3% eye drops. Dosage: The action ensues in 40 minutes and lasts for about 12 hours. Therefore, the drops are instilled 2 or 3 times a day. +3. Echothiophate iodide (Phospholine iodide). It is a long-acting cholinesterase inhibitor. Indications: It is very effective in POAG. Preparations: Available as 0.03, 0.06 and 0.125% eye drops. Dosage: The onset of action occurs within 2 hours and lasts up to 24 hours. Therefore, it is instilled once or twice daily. +4. Demecarium bromide. It is similar to ecothiopate iodide and is used as 0.125% or 0.25% eyedrops. +5. Physostigmine (eserine). It is a reversible (weak) cholinesterase inhibitor. It is used as 0.5% ointment twice a day. +b. SymPAThomImeTIc drugS Sympathomimeties, also known as adrenergic agonists, act by stimulation of alpha, beta or both the receptors. +classification +Depending upon the mode of action, these can be classified as follows: +1. Both alpha and beta-receptor stimulators, e.g., epinephrine. +2. Direct alpha-adrenergic stimulators, e.g., norepinephrine and clonidine hydrochloride. +3. Indirect alpha-adrenergic stimulators, e.g., pargyline. +4. Beta-adrenergic stimulator, e.g., isoproterenol. + +mechanisms of action +1. Increased aqueous outflow results by virtue of both alpha and beta-receptor stimulation. +2. Decreased aqueous humour production occurs due to stimulation of alpha receptors in the ciliary body. +Side-effects +1. Systemic side-effects include hypertension, tachycardia, headache, palpitation, tremors, nervousness and anxiety. +2. Local side-effects are burning sensation, reactive hyperaemia of conjunctiva, conjunctival + +pigmentation, allergic blepharoconjunctivitis, mydriasis and cystoid macular oedema (in aphakics). +Preparations +1. Epinephrine. This direct-acting sympathomimetic drug stimulates both alpha and beta-adrenergic receptors. Indications: (i) It is one of the standard drugs used for the management of POAG. (ii) It is also useful in most of the secondary glaucomas. Preparations: It is available as 0.5%, 1% and 2% eyedrops. Dosage: The action starts within 1 hour and lasts up to 12–24 hours. Therefore, it is instilled twice daily. +2. Dipivefrine (Propine or dipivalylepinephrine). It is a prodrug which is converted into epinephrine after its absorption into the eye. It is more lipophilic than epinephrine and thus its corneal penetration is increased by 17 times.Preparations: It is available as 0.1% eye drops. Dosage:Action and efficacy is similar to 1% epinephrine. It is instilled twice daily. +3. Clonidine hydrochloride. It is a centrally-acting systemic antihypertensive agent, which has been shown to lower the IOP by decreasing aqueous humour production by stimulation of alpha-receptors in the ciliary body. Preparations and dosage: It is used as 0.125% and 0.25% eye drops, twice daily. +4. Brimonidine (0.2%). Mechanism of action. It is a selective alpha-2 adrenergic agonist and lowers IOP by decreasing aqueous production and enhancing uveoscleral outflow. It has an additive effect to beta-blockers. Dosage: It has a peak effect of 2 hours and action lasts for 12 hours; so it is administered twice daily. +5. Apraclonidine (0.5%, 1%). It is also alpha-2 adrenergic agonist like brimonidine. It is an extremely potent ocular hypotensive drug and is commonly used prophylactically for prevention of IOP elevation following laser trabeculoplasty, YAG laser iridotomy and posterior capsulotomy. It is of limited use for long-term administration because of the high rate of ocular side-effects. +c. beTA-AdrenergIc blockerS +These are, presently, the most frequently used antiglaucoma drugs. The commonly used preparations are timolol and betaxolol. Other available preparations include levobunolol, carteolol and metipranolol. +Chapter 19 Ocular Pharmacology 451 + + + +mechanism of action +Timolol and levobunolol are nonselective beta-1 (cardiac) and beta-2 (smooth muscle, pulmonary) receptor blocking agents. Betaxolol has 10 times more affinity for beta-1 than beta-2 receptors. +The drugs timolol and levobunolol lower IOP by blockade of beta-2 receptors in the ciliary processes, resulting in decreased aqueous production. The exact mechanism of action of betaxolol (cardioselective beta-blocker) is unknown. +Additive effects. Beta-blockers have very good synergistic effect when combined with miotics; and are thus often used in combination in patients with POAG, unresponsive to the single drug. +Indication and contraindication +Indications. Beta adrenergic blockers are useful in all types of glaucomas, viz., developmental, primary and secondary; narrow as well as open angle. Unless contraindicated due to systemic diseases, beta-blockers are frequently used as the first choice drug in POAG and all secondary glaucomas. Contraindications. These drugs should be used with caution or not at all, depending on the severity of the systemic disease in patients with bronchial asthma, emphysema, COPD, heart blocks, congestive heart failure or cardiomyopathy. Betaxolol is the beta blocker, of choice in patients at risk for pulmonary diseases. The other contraindication includes known drug allergies. +Side-effects +1. Ocular side-effects are not frequent. These include burning and conjunctival hyperaemia, superficial punctate keratopathy and corneal anaesthesia. +2. Systemic side-effects are also unusually low. However, these are reported more often than ocular side-effects. These include (i) Cardiovascular effects which result from blockade of beta-1 receptors. These are bradycardia, arrhythmias, heart failure and syncope. (ii) Respiratory reactions: These include bronchospasm and airway obstruction, especially in asthmatics. These occur due to blockade of beta-2 receptors; and thus are not known with betaxolol. (iii) Central nervous system effects. These include depression, anxiety, confusion, drowsiness, disorientation, hallucinations, emotional lability, dysarthria and so on. (iv) Miscellaneous effects are nausea, diarrhoea, decreased libido, skin rashes, alopecia and exacerbation of myasthenia gravis. +Preparations +1. Timolol. It is a nonselective beta-1 and beta-2 blocker. It is available as 0.25% and 0.5% eyedrops. + +The salt used is timolol maleate. Its action starts within 30 minutes, peak reaches in 2 hours and effects last up to 24 hours. Therefore, it is used once or twice daily. The drug is very effective, however, the phenomenon of ‘short-term escape’ and ‘long-term drift’ are well known. ‘Short-term escape’ implies marked initial fall in IOP, followed by a transient rise with continued moderate fall in IOP. The ‘long-term drift’ implies a slow rise in IOP in patients who were well controlled with many months of therapy. +2. Betaxolol. It is a cardioselective beta-blocker and thus can be used safely in patients prone to attack of bronchial asthma; an advantage over timolol. It is available as 0.5% suspension, and 0.25% suspension, and is used twice daily. Its action starts within 30 minutes, reaches peak in 2 hours and lasts for 12 hours. It is slightly less effective than timolol in lowering the IOP. +3. Levobunolol. It is available as 0.5% solution and its salient features are almost similar to timolol. +4. Carteolol. It is available as 1% and 2% solution and is almost similar to timolol except that it induces comparatively less bradycardia. +5. Metipranolol. It is available as 0.1%, 0.3% and 0.6% solution and is almost similar to timolol in all aspects. +d. cArbonIc AnhydrASe InhIbITorS (cAIs) These are potent and most commonly used systemic antiglaucoma drugs. These include acetazolamide (most frequently used), methazolamide, dichlorphenamide and ethoxzolamide. +mechanism of action +As the name indicates CAIs inhibit the enzyme carbonic anhydrase which is related to the process of aqueous humour production. Thus, CAIs lower the IOP by reducing the aqueous humour formation. +Indications +Orally used as additive therapy for short-term in the management of all types of acute and chronic glaucomas. Their long-term use is reserved for patients with high risk of visual loss, where all other treatments fail. +Topical CAIs are used as second line of drug and also as adjunct therapy. +Side-effects. Unfortunately, 40–50% of patients are unable to tolerate oral CAIs for long-term because of various disabling side-effects. These include: +1. Paresthesias of the fingers, toes, hands, feet and around the mouth are experienced by most of the +452 Section iV Ocular Therapeutics + + + +patients. However, these are transient and of no consequence. +2.Urinary frequency may also be complained by most of patients due to the diuretic effect. +3. Serum electrolyte imbalances may occur with higher doses of CAIs. These may be in the form of (i) Bicarbonate depletion leading to metabolic acidosis. This is associated with ‘malaise symptom complex’, which includes: malaise, fatigue, depression, loss of libido, anorexia and weight loss. Treatment with sodium bicarbonate or sodium acetate may help to minimize this situation in many patients. (ii) Potassium depletion. It may occur in some patients, especially those simultaneously getting corticosteroids, aspirin or thiazide diuretics. Potassium supplement is indicated only when significant hypokalemia is documented. (iii) Serum sodium and chloride may be transiently reduced; more commonly with dichlorphenamide. 4. Gastrointestinal symptom complex. It is also very common. It is not related to the malaise symptom complex caused by biochemical changes in the serum. Its features include—vague abdominal discomfort, gastric irritation, nausea, peculiar metallic taste and diarrhoea. +5. Sulfonamide related side-effects of CAIs, seen rarely, include renal calculi, blood dyscrasias, Stevens-Johnson syndrome, transient myopia, hypertensive nephropathy and teratogenic effects. +Preparations and doses +1. Acetazolamide (diamox). It is available as tablets, capsules and injection for intravenous use. The acetazolamide 250 mg tablet is used 6 hourly. Its action starts within 1 hour, peak is reached in 4 hours and the effect lasts for 6–8 hours. +2. Dichlorphenamide. It is available as 50 mg tablets. Its recommended dose is 25 to 100 mg three times a day. It causes less metabolic acidosis but has a sustained diuretic effect. +3. Methazolamide. It is also available as 50 mg tablets. It has a longer duration of action than acetazolamide. Its dose is 50–100 mg, 2 or 3 times a day. +4. Ethoxzolamide. It is given in a dosage of 125 mg every 6 hours and is similar to acetazolamide in all aspects. +5.Dorzolamide (2%). It is a topical carbonic anhydrase inhibitor. It is water soluble, stable in solution and has excellent corneal penetration. It decreases IOP by 22% and has got additive effect with timolol. It is administered thrice daily. Its side-effects include burning sensation and local allergic reaction. + +6. Brinzolamide (1%). It is also a topical CAI which decreases IOP by decreasing aqueous production. It is administered twice daily (BD). +e. hyPeroSmoTIc AgenTS +These are the second class of compounds, which are administered systemically to lower the IOP. These include: glycerol, mannitol, isosorbide and urea. +mechanism of action +Hyperosmotic agents increase the plasma tonicity. Thus, the osmotic pressure gradient created between the blood and vitreous draws sufficient water out of the eyeball, thereby significantly lowering the IOP. +Indications +These are used as additive therapy for rapidly lowering the IOP in emergency situations, such as acute angle-closure glaucoma or secondary glaucomas with very high IOP. They are also used as a prophylactic measure prior to intraocular surgery. +Preparations and doses +1. Glycerol. It is a frequently used oral hyperosmotic agent. Its recommended dose is 1–1.5 gm/kg body weight. It is used as a 50% solution. So, glycerol (50 to 80 ml in adults) is mixed with equal amount of lemon juice (preferably) or water before administering orally. Its action starts in 10 minutes, peaks in 30 minutes and lasts for about 5–6 hours. It can be given repeatedly. It is metabolised to glucose in the body. Thus, its repeated use in diabetics is not recommended. +2. Mannitol. It is the most widely used intravenous hyperosmotic agent. It is indicated when the oral agents are felt to be insufficient or when they cannot be taken for reasons such as nausea. Its recommended dose is 1–2 gm/kg body weight. It is used as a 20% solution. It should be administered very rapidly over 20–30 minutes. Its action peaks in 30 minutes and lasts for about 6 hours. It does not enter the glucose metabolism and thus is safe in diabetics. However, it should be used cautiously in hypertensive patients. +3. Urea. When administered intravenously it also lowers the IOP. However, because of lower efficacy and more side-effects than mannitol, it is not recommended for routine use. +4. Isosorbide. It is an oral hyperosmotic agent, similar to glycerol in action and doses. However, metabolically it is inert and thus can be used repeatedly in diabetics. +Chapter 19 Ocular Pharmacology 453 + + + +F. ProSTAglAndIn derIVATIVeS +1. Latanoprost (0.005%). It is a synthetic drug +which is an ester analogue of prostaglandin F2-a. It acts by increasing uveoscleral outflow and by +causing reduction in episcleral venous pressure. It is as effective as timolol. It has additive effect with pilocarpine and timolol. Its duration of action is 24 hours and is, thus, administered once daily. Its side effects include conjunctival hyperaemia, foreign body sensation and increased pigmentation of the iris. +2. Bimatoprost (0.03%). It is a prostamide which decreases IOP by decreasing ocular outflow resistance. It is used once a day (OD). +3. Travoprost (0.004%). It is a synthetic prostaglandin +F2 analogue and decreases IOP by increasing +uveoscleral outflow of aqueous. +4. Unoprostive isopropyl (0.12%). It is a dolosanoid +related in structure to prostaglandin F2-a. It lowers IOP by increasing uveoscleral outflow of aqueous. It +also increases retinal blood flow. + +g. cAlcIum chAnnel blockerS +Calcium channel blockers such as nifedipine, diltiazem and verapamil are commonly used antihypertensive drugs. Recently, some of these have been used as antiglaucoma drugs. +Mechanism of action. The exact mechanism of lowering IOP of topically used calcium channel blockers remains to be elucidated. It might be due to its effects on secretory ciliary epithelium. Preparations. Verapamil has been tried as 0.125% and 0.25% eye drops twice a day. +Indications. Though the IOP lowering effect of verapamil is not superior than the standard topical antiglaucoma drugs, it has a place in the mangement of patients with POAG, where miotics, beta-blockers and sympathomimetics are all contraindicated, e.g., in patients suffering simultaneously from axial cataract, bronchial asthma and raised blood pressure. It can also be used for additive effect with pilocarpine and timolol. +AnTIglAucomA drugS: mechAnISm oF lowerIng IoP AT A glAnce + +Drugs which increase trabecular outflow • Miotics (e.g., pilocarpine) +• Epinephrine, Dipivefrine • Bimatoprost +Drugs which increase uveoscleral outflow • Prostaglandins (latanoprost) + + +• Epinephrine, Dipivefrine • Brimonidine +• Apraclonidine + +Drugs which decrease aqueous production +• Carbonic anhydrase inhibitors (e.g., acetazolamide, dorzolamide). +• Alpha receptor stimulators in ciliary process (e.g., epinephrine, dipivefrine, clonidine, brimonidine, apraclonidine. +• Beta blockers (e.g., timolol, betaxolol, levobunolol). +Hyperosmotic agents (e.g., glycerol, mannitol, urea). + +ANTI-INFLAMMATORY AND IMMUNOSUPPRESSIVE AGENTS + +corTIcoSTeroIdS +These are 21-C compounds secreted by the adrenal cortex. They have potent anti-inflammatory, anti-allergic and anti-fibrotic actions. Corticosteroids reduce inflammation by reduction of leukocytic and plasma exudation, maintenance of cellular membrane integrity with inhibition of tissue swelling, inhibition of lysosome release from granulocytes, increased stabilisation of intracellular lysosomal membranes and suppression of circulating lymphocytes. +classification and relative anti-inflammatory drug potency +Classification and relative anti-inflammatory drug potency of corticosteroids is summarized in Table 19.2. +Preparations and modes of administration Corticosteroids may be administered locally in the form of drops, ointments or injections and systemically in the form of tablets or injections. +A. Topical ophthalmic preparations used commonly are as follows: +• Cortisone acetate As 0.5% suspension and 1.5% ointment +•Hydrocortisone As0.5%suspensionacetate and 0.2% ointment +• Dexamethasone As 0.1% solution and sodium phosphate 0.5% ointment +• Betamethasone As 0.1% solution and sodium phosphate 0.1% ointment +• Medryson 1% suspension +• Fluromethalone 0.1% suspension • Loteprednol 0.5% suspension +454 Section iV Ocular Therapeutics + + + +Table 19.2 Corticosteroids: equivalent anti-inflammatory oral dose (mg) and relative anti-inflammatory potency +Drug Equivalent Relative anti-anti-inflam- inflammatory matory oral potency +dose (mg) +I. Glucocorticoids 1. Short-acting +Hydrocortisone +(Cortisol) 20 1 Cortisone 25 0.8 Prednisolone 5 4 Prednisone 5 4 Methylprednisolone 4 5 +2. Intermediate-acting +Triamcinolone 4 5 Fluprednisolone 1.5 15 +3. Long-acting +Dexamethasone 0.75 26 Betamethasone 0.60 33 +II. Mineralocorticoids +Fludrocortisone 2 10 + +B. Systemic corticosteroid preparations used commonly are: +• Prednisolone As 5 mg, 10 mg tab and solution for injection in the strength of 20 mg/ml +• Dexamethasone As 0.5 mg tab and solution for injection in the strength of 4 mg/ml +• Betamethasone 0.5 mg and 1 mg tab + +ocular indications +1. Topical preparations are used in uveitis, scleritis, allergic conjunctivitis (vernal catarrh and phlyctenular conjunctivitis), allergic keratitis, cystoid macular oedema and after intraocular surgery. +2. Systemic preparations are indicated in posterior uveitis, sympathetic ophthalmic, Vogt-Koyanagi-Harada syndrome (VKH), papillitis, retrobulbar neuritis, anterior ischaemic optic neuropathy, scleritis, malignant exophthalmos, orbital pseudotumours, orbital lymphangioma and corneal graft rejections. +Side-effects +Topical steroids may cause glaucoma, cataract, activation of infection (if given in herpetic, fungal and bacterial keratitis), dry eye and ptosis. Systemic corticosteroids may cause ocular and systemic side-effects. + +Ocular complications include cataract, glaucoma, activation of infection, delayed wound healing, papilloedema, and central retinal vein occlusion. +• Systemic complications include peptic ulcer, hypertension, osteoporosis, aggravation of diabetes mellitus, mental changes, cushingoid state and reactivation of tuberculosis and other infections. +nonSTeroIdAl AnTI-InFlAmmATory drugS Nonsteroidal anti-inflammatory drugs (NSAIDs), often referred to as ‘aspirin-like drugs’, are a heterogeneous group of anti-inflammatory, analgesic and antipyretic compounds. These are often chemically unrelated (although most of them are organic acids), but share certain therapeutic actions and side-effects. +mechanisms of action +The NSAIDs largely act by irreversibly blocking the enzyme cyclo-oxygenase, thus inhibiting the prostaglandin biosynthesis. They also appear to block other local mediators of the inflammatory response such as polypeptides of the kinin system, lysosomal enzymes, lymphokinase and thromboxane A2; but not the leukotrienes. +Preparations +A. NSAIDs available for systemic use can be grouped as follows: +1. Salicylates, e.g., aspirin. +2. Pyrazolone derivatives, e.g., phenylbutazone, oxyphenbutazone, aminopyrine and apazone. +3. Para-aminophenol derivatives, e.g., phenacetin and acetaminophen. +4. Indole derivatives, e.g., indomethacin and sulindac. +5. Propionic acid derivatives, e.g., ibuprofen, naproxen and flurbiprofen. +6. Anthranilic acid derivatives, e.g., mefenamic acid and flufenamic acid. +7. Other newer NSAIDs, e.g.,ketorolactromethamine, carprofen and diclofenac. +B. Topical ophthalmic NSAIDs preparations available include: +1. Indomethacin suspension (0.1%) 2. Flurbiprofen, 0.3% eye drops +3. Ketorolac tromethamine, 0.5% eye drops 4. Diclofenac sodium, 0.1% eye drops +5. Bromefenac, 0.09% eye drops 6. Nepafenac, 0.1% eye drops +Chapter 19 Ocular Pharmacology 455 + + + +ophthalmic indications of nSAIds +1. Episcleritis and scleritis. Recalcitrant cases of episcleritis may be treated with systemic NSAIDs such as oxyphenbutazone 100 mg TDS or indomethacin 25 mg BD. +NSAIDs may also suppress the inflammation in diffuse and nodular varieties of scleritis, but are not likely to control the necrotizing form. +2. Uveitis. NSAIDs are usually not used as the primary agents in therapy of uveitis. They are, however, useful in the longterm therapy of recurrent anterior uveitis, initially controlled by steroid therapy. Phenylbutazone is of use in uveitis associated with ankylosing spondylitis. +3. Cystoid macular oedema (CME). Topical and/or systemic antiprostaglandin drugs are effective in preventing the postoperative CME occurring after cataract operation. The drug (e.g., 0.03% flurbiprofen eye drops) is started 2 days preoperatively and continued for 6–8 weeks postoperatively. +4. Preoperatively to maintain dilatation of the pupil. Flurbiprofen drops used every 5 minutes for 2 hours preoperatively are very effective in maintaining the pupillary dilatation during the operation of extracapsular cataract extraction with or without intraocular lens implantation. + +ImmunoSuPPreSSIVe And AnTImIToTIc drugS +Immunosuppressives refers to the agents used to control immune-mediated inflammation or tissue reaction. + +uses and indications in ophthalmology + +1. Uveitis +• Absolute indications includes Vogt-Koyanagi-Harada syndrome, sympathetic ophthalmia, Behcet’s syndrome and serpiginous choroidopathy. +• Relative indications include intermediate uveitis, retinal vasculitis, chronic cyclitis and cases of uveitis refractory to maximium steroid therapy. +• Questionable indications include children with intermediate uveitis. +• Contraindications include focal chorioretinitis, herpetic uveitis, toxoplasmosis, CMV retinitis, and fungal uveitis. +2. Corneal graft +• Corneal graft rejections, and +• Prevention of corneal graft rejection in prone +patients. + + +3. Immune-mediated corneal ulcer • Mooren’s ulcer +4. Glaucoma filtration surgery +• Prevention of bleb failure in high-risk cases. • Treatment of bleb failure. +5. Recurrent pterygium 6. Scleritis +7. Cicatricial pemphigoid 8. Grave’s ophthalmopathy +9. Ocular myasthenia gravis. + +commonly used immunosuppressive drugs in ophthalmology +I. Immunomodulators +Immunomodulators, e.g., cyclosporine, tacrolimus Mechanism of action.These drugs bind to cytoplasmic receptors termed immunophilines in T-cells, thereby selectively inhibiting T-cell activity. +Cyclosporine. It can be used topically as well as systemically. +• Systemic dose and indications. Systemically, in a dose of 3–5 mg/kg body weight it is indicated in cases of uveitis, scleritis, Graves ophthalmopathy, cicatricial pemphigoid and myasthenia gravis as given below. +• Topically, cyclosporine is used as 0.05% bd in patient with refractory vernal keratoconjunctivitis, and dry eye syndrome. +Tacrolimus can also be used systematically and topically in a dose of 0.05 to 0.2 mg/kg/day. Tacrolimus may be used in various conditions as an alternative to cyclosporine. +• Topically, tacrolimus 0.03% ointment can be effective in atopic keratoconjunctivitis (AKC) and refractory cases of VKC. +II. Cytotoxic drugs +a. Antimetabolites these includes: +1. Azathioprine is a commonly used antimetabolite • Mechanism of action. It inhibits purine synthesis, which interfere with DNA replication and RNA transcription. It suppresses both T-cells and +B-cells, but does not suppress humoral immunity. • Indications are given below. +• Side effects include gastrointestinal intolerance and bone marrow suppressions. It may also cause hepatotoxicity. +2. Methotrexate is another commonly used antimetabolite. +• Mechanism of action. It suppresses both humoral and cell-mediated immune reactions. In addition to being anti-inflammatory, it also diminishes chemotaxis. +456 Section iV Ocular Therapeutics + + + +• Indications and side effects are similar to azathioprine (see above) +b. Alkylating agents. These include: 1. Cyclophosphamide. +• Mechanism of action. It destroys proliferating lymphoid cells but also alkylate DNA and the molecule in some resting cells. +• Indications—ocular inflammatory disease and ocular cancers. +• Side effects are nausea, vomiting, cardiac toxicity, electrolyte imbalance, pancytopenia and hemorrhagic cystitis. + +ANTI-ALLERGIC AND VASOCONSTRICTORS DRUGS + +Following categories of drugs are available for use in allergic conjunctivitis. +1. H1 receptor antagonists available include levocabastine and emedastine difumarate. +Uses. It is used for isolated, acute allergic attacks. +2. Mast cell stabilizers available include cromolyn sodium, lodoxamide, pemirolast, and nedocromil sodium. +Uses. Chronic allergies. +3. Antihistamines with mast cell-stabilizing activity available include olopatadine, alcaftadine, bepotastine, ketotifen fumarate, azelastine, epinastine and bepotastine. +Uses. These medications combine the immediate effect of selective antihistamines with long-term effects of mast cell stabilization. +4. Topical NSAIDs available include flurbiprofen, ketarolac, nepafenac and bromfenac. +Uses. Reduce itching and inflammation. +5. Vasoconstrictors available include naphazoline/ pheniramine, naphazoline/antazoline. +Uses. Relieves redness by causing decongestion. +6. Weak corticosteroids available for topical use include loteprednol, fluorometholone and rime-xolone. +Uses. Useful in serious cases of allergic conj-unctivitis. +7.Oral antihistaminesavailable include fexofenadine, loratadine, cetirizine, ebastine, mizolastine and desloratadine. +Uses. Useful in systemic allergic symptoms. +8. Immunomodulators available include tacrolimus and cyclosporine. +Uses. Refractory cases of allergic conjunctivitis. + +LUBRICATING AGENTS + +Lubricating agents, also known as tear substitute or artificial tears are the mainstay for treatment of dry eye (a condition in which naturally-produced tears are insuffient to lubricate the ocular surface). +Ingredients of commercially available tears substitute +Base ingredients include: +Balanced amount of inorganic electrolytes (salts) to maintain ocular tonicity (0.9% NaCl equivalent). Buffers like boric acid to adjust pH. +Viscosity agents (water soluble polymer system) constitutes the main ingredient which enhance viscosity and promote tear film stability. Preservative to maintain solution sterility include benzal konium chloride, chlorobutanal, thimerosal and so on. +Viscosity agents (polymers) +Commonly used viscosity agents, the main constituent of tear substitute, are described briefly: I. Cellulose esters, are the most commonly used agents. These include: +• Methylcellulose (1%) +• Hydroxypropylmethyl cellulose (0.5 %, and 1%) • Hydroxyethyl cellulose (0.5% and 1%) +• Carboxymethyl cellulose (0.5%). +II. Polyvinyl alcohol base solutions are the other commonly used agents. These include: +• Polyvinyl alcohol (1% and 3%) +• Polyvinyl alcohol 1.4% along with povidine 0.6% makes the better solutions. +• Polyvinyl pyrrolidone polymer base tears solution. III. Increased viscosity agents or longer acting mucoadhesive, which have better duration of actions includes: +• Polycarbophil and dextran, • Hyaluronidase. +IV. Combination of cellulose ester and polyvinyl pyrrolidone and/or other polymers are now becoming the ingredients commonly available commercial proparatia. +V. White petrolatum and lanolin, as mentioned above are available as lubricating ointment (e.g., Lacrilube, lacrigel, etc. are commercially available ointment). +Addition ingredients available in some commercially available tears substitute include: +• Vitamins A typical preparations, and • Certain lipids. +Chapter 19 Ocular Pharmacology 457 + + + +Topical preparations of tear substitute +Tear substitute are available in following forms for topical use: +1. Eye drops (solutions). Most commonly used in form of tear substitute in eye drops with above described ingredients. +• Preservative free solutions are also available in the form of unims. +2. Lubricating gel solutions contain higher strength of the viscosity agents. Examples of commercial preparations are Refresh liquid gel, Genteal gel, Misty gel, etc. +3. Lubricating ointment is the second most common method of ocular lubrication. Most such ointment contain white petrolatum, mineral oil and lanoline. • Indications. Generally preferred for bed time use, +can be used during the day in severe cases. 4.Slow release ocular insert (solid devices) are available as preservative free water soluble polymer insert (e.g., Lacriset). The cylindrical rod which contain 5 mg hydroxyl propylmethyl cellulose is placed in the lower cul-de-sac. It releases polymer to the ocular surface for 12–24 hours. +• Indications. Severe drug eye syndrome. Cost is a deterant to use. + +INTRAOCULAR IRRIGATING SOLUTIONS + +Functions +Intraocular irrigating solutions are the most essential tools for the modern cataract surgery and other intraocular surgeries. These are aqueous solutions which sub-serve the following functions: +• Clear and maintain moisture of the ocular tissues. • Maintain physiological and anatomical integrity +of the intraocular tissues and chamber. +• Provide cellular nutrients required for intercellular and intracellular functions during prolonged intraocular surgery. +• Maintain corneal transparency during intraocular surgery by maintaining endothelial cell metabolism and then avoiding corneal clouding. +• Maintain intraocular pressure during the surgery. + +Indications/uses +• Cataract surgery. Irrigating solutions are essential for each and every step of modern cataract surgery with IOL implantation. +• Glaucoma surgery. In trabeculectomy and other invasive filteration surgery, irrigation solution helps to maintain the chamber, wash delirious substances and maintain tissues moisture. + + +• Corneal surgery and anterior segment reconstruction. • Vitrectomy and posterior segment surgery. +commercially available intraocular irrigating solutions +Commercially available irrigating solutions suitable for intraocular use include: +• Lactated Ringers solution +• Balanced salt solution (BSS) +• Balanced salt solution plus (BSS-Plus) +Salient features of commercially available irrigating solutions: +1. Lactated Ringers solution +Composition in mMoles/liter is: NaCl (102), KCl (4), +CaCl2 (3), and sodium lactate (28). +pH of lactate Ringers solution is 7.2. Osmolality is 279. +Advantages: Maintains the integrity of intraocular tissues. +Disadvantages: Since it contains sodium lactate in much higher concentration than aqueous humour, so prolonged perfusion causes endothelial cell break down and corneal swelling. +2. Balanced salt solution (BSS) +Composition in mmol/liter is: NaCl (110), KCl (10), +CaCl3 (3), MgCl2_(l.5), sodium citrate (8) and sodium acetate (29). +pH of BSS is 7.4. Osmolality is 305. +Advantages: It is better tolerated irrigant which helps to maintain the integrity of intraocular tissues. Disadvantages: BSS is less protective to corneal endothelial cells as compared to BSS plus as it lacks the bicarbonate, glucose and glutathione. After prolonged exposure it may result in: +• Polymegathism, i.e., a significant increase in the coefficient of variation of cell area; +• Pleomorphism, i.e., a significant decrease in the percentage of hexagonal cells; and +• Stressed endothelial monolayer, which may be more susceptible to additional surgical trauma. +3. Balanced salt solution (BSS) plus +Composition: The concentration of constituents of BSS Plus, also known as GBR (glutathione, bicarbonate, Ringers) in mmol/L is NaCl (122.2), +KCl (5.08), MgCl2 (0.98), disodium phosphate (2.5), dextrose (5.11), oxidized glutathione (0.30), and +sodium bicarbonate (25). pH of BSS plus is 7.4, +458 Section iV Ocular Therapeutics + + + +Osmolality (mosm) is 305. Advantages of BSS plus are as below: +• Iso-osmotic with intraocular tissues. +• Corneal endothelium functioning is maintained even on prolonged irrigation and thus minimal changes occur in endothelial morphologic characteristics. +• Lens clarity is maintained in posterior segment surgery. +• Blood aqueous barrier is maintainedby glutathione which protects the cells against oxidative stress and thus inflammation is minimized. + +VISCOELASTIC SUBSTANCES + +Use of viscous or viscoelastic substances has become almost mandatory in the modern microphthalmic surgery, especially intraocular lens implantation, which involves a risk of involuntary tissue damage due to intraocular manipulations. +Properties of viscoelastic substances +An ideal viscoelastic substance should have the following properties: +1. Chemically, the material should be inert, iso-osmotic, free from particulate matter, non-pyrogenic, non-antigenic, non-toxic and sterile. +2. Optically clear. +3. Viscosity of the substances should be enough to provide sufficient space for manipulation within the eye. +4. Hydrophilic and dilutable properties are neces-sary to irrigate the material out of the eye after the operation. +5. Protectability and maintenanceof space.It should protect the endothelium, separate the tissues, maintain the space and act as a lubricant. +Preparations +1. Methylcellulose. It is the most commonly used substance. It is only a viscous and not a viscoelastic substance. Its active ingredient is highly purified 2% hydroxypropyl methylcellulose. +2. Sodium hyaluronate (1%) (Healon). Being extremely viscoelastic and non-inflammatory, it is the best available viscoelastic substance. However, being expensive, it is less popular than methylcellulose. +3. Hypromellose (2%). It is a viscous substance similar to methylcellulose. +4. Chondroitin sulfate (20% and 50%). It is a viscoelastic substance similar to sodium hyaluronate. It is also available as 1:3 mixture + +of 4% chondroitin sulfate and 3% sodium hyaluronate (Viscoat) and in combination with methylcellulose (Ocugel). +Alternatives to viscoelastic substances +Substances used as alternative to viscoelastics for maintenance of anterior chamber are air, serum and other blood products and balanced salt solution. However, none of these match the properties of viscoelastic substances. +clinical uses +1. Cataract surgery with or without IOL implantation. It is the most important indication. Here the viscoelastic substance is used for: +i. Maintenance of anterior chamber; ii. Protection of corneal endothelium; iii.Coating the IOL and +iv. Preventing the entry of blood and fluid in the anterior chamber. +2. Other uses. Viscoelastic substances are also useful in glaucoma surgery, keratoplasty, retinal detachment surgery and repair of the globe in perforating injuries. +Side-effects +Postoperative rise in intraocular pressure may occur if a considerable amount of viscoelastic substance is left inside the anterior chamber; so it must be washed off after surgery. + +ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR AGENTS (Anti-VEGF) + +The vascular endothelial growth factors (VEGF-A) are the key factors blamed for producing neovascularization disorders, e.g., choroidal neovascularization (wet ARMD), retinal neova-scularization (diabetic retinopathy, sickle cell retinopathy, neovascular glaucoma in CRVO, etc.). There are 9 isoforms of VEGF-A of which VEGF-165 is the most abundantly expressed but all isoforms are thought to contribute to ocular angiogenesis. Antivascular endothelial growth factor (anti-VEGF) agents, which have revolutionized the treatment of ocular diseases associated with neovascularization include: +• Ranibizumab (Lucentis), +• Pegaptanib (Macugen), and • Bevacizumab (Avastin). + +ranibizumab +Ranibizumab (marketed as Lucentis by Genentech, USA) is a humanized monoclonal antibody fragment +Chapter 19 Ocular Pharmacology 459 + + + +(fab). Its production is by an E. coli expression system in a nutrient medium. Its molecular weight is 48 KD and it has a short half-life of 2 hours. +Mechanism of action. Ranibizumab binds to all isoforms of VEGF-A and inhibits their biological activity. +Dose. It is the only FDA approved non-selective anti-VEGF agent for the treatment of choroidal neovascularization or as multiple intravitreal injection (every 8 weeks) in the dose of 0.5 mg/0.05 ml. Available as 0.23 ml vial containing 10 mg/ml of the drug. +Pegaptanib +Pegaptanib (marketed as Macugen by Eyetech Pharmaceuticals, USA) is a pegylatedaptamer (i.e. an oligonucleotide with polyethylene glycol covalently attached). Its molecular weight is 50 KD. Mechanism of action. It binds with high affinity to VEGF-165 isoform of VEGF-A and inhibits its activity thereby inhibiting angiogenesis. +Intravitreal doseis 0.3 mg in 90 ml (multiple injections every 6 weeks). +bevacizumab +Bevacizumab (marketed as Avastin by Gentech, USA) is a full length recombinant humanized monoclonal antibody (IgG1) against VEGF-A. Its molecular weight is 149 KD. It is currently approved for colorectal cancers as an intravitreous injection. Its off-label use in ocular neovascular disorders, e.g. wet ARMD have shown its effectivity. +Mechanism of action. It binds to all isoforms of VEGF-A and inhibits their activity. +Intravitreal dose. Available as 4 ml vial containing 100 mg of the drug. Its intravitreal dose is 1.25 mg (0.05 ml). +Uses of anti-VEGF agents include neovascular age-related macular degeneration (common indication), diabetic retinopathy, retinal veinocclusion, neovascular glaucoma, myopic CNV, inflammatory CNV, choroidal osteoma, juxtafoveal telangiectasia, ROP, idiopathic polypoidal choroidopathy, pseudophakic cystoid oedema and central serous retinopathy. Complications of antiVEGFs intravitreal injections include cataract, glaucoma, vitreous haemorrhage, endophthalmitis, retinal detachment, etc. + +DYES USED IN OPHTHALMOLOGY + +Ophthalmic dyes commonly used as a helping tool in the diagnosis and management of ocular disease include: + +• Fluorescein sodium • Fluorexone +• Indocyanine green • Rose Bengal +• Lissamine green • Trypan blue +• Verteporfin, and • Methyline blue +FluoreSceIn SodIum +Fluorescein sodium, a water soluble dibasic acid dye, is the most essential and commonly use in ophthalmology. It is orange red in powder form and yellow in solution. +uses and preparations +Topical formulationsinclude 2% aqueous solution and fluorescein impregnated strips. Presently, use of strips is preferred as the solution may harbor Pseudomonas pyocyanea bacteria. +Uses include: +• Corneal staining to detect abrasion and ulcers. Epithelial defect of cornea stain bright green in white light and opaque green with cobalt blue light and thus are easily visualized (also see page 502). +• Applanation tonometry is the most frequent procedure in which tear film is stained. +• Lacrimal tests includes tear film break up time (TBUT) for any eye and Jane’s test for watering eye. +• Seidel’s test. Tear film is stained to detect leakage of aqueous from the anterior chamber in postoperative shallow anterior chamber, perforating trauma and perforation of corneal ulcer. +• Rigid contact lens fitting is best judged with fluorescein pattern of tear film. +Intravenous fluorescein (10% and 25%) is used for: • Fundus fluorescein angiography (See page 517) • Iris angiography for evaluation of vasculature +• Vitreous fluorophotometry. + +FluoreXone +It is a high molecular weight fluorescent solution (N-bis-aminomethyl fluorescein tetrasodium). + +uses +Fluorexone does not stain most of the soft contact lenses and is thus used in eyes when fluorescein is contraindicated to avoid staining of soft contact lenses: +• Evaluation of corneal integrity of patients wearing hydrogel contact lenses +460 Section iV Ocular Therapeutics + + + +• Tear film BUT test +• Applanation tonometry without removing soft contact lens +• For detecting lathe-cut index marking of toric soft contact lenses. +IndocyAnIne green +Indocyanine green (ICG) has a high protein binding capacity, near infrared fluorescence and peak spectral absorption of 800–810 nm in blood. +uses +• ICG fundus angiography (dose 25 mg in 2 ml) is particularly useful for disorders involving choroidal vasculature, e.g., neovascularization (age-related macular degeneration), idiopathic polypoidal choroidal vasculopathy (IPCV), pigmented choroidal melanomas, choroidal haemangioma, central serous choroiretinopathy, and various types of choroiditis. +• ICG-enhanced anterior capsulorrhexis using 0.5% solution is useful in childhood cataracts and adulthood cataract with no fundus glow. +• ICG-enhanced posterior capsulorrhexis using 0.5% solution is useful in childhood cataracts. +roSe bengAl And lISSAmIne green +Rose Bengal and Lissamine green, both dyes are available as 1% solution as well as impregnated paper strips. +Uses. These dyes stain the devitalized, (degenerated and dead cells of conjunctiva and cornea and also the mucous fibrils. These are particularly useful in ocular surface disorders particularly dry eyes, i.e. keratoconjunctivitis sicca (KCS). +TryPAn blue +Trypan blue is a commonly used dye to enhance the visualization of the anterior lens capsule before + +performing anterior capsulotomy/capsulorrhexis during cataract surgery. Special feature of trypan blue is that it stain the anterior lens capsule without affecting the corneal endothelium. +Aministration and doses. It is available as 1 ml ampule and 2 ml vial. Each ml of solution contain 0.6 mg trypan blue. It is used in diluted form in a concentration range of 0.01 to 0%. +Indications. It is specially indicated in mature and hypermature cataracts when red reflex is not visible. However, some surgeons use it routinely. Precaution. By and large trypan blue is very safe without side effect. However, some cases of post-inflammatory reactions and some cases of bullous keratopathy have been reported. Therefore, it should be used cautiously, when needed and effects should be made to avoid contact with endothelium by using air bubble. Further, it should be washed off immediately with viscoelastic and balanced salt solution. +VerTePorFIn +Verteporfin (commercially available as Visudyne) is a photosensitive second generation porphyrin derivative. +Uses. It is used in photodynamic therapy (PDT) for wet age-related macular degeneration in patients with classic subfoveal choroidal neovascularization (CNVM). +Dosage and mechanism of action. Verteporfin is injected as intravenous infusion in a dose of 6 mg/m2 body surface area in a total infusion volume of 30 ml. After 5 minutes, the area of CNVM is exposed to light from a diode laser source at a wavelength (689 nm) that corresponds to absorption peak of the dye. The light-activated dye than causes disruption of cellular structures an occlusion of CNVM with minimum damage to the adjacent RPE, photoreceptors and capillaries. +20 +Lasers and Cryotherapy in Ophthalmology + + + +Chapter Outline + + +LASERS IN OPHTHALMOLOGY Properties of laser light Production of laser beam Types of lasers +Mechanisms of laser effects and their therapeutic applications +• +• +• +• + + + +LASERS IN OPHTHALMOLOGY + +ProPerties of laser light +The word LASER is an acronym for ‘Light Amplific­ ation by Stimulated Emission of Radiation’. +Properties of laser light are: +• Monochromatic, i.e., it consist of a narrow beam of a single wavelength and thus, is always colored and can never be white. +• Coherence , i.e., its each wave is in phase with the other near it. +• Collimation, i.e., all the rays are exactly parallel. • Polarized in one plane, i.e., easy to pass through +media. + +ProDUCtioN of laser BeaM +In the laser system atomic environments of various types are stimulated to produce laser light. A laser system consists of a transparent crystal rod or a gas or liquid filled cavity constructed with a fully reflective mirror at one end and a partially reflective mirror at the other. Surrounding the rod or cavity is an optical or electrical source of energy that will raise the energy level of the atoms within the cavity or rod to a high and unstable level. This phenomenon is called population inversion. From this level, the atoms spontaneously decay back to a lower energy level, releasing the excess energy in the form of light which is amplified to an appropriate wavelength. Thus, laser is created mainly by two means: population + +CRYOTHERAPY IN OPHTHALMOLOGY +Principle Cryo unit +• +• +• +Modes of action + + + + +inversion in active medium and amplification of appropriate wavelength of light. +tyPes of lasers +There are various types of lasers depending upon the type of atomic environment stimulated to produce the laser beam. Common types of lasers are depicted in Table 20.1. +Table 20.1 Lasers used in ophthalmology + +Type of laser Wave­ Atomic Effects produced length environment +(nm) used +1. Argon 514 Argon gas Photocoagulation 2. Krypton 647 Krypton gas Photocoagulation 3. Diode 840 Diode crystal Photocoagulation +4. Diode 532 Diode and Photocoagulation Pumped Nd:YAG crystals +frequency doubled Nd:YAG +5. Nd:YAG 1064 A liquid dry or a Photodisruption solid compound +of yttrium-aluminium garnet and neodymium +6. Excimer 193 Helium and Photoablation flourine gas +7. Femtosecond 1053 Neodymium- Photodisruption glass +462 Section iV Ocular Therapeutics + + +MeChaNisMs of laser effeCts aND their theraPeUtiC aPPliCatioNs +1. Photocoagulation +The principal lasers used in ophthalmic therapy are the thermal lasers, which depend upon absorption of the laser light by tissue pigments. The absorbed light is converted into heat, thus raising the temperature of the target tissue high enough to coagulate and denature cellular elements. Argon, diode, krypton and diode pump frequency doubled Nd:YAG lasers are based on this mechanism. +Modes of action. Photocoagulation is effective intreating ocular diseases by production of a scar, occlusion of vessels, tissue atrophy, and tissue contraction. Therapeutic applications based on photocoagulation are as follows: +1. Eyelid lesions such as haemangioma. +2. Cornealconditionse.g.,reduction of postoperative astigmatism from cataract sutures—by Argon laser suturotomy and treatment of corneal neovascularisation. +3. Laserforglaucoma.Procedures employed include laser iridotomy for narrow­angle glaucoma, argon laser trabeculoplasty (ALT) for open­ angle glaucoma, laser goniopunctures for developmental glaucoma, prophylactic pan­retinal photocoagulation to prevent neovascular glaucoma in patients with retinal hypoxic states (e.g., central retinal vein occlusion) and cyclophotocoagulation for absolute or near absolute glaucoma. +4. Lesionsofiris.These include laser coreoplasty for updrawn pupil, photomydriasis for pathologic miotic pupil, laser sphincterotomy and laser shrinkage of iris cyst. +5. Lesionsofretinaandchoroid.These form the most important indications. Common conditions are: • Diabetic retinopathy in which panretinal photo­ +coagulation (PRP) is carried out for proliferative retinopathy and focal or grid­photocoagulation for exudative maculopathy. +• Peripheral retinal vascular abnormalities such as Eales’ disease, proliferative sickle cell disease, Coats’ disease and retinopathy of prematurity. +• Intraocular tumours such as retinoblasto­ ma, malignant melanoma and choroidal haemangioma. +• Macular diseases, such as central serous retinopathy, and age­related macular degeneration (ARMD). +• For sealing of holes in retinal detachment. Complications of laser photocoagulation. These include: accidental foveal burns, macular oedema and macular pucker, preretinal fibrosis, haemorrhage + + +from retina and choroid, retinal hole formation, ischaemic papillitis, localised opacification of lens and accidental corneal burns. +2. Photovaporization +Vaporization of tissue to CO2 and water occurs when temperature rises to 60–100 degree Centigrade or +greater, e.g., CO2 absorbed by water of cells and heat generated causes cauterization or causes +disintegration thereby incising the tissue. + +3. Photodisruption +Laser based on this mechanism ionize the electrons of the target tissue producing a physical state called plasma. This plasma expands with momentary pressures as high as 10 kilobars, exerting a cutting/ incising effect upon the tissues. Nd:YAG laser and femtosecond laser are based on this mechanism. Therapeutic applications of Nd:YAG laser include capsulotomy for thickened posterior capsule and membranectomy for pupillary membranes. Recently, it has also been tried for phacolysis (laser phaco surgery) in phacoemulsification technique of cataract extraction. +Femtosecond laser and its uses. The femtosecond laser uses an infrared beam of light to precisely separate the tissues through photodisruption by generating pulses as short as one­quadrillionth of a second (10­15 femtosecond). It has a wavelength of 1053 nm. Uses of femtosecond laser include: +• Creation of coneal flap for LASIK, +• Creation of tunnel for intracorneal rings, +• Arcuate incisions to correct corneal astigmatism, • Keratoplasty incisions, and +• Femtosecond laser assisted cataract surgery (FLACS). +4. Photoablation +Lasers based on this mechanism produce UV light of very short wavelength which breaks chemical bonds of biologic materials, converting them into small molecules that diffuse away. These lasers are collectively called excimer (excited dimer) lasers. These act by tissue modelling. +Therapeutic applications of excimer lasers are: photorefractive keratectomy (PRK), laser assisted in situ keratomileusis (LASIK) for correction of refractive errors and phototherapeutic keratectomy (PTK) for corneal diseases such as bandshaped keratopathy. +5. Photoradiation (Photochemical effect) Photochemical effect following visible/infrared particularly after administration of exogenous +Chapter 20 Lasers and Cryotherapy in Ophthalmology 463 + + +chromophore, e.g., hematoporphyrin or benza­ porphyrin and is used for photodynamic therapy, treatment of ocular tumours and choroidal neovascularization. + +CRYOTHERAPY IN OPHTHALMOLOGY + +Cryopexy means to produce tissue injury by application of intense cold (­40°C to ­100°C). This is achieved by a cryoprobe from a cryo unit. +Principle +Working of cryoprobes is based on the Joule Thompson principle of cooling. +Cryo unit +Cryo unit (Fig. 20.1) uses freon, nitrous oxide or carbon dioxide gas as cooling agent. +Cryoprobes are available in different sizes such as 1 mm for intravitreal use, 1.5 mm straight or curved probe for cataract extraction, 2.5 mm for retina and 4 mm for cyclocryopexy (Fig. 20.2). +Temperature produced depends upon the size of the cryoprobe tip, duration of freezing process and the gas used. +Modes of action +Cryopexy produces the required therapeutic effect by different modes which include tissue necrosis (as in cyclocryopexy and cryopexy for tumours), production of adhesions between tissues (e.g., between retina, pigment epithelium and choroid in retinal detachment), vascular occlusions (as in Coats’ disease) and adherence of the cryoprobe to the iceball in the tissue (as in cataract extraction). + + + + + + + + + + + +Fig. 20.1 Ophthalmic cryo unit + + +A + + + + +B + + + + +C + + + +D + + + + +Fig. 20.2 Cryoprobes: A and B, for cataract extraction straight and curved, respectively; C, for cyclocryopexy; and D, internal structure + +Uses +1. Lids. Cryosurgery may be used for following lesions: (i) Cryolysis for trichiasis, (ii) Cryotherapy for warts and Molluscumcontagiosum, (iii) Cryotherapy for basal cell carcinoma and haemangioma. +2. Conjunctiva.Cryotherapy is used for hypertrophied papillae of vernal catarrh. +3. Cornea. Herpes simplex keratitis may be treated by cryotherapy. +4. Lens. Cryoextraction of the lens used to be the best intracapsular technique. However, nowadays intracapsular cataract extraction (ICCE) is no more performed. +5. Ciliary body.Cyclocryopexy for absolute glaucoma and neovascular glaucoma. +6. Retina. (i) Cryopexy is widely used for sealing retinal holes in retinal detachment. (ii) Prophylactic cryopexy to prevent retinal detachment in certain prone cases. (iii) Anterior retinal cryopexy (ARC) in retinal ischaemic disease e.g., retinopathy of prematurity to prevent neovascularization. (iv) Cryo treatment of retinoblastoma and angioma. +Section V + + + +Systemic and Community Ophthalmology + + + + + + +Section Outline + +21. Systemic Ophthalmology 22. Community Ophthalmology +21 + +Systemic Ophthalmology + + + +Chapter Outline + +OCULAR MANIFESTATIONS OF SYSTEMIC DISEASES Introduction +Ocular manifestations of nutritional deficiencies Ocular manifestations of systemic infections +• +• +• +• +Ocular manifestations of common endocrinal and metabolic disorders + + + +OCULAR MANIFESTATIONS OF SYSTEMIC DISEASES +INTRODUCTION +Ocular involvement in systemic disorders is quite frequent. It is imperative for the ophthalmologists as well as physicians to be well conversant with these. Many a time, the ocular manifestations may be the presenting signs and the ophthalmologist will refer the patient to the concerned specialist for diagnosis and/or management of the systemic disease. While, in other cases the opinion for ocular involvement may be sought for by the physician who knows to look for it. +Ocular lesions of the common systemic disorders are enumerated and a few important ones are described here. +OCULAR MANIFESTATIONS OF NUTRITIONAL DEFICIENCIES +1. Deficiency of vitamin A. Ocular manifestations of vitamin A deficiency are referred to as xerophthalmia. +2. Deficiency of vitamin B1 (thiamine). It can cause corneal anaesthesia, conjunctival and corneal +dystrophy and acute retrobulbar neuritis. +3. Deficiency of vitamin B2 (riboflavin). It can produce photophobia and burning sensation +in the eyes due to conjunctival irritation and vascularisation of the cornea. + +• Ocular manifestations of common disorders of skin and mucous membranes +Ocular manifestations of haematological diseases OCULAR ABNORMALITIES IN TRISOMIES ADVERSE OCULAR EFFECTS OF COMMON SYSTEMIC DRUGS +• + + + +4. Deficiency of vitamin C. It may be associated with haemorrhages in the conjunctiva, lids, anterior chamber, retina and orbit. It also delays wound healing. +5. Deficiency of vitamin D. It may be associated with zonular cataract, papilloedema and increased lacrimation. +XEROPHTHALMIA +The term xerophthalmia is reserved (by a joint WHO and USAID Committee, 1976) to cover all the ocular manifestations of vitamin A deficiency, including not only the structural changes affecting the conjunctiva, cornea and occasionally retina, but also the biophysical disorders of retinal rods and cones functions. +Etiology +It occurs either due to dietary deficiency of vitamin A or its defective absorption from the gut. It has long been recognised that vitamin A deficiency does not occur as an isolated problem but is almost invariably accompanied by protein-energy malnutrition (PEM) and infections. +WHO classification (1982) +The new xerophthalmia classification (modification of original 1976 classification) is as follows: +XN Night blindness X1A Conjunctival xerosis X1B Bitot’s spots +468 Section V Systemic and Community Ophthalmology + + +X2 Corneal xerosis +X3A Corneal ulceration/keratomalacia affecting less than one-third corneal surface +X3B Corneal ulceration/keratomalacia affecting more than one-third corneal surface +XS Corneal scar due to xerophthalmia XF Xerophthalmic fundus. +Clinical features +1. X N (Night blindness). It is the earliest symptom of xerophthalmia in children. It has to be elicited by taking detailed history from the guardian or relative. 2.X1A (conjunctival xerosis).It consists of one or more patches of dry, lustreless, nonwettable conjunctiva (Fig. 21.1), which has been well described as ‘emerging like sand banks at receding tide’ when the child ceases to cry. These patches almost always involve the interpalpebral area of the temporal quadrants and often the nasal quadrants as well. In more advanced cases, the entire bulbar conjunctiva may be affected. Typical xerosis may be associated with conjunctival thickening, wrinkling and pigmentation. +3. X1B (Bitot’s spots). It is an extension of the xerotic process seen in stage X1A. The Bitot’s spot is a raised, silvery white, foamy, triangular patch of keratinised epithelium, situated on the bulbar conjunctiva in the interpalpebral area (Fig. 21.2). It is usually bilateral and temporal, and less frequently nasal. +4. X2 (corneal xerosis). The earliest change in the cornea is punctate keratopathy which begins in the lower nasal quadrant, followed by haziness and/or granular pebbly dryness (Fig. 21.3). Involved cornea lacks lustre. +5. X3A and X3B (corneal ulceration/keratomalacia). Stromal defects occur in the late stage due to colliquative necrosis and take several forms. Small + + + + + + + + + \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_16.txt b/notes/A K Khurana - Comprehensive Ophthalmology_16.txt new file mode 100644 index 0000000000000000000000000000000000000000..380a4d3d078f1907715653d29069635113d276b6 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_16.txt @@ -0,0 +1,1599 @@ + + + + + +Fig. 21.1 Xerophthalmia, stage X1A: Conjunctival xerosis + + + + + + + + + + + + + + +Fig. 21.2 Xerophthalmia, stage X1B: Bitot spots + + + + + + + + + + + + + +Fig. 21.3 Xerophthalmia, stage X2: Corneal xerosis + + +ulcers (1–3 mm) occur peripherally; they are characteristically circular, with steep margins and are sharply demarcated (Fig. 21.4). Large ulcers and areas of necrosis may extend centrally or involve the entire cornea. If appropriate therapy is instituted immediately, stromal defects involving less than one-third of corneal surface (X3A) usually heal, leaving some useful vision. However, larger stromal defects (X3B) (Fig. 21.5) commonly result in blindness. +6. XS (corneal scars). Healing of stromal defects results in corneal scars of different densities and sizes which may or may not cover the pupillary area (Fig. 21.6). A detailed history is required to ascertain the cause of corneal opacity. +7. XFc (Xerophthalmic fundus). It is characterized by typical seed-like, raised, whitish lesions scattered uniformly over the part of the fundus at the level of optic disc (Fig. 21.7). +Treatment +It includes local ocular therapy, vitamin A therapy and treatment of underlying general disease. +Chapter 21 Systemic Ophthalmology 469 + + + + + + + + + + + + + + +Fig. 21.4 Xerophthalmia, stage X3A: Keratomalacia involving less than one-third of corneal surface + + + +Fig. 21.7 Xerophthalmia stage XF: Xerophthalmic fundus + + + + + + + + + +Fig. 21.5 Xerophthalmia, stage X3B: Keratomalacia involving more than one-third of corneal surface + + + + + + + + + + + + + + +Fig. 21.6 Xerophthalmia, stage XS: Corneal scars + +1. Local ocular therapy. For conjunctival xerosis artificial tears (0.7% hydroxypropyl methyl cellulose or 0.3% hypromellose) should be instilled every 3–4 hours. In the stage of keratomalacia, fullfledged treatment of bacterial corneal ulcer should be instituted (see pages 104-105). +2. Vitamin A therapy. Treatment schedules apply to all stages of active xerophthalmia viz. XN, X1A, + +X1B, X2, X3A and X3B. Oral administration is the recommended method of treatment. However, in the presence of repeated vomiting and severe diarrhoea, intramuscular injections of water-miscible preparation should be preferred. The WHO recommended schedule is as given below: +i. All patients above the age of1 year (except women of reproductive age): 200,000 IU of vitamin A orally or 100,000 IU by intramuscular injection should be given immediately on diagnosis and repeated the following day and 4 weeks later. +ii. Children under the age of 1 year and children of any age who weigh less than 8 kg should be treated with half the doses for patients of more than 1 year of age. +iii.Women of reproductive age, pregnant or not: (a) Those having night blindness (XN), conjunctival xerosis (X1A) and Bitot’s spots (X1B) should be treated with a daily dose of 10,000 IU of vitamin A orally (1 sugar coated tablet) for 2 weeks. (b) For corneal xerophthalmia, administration of full dosage schedule (described for patients above 1 year of age) is recommended. +3.Treatment of underlying conditions such as PEM and other nutritional disorders, diarrhoea, dehydration and electrolyte imbalance, infections and parasitic conditions should be considered simultaneously. +Prophylaxis against xerophthalmia +The three major known intervention strategies for the prevention and control of vitamin A deficiency are: 1. Short-term approach. It comprises periodic administration of vitamin A supplements. WHO +470 Section V Systemic and Community Ophthalmology + + +recommended, universal distribution schedule of vitamin A for prevention is as follows: +i. Infants 6–12 months old and any older children who weigh less than 8 kg. 100,000 IU orally every 3–6 months. +ii. Children over 1 year and under 6 years of age 200,000 IU orally every 6 months. +iii.Lactating mothers 20,000 IU orally once at delivery or during the next 2 months. This will raise the concentration of vitamin A in the breast milk and therefore, help to protect the breastfed infant. +iv. Infants less than 6 months old, not being breastfed. 50,000 IU orally should be given before they attain the age of 6 months. +A revised schedule of vitamin A supplements being followed in India since August 1992, under the programme named as ‘Child Survival and Safe Motherhood (CSSM)’ is as follows: +• First dose (1 lakh IU)—at 9 months of age along with measles vaccine. +• Second dose (2 lakh IU)—at 18 months of age along with booster dose of DPT/OPV. +• Third dose (2 lakh IU)—at 2 years of age. 2.Medium-term approach. It includes food fortification with vitamin A. +3. Long-term approach. It should be the ultimate aim. It implies promotion of adequate intake of vitamin A rich foods such as green leafy vegetables, papaya and drumsticks (Fig. 21.8). Nutritional health education should be included in the curriculum of school children. +Note. The short-term approach has been mostly in vogue especially in Asia. The best option perhaps is a combination of all the three methods with a gradual weaning away of the short-term approach. + + + + + + + + + + + + + + + +Fig. 21.8 Rich sources of vitamin A + + +OCULAR MANIFESTATIONS OF SYSTEMIC INFECTIONS + +A. VIRAL INFECTIONS +Measles. Ocular lesions are: catarrhal conjunctivitis, Koplik’s spots on conjunctiva, corneal ulceration, optic neuritis and retinitis. +Mumps. Ocular involvement may occur as conjunctivitis, keratitis, acute dacryoadenitis and uveitis. +Rubella. Ocular lesions seen in rubella (German measles) are congenital microphthalmos, cataract, glaucoma, chorioretinitis and optic atrophy. Whooping cough. There may occur subconjunctival haemorrhages and rarely orbital haemorrhage leading to proptosis. +Ocular involvement in AIDS +AIDS (Acquired Immune Deficiency Syndrome) is caused by Human immuno deficiency virus (HIV) which is an RNA retrovirus. +Modes of spread include: +• Sexual intercourse with an infected person, • Use of infected hypodermic needles, +• Transfusion of infected blood, and +• Transplacental spread to foetus from the infected mothers. +Pathogenesis of AIDS. The HIV infects T-cells, T-helper cells, macrophages and B-cells and thus interferes with the mechanism of production of immune bodies thereby causing immunodeficiency. +Immunedeficiency renders the individuals prone to various infections and tumours, which involve multiple systems and finally cause death. +Ocular manifestations. These occur in about 75% of patients and sometimes may be the presenting features of AIDS in an otherwise healthy person or the patient may be a known case of AIDS when his eye problems occur. Ocular lesions of AIDS may be classified as follows: +1. Retinal microvasculopathy. It develops from vasoocclusive process which may be either due to direct toxic effects of virus on the vascular endothelium or immune complex deposits in the precapillary arterioles. It is characterised by nonspecific lesions (Fig. 21.9): +• Multiple ‘cottonwool spots’ occur in 50% cases, +• Superficial and deep retinal haemorrhages occur in 15–40% cases, and +• Microaneurysms and telangiectasia may also be seen rarely. +2. Usual ocular infections. These are also seen in healthy people, but occur with greater frequency +Chapter 21 Systemic Ophthalmology 471 + + + + + + + + + + + + + + + +Fig. 21.9 Retinopathy in AIDS + +and produce more severe infections in patients with AIDS. These include: +• Herpes zoster ophthalmicus, • Herpes simplex infections, +• Toxoplasmosis (chorioretinitis), and +• Ocular tuberculosis, syphilis and fungal corneal ulcers. +3.Opportunistic infections of the eye. These are caused by micro-organisms which do not affect normal patients. They can infect someone whose cellular immunity is suppressed by HIV infection or by other causes such as leukaemia. These include: +• Cytomegalovirus (CMV) retinitis (see page 268 Fig. 12.5), +• Candida endophthalmitis, • Cryptococcal infections, +• Pneumocystis carinii, and • Choroiditis. +4. Unusual neoplasms includes: +• Kaposi’s sarcoma is a malignant vascular tumour which may appear on the eyelid or conjunctiva as multiple nodules. It is seen in about 3% cases of AIDS. +• Burkitt’s lymphoma of the orbit is also seen in a few patients. +5. Neuro-ophthalmic lesions. These are thought to be due to CMV or other infections of the brain. These include: +• Cranial nerve palsies isolated or multiple resulting in paralysis of eyelids, extraocular muscles, +• Loss of sensory supply to the eye, +• Optic nerve involvement causing loss of vision. Management. It consists of the measures directed against the associated infection/lesions. For example: • CMV infections can be treated by zidovudine, +ganciclovir and foscarnet (see page 446). +• Kaposi’s sarcoma responds to radiotherapy. +• Herpes zoster ophthalmicus is treated by acyclovir. + +B. BACTERIAL INFECTIONS +1. Septicaemia. Ocular involvement may occur in the form of metastatic retinitis, uveitis or endophthalmitis. +2. Diphtheria. There may occur: membranous conjunctivitis, corneal ulceration, paralysis of accommodation and paralysis of extraocular muscles. +3. Brucellosis. It may involve the eye in the form of iritis, choroiditis and optic neuritis. +4. Gonococcal ocular lesions are: ophthalmia neonatorum, acute purulent conjunctivitis in adults and corneal ulceration. +5. Meningococcal infection may be associated with: metastatic conjunctivitis, corneal ulceration, paresis of extraocular muscles, optic neuritis and metastatic endophthalmitis or panophthalmitis. +6. Typhoid fever. It may be complicated by optic neuritis and corneal ulceration due to lagophthalmos. +7. Tuberculosis. Ocular lesions seen are granulomatous conjunctivitis, phlyctenular-keratoconjunctivitis, interstitial keratitis, nongranulomatous and granulomatous uveitis, Eales’ disease, optic atrophy (following chiasmal arachnoiditis secondary to meningitis), and papilloedema (due to raised intracranial pressure following intracranial tuberculoma). +8. Syphilitic lesions (acquired) seen in primary stage are conjunctivitis and chancre of conjunctiva. In secondary stage, there may occur iridocyclitis. Tertiary stage lesions include chorioretinitis and gummata in the orbit. Neurosyphilisis associated with optic atrophy and pupillary abnormalities. Ocular lesions of congenital syphilis are: interstitial keratitis, iridocyclitis and chorioretinitis. +9. Leprosy. Ocular lesions of leprosy include cut-aneous nodules on the eyelids, madarosis, interstitial keratitis, exposure keratitis, gran-ulomatous uveitis and dacryocystitis. +C. PARASITIC INFECTIONS +1. Toxoplasmosis is known to produce necrotising chorioretinitis (see page 164). +2. Taenia echinococcus infestation may manifest as hydatid cyst of the orbit, vitreous and retina. +3. Taenia solium infestation. Cysticercus cysts are known to involve conjunctiva, vitreous, retina, orbit and extraocular muscles. +4. Toxocara infestation may be associated with endophthalmitis (see page 165). +5. Onchocerciasis is a common cause of blindness in African countries. Its ocular features include +472 Section V Systemic and Community Ophthalmology + + +sclerosing keratitis, uveitis, chorioretinitis and optic neuritis invariably ending in optic atrophy. +D. FUNGAL INFECTIONS +Systemic fungal infections may be associated with: • Mycotic corneal ulceration, +• Fungal endophthalmitis, and • Fungal infections of orbit. +OCULAR MANIFESTATIONS OF COMMON ENDOCRINAL AND METABOLIC DISORDERS +Gout +Ocular lesions of gout include: • Episcleritis, +• Scleritis, and • Uveitis. +Diabetes mellitus +Ocular involvement in diabetes is very common. Structure-wise ocular lesions are as follows: +1. Lids. Xanthelasma and recurrent stye or internal hordeolum. +2. Conjunctiva. Telangiectasia, sludging of the blood in conjunctival vessels and subconjunctival haemorrhage. +3. Cornea. Pigment dispersal at back of cornea, decreased corneal sensations (due to trigeminal neuropathy), punctate kerotapathy, Descemet’s folds, higher incidence of infective corneal ulcers and delayed epithelial healing due to abnormality in epithelial basement membrane. +4. Iris. Rubeosis iridis (neovascularization). +5. Lens. Snowflake cataract in patients with IDDM, posterior subcapsular cataract, early onset and early maturation of senile cataract. +6. Vitreous. Vitreous haemorrhage and fibrovascular proliferation secondary to diabetic retinopathy. +7. Retina. Diabetic retinopathy and lipaemia retinalis (see page 276). +8. Intraocular pressure. Increased incidence of POAG, neovascular glaucoma and hypotony in diabetic ketoacidosis (due to increased plasma bicarbonate levels). +9. Optic nerve. Optic neuritis. +10.Extraocular muscles. Ophthalmoplegia due to diabetic neuropathy. +11.Changes in refraction. Hypermetropic shift in hypoglycemia, myopic shift in hyperglycemia and decreased accommodation. +Galactosemia +It is usually associated with congenital cataract (see page 193). +Homocystinuria +It is associated with bilateral subluxation of lens (see page 216). + +Mucopolysaccharidosis Ocular lesions include: • Corneal opacification, +• Pigmentary retinopathy, • Glaucoma, and +• Optic atrophy. + +Hyperthyroidism Ocular lesions include: +• Thyroid ophthalmopathy (see page 414), +• Superior limbic keratoconjunctivitis (see page 119), and +• Optic disc oedema. + +Hypoparathyroidism Ocular lesions include: • Fasciculation, +• Cataract, and +• Optic disc oedema. + +Wilson disease +Ocular lesions include: • Kayser-Fleisher ring • Sunflower cataract. +OCULAR MANIFESTATIONS OF COMMON DISORDERS OF SKIN AND MUCOUS MEMBRANES +1. Atopic dermatitis. It may be associated with conjunctivitis, keratoconus and cataract. +2. Rosacea. Its ocular lesions include blepharitis, conjunctivitis, keratitis and rosacea pannus. +3. Dermatitis herpetiformis. Its ocular complications include recurrent bullae, ulceration and cicatrization. +4. Epidermolysis bullosa. Ocular complications, when they occur, take the form of cicatrizing conjunctivitis and keratitis. +5. Stevens-Johnson syndrome. Stevens-Johnson syndrome is an acute illness often caused by hypersensitivity to drugs, particularly sulphonamides. It is characterized by acute ulceration of the conjunctiva and other mucous membranes like that of mouth and vagina. Conjunctival ulceration is followed by cicatrizing conjunctivitis. The clinical feature at this stage is the same as in ocular pemphigoid. +OCULAR MANIFESTATIONS OF HAEMATOLOGICAL DISEASES +1. Anaemias. Anaemic retinopathy may occur in severe anaemia of any etiology (see page 282). +2. Leukaemias. Ocular involvement in leukaemias may occur in the form of: +• Proptosis due to leukaemic deposits in the orbital tissue. +Chapter 21 Systemic Ophthalmology 473 + + +• Leukaemic retinopathy is of common occurrence in lymphocytic as well as myeloid leukaemias (see page 282). +3. Sickle cell disease. Ocular involvement may occur as: Dilated conjunctival vessels and Sickle cell retinopathy (see page 282). +4. Lymphomas may cause following ocular lesions: • Lid and/or orbital deposits, and uveitis. + +OCULAR ABNORMALITIES IN TRISOMIES + +Trisomy 13 (D Trisomy or Patau Syndrome) • Microphthalmos +• Colobomas (almost 100%) • Retinal dysplasia +• Cataract +• Corneal opacities +• Optic nerve hypoplasia • Cyclopia +• Intraocular cartilage. + +Trisomy 18 (E trisomy or Edwards syndrome) • Blepharophimosis +• Ptosis +• Epicanthal fold • Hypertelorism +• Microphthalmos • Uvealcoloboma +• Congenital glaucoma • Corneal opacities. +Trisomy 21 (G Trisomy or Down’s syndrome) +• Upward slanting palpebral fissure (Mongoloid slant) +• Almond-shaped palpebral fissure • Epicanthus +• Telecanthus +• Narrowed interpupillary distance • Esotropia (35% cases) +• High refractive errors • Cataract +• Iris hypoplasia • Keratoconus. +Ocular abnormalities in chromosomal deletion syndromes +Cri-du-Chat syndrome (5p.) • Hypertelorism +• Epicanthus +• Antimongoloid slant • Strabisums +Cri-du-Chat syndrome (11p.) • Aniridia + +• Glaucoma +• Foveal hypoplasia • Nystagmus +• Ptosis +Cri-du-Chat syndrome (13q.) • Retinoblastoma +• Hypertelorism +• Microphthalmos • Epicanthus +• Ptosis +• Coloboma • Cataract +De Grouchy syndrome (18q.) • Hypertelorism +• Epicanthus • Ptosis +• Strabismus • Myopia +• Glaucoma +• Microphthalmos (with or without cyst) • Coloboma +• Optic atrophy +• Corneal opacity. +Turner syndrome (XO) +• Antimongoloid slant • Epicanthus +• Ptosis +• Strabismus • Blue sclera +• Eccentric pupils • Cataract +• Colour blindness +• Pigmentary disturbances of fundus. + +ADVERSE OCULAR EFFECTS OF COMMON SYSTEMIC DRUGS + +CVS drugs +• Digitalis: Disturbance of colour vision, scotomas • Quinidine: Optic neuritis (rare) +• Thiazides: Xanthopsia (yellow vision), Myopia +• Carbonic anhydrase inhibitors: Ocular hypotony, Transient myopia +• Amiodarone: Corneal deposits +• Oxprenolol: Photophobia, Ocular irritation. +GIT drugs +• Anticholinergic agents: Risk of angle-closure glaucoma due to mydriasis, Blurring of vision due to cycloplegia (Occasional). +CNS drugs +• Barbiturates: Extraocular muscle palsies with diplopia, Ptosis, Cortical blindness +• Chloral hydrate: Diplopia, Ptosis, Miosis +474 Section V Systemic and Community Ophthalmology + + +• Phenothiazines: Deposits of pigment in conjunctiva, cornea, lens and retina, oculogyric crisis +• Amphetamines: Widening of palpebral fissure, dilatation of pupil, paralysis of ciliary muscle with loss of accommodation +• Monoamine oxidase inhibitors: Nystagmus, extraocular muscle palsies, optic atrophy +• Tricyclic agents: Pupillary dilatation (glaucoma risk), Cycloplegia +• Phenytoin: Nystagmus, Diplopia, Ptosis, Slight blurring of vision (rare) +• Neostigmine: Nystagmus, Miosis • Morphine: Miosis +• Haloperidol: Capsular cataract +• Lithium carbonate: Exophthalmos, oculogyric crisis +• Diazepam: Nystagmus. +Hormones +Female sex hormones +• Retinal artery thrombosis • Retinal vein thrombosis +• Papilloedema +• Ocular palsies with diplopia • Nystagmus +• Optic neuritis and atrophy • Retinal vasculitis +• Scotomas • Migraine • Mydriasis +• Cycloplegia +• Macular oedema. Corticosteroids +• Cataract (posterior subcapsular) +• Local immune suppression causing susceptibility to viral (herpes simplex), bacterial and fungal infections +• Steroid-induced glaucoma. +Antibiotics +Chloramphenicol +• Optic neuritis and optic atrophy • Streptomycin: Optic neuritis +• Tetracycline: Pseudotumour cerebri, Transient myopia. + +Antimalarial +Chloroquine +• Macular changes (Bull’s eye maculopathy) • Central scotomas +• Pigmentary degeneration of the retina • Chloroquine keratopathy +• Ocular palsies • Ptosis +• Electroretinographic depression. + +Amoebicides +• Diiodohydroxy quinoline: Subacute myelo-optic neuropathy (SMON), optic atrophy. + +Chemotherapeutic agents +• Sulfonamides: Stevens-Johnson syndrome • Ethambutoli: Optic neuritis and atrophy +• Isoniazid: Optic neuritis and optic atrophy + +Heavy metals +• Goldsalts: Deposits in the cornea and conjunctiva • Lead: Optic atrophy, Papilloedema, Ocular +palsies. + +Chelating agents +• Penicillamine: Ocular pemphigoid, Ocular neuritis, Ocular myasthenia. + +Oral hypoglycemic agents +• Chloropropamide: Transient change in refractive error, Diplopia, Stevens-Johnson syndrome +Vitamins +Vitamin A +• Papilloedema +• Retinal haemorrhages +• Loss of eyebrows and eyelashes • Nystagmus +• Diplopia and blurring of vision +Vitamin D +• Band-shaped keratopathy. + +Antirheumatic agents +• Salicylates: Nystagmus, Retinal haemorrhages, Cortical blindness (rare) +• Indomethacin: Corneal deposits +• Phenylbutazone: Retinal haemorrhages. +22 + +Community Ophthalmology + + + +Chapter Outline + +INTRODUCTION +BLINDNESS AND ITS CAUSES +• Definition of blindness • Magnitude of blindness • Global blindness +• Blindness in India +CAUSES Of BLINDNESS +• Global blindness • Blindness in India +• Developed versus developing countries GLOBAL INITIATIVES fOR +PREVENTION Of BLINDNESS +• WHO: Prevention of Blindness Programme + + + + +INTRODUCTION + +Community ophthalmology, over the years, has developed as an important branch of community medicine. Its activities emphasize the prevention of ocular diseases and visual impairment; reduction of ocular disability; and promotion of ocular health, quality of life and efficiency of a group of people at the community level. Thus, it can be defined as a system (rather than a branch of community medicine) which utilises the full scope of ophthalmic knowledge and skill, methodology of public health and services of other medical and nonmedical agencies to promote ocular health and prevent blindness at the community level with an active, recognised and crucial role of community participation. +The concept of community ophthalmology has become more relevant and essential to achieve the goal of `Vision 2020: The Right to Sight’ and to, accomplish the theme behind `Vision for the Future (VFTF). + +• Vision 2020:The Right to Sight • Vision for the future (VFTF) +NATIONAL PROGRAMME fOR CONTROL Of BLINDNESS IN INDIA +• Goals and major flips • Objectives +• Programme organization and implementation • Plan of action and activities +• Strategic plan for Vision 2020: Right to Sight in India +ROLE Of EyE CAMPS IN PREVENTION Of BLINDNESS EyE BANkING +REhABILITATION Of ThE BLIND + + + + +BLINDNESS AND ITS CAUSES + +DEFINITION OF BLINDNESS +Different definitions and terms for blindness such as total blindness, economic blindness, legal blindness and social blindness are in vogue in different countries so much so that 65 definitions of blindness are listed in a WHO publication (1966).1 In ophthalmology, the term blindness strictly refers to the inability to perceive light (PL absent). +WHO definition of blindness. In order to have comparable national and international statistics, the WHO in 1972 proposed a uniform criterion and defined blindness as, “Visual acuity of less than 3/60 (Snellen) or its equivalent”.2 In order to facilitate the screening of visual acuity by nonspecialised persons, in the absence of appropriate vision charts, WHO in 1979 added the “Inability to count fingers in daylight at a distance of 3 metres” to indicate vision less than 3/60 or its equivalent.3 +476 Section v Systemic and Community Ophthalmology + + +Visual field less than 10°, irrespective of the level of visual acuity is also labelled as blindness (WHO, 1977).4 +NPCB definition of blindness. Under national programme for control of blindness (NPCB) in India, blindness is defined as presenting distance visual acuity of < 6/60 or central visual fields < 20° in the better eye. +Other definitions of blindness in vogue are: +• Economic blindness: Vision in better eye <6/60 to 3/60 +• Social blindness: Vision in better eye <3/60 to 1/60. • Legal blindness: Vision in better eye <1/60 to +perception light +• Total blindness: No light perception (PL-ve). + +Categories of visual impairment +In the Ninth Revision (1977) of the International Classification of Diseases (ICD), the visual impairment (maximum vision less than 6/18 Snellen) has been divided into 5 categories. Categories 1 and 2 constitute “low vision” and categories 3, 4 and 5 constitute “blindness” (Table 22.1). Patients with the visual fields between 5° and 10° are placed in category 3 and those with less than 5° in category 4. +Table 22.1 Categories of visual impairment (WHO, 1977)4 + +Category of visual Level of visual acuity (Snellen) impairment +Normal vision 0 6/6 to 6/18 +1 Less than 6/18 to 6/60 2 Less than 6/60 to 3/60 +Low vision +3 Less than 3/60 (FC at 3 m) to 1/60 (FC at 1 m) or visual field between 5°and 10° +Blindness 4 Less than 1/60 (FC at 1m) to light perception or visual field less than 5° +5 No light perception + +Avoidable blindness +The concept of avoidable blindness includes both preventable blindness and curable blindness. Preventable blindness is that which can be easily prevented by attacking the causative factor at an appropriate time. For example, corneal blindness due to vitamin A deficiency and trachoma can be prevented by timely measures. +Curable blindness is that in which vision can be restored by timely intervention, e.g. cataract blindness can be cured by surgical treatment. + +MAGNITUDE OF BLINDNESS Magnitude of global blindness +The number of blinds across the globe is not within the exact realms of counts. However, from time to time, the World Health Organization (WHO) provides the estimates. +Statistics of blindness.According to WHO estimates5 is as below: +1. Blind due to eye diseases : 37 million +2. Blind due to refractive errors : 08 million 3. Blind due to all causes (1 + 2) : 45 million +4. Low vision due to eye diseases : 124 million +5. Low vision due to refractive errors : 145 million 6. Low vision (all causes) (4 + 5) : 269 million +7. Total visual impairment (blindness + low vision due to all causes) (3 + 6) : 314 million +• 90% of the world’s blind live in developing countries. +• More than 50% of world’s blind due to eye diseases live in: India (9 million), Africa (7 million) and China (6 million). +• Of the 37 million blinds due to eye diseases, the age wise distribution is: 0–14 yrs: 1.4 million, 15–49 yrs: 5.2 million, 50 yrs. or above: 30.3 million. +• Female to male blindness ratio varies from 1.5 to 2.2 : 1. +• About 85% of all visual impairment is avoidable gobally. +• Every 5 seconds, one person in our world goes blind. • Every minute one child goes blind. +• 75 millions will be blind due to eye diseases by 2020 (if trend continues). +Geographical distribution of global blindness +About 90% of the world’s blinds live in devel-oping countries and around 60% of them reside in sub-Saharan Africa, China and India. There is a significant difference in the level of blindness in the developing countries as compared to the developed countries of the world, as there are: +• 3 blind people/1000 population in developed countries of Europe, America and Japan, +• 9 blind people/1000 population in Asia, and • 12 blind people/1000 population in Africa. +Regional burden of blindness +For having an easy means of comparison among different regions of the world, a ratio referred to as the Regional Burden of Blindness (RBB) was evolved. This means the ratio of the proportion of the number of blind in a particular region to the global number of blind and the proportion of the regional population to the world population. The subSaharan Africa, India and other Asia and Islands have RBB +Chapter 22 Community Ophthalmology 477 + + +ratio greater than unity.6 This indicates that in these regions, the burden of blindness is to be taken into special consideration in terms of fixing priorities on a global scale. +Magnitude of blindness in India +While the problem of blindness is global, its magnitude is much higher in India. Of the estimated 45 million, India alone has 9 million blind people, which comes to onefifth of the total in the world.5 The prevalence of blindness in India, as determined by the three major surveys conducted in the last 4 decades and a Rapid Assessment of Avoidable Blindness (RAAB) in India 2007 is as below: +Prevalence Source +1.38% ICMR (1971–74)7 1.49% WHO-NPCB (1986–89)8 1.1% NPCB (2001–2002)9 +1% RAAB (2006–2007)10 +Constraints in controlling blindness in India +The Working Group identified following major-constraints in controlling blindness in India: +• Inequitable distribution of eye surgeons +• Suboptimal utilization of human resources +• Inadequate number of paramedical eye care personnel +• Variation in quality +• Suboptimal coverage +• Overemphasis on cataract • Lack of public awareness • Prevalence of infections +• Man-made blindness due to quack practice and home remedies. +CAUSES OF BLINDNESS Causes of global blindness +Major causes of blindness and the estimated number of blinds (%) due to them are as under:5 +• Cataract 17.6 million (39%) • Glaucoma 4.5 million (10%) • Corneal scarring 1.3 million (3%) +including trachoma +• Age-related macular- 3.2 million (7%) degeneration +• Diabetic retinopathy 1.8 million (4%) • Childhood blindness >1.4 million (3%) +including xerophthalmia +• Onchocerciasis 0.3 million (0.7%) • Others 10 million +Causes of blindness in India +The problem of blindness in India is not only of its gigantic size, but also of its causes, which are largely + +preventable or curable with the present available knowledge and skill. Three major population based surveys and one rapid assessment of avoidable blindess (RAAB) survey have been carried out in India to estimate the magnitude and causes of blindness. These surveys have shown that trends in blindness continue to change, though the major causes of blindness still continue to be the same (Table 22.2).7-10 +Developed versus developing countries +The main causes of blindness in developed countries are different from those of developing countries. +• In developed countries, 50% of all blindness is because of age-related macular degeneration (ARMD), while another 10–20% each is because of glaucoma, diabetic retinopathy and cataract. +• In developing countries the frequent causes are cataract, infectious diseases, xerophthalmia, injuries, glaucoma, and onchocerciasis. + +GLOBAL INITIATIVES FOR PREVENTION OF BLINDNESS +The concept of avoidable blindness (i.e. preventable or curable) has gained increasing recognition during the last three decades. International Agency for the Prevention of Blindness (IAPB) formed in 1975, is an international nongovernmental agency which has a close and complementary relationship with WHO (an international intergovernmental agency in the field of prevention of blindness). +The major global initiatives taken for prevention of blindness are: +• WHO: Prevention of Blindness Programme (PBP) (1978) +• Vision 2020: The Right to Sight (1999), and • Vision For the Future (VFTF) (2001). +WHO: PREVENTION OF BLINDNESS PROGRAMME +The WHO launched the ‘Prevention of Blindness Programme (WHO: PBL)’ in 1978. In accordance with which many countries have already come up with a ‘National Blindness Control Programme’. +Control strategies suggested by WHO include: +1. Assessment of common blinding disorders at local, regional and national levels. +2. Establishment of national level programmes for control of blindness suited to the national and local needs. +3. Training of eye care providers. +4. Operational research to improve and apply appropriate technology. +478 Section v Systemic and Community Ophthalmology + +Table 22.2 Major causes of blindness in India + +RAAB Survey (2006-07)10 NPCB Survey (2001-02)9 WHO-NPCB Survey ICMR Survey (1971-74)7 (1986-89)8 + +Disease condition + +Cataract +Refractive errors (0.7%) + aphakia (5.6%) +Glaucoma Complications of +cataract surgery Corneal opacity +including trachoma Posterior segment +disorders (DR, 0.1% + ARMD 0.7% + others 2.2%) + +Percent blindness +72.2 6.3 + +4.4 3.0 + +6.5 + +3.0 + +Disease condition +Cataract Refractive errors Glaucoma Posterior segment disorders Surgical complications Corneal blindness Others + +Percent blindness +62.6 19.7 5.8 4.7 + + +1.2 + +0.9 + +5.0 + +Disease condition +Cataract Refractive errors Glaucoma Trachoma Aphakic blindness Corneal opacity + +Others + +Percent blindness +80.10 7.35 + +1.70 0.39 4.67 + +1.52 + + +4.25 + +Disease condition +Cataract Malnutrition Glaucoma Trachoma and associated infections Injuries Small pox seaquele Others + +Percent blindness +55.0 2.0 0.5 20.0 + + + +1.2 3.0 + +18.0 + + + + +VISION 2020: THE RIGHT TO SIGHT +‘Vision 2020: The Right to Sight,11 is a global initiative launched by WHO in Geneva on Feb. 18,1999 in a broad coalition with a ‘Task Force of International Non-Governmental Organisations (NGOs)’ to combat the gigantic problem of blindness in the world. +Partners, objective and implementation Partners of Vision 2020: Right to Sight +I. World Health Organization (WHO), +II. Task Force of International NGOs, which has following members: +• International Agency for Prevention of Blindness (IAPB) +• Christopher Blindness Mission (CBM) • Helen Keller International +• ORBIS International +• Sight Savers International • A1 Noor Foundation +• International Federation of Ophthalmological Societies +• Lions Clubs International Foundation • Operation Eye Sight Universal +• The Carter Centre. +objective of vision 2020 +Objective of this new global initiative is to eliminate avoidable blindness by the year 2020 and to reduce the global burden of blindness which currently +affects an estimated 45 million people worldwide. + + +implementation of vision 2020 +Vision 2020 is being implemented through four phases of five year plans, the first one started in 2000, second in 2005 and third in 2010. The last phase of implementation will commence from 2015. + +Strategic Approaches: Global Perspective Strategic approaches of Vision 2020: Right to Sight (Global perspective) are: +• Disease prevention and control, • Training of eye health personnel, +• Strengthening of existing eye care infrastructure, • Use of appropriate and affordable technology,and • Mobilization of resources. + +A. Disease prevention and control +Globally, WHO has identified five major blinding eye conditions, for immediate attention to achieve the goals of Vision 2020, which are: +• Cataract, +• Childhood blindness, • Trachoma, +• Refractive errors and low vision, and • Onchocerciasis. +These conditions have been chosen on the basis of their contribution to the burden of blindness, feasibility and affordability of interventions to control them. Each country will decide on its priorities based on the magnitude of specific blinding conditions in that country. +Chapter 22 Community Ophthalmology 479 + + +1. Cataract +Cataract remains the single largest cause ofblindness. There is an estimated figure of 17.6 million (39%) people worldwide who are blind because of curable cataract.5 +Aim under `Vision 2020’ is to eliminate avoidable blindness due to cataract by the year 2020 by performing cataract extraction with intraocular lens (IOL) implantation. +Strategy to achieve the aim to measure the increase in the cataract surgery rate (CSR), i.e. number of cataract surgeries per million population per year as below: + +Year Global cataract Global number of surgical rate targets cataract operation +targets (million) +2000 2000 12 2010 3000 20 2020 4000 32 + +Emphasis is to be placed on achieving: +• High success rates in terms of restored vision and quality of life outcome +• Affordable and accessible services +• Measures to overcome barriers and increased use of services. +2. Childhood blindness +Childhood blindness is considered a priority area due to the number of years of blindness that ensues. Prevalence is 0.5–1 per 1000 children, aged 0–15 years. There are 1.4 million blind children estimated in the world of whom 1 million live in Asia and 3 lakhs in Africa. There are 5 lakh children going blind each year (one per minute) also. +Causes of childhood blindness vary from place to place and change over time. The main causes include: Vitamin A deficiency, measles, conjunctivitis, ophthalmia neonatorum, congenital cataract and retinopathy of prematurity (ROP). +Aim is to eliminate avoidable causes of childhood blindness by the year 2020. +Strategies. Vision 2020 envisages following strat-egies: +• Strengthening primary eye care programmes within primary healthcare to eliminate preventable causes. +• Developing therapeutic and surgical support services to deal effectively with curable eye problem. +• Establishing optical and low vision services. Activities. Under the global initiative vision 2020 include: + +I.Elimination of preventable blindness by: • Measles immunisation, +• Vitamin A supplementation (see page 469), +• Monitoring use of oxygen in the premature newborn, +• Avoidance of harmful traditional practices, +• Promoting school screening programmes for diagnosis and management of common conditions like refractive errors and trachoma in endemic areas, and +• Promoting eye health education in schools. II.Management of surgically avoidable causes of +childhood blindness such as cataract, glaucoma, and retinopathy of prematurity (ROP). +3. Trachoma blindness +Trachoma is a leading cause of preventable blin-dness worldwide with an estimated 5.9 million persons blind or at immediate risk because of trichiasis.11 The disease accounts for nearly onesixth of the global burden of blindness. In India, blindness due to trachoma (0.39%, WHO-NPCB 1986-89) is on the decline when compared with previous figures (20%,ICMR 1975). The RAAB survey (2006–07) have reported trachoma blindness to be 0.6%. +Effective interventions have been demonstrated in developing nations using the SAFE strategy: +• Surgery to correct lid deformity and prevent blindness, +• Antibiotics for acute infections and community control, +• Facial hygiene, and +• Environmental change including improved access to water and sanitation and health education. +Elimination of blindness due to trachoma is considered feasible, eradication of trachoma is not. Trachoma has disappeared from North America and Europe because of improved socioeconomic conditions and hygiene. Research needs include validation of rapid community assessment techniques, identification of barriers to the acceptance of preventive surgical procedure, studying effectiveness of annual treatment cycles and cost-effective studies. W.H.O. has organized an Alliance for Global Elimination of Trachoma by the year 2020 (GET 2020). +4. Refractive errors and low vision +Aim is to eliminate visual impairment (visual acuity less than 6/18) and blindness due to refractive errors or other causes of low vision. It is estimated that there are 35 million people in the world who require low vision care and 8 million (18%) are blind due to refractive errors.5 +480 Section v Systemic and Community Ophthalmology + + +Strategies recommended under `Vision 2020’ initiative include: +• Create awareness for refractive errors and demand for refractive services. +• Screening to identify individuals with poor vision which can be improved by spectacles or other optical devices. +• Refraction services to be made available to individuals identified with significant refractive errors. +• Ensure optical services to provide affordable spectacles for individuals with significant refractive errors. +• Low vision services and low vision aids to be provided for all those in need. +5. Onchocerciasis +Onchocerciasis (river blindness) is known to be endemic in 37 countries. An estimated 17 million people are infected with onchocerciasis. Approximately 0.3 million (0.7%) people are blind from the disease worldwide.5 About 95% of infected persons reside in Africa, where the disease is most severe along the major rivers in 30 countries. Outside Africa, the disease occurs in Mexico, Guatemala, Ecuador, Columbia, Venezuela and Brazil in the America, and in Yemen in Asia. +Aim is to eliminate blindness due to onchocerciasis by the year 2020. +Target is to develop `National Onchocerciasis Control Programme’ with satisfactory coverage in all the 37 countries where disease is endemic. +Strategy is to introduce community directed treatment with annual doses of Mectizan (ivermectin). The disease in expected to be brought under control by the year 2010, if present efforts in endemic countries are successfully implemented. + +Strategic Plan for ‘Vision 2020’: The Right to Sight in india +It is described under National Programme for Control of Blindness in India (see page 482 ). +VISION FOR THE FUTURE (VFTF) +Vision for the future (VFTF): International Ophth-almology Strategic Plan to Preserve and Restore Vision,12 launched in Feb 2001, is another global initiative (in addition to Vision 2020) for prevention of blindness. +Implementation of this programme is being done by International Council of Ophthalmology (ICO) by working closely with other international, supranational and national organizations. It is parallel to and complementary of ‘Vision 2020’. Care is being taken to avoid duplication. + +Top priorities for action of this programme are: +• Enhancement of ophthalmology residency training around the world, particularly through definition of principles, guidelines and curricula. +• Development of model guidelines and recommendations for ophthalmic clinical care in critical disease areas. +• Dissemination of sample curricula for training of medical students and allied health personnel. +• Advocacy and support for ‘Vision 2020: Right to Sight’, particularly by encouraging national ophthalmologic societies to support the initiative and become involved. +• Helping national ophthalmologic societies develop more effective organizations. + +NATIONAL PROGRAMME FOR CONTROL OF BLINDNESS (NPCB) IN INDIA + +GOALS AND MAjOR FLIPS +India was the first country in the world to launch the ‘National Programme for Control of Blindness (NPCB)’ in year 1976 as 100% centrally sponsored programme with the following goals: +• To provide comprehensive eye care facilities for primary, secondary and tertiary levels of eye healthcare, and +• To reduce the prevalence of blindness in population from 1.38% (ICMR 1971-174) to 0.31 by 2000 AD. +Major flips in NPCB include: +• Inclusion in `Prime Minister’s-20 point programme’ in 1982, was the first major flip for NPCB.Launching of `Cataract Blindness Control Project’ assisted by World Bank from 1994–2001 was another major flip for NPCB. This project was launched to reduce the cataract back-log in 7 States which were identified to have the highest prevalence of cataract blindness by WHO-NPCB survey (1986–89). These, in descending order, are: Uttar Pradesh, Tamil Nadu, Madhya Pradesh, Maharashtra, Andhra Pradesh, Rajasthan and Orissa. +• Adoption of vision 2020: Right to Sight in 2001 is the most prestigious major flip for NPCB. +OBjECTIVES +Vision 2020 has been adopted in NPCB with the objective to eliminate avoidable blindness by the year 2020. +Present objectives of the NPCB include: +• Reduction in the backlog of blindness through identification and treatment of blinds. +• Development and strengthening of comprehensive eyecare facilities in every district. +Chapter 22 Community Ophthalmology 481 + + +• Development of human resources for providing eye care services. +• Improvement in quality of service delivery. +• Securing participation of voluntary organizations and private practitioners in eye care. +• Enhancement in community awareness on eye care. • Setting up of mechanism for referral, coordination and feedback between organizations dedicated to +prevention, treatment and rehabilitation. + +PROGRAMME ORGANIZATION AND IMPLEMENTATION +Since 2001, NPCB is being implemented as per guidelines of the initiative ‘Vision 2020’(described later). During 12th five year plan (2012-2017), from the financial year 2013-14, it has been decided to continue the NPCB under the NCD flexipool within the overarching umbrella of the recently approved ‘National Health Mission’. The contribution of the central government will be 75% and that of state/UT government will be 25% of the total fund requirement for NPCB. +Various programme activities implemented at central, state and district levels are as follows:13 +1. Central level +At the central level, programme organization is the responsibility of the ‘National Programme Management Cell’ located in the office of Director General Health Services (DGHS), Department of Health, Government of India (GOI). To oversee the implementation of the programme three national bodies have been constituted as below: +• National Blindness Control Board, chaired by Secretary Health to GOI. +• National Programme Coordination Committee, chaired by Additional Secretary to GOI. +• National Technical Advisor Committee, headed by Director General Health Services, GOI. +Central level activities include: +1. Procurement of goods (major equipments, bulk consumables, vehicles, etc.) +2. Nonrecurring grant-in-aid to NGOs. +3. Organizing central level training courses. +4. Information, education and communication (IEC) activities (prototype development and mass media). +5. Development of MIS, monitoring and evaluation. 6. Procurement of services and consultancy. +7. Salaries of additional staff at the central level. + +2. State level +The NPCB is implemented through the State Government. A ‘State Programme Cell’ is already in place. All the work related to blindness control + +shall be routed through State Programme Officer/ Joint Director (ophthalmology) in charge of NPCB. The Joint Director shall submit it to Director Health Services for final approval in accordance with the latest norms and parameters laid down for the 12th five year plan. +State level activities include: +• Execution of civil works for new units. +• Repairs and renovation of existing units/ equipments. +• State level training and IEC activities. • Management of State Project Cell. +• Salaries for additional staff. +‘State Blindness Control Society’ (SBCS) is being established in each state for monitoring and implementing the programme at the state level. The SBCS will release grant-in-aid to District Blindness Control Societies (DBCS) for various activities. +3. District level +Under ‘National Health Mission’ the programme activities are to be implemented through ‘District Health Societies’. +To organize the programme at district level, ‘District Blindness Control Societies’ have been established. +District blindness control society +The concept of ‘District Blindness Control Society (DBCS)’ has been introduced, with the primary purpose to plan, implement and monitor the blindness control activities comprehensively at the district level under overall control and guidance of the ‘National Programme for Control of Blindness’. This concepthasbeenimplementedafterpioneering work by DANIDA in five pilot districts in India. Objective of DBCS establishment is to achieve the maximum reduction in avoidable blindness in the district through optimal utilisation of available resources in the district. +Need for establishment of DBCS was considered because of the following factors: +1. To make control of blindness a part of the Government’s policy of designating the district as the unit for implementing various development programmes. +2. To simplify administrative and financial procedures. 3. To enhance participation of the community and +the private sector. +Composition of DBCS. Each DBCS will have a maximum of 20 members, consisting of 10 ex-officio and 10 other members with following structure: +• Chairman: Deputy Commissioner/District Magistrate. +482 Section v Systemic and Community Ophthalmology + + +• Vice Chairman: Civil Surgeon/District Health Officer. +• Member Secretary: District Programme Manager (DPM) or District Blindness Control Coordinator (DBCC), who is appointed by the Chairman. DPM will coordinate the activities of the programme between the government and nongovernment organizations (NGOs). +• Members will include District Eye Surgeon, District Education Officer, President local IMA branch, President Rotary Club, representatives of various NGOs and local voluntary action groups. The ex-officio members will be the members of the society as long as they hold the post. The term of other members is notified by the Chairman. +• Advisor of the society is the State Programme Manager. +• Technical guidance is provided by the Chief Ophthalmic Surgeon/Head of the Ophthalmology Department of Medical College. +Present status. Till date more than 600 DBCSs have been established. +Revised strategies adopted for implementation of programme at district level are: +1. Annual district action plan is to be submitted by DBCS. Funding will be in two instalments through GOI/SBCS. +2. NGO participation made accountable; allotted area of operation. +3. Revised guidelines for DBCS—capping of expenditure; phasing out contract managers. +4. Emphasis on utilization of existing government facilities. +5. Gradual shift from camp surgery to institutional surgery. +6. Development of infrastructure and manpower for IOL surgery. + +PLAN OF ACTION AND ACTIVITIES +The basic plan of action and activities of NPCB, since its inception in 1976, includes the following:13 +i. Extension of eye care services +ii. Establishment of permanent infrastructure +Primary Eye Care, at peripheral level (PHCs and subcentres) is being strengthened by: +• Providing necessary equipment, +• Posting a paramedical ophthalmic assistant, and • Organising refresher courses for doctors and other +staff of PHC on prevention of blindness. Community ophthalmic practice at primary care level is summarized in Table 22.3. Currently, the programme implementation is sub-sumed under ‘National Rural Health Mission’ (NRHM). Secondary Eye Care, at intermediate level, +Tertiary Eye Care, at central level, and +Center of Excellence, at apex level for high quality tertiary eye care, and to provide guidance and leadership for technical matters. +iii. intensification of eye health education. +Note.For the above activities Government of India has adopted ‘Vision 2020: Right to Sight’ under ‘National Programme for Control of Blindness’ at a meeting held in Goa on October 10–13, 2001 and constituted a working group to plan the action and activities. +STRATEGIC PLAN FOR VISION 2020: THE RIGHT TO SIGHT IN INDIA +The draft plan of action submitted by the ‘Working Group’ to the Ministry of Health and Family Welfare Govt. of India in August, 2002 includes following strategies:14 +A. Strengthening advocacy +B. Reduction of disease burden +C. Human resource development, and D. Eye care infrastructure development. + + +Table 22.3 Community ophthalmology practice at primary level + + +Promotive +• Nutrition education +• Improved maternal and child nutrition +• Health education • Face washing +• Good antenatal care • Safe water +• Improved environmental sanitation + +Preventive +• Ocular prophylaxis at birth +• Vitamin A doses • Measles vaccine • Perinatal care +• Avoid medication in pregnancy +• Avoid hypoxia at birth +• Examine neonate’s eyes +• Nutrition supplementation + +Curative +• Vision screening +• Treatment for vitamin A deficiency +• Referral for surgery +• Emergency management • Treatment for trachoma +• Treatment for other common eye diseases + +Rehabilitative +• Provision of low vision services +• Community based rehabilitation +• Counselling of the incurable blind +• Certification of blind by eye surgeon +• Sensitise about concessions +Chapter 22 Community Ophthalmology 483 + + +A. Strengthening advocacy +To strengthen advocacy and generate public awareness various activities are proposed at national, state, and district level under Vision 2020 initiative in India. +National and state level +■Public awareness and information about eye care and prevention of blindness by: +• Frequent press releases and articles in leading newspapers of the country, +• Increased frequency of broadcast and telecast of messages on eye care, and +• Introduction of topics on eye care in school curricula. +■Involvement of professional organizations such as All India Ophthalmological Society (AIOS), Eye Bank Association of India (EBAI) and Indian Medical Association (IMA) in the National Programme for Control of Blindness. +■Publishing quarterly newsletters, articles in scientific journals and developments of prototype print materials. +District level +• To strengthen the functioning of District Blindness Control Society (DBCS). +• To enhance involvement of NGOs, local community societies and community leaders. +• To strengthen hospital retrieval programmes for eye donation through effective grief counselling by involving volunteers, Forensic Deptt., Police, etc. +• Public awareness activities based on local needs through effective media. +• Strong interpersonnel communication through village-based link workers, aphakic motivators and community leaders. +• Multisectoral approach particularly involving departments of education, social welfare, media, etc. +B. Reduction of disease burden (disease-specific approach) +Target diseases identified for intervention under ‘Vision 2020’ initiative in India include: +• Cataract, +• Childhood blindness, +• Refractive errors and low vision, • Corneal blindness, +• Diabetic retinopathy, • Glaucoma, and +• Trachoma (focal). +1. Cataract +Cataract continues to be the single largest cause of blindness. According to latest National Survey + + +in India (1999–2001), 62.6% of blindness in 50+ population of India was found to be cataract related. During ‘Rapid Assessment of Avoidable Blindness (RAAB)’ conducted in 2006–07, the cataract is reported to be responsible for 72.2% of blindness in 50+ population. +Objective. To improve the quantity and quality of cataract surgery. +Targets as per Vision 2020 include: +• Targets for Cataract Surgery Rate (CSR) fixed in the vision 2020 strategy were 4500 per match the year by 2005, 5000 by 2010, 5500 by 2015 and 6000 by 2020. +• To improve the visual outcome of surgery to match the standards set by WHO (i.e. 80% to have visual outcome 6/18 or >6/18 after surgery). +• IOL surgery for >80% by the year 2005 and for all by the year 2010. +• YAG capsulotomy services at all district hospitals by 2010. +Strategic activities to clear backlog of cataract include: • Primary screening by community health worker to identify persons with visual impairment (finger +counting < 6 m in any eye). +• Case selections by eye surgeons at screening camps and at base level (district hospital). +• Cataract extraction with IOL implantation to be done free of cost for bilateral cases and under served poor people, especially women. +• Reduction in disparities based on geographical, socioeconomic and gender based. +Grant-in aid for cataract surgery may continue to be released through DBCS. +Target for 12th plan (2012–2017) is to perform 3.3 crore cataract operations with above 95% being IOL implantations. +2. Childhood blindness +Childhood blindness is an important public health problem in developing countries due to its social and economic implications. Though prevalence of childhood blindness is low as compared to blindness in the aged, it assumes significance due to large number of disability years of every child remaining blind. Extent and causes of problem. Prevalence of childhood blindness in India has been projected to be 0.8/1000 children by using the correlation between under five mortality rate and prevalence. Currently, there are about 270,000 blind children in India. +Common causes of childhood blindness are vitamin A deficiency, measles, conjunctivitis, ophthalmia neonatorum, injuries, congenital cataract, retinopathy of prematurity (ROP), and childhood glaucoma. +Refractive errors are the commonest cause of visual impairment in children. +484 Section v Systemic and Community Ophthalmology + + +Aim is to eliminate avoidable causes of childhood blindness by the year 2020. +Strategies and activities under Vision 2020: Right to Sight initiative in India include: +1. Detection of eye disorders. Following schedule of ophthalmic examination of children is recommended to identify early childhood disorders, refractive errors, squint, amblyopia and corneal diseases: +• At the time of primary immunization, • At school entry, and +• Periodic check up every 3 years for normal and every year for those with defects. +2. Preventable childhood blindness to be taken care of through cost effective measures: +• Prevention of xerophthalmia is of utmost value in preventing childhood blindness (see page 469). +• Prevention and early treatment of trachoma by active intervention (see page 71 and 485). +• Refractive errors to be corrected at primary eye care centres. +• Childhood glaucomas to be treated promptly. +• Harmful traditional/practices need to be avoided. • Prevention of ROP by proper screening and monitoring use of oxygen in premature newborns. 3. Curable childhood blindness due to cataract, ROP, corneal opacity and other causes to be taken care of by the experts at secondary and tertiary level eye +care services. Targets include: +• Establishment of Paediatric Ophthalmology units. In India, 50 Pediatric Ophthalmology were to be established by 2010 for effective management of childhood diseases. +• Establishment of refraction services and low vision centers (see below). +3. Refractive errors and low vision +According to ‘Rapid Assessment of Avoidable Blindness (RAAB)’ conducted in 2006–2007, refractive errors including uncorrected aphakia were responsible for 6.3% of blindness and 35.6 (32.9 + 2.7) % of low vision. Aim and strategies are same as described for `Vision 2020’ Global initiative (see page 477). +Targets. To combat refractive error and low vision following targets have been set in India: +• Refraction services to be available in all primary health centres by 2010. Availability of low-cost, good quality spectacles for children to be insured. +• Low vision service centres are to be established at 150 tertiary level eye care institutions. 50 such centres are to be developed by 2010, another 50 by 2015 and the final 50 by 2020. + + +4. Glaucoma +As per the ‘National Survey on Blindness’ (1999–2001, Govt. of India Report 2002) glaucoma is responsible for 5.8% cases of blindness in 50+ population and as per RAAB (2006–07) the corresponding figure is 4.4%.10 Effective intervention for prevention of glaucoma resultant blindness is quite difficult. Failure of early detection of the disease poses a management problem towards controlling glaucomatous blindness. Population based screening of glaucoma is not recommended as a strategy in developing countries. Following measures are recommended for opportunistic glaucoma screening (case detection) by tonometry and fundus examination: +• Opportunistic screening at eye care institutions should be done in all persons above the age of 35 years, those with diabetes mellitus, and those with family history of glaucoma. +• Community based referral by multi-purpose workers of all persons with diminution of vision, coloured haloes, rapid change of glasses, ocular pain and family history of glaucoma. +• Opportunistic screening at eye camps in all patients above the age of 35 years. +5. Diabetic retinopathy +Diabetic retinopathy (DR) is emerging as an important cause out of 4.7% cases of blindness due to posterior segment disorders in 50+ population (National Survey 1999–2001).9 To prevent visual loss occurring from diabetic retinopathy a periodic follow-up (see page 280) is very important for timely intervention. Following recommendations are made: • Awareness generation by health workers. +• All known diabetics to be examined and referred to Eye Surgeon by the Ophthalmic Assistant. +• Confirmation by fundus fluorescein angiography (FFA) and laser treatment of diabetic retinopathy at tertiary level. +• The strategy must be to bring down the medical management of DR at the secondary level. +6. Corneal blindness +Background. A significant number of cases of visual impairment and gross degree of loss of vision occur due to diseases of the cornea. According to NPCB survey (2001-02),9 corneal blindness accounts for 0.9% of total blindness while according to RAAB (2006–07) corneal opacities including trachoma account for 6.5% cases of blindness. It is reported that there is an addition of 25,000 to 30,000 corneal blindness cases every year in the country. Majority of these persons are affected in the first and second decade of life. +Chapter 22 Community Ophthalmology 485 + + +Major causes of this blindness are corneal ulcers due to infections, trachoma, ocular injuries and keratomalacia caused by nutritional deficiencies. Thus, corneal blindness is one of the outstanding problems in the field of preventive and community ophthalmology and is a great challenge to the medical profession in general and ophthalmolgists in particular. This challenge can be faced boldly by the combined efforts of the public and the government; especially the education department, school teachers, general medical practitioners and ophthalmologists. +Objective regarding corneal blindness under ‘Vision 2020’ in India is: +• To reduce prevalence of preventable and curable corneal blindness. +Strategies for control of corneal blindness are: i. General strategies include: +• Identification of infants at risk in cooperation with RCH programme to take appropriate measures. +• Identification of pre-school children at risk by door to door survey. +• Identification of school children through school health services. +• Identification of senior citizens with post cataract surgery bullous keratopathy. +• To ensure supply of essential drugs required for primary care such as: Tetracycline eye ointment, antibiotic eye drops, and vitamin A supplements. +ii. Disease-specific strategies are as below: +1. Eye infectionsincluding ophthalmia neonatorum. Ocular prophylaxis at birth with broad-spectrum antibiotics is very important. Health education and improvement in personal hygiene will reduce the incidence of conjunctivitis, corneal ulcer and other eye infections. Early treatment of eye infections will prevent corneal blindness. +2. Eye injuries. Education of people regarding avoidance of ocular trauma like cracker blast, industrial accidents, road accidents and other trauma, thereby reducing irreversible corneal blindness. Ocular trauma cases should be immediately referred to specialists for effective management. Facilities for administrating general anaesthesia for ocular trauma patients at secondary eye care level. +3. Trachoma blindness. In India, the corneal blindness due to trachoma (0.39% WHO-NPCB, 1986–88) is on the decline when compared with previous figures (20% ICMR 1975). RAAB (2006-07) reports 0.6% incidence of trachoma blindness. However, in isolated pockets (focal) blindness related to trachoma continues to be important. + +(For prevention of trachoma blindness see page 71 and 479. +4. Prevention of xerophthalmia will make a strong dent in the number of corneal blinds. The three major known intervention strategies for the prevention and control of vitamin A deficiency are described on page 469. +5. A total ban should be placed on the ophthalmic practice by quacks and sale of harmful eye medicines especially various ‘surmas’. +6. Protective measures for the eyes of industrial workers and agriculturists should include use of goggles and eye shades. +iii. Keratoplasty and eye banking. There is a need of around 1.4 lakh corneas per year for transplantation to clear the backlog of corneal blindness. Currently we are collecting around 25000 eyes per year. As keratoplasty operation can restore vision in a significant number of corneal blinds, an intensive publicity and cooperation of government and nongovernment agencies is needed to enhance the voluntary eye donations. Under NPCB, eye donation fortnight is organized from 25th August to 8th Sept. every year to promote eye donation. More eye banks should be established and more ophthalmic surgeons should be trained for corneal grafting. Under Vision 2020: Indian initiative emphasis is on hospital retrieval system to get better donor material. Death certificates should bear one line on eye donations. +C. Human resource development +For ‘Vision 2020’ initiative in India, the human resource needs identified to combat blindness by 2020 are depicted in Table 22.4. +Mid-Level Ophthalmic Personnel (MLOP). The term MLOP has been introduced to include all categories of paramedics who work full time in eye care. Broadly two streams of such personnels are envisaged: +1. Hospital-based MLOP. These include ophthalmic nurses, ophthalmic technicians, optometrists, and orthoptists, etc. +2. Community-based MLOP include those with outreach/field functions such as primary eye care workers and ophthalmic assistants. +D. Eye care infrastructure development +Based on the recommendations of WHO, there is a need to develop the infrastructure pyramid which includes (Fig. 22.1): +1. Primary Level Vision Centres. There is a need to develop 20,000 vision centres, each with one Ophthalmic Assistant or equivalent (Community based MLOP) covering a population of 50,000. +486 Section v Systemic and Community Ophthalmology + +Table 22.4 Human resource needs for the country to combat blindness by 2020 + + +Sr. Category No. + +2001numbers +2005 + +Required by the year +2010 2015 2020 + + + +1. Ophthalmic surgeons 12000 15000 2. Ophthalmic assistants (community) 6000 10000 3. Ophthalmic paramedics (hospital) 18000 30000 4. Eye-care managers 200 500 +5. Community eye health specialists 20 50 + +18000 21000 25000 15000 20000 25000 36000 42000 48000 1000 1500 2000 +100 150 200 + + + + + + + + + + + + + + + + + + + + + + +Fig. 22.1 The infrastructure pyramid, based on the recommendations of WHO + +2. Service Centres. There is a need to develop 2,000 service centres at secondary level—each with two ophthalmologists and 8 paramedics (Hospital based MLOP), covering a population of 5,00,000. One eye care manager will be required at each service centre. 3. Training Centres. There is a need to develop 200 ‘Training Centres’ for the training of Ophth-almologists. Each tertiary level training centre will cater to a population of 5 million. +4.Centre of Excellence (COE).There is need to develop 20 COE with well developed all sub-specialities of Ophthalmology. Each advanced tertiary level centre of excellence will cater to a population of 50 millions. +ROLE OF EYE CAMPS IN PREVENTION OF BLINDNESS +Objectives +Eye camp approach for prevention of blindness still plays a vital role in the developing countries where infrastructure is not fully established. It is particularly more relevant keeping in view the fact that still 62.6% + +of blindness in India is due to cataract which can be very well cured in eye camps. +Organization of an eye camp +Presently two types of eye camps are held: +• Comprehensive eye care camps with ‘Reach-out Approach’, and +• Screening eye camps (Reach-in-Approach with comprehensive eye care). +• As mentioned earlier the recent emphasis is on the ‘Reach-in-Approach’. +I. Comprehensive eye care camps with ‘Reach-Out-Approach’ +A. Preparatory phase is most important for the successful organization of an eye camp. Activities during this phase are: +1. Finalization of organizers and medical team. Presently, most of the eye camps are planned and co-ordinated by the DBCS. Usually, the organizers are voluntary organizations of repute. The medical team is either from district mobile ophthalmic units or charitable hospitals or state mobile ophthalmic units. +2. Permission to hold eye camp. Permission is sought by the organizers from the Chief Medical Officer/Civil Surgeon of the district. +3. Selection of the camp site. The eye camps should preferably be held at CHC/PHC/charitable hospitals/ civil hospital, so that available operation theatre facilities can be used. +4. Publicity and mobilisation of community resources. These are most important aspects for the success of an eye camp. Publicity should start at least a fortnight prior to the actual camp dates. Method of publicity should include public announcements, radio broadcast and display of banners and posters at prominent places like bus stands, railway stations, schools, etc. +5. Other activities. These include arrangement for medicines and food for the patients, stay arrangements for the medical team and mobilization of volunteers and social workers, for rendering assistance to the camp team. +Chapter 22 Community Ophthalmology 487 + + +B. intensive phase. Eye camps should last 7 days out of which 2–3 days should be set apart for intensive phase, during which following activities need to be performed: +1. Medical team comprising at least one resident doctor, 2 nurses, 2 operation theatre assistants and 2paramedical personnel should reach the camp site an evening before the scheduled commencement of the camp. They should set up the OPD, ward and operation theatre. The OT room should be fumigated with formalin vapours and kept closed overnight. 2. Patients are provided comprehensive eye care services including refraction. Those requiring surgical intervention for cataract or other diseases are admitted in the ward. For performing ophthalmic surgery, following guidelines laid down by Govt. of India should be adhered to: +• At least one anaesthetist with arrangements to meet common emergencies should be available. +• At least one, preferably two, operating surgeons should be there and each surgeon should not perform more than 30 operations in a day. +• Presently extracapsular cataract extraction by any technique preferably manual small incision cataract surgery (SICS) or phacoemulsification with posterior chamber intraocular lens implantation is the recommended method. +• Ideally the number of operations performed per day should not exceed 50 and in a camp should not exceed 200 to maintain quality and safety of sterilization, surgery and postoperative care. +• Both the eyes should never be operated at one go. • Cases with poor surgical risk such as severe +diabetics, severe hypertensives and those having cardiac problems should not be operated in camps. The cases associated with problems like these should be referred to the base hospitals. +3. Eye health education is also carried out simultaneously, along with curative and preventive services. +C. Consolidation phase of 4–5 days follows the intensive phase with following activities: +• Care of operated and other admitted patients. • Outpatient’s care including refraction. +• Community eye health and morbidity surveys with greater emphasis on school children. +D. Culmination and retrieval phase. On the morning of last day, each patient is very carefully examined and discharged after proper guidance. After this, the men and material resources are packed up and transported back to the base hospital. +E. Follow-up phase. One ophthalmic surgeon with the help of one ophthalmic assistant, one staff nurse and paramedical personnel conducts the + +follow-up examination after 46 weeks of closing of the camp. During this phase, glasses are prescribed after removing the sutures and the patients are given further necessary advice. +II. Screening eye camps (Reach-in-Approach) According to revised strategies, emphasis is to shift from ‘Reach-out’ to the ‘Reach-in-Approach’. In `Reach-in-Approach’, the ‘screening camps’ are held in rural and remote areas where eye-care facilities are not available. Patients are provided comprehensive eye care services including refraction. Patients in need of cataract surgery are then transported to the nearest well-equipped hospitals (Base hospital approach). Emphasis is on extracapsular cataract extraction with posterior chamber IOL implantation for better quality of vision. Many eye surgeons are now performing sutureless small incision cataract surgery (SICS) with posterior chamber intraocular lens implantation. The trained surgeons are even performing the cataract surgery by latest technique, i.e. phacoemulsification in eye camps. +Documentation, monitoring and evaluation +A complete and meticulous record of the patients treated in the eye camp along with the postoperative complications noted and managed should be kept. Each eye camp should be monitored by the competent authorities and evaluated in terms of various activities assigned to such camps and the results obtained. +EYE BANKING +Eye bank is an organization which deals with the collection, storage and distribution of cornea for the purpose of corneal grafting, research and supply of the eye tissue for other ophthalmic purposes. +Functions of an eye bank +1. Promotion of eye donationby increasing awareness about eye donation to the general public. +2. Registration of the pledger for eye donation. +3. Collection of the donated eyes from the deceased. 4. Receiving and processing the donor eyes. +5. Preservation of the tissue for short, intermediate, long or very long term. +6. Distribution of the donor tissues to the corneal surgeons. +7. Research activities for improvement of the preservation methodology, corneal substitute and utilisation of the other components of eye. +Eye bank personnel +1. Eye bank incharge. He should be a qualified ophthalmologist to evaluate, process and distribute the donor tissue. +488 Section v Systemic and Community Ophthalmology + + +2. Eye bank technician. The duties of a trained eye bank technician are: +• To keep the eye collection kits ready. • To assist in enucleation of donor eyes. +• To record data pertaining to donor material and waiting list of patients. +• To process and treat the donor eyes with antibiotics. • To assist in corneal preservation and storage. +• To maintain asepsis in the eye bank. 3. Clerk-cum-storekeeper. The duties are: • To maintain meticulous records. +• To coordinate with other eye banks. +• To deal with other eye banks and exert with efficiency regarding donor’s correspondence. +• To distribute cornea to eye surgeons/eye banks. 4. Medical social worker or public relation officer is required: +• To supply publicity material to common public. • To promote voluntary eye donation. +He may be a voluntary or paid worker. 5. Driver-cum-projectionist is required: • To maintain vehicle of the eye bank. +• To screen films of eye donation promotion in the community. +Eye collection centres +These are the peripheral satellites of an eye bank for better functioning. One collection centre is viably located at an urban area with a population of more than 200,000. About 4–5 collection centres are attached with each eye bank. +Functions of eye collection centre are: • Local publicity for eye donation. • Registration of voluntary donors. +• Arrangement for collection of eyes after death. +• Initial processing, packing and transportation of collected eyes to the attached eye bank. +Personnel needed for eye collection centre are: • Ophthalmic technician trained in eye bank. +• Local honorary workers/voluntary agencies like Lions Club, Rotary Club, etc. to boost the eye donation campaign. +• Services of honorary ophthalmic surgeon or medical officer trained in enucleation available on call. +Legal aspect +The collection and use of donated eyes come under the preview of ‘The Transplantation of Human Organs Act, 1994’. +Facts about eye donation +• Almost anyone at any age can pledge to donate eyes after death; all that is needed is a clear healthy cornea. + +• The eyes have to be removed within six hours of death. +• Eye donation gives sight to two blind persons as one eye is transplanted to one blind person. +• The eyes can be pledged to an eye bank and can be actually donated to any nearest eye bank at the time of death. +• The donated eyes are never bought or sold. Eye donation is never refused. +• The eyes cannot be removed from a living human being in spite of his/her consent and wish. +REHABILITATION OF THE BLIND +Rehabilitation of the blind is as important as the prevention and control of blindness; spiritually speaking even more. A blind person needs the following types of rehabilitation: +1. Medical rehabilitation. By low vision aids (LVA) many visually handicapped can have a useful vision. 2. Training and psychosocial rehabilitation. It is the most important aspect. First of all the blinds should be assured and made to feel that they are equally useful and not inferior to the sighted persons. Their training should include: +• Mobility training with the help of a stick. +• Training in daily living skills such as bathing, washing, putting on clothes, shaving, cooking and other household work. +3. Educational rehabilitation. It includes education avenues in ‘Blind Schools’ with the facility of Braille system of education. +4. Vocational rehabilitation. It will help them to earn their livelihood and live as useful citizens. Blinds can be trained in making handicrafts, canning, book binding, candle and chalk making, cottage industries and as telephone operators. +To conclude, it should never be forgotten that, one of the basic human rights is the right to see. The strategicians MUST ensure that: +• No citizen goes blind needlessly due to preventable causes. +• All avenues are exhausted to restore the best possible vision to curable blinds. +• Blinds not amenable to curable measures receive comprehensive rehabilitation. + +REFERENCES + +I. WHO (1966). Epi and Vital Statis. Rep., 19: 437. +2. The Prevention of Blindness. Report of a WHO Study Group.Geneva, World Health Organization, 1973 (WHO Technical Report Series, No. 518). +3. WHO (1979). WHO Chronicle 33: 275. +4. WHO (1977). International Classification of Diseases. Vol. 1, p. 242. +Chapter 22 Community Ophthalmology 489 + + +5. Changing patterns in global blindness: 1988–2008. Community Eye Health; 21(67):37–39, Sept. 2008. +6. Thylefors B et al. Global Data on Blindness. Bull. WHO 1995: 73: (1) 115–121. +7. Indian Council of Medical Research : Collaborative study on Blindness (1971–74). +8. Report of National Workshop (1989). National Programme for Control of Blindness. Director General Health Services, Ministry of Health and Family Welfare, New Delhi. +9. Govt. of India, National Survey on Blindness: 1999-2001, Report 2002. +10. Rapid Assessment of Avoidable Blindness (RAAB) in India (200607); PLoS One 2008 Aug. 6; 3(8): e2867. + +11. Strategic plan for Vision 2020: The Right to Sight WHO Report. SEA-Ophthal 177, 2000 +12. Vision for the Future, International ophthalmology strategic plan to Preserve and Restore Vision, 2001. +13. Govt. of India (1992), Present Status of National Programme for Control of Blindness, Ophthalmology Section, DGHS, New Delhi, 1992. +14. Strategic plan for Vision 2020: The Right to sight initiative in India, National Programme for control of blindness, Director General of Health Services, Ministry of Health and Family Welfare Govt. of India. +Section VI Practical Ophthalmology + + + + + + + + +Section Outline + +23. Clinical Methods in Ophthalmology 24. Clinical Ophthalmic Cases +25. Darkroom Procedures +26. Ophthalmic Instruments and Operative Ophthalmology + + +INTRODUCTION TO PRACTICAL OPHTHALMOLOGY + + + +Medical graduates have to apply the knowledge gained during their five and a half years of exhaustive study course, for the management and care of a patient in one or the other way. Therefore, it is imperative for them to learn and practise the art of medicine. Consequently the practical examinations have been given equal importance to that of theory examinations during the entire study course. Practical training is thus supplementary and complementary to the lecture course. +Practical examinations in ophthalmology are conducted with the main aims to evaluate a student for his or her capability to identify and diagnose common eye diseases to provide primary eye care and to timely refer the patients needing secondary and tertiary level services to the eye hospitals as per the indications. +To assess the students for the above-mentioned capabilities, the practical examinations are conducted under the following heads: +1. CLINICAL CASE PRESENTATION +Under this section, students are assessed for their knowledge and art of a meticulous history taking, methods of examination, diagnostic skills and plan of management of an ophthalmic patient. For this purpose, the students are supposed to work up a long case and/or 2 to 3 short cases with common eye disorders. The approach to clinical work up of an ophthalmic patient is given in Chapter 23. The clinical case presentation along with the related viva questions have been described in Chapter 24. +2. DARK ROOM PROCEDURES +Students are evaluated for their knowledge of basic principles, clinical applications, procedures and the equipment required for the commonly performed dark room procedures (DRPs). These procedures along with relevant viva questions have been described in Chapter 25. + +3. OPHTHALMIC INSTRUMENTS AND OPERATIVE OPHTHALMOLOGY +The aim of this part of practical examination is to assess the students for their exposure and acquaintance with functioning of the ophthalmic operation theatre. Students should be able to identify and tell the utility of common eye instruments. They should be able to describe the techniques of local ocular anaesthesia and to enumerate the main steps of a few common eye operations. Students are also supposed to be familiar with the commonly used ophthalmic equipment including use of cryo and lasers in ophthalmology. Subject matter relevant to this part of practical examinations is described in Chapter 26. +4. SPOTTING +In some centres, spotting also forms a part of practical examinations. This allows an overall objective evaluation of the candidate, so also called as, `objectively structured clinical examination (OSCE).’ Commonly employed spots in ophthalmology practical examinations include: a typical photograph of any common eye disorder, an instrument, photograph of any ophthalmic equipment, a darkroom appliance, a fundus photograph or a visual field chart. +5. VIVA QUESTIONS +Viva questions form an integral and important part of each section of the practical examination, viz. clinical case presentation, darkroom examination and description of ophthalmic instruments. Therefore, relevant questions have been described in the concerned sections. +The main aim of the examiner during the session of viva questions is to assess the student’s overall familiarity with common disorders of the eye, their management and important recent developments in the field of ophthalmic practice. +23 +Clinical Methods in Ophthalmology + + + +CHAPTER OUTLINE + +HISTORY AND EXAMINATION History +General physical and systemic examination Ocular examination +• +• +• +• +Testing of visual acuity External ocular examination Fundus examination +Visual field examination Record of ophthalmic case +Techniques of ocular examination and diagnostic tests +• +• +• +• +• +Oblique illumination Tonometry +Techniques of fundus examination Perimetry +Fundus fluorescein angiography + + + +HISTORY AND EXAMINATION +HISTORY +The importance of painstaking meticulous history cannot be overemphasized. The complete history taking should be structured as: +• Demographic data +• Chief presenting complaints • History of present illness +• History of past illness • Family history +Demographic data +Demographic data should include patient’s name, age, sex, occupation and religion. +Name and address. Name and address are primarily required for patient’s identification. It also proves useful for demographic research. +Age and sex. In addition to the utility in patient’s identification, knowledge of age and sex of the patient is also useful for noting down and ruling out the particular diseases pertaining to different age groups and a particular sex. + +• Electroretinography and electrooculography Visually evoked response (VER) +Ocular ultrasonography +• +• +• +Optical coherence tomography SPECIAL EVALUATION SCHEMES* +• +• +• +• +• +• +Evaluation of a case of glaucoma Examination of a case of squint Evaluation of a case of epiphora Evaluation of a case of dry eye Evaluation of a case of proptosis Determination of refractive errors +LABORATORY INVESTIGATIONS* IMAGING TECHNIQUES* PATHOLOGICAL STUDIES* *Discussed in the related chapters RELATED QUESTIONS + + + +Occupation. An information about patient’s occupation is helpful since ophthalmic mani-festations due to occupational hazards are well known, e.g.: +• Ocular injuries and trauma due to foreign bodies have typical pattern in factory workers, lathe workers, farmers and sport persons. +• Computer vision syndrome is emerging as a significant ocular health problem in computer professionals. +• Heat cataract is known in glass factory workers. +• Photophthalmitis is known in welders not taking adequate protective measures. +In addition, information about the patient’s occupation is useful in providing ocular health education and patient’s visual rehabilitation. Religion. Recording the religion of the patient may be helpful in ascertaining the diseases which are more common in a particular community. It also helps in knowing the aptitude and practices prevalent in different communities for various common eye problems. +494 Section VI Practical Ophthalmology + + +Chief presenting complaints +Chief presenting complaints of the patients should always be recorded in a chronological order with their duration. Common presenting ocular complaints are: +• Defective vision +• Watering and/or discharge from the eyes • Redness +• Asthenopic symptoms • Photophobia +• Burning/itching/foreign body sensation • Pain (eyeache and/or headache) +• Deviation of the eye • Diplopia +• Black spots in front of eyes • Coloured halos +• Distorted vision + +History of present illness +The patients should be encouraged to narrate their complaints in detail and the examiner should be a patient listener. While taking history, the examiner should try to make a note of the following points about each complaint: +• Mode of onset with duration • Severity +• Progression +• Accompaniment of each symptom + +History of past illness +A probe into history of past illness should be made to know: +• History of similar ocular complaint in the past. It is specially important in recurrent conditions such as herpes simplex keratitis, uveitis and recurrent corneal erosions. +• History of similar complaints in other eye is important in bilateral conditions such as uveitis, senile cataract and retinal detachment. +• History of trauma to eye in the past may explain occurrence of lesions such as delayed rosette cataract and retinal detachment. +• It is important to know about history of any ocular surgery in the past. +• History of any systemic disease in the past such as tuberculosis, syphilis, leprosy may sometimes explain the occurrence of present ocular disease. +• History of drug intake and allergies is also important. +Family history +Efforts should be made to establish familial predisposition of inheritable ocular disorders like congenital cataract, ptosis, squint, corneal dystrophies, glaucoma and refractive error. + +Common ocular symptoms and their causes +1. Defective vision. It is the commonest ocular symptom. Enquiry should reveal its onset (sudden or gradual), duration, whether it is painless or painful, whether it is more during the day, night or constant, and so on. Important causes of defective vision can be grouped as under: +Sudden painless loss of vision +• Central retinal artery occlusion • Massive vitreous haemorrhage +• Retinal detachment involving macular area • lschaemic central retinal vein occlusion +Sudden painless onset of defective vision • Central serous retinopathy +• Optic neuritis +• Methyl alcohol amblyopia +• Nonischaemic central retinal vein occlusion +Sudden painful loss of vision +• Acute congestive glaucomas (primary or secondary) +• Acute iridocyclitis +• Chemical injuries to the eyeball +• Mechanical injuries to the eyeball +Gradual painless defective vision +• Progressive pterygium involving papillary area • Corneal degenerations +• Corneal dystrophies +• Developmental cataract • Senile cataract +• Optic atrophy +• Chorioretinal degenerations +• Age-related macular degeneration • Diabetic retinopathy +• Refractive errors +Gradual painful defective vision • Chronic iridocyclitis +• Corneal ulceration +• Chronic simple glaucoma +Transient loss of vision (Amaurosis fugax) • Carotid artery disease +• Papilloedema +• Giant cell arteritis • Migraine +• Raynaud’s disease +• Severe hypertension +• Prodromal symptom of CRAO +Night blindness (Nyctalopia) • Vitamin A deficiency +• Retinitis pigmentosa and other tapetoretinal degenerations +Chapter 23 Clinical Methods in Ophthalmology 495 + + +• Congenital night blindness • Pathological myopia +• Peripheral cortical cataract +Day blindness (Hamaropia) +• Central nuclear or polar cataracts • Central corneal opacity +• Central vitreous opacity +• Congenital deficiency of cones (rarely) +Diminution of vision for near only • Presbyopia +• Cycloplegia +• Internal or total ophthalmoplegia • Insufficiency of accommodation +2.Other visual symptoms. Visual symptoms other than the defective vision are as follows: +■Black spots or floaters in front of the eyes may appear singly or in clusters. They move with the movement of the eyes and become more apparent when viewed against a clear surface, e.g. the sky. Common causes of black floaters are: +• Vitreous haemorrhage +• Vitreous degeneration, e.g. +– senile vitreous degeneration +– vitreous degeneration in pathological myopia • Exudates in vitreous +• Lenticular opacity. +Flashes of light in front of the eyes (photopsia). Occur due to traction on retina in following conditions: +• Posterior vitreous detachment +• Prodromal symptom of retinal detachment • Vitreous traction bands +• Sudden appearance of flashes with floaters is a sign of a retinal tear +• Retinitis • Migraine +Distortion of vision +• Central chorioretinitis +• Central serous chorioretinopathy • ARMD +• CNVM +• Keratoconus +• Corneal irregularity +Glare +• Early cataract +• Corneal oedema +• Status postrefractive surgery +Photophobia +• Corneal abrasion +• Acute conjunctivitis • Keratitis + +• Anterior uveitis • Dilated pupil +Coloured halos. Patient may perceive coloured halos around the light. It is a feature of: +• Acute congestive glaucoma +• Corneal edema, e.g. bullous keratopathy • Early stages of cataract +• Mucopurulent conjunctivitis +Diplopia, i.e. perceiving double images of an object is a very annoying symptom. It should be ascertained whether it occurs even when the normal eye is closed (uniocular diplopia) or only when both eyes are open (binocular diplopia). Common causes of diplopia are: +Uniocular diplopia • Subluxated lens • Double pupil +• Incipient cataract • Keratoconus +• Eccentric IOL +Binocular diplopia • Paralytic squint +• Myasthenia gravis • Diabetes mellitus • Thyroid disorders +• Blow-out fracture of floor of the orbit +• Anisometropic glasses (e.g., uniocular aphakic glasses) +• After squint correction in the presence of abnormal retinal correspondence (paradoxical diplopia). +3. Watering from the eyes. Watering from the eyes is another common ocular symptom. Its causes can be grouped as follows: +Excessive lacrimation, i.e. excessive formation of tears occurs in multiple conditions (see page 390). Epiphora, i.e., watering from the eyes due to blockage in the flow of normally formed tears somewhere in the lacrimal drainage system (see page 391). +4. Discharge from the eyes. When a patient complains of a discharge from the eyes, it should be ascertained whether it is mucoid, mucopurulent, purulent, serosanguinous or ropy. Discharge from the eyes is a feature of conjunctivitis, corneal ulcer, stye, burst orbital abscess, and dacryocystitis. +5. Itching, burning and foreign body sensation in the eyes.These are very common ocular symptoms. Their causes are: +• Conjunctivitis (e.g., allergic, chronic simple, and GPC) +• Blepharitis +496 Section VI Practical Ophthalmology + + +• Dry eye +• Trachoma and other conjunctival inflammations • Trichiasis and entropion +6. Redness of the eyes. It is a common presenting symptom in many conditions such as conjunctivitis, keratitis, iridocyclitis, acute glaucomas, conjunctival or corneal foreign body, trichiasis, episcleritis, scleritis, sub-conjunctival haemorrhage, endoph-thalmitis. +7. Ocular pain. Pain in and around the eyes should be probed for its onset, severity, and associated symptoms. It is a feature of ocular inflammations and acute glaucoma. Ocular pain may also occur as referred pain from the inflammation of surrounding structures such as sinusitis, dental caries and abscess. 8. Asthenopic symptoms. Asthenopia refers to mild eyeache, headache and tiredness of the eyes which are aggravated by near work. Asthenopia is a feature of extraocular muscle imbalance and uncorrected mild refractive errors especially astigmatism. +9. Other ocular symptoms include: +• Deviation of the eyeball (squint) +• Protrusion of the eyeball (proptosis) • Drooping of the upper lid (ptosis) +• Retraction of the upper lid +• Sagging down of the lower lids (ectropion) +• Swelling on the lids (e.g. chalazion and tumours) (These specific symptoms have been discussed in +the concerned chapters). + +GENERAL PHYSICAL AND SYSTEMIC EXAMINATION +General physical and systemic examination should be carried out in each case. Sometimes it may help in establishing the aetiological diagnosis, e.g. ankylosing spondylitis may be associated with uveitis. Further, it is essential to treat associated diseases like bronchial asthma, hypertension, diabetes and urinary tract problems before taking up the patient for cataract surgery. +OCULAR EXAMINATION • Testing of visual acuity +• External ocular examination • Fundus examination +• Visual field examination + +I. TESTING OF VISUAL ACUITY +Visual acuity should be tested in all cases, as it may be affected in numerous ocular disorders. In real sense acuity of vision is a retinal function (to be + +more precise of the macular area) concerned with the appreciation of form sense. +Distant and near visual acuity should be tested separately. +Distant visual acuity +Snellen’s test types. The distant central visual acuity is usually tested by Snellen’s test types. The fact that two distant points can be visible as separate only when they subtend an angle of 1 minute at the nodal point of the eye, forms the basis of Snellen’s test-types. It consists of a series of black capital letters on a white board, arranged in lines, each progressively diminishing in size. The lines comprising the letters have such a breadth that they will subtend an angle of 1 min at the nodal point. Each letter of the chart is so designed that it fits in a square, the sides of which are five times the breadth of the constituent lines. Thus, at the given distance, each letter subtends an angle of 5 min at the nodal point of the eye (Fig. 23.1). The letters of the top line of Snellen’s chart (Fig. 23.2) should be read clearly at a distance of 60 m. Similarly, the letters in the subsequent lines should be read from a distance of 36, 24, 18, 12, 9, 6 and 5 m, respectively. +Procedure of testing. For testing distant visual acuity, the patient is seated at a distance of 6 m from the Snellen’s chart, so that the rays of light are practically parallel and the patient exerts minimal accommodation. The chart should be properly illuminated (not less than 20 ft candles). The patient is asked to read the chart with each eye separately and the visual acuity is recorded as a fraction, the numerator being the distance of the patient from the letters, and the denominator being the smallest letters accurately read. +When the patient is able to read up to 6 m line, the visual acuity is recorded as 6/6, which is normal. Similarly, depending upon the smallest line which the patient can read from the distance of 6 m, his vision is recorded as 6/9, 6/12, 6/18, 6/24, 6/36 and 6/60, respectively. If he cannot see the top line from 6 m, he is asked to slowly walk towards the chart till he + + + + + + + +Fig. 23.1 Principle of Snellen’s test types +Chapter 23 Clinical Methods in Ophthalmology 497 + +Visual acuity equivalents in some common notations are depicted in Table 23.1. +Table 23.1 Visual acuity equivalents in some common notations + +Decimal resolution system +1.0 +0.8 +0.7 +0.6 +0.5 +0.4 +0.3 +0.1 + +Snellen 6-m table +6/6 +5/6 +6/9 +5/9 +6/12 +5/12 +6/18 +6/60 + +Snellen 20- Angle foot table table +20/20 1.0 +20/25 1.3 +20/30 1.4 +15/25 1.6 +20/40 2.0 +20/50 2.5 +20/70 3.3 +20/200 10.0 + + + + + + + + + + + + +Fig. 23.2 Snellen’s test types + +can read the top line. Depending upon the distance at which he can read the top line, his vision is recorded as 5/60, 4/60, 3/60, 2/60 and 1 /60, respectively. +If the patient is unable to read the top line even from 1 m, he is asked to count fingers (CF) of the examiner. His vision is recorded as CF-3’, CF-2’, CF-1’ or CF close to face, depending upon the distance at which the patient is able to count fingers. When the patient fails to count fingers, the examiner moves his hand close to the patient’s face. If he can appreciate the hand movements (HM), visual acuity is recorded as HM +ve. When the patient cannot distinguish the hand movements, the examiner notes whether the patient can perceive light (PL) or not. If yes, vision is recorded as PL +ve and if not it is recorded as PL –ve. +Other tests which are based on the same principle as Snellen’s test types are as follows: +(a) Simple picture chart: used for children > 2 years (b) Landolt’s C-chart: used for illiterate patients (c) E-chart: used for illiterate patients + +Visual acuity for near +Near vision is tested by asking the patient to read the near vision chart (Fig. 23.3), kept at a distance of 35 cm in good illumination, with each eye separately. Innear vision charts, a series of different sizes of printer type are arranged in increasing order and marked accordingly. Commonly used near vision charts are as follows: +1. Jaeger’s chart. In this chart, prints are marked from 1 to 7 and accordingly patient’s acuity is labelled as Jl to J7 depending upon the print he can read. +2. Roman test types. According to this chart, the near vision is recorded as N5, N8, N10, N12 and N18 (Printer’s point system) (Fig. 23.3). +3. Snellen’s near vision test types. + +II. EXTERNAL OCULAR EXAMINATION +External ocular examination should be carried out as follows: +A. Inspection in diffuse light should be performed first of all for a preliminary examination of the eyeballs and related structures viz. lids, eyebrows, face and head. +B. Focal (oblique) illumination examination should be carried out for a detailed examination under magnification. It can be accomplished using a magnifying loupe (uniocular or binocular) and a focussing torch light or preferably a slit-lamp. +C. Special examination is required for measuring intraocular pressure (tonometry) and for examining angle of the anterior chamber (gonioscopy). +498 Section VI Practical Ophthalmology + + +J. 1(Sn. 0.5) N5. +As she shoke Moses came slowy), on foot, and sweathing under the deal box which he had strapt round his shoulders like a pediar “Welcome, welcome, Mosesi well, myboy, what have you brought us from the fair” MI have brought +J. 2 (Sn, 0.6) N6 +Five shillings and twopence is no bad day's work. come, let us have itthen."—"I have brought back no money," cried Moses again. "1 have laidit all out in a bargain and here it is, "pulling out a bundle from his +J. 4 (Sn. 0.8) N9 +mother," cried the boy. "why won 't you listen to reason. I had them a dead bargain, or I should not have brought them. The silver rims alone will sell for double the money"—"A fig for +J.6 (Sn. I) N12 +The rims, for they are not worth sixpence; for I perceivethey are only copper varnished over. "-"What! Criedmy wife," not silver! the rims not silver?"—''No,'' +J.8 (Sn. 1.25) N18 +with copper rims and shagreen cases? A murrain take such trumpery! The blockhead has been imposed upon, and should have know his +J.10 (Sn. 1.5) N24 +The idiot!" returned she, "to bring me such stuff: if I had them I would throw them in the fire. "-''There again you are wrong, my +J. 12 (SN. 1.75) N36 +By this time the unfortunate Moseswas undeceived. He now saw that +J.14 (Sn. 2.25) N48 +asked the circumstances ofhis deception. He sold the +Fig. 23.3 Near vision chart + +Scheme of External Ocular Examination Scheme of external ocular examination is described here (For details of the examination techniques see pages 509-522). Scheme of examination includes the structures to be examined and the signs to be looked for. Further, the important causes of the common signs are also listed to fulfill the prerequisite that ‘the eyes see what the mind knows’. Both eyes should be examined in each case. +The external ocular examination should proceed in the following order: +1. Examination for the head posture +Position of the head and chin should be noted first of all. Head posture may be abnormal in a patient with paralytic squint (head is turned in the direction of the action of paralysed muscle to avoid diplopia) and incomplete ptosis (chin is elevated to uncover the pupillary area in a bid to see clearly). + +2. Examination of forehead and facial symmetry +• Forehead may show increased wrinkling (due to overaction of frontalis muscle) in patient with ptosis. +• Complete loss of wrinkling in one-half of the forehead is observed in patients with lower motor neuron facial palsy. +• Facial asymmetry may be noted in patient with Bell’s palsy and facial hemiatrophy. +3. Examination of eyebrows +• Level of the two eyebrows may be changed in a patient with ptosis (due to overaction of frontalis). +• Cilia of lateral one-third of the eyebrows may be absent (madarosis) in patients with leprosy or myxoedema. +4. Examination of the eyelids +All the four eyelids should be examined for their position, movements, condition of skin and lid margins. i. Position. Normally the lower lid just touches the limbus while the upper lid covers about/1/6th (2 mm)of cornea. +• In ptosis, upper lid covers more than 1/6th of cornea. +• Upper limbus is visible due to lid retraction as in thyrotoxicosis and sympathetic overactivity. +ii. Movements of lids. Normally the upper lid follows the eyeball in downward movement but it lags behind in cases of thyroid ophthalmopathy. ■Blinking is involuntary movement of eyelids. +Normal rate is 12–16 blinks per minute. It is increased in local irritation. Blinks are decreased in trigeminal anaesthesia and absent in those with 7th nerve palsy. +■Lagophthalmos is a condition in which the patient is not able to close his eyelids. Causes of lagophthalmos are: +• Facial nerve palsy +• Extreme degree of proptosis • Symblepharon +iii. Lid margin. Note presence of any of the following: ■Entropion (inward turning of lid margin). ■Ectropion (outward turning of lid margin). ■Eyelash abnormalities such as: +• Trichiasisi.e., misdirected cilia rubbing the eyeball. Common causes are trachoma,blepharitis, stye and lid trauma. +• Distichiasis i.e., an abnormal extra row of cilia taking place of meibomian glands. +• Madarosis i.e., absence of cilia may be seen in patients with chronic blepharitis, leprosy and myxoedema. +• Poliosisi.e., greying of cilia is seen in old age and also in patients with Vogt-Koyanagi-Harada’s disease. +Chapter 23 Clinical Methods in Ophthalmology 499 + + +■Scales at lid margins are seen in blepharitis. ■Swelling at lid margin may be stye, papilloma or +marginal chalazion. +iv.Abnormalities of skin.Common lesions are herpetic blisters, molluscum contagiosum lesions,warts, epidermoid cysts, ulcers, traumatic scar, etc. +v. Palpebral aperture. The exposed space between the two lid margins is called palpebral fissure which measures 28–30 mm horizontally and 8–10 mm vertically (in the centre). Following abnormalities may be observed: +■Ankyloblepharon is usually seen following adhesions of the two lids at angles, e.g., after ulcerative blepharitis and burns. It results in horizontally narrow palpebral fissure. +■Blepharophimosis (all around narrow palpebral fissure) is usually a congenital anomaly. +■Vertically narrow palpebral fissure is seen in: +• Inflammatory conditions of conjunctiva, cornea and uvea due to blepharospasm +• Ptosis (drooping) of upper eyelid • Enophthalmos (sunken eyeball) • Anophthalmos (absent eyeball) +• Microphthalmos (congenital small eyeball) • Phthisis bulbi +• Atrophic bulbi +■Vertically wide palpebral fissure may be noted in patients with: +• Proptosis +• Large-sized eyeball (e.g. buphthalmos) • Retraction of upper lid +• Facial nerve palsy. + +5. Examination of lacrimal apparatus +A thorough examination of lacrimal apparatus is indicated in patients with epiphora, corneal ulcer and in all patients before intraocular surgery. The examination should include: +• Inspection of lacrimal sac area for redness, swelling or fistula. +• Inspection of the lacrimal puncta, for any defect such as eversion, stenosis, absence or discharge. +• Regurgitation test.It is performed by pressing over the lacrimal sac area just medial to the medial canthus and observing regurgitation of any discharge from the puncta. Normally it is negative. A positive regurgitation test indicates dacryocystitis. A false negative regurgitation test may be observed in internal fistula, wrong method of performing regurgitation test, patient might have emptied the sac just before coming to the examiner’s chamber, encysted mucocele. + +• Lacrimal syringing. It is done to locate the probable site of blockage in patients with epiphora (see page 391). +• Other tests such as Jone’s dye test I and II, dacryocystography, etc. can be performed when indicated (see page 392). + +6. Examination of eyeball as a whole Observe the following points: +i. Position of eyeballs. Normally, the two eyeballs are symmetrically placed in the orbits in such a way that a line joining the central points of superior and inferior orbital margins just touches the cornea. Abnormalities of the position of eyeball can be: +a. Proptosis/exophthalmos i.e., bulging of eyeballs; note whether proptosis is: +• axial or eccentric +• reducible or nonreducible • pulsatile or nonpulsatile +b. Enophthalmos (sunken eyeball) +ii. Visual axes of eyeballs. Normally the visual axes of the two eyes are simultaneously directed at the same object which is maintained in all the directions of gaze. Deviation in the visual axis of one eye is called squint (complete evaluation of a case of squint is a specialised examination) (see pages 345, 350). +iii. Size of eyeball. Obvious abnormalities in the size of eyeball can be detected clinically. However, precise measurement of size can only be made by ultrasonography (A-scan). The size of eyeball is increased in conditions like buphthalmos and unilateral high myopia. The causes of small-sized eyeball are: congenital microphthalmos, phthisis bulbi, and atrophic bulbi. +iv. Movements of eyeball should be tested uniocularly (ductions) as well as binocularly (versions) in all the six cardinal directions of gaze (see pages 337–339). + +7. Examination of conjunctiva +i. Bulbar conjunctiva can be examined by simply retracting the upper lid with index finger and lower lid with thumb of the left hand. +ii. Lower palpebra! conjunctiva and lower fornix can be examined by just pulling down the lower lid and instructing the patient to look up (Fig. 23.4). +iii. Upper palpebral conjunctiva can be examined only after everting the upper eyelid. Eversion of upper lid can be carried out by one-hand or two-hand technique. +• One-hand technique. In it patient looks down and the examiner grasps the lid margin alongwith lashes with left index finger and thumb. Then +500 Section VI Practical Ophthalmology + + + + + + + + + + + + + + + + +Fig. 23.4 Examination of the lower fornix and lower palpebral conjunctiva + +A B +Fig. 23.5A and B Two-hand technique of upper lid eversion + + + + +swiftly everts the upper lid by making index finger a fulcrum. This, however, requires some practice. +• Two-hand technique. It is comparatively easier. Procedure is same as above, except that here the lid is rotated around a fixed probe which is held above the level of tarsal plate with right hand (Fig. 23.5). In slight modification of two-hand technique, index finger of right hand can be used instead of probe. +iv. Examination of superior fornix requires double eversion of upper lid using Desmarre’s lid retractor. +Conjunctival signs +Normal conjunctiva is a thin semi-transparent structure. A fine network of vessels is distinctly seen in it. Following signs may be observed: ■Discoloration of conjunctiva may be brownish in melanosis and argyrosis (silver nitrate deposits), greyish due to surma deposits, pale in anaemia, bluish in cyanosis and bright red due to subconjunctival haemorrhage. +■Congestion ofvessels. Congestion may be superficial (in conjunctivitis) or ciliary/ circumcorneal/ deep (in iridocyclitis, and keratitis) or mixed (in acute congestive glaucoma). Differences between conjunctival and ciliary congestion are depicted in Table 23.2. +■Conjunctival chemosis (oedema) may be observed in allergic and infective inflammatory conditions. ■Follicles. These are seen as greyish white raised areas (mimicking boiled sago-grains) on fornices and palpebral conjunctiva. Follicles represent areas of aggregation of lymphocytes. Follicles may be seen in following conditions: +• Trachoma +• Acute follicular conjunctivitis +• Chronic follicular conjunctivitis • Benign (School) folliculosis. + + +■Papillae are seen as reddish raised areas with flat tops and velvety appearance. These represent areas of vascular and epithelial hyperplasia. Papillae are seen in the following conditions: +• Trachoma +• Spring catarrh +• Allergic conjunctivitis +• Giant papillary conjunctivitis +■Concretions are seen as yellowish-white hard looking raised areas, varying in size from pin-point to pin-head. They represent inspissated mucous and dead epithelial cells in glands of Henle. Common causes of concretions are trachoma, conjunctival degeneration and idiopathic. +■Foreign bodies are commonly lodged in fornices and sulcus subtarsalis on palpebral conjunctiva. ■Scarring on the conjunctiva may be in the form of a single line in the area of sulcus subtarsalis (Arlt’s line), irregular, or star-shaped. Common causes of scarring are: +• Trachoma +• Healed membranous or pseudomembranous conjunctivitis +• Healed traumatic wounds • Surgical scars +■Pinguecula is a degenerative condition of conjunctiva observed in many adult patients. It is seen on the bulbar conjunctiva, near the limbus, in the form of a yellowish triangular nodule resembling a fat drop. +■Pterygium isa degenerative conjunctival fold which encroaches on the cornea in the palpebral area. It must be differentiated from pseudopterygium (an inflammatory fold of conjunctiva encroaching the cornea). +■ Conjunctival cysts which may be observed are: +Chapter 23 Clinical Methods in Ophthalmology 501 + +Table 23.2 Differences between conjunctival and ciliary congestion + + +S. no. Feature 1. Site +2. Colour +3. Arrangement of vessels 4. On moving conjunctiva +5. On mechanically squeezing out the blood vessels +6. Blanching, i.e., putting one drop of 1 in 10000 adrenaline +7. Common causes + +Conjunctival congestion More marked in the fornices Bright red +Superficial and branching Congested vessels also move +Vessels fill slowly from fornix towards limbus +Vessels immediately blanch + +Acute conjunctivitis + +Ciliary congestion +More marked around the limbus Purple or dull red +Deep and radiating from limbus Congested vessels do not move +Vessels fill rapidly from limbus towards fornices +Do not blanch + +Acute iridocyclitis, keratitis (corneal ulcer) + + + + +• Retention cyst +• Implantation cyst • Lymphatic cyst +• Cysticercosis. +■ Conjunctival tumours. A few common tumours are dermoids, papillomas and squamous cell carcinoma. +8. Examination of sclera +Normally anterior part of sclera covered by bulbar conjunctiva can be examined under diffuse illumination. Following abnormalities may be seen: i. Discoloration. Normally sclera is white in colour. It becomes yellow in jaundice. Bluish discoloration may be seen as an isolated anomaly or in association with osteitis deformans, Marfan’s syndrome, pseudoxanthoma elasticum. Pigmentation of sclera is also seen in naevus of Ota and melanosis bulbi. ii. Inflammation.A superficial localisedpinkor purple circumscribed flat nodule is seen in episcleritis. While a deep, dusky patch associated with marked inflammation and ciliary congestion is suggestive of scleritis. +iii.Staphylomais a thinned out bulging area of sclera which is lined by the uveal tissue. Depending upon its location, scleral staphylomas may be intercalary, ciliary, equatorial and posterior. +iv. Traumatic perforations in blunt trauma are usually seen in the region of limbus or at the equator. +9. Examination of cornea +Loupe and lens examination or preferably slit-lamp biomicroscopy is a must to delineate corneal lesions. While examining the cornea, a note of following points should be made: +i. Size. The anterior surface of normal cornea is elliptical with an average horizontal diameter of 11.7 mm and vertical diameter of 11 mm. Abnorm-alities of corneal size can be: + +• Microcornea, when the anterior horizontal diameter is less than 10 mm. It may occur isolated or as a part of microphthalmos. \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_17.txt b/notes/A K Khurana - Comprehensive Ophthalmology_17.txt new file mode 100644 index 0000000000000000000000000000000000000000..b57c8031b7e1f54e5156141ebb05656261c037ad --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_17.txt @@ -0,0 +1,1599 @@ +• Corneal size also decreases in patients with phthisis bulbi. +• Megalocornea is labelled when the horizontal diameter is more than 13 mm. Common causes are congenital megalocornea and buphthalmos. +ii. Shape (curvature). Normal cornea is like a watch glass with a uniform posterior curve in its central area. In addition to biomicroscopy, keratometry and corneal topography is required to confirm changes in corneal curvature. Abnormalities of corneal shape (curvature) are: +• Keratoglobus. It is an ectatic condition in which cornea becomes thin and bulges out like a globe. +• Keratoconus. It is an ectatic condition in which cornea becomes cone shaped. +• Cornea plana i.e., flat curvature of cornea which may occur in patients with severe hypotony and phthisis bulbi and rarely as a congenital anomaly. iii. Surface. Smoothness of corneal surface is disturbed due to abrasions, ulceration, ectatic scars and facets. Changes in smoothness of surface can be detected by slit-lamp biomicroscopy, window reflex +test and Placido’s disc examination. +Placido’s keratoscopic disc.It is a disc painted with alternating black and white circles (Fig. 23.6). It may be used to assess the smoothness and curvature of corneal surface. Normally, on looking through the hole in the centre of disc a uniform sharp image of the circles is seen on the cornea (Fig. 23.7). Irregularities in the corneal surface cause distortion of the circles (Fig. 23.8). +iv. Sheen. Normal cornea is a bright shining structure. Sheen of corneal surface is lost in ‘dry eye’ conditions. A loss of the normal polish of the corneal surface +502 Section VI Practical Ophthalmology + + + + + + + + + + + + + + + + +Fig. 23.7 Placido’s disc reflex from normal cornea + +Fig. 23.8 Placido’s disc reflex from irregular corneal surface + + + + +Fig. 23.6 Placido’s disc + + +causes loss in the sharpness of the outline of the image of circles on Placido’s disc test. +v. Transparency of cornea is lost in corneal oedema, opacity, ulceration, dystrophies, degenerations, vascularization and due to deposits in the cornea. Examination for corneal ulcer. Once corneal ulcer is suspected, a thorough biomicroscopic examination before and after fluorescein staining should be performed to note the site, size, shape, depth, floor and edges of the corneal ulcer. +Examination for corneal opacity is best done with the help of a slit-lamp. Note the number, site, size, shape, density (nebular, macular or leucomatous) and surface of the opacity. +vi. Corneal vascularization. The cornea is an avascular structure but its vascularization may occur in many diseases. When vessels are present, an exact note of their position, whether superficial or deep and their distribution whether localised, general, or peripheral should be made. +Differences between superificial and deep vascularization of cornea are shown in Table 23.3. vii. Corneal sensations. Cornea is a very sensitive structure, being richly supplied by the nerves. The sensitivity of cornea is diminished in many affections of the cornea, viz., herpetic keratitis, neuroparalytic keratitis, leprosy, diabetes mellitus, trigeminal block for postherpetic neuralgia and absolute glaucoma. +■Testing corneal sensations. Patient is asked to look ahead; the examiner touches the corneal surface with + +a fine twisted cotton wick (which is brought from the side to avoid menace reflex) and observes the blinking response. Normally, there is a brisk reflex closure of lids. Always compare the effect with that on the opposite side. The exact qualitative measurement of corneal sensations is made with the help of an aesthesiometer. +viii. Back of cornea should be examined for keratic precipitates (KPs) which are cellular deposits and a sign of anterior uveitis. +KPs can be of different types such as fine, pigmented or mutton fat (see page 154). +ix. Corneal endothelium. It is examined with specular microscope which allows a clear morphological study of endothelial cells including photographic documentation. The cell density of endothelium is around 3000 cells/mm2 in young adults, which decreases with advancing age. + +Biomicroscopic examination after staining of cornea with vital stains +1. Fluorescein staining of cornea is carried out either using one drop of 2 percent freshly prepared aqueous solution of the dye or a disposable autoclaved filter paper strip impregnated with the dye. The area denuded of epithelium due to abrasions or corneal ulcer when stained with fluorescein appear brilliant green. When examined using cobalt blue light, the stained area appears opaque green. +2. Bengal rose (1%) stains the diseased and devitalized cells red, e.g., as in superficial punctate keratitis and filamentary keratitis. Bengal rose dye is very irritating. Therefore, a drop of 2% xylocaine should be instilled before using this dye. +3. Alcian blue dye stains the excess mucus selectively, +e.g., as in keratoconjunctivitis sicca. +Chapter 23 Clinical Methods in Ophthalmology 503 + +Table 23.3 Differences between superficial and deep corneal vascularization + + +Superficial corneal vascularization +1. Corneal vessels can be traced over the limbus into the conjunctiva. +2. Vessels are bright red and well-defined. + +3. Superficial vessels branch in an arborescent manner. +4. Superficial vessels raise the epithelium and make the corneal surface irregular + +Deep corneal vascularization +Corneal vessels abruptly end at the limbus. + +Vessels are ill-defined and cause only a diffuse reddish blush. +Deep vessels run parallel to each other in a radial fashion. +Deep vessels do not disturb the corneal surface. + + + +10. Examination of anterior chamber +It is best done with the help of a slit-lamp. +i. Depth of anterior chamber. Normal depth of anterior chamber is about 2.5 mm in the centre (slightly shallow in childhood and in old age). On slit-lamp biomicroscopy, an estimate of depth is made from the position of iris. Anterior chamber may be normal, shallow, deep or irregular in depth. +Causes of shallow anterior chamber • Primary narrow angle glaucoma • Hypermetropia +• Postoperative shallow anterior chamber (after intraocular surgery due to wound leak or ciliochoroidal detachment) +• Malignant glaucoma +• Anterior perforations (perforating injuries or perforation of corneal ulcer) +• Anterior subluxation of lens • Intumescent (swollen) lens. +Causes of deep anterior chamber • Aphakia/Pseudophakia +• Total posterior synechiae • Myopia +• Keratoglobus • Buphthalmos • Keratoconus +• Anterior dislocation of lens into the anterior chamber +• Posterior perforation of the globe. +Causes of irregular anterior chamber • Adherent leucoma +• Iris bombe formation due to annular synechiae • Tilting of lens in subluxation. +ii. Contents of anterior chamber: Anterior chamber contains transparent watery fluid—the aqueous humour. Any of the following abnormal contents may be detected on examination: +• Aqueouts flare in anterior chamber occurs due to collection of inflammatory cells and protein particles in patients with iridocyclitis. Aqueous flare is demonstrated in fine beam of slit-lamp light + + +as fine moving (Brownian movements) suspended particles. It is based on the Tyndall phenomenon (see page 155). +• Hypopyon, i.e. Pus in the anterior chamber may be seen in cases of infectious corneal ulcer, iridocyclitis, toxic anterior segment syndrome (TASS), endophthalmitis and panophthalmitis. +• Pseudohypopyon due to collection of tumour cells in anterior chamber and seen in patients with retinoblastoma. +• Foreign bodies—wooden, iron, glass particles, stone particles, cilia, etc., may enter the anterior chamber after perforating trauma. +• Crystalline lens may be observed in anterior chamber after anterior dislocation of lens. +• Lens particles in anterior chamber after trauma, planned extracapsular cataract extraction (ECCE) is a frequent observation. +• Blood in the anterior chamber is called hyphaema and may be seen after ocular trauma, surgery, herpes zoster and gonococcal iridocyclitis, blood dyscrasias, clotting disorder and intraocular tumours (e.g. retinoblastoma, angioma). +• Parasitic cyst, e.g. cysticercus cellulosae has been demonstrated in anterior chamber. +• Artificial lens. Anterior chamber intraocular lens may be observed in patients with pseudophakia. +iii. Examination of angle of anterior chamber is performed with the help of a gonioscope and slit-lamp. Gonioscopy is a specialized examination required in patients with glaucoma (see page 568). +11. Examination of the iris +It should be performed with reference to following points: +i. Colour of the iris. It varies in different races; it is light blue or green in caucasians and dark brown in orientals. Heterochromia iridum (different colour of two iris) and heterochromia iridis (different colour of sectors of the same iris) may be present in some individuals. Heterochromia may be either due to involved iris being lighter or darker than the normal. +504 Section VI Practical Ophthalmology + + +• Causes of iris lighter than normal are: congenital heterochromia, congenital Horner’s syndrome, Fuch’s heterochromic iridocyclitis, atrophic patches in chronic uveitis, juvenile xanthogranuloma, metastatic carcinoma and Wardenburg syndrome. +• Causes of darker iris include, iris naevi, ocular melanocytosis or oculodermal melanocytosis, haemosiderosis, siderosis bulbi, retained iris foreign body, malignant melanoma of iris and lymphoma. +• Darkly pigmented spots (naevi) are common freckles on the iris. +ii. Pattern of normal iris is peculiar due to presence of collarette, crypts and radial striations on its anterior surface. This pattern is disturbed due to `muddy iris’ in acute iridocyclitis and due to atrophy of iris in healed iridocyclitis. +iii. Persistent pupillary membrane (PPM) is seen sometimes as abnormal congenital tags of iris tissue adherent to the collarette area. +iv. Synechiaei.e., adhesions of iris to other intraocular structures may be seen. Synechiae may be anterior (in adherent leucoma) or posterior (in iridocyclitis). Posterior synechiae may be total, annular (ring), or segmental. +v. Iridodonesis (tremulousness of the iris). It is observed when its posterior support is lost as in aphakia and subluxation of lens. +vi. Nodules on the iris surface. These are observed in granulomatous uveitis (Koeppe’s and Busacca’s nodules), melanoma, tuberculoma and gumma of the iris. +vii. Rubeosis iridis (new vessel formation on the iris). It may occur in patients with diabetic retinopathy, central retinal vein occlusion (CRVO), branch retinal vein occlusion (BRVO), ocular ischaemic syndrome, chronic uveitis, chronic retinal detachment, intraocular tumours, e.g. retinobalstoma. +viii. A gap or hole in the iris. It may be congenital coloboma or due to iridectomy (surgical coloboma). Separation of iris from ciliary body is called iridodialysis. +ix. Aniridia or irideremia (complete absence of iris). It is a rare congenital condition. +x. Iris cyst. It may be seen near the pupillary margin in patients using strong miotic drops. +12. Examination of pupil Note the following points: +i. Number. Normally there is only one pupil. Rarely, there may be more than one pupil. This congenital anomaly is called polycoria. + +ii. Location. Normally pupil is placed almost in the centre (slightly nasal) of the iris. Rarely, it may be congenitally eccentric (corectopia). +iii. Size. Normal pupil size varies from 3 to 4 mm depending upon the illumination. But it may be abnormally small (miosis) or large (mydriasis). +Causes of miosis +• Effect of local miotic drugs (parasympathomimetic drugs). +• Effect of systemic morphine. +• Iridocyclitis (narrow, irregular, nonreacting pupil). • Horner’s syndrome. +• Head injury (Pontine haemorrhage). • Senile rigid miotic pupil. +• Due to effect of strong light. +• During sleep pupil is pinpoint. Causes of mydriasis +• Effect of topical sympathomimetic drugs (e.g. adrenaline and phenylephrine). +• Effect of topical parasympatholytic drugs (e.g. atropine, homatropine, tropicamide and cyclopentolate). +• Acute congestive glaucoma (vertically oval large immobile pupil). +• Absolute glaucoma. • Optic atrophy. +• Retinal detachment. +• Internal ophthalmoplegia. • 3rd nerve paralysis. +• Belladonna poisoning. +■Evaluation of anisocoria (see page 317) +iv. Shape. Normal pupil is circular in shape. +• Irregular narrow, pupil is seen in iridocyclitis. +• Festooned pupil is the name given to irregular pupil obtained after patchy dilatation (effect of mydriatics in the presence of segmental posterior synechiae). +• Vertically oval pupil (pear-shaped pupil or updrawn pupil) may occur postoperatively due to incarceration of iris or vitreous in the wound at 12 O’clock position. +v. Colour. Of course, pupil is a hole in the iris, but the pupillary area does exhibit colour depending upon the condition of the structures located behind it. Pupil looks: +• Greyish black normally, • Jet black in aphakia; +• Greyish white in immature senile cortical cataract; • Pearly white in mature cortical cataract; +• Milky white in hypermature cataract; • Brown in cataracta brunescens, and • Brownish black in cataracta nigra. +Chapter 23 Clinical Methods in Ophthalmology 505 + + +• Leucocoria(white reflex in pupil) in children is seen in congenital cataract, retinoblastoma, retrolental fibroplasia (retinopathy of prematurity), persistent primary hyperplastic vitreous and toxocara endophthalmitis. The yellowish white, semidilated, non-reacting pupil seen in retinoblastoma and pseudogliomas is also called as amaurotic cat’s eye reflex. +• Greenish hue is observed in pupillary area in some patients with glaucoma. +• Dirty white exudates may occlude the pupil (occlusio pupillae) in patients with iridocyclitis. +vi. Pupillary reactions. Note as follows: +■Direct light reflex. To elicit this reflex the patient is seated in a dimlylighted room. With the help of a palm one eye is closed and a narrow beam of light is shown to other pupil and its response is noted. The procedure is repeated for the second eye. A normal pupil reacts briskly and its constriction to light is well maintained. +■Consensual light reflex. To determine consensual reaction to light, patient is seated in a dimly lighted room and the two eyes are separated from each other by an opaque curtain kept at the level of nose (either hand of examiner or a piece of cardboard). Then one eye is exposed to a beam of light and pupillary response is observed in the other eye. The same procedure is repeated for the second eye. Normally, the contralateral pupil should also constrict when light is thrown on to one pupil. +■Swinging flash light test. It is performed when relative afferent pathway defect is suspected in one eye (unilateral optic nerve lesion with good vision). To perform this test, a bright flash light is shone on to one pupil and constriction is noted. Then the flash light is quickly moved to the contralateral pupil and response is noted. This swinging to-and-fro of flash light is repeated several times while observing the pupillary response. Normally, both pupils constrict equally and the pupil to which light is transferred remains tightly constricted. In the presence of relative afferent pathway defect in one eye, the affected pupil will dilate when the flash light is moved from the normal eye to the abnormal eye. This response is called `Marcus Gunn pupil’ or a relative afferent pupillary defect (RAPD). It is the earliest indication of optic nerve disease even in the presence of normal visual acuity. +■Near reflex. In it pupil constricts while looking at a near object. This reflex is largely determined by the reaction to convergence but accommodation also plays a part. + +To determine the near reflex, patient is asked to focus on a far object and then instructed suddenly to focus at an object (pencil or tip of index finger) held about 15 cm from patient’s eye. While the patient’s eye converges and focuses the near object, observe the constriction of pupil. +■Abnormal pupillary reactions include (i) amaurotic pupil, (ii) efferent pathway defect, (iii) Wernicke’s hemianopic pupil, (iv) Marcus Gunn pupil, (v) Argyll Robertson pupil, and (vi) the tonic pupil (for details see page 315). +13. Examination of the lens +A thorough examination of the lens can be accomplished with the help of oblique illumination, slit-lamp biomicroscopy and distant direct ophthalmoscopy with fully-dilated pupils. Following points should be noted: +i. Position. A normal lens is positioned in the patellar fossa (space between the vitreous and back of iris) by the zonules. Abnormalities of position may be: +• Dislocation of lens i.e., lens is not present in its normal position (i.e., patellar fossa) and all its supporting zonules are broken. In anterior dislocation the intact lens (clear or cataractous) is present in the anterior chamber. While inposterior dislocation the lens is present in vitreous cavity where it might be floating (lensa nutans) or fixed to the retina (lensa fixata). +• Subluxation of lens, i.e. lens is partially displaced from its position. Here zonules are intact in some quadrant and lens is shifted on that side. With dilated pupil, edge of the subluxated lens is seen as shining golden crescent on focal illumination and as a dark line (due to total internal reflection) on distant direct ophthalmoscopy. In the presence of substantial degree of subluxation, half pupil may be phakic and half aphakic (and patient may experience unilateral diplopia). Common causes of subluxation of lens are trauma. Marfan’s syndrome, homocystinuria, Weill-Marchesani syndrome. +• Aphakia(absence of lens) is diagnosed by jet black pupil, deep anterior chamber, empty patellar fossa on slit lamp biomicroscopy, hypermetropic eye on ophthalmoscopy, retinoscopy and absence of 3rd and 4th Purkinje images. +• Pseudophakia. When posterior chamber IOL is present it is diagnosed by a black pupil, deep anterior chamber, shining reflexes from the anterior surface of IOL and presence of all the four Purkinje’s images. Examination after dilatation of pupil confirms pseudophakia. +506 Section VI Practical Ophthalmology + + +ii. Shape of lens. Normal lens is a biconvex structure, which is nicely demonstrated in an optical section of the lens on slit-lamp examination (Fig. 23.9). The optical section of the lens shows from within outward embryonic, foetal, infantile and adult nuclei, cortex and capsule. An anterior Y-shaped and posterior inverted Y-shaped sutures may also be seen. +Abnormalities of the lens shape include: • Spherophakia, i.e. spherical lens. +• Lenticonus anterior, i.e. an anterior cone-shaped bulge in the lens as seen in Alport syndrome (see page 218). +• Lenticonus posterior, i.e. a cone-shaped bulge in the posterior aspect of lens (see page 218). +• Coloboma of lens, i.e. a notch in the lens (see page 217). +iii. Colour. On focal illumination the normal lens in young age appears almost clear or gives a faint blue hue. +• In old age even the clear lens gives greyish white, hue due to marked scattering of light as a result of increased refractive index of the lens with advancing age. It is usually mistaken for cataract. +• In cortical cataract lens may be greyish white, pearly white or milky white in colour in immature, mature and hypermature cataracts, respectively. +• Innuclear cataractlens may look amber, brown or black in colour. +• A rusty (orange) discoloration is seen in cataractous lens with siderosis bulbi (due to retained intraocular iron foreign body). + + + + + + + + + + + + + + + + + + + +Fig. 23.9 Optical section of the cornea and adult lens as seen on slit-lamp examination + + +iv. Transparency. Normal lens is a transparent structure. Any opacity in the lens is called cataract, which looks greyish or yellowish white on focal illumination. On distant direct ophthalmoscopy the lenticular opacities appear black against a red fundal reflex. On slit lamp biomicroscopy the morphology of cataract can be studied in detail: +• Complicated cataract in the early stages exhibits polychromatic lustre and gives breadcrumb appearance. +• True diabetic cataractpresents ‘snow flake’opacities. • Sunflower cataract is typically seen in disorder of +copper metabolism (Wilson’s disease). +• Rosette-shaped cataract, early as well as late, is typical of concussion injury of lens. +v. Deposits on the anterior surface of lens may be: +• Vossius ring. It is a small ring-shaped pigment dispersal seen on the anterior surface of lens after blunt trauma. It corresponds in shape and size to the miosed pupil, i.e. smaller than the pupil. +• Pigmented clumps may be deposited on the anterior surface of lens in patients with iridocyclitis. +• Dirty white exudates may be present on the anterior surface of lens in patients with uveitis and endophthalmitis. +• Rusty deposits, i.e. deposition of ferrous ions just below the anterior capsule is seen in siderosis bulbi. +• Greenish deposits, i.e. deposition of copper ions is seen in chalcosis. +vi. Purkinje images test. This test does not have much significance and thus is not frequently employed in clinical practice. However, it is described as a tribute to the original worker who used this test to diagnose mature cataract and aphakia. Normally, when a strong beam of light is shown to the eye, four images (Purkinje images) are formed from the four different reflecting surfaces, viz. anterior and posterior surfaces of cornea and anterior and posterior surfaces of lens (Fig. 23.10). In patients with mature cataract, fourth image (formed by posterior surface of the lens) is absent i.e., three Purkinje images are formed. In aphakia, third and fourth Purkinje images (formed by anterior and posterior surface of lens) are absent, i.e., only two images are formed. +14. The intraocular pressure (IOP) +The measurement of IOP (ocular tension) should be made in all suspected cases of glaucoma and in routine after the age of 40 years. A rough estimate of IOP can be made by digital tonometry. For this procedure patient is asked to look down and the +Chapter 23 Clinical Methods in Ophthalmology 507 + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 23.10 Purkinje images + +eyeball is palpated by index fingers of both the hands, through the upper lid, beyond the tarsal plate. One finger is kept stationary which feels the fluctuation produced by indentation of globe by the other finger (Fig. 23.11). It is a subjective method and needs experience. When IOP is raised, fluctuation produced is feeble or absent and the eyeball feels + + + + + + + + + + + + + + + + + + + + +Fig. 23.11 Technique of digital tonometry + +firm to hard. When IOP is very low eye feels soft like a partially filled water bag. +The exact measurement of IOP is done by an instrument called tonometer. Indentation (Schiotz tonometer) and applanation (e.g. Goldmann’s tonometer) tonometers are frequently used (for detailed techniques see pages 509–511). +• Normal IOP range is 10–21 mm of Hg with an average tension of 16 ± 5.0 mm of Hg. +• Hypotony is labelled when IOP is less than 10 mm Hg. Causes of hypotony include ruptured globe, phthisis bulbi, retinal/choroidal detachment, iridocyclitis, ocular ischaemia, postoperative wound leak and traumatic ciliary body shut down. +• Glaucoma should be suspected when IOP is more than 21 mm of Hg and such patients should be thoroughly investigated. +III. FUNDUS EXAMINATION +This is essential to diagnose the diseases of the vitreous, optic nerve head, retina and choroid. For thorough examination of the fundus pupils should be dilated with 5% phenylephrine and/or 1% tropicamide eye drops. The fundus examination can be accomplished by ophthalmoscopy (see page 586) and slit-lamp biomicroscopic examination (see page 588). +Observations during fundus examination +During fundus examination following observations should be made: +1. Media. Normally the ocular media is transparent. Opacities in the media are best diagnosed by distant direct ophthalmoscopy, where the opacities look black against the red glow. +Causes of opacities in media are: corneal opacity, lenticular opacity, vitreous opacities (may be exudates, haemorrhage, degeneration, foreign bodies and vitreous membranes). +2. Optic disc +• Size (diameter) of the optic disc is 1.5 mm which looks roughly 15 times magnified during direct ophthalmoscopy. Disc is slightly smaller in hypermetropes and larger in myopes. +• Shape of the normal disc is circular. In very high astigmatism, disc looks oblong. +• Margins of the disc are well defined in normal cases. Blurring of the margins may be seen in papilloedema,papillitis,postneuriticopticatrophy and in the presence of opaque nerve fibres. +• Colour. Normal disc is pinkish with central pallor area. (i) Hyperaemia of disc is seen in +papilloedema and papillitis, (ii) Paler disc is a sign +508 Section VI Practical Ophthalmology + + +of partial optic atrophy, (iii) Chalky-white disc is seen in primary optic atrophy, (iv) Yellow-waxy disc is typical of consecutive optic atrophy. +• Cup-disc ratio.Normal cup disc ratio is 0.3. (i) Large cup may be physiological or glaucomatous. (ii) Cup becomes full in papilloedema and papillitis. +• Splinter haemorrhages on the disc may be seen in primary open angle glaucoma, normal tension glaucoma and papilloedema. +• Neovascularization of the disc may occur in diabetic retinopathy, CRVO and sickle-cell retinopathy. +• Opticociliary shunt is a sign of orbital meningioma. • Peripapillary crescent is seen in myopia. +• Kesten-Baum index refers to ratio of large blood vessels versus small blood vessels on the disc. Normal ratio is 4:16. This ratio is decreased in patients with optic atrophy. +3.Macula. The macula is situated at the posterior pole with its centre (foveola) being about 2 disc diameters lateral to temporal margin of disc. Normal macula is slightly darker than the surrounding retina. Its centre imparts a bright reflex (foveal reflex). Following abnormalities may be seen on the macula: +• Macular hole. It looks red in colour with punched-out margins. +• Macular haemorrhage is red and round. +• Cherry red spot is seen in central retinal artery occlusion, Tay-Sach’s disease, Niemann-Pick’s disease, Gaucher’s disease and Berlin’s oedema. +• Macular oedema may occur due to trauma, intraocular operations, uveitis and diabetic maculopathy. +• Pigmentary disturbances may be seen after trauma, solar burn, age-related macular degeneration (ARMD), central chorioretinitis and chloroquine toxicity. +• Bull’s eye macular lesions are seen in ARMD, Stargardt disease, chloroquine retinopathy and cone dystrophy. +• Hard exudates.These may be seen in hypertensive retinopathy, exudative diabetic maculopathy, Coat’s disease, CNVM. +• Macular scarring. It may occur following trauma and disciform macular degeneration. +4. Retinal blood vessels. Normal arterioles are bright red in colour and veins are purplish with a caliber ratio of 2 : 3. Following abnormalities may be detected: +• Narrowing of arterioles is seen in hypertensive retinopathy, arteriosclerosis, and central retinal artery occlusion. + +• Tortuosity of veins occurs in diabetes mellitus, central retinal vein occlusion and blood dyscrasias. +• Sheathing of vessels may be seen in periphlebitis retinae (Eale’s disease, sarcoidosis, syphilis, tuberculosis, Behcet’s disease, AIDS) and hypertensive retinopathy. +• Vascular pulsations. Venous pulsations may be seen at or near the optic disc in 10–20% of normal people and can be made manifest by increasing the intraocular pressure by slight pressure with the finger on the eyeball. Venous pulsations are conspicuously absent in papilloedema. Arterial pulsations are never seen normally and are always pathological. The true arterial pulsations may be noticed in patients with aortic regurgitation, aortic aneurysm and exophthalmic goitre. True arterial pulsations are not limited to disc. While a pressure arterial pulse which is seen in patients with very high IOP or very low blood pressure is limited to the optic disc. +5. General background. Normally the general background of fundus is pinkish red in colour. ■Physiological variations include dark red background in black races and tessellated or tigroid fundus due to excessive pigment in the choroid. ■Following abnormal findings may be seen in various pathological states: +• Superficial retinal haemorrhage may be found in hypertension, diabetes, trauma, venous occlusions, and blood dyscrasias. +• Deep retinal haemorrhages are typically seen in diabetic retinopathy. +• Cotton wool spots (old name soft exudates) appear as whitish fluffy spots with indistinct margins. These may occur in hypertensive retinopathy, toxaemic retinopathy of pregnancy, diabetic retinopathy, anaemias and collagen disorders like DLE, PAN and scleroderma. +• Hard exudates are small, discrete yellowish, waxy areas with crenated margins. Common causes are diabetic retinopathy, hypertensive retinopathy, Coats’ disease and circinate retinopathy. +• Colloid bodies also called drusens occur as numerous minute, whitish, retractile spots, mainly involving the posterior pole. They are seen in senile macular degeneration and Doyne’s honeycomb dystrophy. +• Pigmentary disturbances may be seen in tapetoretinal dystrophies, e.g. retinitis pigmentosa and healed chorioretinitis. +• Microaneurysms are seen as multiple tiny dot-like dilatations along the venous end of capillaries. +Chapter 23 Clinical Methods in Ophthalmology 509 + + +They are commonly found in diabetic retinopathy. Other causes include hypertensive retinopathy, retinal vein occlusions, Eales’ disease and sickle cell disease. +• Neovascularization of retina occurs in hypoxic states like diabetic retinopathy, Eales’ disease, sickle-cell retinopathy, and following central retinal vein occlusion. +• Tumours of fundus include retinoblastoma, astrocytoma and melanomas. +• Peripheral retinal degenerations include lattice degeneration, paving stone degeneration, white areas with and without pressure. +• Retinal holes are seen as punched out red areas with or without operculum. These may be round or horse-shoe in shape or giant tears. +• Proliferative retinopathy is seen as disorganized mass of fibrovascular tissue in patients with proliferative diabetic retinopathy, sickle cell retinopathy, following trauma, in Eales’ disease and retinopathy of prematurity. +• Retinal detachment: Retina looks grey, raised and folded. +IV. VISUAL FIELD EXAMINATION +Examination of visual fields is important in many eye diseases. Technique of visual field examination is described on Page 511. Common types of field defects and their causes are mentioned below: +• Altitudinal field defects: Ischaemic optic neuropathy, optic disc disease, high myopia and optic neuritis. +• Enlargement of blind spot: Glaucoma, papilloedema, optic disc drusen, coloboma of optic disc, medullated nerve fibers, and myopic disc with a crescent. +• Central scotoma: Macular disease, optic neuritis, toxic amblyopia, tumours compressing the nerve. +• Constriction of peripheral fields: Glaucoma, retinitis pigmentosa, after panretinal photocoagulation, central retinal artery occlusion with cilioretinal artery sparing, and chronic papillodema. +• Homonymous hemianopia: Lesion of the optic tract, lateral geniculate body, optic radiations in temporal, parietal or occipital lobe lesions of the brain such as stroke, tumours, aneurysm and trauma. +• Bitemporal hemianopia: Lesions involving optic chiasma, such as pituitary adenoma, meningioma, craniopharyngioma and glioma. +• Binasal field defects: Tumours or aneurysm compressing both optic nerves, or chiasma, chiasmatic arachnoiditis, bilateral occipital disease, bitemporal retinal disease (e.g. retinitis pigmentosa) and glaucoma. + +• Arcuate scotoma: Glaucoma, optic disc drusen, high myopia, ischaemic optic neuropathy and optic neuritis. +RECORD OF OPHTHALMIC CASE +Both right and left eye should be examined and findings should be recorded in ophthalmic clinical case sheet (Appendix I, page 526). + +TECHNIQUES OF OCULAR EXAMINATION AND DIAGNOSTIC TESTS +OBLIQUE ILLUMINATION See page 566. + +TONOMETRY +The intraocular pressure (IOP) is measured with the help of an instrument called tonometer. Two basic types of tonometers available are: indentation and applanation. + +Indentation tonometery +Indentation (impression) tonometry is based on the fundamental fact that a plunger will indent a soft eye more than a hard eye. The indentation tonometer in current use is that of Schiotz, who devised it in 1905 and continued to refine it through 1927. Because of its simplicity, reliability, low price and relative accuracy, it is the most widely used tonometer in the world. +Schiotz tonometer. It consists of (Fig. 23.12): +• Handle for holding the instrument in vertical position on the cornea; + + + + + + + + + + + + + + + + + + + + +Fig. 23.12 Schiotz tonometer +510 Section VI Practical Ophthalmology + + +• Footplate which rests on the cornea; +• Plunger which moves freely within a shaft in the footplate; +• Bent lever whose short arm rests on the upper end of the plunger and a long arm which acts as a pointer needle. The degree to which the plunger indents the cornea is indicated by the movement of this needle on a scale; and +• Weights: a 5.5 gm weight is permanently fixed to the plunger, which can be increased to 7.5 and 10 gm +Technique of Schiotz tonometry. Before tonometry, the footplate and lower end of plunger should be sterilized. For repeated use in multiple patients it can be sterilized by dipping the footplate in ether, absolute alcohol, acetone or by heating the footplate in the flame of spirit. +After anaesthetising the cornea with paracaine or 2–4 per cent topical xylocaine, patient is made to lie supine on a couch and instructed to fix at a target on the ceiling. Then the examiner separates the lids with left hand and gently rests the footplate of the tonometer vertically on the centre of cornea. The reading on scale is recorded as soon as the needle becomes steady (Fig. 23.13). +It is customary to start with 5.5 gm weight. However, if the scale reading is less than 3, additional weight should be added to the plunger to make it 7.5 gm or 10 gm, as indicated; since with Schiotz tonometer the greatest accuracy is attained if + + + + + + + + + + + + + + + + + + + + + + +Fig. 23.13 Technique of Schiotz tonometry + +the deflection of lever is between 3 and 4. In the end, tonometer is lifted and a drop of antibiotic is instilled. A conversion table is then used to derive the intraocular pressure in mm of mercury (mm Hg) from the scale reading and the plunger weight. +The main advantages of Schiotz tonometer are that it is cheap, handy and easy to use. Its main disadvantage is that it gives a false reading when used in eyes with abnormal scleral rigidity. False low levels of IOP are obtained in eyes with low scleral rigidity as seen in high myopes and following ocular surgery. + +Applanation tonometry +The concept of applanation tonometry was introduced by Goldmann is 1954. It is based on Iimbert-Fick lawwhich states that the pressure inside a sphere (P) is equal to the force (W) required to flatten its surface divided by the area of flattening (A); i.e., P = W/A. +The commonly used applanation tonometers are: 1. Goldmann tonometer. Currently, it is the most popular and accurate tonometer. It consists of a double prism mounted on a standard slit-lamp. The prism applanates the cornea in an area of 3.06 mm diameter. +Technique (Fig. 23.14). After anaesthetising the cornea with a drop of 2% xylocaine and staining the tear film with fluorescein patient is made to sit in front of slit-lamp. The cornea and biprisms are illuminated with cobalt blue light from the slit-lamp. Biprism is then advanced until it just touches the apex of cornea. At this point two fluorescent semicircles are viewed through the prism. Then, the applanation force against cornea is adjusted until the inner edges of the two semicircles just touch (Fig. 23.15). This is the end point. The intraocular + + + + + + + + + + + + + + + +Fig. 23.14 Technique of applanation tonometry +Chapter 23 Clinical Methods in Ophthalmology 511 + + + + + + + + + + +A B C + +Fig. 23.15 End point of applanation tonometry. (A) too small; (B) too large; (C) end point + + + +pressure is determined by multiplying the dial reading with ten. +2. Perkin’s applanation tonometer (Fig. 23.16). This is a hand-held tonometer utilizing the same biprism as in the Goldmann applanation tonometer. It is small, easy to carry and does not require slit-lamp. However, it requires considerable practice before, reliable readings can be obtained. +3. Pneumatic tonometer. In this, the cornea is applanated by touching its apex by a silastic diaphragm covering the sensing nozzle (which is connected to a central chamber containing pressurised air). In this tonometer, there is a pneumatic-to-electronic transducer, which converts the air pressure to a recording on a paperstrip, from where IOP is read. +4. Pulse air tonometer is a handheld, noncontact tonometer that can be used with the patient in any position. +5. Tono-Pen is a computerised pocket tonometer. It employs a microscopic transducer which applanates the cornea and converts IOP into electric waves. +Tonography +Tonography is a non-invasive technique for determining the facility of aqueous outflow (C-value). The C-value is expressed as aqueous outflow in microlitres per minute per millimetre of mercury. It is estimated by placing Schiotz tonometer on the eye for 4 minutes. For a graphic record the electronic + + + + + + + + + + +Fig. 23.16 Perkin’s hand-held applanation tonometer + +Schiotz tonometer is used. C-value is calculated from special tonographic tables taking into consideration +the initial IOP (P0) and the change in scale reading +over the 4 minutes. +Clinically, C-value does not play much role in the management of a glaucoma patient. Although, in general, C-values more than 0.20 are considered normal, between 0.2 and 0.11 border line, and those below 0.11 abnormal. +TECHNIQUES OF FUNDUS EXAMINATION A. Ophthalmoscopy, and +B. Slit-lamp biomicroscopic examination of the fundus by: +• Indirect slit-lamp biomiscroscopy, • Hruby lens biomicroscopy, +• Contact lens biomicroscopy (For details see page 588). +PERIMETRY +Visual field is a three-dimensional area of a subject’s surroundings that can be seen at any one time around an object of fixation. Traquair described it as an “island of vision surrounded by a sea of darkness”. The extent of normal visual field with a 5 mm white colour object is superiorly 50°, nasally 60°, inferiorly 70° and temporally 90° (Fig. 23.17). The field for blue and yellow is roughly 10° less and that for red and green colour is about 20° less than that for white. Perimetry with a red colour object is particularly useful in the diagnosis of bitemporal hemianopia due to chiasmal compression and in the central scotoma of retrobulbar neuritis. +The visual field can be divided into central and peripheral field (Fig. 23.17): +Central, field includes an area from the fixation point to a circle 30° away. The central zone contains physiologic blind spot on the temporal side. Peripheral field of vision refers to the rest of the area beyond 30° to outer extent of the field of vision. Isopter. Visual field i.e., the three dimensional hill of vision can be divided into many isopters depending +512 Section VI Practical Ophthalmology + + + + + + + + + + + + + + + + + + + +Fig. 23.17 Extent of normal visual field + +upon the perception sensitivity. Thus each isopter can be defined as a threshold line forming points of equal sensitivity on a visual field chart. +Scotoma refers to an area of loss of vision totally (absolute scotoma) or partially (relative scotoma) in the visual field. +Methods of estimating the visual fields +Perimetry. It is the procedure for estimating extent of the visual fields. It can be classified as below: +Kinetic versus static perimetry +Kinetic perimetry. In this the stimulus of known luminance is moved from a peripheral non-seeing point towards the centre till it is perceived to establish the isopters. Various methods of kinetic perimetry are: confrontation method, Lister’s perimetry, tangent screen scotometry and Goldmann’s perimetry. +Static perimetry.This involves presenting a stimulus at a predetermined position for a preset duration with varying luminance in the field of vision. Various methods of static perimetry adopted are Goldmann perimetry, Friedmann perimetry, automated perimetry. +Peripheral versus central field charting Peripheral field charting +• Confrontation method +• Perimetry:Lister’s,Goldmann’s and automated Central field charting +• Campimetry or scotometry • Goldmann’s perimetry +• Automated field analysis. + +Manual versus automated perimetry • Manual perimetry +• Automated perimetry. + +A. MANUAL PERIMETRY +Most of the kinetic methods of field testing are done manually as described below: +1. Confrontation method. This is a rough but rapid and extremely simple method of estimating the peripheral visual field. Assuming the examiner’s fields to be within the normal range, they are compared with patient’s visual fields. +The patient is seated facing the examiner at a distance of 1 metre. While testing the left eye, the patient covers his right eye and looks into the examiner’s right eye. The examiner occludes his left eye and moves his hands in from the periphery keeping it midway between the patient and himself. The patient and the examiner ought to see the hand simultaneously, for the patient’s field to be considered normal. The hand is moved similarly from above, below and from right and left. +2. Lister’s perimeter (Fig. 23.18). It has a metallic semicircular arc, graded in degrees, with a white dot for fixation in the centre. The arc can be rotated in different meridians. Though not in much use now-a-days, the Lister’s perimeter is useful for peripheral field charting. + + + + + + + + + + + + + + + + + + + + + + + +Fig. 23.18 Lister’s perimeter +Chapter 23 Clinical Methods in Ophthalmology 513 + + +The patient is seated facing the arc with his chin firmly in the chin-rest. With one eye occluded, he fixates the white dot in the centre. A test object (usually white and of size 3 to 5 mm) is moved along the arc from extreme periphery towards the centre, and the point at which the patient first sees the object is registered on a chart. The arc is moved through 30° each time and 12 such readings are taken. The details of the object regarding its colour and size are noted. 3. Campimetry (scotometry), though not used now-a-days, it is useful to evaluate the central and paracentral area (30°) of the visual field. For it, the Bjerrum’s screen of either l metre or 2 metres square is used (Fig. 23.19). Accordingly, the patient is seated at a distance of 1 metre or 2 metres, respectively. The screen has a white object for fixation in its centre, around which are marked concentric circles from 5° to 30°. The patient fixates at the central dot with one eye, the other being occluded. A white target (1–10 mm diameter) is brought in from the periphery towards the centre in various meridians. Initially the physiologic blind spot is charted, which corresponds to the optic nerve head and is normally located about 1–5° temporal to the fixation point. Dimensions of blind spots are horizontally 7–8° and vertically 10–11°. +■Central/paracentral scotomas can be found in optic neuritis and open angle glaucoma. +4. Goldmann’s perimeter (Fig. 23.20). It consists of a hemispherical dome. Its main advantage over the tangent screen is that the test conditions and the intensity of the target are always the same. It permits greater reproducibility. + + + + + + + + + + + + + + + + + + +Fig. 23.19 Bjerrum’s screen + + + + + + + + + + + + + + + + + + + +Fig. 23.20 Goldmann’s perimeter + +Note. Presently, the Goldmann perimeter is not in much use. +B. AUTOMATED PERIMETRY +Automated perimeters are computer assisted and test visual fields by a static method. The automated perimeters automatically test suprathreshold and threshold stimuli and quantify depth of field defect. Commonly used automated perimeters are: Octopus, Field Master and Humphrey field analyser (Fig. 23.21). +Advantages of automated perimetry over manual perimetry +Presently, automated perimetry has almost completely replaced the manual perimetry because of the following advantages: +• Automated computerized perimetry offers an unprecedented flexibility, a level of precision and consistency of test method that are not generally possible with manual perimetry. + + + + + + + + + + + + + +Fig. 23.21: Humphrey field analyser (automated perimeter) +514 Section VI Practical Ophthalmology + + +• Other important advantages of automated perimeters are data storage capability, ease of operation, well controlled fixation, menu driven software and on line assistance making them easy to learn and use. +• Automated perimetry also provides facility to compare results statistically with normal individuals of the same age group and with previous tests of the same individual. +Interpretation of automated perimetry print out field charts +Before embarking on the interpretation of automated perimetry printout field charts, it will be worthwhile to have a knowledge about: +• Automated perimeter variables and • Testing strategies and programmes. +The following description is mainly based on Humphrey’s Field Analyzer (HFA). +Automated perimeter variables +1. Background illumination. HFA uses 31.5 apostilb (asb) background illumination. Apostilb (asb) is a unit of brightness per unit area (and is defined as 35–1 candela/m2). +2. Stimulus intensity. HFA uses projected stimuli which can be varied in intensity over a range of more than 5% log units (51 decibels) between 0.08 and 10,000 asb. In decibel notation (db), the value refers to retinal sensitivity rather than to stimulus intensity. Therefore, 0 db corresponds to 10,000 asb and 51 db to 0.08 asb (Fig. 23.22). In contrast to kinetic perimetry, the higher numbers indicate a logarithmic reduction in test object brightness, and hence greater sensitivity of vision (Fig. 23.22). +3. Stimulus size. HFA usually offers five sizes of stimuli corresponding to the Goldmann perimeter stimuli I through V. Unless otherwise instructed, the standard + + + + + + + + + + + + + + +Fig. 23.22 Stimulus intensity scales compared + +target size for automated perimetry is equivalent to Goldmann size III (4 mm2) white target. +4. Stimulus duration. Stimulus duration should be shorter than the latency time for voluntary eye movements (about 0.25 seconds). HFA uses a stimulus duration of 0.2 sec. while octopus has 0.1 sec. +Testing strategies and programmes +The visual threshold is the physiologic ability to detect a stimulus under defined testing conditions. The normal threshold is defined as the mean threshold in normal people in a given age group at a given location in the visual field. It is against these values that the machine compares the patient’s sensitivity. Thresholds are reported in decibels in a range of 0–50. Fifty decibels (db) is the dimmest target the perimeter can project. 0 db is the brightest illumination the perimeter can project. The lower the decibel value the lower the sensitivity; the higher the decibel value, the higher is the sensitivity. +Two basic testing strategies are used in automated static perimetry: +A. Suprathreshold testing. It uses targets that are well above the brightness that the patient should be able to see (suprathreshold). It is simply a screening procedure to detect gross defects. It should not be used to monitor glaucoma. Strategies for suprathreshold testing include: +• Screening central > 6 points. • Full field 120 points. +B. Threshold testing. Threshold is the dimmest target that the patient can see at a test location. Threshold testing provides more precise results than suprathreshold testing and is thus preferred by most clinicians, although it takes more time and the equipment often costs more. Strategies used for threshold testing are: +1. Full threshold testing. A full threshold test determines the threshold value at each point by the bracketing technique (4-2 on the Humphrey and 4-2-1 on the Octopus perimeter). In it, a stimulus is presented at a test point for 0.2 seconds and the machine waits for Yes/No response. If the stimulus is not seen, the intensity of the stimulus is increased in 4 db steps till it is seen. Once the threshold is crossed, the stimulus intensity is decreased in 2 db steps till the stimulus is not seen. A full threshold test is appropriate for a patient’s first test, because it crosses the threshold twice (first with a 4 dB increment). Accurately determined threshold values make subsequent tests easier because it allows the perimeter to begin with +Chapter 23 Clinical Methods in Ophthalmology 515 + + +the previous threshold values for determining future data points. Full threshold test is, however, a time consuming process. +2. Fast Pac. It is a more rapid testing strategy where the threshold is only crossed once (in 3 dB increments), but this strategy is often not appropriate. +3. SITA (Swedish Interactive Threshold Algorithm). It is a strategy of threshold testing which dramatically reduced test time. It is available as SITA-standard and SITA-fast. +Test programmes +The standard test programmes used with static threshold strategy on the Humphrey’s Field Analyser (HFA) can be grouped as below: +A. Central field tests +• Central 30-2 test, • Central 24-2 test, +• Central 10-2 test, and • Macular test +B. Peripheral field tests +• Peripheral 30/60-1, • Peripheral 30/60-2, • Nasal step, and +• Temporal crescent C. Speciality tests +• Neurological-20, • Neurological-50, +• Central 10-12, and • Macular test +D. Custom tests +Central field tests are more commonly required. These include: +1. Central 30-2 test It offers the most comprehensive form of visual field assessment of the central 30 degrees. It consists of 76 points 6 degrees apart on either side of the vertical and horizontal axes, such that the inner most points are three degrees from the fixation point. +2. Central 24-2 test. In it, 54 points are examined. It is near similar to the 30-2 test except that the two peripheral nasal points at 30 degrees on either side of the horizontal axis are not included while testing the central 24 degrees. +3. Central 10-2 test. When most points in the arcuate region between 10 and 30 degrees show marked depression then this test helps to assess and follow-up 68 points 2 degrees apart in the central 10 degree are examined. +4. Macular grid test is used when the field is limited to central 5 degrees. This test examines 10 points spaced on a 29 degree square grid centred on the point of fixation. + +Evaluation of Humphrey single-field printout +The standard HFA single field printout is obtained using a software called Statpac printout. For the purpose of evaluation, the Humphrey single-field printout (Statpac printout) with central 30-2 test can be studied by arbitrarily dividing it in eight parts or zones I to VIII as described below (Fig. 23.23): +I. Patient data and test parameters. At the top of printout page ( Fig. 23.23 part I ) are printed: +• Patients data (name, date of birth, eye (right/ left) pupil size, visual acuity). +• Test parameters (test name, strategy, stimulus used, background). +II. Reliability indices. The part II of the printout shows the reliability indices and test duration (Fig. 23.23). The visual field examination is considered unreliable if three or more of the following reliability indices have below mentioned values: +• Fixation losses > 20%, +• False positive error > 33%, • False negative error > 33%, +• Short-term fluctuations > 4.0 dB, • Total questions > 400. +III. Gray scale simulation of the test data is depicted in Zone III or part III of the printout (Fig. 23.23). The darker the printout, the worse is the field. The gray scale provides the field defects at a glance. However, + + + + + + + + + + + + + + + + + + + + + + + +Fig. 23.23 Arbitrary division of humphrey single field printout (Statpac printout) with central 30-2 test in parts for the purpose of description and understanding +516 Section VI Practical Ophthalmology + + +in general we do not make a diagnosis based on the grey scale. The main emphasis on statistical help shows in part IV to VIII of the printout in Fig. 23.23 (threshold values). +IV. Total deviation plots provide the deviation of patient’s threshold values from that of age corrected normal data. The two total deviation plots are numeric value plot and the probability plot (grey scale symbol plot). +• Numeric value plot represents the differences in decibels. +• Zero valuemeans that the patient has the expected threshold for that age. +• Positive numbers reflect points that are more sensitive than average for that age; whereas +• Negative numbers reflect points that are depressed compared with the average. +• Probability plot (grey scale symbol plot). In the lower half of part of zone IV of the printout, the total deviation plot is represented graphically. The darker the graphic representation the more significant it is. +Note. In general, the total deviation plot is an indicator of the general depression and is not capable of revealing the hidden scotomas that may be present in the overall depressed field. +V. Pattern deviation plots. The two pattern deviation plots (numeric pattern deviation plot and probability pattern deviation plot) shown in part V of the printout are similar to the total deviation plots except that here Statpac software has corrected the results for the changes caused by cataract, small pupil, refractive error, etc. +VI. Global indices are depicted in part VI of the printout. Global indices refer to some calculations made by Statpac to provide overall guidelines to help the practitioner assess the field results as a whole rather than on point-to-point basis as shown in the total deviation and pattern deviation plots. +Below mentioned four global indices are provided with the full threshold program which summarize the status of the visual field at a glance. Principally, the global indices are used to monitor progression of glaucomatous damage rather than for initial diagnosis. +1. Mean deviation (MD). This is the mean difference (in decibel value) between the normative data for that age compared with that of collected data. It is more an indicator of the general depression of the field. Worse than normal value is indicated by a negative value. + +2. Pattern standard deviation (PSD). It is a measure of variability within the field, i.e. it measures the difference between a given point and adjacent points. It actually points out towards localized field loss and is most useful in identifying early defects. ‘P’ values are assigned to if PSD exceeds that found in 90% of the normals. It loses its advantage in marked depression. +3. Short-term fluctuation (SF). It is a measure of the variability between two different evaluations of the same 10 points in the field. A high SF means either decreased reliability or an early finding indicative of glaucoma. . It is not available with SITA strategy in order to shorten the test time +4. Corrected pattern standard deviation (CPSD). It is the PSD corrected for SF. It indicates the variability between adjacent points that may be due to disease rather than due to intra-test variability. Thus, the CPSD is useful in identifying a local scotoma +VII. Glaucoma hemifield test (GHT) compares the five clusters of points in the upper field (above the horizontal midline) with the five mirror images in the lower field. These clusters of points have been developed based on the anatomical distribution of the nerve fibres and are specific to the detection of glaucoma. Depending upon the differences between the upper and lower clusters of points the following five messages may be displayed: +• Outside normal limits. The GHT outside normal limits denotes that either the values between upper and lower clusters differ to an extent found in less than 1 % of the population or any one pair of clusters is depressed to the extent that would be expected in less than 0.5% of the population. +• Border line.The GHT is considered border line when the difference between any one of the upper and lower mirror clusters is what might be expected in less than 3% of population. +• General reduction in sensitivity.The GHT is considered to have general reduction in sensitivity if the best part of visual field is depressed to an extent expected in less than 0.5% of the population. +• Abnormally high sensitivity is labelled when the best part of the visual field is such as would be found in less than 0.5% of the population. +• Within normal limits.GHT is considered within normal limits when none of the above criteria is met. +VIII. Actual threshold values shown in part VIII of the printout (Fig. 23.23) may be inspected for any pattern or scotoma when clinical features are suspecious +Chapter 23 Clinical Methods in Ophthalmology 517 + + +and even if all the seven other parts of the printout are normal. +■Scotoma by definition is the depressed part of the field as compared to the surrounding and not as compared to normals. +Note. When the actual test threshold values are below 15 dB, the sensitivity of the test is lost. +Anderson’s criteria for abnormality in hemifield area +• Localized defect should be a cluster of at least 3 or more non-edge points which have sensitivities occurring in less than 5% of the population and one of which has sensitivity occurring in less than 1% of the population. +• CPSD or PSD has a value that occurs in less than 5 % of the population. +• Glaucoma hemifield test is abnormal. +Diagnosis of glaucoma field defects on HFA single field printout +See page 233. + +FUNDUS FLUORESCEIN ANGIOGRAPHY +Fundus flourescein angiography (FFA) is a valuable tool in the diagnosis and management of a large number of fundus disorders. +Basically, FFA gives information by allowing the examiner to study the changes, produced by various fundus disorders, in the flow of fluorescein dye along the vasculature of the retina and choroid. Indications. It is indicated in many disorders of ocular fundus, viz., (1) Diabetic retinopathy (2) Vascular occlusions; (3) Eales’ disease. (4) Central serous retinopathy, (5) Cystoid macular oedema. Contraindications include renal impairment and known allergy to fluorescein. +Technique. The technique of FFA comprises rapidly injecting 5 mL of 10% solution of sterile sodium fluorescein dye in the antecubital vein and taking serial photographs (with fundus camera) of the fundus of the patient who is seated with pupils fully dilated. The fundus camera has a mechanism to use blue light (420–490 nm wavelength) for exciting the fluorescein present in blood vessels and to use yellow-green filter for receiving the fluorescent light (510–530 nm wavelength) back for photography. +The first photograph is taken after 5 seconds, then every second for next 20 seconds and every 3-5 seconds for next one minute. The last pictures are taken after 10 minutes. +Complications. FFA is a comparatively safe procedure. Minor side effects include: discoloration of skin and + +urine, mild nausea and rarely vomiting. Anaphylaxis or cardiorespiratory problems are extremely rare. However, a syringe filled with dexamethasone and antihistaminic drug alongwith other measures should be kept ready to deal with such catastrophy. Phases of angiogram. Normal angiogram consists of following overlapping phases: +1. Pre-arterial phase. Since the dye reaches the choroidal circulation 1 second earlier than the retinal arteries, therefore in this stage choroidal circulation is filling, without any dye in retinal arteries (Fig. 23.24A). +2. Arterial phase. It starts 1 second after prearterial phase and lasts until the retinal arterioles are completely filled (Fig. 23.24B). +3. Arteriovenous phase. This is a transit phase and involves the complete filling of retinal arterioles and capillaries with a laminar flow along the retinal veins (Fig. 23.24C). +4. Venous phase. In this phase, veins are filling and arterioles are emptying. This phase can be subdivided into early, mid, and late venous phase (Fig. 23.24D). +Abnormalities detected by FFA. In the blood fluorescein is readily bound to the albumin. Normally the dye remains confined to the intravascular space due to the barriers formed by the tight junctions between the endothelial cells of retinal capillaries (inner blood-retinal barrier) and that between the pigment epithelial cells (outer blood-retinal barrier). +In diseased states abnormalities in the form of hyperfluorescence and hypofluorescence may be detected on FFA. +1. Hypofluorescence. The causes are: +• Window defect in RPE due to atrophy shows background choroidal fluorescence. +• Pooling of dye under detached RPE, e.g. ARMD. +• Pooling of dye under sensory retina after breakdown of the outer blood-retinal barrier as occur in central serous retinopathy (CSR). +• Leakage of dye into the neurosensory retina due to the breakdown in inner blood-retinal barrier, e.g. as seen in cystoid macular edema (CME). +• Leakage of dye from the choroidal or retinal neovascularization, e.g. as seen in cases of proliferative diabetic retinopathy, and subretinal neovascular membrane in age-related macular degeneration. +• Staining, i.e. long retention of dye by some tissues, e.g. as seen in the presence of drusen. +• Leakage of dye from optic nerve head as seen in papilloedema. +518 Section VI Practical Ophthalmology + + + + + + + + + + + +A B + + + + + + + + + + +C D +Fig. 23.24 Normal fluorescein angiogram : A, Pre-arterial phase; B, Arterial phase; C, Arteriovenous phase; and D, Late venous phase + + +2. Hypofluorescence. The causes are: +• Blockage of background fluorescence due to abnormal deposits on retina, e.g. as seen due to the presence of retinal haemorrhage, hard exudates and pigmented clumps. +• Occlusion of retinal or choroidal vasculature, e.g. as seen in central retinal artery occlusion and occlusion of capillaries in diabetic retinopathy. +• Loss of vasculature as occurs in patients with choroideremia and myopic degeneration. +ELECTRORETINOGRAPHY AND ELECTRO-OCULOGRAPHY +The electrophysiological tests allow objective evaluation of the retinal functions. These include: electroretinography (ERG), electro-oculography (EOG), and visually evoked response (VER). +Electroretinography (ERG) +Electroretinography (ERG) is the record of changes in the resting potential of the eye induced by a flash of light. It is measured in dark adapted eye with the active electrode (fitted on contact lens) placed on the cornea and the reference electrode attached on the forehead (Fig. 23.25). +Normal record of ERG consists of the following waves (Fig. 23.26): +• a-wave. It is a negative wave possibly arising from the rods and cones (photoreceptors). + +• b-wave.It is a large positive wave which is generated by Muller cells, but represents the activity of the bipolar cells. +• c-wave. It is also a positive wave representing metabolic activity of pigment epithelium (seen only in dark adapted eye). +Both scotopic and photopic responses can be elicited in ERG. Foveal ERG can provide information about the macula. +Uses. ERG is very useful in detecting functional abnormalities of the outer retina (up to bipolar cell layer), much before the ophthalmoscopic signs appear. However, ERG is normal in diseases involving ganglion cells and the higher visual pathway, such as optic atrophy. +Clinical applications of ERG include: +1. Diagnosis and prognosis of retinal disorders such as retinitis pigmentosa, Leber’s congenital amaurosis, retinal ischaemia and other chorio-retinal degenerations. +2. To assess retinal function when fundus examin-ation is not possible, e.g., in the presence of dense cataract and corneal opacity. +3. To assess the retinal function of the babies where possibilities of impaired vision is considered. +Abnormal ERG response. It is graded as follows: +1. Subnormal response. b-wave response is subnormal in early cases of retinitis pigmentosa +Chapter 23 Clinical Methods in Ophthalmology 519 + +Technique (Fig. 23.27). Electrodes are placed over the orbital margin near the medial and lateral canthi. The patient is asked to move the eye sideways (medially and laterally) and keep there for few seconds, during which recording is done. In this procedure, the electrode near the cornea (e.g. electrode placed near lateral canthus, when the eye is rotated laterally) becomes positive. The recording is done every minute for 12 minutes. This procedure is performed first in the dark adapted stage and then repeated for light adapted stage. +Normally, the resting potential of the eye decreases during dark adaptation and reaches its peak in light adaptation. +Interpretation of results.Results of EOG are interpreted by finding out the Arden ratio as follows: +Maximum height of light peak +Arden ratio = × 100 +Minimum height of dark trough + + + + + + +Fig. 23.25 Technique of electroretinogram (ERG) recording + + + + + + + + + + + +Fig. 23.26 Components of normal electroretinogram (ERG) +even before the appearance of ophthalmoscopic signs. A subnormal ERG indicates that a large area of retina is not functioning. +2. Extinguished response is seen when there is complete failure of rods and cones function e.g., advanced retinitis pigmentosa, complete retinal detachment, central retinal artery occlusion and advanced siderosis. +3. Anegative response indicates gross disturbances of the retinal circulation. +Electro-oculography (EOG) +Electro-oculography is based on the measurement of resting potential of the eye which exists between the cornea (+ve) and back of the eye (-ve). + +• Normal curve values are 185 or above. +• Subnormal curve values are less than 150. • Flat curve values are less than 125. +Uses.Since the EOG reflects the presynaptic function of the retina, any disease that interferes with the functional interplay between the retinal pigment epithelium (RPE) and the photoreceptors will + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 23.27 Technique of electro-oculography (EOG) and normal records of electro-oculogram +520 Section VI Practical Ophthalmology + + +produce an abnormal or absent light rise in the EOG. Thus, EOG is affected in diseases such as retinitis pigmentosa, vitamin A deficiency, retinal detachment and toxic retinopathies. Hence, EOG serves as a test that is supplementary and complementary to ERG and in certain states is more sensitive than the ERG, e.g. in diagnosis of Best’s disease. +VISUALLY EVOKED RESPONSE (VER) +As we know when light falls on the retina, a series of nerve impulses are generated and passed on to the visual cortex via the visual pathway. The changes produced in the visual cortex by these impulses can be recorded by electroencephalography (EEG) (Fig. 23.28). Thus, visually-evoked response (VER) is nothing but the EEG recorded at the occipital lobe. VER is the only clinically objective technique available to assess the functional state of the visual system beyond the retinal ganglion cells. Since there is disproportionately large projection of the macular area in the occipital cortex, the VER represents the macula-dominated response. +Techniques of VER +VER is of two types depending upon the techniques used: +1. Flash VER. It is recorded by using an intense flash stimulation. It merely indicates that light has been perceived by the visual cortex. It is not affected by the opacities in the lens and cornea. +Clinical uses include: +• To assess the integrity of macula and visual pathway in infants, mentally retarded and aphasic patients. +• To distinguish between cases of organic and psychological blindness (e.g. malingering and hysterical blindness). +• To detect visual potentials in eyes with opaque media. +2. Pattern reversal VER. It is recorded using some patterned stimulus, as in the checker board. In it the pattern of the stimulus is changed (e.g. black squares go white and white become black) but the overall illumination remains same. The pattern reversal VER depends on form sense and thus may give a rough estimate of the visual acuity. +Normal versus abnormal record of VER +Flash VEP consists of series of negative and positive peaks designated in numerical sequence as +N1,P1,N2,P2,N3 and P3 (Fig. 23.28B). The significant component includes N2 and P2 recorded at 90 and 120 m sec, respectively. +Pattern-reversal VEP consists mainly of a positive +wave (P100) and two negative waves (N75 and N135) (Fig. 23.28 C). The commonest wave used for clinical cases + + + + + + + + + + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + +B + + + + + + + + + + + +C + +Fig. 23.28 Technique of recording visually evoked response (A) and normal records of flash VEP (B) and pattern-reversal VEP (C) +Chapter 23 Clinical Methods in Ophthalmology 521 + + +is P100, since it is a very robust measure with minimal interocular and intra–subject measurement variation. +In the lesions affecting the conduction of the nerve impulse by visual pathway (e.g. retrobulbar neuritis) the amplitude is reduced and there is delay in the transmission time. The timing of the response is more reliable than the amplitude. Increased latency is also common in macular dysfunction; therefore, a delayed VEP should not be considered pathognomic of optic nerve disease. + +OCULAR ULTRASONOGRAPHY Ultrasonography has become a very useful diagnostic tool in ophthalmology. The diagnostic ophthalmic ultrasound is based upon ‘pulse-echo’ technique. Ultrasonic frequencies in the range of 10 MHz are used for ophthalmic diagnosis. Rapidly repeating short bursts of ultrasonic energy are beamed into the ocular and orbital structures. A portion of this signal is returned back to the examining probe (transducer) from areas of reflectivity. The echoes detected by the transducer are amplified and converted into display form. The processed signal is displayed on cathode ray tubes in one of the two modes: A-scan or B-scan (Fig. 23.29). +A-scan (Time amplitude). The A-scan produces a unidimensional image and echoes are plotted as spikes. lnterpretation of A-scan. (i) Distance between the two echo spikes provides an indirect measurement of + + + + + + + +I + + + + + + + + + + + + + +II +Fig. 23.29 Ophthalmic ultrasonic A and B scan machine (I) and diagrammatic depiction of echoes produced by normal +ocular structures with ‘A’ and ‘B’ scan ultrasonography (II) + + +tissue such as eyeball length or anterior chamber depth and lens thickness. +(ii) The height of the spike indicates the strength of the tissue sending back the echo. The cornea, lens and sclera produce very high amplitude spikes, while the vitreous membrane and vitreous haemorrhage produce lower spikes. +B-scan (intensity modulation). B-scan produces two dimensional dotted section of the eyeball. The location, size and configuration of the structures is easy to interpret. +Clinical uses of ocular ultrasound +A-scan is used for measurement of: +• Axial length, mainly for IOL power calculation (biometry), +• Anterior chamber depth and other intraocular distances, and +• Thickness of the intraocular mass. B-scan is used for: +• Assessment of posterior segment in the presence of opaque media, +• Study of intraocular tumours, orbital tumours, and other mass lesions, and +• Localization of intraocular and intraorbital foreign bodies. +OPTICAL COHERENCE TOMOGRAPHY +Optical Coherence Tomography (OCT) is a diagnostic tool that can perform cross-sectional or tomographic images of biological tissues within less than 10 mm axial resolution using light waves. The operation of OCT is analogous to USG B-mode imaging or radar except that light is used rather than acoustic or radiowaves. OCT is specially suited for diagnostic applications in ophthalmology because of the ease of optical access to the anterior and posterior segment of the eye. The information provided by OCT is akin to in-vivo histopathology of the structure. Principle. OCT utilizes the interferometry and low coherence light in near infrared range. +OCT machine (Fig. 23.30) comprises: fundus viewing unit, Interferometric unit, computer display, control panel and colour inkjet printer. +OCT machine is available as: +• Anterior segment OCT machine, +• Posterior segment OCT machine, and +• Combined anterior segment and posterior segment OCT machine. +Types of OCT machines are: +• Time domain OCT (TD-OCT). +• Frequency domain OCT (FD-OCT). +• Specially encoded frequency domain OCT (SEFD-OCT). +522 Section VI Practical Ophthalmology + + + + + + + + + + + + + + + +Fig. 23.30 Examination on OCT machine +• Time encoded frequency domain OCT (TEFD-OCT). +Normal OCT scan of retinashows cross-sectional study of macula (Fig. 23.31A), and optic nerve head (ONH) region including retinal nerve fiber layer (RNFL) of the peripapillary region (Fig. 23.31B). +Clinical applications of OCT +I. Applications of anterior segment OCT +• Imaging of the anterior chamber angle, • Pachymetry, +• Imaging of trabeculotomy blebs, +• Assessment of tumours and cysts of iris and ciliary body. +II. Applications of posterior segment OCT +1. Macular disorders. OCTis very useful in confirming macular pathologies such as macular hole (Fig. 12.27), cystoid macular oedema (Fig. 12.25 B), age-related macular degeneration (ARMD) (Fig. 12.26D), central serous retinopathy (CSR) (Fig. 12.23C) and epiretinal membrane (ERM), etc. + + + + + + + + + + + + + + + + + + +Fig. 23.31 Normal OCT scan of retina: A, Macular region; B, Optic disc region + +2. Glaucoma diagnosis. Optic disc scan (Fig. 10.10C) is very useful in diagnosing and monitoring the glaucomatous changes. It is also useful in evaluating the RNFL for early (pre-perimetric) glaucoma detection. + +RELATED QUESTIONS + +Enumerate the causes of sudden painless loss of vision. +See page 494 +Enumerate the causes of sudden painful loss of vision. +See page 494 +Enumerate causes of gradual painless loss of vision. See page 494 +Enumerate the causes of gradual painful loss of vision. +See page 494 +What are the causes of transient loss of vision (amaurosis fugax) ? +See page 494 +Enumerate the causes of night blindness (nyctalopia). See page 494 +Enumerate the causes of day blindness (hamarlopia). See page 495 +What are the causes of defective vision for near only? See page 495 +Name the common causes of black spots in front of the eyes. +See page 495 +What are the causes of flashes of light in front of the eyes (photopsia)? +See page 495 +What is the most common cause of micropsia (small size of objects), macropsia (large size of objects) and metamorphopsia (distorted shape of objects)? +• Central chorioretinitis. +Enumerate the causes of coloured halos. See page 495 +Enumerate the causes of diplopia. See page 495 +What are the causes of watering from the eyes? See page 39 +Enumerate the common causes of redness of eyes. • Conjunctivitis +• Keratitis +• Iridocyclitis +• Acute glaucomas +• Subconjunctival haemorrhage • Endophthalmitis +Chapter 23 Clinical Methods in Ophthalmology 523 + + +• Panophthalmitis • Ocular injuries +What are the common causes of pain in eyes? +• Inflammatory conditions of lids, conjunctiva, cornea, uvea, sclera, endophthalmitis, panophthalmitis +• Acute glaucomas • Refractive errors • Ocular injuries +• Asthenopia +Enumerate the causes of the foreign body sensation. • Conjunctival or corneal foreign bodies +• Trichiasis +• Corneal abrasion +Itching in the eyes is a feature of which disease? +• Allergic conjunctivitis (marked itching is pathognomonic of spring catarrh). +COMMON OCULAR SIGNS +What are the causes of abnormal head posture? • Paralytic squint +• Severe ptosis +Enumerate the causes of madarosis of eyebrows. • Leprosy +• Myxoedema +Enumerate the causes of ankyloblepharon. • Ulcerative blepharitis +• Burns of lid margins +Enumerate the causes of narrow palpebral fissure. • Oedema of lids +• Ptosis +• Enophthalmos • Anophthahnos +• Microphthalmos • Phthisis bulbi +• Atrophic bulbi +Enumerate the causes of wide palpebral aperture. • Proptosis +• Buphthalmos +• Congenital cystic eyeball • Upper lid retraction +• Facial nerve palsy +Enumerate the causes of lagophthalmos. • Facial nerve palsy +• Leprosy +• Myxoedema +Enumerate the causes of poliosis (greying of eyelashes). +• Vogt-Koyanagi-Harada’s disease • Old age +• Vitiligo +• Albinism + +Enumerate the causes of circumcorneal congestion. • Acute glaucomas +• Keratitis and corneal ulcer • Acute iridocyclitis +Enumerate the causes of conjunctival follicles. • Trachoma +• Acute follicular conjunctivitis +• Chronic follicular conjunctivitis • Benign folliculosis +Enumerate the causes of conjunctival papillae. • Trachoma +• Spring catarrh +• Allergic conjunctivitis +• Giant papillary conjunctivitis +Enumerate the causes of concretions. • Trachoma +• Degenerative conditions • Idiopathic +Enumerate the causes of decreased corneal sensations. +• Herpes simplex keratitis • Neuroparalytic keratitis • Leprosy +• Herpes zoster ophthalmicus • Absolute glaucoma +• Acoustic neuroma +Enumerate the causes of superficial corneal vascularization. +• Trachoma +• Phlyctenular keratoconjunctivitis • Rosacea keratitis +• Superficial corneal ulcer +Enumerate the causes of deep corneal vascularization. • Interstitial keratitis +• Deep corneal ulcers • Chemical burns +• Sclerosing keratitis • After keratoplasty +Enumerate the causes of increased corneal thickness. • Corneal oedema +Enumerate the causes of abnormal corneal surface. • Corneal abrasion +• Corneal ulcer • Keratoconus +Enumerate the causes of shallow anterior chamber. • Primary angle-closure glaucoma +• Hypermetropia +• Malignant glaucoma +• Postoperative shallow anterior chamber due to - Leaking wound +- Ciliochoroidal detachment • Corneal perforation +524 Section VI Practical Ophthalmology + + +• Intumescent (swollen cataractous) lens • Iris bombe formation +• Adherent leucoma +Enumerate the causes of deep anterior chamber. • Aphakia +• Total posterior synechiae • Myopia +• Keratoglobus • Keratoconus +• Anterior dislocation of lens in the anterior chamber • Posterior perforation of the globe +• Buphthalmos +Enumerate the causes of nodules on the iris surface. • Granulomatous uveitis (Koeppe’s and Busacca’s +nodules) +• Melanoma of the iris • Tuberculoma +• Gumma +Enumerate the causes of rubeosis iridis (neova-scularization of iris). +• Diabetes mellitus +• Central retinal vein occlusion • Chronic iridocyclitis +• Sickle-cell retinopathy • Retinoblastoma +Enumerate the causes of iridodonesis. • Dislocation of lens +• Aphakia +• Hypermature shrunken cataract • Buphthalmos +Enumerate the causes of hyphaema. • Ocular injuries +• Postoperative +• Herpes zoster iritis • Gonococcal iritis +• Intraocular tumour +• Spontaneous (from rubeosis iridis). +Enumerate the causes of hypopyon. • Corneal ulcer +• Iridocyclitis +• Retinoblastoma (pseudohypopyon) • Endophthalmitis +• Panophthalmitis +What is diameter of normal pupil? • Diameter 3 to 4 mm +• In infancy pupil is smaller than at birth +• Myopes have larger pupil than hypermetropes +Enumerate the causes of miosis. +• Effect of miotic drugs (parasympathomimetic drugs, e.g. pilocarpine) +• Effect of systemic morphine +• Iridocyclitis (narrow, irregular non-reacting pupil) • Horner’s syndrome +• Head injury (pontine haemorrhage) • Senile rigid miotic pupil + +• During sleep +• Argyll Robertson pupil • Poisonings +- Alcohol +- Barbiturates +- Organophosphorus compounds - Morphine +- Carbolic acid • Hyperpyrexia +Enumerate the causes of mydriasis. +• Topical sympathomimetic drugs such as adrenaline and phenylephrine +• Topical parasympatholytic drugs such as atropine, homatropine, cyclopentolate, tropicamide +• Acute congestive glaucoma (vertically oval, large, immobile pupil) +• Absolute glaucoma • Optic atrophy +• Retinal detachment +• Internal ophthalmoplegia • Third nerve paralysis +• Belladonna poisoning • Coma +• Sympathetic stimulation - Aortic aneurysm +- Cervical rib +- Mediastinal sarcoma, lymphosarcoma, Hodgkin’s disease and pulmonary carcinoma +- Emotional excitement • Severe anaemia +• Adie’s tonic pupil is larger than its fellow +Enumerate the causes of leukocoria (white reflex in pupillary area). +• Congenital cataract • Retinoblastoma +• Persistent hyperplastic primary vitreous • Retrolental fibroplasia +• Toxocara endophthalmitis • Coat’s disease +Enumerate the causes of Marcus Gunn pupil. +(In swinging, flashlight test, the pupil on the diseased side dilates on transferring light to it) +• Optic neuritis • Optic atrophy +• Retinal detachment +• Central retinal artery occlusion • Central retinal vein occlusion +Enumerate the causes of subluxation of lens. • Trauma +• Marfan’s syndrome • Homocystinuria +• Weill-Marchesani syndrome +Enumerate the causes of deposits on anterior surface of lens. +• Vossius ring—pigmented ring seen after blunt trauma +Chapter 23 Clinical Methods in Ophthalmology 525 + + +• Pigment clumps in iridocyclitis +• Rusty (orange) deposits in siderosis bulbi +Enumerate the causes of cherry red spot. • Central retinal artery occlusion +• Commotio retinae (Berlin’s oedema) • Tay-Sachs’ disease +• Niemann-Pick’s disease • Gaucher’s disease +Enumerate the causes of macular oedema. • Trauma +• Intraocular operations • Uveitis +• Diabetic maculopathy +Enumerate the causes of superficial retinal haem-orrhages. +• Hypertensive retinopathy • Diabetic retinopathy +• Central retinal vein occlusion • Anaemic retinopathy +• Leukaemic retinopathy • Retinopathy of AIDS +Enumerate the causes of soft exudates on the retina. • Hypertensive retinopathy +• Retinopathy of toxaemia of pregnancy • Diabetic retinopathy +• Anaemic retinopathy +• LE, PAN and scleroderma • Leukaemic retinopathy +• Retinopathy of AIDS +Enumerate the causes of hard exudates on the retina. • Diabetic retinopathy +• Hypertensive retinopathy • Coats’ disease +• Circinate retinopathy +Enumerate the causes of neovascularization of retina. • Diabetic retinopathy +• Eales’ disease +• Sickle-cell retinopathy +• Central retinal vein occlusion +Enumerate the causes of proliferative retinopathy. • Proliferative diabetic retinopathy +• Sickle cell retinopathy • Eales’ disease +• Ocular trauma +Differential diagnosis of salt and pepper appearance of fundus. +• Prenatal rubella +• Prenatal influenza • Varicella + +• Mumps +• Congenital syphilis +Enumerate the causes of arterial pulsations at the disc. +• Visible arterial pulsations are always pathological • True pulse waves are seen in: +- Aortic regurgitation - Aneurysm +- Exophthalmic goitre +• Pressure pulse is seen in: - Glaucoma +- Orbital tumours +What is the significance of venous pulsations at the disc? +• Are visible in 10 to 20% of normal people • Are absent in papilloedema +In which condition capillary pulsations of the optic disc are seen? +• Are seen in aortic regurgitation as a systolic reddening and diastolic paling of the disc. +Enumerate the causes of enlargement of blind spot. • Primary open-angle glaucoma +• Papilloedema +• Medullated nerve fibres +• Drusen of the optic nerve • Juxtapapillary choroiditis +Enumerate the causes of tubular vision. +• Terminal stage of advanced glaucomatous field defect +• Advanced stage of retinitis pigmentosa +Enumerate the causes of ring scotoma. • Glaucoma +• Retinitis pigmentosa +Enumerate the causes of central scotoma. • Optic neuritis +• Tobacco amblyopia +• Macular hole, cyst, degeneration +Enumerate the causes of bitemporal hemianopia. Central lesions of chiasma: +• Pituitary tumours (common) • Suprasellar aneurysms +• Craniopharyngioma +• Glioma of third ventricle +• Meningiomas at tuberculum sellae +Enumerate the causes of homonymous hemianopia. • Optic tract lesions +526 Section VI Practical Ophthalmology + +Appendix I +Ophthalmic Clinical Case Sheet NAME AND ADDRESS +AGE AND SEX OCCUPATION RELIGION +CHIEF PRESENTING COMPLAINTS HISTORY OF PRESENT ILLNESS PAST HISTORY +PERSONAL HISTORY FAMILY HISTORY +GENERAL PHYSICAL AND SYSTEMIC EXAMINATION FACIAL SYMMETRY +HEAD POSTURE FOREHEAD +OCULAR EXAMINATION + +RIGHT EYE LEFT EYE VISUAL ACUITY +• DISTANCE (WITH AND WITHOUT GLASSES) • NEAR +EYEBROWS • LEVEL +• CILIA ORBIT +• INSPECTION • PALPATION EYEBALLS +• POSITION • SIZE +• ALIGNMENT • MOVEMENTS UNIOCULAR BIOCULAR EYELIDS +• POSITION +• MOVEMENTS • LID MARGIN • EYELASHES +• SKIN OF LIDS PALPEBRAL APERTURE • WIDTH +• HEIGHT • SHAPE +LACRIMAL APPARATUS • PUNCTA +• LACRIMAL SAC AREA • REGURGITATION TEST +• LACRIMAL SYRINGING CONJUNCTIVA +• BULBAR CONJUNCTIVA +• PALPEBRAL CONJUNCTIVA • FORNICES +LIMBUS SCLERA +• DISCOLORATION • NODULE +• ECTASIA +• ANY OTHER ABNORMALITY CORNEA +• SIZE +• SHAPE +Chapter 23 Clinical Methods in Ophthalmology 527 + +RIGHT EYE LEFT EYE • SURFACE +• TRANSPARENCY • ULCER +• OPACITY +• SENSATIONS +• VASCULARIZATION +• BACK OF THE CORNEA - KPs +- PIGMENTATION - ENDOTHELIUM +ANTERIOR CHAMBER • DEPTH +• CONTENTS IRIS +• COLOUR • PATTERN +• SYNECHIAE +• IRIDODONESIS • NODULES +• NEOVASCULARIZATION • GAP OR HOLE +• ANIRIDIA • IRIS CYST +• ANY OTHER ABNORMALITY PUPIL +• NUMBER • SIZE +• SHAPE +• POSITION • COLOUR +• PUPILLARY MARGIN +• PUPILLARY REACTIONS +- DIRECT LIGHT REFLEX +- CONSENSUAL LIGHT REFLEX - SWINGING FLASHLIGHT TEST - NEAR REFLEX +LENS +• POSITION +- APHAKIA +- PSEUDOPHAKIA - SUBLUXATION +- DISLOCATION • SHAPE +• TRANSPARENCY • COLOUR +• DEPOSITS ON THE ANTERIOR SURFACE • PURKINJE-SAMSON IMAGES INTRAOCULAR PRESSURE +• DIGITAL +• SCHIOTZ TONOMETER +• APPLANATION TONOMETER FUNDUS EXAMINATION +• MEDIA • DISC +• BLOOD VESSELS • MACULAR AREA +• GENERAL BACKGROUND PROVISIONAL DIAGNOSIS: +OCULAR DIAGNOSTIC TESTS AND INVESTIGATIONS: FINAL DIAGNOSIS: +TREATMENT: +24 + +Clinical Ophthalmic Cases + + + +Chapter Outline + +INTRODUCTION +DISEASES OF CONJUNCTIVA A case of pterygium +• +DISEASES OF CORNEA AND SCLERA +• +• +• +A case of corneal ulcer +A case of corneal opacity +A case of anterior staphyloma DISEASES OF UVEAL TRACT +• +• +A case of acute iridocyclitis A case of chronic iridocyclitis +DISEASES OF LENS +• +• +• +• +A case of senile cataract +A case of congenital/developmental cataract A case of aphakia +A case of pseudophakia GLAUCOMA +• +A case of primary angle-closure glaucoma + + + + +INTRODUCTION + +Clinical case discussion is the most important method of assessing the students’ clinical acumen. In ophthalmology practical examinations, the students are supposed to workup a long case and/or 2 to 3 short cases with common eye disorders. +Presentation of a long case +Students are supposed to evaluate a long case under following headings: +1. Name, age, sex, occupation and address of the patient +2. Chief complaints 3. History +• History of present illness • History of past illness +• Personal and professional history • Family history +4. General physical examination and relevant systemic examination +5. Ocular examination + +• A case of primary open-angle glaucoma A case of phacomorphic glaucoma +A case of phacolytic glaucoma DISEASES OF EYELIDS +• +• +• +• +• +• +• +• +A case of blepharitis +A case of chalazion (Meibomian cyst) A case of stye +A case of trichiasis and entropion A case of ectropion +A case of ptosis +DISEASES OF LACRIMAL APPARATUS A case of chronic dacryocystitis +• +DISEASES OF ORBIT A case of proptosis +• +DISORDERS OF OCULAR MOTILITY A case of squint +• +OCULAR INJURIES +• +A case of blunt ocular trauma + + + + +6. Provisional diagnosis +7. Differential diagnosis, if any +8. List of diagnostic tests required 9. Line of management. +List of long cases. During the 8 weeks clinical posting in ophthalmology department, students should evaluate and write in their clinical case registers, the common long cases. These include a case of—cataract, aphakia, pseudophakia, glaucoma, iridocyclitis, corneal ulcer (bacterial, viral or fungal), corneal opacity, leukocoria, red eye, chronic dacryocystitis or epiphora and anterior staphyloma. +Presentation of a short case +Students are required to evaluate a short case under following headings: +1. Name, age, sex, occupation and address of the patient +2. Chief complaints with only one or two relevant questions of history. +3. Ocular examination +Chapter 24 Clinical Ophthalmic Cases 529 + + +4. Diagnosis and differential diagnosis if any 5. List of important diagnostic tests +6. Line of management. +List of short cases. During clinical posting in the outdoor (OPD), students should see and evaluate the common short cases. These include a case of chalazion, stye, trichiasis, entropion, ectropion, ptosis, blepharitis, symblepharon, pterygium, pinguecula, phlyctenular conjunctivitis, spring catarrh, trachoma, Bitot’s spots, xerosis, red eye, corneal ulcer, corneal opacity, arcus senilis, band-shaped keratopathy, anterior staphyloma, proptosis, phthisis bulbi, senile cataract (immature, mature, hypermature, nuclear), congenital cataract, traumatic cataract, aphakia, pseudophakia, iridocyclitis, absolute glaucoma, fixed dilated pupil, miosed pupil, amaurotic cat’s eye reflex, etc. +Description of clinical cases and viva questions Description of common clinical cases and related viva questions and other miscellaneous viva questions are described chapterwise. + +DISEASES OF CONJUNCTIVA + +A CASE OF PTERYGIUM + +Case Description +Age and sex. More common in males than females (2:1) and usually occurs past-middle age. Presenting symptoms. Patients usually present with: • A cosmetically unacceptable dirty white growth on +the cornea. Usually, there are no other symptoms in early stages. +• Patient may experience slight irritation or foreign body sensation. +• Diminution of vision may occur due to astigmatism produced by traction on the cornea. Gross diminution of vision occurs when it encroaches upon the pupillary area. +• Occasionally, diplopia may occur due to limitation of ocular movements. +• Usually, there is history of prolonged exposure to sunny, hot, dusty atmosphere. +Signs on examination. A wing-shaped fold of conjunctiva encroaching upon the cornea in the area of palpebral aperture is seen (Fig. 5.32), more commonly on the nasal than the temporal side. +• A fully-developed pterygium consists of three parts: Head (optical part present on the cornea), neck (limbal part) and body (scleral part extending between limbus and the canthus). +• Pterygium may be progressive or regressive. + +• Progressive pterygium is thick, fleshy and vascular with a few infiltrates in the cornea in front of the head (called cap of pterygium). +• Regressive pterygium is thin, atrophic, attenuated with very little vascularity. There is no cap. Ultimately, it becomes membranous (pterygium siccus) but never disappears. +Differential diagnosis: Pterygium must be differentiated from pseudopterygium. + +Related Questions +What is a pterygium? +Pterygium is degenerative condition of the subconjunctival tissue which proliferates as vascularized granulation tissue and is characterized by formation of a triangular fold of conjunctiva encroaching on the cornea. +What is a pseudopterygium; how does it differ from the pterygium? +Pseudopterygium is a fold of bulbar conjunctiva attached to the cornea. It is formed due to adhesions of chemosed bulbar conjunctiva to the marginal corneal ulcer. It usually occurs following chemical burns of the eye. +Differences between the pterygium and pseu-dopterygium are depicted in Table 24.1. + +Table 24.1 Differences between pterygium and pseudopterygium + +Features Pterygium Pseudopterygium + +Etiology A degenerative Inflammatory process process + +Age Usually occurs in Can occur at any elderly persons age + +Site Always situated Can occur at any in the palpebral site +aperture + +Stages Either Always stationary progressive, +regressive or stationary + +Probe test Probe cannot A probe can be +be passed easily passed under underneath its neck + + +What complications can occur in an untreated case of pterygium? +• Cystic degeneration +• Neoplastic change (rarely) to—epithelioma, fibrosarcoma or malignant melanoma. +530 Section Vi Practical Ophthalmology + + +How can we prevent the recurrence after surgical excision of the pterygium? +Recurrence of the pterygium after surgical excision is the main problem (30–50%). It can be reduced by any of the following measures: +• Preoperative use of mitomycin-C +• Postoperative use of antimitotic drops such as mitomycin-C or thiotepa +• Surgical excision with bare sclera +• Surgical excision with mucous membrane grafts • Best method is surgical excision followed by auto- +limbal conjunctival graft. +What is a pinguecula? +Pinguecula is a degenerative condition of the conjunctiva characterised by formation of a yellowish white triangular patch near the limbus. +What are the causes of conjunctival xerosis? Depending upon the etiology, conjunctival xerosis can be divided into two groups: +I. Parenchymatous xerosis: It occurs due to cicatricial disorganisation of the conjunctiva as seen in following conditions: +• Trachoma +• Membranous conjunctivitis • Stevens-Johnson syndrome • Pemphigus +• Pemphigoid +• Conjunctival burns (thermal, chemical or radiational) +• Prolonged exposure of conjunctiva as in lagophthalmos. +II. Epithelial xerosis: It occurs due to hypovitam-inosis A. +What is pannus? +Pannus is infiltration of the cornea associated with vascularization. In progressive pannus, the infiltration is seen ahead of the parallel blood vessels, while in regressive pannus it stops short and the blood vessels extend beyond the corneal haze. + +DISEASES OF CORNEAAND SCLERA + +A CASE OF CORNEAL ULCER + +Case Description +Age and sex. May occur at any age in both the sexes. Comparatively males are more commonly affected due to higher chances of injury to the eyes and exposure to infection because of outdoor activity. + +Presenting symptoms. A case of corneal ulcer presents with pain, photophobia, lacrimation, discharge, redness, swelling of eyelids and detective vision. Predisposing factors. A meticulous history taking may reveal presence of any of the following predisposing factors: +• Injury to the eye by vegetative matter, nail, foreign body, etc. +• Chronic dacryocystitis +• Acute or chronic conjunctivitis +• Chronic foreign body sensation in the eye as in trichiasis and concretions +• Contact lens wear +• Use of topical steroids • Diabetes mellitus. +General physical and systemic examination should be performed with specific aim to rule out presence of vitamin A deficiency, malnutrition, diabetes mellitus, source of infection in the body including nasal cavity, paranasal sinuses and teeth and gums. +Signs on ocular examination (Fig. 6.5 and 6.6): ■Visual acuity is diminished. +■Lids show oedema, blepharospasm, lashes may be matted and trichiasis may be present sometimes. ■Lacrimal sac. Regurgitation test is positive when +there is associated chronic dacryocystitis. ■Conjunctiva reveals conjunctival as well as +circumcorneal congestion and chemosis. Concretions may be seen on tarsal conjunctiva due to old trachoma. +■Cornea on meticulous examination may reveal: • Loss of normal corneal transparency. +• Corneal ulcer (better seen after staining with 2% fluorescein dye) should be described with reference to its site, size, shape, depth, margins and floor. Typical features of the bacterial, fungal or viral ulcer may be seen. +• Window reflex and Placido’s disc reflex are distorted. • Corneal sensations may be diminished or absent. • Superficial peripheral corneal vascularization may +be seen. +• A descematocele may sometimes be seen in a deep ulcer. +■Anterior chamber may or may not show pus (hypopyon). It is a feature of bacterial as well as fungal corneal ulcers. +■Iris may be slightly muddy in colour. +■Pupil may be small due to associated toxin-induced iritis. +■Intraocular pressure is usually normal. IOP may be raised if hypopyon or associated uveitis is present. (Note: To record IOP, Schiotz tonometer is never used in corneal ulcer. Always noncontact tonometer is used). +Chapter 24 Clinical Ophthalmic Cases 531 + + +Differential diagnosis. Efforts should be made to describe the type of corneal ulcer whether bacterial, fungal, viral, degenerative or nutritional. + +Related Questions +Define keratitis +Keratitis refers to inflammation of the cornea. It is characterized by corneal oedema, cellular infiltration and conjunctival reaction. Keratitis may be either ulcerative or nonulcerative. +Define corneal ulcer +Corneal ulcer may be defined as discontinuation in the normal epithelial surface of the cornea associated with necrosis of the surrounding corneal tissue. Pathologically, it is characterized by oedema and cellular infiltration. +Classify keratitis +Keratitis can be classified in two ways: topographically and etiologically. +Topograhical (morphological) classification +A. Ulcerative keratitis (corneal ulcer): It can be further classified variously as follows: +1. Depending on location: a.Central corneal ulcer b.Peripheral corneal ulcer. +2. Depending on purulence: +a.Purulent corneal ulcer or suppurative corneal ulcer (mostly bacterial and fungal corneal ulcers are purulent). +b.Nonpurulent corneal ulcer (most of the viral, chlamydial, allergic and other noninfective corneal ulcers are nonsuppurative). +3. Depending upon association of hypopyon: a.Simple corneal ulcer (without hypopyon) b.Hypopyon corneal ulcer. +4. Depending upon depth: a.Superficial corneal ulcer b.Deep corneal ulcer +c. Corneal ulcer with impending perforation d.Perforated corneal ulcer. +5. Depending upon slough formation: a.Nonsloughing corneal ulcer b.Sloughing corneal ulcer. +B. Nonulcerative keratitis 1. Superficial keratitis +a.Superficial punctate keratitis b.Diffuse superficial keratitis. +2. Deep keratitis a.Nonsuppurative +• Interstitial keratitis +• Disciform keratitis + +• Keratitis profunda • Sclerosing keratitis +b.Suppurative deep keratitis • Central corneal abscess +• Posterior corneal abscess. +Etiological classification 1. Infective keratitis +a.Bacterial b.Viral +c. Fungal d.Chlamydial e. Protozoal +f. Spirochaetal 2. Allergic keratitis +a.Phlyctenular keratitis b.Vernal keratitis +c. Atopic keratitis 3. Trophic keratitis +a.Exposure keratitis b.Neuroparalytic keratitis +4. Keratitis associated with diseases of the skin and mucous membranes. +5. Keratitis associated with systemic collagen vascular disorders. +6. Traumatic keratitis, which may be due to mechanical trauma, chemical burns, radiational burns or thermal burns. +7. Idiopathic keratitis, e.g., a.Mooren’s ulcer +b.Superior limbic keratoconjunctivitis +c. Superficial punctate keratitis of Thygeson. + +Name the common bacteria responsible for corneal ulceration. +Common bacteria associated with corneal ulceration are: Pseudomonas pyocyanea, streptococcus pneumoniae, E.coli, Proteus, Klebsiella, Neisseria gonorrhoeae, Neisseria meningitidis and Corynebacterium diphtheriae. +What is the prerequisite for most of the infecting agents to produce corneal ulceration? +Damage to the corneal epithelium is a prerequisite for most of the infecting organisms to produce corneal ulceration. Damage to corneal epithelium may occur in following forms: +• Corneal abrasion due to small foreign body, misdirected cilia, trivial trauma, etc. +• Necrosis of epithelium as in keratomalacia. +• Epithelial damage due to trophic changes as in neuroparalytic keratitis. +• Desquamation of epithelial cells as a result of corneal oedema, corneal xerosis and exposure keratitis. +532 Section Vi Practical Ophthalmology \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_18.txt b/notes/A K Khurana - Comprehensive Ophthalmology_18.txt new file mode 100644 index 0000000000000000000000000000000000000000..b6bc96762a4e5297a699b485bcf61f4d5e3a0c8e --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_18.txt @@ -0,0 +1,1599 @@ + + +Name the bacteria which can invade the intact corneal epithelium and produce ulceration. +• Neisseria gonorrhoeae • Neisseria meningitidis +• Corynebacterium diphtheriae. +Name the layers of cornea. 1. Epithelium +2. Bowman’s membrane 3. Corneal stroma +4. Descemet’s membrane 5. Endothelium. +What are the pathological stages of corneal ulceration? 1. Stage of progressive infiltration +2. Stage of active ulceration 3. Stage of regression +4. Stage of cicatrization. + +What are the characteristic features of bacterial corneal ulcer? +A clinical diagnosis of bacterial corneal ulcer is made in patients with a greyish white central or marginal ulcer associated with marked pain, photophobia, blepharospasm, lacrimation, circumcorneal congestion, purulent/mucopurulent discharge, presence or absence of hypopyon with or without vascularization. +What do you mean by hypopyon corneal ulcer? +A purulent corneal ulcer associated with collection of pus in the anterior chamber caused by Pneumococcus is called hypopyon corneal ulcer: +Name the common organisms responsible for hypopyon corneal ulceration. +1. Most fungal ulcers are associated with hypopyon. 2. Common bacteria producing hypopyon ulcer are: Pneumococcus, Pseudomonas, Gonococcus and +Staphylococcus. +What is ulcus serpens? +The characteristic hypopyon ulcer caused by Pneumococcus is called ulcus serpens. +Name the complications of corneal ulcer. 1. Toxic iridocyclitis +2. Secondary glaucoma 3. Descemetocele +4. Corneal perforation, which may be complicated by: • Iris prolapse +• Subluxation or dislocation of the lens • Anterior capsular cataract +• Purulent iridocyclitis often leading to endophthalmitis or even panophthalmitis +• Intraocular haemorrhage in the form of a vitreous haemorrhage or expulsive choroidal haemorrhage. + + +5. After healing of corneal ulcer following complications may be left as sequelae: +• Keractasia +• Corneal opacity which may be nebular, macular, leucomatous or adherent leucoma +• Anterior staphyloma which usually follows a sloughing corneal ulceration. +What is a descemetocele? +When a corneal ulcer extends up to Descemet’s membrane, it herniates (bulges out) as a transparent vesicle called the descemetocele or keratocele. +What are the signs of an impending corneal perforation? Descemetocele formation associated with excessive corneal oedema are the signs of an impending corneal perforation. +What are the clinical features of perforation of corneal ulcer? +Following perforation of a corneal ulcer, immediately pain decreases and patient feels some hot fluid (aqueous) coming out of the eyes. Anterior chamber becomes shallow and iris prolapse may occur. +How will you manage a case of corneal ulcer? Management of a case of corneal ulcer is as follows: +Clinical evaluation +1. Meticulous history should be taken and a thorough ocular examination including slit-lamp biomicroscopy should be carried out to reach the clinical diagnosis for the type of corneal ulcer. +2. Regurgitation test and syringing of lacrimal sac should be carried out to rule out associated dacryocystitis. +3. General physical and systemic examination should be carried out to elucidate the associated malnutrition, diabetes mellitus and any other chronic debilitating disease. +Laboratory investigations +1. Routine laboratory investigations such as haemogloin, TLC, DLC, ESR, blood sugar and complete urine examination should be carried out in each case. +2. Microbiological investigations: Material is obtained by scraping the base and margins of the corneal ulcer (under topical anaesthesia) and is used for following investigations: +• Gram and Giemsa-stained smear for possible identification of infecting organisms +• 10% KOH wet preparation is made for, identification of fungal hyphae +• Culture on blood agar medium for aerobic organisms +Chapter 24 Clinical Ophthalmic Cases 533 + + +• Culture on Sabouraud’s dextrose agar medium for fungi. +Treatment of uncomplicated corneal ulcer +I. Specific treatment for the cause: Bacterial corneal ulcer is treated by topical and systemic antibiotics. +1.It is preferable to start concentrated amikacin (40–100 mg/ml) eyedrops along with fortified cephazolin (33 mg/ml) eyedrops every one hourly for first 5 days and then reduced to 2 hourly, 3 hourly, 4 hourly and 6 hourly. +2.Antibiotic eye ointment should be applied at night. +3.Subconjunctival injection of gentamicin 40 mg and cephazolin 125 mg once a day for 5 days should be given in sloughing corneal ulcer. +II. Non-specific treatment includes: +1.Cycloplegic drugs, e.g. 1% atropine, 0.5% homatropine or cyclopentolate. +2.Systemic analgesics and anti-inflammatory drugs to relieve the pain and oedema. +3.Vitamins (A, B-complex and C) help in early healing of the ulcer. +III. Physical and general measures: +1.Hot fomentation gives comfort, reduces pain and causes vasodilatation. +2.Rest and good diet are useful for smooth convalescence. +What do you mean by a nonhealing corneal ulcer? Enumerate its common causes. +When a corneal ulcer does not start healing despite the best therapy for about 7 to 10 days it is labeled as a nonhealing corneal ulcer. Common causes of non-healing corneal ulcers are as follows: +Local causes +• Associated raised intraocular pressure • Multiple large concretions +• Misdirected cilia +• An impacted foreign body • Dacryocystitis +• Wrong diagnosis, e.g., fungal ulcer being treated as a bacterial ulcer +• Lagophthalmos +• Excessive vascularization of the ulcer area + +Systemic causes +• Diabetes mellitus • Severe anaemia +• Malnutrition +• Chronic debilitating diseases +• Immuno-compromised patients • Patients on systemic steroids. + +How will you treat a case of non-healing corneal ulcer? 1. Removal of any known cause of nonhealing: A thorough search should be made to find out any already missed cause of nonhealing and when +found it should be removed. +2. Mechanical debridement of the ulcer to remove necrosed material may hasten the healing. +3. Chemical cauterization with pure carbolic acid or 10 to 20% trichloroacetic acid may be considered in indolent cases. +4. Peritomy, i.e., severing of perilimbal conjunctival vessels may be useful in the presence of excessive corneal vascularization. +What extra measures will you take for the treatment of impending perforation? +1. Patient should be advised to avoid strain during sneezing, coughing, passing stool, etc. +2. Pressure bandage should be applied to give some external support. +3. Lowering of intraocular pressure by simultaneous use of acetazolamide 250 mg qid orally, 0.5% timolol eyedrops twice a day and intravenous mannitol (20%) drip stat. Even paracentesis with slow evacuation of the aqueous from the anterior chamber may be done, if required. +4. Tissue adhesive glue such as cyanoacrylate is helpful in preventing perforation. +5. Conjunctival flap may be used to cover and support the weak tissue. +6. Bandage soft contact lenses are also useful. +7. Therapeutic keratoplasty, when available, is considered the best mode of treatment. +How will you treat a case of perforated corneal ulcer? The best treatment is an immediate therapeutic keratoplasty. However, short of it, depending upon the size and location of the perforation measures like, use of a tissue glue (cyanoacrylate), bandage soft contact lens or conjunctival flap may be used over and above the conservative management with pressure bandage. +What is a marginal catarrhal ulcer? +Marginal catarrhal ulcer is a superficial ulcer situated near the limbus, usually seen in association with chronic staphylococcal blepharoconjunctivitis. It is thought to be caused by hypersensitivity reaction to staphylococcal toxins. +Name the common fungi associated with mycotic corneal ulceration. +The fungi most commonly responsible for mycotic corneal ulceration are: Aspergillus, Candida and Fusarium. +534 Section Vi Practical Ophthalmology + + +What are the predisposing factors for a mycotic corneal ulcer? +1. Injury by vegetative material. +2. Immunosuppressed patients are prone to secondary fungal ulcers. +3. Excessive use of topical antibiotics and steroids predispose the cornea far fungal infections. +What are the characteristic features of a fungal corneal ulcer? +1. A typical fungal corneal ulcer is dry looking, greyish white with elevated rolled out margins and delicate feathery finger-like extensions into the surrounding stroma under the intact epithelium. +2. A sterile immune ring (yellow line of demarcation) may be present where fungal antigen and host antibodies meet. +3. Multiple, small satellite lesions may be around the ulcer. +4. Usually, a massive and thick hypopyon is present even if the ulcer is very small. +5. A history of trauma (especially by vegetative material) and clinical signs out of proportion to the symptoms, i.e., less marked photophobia and lacrimation with intense ciliary and conjunctival congestion support a fungal origin. +How will you confirm the diagnosis of a fungal corneal ulcer? +Confirmation is made by laboratory investigations, which include examination of a wet KOH, Gram’s and Giemsa-stained films for fungal hyphae and culture on Sabouraud’s dextrose agar medium. +Name the ocular antifungal drugs. I. Polyene antifungals, e.g., +1.Nystatin 3.5% eye ointment 2.Amphotericin-B (0.75 to 3% eyedrops) 3.Natamycin 5% suspension +II. Imidazole antifungal drugs, e.g., ketoconazole, fluconazole miconazole, clotrimazole and econazole +III. Pyrimidine, e.g. flucytosine +IV. Silver compounds, e.g., silver sulphadiazine eyedrops. +Enumerate the ocular lesions of herpes simplex. Ocular involvement by herpes simplex virus (HSV) occurs in two forms: +I. Primary herpes: It is characterized by: 1.Vesicular lesions involving the skin of lids 2.Acute follicular conjunctivitis +3.Fine or coarse epithelial punctate keratitis II. Recurrent herpes: Its lesions are as follows: +1.Punctate epithelial keratitis + + +2.Dendritic ulcer +3.Geographical or amoeboid ulcer 4.Disciform keratitis. +Describe the characteristic features of recurrent herpetic keratitis. +Dendritic ulcer is a typical epithelial lesion of the recurrent herpetic keratitis. The ulcer is of an irregular zigzag linear branching shape (Fig. 6.9). The branches are generally knobbed at the ends. Floor of the ulcer stains with fluorescein and the virus laden cells at the margin take up rose bengal stain. There is an associated marked diminution of the corneal sensations. +Sometimes, the branches of the dendritic ulcer enlarge and coalesce to form a large epithelial typically known as geographical or amoeboid ulcer. + +What are the features of herpes simplex virus (HSV)? Herpes simplex virus is an epitheliotropic, DNA virus. It is of two types: HSV type-1 which typically causes infection above the waist (herpes labialis) and HSV type-II which causes infection below the waist (herpes genitalis). + +Name the predisposing/precipitating stress stimuli which trigger an attack of herpetic keratitis. +• Fever, especially malaria • General ill health +• Exposure to ultraviolet rays • Mild trauma +• Use of topical and systemic steroids • Immunosuppression. +What is disciform keratitis? +Disciform keratitis is stromal keratitis which occurs due to delayed hypersensitivity reaction to the HSV antigen. It is characterized by a focal disc-shaped patch of stromal oedema without necrosis. Associated diminished corneal sensations and fine keratic precipitates differentiate it from other causes of stromal oedema. +Name the antiviral drugs. +Idoxuridine (IDU), trifluorothymidine (TFT), adenine arabinoside (vidarabine) and acyclovir. +Which antiviral drug is effective for stromal viral keratitis? +• Acyclovir. +Enumerate the causes of decreased corneal sensations. • Viral keratitis, neuroparalytic keratitis, diabetic +neuropathy and leprosy. + +What is herpes zoster ophthalmicus? +Herpes zoster ophthalmicus is an acute infection of the gasserian ganglion of the fifth cranial nerve by varicella zoster virus. In it, frontal nerve is more frequently affected than the lacrimal and +Chapter 24 Clinical Ophthalmic Cases 535 + + +nasociliary nerve. About 50% cases of herpes zoster ophthalmicus develop ocular complications. +Ocular involvement in herpes zoster ophthalmicus is associated with involvement of which nerve? +• Nasociliary nerve. +What are the characteristic features of herpes zoster? 1. Fever and malaise occur at the onset. +2. The vesicular eruptions are preceded by severe neuralgic pain along the course of the involved nerves. +3. The lesions are strictly limited to one side of the midline of head (pathognomic feature). +Enumerate the ocular lesions of herpes zoster ophthalmicus. +Conjunctivitis, keratitis, episcleritis, scleritis, iridocyclitis and secondary glaucoma. +What is Mooren’s ulcer? +Mooren’s ulcer (chronic serpiginous or rodent ulcer) is a peripheral degenerative ulcerative keratitis of unknown etiology. It is characterized by a shallow furrow-shaped ulcer having whitish overhanging margin at the advancing edge (Fig. 6.14). +What are the features of neuroparalytic keratitis? 1. No pain, no lacrimation and complete loss of +corneal sensations. +2. Marked ciliary congestion. 3. Corneal sheen is dull. +4. Corneal ulcer is usually superficial and involves the interpalpebral area. +What are the causes of exposure keratitis? 1. Extreme proptosis +2. Bell’s palsy +3. Symblepharon +4. Patients in deep coma. + +What is superficial punctate keratitis? Name a few of its causes. +Superficial punctate keratitis (SPK) refers to occurrence of multiple, spotty lesions in superficial layer of cornea. Its common causes are: +1. Viral infections, e.g., adenovirus infection, epidemic keratoconjunctivitis, herpes zoster keratitis, herpes simplex keratitis, and pharyn-goconjunctival fever. +2. Chlamydial infections, e.g., trachoma. +3. Toxic, e.g., in association with blepharoconjunctivitis. 4. Trophic lesions, e.g., exposure keratitis and +neuroparalytic keratitis. +5. Allergic lesions, e.g., vernal keratitis. 6. Keratoconjunctivitis sicca. + +7. Specific type of idiopathic SPK, e.g., Thygeson’s SPK and superior limbic keratoconjunctivitis. +8. Photophthalmitis. + +What is photophthalmia? +Photophthalmia refers to occurrence of multiple epithelial erosions due to exposure to ultraviolet rays having a wavelength of 290–311 µm. It occurs in the following conditions: +1. Exposure to naked arc light as in industrial welding. 2. Exposure to bright light of a short circuit. +3. Snow blindness due to reflected ultraviolet rays from the snow surface. +What is filamentary keratitis/keratopathy? Name its few important causes. +Filamentary keratitis is a type of superficial punctate keratitis associated with formation of corneal epithelial filaments. Its common causes are: +1. Keratoconjunctivitis sicca (KCS) +2. Recurrent corneal erosion syndrome 3. Herpes simplex keratitis +4. Thygeson’s superficial punctate keratitis +5. Prolonged patching of the eye particularly following ocular surgery like cataract +6. Trachoma. +What is interstitial keratitis? What are its common causes? +Interstitial keratitis is inflammation of the corneal stroma without primary involvement of the epithelium or endothelium. Its common causes are: congenital syphilis, tuberculosis, acquired syphilis, Cogan’s syndrome (interstitial keratitis with acute tinnitus, vertigo and deafness). +What are corneal dystrophies? +Corneal dystrophies are inherited disorders characterized by development of corneal haze in otherwise normal eyes that are free of inflammation or vascularization. These are classified as follows: 1. Anterior dystrophies which primarily affect +epithelium and Bowman’s membrane, e.g., recurrent corneal erosion syndrome. +2. Stromal dystrophies: These include—granular dystrophy, macular dystrophy and lattice dystrophy. +3. Posterior dystrophies which primarily affect the corneal endothelium and Descemet’s membrane, e.g., cornea guttata, Fuchs’ dystrophy. +4. Ectatic dystrophies e.g., keratoconus, keratoglobus. +What is Fuchs’ dystrophy? +Also called as epithelial endothelial dystrophy, affects females more than the males between 5th and 7th decade of life. It is a slowly progressive bilateral condition. Its clinical features can be divided into following four stages: +536 Section Vi Practical Ophthalmology + + +• Stage of cornea guttata +• Oedematous stage or stage of endothelial decomp-ensation +• Stage of bullous keratopathy • Stage of scarring. + +Define keratoconus and describe its treatment. Keratoconus is a noninflammatory ectatic condition of the cornea. It is usually bilateral and manifests at puberty with gradual loss of vision. +The high myopic irregular astigmatic refractive error seen in keratoconus may be treated by hard contact lens in early stages. Ultimately penetrating keratoplasty is required. + +A CASE OF CORNEAL OPACITY + +Case Summary +Presenting symptoms. A patient with corneal opacity usually presents with a whitish scar, causing defective vision as well as cosmetic blemish. +History may reveal a history of trauma to the eye or symptoms suggestive of healed corneal ulceration. Examination reveals an opacity on the cornea (Fig. 6.27) which may be nebular, macular or leucomatous. The location, size, shape and density of the opacity must be described. + +Related Questions +What is a corneal opacity? +The term corneal opacity is used for the loss of corneal transparency due to scarring. + +What are common causes of corneal opacity? 1. Congenital opacities +2. Healed corneal wounds 3. Healed corneal ulcers. + +What are the types of corneal opacity? +1. Nebular corneal opacity. It is a faint opacity which results due to scars involving up to a few superficial lamellae of corneal stroma. +2. Macular opacity. It is a dense opacity produced by scars involving up to about half the thickness of the stroma. +3. Leucomatous corneal opacity (leucoma simplex). It is a very dense, white opacity, which results due to scarring of more than half thickness of corneal stroma. +4. Adherent leucoma. It results when healing occurs after perforation of cornea with incarceration of the iris. + +Name the secondary changes which can occur in a long standing case of corneal opacity. +1. Hyaline degeneration +2. Calcareous degeneration 3. Pigmentation +4. Atheromatous ulceration. +How will you treat a case with corneal opacity? +1. Optical iridectomy. It may be performed in cases with central macular or leucomatous corneal opacities; provided vision improves with pupillary dilatation. +2. Keratoplasty. It provides good visual results in uncomplicated cases with corneal opacities; where optical iridectomy is not of much use. +3. Tattooing of scar. It used to be performed for cosmetic purposes. It is suitable only for firm scars in a quite eye without useful vision. Presently, it is sparingly done. +How do you perform tattooing? +First of all, the epithelium covering the opacity removed under topical anaesthesia. Then a piece of blotting paper of the same size and shape soaked in 4% gold chloride (for brown eyes) or 2% platinum chloride (for dark colour) is applied over it. After 2 to 3 minutes, the piece of blotting paper is removed and a few drops of freshly prepared hydrazine hydrate (2%) solution are poured over it. Lastly, eye is irrigated with normal saline and patched after instilling antibiotic and atropine eye ointment. Epithelium grows over the pigmented area. +What are the causes of corneal vascularization? Normal cornea is avascular. In pathological states, superficial or deep corneal vascularization may occur (Fig. 6.29). +1. Superficial corneal vascularization. In it, vessels are arranged in an arborizing pattern, present below the epithelium and their continuity can be traced with the conjunctival vessels. Its common causes are: • Trachoma +• Phlyctenular keratoconjunctivitis • Superficial corneal ulcers +• Rosacea keratitis +2. Deep corneal vascularization. In it, the vessels are generally derived from the anterior ciliary arteries and lie in the corneal stroma. These vessels are usually straight, not anastomosing and their continuity cannot be traced beyond the limbus. Its common causes are: +• Interstitial keratitis • Disciform keratitis +Chapter 24 Clinical Ophthalmic Cases 537 + + +• Deep corneal ulcers • Chemical burns +• Sclerosing keratitis +• Corneal graft vascularization. + +What is keratoplasty? +Keratoplasty is an operation in which the patient’s diseased cornea is replaced by the donor’s healthy clear cornea. It is of two types: +1. Lamellar keratoplasty (partial thickness). +• Anterior lamellar keratoplasty (ALK), and • Deep lamellar keratoplasty (DLK) +2. Penetrating keratoplasty (full thickness). + +Name the indications for keratoplasty. Anterior Lamellar keratoplasty +Indolent corneal ulcer, superficial corneal opacity and lattice dystrophy. +Penetrating keratoplasty +1. Optical, i.e., to improve vision in patient with corneal opacity, bullous keratopathy, corneal dystrophies and advanced keratoconus. +2. Therapeutic, i.e., to replace inflamed cornea not responding to treatment (indolent deep ulcer). +3. Tectonic grafts, i.e., to restore the integrity of eyeball in corneal perforation and marked corneal thinning. +4. Cosmetic, i.e., to improve appearance of the eye in deep leucomas with no vision in the eye. + +What is the optimum time for the removal of donor eyes from the body of a deceased? +The donor eyes should be removed as early as possible (within 6 hours of death) and should be stored under sterile conditions. + +What are the methods of corneal preservation? +1. Short-term storage (up to 48 hours): The whole globe is preserved at 4°C in a moist chamber. +2. Intermediate storage (up to 2 weeks): The donor corneal button is prepared and stored in McCareyKaufman (MK) medium and various chondroitin sulphate-enriched media such as optisol. +3. Long-term storage (up to 35 days): It is done by organ culture method or cryopreservation. + +Enumerate the complications of keratoplasty operation. +I. Early complications are: Flat anterior chamber, iris prolapse, infection, secondary glaucoma, epithelial defects, primary graft failure. +II. Late complications are: Graft rejection, recurrence of disease, marked astigmatism and cystoid macular oedema. + +From which sources cornea derives its nutrition? • Perilimbal capillaries +• Aqueous humour +• Oxygen from atmosphere. + +What is the nerve supply of cornea? +Cornea is supplied by the nasociliary branch of ophthalmic division of the trigeminal nerve. +What is a corneal facet? +A corneal facet is a transparent depressed scar. On slit-lamp examination light beam appears to dip in the area of a facet. +What is kerotomalacia? +Keratomalacia refers to corneal necrosis due to vitamin A deficiency. In this condition, there is no inflammatory reaction. +What is arcus senilis? +Arcus senilis is a degenerative condition of cornea characterized by an annular lipid infiltration concentric to the limbus. The ring of opacity is about 1 mm wide and is separated from the limbus by a clear zone (lucid interval of Vogt). +A CASE OF ANTERIOR STAPHYLOMA + +Case Summary +Presenting symptoms. Patient presents with loss of vision, bluish discoloration and bulging of anterior part of the eyeball. +History is suggestive of symptoms of corneal ulceration (pain, redness, photophobia, watering, loss of vision and whitish discoloration) followed by bluish discoloration and bulging of anterior part of the eye. Examination reveals that cornea is replaced by a lobulated ectatic scar tissue which is blackened due to the iris plastered behind it (Fig. 6.28). + +Related Questions +What is a staphyloma? +Staphyloma refers to the localized bulging of weak and thin outer tunic of the eyeball (cornea or sclera) lined by uveal tissue which shines through the thinned-out fibrous coat. +What are the types of staphyloma? 1. Anterior staphyloma +2. Ciliary staphyloma +3. Intercalary staphyloma 4. Equatorial staphyloma 5. Posterior staphyloma. +How is an anterior staphyloma formed? +In a patient with sloughing corneal ulcer when the whole cornea sloughs out, the inflamed iris is covered +538 Section Vi Practical Ophthalmology + + +with exudates. Ultimately, these exudates organize and form a fibrous layer over which the conjunctival or corneal epithelium rapidly grows and thus a pseudocornea is formed. Since the pseudocornea is thin and cannot withstand the intraocular pressure, it usually bulges forward along with the plastered iris tissue. This ectatic cicatrix is called anterior staphyloma. +What is the treatment of anterior staphyloma? +1. Most of the times there is no chance of getting useful vision in such eyes. Therefore, treatment is carried out to improve the cosmetic appearance. Localized staphylectomy under heavy doses of steroids may be carried out. After healing, cosmetic artificial shell may be advised. +2. In patients where there is a chance of getting useful vision, keratoplasty (wherever possible) or keratoprosthesis may be performed. +What are the causes of posterior staphyloma? • Pathological myopia +• Posterior scleritis +• Perforating injuries. + +What is episcleritis? Describe features of a nodule of episcleritis. +Episcleritis is a benign recurrent inflammation of episclera, involving the overlying Tenon’s capsule but not the underlying sclera. +A typical nodule of episcleritis is flat, pink or purple, surrounded by injection and is usually situated 2 to 3 mm away from the limbus. +What is the differential diagnosis of nodular episcleritis? +• Inflamed pinguecula +• Foreign body embedded in the bulbar conjunctiva • Scleritis. + +DISEASES OF UVEAL TRACT A CASE OF ACUTE IRIDOCYCLITIS +Case Description +Presenting symptoms. A patient with acute iridocyclitis (anterior uveitis) presents with moderate to severe pain which radiates all over the distribution of trigeminal nerve, photophobia, watering, redness and some diminution of vision of sudden onset. History of present illness. In addition to the details about the presenting symptoms, the history of present illness should also explore the following associations: +• History of allergic conditions like bronchial asthma, hay fever, allergic rhinitis, allergic skin conditions. + +• History of joint pains to rule out rheumatoid disease +• History suggestive of urethritis • History of any dental problem +• History of chronic rhinitis and/or sinusitis • History of trauma to eye +Past history should include enquiries about: • History of similar attacks in the past. +• History of chronic systemic infections such as tuberculosis, syphilis, leprosy, measles, mumps and any other infection. +• History of noninfectious systemic disorders such as diabetes, gout, rheumatoid arthritis and collagen disorder. +• History of allergic and autoimmune disorders. General physical and systemic examination should be conducted to rule out systemic diseases enumerated in the history. Special care should be given to dental, ENT, lymph nodes and joint examinations. +Ocular examination may reveal following signs (Fig. 8.8): +• Visual acuity is diminished. +• Lids may show slight oedema. +• Circumcorneal congestion is marked. +• Cornea may be slightly hazy due to oedema and KPs at the back of cornea which are seen on slit-lamp examination. +• Anterior chamber shows aqueous cells and aqueous flare, hypopyon may also be present. +• Iris may show loss of normal pattern, muddy colour, posterior synechiae, iris nodules and patches of atrophy. +• Pupil is narrow, irregular and sluggishly reacting. Exudates may be present in pupillary area, occlusio pupillae and seclusio pupillae may be seen in some cases. +• Lens. Pigment dispersal, exudates and iris adhesion may be seen on anterior capsule. Complicated cataract may also occur. +• lOP may be normal, low or raised. It is raised firstly in hypertensive uveitis and secondly in pupillary block secondary glaucoma. +A CASE OF CHRONIC IRIDOCYCLITIS + +Case Description +Presenting symptoms are mild to moderate dull ache in the eye, mild photophobia and diminution of vision. History of present illness and past history should explore the diseases mentioned in a case of acute iridocyclitis. Ocular examination may reveal mild circumcorneal flush, keratic precipitates, aqueous flare, aqueous cells, iris atrophic patches, iris nodules, posterior synechial neovascularization and irregular pupil. +Chapter 24 Clinical Ophthalmic Cases 539 + + +Related Questions +Define uveitis +Uveitis refers to inflammation of any part or whole of the uveal tract. Uveal tract includes iris, ciliary body and choroid. +How do you classify uveitis? I. Anatomical classification +1.Anterior uveitis (iridocyclitis) 2.Intermediate uveitis (pars planitis) 3.Posterior uveitis (choroiditis) 4.Panuveitis +II. Clinical classification 1.Acute uveitis 2.Chronic uveitis +III. Pathological classification 1.Suppurative or purulent uveitis +2.Non-suppurative uveitis, which may be: i. Non-granulomatous uveitis ii.Granulomatous uveitis +IV.Etiological classification (Duke-Elder’s) 1.Infective uveitis +2.Allergic uveitis 3.Toxic uveitis 4.Traumatic uveitis +5.Uveitis associated with non-infective systemic diseases +6.Idiopathic uveitis. + +What is the differential diagnosis of acute iridocyclitis? Acute iridocyclitis must be differentiated from other causes of acute red eye; especially acute congestive glaucoma and acute conjunctivitis. The differentiating features are shown in Table 8.1. +What are the differences between granulomatous and non-granulomatous uveitis? +These are shown in Table 8.2. +What are the common causes of acute anterior uveitis? +1. Microbial allergy, e.g., allergy to tubercular proteins, streptococcal proteins, spirochaetal proteins, etc. +2. Atopic uveitis +3. HLA associated uveitis, e.g., HLA-B27: Anterior uveitis is associated with ankylosing spondylitis and Reiter’s syndrome. +4. Idiopathic. +What are the causes of granulomatous uveitis? • Tuberculosis +• Syphilis +• Sarcoidosis • Leprosy + + +• Vogt-Koyanagi-Harada’s disease • Sympathetic ophthalmia. +Whatarethecommoncausesofunilateral iridocyclitis? • Traumatic uveitis +• Herpes zoster uveitis +• Fuchs’ heterochromic cyclitis • Retinal detachment +• Haemophthalmitis +• Iridocyclitis secondary to intraocular tumours. + +What are the keratic precipitates; what are their types and significance? +Keratic precipitates are proteinaceous cellular deposits occurring at the back of cornea (Fig. 8.9). These are of the following types: +1. Fine KPs are characteristic of Fuchs’ cyclitis and herpes zoster uveitis. +2. Small and medium size KPs are seen in acute and chronic non-granulomatous uveitis. These are composed of lymphocytes and may number in hundreds (usually 40–60). +3. Mutton fat KPs. These typically occur in granulomatous iridocyclitis and are composed of epithelioid cells and macrophages. They are large, thick, fluffy, lardaceous KPs, having a greasy or waxy appearance. They are usually few (10–15) in number. +What are iris nodules? +Iris nodules typically occur in granulomatous uveitis.Nodules situated at pupillary border are known as Koeppe’s nodules, while those seen near the collarette are called Busacca’s nodules (Fig. 8.12). +What are synechiae? Describe their types. Synechiae are adhesions of the iris with other intraocular structures. These can be divided into following types: +1. Anterior synechiae: These include anterior peripheral synechiae seen in the angle of anterior chamber and anterior central synechiae seen in adherent leucoma. +2. Posterior synechiae: These refer to adhesions of posterior surface of iris to the anterior surface of crystalline lens or intraocular lens implant or posterior capsule or anterior phase of the vitreous. These are of the following types: +• Posterior segmental synechiae (Figs. 8.9 and 8.15) • Annular synechiae (Fig. 8.13), and +• Total posterior synechiae (Fig. 8.14). + +What is seclusio pupillae and iris bombe? +Annular or ring synechiae are 360° adhesions of pupillary margin to anterior capsule of the lens. +540 Section Vi Practical Ophthalmology + + +These prevent the circulation of aqueous humour from posterior to anterior chamber (seclusio pupillae). Thus, the aqueous collects behind the iris and pushes it anteriorly (leading to iris bombe formation). +What is occlusio pupillae? +Occlusio pupillae refers to occlusion of pupil by the exudates. +What is festooned pupil? +When atropine is instilled in the presence of segmental posterior synechiae, the pupil does not dilate in the areas of synechiae, but dilates in the areas without synechiae. This results in an irregular and dilated pupil known as festooned pupil. +Name the various types of HLA associated uveitis. HLA-B27: Anterior uveitis seen with ankylosing +spondylitis and Reiter’s syndrome HLA-B5: Behcet’s disease +HLA-BW54: Glaucomatocyclitic crisis +HLA-BW22: Vogt-Koyanagi-Harada’s syndrome. + +What are the causes of diminution of vision in a patient with iridocyclitis? +Oneormore ofthefollowingfactors causediminution of vision: +• Corneal oedema • Aqueous haze +• Exudates in the pupillary area • Complicated cataract +• Cyclitic membrane • Vitreous haze +• Papillitis +• Macular oedema. +What are the complications of iridocyclitis? • Complicated cataract (Fig. 8.15) +• Secondary glaucoma • Cyclitic membrane +• Cystoid macular oedema +• Secondary periphlebitis retinae • Band-shaped keratopathy +• Phthisis bulbi. + +What is the treatment of iridocyclitis? I. Nonspecific treatment +a. Local therapy +1.Mydriatic cycloplegic drugs, e.g., 1% atropine, eyedrops or ointment; or 2% homatropine eyedrops. +2.Corticosteroid eyedrops such as dexa-methasone eyedrops 4 times a day. +b. Systemic therapy +1.Corticosteroids are quite useful in severe cases. + +2.Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and phenylbutazone are used when steroids are contraindicated. +3.Immunosuppressive drugs are used in desperate and extremely serious cases. +4.Adrenocorticotropic hormone (ACTH) may be required in recalcitrant cases. +c. Physical measures +1.Hot fomentation. It is very soothing, diminishes pain and increases circulation. +2.Dark goggles give feeling of comfort by reducing photophobia. +II. Specific treatment +It consists of treatment of the cause when discovered, e.g., antitubercular drugs for the underlying Koch’s disease, adequate treatment of associated syphilis, toxoplasmosis, etc. +What are the features of Fuchs’ uveitis? +Fuchs’ uveitis is a chronic non-granulomatous type of low-grade anterior uveitis. It is unilateral and affects middle-aged persons. The disease is characterized by: +• Heterochromia of iris +• Fine KPs at the back of cornea • Faint aqueous flare +• Absence of posterior synechiae • A fairly common rubeosis iridis +• Comparatively early development of complicated cataract and secondary glaucoma. +What are the features of glaucomatocyclitic crisis (Posner Schlossman syndrome)? +It typically affects young adults and is characterized by: +• Recurrent attacks of acute rise of IOP (40-50 mm of Hg) without shallowing of anterior chamber +• Fine KPs at the back of cornea without any posterior synechiae +• Epithelial corneal oedema • A dilated pupil +• A white eye (no congestion). +What is sympathetic ophthalmitis? +Sympathetic ophthalmitis is rare bilateral granulomatous panuveitis which occurs following penetrating ocular trauma usually associated with incarceration of uveal tissue in the wound. The injured eye is called exciting eye and the fellow eye which also develops uveitis is called sympathizing eye. +What are Dalen-Fuchs’ nodules? +Dalen-Fuchs’ nodules are proliferation of the pigment epithelium of iris and ciliary body to form nodular aggregations in sympathetic ophthalmitis. +Chapter 24 Clinical Ophthalmic Cases 541 + + +What is Behcet’s disease? +Behcet’s disease is an idiopathic multisystem disease associated with HLA-B5. It is characterized by: +• Recurrent acute iridocyclitis associated with, hypopyon +• Aphthous ulceration • Genital ulceration +• Erythema multiforme. + +What are ocular lesions of sarcoidosis? +1. Sarcoid plaque on the skin of the eyelids +2. Granulomatous infiltration of the lacrimal gland with xerosis +3. Conjunctival sarcoid nodules 4. Episcleritis +5. Iridocyclitis may occur as: • Acute iridocyclitis +• Chronic granulomatous iridocyclitis (more common) with Koeppe’s and Busacca’s nodules on the iris and mutton fat KPs +• Uveoparotid fever (Heerfordt’s syndrome) 6. Vitritis with snowball opacities +7. Choroidal and retinal granulomas +8. Secondary periphlebitis retinae with candle wax droppings. + +What is VKH syndrome? +Vogt-Koyanagi-Harada’s (VKH) syndrome is an idiopathic multisystem disorder associated with HLA-BW22. It is characterized by: +• Cutaneous lesions such as: alopecia, poliosis and vitiligo +• Neurological lesions include meningism, encephalopathy, tinnitus, vertigo and deafness +• Ocular, features are: chronic granulomatous anterior uveitis, posterior uveitis and exudative retinal detachment. + +What is endophthalmitis? Enumerate common causes of purulent endophthalmitis. Endophthalmitis is inflammation of the inner structures of the eyeball which include uveal tissue, retina and vitreous. Purulent endophthalmitis is a dreaded complication. Its common causes are: +1. Exogenous infections following: • Perforating injuries +• Perforation of corneal ulcer +• Intraocular operations such as cataract surgery and glaucoma surgery +2. Endogenous or metastatic endophthalmitis may occur rarely through blood stream from some septic focus in the body such as caries teeth, puerperal sepsis and generalized septicaemia. + +What is panophthalmitis? Describe its treatment. Panophthalmitis is an intense purulent inflammation of the whole eyeball including the Tenon’s capsule. +Since, there is little hope of saving such an eye, evisceration operation should be performed to remove the pus and infected intraocular contents leaving behind the sclera. +Which is the most common presenting symptom in a patient with choroiditis? +Floaters, i.e., moving small black spots in front of the eyes is the most common presenting symptom in a patient with choroiditis. Floaters occur due to pouring of exudates in the vitreous. +What are the symptoms of central choroiditis? • Defective vision +• Floaters +• Micropsia (patient complains of seeing the objects smaller than normal due to separation of cones of macula due to oedema) +• Metamorphopsia (patient perceives distorted imagesof the objects) results due to alteration in the retinal contour caused by a raised patch of choroiditis +• Macropsia, i.e., perception of the objects larger than they are, may occur due to crowding together of cones +• Photopsia, i.e., a subjective sensation of flashes of light may result due to irritation of cones by inflammatory oedema. +What is the most common cause of central choroiditis? • Toxoplasmosis. +What is pathognomic feature of fungal endop-hthalmitis? +Fluffy ball opacities in the vitreous are pathognomic of fungal endophthalmitis. +At what stage vitrectomy operation should be performed in a patient with endophthalmitis? Vitrectomy is the treatment of choice for fungal endophthalmitis. In bacterial endophthalmitis it should be performed when the condition does not improve with intensive conservative therapy for 48 hours. +What is Reiter’s syndrome? +Reiter’s syndrome is characterized by a triad of urethritis, arthritis and conjunctivitis. In 20 to 30% cases, acute non-granulomatous uveitis is also associated. +What are the causes of a patch of iris atrophy? • Senile +• Post-inflammatory • Glaucomatous +542 Section Vi Practical Ophthalmology + + +• Neurogenic, in lesions of ciliary ganglion • Essential iris atrophy. + +DISEASES OF LENS + +A CASE OF SENILE CATARACT + +Case Description +Age and sex. It is seen equally in persons of either sex, usually above the age of 45 years (average 50–60 years). +Presenting symptoms. Patient usually presents with a gradual, painless and progressive loss of vision. In the early stages, there may or may not be associated history of coloured haloes, uniocular polyopia, glare and misty vision. +History of present illness. In addition to the details about the presenting symptoms, the history of present illness should be taken: +• To rule out other cause of acquired cataract, e.g., history of exposure to radiations (radiation cataract) excessive heat in industrial workers especially in glass workers and iron workers (heat cataract), history of injury to the affected eye (traumatic cataract), history of diabetes mellitus (diabetic cataract), history of atopic diseases (atopic cataract), history of steroid intake (steroid cataract), history suggestive of anterior uveitis (complicated cataract), etc. +• To rule out diseases affecting surgical treatment such as history of hypertension, diabetes mellitus, bronchial asthma. +Ocular signs observed in different types of senile cataract are shown in Table 9.1, page 191 +General physical and systemic examination (see page 195). +Ocular examination. In addition to ocular examination to note signs of different types of cataract, the following useful information is essential before the patient is considered for surgery (see page 196): +• Retinal function tests, +• Search for local source of infection, +• Slit-lamp examination for anterior segment status, and +• IOP measurement. + +Related Questions +What is your diagnosis? +Senile cataract (immature, mature, hypermature or nuclear, depending upon the type of cataract). +Define cataract. +Normal crystalline lens is a transparent structure. Any opacity in the lens or its capsule is called a cataract. + +How do you classify cataracts? A.Etiological classification +I. Congenital and developmental cataract II.Acquired cataract +1.Senile cataract 2.Traumatic cataract 3.Complicated cataract 4.Metabolic cataract 5.Electric cataract 6.Radiational cataract 7.Toxic cataract, e.g., +a.Corticosteroid-induced cataract b.Miotics-induced cataract +c. Copper-induced and iron-induced cataracts (in chalcosis and siderosis respectively). +8. Cataract associated with skin diseases (dermatogenic cataract). +9. Cataract associated with osseous diseases. 10. Cataract associated with miscellaneous +syndromes e.g., +• Dystrophic myotonica • Down’s syndrome. +B. Morphological classification (Fig. 9.5) +1. Capsular cataract: It involves the capsule and may be: +a.Anterior capsular cataract b.Posterior capsular cataract +2. Cortical cataract: It involves the cortex of the lens. 3. Nuclear cataract: It involves the nucleus of the +crystalline lens. +4. Polar cataract: It involves the capsule and superficial part of the cortex in the polar region and may be: +a.Anterior polar cataract b.Posterior polar cataract. +What are the types of senile cataract? • Cortical cataract +• Nuclear cataract. + +Name the stages of maturation of senile cortical cataract. +• Stage of lamellar separation • Stage of incipient cataract +• Stage of immature senile cataract (cuneiform or cupuliform) +• Stage of mature senile cataract +• Stage of hypermature senile cataract (Morgagnian or sclerotic type). + +What do you mean by nuclear sclerosis? +Nuclear sclerosis is an aging process in which lens nucleus becomes inelastic and hard. Refractive index of the lens is increased resulting in myopia. These +Chapter 24 Clinical Ophthalmic Cases 543 + + +changes begin centrally and spread peripherally. On oblique illumination pupillary area looks greyish. + +How will you differentiate immature senile cataract (ISC) from nuclear sclerosis without cataract changes? See Table 9.3, Page 192. + +Name the complications which can occur during maturation of cortical cataract. +a. Lens-induced glaucoma, which may be: +1. Phacomorphic glaucoma (secondary narrow-angle glaucoma). It occurs due to intumescent (swollen) lens causing blockage of the angle of anterior chamber and pupil. +2. Phacolytic glaucoma (secondary open-angle glaucoma). It occurs due to blockage of trabecular meshwork by macrophages laden with lens proteins leaked from the Morgagnian hypermature cataract. +b. Phacoanaphylaxis +c. Subluxation or dislocation of the lens. + +What are the characteristics of diabetic cataract? +A true diabetic cataract is characterized by appearance of bilateral snowflake-like opacities hence the name ‘snowflake cataract’ or ‘snow-storm cataract.’ + +What are the characteristics of a complicated cataract? +A typical complicated cataract is characterized by ‘bread-crumb’ appearance of the opacities situated in the posterior subcapsular area, which exhibit ‘polychromatic lustre’ on slit-lamp examination. + +Enumerate the indications for extraction of a catara-ctous lens. +1. Grossly diminished vision hampering easy living 2. Medical indications, e.g., +• Lens-induced glaucoma • Phacoanaphylaxis +• Patient having diabetic retinopathy or retinal detachment, treatment of which is hampered by the presence of lens opacities +3. Cosmetic indication. Some patients may insist for cataract extraction (even with no hope of getting useful vision) in order to obtain a black pupil. + +What preoperative evaluation would you like to carry out before cataract surgery? +1. General physical and systemic examination to rule out: diabetes mellitus, hypertension, obstructive lung disorders and any potential source of infection in the body such as septic gums, urinary tract infection, etc. + +2. Ocular examination with special reference to: 1.Retinal function tests +2.Search for local source of infection, i.e. conjunctivitis, dacryocystitis, blepharitis, etc. +3.Intraocular pressure measurement. + +Name the retinal function tests that you would like to carry out before planning cataract surgery? +1. Light perception (PL) +2. Projection of light rays (PR) +3. A test for Marcus Gunn pupillary response 4. Two-light discrimination test. +What is the most accurate method of predicting the macular potential for visual acuity in the presence of advanced cataract? +• Laser interferometry. +Name the objective tests for evaluating posterior segment of eye in a cataract patient. +1. Ultrasonography (A and B scan) 2. Electroretinography +3. Electro-oculography +4. Visually-evoked response. +Surgical management of adulthood cataracts +For questions related to surgical management of cataract, see page 605. +A CASE OF CONGENITAL/DEVELOPMENTAL CATARACT + +Case Description +Age and sex. Congenital cataract is present since birth. Developmental cataract may occur any time from infancy to adolescence. It is equally common in both sexes. +Presenting symptoms. Parents may bring the child with one or more of the following complaints: +• White reflex in the pupillary area (leukocoria) +• Inability of the child to see well which may be noticed by the parents +• Wandering movements of the eyes • Deviation (squint) in one eye +• Nystagmus. +History of present illness should include: +• Details about the time of appearance and progress of the above symptoms. +• Obstetrical history to explore occurrence of rubella, malnutrition, diabetes mellitus, exposure to radiations and drug intake during pregnancy. +• Birth history should include information about: home or hospital delivery; full-term or premature birth; normal or low birth weight (LBW) for age; history of birth trauma; and history of ocular infections after birth. +544 Section Vi Practical Ophthalmology + + +• Family history should include history of similar complaints in the family, history of any other ocular or systemic defects in the family, history of diabetes mellitus and history of consanguinous marriage. +General physical and systemic examination should be carried out thoroughly with special attention for any associated mental retardation, cerebral palsies, features of rubella, features of galactosaemia, hepatosplenomegaly and cardiovascular anomalies such as patent ductus arteriosus (PDA), ventricular septal defect (VSD) and pulmonary stenosis (PS). Ocular examination. Conspicuous sign is leukocoria (white reflex in pupillary area). Make special note of visual acuity (if possible), any associated squint, nystagmus and other congenital anomalies such as microphthalmos, microcornea, aniridia, iris coloboma, and persistent pupillary membrane. Lens should be examined in detail after dilation of the pupil. If possible fundus should be examined to know the status of the posterior segment. + +Related Questions +Name the types of congenital cataract. +• Cataracta centralis pulverulenta (embryonic nuclear cataract) +• Lamellar (zonular) cataract • Sutural cataract +• Anterior polar cataract • Posterior polar cataract • Coronary cataract +• Blue dot punctate cataract • Total congenital cataract. +Enumerate the etiological factors associated with congenital cataract. +1. Heredity (about 3% cases) 2. Maternal factors, e.g., +• Malnutrition during pregnancy • Rubella infection +• Toxoplasmosis +• Cytomegalo inclusion disease +• Drug ingestion during pregnancy, e.g., thalidomide, corticosteroids +3. Fetal or infantile factors, e.g., +• Anoxia due to placental haemorrhage +• Metabolic disorders, e.g., galactosaemia, neonatal hypoglycaemia +• Lowe’s syndrome +• Myotonia dystrophica • Birth trauma +• Malnutrition in early infancy 4. Idiopathic (about 50% cases). + +What are the features of zonular (lamellar) cataract? Zonular cataract typically occurs in a zone of fetal nucleus surrounding the embryonic nucleus (Fig. 9.7). The area of the lens internal and external to the zone of cataract is clear, except for small linear opacities like spokes of a wheel (riders) which run outwards towards the equator. It is usually bilateral and frequently causes severe visual defect. +What is the differential diagnosis of a white pupillary reflex? +1. Congenital cataract 2. Retinoblastoma +3. Retinopathy of prematurity (retrolental fibroplasia) 4. Persistent hyperplastic primary vitreous +5. Parasitic endophthalmitis +6. Exudative retinopathy of Coats. + +How will you manage a case of congenital cataract? 1. Small stationary lens opacities which do not +interfere with vision can safely be ignored. +2. Incomplete central stationary cataracts may be treated by optical iridectomy or use of mydriatics to improve the vision considerably. +3. Complete cataracts should be removed surgically as early as possible. + +Name the surgical procedures in vogue for mana-gement of childhood cataracts. +1. Discission (needling) operation (almost obsolete) 2. Anterior capsulotomy and irrigation aspiration of +the lens matter. 3. Lensectomy. + +How should paediatric aphakia be corrected? +1. Children above the age of 5 years can be corrected by implantation of posterior chamber intraocular lens during surgery. +2. Those below the age of 5 years should preferably be treated by extended wear contact lens. Spectacles can be prescribed in bilateral cases. At a later stage secondary IOL implantation may be considered. +3. Epikeratophakia and keratophakia are still under trial. +A CASE OF APHAKIA +Case Description +Presenting symptoms. Patient usually gives history of cataract extraction operation (postoperative aphakia). Sometimes, patient may present with such a situation following trauma to the eye (aphakia due to traumatic posterior dislocation of lens) and rarely without any cause (aphakia due to spontaneous posterior dislocation of lens). +Chapter 24 Clinical Ophthalmic Cases 545 + + +• Patient usually has marked loss of vision both for distance and near due to high hypermetropia and absence of accommodation, respectively. +• Patient may complain of seeing red (erythropsia) and blue (cyanopsia) images. This occurs due to excessive entering of ultraviolet and infrared rays in the absence of crystalline lens. +Signs of aphakia seen on ocular examination: • Limbal scar may be seen in surgical aphakia • Anterior chamber is deeper than normal +• Iridodonesis, i.e., tremulousness of the iris can be demonstrated +• Pupil is jet black in colour +• Purkinje image test shows only two images (normally four images are seen) +• Fundus examination shows hypermetropic small disc • Retinoscopy reveals high hypermetropia. +A CASE OF PSEUDOPHAKIA + +Case Description +Presenting symptoms +• Patient usually gives a history of cataract operation and may also be aware of the intraocular lens (IOL) implantation. +• Patient may give history of normal far vision (emmetropia produced by IOL) but defective near vision due to loss of accommodation. +• Some patients may give history of normal near vision but defective far vision (due to 2–3 D myopia produced by a high power IOL). +• Some patients are uncomfortable due to defective vision both for distance and near. This occurs due to hypermetropia produced by a low power IOL and loss of accommodation. +Signs of pseudophakia +• Surgical limbal scar may be seen. +• Anterior chamber is slightly deeper than normal. • When implanted, the angle supported anterior +chamber IOL (Fig. 9.30) and iris claw IOL(Fig. 9.31) are seen in the anterior chamber. +• Mild iridodonesis (tremulousness of iris) may be demonstrated. +• Purkinje image test shows four images. +• Pupil is blackish in colour. When light is thrown in pupillary area, shining reflexes are observed. When examined under magnification after dilating the pupil, the presence of posterior chamber IOL when implanted is confirmed (Fig. 9.32). +• Visual status and refraction of the patient will vary depending upon the power of IOL implanted as described above. + +Related Questions +Define aphakia. +Aphakia literally means absence of the crystalline lens from the eye. However, from the optical point of view, it may be considered as a condition in which the lens is absent from the pupillary area and does not take part in refraction. Optically aphakia may be: • Complete aphakia, i.e., whole of the lens is absent +from its normal position. +• Partial aphakia, i.e., part of the lens is present in the pupillary area. In this situation aphakic and phakic portions are seen simultaneously in pupillary area. +Enumerate the refractive changes which occur in an aphakic eye. +1. Eye becomes highly hypermetropic. +2. Total power of the eye is reduced to +44 DS from +60 DS. +3. Anterior focal distance becomes 23 mm (from 15 mm in normal phakic eye). +4. Posterior focal distance becomes 31 mm (from 24 mm in normal phakic eye). +5. There is anterior shift of nodal point and principal focus. +6. There is complete loss of accommodation due to absence of lens. +7. Astigmatism is induced due to corneal/limbal scar. +Name the various modalities for correction of aphakia and enumerate advantages and disadvantages of each. +1. Spectacles +Advantages: It is cheap, easy and safe method of correcting aphakia. +Disadvantages: (i) Image is magnified by 30 per cent, so not useful in unilateral aphakia (produces diplopia), (ii) problems of spherical and chromatic aberrations may be troublesome, (iii) field of vision is limited, (iv) prismatic effect of thick glasses causes, ‘roving ring scotoma’ (v) cosmetic blemish, especially in young aphakics. +2. Contact lenses +Advantages: (i)Less magnification (5%) of the image, (ii) elimination of aberrations and prismatic effect of thick glasses, (iii) wider and better field of vision, (iv) cosmetically better accepted by young persons. Disadvantages: (i) more cost, (ii) cumbersome to wear, especially in old age and in childhood, (iii) corneal complications may occur. +3. Intraocular lens implantation +It is the best available method of treatment. Advantages: It offers all the advantages which the contact lenses offer over the spectacles. In addition, the +546 Section Vi Practical Ophthalmology + + +disadvantages of contact lenses are also taken care of. Disadvantage: It requires more skilled surgeons and costly equipment. +4. Refractive corneal surgery +It is still under trial and includes keratophakia and epikeratophakia. +What are fundus findings in a patient with high hypermetropia? +Fundus examination in a patient with high hyper-metropia may show: +• Pseudopapillitis +• Shot silk appearance of the retina +Enumerate the signs of aphakia. • Deep anterior chamber +• Iridodonesis +• Jet black pupil +• Purkinje’s image test shows only two images (normally four) +• Fundus examination shows small optic disc • Retinoscopy, reveals high hypermetropia. +What is the average standard power of the lenses required for spectacle correction of aphakia? +In preoperative emmetropic patient, the standard power of the lenses required for spectacle correction of aphakia for distance vision is + 10DS with an additional cylindrical lens for acquired astigmatism. For near vision correction an additional +3 DS is required as the accommodation is absent in an aphakic eye. +What is pseudophakia? +Pseudophakia refers to presence of an intraocular lens in the papillary area. +What is the refractive position of the pseudophakic eye? +A pseudophakic eye may be emmetropic, myopic or hypermetropic depending upon the power of the IOL implanted. +What is the average standard power of the posterior chamber IOL? +Exact power of an IOL to be implanted varies from individual to individual and is calculated by biometry using keratometer and A-scan ultrasound. +What is the average weight of an IOL? +Average weight of an IOL in air is 15 mg and in aqueous humour is about 5 mg. +What is the power of the IOL in air vis-a-vis in the aqueous humour? +Power of an IOL in air is much more (about +60D) than that in the aqueous humour (about + 20D). + +What is the difference in the power of an anterior chamber IOL versus posterior chamber IOL? Equivalent power of an anterior chamber IOL is less (say about +18D) than that of posterior chamber IOL (+20D). +Surgical management of cataract +For questions related to surgical management of a cataract patient, see page 605. + +GLAUCOMA +A CASE OF PRIMARY ANGLE-CLOSURE GLAUCOMA + +Case Description +Age and sex. Primary narrow-angle glaucoma usually presents between 50 and 60 years of age. It occurs more commonly in females than males in a ratio of 4:1. +Presenting symptoms depend upon the stage of the disease as follows: +1. Primary angle-closure suspect (PACS). Patient does not present in this stage as there are no symptoms. It is diagnosed: +• On routine slit-lamp examination in patients presenting with some other eye disease, and +• In fellow eye of the patients presenting with subacute or acute angle-closure glaucoma. +• On glaucoma screening. +2. Primary angle-closure (PAC). Patient presents with transient blurring of vision, coloured haloes around the light due to corneal oedema and mild headache. These symptoms are due to transient rise in intraocular pressure (IOP) and occur in intermittent attacks at irregular intervals. The attacks are usually precipitated by overwork in the evening, anxiety and fatigue. +Acute primary angle-closure (Acute PAC). Patient presents with an attack of sudden onset of very severe pain in the eye which radiates along the branches of fifth nerve. Frequently, there is history of associated nausea, vomiting and prostrations. There is history of rapidly progressive loss of vision, redness, photophobia and watering. About 5% patients give history of typical previous intermittent attacks. +3. Primary angle-closure glaucoma (PACG). Patients may have dull pain and discomfort in the eye along with marked diminution of vision. Patients may or may not give history of preceding attack of acute PAC. 4. Absolute glaucoma. Such patients present with: +• Pain in the eye which is severe and irritating, • Constant headache, +• Watering and redness of the eye, and +Chapter 24 Clinical Ophthalmic Cases 547 + + +• Complete loss of vision (no perception of light) This stage results if PACG is left untreated. +Ocular examination. The signs observed on ocular examination depend upon the stage of glaucoma (See page 239–247): +1. Primary angle-closure suspect (PACS). The eye is white and quiet. Anterior chamber is shallow. Gonioscopy reveals narrow angle. IOP is usually normal. +2. Primary angle-closure (PAC). Usually, the eye looks normal except for a shallow anterior chamber and narrow angle (on gonioscopy). +Acute primary angle-closure. Signs areas follows: • Lids may be oedematous. +• Conjunctiva is chemosed, and congested, (both conjunctival and ciliary vessels are congested). +• Cornea becomes oedematous and insensitive. +• Anterior chamber isvery shallow. Aqueous flare or cells may be seen in anterior chamber. +• Angle of anterior chamber is completely closed as seen on gonioscopy. +• Iris may be discolored. +• Pupil is semidilated, vertically oval and fixed. It is non-reactive to both light and accommodation. +• lOP is markedly elevated, usually between 40 and 70 mm of Hg. +• Optic disc is oedematous and hyperaemic. +• Fellow eye shows shallow anterior chamber and a narrow angle. +3. Primary angle-closure glaucoma (PACG). Signs are as follows: +• The IOP remains constantly raised. +• Eye is painless and white like primary open angle glaucoma. +• Visual field defects appear which are similar to those in POAG. +• Optic disc may show glaucomatous cupping. • Visual acuity is decreased. +• Gonioscopy reveals angle closed by peripheral anterior synechiae. +4. Absolute glaucoma. Signs are as follows: • Lids show mild oedema. +• Palpebral aperture is slightly narrow. +• The anterior ciliary veins are dilated with a slight ciliary flush around the cornea (perilimbal reddish blue zone). +• In long-standing cases, few prominent and enlarged vessels are seen in the form of ‘caput medusae.’ +• Cornea in early cases is clear but insensitive. Slowly it becomes hazy and may develop epithelial bullae (bullous keratopathy) or filaments (filamentary keratitis). + +• Anterior chamber is very shallow. • Iris becomes atrophic. +• Pupil becomes fixed and dilated and gives a greenish hue. +• Optic disc shows glaucomatous optic atrophy. +• Intraocular pressure is high; eyeball becomes stony hard. +A CASE OF PRIMARY OPEN-ANGLE GLAUCOMA + +Case Description +An early case of primary open-angle glaucoma (POAG) is usually not given in undergraduate examinations. However, an advanced or a case of POAG which has been operated for trabeculectomy may be kept as short or long case. +Age and sex. POAG usually affects about 1 in 100 of the general population (of either sex) above the age of 40 years. The disease is essentially bilateral. Presenting symptoms. The disease is insidious and usually asymptomatic. Mild symptoms experienced by the patients include: +• Mild headache and eyeache. +• Difficulty in reading (patients usually give history of frequent change in near vision glasses). +• Occasionally, an observant patient may notice a defect in the visual field (scotoma). +• In late stages patient may complain of delayed dark adaptation. +Ocular examination. Anterior segment is usually normal. In advanced cases, the pupils are sluggishly reacting. Fixed and dilated pupils are seen in absolute glaucoma. Diagnosis is usually made from triad of raised intraocular pressure (IOP), glaucomatous optic disc changes and visual field changes (see pages 239-247). In a case of POAG operated for trabeculectomy, a filteration conjunctival bleb is seen at the site of operation near the limbus. +A CASE OF PHACOMORPHIC GLAUCOMA Presenting symptoms. Patient presents with a sudden onset of severe pain, redness, watering from the eyes and marked loss of vision. Usually, there is associated nausea, vomiting, headache and prostration. Patient always gives history of preceding gradual painless loss of vision. +Ocular examinationreveals following signs (Fig. 10.21): • Lids may be oedematous. +• Conjunctiva is chemosed and congested (both conjunctival and ciliary vessels are congested). +• Cornea becomes oedematous and insensitive. +• Anterior chamber is very shallow (opposite eye normal). Aqueous flare and cells may be seen in the anterior chamber. +548 Section Vi Practical Ophthalmology + + +• Pupil is semidilated, vertically oval and fixed. +• Lens is cataractous, swollen and bulging forward (intumescent cataract). +• IOP is markedly elevated. + +A CASE OF PHACOLYTIC GLAUCOMA + +Case Description +The presenting symptoms and signs are similar to phacomorphic glaucoma except for following differences: +• Anterior chamber is not shallow. It is normal or slightly deep. Aqueous is turbid. +• Lens shows hypermature Morgagnian senile cataract. +RELATED QUESTIONS +What are normal values of intraocular pressure? • Range: 10 to 21 mm of Hg +• Mean: 16 ± 2.5 mm of Hg + +What is the normal amount of aqueous humour present in the eye? +Normal amount of aqueous humour present in the anterior chamber is about 0.25 ml and in posterior chamber is 0.06 ml. +What is the normal rate of aqueous production? • 2.3 ml/minute. + +What is the site of aqueous production? • Ciliary processes. +Name the mechanisms concerned with aqueous production. +• Diffusion +• Ultrafiltration +• Active secretion. +Define glaucoma. +Glaucoma is not a single disease but a group of disorders in which intraocular pressure is sufficiently raised (above the tolerance limit of the affected eye) to impair normal functioning of the optic nerve. +How do you classify glaucoma? I. Congenital/developmental +1.Primary congenital glaucoma (without associated anomalies) +2.Developmental glaucoma with other associated anomalies +II. Primary glaucomas +1.Primary open-angle glaucoma (POAG) 2.Primary angle-closure glaucoma (PACG) 3.Primary mixed mechanism glaucoma +III. Secondary glaucomas. + +What is the incidence of primary angle-closure glaucoma? +• 1 in 1000 people over 40 years • Male to female ratio is 1:4. +Name the predisposing factors for PACG. • Hypermetropic eyes +• Small corneal diameter +• Relative large size of the crystalline lens • Short axial length of eyeball +• Shallow anterior chamber • Plateau iris configuration. +Name the precipitating factors for an attack of acute congestive glaucoma. +• Dim illumination +• Emotional stress, anxiety and excitement • Use of mydriatics. +Describe the mechanism of rise in IOP in acute narrow-angle glaucoma. +Mid-dilated pupil—increased contact between the lens and relative iris pupil block—physiological iris bombe formation—appositional angle closure (causing transient rise in IOP)— synechial angle closure—prolonged rise in IOP. +Name the clinical stages of primary angle-closure glaucoma. +1. Primary angle-closure suspect (PACS) 2. Primary angle-closure (PAC) +• Acute primary angle-closure +3. Primary angle-closure glaucoma (PACG) 4. Absolute glaucoma. +Name the provocative tests used in primary angle-closure suspect (PACS) and primary angle closure (PAC) stage to confirm the diagnosis. +1. Darkroom test 2. Prone test +3. Prone darkroom test +4. Mydriatic test (10% phenylephrine test) +5. Mydriatic-miotic test (10% phenylephrine and 2% pilocarpine test). +Enumerate the sequelae of an attack of acute primary angle closure (Acute PAC). +• Sectoral iris atrophy +• Spiralling of iris fibres +• Iris hole (pseudopolycoria) • Large irregular pupil +• Glaucomflecken +• Peripheral anterior synechiae • Chronic corneal oedema. +Chapter 24 Clinical Ophthalmic Cases 549 + + +How will you treat a case of acute primary angle-closure? +I. Immediate medical treatment to control pain and lower the intraocular pressure +1.Injectable analgesic to relieve the severe pain 2.Acetazolamide 500 mg stat and then 250 mg +qid orally. +3.Hyperosmotic agents, e.g., glycerol 1 to 2 g per kg body weight orally in lemon juice and/ or mannitol 1 to 2 g per kg body weight (20% solution) IV over 30 minutes. +4.Pilocarpine eyedrops 2 to 4% every 15 minutes for one hour and then qid. +5.Timolol maleate eyedrops 0.5% bd. +6.Topical steroid 3 to 4 times a day to control the inflammation. +II. Surgical treatment +1.Peripheral iridectomy/laser iridotomy is sufficient when peripheral anterior synechiae (PAS) are formed in less than 50% of the angle. +2.Filtration surgery (e.g., trabeculectomy) is performed when PAS are formed in more than 50% of the angle. +3.Peripheral iridectomy/laser iridotomy should also be considered as prophylaxis for the fellow eye. + +Name the structures forming angle of the anterior chamber. +1. Root of the iris +2. Anterior most part of the ciliary body 3. Scleral spur +4. Trabecular meshwork +5. Schwalbe’s line (prominent end of Descemet’s membrane of cornea). + +How will you grade the angle width gonioscopically? Shaffer’s grading system is as follows: +Grade 4 (Wide open angle) • Angle width is 35°–45° +• Structures seen are from Schwalbe’s line to ciliary body +• Closure impossible Grade 3 (Open angle) +• Angle width is 20°–35° +• Structures seen are from Schwalbe’s line to scleral spur +• Closure impossible +Grade 2 (Moderately narrow angle) • Angle width is about 20°. +• Structures seen are from Schwalbe’s line to trabecular meshwork +• Angle closure is possible but unlikely + + +Grade 1 (Very narrow angle) • Angle width is about 10° +• Structure seen is Schwalbe’s line only • High-angle closure risk +Grade 0 (Closed angle) • Angle width is 0° +• None of the angle structures are seen (iridocorneal contact) +• Completely closed angle. + +Name the structures forming aqueous outflow system. +• Trabecular meshwork • Schlemm’s canal +• Collector channels. +What is the incidence of primary congenital/ developmental glaucoma? +• Affects 1 in 10,000 live births • Male to female ratio is 3:1. +What is the pathogenesis of developmental glaucoma? +Failure in the absorption of mesodermal tissue resulting in failure of development of the angle structures. +What are gonioscopic findings of developmental glaucoma? +• Barkan’s membrane may be present • Thickening of trabecular meshwork +• Insertion of iris above the scleral spur • Peripheral iris stroma hypoplasia. +What is buphthalmos? +This term is used when eyeball enlarges (corneal diameter becomes more than 13 mm) in children developing congenital glaucoma at an early age (before the age of 3 years). +What is the treatment of primary congenital glaucoma? +• Goniotomy +• Trabeculotomy +• Trabeculectomy (with antifibrosis treatment). +What are the causes of secondary congenital glaucoma? +I. Glaucoma associated with mesodermal dysgenesis of the anterior ocular segment, e.g.: +1.Posterior embryotoxon 2.Axenfeld’s anomaly 3.Rieger’s syndrome 4.Peter’s anomaly +II. Glaucoma associated with aniridia (50%) +III. Glaucoma associated with ectopia lentis syndrome 1.Marfan’s syndrome +550 Section Vi Practical Ophthalmology + + +2.Weill-Marchesani’s syndrome 3.Homocystinuria +IV.Glaucoma associated with phacomatoses: 1.Sturge-Weber syndrome (50% cases) +2.Von Recklinghausen’s neurofibromatosis (25% cases) +V. Miscellaneous conditions 1.Lowe’s syndrome (50% cases) 2.Naevus of Ota 3.Nanophthalmos +4.Congenital microcornea (60%) 5.Congenital rubella syndrome (10% cases). +What is the incidence of primary open-angle glaucoma? +• It affects 1 in 100 population (of either sex) above the age of 40 years. +• It forms about one-third cases of all glaucomas. +What are the features of glaucomatous cupping of the disc? +These include (Fig. 10.10 and 10.11) the following: 1. Cup/disc ratio is increased (normal 0.3 to 0.4), +asymmetry of more than 0.2 is suspicious. 2. Notching of the rim. +3. Nasal shift of the vessels at disc. 4. Pallor area on the disc. +5. Presence of splinter haemorrhages on or near the disc margin. +Name the predisposing factors for POAG. 1. Heredity (positive family history) +2. Age (between 5th and 7th decade) 3. High myopia +4. Diabetes mellitus. + +What is the characteristic triad of POAG? +1. Intraocular pressure more than 21 mm of Hg 2. Glaucomatous cupping of the disc +3. Glaucomatous field defects. + +What is ocular hypertension? +Ocular hypertension or glaucoma suspect is the term used when a patient has an IOP constantly more than 23 mm of Hg but no optic disc or visual field changes. +What is low tension glaucoma (LTG)? +This term is used when typical glaucomatous disc cupping with or without visual field changes is associated with an IOP constantly below 21 mm of Hg. +What are the other ocular associations of POAG? 1. High myopia +2. Fuchs’ dystrophy +3. Retinitis pigmentosa + +4. Central retinal vein occlusion (CRVO) 5. Primary retinal detachment. +What are glaucomatous field defects? 1. Baring of the blind spot +2. Paracentral scotoma in Bjerrum’s area (an arcuate area extending above and below the blind spot upto between 10° and 20° of fixation point) +3. Seidel scotoma +4. Arcuate or Bjerrum’s scotoma 5. Double arcuate scotoma +6. Roenne’s central nasal step +7. Advanced field defects with tubular vision. + +What is the treatment for primary open-angle glaucoma? +1. Medical treatment: It is still the initial therapy. Topical timolol maleate 0.25% BD which may be increased to 0.5% BD Pilocarpine TDS 2% which may be increased to 4% BD was previously used as drug of second choice. Recently latanoprost (0.005%, OD) is being considered the drug of first choice (provided patients can afford to buy it. Dorzolamide (2%, 2–3 times/day) has replaced pilocarpine as the second drug of choice and even as adjunct drug. If the patient does not respond to a single drug the two drugs can be combined. If still the IOP is not controlled, tablet acetazolamide 250 mg TDS may be added. +2. Argon laser trabeculoplasty:It may be considered as an alternative to medical therapy or as an additional measure in patients not responding to medical therapy alone. +3. Surgical therapy: It is usually undertaken when patient does not respond to maximal medical therapy alone or in combination with laser trabeculoplasty. Recently, it is also being considered as the primary line of treatment. Surgical treatment mainly consists of filtration surgery trabeculectomy. +What are secondary glaucomas? +In secondary glaucomas, intraocular pressure is raised due to some other primary ocular or systemic disease. Depending upon the causative primary disease,secondary glaucomas are classified as follows: +1. Lens-induced glaucomas +2. Glaucomas associated with uveitis 3. Pigmentary glaucoma +4. Neovascular glaucoma +5. Pseudoexfoliative glaucoma (glaucoma capsulare) 6. Glaucomas associated with intraocular haemor- +rhages +7. Steroid-induced glaucoma +Chapter 24 Clinical Ophthalmic Cases 551 + + +8. Traumatic glaucoma 9. Glaucoma in aphakia +10. Glaucoma associated with intraocular tumours 11. Glaucomas associated with iridocorneal +endothelial (ICE) syndromes +12. Ciliary block glaucoma (malignant glaucoma). + +What are lens-induced glaucomas? +1. Phacomorphic glaucoma: Here in IOP is raised due to secondary angle closure and/orpupil block by: +i. Intumescent (swollen) cataractous lens (Fig. 10.21) +ii. Anterior subluxated lens iii.Spherophakia +2. Phacolytic glaucoma: Here in IOP is raised due to clogging of trabecular meshwork by the macrophages laden with the leaked lens proteins, usually in hypermature cataract. +3. Lens particle glaucoma: It occurs due to blockage of trabeculae by the lens particles following rupture of the lens or after ECCE. +4. Phacoanaphylactic glaucoma: Sensitization of eye or its fellow to lens proteins. Inflammatory material clogs trabecular meshwork. +5. Phacotoxic glaucoma: Herein IOP is raised due to lens matter induced uveitis. +What is malignant glaucoma? +Malignant or ciliary block glaucoma occurs rarely as a complication of any intraocular operation. Classically, it occurs following peripheral iridectomy or filtration operation for primary narrow angle glaucoma. Its pathogenesis includes cilio-lenticular or ciliovitreal block. +It is characterized by a markedly raised intraocular pressure, persistent flat anterior chamber and a negative Seidel’s test. +What is differential diagnosis of acute congestive glaucoma? +• Acute conjunctivitis • Acute iridocyclitis +• Secondary acute congestive glaucomas – Phacomorphic glaucoma +– Phacolytic glaucoma +– Glaucomatocyclitic crisis. +What is postinflammatory glaucoma? Postinflammatory glaucoma refers to rise in intraocular pressure due to following complications of anterior uveitis: +• Annular synechiae • Occlusio pupillae +• Angle closure following iris bombe formation + +• Angle-closure due to organization of the inflammatory debris. +What is pigmentary glaucoma? +Pigmentary glaucoma refers to raised IOP in patients with pigment dispersion syndrome. It typically affects young myopic males. Its features are similar to POAG with associated pigment deposition on corneal endothelium (Krukenberg’s spindle) trabecular meshwork, iris, lens and zonules. +What is neovascular glaucoma? +Neovascular glaucoma refers to raised IOP occurring due to formation of a neovascular membrane involving angle of the anterior chamber. Usually, stimulus to new vessel formation is retinal ischaemia as seen in diabetic retinopathy, CRVO, Eales’ disease. Other rare causes are chronic uveitis, intraocular tumours, old retinal detachment, CRAO and retinopathy of prematurity. +What is pseudoexfoliation glaucoma? Pseudoexfoliation glaucoma is a type of secondary open-angle glaucoma associated with pseudoexfoliation (PEX) syndrome. PES refers to amyloid like deposits on pupillary border, anterior lens surface, posterior surface of iris, zonules and ciliary processes. +What is steroid-induced glaucoma? +Steroid-induced glaucoma is secondary open-angle glaucoma having features similar to POAG. It probably occurs due to deposition of mucopolysaccharides in the trabecular meshwork in patients using topical steroid eyedrops. Roughly 5% of general population is high steroid responder (develop marked rise of IOP after about 6 weeks of steroid therapy), 35% are moderate and 60% are nonresponders. +Enumerate the causes of glaucoma in aphakia. +• Raised IOP due to postoperative hyphaema, inflammation, vitreous filling the anterior chamber. +• Angle closure due to flat anterior chamber • Pupil block with or without angle closure • Undiagnosed pre-existing POAG +• Steroid-induced glaucoma • Epithelial in growth +• Aphakic malignant glaucoma. + +DISEASES OF EYELIDS + +A CASE OF BLEPHARITIS +Case Description +Age and sex. Though more common in children, blepharitis may occur at any age equally in both sexes. +552 Section Vi Practical Ophthalmology + + +Presenting symptoms. Patients usually complain of deposits at the lid margin, associated with irritation, discomfort, occasional watering and history of falling of cilia or gluing of cilia. +Ocular examination may reveal signs of either seborrhoeic or ulcerative (Fig. 15.7 and 15.8) or mixed blepharitis. +• Signs of seborrhoeic blepharitis are: accummulation of white dandruff-like scales on the lid margin. On removing these scales underlying surface is found to be hyperaemic (no ulcers). Lashes fall out easily. In long standing cases lid margin is thickened and the sharp posterior lid border tends to be rounded leading to epiphora. +• Signs of ulcerative blepharitis. Yellow crusts are seen at the root of cilia which glue them together. Small ulcers, which bleed easily, are seen on removing the crusts. In between the crusts, the anterior lid margin may show dilated blood vessels (rosettes). + +Related Questions +What is blepharitis and how do you classify it? Blepharitis is a chronic inflammation of the lid margins. It can be divided into four classical types: 1. Seborrhoeic or squamous blepharitis +2. Ulcerative blepharitis +3. Mixed ulcerative with seborrhoeic blepharitis 4. Posterior blepharitis or meibomitis. +How will you differentiate squamous blepharitis from ulcerative blepharitis? +1. In squamous blepharitis white dandruff-like scales are seen at the lid margin while in ulcerative blepharitis yellow crusts are seen. +2. On removing the white scales underlying surface is found to be hyperaemic in squamous blepharitis. While in ulcerative blepharitis, small ulcers which bleed easily are seen on removing the crusts. +3. Cilia may be glued together in ulcerative blepharitis, but not so in squamous belpharitis. +What are the complications of ulcerative blepharitis? When not treated for a long time, the following complications may occur: +1. Chronic conjunctivitis 2. Trichiasis +3. Madarosis (sparseness or absence of lashes) 4. Poliosis (greying of cilia) +5. Tylosis (thickening of lid margin) +6. Eversion of punctum leading to epiphora 7. Recurrent styes. + + +How will you treat a case of squamous blepharitis? 1. Scales should be removed from the lid margin +with the help of lukewarm solution of 3% soda-bicarb or some baby shampoo. +2. Combined steroid and broad spectrum eye ointment should be rubbed at the lid margin twice daily. +3. Associated seborrhoea should be treated adequately. +How will you treat a case of ulcerative blepharitis? 1. Hot compresses. +2. Crusts should be removed after softening with 3% soda-bicarb. +3. Antibiotic ointment should be applied at lid margin immediately after removal of crusts. +4. Antibiotic eyedrops should be instilled 3 to 4 times a day. +5. Oral antibiotics such as amoxycillin, cloxacillin, erythromycin or tetracycline may be useful. +A CASE OF CHALAZION (MEIBOMIAN CYST) + +Case Description +Presenting symptoms. Patient usually presents with a painless swelling near the lid margin. Patient may be concerned about the cosmetic disfigurement caused and may also feel mild heaviness in the lids. Sometimes, mild defective vision may occur due to astigmatism caused by pressure of chalazion on the cornea. +Ocular examinations reveal a small, firm to hard, nontender swelling present slightly away from the lid margin (Fig. 15.12). Overlying skin is normal and mobile. The swelling usually points on the conjunctival side as red, purple or grey area seen on everting the lid. Sometimes, the main bulk of swelling may project on the skin side and occasionaly on the lid margin. +Differential diagnosis. Chalazion needs to be differentiated from meibomian gland carcinoma, tuberculomata and tarsitis. +A CASE OF STYE +Presenting symptoms include acute pain and swelling in the lid. Patient also experiences heaviness in the eyelid, mild photophobia and watering. +Ocular examination during stage of cellulitis reveals tender swelling, redness and oedema of the affected lid margins (Fig. 15.11). During stage of abscess formation a visible plus point on the lid margin in relation to the roof of affected cilia is formed. Differential diagnosis. Stye (hordeolum externum) should be differentiated from hordeolum internum. +Chapter 24 Clinical Ophthalmic Cases 553 + + +Related Questions +What is a chalazion? +Chalazion is also known as tarsal or meibomian cyst. It is a chronic noninfective granulomatous inflammation of the meibomian gland. +What is hordeolum externum (stye)? +Hordeolum externum is an acute suppurative inflammation of one of the Zeis’ glands. +It is characterized by a localized, hard, red, tender swelling at the lid margin (PI.IV.I). In advanced stage, a pus point is visible at the lid margin. +What is hordeolum internum? How will you differentiate it from hordeolum externum? Hordeolum internum is a suppurative inflammation of the meibomian gland associated with blockage of the duct. It may occur as primary staphylococcal infection of the meibomian gland or due to secondary infection in a chalazion (infected chalazion). +Its symptoms are similar to hordeolum externum except that pain is more intense due to the swelling being deeply embedded in the dense fibrous tissue. On examination it can be differentiated from hordeolum externum by the facts that in it, the point of maximum tenderness and swelling is away from the lid margin and that pus usually points on the tarsal conjunctiva (seen as a yellowish area on everting the lid) and not on the root of cilia. +When not treated, what complications can occur in a case of chalazion? +1. A large chalazion of the upper lid may press on the cornea and may cause blurred vision due to induced astigmatism. +2. A large chalazion of the lower lid may rarely cause eversion of the punctum or even ectropion and epiphora. +3. Occasionally, a chalazion may burst on the conjunctival side forming a fungating mass of granulation tissue. +4. Due to secondary infection the chalazion may be converted into hordeolum internum. +5. Calcification may occur, though very rarely. +6. Malignant change into meibomian gland carcinoma may be seen occasionally in elderly people. +How do you treat a case of chalazion? +1. Conservative treatment in the form of hot fomentation, topical antibiotic eyedrops and oral anti-inflammatory drugs may lead to self-resolution in a small, soft and recent chalazion. + + +2. Intralesional injection of long acting steroid (triamcinolone) is reported to cause resolution in about 50% cases. +3. Incision and curettage is the conventional and effective treatment for chalazion. +Describe the steps of incision and curettage of a chalazion. +1. Local anaesthesia is obtained by topical instillation of 4% Xylocaine drops in the conjunctival sac and infiltration of the lid in the region of chalazion with 2% Xylocaine. +2. A chalazion clamp is applied with its fenestrated side on the conjunctival side and the lid is everted. +3. A vertical incision is made to avoid injury to the other meibomian glands. +4. The contents are curetted out with the help of a chalazion scoop. +5. To avoid recurrence its cavity should be cauterized with carbolic acid. +6. An antibiotic eye ointment is instilled and eye is padded. +What is the treatment of a marginal chalazion? Destruction by diathermy is the treatment of choice for a marginal chalazion. +A CASE OF TRICHIASIS AND ENTROPION + +Description of a Case of Trichiasis +Presenting symptoms. Patients may present with a foreign body sensation, photophobia, irritation and lacrimation. Sometimes, patient may experience troublesome pain. +Past history of the disease causative of trichiasis such as cicatrizing trachoma, ulcerative blepharitis, membranous conjunctivitis, mechanical injuries, burns and operation of the lid margin may be explored. +Ocular examination reveals one or more misdirected cilia touching the eyeball (Fig. 15.16). There may or may not be signs of the causative disease. + +Description of a Case of Entropion +Presenting symptoms and past history exploration are similar to a case of trichiasis. +Ocular examination reveals inturned lid margin (Fig. 15.18 and 15.19). Depending upon the degree of inturning the entropion can be divided into three grades. In grade I entopion, only the posterior lid border is inrolled. Grade II entropion includes inturning up to the intermarginal strip, while in grade III, the whole lid margin including the anterior lid border is inturned. +Examination may also reveal signs of the causative disease. +554 Section Vi Practical Ophthalmology + + +Related Questions +Define trichiasis +Trichiasis refers to inward misdirection of cilia which rub against the eyeball. +What are the common causes of trichiasis? 1. Cicatrizing trachoma +2. Ulcerative blepharitis +3. Healed membranous conjunctivitis 4. Healed hordeolum externum +5. Mechanical injuries +6. Burns and operative scars on the lid margin. + +When not treated in time, what complications can occur in a case of trichiasis? +1. Corneal abrasions +2. Superficial corneal opacities 3. Corneal vascularization +4. Non-healing corneal ulceration. +What is distichiasis? +Distichiasis is condition of an extra posterior row of cilia which occupy the position of meibomian glands. +How will you treat a case of trichiasis? 1. Epilation: It is a temporary measure. +2. Electrolysis: After local infiltration of anaesthesia, a current of 2 milliampere is passed for about 10 seconds through a fine needle inserted into the lash root. The loosened cilia with destroyed follicles are then removed with the help of an epilation forceps. +3. Cryoepilation: After infiltration anaesthesia, the cryoprobe (– 20°C) is applied for 20 to 25 seconds to the external lid margin. The loosened lash is pulled with an epilation forceps. +4. Surgical correction: It is similar to cicatricial entropion and should be employed when many cilia are misdirected. +Define entropion. +Entropion refers to turning in of the lid margin. + +What are the types of entropion? +Depending upon the cause, entropion may be of the following types: +1. Congenital entropion 2. Cicatricial entropion 3. Spastic entropion +4. Mechanical entropion. + +What are the causes of cicatricial entropion? 1. Trachoma +2. Membranous conjunctivitis 3. Chemical burns +4. Pemphigus +5. Stevens-Johnson syndrome. + + +Name the surgical techniques employed for correcting cicatricial entropion. +1. Resection of skin and muscle +2. Resection of skin, muscle and tarsus 3. Modified Burow’s operation +4. Jaesche-Arlt’s operation +5. Modified Ketssey’s operation. +Name the surgical techniques used to correct a senile (involutional) entropion. +1. Modified Wheeler’s operation +2. Bick’s procedure with Reeh’s modification 3. Weiss operation +4. Tucking of inferior lid retractors (Jones, Reeh and Webing operation). +A CASE OF ECTROPION +CASE DESCRIPTION +Presenting symptoms include watering (epiphora) and cosmetic disfigurement. Patients may also have symptoms of associated chronic conjunctivitis which include irritation, discomfort and mild photophobia. Ocular examination. The lid margin is outrolled (Fig. 15.25). Depending upon the degree of outrolling, ectropion can be divided into three grades. In grade I ectropion, only the punctum is everted. In grade II ectropion lid margin is everted and palpebral conjunctiva is visible while in grade III the fornix is also visible. +Examination may also reveal signs of etiological condition such as scar in cicatricial ectropion (Fig. 15.26B) and seventh nerve palsy in paralytic ectropion. +RELATED QUESTIONS +What is ectropion? +Outrolling or outward turning of the lid margin is called ectropion. +What are the types of ectropion? 1. Senile ectropion +2. Paralytic ectropion 3. Cicatricial ectropion 4. Spastic ectropion. +What is the treatment of senile ectropion? Depending upon the severity of the ectropion, following three operations are commonly performed: 1. Medial conjunctivoplasty +2. Horizontal shortening +3. Byron-Smith’s modified Kuhnt-Szymanowski operation. +What is a symblepharon? +Symblepharon is a condition in which lids become adherent with the eyeball. It results from healing of +Chapter 24 Clinical Ophthalmic Cases 555 + + +the kissing raw surfaces of the palpebral and bulbar conjunctiva. +What are the common causes of symblepharon? 1. Chemical burns +2. Thermal burns +3. Membranous conjunctivitis 4. Conjunctival injuries +5. Ocular pemphigus +6. Stevens-Johnson syndrome. + +What do you mean by ankyloblepharon? Ankyloblepharon refers to the adhesions between margins of the upper and lower lids. It may be congenital or may result after healing of chemical or thermal burns. +What is blepharophimosis? +In blepharophimosis vertical as well as horizontal extent of the palpebral fissure is decreased. +What is lagophthalmos? Enumerate its common causes. +Lagophthalmos refers to the inability to voluntarily close the eyelids. Its common causes are: +1. Paralysis of seventh nerve 2. Marked proptosis +3. Cicatricial contraction of the lids +4. Following over-resection of the levator palpebrae superioris +5. Symblepharon +6. Comatosed patient. +What is belpharospasm? +Belpharospasm refers to the involuntary, sustained and forceful closure of the eyelids. It is of two types: essential belpharospasm and reflex blepharospasm. +A CASE OF PTOSIS + +Case Description +Age and sex. Ptosis may be congenital or acquired. Acquired ptosis may occur at any age in either sex. History. It should include age of onset, family history, history of trauma, eye surgery, and variability in degree of ptosis. +Examination should include: 1. Inspection to note: +• True ptosis or pseudoptosis • Unilateral or bilateral ptosis +• Eyelid crease and function of orbicularis • Presence of Jaw winking phenomenon +• Associated weakness of extraocular muscles • Bell’s phenomenon +2. Measurement of degree of ptosis 3. Assessment of levator function + +4. Special investigations for acquired ptosis (For details see page 380). +RELATED QUESTIONS +What is ptosis? +Abnormal drooping of the upper eyelids is called ptosis. Normally, upper lid covers about upper one sixth (2 mm) of the cornea. Therefore, in ptosis it covers more than 2 mm. +What are the types of ptosis? +I. Congenital ptosis which may be: +1.Simple congenital ptosis (not associated with any other anomaly) (Fig. 15.33A). +2.Congenital ptosis with associated weakness of the superior rectus muscle. +3.As a part of blepharophimosis syndrome (Fig. 15.33B). +4.Congenital synkinetic ptosis (Marcus Gunn jaw winking ptosis). +II. Acquired ptosis includes: 1.Neurogenic ptosis 2.Myogenic ptosis 3.Aponeurotic ptosis 4.Mechanical ptosis. +How do you grade ptosis? +Depending upon the amount of ptosis in mm, it is graded as follows: +1. Mild ptosis (2 mm) +2. Moderate ptosis (3 mm) 3. Severe ptosis (4 mm). +How do you grade levator function? +Depending upon the amount of lid excursion caused by levator muscle (Burke’s method), its function is graded as follows: +Normal : 15 mm +Good : 8 mm or more Fair : 5–7 mm +Poor : 4 mm or less + +Which test is carried out to confirm the diagnosis in a patient with ptosis suspected of myasthenia gravis? • Tensilon or edrophonium test. +Which test is carried out in a patient suspected of Horner’s syndrome? +• Phenylephrine test. +Name the three basic surgical procedures for ptosis correction. +1. Fasanella – Servat operation 2. Levator resection operation 3. Frontalis sling operation +556 Section Vi Practical Ophthalmology + + +Name the common lid tumours. I. Benign tumours +1.Simple papilloma 2.Naevus 3.Haemangioma 4.Neurofibroma +II. Precancerous conditions 1.Solar keratosis 2.Carcinoma in-situ 3.Xeroderma pigmentosa +III. Malignant tumours 1.Squamous-cell carcinoma 2.Basal-cell carcinoma 3.Malignant melanoma 4.Sebaceous gland carcinoma. +Which is the most common malignant tumour of the lids? +• Basal-cell carcinoma. +Which is the most common site for occurrence of basal-cell carcinoma? +• Medial canthus. +What is the structure of an eyelid? +Each eyelid from anterior to posterior consists of the following layers: +1. Skin +2. Subcutaneous areolar tissue +3. Layer of striated muscle (orbicularis oculi and levator palpebrae superioris in upper lid only) +4. Submuscular areolar tissue +5. Fibrous layer (tarsal) plate and septum orbitale 6. Layer of non-striated muscle fibres (Muller’s +muscle) +7. Conjunctiva. +Name the glands of the eyelids. 1. Meibomian glands +2. Glands of Zeis 3. Glands of Moll +4. Accessory lacrimal glands of Wolfring. +What are the causes of pseudoproptosis? • Anophthalmos +• Enophthalmos • Phthisis bulbi • Atrophic bulbi +• Trachoma (stage of sequelae) +• Any tumour or nodule of upper lid. + +DISEASES OF LACRIMALAPPARATUS + +A CASE OF CHRONIC DACRYOCYSTITIS Case Description +Age and sex. The disease may occur at any age and in any sex. However, in general, females are much + + +more commonly affected than males and the disease is more common between 40 and 60 years of age. Presenting symptoms. A patient presents with a long standing history of watering from the eyes which may or may not be associated with a swelling at the inner canthus. +Ocular examination may reveal any of the following signs: +• No swelling is seen at the medial canthus but regurgitation test is positive, i.e., a reflux of mucopurulent discharge from the puncta when pressure is applied over the lacrimal sac area. +• A swelling may be seen at the medial canthus (Fig. 16.8). Milky or gelatinous mucoid fluid regurgitates from the lower punctum on pressing the swelling (lacrimal mucocele). +• Sometimes on pressing the swelling, a frank purulent discharge flows from the lower punctum (lacrimal pyocele). +• Sometimes, a swelling is seen at the inner canthus with a negative regurgitation test (encysted mucocele). + +Related Questions +What are the causes of a watering eye? +Watering from the eyes may occur either due to excessive lacrimation or may result from obstruction to the outflow of normally secreted tears (epiphora). The common causes of watering eye are listed at page 390. +Name the tests which you would like to carry out to evaluate a case of watering eye. +1. Examination with diffuse illumination under magnification to rule out causes of hyperl-acrimation and punctal causes of epiphora +2. Regurgitation test for chronic dacryocystitis 3. Fluorescein dye disappearance test (FDDT) 4. Lacrimal syringing test +5. Jone’s dye test I and II 6. Dacryocystography +7. Lacrimal scintillography. +What is regurgitation test? +In regurgitation test a steady pressure with index finger is applied over the lacrimal sac area above the medial palpebral ligament. Reflux of mucopurulent discharge (a positive regurgitation test) indicates chronic dacryocystitis with obstruction at the lower end of sac or nasolacrimal duct. +What are the causes of a negative regurgitation test? Causes of a negative regurgitation test are: +• Normal sac (no dacryocystitis) • Wrong site of pressure +Chapter 24 Clinical Ophthalmic Cases 557 + + +• Patient might have emptied the sac just before coming to the examiner’s chamber +• Encysted mucocele • Internal fistula. +Name the indications of lacrimal syringing. 1. Diagnostic indications: +• Epiphora +• For dacryocystography 2. Therapeutic indications: +• Congenital dacryocystitis +• Early cases of chronic catarrhal dacryocystitis 3. Prognostic: +After DCR operation. + +Describe the procedure and interpretations of the results of lacrimal syringing. +1. Topical anaesthesia is obtained by instilling 4% Xylocaine in the conjunctival sac. +2. Lower punctum is dilated with a punctum dilator. 3. Normal saline is pushed into the lacrimal sac through the lower punctum with the help of a syringe and lacrimal cannula (Fig. 16.5) and +results are interpreted as follows: +• A free passage of saline through lacrimal passages into the nose indicates either no obstruction or partial obstruction. +• In the presence of obstruction no fluid passes into the nose. When obstruction is in the nasolacrimal duct, the sac fills with the normal saline which refluxes from the upper punctum. +• In case of lower canalicular obstruction, there will be immediate reflux of the saline through the lower punctum. Under these circumstances, the procedure should be repeated through the upper punctum. A free passage of saline into the nose will confirm the blockage in the lower canaliculus while regurgitation back through the same punctum will indicate block at the level of common canaliculus. +What is dacryocystitis, how will you classify it? Dacryocystitis is inflammation of the lacrimal sac. It can be classified as follows: +1. Congenital dacryocystitis +2. Adult dacryocystitis which may occur as: • Chronic dacryocystitis, and +• Acute dacryocystitis. + +What is the etiology of congenital dacryocystitis? How will you treat it? +Congenital dacryocystitis follows stasis of secretions in the lacrimal sac due to congenital blockage in the nasolacrimal duct (usually a membranous occlusion at the lower end of NLD). + +Its treatment, depends upon the age at which child is brought (see page 393). +What is the treatment of choice in adulthood chronic dacryocystitis? +Dacryocystorhinostomy (DCR) operation is the operation of choice since it re-establishes the lacrimal drainage. When DCR is contraindictated, dacryocystectomy may be performed. +What is dacryocystectomy? Enumerate its indications. Dacryocystectomy is the excision of the lacrimal sac. It should be performed only when DCR is contraindicated as in following conditions: +1. Too young (less than 4 years) or too old (more than 60 years) a patient. +2. Markedly shrunken and fibrosed sac. +3. Tuberculosis, syphilis, leprosy or mycotic infection of the sac. +4. Tumours of the sac. +5. Gross nasal diseases like atrophic rhinitis. +6. Anunskilledsurgeon,becauseitissaidthatagood ‘DCT’ is always better than a badly done ‘DCR’. +What are tears? +Tears form the aqueous layer of tear film and are secreted by the accessory and main lacrimal glands. Tears mainly comprise water and small quantities of salts such as sodium chloride, sugar, urea and proteins. Therefore, it is alkaline and saltish in taste. It also contains antibacterial substances like lysozyme, betalysin and lactoferrin. +What are the layers of tear film? +Wolf described the following three layers of tear film: 1. Mucous layer: It is the innermost and thinnest +layer of tear film. It consists of mucin secreted by the conjunctival goblet cells. It converts the hydrophobic corneal surface into a hydrophilic one. +2. Aqueous layer: It consists of tears secreted by the main and accessory lacrimal glands and forms the main bulk of the tear film. +3. Lipid or oily layer: It consists of secretions of the meibomian, Zeis and Moll’s glands. It prevents the overflow of tears and retards their evaporation. +What are the functions of tear film? +1. It keeps the cornea and conjunctiva moist. 2. Provides oxygen to the corneal epithelium. 3. It washes away debris and noxious irritants. +4. It prevents infection due to presence of anti-bacterial substances. +5. It facilitates movement of the lids over the globe. +558 Section Vi Practical Ophthalmology + + +What is dry eye? +Dry eye per se is not a disease entity but a symptom complex occurring as a sequela to deficiency or abnormalities of the tear film. +What are the causes of dry eye? +1. Aqueous deficiency dry eye (keratoconjunctivitis sicca—KCS) +• Congenital alacrimia • Sjogren’s syndrome • Riley-Day syndrome +• Idiopathic hyposecretion 2. Mucin deficiency dry eye +• Hypovitaminosis A (xerophthalmia) • Stevens-Johnson syndrome +• Trachoma +• Chemical burns 3. Lipid abnormalities +• Chronic blepharitis • Chronic meibomitis +4. Impaired eyelid function • Bell’s palsy +• Exposure keratitis • Ectropion +5. Epitheliopathies of corneal surface. + +Name the important tear film tests performed to diagnose the dry eye. +• Tear film break-up-time (BUT) • Schirmer I test +• Rose bengal staining. +What is tear film break-up time? +Tear film break-up time is the interval between a complete blink and appearance of the first randomly distributed dry spot on the corneal surface. Its normal values range between 15 and 35 seconds. Values less than 10 seconds employ an unstable tear film. +What is Schirmer I Test? +Schirmer test measures the total tear secretions with the help of 5 × 35 mm strip of Whatman No. 42 filter paper. Its normal values are more than 15 mm of wetting of the filter paper strip in 5 minutes. Values between 5 and 10 mm are suggestive of mild to moderate keratoconjunctivitis sicca (KCS) and less than 5 mm of severe KCS. +What is Sjogren’s syndrome? +Sjogren’s syndrome is an autoimmune disease usually occurring in women between 40 and 50 years of age. Its main feature is an aqueous deficiency dry eye (KCS). It occurs in two forms: +1. Primary Sjogren’s syndrome: In it, KCS is combined with xerostomia (dry mouth). + + +2. Secondary Sjogren’s syndrome: In it dry eye and/ or dry mouth is associated with an autoimmune disease, commonly rheumatoid arthritis. +What is the treatment of dry eye? +1. Supplementation by artificial tear solution such as: 0.7% methylcellulose, 0.3% hypromellose or 1.4% polyvinyl alcohol. +2. Preservation of existing tears by punctal occlusions with collagen implants or electrocauterization. +3. Mucolytics such as 5% acetylcysteine help by dispersing the mucous threads. + +DISEASES OF ORBIT A CASE OF PROPTOSIS +Case Description +Presenting symptoms. A patient presents with a history of the bulging of the eyeball which may be gradually or rapidly progressive. It may or may not be associated with visual loss, diplopia, pain or other symptoms. Ocular examination reveals outward protusion of the eyeball which may be: +• Unilateral (Fig. 17.7) or bilateral (Fig. 17.11) • Axial or eccentric +• Pulsatile or non-pulsatile +• Reducible or non-reducible +• May or may not be associated with lagophthalmos. + +Related Questions +What is proptosis and exophthalmos? +Proptosis refers to forward displacement of the eyeball beyond the orbital margin. Though the word exophthalmos (out eye) is synonymous with proptosis; somehow it has become customary to use the term exophthalmos for the displacement associated with thyroid eye disease. +What are the causes of unilateral proptosis? 1. Congenital conditions +• Dermoid cyst +• Congenital cystic eyeball • Teratoma +2. Traumatic lesions +• Orbital haemorrhage +• Retained intraorbital foreign body • Traumatic aneurysm +3. Inflammatory lesions +• Orbital cellulitis or abscess • Panophthalmitis +• Cavernous sinus thrombosis • Pseudotumour +4. Circulatory disturbances and vascular lesions +Chapter 24 Clinical Ophthalmic Cases 559 + + +• Orbital varix • Aneurysm +5. Cysts of the orbit +• Implantation cyst • Hydatid cyst +• Cysticercus cellulosae +6. Tumours of the orbit, which may be +• Primary tumours (arising from the various intraorbital structures) +• Secondary tumours (invading from the surrounding structures) +• Metastatic tumours from the distant primary tumours. +Enumerate the causes of bilateral proptosis. 1. Developmental anomalies of the skull +• Oxycephaly +2. Inflammatory conditions • Mikulicz’s syndrome +• Late stage of cavernous sinus thrombosis +3. Endocrine exophthalmos (most common cause) (Fig. 17.11) +4. Orbital tumours, e.g.: +• Lymphoma or lymphosarcoma. • Secondaries from: +– Neuroblastoma – Nephroblastoma – Ewing’s sarcoma +– Leukaemic infiltration 5. Systemic diseases, e.g: +• Histiocytosis-X +• Systemic amyloidosis • Xanthomatosis +• Wegener’s granulomatosis. + +What are the causes of acute proptosis? +1. Orbital emphysema following fracture of medial orbital wall +2. Orbital haemorrhage +3. Rupture of ethmoidal mucocele. + +What are the causes of intermittent proptosis? 1. Orbital varix (most common cause) +2. Periodic orbital oedema 3. Highly vascular tumour. +What are the causes of pulsatile proptosis? +1. Caroticocavernous fistula (most common cause) 2. Saccular aneurysm of ophthalmic artery +3. Congenital orbital encephalocele +4. Hiatus in the orbital roof due to trauma, operation or that associated with neurofibromatosis. +How will you investigate a case of proptosis? Evaluation of a case of proptosis includes the following: + +I. Clinical evaluation a) History +b) Local examination +(1) Inspection; (2) palpation; (3) auscultation; (4) transillumination; (5) visual acuity; (6) papillary reactions; (7) fundoscopy; (8) ocular motility; (9) exophthalmometry +c) Systemic examination II. Laboratory investigations +• Thyroid function tests • Haematological tests +• Stool examination for cysts and ova • Urine analysis +III. Roentgen examination +1. Plain radiograph of orbit 2. CT Scanning +3. Ultrasonography +4. Magnetic resonance imaging (MRI) 5. Carotid angiography +IV. Histopathological studies +1. Fine-needle aspiration biopsy (FNAB) 2. Incisional biopsy +3. Excisional biopsy. + +What is enophthalmos? Enumerate its causes. Enophthalmos is the inward displacement of the eyeball. Its common causes are: +1. Congenital microphthalmos +2. Congenital maxillary hypoplasia +3. Traumatic blow-out fractures of the orbital floor. 4. Post-inflammatory cicatrization of the extraocular +muscles as in pseudotumour syndromes. +5. Paralytic enophthalmos as seen in Horner’s syndrome. +6. Atrophy of the orbital contents, e.g., senile atrophy of orbital fat, atrophy following irradiation of malignant tumours. +What is Graves’ ophthalmopathy? +This is a term coined to denote typical ocular changes which include: lid retraction, lid lag and proptosis (Fig. 17.11). These changes are also known as endocrine exophthalmos, dysthyroid ophthalmopathy, thyroid ophthalmopathy and ocular Graves’ disease (OGD). +Name the extraocular muscle most frequently affected in Graves’ ophthalmopathy. +• Inferior rectus. +What is American Thyroid Association classification of Graves’ ophthalmopathy? +American Thyroid Association (ATA) has classified Graves’ ophthalmopathy irrespective of the hormonal status into the following classes; characterized by the acronym ‘NOSPECS’: +560 Section Vi Practical Ophthalmology + + +Class 0 : No signs and symptoms. +Class 1 : Only signs, no symptoms. Signs are limited to lid retraction with or without lid lag and mild proptosis. +Class 2 : Soft tissue involvement with signs of class I and symptoms including lacrim-ation, photophobia, lid or conjunctival swelling. +Class 3 : Proptosis is well established. +Class 4 : Extraocular muscle involvement (limitation of movements and diplopia). +Class 5 : Corneal involvement (exposure keratitis) Class 6 : Sight loss due to optic nerve involvement +with disc pallor or papilloedema. + +What are the two clinical types of Graves’ ophthal-mopathy? +1. Thyrotoxic exophthalmos (exophthalmic goitre): In this form, a mild exophthalmos is associated with lid signs and all signs of thyrotoxicosis which include: tachycardia, muscle tremors and raised basal metabolism. +2. Thyrotropic exophthalmos (exophthalmic ophthalmoplegia): In this marked exophthalmos and an infiltrative ophthalmoplegia is associated with euthyroidism or hypothyroidism. +What are the causes of pseudoproptosis? 1. Buphthalmos +2. Lid retraction +3. High-axial myopia 4. Staphyloma +5. Enophthalmos of the opposite eye. + +What are the causes of reducible proptosis? • Early stages of ocular Graves’ disease +• Haemangioma • Orbital varix +• Caroticocavernous fistula. + +Which is the most common primary tumour of the orbit presenting as proptosis? +• Cavernous haemangioma. +Name the most common primary orbital tumour of childhood. +• Rhabdomyosarcoma. + +DISORDERS OF OCULAR MOTILITY A CASE OF SQUINT +Case Description +Presenting symptoms. Patient presents with deviation of one eye which may be on medial side (convergent squint) or lateral side (divergent squint). + +History of present illness must include following important points: +• Age of onset +• Mode of onset, sudden or gradual +• Precipitating factors such as, systemic illness ocular cause, emotional breakdown, trauma +• History of diplopia +• Birth history is important in early childhood onset deviation +• History of use of glasses. +Family history is also important in a case of strabismus. Ocular examination should reveal: +• Whether the manifest squint is convergent (Fig. 14.14) or divergent (Fig. 14.16). +• Abnormal head posture associated or not. +• Whether the squint is unilateral or alternating. +• Ocular movements are normal (concomitant squint) or limited (paralytic or nonconcomitant squint). +• Angle of squint on corneal reflex test (Hirschberg’s test). +Note. Detailed orthoptic examination is not expected from an undergraduate student. + +Related Questions +Name the various extraocular muscles. • Superior rectus +• Inferior rectus • Medial rectus • Lateral rectus +• Superior oblique • Inferior oblique. +What is the origin of rectus muscles? +The rectus muscles originate from a common tendinous ring (annulus of Zinn), which is attached at the apex of the orbit. +Where are the rectus muscles inserted? +The rectus muscles are inserted into the sclera by flat tendons at different distances from the limbus as under: +• Medial rectus — 5.5 mm • Inferior rectus — 6.5 mm • Lateral rectus — 6.9 mm • Superior rectus — 7.7 mm +What is the nerve supply of extraocular muscles? The extraocular muscles are supplied by third, fourth and sixth cranial nerves. The third cranial nerve (oculomotor) supplies the superior, medial and inferior recti and inferior oblique muscles. The fourth cranial nerve (trochlear) supplies the superior oblique muscle, and sixth cranial nerve supplies the lateral rectus muscle. +Chapter 24 Clinical Ophthalmic Cases 561 + + +What are the actions of extraocular muscles? Action of each extraocular muscle is as below: + +Muscle Primary Secondary Tertiary action action action +Medial Adduction - -rectus +Lateral Abduction - -rectus +Superior Elevation Intorsion Adduction rectus +Inferior Depression Extorsion Adduction rectus +Superior Intorsion Depression Abduction oblique +Inferior Extorsion Elevation Abduction oblique + +Describe uniocular movements of the eyeball. Uniocular movements of the eyeball are called ductions. These are as follows: +1. Adduction. It is medial rotation along the vertical axis. +2. Abduction. It is lateral rotation along the vertical axis. +3. Infraduction. It is downward movement (depression) alone the horizontal axis. +4. Supraduction. It is upward movement (elevation) along the horizontal axis. +5. Incycloduction (Intorsion). It is rotatory movement along the anteroposterior axis in which superior pole of cornea (12 O’clock point) moves medially. +6. Excycloduction (Extorsion). It is rotatory movement along the anteroposterior axis in which superior pole of cornea (12 O’clock point) moves laterally. +What are version movements of the eyeball? Versions also known as conjugate movements, are synchronous (simultaneous) symmetric movements of both the eyes in the same direction. For example: • Dextroversion is the movement of both eyes to +the right. +• Levoversion is the movernent of both eyes to the left. + +What are vergence movements of the eyeball? Vergences, also called as disjugate movements, are synchronous and symmetric movements of both eyes in opposite directions, e.g.: +• Convergence is simultaneous inward movement of both the eyes. +• Divergence is simultaneous outward movement of both the eyes. + +Define synergists, antagonists and yoke muscles. 1. Synergists are the muscles which have a similar primary action in the same eye, e.g., superior rectus and inferior oblique of the same eye act as synergistic elevators. +2. Antagonists are the muscles which have opposite actions in the same eye, e.g., superior and inferior recti are the antagonists to each other in the same eye. +3. Yoke muscles (contralateral synergists) are a pair of muscles (one from each eye) which contract simultaneously during version movements. Different pairs of yoke muscles are as follows: +• Right medial rectus and left lateral rectus • Right lateral rectus and left medial rectus +• Right superior rectus and left inferior oblique • Right inferior rectus and left superior oblique • Right superior oblique and left inferior rectus • Right inferior oblique and left superior rectus. +What is Hering’s law of equal innervation? According to it, an equal and simultaneous innervation flows from the brain to a pair of muscles which contract simultaneously (yoke muscles) in different binocular movements, e.g., during dextroversion, right lateral rectus muscles and left medial rectus muscle, receiving an equal and simultaneous flow of innervation. +What is Sherrington’s law of reciprocal innervation? According to it, during ocular movements an increased flow of innervation to the contracting muscles is accompanied by a simultaneous decreased flow of innervation to the relaxing antagonists. For example, during dextroversion an increased innervational flow to the right lateral rectus and left medial rectus is accompanied by a decreased flow to the right medial rectus and left lateral rectus muscles. +What is the primary position of gaze? +It is the position assumed by the eyes when fixing a distant object (straight ahead) with the erect position of head. +What are the secondary positions of gaze? +These are the positions assumed by the eyes while looking straight up, and down to the right and to the left. +What are the cardinal positions of gaze? +These are the positions which allow examination of each of the 12 extraocular muscles in their main field of action. There are six cardinal positions of gaze, viz. dextroversion, levoversion, dextroelevation, levoelevation, dextrodepression and levodepression. +562 Section Vi Practical Ophthalmology + + +What are the three grades of binocular single vision? Grade I. Simultaneous macular perception (SMP): It is the power to see two dissimilar objects which can be superimposed to form a joint picture. For example, when the picture of a lion is projected onto the right eye and that of a cage to the left eye, an individual with presence of SMP will see the lion in the cage. Grade II. Fusion: It consists of the power to superimpose two incomplete but similar images to form one complete image. +Grade III. Stereopsis: It consists of the ability to perceive the third dimension (depth perception). +What is squint; how do you classify it? +Normally, visual axes of the two eyes are parallel to each other in the primary position of gaze and this alignment is maintained in all positions. +A misalignment of the visual axes of the two eyes is called squint or strabismus. Broadly, it can be classified as: +1. Apparent squint or pseudostrabismus 2. Latent squint (heterophoria) +3. Manifest squint (heterotropia), which includes: i. Concomitant squint +ii.Incomitant squint. + +What is heterophoria? and what are its types? +Also known as latent squint, it is a condition in which the tendency of the eyes to deviate is kept latent by fusion. Therefore, when the influence of fusion is removed the visual axis of one eye deviates. Common types of heterophoria are: +1. Esophoria: It is a tendency to converge when binocularity is broken by any means. +2. Exophoria: It is a tendency to diverge. +3. Hyperphoria: It is a tendency to deviate upwards, while hypophoria is a tendency to deviate downwards. However, in practice it is customary to use the term right or left hyperphoria, depending on the eye which remains up as compared to the other. +Name a few tests by which heterophoria can be diagnosed. +1. Cover-uncover test 2. Maddox rod test +3. Maddox wing test. +What is suppression? +Suppression is a temporary active cortical inhibition of the image of an object formed on the retina of the squinting eye. This phenomenon occurs only during binocular vision (with both eyes open). It can be tested by Worth’s four-dot test. + +What is abnormal retinal correspondence? Normally, fovea of the two eyes act as corresponding points and have the same visual direction (normal retinal correspondence). Sometimes in a patient with squint, fovea of the normal eye and an extra foveal point on the retina of the squinting eye acquire a common visual direction, i.e., become the corresponding points. This adjustment is called abnormal retinal correspondence (ARC). +Name a few methods by which angle of squint can be measured. +1. Hirschberg’s corneal reflex test. 2. Prism bar cover test (PBCT). +3. By synoptophore (major amblyoscope). 4. Krimsky’s corneal reflex test. +5. Perimeter method. +Describe Hirschberg’s corneal reflex test. Hirschberg’s corneal reflex test is a rough but hand method to estimate the angle of manifest squint. In this, the patient is asked to fixate at a light point held at a distance of 33 cm and the deviation of the corneal light reflex from the centre of pupil is noted in the squinting eye. Roughly, the angle of squint is 15° and 45° when the corneal light reflex falls on the border of pupil and limbus, respectively. +What is a concomitant squint? +Concomitant squint is a type of manifest squint in which the angle of deviation remains constant in all the directions of gaze; and there is no associated limitation of ocular movements. +How do you classify concomitant esotropia? 1. Infantile esotropia. +2. Accommodative esotropia. +3. Non-accommodative esotropia. + +What is accommodative esotropia? Accommodative esotropia occurs due to overaction of convergence associated with accommodation reflex. Refractive type of accommodative esotropia is associated with high hypermetropia (+4 to +7D). +How do you classify concomitant exotropia (divergent squint)? +1. Congenital exotropia 2. Primary exotropia +a. Intermittent b. Constant +– Unilateral – Alternating +3. Secondary (sensory deprivation) exotropia 4. Consecutive exotropia. +Chapter 24 Clinical Ophthalmic Cases 563 + + +What is paralytic squint? +Paralytic squint is a type of incomitant squint in which ocular deviation results from complete or incomplete paralysis of one or more extraocular muscles. \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_19.txt b/notes/A K Khurana - Comprehensive Ophthalmology_19.txt new file mode 100644 index 0000000000000000000000000000000000000000..d60ed2bfeb095c00485267100277982e80b0969d --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_19.txt @@ -0,0 +1,1599 @@ +What are the features of paralytic squint? 1. History of diplopia and confusion. +2. Secondary deviation is greater than primary deviation. +3. Ocular movements are restricted towards the action of paralyzed muscle. +4. Head is turned towards the action of paralyzed muscle. +What are the features of complete third cranial nerve palsy? +These include the following (Fig. 14.26): +1. Ptosis due to paralysis of levator muscle. 2. Eyeball is deviated out and slightly down. +3. Ocular movements are restricted in all the directions except outward. +4. Pupil is fixed and dilated. +5. Accommodation is completely lost. +6. Crossed diplopia is elicited on raising the eyelid. +What are the differences between paralytic and nonparalytic squint? + +Feature Paralytic squint Non-paralytic squint +1. Onset Usually sudden Usually slow +2. Diplopia Usually present Usually absent +3. Ocular Limited in Full movements the direction +of action of paralysed muscle + + +Contd... +6. Nausea and present Absent vertigo +7. Secondary More than Equal to primary deviation the primary deviation +deviation +8. In old cases Present Absent pathological +sequelae in the muscles + +What is nystagmus? +Nystagmus is defined as to-and-fro oscillatory movements of the eyes. +What are pendular and jerk nystagmus? +In pendular nystagmus, movements are of equal velocity in each direction. In jerk nystagmus, the, movements have a slow component in one direction and a fast component in the other direction. The direction of jerk nystagmus is defined by direction of the fast component. +What are clinical types of nystagmus? +1. Physiological nystagmus, e.g., optokinetic nystagmus +2. Congenital nystagmus, e.g., +• Congenital jerk nystagmus • Latent nystagmus +• Spasmus nutans +3. Acquired nystagmus, e.g., +• Acquired ocular nystagmus +• Peripheral vestibular nystagmus • Central vestibular nystagmus +• See-saw nystagmus. + +OCULAR INJURIES + + + +4. False projection + + + + + + + + +5. Head posture + +It is positive, i.e., patient cannot correctly locate the object in space when asked to see in the direction +of paralyzed muscle in early stages. +A particular head posture depending upon the muscle paralyzed may be present + +False projection in negative + + + + + + + + +Normal + + + + + +Contd... + + +A CASE OF BLUNT OCULAR TRAUMA + +Case Description +Age and sex. Trauma to the eyeball may occur at any age in either sex. However, in general, ocular trauma is more common in children than adults and in males than females. +Presenting symptoms and history. Patient usually presents with a direct blow to the eyeball by a large blunt object (tennis ball, cricket ball, fist, etc.) or injuries in a road side accident. There may be associated: +• Visual loss +• Pain and swelling of varying degree +Ocular examination may reveal varying signs depending upon the extent of trauma. In general, the traumatic lesions produced by blunt trauma can be grouped as below: +564 Section Vi Practical Ophthalmology + + +• Closed globe injury • Globe rupture +• Extraocular lesions (For details see page 426). + +Related Questions +What are the common sites for retention of an extraocular foreign body? +• Sulcus subtarsalis • Fornices +• Bulbar conjunctiva • Cornea. +How do you remove a corneal foreign body? +• Eye is anaesthetized with topical instillation of 2 to 4% Xylocaine. +• Lids are separated with universal eye speculum. • An attempt should be made to remove the foreign +body with the help of a cotton swab stick. If it fails then foreign body spud or hypodermic needle should be used. +• After removal of the foreign body, pad and bandage with antibiotic eye ointment is applied for 24 to 48 hours. +How do you classify mechanical ocular injuries? See page 426. +Enumerate the lesions which can result from a blunt trauma to the eye (contusional injury). +1. Lids: Ecchymosis, Black eye, avulsion of the lid, traumatic ptosis. +2. Orbit: Fracture of the orbital walls, orbital haemorrhage, orbital emphysemas. +3. Lacrimal apparatus: Laceration of canaliculi, dislocation of lacrimal gland. +4. Conjunctiva: Subconjunctival haemorrhage, chemosis, lacerating tears of the conjunctiva. +5. Cornea: Abrasion, partial or complete corneal tear, deep corneal opacity. +6. Sclera: Scleral tear. +7. Anterior chamber: Traumatic hyphaema, Collapse of the anterior chamber following perforation. +8. Iris, pupil and ciliary body: Traumatic miosis, traumatic mydriasis, radiating tears in iris stroma, iridodialysis, traumatic aniridia, traumatic cyclodialysis, traumatic uveitis. +9. Lens: Vossius ring, Concussion cataract, Early rosette cataract, Late rosette cataract, Total cataract, Subluxation of the lens, Dislocation of the lens. +10. Vitreous: Traumatic vitreous degeneration, Traumatic vitreous detachment, Vitreous haemorrhage. + +11. Choroid: Rupture of the choroid, choroidal haemorrhage, choroidal detachment, traumatic choroiditis. +12. Retina: Commotio retinae (Berlin’s oedema), retinal haemorrhages, retinal tears, retinal detachment, traumatic macular oedema, traumatic macular degeneration. +13. Optic nerve: +• Laceration of the optic nerve +• Optic nerve sheath haemorrhage • Avulsion of the optic nerve. +What are the effects of a perforating ocular injury? 1. Mechanical effects in the form of wounds of +different parts of the eyeball. +2. Introduction of infection may result in: • Purulent iridocyclitis +• Endophthalmitis • Panophthalmitis +3. Post-traumatic iridocyclitis 4. Sympathetic ophthalmitis. +What is siderosis bulbi? +Siderosis bulbi refers to the degenerative changes produced by an iron foreign body retained inside the eyeball. +The iron particles undergo electrolytic dissoci-ation. The iron ions combine with the intracellular proteins and produce degenerative changes. Epithelial structures of the eye are most affected. +What are the features of siderosis bulbi? +1. Orangish or rusty deposits arranged radially in a ring in the anterior capsule and anterior epithelium of the lens. +2. Greenish or reddish brown staining of the iris. 3. Pigmentary degeneration of the retina. +4. Secondary open-angle glaucoma due to-degenerative changes in the trabecular meshwork. +What is chalcosis? +Chalcosis refers to the specific changes produced by the alloy of copper in the eye. +Copper ions from the alloy are dissociated electrolytically and deposited under the mem-branous structures of the eye. Unlike iron ions, these do not enter into chemical combination with intracellular proteins and thus produce no degenerative changes. +What are clinical manifestations of chalcosis? 1. Kayser-Fleischer ring in cornea. +2. Sunflower cataract. +3. Deposition of golden plaques in retina. +Chapter 24 Clinical Ophthalmic Cases 565 + + +What are the methods of localizing an intraocular foreign body (IOFB): +1. Radiographic localization • Limbal ring method +• Specialized radiographic techniques, e.g., Sweet and Dixon’s method. +2. Ultrasonographic localization. 3. CT Scan. +What are the predisposing factors favouring devel-opment of sympathetic ophthalmitis? +1. A perforating wound. +2. Wounds in the ciliary region (the so called dangerous zone) are more prone to it. +3. Wounds with incarceration of the uveal tissue are more vulnerable. +4. It is more common in children than in adults. +5. It is more common in the absence of suppuration. In fact, it does not occur when actual suppuration develops in the injured eye. +What are the early features of sympathetic ophth-almitis? +• Photophobia • Lacrimation + + +• Transient blurring of near vision • Mild ciliary tenderness +• A few fine keratic precipitates. + +Name the measures to prevent occurrence of symp-athetic ophthalmitis? +1. Early excision of the injured eye with no vision. 2. Meticulous repair of the wound under microscope +followed by systemic and topical steroids should be undertaken in an eye with hope of saving useful vision. +Why alkali burns are more serious than the acid burns? +Alkalies penetrate deep into the tissues unlike acids (which cause instant coagulation of all the proteins which then acts as a barrier and prevents deep penetration) and thus produce more damage. +What are the effects of ultraviolet radiations on the eye? +1. May produce photophthalmia. +2. May be responsible for senile cataract. +What are the effects of infrared radiations on the eye? • Photoretinitis (solar macular burn or eclipse burn). +25 + +Darkroom Procedures + + + +CHAPTER OUTLINE + + +OBLIQUE ILLUMINATION, GONIOSCOPY AND TRANSILLUMINATION +Oblique illumination +• +• +• +• +Loupe and lens examination Slit-lamp examination Gonioscopy Transillumination +CLINICAL REFRACTION Objective refraction +• +• +• +Retinoscopy Autorefractometry Keratometry + + + +Darkroom procedures (DRPs) form an essential part of examination of the eyes in modern ophthalmic practice. Consequently, this section has been given a special slot in the undergraduate as well as postgraduate examinations. Most of the darkroom procedures have been described vividly with the support of self-explanatory illustrations. Common darkroom procedures are: +■Oblique illumination examination • Loupe and lens examination +• Slit-lamp biomicroscopy ■Gonioscopy ■Transillumination ■Retinoscopy ■Ophthalmoscopy + +OBLIQUE ILLUMINATION, GONIOSCOPY AND TRANSILLUMINATION +OBLIQUE ILLUMINATION +Oblique illumination also known as focal illumination, is a method for examination of the structures of the anterior segment of the eye. Karl Himly (1806) was the first to employ the technique of oblique illumination examination. In it, a zone of light is made to fall upon the structure to be examined so that it is brilliantly + +Subjective refraction +Subjective verification of baseline refraction Subjective refinement of refraction Subjective binocular balancing +• +• +• +• +Correction for near vision +TECHNIQUES OF FUNDUS EXAMINATION Ophthalmoscopy +• +• +• +Distant direct ophthalmoscopy Direct ophthalmoscopy Indirect ophthalmoscopy +Slit-lamp biomicroscopic examination of the fundus + + + +illuminated and stands out with special clarity as compared to the surroundings which remain in shadow. +There are two main methods of focal illumination: • Loupe and lens examination; and +• Slit-lamp examination. + +Loupe and Lens Examination +Optical principle. It is based on the principle that when an object is placed between a convex lens and its focal point, its image formed is virtual, erect, magnified and on the same side as the object. Prerequisites. (1) Darkroom, (2) Source of light, (3) Condensing lens of + 13 D, (4) Corneal loupe of +41 D, made with two planoconvex lenses each of 20.5 D (×10 magnification) (Fig. 25.1). +Procedure. (1) Light source is placed about 2 feet away, laterally and slightly in front of the patient’s eye; (2) Light is focused on the structure to be examined with the help of + 13 D condensing lens, held in one hand; (3) The examination is carried out with the help of corneal loupe. The loupe is held between thumb and forefinger of the second hand, the fourth and fifth fingers are supported on the patient’s forehead, while the middle finger is used for elevating the upper lid (Fig. 25.2). The loupe is +Chapter 25 Darkroom Procedures 567 + +brought close to the patient’s eye till the illuminated area is focused. The observer should also move his or her eyes as close to the loupe as possible to have a better view (4) By changing the position of the condensing lens and loupe, various structures of the anterior segment can be examined one by one. + + + + +Fig. 23.3 Binocular loupe + + + + +Fig. 25.1 Corneal loupe + + + + + + + + + + + + + + + + +Fig. 25.2 Technique of loupe and lens examination + +Use of binocular loupe. The corneal loupe may be replaced by a binocular loupe (Fig. 25.3), which gives the added advantage of stereoscopic view and easy manoeuvring,as normally itis fixed to theexaminer’s head by a band. However, the magnification achieved with binocular loupe is much less than that of uniocular corneal loupe. +Slit-Lamp Examination +Slit-lamp biomicroscope was invented in 1911 by Gullstrand. Today, biomicroscopy forms an invaluable and indispensable part of ophthalmological examination. +Parts +Slit-lamp consists of three parts (Fig. 25.4): 1. Observation system (Microscope) +2. Illumination system (Slit-lamp) +3. Mechanical system (Engineering support). +Optics and slit-lamp +• It works on the same principle as a compound microscope. + + + + + +Fig. 25.4 The slit-lamp + +• The objective lens (+22 D) is towards the patient, whose eye forms the object. The objective lens consists of two planoconvex lenses with their convexities facing towards each other. +• The eyepiece is + 10 to + 14 D and is towards the examiner. +• The illuminating system can be adjusted to vary the width, height and angle of incidence of the light beam. +Slit-lamp biomicroscopy routine +While performing slit-lamp biomicroscopy, following routine may be adopted (Fig. 25.5): +1. Patient adjustment. Patient should be positioned comfortably in front of the slit-lamp with his/her chin resting on the chin rest and forehead opposed to head rest. +568 Section VI Practical Ophthalmology + + + + + + + + + + + + + + + +Fig. 25.5 Technique of slit-lamp examination + +2. Instrument adjustment. The height of the table housing the slit-lamp should be adjusted according to patient’s height. The microscope and illumination system should be aligned with the patient’s eye to be examined. Fixation target should be placed at the required position. +3. Beginning slit-lamp examination. Some points to be kept in mind are: +i. Examination should be carried out in semidark room so that the examiner’s eyes are partially dark adapted to ensure sensitivity to low intensities of light. +ii. Diffuse illumination should be used for a short time as necessary. +iii.There should be a minimum exposure of retina to light. +iv. Medications like ointments and anaesthetic eyedrops produce corneal surface disturbances which can be mistaken for pathology. +v. Low magnification should be first used to locate the pathology and higher magnification should then be used to examine it. +Start with diffuse illumination and examine the lid margins, bulbar conjunctiva, limbus, cornea, tear film, aqueous, iris and the lens one by one. +Methods of illumination +There are 7 basic methods of illumination using the slit-lamp as described by Berliner: +1. Diffuse illumination. A diffuse broad beam of light is used, and a general view of the anterior segment of eye is observed. +2. Direct illumination. The slit beam and microscope are focused on the same area, and examination is performed. Changes in the corneal stroma and epithelium are better noted by this technique. +3. Indirect illumination. The slit beam is focused on a position just beside the area to be examined. Corneal + +microcysts and vacuoles can be best observed by this method. +4. Retroillumination. Light is reflected off the iris or fundus, while the microscope is focused on the cornea. This technique is especially helpful in detecting corneal oedema, neovascularization, microcysts and infiltrates. +5. Specular reflection. Here, the angle between the slit-lamp and microscope is increased to 60°, i.e., angle of incidence = angle of reflection. Changes in the endothelium like polymegathism, guttate, etc. can be viewed by this method. +6. Sclerotic scatter. It utilizes the phenomenon of total internal reflection. The slit beam is focused at the temporal limbus, and as it passes through the cornea, it outlines any subtle stromal or epithelial opacities which may lie in its path. +7. Oscillatory illumination of Koeppe. In this, the beam is given an oscillatory movement by which it is often possible to see minute objects or filaments, especially in the aqueous which would otherwise escape detection. +GONIOSCOPY +Owing to lack of transparency of corneoscleral junction and total internal reflection of light (emitted from angle structures) at anterior surface of cornea it is not possible to visualize the angle of anterior chamber directly. Therefore, a device (goniolens) is used to divert the beam of light and this technique of biomicroscopic examination of the angle of anterior chamber is called gonioscopy. +Types of goniolens +i. Indirect goniolens provides a mirror image of the opposite angle, e.g., Goldmann (Fig. 25.6) and the Zeiss goniolens. +ii. Direct goniolens provides a direct view of the angle. Koeppe goniolens is the most popular type. +Procedure +The patient is seated upright on the slit-lamp. A drop of 1% methylcellulose is placed in the concavity of the goniolens and with the patient looking up, one edge of the lens is positioned in the lower fornix. The upper lid is elevated and the patient is instructed to look straight ahead. The lens is rotated into position against the eye. When checking the lateral and medial angles, the slit beam should be horizontal and when checking the superior and inferior angles, the slit beam should be vertical. +Angle structures seen from behind forward are (Fig. 25.7): +Chapter 25 Darkroom Procedures 569 + + + + + + + + + + + + + + + + + + + + + + + +Fig. 25.6 Goldmann’s goniolens (A) and technique of gonioscopy (B) + + + + + + + + + + + + + + + +Fig. 25.7 Structures forming angle of the anterior chamber + +1. Root of the iris, +2. Anteromedial surface of the ciliary body (ciliary band), +3. Scleral spur, +4. Trabecular meshwork and Schlemm’s canal, and 5. Schwalbe’s line. +Applications of gonioscopy +1. Classification of glaucoma into open angle and closed angle based on configuration of the angle. +2. Localization of foreign bodies, abnormal blood vessels or tumours in the angle. + +3. Demonstration of extent of peripheral anterior synechiae (PAS) and hence planning of glaucoma surgery. +4. Direct goniolens is used during goniotomy. + +Gonioscopic grading of angle width See page 220. +TRANSILLUMINATION +Herein an intense beam of light is thrown through the conjunctiva and sclera or pupil and illumination is observed in the pupillary area. +1. Trans-scleral techniques. The beam of light is thrown through the sclera. Normally, the pupil emits a red glow but in the presence of a solid mass (e.g., intraocular tumour) in the path of light, the pupil remains black as the beam is obstructed by the mass. +2. Transpupillary technique. The beam of light is allowed to pass obliquely through the dilated pupil. Normally, the pupil is well illuminated but in detached retina, a greyish reflex is seen. +RELATED QUESTIONS +Who invented the technique of oblique illumination examination? +Karl Himly (1806) was the first to employ the technique of oblique illumination examination. +Who invented the slit-lamp? Gullstrand +What is the power of the condensing lens used in loupe and lens examination technique? ++13 Ds +What is the power of a corneal loupe? +41 Ds +What is the magnification of a corneal loupe? 10× +What are the advantages and disadvantages of a binocular loupe over the monocular corneal loupe? +Advantages +• Binocular loupe provides stereoscopic vision. • It is easier to use. +Disadvantages +• Magnification is less. + +What is the optical principle of oblique illumination? It is based on the principle that when an object is placed between a convex lens and its focal point, the image formed is virtual, erect, magnified and on the same side. +570 Section VI Practical Ophthalmology + + +What are the prerequisites for loupe and lens examin-ation technique? +• A darkroom +• Source of light +• A condensing lens of + 13 Ds • A corneal loupe of +41 Ds. + +Where is the source of light placed in oblique illumin-ation examination? +The source of light is placed slightly laterally and 2 feet in front of the patient’s eye. + +Enumerate the structures which can be examined with a slit-lamp without any additional aid? +• Lid margin • Conjunctiva • Cornea +• Sclera +• Anterior chamber • Iris and pupil +• Lens +• Anterior part of vitreous. +What are the advantages and disadvantages of slit-lamp examination over loupe and lens examination? +Advantages +1. Magnification can be increased and decreased. 2. Stereoscopic vision improves depth perception. 3. Aqueous flare can be better demonstrated. +4. Applanation tonometry and gonioscopy can be performed with the slit-lamp. +Disadvantages +1. Slit-lamp is very costly. 2. It is not handy. + +Enumerate a few ocular conditions where transill-umination test helps in the diagnosis. +1. Intraocular tumour 2. Retinal detachment +3. Vitreous haemorrhage. + + +CLINICAL REFRACTION + +The procedure of determining and correcting refractive errors is termed as clinical refraction. It is an art that can only be mastered by practice. The refraction comprises two complementary methods: • Objective refraction, and +• Subjective refraction. + +OBJECTIVE REFRACTION + +The objective methods of refraction include: • Retinoscopy, +• Refractometry, +• Photorefraction, and • Keratometry. +RETINOSCOPY +Definition +Retinoscopy also called as skiascopy or shadow test is an objective method of finding out the error of refraction by the method of neutralization. +Principle +Retinoscopy is based on the fact that when light is reflected from a mirror into the eye, the direction in which the light will travel across the pupil will depend upon the refractive state of the eye. +Prerequisites for retinoscopy +1. Darkroom preferably 6 m long, or which can be converted into 6 m by use of a plane mirror. +2. Trial box containing spherical and cylindrical lenses of variable plus and minus powers, a pinhole, an occluder and prisms. +3. Trial frame (Fig. 25.8) preferably of adjustable type which can be used in children as well as in adults. +4. Vision box. A Snellen’s self-illuminated vision box (Fig. 25.9). +5. Retinoscope. It is a simple device to perform the + + + + + + + + + + + + + + +Fig. 25.8 Trial frame +Chapter 25 Darkroom Procedures 571 + + + + + + + + + + + + + + + + + + + + + +Fig. 25.9 Snellen’s vision box + +retinoscopy. Broadly, retinoscopes available are of two types: +a. Mirror retinoscopes are cheap and the most commonly employed. A source of light is required when using mirror retinoscope, which is kept above and behind the head of the patient. A mirror retinoscope may consist of a single plane mirror (Fig. 25.10A) or a combination of plane and concave mirrors (Pristley-Smith mirror—Fig. 25.l0B). + + + + + + + + + + + + + + + + + + + + +Fig. 25.10 Mirror retinoscopes: A, plane mirror; B, Pristley-Smith mirror + +b.Self-illuminated retinoscopes are costly but handy. Two types of self-illuminated retinoscopes available are: a spot retinoscope and a streak retinoscope (Fig. 25.11). The streak retinoscope is more popular. In it the usual circular beam of light is modified to produce a linear streak of light by using a planocylindrical retinoscopy mirror. The streak retinoscopy is more sensitive than spot retinoscopy in detecting astigmatism. +Plane versus concave mirror retinoscope +In practice, plane mirror is used for retinoscopy. In patients with hazy media and high degree of ametropia concave mirror is more useful. +Procedure of retinoscopy +The patient is made to sit at a distance of 1 m from the examiner (Fig. 25.12). With the help of a retinoscope, light is thrown onto the patient’s eye, who is instructed to look at a far point (to relax the accommodation). However, when a cycloplegic has been used, the patient can look directly into the light and have the refraction assessed along the actual visual axis. Through a hole in the retinoscope’s mirror, the examiner observes a red reflex in the pupillary area of the patient. Then, the retinoscope is moved in horizontal and vertical meridia keeping a watch on the red reflex (which also moves when the retinoscope is moved). +Characteristics of red reflex to be noted are: +• Speed and brilliance. In low degrees of refractive errors the shadow (red reflex) seen in the pupillary area is faint and moves rapidly with the movement of the mirror; while in high degrees of ametropia it is very dark and moves slowly. + + + + + + + + + + + + + + + + + +Fig. 25.11 Streak retinoscope +572 Section VI Practical Ophthalmology + + + + + + + + + + + + + + + +Fig. 25.12 Procedure of retinoscopy + + +• Width of reflex, when using streak retinoscope, is narrow in high degree of ametropia and wide in low degree of ametropia. +• Swirling of reflex occurs in the presence of astigmatism, when the axis does not correspond with the movement of the mirror. +Use of cycloplegics in retinoscopy +Cycloplegics are the drugs which cause paralysis of accommodation and dilate the pupil (cycloplegia). These are used for retinoscopy, when the examiner suspects that accommodation is abnormally active and will hinder the exact retinoscopy. Such a situation is encountered in young children and hypermetropes. When retinoscopy is performed after instilling cycloplegic drugs it is termed as wet retinoscopy in converse to dry retinoscopy (without cycloplegics). The commonly employed cyclopegics are as follows: +1. Atropine is indicated in children below the age of 5 years. It is used as 1% ointment thrice daily for 3 consecutive days before performing retinoscopy. Its effect lasts for 10 to 20 days. +2. Homatropine is used as 2% drops. One drop is often instilled every 10 minutes for 6 times and the retinoscopy is performed after 1 to 2 hours. Its effect lasts for 48 to 72 hours. It is used for most of the hypermetropic individuals between 5 and 25 years of age. +3. Cyclopentolate is a short acting cycloplegic. Its effect lasts for 6 to 18 hours. It is used as 1% eyedrops in patients between 8 and 20 years of age. One drop of cyclopentolate is instilled after every 10–15 minutes for 3 times (Havener’s recommended dose) and the retinoscopy is performed about 60 to 90 min. later (after estimating the residual accommodation which should not exceed one dioptre). + +4. Only mydriatic (10% phenylephrine) may be needed in elderly patients when the pupil is narrow or media is slightly hazy. +Salient features of the common cycloplegic drugs are summarized in Table 25.1. +Note. The mydriatics should be used with care in adults with shallow anterior chamber, owing to the danger of an attack of narrow-angle glaucoma. In older people, mydriasis should be counteracted by the use of miotic drug (2% pilocarpine). +Observations and inferences +Depending upon the movement of the red reflex (Fig. 25.13) when a plane mirror retinoscope is used at a distance of 1 meter the results are interpreted as: +1. No movement of red reflex indicates myopia of lD. 2. With movement of red reflex along the movement of the retinoscope, indicates either emmetropia +or hypermetropia or myopia of less than 1D. +3. Against movement of red reflex to the movement of the retinoscope implies myopia of more than 1D. Above assertions can be easily remembered from +the Fig. 25.14. +Neutralization +When the red reflex moves with or against the movement of retinoscope we do not exactly know the amount of refractive error. However, when the red glow in the pupil does not move then we know for certain that patient has myopia of 1D. Therefore, to estimate the degree of refractive error, the movement of red reflex is neutralized by addition of increasingly convex (+) spherical lenses (when the red reflex was moving with the movement of plane mirror) or concave (–) spherical lenses (when the red reflex was moving against the movement of plane mirror). When a simple spherical error alone is present, the movements of red reflex will be neutralized in both vertical as well as the horizontal meridia. However, in the presence of an astigmatic refractive error, one meridian is neutralized by adding appropriate cylindrical lens with its axis at right angle to the meridian to be neutralized. It is important to note that sometimes, especially, when pupil is dilated, two light reflexes—one central and other peripheral— may be seen. Under such circumstances one should neutralize the central glow because the central parts of cornea and lens are more important in forming the image on the retina. +End point of retinoscopy +With simple plane mirror retinoscope the end point of retinoscopy is neutralization of red reflex in all the meridia, i.e., either no movement or just reversal of the movement. +Chapter 25 Darkroom Procedures 573 + +Table 25.1 Salient features of common cycloplegic and mydriatic drugs + + +SI. Name of no. the drug + + +1. Atropine sulphate +(1 % ointment) +2. Homatropine hydrobromide (2% drops) + +3. Cyclopentolate hydrochloride (1% drops) + +4. Tropicamide (0.5%, 1% drops) + + + +5. Phenylephrine (5%, 10% drops) + +Age of the patient when indicated +< 5 year + + +5–8 years + + + +8–20 years + + + +Not used as cycloplegic for retino-scopy; used only as mydriatic +Used only as mydriatic alone or in +combination with tropicamide + +Dosage of instillation + + +TDS x 3 days + +One drop every +10 min. for 6 times +One drop every 15 min. for +3 times +One drop every 15 min. for +3 to 4 times + +One drop every 15 min. for 3 to 4 times + +Peak effect + + +2–3 days + + +60–90 min. + + +80–90 min. + + +20–40 min. + + + + +30–40 min. + +Time of +performing retinoscopy +4th day + + +After 90 min. of instillation of first drop +After 90 min. of instillation of first drop + +Duration of action + + +10–20 days + +48–72 hours + + +6–18 hours + + +4–6 hours + + + + +4–6 hours + +Period of postcyclo-plegic test + +After 3 weeks of retinoscopy + +After 3 days of retinoscopy + + +After 3 days of retinoscopy + +Tonus allowance + + +1D + + +0.5D + + + +0. 75D + + + + + + + + + + + + + + +Fig. 25.13 Red reflex during streak retinoscopy: A, Neutralization point; B, With movement; C, Against movement + + + +With a streak retinoscope at the end point streak disappears and the pupil appears completely illuminated or completly dark (Fig. 25.13A). + +Problems in retinoscopy +Certain difficulties encountered duringthe procedure of retinoscopy are summarized below: +1. Red reflex may not be visible or may be poor. This may happen with small pupil, hazy media and high degree of refractive error. In most cases, this difficulty is overcome by causing mydriasis and/or use of converging light with concave mirror retinoscope. + +2. Changing retinoscopy findings are observed due to abnormally active accommodation and is corrected by use of cycloplegia. +3. Scissors shadows may sometimes be seen in patients with regular astigmatism with dilated pupils. Mostly, this difficulty is diminished with the undilated pupil. +4. Conflicting shadows moving in various directions in different parts of the pupillary area are seen in patients with irregular astigmatism. +5. Triangular shadow may be observed in patients with conical cornea (keratoconus), with its apex +574 Section VI Practical Ophthalmology + + + + + + + + + + + + + + + + +Fig. 25.14 Diagrammatic depiction of the relation of movement of pupillary red reflex with the error of refraction + + + +at the apex of cone. On moving the mirror, the triangular reflex appears to swirl around its apex (yawning reflex). +Static versus dynamic retinoscopy +Static retinoscopy refers to the procedure performed without active use of accommodation (as described above). Dynamic retinoscopy implies when the procedure is performed for near vision with active use of accommodation by the patient. However, usefulness of performing dynamic retinoscopy has not yet been established in refraction. +Rough estimate of refractive error after retinoscopy Objectively, a rough estimate of error of refraction is made by taking into account the retinoscopic findings, deductions for distance (e.g., 1D for 1 m and 1.5D when retinoscopy is performed at 2/3rd m distance) and deduction for the cycloplegic when used (e.g., 1D for atropine, 0.5D for homatropine and 0.75D for cyclopentolate). +Amount of refractive error is equal to the retinoscopic findings minus deduction for the distance and deduction for tonus allowance for the cycloplegic drug used. +It is customary to do retinoscopy both vertically and horizontally and note the values separately (Fig. 25.15). In Figure 25.15A, X denotes retinoscopy value along vertical meridian and Y denotes the value along the horizontal meridian. +• When retinoscopy values along horizontal and vertical meridia are equal then there is no astigmatism and a spherical lens is required to correct the refractive error. For example: When retinoscopic finding is 7D with the procedure + +preformed at 1 m distance using atroprine as cycloplegic than appropriate refractive error will be: 7D–1D (for distance) -1D (tonus allowance for atroprine) = 5D (Fig. 25.15B). +• When retinoscopy values along horizontal and vertical meridia are unequal, then it denotes presence of astigmatism which is corrected by a cylindrical lens alone and the refractive error in simple astigmatism (Fig. 25.15C) in combination with a spherical lens and the refractive error in compound astigmatism (Fig. 25.15D). +AUTOREFRACTOMETRY +The refractometry (optometry) is an objective method of finding out the error of refraction by use of an equipment called refractometer (optometer). Presently, the computerized autorefractometers (Fig. 25.16) are being used increasingly. +Principle. Most of the autorefractometers are essentially based on either the Scheiner principle or the optometer principle. +Features. The computerized, autorefractometer quickly gives information about the refractive error of the patient in terms of sphere, cylinder with axis and interpupillary distance. This method is a good alternative to retinoscopy in busy practice. It is also advantageous for mass screening, research programs and epidemiological studies. However, the subjective verification of refraction is a must even after autorefractometry. +Photorefraction +Photorefraction technology allows measurement of refraction in both eyes simultaneously using an infrared camera from a distance of 1 meter. +Chapter 25 Darkroom Procedures 575 + + + + + + + + + + + + + + + + + + + +Fig. 25.15 A: Customary way of writing retinoscopic findings, B to D: Calculation for rough estimate of refractive error: (i) Retinoscopic findings, when performed at 1 m distance under atropine cycloplegia; (ii) Deduction of –1 D for distance and – 1 D for the atropine from the retinoscopic findings. (iii) Rough estimate of refractive error along horizontal and vertical meridian; and (iv) Prescription required + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 25.16 Computerized autorefractometer + +Photorefractometer of one type commercially available is an infrared device (Plusoptix Vision Screener, GmbH, Nuremberg, Germany). In it the acquisition time is as quick as 0.8 seconds. Procedure. The camera is started by pressing a button trigger, which also produces a sound to attract attention of the subject. Measurement can be performed in undilated pupil. The device performs + +real time videoretinoscopy of reflected infrared light in three meridia. +Results. Once the refraction is complete, measurement results are displayed on the screen immediately. The refractive data provided as final output are the median of frames of the acquired video sequence on which the software recognizes both pupils. The readings include full refraction, pupil size, interpupillary distance (IPD), and the symmetry of corneal reflexes. +Advantages. Photorefractor vision screener is portable, hand held, and thus specially useful for refraction among infants and children. The results are not influenced by accommodation. So cycloplegia with atropine is not required in infants and preschool children. +KERATOMETRY +The ‘keratometry’ or ‘ophthalmometry’ is an objective method of estimating the corneal astigmatism by measuring the curvature of central cornea. The keratometry readings are not of much value in routine refraction for prescribing glasses; but are of utmost value for prescribing contact lenses and for calculating the power of intraocular lens to be implanted. +Principle of keratometer +Keratometer is based on the fact that the anterior surface of the cornea acts as a convex mirror; so the size of the image produced varies with its curvature. +576 Section VI Practical Ophthalmology + + +Therefore, from the size of the image formed by the anterior surface of cornea (first Purkinje image), the radius of curvature of cornea can be calculated. The accurate measurement of the image size is obtained by using the principle of visible doubling. +Types of keratometers +Two types of keratometers used in practice are Javal-Schiotz model and Bausch & Lomb model. +1. Javal-Schiotz model keratometer consists of two illuminated ‘mires’ (A and B) fixed on a rotatable circular arc (C) and a viewing telescope T (Fig. 25.17). The double images (aa1 and bb1) of the mires (A and B) are formed on the cornea. Keratometry readings are obtained by coinciding the images a1 and b as shown in Figure 25.18. The readings are noted first in the horizontal meridian and then the arc is rotated by 90° and the readings are noted in the vertical meridian. +2. Bausch & Lomb keratometer (Fig. 25.19). In it, the ‘mires’ are in the form of circles (Fig. 25.20). With this keratometer the radius of curvature of cornea in horizontal and vertical meridia can be measured simultaneously without rotating the mires. + +SUBJECTIVE REFRACTION + +Subjective refraction is meant for finding out the most suitable lenses to be prescribed. It should always be carried out after getting a rough estimate of the refractive error by the objective refraction as described above. When a cycloplegic has been used the subjective refraction, the so called postmydriatic test (PMT) should be carried out preferably after 3 to + + + + + + + + + + + + + + + + + +Fig. 25.17 Basic structure of Javal and Schiotz keratometer + + + + + + + +Fig. 25.18 Mires during keratometry with Javal-Schiotz keratometer + + + + + + + + + + + + + + + + + + +Fig. 25.19 Bausch and Lomb keratometer + + + + + + + + + + + + + + + + + + +Fig. 25.20 Mires during keratometry with Bausch and Lomb keratometer + +4 days (when homatropine or cyclopentolate is used) and 3 weeks (when atropine is used). +The technique of subjective refraction requires the patient’s cooperation in arriving at the proper estimation of the refractive error. The proper subjective refraction includes three steps: +Chapter 25 Darkroom Procedures 577 + + +I. Subjective verification of baseline refraction, II. Subjective refinement of refraction, and +III. Subjective binocular balancing. + +I. Subjective verification of baseline refraction +The subjective verification of baseline refraction can be performed by: the ‘trial-and-error’ method. For this, the patient is seated at a distance of 6 meters from the Snellen’s vision chart. A trial frame is put on the face of the patient and the visual acuity is noted for both the eyes, separately. Then an occluder is put in front of one eye and the appropriate lens combination (as indicated by retinoscopy or automated refractometry) is placed in front of the other eye. By increasing or decreasing the power of lens, the most suitable spherical lens is chosen (the strongest convex lens and the weakest concave lens providing best vision should be chosen in patients with hypermetropia and myopia, respectively). Then the axis of the cylinder and finally its strength should by finalized using the same ‘trial-and-error’ method. The similar procedure is repeated for the second eye. +II. Subjective refinement of refraction +The most suitable combination of lenses chosen after the subjective verification of baseline refraction, are then refined before the final prescription is made. It is always better to first refine the cylinder and then sphere. +1. Refining the cylinder +Cylinder can be refined by either use of Jackson’s cross cylinder (more commonly) or by astigmatic fan test. +i. Jackson’s cross cylinder test +It is used to verify the strength and axis of the cylinder prescribed. The cross cylinder is a combination of two cylinders of equal strength but with opposite sign placed with their axes at right angles to each other and mounted in a handle (Fig. 25.21). The commonly used cross cylinders are of ±0.25D and ±0.5D. Verification of strength of the cylinder. To check the power of the cylinder, the cross cylinder of ± 0.25D is placed with its axis parallel to the axis of the cylinder in the trial frame first with the same sign and then with opposite sign. In the first position, the cylindrical correction is enhanced by 0.25D and in the second it is diminished by the same amount. When the visual acuity does not improve, in either of the positions, the power of cylinder in trial frame is correct. However, if the visual acuity improves in any of the positions, a corresponding correction should be made and reverified till final correction is attained. + + + + + + + + + + + + + + + + + + + +Fig. 25.21 Jackson’s cross cylinder + + +Verification of axis of the cylinder. Cross cylinder (±0.5D) is placed before the eye with its axis at 45° to the axis of cylinder in trial frame (first with -0.5D cylinder and then +0.5D cylinder or vice versa) and the patient is asked to tell about any change in the visual acuity. If the patient notices no difference between the two positions, the axis of the correcting cylinder in the trial frame is correct. However, if the visual improvement is attained in one of the positions, a ‘plus’ correcting cylinder should be rotated in the direction of the plus cylindrical components of the cross cylinder (and vice-versa). The test is then repeated several times until the neutral point is reached. +ii. The astigmatic fan test +It is used to confirm the cylindrical correction. The astigmatic fan consists of a dial of lines radiating at 10° interval to one another (Fig. 25.22). In this test, the patient is asked to see the fan after fogging by +0.5 D added over and above the best suitable combination of lenses chosen. The stigmatic patient will see all the lines equally clear (Fig. 25.22A). In the presence of astigmatism, some lines will be seen more sharply defined (Fig. 25.22B). The concave cylinder is then added with its axis at right angles to the clearest line until all the lines are equally sharp. +iii. A stenopaeic slit-test +Though not practically used now, this test also helps in checking the correction of astigmatism. The 1 mm wide stenopaeic slit (Fig. 25.23) when placed in front of the eye allows clearest vision when it is rotated +578 Section VI Practical Ophthalmology + + + + + + + + + + +A B +Fig. 25.22 Astigmatic fan: A, As seen by an emmetropic person; B, As seen by a patient with +astigmatism at horizontal axis + + +into the axis of astigmatism and the refraction will then be indicated by the strongest convex lens which allows full vision in this axis and again in the axis perpendicular to it. + + + + + + + + + + + + + + + +Fig. 25.23 Stenopaeic slit + +2. Refining the sphere +The spherical correction is refined after refining the cylinder power and axis. Refining of the sphere is done by using following tests: +i. Fogging technique. After the cylinder power and axis have been refined, the eye to be tested is fogged by insertion of about +2D spherical lens in myopic patients and about +4 D in hypermetropic patients over the previously verified sphere. The patient is instructed to see the distant test types through this, and gradually the additional convex lens is reduced (by about 1/2D at a time) until full vision is restored. This method is more useful in hypermetropia. +ii. Duochrome test. It is based on the principle of chromatic aberration (Fig. 25.24A). In this, the patient is asked to read the red and green letters (Fig. 25.24B). In an emmetropic eye, the green rays are focused slightly anterior and red rays slightly posterior to the retina (Fig. 25.24A). Therefore, to + +an emmetropic patient letters of both colours look equally sharp. When the patient tells that he or she sees red letters more clearly than the green, it indicates that he or she is slightly myopic. His or her spherical lenses should be adjusted such that he or she sees letters of both colours with equal clarity. iii. Pin-hole test. It helps in confirming whether the optical correction in the trial frame is correct or not. An improvement in visual acuity while looking through a pin-hole (Fig. 25.25) indicates that optical correction in the trial frame is incorrect. +III. Subjective binocular balancing +The final step in the subjective refraction is binocular balancing—a process sometimes + + + + + +A + + + + + + + + + + + + + + + + + +B + +Fig. 25.24 A, Optical principle of duochrome test; B, Duochrome test box consisting of Snellen’s 6/18 to 6/5 visual acuity letters with red and green background +Chapter 25 Darkroom Procedures 579 + + + + + + + + + + + + + + + + + + + +Fig. 25.25 Pin-hole +known as ‘equalizing the accommodative effort’ or ‘equalization of vision’. This allows both eyes to have the retinal image simultaneously in focus. The details of the techniques of binocular balancing are beyond the scope of this book. +Correction for near vision +Correction for near vision is indicated usually after the age of 40 years. When the distance vision has been satisfactorily corrected, the visual acuity at working distance of the patient should be estimated using any of the near vision charts (Jaeger’s chart or Snellen’s reading test types or number points types standardized by the faculty of ophthalmologists, N5 to N48). In case near vision is defective, a suitable convex lens addition (tested separately for each eye) should be made over the distant correction. The near correction added should be such that about one-third of the amplitude of accommodation should remain as reserve. In general, it is better to undercorrect than to overcorrect the presbyopia (also see page 48). + +RELATED QUESTIONS + +LIGHT AND GEOMETRICAL OPTICS +What is the wavelength of visible spectrum of the light? +Between 390 and 700 nm. +Which light rays are absorbed by the cornea and crystalline lens of the eye? +Cornea absorbs rays having wavelength shorter than 295 nm and the crystalline lens of the eye absorbs rays having wavelength shorter than 350 nm. + +White light consists of how many colours? +Seven, viz. violet, indigo, blue, green, yellow, orange and red (VIBGYOR). +What do you mean by reflection of light? Reflection of light is a phenomenon of change in the path of light rays without any change in the medium. +What are the features of an image formed by a plane mirror? +It is: (i) virtual, (ii) erect and laterally inverted, (iii) of the same size as object, and (iv) at the same distance behind the mirror as the object is in front. +What do you mean by refraction of light? Refraction of light is a phenomenon of change in the path of light when it goes from one medium to another. +Describe the features of the images formed by a concave mirror for different positions of the object. See Table 3.1 +What is total internal reflection? +When a ray of light travelling from an optically denser medium to an optically rarer medium is incident at an angle greater than the critical angle of the pair of media in contact, the ray is totally reflected back into the denser medium. This phenomenon is called total internal reflection. +What is the critical angle? +Critical angle refers to the angle of incidence in the denser medium corresponding to which angle of refraction in the rarer medium is 90°. +What do you mean by Sturm conoid focal interval of Sturm and circle of least diffusion? +Sturm conoid refers to the configuration of the light rays refracted through an astigmatic (toric) surface. The parallel rays of light when refracted through a toric surface are not focused at one point but form two focal lines. Distance between the two lines is called focal interval of Sturm. Circle of least diffusion is formed between these two lines. +Why a patient with mixed astigmatism has comp-aratively better vision? +Because in such patients the circle of least diffusion is formed on the retina. +OPTICS OF THE EYE +What is a ‘reduced eye’? +The focusing system of the eye is composed of cornea, aqueous humour, crystalline lens and vitreous humour, the optics of which, otherwise is +580 Section VI Practical Ophthalmology + + +very complex. However, Listing has chosen a simple data to understand the optics of eye. This is called Listing’s reduced eye. Its cardinal points are: +• Single nodal point situated (in the posterior part of crystalline lens) is 7.2 mm behind the anterior surface of cornea. +• Anterior focal point is 15.7 mm in front of the anterior surface of cornea. +• Posterior focal point (on the retina) is 24.4 mm behind the anterior surface of cornea. +• Total dioptric power is about +60D. + +What is the nodal point of the eyeball? +It is the optical centre of the entire focusing system of the eye consisting of cornea, aqueous and lens when considered as one lens. +What is optical axis of the eyeball? +It is a line passing through the centre of cornea and centre of the lens which meets the retina on the nasal side of fovea. +What is visual axis? +It is a line joining the fixation object, nodal point and the fovea. +What is fixation axis? +It is the line joining the fixation point and the centre of rotation of the eye. +What is visual angle? +It is the angle subtended by an object on the nodal point of the reduced eye. +What are angles alpha, gamma and kappa of the eyeball? +1. Angle alphais the angle formed between the optical axis and visual axis at the nodal point of the eyeball. +2. Angle gamma is the angle formed between the optical axis and fixation axis at the centre of rotation of the eyeball. +3. Angle kappa is formed between the visual axis and control pupillary line. A positive angle kappa results in pseudoexotropia and a negative angle kappa is seen in esotropia. +What is the total refractive power of the eyeball and how much is contributed by cornea and the crystalline lens? +Total refractive power of the eyeball is about +60D; out of this +44D is contributed by the cornea and about + 16D by the crystalline lens. +What are the refractive indices of the media of the eye? Refractive indices of the media of the eye are as follows: +Cornea 1.37 Aqueous humour 1.33 + +Crystalline lens 1.42 Vitreous humour 1.33 +REFRACTIVE ERRORS What is emmetropia? +Emmetropia (optically normal eye) is a state of refraction when the parallel rays of light coming from infinity are focused at the sensitive layer of retina with accommodation at rest. +Define ametropia. +Ametropia (a condition of refractive error) is defined as a state of refraction when the parallel rays of light coming from infinity are focused either in front or behind the retina. It includes myopia, hypermetropia and astigmatism. +Define hypermetropia (Iong-sightedness). Hypermetropia is the refractive state of the eye wherein parallel rays of light coming from infinity are focused posterior to the retina, with accommodation at rest. +What is the refractive status of the eye at birth? +At birth the eyeball is relatively short and thus most infants are born with +2 to +3 D hypermetropia. This is gradually reduced and by the age of 5 to 7 years usually the eye becomes emmetropic. +What are etiological types of ametropic refractive errors? +1. Axial ametropia: There is abnormal axial length of the eyeball, too long in myopia and too short in hypermetropia. +2. Curvatural ametropia: There is abnormal curvature of the cornea or lens or both; too strong in myopia and too weak in hypermetropia. +3. Index ametropia: There is abnormal refractive index of the media; too high in myopia and too low in hypermetropia. +4. Positional ametropia: Forward displacement of the lens causes myopia and backward displacement results in hypermetropia. +What are the components of the hypermetropia? Total hypermetropia = latent + manifest (facultative + absolute) +1. Total hypermetropia: It is the total amount of refractive error estimated after complete cycloplegia with atropine. +2. Latent hypermetropia is that which is corrected by inherent tone of the ciliary muscle. +3. Manifest hypermetropia: It is the remaining portion of total hypermetropia, which is not corrected by the ciliary tone. +Chapter 25 Darkroom Procedures 581 + + +Name the most common factor responsible for myopia and hypermetropia. +Too long axial length and too short axial length are responsible for myopia and hypermetropia, respectively. +Name the complications which may occur in non-treated cases of hypermetropia. +1. Recurrent styes and blepharitis, +2. Accommodative convergent squint, 3. Amblyopia. +Define aphakia. +Aphakia literally means absence of the crystalline lens from the eye. However, from the optical point of view, it may be considered as a condition in which the lens is absent from the pupillary area and does not take part in refraction. +Enumerate the refractive changes which occur in an aphakic eye. +1. Eye becomes highly hypermetropic. +2. Total power of the eye is reduced to +44 Ds from +60 Ds. +3. Anterior focal distance becomes 23 mm (from 15 mm in normal phakic eye). +4. Posterior focal distance becomes 31 mm (from 24 mm in normal phakic eye). +Name the various modalities for correction of aphakia and enumerate advantages and disadvantages of each. +1. Spectacles +Advantages: It is cheap, easy and safe method of correcting aphakia. +Disadvantages: (i) Image is magnified by 30%, so not useful in unilateral aphakia (produce diplopia), (ii) problems of spherical and chromatic aberrations may be troublesome, (iii) field of vision is limited, (iv) prismatic effect of thick glasses causes, ‘roving ring scotoma’ (v) cosmetic blemish, especially in young aphakics. +2. Contact lenses +Advantages: (i) Less magnification (5%) of the image, (ii) Elimination of aberrations and prismatic effect of thick glasses, (iii) Wider and better field of vision, (iv) Cosmetically better accepted by young persons. Disadvantages: (i) More cost, (ii) Cumbersome to wear, especially in old age and in childhood, (iii) Corneal complications may occur. +3. Intraocular lens implantation +It is the best available method of treatment. Advantage: It offers all the advantages which the contact lenses offer over the spectacles. In addition, + + +the disadvantages of contact lenses are also taken care of. +Disadvantages: It requires more skilled surgeons and costly equipments. +4. Refractive corneal surgery +It is still under trial and includes keratophakia and epikeratophakia. +What are fundus findings in a patient with high hypermetropia? +Fundus examination in a patient with high hypermetropia may show: +• Pseudopapillitis +• Shot silk appearance of the retina. +Enumerate the signs of aphakia. • Deep anterior chamber +• Iridodonesis +• Jet black pupil +• Purkinje’s image test shows only two images (normally four) +• Fundus examination shows small optic disc • Retinoscopy reveals high hypermetropia +What is pseudophakia? +Pseudophakia refers to presence of an intraocular lens in the pupillary area. +What is the refractive position of the pseudophakic eye? +A pseudophakic eye may be emmetropic, myopic or hypermetropic depending upon the power of the IOL implanted. +What is the average standard power of the posterior chamber IOL? +Exact power of an IOL to be implanted varies from individual to individual and is calculated by biometry using keratometer and A-scan ultrasound. +What is the average weight of an IOL? +Average weight of an IOL in air is 15 mg and in aqueous humour is about 5 mg. +What is the power of the IOL in air vis-a-vis in the aqueous humour? +Power of an IOL in air is much more (about +60D) than that in the aqueous humour (about + 20D). +What is the difference in the power of an anterior chamber IOL versus posterior chamber IOL? Equivalent power of an anterior chamber IOL is less (say about +18D) than that of posterior chamber IOL (+20D). +What is myopia (short-sightedness)? +Myopia is a refractive error in which parallel rays of +582 Section VI Practical Ophthalmology + + +light coming from infinity are focused in front of the retina when accommodation is at rest. +Name the clinical varieties of myopia. 1. Congenital myopia +2. Simple myopia +3. Pathological or degenerative myopia +4. Acquired myopia which may be: (i) post-traumatic, (ii) post-keratitis, (iii) space myopia, and (iv) consecutive myopia (following overcorrection of aphakia by intraocular lens). +Enumerate the fundus changes in pathological myopia. +1. Optic disc appears large, pale and at its temporal edge characteristic myopic crescent is present. +2. Chorioretinal degeneration. +3. Foster-Fuchs’ spot at the macula. +4. Vitreous shows synchysis and syneresis. 5. Posterior staphyloma may be seen. +Name the surgical treatment of myopia. 1. Radial keratotomy. +2. Photorefractive keratectomy (PRK) using excimer laser +3. Automated microlamellar keratectomy (ALK). +4. Removal of clear crystalline lens by extracapsular cataract extraction (ECCE) is recommended in unilateral very high myopia. +Name the complications of pathological myopia. 1. Complicated cataract +2. Choroidal haemorrhage +3. Tears and haemorrhage in the retina 4. Vitreous haemorrhage +5. Retinal detachment. + +Name the diseases which can be associated with myopia. +1. Microphthalmos +2. Congenital glaucoma 3. Microcornea +4. Retrolental fibroplasia 5. Marfan’s syndrome +6. Turner’s syndrome +7. Ehlers-Danlos syndrome. +What is the basic principle of radial keratotomy operation for myopia? +In radial keratotomy operation, multiple radial incisions are given in the periphery of cornea (leaving central 4 mm optical zone) in order to flatten the curvature of cornea. +What is the principle of photorefractive keratectomy (PRK) operation for myopia? +In it, superficial keratectomy (reshaping) is + +performed in the central part of cornea with the help of excimer laser. +What is ALK operation for myopia? +It is automated lamellar keratectomy. In it a small disc of corneal stroma is removed with the help of an automated machine. +What is LASIK operation for myopia? +It is laser-assisted in-situ keratomileusis. It is performed using ALK machine and the excimer laser. This procedure is good for myopia of more than –8D. +Define astigmatism. +Astigmatism is a type of refractive error, wherein the refraction varies in the different meridia. Consequently, the rays of light entering in the eye cannot converge to a point focus but form focal lines. +What are the clinical types of astigmatism? 1. Regular astigmatism, which may be: +i. With-the-rule (WTR) astigmatism, wherein the vertical meridian is more curved than the horizontal. +ii. Against-the-rule (ATR) astigmatism, wherein the horizontal meridian is more curved than the vertical meridian. +iii.Oblique astigmatism, wherein the two principal meridia are not the horizontal and vertical though these are at right angles to one another (e.g., 45° and 135°). +iv. Bioblique astigmatism, wherein the two principal meridia are not at right angle to each other, e.g., one may be at 30° and the other at 100°. +2. Irregular astigmatism: In it refraction varies in multiple meridia which admits no geometrical analysis. It commonly follows corneal scarring. +What is the treatment of irregular astigmatism? Contact lens prescription, which replaces the anterior surface of the cornea for refraction. +What is simple, compound and mixed astigmatism? 1. Simple astigmatism. Herein the rays of light entering the eye are focused on the retina in one meridian and either in front (simple myopic astigmatism, or behind (simple hypermetropic +astigmatism) the retina in other meridian. +2. Compound astigmatism. In this type of astigmatism, light rays are focused in both the principal meridia either in front (compound myopic astigmatism) or behind (compound hypermetropic astigmatism) the retina. +Chapter 25 Darkroom Procedures 583 + + +3. Mixed astigmatism. In this condition, light rays are focused in front of the retina in one meridian and behind the retina in the other meridian. +What is the most common cause of irregular astig-matism? +Irregular corneal scars. +What is anisometropia? +In it, total refraction of the two eyes is unequal. Practically, a difference of more than 2.5D (which causes more than 5% difference in the retinal images of the two eyes) poses problem of anisometropia. +What is aniseikonia? +Aniseikonia is defined as a condition, wherein the images projected to the visual cortex from the two retina are abnormally unequal in size and shape. +How much image magnification is caused by one dioptre anisometropia? +One dioptre anisometropia produces image magnification by 2%. An image difference up to 5% to 7% is well tolerated. +What are the common causes of aniseikonia? Aniseikonia may be optical (due to high aniso-metropia), retinal (due to stretching or crowding of retina in macular area) or cortical (due to abnormal cortical perception of the images). +ACCOMMODATION AND ITS ANOMALIES Define accommodation. +Accommodation is a mechanism by which the eyes can focus the diverging rays coming from a near object on the retina. In it, there occurs increase in the power of crystalline lens. +What is presbyopia? +Presbyopia is not an error of refraction but a condition of physiological insufficiency of accommodation resulting from the decreased elasticity and plasticity of the lens due to advancing age (usually after the age of 40 years) leading to failing vision for near. +What is near point of the eye? +The nearest point at which small objects can be seen clearly is called near point or punctum proximum. Its value varies with age; being about 7 cm at 10 years of age and about 25 cm at about 40 years of age. +What is far point of the eye? +The farthest point from where objects can be seen by the eye is called far point or punctum remotum. In an emmetropic eye, far point is at infinity. + +Enumerate the causes of premature presbyopia. 1. Uncorrected hypermetropia +2. Premature hardening of the lens +3. General debility causing premature senile weakness of the ciliary muscles +4. Chronic simple glaucoma. + +What is range of accommodation? +Range of accommodation is the distance between the near point and far point of the eye. +What is amplitude of accommodation? +Amplitude of accommodation is the difference between the dioptric power needed to focus at near and far point. +What do you mean by insufficiency of accommod-ation? Enumerate its causes. +Insufficiency of accommodation refers to a significant decrease in accommodation power than the normal physiological limit for the patient’s age. Common causes of insufficiency of accommodation are: +• Premature sclerosis of the lens. +• Weakness of ciliary muscles associated with chronic debilitating disease, anaemia, malnutrition, pregnancy, stress and so on. +• Primary open-angle glaucoma. +DETERMINATION AND CORRECTION OF REFRACTIVE ERRORS +Enumerate objective methods of refraction. • Retinoscopy +• Autorefractometry • Keratometry. + +Name some subjective methods of refraction. • Trial and error method +• Fogging method +• Tests for confirming refraction subjectively – Duochrome test +– Astigmatic fan test +– Jackson’s cross cylinder test – Pin-hole test. + +Define retinoscopy (skiascopy or shadow test). Retinoscopy is an objective method of finding out the error of refraction by the method of neutralization. The end point of neutralization is either no movement or just reversal of the movement of the pupillary shadow. + +What is the principle of retinoscopy? +Retinoscopy is based on the fact that when light is reflected from a mirror into the eye, the direction in +584 Section VI Practical Ophthalmology + + +which light will travel across the pupil will depend upon the refractive state of the eye. +What are the prerequisites for retinoscopy? +1. A darkroom preferably 6-m long or which can be converted into 6 meters by the use of a plane mirror. +2. A trial box containing spherical and cylindrical lenses of variable plus and minus powers, a pin-hole, an occluder and prisms. +3. A trial frame. +4. A Snellen’s self-illuminated vision box. 5. A retinoscope. +What are the common types of retinoscopes? +1. Mirror retinoscopes, which may consist of a simple plane mirror or a combination of a plane mirror (on one end) and a concave mirror (on the other end), e.g., Pristley-Smith’s mirror. +2. Self-illuminated streak retinoscope. + +What are the advantages of a streak retinoscope over a simple plane mirror retinoscope? Thestreakretinoscopeismoresensitivethanthespot retinoscope in detecting astigmatism. +Name the conditions where concave mirror retinoscopy is more useful. +1. Patient with hazy media. +2. Patient with very high degree of refractive error. +What are the indications of using cycloplegic drugs for retinoscopy? +Cycloplegics are used before retinoscopy in patients where the examiner suspects that accommodation is abnormally active and will hinder the exact retinoscopy. Such a situation is encountered in young children especially hypermetropes. +What do you mean by wet retinoscopy and dry retinoscopy? +When retinoscopy is performed after instilling a cycloplegic, it is termed ‘wet-retinoscopy’ in converse to dry retinoscopy (without cycloplegic). +Name the commonly used cycloplegics. 1. Atropine +2. Homatropine 3. Cyclopentolate. +At what distance retinoscopy is performed? One meter or two-third meter. +When retinoscopy is performed with a plane mirror at a distance of 1 m; what inferences are drawn? Depending upon the movement of the red reflex vis-a-vis movement of the plane mirror, following inferences are drawn: + +1. No movement of the red reflex indicates myopia of 1D. +2. With movement of the red reflex indicates either emmetropia or hypermetropia or myopia of less than 1D. +3. Against movement indicates myopia of more than 1D. +What inferences are drawn from the movement of the red reflex when concave mirror retinoscope is used? The inferences drawn while using a concave mirror are reverse to that of plane mirror. +What is the point of neutralization while using a simple plane mirror retinoscope? +The end point of neutralization is either no movement or just reversal of the movement of the pupillary shadow. +What is the end point of neutralization while using a streak retinoscope? +At the end point, the streak disappears and the pupil appears completely illuminated or completely dark. +While performing retinoscopy, if the shadow appears to swirl around, what does it indicate? Astigmatism. +While performing retinoscopy with dilated pupil, one central and another peripheral shadow may be seen. It is important to neutralize which shadow? +Central shadow. +When a cycloplegic retinoscopy has been performed, how many dioptres should be deducted to comp-ensate for the ciliary tone? +• 1 D for atropine +• 0.75 D for cyclopentolate • 0.5 D for homatropine. +What is an autorefractometer? +It is a computerized refractometer which quickly estimates the refractive error of the patient objectively in terms of sphere, cylinder with its axis and interpupillary distance. The subjective verification is a must even after autorefractometry. +What is a duochrome test? +Duochrome test is based on the principle of chromatic aberrations. It helps in verifying the spherical correction subjectively. In it, the patient is asked to tell the clarity of the letters with red background vis-a-vis green background. To an emmetropic patient, letters of both the colours look equally sharp; while to a slightly myopic patient the red letters appear sharper and to a slightly hypermetropic patient the green letters look sharper. +Chapter 25 Darkroom Procedures 585 + + +Name common problems which can arise while performing retinoscopy. +Red reflex may not be visible. It occurs in: 1. Small pupil, +2. Hazy media, and +3. High degree of refractive errors. +DARKROOM APPLIANCES +What is a prism and what are its uses in ophtha-lmology? +Prism is a refracting medium, having two plane surfaces inclined at an angle. Its uses are: +1. Objective measurement of angle of squint (Prism bar cover test, Krimsky’s test). +2. Measurement of fusional reserve. 3. Diagnosis of microtropia. +4. Used in ophthalmic equipments such as gonioscope, keratometer, applanation tonometer, etc. +What are the uses of a convex spherical lens? Its uses are: +1. For correction of hypermetropia, aphakia and presbyopia. +2. In oblique illumination examination. 3. In indirect ophthalmoscopy. +4. As a magnifying lens. +How will you identify a convex lens? +A convex lens can be identified from following features: +1. It is thicker at the centre. +2. An object held close to it appears magnified. +3. When it is moved, the objects seen through it move in the opposite direction. +How will you identify a concave lens? +A concave lens can be identified from following features: +1. It is thin at the centre and thick at the periphery. 2. An object seen through it appears minified. +3. When it is moved, the objects seen through it move in the same direction of the lens. +What are the uses of concave lens? 1. For correction of myopia +2. As Hruby lens for fundus examination. + +How will you identify a cylindrical lens? +1. When it is rotated around its optical axis, objects seen through it become distorted. +2. It acts only in one axis, i.e., when it is moved up and down or sideways the object seen through it moves only in one direction (with the lens in a convex cylinder and against the lens in a concave cylinder). + +What are the uses of cylindrical lenses? +Cylindrical lens is prescribed to: (i) correct astigmatic refractive error, (ii) it is used as a cross cylinder to check the power and axis of the cylindrical lens prescribed subjectively. +What is a cross cylinder and what are its uses? +The Jackson’s cross cylinder is a combination of two cylindrical lenses of equal strength but with opposite sign placed with their axis at right angles to each other and mounted in a handle. The cross cylinder effect is obtained by combining a spherical lens with a cylindrical lens (double the power of spherical lens) with opposite sign –0.25D spherical and +0.5D cylindrical. Commonly used cross cylinders are a combination of 0.25D and 0.5D. +A cross cylinder is used to verify the strength and axis of the cylinder subjectively. +What are the uses of red and green glasses or filters? These are used for: +1. Diplopia charting +2. Worth’s four-dot test 3. Malingering test. +While testing, the red glass is kept in front of the right eye and the green glass is kept in front of the left eye. +Which glass is used most commonly for making spectacles? +Crown glass with refractive index 1.5223 is most commonly used for making spectacles. +What are the types of contact lenses you know of? 1. Hard contact lenses +2. Soft contact lenses +3. Rigid gas-permeable (RGP) contact lenses. + +What are the advantages and disadvantages of hard contact lenses? +Hard contact lenses are made up of PMMA (polymethylmethacrylate) which is a light weight, nontoxic but of hydrophobic material. +Advantages +Cheap, durable and have high optical quality. +Disadvantages +Can cause corneal hypoxia and corneal abrasions. + +What are the advantages and disadvantages of soft contact lenses? +Soft contact lenses are made up of HEMA (hydrox-yethylmethacrylate) which is hydrophilic. +Advantages +Being soft and oxygen permeable, they are most comfortable and so well tolerated. +586 Section VI Practical Ophthalmology + + +Disadvantages +Problems of proteinaceous deposits, getting cracked, limited life, inferior optical quality, more chances of corneal infections, and inability to correct astigmatism of more than one dioptre. + +TECHNIQUES OF FUNDUS EXAMINATION + +Techniques of fundus examination include: A. Ophthalmoscopy, and +B. Slit-lamp biomicroscopic examination of the fundus by: +• Indirect slit-lamp biomiscroscopy • Hruby lens biomicroscopy +• Contact lens biomicroscopy. + +A. OPHTHALMOSCOPY +Ophthalmoscopy is a clinical examination of the interior of the eye by means of an ophthalmoscope. It is primarily done to assess the state of fundus and detect the opacities of ocular media. The ophthalmoscope was invented by Babbage in 1848, however, its importance was not recognized, and it was reinvented by von Helmholtz in 1850. Three methods of examination in vogue are: +1. Distant direct ophthalmoscopy, 2. Direct ophthalmoscopy, and +3. Indirect ophthalmoscopy. + +1. Distant Direct Ophthalmoscopy +It should be performed routinely before the direct ophthalmoscopy, as it gives a lot of useful information (vide infra). It can be performed with the help of a self-illuminated ophthalmoscope or a simple plain mirror with a hole at the centre. +Procedure. The light is thrown into patient’s eye sitting in a semi-darkroom, from a distance of 20–25 cm and the features of the red glow in the pupillary area are noted. +Applications of distant direct ophthalmoscopy include: i. To diagnose opacities in the refractive media. Any opacity in the refractive media is seen as a black shadow in the red glow. The exact location of the opacity can be determined by observing the parallactic displacement. For this, the patient is asked to move the eye up and down while the examiner is observing the pupillary glow. +• Opacities in the pupillary plane remain stationary (2 in Fig. 25.26), +• Opacities in front of the pupillary plane move in the direction of the movement of the eye (1 in Fig. 25.26), and + + + + + + + + + + + + + +Fig. 25.26 Parallactic displacement on distant direct ophthalmoscopy + +• Opacities behind it will move in opposite direction (3, 4, 5 in Fig. 25.26). +ii. To differentiate between a mole and a hole of the iris. A small hole and a mole on the iris appear as a black spot on oblique illumination. On distant direct ophthalmoscopy, the mole looks black (as earlier) but a red reflex is seen through the hole in the iris. iii. To recognize detached retina or a tumour arising from the fundus. A greyish reflex seen on distant direct ophthalmoscopy indicates either a detached retina or a tumour arising from the fundus. + +2. Direct Ophthalmoscopy +It is the most commonly practised method for routine fundus examination. +Optics.The modern direct ophthalmoscope (Fig. 25.27) works on the basic optical principle of glass plate ophthalmoscope introduced by von Helmholtz. Optics of direct ophthalmoscopy is depicted in Fig. 25.28. + + + + + + + + + + + + + + + + + + + +Fig. 25.27 Direct ophthalmoscope +Chapter 25 Darkroom Procedures 587 + + + + + + + + + + + + + + + + + +Fig. 25.28 Optics of direct ophthalmoscopy + +A convergent beam of light is reflected into the patient’s pupil (Fig. 25.28, dotted lines). The emergent rays from any point on the patient’s fundus reach the observer’s retina through the viewing hole in the ophthalmoscope (Fig. 25.28, continuous lines). The emergent rays from the patient’s eye are parallel and brought to focus on the retina of the emmetropic observer when accommodation is relaxed. However, if the patient or/and the observer is/are ametropic, a correcting lens (equivalent to the sum of the patient’s and observer’s refractive error) must be interposed (from the system of plus and minus lenses, inbuilt in the modern ophthalmoscopes). +Characteristics of image formed. In direct ophthal-moscopy, the image is erect, virtual and about 15 times magnified in emmetropes (more in myopes and less in hypermetropes). +Technique. Direct ophthalmoscopy should be performed in a semi-darkroom with the patient seated and looking straight ahead, while theobserver standing or seated slightly over to the side of the eye to be examined (Fig. 25.29). Patients right eye should be examined by the observer with his or her right eye and left with the left eye. +The observer should reflect beam of light from the ophthalmoscope into patient’s pupil. Once the red reflex is seen the observer should move as close to the patient’s eye as possible (theoretically at the anterior focal plane of the patient’s eye, i.e., 15.4 mm from the cornea). Once the retina is focused the details should be examined systematically starting from disc, blood vessels, the four quadrants of the general background and the macula (see page 507–509 for systematic observations to be made on ophthalmoscopy). + +Fig. 25.29 Technique of direct ophthalmoscopy + +3. Indirect Ophthalmoscopy +Indirect ophthalmoscopy introduced by Nagel in 1864, is now a very popular method for examination of the posterior segment. +Optical principle. The principle of indirect ophthalmoscopy is to make the eye highly myopic by placing a strong convex lens in front of patient’s eye so that the emergent rays from an area of the fundus are brought to focus as a real, inverted image between the lens and the observer’s eye, which is then studied (Fig. 25.30). +Characteristics of image. The image formed in indirect ophthalmoscopy is real, inverted and magnified. Magnification of image depends upon the dioptric power of the convex lens, position of the lens in relation to the eyeball and refractive state of the eyeball. About 2.5 times magnification and 35° or 8 disc-diameter field of view is obtained with a +20D lens. With a stronger lens, image will be smaller, but brighter and field of vision will be more. Prerequisites. (i) Darkroom, (ii) Source of light and concave mirror or self-illuminated indirect ophthalmoscope, (iii) Convex lens (now-a-days commonly employed lens is of +20D), (iv) Pupils of the patient should be dilated. + + + + + + + + + +Fig. 25.30 Optics of indirect ophthalmoscopy +588 Section VI Practical Ophthalmology + + +Technique.Patient is made to lie in the supine position, with one pillow on a bed or couch and instructed to keep both eyes open. The examiner throws the light into patient’s eye from an arm’s distance (with the self-illuminated ophthalmoscope). In practice, binocular ophthalmoscope with head band or that mounted on the spectacle frame is employed most frequently (Fig. 25.31). Keeping his or her eyes on the reflex, the examiner then interposes the condensing lens (+20D, routinely) in the path of beam of light, close to patient’s eye, and then slowly moves the lens away from the eye (towards himself) until the image of the retina is clearly seen. The examiner moves around the head of the patient to examine different quadrants of the fundus. He or she has to stand opposite the clock hour position to be examined, e.g., to examine inferior quadrant (around 6 O’ clock meridian) the examiner stands towards patient’s head (12 O’clock meridian) and so on. By asking the patient to look in extreme gaze, and using scleral indenter, the whole peripheral retina up to ora serrata can be examined. Applications. Indirect ophthalmoscopy is essential for the assessment and management of retinal detachment and other peripheral retinal lesions. Difficulties in indirect ophthalmoscopy are: +1. The technique is difficult and can be mastered by hours of practice. + + + + + + + + + + + + + + + + + + + + + + + +Fig. 25.31 Technique of indirect ophthalmoscopy + +2. Reflexes from the corneal surface can be decreased by holding the condensing lens at a distance equal to its focal length from the anterior focus of the eye. +3. Formation of reflexes by the two surfaces of convex lens can be eliminated by slightly tilting the lens and use of aspheric lens. +Advantages of the binocular indirect ophthalmoscope are: +1. Visualization through hazy media is possible due to strong in built illumination system. +2. Field of view is much larger than direct ophthal-moscopy. +3. Examination of peripheral retina up to ora serrata is possible. +4. Depth perception of the lesion is possible due to stereopsis with binocular indirect ophthalmoscope. +5. Visualization of fundus in very high refractive error is also possible, where it may not be possible to focus the lesion with direct ophthalmoscope. +Direct versus indirect ophthalmoscopy(SeeTable 25.2). +B. SLIT-LAMP BIOMICROSCOPIC EXAMINATION OF THE FUNDUS +Biomicroscopic examination of the fundus can be performed after full mydriasis using a slit-lamp and anyone of the following lenses: +1. Indirect slit-lamp biomicroscopy. Using +78 D or +90 D small diameter lens (Fig. 25.32A) is presently the most commonly employed technique for biomicroscopic examination of the posterior pole of fundus. Similar to binocular indirect ophthalmoscopy, the image formed is inverted, real and magnified. This technique (Fig. 25.33) is being considered a better alternative to all the below discussed techniques for slit-lamp biomicroscopy of the fundus. +2. Hruby lens biomicroscopy. Hruby lens is a planoconcave lens with dioptric power 58.6D (Fig. 25.32B). This lens provides a small field with low magnification and cannot visualize the fundus beyond equator. +3. Contant lens biomicroscopy can be performed by following lenses: +• Posterior fundus contact lens is a modified Koeppe’s lens (Fig. 25.32C). The image produced by it is virtual and erect. +• Goldmann’s three-mirror contact lens consists of a central contact lens and three mirrors placed in the cone, each with different angles of inclination (Fig. 25.32D). With this the central as well as peripheral parts of the fundus can be visualized. +Chapter 25 Darkroom Procedures 589 + +Table 25.2 Direct versus indirect ophthalmoscopy + + +Sr. Feature no. +1. Condensing lens +2. Examination distance 3. Image + +4. Magnification 5. Illumination + +6. Area of field in focus 7. Stereopsis +8. Accessible fundus view +9. Examination through hazy media + +Direct ophthalmoscopy + +Not required +As close to patient’s eye as possible Virtual, +Erect +About 15 times +Not so bright; so not useful in hazy media +About 2 disc diameter Absent +Slightly beyond equator +Not possible + +Indirect ophthalmoscopy + +Required +At an arm’s length Real, +Inverted +2.5 times (with +20 D lens) Bright; so, useful for hazy media + +About 8 disc diameter Present +Up to ora serrata +Possible + + + + + + + + + + + + + + + + + + + +Fig. 25.32 Lenses used for slit-lamp biomicroscopic examination of fundus: A, +78 D or + 90 D, small diameter lens. B, Hruby lens; C, Posterior fundus contact lens (modified Koeppe’s lens); D, Goldmann’s three-mirror contact lens + + + + + + + + + + + + + + +Fig. 25.33 Technique of indirect slit-lamp fundus biomicroscopy + +RELATED QUESTIONS + +Define ophthalmoscopy. +It is a darkroom procedure carried out to examine the fundus oculi. + +What are the types of ophthalmoscopy? Ophthalmoscopy is of three types: +1. Distant direct ophthalmoscopy. 2. Direct ophthalmoscopy. +3. Indirect ophthalmoscopy. + +What are the other methods of fundus examination? In addition to ophthalmoscopy fundus can also be examined by focal illumination using a slit-lamp biomicroscope and any of the following lenses: +• Hruby lens +• Posterior fundus contact lens +• Goldmann’s three-mirror contact lens • +78 D and +90 D small diameter lenses. + +When and who invented the direct ophthalmoscope? Babbage in 1848. + +Who reinvented and popularised the ophthalm-oscope? +von Helmholtz in 1850. + +At what distance distant direct ophthalmoscopy is performed? +20–25 cm. + +What are the uses (applications) of distant direct ophthalmoscopy? +1. To diagnose opacities in the ocular media. +2. To differentiate between a mole and a hole of the iris. +590 Section VI Practical Ophthalmology + + +3. To recognize a detached retina. 4. To recognize a subluxated lens. +At what distance ‘direct ophthalmoscopy’should be performed? +As near to the patient’s eye as possible. \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_2.txt b/notes/A K Khurana - Comprehensive Ophthalmology_2.txt new file mode 100644 index 0000000000000000000000000000000000000000..da6b02675d585cdd56d198183c4bc83557a465e8 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_2.txt @@ -0,0 +1,1599 @@ + + + + + + + + +Fig. 3.17 Cylindrical lenses: (A) convex; and (B) concave + + + + + + + + + + +Fig. 3.18 Refraction through a convex cylindrical lens + +Uses of cylindrical lenses +• Prescribed to correct astigmatism. +• As a cross cylinder used to check the refraction subjectively. +• Maddox rod consist of powerful convex cylindrical lenses mounted together. +Types of cylindrical lenses +Cylindrical or astigmatic lens may be of three type: • Simple (curved in one meridian only, either convex +or concave), compound (curved unequally in both the meridians, either convex or concave). +• Compoundcylindricallens is also called spherical cylinder. +• Mixed cylinder, in which one meridian is convex and the other is concave. +Images formed by a cylindrical lens +The images formed by different types of cylindrical lenses are best understood by the study of Sturm’s conoid (see page 42). + +PhYSIOLOGICAL OPTICS (OPTICS Of ThE EYE) + +eye as aN OPticaL iNstrumeNt +Eye as an optical instrument can be compared to a camera where: + +• Eyelids acts as shutter of the camera. +• Corneaand crystallinelens act as focussing system (lens) of the camera. In fact the cornea (1.32) and crystalline lens (1.47) along with aqueous humour (1.33), and vitreous humour (1.33) constitute a homocentric system of lenses, which when combined in action from a very strong refracting system of short focal length. +• Iris acts as a diaphragm which regulates the size of aperture (pupil) and, therefore, the amount of light entering the eye. +• Choroidhelps in forming the darkened interior of the camera. +• Retinaacts as light sensitive plate or film on which image is formed. +Note. To be more precise, the functioning of the eye can be considered to be analogous to a closed circuit colour TV system as depicted in Fig. 3.19. The optic nerve and its connections convey the details of the image to the occipital region of the cerebral cortex, where they are processed before reaching consciousness. +schematic eye: cardiNaL POiNts +The complex optics of eye, forming a homocentric lens system, has been simplified by Gullstrand by resolving it into six cardinal points (schematic eye) as follows (Fig. 3.20A): +• Two principal foci F1 and F2 which lie 15.7 mm in +front and 24.4 mm behind the cornea, respectively. +• Two principal points P1 and P2 which lie in the +anterior chamber, 1.35 mm and 1.60 mm behind the anterior surface of cornea, respectively. +• Two nodal points N1 and N2 which lie in the +posterior part of lens, 7.08 mm and 7.33 mm behind the anterior surface of cornea, respectively. +• Totaldioptricpower of this schematic eye is 58.64 D. + +reduced eye +Understanding of the optics eye has been further simplified by Listing and Donder. From schematic eye, they have given the concept of reduced eye by choosing single principal point and single nodal point lying midway between two principal points and two nodal points, respectively. The simplified data of the Listing’s reduced eye are as follows (Fig. 3.20B): +• Principalpoint(P) lies 1.5 mm behind the anterior surface of cornea. +• Nodal point (N) is situated 7.2 mm behind the anterior surface of cornea. +• Anterior focal point (F1) is 15.7 mm in front of the anterior surface of cornea. +Chapter 3 Elementary and Physiological optics 31 + + + + + + + +A + + + + + + +B + +Fig. 3.19 Functioning of eye as an optical system (A) is in many ways similar to a closed circuit colour TV system + + + + + + + + + + + + + +A + +axes aNd VisuaL aNgLes Of the eye +The eye has three principal axes and three visual angles (Fig. 3.21). +axes of the eye +1.Opticaxisis the line passing through the centre of the cornea (P), centre of the lens (N) and meets the retina (R) on the nasal side of the fovea. +In practice it is impossible to determine accurately the optic axis, since we cannot know the exact centre of cornea. However, it is much easier to estimate centre of the pupil, for example by an image of light on the cornea. Therefore, in practice we substitute the optic axis by a line perpendicular to the cornea at the point coinciding to the centre of pupil. This line is called pupillary line. +2.Visualaxisis the line joining the fixation point (O), nodal point (N), and the fovea (F). +3.Fixation axis is the line joining the fixation point (O) and the centre of rotation (C). + + + +B + +Fig. 3.20 Cardinal points of schematic eye (A); and reduced eye (B) + + + + +• Posteriorfocalpoint (F2) (on the retina) is 24.40 mm +behind the anterior surface of cornea. +• Anterior focal length (f1) is 17.2 mm (15.7 + 1.5) +• Posteriorfocallength(f2) is 22.90 mm (24.40 – 1.5). +• Total dioptric power of reduced eye is about + 60 dioptre. Out of which about + 43 D is contributed by the cornea and + 17 D by the crystalline lens. + + + +Fig. 3.21 Axes of the eye: optic axis (AR); visual axis (OF); fixation axis (OC) and visual angles: angle alpha (ONA, between optical axis and visual axis at nodal point N); angle kappa (OPA, between optical axis and pupillary line–OP); angle gamma (OCA, between optical axis and fixation axis) +32 Section ii optics and Refraction + + +Visual angles +Visual angles eye are (Fig. 3.21): +1.Anglealpha. It is the angle (ONA) formed between the optical axis (AR) and visual axis (OF) at the nodal point (N). +2.Angle gamma. It is the angle (OCA) between the optical axis (AR) and fixation axis (OC) at the centre of rotation of the eyeball (C). +3.Anglekappa. It is the angle (OPA) formed between the visual axis (OF) and pupillary line (AP). The point P on the centre of cornea is considered equivalent to the centre of pupil. +Practically, only the angle kappa can be measured and is of clinical significance. A positive angle kappa results in pseudo-exotropia and a negative angle kappa in pseudo-esotropia. +OPticaL aberratiONs Of the NOrmaL eye The eye, in common with many optical systems in practical use, is by no means optically perfect. The lapses from perfection are called aberrations. Fortunately, the eyes possess these defects to such a small degree that for functional purposes their presence is negligible. +Natural mechanisms to decrease aberrations in the human eye include: +• Cutting off of the peripheral rays by iris, +• High refractive index of the core of nucleus of the lens than that of the peripheral cortex, +• Low sensitivity of the peripheral retina, and +• Stiles-Crawford effect, i.e., more sensitivity of the retina to perpendicular rays than the oblique rays. +It has been said that despite imperfections the overall performance of the eye is little short of astonishing. Physiological optical defects in a normal eye include the following: +1. Diffraction of light. Diffraction refers to the bending of light rays caused by the edge of an aperture or the rim of a lens. The actual pattern of a diffracted image point produced by a lens with a circular aperture or pupil is a series of concentric bright and dark rings with a bright spot in the centre. Such a pattern is termed as the Airydisc (Fig. 3.22). +2. Spherical aberrations. Spherical aberrations occur owing to the fact that spherical lens refracts peripheral rays more strongly than paraxial rays which in the case of a convex lens brings the more peripheral rays to focus closer to the lens (Fig. 3.23). +The human eye, having a power of about +60 D, was long thought to suffer from various amounts of spherical aberrations. However, results from aberroscopy have revealed the fact that the dominant + + + + + + + + + + + + + + + + + + + + +Fig. 3.22 The diffraction of light. Light brought to a focus does not come to a point, but gives rise to a blurred disc of light surrounded by several dark and light bands (the ‘Airy disc’) + +aberration of human eye is not spherical aberration but rather a coma-like aberration. +3. Chromatic aberrations. Chromatic aberrations result owing to the fact that the index of refraction of any transparent medium varies with the wavelength of incident light. In human eye, which optically acts as a convex lens, blue light is focussed slightly in front of the red (Fig. 3.24). In other words, the emmetropic eye is in fact slightly hypermetropic for red rays and myopic for blue and green rays. This in fact forms the basis of bichrome test used in subjective refraction. + + + + + + + + + + + + + + +Fig. 3.23 Spherical aberration. Because there is greater refraction at periphery of spherical lens than near centre, incoming rays of light do not truly come to a point focus +Chapter 3 Elementary and Physiological optics 33 + + + + + + + + + + + + +Fig. 3.24 Chromatic aberration. The dioptric system of the eye is represented by a simple lens. The yellow light is focussed on the retina, and the eye is myopic for blue, and hypermetropic for red +4. Decentring. The cornea and lens surfaces alter the direction of incident light rays causing them to focus on the retina. Actually these surfaces are not centred + +on a common axis. The crystalline lens is usually slightly decentred and tipped with respect to the axis of the cornea and the visual axis of the eye. It has been reported that the centre of curvature of cornea is situated about 0.25 mm below the axis of the lens. However, the effects of deviation are usually so small that they are functionally neglected. +5. Oblique aberration. Objects in the peripheral field are seen by virtue of obliquely incident narrow pencil of rays which are limited by the pupil. Because of this, the refracted pencil shows oblique astigmatism +6. Coma. Different areas of the lens will form foci in planes other than the chief focus. This produces in the image plane a ‘coma effect’ from a point source of light. +4 +Errors of refraction and Accommodation + + + +Chapter Outline + +ERRORS OF REFRACTION Emmetropia and ametropia Hypermetropia +Myopia Astigmatism Anisometropia Aniseikonia +• +• +• +• +• +• +ACCOMMODATION AND ITS ANOMALIES Accommodation +• +• +• +Definition Mechanism +Range and amplitude Anomalies of Accommodation +• +• +Presbyopia +Insufficiency of accommodation + + + +ERRORS OF REFRACTION + +EmmEtropia and amEtropia +Emmetropia (optically normal eye) can be defined as a state of refraction, where in the parallel rays of light coming from infinity are focused at the sensitive layer of retina with the accommodation being at rest (Fig. 4.1). +Ametropia (a condition of refractive error), is defined as a state of refraction, when the parallel rays of light coming from infinity (with accommodation at rest), are focused either in front or behind the sensitive layer of retina, in one or both the meridians. The ametropia includes: +• Myopia, +• Hypermetropia, and • Astigmatism. +Note. The related conditions aphakia and pseud­ ophakia are also discussed here. + +HYPERMETROPIA + +Hypermetropia (hyperopia) or long­sightedness is the refractive state of the eye wherein parallel rays of light coming from infinity are focused behind the + +• Paralysis of accommodation Spasm of accommodation +DETERMINATION OF REFRACTION ERRORS +• +• Objective refraction +• Subjective refraction +CORRECTION OF REFRACTIVE ERRORS Spectacles +Contact lenses +Refractive surgery +• Refractive surgery for myopia +• Refractive surgery for hyperopia +• Refractive surgery for astigmatism +• Management of post-keratoplasty astigmatism +• Refractive surgery for presbyopia + + + +retina with accommodation being at rest (Fig. 4.2). Thus, the posterior focal point is behind the retina, which, therefore, receives a blurred image. +Etiology +Hypermetropia may be axial, curvatural, index, positional and due to absence of crystalline lens. + + + + + + + + +Fig. 4.1 Refraction in an emmetropic eye + + + + + + + + + +Fig. 4.2 Refraction in a hypermetropic eye +Chapter 4 Errors of refraction and Accommodation 35 + + +1. Axial hypermetropia is by far the commonest form. In this condition, the total refractive power of eye is normal but there is an axial shortening of eyeball. About 1 mm shortening of the anteroposterior diameter of the eye results in 3 dioptres of hypermetropia. Axial hypermetropia may be developmental or pathological. High hypermetropia occurs in microophthalmos and nanophthalmos due to markedly short axial length (usually less than 20 mm). +2. Curvatural hypermetropia is the condition in which the curvature of cornea, lens or both is flatter than the normal resulting in a decrease in the refractive power of eye. About 1 mm increase in radius of curvature results in 6 dioptres of hypermetropia. It may be developmental or rarely pathological. +3. Index hypermetropia occurs due to decrease in refractive index of the lens in old age due to cortical sclerois. It may also occur in diabetics under treatment. +4. Positional hypermetropia results from posteriorly placed crystalline lens. +5. Absence of crystalline lens either congenitally or acquired (following surgical removal or posterior dislocation) leads to aphakia—a condition of high hypermetropia. +Clinical types +There are three clinical types of hypermetropia: +1. Simple or developmental or physiological hyper­ metropia is the commonest form. It results from normal biological variations in the development of eyeball. It includes: +• Developmental axial hypermetropia, and • Developmental curvatural hypermetropia. +2. Non­physiological hypermetropia results due to either conditions of the eyeball which are outside the normal biological variations of the development. It includes: +Congenital non-physiological hypermetropia is seen in following conditions: +• Microphthalmos, • Nanophthalmos, • Microcornea, +• Congenital posterior subluxation of lens, and • Congenital aphakia. +Acquired non-physiological hypermetropia includes: a. Senile hypermetropia or frequently designated as acquired hypermetropia occurs in old age due to two causes: +• Index hypermetropia due to acquired cortical sclerosis in old age, and + +• Curvatural hypermetropia due to decreased curvature of the outer lens fibers developing later in life. +b. Positional hypermetropia due to posterior subluxation of lens. +c. Aphakia, i.e., congenital or acquired, absence of lens. +d. Consecutive hypermetropia due to surgically over­ corrected myopia. +e. Acquired axial hypermetropia due to forward displacement of the retina as seen in retinal detachment, central serous retinopathy and orbital tumours. +f. Acquired curvatural hypermetropia may occur due to post­traumatic or post­inflammatory corneal flattening. +g. Pseudophakic hypermetropia occurs due to implantation of an underpowered intraocular lens. 3. Functional hypermetropia results from paralysis of accommodation as seen in patients with third nerve paralysis and internal ophthalmoplegia. +Components of hypermetropia (effect of accommodation) +Nomenclature for various components of the hypermetropia vis­a­vis accommodation is as follows: +Total hypermetropia is the total amount of refractive error, which is estimated after complete cycloplegia with atropine. It consists of latent and manifest hypermetropia. +1. Latent hypermetropia implies the amount of hypermetropia (about 1D) which is normally corrected by the inherent tone of ciliary muscle. The degree of latent hypermetropia is high in children and gradually decreases with age. The latent hypermetropia is disclosed when refraction is carried after abolishing the tone with atropine. +2. Manifest hypermetropia is the remaining portion of total hypermetropia, which is not corrected by the ciliary tone. It consists of two components, the facultative and the absolute hypermetropia. +a. Facultative hypermetropia constitutes that part which can be corrected by the patient’s accommodative effort. +b. Absolute hypermetropia is the residual part of manifest hypermetropia which cannot be corrected by the patient’s accommodative efforts. + +Thus, briefly: +Total hypermetropia = latent + manifest (facultative + congenital or acquired) +36 Section ii Optics and refraction + + +age and hypermetropia +At birth, the eyeball is relatively short, having +2 to +3 hypermetropia. This is gradually reduced until by the age of 5–7 years, the eye is emmetropic and remains so till the age of about 50 years. After this, there is a tendency to develop hypermetropia again, which gradually increases until the extreme of life by which the eye has the same +2 to +3 with which it started. This senile hypermetropia is due to changes in the crystalline lens. +Clinical features Symptoms +In patients with hypermetropia, the symptoms vary depending upon the age of patient and the degree of refractive error. These can be grouped as under: 1. Asymptomatic. A small amount of refractive error in young patients is usually corrected by mild accommodative effort without producing any symptom. 2. Asthenopic symptoms. At times the hypermetropia is fully corrected by the use of accommodation. Thus vision is normal, but due to sustained accommodative efforts patient develops asthenopic symptoms. These include: tiredness of eyes, frontal or frontotemporal headache, watering and mild photophobia. These asthenopic symptoms are especially associated with near work and increase towards evening. +3. Defective vision with asthenopic symptoms. When the amount of hypermetropia is such that it is not fully corrected by the voluntary accommodative efforts, then the patients complain of defective vision which is more for near than distance and is associated with asthenopic symptoms due to sustained accommodative efforts. +4. Defective vision only. When the amount of hypermetropia is very high, the patients usually do not accommodate (especially adults) and there occurs marked defective vision for near and distance. • Effect of ageing on vision. Typically patients with low hypermetropia have good vision in young age. However, with ageing, due to decrease in accommodative power, the hypermetropia becomes manifest and patients complain of progressive decrease in vision. To begin with blurring occurs for +near vision and then for distant vision also. +Signs +1. Size of eyeball may appear small as a whole especially in high hypermetropia. +2. Cornea may be slightly smaller than the normal. 3. Anterior chamber is comparatively shallow. +4. Retinoscopy and autorefractometry reveals hypermetropic refractive error. +5. Fundus examination reveals a small optic disc which may look more vascular with ill­defined + + +margins and even may simulate papillitis (though there is no swelling of the disc, and so it is called pseudopapillitis). The retina as a whole may shine due to greater brilliance of light reflections (shot silk appearance). +6. A-scan ultrasonography (biometry) may reveal a short anteroposterior length of the eyeball in axial hypermetropia. + +Grading of hypermetropia +American Optometric Association (AOA) has defined three grades of hypermetropia as below: +• Low hypermetropia, when the error is < + 2D. +• Moderate hypermetropia, when the error is between +2 to + 5D. +• High hypermetropia, when the error is > + 5D. + +Complications +If hypermetropia is not corrected for a long time the following complications may occur: +1. Recurrent styes, blepharitis or chalazia may occur, probably due to infection introduced by repeated rubbing of the eyes, which is often done to get relief from fatigue and tiredness. +2. Accommodative convergent squint may develop in children (usually by the age of 2–3 years) due to excessive use of accommodation. +3. Amblyopia may develop in some cases. It may be anisometropic (in unilateral hypermetropia), strabismic (in children developing accom­ modative squint) or ametropic (seen in children with uncorrected bilateral high hypermetropia). +4. Predisposition to develop primary narrow angle glaucoma. The eye in hypermetropes is small with a comparatively shallow anterior chamber. Due to regular increase in the size of the lens with increasing age, these eyes become prone to an attack of narrow angle glaucoma. This point should be kept in mind while instilling mydriatics in elderly hypermetropes. + +treatment +A. Optical treatment. Basic principle of treatment is to prescribe convex (plus) lenses, so that the light rays are brought to focus on the retina (Fig. 4.3). ■Fundamental rules for prescribing glasses in hypermetropia include: +1. Total amount of hypermetropia should always be discovered by performing refraction under complete cycloplegia. +2. The spherical correction given should be com­ fortably acceptable to the patient. However, the +astigmatism should be fully corrected. +Chapter 4 Errors of refraction and Accommodation 37 + + + + + + + + + + + + + +Fig. 4.3 Refraction in a hypermetropic eye corrected with convex lens + +3. Gradually increase the spherical correction at 6 months interval till the patient accepts manifest hypermetropia. +4. In the presence of accommodative convergent squint, full cycloplegic correction should be given at the first sitting. +5. If there is associated amblyopia, full correction with occlusion therapy should be started. + +Modes of prescription of convex lenses +1. Spectacles are most comfortable, safe and easy method of correcting hypermetropia. +2. Contact lenses are indicated in unilateral hypermetropia (anisometropia). For cosmetic reasons, contact lenses should be prescribed once the prescription has stabilised, otherwise, they may have to be changed many a times. +B. Surgical treatment (see page 54). + +apHaKia +Aphakia literally means ‘absence of crystalline lens’ from the eye. However, from the optical point of view, it may be considered a condition in which the lens is absent from the pupillary area. Aphakia produces a high degree of hypermetropia. +Causes +1. Congenital absence of lens. It is a rare condition. 2. Surgical aphakia occurring after removal of lens +is the commonest presentation. +3. Aphakia due to absorption oflens matter isnoticed rarely after trauma in children. +4. Traumatic extrusion of lens from the eye also constitutes a rare cause of aphakia. +5. Posterior dislocation of lens in vitreous causes optical aphakia. +optics of aphakic eye +Following optical changes occur after removal of crystalline lens: + +• Hypermetropia of high degree. +• Total power of eye is reduced to about +44 D from +60 D. +• Anterior focal point becomes 23.2 mm in front of the cornea (Normal: 15.7 mm). +• Posterior focal point is about 31 mm behind the cornea i.e., about 7 mm behind the eyeball (The anteroposterior length of eyeball is about 24 mm). +• Accommodation is lost fully. + +Clinical features Symptoms +• Defective vision. Main symptom in aphakia is marked defective vision for both far and near due to high hypermetropia and absence of accommodation. +• Erythropsia and cyanopsia i.e., seeing red and blue images. This occurs due to excessive entry of ultraviolet and infrared rays in the absence of crystalline lens. +Signs of aphakia +• Limbal scar may be seen in surgical aphakia. • Anterior chamber is deeper than normal. +• Iridodonesis i.e., tremulousness of iris can be demonstrated. +• Pupil is jet black in colour. +• Purkinje’s image test shows only two images (nor­ mally four images are seen­ see page 506 and Fig. 23.10). +• Fundus examination shows hypermetropic small disc. +• Retinoscopy and autorefractometry reveals high hypermetropia. +treatment +Optical principle is to correct the refractive error by convex lenses of appropriate power so that image is formed on the retina (Fig. 4.3 ). +Modalities for correcting aphakia include: (1) spectacles, (2) contact lens, (3) intraocular lens, and (4) refractive corneal surgery. +1. Spectacles prescription has been the most commonly employed method of correcting aphakia in the past, especially in developing countries. Presently, use of aphakic spectacles has decreased markedly. Roughly, about+10D with cylindrical lenses for surgically induced astigmatism are required to correct aphakia in previously emmetropic patients. However, exact number of glasses will differ in individual case and should be estimated by refraction. An addition of +3 to +4 D is required for near vision to compensate the loss of accommodation. +38 Section ii Optics and refraction + + +■Disadvantages of spectacles. (i) Image is magnified by 30%, so not useful in unilateral aphakia (produce diplopia). (ii) Problem of spherical and chromatic aberrations of thick lenses. (iii) Field of vision is limited. (iv) Prismatic effect of thick glasses. (v) ‘Roving ring Scotoma’ (Jack in the box phenomenon). (vi) Cosmetic blemish especially in young aphakes. +2. Contact lenses. Advantages of contact lenses over spectacles include: (i) Less magnification of image. (ii) Elimination of aberrations and prismatic effect of thick glasses. (iii) Wider and better field of vision. (iv) Cosmetically more acceptable. (v) Better suited for uniocular aphakia. +■Disadvantages of contact lenses are: (i) more cost; (ii) cumbersome to wear, especially in old age and in childhood; and (iii) corneal complications may be associated. +3. Intraocular lens implantation is the best available method of correcting aphakia. Therefore, it is the commonest modality being employed nowadays. +• Primary intraocular lens implantation is done during cataract surgery. +• Secondary intraocular lens implantation is done in already aphakic patients. +(For detail see page 207). +4. Refractive corneal surgery includes: +• Keratophakia and Epikeratophakia have been tried without much success. In keratophakia a lenticule prepared from the donor cornea is placed between the lamellae of patient’s cornea and in epikeratophakia, the lenticule prepared from the donor cornea is stitched over the surface of cornea after removing the epithelium. +• Hyperopic Lasik may be tried in cases where secondary IOL cannot be implanted (see page 54). +pSEUdopHaKia +The condition of aphakia when corrected with an intraocular lens implant (IOL) is referred to as pseudophakia or artephakia. For types of IOLs and details of implantation techniques and complications (see page 207). +Refractive status of a pseudophakic eye depends upon the power of the IOL implanted as follows: +1. Emmetropia is produced when the power of the IOL implanted is exact. It is the most ideal situation. Such patients need plus glasses for near vision only. 2.Consecutive myopiaoccurs when the IOL implanted overcorrects the refraction of eye. Such patients require glasses to correct the myopia for distance vision and may or may not need glasses for near vision depending upon the degree of myopia. + +3. Consecutive hypermetropia develops when the under power IOL is implanted. Such patients require plus glasses for distance vision and additional +2 to +3 D for near vision. +Note. Varying degree of surgically induced astigmatism is also present in pseudophakia. +Signs of pseudophakia(with posterior chamber IOL). • Surgical scar may be seen near the limbus. +• Anterior chamber is slightly deeper than normal. • Mild iridodonesis (tremulousness) of iris may be +demonstrated. +• Purkinje image test shows four images. +• Pupil is blackish in colour but when light is thrown in pupillary area shining reflexes are observed. +• Presence of IOL is confirmed (see Fig. 9.32) on slit­ lamp examination after dilating the pupil. +• Visual status and refraction will vary depending upon the power of IOL implanted as described above. +Management of pseudophakia includes: +1. Spectacles for near vision alone (in pseudophakia with emmetropia) or as bifocal/progressive glasses for both distance and near vision (in pseudophakia with consecutive refractive error) are required. +2. LASIK or Advanced surface ablation (ASA) may be required in moderate consecutive refractive error. 3. Intraocular lens (IOL) exchange or pigiback IOL is required when the consecutive refractive error is large. + +MYOPIA + +Myopia or shortsightedness is a type of refractive error in which parallel rays of light coming from infinity are focused in front of the retina when accommodation is at rest (Fig. 4.4). +Etiological classification +1. Axial myopia results from increase in antero­ posteriorlength of the eyeball. It is the commonest form. +2. Curvatural myopia occurs due to increased curvature of the cornea, lens or both. + + + + + + + + + +Fig. 4.4 Refraction in a myopic eye +Chapter 4 Errors of refraction and Accommodation 39 + + +3. Positional myopia is produced by anterior placement of crystalline lens in the eye. +4. Index myopia results from increase in the refractive index of crystalline lens associated with nuclear sclerosis. +5. Myopia due to excessive accommodation occurs in patients with spasm of accommodation. +Grading of myopia +American Optometric Association (AOA) has defined three grades of myopia: +• Low myopia, when the error is ≤–3D. +• Moderate myopia, when the error is between­3D to –6D. +• High myopia, when the error is ≥–6D. +Clinical varieties of myopia 1. Congenital myopia. +2. Simple or developmental myopia. +3. Pathological or degenerative myopia. +4. Acquired or secondray myopia which occurs secon­ dary to some other disease/factors are as follows: • post­traumatic, +• post­keratitic, • drug­induced, +• pseudomyopia, • space myopia, +• night myopia, and +• consecutive myopia. + +ConGEnital myopia +• Present since birth, the congenital myopia, is usually diagnosed by the age of 2–3 years. +• Anisometropia is usually present, hence most of the time the error is unilateral. Rarely, it may be bilateral. +• High degree of error, about 8 to 10D, is usually present, which mostly remains constant. +• Convergent squint may develop in order to preferentially see clear at its far point (which is about 10–12 cm). +• Associations may include other congenital anom­ alies such as cataract, microphthalmos, aniridia, megalocornea, and congenital separation of retina. +• Early correction of congenital myopia is desirable. +SimplE myopia +Simple or developmental myopia is the commonest variety. It is considered as a physiological error not associated with any disease of the eye. Overall reported prevalence is 20–40% of population. Since, the sharpest rise occurs at school going age i.e., between 8 years to 12 years so, it is also called school myopia. +Etiology +It results from normal biological variation in the development of eye which may or may not be + +genetically determined. Some factors associated with simple myopia are as follows: +■Axial type of simple myopia may signify just a physiological variation in the length of the eyeball or it may be associated with precocious neurological growth during childhood. +■Curvatural type of simple myopia is considered to be due to underdevelopment of the eyeball. +■Role of diet in early childhood has also been reported without any conclusive results. +■Role of genetics. Genetics plays some role in the biological variation of the development of eye, as prevalence of myopia is more in children with both parents myopic (20%) than the children with one parent myopic (10%) and children with no parent myopic (5%). +■Theory of excessive near work in childhood was also put forward, but did not gain much importance. In fact, there is no truth in the folklore that myopia is aggravated by close work, watching television and by not using glasses. +Clinical features +Symptoms +■Poor vision for distance (short­sightedness) is the main symptom of myopia. +■Asthenopic symptoms may occur in patients with small degree of myopia. +■Half shutting of the eyes may be complained by parents of the child. The child does so to achieve the greater clarity of stenopaeic vision. +Signs +■Prominent eyeballs. The myopic eyes typically are large and somewhat prominent. +■Anterior chamber is slightly deeper than normal. ■Pupils are somewhat large and a bit sluggishly reacting. +■Fundus is normal; rarely temporal myopic crescent may be seen. +■Magnitude of refractive error. Simple myopia usually occurs between 5 and 10 years of age and it keeps on increasing till about 18–20 years of age at a rate of about –0.5 ± 0.30 every year. In simple myopia, usually the error is low to moderate that usually does not exceed –6D. +diagnosis +Diagnosis is confirmed by performing refraction (see page 570). +patHoloGiCal myopia Pathological/degenerative/progressive myopia, as the name indicates, is a rapidly progressive error which starts in childhood at 5–10 years of age and +40 Section ii Optics and refraction + + +results in high myopia (>–6D) during early adult life which is usually associated with degenerative changes in the eye. It is less common (about 2% of population). +Etiology +It is unequivocal that the pathological myopia results from a rapid axial growth of the eyeball which is outside the normal biological variations of development. To explain this spurt in axial growth various theories have been put forward. So far no satisfactory hypothesis has emerged to explain the etiology of pathological myopia. However, it is definitely linked with (i) heredity and (ii) general growth process. +1. Role of heredity. It is now confirmed that genetic factors play a major role in the etiology, as the progressive myopia is: (i) familial; (ii) more common in certain races like Chinese, Japanese, Arabs and Jews, (iii) uncommon among Negroes, Nubians and Sudanese and (iv) more common in women than men. Autosomal dominant pathological myopia has been linked to genes 18p11.31 and 12q21.23. +It is presumed that heredity­linked growth of retina is the determinant in the development of myopia. The sclera due to its distensibility follows the retinal growth but the choroid undergoes degeneration due to stretching, which in turn causes degeneration of retina. 2. Role of general growth process, though minor, cannot be denied on the progress of myopia. Lengthening of the posterior segment of the globe commences only during the period of active growth and probably ends with the termination of the active growth. Therefore, the factors (such as nutritional deficiency, debilitating diseases, endocrine disturbances and indifferent general health) which affect the general growth process will also influence the progress of myopia. +Etiological hypothesis for pathological myopia is summarised in Fig. 4.5. + + + + + + + + + + + +Fig. 4.5 Etiological hypothesis for pathological myopia + +Clinical features +Symptoms +1. Defective vision. There is considerable failure in visual function as the error is usually high. Further, due to progressive degenerative changes, an uncorrectable loss of vision may occur. +2. Muscae volitantes i.e., floating black opacities in front of the eyes are also complained by many patients. These occur due to degenerated liquefied vitreous. +3. Night blindness may be complained by very high myopes having marked degenerative changes. +Signs +1. Prominent eyeballs. The eyes are often prominent, appearing elongated and even simulating an exophthalmos, especially in unilateral cases. The elongation of the eyeball mainly affects the posterior pole and surrounding area; the part of the eye anterior to the equator may be normal (Fig. 4.6). +2. Cornea is large. +3. Anterior chamber is deep. +4.Pupils are slightly large and react sluggishly to light. 5. Fundus examination reveals following characteristic signs: +a. Optic disc appears large and pale and at its temporal edge a characteristic myopic crescent is present (Fig. 4.7). Sometimes peripapillary crescent encircling the disc may be present, where the choroid and retina is distracted away from the disc margin. A super­traction crescent (where the retina is pulled over the disc margin) may be present on the nasal side. + + + + + + + + + + + + + + + + + + + +Fig. 4.6 Elongation of the eyeball posterior to equator in pathological myopia +Chapter 4 Errors of refraction and Accommodation 41 + + + + + + + + + + + + + + + +Fig. 4.7 Myopic crescent + + +b. Degenerative changes in retina and choroid are common in progressive myopia (Fig. 4.8). These are characterized by: +• Chorioretinal atrophic patches at the macula with a little heaping up of pigment around them. +• Foster-Fuchs’ spot (dark red circular patch due to sub­retinal neovascularization and choroidal haemorrhage) may be present at the macula. +• Cystoid degeneration may be seen at the periphery. • Lattice degeneration and or snail track lesions with or without retinal holes/tears may be present; which later may be complicated by retinal +detachment. +• Total retinal atrophy, particularly in the central area may occur in an advanced case. +c. Posterior staphyloma due to ectasia of sclera at posterior pole may be apparent as an excavation with the vessels bending backward over its margins. d. Degenerative changes in vitreous include: liquefaction, vitreous opacities, and posterior vitreous detachment (PVD) appearing as Weiss’ reflex. + + + + + + + + + + + + + + +Fig. 4.8 Fundus changes in pathological myopia + +6. Visual fields may show contraction and in some cases ring scotoma may be seen. +7. ERG may reveal subnormal electroretinogram due to chorioretinal atrophy. +Complications +• Retinal detachment, +• Complicated cataract, • Vitreous haemorrhage, +• Choroidal haemorrhage, +• Strabismus fixus convergence, and +• Primary open angle glaucoma, not a complication, but is a reported association. +treatment of myopia +1. Optical treatment of myopiaconstitutes prescription of appropriate concave lenses, so that clear image is formed on the retina (Fig. 4.9). +■Basic rule of correcting myopia is converse of that in hypermetropia, i.e., the minimum acceptance providing maximum vision should be prescribed. In very high myopia undercorrection is always better to avoid the problem of near vision and that of minification of images. +■Modes of prescribing concave lenses are spectacles and contact lenses. Their advantages and disadvantages over each other are the same as described for hypermetropia. Contact lenses are particularly justified in cases of high myopia as they avoid peripheral distortion and minification produced by strong concave spectacle lens. +2. Surgical treatment of myopia has become very popular now­a­days (for details see page 52). +3. General measures empirically believed to affect the progress of myopia (unproven usefulness) include: • Balanced diet rich in vitamins and proteins. +• Early management of associated debilitating disease. +• Visual hygiene is very important to avoid asthenopic symptoms. Care should be taken for proper posture and adequate illumination, especially for near work. Clarity of the print should be good + + + + + + + + + +Fig. 4.9 Refraction in a myopic eye corrected with concave lens +42 Section ii Optics and refraction + + +and continuous reading especially, at night hours, should be avoided to prevent undue ocular fatigue. +• Avoidance of outdoor sports and strenuous activities is advised to reduce the risk of ocular trauma and consequent complication of retinal detachment. +4.Low visionaids(LVA) are indicated in patients with progressive myopia having advanced degenerative changes, where useful vision cannot be obtained with spectacles and contact lenses. +5. Prophylaxis (genetic counselling). As the pathological myopia has a strong genetic basis, the hereditary transfer of disease may be decreased by advising against marriage between two individuals with progressive myopia. However, if they do marry, they should not produce children. + +ASTIGMATISM + +Astigmatism is a type of refractive error wherein the refraction varies in different meridia of the eye. Consequently, the rays of light entering the eye cannot converge to a point focus but form focal lines. Broadly, there are two types of astigmatism: regular and irregular. +rEGUlar aStiGmatiSm +The astigmatism is regular when the refractive power changes uniformly from one meridian to another (i.e., there are two principal meridians). +Etiology +1.Corneal astigmatism is the result of abnormalities of curvature of cornea. It constitutes the most common cause of astigmatism. +2. Lenticular astigmatism is rare. It may be: +• Curvatural due to abnormalities of curvature of lens as seen in lenticonus. +• Positional due to tilting or oblique placement of lens as seen in subluxation. +• Index astigmatismmay occur rarely due to variable refractive index of lens in different meridian. +3. Retinal astigmatism due to oblique placement of macula may also be seen occasionally. +types of regular astigmatism +Depending upon the axis and the angle between the two principal meridians, regular astigmatism can be classified into the following types: +1.With-the-rule astigmatism (WTR). In this type the two principal meridians are placed at right angles to one another but the vertical meridian is more curved than the horizontal. Thus, correction of this astigmatism will require the concave cylinder at 180° ± 20° or convex cylindrical lens at 90° ± 20°. This is called ‘with­the­ + +rule’ astigmatism, because similar astigmatic condition exists normally (the vertical meridian is normally rendered 0.25 D more convex than the horizontal meridian probably by the pressure of eyelids). +2. Against-the-rule astigmatism (ATR) refers to an astigmatic condition in which the horizontal meridians is more curved than the vertical meridian. Therefore, correction of this astigmatism will require the prescription of convex cylindrical lens at 180° ± 20° or concave cylindrical lens at 90° ± 20° axis. 3.Oblique astigmatism is a type of regular astigmatism where the two principal meridians are not the horizontal and vertical though these are at right angle to one another e.g., 45° and 135°. +4. Bioblique astigmatism. In this type of regular astigmatism the two principal meridians are not at right angle to each other e.g., one may be at 30° and other at 100°. +optics of regular astigmatism +As already mentioned, in regular astigmatism the parallel rays of light are not focused on a point but form two focal lines. +Sturm’s conoid +The configuration of rays refracted through a toric surface is called the Sturm’s conoid. The shape of bundle of the light rays at different levels in Sturm’s conoid (Fig. 4.10) is as follows: +• At point A, the vertical rays (V) are converging more than the horizontal rays (H); so the section here is a horizontal oval or an oblate ellipse. +• At point B (first focus), the vertical rays have come to a focus while the horizontal rays are still converging and so they form a horizontal line. +• At point C, the vertical rays are diverging and their divergence is less than the convergence of the horizontal rays; so a horizontal oval is formed here. + + + + + + + + + + + + + + + +Fig. 4.10 Sturm’s conoid +Chapter 4 Errors of refraction and Accommodation 43 + + +• At point D, the divergence of vertical rays is exactly equal to the convergence of the horizontal rays from the axis. So, here the section is a circle, which is called the circle of least diffusion. +• At point E, the divergence of vertical rays is more than the convergence of horizontal rays; so, the section here is a vertical oval. +• At point F (second focus), the horizontal rays have come to a focus while the vertical rays are divergent and so a vertical line is formed here. +• Beyond F (as at point G), both horizontal and vertical rays are diverging and so the section will always be a vertical oval or prolate ellipse. +• Focal interval of Sturm refers to the distance between the two foci (B and F). +Refractive types of regular astigmatism +Depending upon the position of the two focal lines in relation to retina, the regular astigmatism is further classified into three types: +1.Simple astigmatism, wherein the rays are focused on the retina in one meridian and either in front (simple myopic astigmatism, Fig. 4.11A) or behind (simple hypermetropic astigmatism, Fig. 4.11B) the retina in the other meridian. +2. Compound astigmatism. In this type, the rays of light in both the meridians are focused either in front or behind the retina and the condition is labelled as compound myopic or compound hypermetropic astigmatism, respectively (Figs. 4.11C and D). +3. Mixed astigmatism refers to a condition wherein the light rays in one meridian are focused in front and in other meridian behind the retina (Fig. 4.11E). Thus, in one meridian eye is myopic and in another hypermetropic. Such patients have comparatively less symptoms as ‘circle of least diffusion’ is formed on the retina (see Fig. 4.10). +Clinical features +Symptoms +1. Asthenopia (tiredness of eyes relieved by closing the eyes) characterised by difficulty in focussing, transient blurred vision, dull ache in eyes, frontal headache and sometimes nausea and even drowsiness is especially marked in low astigmatism <1D. +2. Blurred vision and defective vision is reported when the astigmatism is > 1D. +3. Elongation of objects proportionate to the degree and type of astigmatism may be noticed in high astigmatism. +4. Keeping the reading material close to the eyes may be needed to achieve large but blurred retinal image. + + + + + + +A + + + + + + + + +B + + + + + + +C + + + + + + +D + + + + + + + +E + +Fig. 4.11 Types of astigmatism : (A) simple myopic; (B) simple hypermetropic; (C) compound myopic; (D) compound hypermetropic; and (E) mixed + + +Signs +1. Half closure of the lid. Like myopes, the astigmatic patients may half shut the eyes to achieve the greater clarity of stenopaeic vision. +2. Head tilt. The astigmatic patients may (very exceptionally) develop a torticollis in an attempt to bring their axes nearer to the horizontal or vertical meridians. +3. Oval or tilted optic disc may be seen on ophth­ almoscopy in patients with high degree of astigmatism. +44 Section ii Optics and refraction + + +4. Different power in two meridians is revealed on retinoscopy or autorefractometry. + +investigations +1. Retinoscopy reveals different power in two different axes. +2. Keratometry. Keratometry and computerized corneal topography reveal different corneal curvature in two different meridians in corneal astigmatism. +3. Astigmatic fan test (see page 577) and +4. Jackson’s cross cylinder test (see page 577). +These tests are useful in confirming the power and axis of cylindrical lenses. +treatment +1.Optical treatmentof regular astigmatism comprises the prescription of appropriate cylindrical lens, discovered after accurate refraction. +• Spectacles with full correction of cylindrical power and appropriate axis should be used for distance and near vision. +• Contact lenses. Rigid contact lenses may correct upto 2–3D of regular astigmatism, while soft contact lenses can correct only little astigmatism. For higher degrees of astigmatism toric contact lenses are needed. In order to maintain the correct axis of toric lenses, ballasting or truncation is required. +2. Surgical correction of astigmatism is quite effective (For details see page 54). +irrEGUlar aStiGmatiSm +It is characterized by an irregular change of refractive power in different meridians. There are multiple meridians which admit no geometrical analysis. + +Etiological types +1. Curvatural irregular astigmatism is found in patients with extensive corneal scars or keratoconus. +2. Index irregular astigmatism due to variable refractive index in different parts of the crystalline lens may occur rarely in patients with cataract. + +Clinical features +Symptoms of irregular astigmatism include: • Defective vision, +• Distortion of objects, and +• Polyopia (seeing multiple images). + +Signs depicted on investigations are as below: +• Retinoscopy reveals irregular pupillary reflex. +• Slit-lamp examination may reveal corneal irregularity or Keratoconus. + +• Placido’s disc test reveals distorted circles (see page 501). +• Photokeratoscopy and computerized corneal topography give photographic record of irregular corneal curvature. + +treatment +1. Optical treatment of irregular astigmatism consists of contact lens which replaces the anterior surface of the cornea for refraction. +2. Phototherapeutic keratectomy (PTK) performed with excimer laser may be helpful in patients with superficial corneal scar responsible for irregular astigmatism. +3. Surgical treatment is indicated in extensive corneal scarring (when vision does not improve with contact lenses) and consists of penetrating keratoplasty or deep anterior lamellar keratoplasty (DALK). + +ANISOMETROPIA + +The optical state with equal refraction in the two eyes is termed isometropia. When the total refraction of the two eyes is unequal the condition is called anisometropia. Small degree of anisometropia is of no concern. A difference of 1D in two eyes causes a 2% difference in the size of the two retinal images. A difference up to 5% in retinal images of two eyes is well tolerated. In other words, an anisometropia up to 2.5D is well tolerated and that between 2.5 and 4D can be tolerated depending upon the individual sensitivity. However, if it is more than 4D, it is not tolerated and is a matter of concern. +Etiology +1. Congenital and developmental anisometropia occurs due to differential growth of the two eyeballs. +2. Acquired anisometropia may occur due to asymmetric age change, uniocular aphakia after removal of cataractous lens or due to implantation of IOL of wrong power. +Clinical types +1. Simple anisometropia. In this, one eye is normal (emmetropic) and the other either myopic (simple myopic anisometropia) or hypermetropic (simple hypermetropic anisometropia). +2. Compound anisometropia. Wherein both eyes are either hypermetropic (compound hypermetropic anisometropia) or myopic (compound myopic anisometropia), but one eye is having higher refractive error than the other. +Chapter 4 Errors of refraction and Accommodation 45 + + +3. Mixed anisometropia. In this, one eye is myopic and the other is hypermetropic. This is also called antimetropia. +4. Simple astigmatic anisometropia. When one eye is normal and the other has either simple myopic or hypermetropic astigmatism. +5. Compound astigmatic anisometropia. When both eyes are astigmatic but of unequal degree. +Status of binocular vision in anisometropia Three possibilities are as follows: +1. Binocular single vision is present in small degree of anisometropia (less than 3D). +2. Uniocular vision. When refractive error in one eye is of high degree, that eye is suppressed and develops anisometropic amblyopia. Thus, the patient has only uniocular vision. +3. Alternate vision occurs when one eye is hyperme­ tropic and the other myopic. The hypermetropic eye is used for distant vision and myopic for near vision. +diagnosis +Diagnosis of anisometropia is made after retinoscopic examination and/or autorefractometry in patients with defective vision. + +treatment +1. Spectacles. The corrective spectacles can be tolerated up to a maximum difference of 4D. After that there occurs diplopia. +2. Contact lenses are advised for higher degrees of anisometropia. +3. Aniseikonic glasses are also available, but their clinical results are often disappointing. +4. Other modalities of treatment include: +• Intraocular lens–implantation for uniocular aphakia. +• Refractive corneal surgery for unilateral high myopia, astigmatism and hypermetropia. +• Phakic Refractive Lenses (PRL) and Refractive Lens Exchange (RLE) are quite useful in very high degree anisometropia. +Note. Efforts should be made to fully correct the anisometropia in children to prevent anisometropic amblyopia. In adults with amblyopia under correction of more ametropic eye may be required to avoid ocular discomfort. + +ANISEIkONIA + +Aniseikonia is defined as a condition wherein the images projected to the visual cortex from the two retinae are abnormally unequal in size and/or shape. Up to 5% aniseikonia is well tolerated. + + +Etiological types +1. Optical aniseikonia may occur due to either inherent or acquired anisometropia of high degree. +2. Retinal aniseikonia may develop due to: displacement of retinal elements towards the nodal point in one eye due to stretching or oedema of the retina. +3. Cortical aniseikonia implies asymmetrical simultaneous perception inspite of equal size of images formed on the two retinae. +Clinical types +Clinically, aniseikonia may be of different types (Fig. 4.12): +1. Symmetrical aniseikonia +a.Spherical, image may be magnified or minified equally in both meridians (Fig. 4.12A). +b.Cylindrical, image is magnified or minified symmetrically in one meridian (Fig. 4.12B). +2. Asymmetrical aniseikonia +a.Prismatic. In this image, difference increases progressively in one direction (Fig. 4.12C). +b.Pincushion. In this image, distortion increases progressively in both directions, as seen with high plus correction in aphakia (Fig. 4.12D). +c. Barrel distortion. In this image, distortion decreases progressively in both directions, as seen with high minus correction (Fig. 4.12E). +d.Oblique distortion. In this, the size of image is same, but there occurs an oblique distortion of shape (Fig. 4.12F). +Symptoms +1. Asthenopia, i.e., eyeache, browache and tiredness of eyes. +2. Diplopia due to difficult binocular vision when the difference in images of two eyes is more than 5%. +3. Difficulty in depth perception is often noticed. +treatment +1. Optical aniseikonia may be corrected by aniseikonic glasses, contact lenses or intraocular lenses or other refractive surgery depending upon the situation. +2. Retinal aniseikonia may be corrected by treating the cause. +3. Cortical aniseikonia is very difficult to treat. + +ACCOMMODATION AND ITS ANOMALIES + +ACCOMMODATION + +definition +As we know that in an emmetropic eye, parallel rays of light coming from infinity are brought to focus on the retina, with accommodation being at rest. +46 Section ii Optics and refraction + + + + + + + + + + + + + + + + + + + + +Fig. 4.12 Types of aniseikonia: A, spherical; B, cylindrical; C, prismatic; D, pin cushion; E, barrel distortion; F, oblique distortion +However, our eyes have been provided with a unique A B mechanism by which we can even focus the diverging +rays coming from a near object on the retina in a bid to see clearly (Fig. 4.13). This mechanism is called accommodation. In this increase in the power of crystalline lens occurs due to increase in curvature of its surfaces (Fig. 4.14). +At rest the radius of curvature of anterior surface of the lens is 10 mm and that of posterior surface is 6 mm (Fig. 4.14A). During accommodation, curvature of the posterior surface remains almost the same but that of anterior surface changes. In strong accommodation radius of curvature of anterior surface also becomes 6 mm (Fig. 4.14B). +mechanism of accommodation +According to von Helmholtz’s capsular theory the process of accommodation is achieved by a change in the shape of lens as below: + +When the eye is at rest (unaccommodated), the ciliary ring is large and keeps the zonules tense. Because of zonular tension the lens is kept compressed (flat) by the capsule (Fig. 4.14A). + + + + + + +Fig. 4.13 Effect of accommodation on divergent rays entering the eye + +Fig. 4.14 Changes in the crystalline lens during accommodation + +Contraction of the ciliary muscle causes the ciliary ring to shorten and thus releases zonular tension on the lens capsule. This allows the elastic capsule to act unrestrained to deform the lens substance. The lens then alters its shape to become more convex or conoidal (to be more precise) (Fig. 4.14B). The lens assumes conoidal shape due to configuration of the anterior lens capsule which is thinner at the centre and thicker at the periphery. +Chapter 4 Errors of refraction and Accommodation 47 + + +Far point and near point +The nearest point at which small objects can be seen clearly is called near point or punctum proximum and the distant (farthest) point is called far point or punctum remotum. +Far point and near point of the eye. These vary with the static refraction of the eye as shown below (Fig. 4.15): • In an emmetropic eye far point is infinity (Fig. +4.15A) and near point varies with age. +• In hypermetropic eye far point is virtual and lies behind the eye (Fig. 4.15B). +• In myopic eye, it is real and lies in front of the eye (Fig. 4.15C). +range and amplitude of accommodation +Range of accommodation. The distance between the near point and the far point is called the range of accommodation. +Amplitude of accommodation. The difference between the dioptric power needed to focus at near point (P) and far point (R) is called amplitude of accommodation (A). Thus A = P–R. +■Amplitude of accommodation and thus the near point of vision (punctum proximum) vary with age. Rough estimate is depicted in Table 4.1. + + + + + + + + + +A + + + + + + + + +B + + + + + + +C + + +Fig. 4.15 Far point in (A) emmetropic eye; (B) hypermetropic eye; (C) myopic eye + + +Table 4.1 Rough estimate of amplitude of accommodation and near point at different ages + +Age (in years) Amplitude of Near point in accommodation cms + +10 14D 7 + +20 10D 10 + +30 07D 14 + +40 04D 25 + +50 02D 50 + +60 01D 100 + + +ANOMALIES OF ACCOMMODATION + +Anomalies of accommodation are not uncommon. These include: +• Presbyopia, +• Insufficiency of accommodation, • Paralysis of accommodation, and • Spasm of accommodation. +prESByopia pathophysiology and causes +Presbyopia (eye sight of old age) is not an error of refraction but a condition of physiological insufficiency of accommodation leading to a progressive fall in near vision. +Pathophysiology +To understand the pathophysiology of presbyopia a working knowledge about accommodation (as described above) is mandatory. As we know, in an emmetropic eye far point is infinity (∞) and near point varies with age (being about 7 cm at the age of 10 years, 25 cm at the age of 40 years and 33 cm at the age of 45 years). Therefore, at the age of 10 years, amplitude of accommodation (A) =100/7 (dioptric power needed to see clearly at near point)–1/∞ (dioptric power needed to see clearly at far point) i.e., A (at age 10) = 14 dioptres; +Similarly A (at age 40) = 100 1 = 4 dioptres. +− +¥ +25 +Since, we usually keep the book at about 25 cm, so we can read comfortably up to the age of 40 years. After the age of 40 years, near point of accommodation recedes beyond the normal reading or working range. This condition of failing near vision due to age-related decrease in the amplitude of accommodation or increase in punctum proximum is called presbyopia. +48 Section ii Optics and refraction + + +Causes +Decrease in the accommodative power of crystalline lens with increasing age, leading to presbyopia, occurs due to: +1. Age-related changes in the lens which include: +• Decrease in the elasticity of lens capsule, and +• Progressive increase in size and hardness (sclerosis) of lens substance which is less easily moulded. +2. Age-related decline in ciliary muscle power may also contribute in causation of presbyopia. +Causes of premature presbyopia are: • Uncorrected hypermetropia. +• Premature sclerosis of the crystalline lens. +• General debility causing presenile weakness of ciliary muscle. +• Chronic simple glaucoma. +Symptoms +1. Difficulty in near vision. Patients usually complaint of difficulty in reading small prints (to start with in the evening and in dim light and later even in good light). Another important complaint of the patient is difficulty in threading a needle, etc. +2. Asthenopic symptoms due to fatigue of the ciliary muscle are also complained after reading or doing any near work. +3. Intermittent diplopia, occurring due to disturbed relationship between accommodation and convergence, may be experienced by few patients. +treatment +1. Optical treatment. The treatment of presbyopia is the prescription of appropriate convex glasses for near work. +Rough guide for providing presbyopic glasses in an emmetrope can be made from the age of the patient. • 45 years : + 1 to + 1.25D +• 50 years : +1.5 to 1.75D • 55 years : +2 to + 2.25D • 60 years : +2.5 to + 3D +Exact presbyopic addition required, should however, be estimated individually in each eye in order to determine how much is necessary to provide a comfortable range. +Basic principles for presbyopic correction are: +• Always find out refractive error for distance and first correct it. +• Find out the presbyopic correction needed in each eye separately and add it to the distant correction. +• Near point should be fixed by taking due consi­ deration for profession of the patient. +• The weakest convex lens with which an individual can see clearly at the near point should be prescribed, since overcorrection will also result in asthenopic symptoms. + +Presbyopic spectacles may be unifocal, bifocal or varifocal, i.e. progressive (see page 55). +2. Surgical treatment of presbyopia is also being considered (see page 55). +inSUFFiCiEnCy oF aCCommodation +The term insufficiency of accommodation is used when the accommodative power is significantly less than the normal physiological limits for the patient’s age. Therefore, it should not be confused with presbyopia in which the physiological insufficiency of accommodation is normal for the patient’s age. +Causes +1. Premature sclerosis of lens. +2. Weakness of ciliary muscle due to systemic causes of muscle fatigue such as debilitating illness, anaemia, toxaemia, malnutrition, diabetes mellitus, pregnancy, stress and so on. +3. Weakness of ciliary muscle associated with primary open­angle glaucoma. +Clinical features +All the symptoms of presbyopia are present, but those of asthenopia are more prominent than the blurring of vision. + +treatment +1. Treatment of underlying cause is essential. +2. Near vision spectacles in the form of weakest convex lens which allows adequate vision should be given till the power of accommodation improves. +3. Accommodation exercises help in recovery, if the underlying debility has passed. +paralySiS oF aCCommodation +Paralysis of accommodation also known as cycloplegia refers to complete absence of accommodation. + +Causes +1. Drug induced cycloplegia results due to the effect of atropine, homatropine or other parasympatholytic drugs. +2. Paralytic internal ophthalmoplegia (paralysis of ciliary muscle and sphincter pupillae) may result from neuritis associated with diphtheria, syphilis, diabetes, alcoholism, cerebral or meningeal diseases. +3. Paralysis of accommodation as a component of complete third nerve paralysis may occur due to intracranial or orbital causes. The lesions may be traumatic, inflammatory or neoplastic in nature. + +Clinical features +1. Blurring of near vision is the main complaint in previously emmetropic or hypermetropic +Chapter 4 Errors of refraction and Accommodation 49 + + +patients. Blurring of near vision may not be marked in myopic patients. +2. Photophobia (glare) due to accompanying dilatation of pupil (mydriasis) is usually associated with blurring of near vision. +3. Abnormal receding of near point and markedly decreased range of accommodation may be required on assessment. +treatment +1. Self-recovery occurs in drug­induced cycloplegia and in diphtheric cases (once the systemic disease is treated). +2. Dark glasses are effective in reducing the glare. 3. Convex lenses for near vision may be prescribed if +the paralysis is permanent. + +SpaSm oF aCCommodation +Spasm of accommodation refers to exertion of abnormally excessive accommodation. + +Causes +1. Drug-induced spasm of accommodation is known to occur after use of strong miotics such as echothiophate and DFP. +2. Spontaneous spasm of accommodation is occasionally found in children who attempt to compensate for a refractive anomaly that impairs their vision. It usually occurs when the eyes are used for excessive near work in unfavourable circumstances such as bad illumination, bad reading position, lowered vitality, state of neurosis, mental stress or anxiety. + +Clinical features +1. Defective vision due to induced myopia. +2. Asthenopic symptoms are more marked than the visual symptoms. +diagnosis +It is made with refraction under atropine cycloplegia. + +treatment +1. Relaxation of ciliary muscle by atropine for few weeks and prohibition of near work allow prompt recovery from spasm of accommodation. +2. Correction of associated causative factors prevent recurrence. +3. Assurance and if necessary psychotherapy should be given. + +DETERMINATION OF REFRACTIVE ERRORS +The procedure of determining refractive errors is termed as clinical refraction. + + +methods of refraction +1. Objective refraction methods includes: • Retinoscopy, +• Autorefractometry, and • Photorefraction. +2. Subjective refraction steps include: • Monocular subjective refraction, • Binocular balancing, and +• Correction for near vision. (for details see chapter 25 page 576) + +CORRECTION OF REFRACTIVE ERRORS +Modes of correcting refractive errors include: • Spectacles, +• Contact lenses and • Refractive surgery. + +SPECTACLES + +The lenses fitted in a frame constitute the spectacles. It is a common, cheap and easy method of prescribing corrective lenses in patients with refractive errors and presbyopia. Some important aspects of the spectacles are described here: +lens materials +Broadly the lens material can be either glass or plastic. +1. Glass lenses +Glass lenses are in use for spectacles since long. Mostly crown glass, with refractive index of 1.5223 is used. +Problems with glass lenses include: • Shattering on impact, and +• Thicker and heavy, especially in high powered lenses, due to lower refractive index. +2. Plastic lenses +Plastic lenses being break resistance and light weight have become more popular. Various materials used are: +Resin lenses or CR­39 plastic lenses made of an allye resin with refractive index of 1.49 are good alternative to crown glass lenses. These are light, unbreakable but less scratch resistant and thus need protective coating. Further, because of low refractive index, these lenses are a bit thicker. +High index plastic lenses (refractive index 1.55 to 1.74) being thinner are preferred especially for high powered spectacles. Various plastic materials with high refractive index include polyurethane (Hyperindex), co­polymer (RLX­light) or allye base (True light). +Polycarbonate, with a refractive index of 1.58, is another synthetic material used for making lenses. +50 Section ii Optics and refraction + + +Such lenses are thinner, light weight, impact resistant and also have property of ultraviolet prot­ ection. +lens shapes +1. Meniscus lenses are used for making spectacles in small or moderate degree of refractive errors. The standard curved lenses are ground with a concave posterior surface (–1.25D in the periscopic type or –6.0D in the deep meniscus type) and the spherical correction is then added to the anterior surface. +2. Lenticular form lenses are used for high plus and high minus lenses. In this type, the central portion is corrective and the peripheral surfaces are parallel to one another. +3. Aspheric lenses are also used to make high plus aphakic lenses by modifying the lens curvature peripherally to reduce aberrations and provide better peripheral vision. +Single versus multiple power lenses +1. Single vision lens refers to a lens having the same corrective power over the entire surface. These are used to correct myopia, hypermetropia, astigmatism or presbyopia. +2. Bifocal lenses have different powers to upper (for distant vision) and lower (for near vision) segments. Different styles of bifocal lenses shown in Fig. 4.16 are: • Two piece bifocals, +• Cemented supplementary wafer, • Inserted wafer, +• Fused bifocals, and • Solid bifocals. +3. Trifocal lenses have three portions, upper (for distant vision), middle (for intermediate range vision) and lower (for near vision). +4. Multifocal (varifocal) or progressive lenses having many portions of different powers are also available. + + + + + + + + + + + + +Fig. 4.16 Bifocal lenses. (A) two-piece; (B) cemented supplementary wafer; (C) inserted wafer; (D) fused; (E) solid + +tinted lenses +Tinted glassesreduce the amount of light they transmit and provide comfort, safety and cosmetic effect. They are particularly prescribed in patients with albinism, high myopia and glare prone patients. Good tinted glasses should be dark enough to absorb 60–80% of the incident light in the visible part of the spectrum and almost all of the ultraviolet and infrared rays. Photochromatic lenses alter their colour according to the amount of ultraviolet exposure. These lenses do not function efficiently indoors and in automobiles. +Centring and decentring +• For proper centring, the visual axis of the patient and the optical centre of the spectacle lens should correspond, otherwise prismatic effect will be introduced. The distance between the visual axes is measured as interpupillary distance (IPD). +• Decentring of the lens is indicated where prismatic effect is required. One prism dioptre effect is produced by 1 cm decentring of a lD lens. +• Reading glasses should be decentred by about 2.5 mm medially and about 6.5 mm downward as the eyes are directed down and in during reading. +Frames +The spectacle frame selected should be comfortable, i.e. neither tight nor loose, light in weight and should not put pressure on the nose or temples of the patient, and should be of optimum size. In children large glasses are recommended to prevent viewing over the spectacles. Ideally, the lenses should be worn 15.3 mm from the cornea (the anterior focal plane of eye), as at this distance the images formed on the retina are of the same size as in emmetropia. + +CONTACT LENSES + +Contact lens is an artificial device whose front surface substitutes the anterior surface of the cornea. Therefore, in addition to correction of refractive error, the irregularities of the front surface of cornea can also be corrected by the contact lenses. +parts, curves, and nomenclature for contact lens To understand the contact lens specifications following standard nomenclature has been recommended (Fig. 4.17). +1. Diameters of the contact lens are as follows: +a. Overall diameter (OD) of the lens is the linear measurement of the greatest distance across the physical boundaries of the lens. It is expressed in millimetres (It should not be confused as being twice the radius of curvature). +Chapter 4 Errors of refraction and Accommodation 51 + + + + + + + + + + + + + + + + + +Fig. 4.17 A contact lens + +b.Optic zone diameter (OZ) is the dimension of the central optic zone of lens which is meant to focus rays on the retina. +2. Curves of the lens are as follows: +a.Base curve (BC) or central posterior curve (CPC) is a curve on the back surface of the lens to fit the front surface of cornea. +b.Peripheral curves. These are concentric to base curve and include intermediate posterior curve (IPC) and peripheral posterior curve (PPC). These are meant to serve as reservoir of tears and to form a ski for lens movements. +c. Central anterior curve(CAC) or front curve (FC) is the curve on the anterior surface of the optical zone of the lens. Its curvature determines the power of contact lens. +d.Peripheral anterior curve (PAC) is a slope on the periphery of anterior surface which goes up to the edge. +e. Intermediate anterior curve (IAC) is fabricated only in the high power minus and plus lenses. It lies between the CAC and PAC. +3.Edge of the lens. It is the polished and blended union of the peripheral posterior and anterior curves of the lens. +4.Power of the lens. It is measured in terms of posterior vertex power in dioptres. +5. Thickness of the lens. It is usually measured in the centre of the lens and varies depending upon the posterior vertex power of the lens. +6. Tint. It is the colour of the lens. + +types of contact lenses +Depending upon the nature of the material used in their manufacturing, the contact lenses can be divided into following three types: + +• Hard lenses, +• Rigid gas permeable lenses, and • Soft lenses. +1. Hard lenses are manufactured from PMMA (polymethylmethacrylate). The PMMA has a high optical quality, stability and is light in weight, nontoxic, durable and cheap. The hard corneal lenses have a diameter of 8.5–10 mm. Presently, these are not used commonly. +■Disadvantages of PMMA hard contact lenses. +(i) PMMA is practically impermeable to O2 thus restricting the tolerance. (ii) Being hard, it can cause +corneal abrasions. (iii) Being hydrophobic in nature, resists wetting but a stable tear film can be formed over it. +Note. PMMA contact lenses are sparingly used in clinical practice because of poor patient acceptance. 2. Rigid gas permeable (RGP) lenses are made up of materials which are permeable to oxygen. Basically +these are also hard, but somehow due to their O2 +permeability they have become popular by the name of semisoft lenses. Gas permeable lenses are commonly manufactured from: +• Silicone acrylate a copolymer of PMMA and silicone containing vinyl monomer. +• Cellulose acetate butyrate (CAB), a class of thermoplastic material derived from special grade wood cellulose has also been used, but is not popular. +3. Soft lenses are made up of HEMA (hydroxye­ thylmethacrylate). These are made about 1–2 mm larger than the corneal diameter. +■Advantages: Being soft and oxygen permeable, they are most comfortable and so well tolerated. ■Disadvantages include problem of wettability, proteinaceous deposits, getting cracked, limited life, inferior optical quality, more chances of corneal infections and inability to correct astigmatism of more than 2 dioptres. +Note. In clinical practice soft lenses are most frequently prescribed. +indications of contact lens use +1. Optical indications. Optically contact lenses can be used by every patient having refractive error, if so required, for cosmetic purposes. However, the absolute indications include anisometropia, unilateral aphakia, high myopia, keratoconus and irregular astigmatism. +Advantages of contact lenses over spectacles: +• Irregular corneal astigmatism which is not possible to correct with glasses can be corrected with contact lenses. +52 Section ii Optics and refraction + + +• Contact lenses provide normal field of vision. +• Aberrations associated with spectacles (such as peripheral aberrations and prismatic distortions) are eliminated. +• Binocular vision can be retained in high anisometropia (e.g., unilateral aphakia) owing to less magnification of the retinal image. +• Rain and fog do not condense upon contact lenses as they do on spectacles. +• Cosmetically more acceptable especially by females and all patients with thick glasses in high refractive errors. +2. Therapeutic indications are as follows: +• Corneal diseases e.g., non­healing corneal ulcers, bullous keratopathy, filamentary keratitis and recurrent corneal erosion syndrome. +• Diseases of iris such as aniridia, coloboma and albinism to avoid glare. +• In glaucoma as vehicle for drug delivery. +• In amblyopia, opaque contact lenses are used for occlusion. +• Bandage soft contact lenses are used following keratoplasty and in microcorneal perforation. +3. Preventive indications include: +• Prevention of symblepharon and restoration of fornices in chemical burns. +• Exposure keratitis. • Trichiasis. +4. Diagnostic indications use during (i) gonioscopy; (ii) electroretinography; (iii) examination of fundus in the presence of irregular corneal astigmatism; (iv) fundus photography; (v) Goldmann’s 3 mirror examination. +5. Operative indications. Contact lenses are used during (i) goniotomy operation for congenital glaucoma; (ii) vitrectomy; and (iii) endocular photocoagulation. +6. Cosmetic indications include (i) unsightly corneal scars (colour contact lenses); (ii) ptosis (haptic contact lens); and (iii) cosmetic scleral lenses in phthisis bulbi. 7. Occupational indications include use by (i) sportsmen; (ii) pilots; and (iii) actors. +Contraindications for contact lens use +(i) Mental incompetence, and poor motivation; (ii) chronic dacryocystitis; (iii) chronic blepharitis and recurrent styes; (iv) chronic conjunctivitis; (v) dry eye syndromes; (vi) corneal dystrophies and degenerations; and (vii) recurrent diseases like episcleritis, scleritis and iridocyclitis. +principles of fitting and care of lenses +It is beyond the scope of this chapter. Interested readers are advised to consult some textbooks on contact lenses. + +REFRACTIVE SURGERY + +Surgery to correct refractive errors has become very popular. It should be performed after the refractive error has stabilized; preferably after 20 years of age. Various surgical techniques in vogue are described below: +rEFraCtivE SUrGEry For myopia a. Cornea based procedures +1. Radial keratotomy (RK) +Radial keratotomy (RK) refers to making deep (90% of corneal thickness) radial incisions in the peripheral part of cornea leaving the central 4 mm optical zone (Fig. 4.18). These incisions on healing; flatten the central cornea thereby reducing its refractive power. This procedure gives good correction in low to moderate myopia (2 to 6 D). +However, because of its disadvantages and advent of safe techniques (LASIK and PRK) RK is not recommended presently. +■Disadvantages of RK: (i) Cornea is weakened, so chances of globe rupture following trauma are more after RK than after PRK. This point is particularly important for patients who are at high risk of blunt trauma, e.g., sports persons, athletes and military personnel. (ii) Rarely, uneven healing may lead to irregular astigmatism. (iii) Patients may feel glare at night. +2. Laser ablation corneal procedures +a. Photorefractive keratectomy (PRK). In this technique, to correct myopia a central optical zone of anterior corneal stroma is photoablated using excimer laser (193­nm UV flash) to cause flattening of the central cornea (Fig. 4.19). Like RK, the PRK also gives very good correction for –2 to –6 D of myopia. + + + + + + + + + +A + + + + + + +B + +Fig. 4.18 Radial keratotomy. (A) configuration of radial incisions; (B) depth of incision +Chapter 4 Errors of refraction and Accommodation 53 + + + + + + + + + +A + + + + + + +B + +Fig. 4.19 Photorefractive keratectomy (PRK) for myopia as seen (A) from front; (B) in cross section + +b. Laser in­situ keratomileusis (LASIK). In this technique first a flap of 130–160 micron thickness of anterior corneal tissue is raised with the help of an automated microkeratome. Recently, femtosecond laser is being used for more accurate and smooth flaps. After creating a corneal flap midstromal tissue is ablated directly with an excimer laser beam, ultimately flattening the cornea (Fig. 4.20). Currently, this procedure is being considered the refractive surgery of choice for myopia of up to –8 D. +Patient selection criteria are: +• Patients above 20 years of age. +• Stable refraction for at least 12 months. • Motivated patient. +• Absence of corneal pathology. +• Presence of ectasia or any other corneal pathology and a corneal thickness less than 450 mm is an absolute contraindication for LASIK.. + + + + + + + + + + + + + + +Fig. 4.20 Procedure of laser in-situ keratomileusis (LASIK) + +Advances in LASIK. Recently many advances have been made in LASIK surgery. Some of the important advances are: +• Customized (C) LASIK. C­LASIK is based on the corneal topography and wave front technology. This technique, in addition to spherical and cylindrical correction, also corrects the aberrations present in the eye and gives vision beyond 6/6 i.e., 6/5 or 6/4. +• Femto–LASIK also known as ‘All laser LASIK’ or ‘No blade LASIK’ refers to the technique in which the corneal flap is made with the help of femtosecond laser (rather than the micro keratome) for greater precision and consistency. +• Custom Femto–LASIK (C F – LASIK ) refers to corneal topography and wave front guided LASIK in which corneal flap is made with femtosecond laser. +• Epi-(E) LASIK.In this technique instead of corneal stromal flap only the epithelial sheet is separated mechanically with the use of a customized device (Epiedge Epikeratome). Being an advanced surface ablation procedure, it is devoid of complications related to corneal stromal flap. +Advantages of LASIK. (i) Minimal or no postoperative pain. (ii) Recovery of vision is very early as compared to PRK. (iii) No risk of perforation during surgery and later rupture of globe due to trauma unlike RK. (iv) No residual haze unlike PRK where subepithelial scarring may occur. (v) LASIK is effective in correcting myopia of –8 D. +Disadvantages. 1. LASIK is much more expensive. 2. It requires greater surgical skill than RK and PRK. 3. There is potential risk of flap related complications which include (i) intraoperative flap amputation, (ii) wrinkling of the flap on repositioning, (iii) postoperative flap dislocation/subluxation, (iv) epithelization of flap­bed interface, and (v) irregular astigmatism. 4. Other possible complications include infection, diffuse lamellar keratitis, dry eye, corneal ectasia, glare and regression. +3. Refractive lenticule extraction (ReLEx) +Refractive lenticule extraction (ReLEx), also called as ‘All–Femtolaser­Vision­Correction’, is a technique in which a lenticule of corneal stroma is extracted with the help of femtosecond laser. The technique is now named SMILE (small incision lenticule extraction) (Fig. 4.21). This technique can correct myopia, with and without astigmatism, upto 10D. +4. Intercorneal ring (ICR) implantation +Intercorneal ring (ICR) implantation into the peripheral cornea at approximately 2/3 stromal depth +54 Section ii Optics and refraction + + + + + + + + + + + + + + + + +A B +Fig. 4.21 Surgical technique of small incision lenticule extraction (SMILE): A, Creation of lenticule and anterior side-cut; and B, Removal of lenticule + + +is being considered. It results in a vaulting effect that flattens the central cornea, decreasing myopia. The ICR procedure has the advantage of being reversible. +Disadvantages of ICR include unpredictable results and keratitis. +5. Orthokeratology +Orthokeratology is a non­surgical reversible method of molding the cornea with overnight wear of unique rigid gas permeable contact lenses. It is being considered for correction of myopia upto –5D. It can be used even in patients below 18 years of age. +B. lens based procedures +1. Refractive lens exchange. Extraction of clear crystalline lens (Fucala’s operation) has been advocated long back for myopia of –16 to –18D, especially in unilateral cases. Recently, clear lens extraction with intraocular lens (IOL) implantation of appropriate power, i.e., refractive lens exchange (RLE) is being recommended as the refractive surgery for myopia of more than 12D. +Possible Complications include endophthalmitis, after cataract and retinal detachment. +2.Phakic refractive lens(PRL) or implantable contact lens (ICL) is also being considered for correction of myopia of >8D. In this technique, a special type of intraocular lens (IOL) is implanted in the anterior chamber or posterior chamber anterior to the natural crystalline lens. +Possible Complications include endophthalmitis, Iridocyclitis, cataract formation and secondary glaucoma. +rEFraCtivE SUrGEry For HypEropia +In general, refractive surgery for hyperopia is not as effective or reliable as for myopia. However, following procedures are used: + +i. Cornea based procedures +1. Thermal laser keratoplasty (TLK) has been used for low degree of hyperopia. In this technique, 8 laser spots are applied in a ring at the periphery to produce central steepening with mid­infrared energy from Thallium­Holmium­Chromium (THC):YAG laser. Regression effect and induced astigmatism are the main problems. +2. Hyperopic PRK using excimer laser has also been tried. Regression effect and prolonged epithelial healing are the main problems encountered. +3. Hyperopic LASIK is effective in correcting hypermetropia upto +4D. +4. Conductive keratoplasty (CK) is nonablative and nonincisional procedure in which cornea is steepened by collagen shrinkage through the radiofrequency energy applied through a fine tip inserted into the peripheral corneal stroma in a ring pattern. This technique is effective for correcting hyperopia of upto 3D. + +ii. lens based procedures +1. Phakic refractive lens (PRL) or implantable contact lens (ICL) is being considered a surgical option for hyperopia of more than + 4D. +2. Refractive lens exchange (RLE) is a good option for high hyperopia especially in presbyopic age. + +rEFraCtivE SUrGEry For aStiGmatiSm Refractivesurgical techniques employed for myopia can be adapted to correct astigmatism alone or simultaneously with myopia as follows: +1. Astigmatic keratotomy (AK) refers to making transverse cuts in the mid­periphery of the steep corneal meridian (Fig. 4.22). AK can be performed +Chapter 4 Errors of refraction and Accommodation 55 + + + + + + + + +Fig. 4.22 Astigmatic keratotomy. (A) showing flat and deep meridians of cornea; (B) paired transverse incisions to flatten the steep meridian; (C) showing correction of astigmatism after astigmatic keratotomy +alone (for astigmatism only) or along with RK (for associated myopia). +2. Photo-astigmatic refractive keratotomy (PARK) is performed using excimer laser. +3. LASIK procedure can also be adopted to correct astigmatism upto 5 D. +4. SMILE procedure can also be adopted to correct astigmatism. +manaGEmEnt oF poSt-KEratoplaSty aStiGmatiSm +1. Selective removal of sutures in steep meridians may improve varying degrees of astigmatism and should be tried first of all. +Note. Other procedures mentioned below should be performed only after all the sutures are out and refraction is stable. +2. Arcuate relaxing incisions in the donor cornea along the steep meridian may correct astigmatism up to 4–6D. +3. Relaxing incisions combined with compression sutures may correct astigmatism up to 10D. +4. Corneal wedge resection with suture closure of the wound may be performed in the flat meridian to correct astigmatism greater than 10D. +5. LASIK procedure can also be adopted to correct post­keratoplasty astigmatism. +rEFraCtivE SUrGEry For prESByopia Refractive surgery for presbyopia, still under trial, includes: + +I. Cornea based procedures +1. Monovision LASIK, i.e., one eye is corrected for distance and other is made slightly near sighted. +2. Monovision conductive keratoplasty (CK) is being considered increasingly to correct presbyopia in one eye (non­dominant). Principle is same as for correction of hypermetropia (see page 54). +3. Presbyopic bifocal LASIK or LASIK-PARM, i.e., LASIK by Presbyopia Avalos Rozakis Method is a technique undertrial in which the shape of the cornea is altered to have two concentric vision zones that help the presbyopic patient to focus on near and distant objects. +II. Lens based procedures +Multifocal or accommodating IOL implantation after lens extraction especially in patients with cataract or high refractive errors (refractive lens exchange) correct far as well as near vision. +Monovision with intraocular lenses, i.e., correction of one eye for distant vision and other for near vision with IOL implantation after bilateral cataract extraction also serves as a solution for far and near correction. Similarly, monovision with clear lens extraction and intraocular lens implantation (refractive lens exchange i.e., RLE) is also being considered increasingly in presbyopic patients with associated higher refractive errors. +III. Sclera based procedures +Following scleral expansion procedures are being tried, but results are controversial. +1. Anterior ciliary sclerotomy (ACS), with tissue barriers is currently under trial. With initial encouraging results, multi­site clinical studies are planned for US and Europe to evaluate this technique. +2. Scleral spacing procedures and scleral ablation with erbium: YAG laser are other sclera­based procedures still under trial. +3. Scleral expansion with insertion of intrascleral segments of collagen or silicone expansion plugs +may help by improving accommodation. +Section III Diseases of Eye + + + + + + + +Section Outline + +5. Diseases of Conjunctiva 6. Diseases of Cornea +7. Diseases of Sclera +8. Diseases of Uveal Tract 9. Diseases of Lens +10. Glaucoma +11. Diseases of Vitreous 12. Diseases of Retina +13. Neuro-Ophthalmology +14. Disorders of Ocular Motility 15. Disorders of Eyelids +16. Diseases of Lacrimal Apparatus 17. Diseases of Orbit +18. Ocular Injuries +5 +Diseases of Conjunctiva + + + +CHAPTER OUTLINE + + +APPLIED ANATOMY Parts +Structure Glands +• +• +• +INFLAMMATIONS OF CONJUNCTIVA Infective conjunctivitis +• +– +– +– +– +Bacterial Chlamydial Viral Granulomatous +• +• +• +Allergic conjunctivitis Cicatricial conjunctivitis Toxic conjunctivitis + + + +APPLIED ANATOMY + +Conjunctiva is a translucent mucous membrane which lines the posterior surface of the eyelids and anterior aspect of the eyeball. The name conjunctiva (conjoin: to join) has been given to this mucous membrane owing to the fact that it joins the eyeball to the lids. It stretches from the lid margin to the limbus, and encloses a complex space called conjunctival sac which is open in front at the palpebral fissure. +PARTS OF CONJUNCTIVA +Conjunctiva can be divided into three parts (Fig. 5.1): 1. Palpebral conjunctiva. It lines the lids and can be subdivided into marginal, tarsal and orbital conjunctiva. +i. Marginal conjunctiva extends from the lid margin to about 2 mm on the back of lid up to a shallow groove, the sulcus subtarsalis. It is actually a transitional zone between skin and the conjunctiva proper. +ii. Tarsal conjunctiva is thin, transparent and highly vascular. It is firmly adherent to the whole tarsal plate in the upper lid. In the lower lid, it is adherent only to half width of the tarsus. The tarsal glands are seen through it as yellow streaks. + +DEGENERATIVE CONDITIONS Pinguecula +Pterygium Concretions +• +• +• +• +Amyloid degeneration +SYMPTOMATIC CONDITIONS OF CONJUNCTIVA Hyperaemia +• +• +• +• +• +Chemosis Ecchymosis Xerosis Discoloration +CYSTS AND TUMOURS Cysts of conjunctiva Tumours of conjunctiva +• +• + + + +iii. Orbital part of palpebral conjunctiva lies loose between the tarsal plate and fornix. +2. Bulbar conjunctiva. It is thin, transparent and lies loose over the underlying structures and thus can be moved easily. It is separated from the anterior sclera by episcleral tissue and Tenon’s + + + + + + + + + + + + + + + + + + +Fig. 5.1 Parts of conjunctiva and conjunctival glands +60 Section III Diseases of Eye + + +capsule. A 3 mm ridge of bulbar conjunctiva around the cornea is called limbal conjunctiva. In the area of limbus, the conjunctiva, Tenon’s capsule and the episcleral tissue are fused into a dense tissue which is strongly adherent to the underlying corneoscleral junction. At the limbus, the epithelium of conjunctiva becomes continuous with that of cornea. +3. Conjunctival fornix. It is a continuous circular cul-de-sac which is broken only on the medial side by caruncle and the plica semilunaris. Conjunctival fornix joins the bulbar conjunctiva with the palpebral conjunctiva. It can be subdivided into superior, inferior, medial and lateral fornices. +Structure of conjunctiva +Histologically, conjunctiva consists of three layers namely, epithelium, adenoid layer, and fibrous layer (Fig. 5.2). +1. Epithelium. This is a 2–5 layered, non-keratinized epithilium. It also contains goblet cells which constitute about 10% of epithelium. The layer of epithelial cells in conjunctiva varies from region to region and in its different parts as follows: + + + + + + + + + +A + + + + + + + + + + + + + + + +B + +Fig. 5.2 Microscopic structure of conjunctiva showing three layers (A), and arrangement of epithelial cells in different regions of conjunctiva (B) + +• Marginal conjunctiva has 5-layered stratified squamous type of epithelium. +• Tarsal conjunctiva has 2-layered epithelium: superficial layer of cylindrical cells and a deep layer of flat cells. +• Fornix and bulbar conjunctiva have 3-layered epithelium: a superficial layer of cylindrical cells, middle layer of polyhedral cells and a deep layer of cuboidal cells. +• Limbal conjunctiva has again many layered (5 to 6) stratified squamous epithelium. Limbal stem cells are present in basal layer of this part. +2. Adenoid layer. It is also called lymphoid layer and consists of fine connective tissue reticulum in the meshes of which lie lymphocytes. This layer is most developed in the fornices. It is not present since birth but develops after 3–4 months of life. For this reason, conjunctival inflammation in an infant does not produce follicular reaction. +3. Fibrous layer. It consists of a meshwork of collagenous and elastic fibres. It is thicker than the adenoid layer, except in the region of tarsal conjunctiva, where it is very thin. This layer contains vessels and nerves of conjunctiva. It blends with the underlying Tenon’s capsule in the region of bulbar conjunctiva. +Glands of conjunctiva +The conjunctiva contains two types of glands (Fig. 5.1) +1. Mucin secretory glands. These include: +• Goblet cells (the unicellular glands located within the epithelium), +• Crypts of Henle (present in the tarsal conjunctiva), and +• Glands of Manz (found in limbal conjunctiva). These glands secrete mucus which is essential for wetting the cornea and conjunctiva. +2. Accessory lacrimal glands. These are: +• Glands of Krause, present in subconjunctival connective tissue of fornices, about 42 in the upper fornix and 8 in the lower fornix, and +• Glands of Wolfring, present along the upper border of superior tarsus and along the lower border of inferior tarsus. + +Plica semilunaris +It is a pinkish crescentric fold of conjunctiva, present in the medial canthus. Its lateral free border is concave. It is a vestigeal structure in human beings and represents the nictitating membrane (or third eyelid) of lower animals. +Chapter 5 Diseases of Conjunctiva 61 + + +Caruncle +The caruncle is a small, ovoid, pinkish mass, situated in the inner canthus, just medial to the plica semilunaris. In reality, it is a piece of modified skin and so is covered with stratified squamous epithelium and contains sweat glands, sebaceous glands and hair follicles. +Blood supply of conjunctiva +Arteries supplying the conjunctiva are derived from three sources (Fig. 5.3): (1) peripheral arterial arcade of the eyelid; (2) marginal arcade of the eyelid; and (3) anterior ciliary arteries. +■Palpebral conjunctiva and fornices are supplied by branches from the peripheral and marginal arterial arcades of the eyelids. +■Bulbar conjunctiva is supplied by two sets of vessels: +• Posterior conjunctival arteries which are branches from the arterial arcades of the eyelids; and +• Anterior conjunctival arteries which are the branches of anterior ciliary arteries. Terminal branches of the posterior conjunctival arteries anastomose with the anterior conjunctival arteries to form the pericorneal plexus. +Veins from the conjunctiva drain into the venous plexus of eyelids and some around the cornea into the anterior ciliary veins. +Lymphatics of the conjunctiva are arranged in two layers: a superficial and a deep. Lymphatics from the lateral side drain into preauricular lymph nodes and those from the medial side into the submandibular lymph nodes. +Nerve supply of conjunctiva +• A circumcorneal zone of conjunctiva is supplied by the branches from long ciliary nerves which supply the cornea. + + + + + + + + + + + + + + +Fig. 5.3 Blood supply of conjunctiva + + +• Rest of the conjunctiva is supplied by the branches from lacrimal, infratrochlear, supratrochlear, supraorbital and frontal nerves. + +INFLAMMATIONS OF CONJUNCTIVA + +Inflammation of the conjunctiva (conjunctivitis) is classically defined as conjunctival hyperaemia associated with a discharge which may be watery, mucoid, mucopurulent or purulent. +Types of Conjunctivitis +Common types of conjunctivitis include: +A. Infective conjunctivitis 1. Bacterial conjunctivitis +• Acute bacterial conjunctivitis +• Hyperacute bacterial conjunctivitis • Chronic bacterial conjunctivitis +• Angular bacterial conjunctivitis 2. Chlamydial conjunctivitis +• Trachoma +• Adult inclusion conjunctivitis +• Neonatal chlamydial conjunctivitis 3. Viral conjunctivitis +• Adenovirus conjunctivitis +– Epidemic keratoconjunctivitis – Pharyngoconjunctival fever +• Enterovirus conjunctivitis +• Molluscum contagiosum conjunctivitis • Herpes simplex conjunctivitis +4. Ophthalmia neonatorum (A separate entity) 5. Granulomatous conjunctivitis +• Parinaud oculoglandular syndrome +B. Allergic Conjunctivitis +1. Simplex allergic conjunctivitis +• Hay fever conjunctivitis (rhino conjunctivitis) • Seasonal allergic conjunctivitis (SAC) +• Perennial allergic conjunctivitis (PAC) 2. Vernal keratoconjunctivitis (VKC) +3. Atopic keratoconjunctivitis +4. Giant papillary conjunctivitis (GPC) 5. Phlyctenular conjunctivitis (PKC) +6. Contact dermoconjunctivitis (drop conjunctivitis) +C. Cicatricial conjunctivitis +• Ocular mucous membrane pemphigoid (OMMP), • Stevens Johnson syndrome (SJS), +• Toxic epidermal necrolysis (TeN), and • Secondary cicatricial conjunctivitis. +D. Toxic conjunctivitis + +A. INFECTIVE CONJUNCTIVITIS + +Infective conjunctivitis, i.e., inflammation of the conjunctiva caused by micro-organisms is the +62 Section III Diseases of Eye + + +commonest variety. This is in spite of the fact that the conjunctiva has been provided with natural protective mechanisms in the form of: +• Low temperature due to exposure to air, • Physical protection by lids, +• Flushing action of tears, +• Antibacterial activity of lysozymes, and +• Humoral protection by the tear immunoglobulins. + +BACTERIAL CONJUNCTIVITIS + +There has occurred a relative decrease in the incidence of bacterial conjunctivitis in general and those caused by Gonococcus and Corynebacterium Diphtheriae in particular. However, in developing countries it still continues to be the commonest type of conjunctivitis. It can occur as sporadic and epidemics cases. Outbreaks of bacterial conjunctivitis, epidemics are quite frequent during monsoon season. +Etiology +A. Predisposing factors for bacterial conjunctivitis, especially epidemic forms, are flies, poor hygienic conditions, hot dry climate, poor sanitation and dirty habits. These factors help the infection to establish, as the disease is highly contagious. +B. Causative organisms. It may be caused by a wide range of organisms in the following approximate order of frequency: +• Staphylococcus aureus is the most common cause of bacterial conjunctivitis and blepharoconjunctivitis. +• Staphylococcus epidermidis is an innocuous flora of lid and conjunctiva. It can also produce blepharoconjunctivitis. +• Streptococcus pneumoniae (pneumococcus) produces acute conjunctivitis usually associated with petechial subconjunctival haemorrhages. The disease has a self-limiting course of 9–10 days. +• Streptococcus pyogenes (haemolyticus) is virulent and usually produces pseudomembranous conjunctivitis. +• Haemophilus influenzae (aegyptius, Koch-Weeks bacillus). It classically causes epidemics of mucopurulent conjunctivitis, known as ‘red-eye’ especially in semitropical countries. +• Moraxella lacunata (Moraxella Axenfeld Bacillus) is most common cause of angular conjunctivitis and angular blepharoconjunctivitis. +• Pseudomonas pyocyanea is a virulent organism, which readily invades the cornea. +• Neisseria gonorrhoeae typically produces acute purulent conjunctivitis in adults and ophthalmia + +neonatorum in newborn. It is capable of invading intact corneal epithelium. +• Neisseria meningitidis (meningococcus) may produce mucopurulent conjunctivitis. +• Corynebacterium diphtheriae causes acute membranous conjunctivitis. Such infections are not known nowadays. \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_20.txt b/notes/A K Khurana - Comprehensive Ophthalmology_20.txt new file mode 100644 index 0000000000000000000000000000000000000000..c7d1a3d21be6803e936e9eb46798882ed4265f38 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_20.txt @@ -0,0 +1,1596 @@ +What are the features of the image formed in direct ophthalmoscopy? +The image formed is erect, virtual and about 15 times magnified in an emmetrope. +When and who invented the indirect ophthalm-oscopy? +Nagel in 1864. +What is the principle of indirect ophthalmoscopy? The principle of indirect ophthalmoscopy is to make the eye highly myopic by placing a strong convex lens in front of the patient’s eye so that emergent rays from an area of the fundus are brought to focus as a real, inverted image between the lens and the observer’s eye. +What is the power of the convex lens most commonly used in indirect ophthalmoscopy? ++20 D. +What are the characteristics of the image formed in indirect ophthalmoscopy? +It is real, inverted, magnified about 2.5 times when +20 D lens is used and is formed between the convex lens and the observer. + +What are the advantages of indirect ophthalmoscopy over direct ophthalmoscopy? +1. It allows a stereoscopic view of the fundus. 2. It allows examination in hazy media. +3. Periphery of the retina up to ora serrata can be examined. +What are the advantages of direct ophthalmoscopy over indirect ophthalmoscopy? +1. It is a handy procedure. 2. Easy to perform. +3. Allows examination of the minute details of the approachable lesion, since image formed is 15 times magnified. +4. Orientation and understanding of the lesion is easy as the image formed is erect. +Name the common diseases of the optic disc which can be diagnosed on direct ophthalmoscopy. +• Papillitis +• Papilloedema • Optic atrophy +• Glaucomatous cupping. +Name few common retinal disorders diagnosed on direct/indirect ophthalmoscopy. +• Diabetic retinopathy +• Hypertensive retinopathy • Retinal detachment +• Retinitis pigmentosa. +26 +Ophthalmic Instruments and Operative Ophthalmology + + + +Chapter Outline + +INTRODUCTION +ANAESTHESIA FOR OCULAR SURGERY Regional (local) anaesthesia +• +• +General anaesthesia +OPHTHALMIC EQUIPMENT AND INSTRUMENTS Essential equipment for ophthalmic operation theatre +• + + + +INTRODUCTION + +To perform well in this section of practical examinations, students are supposed to be well versed with the following topics: +■ Anaesthesia for ocular surgery ■ Ophthalmic equipment +■ Ophthalmic instruments ■ Sterilization techniques +■ Surgical steps of common eye operations: • Cataract surgery (see pages 199-210) +• Glaucoma surgery (see page 253) +• Enucleation operation (see page 307) • Evisceration operation (see page 173) +■ Lasers and cryotherapy in ophthalmology (see pages 461-463). + +ANAESTHESIA FOR OCULAR SURGERY +Ocular surgery may be performed under topical, local or general anaesthesia. Local anaesthesia is more frequently employed as it entails little risk and is less dependent upon patient’s general health. It is easy to perform, has got rapid onset of action and provides a low intraocular pressure with dilated pupil. Above all, in developing countries like India, with a large number of cataract cases, it is much more economical. + +REGIONAL (LOCAL) ANAESTHESIA Indications. Almost all ocular operations, namely, cataract extraction, glaucoma surgery, keratoplasty + +• Ophthalmic instruments +STERILIZATION, DISINFECTION AND FUMIGATION +• Sterilization and disinfection +• Fumigation of operation theatre RELATED QUESTIONS + + + +and other corneal surgeries, iridectomy, squint and retinal detachment surgery in adults can be performed under local anaesthesia. +Goals. The main goals of regional anaesthesia for successful ocular surgery are: globe and conjunctival anaesthesia, orbicularis akinesia, ocular akinesia and low intraocular and intraorbital pressure. +These goals can be achieved by a local anaesthesia comprising either surface anaesthesia, facial block and retrobulbar block or a combination of surface anaesthesia and peribulbar block. +Surface (Topical) anaesthesia +Surface anaesthesia is achieved by topical instillations of 2 to 4% xylocaine or 1% amethocaine or proparacaine 0.5% (most preferred for topical anesthesia). Usually, a drop of anaesthetic solution instilled 4 times after every 4 minutes, is sufficient to produce conjunctival and corneal anaesthesia. Cataract surgery by phacoemulsification can be performed even under topical anaesthesia only. +Facial block +For intraocular surgery, it is necessary to block the facial nerve which supplies the orbicularis oculi muscle, so that patient cannot squeeze the eyelids. Orbicularis akinesia can be achieved by blocking the facial nerve at its terminal branches (van Lint block), superior branches (Atkinson block) or proximal trunk (O’ Brien or Nadbath block). +1. Blocking the peripheral branches of facial nerve (van +Lint’s block): This technique blocks the terminal +592 Section Vi Practical Ophthalmology + + +branches of the facial nerve, producing localized akinesia of the orbicularis oculi muscle without associated facial paralysis. +In this technique, 2.5 ml of anaesthetic solution is injected in deeper tissues just above the eyebrow and just below the inferior orbital margin, through a point about 2 cm behind the lateral orbital margin, level with outer canthus (Fig. 26.1). +2. Facial nerve trunk block: At the neck of mandible (O’Brien’s block). In it, facial nerve is blocked near the condyloid process. The condyle is located 1 cm anterior to the tragus. It is easily palpated if the patient is asked to open and close the mouth with the operator’s index finger located across the neck of the mandible. At this point, the needle is inserted until contact is made with the periosteum and then 4 to 6 ml of local anaesthetic is injected while the needle is withdrawn (Fig. 26.2). +This technique is associated with pain at the injection site and unwanted facial paralysis. +3. Nadbath block: In this technique, the facial nerve is blocked as it leaves the skull through the stylomastoid foramen. This block is also painful. +4. Atkinson’s block: In it superior branches of the facial nerve are blocked by injecting anaesthetic solution at the inferior margin of the zygomatic bone. +Retrobulbar block +Retrobulbar block was introduced by Herman Knapp in 1884. It is administered by injecting 2 ml of anaesthetic solution (2% xylocaine with added hyaluronidase 5 IU/ml and with or without adrenaline one in one lac) into the muscle cone behind the + + + + + + + + + + + + + + + + +Fig. 26.1 Technique of van Lint’s block + + + + + + + + + + + + + + + +Fig. 26.2 Diagrammatic distribution of the facial nerve and technique of O’Brien’s block + + +eyeball (Fig. 26.3 ‘A’ ). It is usual to give the injection through the inferior fornix or the skin of outer part of lower lid with the eye in primary gaze (Fig. 26.4 ‘A’). The needle is first directed straight backwards then slightly upwards and inwards towards the apex of the orbit, up to a depth of 2.5 to 3 cm. +Retrobulbar block anaesthetizes the ciliary nerves, ciliary ganglion and third and sixth cranial nerves thus producing globe akinesia, anaesthesia and analgesia. The superior oblique muscle is not usually paralyzed as the fourth cranial nerve is outside the muscle cone. +Complications encountered with it include retrobulbar haemorrhage, globe perforation, optic nerve injury, and extraocular muscle palsies. + + + + + + + + + + + + + + +Fig. 26.3 (A) Position of needle for retrobulbar block in the muscle cone, (B) for peribulbar block in the peripheral orbital space +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 593 + + +Peribulbar block +This technique described in 1986 by Davis and Mandel has almost replaced the time-tested combination of retrobulbar and facial blocks, because of its fewer complications and by obviating the need for a separate facial block. +Primarily, the technique involves the injection of 6 to 7 ml of local anaesthetic solution in the peripheral space of the orbit (Fig. 26.3 position ‘B’), from where it diffuses into the muscle cone and lids; leading to globe and orbicularis akinesia and anaesthesia. Classically, the peribulbar block is administered by two injections; first through the upper lid (at the junction of medial one-third and lateral two-third) and second through the lower lid (at the junction of lateral one-third and medial two-third) (Fig. 26.4 ‘B’). After injection orbital compression for 10 to 15 minutes is applied with superpinky or any other method. +The anaesthetic solution used for peribulbar anaesthesia consists of a mixture of 2% lignocaine, and 0.5 to 0.75% bupivacaine (in a ratio of 2:1) with hyaluronidase 5 IU/ml and adrenaline one in one lac. +GENERAL ANAESTHESIA +Indications include infants and children, anxious, non co-operative and mentally retarded adults, perforating ocular injuries, major operations like + + + + + + + + + + + + + + + + + +Fig. 26.4 (A) Position of the needle on the skin for retrobulbar block, (B) for peribulbar block + +exenteration and the patients willing for operation under general anaesthesia. +Important considerations. During general anaesthesia for ocular surgery, use of relaxants, endotracheal intubation and controlled respiration is preferred. Under general anaesthesia, it must be ensured that patient does not develop carbon dioxide retention. When this occurs, choroid swells to many times its normal value and ocular contents prolapse as soon as the eye is opened. +In perforating injuries and other ocular emergency cases, use of suxamethonium should always be preferred over non-depolarizing relaxants as the risk of vomiting and regurgitation of stomach contents is less with it. + +OPHTHALMIC EQUIPMENT AND INSTRUMENTS +ESSENTIAL EQUIPMENT FOR OPHTHALMIC OPERATION THEATRE +In addition to the basic requirements of general operation theatre with equipment for general anaesthesia and facilities to deal with the cardio-respiratory emergency situations, a modern ophthalmic operation theatre should also have the following equipment: +• An operating microscope (Fig. 26.5A), • An ophthalmic cryo unit (Fig. 26.5B), +• A wet-field bipolar cautery (Fig. 26.5C), • An electrolysis machine, +• An electromagnetic unit for removal of intraocular foreign bodies, +• A vitrectomy unit (Fig. 26.5D), and +• Phacoemulsification machine (Fig. 26.5E) for modern cataract surgery. +OPHTHALMIC INSTRUMENTS +Commonly used ophthalmic instruments can be grouped as under: +I. Lid speculums +Three types of speculums are in use: +1. Universal metallic eye speculum (Fig. 26.6). It is called universal eye speculum because it can be used for both eyes, i.e., right as well as left. It has two limbs and a spring mechanism with a screw to adjust the limbs. Its blades are open. +594 Section Vi Practical Ophthalmology + + + + + + + + + + + +A B + + + + + + + + + + +C D + + + + + + + + + + +E +Fig. 26.5 Essential equipment for ophthalmic operation theatre: A, Operating microscope; B, Ophthalmic cryo unit; C, Wet-field bipolar cautery; D, Vitrectomy unit; and E, Phacoemulsification machine + + +2. Eye speculum with guard or with solid blades (Fig. 26.7). It retracts the lids and its solid blades keep the lashes away from the field of operation. + + + + + + +Fig. 26.6 Fig. 26.7 +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 595 + + +3. Wire speculum (Fig. 26.8). It is very light and causes minimal pressure on the eyeball. It is also universal. + + + + + + + + + + + +Fig. 26.8 +Uses. Eye speculums are used to keep the lids apart during: +• Intraocular operations such as cataract surgery, glaucoma surgery and keratoplasty. +• Extraocular surgery, e.g., squint surgery, pterygium surgery. +• Enucleation and evisceration operation. +• Removal of conjunctival and corneal foreign bodies. +• Cauterization of corneal ulcer. +• Examination of the eye in a patient with blepharo- spasm. +II. Forceps +Many kinds of forceps are available for different purposes. A few common ones are mentioned here. 1. Plain forceps (Fig. 26.9). It is simple forcep without any teeth. Serrations (either horizontal or vertical) are present near the tip. Uses: (i) To hold the conjunctiva during any surgical procedure. (ii) To tie sutures. (iii) To hold scleral flap in trabeculectomy. (iv) To hold skin during eyelid surgery. (v) To hold nasal mucosal flaps and lacrimal sac flaps in DCR operation. + + + +Fig. 26.9 + +2. Globe fixation forceps (Fig. 26.10). It has 2 × 3 or 3 × 4 teeth at the tip. It is applied near the limbus to hold the conjunctiva and episcleral tissue together. Uses: (i) To fix the eyeball during operations on the eyeball. (ii) To hold the eyeball during forced-duction test. + + + +Fig. 26.10 + +3. Superior rectus holding forceps (Fig. 26.11). It is a toothed forceps (1 × 2 teeth) with S-shaped double curve near the tip. Uses: It is used to hold the superior rectus muscle while passing a bridle suture under it; to stabilize the eyeball during any operation such as cataract surgery, glaucoma surgery, corneal surgery, etc. + + + +Fig. 26.11 + +4. Corneo-scleral forceps. These are available in many shapes and designs. Commonly used are: +Colibri forceps (Fig. 26.12 A) and Lim’s forceps (Fig. 26.12 B). These are the forceps with very fine teeth (1 × 2) at the tip. Use: These are used to hold the cornea or scleral edge (of incision) for suturing during cataract, glaucoma, repair of corneal and/or scleral tears and keratoplasty operations. + + + + +Fig. 26.12 A + + + +Fig. 26.12 B + +5. Iris forceps (Fig. 26.13). These are small and delicate forceps having fine 1 × 2 teeth on the inner side of the limbs. These are also available in various shapes and designs. Use: These are used to catch the iris for the purpose of iridectomy during operations for cataract, glaucoma, optical iridectomy and excision for iris prolapse, tumours and entangled foreign bodies. + + + +Fig. 26.13 + +6. Arruga’s intracapsular (capsule holding) forceps (Fig. 26.14). Intracapsular forceps have a cup on the inner side of the tip of each limb. The margins of the cup are very smooth which do not damage the lens capsule when applied. Use: Not used nowadays. In the era of intracapsular cataract extraction (ICCE) it was used to hold the lens capsule (usually at 6 O’clock position) during capsule forceps method of lens delivery in intracapsular cataract extraction and to grasp and remove the capsular remnants after accidental extracapsular lens extraction. +596 Section Vi Practical Ophthalmology + + + + + +Fig. 26.14 +7. Epilation forceps (Fig. 26.15). These are small stout forceps with blunt and flat ends. Uses: These are used to epilate the cilia in trichiasis and stye, to remove cilia after electrolysis and cryolysis and to remove cilia lodged in the punctum. + + + +Fig. 26.15 +8. Artery (haemostatic) forceps (Fig. 26.16). It is a blunt-tipped stout forceps having a scissors-like configuration. It has multiple straight grooves (at right angle to the limbs) near the tip and a locking mechanism near the ringed end. These are available in large, medium and small size. The small-sized artery forceps, also called as mosquito artery forceps are more commonly used in ophthalmology. These can be straight or with curved ends. Uses: (i) To catch the bleeding vessels during operations of the lids and lacrimal sac. (ii) To hold the skin and muscle stay sutures. (iii) To hold small ‘pea-nut’ gauze pellets for blunt dissection in lacrimal sac surgery and other extraocular surgery. (iv) To hold gauze pieces while packing the socket after enucleation or exenteration operation. + + + + + + + + +Fig. 26.16 + +Ill. Hooks and retractors +1. Lens expressor (hook) (Fig. 26.17). It is a flat metal handle with a rounded curve at one end. Tip of the curve is knobbed. The plane of the handle is at right angle to the curvature of the hook. Uses: (i) To express the nucleus in extracapsular cataract extraction. (ii) It can also be used as muscle hook if the latter is not available. (iii) Also used along with wire vectis to extract out the dislocated lens. (iv) In the era of ICCE, it was used to apply pressure on the limbus at the 6 O’clock position during the delivery of lens in intracapsular cataract extraction with Smith’s (tumbling) and capsule forceps techniques. + +Fig. 26.17 +2. Muscle (strabismus) hook (Fig. 26.18). It is similar to the lens expressor in appearance but has a blunt gaurding knob at the end to prevent muscle slip page. The plane of the handle is the same as that of the curvature of the hook. Uses: (i) It is used to engage the extraocular muscles during surgery for squint, enucleation, and retinal detachment. (ii) In the absence of lens expressor, it may be used in its place. + + +Fig. 26.18 +3. Desmarre’s retractor (Fig. 26.19). It is a saddle-shaped instrument folded on itself at one end. It is available in two sizes: small (paediatric) and large (adult). Use: It is used to retract the lids during examination of the eyeball in cases of blepharospasm in children, in cases with marked swelling and ecchymosis, removal of corneoscleral sutures, removal of corneal foreign body and for double eversion of upper lid to examine the superior fornix. Advantages.Allows continuous adjustment of the lids and width of the palpebral aperture. + + + +Fig. 26.19 +Disadvantages. It is not self-retaining, so an assistant is needed to hold it. +4. Cat’s paw lacrimal wound retractor (Fig. 26.20). It is a fork-like instrument with the terminals bent inward. Use: It is used to retract the skin during lacrimal sac and lid surgery. + + +Fig. 26.20 +5. Self-retaining lacrimal wound (Muller’s) retractor (Fig. 26.21). It is made up of two limbs with three curved pins on each for engaging the edges of the skin incision. The limbs are kept in a retracted position with the help of a fixing screw. Use: It is used to retract the skin during surgery on the lacrimal sac (e.g. DCT or DCR). + + + + + + + +Fig. 26.21 +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 597 + + +6. Iris retractor (Fig. 26.22). It consists of a handle with a curved blade (which conforms to the pupillary margin) at one end. Its edges and corners are rounded so as not to damage either the iris or the lens capsule. Use: To retract the upper edge of pupil in cryoextraction technique of ICCE and also to aspirate the lens matter from behind the iris at 12 O’clock position in ECCE. + +Fig. 26.22 + +IV. Needle holders +1. Spring action (Barraquer’s type) needle holder (Fig. 26.23). These are available in various sizes with straight or curved tips, in different shapes and may be with or without locking system. The jaws of the needle holder are finely serrated to hold the fine needles firmly. Use: Spring type needle holders are used for passing sutures in the conjunctiva, cornea, sclera and extraocular muscles. + + + + +Fig. 26.23 +2. Castroviejo’s needle holder (Fig. 26.24). It is a medium-sized spring action needle holder with a S-shaped locking system. Use: It is generally used in extraocular surgery, e.g., conjunctival suturing, squint surgery, etc. It can also be used for intraocular surgery. + + + +Fig. 26.24 +3. Arruga’s, Steven, Silcock’s and kelt needle holder (Fig. 26.25). These are large needle holders and all are of similar type with slight model differences. The upper shank of these needle holders has a flat and broad plate to accommodate the surgeon’s thumb. These are available with and without locking device. Use:These are very commonly used in lid surgery and also for passing superior rectus suture. + + + +Fig. 26.25 + +V. Callipers and rules +1. Castroviejo calliper (Fig. 26.26). It is a divider-like instrument, to one arm of which is attached to a graduated scale (in mm). Its other arm can be + +moved by a screw over the scale. Use: It is used to take measurements during squint, ptosis, retinal detachment and pars plana vitrectomy surgery. It is also used to measure corneal diameter and visible horizontal iris diameter. + + + + + + +Fig. 26.26 +2. Metallic rule:It is used as a scale for the Castroviejo calliper for exact measurements and to measure the palpebral aperture width. +VI. Knives and knife-needles +1. Von Graefe’s knife (Fig. 26.27). It is a long, narrow, thin and straight blade with a sharp tip and cutting edge on one side. It is not used presently. Uses: (i) Previously, it was used for making an abinterno corneoscleral incision during cataract surgery and for iridectomy operation. (ii) It is also used for four dotiridectomy operation in patients with iris bombe formation. (iii) For making a puncture in pars plana area during lensectomy and vitrectomy operation. + + +Fig. 26.27 +2. Keratomes (Fig. 26.28). A keratome has a thin diamond-shaped blade with a sharp apex and two cutting edges. Straight as well as curved keratomes are available in various sizes (2.8 mm, 3 mm, 3.5 mm, 5.5 mm). Presently disposable curved keratomes are more commonly used. Use: Keratomes are used to make valvular corneal incisions for entry into the anterior chamber for all modern techniques of cataract extraction viz. phacoemulsification, SICS and even conventional ECCE and other intraocular surgeries, e.g., iridectomies and paracentesis. + + + + +Fig. 26.28 +3. Paracentesis needle (Fig. 26.29). It is a small lancet-shaped needle with sharp cutting edges resembling in appearance to a small keratome. It has got a guard to prevent in advertent injury to the deeper structures. Use:It is used for paracentesis and to make very small corneoscleral incisions. + + +Fig. 26.29 +598 Section Vi Practical Ophthalmology + + +4. Tooke’s knife (Fig. 26.30). It has a short flat blade with a semicircular blunt dissecting edge, which is bevelled on both the surfaces like a chisel. Uses: (i) It can be used to separate the conjunctiva and sub conjunctival tissue from the sclera and limbus when limbal based flap is made for trabeculectomy surgery. (ii) It can also be used to separate partial thickness lamellae of sclera during trabeculectomy.(iii) To separate pterygium head or limbal dermoid from the underlying corneal lamellae. (iv) To separate corneal lamellae in lamellar keratoplasty. + + +Fig. 26.30 + +5. 15° side port entry blade (Fig. 26.31). It is a fine straight knife with a sharp pointed tip and cutting edge on one side. Use. It is used to make a small valvular clear corneal incision (commonly called as side port incision) in phacoemulsification and other intraocular surgeries including pars plana vitrectomy. + + + +Fig. 26.31 +6. MVR or V lance blade (Fig. 26.32). It is a fine straight but triangular knife similar to 15° side port entry blade but with cutting edges on both sides. Use: Its uses are similar to 15° side port entry blade. + + +Fig. 26.32 + +7. Cystitome or capsulotome (Fig. 26.33). It is a small needle knife with a bent tip which is sharp on both the edges. Presently, disposable cystitome is prepared by bending the disposable 26 gauge or 30 gauge hypodermic needle. Use: It is used for doing anterior capsulotomy or capsulorhexis during extracapsular cataract extraction. + + + + + +Fig. 26.33 + +8. Foreign body spud (Fig. 26.34). It has a small, stout and flat blade with blunt tip and edges on both sides. Use: It is used to remove corneal foreign body. + +Fig. 26.34 + +9. Razor blade fragmemt with blade holder. Razor blade fragment holder (Fig. 26.35) is designed to hold the razor blade fragment firmly in its jaws and has a locking device. The razor blade fragments broken to a uniform size and shape have the sharpest possible metal edge with an absolute point. Presently, presterilized razor blade fragments mounted on a disposable plastic handle (Fig. 26.36) are also being preferred. Use: It is the most commonly used cutting device for making incisions in cataract, glaucoma, keratoplasty, sclerotomy, pterygium and many other operations. + + + + + +Fig. 26.35 + + + +Fig. 26.36 +10. Crescent knife (Fig. 26.37). It is blunt-tipped, bevel up knife having cut-splitting action at the tip and at both sides. Its blade is curved and either mounted on a plastic handle (disposable) or can be fixed with metallic handle. Use: It is used to make tunnel incision in the sclera and cornea for phacoemulsification, manual small incision cataract surgery (SICS), and sutureless trabeculectomy. + + +Fig. 26.37 + +VII. Scissors +1. Plain straight scissors (ringed) (Fig. 26.38). It is a fine pointed scissors with straight sharp cutting blades. Use: It is used to cut conjunctival sutures, eyelashes, and muscles. + + + + + + + + +Fig. 26.38 +2. Plain curved scissors (ringed) (Fig. 26.39). It is a fine pointed scissors with curved, sharp cutting blades. Use: It is used to cut and undermine conjunctiva in various operations and to undermine skin during operations on lids and lacrimal sac. +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 599 + +the arms. The blades are kept apart, making V-shape, by spring action. Use:It is used to perform iridectomy, iridotomy and to cut the prolapsed form vitreous and pupillary membrane. + + + + + +Fig. 26.39 +3. Tenotomy scissors or strabismus scissors (Fig.26.40). They are plain straight or curved scissors with blunt ends. Uses: (i) To cut the extraocular muscles during squint surgery and enucleation operation. (ii) To separate the delicate tissues without damaging the surrounding area in oculoplastic operations and squint surgery. + + + + + + + + + +Fig. 26.40 +4. Corneal scissors or section enlarging scissors (Fig. 26.41 A and B). They are fine curved scissors. Their cutting blades are kept apart by spring action. They are available in various shapes and sizes. The universal corneal scissors can be used for both sides while right and left curved corneal scissors are separated for the two sides. Uses: (i) These are used to enlarge corneal or corneoscleral incision for conventional intra capsular and extra capsular cataract extraction techniques (sparingly performed procedures nowadays) of cataract surgery. (ii) To enlarge corneal incision in keratoplasty operation. (iii) To cut the scleral and trabecular tissue in trabeculectomy. (iv) It can also be used for cutting and undermining conjunctiva in various operations. + + + + +Fig. 26.41A + + + + +Fig. 26.41B +5. de Wecker’s scissors (Fig. 26.42). They are fine scissors with small blades directed at right angles to + +Fig. 26.42 +6. Spring scissors (Westcott’s) (Fig. 26.43). They are stout scissors available with straight or curved blades with sharp or blunt tips. The blades are kept apart by spring action. Use: They are used as a handy alternative to plain straight and plain curved ringed scissors for cutting and undermining conjunctiva in various operations and to cut sutures. + + + +Fig. 26.43 +7. Vannas scissors (Fig. 26.44). These are very fine delicate scissors with small cutting blades kept apart by spring action. The blades may be straight or curved. Uses: (i) These are used for cutting anterior capsule of the lens in extra capsular surgery and for cutting 10–0 nylon sutures. (ii) For cutting inner scleral flap in trabeculectomy. (iii) For doing pupillary sphincterotomy. (iv) For performing iridectomy. (v) For cutting pupillary membrane. + + + + +Fig. 26.44 +8. Enucleation scissors (Fig. 26.45). They are large, stout and strong scissors having curved sharp blades with blunt ends. Use: They are used to cut the optic nerve during enucleation operation. + + + + +Fig. 26.45 + +VIII. Clamps +1. Lid clamp or entropion clamp (Fig. 26.46). It consists of a D-shaped plate opposed by a U-shape rim, which when tightened with the help of a screw, clamps the tissues. Two clamps are required; one can be used for right upper and left lower lid and the second for right lower and left upper lid. While applying the lid clamp, the plate is kept towards the conjunctival side, the rim on the skin side, and the handle is always situated on the temporal side. +600 Section Vi Practical Ophthalmology + + +Advantage over lid spatula: It is a self-retaining instrument and does not need an assistant to hold. Disadvantages: (i) Operative field is less. (ii) Pressure necrosis can occur if fitted tightly. Uses:It is used in lid surgery, e.g., entropion, and ectropion corrections. It protects the eyeball, supports the lid tissue and provides haemostasis during surgery. + + + + + + + +Fig. 26.46 +2. Chalazion clamp (Fig. 26.47). It consists of two limbs like a forceps, which can be clamped with the help of a screw. The tip of one limb is flattened in the form of round disc while the tip of the other arm has a small circular ring. Usually, the flat disc is applied on the skin side and ring on the conjunctival side of the chalazion. However, rarely when the chalazion points towards the skin, the ring side is applied to the skin. Use: To fix the chalazion and achieve haemostasis during the incision and curettage operation. + + + + + +Fig. 26.47 +3. Ptosis clamp (Fig. 26.48). It is like a forceps with J-shaped ends having internal serrations. The clamp has a locking mechanism. Use: To hold levator palpebrae superioris muscle during ptosis surgery. + + +Fig. 26.49 +2. Wire vectis (Fig. 26.50). It is a wire loop attached to a metallic handle. Use: It is used to remove subluxated lens and anteriorly dislocated lens in ICCE technique and the nucleus in ECCE technique. + +Fig. 26.50 +3. Irrigating wire vectis (Fig. 26.51). It is a modified vectis in which the loop is made of a thick hollow wire. The anterior end of the loop has three 0.3 mm openings. The posterior end of the loop is continuous with a hollow handle. The posterior end of the hollow handle has a hub similar to that of a hypodermic needle to which is attached a syringe or infusion set. The size of the loop of the vectis is variable. In commonly used wire vectis, the loop is 4 mm in width and about 8–9 mm in length. The superior surface of the loop has a slight concavity to accommodate the lens nucleus. Use: Irrigating wire vectis is most commonly used to deliver nucleus in the manual small incision cataract surgery (SICS) and in conventional ECCE by hydro expression or visco expression technique. + + + + +Fig. 26.51 +4. Two-way irrigation and aspiration cannula (Fig.26.52). It is available in various designs, commonly used are Simcoe’s classical or reverse cannula. Uses: (i) For irrigation and aspiration of the lens matter in extracapsular cataract extraction. (ii) +Aspiration of hyphaema. + + + + + + + +Fig. 26.48 + + +IX. Additional instruments for cataract surgery +1. Lens spatula (Fig. 26.49). It is a flat metallic handle with tiny spoon-shaped ends. It is used to apply counter-pressure at 12 O’clock position during expression of nucleus in extra capsular cataract extraction. In the era of ICCE, it was used in a similar way to extract cataractous lens in Smith’s technique. + + + +Fig. 26.52 + +5. Iris repositor (Fig. 26.53). It consists of a delicate, flat, malleable, straight or bent blade with blunt edges and tip attached to a handle. Uses: (i) To reposit the iris in the anterior chamber in any intraocular surgery.(ii) To break synechiae at the pupillary margin. +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 601 + + + + +Fig. 26.53 + +X. Additional instruments for intraocular lens implantation +For lOL implantation, the cataract surgery set should contain the following basic additional instruments: 1. IOL holding forceps (Fig. 26.54). It is a spring action forceps with short, blunt and curved blade shaving smooth edges and tips with platform (no teeth or serrations). Use:To hold optic of non-foldable PMMA IOL during implantation. + + + + +Fig. 26.54 +2. Kelman-McPherson forceps (Fig. 26.55). These are fine forceps with bent limbs. Uses: (i) To hold the superior haptic of IOL during its placement. (ii) To tear-off the anterior capsular flap in ECCE. (iii) Can be used for suture tying. + + + +Fig. 26. 55 +3. Sinskey hook or IOL dialer(Fig. 26.56). It is a fine but stout instrument with a bent tip. The tip engages the dialing holes of the IOL. Uses: (i) It is used to dial the PMMA non-foldable IOL for proper positioning in the capsular bag or ciliary sulcus. (ii) It can also be used to manipulate the nucleus in phacoemulsification surgery. Nucleus manipulation may be in the form of nucleus rotation in the capsular bag, cracking of the nucleus and feeding of the nuclear fragments into the phaco tip. + + +Fig. 26.56 +4. Hydrodissection cannula (Fig. 26.57). It is a single bore 25G, 27G or 30G cannula with a 45° angulation at about 10 to 12 mm from the free end. The tip at the free end can be flattened or bevelled. Use: It is used to perform hydro dissection (separation of cortex from the posterior capsule) and hydrodelineation (separation of cortex from the nucleus) in phacoemulsification and manual SICS. This cannula is attached to the syringe carrying irrigating fluid. For hydrodissection its tip is introduced beneath the anterior capsular margin after capsulorhexsis and fluid is injected to obtain subcapsular dissection. + + + + + +Fig. 26.57 +5. Chopper (Fig. 26.58). The chopper is a fine instrument resembling sinskey hook in shape. The inner edge of the bent tip is cutting and may have different angles. Use: It is used to split or chop the nucleus into smaller pieces and also for nuclear manipulation in phacoemulsification surgery. + + +Fig. 26.58 +6. Ring capsule polisher or posterior capsule polishing curette (Fig. 26.59). It consists of a long handle and a bent slender neck. The tip of the instrument has a tiny circular ring. Use: It is used to clear and polish the posterior lens capsule to make it more clear in the extracapsular cataract surgery. It is specially used when a plaque or sticky cortex is adhered to the posterior capsule. + +Fig. 26.59 + +XI. Additional instruments for glaucoma surgery +1. Scleral punch (Fig. 26.60). It is similar in shape to corneal scissors with spring action mechanism. Its one blade is sharp and thick which presses into the second blade which is a hollow rectangular frame. Use: To perform punch sclerectomy during glaucoma surgery. + + + + + + + + +Fig. 26.60 +2. Kelley’s punch (Fig. 26.61). It consists of two blades. The inner larger blade is a stout thin rod with a cup like depression having sharp margins and facing backward. The outer smaller blade is a hollow tube which slides with a spring mechanism around the inner blade. While in use during trabeculectomy operation, its punch cuts the posterior lip of the anterior chamber entry site (see page 255). Use: It is used to punch out trabecular tissue in conventional as well as sutureless trabeculectomy operation. +602 Section Vi Practical Ophthalmology + + + + + +Fig. 26.61 + +XII. Additional instruments for lid surgery +1. Chalazion scoop (Fig. 26.62). It has a small cup with sharp margins attached to a narrow handle. Use: To scoop out contents of the chalazion during incision and curettage. + +4. Bone punch (Fig. 26.67). It consists of a stout spring handle and two blades attached at right angle. The upper blade has a small hole with a sharp cutting edge. The lower blade has a cup-like depression. Use: It is used to enlarge the bony opening during DCR operation by punching the bone from margins of the opening. Carelessness during this step can cause accidental damage to the nasal mucosa and the nasal septum. + + + +Fig. 26.62 +2. Lid spatula (Fig. 26.63). It is a simple metal plate having slightly convex surfaces at either end. Use: To protect the globe and support the lid during entropion, ectropion, ptosis and other lid surgeries. + + + + +Fig. 26.63 + +XIII. Additional instruments for lacrimal sac surgery (DCT and DCR) +1. Punctum dilator (Nettleship’s) (Fig. 26.64). It has a cylindrical corrugated metal handle with a conical pointed tip. Use: To dilate the punctum and canaliculus during syringing, probing, dacryocystography, DCT and DCR procedures. + +Fig. 26.64 +2. Lacrimal probes (Bowmam’s) (Fig. 26.65). These are a set of straight metal wires of varying thickness (size 0–8) with blunt rounded ends and flattened central platform. Uses: (i) To probe nasolacrimal duct in congenital blockage. (ii) To identify the lacrimal sac during DCT and DCR operations. + + +Fig. 26.65 +3. Lacrimal cannula (Fig. 26.66). It is a long curved hypodermic needle with blunt tip. Use: (i) For syringing the lacrimal passages. (ii) As AC cannula for putting air, tryphan blue dye, pilocarpine and balanced salt solution in the anterior chamber during intraocular surgery. + + + + +Fig. 26.66 + +Fig. 26.67 +5. Chisel (Fig. 26.68). It consists of a blade having a sharp-cutting straight edge with one surface bevelled. It has a long and stout handle. Use: To cut the bone during DCR and or bitotomy operations. + + +Fig. 26.68 +6. Hammer (Fig. 26.69). It is a small steel hammer attached to a corrugated handle. Use: To hammer the chisel during DCR and orbitotomy operations. + + + + +Fig. 26.69 +7. Lacrimul sac dissector and curette (Fig. 26.70). It is a cylindrical instrument, one end of which is a blunt-tipped dissector and the other end is curetted.Use: In lacrimal sac surgery. + + +Fig . 26.70 +8. Bone gouge (Fig. 26.71). It consists of a stout metallic handle, one end of which is longitudinally scooped. The edges of the scoop are sharp. Use: To smoothen the irregularly cut margins of the bone by nibbling small projecting bone and in DCR operation and in orbitotomy operation. + + + +Fig. 26.71 +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 603 + + +XIV. Additional instruments for enucleation and evisceration +1. Optic nerve guide (enucleation spoon) (Fig. 26.72). It is a spoon-shaped instrument with a central cleavage. Use: To engage the optic nerve during enucleation. + + + +Fig. 26.72 +2. Evisceration spatula (Fig. 26.73). It consists of a small but stout rectangular blade with slightly convex surface and blunt edges attached to a handle. Use: To separate out the uveal tissue from the sclera during evisceration operation. + + +Fig. 26.73 +3. Evisceration curette (Fig. 26.74). It consists of an oval or rounded shallow cup with blunt margins attached to a stout handle. Use: To curette out the intraocular contents during evisceration operation. + + +Fig. 26.74 + +STERILIZATION, DISINFECTION AND FUMIGATION +STERILIZATION AND DISINFECTION +It is a process which kills or removes all micro-organisms including bacterial spores from an article, surface or medium. It must be differentiated from disinfection which destroys pathogenic micro-organisms but does not kill or remove spores. +Sterilization can be accomplished by physical agents (viz. sunlight, heat, filtration and radiation) and chemical agents (such as alcohols, aldehydes, halogens, phenol, surface acting agents and gases). + +Methods +A. Heat sterilization +Both dry and moist heat can be used. + +Dry heat sterilization methods +1. Flaming. It can be used to sterilize points of forceps, hypodermic needles, tips of AC cannula and scraping spatulas. The instrument is held in a bunsen flame till it becomes red hot. +2. Incineration. It is used to destroy soiled dressings, beddings and pathological materials. +3. Hot air oven. It is the most commonly used method of sterilization by dry heat. It kills bacteria, spores and viruses. This method is employed to sterilize + + +instruments like forceps, scissors, scalpels, glass syringes, glassware, etc. The article must be double-wrapped and kept at 150° C for 1 hour or 180° C for 20 minutes. + +Moist heat sterilization methods +1. Boiling. It kills bacteria and viruses. Heavier metallic ophthalmic instruments, e.g., Bard-Parker handles, lid guards, etc. can be sterilized by boiling in water for 30 minutes. This method, however, blunts the cutting instruments. +2. Steaming. It kills most bacteria and viruses, but not spores. The instruments are placed on a shelf above the level of water and steamed for about 30 minutes. Most of the metallic instruments, e.g., scissors and knives can be sterilized by this method. +3. Autoclaving (steam under pressure). It is the most widely used method for sterilization. It is based on the principle that at boiling point of water, the vapour pressure equates the atmospheric pressure. So, if the pressure is increased, boiling point tends to rise, which increases the penetrating power of the steam. +Autoclaving at 134°C at 34 psi preserve for 3 minutes or 121°C under 15 lb/in2 pressure for 20 min. or at 116°C under 10 lb/in2 pressure for 40 min. kills bacteria, spores and viruses. This method is suitable for sterilizing various instruments, linen, glasswares, rubber goods, gowns, towels, gloves dressings and eyedrops. +In autoclaving, sterilization occurs due to the latent heat which is given out when steam condenses to water. Therefore, to sterilize effectively the steam must come into direct contact with the surface to be sterilized. +B. Chemical sterilization +l. Savlon. It comprises of cetavlon or cetrimide and chlorhexidine. Cetavlon is a surface active agent and chlorhexidine is a phenol. It is active against most Gram-positive organisms. It is used for cleaning/ preparation of skin. Scissors, catheters, knives, etc. may also be sterilized with it. +2. Spirit (95% alcohol). It kills bacteria and spores, but not viruses. It is mostly used with savlon. +3. Methylated spirit. It is 70% isopropyl alcohol. Schiotz tonometer can be sterilized by it. +4. Formaldehyde +i. Formalin chamber. 10% solution of formalin in has a marked bactericidal, sporicidal and some viricidal activity. It is suitable for cryoextractor probes and ophthalmoscopy lenses and heat +sensitive instruments. +604 Section Vi Practical Ophthalmology + + +ii. Formaldehyde gas. It may be used for fumigating wards, sick rooms and laboratories. But this gas is irritant and toxic when inhaled. +5. Glutaraldehyde (2%). It is available as ‘Cidex’ solution. It has a special activity against tubercle bacilli, fungi and viruses. It is mostly used for sterilising endoscopes because it has no damaging effect on the lenses. It can be safely used for catheters, face-masks, anaesthetic tubes and metal instruments. However, it is not suitable for silicone tubing. It is specially used to sterilise sharp instruments, as it does not affect the sharpness. In three hours, the instruments are free of pathogens and spores. Instruments should be thoroughly washed with sterile distilled water before use. +6. Hydrogen peroxide. 3% solution of H2O2 is used for sterilisation of applanation tonometers, prisms and +ophthalmoscopy lenses. It is specially active against AIDS and herpes viruses. +7. Ethylene oxide gas: Ethylene oxide (ETO) is a highly inflammable gas and is usually mixed with an inert gas like nitrogen or carbon dioxide. It denatures the protein molecules by alkylation in which hydrogen atom is replaced by a hydroxyl ethyl radical with in the protein molecule. When a sufficient number of proteins within molecules of micro-organisms are alkylated, death ensues. The process kills all micro-organisms including tubercular bacilli, other bacteria, spores and viruses. +Uses: Goniotomy lenses, indirect ophthalmoscopy lenses, OCR tubings, vitrectomy cutters, lens probes, diathermy leads, most disposable items and cryoprobes can be sterilized with it. +Procedure. The articles to be sterilized are put in the ETO chamber which is then heated up to 40– 60°C. Steam is introduced to rehumidify the load. (Moisture enhances diffusion of ETO). The ETO gas (400–1000 mg/l space) is then introduced from a cylinder. The gas is removed and the chamber and its contents are flushed with filtered air. Sterilization time may vary from 1 to 12 hours depending upon the absorbency of the load, temperature and air exchange rate. +8. Acetone. Use of acetone is a quick and cheap method of sterilising instruments. Instruments should be kept in acetone for 5 minutes and then thoroughly washed with sterile water before use. +(C) Radiation sterilization +1. Ionising radiations: These include X-rays,gamma-rays, cosmic rays. They are highly lethal to DNA and thus kill all types of micro-organisms. They can penetrate solids and liquids without raising the temperature appreciably (cold sterilisation). They are + +used for sterilising plastic syringes, swabs, catheters, tubings, etc. +2. Non-ionising radiatiom: They act as a form of hot air sterilization since they are absorbed as heat. They include the infrared rays which is used for rapid mass sterilisation of disposable syringes. +FUMIGATION OF OPERATION THEATRE Fumigation refers to disinfection of the operating room by exposure to the fumes of a vaporised disinfectant. Formaldehyde is an effective agent commonly used to sterilise the operating room. For optimum disinfection, formaldehyde fumigation is recommended fornightly as a routine and at the end of an operating session of a grossly infected case. +Method of fumigation involves following steps: +• Cleaning and scrubbing of the operating room is done thoroughly. +• Carbolisation of the floor is carried out after the cleaning. +• Sealingof all the apertures in the room is done with adhesive tape prior to fumigation leaving only one door open. +• Generation of formaldehyde is done by addition of +150 gm of potassium permanganate (KMnO4) to +280 ml of formalin in a steel bucket for every 1000 cubic feet of room volume. Alternatively, 500 ml of 40% formaldehyde in one liter of water is put into an electric boiler or in a large bowl placed on a electric hot plate with safety cut-out when dry on boiling. +• Closure and sealing of the door is done quickly. After formaldehyde vapour is generated the room should be left closed for 24 to 48 hours. +• Neutralisation of formaldehyde is then carried out with ammonium solution left in the operating room for a few hours. One liter of ammonium solution plus one liter of water is required to neutralize every liter of 40% formaldehyde used. +• Replacement of left out formalin with air. Subsequently, the room doors may be opened for a short period or the air-conditioning be switched on to replace the formalin with air. + +RELATED QUESTIONS +ANAESTHESIA FOR OCULAR SURGERY +How topical ocular anaesthesia is achieved? What are its indications? +Topical ocular anaesthesia is achieved by instillation of 2 to 4% xylocaine or 1% amethocaine, 4 times every 4 minute. +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 605 + + +Indications +• For minor procedures like removal of corneal foreign body, removal of stitches, etc. +• Along with retrobulbar block. +• Recently, phacoemulsification operation is being done under topical anaesthesia. +What are various techniques of facial block ana-esthesia? +• Van Lint’s block: Terminal branches of facial nerve are blocked by injecting 2.5 ml of anaesthetic solution in deeper tissues just above the eyebrows and just below the inferior orbital margin. +• O’Brien’s block: Facial nerve is blocked at the neck of mandible. +• Nadbath block: Facial nerve is blocked near the stylomastoid foramen. +• Atkinson’s block: Only superior branches of facial nerve are blocked by an injection at the inferior margin of zygomatic bone. +Where injection is made for retrobulbar block? +For a retrobulbar block, 2 ml of 2% xylocaine is injected into the muscle cone. +What are the effects of retrobulbar block? • Ciliary nerve and ciliary ganglion block • Ocular akinesia +• Ocular anaesthesia and analgesia • Dilatation of the pupil +• Ocular hypotony. +Enumerate complications of retrobulbar block. • Retrobulbar haemorrhage +• Globe perforation • Optic nerve injury +• Extraocular muscle palsies. +What is the technique of peribulbar block? +An anaesthetic solution, 6 to 9 ml (a mixture of 2% xylocaine and 0.5–0.75% bupivacaine) in a ratio of 2:1 with hyaluronidase 5 IU/ml with or without adrenaline 1:1 lac is injected into the peripheral orbital space. +What are the advantages of peribulbar block? • No separate facial block is required. +• Complications associated with retrobulbar block are almost eliminated. +OPHTHALMIC INSTRUMENTS AND EYE OPERATIONS +Usually, a student is asked to describe a particular ophthalmic instrument in reference to following aspects: +• Identification of the instrument • Methods of its sterilization + +• Uses of the instrument +• Advantages or disadvantages of the use of any particular instrument. +OPERATIONS FOR CATARACT EXTRACTION Name the instruments required for the basic intraocular surgery set. +The instruments required include superior rectus holding forceps, Stevens’ needle holder, artery forceps, plane forceps, curved ringed scissors, heat cautery or wet-field cautery, razor-blade fragment holder, corneoscleral suturing forceps, corneoscleral section enlarging scissors, iris forceps, deWecker’s iridectomy scissors, lens spatula, lens hook, anterior chamber cannula, iris repositor, spring action fine needle holder. +These instruments form the basic intraocular surgery set. +Name the additional instruments required for extracapsular cataract extraction. +Cystitome, Vannas’ scissors, McPherson’s forceps, two-way irrigation-aspiration cannula; posterior capsule polisher. +Name (pick up) the additional instruments required for an intraocular lens implantation. +Anterior chamber cannula for injecting viscoelastic substance, intraocular lens (implant) holding forceps, foldable IOL injector and intraocular lens dialer. +What are the advantages of ECCE over ICCE? +1. Extracapsular cataract extraction is a universal operation and can be performed at all ages, except when zonules are not intact. While ICCE cannot be performed below 40 years of age. +2. Posterior chamber IOL can be implanted after ECCE, while it cannot be implanted after ICCE. +3. Postoperative vitreous-related problems (such as herniation in anterior chamber, pupillary block and vitreous touch syndrome) associated with ICCE are not seen after ECCE. +4. Incidence of postoperative complications such as endophthalmitis, cystoid macular oedema and retinal detachment is much less after ECCE as compared to that after ICCE. +What are the advantages of ICCE over ECCE? +1. The technique of ICCE as compared to ECCE is simple, cheap, easy and does not need sophisticated microinstruments. +2. Postoperative opacification of posterior capsule is seen in a significant number of cases after ECCE. No such problem is there after ICCE. +606 Section Vi Practical Ophthalmology + + +3. ICCE is less time consuming and hence more useful than ECCE for mass scale operations in eye-camps. +Name the different techniques of extracapsular cataract extraction. +1. Discission or needling (obsolete) +2. Linear extraction or curette evacuation (obsolete) 3. Modern extracapsular cataract extraction (ECCE) 4. Small incision cataract surgery (SICS) +5. Lensectomy +6. Phacoemulsification. +What are the main steps of lens removal in ECCE operation? +1. Anterior capsulotomy 2. Removal of nucleus +3. Aspiration of the cortical lens matter. +Name the techniques of anterior capsulotomy 1. Can-opener technique +2. Linear capsulotomy (envelope technique) 3. Continuous circular capsulorhexis (CCC). +What is phacoemulsification? +Phacoemulsification is a technique of extracapsular cataract extraction in which after the removal of anterior capsule (by capsulorhexis), the lens nucleus is emulsified and aspirated with the probe of a phacoemulsification machine. +What are the advantages of phacoemulsification over the conventional ECCE operation? +1. Corneoscleral incision required is very small (3 mm). Therefore, sutureless surgery is possible with a self-sealing scleral tunnel incision. +2. Early visual rehabilitation of the patient. 3. Very less astigmatism. +What is femtosecond laser-assisted cataract surgery (FLACS)? +FLACS is the most recent technique of micro-incision cataract surgery (MICS) in which femtosecond laser is used to perform certain steps which include capsulotomy, primary and secondary clear corneal incisions, astigmatic arcuate incisions and nuclear fragmentation. +What are advantages of FLACS over conventional microphacoemulsification? +• Capsulotomy is precise, accurate and predictable. Especially useful in mature and hypermature cataracts and when premium IOLs are planned. +• Corneal incisions offer the advantages of decreased leakage, added stability, accuracy, and reproducibility. + +• Nuclear fragmentation with FSL, decreases the use of ultrasound energy and instrumentation and manipulation. This improves safety and decreases complications. +What are the main types of intraocular lenses (IOL)? The major classes of IOL based on the method of fixation in the eye are as follows: +1. Anterior chamber IOL, e.g., ‘Kelman multiplex (IOL)’. +2. Iris supported lenses e.g., Singh-Worst’s iris claw lens. +3. Posterior chamber IOL. +When and who performed the first successful intraocular implant operation? +Harold Ridley, a British ophthalmologist, per-formed the first IOL implantation on November 29, 1949. +Name a few preoperative complications of cataract operation. +1. Injury to cornea (Descemet’s detachment) 2. Accidental rupture of the lens capsule +3. Vitreous loss +4. Expulsive choroidal haemorrhage. +Name some early postoperative complications of cataract extraction. +1. Hyphaema 2. lris prolapse +3. Striate keratopathy +4. Flat (shallow) anterior chamber 5. Bacterial endophthalmitis. +What are delayed complications of cataract extraction? +1. Cystoid macular oedema (CME) 2. Retinal detachment (RD) +3. Epithelial in growth 4. After-cataract. +What are the types of after-cataract? +1. Thin membranous after-cataract (thickened posterior capsule). +2. Dense membranous after-cataract 3. Soemmerring’s ring after-cataract 4. Elschnig’s pearls. +Name the IOL-related complications. +1. Malpositions of the IOL, e.g., inferior subluxation (Sunset syndrome), superior subluxation (Sunrise syndrome), dislocation of IOL in the vitreous cavity (lost lens syndrome). +2. Toxic lens syndrome (IOL-induced iritis). +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 607 + + +What are the advantages of an IOL implantation over spectacle correction of aphakia? +1. No magnification of the object. +2. No problem of anisometropia in uniocular aphakia. 3. Elimination of aberrations and prismatic effect of +thick glasses. +4. Wider and better field of vision. 5. Cosmetically more acceptable. +What is postoperative management of cataract operation? +1. The patient is asked to lie quietly upon his/her back for about one hour and advised to take nil orally. +2. For mild to moderate postoperative pain, injection diclofenac sodium (Voveran) may be given intramuscularly. +3. In the morning after about 24 hours of operation, bandage is removed and the eye is inspected thoroughly for any postoperative complication. Under normal circumstances, eye is opened with the use of one drop of 1% cyclopentolate, one drop of antibiotic and steroid drops and tinted glasses are advised. +4. Antibiotic steroid eyedrops are continued for four times, three times, two times and then once a day for 2 weeks each. +5. Final spectacles are prescribed after about 8 weeks of operation. +What do you understand by primary and secondary IOL implantation? +Primary IOL implantation refers to the use of IOL during surgery for cataract, while secondary IOL is implanted to correct aphakia in a previously operated eye. +How will you calculate the power of posterior chamber IOL to be implanted? +The power of the IOL to be implanted can be calculated using keratometry and A-scan ultrasound. SRK formula commonly employed to calculate IOL power is as follows: +P = A–2.5L–0.9K; where P = IOL power in dioptres, A = specific constant of the IOL, L= axial length of the eyeball in mm and K= average keratometric reading. +IRIDECTOMY OPERATION +What is iridectomy and what are its types? Iridectomy is an abscission of a part of the iris. It is of the following types: +• Peripheral iridectomy • Key-hole iridectomy +• Broad or sector iridectomy. + +What are the indications of iridectomy operation? 1. Abscission of the prolapsed iris +2. For optical purposes (optical iridectomy) 3. As a part of glaucoma operation +4. For removal of foreign body, cyst or tumour of the iris. +What is iridotomy and how is it performed? Iridotomy means just incising a part of the iris. It can be performed by two methods: +• Surgical iridotomy • Laser iridotomy. +What are indications of iridotomy operation? +1. Laser iridotomy for primary narrow-angle glaucoma 2. Four-dot iridotomy for iris bombe. +SURGICAL PROCEDURES FOR GLAUCOMA +Name the various surgical procedures for glaucoma. 1. Peripheral iridectomy +2. Goniotomy +3. Trabeculotomy +4. Filtration operations +5. Seton operation (glaucoma valve operation) 6. Cycloablative procedures. +Peripheral iridectomy operation is performed for which type of glaucoma? +• Primary angle closure suspect (PACS) with positive provocative test. +• PAC suspect in fellow eye of patient with PAC glaucoma in other eye. +• Primary angle closure (manifest). • Primary angle closure glaucoma. +What are filtration operations for glaucoma? +In filtration operations, passage is made for the drainage of aqueous humour into the sub-conjunctival space. Trabeculectomy is presently the most frequently performed filtration surgery. Other filtration operations which are not performed now included: Elliot’s sclerocorneal trephining, punch sclerectomy, iridencleisis, Scheie’s thermal sclerostomy and cyclodialysis. +What are the indications of trabeculectomy operation? +1. Primary angle-closure glaucoma with peripheral anterior synechiae involving more than half of the angle. +2. Primary open-angle glaucoma. +3. Congenital and development glaucoma where trabeculotomy and goniotomy fail. +4. Selective cases of secondary open angle glaucoma and secondary narrow-angle glaucoma. +608 Section Vi Practical Ophthalmology + + +What are the advantages of trabeculectomy over other filtration operations? +1. Incidence of postoperative shallow or flat anterior chamber is very less. +2. Incidence of postoperative hypotony is very low. 3. Chances of postoperative infection through the +filtration bleb are low. +4. Quality of filtration bleb formed is good. +What is Seton operation? +In this operation, a valvular synthetic tube is implanted which drains the aqueous humour from the anterior chamber into the subconjunctival space. It is performed for neovascular glaucoma and intractable cases of primary and other secondary glaucomas where medical treatment and +conventional filtration surgery fail. +What are cycloablative procedures? +In these procedures, ciliary epithelium is destroyed to control the intraocular pressure. These procedures are used for absolute glaucoma. Commonly employed cycloablative procedures include: cyclocryopexy, cyclophotocoagulation and cyclodiathermy. +Cyclodialysis operation is useful in which type of glaucoma? +• Glaucoma in aphakes + +ENUCLEATION AND EVISCERATION OPERATIONS +What is enucleation operation? +It is complete excision of the eyeball. + +Enumerate indications of enucleation. +Absolute indications are: • Retinoblastoma +• Malignant melanoma + +Relative indications are: • Painful blind eye +• Mutilating ocular injury • Phthisis bulbi +• Anterior staphyloma +Indication for eye donation. Removal of eyes from the cadaver is presently the most common indication for enucleation. +What precautions should be taken while performing enucleation in a patient with retinoblastoma? During enucleation the longest possible piece of optic nerve should be excised. +What is evisceration operation? +It is removal of the contents of the eyeball leaving behind the sclera. Frill evisceration is preferred over + + +simple evisceration. In this, only about 3 mm frill of the sclera is left around the optic nerve. +What are the indications of evisceration? • Panophthalmitis +• Expulsive choroidal haemorrhage • Bleeding anterior staphyloma. + +How can the cosmetic appearance be improved after enucleation or evisceration operation? +For best results, an orbital implant should be implanted at the time of surgery and an artificial eye of plastic should be worn after about 2 weeks of surgery. A delay in the use of artificial eye may lead to a contracted socket. + +OPERATIONS ON EYELIDS +For important questions related to eyelid operations see pages 551-556. + +LACRIMAL APPARATUS OPERATIONS +Questions related to operations on the lacrimal apparatus are described on pages 556-558. + +LASERS AND CRYOTHERAPY IN OPHTHALMOLOGY +What are the properties of laser light? • Monochromaticity +• Coherence • Collimation + +Name the different types of lasers and their mechanism of action. +Type of laser Mechanism of action Argon Photocoagulation Krypton Photocoagulation Diode Photocoagulation Frequency doubled +Nd-YAG Photocoagulation Nd-YAG Photodisruption Excimer Photoablation +Enumerate uses of argon/diode laser. In glaucoma: +1. Laser trabeculoplasty for primary open-angle glaucoma. +2. Laser goniopuncture for developmental glaucoma. +3. Laser iridotomy for narrow-angle glaucoma. +4. Cyclophotocoagulation for absolute glaucoma. + +In lesions of retina: +1. Diabetic retinopathy 2. Eales’ disease +3. Coats’ disease +Chapter 26 Ophthalmic Instruments and Operative Ophthalmology 609 + + +4. Sickle-cell retinopathy +5. Exudative age-related macular degeneration. +What are the therapeutic uses of Nd-YAG laser? 1. Capsulotomy for thickened posterior capsule. 2. Membranectomy for pupillary membranes. +What are therapeutic applications of excimer laser? 1. LASIK for correction of refractive errors. +2. Photorefractive keratectomy (PRK) for correction of myopia and hypermetropia. +3. Phototherapeutic keratectomy (PTK) for corneal diseases such as band-shaped keratopathy. +Describe the laser treatment for diabetic retinopathy. Photocoagulation by frequency doubled Nd-YAG laser (532 nm) is employed as follows: +1. Panretinal photocoagulation (PRP) is indicated in severe cases of preproliferative and proliferative diabetic retinopathy. +2. Focal laser burns are applied in the centre of the hard exudate’s ring in focal exudative maculopathy. +3. Grid pattern laser burns are applied in diffuse exudative maculopathy. +What is femtosecond laser? Enumerate its applic-ations. +A femtosecond laser uses an infrared beam of light to precisely separate the tissues through a process called photo-disruption by generating pulses as short as one-quadrillionth of a second (10–15 = femtosecond). It has a wavelength of 1053 nm and is based upon the technology whereby focused laser pulses divide material at the molecular level without transfer of heat or impact to the surrounding tissue. Uses of femtosecond laser include: +• Creation of a corneal flap for LASIK +• Creation of corneal tunnels for implanting intracorneal ring implants + +• Arcuate incisions to correct astigmatism • Corneal keratoplasty incisions +• Femtosecond laser assisted cataract surgery (FLACS). + +What do you mean by cryopexy? +Cryopexy means to produce tissue injury by application of extremely low temperature (–100° C to –40° C). This is achieved by a cryoprobe from a cryo-unit. + +On what principle is the working of a cryoprobe based? +Working of a cryoprobe is based on the Joule Thom-pson principle of cooling. + +Which gas is used in a cryo-machine? +The cryounit uses freon, nitrous oxide or carbon dioxide gas as a cooling agent. + +Enumerate the applications of cryo in ophthalmology. 1. Lids: (i) cryolysis for trichiasis, (ii) cryotherapy for warts and molluscum contagiosum, (iii) cryotherapy for basal cell carcinoma and +haemangioma. +2. Conjunctiva: Cryotherapy for hypertrophied papillae of vernal catarrh. +3. Lens: Cryoextraction of the cataractous lens by ICCE technique was done in olden days (not done nowaday). +4. Ciliary body: Cyclocryopexy for absolute glaucoma and neovascular glaucoma. +5. Retina: (i) Cryopexy is widely used for sealing retinal breaks in retinal detachment, (ii) Prophylactic cryopexy to prevent retinal detach-ment in certain prone cases, (iii) Anterior retinal cryopexy (ARC) for neovascularization and, (iv) Cryotreatment of retinoblastoma. + +Index + + + + + + + +A + +Abnormal retinal correspondence, 342, 562 Abrasion, corneal, 428 +Acanthamoeba keratitis, 112 Accommodation, 45-49 +amplitude, 47 anomalies, 47 insufficiency of, 48 paralysis of, 48 spasm of, 49 +Acetazolamide, 452 Achromatopsia, 330 +Acne rosacea, keratitis, 117 +Acquired immune deficiency syndrome (AIDS), 470 Acute multifocal placoid pigment epitheliopathy, 170 Acyclovir, 447 +Adaptation-dark, 16 Adenocarcinoma, 400 Adie’s pupil, 317 +Advanced surface ablation, 38 Afibercept, 296 +Age-related cataract, 187 +corneal degenerations, 123 macular degeneration, 295 +Amaurosis, 331 Amblyopia, +congenital, 331 ethyl alcohol, 320 ex anopsia, 342 +hysterical blindness, 332 methyl alcohol, 320 quinine, 322 +tobacco, 320 Amblyoscope major, 352 Ametropia, 34 Aminoglycosides, 445 Amoxycillin, 445 Amphotericin B, 448 Ampicillin, 445 +Amplitude of accommodation 47, 583 Anaesthesia, ocular surgery, 591-593 Anatomy of +angle of anterior chamber, 219 + + +anterior chamber, 3 ciliary arteries, 148-149 ciliary body, 147 conjunctiva, 59 +cornea, 95 +extraocular muscles, 336 eyeball, 3 +iris, 146 +lacrimal apparatus, 386 lens, 179 +lids, 362 +optic disc, 263 +optic nerve, 310, 312, 314 ora serrata, 264 +orbit, 401 retina, 263 sclera, 140 uveal tract, 146 +visual pathway, 4,310 vitreous, 257 +Anderson’s criteria, 517 Angiography, fluorescein, 517 Angiomatosis, retinae, 309 Angle kappa, 31, 344 +Angular bacterial conjunctivitis, 66 Aniridia, 149 +Aniseikonia, 45 Anisocoria, 317 Anisometropia, 44 Ankyloblepharon, 377 +Ankylosing spondylitis, 168 Annular scleritis, 143 Annular synechia, 155 Anomaloscope, Nagel’s, 331 Anterior chamber +anatomy of, 3 angle, 219 examination, 503 +flat or shallow postoperative, 213 Anterior embryotoxon, 97 +Anterior ischaemic optic neuropathy, 321 +Antibacterial agents, 444 Antifungal agents, 448 Antiglaucoma drugs, 449-453 +612 Comprehensive Ophthalmology + + +Anti VEGF, 272, 281, 458 Antiviral agents, 446 Aphakia, 37, 187 Applanation tonometer, 511 Aqueous flare, 155 Aqueous humour, 219 +drainage, 220 +nature and formation/ production, 221 +Aqueous veins, 221 +Arcus senilis and juvenilis, 122 +Argon laser trabeculoplasty, 237, 550 Argyll Robertson pupil, 317 Argyrosis, 91 +Arlt’s line, 69 Arteries, 5 Astigmatic fan, 577 Astigmatism, 42 +against the rule, 42 bioblique, 42 +compound hypermetropic, 43 compound myopic, 43 irregular, 44 +mixed, 43 regular, 43 +simple hypermetropic, 43 simple myopic, 43 +with the rule, 42 +Atopic keratoconjunctivitis, 82 Atropine, 104, 121, 156, 572 Atropine bulbi, 157, 247 +Auto refractometry, 574 Aqueous outflow pump, 222 Axenfeld-Reiger syndrome, 228 Axes of the eye, 31 +Azelastine, 81, 83, 456 + +B + +Basal cell carcinoma conjunctiva, 94 lids, 384 +Band keratopathy, 123 Behcet’s disease, 168 Bell’s phenomenon, 380 Benedikt’s syndrome, 334 Bergmester’s papilla, 267 Berlin’s oedema, 431 +Best’s disese, 291 +Beta-adrenergic blockers, 450 Binocular loupe, 567 Binocular vision, 342 +anomalies of, 342 grades of, 341 +Bird-shot retinochoroidopathy, 170 Bitot’s spots, 468 + +Bjerrum’s scotoma, 233 screen, 513 +Blepharitis, 365 squamous, 366 ulcerative, 365, 552 +Blepharophimosis syndrome, 379 Blepharospasm, 378 +Blindness +cataract, 480, 483 causes, 478 childhood 479, 483 colour, 329 corneal, 484 cortical, 331 definition, 475 glaucoma, 484 hysterical, 332 magnitude, 476 +prevention, 477-488 snow, 119 +Blood vessels of eye, 5 Blue sclera, 144 Bowman’s membrane, 96 Brown’s syndrome, 357 Bruch’s membrane, 148 Buphthalmos, 226 +Burns +chemical, 439 thermal, 440 +Burow’s operation, 554 +Busacca’s nodules, 153, 156, 504, 524 + +c + +Calcific corneal degeneration, 122 Campimetry, 513 +Canal of Cloquet, 258 Canal of Schlemm, 220 Candidiasis uveitis in, 166 Capsulotomy, 201, 203 +anterior, 201, 203 +posterior capsulorhexis, 206 Carbonic anhydrase inhibitors, 453, 473 Carcinoma +of conjunctiva, 92 of lids, 384 +Caruncle, 61 Cataract, 181-215 +acquired, 182, 187 after, 210, 214 anterior capsular, 183 black, 190 +capsular, 183 complicated, 194 +concussion, rosette-shaped, 430, 506 +Index 613 + + +congenital, 185, 186 coronary, 185 cupuliform, 189 developmental, 186 diabetic, 193 electric, 195 +etiological classification of, 182 extraction, extracapsular, 198, 201 galactosaemic, 193 +implant surgery of, 207, 210 intracapsular extraction of, 198, 200 incipient, 189 +intumescent, 189 irradiation, 195 lamellar, 184 mature, 189 metabolic, 193 +morgagnian,189, 190 morphological classification of, 182 myotonia dystrophica, 183 +nuclear, 184 parathyroid tetany, 193 +phacoemulsification, 198, 203 polar, 182 +posterior subcapsular, 187, 189 punctate, 184 +reduplicated, 184 rosette, 430 secondary, 214 senile, 187 SICS, 198-204 sunflower, 194 toxic, 195 traumatic, 429 +treatment of, 186, 195 unilateral, treatment of, 187 zonular, 184 +Cataracta brunescens, 190 Cauterisation, corneal ulcer, 105 Cavernous sinus, 411 +Cavernous sinus thrombosis, 411 Central retinal artery occlusion, 269 Central serous choroioretinopathy, 292 Cephalosporins, 445 +Chalazion, 368 clamp, 553, 600 +Chalcosis, 434, 564 Chemical injuries, 438 Chemosis, conjunctival, 90 Cherry-red spot, 269, 431 +Chiasmal syndrome, 313, 335 Chlamydia, 61 +Chloroquine maculopathy, 291 Choriocapillaris, 148 +Choroid, 148 + + +Choroidal atrophy, 174 coloboma, 149 +degeneration, 174 detachment, 213 haemorrhage, expulsive, 213 melanoma, 174 +rupture, 430 Choroiditis, 162 +anterior, 162 central, 162 diffuse, 163 disseminated, 163 juxtapapillary, 162 syphilitic, 164 treatment, 163 tubercular, 163 +Chromatic aberrations, 32 Ciliary body, 147 +anatomy of, 147 injury, 564 +tumours of, 174, 177 Ciliary ganglion, 6 Ciliary muscle, 147 Ciliary processes, 148 Ciliary staphyloma, 144 +Circle of least diffusion, 43 Coats’ disease, 285 Colloid bodies, 288, 508 Coloboma +fundus, 266 iris, 149 lens, 218 lid, 364 +optic disc, 266 uveal tract, 149 +Colour +blindness, 329 sense, 18 vision, 18, 329 testing of, 330 +Commotio retinae, 431 Concretions, 69 Cones, 264 Confrontation test, 512 Conical cornea, 131 +Conjunctiva/conjunctival anatomy of, 59 chemosis, 90 congestion, 90 +cysts, 92 +degenerative conditions, 86 discoloration of, 91 ecchymosis, 90 examination, 499 +614 + +hyperaemia, 89 oedema, 90 pinguecula, 86 pterygium, 87 tumours, 92 xerosis, 91, 468 +Conjunctivitis +acute haemorrhagic, 76 allergic, 78 +atopic, 82 +angular bacterial, 66 bacterial, 62 chlamydial, 67 follicular, 73 +giant papillary, 82 granulomatous, 78 inclusion, 72 infective, 61 membranous, 62 mucopurulent, 63 phlyctenular, 83 purulent, 64 +pseudomembranous, 65 simple chronic, 65 vernal, 79 +viral, 73 +Consensual light reflex, 315, 505 Contact dermatoconjunctivitis, 85 Contact lenses, 50 +Contusional injuries, 428 Convergence +insufficiency, 347 near point, 346 +Corectopia, 149 Cornea/corneal +abrasion, 495 anatomy, 95 +congenital anomalies, 97 degenerations, 122 dystrophies, 124-131 epikeratophakia, 38 examination, 501 +facet, 134 fistula, 103 guttata, 130 histology, 95 inflammation, 98 +keratoplasty, 133 leucoma, 134 macula, 134 metabolism, 97 nebula, 133 oedema, 133 opacity, 133 perforation, 100, 103 + + +Comprehensive Ophthalmology + + +physiology, 14, 95 sensitivity, 502 staining, 502 vascularization, 135 xerosis, 468 +Corneal dystrophies 124-131 +congenotal hereditarty endothelial, 131 congenital stromal, 129 +epithelial basement membrane, 125 epithelial recurrent erosion, 126 Fuch’s endothelial, 130 +granular, 128 lattice, 128 macular, 129 +Reis- bucklers, 127 Corneal ulcer, 98 +bacterial, 98 complications, 103 dendritic, 108 fungal, 106 healing, 100 hypopyon, 102 marginal, 106 Mooren’s, 116 Neurotrophic, 114 mycotic, 106 perforation of, 103 serpiginous, 116 treatment of, 103 trophic, 114 +viral, 107 +Coronary cataract, 185 Cortical blindness, 331 Corticosteroids, 453 Cover test, 345, 350 +Craniofacial dysostosis, 407 Craniosynostosis, 407 Cross-cylinder, 577 Cryotherapy, 463 Cryptophthalmos, 364 Cupping of disc +glaucomatous, 231 physiological, 232 +Cupuliform cataract, 189 Cyclitis, 150 Cyclocryopexy, 256 Cycloplegia, 572 Cycloplegics, 104, 159, 572 Cyst, +conjunctival, 92 tarsal, 368 +Cysticercus in conjunctiva, 92 Cystoid macular oedema, 214, 294 Cytomegalovirus retinitis, 166 +Index 615 + + +D + +Dacryoadenitis, 398 Dacryocystectomy, 395 Dacryocystitis, 392-395 Dacryocystography, 395 Dacryocystorhinostomy, 396 +conventional, 396 endonasal, 397 +Dacryopes, 399 +Dalen-Fuch’s nodules, 437 Dalrymple’s sign, 414 +Day blindness, 329 Deep keratitis, 120 Defective vision +causes, 494 Degenerations +conjunctival, 87 corneal, 122 macular, 295 retinal, 287-290 uveal tract, 173 +Demyelinating diseases, 335 Dendritic ulcer, 108 Dermoids +conjunctival, 93 orbital, 417 +Dermo-lipoma, (lipodermoid) conjunctival, 92 Descemetocele, 96 +Descemet’s membrane, 96 Detachment of +cilio-choroid, 213 retina, 298 vitreous, 258 +Deuteranopia, 330 Development of +eyeball, 8-13 +ocular structures, 10-12 Deviation, +primary, 354 secondary, 354 +Devic’s disease, 335 Diabetic +cataract, 193 retinopathy, 276 +Diffraction of light, 32 Dilator pupillae, 147 Diplopia, 343, 351, 354, 495 Disciform +keratitis, 109 +sub-retinal scarring macula, 295 Distichiasis, 371 +Doyne’s honeycomb dystrophy, 508 Dry eye, 389 +Duane’s retraction syndrome, 357 + + +Dua’s layer, 96 Duochrome test, 578 Dystrophies +corneal, 124 retinal, 287 + +E + +Eales’ disease, 268 Ecchymosis, conjunctival, 90 Ectopia lentis, 215, 218 Ectropion of lid, 374 +cicatricial, 374 involutional, 374 paralytic. 374 +Edinger-Westphal nucleus, 7 Electromagnet, 436 +Electro-oculography, 518 Electroretinogram, 519 Elschnig’s pearls, 214 Emmetropia, 34 +Encephalofacial angiomatosis, 309 Endophthalmitis, 170 Enophthalmos, 406 +Entropion, 371 cicatricial, 371 congenital, 371 senile, 372, 373 spastic, 379 +Enucleation, 307 Epicanthus, 364 +Epidemic keratoconjunctivitis, 74 Epikeratophakia, 38 +Epiphora, 390 Episcleritis, 141 +Errors of refraction, 34-45 astigmatism, 42 hypermetropia, 34 myopia, 38 +Esophoria, 344 +Esotropia concomitant, 348 Evisceration of eyeball, 173 Examination of eye +anterior chamber, 503 conjunctiva, 499 cornea, 501 +external eye, 497 field of vision, 511 fundus oculi, 507 iris, 503-504 +lacrimal apparatus, 499 lens, 505 +lid, 497 +oblique illumination, 566 pupil, 504-505 +616 + + +sclera. 501 slit lamp, 588 +Excimer laser, 42 Exophoria, 344 Exophthalmometry, 405 +Exophthalmos (Proptosis), 403 bilateral, 404 endocrinal,404 +pulsating, 404 thyrotoxic, 404 thyrotropic, 404 unilateral, 404 +Exotropia, concomitant, 349 Exposure keratopathy, 115 Eyeball +anatomy of, 3 development of, 7-13 dimensions of, 3 +Eye banking,487 Eye camps, 486 + +F + + +Comprehensive Ophthalmology + + +Fundus examination, 507 +posterior fundus contact lens, 589 Fungal corneal ulcer, 106 + +G + +Galactosaemia, cataract, 193 Giant papillary conjunctivitis, 82 +Glaucoma progression analysis, 234 Glaucoma, +absolute, 247 +angle closure, 239-247 aphakic, 251 capsulare, 250 +chronic simple, 228 congenital/developmental, 225 infantile, 225 +inflammatory, 160, 249 juvenile, 225 +medical therapy of, 236 neovascular, 250 normal tension, 239 + +Faden operation, 358 +Far point of eye (punctum remoturn), 47 Farnsworth-Munsell test, 330 +Fasanella-Servat operation, 381 Favre-Goldmann syndrome, 291 Femtosecond laser, 205, 462 Femto-LASIK, 53 +Femto-assisted cataract surgery, 205 Field of vision, 511 +Fincham’s test, 244 Fixation, eccentric, 351 Fleischer’s ring, 194 +Fluorescein angiography, 517 Fluoroquinolones, 446 Fogging technique, 578 Follicular conjunctivitis, 68 Foreign body +chalcosis, 434 diagnosis, 435 extraocular, 427 intraocular, 433 removal, 427 siderosis, 434 +Form sense, 17 Foster Fuch’s spot, 41 Fovea central is, 265 +Foville’s syndrome, 335 Frontal nerve, 5, 110 +Fuch’s corneal dystrophy, 130 Fuch’s heterochromic +iridocyclitis, 169 Fumigation, 604 + +open angle, 228 phacolytic, 193, 248 phacomorphic, 248 pigmentary, 250 postinflammatory, 160, 249 primary, 228, 239 secondary, 247-253 steroid induced, 251 surgical procedures, 253 +Glaucomatocyclitic crisis, 169 Glioma, optic nerve, 419 +Goldmann three-mirror contact lens, 589 Gonioscopy, 568 +Goniotomy, 227 +Gonococcal conjunctivitis, 64, 151 Granular corneal dystrophy, 128 Granulomatous +conjunctivitis, 78 uveitis, 150, 156 +Graves’ ophthalmopathy, 414 + +H + +Haemangioma choroidal, 174 lids, 383, 384 orbit, 418 +Haemorrhage choroidal, 213 expulsive, 213 subhyaloid, 282 vitreous, 260 +Halos +Index 617 + + +cataract, 191 glaucoma, 244 +Hamarlopia, 329 +Hand-Schuller-Christian disease, 422 Hassal-Henle bodies, 122 +Head injury, ocular signs, 335 Hemianopia, 313 +binasal, 313 bitemporal, 313 homonymous, 315, 509 +Hering’s law, 339 +Herpes simplex keratitis, 107 +Herpes zoster ophthalmicus, 110, 166 Hess screen, 356 +Heterochromia iridis, 149 iridurn, 149 +Heterochromic iridocyclitis, 169 Heterophoria, 344 +esophoria, 344 exophoria, 344 +Histiocytosis-X, 422 Hordeolum +external, 367 internal, 368 +Horner’s syndrome, 379 Hruby’s lens, 588 Hutchinson’s pupil, 335 Hyperlacrimation, 388, 390 Hypermetropia, 34 +Hypertensive choroidopathy, 274 Hypertensive retinopathy, 273 Hyphaema, 213, 429 +Hypopyon ulcer, 98 Hysterical blindness, 332 + +I + +Idoxuridine eye drops, 534 Immunomodulators, 455 Inclusion conjunctivitis, 73 InfantiIe glaucoma, 225 +Infantile nystagmus syndrome, 359 Inflammations of +conjunctiva, 61 cornea, 98 orbit, 408 retina, 267 sclera, 141 uvea, 150 +Injuries, ocular chemical, 438 choroid, 430 +closed globe, 428, 431 contusion, 426 + +cornea, 428 electrical, 440 globe rupture, 431 +iris and ciliary body, 429 lens, 430 +mechanical, 426 open globe, 432 optic nerve, 432 perforating, 422 radiational, 440 retina, 431 sclera, 429 thermal, 440 vitreous, 430 +Instruments, ophthalmic, 591-603 Interphotoreceptor matrix, 264 Interstial keratitis, 120 +cogan, 121 syphilitic, 121 tubercular, 121 +Intraocular foreign bodies, 433 Intraocular lens implantation, 207 Intraocular pressure, 223 +measurement of, 307, 509 Iridectomy, 603 +for glaucoma, 251 optical, 132 technique of, 251 +Irideremia (Aniridia), 504 +Iridocorneal endothelial syndrome, 248 Iridocyclitis, 148 +acute, 156 chronic, 534 +granulomatous, 154, 165 heterochromic, 153 hypertensive, 157, 250 purulent, 564 +treatment, 159 Iridodialysis, 427 Iridodonesis, 37, 215, 500 Iridotomy, laser, 241, 607 Irrigating solution, 441 +Iris +anatomy, 144 antiflexion, 428 atrophy, 171 coloboma, 148 colour, 154 examination, 503 rupture, injury, 429 tumours. 178 +Iritis, 148 +Irradiation cataract, 195 Ishihara pseudo-isochromatic +charts, 330 +618 + +J + +Jackson’s Cross Cylinder, 577 Jaeger’s test types, 497 Jaesche-Arlt operation, 554 Jaw-winking ptosis, 379 Jones dye test, 392 Junctional scotoma, 313 +Juvenile idiopathic arthritis, 168 + +K + +Kaposi’s sarcoma, 471 Kayser-Fleischer’s ring, 434 Kerectasia, 134 +Keratic precipitate, 153, 502 Keratitis, 91-114 +acanthamoeba, 112 acne rosacea, 117 deep, 120 +dendritic, 108 disciform, 109 exposure, 115 filamentary, 120 geographical, 108 infective, 95 interstitial, 120 metaherpetic, 110 non ulcerative, 117 phlyctenular, 83 punctate, 117 purulent, 98 suppurative, 98 syphilitic, 121 Thygeson’s, 120 ulcerative, 95 +kerato-conjunctivitis sicca, 389 Keratoconus, 131 +Keratoglobus, 95, 132 Keratomalacia, 468 Keratometery, 575 Keratopathy +band-shaped, 123 bullous, 130, 207 filamentary, 120 lipoid, 122 +Keratoplasty, 136 Keratoprosthesis, 139 Keratotomy, radial, 52 Koeppe’s nodule, 153, 504 + +L + +Lacrimal apparatus +anatomy and physiology, 386-388 examination, 499 +gland, 386 + + +Comprehensive Ophthalmology + + +passage, 387 syringing, 394 tumours, 399 +Lacrimal nerve, 51 Lagophthalmos, 378 +Lasers in ophthalmology, 461 Lasik, 53 +Latanoprost, 453 +Lattice corneal dystrophy, 128 Lattice degeneration, 289 +Laurence-Moon-Biedl syndrome, 288 Leber’s disease, 317 +Lens (crystalline) anatomy, 179 capsule, 179 coloboma, 217 +congenital anomalies, 217 cortex, 180 +development of, 12 dislocation, 37, 211 displacement, 215 examination, 505 extraction, 199-214 injury, 430, 432 nucleus, 180 vesicle, 9 +Lensectomy, 206 Lenses (optical), 28 +cylinders, 42 spherical, 28 Lenticonus, 218 +Leucoma adherent, 134 corneal, 134 +Lids +abnormalities, congenital, 364 anatomy, 362 +inflammations, 365 tumours, 382 +Light reflex, 312, 505 Light sense, 16 +Lipodermoid, conjunctival, 93 Low vision aids, 42, 289 Lymphatic drainage, 7, 9 + +M + +Macropsia, 162 +Macular corneal dystrophy, 129 Macular degeneration, 295 Macular disorders, 291 Macular function tests, 197 Macular hole, 297 +Macular oedema cystoid, 214, 294 traumatic, 431 +Index 619 + + +Madarosis, 70, 498 Maddox rod test, 346 Maddox wing test, 347 Malingering, 331 Mannitol, 452 +Marcus Gunn pupil, 316 Marfan’s syndrome, 215 Marginal ulcer, 105 Medullated nerve fibres, 267 Megalocornea, 97 Meibomian glands, 363 Meibomitis, 366 +Melanoma-malignant of choroid, 174 +ciliary body, 177 conjunctiva, 94 iris, 178 +lids, 385 +MembranouS conjunctivitis, 62 Meningioma +primary orbital, 419 secondary orbital, 420 +Metamorphopsia, 162 +Methyl alcohol amblyopia, 320 Microincision cataract surgery, 205 Microcornea, 97 +Micropsia, 162 +Mikulicz’s syndrome, 399 Millard-Gubler’s syndrome. 334 Miosis, 504 +Miotics. 453 Mittendorf dot, 267 +Molluscum contagiosum, 370 Mooren’s ulcer, 116 Morgagnian cataract, 190 Movements ocular, 337 Mucopurulent conjunctivitis, 62 Mucormycosis, orbital, 410 Multiple sclerosis, 335 Muscles +antagonists, 339 extraocular, 336 synergists, 339 +Mycotic corneal ulcer, 106 Mydriasis. 504 +Mydriatics, 196 Myopia, 38 + +N + +Nagel’s anomaloscope, 331 Nasociliary nerve, 5 Natamycin, 448 +National Programme for Control of blindness (PCB), 480 + +near point of eye (Punctum proximum), 47 near reflex, 315 +Near vision, correction of, 579 Nebula, corneal, 133 +Nerves, 5, 96 Neurofibromatosis. 309 Neuromyelitis optica, 335 Neurotropic keratitis, 114 Niemann-Pick’s disease, 508 Night blindness. 329, 467, 494 Nodal point, 28 +Non-steroidal anti-inflammatory agents, 454 Nystagmoid movements, 361 +Nystagmus, 358 + +o + +Oblique illumination, 566 Oblique muscles, 336 Occlusio pupillae, 156, 505 Ocular examination, 496-509 +Ocular histoplasma syndrome, 165 Ocular hypertension, 238 +Ocular ischaemic syndrome, 286 Ocular movements, 337 Olopatidine, 79, 81 +Opaque nerve fibres, 267 Open angle glaucoma, 228 Ophthalmia +neonatorum, 76 nodosa,78 +Ophthalmic artery, 5 +Ophthalmic instruments, 593-603 Ophthalmic nerve, 5, 6 Ophthalmoplegia +external, 355 internal, 48 internuclear, 355 total, 355 +Ophthalmoscopy, 586 direct, 586 +distant-direct, 586 indirect, 587 +Optical abberations, 32 +Optical coherence tomography, 521 Optic-atrophy, 321 +Optic cup, 9 +Optic chiasma, lesions, 313 Optic disc, 507 +anatomy, 263, 307 coloboma. 266 drusen, 267 +glaucomatous cupping, 235 hypoplasia, 267 +oedema, 323 +620 Comprehensive Ophthalmology + + +Optic Nerve, 310 +toxic amblyopias, 320 tumours, 419 +Optic neuritis, 317 Optic tract +anatomy of, 310 lesions of, 313 +Optic vesicle. 8 Optics +geometrical, 24 of the eye, 30 +Opto-kinetic nystagmus, 359 Ora serrata, 264 +Orbital apex syndrome, 413 Orbit/orbital +anatomy, 401 cellulitis, 409-410 +developmental anomalies, 407 exenteration, 425 +fracture, blow-out, 422 inflammations, 408 surgical spaces, 403 tumours, 417-422 +Orbitotomy, 424 OSNN, 93 + +p + +Pannus, trachomatous, 69 Panophthalmitis, 172 Papillitis, 318 Papilloedema, 323 Paralytic squint, 353 +Parinaud’s oculoglandular syndrome, 78 Pars plana vitrectomy, 280 +Pars planitis, 150 Pemphigus, ocular, 377 Penicillins. 445 Perforating injuries, 433 Perimeter/perimetry, 511 +automated, 513 manual, 512 +Peripheral ulcerative keratopathies, 115 Periphlebitis retinae, 270 +Persistent pupillary membrane, 149 Peter’s anomaly, 228 Phacoanaphylactic uveitis, 169, 192 Phacoemulsification, 197, 203 Phacolytic glaucoma, 193, 248 Phacomatosis, 308 +Phlyctenular conjunctivitis, 83 keratitis, 83 +Photocoagulation, 281, 462 Photo-ophthalmia, 119 Photorefraction, 574 + +Photorefractive keratectomy (PRK), 52 Photo retinitis, 291 +Phototherapeutic keratectomy, 138 Phthisis bulbi, 157 +Physiology of cornea, 14, 96 +crystalline lens, 14, 180 tears, 387 +vision, 14 +Pigmentary retinal dystrophy, 287 Pilocarpine, 237, 449 Pinguecula, 86 +Pin hole test, 578 +Placido’s keratoscopic disc, 501 Pleomorphic, 399 Polychromatic luster, 194 Polycoria, 149 +Posterior embryotoxom, 97, 228 Pre-Desemet’s membrane, 96 Presbyopia, 47 +Presumed ocular histoplasmosis syndrome, 165 +Primary angle closure, 239, 240 suspect, 240, 242 glaucoma, 240-242 +Primary open angle glaucoma, 228 Prisms, 27 +Proptosis, 403-407 Prostaglandin derivatives, 453 +latanoprost, 453 Protozoal keratitis, 112 Provocative tests, for +narrow angle glaucoma, 243 open angle glaucoma, 235 +Pseudopapillitis, 36, 325 Pseudophakia, 38 Pseudopterygiurn, 88 Pseudotumours of the orbit, 413 Pterygium, 87 +Ptosis, 379 +Punctate keratitis, 118 PupiI/pupiIlary +Adie’s tonic, 317 Argyll-Robertson, 317 contraction, 315 examination, 504 +membrane, persistent, 149 miosis, 504 +mydriasis, 504 reflexes, 313 +Purkinje’s images, 505 + +Q + +Quinine amblyopia, 321 +Index 621 + + +R + +Radial keratotomy, 52 Radiational cataract, 182 Rectus muscles, 337 +recession, 358 resection, 358 +Reduced eye, 30 Refraction +determination, 583 errors of, 34 objective, 570 subjective, 576 +Refractive lenticule extraction, 53 Refractive surgery, 52-55 Refractometry, 574 +Reis- Bucklers corneal dystrophy, 127 Reiter’s disease, 168 +Retina/retinal anatomy, 263 +artery occlusion, 269 breaks, 300 coloboma, 266 degenerations, 287 detachment, 299 dystrophies, 287 holes, 289 +oedema, traumatic, 430 tears, 430 +tumours of, 303 vein occlusion, 270 +Retinitis, 267 +Retinitis pigmentosa, 287 Retinoblastoma, 303 Retinopathy +central serous, 292 coats’, 285 diabetic, 276 hypertensive, 273 +in toxaemia of pregnancy, 276 prematurity, 283 +sickle cell, 282 Retinoschisis. 290 Retinoscopy, 570 Retrobulbar neuritis, 318 Rhabdomyosarcoma, 418 Rhodopsin, 15 +Roenne’s central nasal step, 233 Rosacea keratitis, 117 +Rubeosis iridis, 155, 250, 271 + +s + +Saccadic system, 341 Sarcoidosis + +conjunctivitis, 78 uveitis, 167 +Schematic eye, 30 Schirmer’s test, 389 Schwalbe’s line, 219 Sclera +anatomy, 140 blue, 144 examination, 501 +Scleritis, 141 Scotoma, +arcuate, 233 Bjerrum’s, 233 ring, 233, 288 sickle-shaped, 233 +Scotometry, 513 Seclusio pupillae, 156 Seidel’s test, 213 +SeniIe macular degeneration, 291 Serpiginous ulcer, 116 +Shadow test, 583 SICS, 197, 198, 201 Siderosis bulbi, 434 +Sinus-cavernous thrombosis, 411 Sjogren’s syndrome, 390 Skiascopy, 583 +Slit-lamp, 567 +Snow blindness, 119 Soemmering’s ring, 215 Spasm of accommodation, 49 Spectacles, 49 +Spherical aberrations, 32 Sphincter pupillae, 147 Spring catarrh, 71 Squamous blepharitis, 366 Squamous cell carcinoma +of conjunctiva, 92 of lids, 384 +Staphylomas, 144, 501 anterior, 134 +ciliary, 144 equatorial, 144 inter calary, 144 posterior, 144 +Stargardt’s desease, 508 +Stevens-Johnson syndrome, 377, 389 Stenopaeic slit test, 577 +Sterilization, 603 Stickler syndrome, 290 +Strabismus or squint, 344-358 alternating, 348 concomitant, 348 convergent, 344 +divergent, 344 incomitant, 353 +622 Comprehensive Ophthalmology + + +latent, 344 paralytic, 353 pseudo, 344 +Sturge-Weber syndrome, 309 Sturm’s conoid, 30, 42 +Stye, 368 +Subconjunctival haemorrhage, 91, 335 Subjective refraction, 576 +Superior limbic keratoconjunctivitis, 119 Superior ophthalmic vein, 5, 266 Swimming pool conjunctivitis, 73 Swinging flashlight test, 524 Symblepharon, 374 +Sympathetic ophthalmitis, 163, 437 Sympathomimetic drugs, 449 Synchysis scintillans, 260 Synechiae +anterior peripheral, 173 posterior, 156 +Synoptophore, 352 Systemic diseases, ocular +manifestations of, 467-473 + +T + +Tarsorrhaphy, 378 +Tattooing, corneal opacity, 133 Tay-Sach’s disease, 504 +Tear film, 366 Test types +Jaeger’s, 497 Snellen’s, 497 +Therapeutics, ocular administration of, 444 antibacterial agents, 444 antifungal agents, 448 antiglaucoma drugs, 449-453 antiviral drugs, 444 corticosteroids, 453 +non-steroidal anti-inflammatory drugs, 158 +viscoelastic substances, 201 timolol, 451 +Tobacco amblyopia, 320 Tolosa-Hunt syndrome, 413 Tonometer/tonometry, 509-511 +applanation, 510 indentation, 509 Schiotz, 509 +Total internal reflection, 27 Toxaemia of pregnancy, +retinopathy, 276 Toxic amblyopia, 320 Toxocara, 165 Toxoplasmosis, 181 + +Trabecular meshwork, 219 Trabeculectomy, 239 Trabeculotomy, 253 Trachoma, 65 Transillumination, 562 Traumatic cataract, 430 +Traumatic optic neuropathy, 323 Trichiasis, 370 +Trophic corneal ulcer, 114 Tuberculosis of +uveal tract, 160 Tuberous sclerosis, 309 Tumours of +conjunctiva, 92 lacrimal gland, 399 lids, 382 +orbit, 419 retina, 303 uveal tract, 174 +Tylosis, 68 + +U + +Ulcer, corneal, 96 Ulcus serpens, 100 Ultrasonography, 517 Uveal tract, +anatomy of, 146 blood supply, 148 coloboma, 147 +congenital anomalies, 149 degeneration, 173 inflammations of, 153 +Uveitis 150-170 aetiology, 150 anterior, 154 hypertensive, 157, 250 leprotic, 163 +pathology of, 152 posterior, 161 purulent, 170 sarcoid, 167 syphilitic, 164 toxoplasmosis, 164 tubercular, 163 viral, 166 + +v + +Vasoconstrictors, 456 Veins, 5 +Vernal kerato conjunctivitis, 61 Viral +conjunctivitis, 61 uveitis, 163 +Viscoelastic substances, 458 +Index 623 + + +Vision +binocular, 342 colour, 18, 328 distant, 44 field of, 511 near, 579 +physiology of, 14 Vision 2020, 480, 482 Visual acuity, 17, 496 Visual agnosia, 332 Visual field +confrontation test, 512 defects in glaucoma, 231 examination of, 505 +Visual field index, 234 Visual hallucination, 332 Visual illusions, 333 Visual pathway +anatomy of, 310 lesions of, 312 +Visually evoked response, 520 Vitrectomy +open sky, 261 pars plana, 261 +Vitreous anatomy, 257 +detachment, 258 haemorrhage, 260 liquefaction, 258 opacities, 259 substitute of, 261 +Vitreoretinal degenerations, 290 + + +Vogt-Koyanagi-Harada syndrome, 169 +Von Hippel-Lindau syndrome, 309 +Von Recklinghausen’s disease, 309 Vossius’s ring, 430 + +w + +Wagner’s syndrome, 290 Water drinking test, 235 Watering eye, 390 Weber’s syndrome, 334 +Wernicke’s hemianopic pupil, 317 Wiegert’s ligament, 258 + +x + +Xanthelasma, 383 Xerophthalmia, 467 +prophylaxis, 301, 427, 438, 469 Xerosis, conjunctiva, 91 + +y + +Yoke muscles, 339 + +z + +Zeis’s gland, 363 Zonular cataract, 184 Zonules of Zinn, 180 Zoster, herpes, 110, 166 diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_3.txt b/notes/A K Khurana - Comprehensive Ophthalmology_3.txt new file mode 100644 index 0000000000000000000000000000000000000000..d094a070ea89d414ec174522b3ef42b3de50ba59 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_3.txt @@ -0,0 +1,1599 @@ +C. Mode of infection. Conjunctiva may get infected from three sources, viz, exogenous, local surrounding structures and endogenous, by following modes: +1. Exogenous infections may spread: +• Directly through close contact, as airborne infections or as waterborne infections; +• Vector transmission (e.g., flies); +• Material transfer such as infected fingers of doctors, nurses, common towels, handkerchiefs, and infected tonometers. +2. Local spread may occur from neighbouring structures such as infected lacrimal sac, lids, and nasopharynx. In addition to these, a change in the character of relatively innocuous organisms present in the conjunctival sac itself may cause infections. 3. Endogenous infections may occur very rarely through blood, e.g., gonococcal and meningococcal infections. +Pathology +Pathological changes of bacterial conjunctivitis consist of: +1. Vascular response. It is characterised by congestion and increased permeability of the conjunctival vessels associated with proliferation of capillaries. +2. Cellular response. It is in the form of exudation of polymorphonuclear cells and other inflammatory cells into the substantia propria of conjunctiva as well as in the conjunctival sac. +3. Conjunctival tissue repsonse. Conjunctiva becomes oedematous. The superficial epithelial cells degenerate, become loose and even desquamate. There occurs proliferation of basal layers of conjunctival epithelium and increase in the number of mucin-secreting goblet cells. +4. Conjunctival discharge. It consists of tears, mucus, inflammatory cells, desquamated epithelial cells, fibrin and bacteria. If the inflammation is very severe, diapedesis of red blood cells may occur and discharge may become blood stained. +Severity of pathological changes varies depending upon the severity of inflammation and the causative organism. The changes are thus more marked in purulent conjunctivitis than mucopurulent conjunctivitis. +Chapter 5 Diseases of Conjunctiva 63 + + +Clinical types of bacterial conjunctivitis Depending upon the causative bacteria and the severity of infection, bacterial conjunctivitis may present in following clinical forms: +• Acute bacterial conjunctivitis, +• Hyperacute bacterial conjunctivitis, • Chronic bacterial conjunctivitis, and • Angular bacterial conjunctivitis. +ACUTE BACTERIAL CONJUNCTIVITIS +Acute bacterial conjunctivitis is characterised by marked conjunctival hyperaemia and mucopurulent discharge from the eye. So, clinically, it is called acute mucopurulent conjunctivitis. It is the most common type of bacterial conjunctivitis. +Common causative bacteria are: Staphylococcus aureus, Koch-Weeks Bacillus, Pneumococcus and Streptococcus. Mucopurulent conjunctivitis generally accompanies exanthemata such as measles and scarlet fever. +Clinical features Symptoms +• Discomfort, foreign body, grittiness, blurring and redness of sudden onset (due to engorgement of vessels) are the usual presenting symptoms. +• Mild photophobia, i.e., difficulty to tolerate light. • Mucopurulent discharge from the eyes. +• Sticking together of lid margins with discharge during sleep. +• Slight blurring of vision due to mucous flakes in front of cornea. +• Coloured halos, may be complained by some patients due to prismatic effect of mucus present on cornea. +Signs (Fig. 5.4) +• Flakes of mucopus seen in the fornices, canthi and lid margins is a critical sign. + + + + + + + + + + + + + + +Fig. 5.4 Signs of acute mucopurulent conjunctivitis + + +• Conjunctival congestion, which is more marked in palpebral conjunctiva, fornices and peripheral part of bulbar conjunctiva, giving the appearance of ‘fiery red eye’. The congestion is typically less marked in circumcorneal zone. +• Chemosis, i.e., swelling of conjunctiva. • Papillae of fine type may be seen. +• Petechial haemorrhages are seen when the causative organism is Pneumococcus. +• Cilia are usually matted together with yellow crusts. +• Eyelids may be slightly oedematous. +Clinical course.Mucopurulent conjunctivitis is usually bilateral, although one eye may become affected 1–2 days before the other. The disease usually reaches its height in three to four days. If untreated, in mild cases the infection may be overcome and the condition is cured in 10–15 days; or it may pass to less intense form, the ‘chronic catarrhal conjunctivitis.’ +Complications. Occasionally the disease may be complicated by superficial punctate epitheliopathy, marginal corneal ulceration, superficial keratitis, blepharitis, or dacryocystitis. +Differential diagnosis +1. From other causes of acute red eye (see page 158 and Table 8.1). +2. From other types of conjunctivitis. It is made out from the typical clinical feature of disease and is confirmed by conjunctival cytology and bacteriological examination of secretions and scrapings (Table 5.1). +Treatment +1. Topical antibiotics to control the infection constitute the main treatment of acute bacterial conjunctivitis. Ideally, the antibiotic should be selected after culture and sensitivity tests but in practice, it is difficult. However, in routine, most of the patients respond well to broad spectrum antibiotics. Therefore, treatment may be started with chloramphenicol (1%), or gentamicin (0.3%), or tobramycin 0.3% or framycetin 0.3% eye drops 3–4 hourly in day and ointment used at night will not only provide antibiotic cover but also help to reduce the early morning stickiness. If the patient does not respond to these antibiotics, then the quinolone antibiotic drops such as ciprofloxacin (0.3%), ofloxacin (0.3%), gatifloxacin (0.3%) or moxifloxacin (0.5%) may be used. +2. Irrigation of conjunctival sac with sterile warm saline once or twice a day will help by removing the deleterious material. Frequent eyewash (as +64 Section III Diseases of Eye + +Table 5.1 Differentiating features of common types of conjunctivitis + + + +(A) CLINICAL SIGNS 1. Congestion +2. Chemosis +3. Subconjunctival haemorrhages 4. Discharge + +5. Papillae 6. Follicles +7. Pseudomembrane 8. Pannus +9. Preauricular lymph nodes +(B) CYTOLOGICAL FEATURES 1. Neutrophils +2. Eosinophils 3. Lymphocytes 4. Plasma cells +5. Multinuclear cells 6. Inclusion bodies: +Cytoplasmic Nuclear +7. Micro-organisms + +Bacterial + +Marked ++ +± +Purulent or mucopurulent ± +– ± – + + ++ – – – – + +– – + + +Viral + +Moderate ± +± Watery + +– + ± – ++ + ++ (Early) – ++ – + + ++ (Pox) ++ (Herpes) – + +Allergic + +Mild to moderate ++ +– +Ropy/ watery + +++ – – +– (Except vernal) – + +– + – – – + +– – – + +Chlamydial (TRIC) + +Moderate ± +– Mucopurulent + +± ++ – + ± + ++ – + + – + ++ – – + + + + +advocated earlier) is, however, contraindicated as it will wash away the lysozyme and other protective proteins present in the tears. +3. Dark goggles should be used to prevent photo-phobia. +4. No bandage should be applied in patients with mucopurulent conjunctivitis. Exposure to air keeps the temperature of conjunctival cul-de-sac low which inhibits the bacterial growth; while after bandaging, conjunctival sac is converted into an incubator, and thus infection flares to a severe degree within 24 hours. Further, bandaging of eye will also prevent the escape of discharge. +5. No steroids should be applied, otherwise infection will flare up and bacterial corneal ulcer may develop. 6. Anti-inflammatory and analgesic drugs (e.g., ibuprofen and paracetamol) may be given orally for 2–3 days to provide symptomatic relief from mild pain especially in sensitive patients. +Preventive measures to reduce risk of transmission to the close contacts include: +• Frequent handwashing, and +• Avoidance of sharing towel, handkerchief and pillow with others. +HYPERACUTE BACTERIAL CONJUNCTIVITIS Hyperacute bacterial conjunctivitis also known as acute purulent conjunctivitis or acute blenorrhea is characterised by a violent inflammatory response. + + +It occurs in two forms: +1. Adult purulent conjunctivitis, and +2. Ophthalmia neonatorum in newborn (see page 76). + +Hyperacute Conjunctivitis of Adults (Gonococcal Conjunctivitis) +Etiology +The disease affects adults, predominantly males. Gonococcal infection directly spreads from genitals to eye. Presently, incidence of gonococcal conjunctivitis has markedly decreased. + +Clinical feature +Onset is hyperacute (12 to 24 hours) +Symptoms include: +• Pain which is moderate to severe, +• Purulent discharge, which is usually copious, and • Swelling of eyelids, which is usually marked. +Signs are as follows (Fig. 5.5): +• Eyelids are tense and swollen. • Tenderness is marked. +• Discharge is thick purulent, copius trickling down the cheeks. +• Conjunctiva shows marked chemosis, congestion and papillae, giving bright red velvety appearance. Frequently, a pseudomembrane may be seen on the conjunctival surface (Fig. 5.6). +Chapter 5 Diseases of Conjunctiva 65 + + + + + + + + + + + + + + + + +Fig. 5.5 Hyperacute conjunctivitis + + + + + + + + + + + + + + + +Fig. 5.6 Pseudomembranous conjunctivitis + +• Preauricular lymph nodes are usually enlarged and tender. +Associations. Gonococcal conjunctivitis is usually associated with urethritis and arthritis. +Complications +1. Corneal involvement is quite frequent as the gonococcus can invade the normal cornea through an intact epithelium. It may occur in the form of diffuse haze and oedema, central necrosis, corneal ulceration or even perforation. +2. Iridocyclitis may also occur, but is not as common as corneal involvement. +3. Systemic complications, though rare, include gonorrhoea arthritis, endocarditis and septicaemia. +Treatment +1. Systemic therapy is far more critical than the topical therapy for the infections caused by N. gonorrhoeae. Any of the following regimes can be adopted: +• Third generation cephalosporin such as cefoxitim 1.0 gm or cefotaxime 500 mg IV qid or ceftriaxone + +1.0 gm IM qid, all for 5 days; should be preferred treatment. +• Quinolones such as norfloxacin 1.2 gm orally qid for 5 days, or +• Spectinomycin 2.0 gm IM for 3 days, may be used alternatively. +All of the above regimes should then be followed by a one week course of either doxycycline 100 mg bid or erythromycin 250–500 mg orally qid. +2. Topical antibiotic therapy, presently recommended includes ofloxacin, ciprofloxacin or tobramycin eye drops or bacitracin or erythromycin eye ointment every 2 hours for the first 2–3 days and then 5 times daily for 7 days. +3. Irrigation of the eyes frequently with sterile saline is very therapeutic in washing away infected debris. +4. Other general measures are similar to acute mucopurulent conjunctivitis. +5. Topical atropine 1% eye drops should be instilled once or twice a day if cornea is involved. +Note. Sexual partner should also be treated with systemic antibiotics. Further, both the patient and the sexual partner should be referred for evaluation of other sexually transmitted diseases. +CHRONIC BACTERIAL CONJUNCTIVITIS Chronic bacterial conjunctivitis also known as ‘Chronic catarrhal conjunctivitis’ or ‘simple chronic conjunctivitis’ is characterised by mild catarrhal inflammation of the conjunctiva. +Etiology +A. Predisposing factors +1. Chronic exposure to dust, smoke, and chemical irritants. +2. Local cause of irritation such as trichiasis, concretions, foreign body and seborrhoeic scales. +3. Eye strain due to refractive errors, phorias or convergence insufficiency. +4. Abuse of alcohol, insomnia and metabolic disorders. +B. Causative organisms +• Staphylococcus aureus is the commonest cause of chronic bacterial conjunctivitis. +• Gram negative rods such as Proteus mirabilis, Klebsiella pneumoniae, Escherichia coli and Moraxella lacunata are other rare causes. +C.Source and mode of infection.Chronic conjunctivitis may occur: +1. As continuation of acute mucopurulent conjunctivitis when untreated or partially treated. +2. As chronic infection from associated chronic +66 Section III Diseases of Eye + + +dacryocystitis, chronic rhinitis or chronic upper respiratory catarrh. +3. As a mild exogenous infection which results from direct contact, airborne or material transfer of infection. +Clinical features +Symptoms of simple chronic conjunctivitis include: • Burning and grittiness in the eyes, especially in +the evening. +• Mild chronic redness in the eyes. Feeling of heat and dryness on the lid margins. +• Difficulty in keeping the eyes open. +• Mild mucoid discharge especially in the canthi. • Watering, off and on is often a complaint. +• Feeling of sleepiness and tiredness in the eyes. +Signs. Grossly the eyes look normal but careful examination may reveal following signs: +• Congestion of posterior conjunctival vessels. +• Mild papillary hypertrophy of the palpebral conjunctiva. +• Sticky look of surface of the conjunctiva. • Lid margins may be congested. +Treatment +1. Eliminate predisposing factors when associated. 2. Topical antibiotics such as chloramphenicol, +tobramycin or gentamicin should be instilled 3–4 times a day for about 2 weeks to eliminate the mild chronic infection. +3. Astringent eye drops such as zinc-boric acid drops provide symptomatic relief. +ANGULAR BACTERIAL CONJUNCTIVITIS +It is a type of chronic conjunctivitis characterised by mild grade inflammation confined to the conjunctiva and lid margins near the angles (hence the name) associated with maceration of the surrounding skin. +Etiology +1. Predisposing factors are same as for ‘simple chronic conjunctivitis’. +2. Causative organisms. Moraxella Axenfield (MA) is the commonest causative organism. MA bacilli are placed end to end, so the disease is also called ‘diplobacillary conjunctivitis’. Rarely, staphylococci may also cause angular conjunctivitis. +3. Source of infection is usually nasal cavity. +4. Mode of infection. Infection is transmitted from nasal cavity to the eyes by contaminated fingers or handkerchief. +Pathology +The causative organism, i.e., MA bacillus produces a proteolytic enzyme which acts by macerating the + +epithelium. This proteolytic enzyme collects at the angles by the action of tears and thus macerates the epithelium of the conjunctiva, lid margin and the skin, the surrounding angles of eye. The maceration is followed by vascular and cellular responses in the form of mild grade chronic inflammation. Skin may show eczematous changes. +Clinical features Symptoms include: +• Irritation, burning sensation and feeling of discomfort in the eyes. +• Historyof collectionof dirty-white foamy discharge at the angles. +• Redness in the angles of eyes. +Signs include (Fig. 5.7): +• Hyperaemia of bulbar conjunctiva near the canthi. +• Hyperaemia of lid margins near the angles. • Excoriation of the skin around the angles. +• Foamy mucopurulent discharge at the angles is usually present. +Complications include: blepharitis and shallow marginal catarrhal corneal ulceration. +Treatment +A.Prophylaxis includes treatment of associated nasal infection and good personal hygiene. +B. Curative treatment consists of: +1. Oxytetracycline (1%) eye ointment, 2–3 times a day for 9–14 days will eradicate the infection. +2. Zinc lotion instilled in day time and zinc oxide ointment at bed time inhibits the proteolytic ferment and thus helps in reducing the maceration. + + + + + + + + + + + + + + + + + +Fig. 5.7 Signs of angular conjunctivitis +Chapter 5 Diseases of Conjunctiva 67 + + +CHLAMYDIAL CONJUNCTIVITIS + +Chlamydialie midway between bacteria and viruses sharing some of the properties of both. Like viruses, they are obligate intracellular and filterable, whereas like bacteria they contain both DNA and RNA, divide by binary fission and are sensitive to antibiotics. +The Chlamydia combinedly form the PLT group (Psittacosis, Lymphogranuloma venereum and Trachomatis group). +Life cycle of the Chlamydia. The infective particle invades the cytoplasm of epithelial cells, where it swells up and forms the ‘initial body’. The initial bodies rapidly divide into ‘elementary bodies’ embedded in glycogen matrix which are liberated when the cells burst. Then the ‘elementary bodies’ infect other cells where the whole cycle is repeated. +Ocular infections produced by chlamydia in human beings are summarised in Table 5.2. +TRACHOMA +Trachoma (previously known as Egyptian ophthalmia) is a chronic keratoconjunctivitis, primarily affecting the superficial epithelium of conjunctiva and cornea simultaneously. It is characterised by a mixed follicular and papillary response of conjunctival tissue. It is still one of the leading causes of preventable blindness in the world. The word ‘trachoma’ comes from the Greek word for ‘rough’ which describes the surface appearance of the conjunctiva in chronic trachoma. +Etiology +A. Causative organism. Trachoma is caused by a Bedsonian organism, the Chlamydia trachomatis belonging to the Psittacosis-lymphogranuloma trachoma (PLT) group. The organism is epitheliotropic and produces intracytoplasmic inclusion bodies + + +called HP bodies (Halberstaedter Prowazek bodies). Presently, 11 serotypes of Chlamydia (A, B, Ba, C, D, E, F, G, H, J and K) have been identified using microimmunofluorescence techniques. +• Serotypes A, B, Ba and C are associated with hyperendemic (blinding) trachoma. +• Serotypes D to K are associated with inclusion conjunctivitis (oculogenital chlamydial disease). +B. Predisposing factors. These include age, sex, race, climate, socioeconomic status and environmental factors. +1. Age. The infection is usually contracted during infancy and early childhood. Otherwise, there is no age bar. +2. Sex. As far as sex is concerned, there is general agreement that preponderance exists in the females both in number and in severity of disease. +3. Race. No race is immune to trachoma, but the disease is very common in Jews and comparatively less common among Negroes. +4. Climate. Trachoma is more common in areas with dry and dusty weather. +5. Socioeconomic status. The disease is more common in poor classes owing to unhygienic living conditions, overcrowding, unsanitary conditions, abundant fly population, paucity of water, lack of materials like separate towels and handkerchiefs, and lack of education and understanding about spread of contagious diseases. +6. Environmental factors like exposure to dust, smoke, irritants, sunlight, etc. increase the risk of contracting disease. Therefore, outdoor workers are more affected in comparison to office workers. +C. Source of infection. In trachoma endemic zones the main source of infection is the conjunctival discharge of the affected person. Therefore, + + + +Table 5.2 Summary of ocular infections caused by chlamydia +68 Section III Diseases of Eye + + +superimposed bacterial infections help in trans-mission of the disease by increasing the conj-unctival secretions. +D. Modes of infection. Infection may spread from eye to eye by any of the following modes: +1. Direct spread of infection may occur through contact by airborne or waterborne modes. +2. Vector transmission of trachoma is common through flies. +3. Material transfer plays an important role in the spread of trachoma. Material transfer can occur through contaminated fingers of doctors, nurses and contaminated tonometers. Other sources of material transfer of infection are use of common towel, handkerchief, bedding and surma-rods. +Prevalence +Trachoma is a worldwide disease but it is highly prevalent in North Africa, Middle East and certain regions of South-East Asia. It is believed to affect some 500 million people in the world. There are about 150 million cases with active trachoma and about 30 million having trichiasis, needing lid surgery. Trachoma is responsible for 15–20% of the world’s blindness, being second only to cataract. +Clinical features +Clinical features of trachoma can be described into two phases: +I. Phase of active trachoma +Phase of active trachoma usually occurs during childhood due to active chlamydial infection. +• Incubation period of active trachoma varies from 5 to 22 days. +• Onset of disease is usually insidious (subacute), however, rarely it may present in acute form. + +Symptoms +Symptoms of active trachoma are determined by the absence or presence of secondary bacterial infection (a very common situation). +■In the absence of secondary infection, a pure trachoma is characterized by following symptoms: • Mild foreign body sensation, +• Occasional lacrimation, +• Slight stickiness of the lids, and • Scanty mucoid discharge. +Note. The above symptoms are so mild that the disease is usually neglected. +■In the presence of secondary bacterial infection, typical symptoms of acute mucopurulent conjunctivitis develop (see page 63). + + +Signs + +A. Conjunctival signs +1. Congestion of upper tarsal and forniceal conjunctiva. +2. Conjunctival follicles. Follicles (Figs 5.8 and 5.9) look like boiled sagograins and are commonly seen on upper tarsal conjunctiva and fornix; but may also be present in the lower fornix, plica semilunaris and caruncle. Sometimes, follicles may be seen on the bulbar conjunctiva (pathognomonic of trachoma). +■Structure of follicle. Follicles are formed due to scattered aggregation of lymphocytes and other cells in the adenoid layer. Central part of each follicle is made up of mononuclear histiocytes, few lymphocytes and large multinucleated cells called Leber cells. The cortical part is made up of a zone of lymphocytes showing active proliferation. Blood vessels are present in the most peripheral part. In later stages signs of necrosis are also seen. Presence of Leber cells and signs of necrosis differentiate trachoma follicles from follicles of other forms of follicular conjunctivitis. + + + + + + + + + + + + +Fig. 5.8 Signs of active trachoma (diagrammatic) + + + + + + + + + + + + + + +Fig. 5.9 Trachomatous inflammation follicular (TF) +Chapter 5 Diseases of Conjunctiva 69 + +3. Papillary hyperplasia. Papillae are reddish, flat topped raised areas which give red and velvety appearance to the tarsal conjunctiva (Fig. 5.10). Each papilla consists of central core of numerous dilated blood vessels surrounded by lymphocytes and covered by hypertrophic epithelium. +B. Corneal signs +1. Superficial keratitis may be present in the upper +part. A B 2. Herbert follicles refer to typical follicles present in +the limbal area. These are histologically similar to conjunctival follicles. +3. Progressive pannus i.e., infiltration of the cornea associated with vascularization is seen in upper part (Fig. 5.11). The vessels are superficial and lie between epithelium and Bowman’s membrane. Later on, Bowman’s membrane is also destroyed. Pannus in active trachoma is progressive in which infiltration of cornea is ahead of vascularization (Fig. 5.11A). +4. Corneal ulcer may sometime develop at the advancing edge of pannus. Such ulcers are usually shallow which may become chronic and indolent. C + +II. Phase of cicatricial trachoma +Cicatricial phase of trachoma manifests in middle age. It results due to continued mild grade chronic inflammation. Infact recurrent infection elicits chronic immune response consisting of cell-mediated delayed hypersensitivity (Type IV) reaction to the intermittent presence of chlamydial antigen, which is responsible for cicatricial phase of trachoma. The end stage of cicatricial trachoma is also referred to as sequelae of trachoma. This phase is characterized by following clinical features: +A. Conjunctival signs +i. Conjunctival scarring (Fig. 5.12), which may be irregular, star-shaped or linear. Linear scar + + + + + + + + + + + + + + + +Fig. 5.10 Trachomatous inflammation intense (TI) + + +Fig. 5.11 Trachomatous pannus: (A) progressive, +(B) regressive (diagrammatic) and (C) clinical photograph + +present in the sulcus subtarsalis is called Arlt’s line. +ii. Concretions are hard looking whitish deposits varying from pin point to 2 mm in size (Fig. 5.13). These are not calcareous deposits, but are formed due to accumulation of dead epithelial cells and inspissated mucus in the depressions called glands of Henle. Hence, the name is misnomer. +iii.Other conjunctival sequelae include concretions, pseudocyst, xerosis and symblepharon. + + + + + + + + + + + + + + +Fig. 5.12 Trachomatous scarring (TS) +70 Section III Diseases of Eye + + + + + + + + + + + + + + + + +Fig. 5.13 Concretions in upper palpebral conjunctiva + + + + + + + + + + + + + + + +Fig. 5.14 Trachomatous Herbert’s pits + + + + + + + + + + + + + + + +Fig. 5.15 Trachomatous corneal opacity (CO) + + +B. Corneal sign +i. Regressive pannus (pannus siccus) in which (Fig. 5.11B) vessels extend a short distance beyond the area of infiltration. +ii. Herbert pits are the oval or circular pitted scars, + + +Fig. 5.16 Trachomatous trichiasis (TT) + +left after healing of Herbert follicles in the limbal area (Fig. 5.14). +iii.Corneal opacity (Fig. 5.15) may be present in the upper part. It may even extend down and involve the papillary area. It is the end result of trachomatous corneal lesions. +iv. Other corneal sequelae may be corneal ectasia, corneal xerosis and total corneal pannus (blinding sequelae). +C.Lid signs. Sequelae in the lids may be trichiasis (Fig. 5.16), entropion, tylosis (thickening of lid margin), ptosis, madarosis and ankyloblepharon. +D. Lacrimal appratus sequelae may be chronic dacryocystitis, and chronic dacryoadenitis. +Grading of trachoma +McCallan’s classification +McCallan in 1908, divided the clinical course of the trachoma into four stages: +• Stage I (Incipient trachoma or stage of infiltration). It is characterized by hyperaemia of palpebral conjunctiva and immature follicles. +• Stage II (Established trachoma or stage of florid infiltration). It is characterized by appearance of mature follicles, papillae and progressive corneal pannus. +• Stage III (Cicatrising trachoma or stage of scarring). It includes obvious scarring of palpebral conjunctiva. +• Stage IV (Healed trachoma or stage of sequelae). The disease is quiet and cured but sequelae due to cicatrisation, give rise to symptoms. +WHO classification +The latest simplified classification suggested by WHO in 1987 is as follows (FISTO): +1. TF: Trachomatous inflammation-follicular. It is the stage of active trachoma with predominantly +Chapter 5 Diseases of Conjunctiva 71 + + +follicular inflammation. To diagnose this stage at least five or more follicles (each 0.5 mm or more in diameter) must be present on the upper tarsal conjunctiva (Fig. 5.9). Further, the deep tarsal vessels should be visible through the follicles and papillae. +2. TI: Trachomatous inflammation intense. This stage is diagnosed when pronounced inflammatory thickening of the upper tarsal conjunctiva obscures more than half of the normal deep tarsal vessels (Fig. 5.10). +3. TS: Trachomatous scarring. This stage is diagnosed by the presence of scarring in the tarsal conjunctiva. These scars are easily visible as white, bands or sheets (fibrosis) in the tarsal conjunctiva (Fig. 5.12). +4. TT: Trachomatous trichiasis. TT is labelled when at least one eyelash rubs the eyeball. Evidence of recent removal of inturned eyelashes should also be graded as trachomatous trichiasis (Fig. 5.16). +5. CO: Corneal opacity. This stage is labelled when easily visible corneal opacity is present over the pupil (Fig. 5.15). This sign refers to corneal scarring that is so dense that at least part of pupil margin is blurred when seen through the opacity. The definition is intended to detect corneal opacities that cause significant visual impairment (less than 6/18). +Complications +The only complication of trachoma is corneal ulcer which may occur due to rubbing by concretions, or trichiasis with superimposed bacterial infection. +Diagnosis +A. Clinical diagnosis of trachoma is made from its typical signs. Clinical grading of each case should be done as per WHO classification into TF, TI, TS, TT or CO. +B. Laboratory diagnosis. Advanced laboratory tests are employed for research purposes only. Laboratory diagnosis of trachoma includes: +1. Conjunctival cytology. Giemsa-stained smears showing a predominantly polymorphonuclear reaction with presence of plasma cells and Leber cells is suggestive of trachoma. +2. Detection of inclusion bodies in conjunctival smear may be possible by Giemsa stain, iodine stain or immunofluorescent staining, specially in cases with active trachoma. +3. Enzyme-linked immunosorbent assay (ELISA) for chlamydial antigens. + +4. Polymerase chain reaction (PCR) is also useful. 5. Isolation of Chlamydia is possible by yolk-sac +inoculation method and tissue culture technique. Standard single-passage McCoy cell culture requires at least 3 days. +6. Serotyping of TRIC agents is done by detec-ting specific antibodies using microim-munofluorescence (micro-IF) method. Direct monoclonal fluorescent antibody microscopy of conjunctival smear is rapid and inexpensive. +Differential diagnosis +1. Trachoma with follicular hypertrophy must be differentiated from acute adenoviral follicular conjunctivitis (epidemic keratoconjunctivitis) as follows: +• Distribution of follicles in trachoma is mainly on upper palpebral conjunctiva and upper fornix, while in EKC lower palpebral conjunctiva and lower fornix is predominantly involved. +• Associated signs such as papillae and pannus are characteristic of trachoma. +• Laboratory diagnosis of trachoma helps in differentiation of clinically indistinguishable cases. 2. Trachoma with predominant papillary hypertrophy needs to be differentiated from palpebral form of +spring catarrh as follows: +• Papillae are large in size and usually there is typical cobble-stone arrangement in spring catarrh. +• pH of tears is usually alkaline in spring catarrh, while in trachoma it is acidic. +• Discharge is ropy in spring catarrh. +• Follicles and pannus may also be present in trachoma. +• Conjunctival cytology and other laboratory tests for trachoma usually help in diagnosis in clinically indistinguishable cases. +Management +Management of trachoma should involve curative as well as prophylactic measures. +A. Treatment of active trachoma +Antibiotics for treatment of active trachoma may be given locally or systemically, but topical treatment is preferred because: +• It is cheaper, +• There is no risk of systemic side-effects, and +• Local antibiotics are also effective against bacterial conjunctivitis which may be associated with trachoma. +Therapeutic regimes recommended are: +1. Topical therapy regimes are best for individual cases and consist of: +72 Section III Diseases of Eye + + +• Tetracycline (1%) or erythromycin (1%) eye ointment 4 times a day for 6 weeks, or +• Sulfacetamide (20%) eye drops three times a day along with 1% tetracycline eye ointment at bed time for 6 weeks. +2. Systemic therapy regimes include: +• Azithromycin 20 mg/kg body weight up to maximum 1 gm stat or 250 mg od × 4 days. It is presently considered the first drug of choice. It is not used in pregnancy and children below 6 years of age. +• Tetracycline or erythromycin 250 mg orally, four times a day for 3–4 weeks or +• Doxycycline 100 mg orally twice daily for 3–4 weeks. +3. Combined topical and systemic therapy regime. It is preferred when the ocular infection is severe (TI) or when there is associated genital infection. It includes: • Tetracycline (1%) or erythromycin eye ointment 4 times a day for 6 weeks; and oral azithromycin (first choice) tetracycline or erythromycin 250 mg +orally 4 times a day for 2 weeks. +B. Treatment of trachoma sequelae +1. Concretions should be removed with a hypodermic needle. +2. Trichiasis may be treated by epilation, electrolysis or cryolysis (see page 370). +3. Cicatricial entropion should be corrected surgically (see page 372). +4. Conjunctival xerosis should be treated by artificial tears. +C. Prophylaxis for trachoma infection and blindness Since immunity is very poor and short lived, so reinfections and recurrences are likely to occur. So, prophylactic measures are essential. +WHO defines blinding trachoma elimination as: • TF prevalence, 5% in 1–9 years children, and +• TI prevalence, 1 per 1000 in total population. + +SAFE strategy +An action plan has been made to implement the WHO endorsed SAFE strategy effectively, also adopted by the alliance for Global Elimination of Trachoma by 2020 (GET 2020), for prophylaxis against trachoma infection and prevention of blindness. +SAFE strategy includes: +S : Surgery (Tertiary prevention), +A : Antibiotic use (Secondary prevention), +F : Facial hygiene (Primary prevention), and +E : Environmental changes (Primordial prevention). 1. Environmental changes (Primordial prevention). Flies and other fomites are the common causes of +spread of trachoma. So, environmental sanitation + +will constitute the primordial prevention for trachoma. Recommended environmental sanitation measures include: +• Provision of water latrines and good water supply to reduce flies and improve washing habits, +• Refuse dumps, +• Sprays to control flies, +• Animal pens away from human household, and +• Health education to improve personal and environmental hygiene. +2.Facial hygiene (Primary prevention). Facial hygiene is critical measure for primary prevention of trachoma and should include: +• Frequent face wash with clean water to eliminate the potentially infectious ocular secretions. +• Avoidance of common use of towel, handkerchief, surma-rods, etc. are important facial hygienic measures to prevent spread of trachoma infections. 3. Antibiotics for prevention against trachoma (Secondary prevention). Use of antibiotics constitutes the secondary prevention against trachoma. Current WHO recommendations for community-based mass +antibiotic therapy in endemic areas are as below: i.In areas with 10% or more prevalence of TF in children 1–9 years or below: +• Oral azithromycin (single dose of 20 mg/kg up to 1 g), should be administered to all community members. +• Tetracycline eye ointment twice daily for 6 weeks is recommended for all pregnant women, children, 6 months and those allergic to macrolides. +• Mass antibiotic therapy should be given once in a year for continuous three years. +• Reassessment of prevalence should be made after 3 years and the annual treatment should be continued till the TF prevalence in 1–9 years children of that area becomes less than 5%. +ii. In areas with prevalence between more than 5% and less than 10%, the targeted antibiotic therapy is recommended only among family members and close contacts of the patients. +iii. In areas with prevalence less than 5%, treatment of patients only is recommended. +4. Surgery (Tertiary prevention). Surgery for trichiasis and entropion constitutes tertiary prevention for trachomatous corneal blindness. WHO recommends bilamellar tarsal rotation surgery at community level for the affected persons. +ADULT INCLUSION CONJUNCTIVITIS +It is a type of acute follicular conjunctivitis associated with mucopurulent discharge. It usually affects the sexually active young adults. +Chapter 5 Diseases of Conjunctiva 73 + + +Etiology +• Serotypes D to K of Chlamydia trachomatis are associated with inclusion conjunctivitis. +• Primary source of infection is urethritis in males and cervicitis in females. +• Transmission of infection may occur to eyes either through contaminated fingers or more commonly through contaminated water of swimming pools (hence the name swimming pool conjunctivitis). +Clinical features +Incubation period of the disease is 4–12 days. Symptoms are similar to acute mucopurulent conjunctivitis and include: +• Ocular discomfort, foreign body sensation, • Mild photophobia, and +• Mucopurulent discharge from the eyes. Signs of inclusion conjunctivitis are (Fig. 5.17): +• Conjunctival hyperaemia, more marked infornices. • Acute follicular hypertrophy predominantly of +lower palpebral conjunctiva. +• Superficial keratitis in upper half of cornea. Sometimes, superior micropannus may also occur. +• Pre-auricular lymphadenopathy is a usual finding. +Clinical course. The disease runs a benign course and often evolves into the chronic follicular conjunctivitis. +Investigations required, their role and status is same as described above for trachoma. +Differential diagnosis must be made from other causes of acute follicular conjunctivitis. +Treatment +1. Topical therapy. It consists of tetracycline (1%) eye ointment 4 times a day for 6 weeks. +2. Systemic therapy is very important, since the condition is often associated with an asymptomatic venereal infection. Commonly employed antibiotics are: + + + + + + + + + + + + + + +Fig. 5.17 Signs of acute follicular conjunctivitis + + +• Azithromycin 1 gm as a single dose repeated after one week is currently drug of choice, a 3rd dose is required in 30% cases. +• Tetracycline 250 mg four times a day for 3–4 weeks, or • Erythromycin 250 mg four times a day for 3–4 weeks (only when the tetracycline is contraindicated, e.g., +in pregnant and lactating females), or +• Doxycycline 100 mg twice a day for 1–2 weeks or 200 mg weekly for 3 weeks is an effective alternative to tetracycline. +3. Referral to genitourinary specialist is mandatory. Sexual partners should be treated simultaneously. Attention should also be given to other sexually transmitted diseases, contact tracing and pregnancy testing. +Prophylaxis +• Improvement in personal hygiene. +• Regular chlorination of swimming pool water will definitely decrease the spread of disease. +• Patient's sexual partner should be examined and treated. Abstinence of sexual contact until completion of treatment. + +VIRAL CONJUNCTIVITIS + +Most of the viral infections tend to affect the epithelium, both of the conjunctiva and cornea; so, the typical viral lesion is a ‘keratoconjunctivitis’. In some viral infections, conjunctival involvement is more prominent (e.g., pharyngoconjunctival fever), while in others cornea is more involved (e.g., herpes simplex). +Viral infections of conjunctiva include: • Adenovirus conjunctivitis, +• Herpes simplex keratoconjunctivitis, • Herpes zoster conjunctivitis, +• Molluscum contagiosum conjunctivitis, • Poxvirus conjunctivitis, +• Myxovirus conjunctivitis, +• Paramyxovirus conjunctivitis, and • ARBOR virus conjunctivitis. +Clinical presentations of acute viral conjunctivitis include: +• Acute follicular conjunctivitis, and • Acute haemorrhagic conjunctivitis. + +ADENOVIRAL CONJUNCTIVITIS +Adenoviruses are the commonest causes of viral conjunctivitis. These are non-enveloped, double-stranded DNA viruses, which replicate within the nucleus of host cells. General reservoir of +adenoviruses is only human. +74 Section III Diseases of Eye + + +Types of adenoviral conjunctivitis include: • Epidemic keratoconjunctivitis (EKC), +• Nonspecific acute follicular conjunctivitis, • Pharyngoconjunctival fever (PCF), and +• Chronic relapsing adenoviral conjunctivitis. + +Epidemic Keratoconjunctivitis (EKC) +It is a type of acute follicular conjunctivitis mostly associated with superficial punctate keratitis and usually occurs in epidemics, hence the name EKC. +Etiology +EKC is mostly caused by adenoviruses type 8 and 19. The condition is markedly contagious and spreads through contact with contaminated fingers, solutions and tonometers. +Clinical features +Incubation period after infection is about 8 days and virus is shed from the inflamed eye for 2–3 weeks. +Symptoms +Symptoms are similar to severe form of acute catarrhal conjunctivitis and include: +• Redness of sudden onset associated with watering, usually profuse, with mild mucoid discharge, +• Ocular discomfort and foreign body sensation, +• Photophobia, usually mild, becomes marked when cornea is involved. +Signs +Eyelids are swollen causing narrowing of palpebral aperture. +Conjunctival signs are: +• Hyperaemia is usually marked and prominent. • Chemosis of conjunctiva is often present. +• Follicles of small to moderate size typically involving the lower fornix and palpebral conjunctiva form the characteristic feature (Fig. 5.18). + + + + + + + + + + + + + + + +Fig. 5.18 Acute follicular adenoviral conjunctivitis + + + + + + + + + + + + + + +Fig. 5.19 Pseudomembrane and petechial subconjunctival haemorrhage in acute epidemic keratoconjunctivitis (EKC) + +• Papillary reaction may also be seen in many cases. • Petechial subconjunctival haemorrhages may be seen in severe adenoviral conjunctivitis (Fig. +5.19). +• Pseudomembrane lining the lower fornix and palpebral conjunctiva (Fig. 5.19) may be formed in about 3% patients with severe inflammation. +Corneal involvement occurs in about 80% of cases and is characterized by following lesions: +• Epithelial microcystic diffuse fine non-staining lesions are common during the early stage. +• Superficial punctate keratitis (SPK), a typical feature of EKC (Fig. 5.20), usually occurs after 10 days of onset of symptoms and lasts for 3 weeks even after subsidence of conjunctival inflammation. +• Subepithelial infiltrates may develop under the focal epithelial lesions in 20–50% of cases . These opacities may be initially disabling and may persist for months to years. +Pre-auricular lymphadenopathy is associated in almost all cases of EKC. + + + + + + + + + + + + + + + +Fig. 5.20 Superficial punctate keratitis in EKC +Chapter 5 Diseases of Conjunctiva 75 + + +Differential diagnosis +Epidemic keratoconjunctivitis (EKC) needs to be differentiated from other causes of acute follicular conjunctivitis which include: +■Other types of adenoviral keratoconjunctivitis such as: • Nonspecific acute follicular conjunctivitis, and +• Pharyngoconjunctival fever. ■Acute haemorrhagic conjunctivitis, ■Herpes simplex virus conjunctivitis, +■Systemic viral infections such as herpes zoster conjunctivitis, measles, mumps and chickunguiya virus conjunctivitis, and +■Adult inclusion conjunctivitis. +Differentiation is made from: +■Typical clinical features of each entity described. ■Investigations are required mainly for research purposes and in some nonresolving cases, and include: +• Conjunctival cytology with Giemsa stain shows predominantly mononuclear cells in adenoviral conjunctivitis and multinucleated gaint cells in herpetic conjunctivitis. +• Polymerase chain reaction (PCR) test is sensitive and specific for viral DNA. +• Point-of-care immunochromatography test takes only 10 minutes to detect adenoviral antigens in tears and have excellent sensitivity and specificity. +• Viral cultures are tedious and time consuming with variable sensitivity but 100% specificity. +Treatment +1. Supportive treatmentfor amelioration of symptoms is the only treatment required and includes: +• Cold compresses, and sun glasses to decrease glare, • Decongestant and lubricant tear drops to decrease +discomfort. +2. Topical antibiotics help to prevent superadded bacterial infections. +3. Topical antiviral drugs are not beneficial in adenoviral conjunctivitis. Recently promising results are reported with adenine arabinosides (Ara-A) and cidofovir. +4. Topical steroids should not be used during active inflammation as these may enhance viral replication and extend the period of infectivity. Weak steroids such as fluorometholone or loteprednol (0.5%) are indicated in patients with subepithelial infiltrates, and in those with membrane formation. +Prevention of spread of infection to the contacts +It is very important as the adenoviral conjunctivitis is highly contagious and patients may be infectious for up to 11 days after onset. + + +Transmission usually occurs: +• From eye to fingers to eyes. +• Tonometers, contact lenses and eye drops are other routes of transmission. +Preventive measures include: • Frequent handwashing, +• Relative isolation of infected individual, +• Avoiding eye rubbing and common use of towel or handkerchief sharing, and +• Disinfection of ophthalmic instruments and clinical surfaces after examination of a patient is essential. +Nonspecific Acute Follicular Conjunctivitis +• Most common form of acute follicular conjunctivitis. • Caused by adenovirus serotypes 1 to 11 and 19. +• Clinical features are of milder form of acute follicular conjunctivitis. Corneal involvement is not known. +• Treatment and preventive measures are similar to as described for EKC. + +Pharyngoconjunctival Fever (PCF) +Etiology. It is an adenoviral infection commonly associated with subtypes 3 and 7. +Clinical features. Pharyngoconjunctival fever primarily affects children and appears in epidemic form. It is characterised by an: +• Acute follicular conjunctivitis, associated with pharyngitis. +• Fever and pre-auricular lymphadenopathy. +• Corneal involvement in the form of superficial punctate keratitis is seen only in 30% of cases. +Treatment is usually supportive as described for EKC. + +Newcastle Conjunctivitis +Etiology. It is a rare type of acute follicular conjunc-tivitis caused by Newcastle virus. The infection is derived from contact with diseased owls; and thus the condition mainly affects poultry workers. Clinically, the condition is similar to pharyngo-conjunctival fever. + +ACUTE HERPETIC CONJUNCTIVITIS +Acute herpetic follicular conjunctivitis is always an accompaniment of the ‘primary herpetic infection’, which mainly occurs in small children and in adolescents. +Etiology +The disease is commonly caused by herpes simplex virus type 1 and spreads by kissing or other close personal contacts. HSV type 2 associated with genital +76 Section III Diseases of Eye + + +infections, may also involve the eyes in adults as well as children, though rarely. +Clinical features +Acute herpetic follicular conjunctivitis is usually a unilateral affection with an incubation period of 3–10 days. It may occur in two clinical forms—typical and atypical. +• In typical form, the follicular conjunctivitis is usually associated with other lesions of primary infection such as vesicular lesions of face and lids. +• In atypical form, the follicular conjunctivitis occurs without lesions of the face, eyelid and the condition then resembles epidemic keratoconjunctivitis. The condition may evolve through phases of no-specific hyperaemia, follicular hyperplasia and pseudomembrane formation. +• Corneal involvement, though rare, is not uncommon in primary herpes. It may be in the form of fine or coarse epithelial keratitis or typical dendritic keratitis. +• Preauricular lymphadenopathy occurs almost always. +Treatment +Primary herpetic infection is usually self-limiting. +• The topical antiviral drugs control the infection effectively and prevent recurrences. +• Supportive measures are similar to EKC. + +ACUTE HAEMORRHAGIC CONJUNCTIVITIS +It is an acute inflammation of conjunctiva characterised by multiple conjunctival haemorrhages, conjunctival hyperaemia and mild follicular hyperplasia. +Etiology +The disease is caused by picornaviruses (enterovirus type 70) which are RNA viruses of small (pico) size. The disease is very contagious and is transmitted by direct hand-to-eye contact. +Clinical features +The disease has occurred in an epidemic form in the far East, Africa and England and hence the name ‘epidemic haemorrhagic conjunctivitis (EHC)’ has been suggested. An epidemic of the disease was first recognized in Ghana in 1969 at the time when Apollo XI spacecraft was launched, hence the name ‘Apollo conjunctivitis’. +• Incubation period of EHC is very short (1–2 days). • Symptoms include pain, redness, watering, mild photophobia, transient blurring of vision and lid +swelling. + + + + + + + + + + + + + + +Fig. 5.21 Acute haemorrhagic conjunctivitis + +• Signs of EHC are conjunctival congestion, chemosis, multiple haemorrhages in bulbar conjunctiva, mild follicular hyperplasia, lid oedema and pre-auricular lymphadenopathy (Fig. 5.21). +• Corneal involvement may occur in the form of fine epithelial keratitis. +Treatment +EHC is very infectious and poses major potential problems of cross-infection. +• Prophylactic measures are very important and are same as described for EKC. +• No specific effective curative treatment is known. However, broad-spectrum antibiotic eyedrops may be used to prevent secondary bacterial infections. +• Usually the disease has a self-limiting course of 7 days. +• Supportive measures are same as EKC. + +OPHTHALMIA NEONATORUM + +Ophthalmia neonatorum is the name given to bilateral inflammation of the conjunctiva occurring in an infant, less than 30 days old. It is a preventable disease usually occurring as a result of carelessness at the time of birth. As a matter of fact any discharge or even watering from the eyes in the first week of life should arouse suspicion of ophthalmia neonatorum, as tears are not formed till then. +Etiology +Source and mode of infection +Infection may occur in three ways: before birth, during birth or after birth. +1. Before birth infection is very rare through infected liquor amnii in mothers with ruptured membrances. +Chapter 5 Diseases of Conjunctiva 77 + + +2 During birth. It is the most common mode of infection from the infected birth canal especially when the child is born with face presentation or with forceps. +3. After birth. Infection may occur during first bath of newborn or from soiled clothes or fingers with infected lochia. +Causative agents +1. Chemical conjunctivitis. It is caused by (in older days silver nitrate was the common cause) or antibiotics used for prophylaxis. +2. Gonococcal infection was considered a serious disease in the past, as it used to be responsible for 50% of blindness in children. But, recently the decline in the incidence of gonorrhoea as well as effective methods of prophylaxis and treatment have almost eliminated it in developed countries. However, in many developing countries it still continues to be a problem. +3. Other bacterial infections, responsible for ophthalmia neonatorum are Staphylococcus aureus, Streptococcus haemolyticus, and Streptococcus pneumoniae. +4. Neonatal inclusion conjunctivitis caused by serotypes D to K of Chlamydia trachomatis is the commonest cause of ophthalmia neonatorum in developed countries. +5. Herpes simplex ophthalmia neonatorum is a rare condition caused by herpes simplex-II virus. +Clinical features +Incubation period +It varies depending on the type of the causative agent as shown below: +Causative agent Incubation period • Chemical 6 hours +• Gonococcal 4 days • Other bacterial 5 days • Neonatal inclusion 21 days +conjunctivitis +• Herpes simplex 15 days +Symptoms and signs +1. Pain and tenderness in the eyeball. +2. Conjunctival discharge. It is purulent in gonococcal ophthalmia neonatorum (Fig. 5.22) and mucoid or mucopurulent in other bacterial cases and neonatal inclusion conjunctivitis. +3. Lids are usually swollen in infective cases. Eyelids and periocular vesicles may occur in HSV infection. +4. Conjunctivamay show hyperaemia and chemosis. There might be mild papillary response in + + + + + + + + + + + + + +Fig. 5.22 Gonococcal ophthalmic neonatorum +neonatal inclusion conjunctivitis and herpes simplex ophthalmia neonatorum. +5. Corneal involvement, though rare, may occur in the form of superficial punctate keratitis especially in herpes simplex ophthalmia neonatorum. +Complications +Untreatedcases,especially ofgonococcal ophthalmia neonatorum, may develop corneal ulceration, which may perforate rapidly resulting in corneal opacification or staphyloma formation. +Treatment +Prophylactic treatment is always better than curative. A. Prophylaxis needs antenatal, natal and postnatal care. +1. Antenatal measures include thorough care of mother and treatment of genital infections when suspected . +2. Natal measures are of utmost importance, as mostly infection occurs during childbirth. +• Deliveries should be conducted under hygienic conditions taking all aseptic measures. +• The newborn baby’s closed lids should be thoroughly cleansed and dried. +3. Postnatal measures include: +• Povidon- iodine 2.5% solution is effective against the common pathogens. +• Use of either 1% tetracycline ointment or 0.5% erythromycin ointment into the eyes of the babies immediately after birth are useful for preventing bacterial and chalamydial ophthalmia neonatorum. +• Single injection of ceftriaxone 50 mg/kgIMorIV(not to exceed 125 mg) should be given to infants born to mothers with untreated gonococcal infection. +Note. In the past 1% silver nitrate solution was put in the eyes of babies immediately after birth (Crede’s method). It is mentioned here just for the historical value. +78 Section III Diseases of Eye + + +B. Curative treatment. As a rule, conjunctival cytology samples and culture sensitivity swabs should be taken before starting the treatment. +1. Chemical ophthalmia neonatorum is a self-limiting condition, and does not require any treatment. +2. Gonococcal ophthalmia neonatorum needs prompt treatment to prevent complications. +a. Topical therapy should include: +• Saline lavage hourly till the discharge is eliminated. • Bacitracin eye ointment 4 times/day. Because of resistant strains topical penicillin therapy is not reliable. However, in cases with proved penicillin susceptibility, penicillin drops 5000 to 10000 units per ml should be instilled every minute for half an hour, every five minutes for next half an hour and then half hourly till the infection is controlled. +• If cornea is involved then atropine sulphate ointment should be applied. +b. Systemic therapy. Neonates with gonococcal ophthalmia should be treated for 7 days with one of the following regimes. +• Ceftriaxone 75–100 mg/kg/day IV or IM, qid or +• Cefotaxime 100–150 mg/kg/day IV or IM, 12 hourly or • Ciprofloxacin 10–20 mg/kg/day or norfloxacin 10 +mg/kg/day or +• If the gonococcal isolate is proved to be susceptible to penicillin, crystalline benzyl penicillin G 50,000 units to full term, normal weight babies and 20,000 units to premature or low weight babies should be given intramuscularly twice daily for 3 days. +3. Other bacterial ophthalmia neonatorum should be treated for 2 weeks by broad-spectrum antibiotic drops and ointments such as neomycin-bacitracin or tobramycin. +4. Neonatal inclusion conjunctivitis responds well to topical tetracycline 1% or erythromycin 0.5% eye ointment qid for 3 weeks. However, systemic erythromycin (125 mg orally, qid for 3 weeks) should also be given since the presence of chlamydia agents in the conjunctiva implies colonization of upper respiratory tract as well. Both parents should also be treated with systemic erythromycin. +5. Herpes simplex conjunctivitis is usually a self-limiting disease. However, topical antiviral drugs control the infection more effectively and may prevent the recurrence. High dose intravenous acyclovir is indicated in cases suspected of systemic herpes infection. + +GRANULOMATOUS CONJUNCTIVAL INFLAMMATIONS + +Granulomatous inflammations of the conjunctiva are characterised by proliferative lesions which usually + +tend to remain localized to one eye and are mostly associated with regional lymphadenitis. +Common granulomatous conjunctival inflammations are: +• Tuberculosis of conjunctiva • Sarcoidosis of conjunctiva • Syphilitic conjunctivitis +• Leprotic conjunctivitis +• Conjunctivitis in tularaemia • Ophthalmia nodosa +PARINAUD’S OCULOGLANDULAR SYNDROME +It is the name given to a group of conditions charact-erised by: +• Unilateral granulomatous conjunctivitis (nodular elevations surrounded by follicles), +• Pre-auricular lymphadenopathy, and • Fever. +Common causes are tularaemia, cat-scratch disease, tuberculosis, syphilis and lymphogranuloma venereum. +Note. This term (Parinaud’s oculoglandular syndrome) is largely obsolete, since the infecting agents can now be usually determined. +OPHTHALMIA NODOSA (CATERPILLAR HAIR CONJUNCT IVITIS) +It is a granulomatous inflammation of the conjunctiva characterized by: +• formation of a nodule on the bulbar conjunctiva in response to irritation caused by the retained hair of caterpillar. The disease is, therefore, common in summers. +• The condition may be often mistaken for a tubercular nodule. Histopathological examination reveals hair surrounded by giant cells and lymphocyte. +Treatment consists of excision biopsy of the nodule. + +B. ALLERGIC CONJUNCTIVITIS + +It is the inflammation of conjunctiva due to allergic or hypersensitivity reactions which may be immediate (humoral) or delayed (cellular). The conjunctiva is ten times more sensitive than the skin to allergens. +Types +1. Simple allergic conjunctivitis +• Seasonal allergic conjunctivitis (SAC) • Perennial allergic conjunctivitis (PAC) 2. Vernal keratoconjunctivitis (VKC) +3. Atopic keratoconjunctivitis (AKC) 4. Giant papillary conjunctivitis (GPC) +Chapter 5 Diseases of Conjunctiva 79 + + +5. Phlyctenular keratoconjunctivitis (PKC) 6. Dermatoconjunctivitis (ADC) +SIMPLE ALLERGIC CONJUNCTIVITIS +It is a mild, nonspecific allergic conjunctivitis characterized by itching, hyperaemia and mild papillary response. Basically, it is an acute or subacute urticarial reaction. +Etiology +Simple allergic conjunctivitis, is a type-I immediate hypersensitivity reaction mediated by IgE and subsequent mast cell activation, following exposure of ocular surface to airborne allergens. Family history of atopy might be present. Simple allergic conjunctivitis is known to occur in two forms: +1. Seasonal allergic conjunctivitis (SAC). SAC is a response to seasonal allergens such as tree and grass pollens. It is of very common occurrence and may be associated with hay fever (allergic rhinitis) and also known as hay fever conjunctivitis. It manifest as acute allergic conjunctivitis. +2. Perennial allergic conjunctivitis (PAC) is a response to perennial allergens such as house dust, animal dander and mite. It is not so common. The onset is subacute, the condition is chronic in nature and occurring all through the year. +Pathology +Pathological features of simple allergic conjunctivitis comprise vascular, cellular and conjunctival responses. +1. Vascular response is characterised by sudden and extreme vasodilation and increased permeability of vessels leading to exudation. +2. Cellular response is in the form of conjunctival infiltration and exudation in the discharge of eosinophils, plasma cells and mast cells producing histamine and histamine-like substances. +3. Conjunctival response is in the form of boggy swelling of conjunctiva followed by increased connective tissue formation and mild papillary hyperplasia. +Clinical features +Symptoms +• Intense itching and burning sensation in the eyes associated with +• Watery mucus, stringy discharge, and • Mild photophobia. +Signs +• Hyperaemia and chemosis which give a swollen juicy appearance to the conjunctiva. + +• Mild papillary reaction may be seen on palpebral conjunctiva. +• Oedema of lids is often present. + +Diagnosis +Diagnosis is made from: +• Typical symptoms and signs, +• Normal conjunctival flora, and +• Presence of abundant eosinophils in the discharge. + +Treatment +1. Elimination of allergens if possible. +2. Topical vasoconstrictors like naphazoline, antizoline and tetrahydrozoline provide imm-ediate decongestion. +3. Artificial tears like carboxymethyl cellulose provide soothing effect. +4. Mast cell stabilizerssuch as sodium cromoglycate and nedocromil sodium are very effective in preventing recurrences in atopic cases. +5. Dual action antihistamines and mast cell stabilizers such azilastine, olopatidine and ketotifen are very effective for exacerabations. +6. Steroid eyedrops should be avoided. However, these may be prescribed for short duration in severe and non-responsive patients. +7. Systemic antihistaminic drugs are useful in acute cases with marked itching. +8. Desensitization has been tried without much rewarding results. However, a trial may be given in recurrent cases. + +VERNAL KERATOCONJUNCTIVITIS (VKC) OR SPRING CATARRH +VKC is a recurrent, bilateral, interstitial, self-limiting, allergic inflammation of the conjunctiva having a periodic seasonal incidence. + +Etiopathogenesis +Vernal keratoconjunctivitis (VKC) has long been considered an atopic disorder, mainly type-I IgE-mediated hypersensitivity reaction to pollen allergens. However, now it is believed that pathogenesis of VKC is characterized by Th2 lymphocyte alteration and that the exaggerated IgE response to common allergens is a secondary event. +Predisposing factors +1. Age and sex. 4–20 years; more common in boys than girls. +2. Season. More common in summer; hence the name spring catarrh seems to be a misnomer. Recently, it is being labelled as ‘Warm weather conjunctivitis’. +80 Section III Diseases of Eye + + +3. Climate. More prevalent in tropics, less in temperate zones and almost non-existent in cold climate. +Pathology +1. Conjunctival epithelium undergoes hyperplasia and sends downward projections into the subepithelial tissue. +2. Adenoid layer shows marked cellular infiltration by eosinophils, plasma cells, lymphocytes and histiocytes. +3. Fibrous layer shows proliferation which later on undergoes hyaline changes. +4. Conjunctival vessels also show proliferation, increased permeability and vasodilation. +All these pathological changes lead to formation of multiple papillae in the upper tarsal conjunctiva. +Clinical features +Symptoms. Spring catarrh is characterised by: +• Marked burning and itching sensation which is usually intolerable and accentuated when patient comes in a warm humid atmosphere. Itching is more marked with palpebral form of disease. +• Other associated symptoms include: mild photophobia, lacrimation, stringy (ropy) discharge and heaviness of lids. +Signs of vernal keratoconjunctivitis can be described in following three clinical forms: +1. Palpebral form. Usually upper tarsal conjunctiva of both eyes is involved. The typical lesion is the presence of hard, flat topped, papillae arranged in a ‘cobble-stone’ or ‘pavement stone’, fashion along with conjunctival hyperemia (Fig. 5.23). In severe cases, papillae may hypertrophy to produce cauliflower-like excrescences of ‘giant papillae’. Conjunctival changes are associated with white ropy discharge. + + + + + + + + + + + + + +A + + + + + + + + + + + + + + + +B +Fig. 5.24 Bulbar form of VKC depicting: A, Gelatimous membrane around limbus; B, Tranta’s spots at limbus + + + + + + +Fig. 5.25 Artist’s diagram of mixed form of vernal keratoconjunctivitis + +2. Bulbar limbal form. It is characterised by: +• Dusky red triangular congestion of bulbar conjunctiva in palpebral area, +• Gelatinous thickened accumulation of tissue around the limbus (Fig. 5.24A), and +• Presence of discrete whitish raised dots along the Fig. 5.23 Palpebral form of vernals keratoconjunctivitis limbus (Horner-Tranta’s spots) (Fig. 5.24B). +Chapter 5 Diseases of Conjunctiva 81 + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 5.26 Vernal keratopathy: A, Shield ulcer; B, Vernal corneal plaque + +3. Mixed form. It shows combined features of both palpebral and bulbar forms (Fig. 5.25). +Vernal keratopathy. Corneal involvement in VKC may be primary or secondary due to extension of limbal lesions. Vernal keratopathy is more frequent with palpebral form and includes following five types of lesions: +1. Punctate epithelial keratitis involving upper cornea is usually associated with palpebral form of disease. The lesions always stain with rose bengal and invariably with fluorescein dye. +2. Ulcerative vernal keratitis (shield ulceration) presents as a shallow transverse ulcer in upper part of cornea (Fig. 5.26A). The ulceration results due to epithelial macroerosions. It is a serious problem which may be complicated by bacterial keratitis. +3. Vernal corneal plaques result due to coating of bare areas of epithelial macroerosions with a layer of altered exudates (Fig. 5.26B). +4. Subepithelial scarring occurs in the form of a ring scar. +5. Pseudogerontoxon can develop in recurrent limbal disease and is characterised by a classical ‘cupid’s bow’ outline. + +Clinical course of disease is often self-limiting and usually burns out spontaneously after 5–10 years. +Differential diagnosis. Palpebral form of VKC needs to be differentiated from trachoma with predominant papillary hypertrophy (see page 71). +Treatment +A. Topical anti-inflammatory therapy +Topical anti-inflammatory therapy with combined steroids, mast cell stabilizers, antihistamines, and NSAIDs forms the mainstay of treatment of VKC. +1. Topical steroids. These are effective in all forms of spring catarrh. However, their use should be minimised, as they frequently cause steroid induced glaucoma. Therefore, monitoring of intraocular pressure is very important during steroid therapy. Frequent instillation (4 hourly) to start with (2 days) should be followed by maintenance therapy for 4 times a day for 2 weeks. +Commonly used steroid solutions are of fluorometholone, medrysone, betamethasone or dexamethasone. Medrysone and fluorometholone are safest of all these. +2. Mast cell stabilizers such as sodium cromoglycate (2%) drops 5 times a day are quite effective in controlling VKC, especially atopic cases. +3. Dual action antihistamines and mast cell stabilizers such as azelastine, olopatidine and ketotifen are very effective for control and prevention of exacerbations. 4. NSAIDs eye drops such as ketorolac and diclofenac give added benefits. +5. Topical cyclosporine (0.5 to 1%), the immune-modulator, is indicated when steroids are ineffective, inadequate, or poorly tolerated, or when given as a steroid-sparing agent in patients with severe disease. 6. Tacrolimus (0.03% ointment) is another immune-modulator, which can be useful in refractory cases. +B. Topical lubricating and mucolytics +1. Artificial tears, such as carboxymethyl cellulose, provide soothing effect. +2. Acetyl cysteine (0.5%) used topically has mucolytic properties and is useful in the treatment of early plaque formation. +C. Systemic therapy +1. Oral antihistaminics may provide some relief from itching in severe cases. +2. Oral steroids for a short duration have been recommended for advanced, very severe, non-responsive cases. +D. Treatment of large papillae +Very large (giant) papillae can be tackled either by: • Supratarsal injection of long acting steroid, or +• Cryo application, or +• Surgical excision is recommended for extra ordinarily large papillae. +82 Section III Diseases of Eye + + +E. General measures include: +• Dark goggles to prevent photophobia. +• Cold compresses and ice packs have soothing effects. • Change of place from hot to cold area is recom- +mended for recalcitrant cases. +F. Desensitization +Desensitization has also been tried without much rewarding results. +G. Treatment of vernal keratopathy +• Punctate epithelial keratitis requires no extra treatment except that instillation of steroids should be increased. +• A large vernal plaque requires surgical excision by superficial keratectomy. +• Severe shield ulcer resistant to medical therapy may need surgical treatment in the form of debridement, superficial keratectomy, excimer laser therapeutic keratectomy as well as amniotic membrane transplantation to enhance re-epithelialization. +ATOPIC KERATOCONJUNCTIVITIS (AKC) +It can be thought of as an adult equivalent of vernal keratoconjunctivitis and is often associated with atopic dermatitis. Most of the patients are young atopic adults, with male predominance. + +Pathogenesis +In AKC both IgE and cell-mediated immune mechanisms play role, i.e., type-I as well as type-IV hypersensitivity reactions are responsible for the inflammatory changes of conjunctiva and cornea. +Clinical features Symptoms include: +• Itching, soreness, dry sensation. • Mucoid discharge. +• Photophobia or blurred vision. Signs +1. Eyelid signs +• Lid margins are chronically inflamed with rounded posterior borders. +• Extra lid folds (Dennie–Morgan fold) may occur due to chronic eyelid rubbing. +• Loss of lateral eyebrows (Hertoghe’s sign) may be seen. +2. Conjunctival signs +• Tarsal conjunctiva has a milky appearance. There are very fine papillae, hyperaemia and scarring with shrinkage. +• Bulbar conjunctiva is chemosed and congested. • Limbal conjunctiva may show gelatinous deposits +and Trantas dots as seen in VKC. 3. Corneal signs +• Punctate epithelial erosions, often more severe in +the lower half of cornea, may be seen. + +• Persistent epithelial defects, sometimes associated with focal thinning, can also occur. +• Plaque formation may occur similar to VKC. +• Peripheral vascularization and stromal scarring are more common than VKC. +4. Associations +• Keratoconus is associated in about 15% cases. +• Atopic cataract, in the form of anterior or posterior subcapsular opacities, may be associated. +• Retinal detachment, incidence is more higher than in general public. +Clinical course. Like the dermatitis eczema with which it is associated, AKC has a protracted course with exacerbations and remissions. Like vernal keratoconjunctivitis it tends to become inactive when patient reaches the fifth decade. +Treatment +• Treatment of AKC is exactly on the same lines as described for VKC (see page 81), except that the AKC is generally less responsive and requires more intensive and prolonged therapy. +• Lid margin inflammation and facial eczema should be treated by oral NSAIDs, oral antibiotics (Doxycycline or azithromycin) and local application of steroids and antibiotic eye ointment. +GIANT PAPILLARY CONJUNCTIVITIS (GPC) GPC is the inflammation of conjunctiva with formation of very large sized papillae. +Etiology +GPC, also known as mechanically-induced papillary conjunctivitis, is a localised allergic response to a physically rough or deposited surface (contact lens, prosthesis, exposed nylon sutures and scleral buckle). Probably, it is a sensitivity reaction to components of the plastic leached out by the action of tears. +Clinical features +Symptoms. Itching, stringy discharge and reduced wearing time of contact lens or prosthetic shell. +Signs. Papillary hypertrophy (0.5 mm to 1 mm in diameter) of the upper tarsal conjunctiva, similar to that seen in palpebral form of VKC with hyperaemia are the main signs (Fig. 5.27). +Treatment +1. The offending cause should be removed. After discontinuation of contact lens or artificial eye or removal of nylon sutures, the papillae resolve over a period of one month. +2. Mast cell stabilizer such as sodium cromoglycate is known to relieve the symptoms and enhance the rate of resolution. +Chapter 5 Diseases of Conjunctiva 83 + + + + + + + + + + + + + + +Fig. 5.27 Giant papillary conjunctivitis (GPC) + +3. Combined antihistamines and mast cell stabilizers like azelastine and olopatadine are very effective. +4. Steroids may be required in resistant cases. + +PHLYCTENULAR KERATOCONJUNCTIVITIS Phlyctenular keratoconjunctivitis is a characteristic nodular affection occurring as an allergic response of the conjunctival and corneal epithelium to some endogenous allergens to which they have become sensitized. Phlyctenular conjunctivitis is of worldwide distribution. However, its incidence is higher in developing countries. +Etiology +It is believed to be a delayed hypersensitivity (Type IV-cell mediated) response to endogenous microbial proteins so called as microbial allergic conjunctivitis. +I. Causative allergens +1. Tuberculous proteins were considered, previously, as the most common cause. +2. Staphylococcus proteins are now thought to account for most of the cases. +3. Other allergens may be proteins of Moraxella Axenfeld bacillus and certain parasites (worm infestation). +II. Predisposing factors +1. Age. Peak age group is 3–15 years. +2. Sex. Incidence is higher in girls than boys. +3. Undernourishment. Disease is more common in undernourished children. +4. Living conditions. Overcrowded and unhygienic. 5. Season. It occurs in all climates but incidence is +high in spring and summer seasons. + +Pathology +1. Stage of nodule formation. In this stage, there occurs exudation and infiltration of leucocytes into the deeper layers of conjunctiva leading to a nodule formation. The central cells are polymorphonuclear and peripheral cells are + +lymphocytes. The neighbouring blood vessels dilate and their endothelium proliferates. +2. Stage of ulceration. Later on necrosis occurs at the apex of the nodule and an ulcer is formed. Leucocytic infiltration increases with plasma cells and mast cells. +3. Stage of granulation. Eventually, floor of the ulcer becomes covered by granulation tissue. +4. Stage of healing. Healing occurs usually with minimal scarring. +Clinical features +Symptoms in simple phlyctenular conjunctivitis are few, like mild discomfort in the eye, irritation and reflex watering. However, usually there is associated mucopurulent conjunctivitis due to secondary bacterial infection. +Signs. The phlyctenular conjunctivitis can present in three forms: simple, necrotizing and miliary. +1. Simple phylctenular conjunctivitis. It is the most commonly seen variety. It is characterised by the presence of a typical pinkish white nodule surrounded by hyperaemia on the bulbar conjunctiva, usually near the limbus. Most of the times there is solitary nodule but at times there may be two nodules (Fig. 5.28). In a few days the nodule ulcerates at apex which later on gets epithelised. Rest of the conjunctiva is normal. 2. Necrotizing phlyctenular conjunctivitis is chara-cterised by the presence of a very large phlycten with necrosis and ulceration leading to a severe pustular conjunctivitis. +3. Miliary phlyctenular conjunctivitis is characterised by the presence of multiple phlyctens which may be arranged haphazardly or in the form of a ring around the limbus and may even form a ring ulcer. Phlyctenular keratitis. Corneal involvement may occur secondarily from extension of conjunctival phlycten; or rarely as a primary disease. It may present in two forms: the ‘ulcerative phlyctenular keratitis’ or ‘diffuse infiltrative keratitis’. + + + + + + + + + + + + +Fig. 5.28 Phylctenular conjunctivitis +84 Section III Diseases of Eye + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 5.29 Fascicular corneal ulcer. A, Diagrammatic; B, Clinical photograph +A. Ulcerative phlyctenular keratitis may occur in the following three forms: +1. Sacrofulous ulcer is a shallow marginal ulcer formed due to breakdown of small limbal phlycten. It differs from the catarrhal ulcer in that there is no clear space between the ulcer and the limbus and its long axis is frequently perpendicular to limbus. Such an ulcer usually clears up without leaving any opacity. +2. Fascicular ulcer has a prominent parallel leash of blood vessels (Fig. 5.29). This ulcer usually remains superficial but leaves behind a band-shaped superficial opacity after healing. +3. Miliary ulcer. In this form multiple small ulcers are scattered over a portion of or whole of the cornea. +B. Diffuse infiltrative phlyctenular keratitis may appear in the form of central infiltration of cornea with characteristic rich vascularization from the periphery, all around the limbus. It may be superficial or deep. + +Clinical course is usually self-limiting and phlycten disappears in 8–10 days leaving no trace. However, recurrences are very common. +Differential diagnosis +Phlyctenular conjunctivitis needs to be differentiated from the episcleritis, scleritis, and conjunctival foreign body granuloma. +Presence of one or more whitish raised nodules on the bulbar conjunctiva near the limbus, with hyperaemia usually of the surrounding conjunctiva, in a child living in bad hygienic conditions (most of the times) are the diagnostic features of the phlyctenular conjunctivitis. +Management +It includes treatment of phlyctenular conjunctivitis by local therapy, investigations and specific therapy aimed at eliminating the causative allergen and general measures to improve the health of the child. +1. Local therapy +i. Topical steroids, in the form of eye drops or ointment (dexamethasone or betamethasone) produce dramatic effect in phlyctenular keratoconjunctivitis. +ii. Antibiotic drops and ointment should be added to take care of the associated secondary infection (mucopurulent conjunctivitis). +iii.Atropine (1%) eye ointment should be applied once daily when cornea is involved. +2. Specific therapy +Attempts must be made to search and eradicate the following causative conditions: +i. Tuberculous infection should be excluded by X-rays chest, Mantoux test, TLC, DLC and ESR. In case, a tubercular focus is discovered, antitubercular treatment should be started to combat the infection. +ii. Septic focus, in the form of tonsillitis, adenoiditis, or caries teeth, when present should be adequately treated by systemic antibiotics and necessary surgical measures. +iii.Parasitic infestation should be ruled out by repeated stool examination and when discovered should be adequately treated for complete eradication. +3. General measures +General measuresaimed to improve the health of child are equally important. Attempts should be made to provide high protein diet supplemented with vitamins A, C and D. +Chapter 5 Diseases of Conjunctiva 85 + + +CONTACT DERMATOCONJUNCTIVITIS +It is an allergic disorder, involving conjunctiva and skin of lids along with surrounding area of face. +Etiology +It is in fact a delayed hypersensitivity (Type IV) response to prolonged contact with chemicals and drugs. A few common topical ophthalmic medications known to produce contact dermatoconjunctivitis are atropine, penicillin, neomycin, soframycin and gentamicin. +Clinical features +1. Cutaneous involvement is in the form of weeping eczematous reaction, involving all areas with which medication comes in contact. +2. Conjunctival responseis in the form of hyperaemia with a generalised papillary response affecting the lower fornix and lower palpebral conjunctiva more than the upper. +3. Cornea may show punctate epithelial keratitis and erosions. + +Diagnosis +• Clinical features is usually typical. +• Conjunctival cytology shows a lymphocytic response with masses of eosinophils. +• Skin test to the causative allergen is positive in most of the cases. + +Treatment +1. Discontinuation of the causative medication, +2. Topical steroid eyedrops to relieve symptoms, and 3. Application of steroid ointment on the involved +skin. + +C. CICATRICIAL CONJUNCTIVITIS + +OCULAR MUCOUS MEMBRANE PEMPHIGOID (OMMP) + +Etiology +• OMMP is thought to be a type II hypersensitivity reaction involving basement membrane of epithelial cells of conjunctiva, other mucosal surfaces and even skin. +• Age. Usually occurs after 60 years of age, but may occur in adolescence. +• Sex. Slightly more common in female than male. + +Pathology +It is chronic inflammatory subepithelial blistering disease with subsequent cicatrization of the involved mucosa. + + + + + + + + + + + + + + + +Fig. 5.30 Ocular mucous membrane pemphigoid with inferior symblepharon formation + +Clinical features I. Ocular features +Symptoms include insidious onset of bilateral redness, foreign body sensation, watering and photophobia. Signs progress as below (Fig. 5.30): +• Inflammatory signs include hyperaemia, chronic papillae and subconjunctival vesicles which later ulcerate. +• Cicatrization signs include loss of plica semilunaris and fornices, formation of symblepharon (usually inferior and ankyloblepharon) ending in severe dry eye syndrome. +• Corneal involvementoccurs as superficial punctate keratitis, secondary microbial keratitis, corneal neovascularization and even perforation. +• Lid sequelae include trichiasis and entropion formation. +II. Systemic features +• Mucosa of oral cavity, anus, vagina and urethra may be involved. +• Desquamative gingivitis is common association. • Cutaneous vesicles, bullae and scar formation may +occur. +• Involvement of trachea and esophagus is potentially life-threatening. +Differential diagnosis need to be made from Stevens-Johnson syndrome and other cicatrizing disorders. +Treatment +1. Topical treatment comprise: +• Tear substitutes, to be used frequently. • Antibiotics for secondary infection. +• Steroids may help in reducing inflammation (caution for corneal melting). +2. Systemic immunosuppression is typically required to suppress the acute phase of disease. +86 Section III Diseases of Eye + + +• Mild disease—use dapsone (1 mg/kg). +• Moderate disease—use antimetabolite such as methotrexate or azathioprine. +• Severe disease—use intravenous methyl-prednisolone with or without cyclophosphamide for 4 days, followed by oral prednisolone. +3. Surgical intervention required in late stage (depending upon the condition) may be: +• Punctal occlusion for dry eye. +• Silicon hydrogel contact lens use. +• Correction of trichiasis and entropion. +• Ocular surface reconstruction for advanced scarring. +• Corneal transplantation. +• Keratoprosthesis in extensive corneal and ocular surface scarring. +STEVENS-JOHNSON SYNDROME AND TOXIC EPIDERMAL NECROSIS +Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN) (Lyell syndrome) are acute mucocutaneous blistering diseases usually associated with severe ocular complications. +Etiology +These conditions are thought to result from a Type III hypersensitivity response to certain drugs (such as sulfonamides, anticonvulsants and allopurinol) and infectious agents (such as mycoplasma, pneu-moniae, herpes simplex virus and adenovirus). +Clinical features +Symptoms +Symptoms include acute onset of fever, skin rash, red eyes, malaise, arthralgia and respiratory tract symptoms. +Systemic signs +• Classic ‘target’ skin lesions are maculopapules with a red crator and white surrounding area or bullae. +• Haemorrhagic inflammation of mucous membranes, e.g., haemorrhagic lip crusting. +• Ulcerative stomatitis. +• Sloughing of epidermal surface (seen in TEN) is called Nikolsky sign. +Ocular signs +Acute disease is characterized by papillary or mucopurulent or pseudomembranous conjunctivitis, episcleritis, and iritis. +Late disease is characterized by: +• Conjunctival scarring and symblepharon formation, +• Trichiasis and lid deformities, +• Dry eye resulting from loss of Goblet cells and destruction of lacrimal gland ductules, and + +• Corneal neovascularization, ulceration, perforation and scarring. +Treatment +Systemic treatment in acute phase includes: +Removal (e.g., causative drugs) or treatment (e.g., of causative infection) of the inciting factor: +• Intravenous immunoglobulin, +• Role of systemic steroids is controversial, • Maintenance of hydration, and +• Debridement and replacement of sloughing skin. +Ocular treatment during acute phase includes: +• Topical tear drops and prevention of exposure, • Topical antibiotics and steroid eyedrops, and +• Pseudomembrane peel and symblepharon lysis with glass rod or moistened cotton swab should be done daily. +Late stage interventions are similar to OMMP (see page 85-86). +SECONDARY CICATRICIAL CONJUNCTIVITIS Cicatricial conjunctivitis may occur secondary to: Injuries to conjunctiva (such as thermal, radiational or chemical burns) and infective conjunctivitis (such as trachoma and viral pseudomembranous conjunctivitis). + +D. TOXIC CONJUNCTIVITIS + +1. Toxic conjunctivitis secondary to molluscum contagiosum +It is a type of chronic follicular conjunctivitis that occurs as a response to toxic cellular debris desquamated into the conjunctival sac from the molluscum contagiosum nodules present on the lid margin (the primary lesion). +2. Chemical toxic conjunctivitis +• It is an irritative follicular conjunctival response which occurs after prolonged administration of topical medication. +• Common topical preparations associated with chronic follicular conjunctivitis are: idoxuridine (IDU), eserine, pilocarpine, DFP adrenaline, neomycin and preservatives including contact lens solutions. + +DEGENERATIVE CONDITIONS + +PINGUECULA +Pinguecula is an extremely common degenerative condition of the conjunctiva. It is characterized by formation of a yellowish white patch on the bulbar conjunctiva near the limbus. This condition is termed pinguecula, because of its resemblance to fat, which means pinguis. +Chapter 5 Diseases of Conjunctiva 87 + + + + + + + + + + + + + + + + +Fig. 5.31 Pinguecula + +Etiology of pinguecula is not known exactly. It has been considered as an age-change, occurring more commonly in persons exposed to strong sunlight, dust and wind. It was considered a precursor of pterygium. However, currently it is suggested that pinguecula does not progress to pterygium and that the two are distinct disorders. +Pathology. There is an elastotic degeneration of collagen fibres of the substantia propria of conjunctiva, coupled with deposition of amorphous hyaline material in the substance of conjunctiva. +Clinical features. Pinguecula is a bilateral, usually stationary condition, presenting as yellowish white triangular patch near the limbus (Fig. 5.31). Apex of the triangle is away from the cornea. It affects the nasal side first and then the temporal side. When conjunctiva is congested, it stands out as an avascular prominence. +Complications of pinguecula include its inflam-mation, intraepithelial abscess formation and rarely calcification and doubtful conversion into pterygium. +Treatment. In routine no treatment is required for pinguecula. However, when cosmetically unaccepted and if so desired, it may be excised. When inflamed it is treated with topical steroid. +PTERYGIUM +Pterygium (L. Pterygion = a wing) is a wing-shaped fold of conjunctiva encroaching upon the cornea from either side within the interpalpebral fissure. +Etiology +Etiology of pterygium is not definitely known. But the disease is more common in people living in hot climates. Therefore, the most accepted view is that + +it is a response to prolonged effect of environmental factors such as exposure to sun (ultraviolet rays), dry heat, high wind and abundance of dust. +Pathology +Pathologically pterygium is a degenerative and hyperplastic condition of conjunctiva. The subconjunctival tissue undergoes elastotic degener-ation and proliferates as vascularised granulation tissue under the epithelium, which ultimately encroaches the cornea. The corneal epithelium, Bowman’s layer and superficial stroma are destroyed. +Clinical features +Demography +• Age: Usually seen in old age. +• Sex: More common in males doing outdoor work than females. +• Laterality: It may be unilateral or bilateral. Usually present on the nasal side but may also occur on the temporal side. +Symptoms +• Cosmetic intolerance may be the only issue in otherwise asymptomatic condition in early stages. +• Foreign body sensation and irritation may be experienced. +• Defective vision occurs when it encroaches the pupillary area or due to corneal astigmatism induced by fibrosis in the regressive stage. +• Diplopia may occur occasionally due to limitation of ocular movements. +Signs +Pterygium presents as a triangular fold of conjunctiva encroaching on the cornea in the area of palpebral aperture usually on the nasal side (Fig. 5.32) but may also occur on the temporal side. Very rarely, both nasal and temporal sides are involved (primary double pterygium). + + + + + + + + + + + + + + +Fig. 5.32 Pterygium +88 Section III Diseases of Eye + + +Parts of a fully-developed pterygium are as follows: (Fig. 5.32): +• Head: Apical part present on the cornea, +• Neck: Constricted part present in the limbal area, and +• Body: Scleral part, extending between limbus and the canthus. +• Cap: Semilunar whitish infiltrate present just in front of the head. +Types. Depending upon the progression it may be progressive or regressive pterygium. +• Progressive pterygium is thick, fleshy and vascular with a few whitish infiltrates in the cornea, in front of the head of the pterygium known as Fuch’s spots or islets of Vogt also called cap of pterygium. +• Regressive pterygium is thin, atrophic, attenuated with very little vascularity. There is no cap, but deposition of iron (Stocker’s line) may be seen sometimes, just anterior to the head of pterygium. Ultimately, it becomes membranous but never disappears. +Complications +• Cystic degeneration and infection are infrequent. • Neoplastic change to epithelioma, fibrosarcoma or +malignant melanoma, may occur rarely. +Differential diagnosis +Pterygium must be differentiated from pseudop-terygium. Pseudopterygium is a fold of bulbar conjunctiva attached to the cornea. It is formed due to adhesions of chemosed bulbar conjunctiva to the marginal corneal ulcer. It usually occurs following chemical burns of the eye. +Differences between pterygium and pseudo-pterygium are given in Table 5.3. + +Table 5.3 Differences between pterygium and pseudopterygium +Pterygium Pseudopterygium +1. Etiology Degenerative Inflammatory process process +2. Age Usually occurs in Can occur at any elder persons age +3. Site Always situated Can occur at any site in the palpebral +aperture +4. Stages Either progressive, Always stationary regressive or +stationary +5. Probe Probe cannot be A probe can be test passed underneath passed under the +neck + +Treatment +Surgical excision is the only satisfactory treatment, which may be indicated for: +• Cosmetic disfigurement. +• Visual impairment due to significant regular or irregular astigmatism. +• Continued progression threatening to encroach onto the pupillary area (once the pterygium has encroached pupillary area, wait till it crosses on the other side). +• Diplopia due to interference in ocular movements. Recurrence of the pterygium after surgical excision is the main problem (30–50%). However, it can be reduced by any of the following measures: +• Surgical excision with free conjunctival limbal autograft (CLAU) taken from the same eye or other eye is presently the preferred technique. +• Surgical excision with amniotic membrane graft and mitomycin-C (MMC) (0.02%) application may be required in recurrent pterygium or when dealing with a very large pterygium. +• Surgical excision with lamellar keratectomy and lamellar keratoplasty may be required in deeply infiltrating recurrent recalcitrant pterygia. +• Old methods to prevent recurrence (not preferred now) included transplantation of pterygium in the lower fornix (McRaynold’s operation) and postoperative use of beta irradiations. +Surgical technique of pterygium excision +1. After topical anaesthesia, eye is cleansed, draped and exposed using universal eye speculum. +2. Head of the pterygium is lifted and dissected off the cornea very meticulously (Fig. 5.33A). +3. Main mass of pterygium is then separated from the sclera underneath and the conjunctiva superficially. +4. Pterygium tissue is then excised taking care not to damage the underlying medial rectus muscle (Fig. 5.33B). +5. Haemostasis is achieved and the episcleral tissue exposed is cauterised thoroughly. +6. Conjunctival limbal autograft (CLAU) transplant-ation to cover the defect after pterygium excision (Fig. 5.33C). It is the latest and most effective technique in the management of pterygium. Use of fibrin glue to stick the autograft in place reduces operating time as well as discomfort associated with the sutures. +CONCRETIONS +Etiology.Concretions are formed due to accumulation of inspissated mucus and dead epithelial cell debris into the conjunctival depressions called loops of +Chapter 5 Diseases of Conjunctiva 89 + + + + + + + + + + +A + + + + + + + +B + + + + + + + +C + +Fig. 5.33 Surgical technique of pterygium excision: A, dissection of head from the cornea; B, excision of pterygium tissue under the conjunctiva; C, conjunctival limbal autograft after excising the pterygium + +Henle. They are commonly seen in elderly people in a degenerative condition and also in patients with scarring stage of trachoma. The name concretion is a misnomer, as they are not calcareous deposits. +Clinical features. Concretions are seen on palpebral conjunctiva, more commonly on upper than the lower. They may also be seen in lower fornix. These are yellowish white, hard looking, raised areas, varying in size from pin point to pin head (Fig. 5.13). Being hard, they may produce foreign body sensations and lacrimation by rubbing the corneal surface. Occasionally, they may even cause corneal abrasions. +Treatment. It consists of their removal with the help of a hypodermic needle under topical anaesthesia. +AMYLOID DEGENERATION OF CONJUNCTIVA +Etiology +Conjunctival amyloid, though rare, is reported to occur in two forms: +• Primary conjunctival amyloid is associated with deposition of light-chain immunoglobulin by the monoclonal B cells and plasma cells. + +• Secondary conjunctival amyloid may occur secondary to systemic diseases or secondary to chronic conjunctival inflammations. +Clinical features +• Deposition of yellowish, well-demarcated, irregular amyloid material in the conjunctiva with superior fornix and tarsal conjunctiva being more commonly involved areas. +• Subconjunctival haemorrhage may be associated with amyloid deposition in blood vessels. + +Treatment +• Lubricating drops for mild symptoms. +• Excision biopsy can be performed in patients with marked irritation due to raised lesions. + +SYMPTOMATIC CONDITIONS OF CONJUNCTIVA +Common symptomatic conditions of conjunctiva include: +• Hyperaemia of conjunctiva, • Chemosis of conjunctiva, +• Ecchymosis of conjunctiva, • Xerosis of conjunctiva, and +• Discoloration of conjunctiva. + +SIMPLE HYPERAEMIA OF CONJUNCTIVA Simple hyperaemia of conjunctiva means congestion of the conjunctival vessels without being associated with any of the established diseases. + +Etiology +It may be acute and transient, or recurrent and chronic. +1. Acute transient hyperaemia. It results due to temporary irritation caused by: +i. Direct irritants such as a foreign body, misdirected cilia, concretions, dust, chemical fumes, smoke, stormy wind, bright light, extreme cold, extreme heat and simple rubbing of eyes with hands. +ii. Reflex hyperaemia due to eye strain, from inflammations of nasal cavity, lacrimal passages and lids. +iii.Hyperaemia associated with systemic febrile conditions. +iv. Nonspecific inflammation of conjunctiva. +2. Recurrent or chronic hyperaemia. It is often noticed in chronic smokers, chronic alcoholics, people residing in dusty, ill ventilated rooms, workers exposed to prolonged heat, in patients sufffering from rosacea and insomnia or otherwise having less sleep. +90 Section III Diseases of Eye + + +Clinical features +• Patients with simple hyperaemia usually complain of a feeling of discomfort, heaviness, grittiness, tiredness and tightness in the eyes. +• There may be associated mild lacrimation and minimal mucoid discharge. +• On cursory examination, the conjunctiva often looks normal. However, eversion of the lids may reveal mild to moderate congestion being more marked in fornices. +Treatment +• Removal of the cause of hyperaemia, e.g., in acute transient hyperaemia the removal of irritants (e.g., misdirected cilia) gives prompt relief. +• Symptomatic relief may be achieved by use of topical decongestants (e.g., 1:10000 adrenaline drops) or naphazoline drops. +CHEMOSIS OF CONJUNCTIVA +Chemosis or oedema of the conjunctiva is of frequent occurrence owing to laxity of the tissue. +Causes. The common causes of chemosis can be grouped as under: +1. Local inflammatory conditions. These include conjunctivitis, corneal ulcers, fulminating iridocyclitis, endophthalmitis, panophthalmitis, styes, acute meibomitis, orbital cellulitis, acute dacryoadenitis, acute dacryocystitis, tenonitis and so on. +2. Local obstruction to flow of blood and/or lymph. It may occur in patients with orbital tumours, cysts, endocrine exophthalmos, orbital pseudotumours, cavernous sinus thrombosis, caroticocavernous fistula, blockage of orbital lymphatics following orbital surgery, acute congestive glaucoma, etc. +3. Systemic causes. These include severe anaemia and hypoproteinaemia, congestive heart failure, nephrotic syndrome, urticaria, and angioneurotic oedema. +Clinical features and management of chemosis depends largely upon the causative factor. +ECCHYMOSIS OF CONJUNCTIVA +Ecchymosis or subconjunctival haemorrhage is of very common occurrence. It may vary in extent from small petechial haemorrhage to an extensive one spreading under the whole of the bulbar conjunctiva and thus making the white sclera of the eye invisible. The condition though draws the attention of the patients immediately as an emergency but is most of the time trivial. +Etiology +Subconjunctival haemorrhage may be associated with following conditions: + + +1. Trauma. It is the most common cause of subconjunctival haemorrhage. It may be in the form of (i) local trauma to the conjunctiva including that due to surgery and subconjunctival injections, (ii) retrobulbar haemorrhage which almost immediately spreads below the bulbar conjunctiva. Mostly, it results from a retrobulbar injection and from trauma involving various walls of the orbit. +2. Inflammations of the conjunctiva. Petechial subconjunctival haemorrhages are usually associated with acute haemorrhagic conjunctivitis caused by picorna viruses, pneumococcal conjunctivitis and leptospirosis, icterohae-morrhagica conjunctivitis. +3. Sudden venous congestion of head. The subconjunctival haemorrhages may occur owing to rupture of conjunctival capillaries due to sudden rise in pressure. Common conditions are whooping cough, epileptic fits, strangulation or compression of jugular veins and violent compression of thorax and abdomen as seen in crush injuries. +4. Spontaneous rupture of fragile capillaries may occur in vascular diseases such as arteriosclerosis, hypertension and diabetes mellitus. +5. Local vascular anomalies like telangiectasia, varicosities, aneurysm or angiomatous tumour. +6. Blood dyscrasias like anaemias, leukaemias and dysproteinaemias. +7. Bleeding disorderslike purpura, haemophilia and scurvy. +8. Acute febrile systemic infections such as malaria, typhoid, diphtheria, meningococcal septicaemia, measles and scarlet fever. \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_4.txt b/notes/A K Khurana - Comprehensive Ophthalmology_4.txt new file mode 100644 index 0000000000000000000000000000000000000000..08ee45e3d0a3326bcfe80e7c711b873bc16cda80 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_4.txt @@ -0,0 +1,1599 @@ +9. Vicarious bleeding associated with menstruation is an extremely rare cause of subconjunctival haemorrhage. +Clinical features +• Subconjunctival haemorrhage per se is sympt-omless. However, there may be symptoms of associated causative disease. +• On examination, subconjunctival haemorrhage looks as a flat sheet of homogeneous bright red colour with well-defined limits (Fig. 5.34). +• In traumatic subconjunctival haemorrhage, posterior limit is visible when it is due to local trauma to eyeball, and not visible when it is due to head injury or injury to the orbit. +• Most of the time it is absorbed completely within 7 to 21 days. During absorption colour changes are noted from bright red to orange and then yellow. In severe cases, some pigmentation may be left behind after absorption. +Chapter 5 Diseases of Conjunctiva 91 + + + + + + + + + + + + + + + +Fig. 5.34 Subconjunctival haemorrhage + +Treatment +• Treat the cause when discovered. +• Placebo therapy with astringent eye drops. +• Psychotherapy and assurance to the patient is most important part of treatment. +• Cold compresses to check the bleeding in the initial stage and hot compresses may help in absorption of blood in late stages. +XEROSIS OF CONJUNCTIVA +Xerosis of the conjunctiva is a symptomatic condition in which conjunctiva becomes dry and lustreless. Normal conjunctiva is kept moist by its own secretions, mucin from goblet cells and aqueous solution from accessory lacrimal glands. Therefore, even if the main lacrimal gland is removed, xerosis does not occur. Depending upon the etiology, conjunctival xerosis can be divided into two groups, parenchymatous and epithelial xerosis. +1. Parenchymatous xerosis. It occurs following cicatricial disorganization of the conjunctiva due to local causes which can be in the form of: +• Destructive interstitial conjunctivitis as seen in trachoma, diphtheric membranous conjunctivitis, Steven-Johnsons syndrome, pemphigus or pemphigoid conjunctivitis, thermal, chemical or radiational burns of conjunctiva. +• Exposure of conjunctiva to air as seen in marked degree of proptosis, facial palsy, ectropion, lack of blinking (as in coma), and lagophthalmos due to symblepharon. +2. Epithelial xerosis. It occurs due to hypo-vitaminosis-A. Epithelial xerosis may be seen in association with night blindness or as a part and parcel of the xerophthalmia (the term which is applied to all ocular manifestations of vitamin A deficiency) which range from night blindness to keratomalacia (see pages 467–470). + +Clinical features. Epithelial xerosis typically occurs in children and is characterized by varying degree of conjunctical dryness, thickening, wrinkling and pigmentation. +Treatment. Treatment of conjunctival xerosis consists of: +• Treatment of the cause, +• Symptomatic local treatment with artificial tear preparations (0.7% methyl cellulose or 0.3% hypromellose or polyvinyl alcohol), which should be instilled frequently. +DISCOLORATION OF CONJUNCTIVA +Normal conjunctiva is a thin transparent structure. In the bulbar region, underlying sclera and a fine network of episcleral and conjunctival vessels can be easily visualized. In the palpebral region and fornices, it looks pinkish because of underlying fibrovascular tissue. +Causes. Conjunctiva may show discoloration in various local and systemic diseases given below: +1. Red discoloration. A bright red homogeneous discoloration suggests subconjunctival haemorrhage (Fig. 5.34). +2. Yellow discoloration. It may occur due to: (i) bile pigments in jaundice, (ii) blood pigments in malaria and yellow fever, (iii) conjunctival fat in elder and Negro patients. +3. Greyish discoloration. It may occur due to application of Kajal (surma or soot) and mascara in females. +4. Brownish grey discoloration. It is typically seen in argyrosis, following prolonged application of silver nitrate for treatment of chronic conjunctival inflammations. The discoloration is most marked in lower fornix. +5. Blue discoloration. It is usually due to ink tattoo from pens or effects of manganese dust. Blue discoloration play also be due to pseudopigmentation as occurs in patients with blue sclera and scleromalacia perforans. +6. Brown pigmentation. Its common causes can be grouped as under: +a. Non-melanocytic pigmentation +i. Endogenous pigmentation. It is seen in patients with Addison’s disease and ochronosis. +ii. Exogenous pigmentation. It may follow long-term use of adrenaline for glaucoma. Argyrosis may also present as dark brown pigmentation. +b. Melanocytic pigmentation +i. Conjunctival epithelial melanosis (Fig. 5.35). It develops in early childhood, and then remains stationary. It is found in 90% of the blacks. The +92 Section III Diseases of Eye + + + + + + + + + + + + +Fig. 5.35 Conjunctival epithelial melanosis + +pigmented spot freely moves with the movement of conjunctiva. It has got no malignant potential and hence no treatment is required. +ii. Subepithelial melanosis. It may occur as an isolated anomaly of conjunctiva (congenital melanosis oculi, Fig. 5.36) or in association with the ipsilateral hyperpigmentation of the face (oculodermal melanosis or Naevus of Ota). iii.Pigmented tumours. These can be benign naevi, precancerous melanosis or malignant +melanoma. + +CYSTS AND TUMOURS + +CYSTS OF CONJUNCTIVA +The common cystic lesions of the conjunctiva are: 1. Congenital cystic lesions. These are of rare +occurrence and include congenital corneoscleral cyst and cystic form of epibulbar dermoid. +2. Lymphatic cysts of conjunctiva. These are common and usually occur due to dilatation of lymph spaces in the bulbar conjunctiva. Lymphangiectasis is characterized by a row of small cysts. Rarely, lymphangioma may occur as a single multilocular cyst. +3. Retention cysts. These occur occasionally due to blockage of ducts of accessory lacrimal glands of Krause in chronic inflammatory conditions, viz., + + + + + + + + + + + + +Fig. 5.36 Congenital melanosis oculi + +trachoma and pemphigus. Retention cysts are more common in upper fornix. +4. Epithelial implantation cyst (traumatic cyst). It may develop following implantation of conjunctival epithelium in the deeper layers, due to surgical or non-surgical injuries of conjunctiva. +5. Epithelial cysts due to downgrowth of epithelium are rarely seen in chronic inflammatory or degenerative conditions, e.g., cystic change in pterygium. +6. Aqueous cyst. It may be due to healing by cystoid cicatrix formation, following surgical or non-surgical perforating limbal wounds. +7. Pigmented epithelial cyst. It may be formed sometimes following prolonged topical use of cocaine or epinephrine. +8. Parasitic cysts such as subconjunctival cysticercus (Fig. 5.37), hydatid cyst and filarial cyst are not infrequent in developing countries. +Treatment +Conjunctival cysts need a careful surgical excision. The excised cyst should always be subjected to histopathological examination. +TUMOURS OF CONJUNCTIVA Classification +Non-pigmented tumours +i. Congenital: Dermoid and lipodermoid (choristomas). +ii. Benign:Simple granuloma, papilloma, adenoma, fibroma and angiomas. +iii.Premalignant: Intraepithelial epithelioma (Bowen’s disease). +iv. Malignant: Epithelioma or squamous cell carcinoma, basal cell carcinoma. +Pigmented tumours +i. Benign: Naevi or congenital moles. +ii. Precancerous melanosis: Superficial spreading melanoma and lentigo maligna (Hutchinson’s freckle). + + + + + + + + + + + + +Fig. 5.37 Cysticercosis of conjunctiva +Chapter 5 Diseases of Conjunctiva 93 + + +iii. Malignant: primary melanoma (malignant melanoma). +A. Non-pigmented tumours +I. Congenital tumours +1. Dermoids. These are common congenital tumours which usually occur at the limbus. They appear as solid white masses, firmly fixed to the cornea (Fig. 5.38). Dermoid consists of collagenous connective tissue, sebaceous glands and hair, lined by epidermoid epithelium. Treatment is simple excision. +2. Lipodermoid (Fig. 5.39). It is a congenital tumour, usually found at the limbus or outer canthus. It appears as soft, yellowish white, movable subconjunctival mass. It consists of fatty tissue and the surrounding dermis-like connective tissue, hence the name lipodermoid. +Sometimes, the epibulbar dermoids or lipode-rmoids may be associated with accessory auricles and other congenital defects (Goldenhar’s syndrome). +II. Benign tumours +1. Simple granuloma. It consists of an extensive polypoid, cauliflower-like growth of granulation tissue. Simple granulomas are common following squint surgery, as foreign body granuloma and following inadequately scraped chalazion. + + + + + + + + + + + +Fig. 5.38 Limbal dermoid + + + + + + + + + + + + + + +Fig. 5.39 Lipodermoid + +■Treatment consists of complete surgical removal. 2. Papilloma. It is a benign polypoid tumour usually occurring at inner canthus, fornices or limbus. It may resemble the cocks comb type of conjunctival tubercular lesion. It has a tendency to undergo malignant change and hence needs complete excision. 3. Fibroma. It is a rare soft or hard polypoid growth usually occurring in lower fornix. +III. Premalignant tumours +Bowen’s intraepithelial epithelioma (carcinoma in situ). It is a rare, precancerous condition, now included in ocular surface squamous neoplasia (OSSN). +IV. Malignant tumours +1. Squamous cell carcinoma (epithelioma) (Fig. 5.40). It usually occurs at the transitional zones, i.e., at limbus and the lid margin. The tumour invades the stroma deeply and may be fixed to underlying tissues. Histologically, it is similar to squamous cell carcinomas occurring elsewhere (see page 385). Now it is also included in ocular surface squamous neoplasia (OSSN). +Ocular Surface Squamous Neoplasia Ocular surface squamous neoplasia (OSSN) is the term coined to denote the wide spectrum of dysplastic changes involving epithelium of conjunctiva, cornea and limbus. It includes squamous dysplasia, carcinoma-in-situ i.e. corneal and conjunctival intraepithelial neoplasia (CIN) and squamous cell carcinoma(SCC). CIN is characterised by partial to full thickness intraepithelial neoplasia with an intact basement membrane without involvement of the underlying substantia propria. While, SCC occurs when neoplastic cells penetrate the basement membrane and invade the underlying stroma. Very few CIN progress to SCC. + + + + + + + + + + + + + + + +Fig. 5.40 Squamous cell carcinoma at the limbus +94 Section III Diseases of Eye + + +Risk factors for OSSN include: +• Exposure to intense UV radiation, • Aadvanced age, +• Cigarette smoking, +• AIDS and conjunctival Human papilloma virus (HPV) infections, +• History of squamous cell carcinoma in head and neck, +• Xeroderma pigmentosa, and • Light complexion. +Pathogenesis. Since OSSN usually arise at the limbus, so it has been postulated that various predisposing factors probably act on the stem cells causing their abnormal maturation and proliferation resulting in OSSN (Stem cell theory). +Clinical features. Since, initially it is not possible to clinically differentiate between squamous dysplasia, carcinoma-in-situ and SCC; so that term OSSN is used. Three morphological patterns are described: • Leukoplakic form appears as a focal thickening +of the epithelium with overlying hyperkeratotic plaque, +• Papillomatous form appears as well-defined soft vascularised mass, and +• Gelatinous form appears as an ill-defined translucent thickening. +Over the period a nodular tumour involving the stroma deeply may occur as SCC (Fig 5.40). Treatment. Surgical excision with surrounding 2-4 mm of normal tissue is the treatment of choice. Measures to decrease recurrence include: +• Cryotherapy to surrounding tissue, +• Topical chemotherapy with mitomycin +Radical excision including enucleation and even exentration may be needed along with postoperative radiotherapy in advanced cases of SCC +2. Basal cell carcinoma. It may invade the conjunctiva from the lids or may arise pari-passu from the plica + + + + + + + + + + + + + + +Fig. 5.41 Conjunctival naevus + + +semilunaris or caruncle. Though it responds very favourably to radiotherapy, the complete surgical excision, if possible, should be preferred to avoid complications of radiotherapy. +B. Pigmented tumours +1. Naevi or congenital moles. These are common pigmented lesions, usually presenting as grey gelatinous, brown or black, flat or slightly raised nodules on the bulbar conjunctiva, mostly near the limbus (Fig. 5.41). They usually appear during early childhood and may increase in size at puberty or during pregnancy. Histologically, they resemble their cutaneous brethren. Malignant change is very rare and when occurs is indicated by sudden increase in size or increase in pigmentation or appearance of signs of inflammation. Therefore, excision is usually indicated for cosmetic reasons and rarely for medical reasons. Whatever may be the indication, excision should be complete. +2. Precancerous melanosis. Precancerous melanosis (intraepithelial melanoma) of conjunctiva occurs in adults as ‘superficial spreading melanoma’. It never arises from a congenital naevus. +■Clinically, a small pigmented tumour develops at any site on the bulbar or palpebral conjunctiva, which spreads as a diffuse, flat, asymptomatic pigmented patch. As long as it maintains its superficial spread, it does not metastasize. However, ultimately in about 20% cases it involves the subepithelial tissues and proceeds to frank malignant change. +■Treatment. In early stages local excision with postoperative radiotherapy may be sufficient. But in case of recurrence, it should be treated as malignant melanoma. +3. Malignant melanoma (primary melanoma). Malignant melanoma of the conjunctiva mostly arises de-novo, usually near the limbus, or rarely it may occur due to malignant change in pre-existing naevus. The condition usually occurs in elderly patients. +■Clinically, it may present as pigmented or nonpigmented mass near limbus or on any other part of the conjunctiva. It spreads over the surface of the globe and rarely penetrates it. Distant metastasis occurs elsewhere in the body, commonly in liver. ■Histologically, the neoplasm may be alveolar, round-celled or spindle-celled. +■Treatment. Once suspected, enucleation or exenteration is the treatment of choice, depending +upon the extent of growth. +6 + +Diseases of Cornea + + + +CHAPTER OUTLINE + +ANATOMY AND PHYSIOLOGY Applied anatomy +Applied physiology CONGENITAL ANOMALIES INFLAMMATIONS OF CORNEA Ulcerative keratitis +• +• +Infective keratitis Bacterial corneal ulcer Mycotic corneal ulcer Viral corneal ulcer Protozoal keratitis +• +• +• +• +Allergic keratitis Trophic corneal ulcer +• +• +Neurotrophic keratopathy Exposure keratopathy +Peripheral ulcerative keratopathies Non-ulcerative keratitis +• +• +Superficial Deep +CORNEAL DEGENERATIONS +• +Age-related corneal degenerations + + + +ANATOMY AND PHYSIOLOGY + +APPLIED ANATOMY +Cornea is a transparent, avascular, watch-glass like structure. It forms anterior one-sixth of the outer fibrous coat of the eyeball. +Dimensions +• Anterior surface of cornea is elliptical with an average horizontal diameter of 11.7 mm and vertical diameter of 11 mm. +• Posterior surface of cornea is circular with an average diameter of 11.5 mm. +• Thickness of cornea in the centre varies from 0.5 to 0.6 mm while at the periphery it varies from 1 to 1.2 mm. +• Radius of curvature. The central 5 mm area of the cornea forms the powerful refracting surface of the eye. The anterior and posterior radii of curvature of this central part of cornea are 7.8 mm and 6.5 mm, respectively. + +• Pathological corneal degenerations CORNEAL DYSTROPHIES +Epithelial and subepithelial dystrophies Bowman layer dystrophies +• +• +• +• +Stromal corneal dystrophies +Descemet membrane and endothelial corneal dystrophies ECTATIC CONDITIONS OF CORNEA +• +• +• +Keratoconus Keratoglobus Keratoconus posterior +ABNORMALITIES OF CORNEAL TRANSPARENCY Corneal oedema +• +• +• +Corneal opacity Corneal vascularization +CORNEAL SURGERY Keratoplasty +• +• +• +• +Refractive corneal surgery Phototherapeutic keratectomy Keratoprosthesis + + + +• Refractive index of the cornea is 1.376. +• Refractivepowerof the cornea is about 45dioptres, which is roughly three-fourth of the total refractive power of the eye (60 dioptres). +Histology +Histologically, the cornea consists of six layers. From anterior to posterior these are: epithelium, Bowman’s membrane, substantia propria (corneal stroma), Pre-Descemet’s membrane (Dua’s layer), Descemet’s membrane and endothelium (Fig. 6.1). +1. Epithelium. It is of stratified squamous type and becomes continuous with epithelium of bulbar conjunctiva at the limbus. It consists of 5–6 layers of cells. The deepest (basal) layer is made up of columnar cells, next 2–3 layers of wing or umbrella cells and the most superficial two layers are made of flattened cells. Tight junctions between superficial epithelial cells prevent penetration of tear fluid into the stroma. ■Limbal epithelium. The basal epithelial cells of the limbal area constitute the limbal stem cells which +96 Section III Diseases of Eye + + + + + + + + + + + + + + + + + + + + +Fig. 6.1 Microscopic structure of the cornea + +amplify, proliferate, and differentiate into corneal epithelium. Damage to this area results in the invasion of conjunctival epithelium on to the cornea. 2. Bowman’s membrane. This layer consists of acellular mass of condensed collagen fibrils. It is about 12 mm in thickness and binds the corneal stroma anteriorly with basement membrane of the epithelium. It is not a true elastic membrane but simply a condensed superficial part of the stroma. It shows considerable resistance to infection. But once destroyed, it is unable to regenerate and, therefore, heals by scarring. +3. Stroma (substantia propria). This layer is about 0.5 mm in thickness and constitutes most of the cornea (90% of total thickness). It consists of collagen fibrils (type-I and type-V fibrillae interwined with filaments of type-VI collagen) embedded in hydrated matrix of proteoglycans (chondroitin sulphate and keratan sulphate). The lamellae are arranged in many layers. In each layer they are not only parallel to each other but also to the corneal plane and become continuous with scleral lamellae at the limbus. The alternating layers of lamellae are at right angle to each other. Among the lamellae are present keratocytes (modified fibroblasts), wandering macrophages, histiocytes and a few leucocytes. +4. Pre–Descemet’s membrane, also known as Dua’s layer has been discovered in 2013 by Dr Harminder Dua, an Indian ophthalmologist working in Great Britain. Located anterior to the Descemet’s membrane, it is about 15 micrometer thick acellular structure which is very strong and imprevious to air. + +5. Descemet’s membrane (posterior elastic lamina). The Descemet’s membrane is a strong homogenous basement membrane of the corneal endothelium which is separated from the stroma by pre-Descemet’s membrane. It is very resistant to chemical agents, trauma and pathological processes. Therefore, ‘Descemetocele’can maintain the integrity of eyeball for long. Descemet’s membrane consists of collagen and glycoproteins. Unlike Bowman’s membrane it can regenerate. Normally, it remains in a state of tension and when torn, it curls inwards on itself. In the periphery it appears to end at the anterior limit of trabecular meshwork as Schwalbe’s line (ring). 6. Endothelium. It consists of a single layer of flat polygonal (mainly hexagonal) epithelial cells (misnamed as endothelium) which on slit-lamp biomicroscopy appear as a mosaic. The cell density of endothelium is around 3000 cells/mm2 in young adults, which decreases with the advancing age. The human endothelium cells do not proliferate in vivo and the cell loss with age is compensated by enlargement (polymegathism) and migration of neighbouring cells. There is a considerable functional reserve for the endothelium. Therefore, corneal decompensation occurs only after more than 75% of the cells are lost. The endothelial cells contain ‘active-pump’ mechanism which keeps cornea dehydrated. +Blood supply +Cornea is an avascular structure. Small loops derived from the anterior ciliary vessels invade its periphery for about 1 mm. Actually, these loops are not in the cornea but in the subconjunctival tissue which overlaps the cornea. +Nerve supply +Cornea is supplied by anterior ciliary nerves which are branches of ophthalmic division of the 5th cranial nerve (see page 5). After going about 2 mm in cornea the nerves lose their myelin sheath and divide dichotomously, and form three plexuses: the stromal, subepithelial and intraepithelial. +APPLIED PHYSIOLOGY +The two primary physiological functions of the cornea are (i) to act as a major refracting medium; and (ii) to protect the intraocular contents. Cornea performs these functions by maintaining its transparency and regular replacement of its tissues. +Corneal transparency +The corneal transparency is the result of: +• Peculiar arrangement of corneal lamellae (lattice theory of Maurice). +Chapter 6 Diseases of Cornea 97 + + +• Peculiar refractive index of corneal lamellae with variation less than 200 mm (Goldmann and Benedek theory). +• Avascularity of cornea. +• Relative state of dehydration (78% water content), which is maintained by the barrier effects of epithelium and endothelium and the active Na+ K+ ATPase pump of the endothelium. +• Swellingpressure (SP) of the stroma which counters the imbibition effect of intraocular pressure (IOP). +• Corneal crystallins, i.e, water soluble proteins of keratocytes (transketolase and aldehyde dehydrogenase class IA1) also contribute to corneal transparency at the cellular level. +For these processes, cornea needs some energy. +Metabolism of cornea +Most actively metabolizing layers of the cornea are epithelium and endothelium, the former being 10 times thicker than the latter requires a proportionately larger supply of metabolic substrates. +Source of nutrients for cornea are: +1. Solutes (glucose and others) enter the cornea by either simple diffusion or active transport through aqueous humour and by diffusion from the perilimbal capillaries. +2. Oxygen is derived directly from air through the tear film. This is an active process undertaken by the epithelium. Therefore, corneal hypoxia may occur with over wear of contact lenses. Some oxygen may reach the superficial layers of cornea from the perilimbal capillaries (especially when eyelids are closed) and deeper corneal layers through the aqueous humour. +Endothelium requires oxygen and glucose for metabolic activities and proper functioning of Na+ - K+ATPase pump. +Like other tissues, the epithelium can metabolize glucose both aerobically and anaerobically into carbon dioxide and water and lactic acid, respectively. Thus, under anaerobic conditions lactic acid accumulates in the cornea. +Respiratory quotient of cornea is 1%. + +CONGENITAL ANOMALIES + +ANOMALIES OF SIZE AND SHAPE Megalocornea +Definition. Horizontal diameter of cornea at birth is about 10 mm and the adult size of about 11.7 mm is attained by the age of 2 years. Megalocornea is labelled when the horizontal diameter of cornea is of adult size at birth or 13 mm or greater after the age of 2 years. + +Salient features. Cornea is usually clear with normal thickness and vision. The condition is not progressive. Systemic associations include Marfan’s, Apert, Ehlers Danlos and Down syndromes. +Differential diagnosis includes: +1. Buphthalmos. In this condition IOP is raised and the eyeball is enlarged as a whole. The enlarged cornea is usually associated with central or peripheral clouding and Descemet’s tears (Haab’s striae). +2. Keratoglobus. In this condition, there is thinning and excessive protrusion of cornea, which seems enlarged; but its diameter is usually normal. +Microcornea +In microcornea, the horizontal diameter is less than 10 mm since birth. The condition may occur as an isolated anomaly (rarely) or in association with nanophthalmos (normal small eyeball) or microphthalmos (abnormal small eyeball). +Cornea plana +This is a rare anomaly in which bilaterally cornea is comparatively flat since birth. It may be associated with microcornea. Cornea plana usually results in marked astigmatic refractive error. + +ANOMALIES OF CORNEAL TRANSPARENCY Normal cornea is a transparent structure. A few congenital conditions in which corneal transparency is disturbed are as given below: +1. Anterior embryotoxon. It is characterized by congenitally broad limbus superiorly. +2. Posterior embryotoxon. It refers to thickening and anterior displacement of Schwalbe’s line. +3. Congenital corneal opacity. Corneal opacity, i.e., scarring of corneal stroma, is often an acquired condition but has been reported to occur congenitally in isolation and also in association with Lowe’s syndrome, Axenfeld’s anomaly, Rieger’s syndrome and Peter’s anomaly. +4. Sclerocornea refers to sclera like cloudy cornea, which may be peripheral or diffuse. +5. Dermoidsusually occur at inferotemporal limbus and are round, dome shaped, and pink to white to yellow in colour (see page 93, Fig. 5.38). Rarely the dermoids may involve large area of cornea, the entire limbus, the entire cornea, or even the interior of the eye. +Differential diagnosis of neonatal cloudy cornea. The acronym ‘STUMPED’ helps to remember the common conditions to be included in differential diagnosis of neonatal cloudy cornea. The conditions +are as follows: +98 Section III Diseases of Eye + + +• Sclerocornea +• Tears in Descemet’s membrane • Ulcer +• Metabolic conditions +• Posterior corneal defect • Endothelial dystrophy +• Dermoid. + +INFLAMMATIONS OF CORNEA + +Inflammation of cornea (keratitis) is characterised by corneal oedema, cellular infiltration and ciliary congestion. +Classification +It is difficult to classify and assign a group to each and every case of keratitis; as overlapping or concurrent findings tend to obscure the picture. However, the following simplified topographical and etiological classifications provide a workable knowledge. +Topographical (morphological) classification + +A. Ulcerative keratitis (corneal ulcer) +Corneal ulcer can be further classified variously: 1. Depending on location +• Central corneal ulcer +• Peripheral corneal ulcer 2. Depending on purulence +• Purulent corneal ulcer or suppurative corneal ulcer (most bacterial and fungal corneal ulcers are suppurative). +• Non-purulent corneal ulcers (most of viral, chlamydial and allergic corneal ulcers are non-suppurative). +3. Depending upon association of hypopyon +• Simple corneal ulcer (without hypopyon) • Hypopyon corneal ulcer +4. Depending upon depth of ulcer • Superficial corneal ulcer +• Deep corneal ulcer +• Corneal ulcer with impending perforation • Perforated corneal ulcer +5. Depending upon slough formation • Non-sloughing corneal ulcer +• Sloughing corneal ulcer + +B. Non-ulcerative keratitis 1. Superficial keratitis +• Diffuse superficial keratitis +• Superficial punctate keratitis (SPK) 2. Deep keratitis +a. Non-suppurative • Interstitial keratitis +• Disciform keratitis + +• Keratitis profunda • Sclerosing keratitis +b. Suppurative deep keratitis • Central corneal abscess +• Posterior corneal abscess. +Etiological classification 1. Infective keratitis +• Bacterial keratitis • Viral keratitis +• Fungal keratitis +• Chlamydial keratitis • Protozoal keratitis +• Spirochaetal keratitis 2. Allergic keratitis +• Phlyctenular keratitis • Vernal keratitis +• Atopic keratitis 3. Trophic keratitis +• Exposure keratitis +• Neurotrophic keratopathy • Keratomalacia +• Atheromatous ulcer +4. Keratitis associated with diseases of skin and mucous membrane. +5. Keratitisassociatedwithsystemiccollagenvascular disorders. +6. Traumatic keratitis which may be due to mechanical trauma, chemical trauma, thermal burns, radiations. +7. Idiopathic keratitis e.g., +• Mooren’s corneal ulcer +• Superior limbic keratoconjunctivitis +• Superficial punctate keratitis of Thygeson. + +ULCERATIVE KERATITIS + +Corneal ulcer may be defined as discontinuation in normal epithelial surface of cornea associated with necrosis of the surrounding corneal tissue. Pathologically, it is characterised by oedema and cellular infiltration. Common types of corneal ulcers are described below. + +INFECTIVE KERATITIS + +BACTERIAL CORNEAL ULCER + +Being the most anterior part of eyeball, the cornea is exposed to atmosphere and hence prone to get infected easily. At the same time cornea is protected from day-to-day minor infections by the normal defence mechanisms present in tears in the form of +Chapter 6 Diseases of Cornea 99 + + +lysozyme, betalysin and other protective proteins. Therefore, infective corneal ulcer may develop when: • Either the local ocular defence mechanism is +jeopardised, or +• There is some local ocular predisposing disease, or • Host’s immunity is compromised, or +• The causative organism is very virulent. + +Etiology +There are two main factors in the production of purulent corneal ulcer: +• Damage to corneal epithelium; and • Infection of the eroded area. +However, following three pathogens can invade theintactcornealepithelium and produce ulceration: Neisseriagonorrhoeae,Corynebacteriumdiphtheriae and Neisseria meningitidis. +1. Corneal epithelial damage. It is a pre-requisite for most of the infecting organisms to produce corneal ulceration. It may occur in following conditions: +• Corneal abrasion due to small foreign body, misdirected cilia, concretions and trivial trauma in contact lens wearers or otherwise. +• Epithelial drying as in xerosis and exposure keratitis. +• Necrosis of epithelium as in keratomalacia. +• Desquamation of epithelial cells as a result of corneal oedema as in bullous keratopathy. +• Epithelial damage due to trophic changes as in neuroparalytic keratitis. +2. Sources of infection include: +• Exogenous infection. Most of the times corneal infection arises from exogenous source like conjunctival sac, lacrimal sac (dacryocystitis), infected foreign bodies, infected vegetative material and waterborne or airborne infections. +• Fromtheoculartissue.Owing to direct anatomical continuity, diseases of the conjunctiva readily spread to corneal epithelium, those of sclera to stroma, and of the uveal tract to the endothelium of cornea. +3. Causative organisms. Bacteria reported to be associated with keratitis can be classified as below: • Gram positive cocci: Staphylococcus aureus, +Staphylococcus epidermidis and Streptococcus pneumoniae. +• Gram negative cocci: Neisseria gonorrhoeae, Neisseria meningitidis. +• Grampositivebacilli:Corynebacteriumdiptheriae, C. xerosis, Bacilluscereus, Propionibacteriumacne, listeria and clostridium. +• Gram negative bacilli: Pseudomonas aeruginosa, Enterobacteriaceae (Klebsiella, Proteus, E. coli, + +Serratia), Moraxella lacunata (diplobacillus), Haemophilus influenzae (cocobacillus). +• Grampositivefilamentousbacteria:Actinomyces, Nocardia. +• Mycobacteria:Non-tuberculous mycobacteria and M. tuberculosis. +Common bacteria associated with corneal ulceration include Staphylococci, Pseudomonas, Streptococcus pneumonia, Enterobacteriaceae and Neisseria. + +Pathogenesis and pathology of corneal ulcer +1. Once the damaged corneal epithelium is invaded by the offending agents, the sequence of pathological changes which occur during development of corneal ulcer can be described under four stages: +• Stage of progressive infiltration, • Stage of active ulceration, +• Stage of regression, and • Stage of cicatrization. +2. Terminal course of corneal ulcer depends upon the virulence of infecting agent, host defence mechanism and the treatment received. +3. Depending upon the prevalent circumstances the course of corneal ulcer may take one of the three forms: +• Ulcer may become localised and heal, +• Penetrate deep leading to corneal perforation, and • Spread fast to involve the whole cornea as +sloughing corneal ulcer. +The salient pathological features of these are described below: +A. Pathology of localised corneal ulcer +1. Stage of progressive infiltration (Fig. 6.2A). It is characterised by the infiltration of polymor-phonuclear and/or lymphocytes into the epithelium from the peripheral circulation supplemented by similar cells from the underlying stroma if this tissue is also affected. Subsequently, necrosis of the involved tissue may occur, depending upon the virulence of offending agent and the strength of host defence mechanism. +2.Stage of active ulceration(Fig. 6.2B). Active ulceration results from necrosis and sloughing of the epithelium, Bowman’s membrane and the involved stroma. The walls of the active ulcer project owing to swelling of the lamellae by the imbibition of fluid and the packing of masses of leucocytes between them. This zone of infiltration may extend to a considerable distance both around and beneath the ulcer. At this stage, sides and floor of the ulcer may show grey infiltration and sloughing. +100 Section III Diseases of Eye + + + + + + + +A + + + + + +B + + + + +C + + + + + +D + +Fig. 6.2 Pathology of corneal ulcer: A, stage of progressive infiltration; B, stage of active ulceration; C, stage of regression; D, stage of cicatrization + +■ Duringthisstageofactiveulceration,thereoccurs: • Hyperaemia of circumcorneal network of vessels which results into accumulation of purulent +exudates on the cornea. +• There also occurs vascular congestion of the iris and ciliary body and some degree of iritis due to absorption of toxins from the ulcer. Exudation into the anterior chamber from the vessels of iris and ciliary body may lead to formation of hypopyon. +• Ulcerationmayfurtherprogress by lateral extension resulting in diffuse superficial ulceration or it may progress by deeper penetration of the infection leading to Descemetocele formation and possible corneal perforation. When the offending organism is highly virulent and/or host defence mechanism is jeopardised there occurs deeper penetration during stage of active ulceration. +3.Stage of regression (Fig. 6.2C). Regression is induced by the natural host defence mechanisms (humoral antibody production and cellular immune defences) and the treatment which augments the normal host response. A line of demarcation develops around the ulcer, which consists of leucocytes that neutralize and eventually phagocytose the offending organisms and necrotic cellular debris. The digestionof necrotic material may result in initial enlargement of the ulcer. This process may be accompanied by superficial + +vascularization that increases the humoral and cellular immune response. The ulcer now begins to heal and epithelium starts growing over the edges. 4. Stage of cicatrization (Fig. 6.2D). In this stage healing continues by progressive epithelization which forms a permanent covering. Beneath the epithelium, fibrous tissue is laid down partly by the corneal fibroblasts and partly by the endothelial cells of the new vessels. The stroma thus thickens and fills in under the epithelium, pushing the epithelial surface anteriorly. +The degree of scarring from healing varies. If the ulcer is very superficial and involves epithelium only, it heals without leaving any opacity behind. When ulcer involves Bowman’s membrane and few superficial stromal lamellae, the resultant scar is called a ‘nebula’. Macula and leucoma result after healing of ulcers involving up to one-third and more than that of corneal stroma, respectively. +B. Pathology of perforated corneal ulcer +Perforation of corneal ulcer occurs when the ulcerative process deepens and reaches up to Descemet’s membrane. This membrane is tough and bulges out as Descemetocele (Fig. 6.3). At this stage, + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 6.3 Descemetocele: A, Diagrammatic depiction; B, +Clinical photograph +Chapter 6 Diseases of Cornea 101 + + +any exertion on the part of patient, such as coughing, sneezing, straining for stool etc., will perforate the corneal ulcer. Immediately after perforation, the aqueous escapes, intraocular pressure falls and the iris-lens diaphragm moves forward. The effects of perforation depend upon the position and size of perforation. When the perforation is small and opposite to iris tissue, it is usually plugged and healing by cicatrization proceeds rapidly (Fig. 6.4). Adherent leucoma is the commonest end result after such a catastrophe. +C. Pathology of sloughing corneal ulcer and formation of anterior staphyloma +When the infecting agent is highly virulent and/or body resistance is very low, the whole cornea sloughs with the exception of a narrow rim at the margin and total prolapse of iris occurs. The iris becomes inflamed and exudates block the pupil and cover the iris surface; thus a falsecorneais formed. Ultimately, these exudates organize and form a thin fibrous layer over which the conjunctival or corneal epithelium rapidly grows and thus a pseudocornea is formed. Since, the pseudocornea is thin and cannot withstand the intraocular pressure, so it usually bulges forward + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 6.4 Perforated corneal ulcer with prolapse of iris: A, +Diagrammatic depiction; B, Clinical photograph + +along with the plastered iris tissue. This ectatic cicatrix is called anteriorstaphylomawhich, depending upon its extent, may be either partial or total. The bands of scar tissue on the staphyloma vary in breadth and thickness, producing a lobulated surface often blackened with iris tissue which resembles a bunch of black grapes (hence the name staphyloma). +Clinical features +In bacterial infections the outcome depends upon the virulence of organism, its toxins and enzymes, and the response of host tissue. +Broadly bacterial corneal ulcers may manifest as: • Purulent corneal ulcer without hypopyon; or +• Hypopyon corneal ulcer. +In general, following symptoms and signs may be present: +Symptoms +1. Pain and foreign body sensation occurs due to mechanical effects of lids and chemical effects of toxins on the exposed nerve endings. +2. Watering from the eye occurs due to reflex hyperlacrimation. +3. Photophobia,i.e., intolerance to light results from stimulation of nerve endings. +4. Blurred vision results from corneal haze. +5. Redness of eyes occurs due to congestion of circumcorneal vessels. +Signs +1. Swelling of lids of varying degree is present. 2. Blepharospasm may be moderate to severe. +3. Conjunctiva is chemosed and shows conjunctival hyperaemia and ciliary congestion. +4. Corneal ulcer usually starts as an epithelial defect associated with greyish-white circumscribed infiltrate (seen in early stage). Soon the epithelial defect and infiltrate enlarges and stromal oedema develops. A well established bacterial ulcer is characterized by (Fig. 6.5): +• Yellowish-white area of ulcer which may be oval or irregular in shape. +• Margins of the ulcer are swollen and over hanging. • Floor of the ulcer is covered by necrotic material. • Stromal oedema is present surrounding the ulcer +area. +Characteristic features produced by some of the common causative bacteria are as follows: +• Staphylococcus aureus and Streptococcus pneumoniae usually produce an oval, yellowish white densely opaque ulcer which is surrounded by relatively clear cornea (Fig. 6.5A). +• Pseudomonasspeciesusually produce an irregular sharp ulcer with thick greenish mucopurulent +102 Section III Diseases of Eye + + + + + + + + + + + + +A B +Fig. 6.5 Bacterial corneal ulcer: A, Oval ulcer; B, Ring-shaped ulcer + + +exudate, diffuse liquefactive necrosis and semiopaque (ground glass) surrounding cornea. Such ulcers are usually associated with hypopyon, spread very rapidly and may even perforate within 48 to 72 hours. +• Enterobacteriae(E.coli,Proteussp.,and Klebsiella sp.) usually produce a shallow ulcer with greyish white pleomorphic suppuration and diffuse stromal opalescence. The endotoxins produced by these Gram -ve bacilli may produce ring-shaped corneal infiltrate (Fig. 6.5B). +5. Anterior chambermay or may not show pus (hypopyon). In bacterial corneal ulcers the hypopyon remains sterile so long as the Descemet’s membrane is intact. +6. Iris may be slightly muddy in colour. +7.Pupil may be small due to associated toxin induced iritis. +8. Intraocular pressure may sometimes be raised (inflammatory glaucoma). +HYPOPYON CORNEAL ULCER +Etiopathogenesis +Causative organisms. It is customary to reserve the term ‘hypopyon corneal ulcer’ for the characteristic ulcer caused by Pneumococcus and the term ‘corneal ulcer with hypopyon’ for the ulcers associated with hypopyonduetootherorganismssuchasStaphylococci, Streptococci, Gonococci, Moraxella and Pseudomonas pyocyanea.The characteristic hypopyon corneal ulcer caused by Pneumococcusis called ulcusserpens. Source of infection for pneumococcal infection is usually the chronic dacryocystitis. +Factors predisposing to development of hypopyon. Two main factors which predispose to development of hypopyon in a patient with corneal ulcer are the virulence of the infecting organism and the resistance of the tissues. Hence, hypopyon ulcers are much more common in old debilitated or alcoholic subjects. Mechanism of development of hypopyon. Corneal ulcer is often associated with some iritis owing to diffusion + +of bacterial toxins. When the iritis is severe the outpouring of leucocytes from the vessels is so great that these cells gravitate to the bottom of the anterior chamber to form a hypopyon. Thus, it is important to note that the hypopyon is sterile since the outpouring of polymorphonuclear cells is due to the toxins and not due to actual invasion by bacteria. Once the ulcerative process is controlled, the hypopyon is absorbed. + +Clinical features +Symptoms are same as described above for bacterial corneal ulcer. However, it is important to note that during initial stage of ulcus serpens there is remarkably little pain. As a result, the treatment is often unduly delayed. +Signs. In general, the signs are same as described above for the bacterial ulcer. +Characteristic features of ulcus serpens are: +• Ulcus serpens is a greyish white or yellowish disc-shaped ulcer occurring near the centre of cornea (Fig. 6.6). +• Theulcer has a tendency to creep over the cornea in a serpiginous fashion. One edge of the ulcer, along which the ulcer spreads, shows more infiltration. The other side of the ulcer may be undergoing simultaneous cicatrization and the edges may be covered with fresh epithelium. +• Violent iridocyclitis is commonly associated with a definite hypopyon. +• Hypopyon increases in size very rapidly and often results in secondary glaucoma. +• Ulcer spreads rapidly and has a great tendency for early perforation. + +Management +Management of hypopyon corneal ulcer is same as for other bacterial corneal ulcer. +Chapter 6 Diseases of Cornea 103 + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 6.6 Hypopyon corneal ulcer: A, Diagrammatic +depiction; B, Clinical photograph + +4. Perforation of corneal ulcer. Sudden strain due to cough, sneeze or spasm of orbicularis muscle may convert impending perforation into actual perforation (Fig. 6.4). Following perforation, immediately pain is decreased and the patient feels some hot fluid (aqueous) coming out of eyes. Sequelae of corneal perforation include: +• Prolapse of iris. It occurs immediately following perforation in a bid to plug it. +• Subluxation or anterior dislocation of lens may occur due to sudden stretching and rupture of zonules. +• Anterior capsular cataract. It is formed when the lens comes in contact with the ulcer following a perforation in the pupillary area. +• Corneal fistula. It is formed when the perforation in the pupillary area is not plugged by iris and is lined by epithelium which gives way repeatedly. There occurs continuous leak of aqueous through the fistula. +• Purulent uveitis, endophthalmitis or even panophthalmitis may develop due to spread of intraocular infection. +• Intraocular haemorrhage in the form of either vitreous haemorrhage or expulsive choroidal haemorrhage may occur in some patients due to sudden lowering of intraocular pressure. +5.Corneal scarring. It is the usual end result of healed corneal ulcer. Corneal scarring leads to permanent visual impairment ranging from slight blurring to total blindness. Depending upon the clinical course + +Special points which need to be considered are: +• Secondary glaucoma should be anticipated and treated with 0.5% timolol maleate, B.I.D. eye drops and oral acetazolamide. +• Source of infection, i.e., chronic dacryocystitis if detected, should be treated by dacryocystectomy. + +Complications of Corneal Ulcer +1.Toxic iridocyclitis. It is usually associated with cases of purulent corneal ulcer due to absorption of toxins in the anterior chamber. +2. Secondary glaucoma. It occurs due to fibrinous exudates blocking the angle of anterior chamber (inflammatory glaucoma). +3. Descemetocele. Some ulcers caused by virulent organisms extend rapidly up to Descemet’s membrane, which gives a great resistance, but due to the effect of intraocular pressure it herniates as a transparent vesicle called the descemetocele or keratocele (Fig. 6.3). This is a sign of impending perforation and is usually associated with severe pain. + +of ulcer, corneal scar noted may be nebula, macula, leucoma, ectatic cicatrix or kerectasia, adherent leucoma or anterior staphyloma (for details see page 135). +MANAGEMENT OF A CASE OF CORNEAL ULCER +Since corneal ulcer is sight threatening, it needs urgent treatment by identification and eradication of causative bacteria. Preferably such patients should be hospitalized. The management includes: +• Clinical evaluation, +• Laboratory investigations, and • Treatment. +A. Clinical evaluation +Each case with corneal ulcer should be subjected to: +1. Thorough history taking to elicit mode of onset. +2. General physical examination, especially for built, nourishment, anaemia and any immuno-compromising disease. +104 Section III Diseases of Eye + + +3. Ocular examination should include: +• Diffuse light examination for gross lesions of lids, conjunctiva and cornea including testing for sensations. +• Regurgitationtestand syringingto rule out lacrimal sac infection. +• Biomicroscopic examination after staining of corneal ulcer with 2% freshly prepared aqueous solution of fluorescein dye or sterilised fluorescein impregnated filter paper strip. Ulcer area stains as brilliant green, which looks opaque green when seen with blue filter. Note site, size, shape, depth, margin, floor and vascularization of corneal ulcer. On biomicroscopy also note presence of keratic precipitates at the back of cornea, depth and contents of anterior chamber, colour and pattern of iris and condition of crystalline lens. +B. Laboratory Investigations +1. Routine laboratory investigations such as haemoglobin, TLC, DLC, ESR, blood sugar, complete urine and stool examination should be carried out in each case. +2. Microbiological investigations. These studies are essential to identify causative organism, confirm the diagnosis and guide the treatment to be instituted. Material for such investigations is obtained by scraping the base and margins of the corneal ulcer (under local anaesthesia, using 2% xylocaine or preferably paracain) with the help of a modified Kimura spatula or by simply using the bent tip of a 20 gauge hypodermic needle. The material obtained is used for the following investigations: +• Gram and Giemsa stained smears for possible identification of infecting organisms. +• 10% KOH wet preparation for identification of fungal hyphae. +• Calcofluor white (CFW) stain preparation is viewed under fluorescence microscope for fungal filaments, the walls of which appear bright apple green. +• Culture on blood agar medium for aerobic organisms. +• Culture on Sabouraud’s dextrose agar medium for fungi. +C. Treatment +I. Treatment of uncomplicated corneal ulcer +Treatment of corneal ulcer can be discussed under three headings: +• Specific treatment of the cause. • Nonspecific supportive therapy. • Physical and general measures. + + +1. Specific treatment +a. Topical antibiotics +• Initial therapy (before results of culture and sensitivity are available) should be with combination therapy to cover both gram-negative and gram-positive organisms. To begin with any of the following two drugs may be instilled: +• Fortified Cefazoline, 5% i.e., 50 mg/ml freshly prepared by adding sterile water to 500 mg powder to make 10 ml solution, and +• Fortified tobramycin, 1.3%, i.e., 13.6 mg/ml prepared by adding 2 ml of tobramycin injection (40 mg/ml in 5 ml bottle of commercially available 0.3% tobramycin drops). +or +• Freshly prepared fortified vancomycin 5%, i.e., 50 mg/ml (prepared by adding sterile water to 500 mg vancomycin powder to form 10 ml solution) and one of commercially available fluoroquinolones eye drops (0.3% ciprofloxacin, or 0.3% ofloxacin or 0.3% gatifloxacin or 0.5% moxifloxacin). +■Frequency of instillation. The chosen two drugs should be instilled alternately as below: +• Every 5 minutes for 30 minutes, • Every 15 minutes for 2 hours, +• 1 hourly round the clock for first 48 hours, +• 2 hourly during day and 4 hourly at night till healing is ensured, and then +• 4–6 hourly till healing occurs. +• Once the favourable response is obtained, the fortified drops can be substituted by the commercially available eye drops. +■Subsequent therapy. There is no need to change initial antibiotics, if the response is good. However, if the response is poor, immediately change the antibiotics as per culture and sensitivity report. +b. Systemic antibiotics +Systemic antibiotics are usually not required. However, a cephalosporine and an aminoglycoside or oral ciprofloxacin (750 mg twice daily) may be given in fulminating cases with perforation or when sclera is also involved. +2. Nonspecific treatment +a. Cycloplegic drugs. Preferably 1% atropine eye ointment or drops should be used: +• To reduce pain from ciliary spasm and +• To prevent the formation of posterior synechiae from secondary iridocyclitis. +• Atropine also increases the blood supply to anterior uvea by relieving pressure on the anterior ciliary arteries and so brings more antibodies in the aqueous humour. +Chapter 6 Diseases of Cornea 105 + + +• It also reduces exudation by decreasing hyperaemia and vascular permeability. +• Other cycloplegic which can be used is 2% homatropine eye drops. +b. Systemic analgesics and anti-inflammatory drugs such as paracetamol and ibuprofen relieve the pain and decrease oedema. +c. Vitamins (A, B-complex and C) help in early healing of ulcer. +3. Physical and general measures +• Hot fomentation. Local application of heat (preferably dry) gives comfort, reduces pain and causes vasodilatation. +• Darkgogglesmay be used to prevent photophobia. • Rest, good diet and fresh air may have a soothing +effect. +II. Treatment of non-healing corneal ulcer +If the ulcer progresses despite the above therapy the following additional measures should be taken: +1. Removal of any known cause of non-healing ulcer. A thorough search for any already missed cause not allowing healing should be made and when found, such factors should be eliminated. Common causes of non-healing ulcers are as under: +• Local causes. Associated raised intraocular pressure, concretions, misdirected cilia, impacted foreign body, dacryocystitis, inadequate therapy, wrong diagnosis, lagophthalmos and excessive vascularization of ulcer. +• Systemiccauses:Diabetes mellitus, severe anaemia, malnutrition, chronic debilitating diseases and patients on systemic steroids. +2. Mechanical debridement of ulcer to remove necrosed material by scraping floor of the ulcer with a spatula under local anaesthesia may hasten the healing. +3. Cauterisation of the ulcer may also be considered in non-responding cases. Cauterisation may be performed with pure carbolic acid or 10–20% trichloracetic acid. 4. Bandage soft contact lens may also help in healing. 5. Peritomy, i.e., severing of perilimbal conjunctival vessels may be performed when excessive corneal vascularization is hindering healing. +III. Treatment of impending perforation +When ulcer progresses and perforation seems imminent, the following additional measures may help to prevent perforation and its complications: 1. Nostrain.The patient should be advised to avoid +sneezing, coughing and straining during stool, etc. He should be advised strict bed rest. +2. Pressurebandageshould be applied to give some external support. + + +3. Loweringofintraocularpressureby simultaneous use of acetazolamide 250 mg QID orally, intravenous mannitol (20%) drip stat, oral glycerol twice a day, 0.5% timolol eye drops twice a day, and even paracentesis with slow evacuation of aqueous from the anterior chamber may be performed if required. +4. Tissue adhesive glue such as cyanoacrylate is helpful in preventing perforation. +5. Bandage soft contact lens may also be used. +6. Conjunctival flap. The cornea may be covered completely or partly by a conjunctival flap to give support to the weak tissue. +7. Amniotic membrane transplantation may also be considered as an option. +8. Penetrating therapeutic keratoplasty (tectonic graft) may be undertaken in suitable cases, when available. +IV. Treatment of perforated corneal ulcer +Best is to prevent perforation. However, if perforation has occurred, immediate measures should be taken to restore the integrity of perforated cornea. Depending upon the size of perforation and availability, measures like use of tissue adhesive glues, covering with conjunctival flap, use of bandage soft contact lens or therapeutic keratoplasty should be undertaken. Best option is an urgent tectonic keratoplasty. +MARGINAL CATARRHAL ULCER +These superificial ulcers situated near the limbus are frequently seen especially in old people. +Etiology +Marginal catarrhal ulcer is thought to be caused by a hypersensitivity reaction to Staphylococcal toxins. It occurs in association with chronic Staphylococcal blepharoconjunctivitis. Moraxella and Haemophilus are also known to cause such ulcers. +Clinical features +• Patientusuallypresentswithmild ocular irritation, pain, photophobia and watering. +• Ulcer is shallow, slightly infiltrated and often multiple, usually associated with Staphylococcal conjunctivitis (Fig. 6.7). +• Vascularization occurs soon and is followed by resolution. +• Recurrences are very common. + +Treatment +• Ashortcourseoftopicalcorticosteroiddropsalong with adequate antibiotic therapy often heals the condition. +106 Section III Diseases of Eye + + + + + + + + + + + + + + + +Fig. 6.7 Marginal corneal ulcer in a patient with acute conjunctivitis + +• Adequate treatment of associated blepharitis and chronic conjunctivitis is important to prevent recurrences. + +MYCOTIC CORNEAL ULCER + +The incidence of suppurative corneal ulcers caused by fungi has increased in the recent years due to injudicious use of antibiotics and steroids. +Etiology +1. Fungi. The fungi can be classified as below: +i. Filamentous fungi e.g., Aspergillus, Fusarium, Alternaria, Cephalosporium, Curvularia and Penicillium are septate multicellular fungi. Mucor and rhizopus are non- septate organisms. +ii. Yeasts e.g., Candida and Cryptococcus are unicellular fungi that reproduce by budding. +iii Dimorphicfungisuch as histoplasma, coccidioides and blastomyces demonstrate both yeast phase that occurs in the tissues and a mycelia phase that appears in culture media and on saprophytic surfaces. +Fungi commonly responsible for mycotic corneal ulcers are Aspergillus(most common), Candidaand Fusarium. +2. Modes of infection +i. Injury by vegetative material such as crop leaf, branch of a tree, straw, hay or decaying vegetable matter. Common sufferers are field workers especially during harvesting season. +ii. Injurybyanimaltailis another mode of infection. iii.Secondary fungal ulcers are common in patients who are immunosuppressed systemically or locally such as patients suffering from dry eye, herpetic keratitis, bullous keratopathy or +postoperative cases of keratoplasty. + +3. Role of antibiotics and steroids. Antibiotics disturb the symbiosis between bacteria and fungi; and the steroids make the fungi facultative pathogens which are otherwise symbiotic saprophytes. Therefore, excessive use of these drugs predisposes the patients to fungal infections. + +Clinical features +Symptoms are similar to the central bacterial corneal ulcer (see page 101), but in general they are less marked than the equal-sized bacterial ulcer and the overall course is slow and torpid. +Signs. A typical fungal corneal ulcer has following salient features (Fig. 6.8): +• Corneal ulcer is dry-looking, greyish white, with elevated rolled out margins. +• Pigmented ulcer (brownish) may be caused by some species of fungi, e.g., dermatiaceous fungi. +• Delicate featheryfinger-likeextensionsare present into the surrounding stroma under the intact epithelium. +• A sterileimmunering(yellow line of demarcation) may be present where fungal antigen and host antibodies meet. +• Multiple, small satellite lesions may be present around the ulcer. +• Usually a bighypopyonis present even if the ulcer is very small. Unlike bacterial ulcer, the hypopyon may not be sterile as the fungi can penetrate into the anterior chamber without perforation. +• Endothelial plaque, composed of fibrin and leucocytes, may be located under the stromal lesion. It may be present in the absence of hypopyon. +• Perforation in mycotic ulcer is rare but can occur. • Corneal vascularization is conspicuously absent +in pure mycotic ulcer. + + + + + + + + + + + + + + +Fig. 6.8 Fungal corneal ulcer +Chapter 6 Diseases of Cornea 107 + + +Diagnosis +1. Typical clinical manifestations associated with history of injury by vegetative material are highly suspicious of a mycotic corneal ulcer. +2. Chronic ulcer worsening inspite of most efficient treatment should arouse suspicion of mycotic involvement. +3. Laboratoryinvestigationsrequired for confirmation, include examination of wet KOH, Calcofluor white, Gram’s and Giemsa-stained films for fungal hyphae and culture on Sabouraud’s agar medium. Methods of sample collection for microbiological evaluation are as below: +• Corneal scrapings should be performed from the base and leading edge of ulcer. +• Anterior chamber paracentesis may be carried out in cases with intraocular extension. +• Corneal biopsy is indicated in cases with deep stromal abscess or in cases where repeated cultures from scrapings are negative. +4. Confocal microscopic examination of cornea is reported to identify actual fungi. +5. Polymerase chain reaction (PCR) is also being recommended for its rapid results. +Treatment +A. Specific treatment includes antifungal drugs: +1. Topical antifungal eyedrops should be used for a long period (6 to 8 weeks). These include: +• Natamycin(5%), AmphotericinB (0.1 to 0.3%), and either Fluconalzole(0.2%), or miconazole (10 mg/ ml) or voriconazole (10%) eyedrops to be instilled initially one hourly around the clock, then taper slowly over 6 to 8 weeks. These are effective against Aspergillus and Fusarium. +• Nystatin (3.5%) eye ointment, five times a day is effective against Candida. (For details see page 448). +2. Intracameral and intracorneal/intrastromal administration of voriconazole may be considered in cases with intraocular extension or anterior chamber involvement. +3. Systemic antifungal drugs may be required for severe cases of deeper fungal keratitis. Tablet fluconazole or ketoconazole or voriconazole may be given for 2–3 weeks. +B. Non-specific treatment. Non-specific treatment and general measures are similar to that of bacterial corneal ulcer (see page 104). +C. Therapeutic penetrating keratoplasty may be required for nonresponsive cases. + +VIRAL CORNEAL ULCER + +Incidence of viral corneal ulcers has become much greater especially because of the role of antibiotics in eliminating the pathogenic bacterial flora. Most of the viruses tend to affect the epithelium of both the conjunctiva and cornea, hence the typical viral lesions constitute the viral keratoconjunctivitis. Common viral infections include herpes simplex keratitis, herpes zoster ophthalmicus and adenovirus keratitis. +HERPES SIMPLEX KERATITIS +Ocular infections with herpes simplex virus (HSV) are extremely common and constitute herpetic keratoconjunctivitis and iritis. +Etiology +Herpes simplex virus (HSV). It is a DNA virus. Its only natural host is man. Basically, HSV is epitheliotropic but may become neurotropic. According to different clinical and immunological properties, HSV is of two types: HSV type I typically causes infection above the waist and HSV type II below the waist (herpes genitalis). HSV-II has also been reported to cause ocular lesions. +Mode of infection are as below: +• HSV-Iinfection.It is acquired by kissing or coming in close contact with a patient suffering from herpes labialis. +• HSV-II infection. It is transmitted to eyes of neonates through infected genitalia of the mother. +Ocular lesions of herpes simplex +Ocular involvement by HSV occurs in two forms, primary and recurrent; with following lesions: +A. Primary herpes 1.Skin lesions +2.Conjunctiva-acute follicular conjunctivitis 3.Cornea +• Fine epithelial punctate keratitis +• Coarse epithelial punctate keratitis • Dendritic ulcer +B. Recurrent herpes 1.Active epithelial keratitis +• Punctate epithelial keratitis • Dendritic ulcer +• Geographical ulcer 2.Stromal keratitis +i. Disciform keratitis; +ii. Diffuse stromal necrotic keratitis 3. Trophic keratitis (meta-herpetic) 4. Herpetic iridocyclitis +108 Section III Diseases of Eye + + +A. Primary Ocular Herpes +Primary infection (first attack) involves a nonimmune person. It typically occurs in children of 6 months till 5 years of age and in teenagers. Initial infection occurs by direct contact of mucous membranes with infected secretions. +Clinical features +1. Systemic features include mild fever, malaise and non-suppurative lymphadenopathy. Rarely, severe morbidity can result from multi-system failure. Disease may be fatal when encephalitis develops. 2. Skin lesions. Vesicular lesions may occur involving skin of face, lips, lids, periorbital region and the lid margin (vesicular blepharitis). +3. Ocular lesion includes: +• Acute follicular conjunctivitis with regional lymphadenitis is the usual and sometimes the only manifestation of the primary infection. +• Keratitis. Cornea is involved in about 50% of the cases. The keratitis can occur as a coarse punctate or diffuse branching epithelial keratitis that does not usually involve the stroma. +Note. Primary infection is usually self-limiting but virus travels up to the trigeminal ganglion and establishes the latent infection. + +B. Recurrent Ocular Herpes +The virus which lies dormant in the trigeminal ganglion, periodically reactivates and replicates. The reactivated virus in enveloped infectious form travels down along the trigeminal nerve to cause recurrent infection. The recurrent herpatic ocular infection is not associated with systemic features and typically is a unilateral disease. +Predisposing stress stimuli which trigger an attack of herpetic keratitis include fever such as malaria, flu, exposure to ultraviolet rays, general ill health, emotional or physical exhaustion, mild trauma, menstrual stress following administration of topical or systemic steroids and immunosuppressive agents. +1. Epithelial keratitis +Symptoms +Symptoms of epithelial HSV keratitis include redness, pain, photophobia, tearing and decreased vision. +Signs +Three distinct patterns of epithelial keratitis seen are: punctate epithelial keratitis, dendritic ulcer and geographical ulcer. +1. Punctate epithelial keratitis (Figs. 6.9A and B). The initial epithelial lesions of recurrent herpes resemble + + +those seen in primary herpes and may be either in the form of fine or coarse superficial punctate lesions. 2. Dendritic ulcer (Figs. 6.9C and D). Dendritic ulcer is a typical lesion of recurrent epithelial keratitis. The ulcer is of an irregular, zigzag linear branching shape. The branches are generally knobbed at the ends. Floor of the ulcer stains with fluorescein and the virus-laden cells at the margin take up rose bengal. There is an associated marked diminution of corneal sensations. +3. Geographical ulcer (Figs. 6.9E and F). Sometimes, the branches of dendritic ulcer enlarge and coalesce to form a large epithelial ulcer with a ‘geographical’ or ‘amoeboid’ configuration, hence the name. The use of steroids in dendritic ulcer hastens the formation of geographical ulcer. +Treatment +A. Specific treatment +1. Antiviral drugs are the first choice presently. Any one of the following drugs may be given: +• Acycloguanosine(Aciclovir) 3% ointment: 5 times a day for 14–21 days. It is least toxic and most commonly used antiviral drug. It penetrates intact corneal epithelium and stroma, achieving therapeutic levels in aqueous humour, and can therefore be used to treat herpetic keratitis. +• Ganciclovir (0.15% gel), 5 times a day until ulcer heals and then 3 times a day for 5 days. It is more toxic than aciclovir. +• Triflurothymidine1% drops: Two hourly until ulcer heals and then 4 times a day for 5 days. +• Adenine arabinoside (Vidarabine) 3% ointment: 5 times a day until ulcer heals and then 3 times a day for 5 days. +2. Mechanical debridement of the involved area along with a rim of surrounding healthy epithelium with the help of sterile cotton applicator under magnification helps by removing the virus-laden cells. +Before the advent of antiviral drugs, it was the treatment of choice. Now it is reserved for resistant cases, cases with noncompliance and those allergic to antiviral drugs. +3. Systemic antiviral drugs for a period of 10 to 21 days are increasingly being considered for recurrent and even acute cases in following doses: +• Acyclovir 400 mg p.o. tid to bid, or • Famcyclovir 250 mg p.o. bid, or +• Valacyclovir 500 mg p.o.bid. +B. Non-specific supportive therapy and physical and general measures are same as for bacterial corneal +ulcer (see page 104). +Chapter 6 Diseases of Cornea 109 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 6.9 Lesions of recurrent herpes simplex keratitis; diagrammatic depiction and Clinical photograph; A and B, Punctate epithelial keratitis; C and D, Dendritic ulcer; E and F, Geographical ulcer; and G and H, Disciform keratitis + + +2. Stromal keratitis a. Disciform keratitis +Pathogenesis.It occurs due to delayed hypersensitivity reaction to the HSV antigen. Primarily, there occurs endothelitis. Endothelial damage results in disciform corneal stromal oedema due to imbibition of aqueous +humour. + +Symptoms include photophobia, mild to moderate ocular discomfort, and a reduction in visual acuity. Signs. Disciform keratitis is characterized by (Figs. 6.9 G and H): +• Focaldisc-shapedpatchof stromal oedema without necrosis, usually with an intact epithelium. +• Folds in Descemet’s membrane. +• Keraticprecipitatesunder the round area of stromal edema. +• Ring of stromal infiltrate (Wessley immune ring) may be present surrounding the stromal oedema. It signifies the junction between viral antigen and host antibody. +• Corneal sensations are diminished. +• Intraocular pressure (IOP) may be raised despite only mild anterior uveitis due to trabeculitis. In severe cases, anterior uveitis may be marked. +Important note. During active stage diminished corneal sensations and keratic precipitates are the differentiating points from other causes of stromal oedema. +Treatment consists of: +• Diluted steroid eye drops instilled 4–5 times a day with an antiviral cover (aciclovir 3%) twice a day. Steroids should be tapered over a period of several weeks. When disciform keratitis is present with an infected epithelial ulcer, antiviral drugs should be started 5–7 days before the steroids. +• Non-specific and supportive treatment (see page 104). +b. Stromal necrotic keratitis +It is a type of interstitial keratitis (IK) caused by active viral invasion and tissue destruction. +Symptoms. Pain, photophobia and redness are common symptoms. +Signs are as below: +• Corneal lesions include necrotic, blotchy, cheesy white infiltrates that may lie under the epithelial ulcer or may present independently under the intact epithelium. +• Mild iritis and keratic precipitates are usually associated (herpetic keratouveitis). +• Stromal vascularization may occur. +Treatment is similar to disciform keratitis but frequently the results are unsatisfactory. +• Systemicantiviraldrugsfor 10 to 21 days are being considered in recurrent cases and in those with associated herpetic uveitis. +110 Section III Diseases of Eye + + +• Keratoplasty should be deferred until the eye has been quiet with little or no steroidal treatment for several months; because viral interstitial keratitis is the form of herpes which is most likely to recur in a new graft. +3. Metaherpetic keratitis +Metaherpetic keratitis (epithelial sterile trophic ulceration) is not an active viral disease, but is a mechanical healing problem due to persistent defects in the basement membrane of corneal epithelium (similar to recurrent traumatic erosions) which occurs at the site of a previous herpetic ulcer. Clinical features. It presents as an indolent linear or ovoid epithelial detect. Margin of the ulcer is grey and thickened due to heaped up epithelium. +Treatment is aimed to promote healing by use of lubricants (artificial tears), bandage soft contact lens and lid closure (tarsorrhaphy). +HERPES ZOSTER OPHTHALMICUS +Herpes zoster ophthalmicus is an acute infection of Gasserian ganglion of the fifth cranial nerve by the varicella-zoster virus (VZV). It constitutes approximately 10% of all cases of herpes zoster. Herpes zoster occurs more commonly in immuno-compromised individuals. + +Etiology +Varicella-zoster virus. It is a DNA virus and produces acidophilic intranuclear inclusion bodies. It is neurotropic in nature. +Pathogenesis. The infection is contracted in childhood, which manifests as chickenpox and the child develops immunity. The virus then remains dormant in the sensory ganglion of trigeminal nerve. It is thought that, usually in elderly people (can occur at any age) with depressed cellular immunity, the virus reactivates, replicates and travels down along one or more of the branches of the ophthalmic division of the fifth nerve to produce cutaneous and ocular lesions. +Clinical Features +• Frontalnerve is more frequently affected than the lacrimal and nasociliary nerves in herpes zoster ophthalmicus. +• Ocularcomplicationsoccurs in about 50% cases of herpes zoster ophthalmicus. +• Hutchinson’s rule, which implies that ocular involvement is frequent if the side or tip of nose presents vesicles (cutaneous involvement of nasociliary nerve), is useful but not infallible. + +• Lesionsarestrictlylimitedto one side of the midline of head. +Clinical phases of H. zoster ophthalmicus are: +I. Acute phase lesions, which may totally resolve within few weeks. +II. Chronic phase lesions, which may persist for years. +III. Relapsing phase lesions, where acute or chronic lesions reappear sometimes years later. +I. Acute phase lesions +A. General features. The onset of illness is sudden with fever, malaise and severe neuralgic pain along the course of the affected nerve. The distribution of pain is so characteristic of zoster that it usually arouses suspicion of the nature of the disease before appearance of vesicles. +B. Cutaneous lesions. Cutaneous lesions (Fig. 6.10) in the area of distribution of the involved nerve appear usually after 3 to 4 days of the onset of disease. To begin with, the skin of lids and other affected areas become red and oedematous (mimicking erysipelas), followed by vesicle formation. In due course of time vesicles are converted into pustules, which subsequently burst to become crusting ulcers. When crusts are shed, permanent pitted scars are left. The active eruptive phase lasts for about 3 weeks. Main symptom is severe neuralgic pain which usually diminishes with the subsidence of eruptive phase. C.Ocular lesions.Ocular complications usually appear at the subsidence of skin eruptions and may present as a combination of two or more of the following lesions: 1. Conjunctivitis is one of the most common complication of herpes zoster. It may occur as mucopurulent conjunctivitis with petechial haemorrhages or acute follicular conjunctivitis + + + + + + + + + + + + + + +Fig. 6.10 Cutaneous lesions of herpes zoster ophthalmicus +Chapter 6 Diseases of Cornea 111 + + +with regional lymphadenopathy. Sometimes, severe necrotizing membranous inflammation may be seen. +2. Zoster keratitis occurs in 40% of all patients and sometimes may precede the neuralgia or skin lesions. It may occur in several forms (Fig. 6.11): +• Epithelial keratitis. To begin with there occurs fine or coarse punctate epithelial keratitis (Figs. 6.11A and B). It is followed by microdendritic epithelialulcers(Figs. 6.11C and D) which unlike dendritic ulcers of herpes simplex are usually peripheral and stellate rather than exactly dendritic in shape. In contrast to Herpes simplex dendrites, they have tapered ends which lack bulbs. +• Nummular keratitis (Figs. 6.11E and F) characterised by anterior stromal infiltrates is seen in about one-third number of total cases. It typically occurs as multiple tiny granular deposits surrounded by a halo of stromal haze. After healing ‘nummular scars’ are left behind. +• Disciform keratitis (Figs. 6.11G and H) occurs in about 50% of cases and is always preceded by nummular keratitis. +3. Episcleritis and scleritis occur in about one-half of the cases. These usually appear at the onset of the rash but are frequently concealed by the overlying conjunctivitis. +4. Iridocyclitis is of a frequent occurrence and may or may not be associated with keratitis. There may be associated hypopyon and hyphaema (acute haemorrhagic uveitis). +5. Acute retinal necrosis may occur in some cases. +6. Secondary glaucoma. It may occur due to trabeculitis in early stages and synechial angle closure in late stages. +7. Anterior segment necrosis and phthisis bulbi, may occur rarely as a result from zoster vasculitis and ischemia. +D. Associated neurological complications. Herpes zoster ophthalmicus may also be associated with other neurological complications such as: +1. Motornervepalsiesespecially involving the third, fourth, sixth or seventh nerve. +2. Optic neuritis occurs in about 1% of cases. +3. Encephalitis occurs rarely with severe infection. +II. Chronic phase lesions +Chronic phase lesions are basically sequelae of acute phase, which may persist for up to 10 years. +1. Post-herpetic neuralgia refers to persistence of pain even after subsidence of eruptive phase of zoster which occurs in about 10% cases. Pain is mild + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 6.11 Types of zoster keratitis. Diagrammatic depictions and clinical photographs of: A and B, Punctate epithelial keratitis; C and D, Microdendritic epithelial ulcer; E and F, Nummular keratitis; G and H, Disciform keratitis + +to moderate in intensity, worsens at night and is aggravated by touch and heat. But sometimes it may persist for years with little diminution of intensity. There occurs some anaesthesia of the affected skin which when associated with continued postherpetic neuralgia is called anaesthesia dolorosa. +2. Lid lesions which occur as sequelae of scarring include ptosis, trichiasis, entropion and notching. +112 Section III Diseases of Eye + + +3. Conjunctival lesions include chronic mucous secreting conjunctivitis. +4. Corneal lesions are as below: +• Neuroparalyticulcerationmay occur as a sequelae of acute infection and Gasserian ganglion destruction. +• Exposure keratitis may supervene in some cases due to associated facial palsy. +• Mucous plaque keratitis develops in 5% of cases between 3rd and 5th months and is characterised by sudden development of elevated mucous plaque which stain brilliantly with rose bengal. +5. Scleritis and Uveitis may persist in chronic form. + +III. Relapsing phase lesions +Relapsing phase lesions, which may recur even after ten years of acute phase include nummular keratitis, mucous plaque keratitis, episcleritis, scleritis and secondary glaucoma. + +Treatment +Therapeutic approach to herpes zoster ophthalmicus should be vigorous and aimed at preventing severe devastating ocular complications and promoting rapid healing of the skin lesions without the formation of massive crusts which result in scarring of the nerves and postherpetic neuralgia. The following regime may be followed: +I. Systemic therapy for herpes zoster +1. Oral antiviral drugs. These significantly decrease pain, curtail vesiculation, stop viral progression and reduce the incidence as well as severity of keratitis and iritis. In order to be effective, the treatment should be started immediately after the onset of rash. It has no effect on post herpetic neuralgia. +• Acyclovir in a dose of 800 mg 5 times a day for 10 days, or +• Valaciclovir in a dose of 500 mg TDS. +2. Analgesics. Pain during the first 2weeks of an attack is very severe and should be treated by analgesics such as combination of mephenamic acid and paracetamol or pentazocin or even pethidine (when very severe). +3. Systemic steroids. They appear to inhibit development of postherpetic neuralgia when given in high doses. However, the risk of high doses of steroids in elders should always be taken into consideration. Steroids are commonly recommended in cases developing neurological complications such as third nerve palsy and optic neuritis. +4. Cimetidine in a dose of 300 mg QID for 2–3 weeks starting within 48–72 hours of onset has also been + +shown to reduce pain and pruritis in acute zoster— presumably by histamine blockade. +5. Amitriptyline should be used to relieve the accompanying depression in acute phase. +II. Local therapy for skin lesions +1. Antibiotic-corticosteroid skin ointment or lotions. These should be used three times a day till skin lesions heal. +2. No calamine lotion. Cool zinc calamine application, as advocated earlier, is better avoided, as it promotes crust formation. +III. Local therapy for ocular lesions +1. For zoster keratitis, iridocyclitis and scleritis • Topical steroid eyedrops 4 times a day. +• Cycloplegics such as cyclopentolate eyedrops BD or atropine eye ointment OD. +• Topical acyclovir 3% eye ointment should be instilled 5 times a day for about 2 weeks. +2. Topreventsecondaryinfectionstopical antibiotics are used. +3. For secondary glaucoma +• 0.5% timolol or 0.5% betaxolol drops, BD. • Acetazolamide 250 mg, QID. +4. For mucous plaques, add topical mucolytics e.g. acetyl cysteine 5 to 10%, three times a day. +5. For persistent epithelial defects use: • Lubricating artificial tear drops, and • Bandage soft contact lens. +IV. Surgical treatment +For neuroparalytic corneal ulcer caused by herpes zoster: +1. Lateral tarsorrhaphy should be performed. +2. Amniotic membrane transplantation (AMT) or conjunctival flap should be considered for non-healing cases. +3. Tissue adhesive with bandage contact lens for corneal perforation. +4. Keratoplasty. It may be required for visual rehabilitation of zoster patients with dense scarring. However, these are high risk patients. + +PROTOZOAL KERATITIS + +ACANTHAMOEBA KERATITIS +Acanthamoeba keratitis has recently gained importance because of its increasing incidence, difficulty in diagnosis and unsatisfactory treatment. +Etiology +Acanthamoeba castellani, the causative organism is a free lying amoeba found in soil, fresh water, +Chapter 6 Diseases of Cornea 113 + + +well water, sea water, sewage and air. It exists in trophozoite and encysted forms. +Mode of infection. Corneal infection with acanth-amoeba results from direct corneal contact with any material or water contaminated with the organism. Following situations of contamination have been described: +1. Contact lens wearers using home-made saline (from contaminated tap water and saline tablets) is the commonest situation recognised for acanthamoeba infection in western countries. +2. Non-contact lens related situations include mild trauma associated with contaminated vegetable matter, salt water diving, wind blown contaminant and hot tub use. Trauma with organic matter and exposure to muddy water are the major (90% cases) predisposing factors in developing countries. +3. Opportunistic infection. Acanthamoeba keratitis can also occur as opportunistic infection in patients with herpetic keratitis, bacterial keratitis, bullous keratopathy and neuroparalytic keratitis. + +Clinical features +Symptoms +These vary from asymptomatic to foreign body sensation, mild pain to severe pain (out of proportion to the degree of inflammation), watering, photophobia, blepharospasm and blurred vision. +Signs +Acanthamoeba keratitis evolves over several months as a gradual worsening keratitis with periods of temporary remission. Presentation is markedly variable, making the diagnosis difficult. +Reported lesions of acanthamoeba keratitis are as below: +1. Epithelial lesions include: +• Epithelial roughening and irregularities, often mistaken for punctate epitheliopathy, +• Epithelial ridges,i.e., raised epithelial lines, • Pseudodendrites formation, and +• Epithelial and subepithelial curvilinear opacities (usually fine). +2. Stromal lesions include: +• Radial keratoneuritis (Fig. 6.12A), reported in 50% cases, seems to be pathognomonic early sign. It is thought to be the cause of severe pain disproportionate to inflammation. +• Patchy and satellite stromal infiltrates. +• Ring infiltrates, central or paracentral, with overlying epithelial defects and underlying keratic precipitates (Fig. 6.12B). + +• Ring abscess (Fig. 6.12C) associated with stromal necrosis and hypopyon may occur in late stages and mimics any suppurative keratitis. +3. Limbal and scleral lesions include: +• Limbitis is reported in majority of cases in early stages of infection. +• Scleritis, usually anterior diffuse or nodular, can be contiguous with keratitis. Rarely posterior scleritis with optic neuritis is also reported. + + + + + + + + + + + + + + +A + + + + + + + + + + + + + +B + + + + + + + + + + + + + +C +Fig. 6.12 Acanthamoeba keratitis: A, Radial +keratoneuritis; B, Ring infiltrate; and C, Ring abscess +114 Section III Diseases of Eye + + +Differential diagnosis +1. Viral keratitis. In early stages both epithelial lesions and early infiltrates are often mistaken for viral keratitis. +2. Fungal keratitis can also be misdiagnosed when ring infiltrates are associated with hypopyon. +3. Suppurative keratitis due to bacterial or other causes may be misdiagnosed in stage of stromal necrosis, and ring abscess formation. +Diagnosis +1. Clinical diagnosis. It is difficult and usually made by exclusion with strong clinical suspicion out of the non-responsive patients being treated for herpetic, bacterial or fungal keratitis. +2. Confocal microscopy, when available allows direct visualization of the cysts, which is diagnostic. +3. Laboratory diagnosis. Corneal scrapings may be helpful in some cases as under: +a. Potassium hydroxide (KOH) mount is reliable in experienced hands for recognition of acanthamoeba cysts. +b. Calcofluor white stain is a fluorescent brightener which stains the cysts of acanthamoeba bright apple green under fluorescence microscope. +c. Lactophenol cotton blue stained film is also useful for demonstration of acanthamoeba cysts in the corneal scrapings. +d. Culture on non-nutrient agar (E.coli enriched) may show trophozoites within 48 hours, which gradually turn into cysts. +e. Polymerase chain reaction (PCR) for amoebic DNA is reported to be useful. +f.Corneal biopsy,may be required in non-conclusive cases, may be positive for amoebic cyst. +Treatment +It is usually unsatisfactory. +1. Non-specific treatment is on the general lines for corneal ulcer (see page 104). +2. Specific treatment +a. Topical antiamoebic agents include: +• Diamidines:Propamidine isethionate (0.1 %), and hexamidine (0.1%). +• Biguanides: Polyhexamethylene biguanide (PHMB), 0.02% and chlorhexidine, 0.02%. +• Aminoglycosides: Neomycin and Paromycin Imidazoles: Clotrimazole and miconazole. +■Multipledrugtherapyisneeded for a long time (3–4 months) for early epithelial lesions and 6–12 months for stromal lesions. Any of the following combination may be choosen: +• Propamidine or hexamidine + PHMB or + + +• Chlorhexidine + Neomycin or +• Paromycin + clotrimazole or miconazole or itraconazole. +• Frequency of instillation: hourly for a week, then taper slowly over 3–4 months for epithelial lesions and 6–12 months for stromal lesions. +b. Oral ketoconazole 200 mg BID, or itraconazole 100 mg BD may be added in advanced cases. +3. Long-term prophylactic therapy with PHMB, twice a day for a year is recommended. +4. Penetrating keratoplasty is frequently required in non-responsive cases. Surgery should be performed after a full course of maximum medical therapy and a quiescent phase of at least six months. + +ALLERGIC KERATITIS + +1. Phlyctenular keratitis (see page 83) 2. Vernal keratitis (see page 79) +3. Atopic keratitis (see page 82) + +TROPHIC CORNEAL ULCERS + +Trophic corneal ulcers develop due to disturbance in metabolic activity of epithelial cells. This group includes: Neurotrophic keratopathy and Exposure keratopathy. +NEUROTROPHIC KERATOPATHY +Neurotrophic keratopathy occurs due to decreased corneal sensations owing to damage of sensory nerve supply of the cornea. +Causes +A. Congenital +1. Familial dysautonomia (Riley-Day syndrome). 2. Congenital insensitivity to pain. +3. Anhidrotic ectodermal dysplasia. +B. Acquired +1. Following alcohol-block or electrocoagulation of Gasserian ganglion or section of the sensory root of trigeminal nerve for trigeminal neuralgia. +2. A neoplasm pressing on Gasserian ganglion. +3. Gasserian ganglion destruction due to acute infection in herpes zoster ophthalmicus. +4. Acute infection of Gasserian ganglion by herpes simplex virus. +5. Syphilitic (luetic) neuropathy. +6. Involvement of corneal nerves in leprosy, diabetes. +7. Injury to Gasserian ganglion. +Pathogenesis +Exact pathogenesis is not clear; presumably, the disturbances in the corneal sensations occur due to +Chapter 6 Diseases of Cornea 115 + + +damage to sensory nerves. As a consequence, metabolic activity of corneal epithelium is disturbed, leading to accumulation of metabolites; which in turn cause oedema and exfoliation of epithelial cells followed by ulceration. Corneal changes can occur in the presence of a normal blink reflexand normal lacrimal secretions. +Clinical features +Symptoms +• Red eye, swollen eyelids and defective vision are common complaints. +• No pain, and no tearing are characteristic features. +Signs +1. Ciliary congestion is marked, 2. Corneal signs include: +• Sensations are decreased, • Sheen is lost (dull sheen), +• Punctate epithelial erosions involving the inter-palpebral area are initial lesions, which soon converts into, +• Frankepithelialdefects due to exfoliation of corneal epithelium, later followed by, +• Corneal ulcer formation, which is typically horizontally oval, located in the lower one-half of the cornea and have grey heaped-up epithelial borders (Fig 6.13A). +Note. Relapses are very common, even the healed scars quickly breakdown again. +Treatment +■Conventional treatment with antibiotics, cycloplegics, lubricating drops and patching should be started immediately. +■Special treatment recommended is topical nerve growth factor drops and autologous serum drops. ■Amnioticmembranetransplantationisrecommended when patients present with large non-healing ulcers. ■Lateraltarsorrhaphyis usually required to promote healing and prevent relapses. It should be kept at least for one year alongwith and prolonged use of artificial tears is also recommended. +EXPOSURE KERATOPATHY +Normally cornea is covered by eyelidsduring sleep and is constantly kept moist by blinking movements during awakening. When eyes are covered insufficiently by the lids and there is loss of protective mechanism of blinking, the condition of exposure keratopathy (keratitis lagophthalmos) develops. +Causes +Following factors which produce lagophthalmos may lead to exposure keratopathy: + +1. Extreme proptosis due to any cause will allow inadequate closure of lids. +2. Bell’s palsy or any other cause of facial palsy. 3. Ectropion of severe degree. +4. Symblepharon causing lagophthalmos. +5. Deepcomaassociated with inadequate closure of lids. +6. Physiological lagophthalmos. Occasionally, lagophthalmos during sleep may occur in healthy individuals. + +Pathogenesis +Due to exposure the corneal epithelium dries up followed by dessication. After the epithelium is cast off, invasion by infective organisms may occur. +Clinical features +Symptoms and signsof the causative disease are evident. Symptoms of exposure keratopathy include ocular irritation, burning, foreign body sensation and redness. Symptoms are usually worse in the morning. Signs of exposure keratopathy are: +■Drying of cornea occurs to begin with due to inadequate blinking or closure of the lids. +■Punctateepithelialdefectsdevelop in the lower third of cornea or as a horizontal band in the region of palpebral fissure (Fig. 6.13). +■Corneal ulceration may develop soon due to necrosis followed by bacterial superinfection. If neglected, corneal ulcer may even perforate soon. +Treatment +1. Prophylaxis. Once lagophthalmos is diagnosed following measures should be taken to prevent exposure keratitis. +• Artificial tears should be instilled frequently. +• Instillationofointmentand closure of lids by a tape or bandage during sleep. +• Softbandagecontactlenswith frequent instillation of artificial tears is required in cases of moderate exposure. +• Treatment of the cause of exposure: e.g., proptosis, ectropion, symblepharon should be taken up. +2. Treatment of the corneal ulcer once developed is on the general lines (see page 104). Tarsorrhaphy is invariably required when it is not possible to treat the cause or when recovery of the cause (e.g., facial palsy) is not anticipated. + +PERIPHERAL ULCERATIVE KERATOPATHIES + +Peripheral ulcerative keratopathies (PUKs), characterized by peripheral corneal thinning, infiltrates +116 Section III Diseases of Eye + + + + + + + + + + + + +A B +Fig. 6.13 Trophic corneal ulcers: A, Neurotrophic; B, Exposure keratitis (Note punctate epithelial defects in the lower third of cornea) + + +and ulceration, includes various conditions with different etiologies. Some of the PUKs are as follows: • Peripheral ulcerative keratitis associated with +connective tissue disorders, • Mooren’s ulcer, +• Rosacea keratitis, +• Marginal keratitis (catarrhal ulcer) of Staphy-lococcal hypersensitivity (see page 105), +• Terrien marginal degeneration (see page 124), • Pellucid marginal degeneration (see page 124), • Phlyctenular keratitis (see page 84), and +• Dellen. + +PERIPHERAL ULCERATIVE KERATITIS ASSOCIATED WITH CONNECTIVE TISSUE DISEASES (MARGINAL KERATOLYSIS) +Causes +Peripheral corneal ulceration and/or melting of corneal tissue is not of infrequent occurrence in patients suffering from connective tissue diseases such as: +• Rheumatoid arthritis, +• Systemic lupus erythematosus (SLE), • Polyarteritis nodosa, and +• Wegener’s granulomatosis. +Clinical features +• Peripheral acute corneal ulceration with rapid progression, usually in one sector, associated with inflammation at the limbus in one or both eyes. +• Peripheralcornealguttering or thinning may involve entire corneal periphery (contact lens cornea). +• Peripheral corneal melting may result in descemetocele formation or even perforation. +• Cornealulceration may be the first manifestation of the systemic disease and there may be associated systemic features of any of the causative disease. +Treatment +Such corneal ulcers are usually indolent and difficult to treat. + +1. Topical medication include, antibiotics, cyclop-legics and frequent instillation of lubricating drops. Topical steroids may be used with great caution, but not in the presence of significant thinning. +2. Systemic medication includes immunosupp-ressants (corticosteroids, or methotrexate, cycloph-osphamide), doxycycline and oral vitamin C (to promote a healing stromal environment). +3. Surgical measures needed include: +• Excision of adjacent inflamed conjunctiva, +• Bandage contact lens or conjunctival flap for impending perforation, +• tissue adhesive or peripheral tectonic keratoplasty for actual perforation. +MOOREN’S ULCER +Mooren’s ulcer (chronic serpiginous or rodent ulcer) is a severe inflammatory peripheral ulcerative keratitis. + +Etiology +Exact etiology is not known. Most probably it is an autoimmune disease (antibodies against corneal epithelium have been demonstrated in serum). +Clinical features +Two clinical varieties of Mooren’s ulcer have been recognised. +1. Benignorlimitedformwhich is usually unilateral, affects the elderly Caucasians and is characterised by a relative slow progress. +2. Virulent type also called the progressive form is bilateral, more often occurs in young African patients. The ulcer is rapidly progressive with a high incidence of scleral involvement. +Symptoms. These include severe pain, photophobia, lacrimation and defective vision. +Signs. Features of Mooren’s ulcer are shown in Fig. 6.14. • It is a superficial ulcer which starts at the corneal margin as patches of grey infiltrates which coalesce +to form a shallow furrow over the whole cornea. +Chapter 6 Diseases of Cornea 117 + + + + + + + + + + + + + + + +A + + + + + + + + + + + + + +B +Fig. 6.14 Mooren’s ulcer: A, Diagrammatic depiction; B, Clinical photograph + +• Peripheral ulcer is associated with undermining of the epithelium and superficial stromal lamellae at the advancing border which forms a characteristic whitish overhanging edge. Base of the ulcer soon becomes vascularized. The spread may be self-limiting or progressive. +• At the end-stage, the cornea is thinned and conjunctivalised. +• Ulcer rarely perforates and the sclera remains uninvolved. +Treatment +Since exact etiology is still unknown, its treatment is highly unsatisfactory. Following measures may be tried: +1. Topical corticosteroids instilled every 2–3 hours are tried as initial therapy with limited success. +2. Immunosuppressive therapy with systemic steroids may be of help. Immunosuppression with cyclosporinor other cytotoxic agents may be quite useful in virulent type of disease. +3. Softcontactlenseshave also been used with some relief in pain. + +4. Lamellarorfullthicknesscornealgraftsoften melt or vascularize. +ROSACEA KERATITIS +Corneal ulceration is seen in about 10% cases of acne rosacea, which is primarily a disease of the sebaceous glands of the skin. +Clinical features +1. Facial eruptions presenting in butterfly configuration, predominantly involving the malar and nasal area of face typically occurs in elderly women. +2. Ocular lesions include chronic blepha-roconjunctivitis and keratitis. Rosacea keratitis occurs as yellowish white marginal infiltrates, and small ulcers that progressively advance across the cornea and almost always become heavily vascularised. +Treatment +1. Local treatment. Rosacea keratitis responds to topical steroids, but recurrences are very common. +2. Systemic treatment. The essential and most effective treatment of rosacea keratitis is a long course of systemic tetracycline (250 mg QID × 3 weeks, TDS × 3 weeks, BID × 3 weeks, and once a day for 3 months). + +NON-ULCERATIVE KERATITIS + +Non-ulcerative keratitis can be divided into two groups: Non-ulcerative superficial keratitis and Non-ulcerative deep keratitis. + +NON-ULCERATIVE SUPERFICIAL KERATITIS + +This group includes a number of conditions of varied etiology. Here, the inflammatory reaction is confined to epithelium, Bowman’s membrane and superficial stromal lamellae. Non-ulcerative superficial keratitis may present in two forms: +• Diffuse superficial keratitis and • Superficial punctate keratitis. + +DIFFUSE SUPERFICIAL KERATITIS + +Diffuse inflammation of superficial layers of cornea occurs in two forms, acute and chronic. +1. Acute diffuse superficial keratitis +Etiology. Mostly of infective origin, may be associated with Staphylococcal or gonococcal infections. Clinical features. It is characterised by faint diffuse epithelial oedema associated with grey farinaceous +118 Section III Diseases of Eye + +appearance being interspersed with relatively clear area. Epithelial erosions may be formed at places. If uncontrolled, it usually converts into ulcerative keratitis. +Treatment. It consists of frequent instillation of antibiotic eyedrops such as tobramycin or gentamycin 2–4 hourly. +2. Chronic diffuse superficial keratitis +It may be seen in rosacea, phlyctenulosis and is typically associated with pannus formation. + + +SUPERFICIAL PUNCTATE KERATITIS (SPK) + +Superficial punctate keratitis is characterised by occurrence of multiple, spotty lesions in the superficial layers of cornea. It may result from a number of conditions, identification of which (causative condition) might not be possible most of the times. +Causes +Some important causes of superficial punctate keratitis are listed here. +1. Viral infections are the chief cause. Of these more common are: herpes zoster, adenovirus infections, epidemic keratoconjunctivitis, pharyngoconjunctival fever and herpes simplex. +2. Chlamydial infections include trachoma and inclusion conjunctivitis. +3. Toxic lesions e.g., due to Staphylococcal toxin in association with blepharoconjunctivitis. +4. Trophic lesions e.g., exposure keratitis and neuroparalytic keratitis. +5. Allergic lesions e.g., vernal keratoconjunctivitis. 6. Irritativelesions e.g., effect of some drugs such as +idoxuridine. +7. Disordersofskinandmucousmembrane, such as acne rosacea and pemphigoid. +8. Dryeyesyndrome, i.e., keratoconjunctivitis sicca. 9. Specific type of idiopathic SPK e.g., Thygeson’s superficial punctate keratitis and Theodore’s +superior limbic keratoconjunctivitis. 10. Photo-ophthalmia. +Morphological types +1. Punctate epithelial erosions (multiple superficial erosions). +2. Punctate epithelial keratitis (Figs. 6.15A and B). 3. Punctate subepithelial keratitis (Figs. 6.15C and D). 4. Punctate combined epithelial and subepithelial +keratitis (Figs. 6.15E and F). +5. Filamentary keratitis (Figs. 6.15G and H). + + + + + + + + + + + + + + + + + + + + + + +Fig. 6.15 Morphological types of superficial punctate keratitis. diagrammatic depictions and clinical photographs of: A and B, Punctate epithelial; C and D, Punctate sub-epithelial keratitis; E and F, Punctate combined epithelial and subepithelial keratitis; G and H, Filamentary keratitis + + +Clinical features +Superficial punctate keratitis may present as different morphological types as enumerated above. Punctate epithelial lesions usually stain with fluorescein, rose bengal and other vital dyes. The condition mostly presents with acute pain, photophobia and lacrimation; and is usually associated with conjunctivitis. +Treatment +Treatment of most of these conditions is symptomatic. 1. Topicalsteroidshave a marked suppressive effect. 2. Artificial tears have soothing effect. +3. Specific treatment of cause should be instituted +Chapter 6 Diseases of Cornea 119 + + +whenever possible e.g., antiviral drugs in cases of herpes simplex. +PHOTO-OPHTHALMIA +Photo-ophthalmia refers to occurrence of multiple epithelial erosions due to the effect of ultraviolet rays especially from 311 to 290 m. +Causes +• Exposure to bright light of a short circuit. +• Naked arc light exposure as in industrial welding and cinema operators. +• Snow blindness due to reflected ultraviolet rays from snow surface. +Pathogenesis +After an interval of 4–5 hours (latent period) of exposure to ultraviolet rays, there occurs desqua-mation of corneal epithelium leading to formation of multiple epithelial erosions. +Clinical features +• Typically,patientpresentswith severe burning pain, lacrimation, photophobia, blepharospasm, swelling of palpebral conjunctiva and retrotarsal folds. +• History of exposure to ultraviolet rays 4–5 hours earlier is positive. +• On fluorescein staining multiple spots are demonstrated on both corneas. +Prophylaxis +• Crooker’s glass which cuts off all infrared and ultraviolet rays should be used by those who are prone to exposure e.g., welding workers, cinema operators, etc. +Treatment +• Cold compresses. +• Patching with antibiotic ointment for 24 hours, heals most of the cases. +• Oralanalgesicsmay be given if pain is intolerable. • Single dose of tranquilizer may be given to +apprehensive patients. + +SUPERIOR LIMBIC KERATOCONJUNCTIVITIS Superior limbic keratoconjunctivitis of Theodore is the name given to inflammation of superior limbic, bulbar and tarsal conjunctiva associated with punctate keratitis of the superior part of cornea. +Etiology +Exact etiology is not known. It occurs with greater frequency in patients with hyperthyroidism and is more common in females. + +Symptoms include: +• Bilateral ocular irritation. +• Mild photophobia, and redness in superior bulbar conjunctiva. +Signs include (Fig. 6.16): +• Congestion of superior limbic, bulbar and tarsal conjunctiva. +• Punctate keratitis which stains with fluorescein and rose Bengal stain is seen in superior part of cornea. +• Corneal filaments are also frequently seen in the involved area. +Treatment +• Artificial tears provide soothing effect. +• Topicalcorticosteroidsin low doses may reduce the symptoms temporarily. +• Faint diathermy of superior bulbar conjunctiva in a checker board pattern gives acceptable results. +• Recessionorresection of a 3–4 mm wide perilimbal strip of conjunctiva from the superior limbus (from 10.30 to 1.30 O’clock position) may be helpful, if other measures fail. +• Therapeutic soft contact lenses for a longer period may be helpful in healing the keratitis. + + + + + + + + + + + + + +A + + + +Clinical features +Clinical course is chronic with remissions and exacerbations. + + \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_5.txt b/notes/A K Khurana - Comprehensive Ophthalmology_5.txt new file mode 100644 index 0000000000000000000000000000000000000000..1eda32989c6026a8451c428306ace19880efc54e --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_5.txt @@ -0,0 +1,1599 @@ +B +Fig. 6.16 Superior limbic keratoconjunctivitis: A, Diagrammatic depiction; B, Clinical photograph +120 Section III Diseases of Eye + + +THYGESON’S SUPERFICIAL PUNCTATE KERATITIS +It is a type of chronic, recurrent bilateral superficial punctate keratitis, which has got a specific clinical identity. +Etiology +Exact etiology is not known. +• A viral origin has been suggested without any conclusion. +• An allergic or dyskeratotic nature also has been suggested owing to its response to steroids. +Clinical features +• Age and sex. It may involve all ages with no sex predilection. +• Laterality. Usually bilateral. +• Course. It is a chronic disease characterised by remissions and exacerbations. +Symptoms +It may be asymptomatic, but is usually associated with foreign body sensation, photophobia and lacrimation. +Signs +• Conjunctiva is uninflamed (no conjunctivitis). +• Corneallesions.There are coarse punctate epithelial lesions (snow flake) circular, oval or stellate in shape, slightly elevated and situated in the central part (pupillary area) of cornea. Each lesion is a cluster of heterogeneous granular grey dots. +Treatment +• Disease is self-limiting with remissions and may permanently disappear in a period of 5–6 years. +• Topical steroids during exacerbations the lesions and associated symptoms usually respond quickly to topical steroids (so, should be tapered rapidly). +• Therapeutic soft contact lenses may be required in steroid-resistant cases. +FILAMENTARY KERATITIS +It is a type of superficial punctate keratitis, associated with formation of corneal epithelial filaments. +Pathogenesis +Corneal filaments which essentially consist of a tag of elongated epithelium are formed due to aberrant epithelial healing. Therefore, any condition that leads to focal epithelial erosions may produce filamentary keratopathy. +Causes +Common conditions associated with filamentary keratopathy are: +1. Keratoconjunctivitis sicca (KCS). +2. Superior limbic keratoconjunctivitis. + + +3. Epitheliopathy due to radiation keratitis. +4. Following epithelial erosions as in herpes simplex keratitis, Thygeson’s superficial punctate keratitis, recurrent corneal erosion syndrome and trachoma. +5. Prolonged patching of the eye particularly following ocular surgery like cataract. +6. Systemic disorders like diabetes mellitus, ectodermal dysplasia and psoriasis. +7. Idiopathic. + +Clinical features +Symptoms +Patients usually experience moderate pain, ocular irritation, lacrimation and foreign body sensation. +Signs +Corneal examination reveals (Fig. 6.15G and H): +• Filaments i.e., fine tags of elongated epithelium which are firmly attached at the base, intertwined with mucus and degenerated cells. The filament is freely movable over the cornea. +• Superficial punctate keratitis of varying degree is usually associated with corneal filaments. +Treatment +1. Managementoffilamentsinclude their mechanical debridement and patching for 24 hours followed by lubricating drops. +2. Therapeutic soft contact lenses may be useful in recurrent cases. +3. Treatment of the underlying cause to prevent recurrence. + +DEEP KERATITIS + +An inflammation of corneal stroma with or without involvement of posterior corneal layers constitutes deep keratitis, which may be non-suppurative or suppurative. +■Non-suppurativedeepkeratitisincludes, interstitial keratitis, disciform keratitis, keratitis profunda and sclerosing keratitis. ■Suppurativedeepkeratitisincludes central corneal abscess and posterior corneal abscess, which are usually metastatic in nature. +INTERSTITIAL KERATITIS +Interstitial keratitis denotes an inflammation of the corneal stroma without primary involvement of the epithelium or endothelium. +Causes. Its common causes are: • Congenital syphilis +• Tuberculosis +• Cogan’s syndrome +Chapter 6 Diseases of Cornea 121 + + +• Acquired syphilis • Trypanosomiasis • Malaria +• Leprosy +• Sarcoidosis. + +Syphilitic (Luetic) Interstitial Keratitis Syphilitic interstitial keratitis is associated more frequently (90%) with congenital syphilis than the acquired syphilis. The disease is generally bilateral in inherited syphilis and unilateral in acquired syphilis. In congenital syphilis, manifestations develop between 5–15 years of age. +Pathogenesis +It is now generally accepted that the disease is a manifestation of local antigen-antibody reaction. It is presumed that Treponema pallidum invades the cornea and sensitizes it during the period of its general diffusion throughout the body in the foetal stage. Later a small scale fresh invasion by Treponema or toxins excite the inflammation in the sensitized cornea. The inflammation is usually triggered by an injury or an operation on the eye. +Clinical features +Interstitial keratitis characteristically forms one of the late manifestations of congenital syphilis. Many times it may be a part of Hutchinson’s triad, which includes interstitial keratitis, Hutchinson’s teeth and vestibular deafness. +The clinical features of interstitial keratitis can be divided into three stages: initial progressive stage, florid stage and stage of regression. +1. Initial progressive stage. The disease begins with oedema of the endothelium and deeper stroma, secondary to anterior uveitis, as evidenced by the presence of keratic precipitates (KPs). There is associated pain, lacrimation, photophobia, blepharospasm and circumcorneal injection followed by a diffuse corneal haze giving it a ground glassappearance.This stage lasts for about 2 weeks. 2. Florid stage. In this stage, eye remains acutely inflamed. Deep vascularization of cornea, consisting of radial bundle of brush-like vessels develops. Since, these vessels are covered by hazy cornea, they look dull reddish pink which is called ‘Salmon patch appearance’ (Fig. 6.17). There is often a moderate degree of superficial vascularization. These vessels arising from the terminal arches of conjunctival vessels, run a short distance over the cornea. These vessels and conjunctiva heap at the limbus in the form of epulit. This stage lasts for about 2 months. + + + + + + + + + + + + + + +Fig. 6.17 Intenstitial keratitis: Salmon patch appearance + +3.Stage of regression. The acute inflammation resolves with the progressive appearance of vascular invasion. Clearing of cornea is slow and begins from periphery and advances centrally. Resolution of the lesion leaves behind some opacities and ghostvessels.This stage may last for about 1 to 2 years. +Diagnosis +The diagnosis is usually evident from the clinical profile. A positive VDRL or Treponema pallidum immobilization test confirms the diagnosis. +Treatment +The treatment should include topical treatment for keratitis and systemic treatment for syphilis. +1. Local treatment includes: +• Topical corticosteroid drops e.g., dexamethasone 0.1% drops every 2–3 hours. As the condition is allergic in origin, corneal clearing occurs with steroids if started well in time and a useful vision is obtained. +• Atropine eye ointment 1% 2–3 times a day. • Dark goggles to be used for photophobia. +• Keratoplasty is required in cases where dense corneal opacities are left. +2. Systemic treatment includes: +• Penicillin in high doses should be started to prevent development of further syphilitic lesions. However, an early treatment of congenital syphilis usually does not prevent the onset of keratitis at a later stage. +• Systemicsteroidsmay be added in refractory cases of keratitis. + +Tuberculous Interstitial Keratitis +The features of tubercular interstitial keratitis are similar to syphilitic interstitial keratitis except that it is more frequently unilateral and sectorial (usually involving a lower sector of cornea). +122 Section III Diseases of Eye + + +Treatment consists of systemic antitubercular drugs, topical steroids and cycloplegics. + +Cogan’s Syndrome +This syndrome comprises the interstitial keratitis of unkown etiology, acute tinnitus, vertigo, and deafness. It typically occurs in middle-aged adults and is often bilateral. +Treatment consists of topical and systemic cortico-steroids. An early treatment usually prevents permanent deafness and blindness. + +CORNEAL DEGENERATIONS + +Corneal degenerations refers to the conditions in which the normal cells undergo some degenerative changes under the influence of age or some pathological condition. +Classification +A. Depending upon location +I. Axial corneal degenerations 1. Fatty degeneration +2. Hyaline degeneration 3. Amyloidosis +4. Calcific degeneration (Band keratopathy) 5. Salzmann’s nodular degeneration. +II. Peripheral degenerations 1. Arcus senilis +2. Vogt’s white limbal girdle 3. Hassall-Henle bodies +4. Terrien’s marginal degeneration 5. Mooren’s ulcer +6. Pellucid marginal degeneration +7. Furrow degeneration (senile marginal degen-eration). +B. Depending upon etiology +I. Age-related degenerations. Arcus senilis, Vogt’s white limbal girdle, Hassall-Henle bodies, Mosaic degeneration. +II. Pathological degenerations. Fatty degeneration, amyloidosis, calcific degeneration, Salzmann’s nodular degeneration, Furrow degeneration, spheroidal degeneration, Pellucid marginal degeneration, Terrien’s marginal degeneration, Mooren’s ulcer. +I. AGE-RELATED CORNEAL DEGENERATIONS +Arcus Senilis +Arcus senilis refers to an annular lipid infiltration of corneal periphery. This is an age-related change occurring bilaterally in 60% of persons between 40 and 60 years of age and in nearly all individuals over + +the age of 80. Sometimes, similar changes may occur in young persons (arcusjuvenilis)which may or may not be associated with hyperlipidemia. + +Clinical features +• The arcus starts in the superior and inferior quadrants and then progresses circumferentially to form a ring which is about 1 mm wide. Peripheral border of this ring opacity is sharp while central border is diffuse. +• This ring of opacity is separated from the limbus by a clear zone (the lucid interval of Vogt) (Fig. 6.18). +• Sometimes there may be double ring of arcus. + +Vogt’s White Limbal Girdle +It is also an age-related change seen frequently in elderly people. It appears as bilateral chalky white opacities in the interpalpebral area both nasally and temporally. There may or may not be a clear area between opacity and the limbus. The opacity is at the level of Bowman’s membrane. + +Hassall-Henle Bodies +Hassall-Henle bodies are drop-like excrescences of hyaline material projecting into the anterior chamber around the corneal periphery. These arise from Descemet’s membrane. These form the commonest senile change seen in the cornea. In pathological conditions, they become larger and invade the central area and the condition is called cornea guttata. + +II. PATHOLOGICAL CORNEAL DEGENERATIONS Fatty Degeneration (Lipoid Keratopathy) Fatty degeneration of cornea is characterised by whitish or yellowish deposits. The fat deposits mostly consist of cholesterol and fatty acids. Initially fat deposits are intracellular but some become extracellular with necrosis of stromal cells. Lipid keratopathy can be primary or secondary. + + + + + + + + + + + + + + + +Fig. 6.18 Arcus senilis +Chapter 6 Diseases of Cornea 123 + + +1. Primary lipid keratopathy is a rare condition which occurs in a cornea free of vascularization. Serum lipid levels are normal in such patients. +2. Secondarylipidkeratopathyoccurs in vascularised cornea secondary to diseases such as corneal infections, interstitial keratitis, ocular trauma, glaucoma, and chronic iridocyclitis. +Treatment is usually unsatisfactory. In some cases slow resorption of lipid infiltrate can be induced by argon laser photocoagulation of the new blood vessels. + +Hyaline Degeneration +Hyaline degeneration of cornea is characterised by deposition of hyaline spherules in the superficial stroma and can be primary or secondary. +1. Primary hyaline degeneration is bilateral and noted in association with granular dystrophy. +2. Secondary hyaline degeneration is unilateral and associated with various types of corneal diseases including old keratitis, long-standing glaucoma, trachomatous pannus. It may be complicated by recurrent corneal erosions. +Treatment of the condition when it causes visual disturbance is keratoplasty. + +Amyloid Degeneration +Amyloid degeneration of cornea is characterised by deposition of amyloid material underneath its epithelium. It is very rare condition and occurs in primary (in a healthy cornea) and secondary forms (in a diseased cornea). + +Calcific Degeneration (Band Shape Keratopathy) +Band shape keratopathy (BSK) is essentially a degenerative change associated with deposition of calcium salts in Bowman’s membrane, most superficial part of stroma and in deeper layers of epithelium. +Etiology +• Oculardiseasescomplicated by band keratopathy include chronic uveitis in adults, children with Still’s disease, phthisis bulbi, chronic glaucoma, chronic keratitis and ocular trauma. +• Age-relatedBSK is common and affects otherwise healthy cornea. +• Primary BSK is familial. +• Metabolic conditions rarely associated with BSK include hypercalcaemia, hyperphosphataemia, hyperuricemia and chronic renal failure. +Clinical features +It typically presents as a band-shaped opacity in the interpalpebral zone with a clear interval between the ends of the band and the limbus (Fig. 6.19). The + + + + + + + + + + + + + + +Fig. 6.19 Band-shaped keratopathy in a patient with chronic uveitis + +condition begins at the periphery and gradually progresses towards the centre. The opacity is beneath the epithelium which usually remains intact. Surface of this opaque band is stippled due to holes in the calcium plaques in the area of nerve canals of Bowman’s membrane. In later stages, transparent clefts due to cracks or tears in the calcium plaques may also be seen. +Treatment +1. Chelation, i.e., chemical removal of deposited calcium salts is an effective treatment. First of all, corneal epithelium is scraped under local anaesthesia. Then 0.01 molar solution of EDTA (chelating agent) is applied to the denuded cornea with the help of a cotton swab for about 10 minutes. This removes most of the deposited calcium. Pad and bandage is then applied for 2–3 days to allow the epithelium to regenerate. +2. Phototherapeutickeratectomy(PTK) with excimer laser is very effective in clearing the cornea. +3. Keratoplasty may be performed when the band keratopathy is obscuring useful vision. +4. Treatment of underlying causative disease. + +Salzmann’s Nodular Degeneration +Etiology. This condition occurs in eyes with recurrent attacks of phlyctenular keratitis, rosacea keratitis and trachoma. The condition occurs more commonly in women and is usually unilateral. +Pathogenesis. In Salzmann’s nodular degeneration, raised hyaline plaques are deposited between epithelium and Bowman’s membrane. There is associated destruction of Bowman’s membrane and the adjacent stroma. +Clinical features. Clinically, one to ten bluish white elevations (nodules), arranged in a circular fashion, +124 Section III Diseases of Eye + + + + + + + + + + + + + + + + +Fig. 6.20 Salzmann’s nodular degeneration + +are seen within the cornea (Fig. 6.20). Patient may experience discomfort due to loss of epithelium from the surface of nodules. Visual loss occurs when nodules impinge on the central zone. +Treatment is essentially by keratoplasty. +Furrow Degeneration (Senile Marginal Degeneration) +In this condition, thinning occurs at the periphery of cornea leading to formation of a furrow. In the presence of arcus senilis, the furrow occupies the area of lucid interval of Vogt. Thinning occurs due to fibrillar degeneration of the stroma. +Patient develops defective vision due to induced astigmatism. +Treatment is usually not necessary. +Spheroid Degeneration +(Climatic droplet keratopathy/Labrador keratopathy/ Bietti’s nodular dystrophy)/corneal elastosis). Etiology.It typically occurs in men who work outdoors, especially in hostile climates. Its occurrence has been related to exposure to ultraviolet rays and/ or ageing and/or corneal disease. +Clinical features. In this condition, amber-coloured spheroidal granules (small droplets) accumulate at the level of Bowman’s membrane and anterior stroma in the interpalpebral zone (Fig. 6.21). In marked degeneration, the vision is affected. Treatment in advanced cases is by corneal trans-plantation. +Pellucid Marginal Degeneration +It is characterised by corneal thinning involving the periphery of lower cornea. It induces marked astigmatism which is corrected by scleral type contact lenses. +Terrien’s Marginal Degeneration +Terrien’s marginal degeneration is non-ulcerative thinning of the marginal cornea. + + +Fig. 6.21 Spheroid corneal degeneration + +Clinical features are as follows: +1. Predominantly affects males usually after 40 years of age. +2. Mostly involves superior peripheral cornea. +3. Initial lesion is asymptomatic corneal opacification separated from limbus by a clear zone. +4. The lesion progresses very slowly over many years with thinning and superficial vascularization. Dense yellowish white deposits may be seen at the sharp leading edge (Fig. 6.22). Patient experiences irritation and defective vision (due to astigmatism). Complications such as perforation (due to mild +trauma) and pseudopterygia may develop. Treatment isnon-specific. In severe thinning, a patch of corneal graft may be required. + +CORNEAL DYSTROPHIES + +Corneal dystrophies are inherited disorders in which the cells have some inborn defects due to which pathological changes may occur with passage of time leading to development of corneal haze in otherwise normal eyes that are free from inflammation or + + + + + + + + + + + + + + + +Fig. 6.22 Terrien’s marginal degeneration +Chapter 6 Diseases of Cornea 125 + + +vascularization. There is no associated systemic disease. Dystrophies occur bilaterally, manifesting occasionally at birth, but more usually during first or second decade and sometimes even later in life. +Note. Recent studies have revealed that all the above definitions are not true for every type of corneal dystrophy. However, the International Committee for Classification of Corneal Dystrophies (2008) has decided to continue with the above given customary definition of corneal dystrophies. +Classification +The International Committee for Classification of Corneal Dystrophies (IC3D) in 2008 has proposed a new classification of corneal dystrophies, which in addition to the anatomic basis (site primarily involved) also incorporates the current clinical, pathological and genetic basis. Therefore, dystrophies with a common genetic basis, i.e., TGFB1 dystrophies have been grouped together (irrespective of the primary location of the lesion). The new IC3D classification of corneal dystrophies is as below: +I. Epithelial and subepithelial dystrophies +1. Epithelial basement membrane dystrophy (EBMD). +2. Epithelial recurrent erosion dystrophy (ERED). 3. Subepithelial mucinous corneal dystrophy +(SMCD). +4. Mutation in keratin genes: Meesmann corneal dystrophy (MECD). +5. Lisch epithelial corneal dystrophy (LECD). +6. Gelatinous drop-like corneal dystrophy (GDLD). +II. Bowman layer dystrophies +1. Reis-Bucklers corneal dystrophy (RBCD) Granular corneal dystrophy type 3. +2. Thie-Behnke corneal dystrophy (TBCD). +3. Grayson-Wilbrandt corneal dystrophy (GWCD). III. Stromal dystrophies +1. TGFb1 corneal dystrophies a. Lattice corneal dystrophy +i. Classic lattice corneal dystrophy 1 (LCD 1) ii. Lattice corneal dystrophy, gelsolin type 2 +(LCD 2) +b. Granular corneal dystrophy +i. Granular corneal dystrophy, type 1 (classic) (GCD 1) +ii. Granular corneal dystrophy, type 2 (granular lattice) (GCD 2) +iii.Granular corneal dystrophy, type 3 (GCD 3) 2. Macular corneal dystrophy (MCD). +3. Schnyder corneal dystrophy (SCD). +4. Congenital stromal corneal dystrophy (CSCD). + +5. Fleck corneal dystrophy (FCD). +6. Posterior amorphous corneal dystrophy (PACD). +7. Central cloudy dystrophy of Francois (CCDF). 8. Pre-Descemet corneal dystrophy (PDCD). +IV.Descemet membrane and endothelial dystrophies 1. Fuchs endothelial corneal dystrophy (FECD). 2. Posterior polymorphous corneal dystrophy +(PPCD). +3. Congenital hereditary endothelial dystrophy 1 (CHED 1). +4. Congenital hereditary endothelial dystrophy 2 (CHED 2). +5. X-linked endothelial corneal dystrophy (XECD). + +I. EPITHELIAL AND SUBEPITHELIAL DYSTROPHIES + +1. Epithelial Basement Membrane Dystrophy Epithelial basement membrane dystrophy (EBMD) is also known as map-dot-fingerprint dystrophy or Cogan microcystic epithelial dystrophy or anterior basement membrane dystrophy. +Inheritance. Most cases have no inheritance documented. +Genetic locus and gene are 5q31 and TGFb1, respectively. +Onset, course and symptoms. Presents in adult life, rarely seen in children. Asymptomatic or recurrent erosions with pain, lacrimation and blurred vision are observed. Except for the bleb pattern, on-axis lesions may also cause blurred vision due to irregular astigmatism. Location and degree of pathology can fluctuate with time. +Signs. Typical lesions include (Fig. 6.23): +• Maps. Irregular islands of thickened, gray, hazy epithelium with scalloped, circumscribed borders, + + + + + + + + + + + + + + +Fig. 6.23 Epithelial basement membrane dystrophy +126 Section III Diseases of Eye + + +particularly affecting the central or paracentral cornea. Isolated or combined with other signs. +• Dots (Cogan). Irregular round, oval or comma-shaped, non-staining, putty-gray opacities. Clustered like an archipelago in the central cornea. Typically combined with other signs, especially with maps. +• Fingerprint lines. Parallel, curvilinear lines, usually paracentral, best seen in retroillumination. They may be isolated or combined with other signs, especially maps. +• Bleb pattern (Bron). A subepithelial pattern like pebbled glass, best seen by retroillumination. Isolated or combined with other signs. +Note. Poor adhesion of basal epithelial cells to abnormal basal laminar material is thought predisposition to recurrent erosions. +2. Epithelial Recurrent Erosion Dystrophy Onset and course. Epithelial recurrent erosion dystrophy (ERED), also known as corneal erosions or recurring hereditary dystrophy, usually occurs in first decade of life. +Inheritance is autosomal dominant. +Genetic locus and gene involved are unknown. +Onset and course. Recurrent corneal erosions appear typically at 4–6 years of age but occasionally as early as 8 months of age. Attacks generally decline in frequency in intensity and cease by the age of 50 years. Signs include (Fig. 6.24): +• Corneal erosions are seen during the attack recurrent corneal erosions appear typically at 4–6 years of age but occasionally as early as 8 months of age. Attacks generally decline in frequency and intensity and cease by the age of 50 years. +• Subepithelial haze or blebs may be seen between the attacks. + + + + + + + + + + + + + + +Fig. 6.24 Lattice corneal dystrophy + + +• Central subepithelial corneal opacities, may appear as early as 7 years of age. These vary from subepithelial fibrosis to protruding keloid-like nodules. +Symptoms are precipitated by minimal trauma or occur spontaneously and are in the form of attacks of redness, photophobia, epiphora and ocular pain. Treatment. About 25% of the patients may eventually need corneal grafts at the mean age of 45 years. + +3. Subepithelial Mucinous Corneal Dystrophy +Inheritance is autosomal dominant. Genetic locus and gene is unknown. +Onset and course. Onset is in the first decade of life and progressive loss of vision occurs in adole-scence. +Signs include bilateral subepithelial opacities and haze, most dense centrally, involving the entire cornea. Symptoms include painful episodes of recurrent corneal erosions, which decrease during adolescence. +4. Mutations in Keratin Genes: Meesmann Corneal Dystrophy +Onset and course. Meesmann corneal dystrophy (MECD) also known as juvenile hereditary epithelial dystrophy occurs in early childhood and the condition is slowly progressive. Its variant is Stocker-Holt dystrophy. +Inheritance is autosomal dominant. +Genetic loci are 12q13 (KRT3) and 17q12 (KRT 12) for Stocker-Holt variant . +Genes involved are Keratin K3 (KRT3) and Keratin K12 (KRT12) for Stocker-Holt variant. +Signs. Characteristic lesions include: +• Multiple,tinyepithelialvesicleswhich extend to the limbus and are most numerous in the interpalpebral area with clear surrounding epithelium. +• Whorled and wedge-shaped epithelial patterns have also been reported. +• Corneal thinning and reduction in corneal sensation may be noted. +• In Stocker-Holt variant, the entire cornea demonstrates fine, grayish punctate epithelial opacities that stain with fluorescein and fine linear opacities that may appear in a whorl pattern. +Symptoms. Patients are typically asymptomatic or may have mild visual reduction, although some patients complain of glare and light sensitivity. Recurrent painful punctiform epithelial erosions may occur. Rarely, blurred vision results from corneal irregularity and scarring. +Chapter 6 Diseases of Cornea 127 + + +5. Lisch Epithelial Corneal Dystrophy +Onset and course. Lisch epithelial corneal dystrophy (LECD) also known as band-shaped and whorled microcystic dystrophy of the corneal epithelium occurs in childhood and there occurs slow progression of opacities with possible deterioration in vision. Inheritance is X-chromosomal dominant. +Signs are as below. +• Direct illumination shows localized gray opacities in different patterns: whorl-like, radial, band-shaped, flame/feathery shaped, and club shaped. +• Indirect illumination demonstrates multiple, densely crowded clear cysts with clear surrounding epithelium. +Symptoms. The condition is asymptomatic, blurring of vision occurs if the pupillary zone is involved. +6. Gelatinous Drop-Like Corneal Dystrophy (GDLD) +Onset and course. Gelatinous drop-like corneal dystrophy (GDLD) also known as subepithelial amyloidosis or primary familial amyloidosis (Grayson) occurs in the first decade of life and the condition is progressive. +Genetic locus is 1p32 and gene involved is tumour-associated calcium signal transducer 2 (TACSTD2) Inheritance is autosomal recessive. +Signs include: +• Subepithelial lesions which appear initially may be similar to band-shaped keratopathy or there may be groups of small multiple nodules, that is, mulberry configuration. +• Superficial vascularization is frequently seen. +• Stromalopacificationor larger nodular lesions, that is, kumquat-like lesions may appear in later life. Symptoms include significant decrease in vision, +photophobia, irritation, redness, and tearing. + +II. BOWMAN LAYER DYSTROPHIES +1. Reis-Bucklers Corneal Dystrophy +Onset and course. Reis-Bucklers corneal dystrophy (RBCD) also known as corneal dystrophy of Bowman layer, type I (CDB I) or geographic corneal dystrophy (Weidle), occurs in childhood and causes slowly progressive deterioration of vision. +Genetic locus is 5q31 and the gene involved is TGFBI. Inheritance is autosomal dominant. +Signs include confluent irregular and coarse geographic-like opacities with varying densities + + +which develop at the level of Bowman layer and superficial stroma, initially separated from one another. Opacities may extend to the limbus and deeper stroma with time. +Symptoms. Vision is impaired from childhood. Recurrent corneal erosions cause ocular discomfort and pain in the first decade but may become less severe from the end of the second decade. +2. Thiel-Behnke Corneal Dystrophy +Onset and course. Thiel-Behnke corneal dystrophy (TBCD) also known as corneal dystrophy of Bowman layer, type II (CDB2) or honeycomb-shaped corneal dystrophy occurs in childhood and causes slowly progressive deterioration of vision. +Genetic locus is 5q31 and the gene involved is TGFB1. Inheritance is autosomal dominant. +Onset and course. Occurs in childhood and there occurs slowly progressive deterioration of vision from increasing corneal opacification. +Signs include symmetrical subepithelial reticular (honeycomb) opacities with peripheral cornea typically uninvolved, which can progress to deep stromal layers and corneal periphery. +Symptoms. Recurrent corneal erosions cause ocular discomfort and pain in the first and second decade. Gradual visual impairment develops later. +3. Grayson-Wilbrandt Corneal Dystrophy (GWCD) +Onset and Course. Occurs during first to second decade of life and the condition is progressive. Inheritance is autosomal dominant. +Signs. Bowman layer demonstrates variable patterns of opacification from diffuse mottling to diffuse gray-white opacities, which extend anteriorly into the epithelium. The cornea between the deposits is clear. Refractile bodies are described in corneal stroma. +Symptoms. Decreased to normal visual acuity. Recurrent corneal erosions may cause ocular discomfort and pain. +III. STROMAL CORNEAL DYSTROPHIES +1. TGFB1 Corneal Dystrophies These include: +A. Lattice corneal dystrophy, which is of two types: i. Classic lattice corneal dystrophy (LCD1) +ii. Lattice corneal dystrophy, gelsolin type (LCD2) B. Granularcornealdystrophy, which is of three types: i. Granular corneal dystrophy, type 1 (classic) +(GCD1) +128 Section III Diseases of Eye + + +ii. Granular corneal dystrophy, type 2 (granular lattice) (GCD2) +iii.Granular corneal dystrophy, type 3 (GCD3). + +A. Lattice corneal dystrophy +i. Classical lattice corneal dystrophy: +Classic lattice corneal dystrophy (LCD1) is also known as Biber-Haab-Dimmer dystrophy. +Genetic locus is 5q31 and the gene involved is TGFB1. Inheritance is autosomal dominant. +Onset, symptoms and course. It appears at the age of 2 years and the condition is progressive. Recurrent erosions are frequent and ocular discomfort and pain occurs sometimes starting as early as in the first decade of life. Progressive clouding of central cornea is apparent by the age of 20 years. Soon, visual acuity is impaired. Usually penetrating keratoplasty is required by the age of 30–40 years. +Signs. The disease is characterised by branching spider-like amyloid deposits forming an irregular lattice work in the corneal stroma, sparing the periphery (Fig. 6.24). The number of lattice lines may differ between the 2 eyes and the dystrophy may be difficult to diagnose in some younger patients. +ii. Lattice corneal dystrophy, Gelsolin Type (LCD2) Lattice corneal dystrophy, Gelsolin type is also known as Familial amyloidosis of Finnish (FAF) or Meretoja syndrome. +Genetic locus is 9q34 and the geneinvolved is Gelsolin GSN. +Inheritance is autosomal dominant. +Onset and course. Onset occurs in third to fourth decade of life, the condition is slowly progressive and the majority of patients are in good health even in the seventh decade. +Signs include: +• Lattice lines appear in the corneal stroma (spreading centripetally from the limbus) which are more peripheral and less numerous than those of lattice dystrophy, type 1. The central cornea is relatively spared. +• Corneal sensitivity is reduced or absent. +Symptoms include: +• Dry eye symptoms are frequent, and corneal erosions may occur late in life. +• Visual acuity is usually normal until the sixth decade because the dystrophy progresses from the peripheral to central cornea. +B. Granular dystrophy +i. Granular corneal dystrophy, Type 1 (Classic) (GCDl) Onset and course. Granular corneal dystrophy, Type 1 (Classic) (GCD 1), also known Corneal dystrophy + +Groenouw type 1 occurs in childhood, may be seen as early as 2 years of age. As the condition progresses, the opacities become more confiuent in the superficial cornea. +Genetic locus is5q31 and thegene involved is TGFB1. Inheritance is autosomal dominant. +Signs. The condition is characterised by (Fig. 6.25) milky granular hyaline deposits in anterior stroma. Intervening stroma is clear. Opacities do not extend to the limbus. In children, there may be a vortex pattern of brownish granules superficial to Bowman layer. In later life, granules may extend into the deeper stroma down to Descemet membrane. Symptoms include: +• Glare and photophobia are early symptoms. +• Recurrenterosionsoccur frequently causing ocular discomfort, pain and watering. +• Visualacuitydecreases as opacification progresses with age. +ii. Granular corneal dystrophy, Type 2 (Granular- +Lattice) (GCD2) +Onset and course. Granular corneal dystrophy, Type 2 (Granular-Lattice) (GCD2) also known as combined granular-lattice corneal dystrophy or Avellino corneal dystrophy, occurs in first decade, may be as early as 3 years of age and the condition is generally progressive. Genetic locus is 5q31 and gene involved is TGFB1. Inheritance is autosomal dominant. +Signs include: +• Subtle superficial stromal tiny whitish dots are initial lesions. +• Ringsorstellate-shapedsnowflakestromalopacities appearing between the superficial stroma and the mid stroma are next lesions. +• Latticelinesin deeper cornea may be seen in some patients. Typically, these lines are located deeper than the snowflake stromal opacity. + + + + + + + + + + + + + +Fig. 6.25 Granular corneal dystrophy type 1 +Chapter 6 Diseases of Cornea 129 + + +• Superficial, translucent flattened breadcrumb opacities are seen in the final stages, which may coalesce in the anterior stroma. +Symptoms include: +• Visiondecreases with age as the central visual axis becomes affected. +• Pain and ocular discomfort may accompany mild corneal erosions. + +2. Macular Corneal Dystrophy +Onset and course. Macular corneal dystrophy (MCD), also known as Groenouw corneal dystrophy type II or Fehr spotted dystrophy, occurs in childhood and is slowly progressive. +Genetic locus is 16q22 and gene involved is carbohydrate sulfotransferase 6 gene—CHST6. Inheritance is autosomal recessive. +Signs include: +• Diffusestromalhazeextending to the limbus is the initial lesion. +• Macules,i.e., superficial, central, elevated, irregular whitish opacities develop later and give the condition its name (Fig. 6.26). +• Posterior peripheral white lesions are also seen. • Corneal sensitivity is reduced. +Symptoms include: +• Recurrent corneal erosions cause photophobia and pain. +• Visualimpairment,usually severe, occurs between 10 and 30 years of age. + +3. Schnyder Corneal Dystrophy +Schnyder corneal dystrophy (SCD) is also known as hereditary crystalline stromal dystrophy of Schnyder. Affected patients and non-affected members of the pedigrees may have hyperlipoproteinemia. Genetic locus is 1 p36 and the gene involved is UbiA prenyltransferase domain containing 1—UBIAD1. + + + + + + + + + + + + + +Fig. 6.26 Macular corneal dystrophy + +Inheritance is autosomal dominant. +Onset and course. The dystrophy appears in early infancy or at birth or sometimes in the first decade of life. It is slowly progressive and usually asymptomatic. Signs include: +• Round ring-shaped central corneal stromal opacities due to deposition of fine needle-like cholesterol crystals, which may be white to yellow or polychromatic in colour are characteristic lesions. +• Corneal sensations decrease with age. +Symptoms include: +• Visual acuity progressively decreases with age. Although scotopic vision may be remarkably good, photopic vision may be disproportionately decreased. +• Glare which increase with age. +4. Congenital Stromal Corneal Dystrophy Onset and course. Congenital stromal corneal dystrophy (CSCD), also known as congenital hereditary stromal dystrophy occurs congenitally and is a nonprogressive or slowly progressive condition. Genetic locus is 12q2l.33 and the gene involved is decorin—DCN. +Inheritance is autosomal dominant. +Signs and symptoms. The characteristic lesions are diffuse, bilateral, corneal clouding with flake-like, whitish stromal opacities throughout the stroma, causing moderate to severe visual loss. +5. Fleck Corneal Dystrophy +Onset and course. Fleck corneal dystrophy (FCD) also known as Francois-Neetens speckled corneal dystrophy occurs congenitally and is a non-progressive condition. +Gene locus is 2q35 and the gene involved is phosphatidylinositol-3-phosphate/phospha-tidylinositol 5-Kinase type III—PIP5K3. +Inheritance is autosomal dominant. +Signs and symptoms. The condition is asymptomatic characterized by small, translucent, discoid opacities or discrete, flat, gray-white, dandruff-like (sometimes ring-shaped) opacities scattered sparsely throughout any level of the otherwise clear stroma. +6. Posterior Amorphous Corneal Dystrophy Onset and course. Posterior amorphous corneal dystrophy (PACD), also known as Posterior amorphous stromal dystrophy, often occurs in the first decade of life. It has been noted as early as 16 weeks, suggesting a congenital nature. The condition is non or slowly progressive. +130 Section III Diseases of Eye + + +Inheritance is autosomal dominant. +Signs and symptoms. It presents as diffuse gray-white, sheet-like opacities that can involve any layer of the stroma but are most prominent posteriorly. The condition is largely asymptomatic except for mild decrease in visual acuity (usually better than 6/12). +7. Central Cloudy Dystrophy of Francois Onset and course. Central cloudy dystrophy of Francois (CCDF) occurs in first decade and is non-progressive. +Inheritance is unknown. +Signs and symptoms. The condition is mostly asymptomatic and is characterized by cloudy central polygonal or rounded stromal opacities that fade anteriorly and peripherally and are surrounded by clear tissue. +8. Pre-Descemet Corneal Dystrophy +Onset and course. Onset usually occurs after 30 years of age but has been found in children as young as 3 years. The condition is usually non-progressive, some conditions may show progression. Inheritance is unknown. +Signs and symptoms. The condition is usually asymptomatic and is characterized by focal, fine, gray opacities in the deep stroma immediately anterior to Descemet membrane with a variety of shapes. +IV. DESCEMET MEMBRANE AND ENDOTHELIAL CORNEAL DYSTROPHIES + +1. Fuchs Endothelial Corneal Dystrophy Onset and course. Fuchs endothelial corneal dystrophy (FECD), also known as endoepithelial corneal dystrophy, is frequently seen as a slowly progressive bilateral condition affecting females more than males (F:M::4:1), usually between fifth and seventh decade of life. Primary open angle glaucoma is its common association. +Inheritance. It may be autosomal dominant or sporadic (more common) in nature. +Genetic locus is 13p. No gene has been associated. Clinical features can be divided into following four stages: +1. Stage of cornea guttata. It is characterised by the presence of Hassall-Henle type of excrescenses in the central part of cornea. A gradual increase of central guttae with peripheral spread and confluence gives rise to the so called ‘beaten-metal’appearance. This stage is asymptomatic. +2. Oedematous stage or stage of endothelial decompensation (Fig. 6.27) is characterised by the + + + + + + + + + + + + + + +Fig. 6.27 Fuch’s endothelial corneal dystrophy + +occurrence of early stromal oedema and epithelial dystrophy. Patients complaint of blurring vision. +3. Stageofbullouskeratopathy.This stage follows long-standing stromal oedema and is characterised by marked epithelial oedema with formation of bullae, when rupture cause pain, discomfort and irritation with associated decreased visual acuity. +4. Stage of scarring. In this stage, epithelial bullae are replaced by scar tissue and cornea becomes opaque and vascularized. The condition may sometimes be complicated by occurrence of secondary infection or glaucoma. +Specular microscopy reveals decreased endothelial cell count, increased average cell diameter, decreased hexagons and increased variation in cell size. +Treatment is as follows: +1. Hypertonic saline: (5% sodium chloride) may be of some use in early oedematous stage. +2. Warmairblown on the eyes (e.g. hair dryer) helps in reducing oedema. +3. Intraocular pressure lowering drugs e.g. 0.5% timolol or others should be used to treat associated ocular hypertension. +4. Bandagesoftcontactlensesprovide some relief from disturbing symptoms in bullous keratopathy stage. +5. Penetratingkeratoplastyis the treatment of choice when the visual acuity is reduced markedly. +2. Posterior Polymorphous Corneal Dystrophy (PPCD) +Onset and course. Posterior polymorphous corneal dystrophy (PPCD) also known as Schlichting dystrophy occurs in early childhood and is very slowly progressive. +Inheritance is autosomal dominant. +Genetic Loci are PPCD 1—20p 1–1.2q 1–1.2; PPCD 2— 1 p34.3—p32.3; PPCD 3—10p 1–1.2. +Chapter 6 Diseases of Cornea 131 + + +Genes involved are: PPCD 1—unknown; PPCD 2— collagen type VIII alpha 2, COL8A2 and PPCD 3— two- handed zinc-finger homeodomain transcription factor 8—ZEB 1. +Signs and symptoms. The condition is often asymptomatic. The signs include: +• Deep corneal lesions of various shapes including nodular, vesicular (isolated, in clusters, or confluent) and blister-like lesions. +• Railroad tracks appearance lesions (multiple and isolated) (Fig. 6.28). +• Varying gray tissue at the level of Descemet membrane. + +3. Congenital Hereditary Endothelial Dystrophy 1 +Onset and course. Congenital hereditary endothelial dystrophy 1 (CHED 1 ) occurs in first or second year of life, occasionally congenital. Progression of corneal clouding occurs over 1–10 years. +Genetic Locus is 20p 1 1.2 q 1–1.2 (pericentromeric region) and gene is unknown. +Inheritance is autosomal dominant. Signs and symptoms include: +• Endothelial changes in form of moon crater-like appearance and peau d’orange texture may be seen (Such patients are asymptomatic). +• Corneal clouding ranging from a diffuse haze to a ground-glass, milky appearance with occasional focal gray spots causing blurred vision associated with photophobia and watering. Vision is characteristically worse in the morning. +• Thickening of the cornea, can be 2–3 times of normal thickness. +• Subepithelial band keratopathy may be seen occasionally. +• IOP may be elevated rarely. + + + + + + + + + + + + + + +Fig. 6.28 Posterior polymorphous corneal dystrophy + +4. Congenital Hereditary Endothelial Dystrophy 2 +Onset and course. Congenital hereditary endothelial dystrophy 2 (CHED2) also called as Maumenee corneal dystrophy occurs congenitally and is a relatively stationary condition. +Genetic locus is 20p 13 (telomeric portion) and the gene involved is solute carrier family 4, sodium borate transporter, member 11—SLC4A 11. Inheritance is autosomal recessive. +Signs and symptoms are similar to CHED 1 except: +• The condition is more common and severe than CHED 1. +• Nystagmus is often associated. + +5. X-linked Endothelial Corneal Dystrophy Onset and course. X-linked endothelial corneal dystrophy (XECD) occurs congenitally and is a progressive condition in males and non-progressive in females. +Genetic locus is Xq25 and the gene involved is unknown. +Inheritance is X-chromosomal dominant. Signs and symptoms are as below: +Malepatientshave blurring of vision associated with: • Cornealcloudingsince birth ranging from a diffuse +haze to a ground-glass, milky appearance. • Moon crater-like endothelial changes. +• Subepithelial band keratopathy combined with moon crater-like endothelial changes. +• Nystagmus may be associated. Femalepatientsare asymptomatic having only moon crater-like endothelial changes. + +ECTATIC CONDITIONS OF CORNEA + +KERATOCONUS +Keratoconus (conical cornea) (Fig. 6.29A to C) is a non-inflammatory bilateral (85%) ectatic condition of cornea in its axial part. It usually starts at puberty and progresses slowly. +Etiopathogenesis. It is still not clear. Various theories proposed so far label it as developmental condition,degenerative condition, hereditary dystrophy and endocrine anomaly. +Essential pathological changes are progressive thinning and ectasia which occur as a result of defective synthesis of mucopolysaccharide and collagen tissue. Clinical features. Symptoms. Patient presents with a defective vision due to progressive myopia and irregular astigmatism, which does not improve fully despite full correction with glasses. +132 Section III Diseases of Eye + + + + + + + + + + + + +A + + + + + + +B + + + + + + + + + + + + +C +Fig. 6.29 Keratoconus showing: A, Diagrammatic depiction of configuration of cone-shaped cornea; B, Irregular circles on Placido disc examination; C, Clinical photograph (note Munson’s sign) +Signs. Following signs may be elicited: 1. Window reflex is distorted. +2. Placidodiscexaminationshows irregularity of the circles (Fig. 6.29B). +3. Slit-lamp examination may show thinning and ectasia of central cornea, opacity at the apex and Fleischer’s ring at the base of cone, folds in Descemet’s and Bowman’s membranes. Very fine, vertical, deep stromal striae (Vogt lines) which disappear with external pressure on the globe are peculiar feature. +4. On retinoscopy a yawning reflex (scissor reflex) and high oblique or irregular astigmatism is obtained. +5. Ondistantdirectophthalmoscopyan annular dark shadow (due to total internal reflection of light) is seen which separates the central and peripheral areas of cornea (oil droplet reflex). + +6. Munson’ssign,i.e., localised bulging of lower lid when patient looks down is positive in late stages (Fig. 6.29C). +7. Keratometry.Normal average keratometric values are 45 D. In keratoconus keratometric values are increased and based on it the severity of keratoconus is graded as: mild (< 48 D), moderate (48–54 D), and severe (>54 D). +8. Cornealtopography,i.e., study of shape of corneal surface, is the most sensitive method for detecting early keratoconus, Forme fruste refers to the earliest subclinical form of keratoconus detected on topography. +Morphological classification. Depending upon the size and shape of the cone, the keratoconus is of three types: +• Nipple cone has a small size (<5 mm) and steep curvature. +• Ovalconeis larger (5–6 mm) and ellipsoid in shape. • Globus cone is very large (>6 mm) and globe like. Complications. Keratoconus may be complicated by development of acute hydrops due to rupture of Descemet’s membrane. The condition is characterized by sudden development of corneal oedema associated with marked defective vision, pain, photophobia and lacrimation. +Associations. Keratoconus may be associated with: • Ocular conditions e.g., ectopia lentis, congenital +cataract, aniridia, retinitis pigmentosa, and vernal keratoconjunctivitis (VKC). +• Systemicconditionse.g., Marfan’s syndrome, atopy, Down’s syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta and mitral valve prolapse. +Treatment modalities include: +1. Spectacle correction may improve vision in early cases. However, later in the course of disease the falling vision may not be corrected by glasses due to irregular astigmatism. +2. Contact lenses (rigid gas permeable) usually improve the vision in early cases. In early to moderate cases a specially designed scleral contact lens (Rose-K) may be useful. +3. Intacs, the intracorneal ring segments, are reported to be useful in early to moderate cases. +4. Cornealcollagencrosslinkingwith riboflavin (CXL or C3R) and UV-A rays may slow the progression of disease. +5. Keratoplasty may be required in later stages. Deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PK) may be performed. +KERATOGLOBUS +It is a familial and hereditary bilateral congenital disorder characterised by thinning and hemispherical +Chapter 6 Diseases of Cornea 133 + + + + + + + + + + + + + + + +Fig. 6.30 Keratoglobus +protrusion of the entire cornea (Fig. 6.30). It is non-progressive and inherited as an autosomal recessive trait. It must be differentiated from congenital buphthalmos, where increased corneal size is associated with raised intraocular pressure, angle anomaly and/or cupping of optic disc. +KERATOCONUS POSTERIOR +In this extremely rare condition there is slight cone-like bulging of the posterior surface of the cornea. It is non-progressive. + +ABNORMALITIES OF CORNEAL TRANSPARENCY +Normal cornea is a transparent structure. Any condition which upsets its anatomy or physiology causes loss of its transparency to some degree. +Common causes of loss of corneal transparency are: • Corneal oedema +• Drying of cornea +• Depositions on cornea +• Inflammations of cornea • Corneal degenerations +• Dystrophies of cornea +• Vascularization of cornea +• Scarring of cornea (corneal opacities). +Most of the conditions responsible for decreased transparency of cornea have been described earlier. +However, some important symptomaticconditions ofthecorneasuch as corneal oedema, corneal opacity and vascularization of cornea are described here. +CORNEAL OEDEMA +The water content of normal cornea is 78%. It is kept constant by a balance of factors which draw water in the cornea (e.g., intraocular pressure and swelling pressure of the stromal matrix = 60 mm of Hg) and the factors which draw water out of cornea (viz. the active pumping action of corneal endothelium, and + +the mechanical barrier action of epithelium and endothelium). +Disturbance of any of the above factors leads to corneal oedema, wherein its hydration becomes above 78%, central thickness increases and transparency reduces. +Causes of corneal oedema +1. Raised intraocular pressure 2. Endothelial damage +• Due to injuries, such as birth trauma (forceps delivery), surgical trauma during intraocular operation, contusion injuries and penetrating injuries. +• Endothelial damage associated with corneal dystrophies such as, Fuchs dystrophy, congenital hereditary endothelial dystrophy and posterior polymorphous dystrophy. +• Endothelial damage secondary to inflammations such as uveitis, endophthalmitis and corneal graft infection. +3. Epithelial damage due to: • mechanical injuries, +• chemical burns, +• radiational injuries, • thermal injuries, +• inflammation and infections. + +Clinical features +Initially there occurs stromal haze with reduced vision. In long-standing cases with chronic endothelial failure (e.g., in Fuch’s dystrophy) there occurs permanent oedema with epithelial vesicles and bullae formation (bullouskeratopathy).This is associated with marked loss of vision, pain, discomfort and photophobia, due to periodic rupture of bullae. +Treatment +1. Treatthecausewherever possible, e.g., raised IOP and ocular inflammations. +2. Dehydration of cornea may be tried by use of: +• Hypertonic agents e.g., 5% sodium chloride drops or ointments or anhydrous glycerine may provide sufficient dehydrating effect. +• Hot forced air from hair dryer may be useful. +3. Therapeutic soft contact lenses may be used to get relief from discomfort of bullous keratopathy. +4. Penetrating keratoplasty is required for long-standing cases of corneal oedema, non-responsive to conservative therapy. +CORNEAL OPACITY +The word ‘corneal opacification’ literally means loss of normal transparency of cornea, which can +134 Section III Diseases of Eye + + +occur in many conditions. Therefore, the term ‘corneal opacity’ is used particularly for the loss of transparency of cornea due to scarring. +Causes +1. Congenital opacities may occur as developmental anomalies or following birth trauma. +2. Healed corneal wounds. 3. Healed corneal ulcers. +Clinical features +Corneal opacity may produce loss of vision (when dense opacity covers the pupillary area) or blurred vision (due to astigmatic effect). +Types of corneal opacity +Depending on the density, corneal opacity is graded as nebula, macula and leucoma. +1. Nebular corneal opacity. It is a faint opacity which results due to superficial scars involving Bowman’s layer and superficial stroma (Figs. 6.31A and 6.32A). A thin, diffuse nebula covering the pupillary area interferes more with vision than the localised leucoma away from pupillary area. Further, the nebula produces more discomfort to patient due to blurred image owing to irregular astigmatism than the leucoma which completely cuts off the light rays. + + + + + + + + + + + + + +A + + + + + + + + + + + + +C + + + + + + + + + + + +Fig. 6.31 Diagrammatic depiction of corneal opacity: A, Nebular; B, Macular: C, Leucomatous; D, Adherent leucoma + + +2. Macular corneal opacity. It is a semi-dense opacity produced when scarring involves about half the corneal stroma (Figs. 6.31B and 6.32B). +3. Leucomatous corneal opacity (leucoma simplex). It is a dense white opacity which results due to scarring of more than half of the stroma (Figs. 6.31C and 6.32C). 4. Adherent leucoma. It results when healing occurs after perforation of cornea with incarceration of iris (Figs. 6.31D and 6.32D). +5. Corneal facet. Sometimes, the corneal surface is depressed at the site of healing (due to less fibrous tissue); such a scar is called facet. + + + + + + + + + + + + + +B + + + + + + + + + + + + +D + +Fig. 6.32 Clinical photographs of corneal opacity: A, Nebular; B, Macular; C, Leucomatous; D, Adherent leucoma +Chapter 6 Diseases of Cornea 135 + + +6. Kerectasia. In this condition, corneal curvature is increased at the site of opacity (bulge due to weak scar). +7. Anterior staphyloma. An ectasia of pseudocornea (the scar formed from organised exudates and fibrous tissue covered with epithelium) which results after total sloughing of cornea, with iris plastered behind it is called anterior staphyloma (Figs. 6.33A and B). +Secondary changes in corneal opacity which may be seen in long-standing cases include: hyaline degeneration, calcareous degeneration, pigmentation and atheromatous ulceration. +Treatment +1. Optical iridectomy. It may be performed in cases with central macular or leucomatous corneal opacities, provided vision improves with pupillary dilatation. + + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B + +Fig. 6.33 Anterior staphyloma: A, Diagrammatic cross-section; B, Clinical photograph + +2. Phototherapeutic keratectomy (PTK) performed with excimer laser is useful in superficial (nebular) corneal opacities. +3. Keratoplasty provides good visual results in uncomplicated cases with corneal opacities, where optical iridectomy is not of much use. +4. Cosmetic coloured contact lens gives very good cosmetic appearance in an eye with ugly scar having no potential for vision. Presently, this is considered the best option, even over and above the tattooing for cosmetic purpose. +5. Tattooing of scar. It was performed for cosmetic purposes in the past. It is suitable only for firm scars in a quiet eye without useful vision. For tattooing Indian black ink, gold or platinum may be used. To perform tattooing, first of all, the epithelium covering the opacity is removed under topical anaesthesia (2% or 4% xylocaine). Then a piece of blotting paper of same size and shape, soaked in 4% gold chloride (for brown colour) or 2% platinum chloride (for dark colour) is applied over it. After 2–3 minutes, the piece of filter paper is removed and a few drops of freshly prepared 2% hydrazine hydrate solution are poured over it. Lastly, eye is irrigated with normal saline and patched after instilling antibiotic and atropine eye ointment. Epithelium grows over the pigmented area. +CORNEAL VASCULARIZATION +Normal cornea is avascular except for small capillary loops which are present in the periphery for about 1 mm. In pathological states, it can be invaded by vessels as a defence mechanism against the disease or injury. However, vascularization interferes with corneal transparency and occasionally may be a source of irritation. +Pathogenesis +Pathogenesis of corneal vascularization is still not clear. It is presumed that mechanical and chemical factors play a role. +Vascularization is normally prevented by the compactness of corneal tissue. Probably, due to some vasoformative stimulus (chemical factor) released during pathological states, there occurs proliferation of vessels which invade from the limbus; when compactness of corneal tissue is loosened (mechanicalfactor) due to oedema (which may be traumatic, inflammatory, nutritional, allergic or idiopathic in nature). +Clinico-etiological features +Clinically, corneal vascularization may be superficial or deep. +1. Superficial corneal vascularization. In it vessels are arranged usually in an arborising pattern, +136 Section III Diseases of Eye + + +present below the epithelial layer and their continuity can be traced with the conjunctival vessels (Fig. 6.34A). +■Common causes of superficial corneal vascula-rization are: trachoma, phlyctenular kerato-conjunctivitis, superficial corneal ulcers and rosacea keratitis. +■Pannus. When extensive superficial vascularization is associated with white cuff of cellular infiltration, it is termed as pannus.In progressive pannus, corneal infiltration is ahead of vessels while in regressive pannus it lags behind. +2. Deep vascularization. In this vessels are generally derived from anterior ciliary arteries and lie in the corneal stroma. These vessels are usually straight, not anastomosing and their continuity cannot be traced beyond the limbus. Deep vessels may be arranged as terminal loops (Fig. 6.34B), brush (Fig. 6.34C), parasol, umbel (Fig. 6.34D), network or interstitial arcade. ■Common causes of deep vascularization are: interstitial keratitis, disciform keratitis, deep corneal ulcer, chemical burns, sclerosing keratitis and corneal grafts. +Treatment +Treatment of corneal vascularization is usually unsatisfactory. Vascularization may be prevented by timely and adequate treatment of the causative conditions. +• Corticosteroids may have vasoconstrictive and suppressive effect on permeability of capillaries. + + + + + + + + + + + + + + + + + + + + +Fig. 6.34 Corneal vascularization : A, Superficial; B, Terminal loop type; C, Brush type; D, Umbel type + +• Application of irradiation is more useful in superficial than the deep vascularization. +• Surgicaltreatmentin the form of peritomy may be employed for superficial vascularization. + +CORNEAL SURGERY + +KERATOPLASTY +Keratoplasty, also called corneal grafting or corneal transplantation, is an operation in which the patient’s diseased cornea is replaced by the healthy clear cornea. +Types +A. Autokeratoplasty, which can be: +1. Rotational keratoplasty, in which patient’s own cornea is trephined and rotated to transfer the pupillary area having a small corneal opacity to the periphery. +2. Contralateral keratoplasty. It is indicated when cornea of one eye of the patient is opaque and the other eye is blind due to posterior segment disease (e.g., optic atrophy and retinal detachment, etc.) with clear cornea. In contralateral autokeratoplasty cornea of the two eyes are exchanged with each other. +B. Allografting or Allo-keratoplasty. In it, patient’s diseased cornea is replaced by the donor’s healthy cornea. It can be of following types: +1. Penetrating Keratoplasty (PK) (full-thickness-grafting) +2. LamellarKeratoplasty(partial-thickness grafting) which may be: +• Deep anterior lamellar keratoplasty (DALK). It is performed when endothelium and Descemet’s membrane are normal e.g. keratoconus. +• Descemet’s stripping endothelial keratoplasty (DSEK). It is performed when only endothelium is defective e.g. after the surgical trauma during phacoemulsification. +3. Small patch graft (for small defects), which may be full thickness or partial thickness. +Indications +1. Optical, i.e., to improve vision. Important indications are: corneal opacity, bullous keratopathy, corneal dystrophies, advanced keratoconus. +2. Therapeutic, i.e., to replace inflamed cornea not responding to conventional therapy. +3. Tectonicgrqft,i.e., to restore integrity of eyeball e.g. after corneal perforation and in marked corneal thinning. +4. Cosmetic, i.e., to improve the appearance of the eye. +Chapter 6 Diseases of Cornea 137 + + +Donor tissue +The donor eye should be removed as early as possible (within 6 hours of death). It should be stored under sterile conditions. +Evaluation of donor cornea. Biomicroscopic examination of the whole globe, before processing the tissue for media storage, is very important. The donor corneal tissue is graded into excellent, very good, good, fair, and poor depending upon the condition of corneal epithelium, stroma, Descemet’s membrane and endothelium (Table 6.1). +Methods of corneal preservation +1. Short-term storage (up to 48 hours). The whole globe is preserved at 4° C in a moist chamber. +2. Intermediate storage (up to 2 weeks) of donor cornea can be done in McCarey-Kaufman (MK) medium and various chondroitin sulfate enriched media such as optisol medium. +3. Long-termstorageup to 35 days is done by organ culture method or by cryopreservation at –70°C. + +Surgical technique of penetrating keratoplasty +1. Excision of donor corneal button. The donor corneal button should be cut 0.25 mm larger than the recipient, taking care not to damage the endothelium. Donor cornea is placed in a tephlon block and the button is cut with the help of a trephine from the endothelial side (Fig. 6.35A). +2. Excisionofrecipientcornealbutton.With the help of a corneal trephine (7.5 mm to 8 mm in size) a partial thickness incision is made in the host cornea (Fig. 6.35B). Then, anterior chamber is + + +entered with the help of a razor blade knife and excision is completed using corneoscleral scissors (Fig. 6.35C). +3. Suturing of corneal graft into the host bed (Fig. 6.35D) is done with either continuous (Fig. 6.35E) or interrupted (Fig. 6.35F) 10–0 nylon sutures. +Complications +1. Early complications. These include flat anterior chamber, iris prolapse, infection, secondary glaucoma, epithelial defects and primary graft failure. +2. Latecomplications.These include graft rejection, recurrence of disease and astigmatism. +Graft rejection +It refers to the immunological response of the host to the donor corneal tissue. It can occur as early as 2 weeks and upto several years after grafting. Graft rejection is classically believed to be a delayed type of hypersensitivity response. +Risk factorsinclude younger age of recipient, previous graft failure, corneal vascularization, larger graft size, donor epithelium and massive blood transfusion. Clinical presentations include: +■Epithelial rejection characterized by an elevated epithelial rejection line which stains with fluorescein. ■Subepithelial infiltrates known as Kayes dots. ■Stromalrejectionis characterized by sudden onset of full thickness stromal haze in a previously clear graft. +■Endothelial rejection may present as: +• Khodadaust line demarcating healthy and damaged endothelium. +• Diffuse endothelial rejection with lot of Keratic precipitates. + + + +Table 6.1 Grading of donor cornea on slit-lamp biomicroscopic examination + +Grade of donor corneal tissue + +Parameter + +Epithelial defects and haze +Corneal stromal clarity +Arcus senilis + +Descemet’s membrane +Endothelium + +Grade I (Excellent) +None + + +Crystal clear + +None + +No folds + +No defect + +Grade II (Very good) +Slight epithelial haze or defects + +Clear + +Slight + +Few shallow folds + +No defect + +Grade III (Good) +Obvious moderate epithelial defects +Slight cloudiness + +Moderate (<2.5 mm) +Numerous shallow folds +Few vacuolated cells + +Grade IV (Fair) + + + +Moderate cloudiness +Heavy +(>2.5 mm – 4 mm) +Numerous deep folds +Moderate guttate + +Grade V (Poor) + + + +Marked cloudiness +Very heavy (>4 mm) +Marked deep folds +Marked guttate +138 Section III Diseases of Eye + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 6.35 Technique of keratoplasty: A, Excision of donor corneal button; B & C, Excision of recipient corneal button; D, Suturing of donor button into recipient’s bed; E, Showing pattern of continuous sutures in keratoplasty; F, Clinical photograph of a patient with interrupted sutures in keratoplasty + + + +REFRACTIVE CORNEAL SURGERY Refractive corneal surgery includes: +• Radial Keratotomy (RK), +• Astigmatic Keratotomy (AK), +• Photorefractive Keratotomy (PRK), +• Laser assisted in situ Keratomileusis (LASIK) and its varieties, +• Thermal Laser Keratoplasty (TLK), • Conductive Keratoplasty (CK), +• Orthokeratoplasty, and +• Intracorneal Ring (ICR) implants (For details see page 52 to 55). + +PHOTOTHERAPEUTIC KERATECTOMY Phototherapeutic Keratectomy (PTK) refers to the ablation of superficial corneal lesion with the help of excimer laser (198 nm). +Indications include: +• Superficial corneal scars, +• Corneal degenerations, e.g. band-shaped Keratopathy, Salzman nodular degeneration and oil droplet keratopathy, + + +• Epithelial dystrophies (e.g. Reis-Buckler dystrophy), and +• Recurrent corneal erosions. +Procedure. The modern excimer laser machines have two modes for PTK: +• Spot mode, where a small spot (<1 mm) can be ablated, and +• Shappingmode,which allows uniform removal of corneal tissue from a large zone. +Contraindications include: • Excessive thin corneas, +• Moderate to severe dry eye, and • Deep corneal lesions. +Complications. Faint corneal haze is a usual end result of the PTK. Other complications include: +• Secondary infections, +• Induced hypermetropia, and • Secondary keractesia. +KERATOPROSTHESIS +Keratoprosthesis refers to an artificial corneal device used in patients unsuitable for keratoplasty. +Chapter 6 Diseases of Cornea 139 + + +Types. Keratoprosthesis basically consists of a central optical cylindrical part made of poly-methylmethaacrylate (PMMA). Based on the surrounding fixation device, the commonly used keratoprosthesis of various designs are as below: +• Boston keratoprosthesis (6.36A) consists two plates and one cylinder. It is fixed using the donor cornea. +• Alfa cor keratoprosthesis (6.36B) consists of an outer porous skirt made up of high water content PHEMA and a transparent central optic made from low water content PHEMA. An interpenetrating polymer network (IPN), which is a junction zone between the skirt and central optic and serve as a permanent bond. It has a refractive power close to that of human cornea. +• Osteo-odonto-keratoprosthesis (Fig. 6.36C) is fixed with the help of patients own tooth root and alveolar bone. +• Chondro-keratoprosthesis is fixed with patients own cartilage. +• Onycho-keratoprosthesis is fixed with patient’s nails. +• Stanford keratoprosthesis is a recently introduced device which incorporates the grafting of bio-active factors with a change in the bulk material design. +• Singh and Worst collar-stud keratoprosthesis is fixed with stainless steel sutures. +Indications. Prerequisites for keratoprosthesis include bilateral blindness due to corneal diseases (not suitable for keratoplasty) with accurate perception of light, normal electrophysiological tests and absence of gross posterior segment disorders on ultrasonography, e.g: +• Stevens-Johnson syndrome, • Chemical burns, +• Ocular cicatricial pemphigoid, • Severe trachoma +• Multiple previous failed corneal grafts. Complications include: +• Extrusion of prosthesis, + + + + + + + + + + + + +A + + + + + + + + + + +B + + + + + + + + + + +C + +Fig. 6.36 Keratoprosthesis: A, Boston; B, Alfa cor; C, Osteo-odonto + + +• Intractable glaucoma, +• Retroprosthetic membrane formation, • Uveitis, and +• Retinal detachment. +7 + +Diseases of Sclera + + + +Chapter Outline + + +APPLIED ANATOMY Thickness Apertures +Microscopic structure INFLAMMATIONS +• +• +• +• +• +Episcleritis Scleritis + + + +APPLIED ANATOMY + +Sclera forms the posterior five-sixth opaque part of the external fibrous tunic of the eyeball. Its whole outer surface is covered by Tenon’s capsule. In the anterior part it is also covered by bulbar conjunctiva. Its inner surface lies in contact with choroid with a potential suprachoroidal space in between. In its anterior most part near the limbus there is a furrow which encloses the canal of Schlemm. +Thickness of sclera varies considerably in different individuals and with the age of the person. It is generally thinner in children than the adults and in females than the males. Sclera is thickest posteriorly (1 mm) and gradually becomes thin when traced anteriorly. It is thinnest at the insertion of extraocular muscles (0.3 mm). Lamina cribrosa is a sieve-like sclera from which fibres of optic nerve pass. Apertures. Sclera is pierced by three sets of apertures (Fig. 7.1). +1. Posterior apertures are situated around the optic nerve and transmit long and short ciliary nerves and vessels. +2. Middle apertures (four in number) are situated slightly posterior to the equator; through these pass the four vortex veins (vena verticosae). +3. Anterior apertures are situated 3 to 4 mm away from the limbus. Anterior ciliary vessels and branches from long ciliary nerves pass through these apertures. + +BLuE ScLErA +STAPHYLOMAS +• Anterior staphyloma Intercalary staphyloma Ciliary staphyloma Equatorial staphyloma Posterior staphyloma +• +• +• +• + + + +Microscopic structure. Histologically, sclera consists of following three layers: +1. Episcleral tissue. It is a thin, dense vascularised layer of connective tissue which covers the sclera proper. Fine fibroblasts, macrophages and lymphocytes are also present in this layer. +2. Sclera proper. It is an avascular structure which consists of dense bundles of collagen fibres. The bands of collagen tissue cross each other in all directions. + + + + + + + + + + + + + + + + + +Fig. 7.1 Apertures in the sclera. (posterior view): SCN, short ciliary nerve; SPCA, short posterior ciliary artery; LPCA, long posterior ciliary artery; VC, vena verticosa +Chapter 7 Diseases of Sclera 141 + +3. Lamina fusca. It is the innermost part of sclera which blends with suprachoroidal and supraciliary laminae of the uveal tract. It is brownish in colour owing to the presence of pigmented cells. +Nerve supply. Sclera is supplied by branches from the long ciliary nerves which pierce it 2–4 mm from the limbus to form a plexus. + +INFLAMMATIONS OF SCLERA + + +EpisclEritis +Episcleritis is benign recurrent inflammation of the episclera, involving the overlying Tenon’s capsule but not the underlying sclera. It typically affects young adults, being twice as common in women than men. +Etiology +1. Idiopathic. Exact etiology is not known in many cases. +2. Systemic diseases associated with episcleritis, include gout, rosacea, psoriasis and connective tissue diseases. +3. Hypersensitivity reaction to endogenous tubercular or streptococcal toxins is also reported. +4. Infectious episcleritis may be caused by herpes zoster virus, syphillis, Lyme disease and tuberculosis. +pathology + + + +A + + + + + + + + + + + + +B +Fig. 7.2 Episcleritis: A, Diffuse; B, Nodular + + + +Histologically, there occurs localised lymphocytic infiltration of episcleral tissue associated with oedema and congestion of overlying Tenon’s capsule and conjunctiva. +clinical features +Symptoms. Episcleritis is characterised by redness, mild ocular discomfort described as gritty, burning or foreign body sensation. Many a time it may not be accompanied by any discomfort at all. Rarely, mild photophobia and lacrimation may occur. +Signs. On examination two clinical types of episcleritis, simple and nodular may be recognised. Episclera is seen acutely inflamed in the involved area. +• Simple episcleritis is characterised by sectorial (occasionally diffuse) inflammation of episclera. The engorged episcleral vessels are large and run in radial direction beneath the conjunctiva (Fig. 7.2A). +• Nodular episcleritis is characterised by a pink or purple flat nodule surrounded by injection, usually situated 2–3 mm away from the limbus (Fig. 7.2B). The nodule is firm, tender, can be + + +moved separately from the sclera and the overlying conjunctiva also moves freely. +Clinical course. Episcleritis runs a limited course of 10 days to 3 weeks and resolves spontaneously. However, recurrences are common and tend to occur in bouts. Rarely, a fleeting type of disease (episcleritis periodica) may occur. +Differential diagnosis +• Simple episcleritis may be confused rarely with conjunctivitis. +• Nodular episcleritis may be confused with inflamed pinguecula, swelling and congestion due to foreign body lodged in bulbar conjunctiva and, very rarely with scleritis. +treatment +1. Topical NSAIDs,e.g., ketorolac 0.3% may be useful. 2. Topical mild corticosteroid eyedrops e.g., fluorometholone or loteprednol instilled 2–3 hourly, render the eye more comfortable and +resolve the episcleritis within a few days. +3. Topical artificial tears e.g., 0.5% carboxy methyl cellulose have soothing effect. +142 Section iii Diseases of Eye + + +4. Cold compresses applied to the closed lids may offer symptomatic relief from ocular discomfort. +5. Systemic nonsteroidal anti-inflammatory drugs (NSAIDs) such as flurbiprofen (300 mg OD), indomethacin (25 mg three times a day), or oxyphenbutazone may be required in recurrent cases. +sclEritis +Scleritis refers to a inflammation of the sclera proper. It is a comparatively serious disease which may cause visual impairment and even loss of the eye if treated inadequately. Fortunately, its incidence is much less than that of episcleritis. It usually occurs in elderly patients (40-70 years) involving females more than the males. +Etiology +Overall about 50% cases of scleritis are associated with some systemic diseases, most common being connective tissue diseases. +common conditions are as follows: +1. Autoimmune collagen disorders, especially rheumatoid arthritis, is the most common association. About 0.5% of patients (1 in 200) suffering from seropositive rheumatoid arthritis develop scleritis. Other associated collagen disorders are Wegener’s granulomatosis, polyarteritis nodosa (PAN), systemic lupus erythematosus (SLE) and ankylosing spondylitis. +2. Metabolic disorders like gout and thyrotoxicosis have also been reported to be associated with scleritis. +3. Some infections, particularly herpes zoster ophthalmicus, chronic staphylococcal and streptococcal infection have also been known to cause infectious scleritis. +4. Granulomatous diseases like tuberculosis, syphilis, sarcoidosis, leprosy can also cause scleritis. +5. Miscellaneous conditions like irradiation, chemical burns, Vogt-Koyanagi-Harada syndrome, Behcet’s disease and rosacea are also implicated in the etiology. +6. Surgically induced scleritis (SIS) is a rare complication of ocular surgery. It occurs within 6 months postoperatively. Exact mechanism not known, may be precipitation of underlying systemic cause. +7. Idiopathic. In many cases of scleritis, cause is unknown. +pathology +Histopathological changes are that of a chronic granulomatous disorder characterised by fibrinoid necrosis, destruction of collagen together with infiltration by polymorphonuclear cells, lymphocytes, plasma cells and macrophages. The granuloma is + +surrounded by multinucleated epithelioid giant cells and old and new vessels, some of which may show evidence of vasculitis. +classification +Scleritis can be classified as follows: A. Non-infectious scleritis +I. Anterior scleritis (98%) +a. Non-necrotizing scleritis (85%) 1. Diffuse +2. Nodular +b. Necrotizing scleritis (13%) 1. with inflammation +2. without inflammation (scleromalacia perforans) +II. Posterior scleritis (2%) B. Infectious scleritis +clinical features Symptoms +■Pain: Patients complain of moderate to severe pain which is deep and boring in character and often wakes the patient early in the morning. Ocular pain radiates to the jaw and temple. +■Redness may be localized or diffuse. ■Photophobia and lacrimation may be mild to +moderate. +■Diminution of vision may occur occasionally. +Signs + +A. Non-infectious scleritis +Salient features of different clinical types of non-infectious scleritis are as below: +I. Anterior scleritis +a. Non–necrotizing anterior scleritis +1. Non-necrotizing anterior diffuse scleritis. It is the commonest variety, characterised by widespread inflammation involving a quadrant or more of the anterior sclera. The involved area is raised and salmon pink to purple in colour (Fig. 7.3). + + + + + + + + + + + + + + +Fig. 7.3 Non-necrotizing anterior diffuse scleritis +Chapter 7 Diseases of Sclera 143 + + +2. Non-necrotizing anterior nodular scleritis. It is characterised by one or two hard, purplish elevated immovable scleral nodules, usually situated near the limbus (Fig. 7.4). Sometimes, the nodules are arranged in a ring around the limbus (annular scleritis). +b. Necrotizing anterior scleritis +1. Anterior necrotizing scleritis with inflammation. It is an acute severe form of scleritis characterised by intense localised inflammation associated with areas of infarction due to vasculitis (Fig. 7.5). The affected necrosed area is thinned out and sclera becomes transparent and ectatic with uveal tissue shining through it. It is usually associated with anterior uveitis. 2. Anterior necrotizing scleritis without inflammation (scleromalacia perforans). This specific entity typically occurs in elderly females usually suffering from long-standing rheumatoid arthritis. It is characterised by development of yellowish patch of melting sclera (due to obliteration of arterial supply); which often together with the overlying episclera and conjunctiva completely separates from the surrounding normal sclera. This sequestrum of sclera becomes dead white + + + + + + + + + + + + + +Fig. 7.4 Non-necrotizing anterior nodular scleritis + + + + + + + + + + + + + + + +Fig. 7.5 Anterior necrotizing scleritis with inflammation + +in colour, which eventually absorbs leaving behind it a large punched out area of thin sclera through which the uveal tissue shines (Fig. 7.6). Spontaneous perforation is extremely rare. + +II. Posterior scleritis. +It is an inflammation involving the sclera behind the equator. The condition is frequently misdiagnosed. It is characterised by features of associated inflammation of adjacent structures, which include: exudative retinal detachment, macular oedema, proptosis and limitation of ocular movements. + +B. Infectious scleritis +• Infectious scleritis accounts for 5–10% of all cases. • In the early stage diagnosis becomes difficult as +presentation is similar to as non-infectious scleritis. • Scleritis with purulent exudates (Fig. 7.7) or +infiltrates should raise the suspicion of an infectious etiology. +• Formation of fistulae, painful nodules, conjunctival and scleral ulcers are usually the signs of infectious scleritis. + + + + + + + + + + + + + +Fig. 7.6 Anterior necrotizing scleritis without inflammation (Scleromalacia perforans) + + + + + + + + + + + + + + +Fig. 7.7 Infectious scleritis +144 Section iii Diseases of Eye + + +complications +These are quite common with necrotizing scleritis and include sclerosing keratitis, keratolysis, complicated cataract and secondary glaucoma. + +investigations +Following laboratory studies may be helpful in identifying associated systemic diseases or in establishing the nature of immunologic reaction: +1. TLc, DLc and ESR. +2. Serum levels of complement (c3), immune complexes, rheumatoid factor, antinuclear antibodies and L.E cells for an immunological survey. +3. FTA–ABS, VDRL for syphilis. 4. Serum uric acid for gout. +5. Urine analysis. 6. Mantoux test. +7. X-rays of chest, paranasal sinuses, sacroiliac joint and orbit (to rule out foreign body especially in patients with nodular scleritis). +treatment +A. Non-infectious scleritis +I. Non-necrotizing scleritis. It is treated by: • Topical steroid eyedrops +• Systemic indomethacin 75 mg twice a day until inflammation resolves. +II. Necrotizing scleritis. It is treated by: • Topical steroids +• Oral steroids on heavy doses, tapered slowly. +• Immunosuppressive agents like methotrexate or cyclophosphamide may be required in non-responsive cases. +• Subconjunctival steroids are contraindicated because they may lead to scleral thinning and perforation. +• Surgical treatment, in the form of scleral patch graft may be required to preserve integrity of the globe in extensive scleral melt and thinning. +B. Infectious scleritis +• Most of the time diagnosis is delayed and patients are put on topical and oral steroids which worsen the infective scleritis. +• Antimicrobial therapy, both with topical and oral agents is required in an aggressive manner. +• Surgical debridementis found useful by debulking the infected scleral tissue and also facilitating the effect of antibiotics. + +BluE sclErA +It is an asymptomatic condition characterised by marked, generalised blue discoloration of sclera due to thinning (Fig. 7.8). It is typically associated + + + + + + + + + + + + + + + +Fig. 7.8 Blue sclera + +with osteogenesis imperfecta. Its other causes are Marfan’s syndrome, Ehlers-Danlos syndrome, pseudoxanthoma elasticum, buphthalmos, high myopia and healed scleritis. + +STAPHYLOMAS + +Staphyloma refers to a localised bulging of weak and thin outer tunic of the eyeball (cornea or sclera), lined by uveal tissue which shines through the thinned out fibrous coat. +types +Anatomically, it can be divided into anterior, intercalary, ciliary, equatorial and posterior staphyloma (Fig. 7.9). 1. Anterior staphyloma (see page 135). +2. Intercalary staphyloma. It is the name given to the localised bulge in limbal area lined by root of iris (Figs. 7.9A and 7.10). +• It results due to ectasia of weak scar tissue formed at the limbus, following healing of a perforating injury or a peripheral corneal ulcer. +• Secondary angle closure glaucoma, may cause progression of bulge if not treated. +• Defective vision occurs due to marked corneal astigmatism. +Treatment consists of localised staphylectomy under heavy doses of oral steroids. +3. Ciliary staphyloma. As the name implies, it is the bulge of weak sclera lined by ciliary body. It occurs about 2–3 mm away from the limbus (Figs. 7.9B and 7.11). Its common causes are thinning of sclera following perforating injury, scleritis and absolute glaucoma. +4. Equatorial staphyloma. It results due to bulge of sclera lined by the choroid in the equatorial region (Fig. 7.9c). Its causes are scleritis and degeneration of sclera in pathological myopia. It occurs more +Chapter 7 Diseases of Sclera 145 + + + + + + + + + + + + + + + + +A + + + + + +Fig. 7.9 Staphylomas (diagrammatic depiction) A, Intercalary; B, Ciliary; C, Equatorial; D, Posterior + + + + + + + + + +B +Fig. 7.12 Fundus photograph (A) and diagrammatic depiction (B) of excavation of retinal tissue and blood vessels in posterior staphyloma + +Fig. 7.10 Intercalary staphyloma + + +commonly at the regions of sclera which are perforated by vortex veins. +5. Posterior staphyloma. It refers to bulge of weak sclera lined by the choroid behind the equator (Fig. 7.9D). Here again the common causes are pathological myopia, posterior scleritis and perforating injuries. It is diagnosed on ophthalmoscopy. The area is excavated with retinal vessels dipping in it (just like marked cupping of optic disc in glaucoma) (Fig. 7.12). Its floor is focussed with minus lenses in ophthalmoscope as compared to its margins. +Fig. 7.11 Ciliary staphyloma +8 + +Diseases of Uveal Tract + + + +CHAPTER OUTLINE + +APPLIED ANATOMY Iris +Ciliary body Choroid +• +• +• +• +Blood supply of uveal tract +CONGENITAL ANOMALIES OF UVEAL TRACT Heterochromia of iris +• +• +• +Corectopia +Congenital coloboma of uveal tract +UVEITIS +General considerations Definition Classification +• +• +• +Etiology + + + +APPLIED ANATOMY + +Uveal tissue constitutes the middle vascular coat of the eyeball. From anterior to posterior, it can be divided into three parts, namely, iris, ciliary body and choroid. However, the entire uveal tract is developmentally, structurally and functionally one indivisible structure. +THE IRIS +Iris is the anterior most part of the uveal tract. It is a thin circular disc corresponding to the diaphragm of a camera. In its centre is an aperture of about 4 mm diameter called pupil which regulates the amount of light reaching the retina. At periphery, the iris is attached to the middle of anterior surface of the ciliary body. It divides the space between the cornea and lens into anterior and posterior chambers. +Macroscopic appearance +Anterior surface of the iris can be divided into a ciliary zone and a pupillary zone by a zigzag line called collarette (Fig. 8.1). +1. Ciliary zone. It presents series of radial streaks due to underlying radial blood vessels and crypts + +• Pathology +Non-suppurative uveitis Anterior uveitis (Iridocyclitis) Intermediate uveitis Posterior uveitis +• +• +• +• +Specific clinico-etiological types of non-suppurative uveitis Purulent uveitis +• +• +Endophthalmitis Panophthalmitis +DEGENERATIVE CONDITIONS Degenerations of the Iris +• +• +Degenerations and dystrophies of the choroid TUMOURS +• +• +• +Of choroid +Of ciliary body Of iris + + + +which are depressions where superficial layer of iris is missing. Crypts are arranged in two rows—the peripheral present near the iris root and the central present near the collarette. +2. Pupillary zone. This part of the iris lies between the collarette and pigmented pupillary frill and is relatively smooth and flat. + + + + + + + + + + + + + + + +Fig. 8.1 Macroscopic appearance of anterior surface of iris +Chapter 8 Diseases of Uveal Tract 147 + + + + + + + + + + + + + + + + + \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_6.txt b/notes/A K Khurana - Comprehensive Ophthalmology_6.txt new file mode 100644 index 0000000000000000000000000000000000000000..d7a5a7d8f9440653151e044091ee882f474bfc80 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_6.txt @@ -0,0 +1,1599 @@ +Fig. 8.2 Microscopic structure of iris and ciliary body + + + +Microscopic structure +The iris consists of four layers which from anterior to posterior are (Fig. 8.2): +1. Anterior limiting layer. It is the anterior most condensed part of the stroma. It consists of melanocytes and fibroblasts. Previously, this layer was called endothelial layer of iris which was a misnomer. This layer is deficient in the areas of crypts. The definitive colour of the iris depends on this layer. In blue iris this layer is thin and contains few pigment cells. While in brown iris it is thick and densely pigmented. +2. Iris stroma. It consists of loosely arranged collagenous network in which are embedded the sphincter pupillae muscle, dilator pupillae muscle, vessels, nerves, pigment cells and other cells which include lymphocytes, fibroblasts, macrophages and mast cells. +• Sphincter pupillae muscle forms one millimetre broad circular band in the pupillary part of the iris. It is supplied by parasympathetic fibres through third nerve (see page 6). It constricts the pupil. +• Dilator pupillae muscle lies in the posterior part of stroma of the ciliary zone of iris. Its myofilaments are located in the outer part of the cells of anterior pigment epithelial layer. It is supplied by cervical sympathetic nerves (see page 6) and dilates the pupil. +3. Anterior epithelial layer. It is anterior continuation of the pigment epithelium of retina and ciliary body. This layer gives rise to the dilator pupillae muscle. +4. Posterior pigmented epithelial layer. It is anterior continuation of the nonpigmented epithelium of ciliary body. At the pupillary margin, it forms the + +pigmented frill and becomes continuous with the anterior pigmented epithelial layer. + +CILIARY BODY +Ciliary body is forward continuation of the choroid at ora serrata. In cut-section, it is triangular in shape. The anterior side of the triangle forms the part of the angle of anterior and posterior chambers. In its middle the iris is attached. The outer side of the triangle lies against the sclera with a suprachoroidal space in between. The inner side of the triangle is divided into two parts. The anterior part (about 2 mm) having finger-like ciliary processes is called pars plicata and the posterior smooth part (about 4 mm) is called pars plana (Fig. 8.2). + +Microscopic structure +From without inwards ciliary body consists of following five layers (Fig. 8.2): +1. Supraciliary lamina. It is the outermost condensed part of the stroma and consists of pigmented collagen fibres. Posteriorly, it is the continuation of suprachoroidal lamina and anteriorly it becomes continuous with the anterior limiting membrane of iris. 2. Stroma of the ciliary body. It consists of connective tissue of collagen and fibroblasts. Embedded in the stroma are ciliary muscle, vessels, nerves, pigment and other cells. +■Ciliary muscle occupies most of the outer part of ciliary body. In cut section it is triangular in shape. It is a nonstriated muscle having three parts: +• Longitudinal or meridional fibres which help in aqueous outflow; +• Circular fibres which help in accommodation; and • Radial or oblique fibres act in the same way as the +longitudinal fibres. +148 Section III Diseases of Eye + + +• Nerve supply. Ciliary muscle is supplied by parasympathetic fibres through the short ciliary nerves. +3. Layer of pigmented epithelium. It is forward continuation of the retinal pigment epithelium. Anteriorly, it is continuous with the anterior pigmented epithelium of the iris. +4. Layer of nonpigmented epithelium. It consists mainly of low columnar or cuboidal cells, and is the forward continuation of the sensory retina. It continues anteriorly as the posterior (internal) pigmented epithelium of the iris. +5. Internal limiting membrane. It is the forward continuation of the internal limiting membrane of the retina. It lines the nonpigmented epithelial layer. +Ciliary processes +These are finger-like projections from the pars plicata part of the ciliary body. These are about 70–80 in number. Each process is about 2 mm long and 0.5 mm in diameter. These are white in colour. ■Structure. Each process is lined by two layers of +epithelial cells. The core of the ciliary process contains blood vessels and loose connective tissue. These processes are the site of aqueous production. +Functions of ciliary body +• Formation of aqueous humour. +• Ciliary muscles help in accommodation. + +CHOROID +Choroid is posterior most part of the vascular coat of the eyeball. It extends from optic disc to the ora serrata. Its inner surface is smooth, brown and lies in contact with pigment epithelium of the retina. The outer surface is rough and lies in contact with the sclera. + +Microscopic structure +From without inwards choroid consists of following three layers (Fig. 8.3): +1. Suprachoroidal lamina. It is a thin membrane of condensed collagen fibres, melanocytes and fibroblasts. It is continuous anteriorly with the supraciliary lamina. The potential space between the membrane and sclera is called suprachoroidal space which contains long and short posterior ciliary arteries and nerves. +2. Stroma of the choroid.It consists of loose collagenous tissue with some elastic and reticulum fibres. It also contains pigment cells and plasma cells. Its main bulk is formed by vessels which are arranged in three layers. From without inwards these are: (i) layer of large vessels (Hailer’s layer), (ii) layer of medium vessels (Sattler’s layer) and (iii) layer of choriocapillaris which nourishes the outer layers of the retina. + + + + + + + + + + + + +Fig. 8.3 Microscopic structure of the choroid + +3. Basal lamina. It is also called Bruch’s membrane and lines the layer of choriocapillaris. It lies in approximation with pigment epithelium of the retina. +BLOOD SUPPLY OF UVEAL TRACT +Arterial supply +The uveal tract is supplied by three sets of arteries (Fig. 8.4): +1. Short posterior ciliary arteries. These arise as two trunks from the ophthalmic artery. Each trunk divides into 10–20 branches which pierce the sclera around the optic nerve and supply the choroid in a segmental manner. +2. Long posterior ciliary arteries. These are two in number, nasal and temporal. These pierce the sclera obliquely on medial and lateral side of the optic nerve and run forward in the suprachoroidal space to reach the ciliary muscle, without giving any + + + + + + + + + + + + + + + + + + + + + +Fig. 8.4 Blood supply of uveal tract +Chapter 8 Diseases of Uveal Tract 149 + + +branch. At the anterior end of ciliary muscle these anastomose with each other and with the anterior ciliary arteries and give rise to branches which supply the ciliary body. +3. Anterior ciliary arteries. These are derived from the muscular branches of ophthalmic artery. These are 7 in number, i.e., 2 each from arteries of superior rectus, inferior rectus, and medial rectus muscle and one from that of lateral rectus muscle. These arteries pass anteriorly in the episclera, give branches to sclera, limbus and conjunctiva and ultimately pierce the sclera near the limbus to enter the ciliary muscle; where they anastomose with the two long posterior ciliary arteries to form the circulus arteriosus major, near the root of iris. Several branches arise from the circulus arteriosus major and supply the ciliary processes (one branch for each process). Similarly, many branches from this major arterial circle run radially through the iris towards pupillary margin, where they anastomose with each other to form circulus arteriosus minor. +Venous drainage +A series of small veins which drain blood from the iris, ciliary body and choroid join to form the vortex veins. The vortex veins are four in number— superior temporal, inferior temporal, superior nasal and inferior nasal. They pierce the sclera behind the equator and drain into superior and interior ophthalmic veins, which in turn, drain into the cavernous sinus (see Fig. 1.7, page 6). + +CONGENITAL ANOMALIES OF UVEAL TRACT + +HETEROCHROMIA OF IRIS +It refers to variations in the iris colour and is a common congenital anomaly. +• Heterochromia iridium, colour of one iris differs from the other. +• Heterochromia iridis, one sector of the iris differs from the remainder of iris. +Congenital heterochromia must be differentiated from the acquired heterochromia as seen in heterochromic cyclitis, siderosis, Horner’s syndrome and malignant melanoma of iris. +CORECTOPIA +It refers to abnormally eccentric placed pupil. Normally pupil is placed slightly nasal to the centre. +POLYCORIA +In this condition, there are more than one pupil. + + +CONGENITAL ANIRIDIA (IRIDREMIA) +It refers to congenital absence of iris. True aniridia, i.e., complete absence of the iris is extremely rare. Usually, a peripheral rim of iris is present and this condition is called ‘Clinical aniridia’. Zonules of the lens and ciliary processes are often visible. The condition is usually familial and may be associated with glaucoma due to angle anomalies. + +PERSISTENT PUPILLARY MEMBRANE +It represents the remnants of the vascular sheath of the lens. It is characterised by stellate-shaped shreds of the pigmented tissue coming from anterior surface of the iris (attached at collarette) (Fig. 8.5). These float freely in the anterior chamber or may be attached to the anterior surface of the lens. + +CONGENITAL COLOBOMA OF UVEAL TRACT Congenital coloboma (absence of tissue) of iris (Fig. 8.6), ciliary body and choroid (Fig. 8.7) may be seen in association or independently. Coloboma may be typical or atypical. +Typical coloboma is seen in the inferonasal quadrant and occurs due to defective closure of the embryonic fissure. Typical coloboma may be complete or incomplete. +■Complete coloboma extends from pupil to the optic nerve, with a sector-shaped gap occupying about one-eighth of the circumference of the retina, choroid, ciliary body, iris and causes a corresponding indentation of the lens where the zonular fibres are missing. +■Incomplete coloboma may involve the iris alone, or iris and ciliary body (more common), or iris, ciliary body and part of choroid (i.e. stops short of optic nerve). Atypical coloboma is occasionally found in other positions. It is usually incomplete. + + + + + + + + + + + + + + + +Fig. 8.5 Persistent pupillary membrane +150 Section III Diseases of Eye + + + + + + + + + + + + + + + +Fig. 8.6 Typical coloboma of the iris + + + + + + + + + + + + + + +Fig. 8.7 Coloboma of the choroid + +UVEITIS + +GENERAL CONSIDERATIONS + +DEFINITION +The term uveitis strictly means inflammation of the uveal tissue only. However, clinically there is always some associated inflammation of the adjacent structures such as retina, vitreous, sclera and cornea. Due to close relationship of the anatomically distinct parts of the uveal tract, the inflammatory process usually tends to involve the uvea as a whole. +CLASSIFICATION +I. Anatomical classification +1. Anterior uveitis. It is inflammation of the uveal tissue from iris up to pars plicata of ciliary body. It may be subdivided into: +• Iritis, in which inflammation predominantly affects the iris. +• Iridocyclitis in which iris and pars plicata part of ciliary body are equally involved, and +• Anterior cyclitis, in which pars plicata part of ciliary body is predominantly affected. + +2. Intermediate uveitis. It includes inflammation of the pars plana and peripheral part of the retina and underlying ‘choroid.’ It is also called ‘pars planitis.’ +3. Posterior uveitis. It refers to inflammation of the choroid (choroiditis). Almost always there is associated inflammation of retina and hence the term ‘chorioretinitis’ is used. +4. Panuveitis. It is inflammation of the whole uvea. +II. Clinical classification +1. Acute uveitis. It has got a sudden symptomatic onset and the disease lasts for 3 months or less. +2. Chronic uveitis. It frequently has an insidious and asymptomatic onset. It persists longer than 3 months and is usually diagnosed when it causes defective vision. +3. Recurrent uveitis. This is characterised by repeated episodes separated by inactive periods of >3 months without treatment. +III. Pathological classification +1. Suppurative or purulent uveitis. +2. Nonsuppurative uveitis. It has been further subdivided into two groups (Wood’s classification). +i. Nongranulomatous uveitis, and ii. Granulomatous uveitis. +IV. Etiological (Duke Elder’s) classification 1. Infective uveitis +2. Immune-related uveitis 3. Toxic uveitis +4. Traumatic uveitis +5. Uveitis associated with noninfective systemic diseases +6. Idiopathic uveitis. + +ETIOLOGY +Despite a great deal of experimental research and many sophisticated methods of investigations, etiology and immunology of the uveitis is still largely not understood. Even today, the cause of many clinical conditions is disputed (remains presumptive) and in many others etiology is unknown. The etiological concepts of uveitis as proposed by Duke Elder, in general, are discussed here. +1. Infective uveitis +In this, inflammation of the uveal tissue is induced by invasion of the organisms. Uveal infections may be exogenous, secondary or endogenous. +i. Exogenous infectionwherein the infecting organisms directly gain entrance into the eye from outside. It can occur following penetrating injuries, perforation of corneal ulcer and postoperatively (after intraocular operations). Such infections usually result in an acute iridocyclitis of suppurative (purulent) nature, +Chapter 8 Diseases of Uveal Tract 151 + + +which soon turns into endophthalmitis or even panophthalmitis. +ii. Secondary infection of the uvea occurs by spread of infection from neighbouring structures, e.g., acute purulent conjunctivitis (pneumococcal and gonococcal), keratitis, scleritis, retinitis, orbital cellulitis and orbital thrombophlebitis. +iii. Endogenous infections are caused by the entrance of organisms from some source of infection situated elsewhere in the body, by way of the bloodstream. Endogenous infections play important role in the inflammations of uvea. +Types of infectious uveitis +Depending upon the causative organisms, the infectious uveitis may be classified as follows: +i. Bacterial infections. These may be granulomatous, e.g., tubercular, leprotic, syphilitic, brucellosis or pyogenic such as streptococci,staphylococci, pneumococci and gonococcus. +ii. Viral infections associated with uveitis are herpes simplex, herpes zoster and cytomegalo virus (CMV). iii. Fungal uveitis is rare and may accompany systemic aspergillosis, candidiasis and blastomycosis. It also includes presumed ocular histoplasmosis syndrome. iv. Parasitic uveitis is known in toxoplasmosis, toxocariasis, onchocerciasis and amoebiasis. +v. Rickettsial uveitis may occur in scrub typhus and epidemic typhus. +2. Immune related uveitis +Immune related uveitis is one of the commonest occurrence in clinical practice. The complex subject of immune linked inflammation of uveal tissue is still not clearly understood. It may be caused by the following ways: +i.Microbial allergy.In this, primary source of infection is somewhere else in the body and the escape of the organisms or their products into the bloodstream causes sensitisation of the uveal tissue with the formation of antibodies. At a later date a renewal of infection in the original focus may again cause dissemination of the organisms or their products (antigens); which on meeting the sensitised uveal tissue excite an allergic inflammatory response. +Primary focus of infection can be a minute tubercular lesion in the lymph nodes or lungs. Once it used to be the most common cause of uveitis worldwide, but now it is rare. However, in developing countries like India, tubercular infections still play an important role. Other sources of primary focus are streptococcal and other infections in the teeth, paranasal sinuses, tonsils, prostate, genitals and urinary tract. + +ii. Anaphylactic uveitis. It is said to accompany the systemic anaphylactic reactions like serum sickness and angioneurotic oedema. +iii. Atopic uveitis. It occurs due to airborne allergens and inhalants, e.g., seasonal iritis due to pollens. A similar reaction to such materials as danders of cats, chicken feather, house dust, egg albumin and beef proteins has also been noted. +iv. Autoimmune uveitis. It is found in association with autoimmune disorders such as Still’s disease, rheumatoid arthritis, Wegener’s granulomatosis, systemic lupus erythematosus, Reiter’s disease and so on. +In phacoanaphytic endophthalmitis, lens proteins play role of autoantigens. Similarly, sympathetic ophthalmitis has been attributed to be an autoimmune reaction to uveal pigments, by some workers. +v. HLA-associated uveitis. Human leucocytic antigens (HLA) is the old name for the histocompatibility antigens. There are about 70 such antigens in human beings, on the basis of which an individual can be assigned to different HLA-phenotypes. Recently, lot of stress is being laid on the role of HLA in uveitis, since a number of diseases associated with uveitis occur much more frequently in persons with certain specific HLA phenotype. A few examples of HLA-associated diseases with uveitis are as follows: +• HLA-B27: Acute anterior uveitis associated with ankylosing spondylitis and also in Reiter’s syndrome. +• HLA-B5: Uveitis in Behcet’s disease. +• HLA-D R4 and DW15: Vogt Koyanagi Harada’s disease. +3. Toxic uveitis +Toxins responsible for uveitis can be endotoxins, endocular toxins or exogenous toxins. +i. Endotoxins produced inside the body play a major role. These may be autotoxins or microbial toxins (produced by organisms involving the body tissues). Toxic uveitis seen in patients with acute pneumococcal or gonococcal conjunctivitis, and in patients with fungal corneal ulcer, is thought to be due to microbial toxins. +ii. Endocular toxins are produced from the ocular tissues. Uveitis seen in patients with blind eyes, long-standing retinal detachment and intraocular haemorrhage is said to be due to endocular toxins. Other examples are uveitis associated with intraocular tumours and phacotoxic uveitis. +iii. Exogenous toxins causing uveitis are irritant chemical substances of inorganic, animal or +152 Section III Diseases of Eye + + +vegetative origin. Certain drug causing uveitis (such as miotics and cytotoxic drugs) are other examples of exogenous toxins. +4. Traumatic uveitis +It is often seen in accidental or operative injuries to the uveal tissue. Different mechanisms which may produce uveitis following trauma include: +• Direct mechanical effects of trauma, +• Irritative effects of blood products after intraocular haemorrhage (haemophthalmitis), +• Microbial invasion, +• Chemical effects of retained intraocular foreign bodies, and +• Sympathetic ophthalmia in the other eye. + +5. Uveitis associated with non-infective systemic diseases +Certain systemic diseases frequently complicated by uveitis include: +• Sarocoidosis, +• Collagen related diseases (polyarteritis nodosa (PAN), disseminated lupus erythematosus (DLE), rheumatic and rheumatoid arthritis), +• Metabolic diseases (diabetes mellitus and gout), • Disease of the central nervous system (e.g., +disseminated sclerosis), and +• Diseases of skin (psoriasis, lichen planus, erythema nodosum, pemphigus and so on). +6. Idiopathic uveitis +It may be specific or nonspecific. +i. Idiopathic specific uveitis entities include the conditions which have certain special characteristics of their own, e.g., pars planitis, sympathetic ophthalmitis and Fuchs’ heterochromic iridocyclitis. +ii. Nonspecific idiopathic uveitis entities include the condition which do not belong to any of the known etiological groups. About more than 25% cases of uveitis fall in this group. +PATHOLOGY OF UVEITIS +Inflammation of the uvea fundamentally has the same characteristics as any other tissue of the body, i.e., a vascular and a cellular response. However, due to extreme vascularity and looseness of the uveal tissue, the inflammatory responses are exaggerated and thus produces special results. +Pathologically, inflammations of the uveal tract may be divided into suppurative (purulent) and non-suppurative (non-purulent) varieties. Wood has further classified non-suppurative uveitis into nongranulomatous and granulomatous types. Although morphologic description is still of some value, the rigid division of uveitis by Wood into these + +two categories has been questioned on both clinical and pathological grounds. Certain transitional forms of uveitis have also been recognised. Some of these (e.g., phacoanaphylactic endophthalmitis and sympathetic ophthalmia) showing pathological features of granulomatous uveitis are caused by hypersensitivity reactions. While uveitis due to tissue invasion by leptospirae presents with manifestation of nongranulomatous uveitis. Nonetheless, the classification is often useful in getting oriented towards the subject of uveitis, its workup and therapy. Therefore, it is worthwhile to describe the pathological features of these overlapping (both clinically and pathologically) conditions as distinct varieties. +1. Pathology of suppurative uveitis +Purulent inflammation of the uvea is usually a part of endophthalmitis or panophthalmitis occurring as a result of exogenous infection by pyogenic organisms which include Staphylococcus, Streptococcus, Pseudomonas, Pneumococcus and Gonococcus. +The pathological reaction is characterised by an outpouring of purulent exudate and infiltration by polymorphonuclear cells of uveal tissue, anterior chamber, posterior chamber and vitreous cavity. As a result, the whole uveal tissue is thickened and necrotic and the cavities of eye become filled with pus. +2. Pathology of nongranulomatous uveitis Nongranulomatous uveitis may be an acute or chronic exudative inflammation of uveal tissue (predominantly iris and ciliary body), usually occurring either due to a physical and toxic insult to the tissue, or as a result of different hypersensitivity reactions. +The pathological alterations of the nongran-ulomatous reaction consists of marked dilatation and increased permeability of vessels, breakdown of blood aqueous barrier with an outpouring of fibrinous exudate and infiltration by lymphocytes, plasma cells and large macrophages of the uveal tissue, anterior chamber, posterior chamber and vitreous cavity. The inflammation is usually diffuse. As a result of these pathological reactions iris becomes waterlogged, oedematous, muddy with blurring of crypts and furrows. As a consequence its mobility is reduced, pupil becomes small in size due to sphincter irritation and engorgement of radial vessels of iris. Exudates and lymphocytes poured into the anterior chamber result in aqueous flare and deposition of fine KPs at the back of cornea. Due to exudates in the posterior chamber, +Chapter 8 Diseases of Uveal Tract 153 + + +the posterior surface of iris adheres to the anterior capsule of lens leading to posterior synechiae formation. In severe inflammation, due to pouring of exudate from ciliary processes, behind the lens, an exudative membrane called cyclitic membrane may be formed. +After healing, pin-point areas of necrosis or atrophy are evident. Subsequent attacks lead to structural changes like atrophy, gliosis and fibrosis which cause adhesions, scarring and eventually destruction of eye. +3. Pathology of granulomatous uveitis Granulomatous uveitis is a chronic inflammation of proliferative nature which typically occurs in response to anything which acts as an irritant foreign body, whether it be inorganic or organic material introduced from outside, a haemorrhage or necrotic tissue within the eye, or one of the certain specific organisms of non-pyogenic and relatively non-virulent character. The common organisms which excite this type of inflammation are those responsible for tuberculosis, leprosy, syphilis, brucellosis, leptospirosis, as well as most viral, mycotic, protozoal and helminthic infections. A typical granulomatous inflammation is also seen in sarcoidosis, sympathetic ophthalmitis and Vogt-Koyanagi-Harada’s disease. +The pathological reaction in granulomatous uveitis is characterised by infiltration with lymphocytes, plasma cells and mobilization and proliferation of large mononuclear cells which eventually become epithelioid and giant cells and aggregate into nodules. Iris nodules are usually formed near pupillary border (Koeppe’s nodules) and some times near collarette (Busacca nodules). Similar nodular collection of the cells is deposited at the back of cornea in the form of mutton fat keratic precipitates and aqueous flare is minimal. Necrosis in the adjacent structures leads to reparative process resulting in fibrosis and gliosis of the involved area. + +NON-SUPPURATIVE UVEITIS + +ANTERIOR UVEITIS (IRIDOCYCLITIS) + +Definition See page 150. + +Etiology See page 150. + +Clinical Features +Though anterior uveitis, almost always presents as a combined inflammation of iris and ciliary body (iridocyclitis), the reaction may be more marked in iris (iritis) or ciliary body (cyclitis). +Symptoms +Clinically, it may present as acute or chronic anterior uveitis. +• Main symptoms of acute anterior uveitis are pain, photophobia, redness, lacrimation and decreased vision. +• In chronic uveitis , however the eye may be white with minimal symptoms even in the presence of signs of severe inflammation. +1. Pain. It is dominant symptom of acute anterior uveitis. Patients usually complain of a dull aching throbbing sensation which is typically worse at night. The ocular pain is usually referred along the distribution of branches of fifth nerve, especially towards forehead and scalp. +2. Redness. It is a feature of acute anterior uveitis and occurs due to circumcorneal congestion, which is result of active hyperaemia of anterior ciliary vessels due to the effect of toxins, histamine and histamine-like substances and axon reflex. +3. Photophobia and blepharospasm observed in patients with acute anterior uveitis is due to a reflex between sensory fibres of fifth nerve (which are irritated) and motor fibres of the seventh nerve, supplying the orbicularis oculi muscle. +4. Lacrimation occurs as a result of lacrimatory reflex mediated by fifth nerve (afferent) and secretomotor fibres of the seventh nerve (efferent). +5. Defective vision in a patient with iridocyclitis may vary from a slight blur in early phase to marked deterioration in late phase. Factors responsible for visual disturbance include induced myopia due to ciliary spasm, corneal haze (due to oedema and KPs), aqueous turbidity, pupillary block due to exudates, complicated cataract, vitreous haze, cyclitic membrane, associated macular oedema, papillitis or secondary glaucoma. One or more factors may contribute in different cases depending upon the severity and duration of the disease. +Signs +Slit-lamp biomicroscopic examination is essential to elicit most of the signs of uveitis (Fig. 8.8). +A. Lid oedema +Lid oedema usually mild, may accompany a severe attack of acute anterior uveitis. +154 Section III Diseases of Eye + + +B. Circumcorneal congestion +Circumcorneal congestion is marked in acute iridocyclitis and minimal in chronic iridocyclitis. It must be differentiated from superficial congestion occurring in acute conjunctivitis (see page 158, Table 8.1) . +C. Corneal signs +Corneal signs include corneal oedema, KPs and posterior corneal opacities. + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 8.8 Signs of anterior uveitis: A, diagrammatic depiction; B, clinical photograph of a patient with acute anterior uveitis + + + + + + + + + + + + + + +A + +1. Corneal oedema is due to toxic endothelitis and raised intraocular pressure when present. +2. Keratic precipitates (KPs) are proteinaceous-cellular deposits occurring at the back of cornea. Mostly, these are arranged in a triangular fashion occupying the centre and inferior part of cornea due to convection currents in the aqueous humour (Fig. 8.9). The composition and morphology of KPs varies with the severity, duration and type of uveitis. Following types of KPs may be seen: +i. Mutton fat KPs. These typically occur in granulomatous iridocyclitis and are composed of epithelioid cells and macrophages. They are large, thick, fluffy, lardaceous KPs, having a greasy or waxy appearance. Mutton fat KPs are usually a few (10 to 15) in number (Fig. 8.9B). +ii. Small and medium KPs (granular KPs). These are pathognomic of nongranulomatous uveitis and are composed of lymphocytes. These small, discrete, dirty white KPs are arranged irregularly at the back of cornea. Small KPs may be numerous. +iii.Fine KPs, also called as ‘stellate’ KPs, typically cover entire corneal endothelium and form the so called endothelial dusting. These are seen in Fuch’s heterochromic iridocyclitis, herpetic iritis and CMV retinitis. +iv. Old KPs. These are sign of healed uveitis. Either of the above described KPs with healing process shrink, fade, become pigmented and irregular in shape (crenated margins). Old mutton fat KPs usually have a ground glass appearance due to hyalinization. +3. Posterior corneal opacity may be formed in long-standing cases of iridocyclitis. +D. Anterior chamber signs +1. Aqueous cells. It is an early feature of iridocyclitis. The cells should be counted in an oblique slit-lamp + + + + + + + + + + + + + +B + +Fig. 8.9 Keratic precipitates (KPs); A, diagrammatic depiction; B, clinical photograph of a patient with granulomatous anterior uveitis showing mutton fat KPs and broad segmental synechiae +Chapter 8 Diseases of Uveal Tract 155 + + +beam, 1 mm long and 1 mm wide, with maximal light intensity and magnification, and graded as per ‘Standardization of Uveitis Nomenclature (SUN)’ working group as below: +• – = < 1 cells, • ± = 1–5 cells, +• + 1 = 6–15 cells, • + 2 = l 6–25 cells, +• + 3 = 26–50 cells, and • + 4 = over 50 cells. +2. Aqueous flare. It is due to leakage of protein particles into the aqueous humour from damaged blood vessels. It is demonstrated on the slit-lamp examination by a point beam of light passed obliquely to the plane of iris (Fig. 8.10). In the beam of light, protein particles are seen as suspended and moving dust particles. This is based on the ‘Brownian movements’ or ‘Tyndall phenomenon.’ Aqueous flare is usually marked in nongranulomatous and minimal + + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + + + +B +Fig. 8.10 Aqueous flare: A, diagrammatic depiction; B, clinical photograph of the patient + + +in granulomatous uveitis. The flare is graded from 0 to +4. Grade as per SUN working group grading scheme: +• 0 = no aqueous flare. +• + 1 = faint, i.e., just detectable. +• +2 = moderate flare with clear iris and lens details. • +3 = marked flare (iris and lens details hazy). +• +4 = intense flare (Fibrin or plastic aqueous). +3. Hypopyon. When exudates are heavy and thick, they settle down in lower part of the anterior chamber as hypopyon (sterile pus in the anterior chamber) (Fig. 8.11). +• Dense immobile hypopyon, slow to absorb due to high fibrin content, is seen in HLA-B27 acute anterior uveitis. +• Hypopyon in Behcet’s syndrome has minimal fibrin and, therefore, shifts with the head position and is quick to absorb. +• Haemorrhagic hypopyon is a feature of uveitis associated with herpetic infection, trauma and rubeosis iridis. +4. Changes in depth and shape of anterior chamber may occur due to synechiae formation as below: +• Deep and irregular in posterior synechiae. +• Funnel-shaped in annular synechiae with iris bombe. +5. Changes in the angle of anterior chamber are observed with gonioscopic examination. In active stage, cellular deposits and in chronic stage peripheral anterior synechiae may be seen. +E. Iris signs +1. Loss of normal pattern. It occurs due to oedema and waterlogging of iris in active phase and due to atrophic changes in chronic phase. Iris atrophy is typically observed in Fuchs’ heterochromic iridocyclitis. + + + + + + + + + + + + + + + +Fig. 8.11 Hypopyon in acute anterior uveitis +156 Section III Diseases of Eye + + +2. Changes in iris colour. Iris usually becomes muddy in colour during active phase and may show hyperpigmented and depigmented areas in healed stage. +3. Iris nodules (Fig. 8.12). These occur typically in granulomatous uveitis. +• Koeppe’s nodules are situated at the pupillary border and may initiate posterior synechia. +• Busacca’s nodules situated near the collarette are large but less common than the Koeppe’s nodules. 4. Posterior synechiae. These are adhesions between the posterior surface of iris and anterior capsule of crystalline lens (or any other structure which may be artificial lens, after cataract, posterior capsule left after extracapsular cataract extraction) or anterior hyaloid face. These are formed due to organisation of the fibrin-rich exudates. Morphologically, posterior +synechiae may be segmental, annular or total. +i. Segmental posterior synechiae refers to adhesion of iris to the lens at some points (Fig. 8.8). + + +ii. Annular posterior synechiae (ring synechiae) are 360° adhesions of pupillary margin to anterior capsule of lens. These prevent the circulation of aqueous humour from posterior chamber to anterior chamber (seclusio pupillae). Thus, aqueous collects behind the iris and pushes it anteriorly (leading to ‘iris-bombe’ formation) (Fig. 8.13). This is usually followed by a rise in intraocular pressure. +iii.Total posterior synechiae due to plastering of total posterior surface of iris with the anterior capsule of lens are rarely formed in acute plastic type of uveitis. This results in deepening of anterior chamber (Fig. 8.14). +5. Neovascularisation of iris (rubeosis iridis) develops in some eyes with chronic iridocyclitis and in Fuch’s heterochromic iridocyclitis. +F. Pupillary signs +1.Narrow pupil.It occurs in acute attack of iridocyclitis (Fig. 8.8B) due to irritation of sphincter pupillae by toxins. Iris oedema and engorged radial vessels of iris also contribute in making the pupil narrow. +2. Irregular pupil shape. It results from segmental posterior synechiae formation. Dilatation of pupil with mydriatics (e.g., atropine) at this stage results in festooned pupil (Figs 8.8A and 8.15). +3.Ectropion pupillae (evertion of pupillary margin). It may develop due to contraction of fibrinous exudate on the anterior surface of the iris. +4.Pupillary reactionbecomes sluggish or may even be absent due to oedema and hyperaemia of iris which hamper its movements. +5. Occlusio pupillae results when the pupil is completely occluded due to organisation of the exudates across the entire pupillary area. + + + +A + + + + + + + + + + + + +B +Fig. 8.12 Iris nodules: A, diagrammatic depiction; B, clinical +photograph showing Koeppe’s nodules at the pupillary +margins in a patient with sarcoidosis Fig. 8.13 Annular posterior synechiae +Chapter 8 Diseases of Uveal Tract 157 + + + + + + + + + + + + + + + + + + + + +Fig. 8.14 Total posterior synechiae causing deep anterior chamber + +G. Changes in the lens +1. Pigment dispersal on the anterior capsule of lens is almost of universal occurrence in case of anterior uveitis. +2. Exudatesmay be deposited on the lens in cases with acute plastic iridocyclitis. +3. Complicated cataract may develop as a complication of persistent iridocyclitis. Typical features of a complicated cataract in early stage are ‘polychromatic luster’ and ‘bread-crumb’ appearance of the early posterior subcapsular opacities. In the presence of posterior synechiae, the complicated cataract progresses rapidly to maturity (Fig. 8.15). +H. Changes in the vitreous and retina +1. Exudatesand inflammatory cellsmay be seen in the anterior vitreous after an attack of acute iridocyclitis. 2.Cystoid macular oedema(CME) may occur, specially in chronic iridocyclitis. +I. Changes in the intraocular pressure IOP may be: +• Normal, or +• Increased (secondary glaucoma) or, +• Decreased (in acute iridocyclitis due to acute ciliary shock and in chronic, longstanding iridocyclitis due to atrophy of ciliary process ultimately leading to phthisis bulbi). + +Complications and Sequelae +1. Complicated cataract. It is a common complication of iridocyclitis as described above (Fig. 8.15). +2. Secondary glaucoma.It may occur as an early or late complication of iridocyclitis. + +i. Early glaucoma. In active phase of the disease, presence of exudates and inflammatory cells in the anterior chamber may cause clogging of trabecular meshwork resulting in the decreased aqueous drainage and thus a rise in intraocular pressure (hypertensive uveitis). +ii. Late glaucoma in iridocyclitis (post-inflammatory glaucoma) is the result of pupil block (seclusio pupillae due to ring synechiae formation, or occlusio pupillae due to organised exudates) not allowing the aqueous to flow from posterior to anterior chamber. There may or may not be associated peripheral anterior synechiae formation. +3. Cyclitic membrane. It results due to organisation of exudates present behind the lens. It is a late complication of acute plastic type of iridocyclitis. +4. Choroiditis. It may develop in prolonged cases of iridocyclitis owing to their continuity. +5. Retinal complications. These include cystoid macular oedema, macular scar, macular hole, epiretinal membrane, exudative retinal detachment, secondary periphlebitis retinae, retinal scars and sub-retinal fibrosis. +6. Papillitis (inflammation of the optic disc). It may be associated in severe cases of iridocyclitis. +7. Band-shaped keratopathy. It occurs as a complication of long-standing chronic uveitis (see Fig. 6.19), especially in children having Still’s disease. 8. Phthisis bulbi. It is the final stage end result of any form of chronic uveitis in which the eye becomes soft, shrink and atrophic. Development of phthisis bulbi can be divided into three overlapping stages: ■Stage of atrophic bulbi without shrinkage is the initial stage of loss of function of ocular tissues which occurs due to continued inflammation and loss of nutritional support. In this stage: + + + + + + + + + + + + + + +Fig. 8.15 Iridocyclitis with posterior synechiae, festooned pupil and complicated cataract +158 Section III Diseases of Eye + + +• Shape of globe is maintained, • Vision is completely lost, +• Lens becomes cataractous, +• Retina develops serous detachment and atrophic changes, and +• IOP is raised in early stages due to inflammatory glaucoma. +■Stage of atrophic bulbi with shrinkage occurs due to continued ciliary body dysfunction. In this stage: • IOP is lowered, +• Cornea becomes edematous and vascularised, • Anterior chamber is collapsed, and +• Eyeball becomes smaller and square shaped (maintained by four recti). +■Atrophic bulbi with disorganization is the final stage known as phthisis bulbi. In this stage due to continued disorganization of ciliary body: +• IOP is markedly lowered, +• Size of eyeball is markedly decreased, and • Cornea becomes sclera like. +Histopathological examinationat this stages reveals: • Disorganization of all the intraocular tissues, +• Calcification may occur in Bowman’s layer of cornea, lens and retina, +• Intraocular ossification (bone formation) may occur due to metaplasia in the retinal pigment epithelium, in the end stage of phthisis bulbi, and +• Sclera become markedly thickened. + +Differential Diagnosis +1. Acute red eye. Acute iridocyclitis must be differentiated from other causes of acute red eye, especially acute congestive glaucoma and acute conjunctivitis. The differentiating features are summarised in Table 8.1. +2. Granulomatous versus nongranulomatousuveitis. Once diagnosis of iridocyclitis is established, an attempt should be made to know whether the condition is of granulomatous or nongranulomatous type. The main clinical differences between the two are summarised in Table 8.2. +3. Etiological differential diagnosis. Efforts should also be made to distinguish between the different etiological varieties of iridocyclitis. This may be possible in some cases after thorough investigations and with a knowledge of special features of different clinical entities, which are described under the subject of ‘special types of iridocyclitis’ (see pages 163-170). + +Investigations +Before ordering investigations, a thorough ocular systemic examination is required, which may provide clues to the underline disease. +Investigations include a battery of tests because of its varied etiology. However, an experienced ophthalmologist soon learns to order a few investigations of considerable value, which will + + +Table 8.1 Distinguishing features between, acute conjunctivitis, acute iridocyclitis and acute congestive glaucoma + + +Feature 1. Onset 2. Pain + + +3. Discharge +4. Coloured halos 5. Vision +6. Congestion 7. Tenderness 8. Pupil +9. Media + + +10. Anterior chamber 11. Iris +12. Intraocular pressure +13. Constitutional symptoms + +Acute conjunctivitis Gradual +Mild discomfort + + +Mucopurulent May be present Good +Superficial conjunctival Absent +Normal Clear + + +Normal Normal Normal +Absent + +Acute iridocyclitis Usually gradual +Moderate in eye and along the first division of trigeminal nerve +Watery Absent +Slightly impaired Deep ciliary Marked +Small and irregular +Hazy due to KPs, aqueous flare and pupillary exudates +May be deep Muddy +Usually normal +Little + +Acute congestive glaucoma Sudden +Severe in eye and the entire trigeminal area + +Watery Present +Markedly impaired Deep ciliary Marked +Large and vertically oval +Hazy due to oedematous cornea + +Very shallow Oedematous Raised +Prostration and vomiting +Chapter 8 Diseases of Uveal Tract 159 + + +Table 8.2 Differences between granulomatous and nongranulomatous uveitis + + +Feature 1. Onset 2. Pain +3. Photophobia +4. Ciliary congestion +5. Keratic precipitates (KPs) 6. Aqueous flare +7. Iris nodules +8. Posterior synechiae +9. Fundus + +Granulomatous Insidious Minimal +Slight Minimal Mutton fat Mild +Usually present +Thick and broad based +Nodular lesions + +Nongranulomatous Acute +Marked Marked Marked Small Marked Absent +Thin and tenuous +Diffuse involvement + + + +differ in individual case depending upon the information gained from thorough clinical work up. A few common investigations required are listed here: +1. Haematological investigations +• TLC and DLC to have a general information about inflammatory response of body. +• ESR to ascertain existence of any chronic inflammatory condition in the body. +• Blood sugar levels to rule out diabetes mellitus. +• Blood uric acid in patients suspected of having gout. +• Serological tests for syphilis, toxoplasmosis and histoplasmosis. +• Testsforantinuclear antibodies, Rh factor, LE cells, C-reactive proteins antistreptolysin-0, ACE (for sarcoidosis). +2. Urine examination for WBCs, pus cells, RBCs and culture to rule out urinary tract infections. +3. Stool examination for cyst and ova to rule out parasitic infestations. +4. Radiological investigations include: +• X-rays of chest, paranasal sinuses, sacroiliac joints and lumbar spine. +• CT scan high resolution. CT scan of thorax should be considered for suspected sarcoidosis cases. +• MRI scan of head for suspected sarcoidosis, demyelination and lymphomas. +5. Skin tests. These include tuberculin test, Kveim’s test for sarcoidosis, toxoplasmin test, lepromin test and pathergy test for Behcet’s disease. + +Treatment of Iridocyclitis I. Nonspecific treatment +a. Local therapy +1. Cycloplegic drugs. These are very useful and most effective during acute phase of iridocyclitis. Commonly used drug is 1% atropine sulfate eye ointment or + +drops instilled 2-3 times a day. In case of atropine allergy, other cycloplegics like 2% homatropine or 1% cyclopentolate eyedrops may be instilled 3-4 times a day. Alternatively for more powerful cycloplegic effect, a subconjunctival injection of 0.25 ml in mydricain (a mixture of atropine, adrenaline and procaine) should be given. The cycloplegics should be continued for at least 2–3 weeks after the eye becomes quiet, otherwise relapse may occur. +■Mode of action. In iridocyclitis, atropine (i) gives comfort and rest to the eye by relieving spasm of iris sphincter and ciliary muscle, (ii) prevents the formation of synechiae and may break the already formed synechiae, (iii) reduces exudation by decreasing hyperaemia and vascular permeability and (iv) increases the blood supply to anterior uvea by relieving pressure on the anterior ciliary arteries. As a result, more antibodies reach the target tissues and more toxins are absorbed. +2. Corticosteroids, administered locally, are very effective in cases of iridocyclitis. +■Mode of action: They reduce inflammation by their anti-inflammatory effect; being anti-allergic, are of special use in allergic type of uveitis; and due to their antifibrotic activity, they reduce fibrosis and thus prevent disorganisation and destruction of the tissues. ■Commonly used steroidal preparations contain dexamethasone, betamethasone, hydrocortisone or prednisolone (see page 453). +■Route of administration: Locally, steroids are used as (i) eye drops 4–6 times a day, (ii) eye ointment at bed time, and (iii) Anterior sub-Tenon injection is given in severe cases. +3. Broad spectrum antibiotic drops, though of no use in iridocyclitis, are usually prescribed with topical steroid preparations to provide an umbrella cover for them. +160 Section III Diseases of Eye + + +b. Systemic therapy +1. Corticosteroids. When administered systemically they have a definite role in nongranulomatous iridocyclitis, where inflammation, most of the times, is due to antigen-antibody reaction. Even in other types of uveitis, the systemic steroids are helpful due to their potent nonspecific anti-inflammatory and antifibrotic effects. Systemic corticosteroids are usually indicated in intractable anterior uveitis resistant to topical therapy. +Dosage schedules. A wide variety of steroids are available. Usually, treatment is started with high doses of prednisolone (60–100 mg) or equivalent quantities of other steroids (dexamethasone or betamethasone). +• Daily therapy regime is preferred for marked inflammatory activity for at least 2 weeks. +• In the absence of acute disease, alternate day therapy regime should be chosen. +• Dose of steroids is decreased by a week’s interval and tapered completely in about 6–8 weeks in both the regimes. +Note.Steroids (both topical and systemic) may cause many ocular (e.g., steroid-induced glaucoma and cataract) and systemic side-effects. Hence, an eagle’s eye watchfulness is required for it. +2. Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin can be used where steroids are contraindicated. Phenylbutazone and oxyphenbutazone are potent anti-inflammatory drugs of particular value in uveitis associated with rheumatoid disease. Naproxen is useful in patients with ankylosing spondylitis. +3. Immunosuppressive drugs. These should be used only in desperate and extremely serious cases of uveitis, in which vigorous use of steroids have failed to resolve the inflammation and there is an imminent danger of blindness. These drugs are dangerous and should be used with great caution in the supervision of a haematologist and an oncologist. These drugs are specially useful in severe cases of Behcet’s syndrome, sympathetic ophthalmia, pars planitis and VKH syndrome. A few available cytotoxic immunosuppressive drugs include cyclophosphamide, chlorambucil, azathioprine and methotrexate. Cyclosporin is a powerful anti-T-cell immunosuppressive drug which is effective in cases resistant to cytotoxic immunosuppressive agents, but it is a highly renal toxic drug. +4. Azithromycin or tetracycline or erythromycin should be considered to treat chlamydial infection in patients and their sexual partners with Reiter’s syndrome having urethritis and iritis. + +c. Physical measures +1. Hot fomentation. It is very soothing, diminishes pain and increases circulation, and thus reduces the venous stasis. As a result, more antibodies are brought and toxins are drained. Hot fomentation can be done by dry heat or wet heat. +2. Dark goggles. These give a feeling of comfort, especially when used in sunlight, by reducing photophobia, lacrimation and blepharospasm. +II. Specific treatment of the cause +Nonspecific treatment described above is very effective and usually controls the uveal inflam-mation, in most of the cases, but it does not cure the disease, resulting in relapses. Therefore, all possible efforts should be made to find out and treat the underlying cause. Unfortunately, in spite of the advanced diagnostic tests, still it is not possible to ascertain the cause in a large number of cases. +So, a full course of antitubercular drugs for underlying Koch’s disease, adequate treatment for syphilis, toxoplasmosis, etc., when detected should be carried out. When no cause is ascertained, a full course of broad spectrum antibiotics may be helpful by eradicating some masked focus of infection in patients with nongranulomatous uveitis. +III. Treatment of complications +1. Inflammatory glaucoma (hypertensive uveitis). In such cases, drugs to lower intraocular pressure such as 0.5% timolol maleate eyedrops twice a day and tablet acetazolamide (250 mg thrice a day) should be added, over and above the usual treatment of iridocyclitis. Pilocarpine and latanoprost eye drops are contraindicated in inflammatory glaucoma. +2. Postinflammatory glaucoma due to ring synechiae is treated by laser iridotomy. Surgical iridectomy may be done when laser is not available. However, surgery should be performed in a quiet eye under high doses of corticosteroids. +3. Complicated cataract requires lens extraction with guarded prognosis in spite of all precautions. Presence of fresh KPs is considered a contraindication for intraocular surgery. +4.Retinal detachment of exudative type usually settles itself if uveitis is treated aggressively. A tractional detachment requires vitrectomy and management of complicated retinal detachment, with poor visual prognosis. +5. Phthisis bulbi especially when painful, requires removal by enucleation operation. +Chapter 8 Diseases of Uveal Tract 161 + + +INTERMEDIATE UVEITIS + +Intermediate uveitis refers to inflammation involving pars plana ciliaris, peripheral retina, choroid and vitreous base. +Epidemiology +• Accounts for 10% of all cases of uveitis and 20% of cases of uveitis in children, +• Bilateral in 80% of cases, +• Males and females are equally affected, +• Age: onset typically in 2nd and 4th decade (bimodal). +Etiology +• Idiopathic in about 85% cases. Immunogenic predisposition is reported with a positive correlation with HLA-DR2. +• Known causes (15% cases) include tuberculosis, syphilis, sarcoidosis, and Lyme disease. +Clinical features +Symptoms +• Asymptomatic in many cases, +• Floaters of insidious onset is most common presentation, +• Blurring of vision and decreased vision may occur later, +• Pain, photophobia and redness are conspicuously absent. +Signs +Anterior segment signs. On cursory examination eye looks white and quiet. Anterior segment may or may not show signs of minimal activity in the form of: +• Low grade flare and cells, +• Few KPs due to spillover anterior uveitis, +• Lens may show complicated cataract in late stages. Posterior segment signs pathognomic of intermediate uveitis are: +• Vitreous cells (+1 to +4), +• Anterior vitreous condensation, +• Snowball or cotton ball opacities (Ant’s eggs) refers to typical exudates present near the ora serrate in the inferior quadrant. +• Snow banking, i.e., grey white fibrovascular plaque over the pars plana with or without associated peripheral retinal periphlebits form the hallmark of intermediate uveitis. These are best seen with indirect ophthalmoscopy and Goldman three mirror examination. +• Severe vitreous opacification obscuring retina and even presenting as leucocoria may occur rarely. +Course, prognosis and complications +Course and prognosis. Relatively good prognosis if well treated. Course is usually chronic with three distinct patterns: + + +• Single, mild self limiting episode (10%) cases, +• Prolonged course without exacerbations (60% cases), and +• Chronic smoldering course with multiple subacute exacerbations (30% cases). +Complications include: Complicated cataract, cystoid macular oedema, band keratopathy, secondary glaucoma, vitreous haemorrhage and tractional retinal detachment. +Treatment +Modified 4 step protocol of Kaplan is as below: Step 1: Periocular and systemic steroids. Topical steroids are not of much use. +• Posterior subtenon injection of triamcinolone 40 mg/3 weeks × 3 injections are indicated initially. +• Systemic steroids are given in unresponsive cases. Step 2: Immunosuppressive drugssuch as cyclosporine, azathioprine, methotrexate or cyclophosphamide should be given with careful monitoring of effects and potential side effects when step 1 measures fails. Step 3: Cryotherapy or indirect laser photocoagulation should be tried in cases with snowbanking. +Step 4: Pars-plana vitrectomy is indicated in severe cases and when step 3 measures fail. It helps by removing inflammatory debris, antigenic load and possible traction on macula. Its role in tractional RD is unequivocal. + +POSTERIOR UVEITIS + +Posterior uveitis refers to inflammation of the choroid (choroiditis). Since the outer layers of retina are in close contact with the choroid and also depend on it for the nourishment, the choroidal inflammation almost always involves the adjoining retina, and the resultant lesion is called chorioretinitis. + +Etiology and Pathology +These are same as described for uveitis in general considerations. + +Clinical features +Symptoms +Choroiditis (non-suppurative inflammation) is a painless condition, usually characterised by visual symptoms due to associated vitreous haze and involvement of the retina. Therefore, small patches situated in periphery may be symptomless and are usually discovered as healed patches on routine fundus examination. On the contrary, a central patch produces marked symptoms which draw immediate attention. Various visual symptoms experienced by a patient of choroiditis are summarised below: +162 Section III Diseases of Eye + + +1. Defective vision. It is usually mild due to vitreous haze, but may be severe as in central choroiditis. +2. Photopsia.It is a subjective sensation of flashes of light resulting due to irritation of rods and cones. +3. Black spots floating in front of the eyes. It is a very common complaint of such patients. They occur due to large exudative clumps in the vitreous. +4. Metamorphopsia. Herein, patients perceive distorted images of the object. This results due to alteration in the retinal contour caused by a raised patch of choroiditis. +5. Micropsia which results due to separation of visual cells is a common complaint. In this, the objects appear smaller than they are. +6. Macropsia, i.e., perception of the objects larger than they are, may occur due to crowding together of rods and cones. +7. Positive scotoma, i.e., perception of a fixed large spot in the field of vision, corresponding to the lesion may be noted by many patients. + +Signs +I. Anterior segment signs. Usually there are no external signs and the eye looks quiet. However, fine KPs may be seen on biomicroscopy due to associated cyclitis. +II. Vitreous opacities due to choroiditis are usually present in its middle or posterior part. These may be fine, coarse, stringy or snowball opacities. +Features of a patch of choroiditis are as below. +1. Active patch of choroiditis, looks as a pale-yellow or dirty white raised area with ill-defined edges. This results due to exudation and cellular infiltration of the choroid which hide the choroidal vessels. The lesion is typically deeper to the retinal vessels. The overlying retina is often cloudy and oedematous. There may be associated vasculitis. +2. Healed patch of choroiditis, when active inflammation subsides, becomes more sharply defined and delineated from the rest of the normal area due to atrophy of choroidal tissue. The involved area shows white sclera below the atrophic choroid and black pigmented clumps at the periphery of the lesion (Figs. 8.16 and 8.17). A healed patch of chorioretinitis must be differentiated from the degenerative conditions such as pathological myopia and retinitis pigmentosa. + +Clinical types of choroiditis +Depending upon the number and location of lesions choroiditis can be classified into three types: focal, +multifocal and diffuse. + +Focal choroiditis +Focal choroiditis also known as localized or circumscribed choroiditis. It is characterised by a single patch or a few small patches of inflammation localised in a particular area. Such patches of choroiditis are described by a name depending upon the location of the lesion which are as follows: +1. Central choroiditis. As the name indicates it involves the macular area and may occur either alone (Fig. 8.16) or in combination with disseminated choroiditis. A typical patch of central choroiditis may occur in toxoplasmosis, histoplasmosis, tuberculosis, syphilis and rarely due to visceral larva migrans. +2. Juxtacaecal or juxtapapillary choroiditis. It is the name given to a patch of choroiditis involving an area adjoining the optic disc. One example is Jensen’s choroiditis which typically occurs in young persons. 3.Anterior peripheral choroiditis.It implies occurrence of multiple small patches of choroiditis in the peripheral part of choroid (anterior to equator). Such lesions are often syphilitic in origin. +4. Equatorial choroiditis. It involves the choroid in the equatorial region only. + + + + + + + + + + + + + + +Fig. 8.16 A healed patch of central chorioretinitis + + + + + + + + + + + + + + +Fig. 8.17 Healed lesions of multifocal choroiditis +Chapter 8 Diseases of Uveal Tract 163 + + +Multifocal choroiditis +Multifocal choroiditis also known as disseminated choroiditis is characterised by multiple but small areas ofinflammation scattered over the greater part of choroid (Fig. 8.17). Such a condition may be due to syphilis or tuberculosis, but in many cases the cause is obscure. +Diffuse choroiditis +It refers to large spreading lesions involving most of the choroidal tissue. It is usually tubercular or syphilitic in origin. +Complications +These include extension of the inflammation to anterior uvea, complicated cataract, vitreous degeneration, macular oedema, secondary periphlebitis retinae and retinal detachment. +Treatment +Periocular and systemic corticosteroids constitute the mainstay of treatment. Posterior subtenon injections of depot corticosteroids are effective in checking the acute phase of posterior uveitis. Immunosuppressive agents may be required to check the inflammation in cases not responding to steroids. Specific treatment is required for the causative disease such as toxoplasmosis, toxocariasis, tuberculosis, syphilis, etc. + +SPECIFIC CLINICO-ETIOLOGICAL TYPES OF NON-SUPPURATIVE UVEITIS + +Detailed description of each such clinical entity is beyond the scope of this chapter. However, classification and salient features of some common clinico-etiological types of non-suppurative uveitis are described here: +Classification +A. INFECTIOUS UVEITIS +I. Uveitis in chronic systemic bacterial infections: 1. Tubercular uveitis +2. Leprotic uveitis II. Spirochetal uveitis +1. Syphilitic uveitis III. Viral uveitis +1. Herpes simplex uveitis 2. Herpes zoster uveitis +3. Acquired cytomegalovirus uveitis +4. Uveitis in acquired immune deficiency syndrome (AIDS) +IV. Parasitic uveitis 1. Toxoplasmosis 2. Toxocariasis +3. Onchocerciasis 4. Amoebiasis + + +V. Fungal uveitis +1. Presumed ocular histoplasmosis syndrome 2. Candidiasis +B. NON-INFECTIOUS UVEITIS +I. Uveitis in non-infectious systemic diseases 1. Uveitis in sarcoidosis +2. Behcet’s disease +II. Uveitis associated with arthritis +1. Uveitis with Ankylosing spondylitis 2. Reiter’s syndrome +3. Still’s disease +III. Lens-induced uveitis 1. Phacotoxic uveitis +2. Phacoanaphylactic endophthalmitis IV. Traumatic uveitis +V. Uveitis associated with malignant intraocular tumours +VI. Idiopathic specific uveitis syndromes 1. Fuchs’ uveitis syndrome +2. Intermediate uveitis (see page 161) +3. Sympathetic ophthalmitis (see page 437) 4. Glaucomatocyclitic crisis +5. Vogt-Koyanagi-Harada’s syndrome 6. Bird shot retinochoroidopathy +7. Acute multifocal placoid pigment epithelio-pathy (AMPPE) +8. Serpiginous choroidopathy + +A. INFECTIOUS UVEITIS + +I. UVEITIS IN CHRONIC SYSTEMIC BACTERIAL INFECTIONS +Tubercular Uveitis +Tuberculosis is a chronic granulomatous infection caused by bovine or human tubercle bacilli. It may cause both anterior and posterior uveitis. At one time very common, it is still not a rare cause. It accounts for 1% of uveitis in developed countries. However, in developing countries it still continues to be a common cause of uveitis. +Clinical presentations +1. Tubercular anterior uveitis. It may occur as acute nongranulomatous iridocyclitis or granulomatous anterior uveitis which in turn may be in the form of miliary tubercular iritis or conglomerate granuloma (solitary tuberculoma). +2. Tubercular posterior uveitis. It may occur as: +i. Multiple miliary tubercles in the choroid which appear as round yellow white nodules one-sixth to two and half disc diameter in size. These are usually associated with tubercular meningitis. +164 Section III Diseases of Eye + + +ii. Douse or multifocal choroiditis may occur in chronic tuberculosis. +iii.Choroidal granuloma may occur rarely as a focal lesion. +3. Vasculitis. (Eales’ disease) is another manifestation of tuberculosis (see page 268). +Diagnosis +There is no specific clinical finding in tubercular uveitis. Diagnosis is made from positive skin test, associated findings of systemic tuberculosis, intractable uveitis unresponsive to steroid therapy, a positive response to isoniazid test (a dramatic response of iritis to isoniazid 300 mg OD for 3 weeks). +Treatment +In addition to usual treatment of uveitis, chemotherapy with rifampicin and isoniazid should be given for 12 months. Systemic corticosteroids should be deferred. + +Leprotic Uveitis +Leprosy (Hansen’s disease) is caused by Mycob-acterium leprae which is an acid-fast bacillus. The disease occurs in two principal forms: lepromatous and tuberculoid. Leprosy involves predominantly anterior uvea; more commonly in lepromatous than in the tuberculoid form of disease. +Clinical types +Lepromatous uveitis may occur as acute iritis (non-granulomatous) or chronic iritis (granulomatous). 1. Acute iritis. It is caused by antigen-antibody deposition and is characterised by severe exudative reaction. +2. Chronic granulomatous iritis. It occurs due to direct organismal invasion and is characterised by presence of small glistening ‘iris pearls’ near the pupillary margin in a necklace form; small pearls enlarge and coalesce to form large pearls. Rarely, a nodular lepromata may be seen. +Treatment +Besides usual local therapy of iridocyclitis antileprotic treatment with Dapsone 50–100 mg daily or other drugs should also be instituted. + +II. SPIROCHETAL UVEITIS + +Acquired Syphilitic Uveitis +Acquired syphilis is a chronic venereal infection caused by Treponema pallidum (spirochaete). It affects both the anterior and posterior uvea. +1. Syphilitic anterior uveitis +It may occur as acute plastic iritis or granulomatous iritis. Acute plastic iritis typically occurs in the + +secondary stage of syphilis and also as a Herxheimer reaction 24–48 hours after therapeutic dose of the penicillin. +Gummatous anterior uveitis occurs late in the secondary or rarely during the tertiary stage of syphilis. It is characterised by formation of yellowish red highly vascularised multiple nodules arranged near the pupillary border or ciliary border of iris. +2. Syphilitic posterior uveitis +It may occur as disseminated, peripheral or diffuse choroiditis. +Diagnosis. Once suspected clinically, diagnosis is confirmed by FTA-ABS (fluorescent treponemal antibody absorption) blood test, which is specific and more sensitive than TPI (treponema pallidum immobilisation) test and VDRL tests. +Treatment. In addition to local therapy of the uveitis, patient should be treated by systemic penicillin or other antisyphilitic drugs. +III. PARASITIC UVEITIS + +Toxoplasmosis +It is a protozoan infestation caused by Toxoplasma gondii, derived from cats (definitive host). Humans and other animals (cattle, sheep and pigs) are intermediate hosts. The disease primarily affects central nervous system (brain and retina). Systemic lesions are more marked in immunocompromised patients (e.g., HIV+ patients) as compared to immunocompetent patients. Toxoplasmosis is the most common cause of posterior uveitis and accounts for approximately 90% of focal necrotizing retinitis. +Clinical presentation +Systemic toxoplasmosis occurs in humans in three forms: congenital, acquired and recurrent. +1. Congenital toxoplasmosis +It is much more common than the acquired form, and the infestation is acquired by the foetus through transplacental route from the mother contracting acute infestation during pregnancy. When pregnant females catch disease, about 49% infants are born with the disease which may be active or inactive at birth. +Most of the infants are born with inactive disease, characterised by bilateral healed punched out heavily pigmented chorioretinal scars in the macular area (Fig. 8.16), which is usually discovered when the child is brought for defective vision or squint check up. +2. Acquired toxoplasmosis +In the past, acquired toxoplasmosis was considered of doubtful existence and most toxoplasmosis was thought to be congenital but acquired disease is +Chapter 8 Diseases of Uveal Tract 165 + + +increasingly recognized. The infestation is acquired by eating the under-cooked meat of intermediate host containing cyst form of the parasite. Most of the patients are subclinical (asymptomatic); and the typical chorioretinal lesion similar to congenital toxoplasmosis is discovered by chance. Other lesions include punctate outer retinal toxoplasmosis (PORT). More common in HIV+ patients. +3. Recurrent toxoplasmic retinochoroiditis Pathogenesis. The parasites reaching the foetus through placenta involve its brain and retina, and also excite antibodies formation. After healing of the active retinal lesion (with which the infant is born), the parasites remain encysted there in inactive form. After about 10–40 years (average 25 years), the retinal cysts rupture and release hundreds of parasites, which by direct invasion cause a fresh lesion of focal necrotizing retinochoroidits, adjacent to the edge of old inactive pigmented scar. In addition to this lesion, an inflammation in the iris, choroid and retinal vessels is excited due to antigen-antibody reaction. Characteristic features. Recurrent toxoplasmic retinochoroiditis is a very common disease. It is characterised by a whitish-yellow, slightly raised area of infiltration located near the margin of old punched out scarred lesion in the macular region associated with severe vitritis. There may be associated non-granulomatous type of mild anterior uveitis. +Diagnosis and treatment +Diagnosis. The clinically suspected lesion is confirmed by ‘Indirect fluorescein antibody test’, haemagglutination test or ELISA test. The old methylene blue dye test is obsolete. +Treatment. The active lesion of toxoplasmosis is treated by topical and systemic steroids along with a course of a antitoxoplasmic drug either spiramycin, clindamycin, sulfadiazine or pyremethamine. + +Toxocariasis +It is an infestation caused by an intestinal roundworm of dogs (Toxocara canis) and cats (Toxocara catis). The young children who play with dogs and cats or eat dirt are infested by ova of these worms. These ova develop into larva in the human gut, and then produce the condition visceral larva migrans (VLM). Ocular toxocariasis. It is ocular infestation by these larva and is almost always unilateral. Clinically, it can present as follows: +■Toxocara chronic endophthalmitis. It usually presents with leucocoria due to marked vitreous clouding. The condition is seen in children between the age of 2–10 years and mimics retinoblastoma. + +■Posterior pole granuloma. It presents as a yellow-white, round, solitary, raised nodule, about 1–2 disc diameter in size, located either at the macula or in the centrocaecal area. The condition is usually seen in children between 5 and 15 years of age, presenting with unilateral loss of vision. +■Peripheral granuloma. It is situated anterior to the equator and may be associated with vitreous band formation. It may present from 6 to 40 years of age. Diagnosis is made on the basis of clinical feature and ELISA blood test. +Treatment. It consists of periocular (posterior sub-Tenon) injection of steroid and systemic steroids. Pars plana vitrectomy may be required in unresponsive patients with endophthalmitis and in patients with vitreous band formation. +IV. FUNGAL UVEITIS + +Presumed Ocular Histoplasmosis Syndrome (POHS) +Etiology +It is thought to be caused by the fungus Histoplasma capsulatum (though the fungus has not been isolated from the affected eyes); as the disease is more common in areas where histoplasmosis is endemic (e.g., Mississippi-Ohio-Missouri river valley) and 90% of patients with POHS show positive histoplasmin skin test. POHS has also been reported from United Kingdom, suggesting that perhaps some other etiological agents are also capable of producing the disease. +Clinical features +POHS is characterised by following features: Histospots. These are atrophic spots scattered in the mid-retinal periphery. They are roundish, yellowish-white lesions measuring 0.2 to 0.7 disc diameter in size. These begin to appear in early childhood and represent the scars of disseminated histoplasma choroiditis. +Macular lesion. It starts as atrophic macular scar (macular histospot); followed by a hole in the Bruch’s membrane, which then allows ingrowth of capillaries leading to sub-retinal choroidal neovascularisation. Leakage of fluid from the neovascular membrane causes serous detachment, which when complicated by repeated haemorrhages constitutes haemorrhagic detachment. Ultimately, there develops fibrous disciform scar, which is associated with a marked permanent visual loss. +Diagnosis +The clinical diagnosis is supported but not confirmed by positive histoplasmin test, and complement +166 Section III Diseases of Eye + + +fixation tests (negative in two-thirds cases). Fluorescein angiography helps in early diagnosis of subretinal neovascular membrane. +Treatment +Active lesions at the macula are often treated with systemic corticosteroids. Early laser photocoagulation of subretinal neovascular membrane may prevent marked permanent visual loss which occurs due to fibrous disciform scars. For subfoveal membrane PDT should be considered. Emerging threapy include anti-VEGF treatment. + +Candidiasis +It is an opportunistic infection caused by Candida albicans. It occurs in immunocompromised patients which include: patients suffering from AIDS, malignancies, those receiving long-term antibiotics, steroids or cytotoxic drugs. Patients with long-term indwelling intravenous catheter used for haemodialysis, and drug addicts are also prone to such infection. +Ocular candidiasis +It is not a common condition. It may occur as anterior uveitis, multifocal chorioretinitis, or endophthalmitis. +1. Anterior uveitis is associated with hypopyon. +2. Multifocal chorioretinitis is a more common manifestation. It is characterised by occurrence of multiple small, round, whitish areas, which may be associated with areas of haemorrhages with pale centre (Roth’s spots). +3. Candida endophthalmitis is characterised by areas of severe retinal necrosis associated with vitreoretinal abscesses. Vitreous exudates present as ‘puff ball’ or ‘cotton ball’ colonies, which when joined by exudative strands form ‘string of pearls’. +Treatment +It consists of: +• Topical cycloplegics, and antifungal drugs. +• Systemic antifungal drugs like ketoconazole, flucytosine or amphotericin-B are also needed. +• Pars plana vitrectomy is required for Candida endophthalmitis. +V. VIRAL UVEITIS + +Uveitis in Herpes Zoster Ophthalmicus Herpes zoster ophthalmicus (HZO) is the involvement of ophthalmic division of fifth nerve by varicella zoster (described on page 110). +Anterior uveitis develops in 40–50% cases with HZO within 2 weeks of onset of the skin rashes. A typical HZO keratitis may be associated with mild iritis especially in patients with a vesicular eruption on the + +tip of nose. The iridocyclitis is non-granulomatous characterised by presence of small KPs, mild aqueous flare and occasional haemorrhagic hypopyon. Complications like iris atrophy and secondary glaucoma are not uncommon. Complicated cataract may also develop in late stages. +Treatment. Topical steroids and cycloplegics to be continued for several months. Systemic acyclovir helps in early control of lesions of HZO. + +Herpes Simplex Uveitis +It is associated with keratitis in most of the cases. It may be seen in association with dendritic or geographical corneal ulceration or with disciform keratitis. Rarely, anterior uveitis may occur even without keratitis. It is a mild grade non-granulomatous iridocyclitis excited by hypersensitivity reaction. +Treatment.Keratitis is treated with antiviral drugs and cycloplegics. Steroids for iritis are contraindicated in the presence of active viral ulcers. Nonsteroidal anti-inflammatory drugs may be added in such cases. + +Cytomegalovirus Retinitis +Cytomegalovirus (CMV) retinitis usually occurs in immunocompromised patients e.g., those suffering from AIDS, on cytotoxic chemotherapy, or long term immunosuppression following renal transplantation. It is the most frequent (40% prevalance) ocular opportunistic infection in patients with AIDS. It occurs only when CD 4+ counts < 50 cells mm3. However, since the advent of Highly Active Antiretroviral Therapy (HAART) there has occured a dramatic reduction in CMV retinitis. +Clinical features +Symptoms. Often asymptomatic, some patients may present with scotoma or decreased vision and/or floaters in one or both eyes. +Anterior segment signs are usually absent. Rarely few stellate KPs may be seen. +Posterior segment signs include: +■Haemorrhagic retinitis (see Fig. 12.5) characterised by areas of necrosis (yellow white exudates) associated with areas of vasculitis (perivascular sheathing), retinal haemorrhages and loss of fundal details (pizza pie appearance) is a typical presentation in fulminant form of the disease. There occurs progressive retinal atrophy. +■Granular retinitis characterised by peripheral granular opacities with occasional haemorrhage seen in indolent form of the disease. ■Complications include retinal detachment (up to 30%), retinal atrophy and optic nerve disease. +Chapter 8 Diseases of Uveal Tract 167 + + +Treatment +• HAART is recommended to reduce retroviral load and to increase CD4+ count in patients with AIDS. +• Specific anti-CMV treatment includes: valagan-ciclovir, ganciclovir, foscarnet, and intravenous inje-ctions of cidofovir individually or in combination. + +Acute Retinal Necrosis +Etiology +Acute retinal necrosis (ARN) is a rare clinical syndrome caused by any of the following viruses: +• Varicella-zoster virus (VZV). It is the commonest cause of ARN, particularly in older patients. +• Herpes simplex virus 1and 2 (HSV 1 & 2) both cause ARN, typically in younger patients. +• Cytomegalovirus (CMV) can also cause ARN, very rarely. +Clinical features +Symptoms include decreased visual acuity, floaters, ocular discomfort, pain and photophobia. +Signs are as follows: +• Anterior segment may or may not show signs of inflammation in the anterior chamber. +• Vitritis is usually marked. +• Retinal lesions include areas of focal, well demarcated peripheral necrotising retinitis, associated with occlusive arteritis. Posterior pole is typically spared. +Complications include: retinal detachment (rhe-gmatogenous or tractional), and ischaemic optic neuropathy. +Treatment +• Systemic antiviral drugs e.g., aciclovir IV 10 mg/kg body weight TID, for two weeks then PO dose for 6–12 weeks. Alternative drug is valaciclovir. +Note. Lifelong antiviral cover is required in immunosuppressed patients. +• Systemic steroids are needed to control inflammation. +• Aspirin to prevent arterial occlusion. +• Barrier laser photocoagulation for retinal breaks. • Vitrectomy with silicon oil injection for associated +retinal detachment. + +Progressive Outer Retinal Necrosis Progressive outer retinal necrosis (PORN) is a very rare devastating necrotizing retinitis caused by a Varicella Zoster Virus (VZV) infection in immunocompromised patients (usually in patients suffering with AIDS with CD4+ T-cell counts <50/ mm2). + +Clinical features +• Painless rapid loss of vision in one or both eyes is the presenting symptom. +• Retinal lesions include rapidly coalescing white areas of outer retinal necrosis (often central as well as peripheral) but with minimal vasculitis, retinitis or viritis (cf ARN). Retinal detachment is an extremely common complication. +Treatment +Treatment consists of intravenous injection of ganciclovir or foscarnet combined with intravitreal ganciclovir. + +B. NON-INFECTIOUS UVEITIS + +I. UVEITIS ASSOCIATED WITH NON-INFECTIOUS SYSTEMIC DISEASES + +Uveitis in Sarcoidosis +Sarcoidosis is a granulomatous multi-system disease of unknown etiology, characterised by formation of non-caseating epithelioid cell granuloma in the affected tissue. The disease typically affects young adults (20–50 years), being more common in females than males, and more common in those of African heritage than Caucasians. It frequently presents with bilateral hilar lymphadenopathy, pulmonary infiltration, skin and ocular lesions. +Ocular lesions +Ocular lesions, occur in 20–50% patients with sarcoidosis and include sarcoid uveitis, conjunctival lesions and lacrimal gland involvement. +I. Sarcoid uveitis +Sarcoid uveitis accounts for 2% cases and may be anterior, intermediate, posterior or panuveitis. +1. Anterior uveitis.Typically presents as granulomatous iridocyclitis characterized by iris nodules, large mutton fat KPs (in a triangular distribution), anterior chamber cells and flare, and posterior synechiae. +2. Intermediate uveitis is characterized by vitreous cells, snowball opacities and snowbanking. +3. Posterior uveitis lesions include choroidal and retinal granulomas, cystoid macular oedema, periphlebitis retinae with sheathing, appearing as candle wax droppings. Peripheral multifocal chorioretinitis characterised by small, punched out atrophic spots, are highly suggestive of sarcoidosis. Uveoparotid fever (Heerfordt’s syndrome). It is characterised by bilateral granulomatous pan-uveitis, painful enlargement of parotid glands, cranial nerve palsies, skin rashes, fever and malaise. +168 Section III Diseases of Eye + + +Complications of sarcoid uveitis include complicated cataract, inflammatory glaucoma and cystoid macular oedema. +II. Other ocular lesions of sarcoidosis +1. Conjunctival lesions include sarcoid nodules, and keratoconjunctivitis sicca. +2. Lacrimal glands may be enlarged. When associated with diffuse swelling of salivary glands, constitute the so called Mickulicz’s syndrome. +Diagnosis and treatment +Diagnosis.Once suspected clinically, it is supported by positive Kveim test, abnormal X-ray chest (in 90% cases) and raised levels of serum angiotensin converting enzyme (ACE). Confirmation of the disease is made by histological proof from biopsy of the conjunctival nodule, skin lesions or enlarged lymph node. Treatment of sarcoid uveitis is on general lines (see page 159). In short, topical, periocular and systemic steroids constitute the treatment of sarcoid uveitis, depending upon the severity. + +Behcet’s Disease +It is an idiopathic multisystem disease characterised by recurrent, non-granulomatous uveitis, aphthous ulceration, genital ulcerations and erythema multi-forme. +Etiology. It is still unknown; the basic lesion is an obliterative vasculitis probably caused by circulating immune complexes. The disease typically affects the young men who are positive for HLA-B51. +Clinical features. Uveitis seen in Behcets disease is typically bilateral, acute recurrent iridocyclitis associated with hypopyon. It may also be associated with posterior uveitis, vitritis, periphlebitis retinae and retinitis in the form of white necrotic infiltrates. +Treatment. No satisfactory treatment is available, and thus the disease has got comparatively poor visual prognosis. +• Corticosteroids may be helpful initially but ultimate response is poor. +• Immunosuppressive drugs such as methotrexate, azathioprine and cyclosporine are needed in resistant cases and for an acute flare. +II. UVEITIS ASSOCIATED WITH ARTHRITIS +Uveitis with Ankylosing Spondylitis Ankylosing spondylitis is an idiopathic chronic inflammatory arthritis, usually involving the sacroiliac and posterior inter-vertebral joints. The disease affects young males (20–40 years) who are positive for HLA-B27. About 30 to 35% patients with ankylosing spondylitis develop uveitis. + +Clinical features. Uveitis associated with ankylosing spondylitis is characteristically an acute, recurrent, non-granulomatous type of iridocyclitis. The disease usually affects one eye at a time. +Treatment. It is on the lines of usual treatment of anterior uveitis (see page 159). Long-term aspirin or indomethacin may decrease the recurrences. +Reiter’s Syndrome +It is characterised by a triad of urethritis, arthritis and conjunctivitis with or without iridocyclitis. Etiology. It is not known exactly. The syndrome typically involves young males who are positive for HLA-B27. The disease occurs in three forms: postvenereal due to non-gonococcal arthritis, postdysenteric and articular form. +Ocular features. These include: +• Acute mucopurulent conjunctivitis which may be associated with superficial punctate keratitis. +• Acute non-granulomatous type of iridocyclitis occurs in 20–30% cases of Reiter’s syndrome. +Treatment. The iridocyclitis responds well to usual treatment (see page 159). A course of systemic tetracycline 250 mg QID for 10 days may be useful in postvenereal form suspected of being caused by Chlamydia infection. +Juvenile Idiopathic Arthritis +Juvenile idiopathic arthritis (JIA) is a chronic inflammatory arthritis involving multiple joints (knee, elbow, ankle and interphalangeal joints) in children below the age of 16 years. The disease is also referred as Juvenile rheumatoid arthritis, though the patients are sero-negative for rheumatoid factor. In 30% cases, polyarthritis is associated with hepatosplenomegaly and other systemic features, and the condition is labelled as Still’s disease. Anterior uveitis associated with JIA is a bilateral (70%), chronic non-granulomatous disease, affecting female children more than the male (4:1). It usually develops before the age of 6 years. Nearly half of the patients are positive for HLA-DW5 and 75% are positive for antinuclear antibodies (ANA). The onset of uveitis is asymptomatic and the eye is white even in the presence of severe uveitis. Therefore, slit-lamp examination is mandatory in children suffering from JIA. Complications like posterior synechiae, complicated cataract and band-shaped keratopathy are fairly common. +Treatment is on the usual lines (see page 159). +III. LENS-INDUCED UVEITIS +Phacoanaphylactic Uveitis +It is an immunologic response to lens proteins in the sensitized eyes presenting as severe granulomatous +Chapter 8 Diseases of Uveal Tract 169 + + +anterior uveitis. The disease may occur following extracapsular cataract extraction, trauma to lens or leak of proteins in hypermature cataract. +Clinical features. These include severe pain, loss of vision, marked congestion and signs of granulomatous iridocyclitis associated with presence of lens matter in the anterior chamber. +Treatment. It consists of removal of causative lens matter, topical steroids and cycloplegics. Visual prognosis is usually poor. +Phacotoxic Uveitis +It is an ill-understood entity. This term is used to describe mild iridocyclitis associated with the presence of lens matter in the anterior chamber either following trauma or extracapsular cataract extraction or leak from hypermature cataracts. The uveal response due to direct toxic effect of lens matter or a mild form of allergic reaction is yet to be ascertained. +Treatment. It consists of removal of lens matter, topical steroids and cycloplegics. +IV. TRAUMATIC UVEITIS See page 430 + +V. UVEITIS ASSOCIATED WITH INTRAOCULAR TUMOURS +See pages 175 and 306 + +VI. IDIOPATHIC SPECIFIC UVEITIS SYNDROMES + +Fuchs’ Uveitis Syndrome (FUS) +Fuchs’ ‘heterochromic iridocyclitis’ is a chronic non-granulomatous type of low grade anterior uveitis typically associated with ealy cataract formation. It typically occurs unilaterally in middle-aged persons. +Clinical features +The disease is characterised by: • Heterochromia of iris, +• Diffuse stromal iris atrophy, (moth-eaten appearance), may cause transillumination defects, +• Fine stellate KPs at the back of cornea, • Faint aqueous flare, +• Absence of posterior synechiae, +• A fairly common rubeosis iridis, sometimes associated with neovascularisation of the angle of anterior chamber, and +• Comparatively early development of complicated cataract and secondary glaucoma (usually open angle type). +Treatment +• Topical corticosteroids are all that is required. +• Cycloplegics are not required as usually there are no posterior synechiae. + +• Associated glaucoma should be treated as for POAG. + +Glaucomatocyclitic Crisis +Clinical features +Posner Schlossman syndrome is characterised by: • Recurrent unilateral attacks of acute rise of +intraocular pressure (40–50 mm of Hg) without shallowing of anterior chamber associated with, +• Fine KPs at the back of cornea, without any posterior synechiae, +• Epithelial oedema of cornea, • Dilated pupil, +• White eye (no congestion), and +• The disease typically affects young adults, 40% of whom are positive for HLA-BW54. +Treatment +• Antiglaucoma drugs, to lower intraocular pressure, and along with +• Topical steroids, a short course. + +Sympathetic Ophthalmitis +It is a rare bilateral granulomatous panuveitis which is known to occur following penetrating ocular trauma usually associated with incarceration of uveal tissue in the wound. The injured eye is called ‘exciting eye’ and the fellow eye which also develops uveitis is called `sympathising eye’. (For details see page 437). + +Vogt-Koyanagi-Harada (VKH) Syndrome +It is an idiopathic multisystem disorder which includes cutaneous, neurological and ocular lesions. The disease is comparatively more common in Japanese who are usually positive for HLA-DR4 and DW15. +Clinical features are as follows: +1. Cutaneous lesions include: alopecia, poliosis and vitiligo. +2. Neurological lesions are in the form of meningism, and encephalopathy. +3. Auditory features: tinnitus, vertigo and deafness. 4. Ocular features include: +i. Anterior uveitis is typically bilateral chronic granulomatous characterised by iris nodules, posterior synechiae. +ii. Posterior uveitis lesions include multifocal choroiditis leading to exudative retinal detachment, choroidal depigmentation (sunset glow fundus), Dalen-Fuch’s nodules and peripheral yellow-white choroidal granuloma. +Complications include: cataract, glaucoma and CNV membrane. +Treatments of uveitis is on general lines (see page 159). +170 Section III Diseases of Eye + + +■Corticosteroids administered topically, periocularly and systemically (in high doses) constitute the main stay of treatment. +■Immunosuppressive drugs such as methotrexate, azathioprine, and cyclosporine should be considered for resistant and recurrent cases. + +Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE) +Clinical features. It is a rare idiopathic self-limiting disorder characterised by: +■Bilateral, deep, placoid, cream coloured or grey white chorioretinal lesions involving the posterior pole and post-equatorial part of the fundus. +■Visual loss, seen in early stage due to macular lesions, usually recovers within 2 weeks. +■After healing, multifocal areas of depigmentation and pigment clumping involving the retinal pigment epithelium are left. +Complications, though rare, include mild anterior uveitis, vascular sheathing, and exudative retinal detachment. +Treatment. No treatment is effective. + +Serpiginous Geographical Choroidopathy +It is a rare, idiopathic, recurrent, bilaterally asymm-etrical inflammation involving the chorioca-pillaris and pigment epithelium of the retina. The disease: +• Typically affects patients between 40 and 60 years of age. +• Characteristic lesions are: Cream coloured patches with hazy borders present around the optic disc which spread in a tongue fashion. +• After few weeks the lesions heal leaving behind punched out areas of retinal pigment epithelium and choroidal atrophy. +• No treatment is effective. + +Bird-shot Retinochoroidopathy +It is a rare, idiopathic, bilaterally symmetrical chronic multifocal chorioretinitis characterised by: +• Numerous flat creamy-yellow spots due to focal chorioretinal hypopigmentation, resembling the pattern of ‘bird-shot scatter from a shotgun’. +• The disease, more common in females than males, typically affects middle-aged healthy persons who are positive for HLA-A29. +• It runs a long chronic course of several years. Treatment with corticosteroids is usually not effective. + + +PURULENT UVEITIS + +Purulent uveitis is suppurative inflammation of the uveal tract occurring as a result of direct invasion by the pyogenic organisms. It may start as purulent anterior uveitis (iridocyclitis) or purulent posterior uveitis (choroiditis) which soon progresses to involve the retina and vitreous, resulting in purulent endophthalmitis and ultimately leading to panophthalmitis. +ENDOPHTHALMITIS +Endophthalmitis is defined as an inflammation of the inner structures of the eyeball, i.e., uveal tissue and retina associated with pouring of exudates in the vitreous cavity, anterior chamber and posterior chamber. +Etiology +Etiologically endophthalmitis may be infectious or non-infectious (sterile). +A. Infective endophthalmitis Modes of infection +1. Exogenous infections. Purulent inflammations are generally caused by exogenous infections following perforating injuries, perforation of infected corneal ulcers or as postoperative infections following intraocular operations. +2. Endogenous or metastatic endophthalmitis. It may occur rarely through bloodstream from some infected focus in the body such as caries teeth, generalised septicaemia and puerperal sepsis. +3. Secondary infections from surrounding structures. It is very rare. However, cases of purulent intraocular inflammation have been reported following extension of infection from orbital cellulitis, thrombophlebitis and infected corneal ulcers. +Causative organisms +1. Bacterial endophthalmitis. The most frequent pathogens causing acute bacterial endophthalmitis are Gram-positive cocci, i.e., Staphylococcusepidermidis and Staphylococcus aureus. Other causative bacteria include Streptococci, Pseudomonas, Pneumococci and Corynebacterium. Propionibacterium acnes and Actinomyces are gram-positive organisms capable of producing slow grade endophthalmitis. +2. Fungal endophthalmitis is comparatively rare. It is caused by Aspergillus, Fusarium, Candida, etc. +B. Non-infective (sterile) endophthalmitis +Sterile endophthalmitis refers to inflammation of inner structures of eyeball caused by certain toxins/ toxic substances. It occurs in following situations. +Chapter 8 Diseases of Uveal Tract 171 + + +1. Postoperative sterile endophthalmitis may occur as toxic reaction to: +• Chemicals adherent to intraocular lens (IOL) or • Chemicals adherent to instruments. +• Severe reaction mainly confined to the anterior segment is also called ‘Toxic anterior segment syndrome’ (TASS). +2. Post-traumatic sterile endophthalmitis may occur as toxic reaction to retained intraocular foreign body, e.g., pure copper. +3. Phacoanaphylactic endophthalmitis may be induced by lens proteins in patients with Morgagnian cataract. 4. Intraocular tumour necrosis may present as sterile endophthalmitis (masquerade syndrome). +Note. Since postoperative acute bacterial endoph-thalmitis is most important, so clinical features and treatment described below pertain to this condition. +Clinical feature of acute bacterial endophthalmitis Acute postoperative endophthalmitis is a catastrophic complication of intraocular surgery with an incidence of about 0.1%. +Source of infection. In most of the cases is thought to be patient’s own periocular bacterial flora of the eyelids, conjunctiva, and lacrimal sac. Other potential sources of infection include contaminated solutions and instruments, and environmental flora including that of surgeon and operating room personnel. +Onset may be acute or delayed +■Acute onset of bacterial endophthalmitis usually occurs between 1–7 days of operation. +■Delayed onset endophthalmitis occurs a week to month after surgery. Fungi are the most common cause and Propionibacterium acne is the second most common cause of delayed endophthalmitis. +Symptoms. Acute bacterial endophthalmitis is characterized by severe ocular pain, redness, lacrimation, photophobia and loss of vision. +Signs of an established case are as follows (Fig. 8. 18): 1. Lids become red and swollen. +2. Conjunctiva shows chemosis and marked circumcorneal congestion. +3. Cornea is oedematous, cloudy and ring infiltration may be formed. +4. Edges of wound become yellow and necrotic and wound may gape (Fig. 8.19) in exogenous form. +5. Anterior chamber shows hypopyon; soon it becomes full of pus. +6. Iris, when visible, is oedematous and muddy. +7. Pupil shows yellow reflex due to purulent exudation in vitreous. When anterior chamber becomes full of pus, iris and pupil details are not seen. + +8. Vitreous exudation. In metastatic forms and in cases with deep infections, vitreous cavity is filled with exudation and pus. Soon a yellowish white mass is seen through fixed dilated pupil. This sign is called amaurotic cat’s-eye reflex. +9. Intraocular pressure is raised in early stages, but in severe cases, the ciliary processes are destroyed, and a fall in intraocular pressure may ultimately result in shrinkage of the globe. +Treatment +An early diagnosis and vigorous therapy is the hallmark of the treatment of endophthalmitis. Following therapeutic regime is recommended for suspected bacterial endophthalmitis. +A. Antibiotic therapy +1. Intravitreal antibiotics and diagnostic tap should be made as early as possible. It is performed transconjunctivally under topical anaesthesia from the area of pars plana (4-5 mm from the limbus). The vitreous tap is made using 23-gauge needle followed by the intravitreal injection using a disposable tuberculin syringe and 30-gauge needle. +The mainstay of treatment of acute bacterial endophthalmitis is intravitreal injection of antibiotics at the earliest possible. Usually a combination of two antibiotics—one effective against gram-positive coagulase negative Staphylococci and the other against Gram-negative Bacilli is used as below: +• First choice: Vancomycin 1 mg in 0.1 ml plus ceftazidime 2.25 mg in 0.1 ml. +• Second choice: Vancomycin 1 mg in 0.1 ml plus amikacin 0.4 mg in 0.1 ml. + +Note. +■Some surgeons prefer to add dexamethasone 0.4 mg in 0.1 ml to limit postinflammatory consequences. ■Gentamycin is 4 times more retinotoxic (causes macular infarction) than amikacin. Preferably the aminoglycosides should be avoided. + + + + + + + + + + + + + +Fig. 8.18 Postoperative acute endophthalmitis +172 Section III Diseases of Eye + + + + + + + + + + + + + + + +Fig. 8.19 Severe postoperative endophthalmitis with wound gape +■The aspirated fluid sample from vitreous cavity should be used for bacterial culture and smear examination. If vitreous aspirate is collected in an emergency when immediate facilities for culture are not available, it should be stored promptly in refrigerator at 4°C. +■If there is no improvement, a repeat intravitreal injection should be given after 48 hours taking into consideration the reports of bacteriological examination. +2. Topical concentrated antibiotics should be started immediately and used frequently (every 30 minute to 1 hourly). To begin with, a combination of two drugs should be preferred, one having a predominant effect on the gram-positive organisms and the other against gram-negative organisms as below: +• Vancomycin (50 mg/ml) or cefazoline (50 mg/ ml) plus. +• Amikacin (20 mg/ml) or tobramycin (15 mg%). 3. Systemic antibiotics have limited role in the management of endophthalmitis, but most of the surgeons do use them. +• Ciprofloxacin intravenous infusion 200 mg BD for 3–4 days followed by orally 500 mg BD for 6-7 days, or +• Vancomycin 1 gm IV BD and ceftazidime 2 g IV 8 hourly, or +• Cefazoline 1.5 gm IV 6 hourly and amikacin 1 gm IV three times a day. +B. Steroid therapy +Steroids limit the tissue damage caused by inflammatory process. Most surgeons recommend their use after 24 to 48 hours of control of infection by intensive antibiotic therapy. However, some surgeons recommend their immediate use (controversial). Routes of administration and doses are: +• Intravitreal injection of dexamethasone 0.4 mg in 0.1 ml along with antibiotics. + +• Topical dexamethasone (0.1%) or predacetate (1%) used frequently. +• Systemic steroids. Oral corticosteroids should preferably be started after 24 hours of intensive antibiotic therapy. A daily therapy regime with 60 mg prednisolone to be followed by 50, 40, 30, 20 and 10 mg for 2 days, each may be adopted. +• Lansoprazole 30 mg OD should be given before steroids for gastric protection. +C. Supportive therapy +1. Cycloplegics. Preferably 1% atropine or alternatively 2% homatropine eyedrops should be instilled TDS or QID. +2. Antiglaucoma drugs. In patients with raised intraocular pressure drugs such a oral acetazolamide (250 mg TDS) and timolol (0.5% BD) may be prescribed. +D. Vitrectomy +Vitrectomy operation should be performed if the patient does not improve with the above intensive therapy for 48 to 72 hours or when the patient presents with severe infection with visual acuity reduced to hand movement close to face. Vitrectomy helps in removal of infecting organisms, toxins and enzymes present in the infected vitreous mass. +PANOPHTHALMITIS +It is an intense purulent inflammation of the whole eyeball including the Tenon’s capsule. The disease usually begins either as purulent anterior or purulent posterior uveitis; and soon a full-fledged picture of panophthalmitis develops, following through a very short stage of endophthalmitis. +Etiology +• Panophthalmitis is an acute bacterial infection. +• Mode of infection and causative organisms are same as described for infective bacterial endophthalmitis (see page 170). +Clinical features Symptoms include: +• Severe ocular pain and headache, • Complete loss of vision, +• Profuse watering, +• Purulent discharge, +• Marked redness and swelling of the eyes, and +• Associated constitutional symptoms are malaise and fever. +Signs are as follows (Fig. 8.20): +1. Lids show a marked oedema and hyperaemia. +2. Eyeball is slightly proptosed, ocular movements are limited and painful. +Chapter 8 Diseases of Uveal Tract 173 + + +3. Conjunctiva shows marked chemosis and ciliary as well as conjunctival congestion. +4. Cornea is cloudy and oedematous. 5. Anterior chamber is full of pus. +6. Vision is completely lost and perception of light is absent. +7. Intraocular pressure is markedly raised. +8. Globe perforation may occur at limbus, pus comes out and intraocular pressure falls. +Complications include: • Orbital cellulitis, +• Cavernous sinus thrombosis, and • Meningitis or encephalitis. +Treatment +There is little hope of saving such an eye and the pain and toxaemia lend an urgency to its removal. +1. Anti-inflammatory and analgesics should be started immediately to relieve pain. +2. Broad spectrum antibiotics should be administered to prevent further spread of infection in the surrounding structures. +3. Evisceration operation should be performed to avoid the risk of intracranial dissemination of infection. + +Evisceration +It is the removal of the contents of the eyeball leaving behind the sclera. Frill evisceration is preferred over simple evisceration. In it, only about 3 mm frill of the sclera is left around the optic nerve. +Indications. These include: panophthalmitis, expulsive choroidal haemorrhage and bleeding anterior staphyloma. +Surgical steps of frill evisceration (Fig. 8.21). +Initial steps upto separation of the conjunctiva and Tenon’s capsule are similar to enucleation (see page 308). + + + + + + + + + + + + + + +Fig. 8.20 Panophthalmitis + +Removal of cornea. A cut at the limbus is made with a razor blade fragment or with a No. 11 scalpel blade and then the cornea is excised with corneoscleral scissors. +Removal of intraocular contents. The uveal tissue is separated from the sclera with the help of an evisceration spatula and the contents are scooped out using the evisceration curette. +Separation of extraocular muscles is done as for enucleation. +Removal of sclera. Using curved scissors the sclera is excised leaving behind only a 3 mm frill around the optic nerve. +Closure of Tenon’s capsule and conjunctiva and other final steps are similar to enucleation (see page 308). + +DEGENERATIVE CONDITIONS OF UVEAL TRACT + +DEGENERATIONS OF THE IRIS +1. Simple iris atrophy. It is characterised by depigmentation with thinning of iris stroma. Small patches of depigmentation are usually seen near the pupillary margin. Differential diagnosis of patch of simple iris atrophy may be senile atophy, post-inflammatory, glaucomatous or neurogenic due to lesions of the ciliary ganglion. +2.Essential iris atrophy.It is a rare idiopathic condition characterised by unilateral progressive atrophy of the iris. The condition typically affects young females 5 times more than the males. Initially there occurs displacement of pupil away from the atrophic zone. Slowly the iris tissue melts away at many places resulting in pseudopolycoria. In advanced cases, intractable glaucoma supervenes due to formation of dense anterior peripheral synechiae. +3. Iridoschisis. It is a rare bilateral atrophy occurring as a senile degeneration in patients over 65 years of + + + + + + + + + + + + + + +Fig. 8.21 Removal of intraocular contents in evisceration +174 Section III Diseases of Eye + + +age. It may also occur as a later effect of iris trauma. It is characterised by formation of a cleft between the anterior and posterior stroma of the iris. As a consequence the strands of anterior stroma float into the anterior chamber. +DEGENERATIONS AND DYSTROPHIES OF THE CHOROID +I. Primary choroidal degenerations +1. Senile central choroidal atrophy. It is characterised by formation of multiple drusens (colloid bodies) which look as yellowish spots. These are scattered throughout the fundus, but more marked in the macular area. +2. Central areolar choroidal atrophy. It comprises bilateral punched out, circular atrophic lesion in the macular region. The lesion is characterised by white shining sclera, traversed by large ribbon-shaped choroidal vessels. Thus, there occurs atrophy of the choriocapillaris, retinal pigment epithelium and photoreceptors. +3. Essential gyrate atrophy. It is an inborn error of amino acid (ornithine) metabolism characterised by progressive patches of atrophy of choroid and retinal pigment epithelium (RPE). The disease begins in first decade of life with symptoms of night blindness and progresses slowly to involve the whole fundus by the age of 40–50 years with preservation of only macula. +4. Choroidremia. It is a hereditary choroidal dystrophy involving the males. The disease begins in first decade of life with symptoms of night blindness and fine whitish patches of choroidal and RPE atrophy. The lesions progress slowly and by the age of 40 years almost whole of the choroidal tissue and RPE disappear rendering the patient blind. At this age fundus picture is characterised by whitish sclera with overlying almost normal retinal vessels. +5. Myopic chorioretinal degeneration. (see page 41) + +II. Secondary choroidal degeneration +Secondary choroidal degeneration occurs following inflammatory lesions of the fundus. It is characterised by scattered area of chorioretinal atrophy and pigment clumping. Ophthalmoscopic picture resembles retinitis pigmentosa and hence also labelled sometimes as ‘pseudoretinitis pigmentosa’. + +TUMOURS OF UVEAL TRACT + +CLASSIFICATION I. Tumours of choroid +a. Benign 1. Naevus + +2. Haemangioma 3. Melanocytoma +4. Choroidal osteoma b. Malignant 1. Melanoma +II. Tumours of ciliary body +a. Benign 1. Hyperplasia 2. Benign cyst +3. Meduloepithelioma b. Malignant 1. Melanoma +III. Tumours of iris +a. Benign 1. Naevus +2. Benign cyst +3. Naevoxanthoendothelioma b. Malignant 1. Melanoma +TUMOURS OF CHOROID + +Naevus +It is a commonly occurring asymptomatic lesion, usually diagnosed on routine fundus examination. It typically presents as a flat, dark grey lesion with feathered margins, usually associated with overlying colloid bodies. +Once diagnosed, it should be followed regularly, since it may undergo malignant change which is evidenced by: (i) Increasing pigmentation or height of the naevus. (ii) Appearance of orange patches of lipofuscin over the surface and (iii) Appearance of serous detachment in the area of a naevus. +Choroidal Haemangioma It occurs in two forms: +1. Localised choroidal haemangioma. It present as a raised, domeshaped, salmon pink swelling usually situated at the posterior pole of the eye. Overlying retina may show serous detachment, cystoid degeneration and pigment epithelial mottling. Fluorescein angiography is usually diagnostic. +2. Diffuse choroidal haemangioma. It is seen in association with Sturge-Weber syndrome and causes diffuse deep red discoloration of the fundus. + +Melanocytoma +It is a rare tumour which presents as a jet black lesion around the optic disc. +Choroidal Osteoma +It is a very rare benign tumour which presents as elevated, yellowish-orange lesion in the posterior pole. It typically affects the young women. +Malignant Melanoma of Choroid +It is the most common primary intraocular tumour of adults, usually seen between 40–70 years of age. It is rare in blacks and comparatively more common +Chapter 8 Diseases of Uveal Tract 175 + + +in whites. It arises from the neural crest derived pigment cells of the uvea as a solitary tumour and is usually unilateral. +Pathology +Gross pathology. The tumour may arise from a pre-existing naevus or denovo from the mature melanocytes present in the stroma. It may occur in two forms: +1. Circumscribed (pedunculated) tumour: Initially it appears as flat, slate-grey area, which becomes raised and pigmented with growth and eventually ruptures through the Bruch’s membrane (Collar-Stud tumour). Further, growth of the tumour produces exudative retinal detachment. +2. Diffuse (flat) malignant melanoma: It spreads slowly throughout the uvea, without forming a tumour mass. It accounts for only 5% cases. In it symptoms occur late. +Histopathology. Microscopically uveal melanomas are of following four types (Modified Callender’s classification): +1. Spindle cell melanomas. These are composed of spindle-shaped cells and make up 45% of all tumours. Such tumours have best prognosis (80% 10 year survival). +2. Epithelioid cell melanomas.These consist of large, oval or round, pleomorphic cells with larger nuclei and abundant acidophilic cytoplasm. This type of tumours have the worst prognosis (35% 10 year survival). These make up 5% of all tumours. +3. Mixed cell melanomas. These are composed of both spindle and epithelioid cells and thus carry an intermediate prognosis (45% 10 year survival). These make up 45% of all tumours. +4. Necrotic melanomas. These make up the remaining 5% of the all tumours. In these tumours, the predominant cell type is unrecognizable. +Clinical features +For the purpose of description only the clinical features can be divided into four stages. +1. Quiescent stage. During this stage symptoms depend upon the location and size of tumour. Small tumour located in the periphery may not produce any symptom, while tumours arising from the posterior pole present with early visual loss. A large tumour associated with exudative retinal detachment may produce marked loss of vision. +Signs. Fundus examination during this stage may reveal following signs: + +i. A small tumour limited to the choroid appears as an elevated pigmented oval mass (Fig. 8.22). Rarely the tumour may be amelanotic. The earliest pathognomic sign at this stage is appearance of orange patches in the pigment epithelium due to accumulation of the lipofuscin. +ii. A large tumour which penetrates through the Bruch’s membrane and grows in the subretinal space is characterised by a large exudative retinal detachment (Fig. 8.23). At the central summit, the retina is in contact with the tumour. Ribbon-like wide vessels are seen coursing over the tumour surface in the area. Other associated features which can be seen occasionally include subretinal or intraretinal haemorrhage, choroidal folds and vitreous haemorrhage. As the tumour grows, the exudative retinal detachment deepens and gradually the tumour fills the whole eye. +2. Glaucomatous stage. It develops when tumour is left untreated during the quiescent stage. Glaucoma may develop due to obstruction to the venous outflow by pressure on the vortex veins, blockage of the angle of anterior chamber by forward displacement of the lens iris diaphragm due to increasing growth of the tumour. +Symptoms. The patient complains of severe pain, redness and watering in an already blind eye. Signs. (i) Conjunctiva is chemosed and congested. (ii) Cornea may show oedema. (iii) Anterior chamber is usually shallow. (iv) Pupil is fixed and dilated. (v) Lens is usually opaque, obstructing the back view. (vi) Intraocular pressure is raised, usually eye is stony hard. (vii) Sometimes features of iridocyclitis may be seen due to tumour-induced uveitis. +3. Stage of extraocular extension. Due to progressive growth the tumour may burst through sclera, usually + + + + + + + + + + + + + + +Fig. 8.22 Fundus photograph showing choroidal melanoma as raised pigmented subretinal mass +176 Section III Diseases of Eye + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 8.23 Malignant melanoma of the choroid causing exudative retinal detachment : A, diagrammatic depiction in cut section; B, fundus photograph + +at the limbus. The extraocular spread may occur even early along the perivascular spaces of the vortex veins or ciliary vessels. It is followed by rapid fungation and involvement of extraocular tissues resulting in marked proptosis (Fig. 8.24). +4. Stage of distant metastasis. Lymphatic spread is usually not known. Blood-borne metastasis usually occurs in liver and is the commonest cause of death. +Differential diagnosis +1. During quiescent stage differential diagnosis may be considered as below: +i. A small tumour without an overlying exudative retinal detachment should be differentiated from a naevus, melanocytoma and hyperplasia of the pigment epithelium. +ii. A tumour with overlying exudative retinal detachment should be differentiated from simple retinal detachment and other causes of exudative detachment especially choroidal haemangioma and secondary deposits. + +Fig. 8.24 Extensive malignant melanoma of the choroid involving orbit + +2. During glaucomatous stage differentiation is to be made from other causes of acute glaucoma. +Investigations +1. Indirect ophthalmoscopic examination. It allows three-dimensional stereoscopic view of the lesion. It also depicts the presence of shifting fluid, which is pathognomic of exudative retinal detachment. +2. Transillumination test. It indicates a tumour mass and thus helps to differentiate from choroidal detachment and simple retinal detachment. +3. Ultrasonography. Both A and B scan (Fig. 8.25) help to outline the tumour mass in the presence of hazy media. +4. Fluorescein angiography is of limited diagnostic value because there is no pathognomic pattern. +5. Radioactive tracer. It is based on the fact that the neoplastic tissue has an increased rate of phosphate (32p) uptake. +6. MRI. Choroidal melanomas are hyperintense in T1-weighted and hypointense in T2-weighted images. +Treatment +I. Observation. When the diagnosis is doubtful, observation is indicated especially for small asymptomatic lesions with absence of suspicious features (i.e., associated subretinal fluid/detachment, lipofuscin on the surface, thickness >2 mm). +II. Conservative treatment to salvage the eyeball should be instituted when there is no doubt of diagnosis and the tumour is not very large. Methods used for conservative treatment and their indications are: +1. Brachytherapy using cobalt-60 or iodine-125 plaques surgically placed externally on the sclera is usually the treatment of choice in tumours less than 10 mm in elevation and less than 16 mm in basal +Chapter 8 Diseases of Uveal Tract 177 + + + + + + + + + + + + + + + + + + +Fig. 8.25 B-scan of a patient with choroidal melanoma showing dome-shaped tumour + +diameter. Supplemental transpupillary thermotherapy may be required to enhance the results. +2. External beam radiotherapy (EBR) with protons or helium ions is indicated in tumours unsuitable for brachytherapy either because of size or posterior location to within 4 mm of disc or fovea. +3. Transpupillary thermotherapy (TTT)with diode laser is indicated in selected small tumours, particularly if pigmented and located near the fovea or optic disc. It can also be supplemented over brachytherapy to enhance results. +4. Trans-scleral local resection is indicated in tumours that are too thick for radiotherapy and usually less than 16 mm in diameter. It is a very difficult procedure which is performed under systemic arterial hypotension. +5. Stereotactic radiosurgery is a new method indicated in large tumours. It involves single-session delivery of ionizing radiation to a stereotactically localized volume of tissue with the help of Gamma knife. +III.Enucleation. It is indicated for very larger tumours >16 mm basal diameter or >10 mm apical height in which conservative methods to salvage the eyeball are not effective. +IV. Exenteration or debulking with chemotherapy and radiotherapy is required at the stage of extraocular spread. +V. Palliative treatment with chemotherapy and immunotherapy may be of some use in prolonging life of the patients with distant metastasis. + +Prognostic indicators in uveal melanomas +• Age of the patient. Prognosis worsens with increasing age. +• Size of tumour. Larger the tumour, worse is the prognosis. +• Location of tumour. Ciliary melanomas carry worse prognosis as compared to choroidal melanomas. +• Evidence of invasion. Extrascleral or vortex vein involvement carry poor prognosis. +• Cell type. Spindle A carries the best prognosis followed by spindle B, mixed and epitheloid melanoma (worst). +• Cytology. Prognosis worsens with nucleolar size variation, vascular loops and mitotic activity. +• Chromosomal abnormalities, like monosomal 3 and partial duplication of chromosome 8 are associated with increased risk of metastasis and death. + +TUMOURS OF CILIARY BODY + +Hyperplasia and Benign Cyst +These are insignificant lesions of the ciliary body. + +Medulloepithelioma (Diktyoma) +It is a rare congenital tumour arising from the nonpigmented epithelium of the ciliary body. It presents in the first decade of life. + +Malignant Melanoma +In the ciliary body it is usually diagnosed very late, due to its hidden location. It may extend anteriorly, posteriorly or grow circumferentially. +Clinical features +1. Earliest features of a localised melonoma include slight hypotony, unaccountable defective vision and localised ‘sentinel’ dilated episcleral veins in the quadrant containing tumour. +2. An anterior spreading tumour may present as follows: +i. It may cause pressure on the lens resulting in anterior displacement, subluxation and cataract formation. +ii. It may involve iris and is visible immediately. Soon, it may involve the angle of anterior chamber resulting in secondary glaucoma. +iii.It may extend out through sclera along the vessels, presenting as an epibulbar mass. +178 Section III Diseases of Eye + + +3. Posterior spreading tumour may involve choroid and present as exudative retinal detachment. +4. The tumour may extend circumferentiallyinvolving whole of the ciliary body. +Pathological features +These are similar to that of choroidal melanoma. +Treatment +1. Enucleation. It is required for large ciliary body tumours extending anteriorly, posteriorly or circumferentially. +2. Local resection. Cyclectomy or iridocyclectomy may be enough, if fortunately tumour is detected in early stage. +TUMOURS OF IRIS + +Naevus +It is the most common lesion of the iris. It presents as a flat, pigmented, circumscribed lesion of variable size. Rarely malignant change may occur in it, so it +should be observed. + +Naevoxanthoendothelioma +It is a rare fleshy vascular lesion seen in babies. It may cause recurrent hyphaema. It is treated with X-rays or steroids. + +Malignant Melanoma +It presents as a single or multiple rapidly growing vascular nodules. It spreads in the angle producing secondary glaucoma. It may penetrate through limbus and present as epibulbar mass. Pathological features are similar to that of melanoma of the choroid. +Treatment +1. Wide iridectony. It is performed for a tumour limited to the iris. +2. Iridocyclectomy. It is required for a tumour involving iris and ciliary body. +3. Enucleation. It should be performed when iris melanoma is associated with secondary glaucoma. +9 + +Diseases of Lens + + + +CHAPTER OUTLINE + +ANATOMY AND PHYSIOLOGY Applied anatomy +Applied physiology and biochemistry CATARACT +• +• +• +• +• +Congenital and developmental cataracts Acquired cataract +Management of cataract in adults SURGICALTECHNIQUES FOR CATARACT EXTRACTION +• +• +• +• +• +Intracapsular cataract extraction +Conventional extracapsular cataract extraction Manual small incision cataract surgery Phacoemulsification +Surgical techniques of extracapsular cataract extraction for childhood cataract + + + +ANATOMY AND PHYSIOLOGY +APPLIED ANATOMY +• Shape, transparency and location. The lens is a transparent, biconvex, crystalline structure placed between iris and the vitreous in a saucer shaped depression, the patellar fossa. +• Diameter is 9–10 mm. +• Thickness varies with age from 3.5 mm (at birth) to 5 mm (at extreme of age). +• Weight varies from 135 mg (0–9 years) to 255 mg (40–80 years of age). +• Surfaces. Anterior surface is less convex (radius of curvature 10 mm) than the posterior (radius of curvature 6 mm). These two surfaces meet at the equator. +• Refractive index is 1.39. +• Totaldioptricpower is about 18 D (range 16–20D). • Accommodative power of lens varies with age, being 14–16 D (at birth); 7–8 D (at 25 years of age) +and 1–2 D (at 50 years of age). + +Structure +Lens consists of (Fig. 9.1) +1. Lens capsule. It is a thin, transparent, hyaline membrane surrounding the lens which is thicker + +• Intraocular lens implantation +Postoperative management after cataract operation Complications of cataract surgery and their management +• +• +DISPLACEMENTS OF LENS Clinico-etiological types +Topographical types Subluxation Dislocation +• +• +CONGENITAL ANOMALIES OF LENS Coloboma of lens +• +• +• +Lenticonus Microspherophakia + + + +over the anterior than the posterior surface. The lens capsule is thickest at pre-equator regions (14 m) and thinnest at the posterior pole (3 m). +2. Anterior epithelium. It is a single layer of cuboidal cells which lies deep to the anterior capsule. In the equatorial region these cells become columnar, + \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_7.txt b/notes/A K Khurana - Comprehensive Ophthalmology_7.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1733d3abd106b6702a30ff622ce76525977346c --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_7.txt @@ -0,0 +1,1599 @@ + + + + + + + + + + + + + + + + + +Fig. 9.1 Structure of the crystalline lens +180 Section II Diseases of Eye + + +are actively dividing and elongating to form new lens fibres throughout the life. There is no posterior epithelium, as these cells are used up in filling the central cavity of lens vesicle during development of the lens. +3. Lens fibres. The epithelial cells elongate to form lens fibres which have a complicated structural form. Mature lens fibres are cells which have lost their nuclei. As the lens fibres are formed throughout the life, these are arranged compactly as nucleus and cortex of the lens (Fig. 9.2). +i. Nucleus.It is the central part containing the oldest fibres. It consists of different zones, which are laid down successively as the development proceeds. In the beam of slit-lamp these are seen as zones of discontinuity. Depending upon the period of development, the different zones of the lens nucleus include: +• Embryonic nucleus. It is the innermost part of nucleus which corresponds to the lens upto first 3 months of gestation. It consists of primary lens fibres which are formed by elongation of the cells of posterior wall of lens vesicle, +• Fetal nucleus. It lies around the embryonic nucleus and corresponds to the lens from 3 months of gestation till birth. Its fibres meet around sutures which are anteriorly Y-shaped and posteriorly inverted Y-shaped (Fig. 9.2), +• Infantilenucleuscorresponds to the lens from birth to puberty, and +• Adult nucleus corresponds to the lens fibres formed after puberty to rest of the life. +ii. Cortex. It is the peripheral part which comprises the youngest lens fibres. + + + + + + + + + + + + + + + + +Fig. 9.2 Y-shaped sutures of the fetal nuclear fibres + + +Suspensory ligaments of lens +Suspensory ligaments of lens (Zonules of Zinn), also called as ciliary zonules, consist essentially of a series of fibres passing from ciliary body to the lens. These hold the lens in position and enable the ciliary muscle to act on it. +Arrangement of zonular fibres +According to new concept the zonular fibres run a more or less complex but continuous course from ora serrata to the edge of lens. However, for the purpose of description only, the zonular complex can be divided into following parts (Fig. 9.3): +1. Pars orbicularis refers to the feltwork of zonular fibres which line pars plana part of ciliary body. +2. Zonular plexuses refers to the intervening network of zonular fibres which are attached between ciliary processes in the region of pars plicata part of ciliary body. +3. Zonular fork refers to the consolidated bundle of zonular fibres which bend at right angle from the anterior margin of pars plicata towards the lens after dividing into three zonular limbs: +• Anterior zonular limb fibres are denser and insert on the anterior lens capsule about 1.5 mm from the equator. +• Equatorial zonular limb fibres are sparse and fan out in a brush-like manner to get inserted into the lens capsule of equatorial region. +• Posterior zonular limb fibres are inserted on the posterior lens capsule about 1.25 mm from the equator. +APPLIED PHYSIOLOGY AND BIOCHEMISTRY The crystalline lens is a transparent structure playing main role in the focussing mechanism for vision. Its physiological aspects include: + + + + + + + + + + + + + + + + +Fig. 9.3 Arrangement of main zonular fibres (New cocept) +Chapter 9 Diseases of Lens 181 + + +• Lens transparency, +• Metabolic activities of the lens, and • Accommodation (see page 45). +Lens transparency +Factors that play significant role in maintaining outstanding clarity and transparency of the crystalline lens are: +• Avascularity of the lens. +• Characteristic of lens fibre: +– Tightly-packed nature of lens cells, – Narrow lens fibre membranes, +– Loss of organelles +• Roleoflensproteins. Major intrinsic proteins of the lens belong to superfamily of aquaporines and is classified as aquaporine MIP26 or aquaporin 0. +• Lens capsule. Semipermeable character. +• Pump mechanism of lens fibre membranes that regulate the electrolyte and water balance in the lens, maintaining relative dehydration and +• Auto-oxidationandhighconcentrationofreduced glutathione in the lens maintains the lens proteins in a reduced state and ensures the integrity of the cell membrane pump. +Metabolism +Lens requires a continuous supply of energy (ATP) for active transport of ions and aminoacids, maintenance of lens dehydration, and for a continuous protein and GSH synthesis. Most of the energy produced is utilized in the epithelium which is the major site of all active transport processes. Only about 10–20% of the ATP generated is used for protein synthesis. +Source of nutrient supply. The crystalline lens, being an avascular structure is dependent for its metabolism on chemical exchanges with the aqueous humour. The chemical composition of the lens vis-a-vis aqueous humour and the chemical exchange between the two is depicted in Fig. 9.4. Some nutrition is also derived from the vitreous humour, but it is much less than that derived from the aqueous humour. +Pathways of glucose metabolism. Glucose is very essential for the normal working of the lens. Metabolic activity of the lens is largely limited to epithelium and cortex, while the nucleus is relatively inert. Pathways of glucose metabolism in the lens are as follows: +• Glycolytic pathway. In the lens, 80% glucose is metabolised anaerobically by this pathway. +• Pentose, Hexose, Monophosphate (HMP) shunt is responsible for metabolism of 15% of glucose. +• Kreb’s citric acid cycle metabolises only a small proportion by the oxidative process. + + + + + + + + + + + + + + + + + +Fig. 9.4 Chemical composition of the lens vis-a-vis aqueous humour and the chemical exchange (pump-leak mechanism) between them. Values are in mmol/kg of lens water unless otherwise stated + +• Sorbitol pathway is relatively inconsequential in the normal lens; however, it is extremely important in the production of cataract in diabetic and galactosemic patients. +Antioxidant mechanisms of lens +The crystalline lens has protective mechanisms against oxidative damage caused by various oxidants (oxygen intermediates) generated in vivo such as +superoxide anion (O2–), hydrogen peroxide (H2O2), +lipid peroxide and lipid hydroperoxides. Of these, superoxide radicals may be most toxic to the lens proteins. +Preventive antioxidant mechanisms of lens are: +• Enzymatic defence mechanism, which includes reduced glutathione (most important), glutathione peroxide, superoxide dismutase and catalase. +• Non-enzymatic defence mechanism includes vitamin C, vitamin E and possibly carotenoids. Pathogenesis of age-related cataract involves oxidation of lens proteins and lipids due to deficient preventive +anti-oxidant mechanisms. Respiratory quotient of lens is 1. + +CATARACT +DEFINITION +The word ‘cataract’ dates from the Middle Ages and has been derived from the Greek word ‘katarraktes’ which means ‘waterfall’. This term was coined assuming that an ‘abnormal humour’ developed and flowed in front of the lens to decrease the vision. The present definition of cataract came much later after the understanding of the lens anatomy +182 Section II Diseases of Eye + + +and of the fact that normal lens is a transparent structure. +As of today, the term cataract refers to development of any opacity in the lens or its capsule. Cataract, thus may occur, either due to formation of opaque lens fibres (congenital and developmental cataracts) or due to degenerative process leading to opacification of the normally formed transparent lens fibres (acquired cataract). +Clinically, the term cataract refers to an opaci-fication of sufficient severity to impair the vision (Dorland’s Illustrated Medical Dictionary, W.B. Saunders, Philadelphia). +CLASSIFICATION +A. Etiological classification +I. Congenital and developmental cataract II. Acquired cataract +1. Senile cataract +2. Traumatic cataract (see page 429) 3. Complicated cataract +4. Metabolic cataract 5. Electric cataract +6. Radiational cataract 7. Toxic cataract e.g., +i. Corticosteroid-induced cataract ii. Miotics-induced cataract +iii. Copper (in chalcosis) and iron (in siderosis) induced cataract +8. Cataract associated with skin diseases (Dermatogenic cataract) +9. Cataract associated with osseous diseases 10. Cataract with miscellaneous syndromes e.g., +i. Dystrophica myotonica ii. Down’s syndrome iii.Lowe’s syndrome +iv. Treacher-Collin’s syndrome. +B. Morphological classification (Fig. 9.5) +1. Capsularcataract. It involves the capsule and may be: +i. Anterior capsular cataract ii. Posterior capsular cataract +2. Subcapsular cataract. It involves the superficial most part of the cortex (just below the capsule) and includes: +i. Anterior subcapsular cataract ii. Posterior subcapsular cataract +3. Corticalcataract. It involves the major part of the cortex. +4. Supranuclearcataract. It involves only the deeper parts of cortex (just outside the nucleus). +5. Nuclear cataract. It involves the nucleus of the crystalline lens. + + + + + + + + + + + + + + + + + + + + +Fig. 9.5 Morphological shapes of cataract + +6. Polar cataract. It involves the capsule and superficial part of the cortex in the polar region only and may be: +i. Anterior polar cataract ii. Posterior polar cataract + +CONGENITAL AND DEVELOPMENTAL CATARACTS + +Congenital and developmental cataracts occur due to some disturbance in the normal growth of the lens. When the disturbance occurs before birth, the child is born with a congenital cataract. Therefore, in congenital cataract the opacity is limited to either embryonic or foetal nucleus. Developmental cataract may occur from infancy to adolescence. Therefore, such opacities may involve infantile or adult nucleus, deeper parts of cortex or capsule. Developmental cataract typically affects the particular zone which is being formed when this process is disturbed. The fibres laid down previously and subsequently are often normally formed and remain clear. Congenital and developmental opacities assume most variegated appearance and minute opacities (without visual disturbance) are very common in normal population. These are detected with the beam of slit-lamp under full mydriasis. +ETIOLOGY +About one-third cases are idiopathic, one-third are hereditary, and the rest one-third due to other causes. +Chapter 9 Diseases of Lens 183 + + +I. Idiopathic +About 33% cases are sporadic and of unknown etiology. +II. Heredity +About one-third of all congenital cataracts are hereditary. +■Inherited cases without systemic disorders. In these cases, the mode of inheritance is usually autosomal dominant. +■Inherited cases with systemic disorders include: • Chromosomal disorders (e.g. trisomy 21), +• Skeletal disorders (e.g. Stickler syndrome), +• Central nervous system disorders (e.g. cerebro-oculo-facial syndrome), +• Renal system disorders (e.g. Lowe’s syndrome) +Common familial cataracts include: • Cataracta pulverulenta, +• Zonular cataract (also occurs as nonfamilial), +• Coronary cataract and total soft cataract (may also occur due to rubella). +III. Maternal factors +1. Malnutrition during pregnancy has been associated with nonfamilial zonular cataract. +2. Infections. Maternal infections like rubella are associated with cataract in 50% of cases. Other maternal infections associated with congenital cataract include toxoplasmosis and cytomegalic inclusion disease. +3. Drugs ingestion. Congenital cataracts have also been reported in the children of mothers who have taken certain drugs during pregnancy (e.g., thalidomide, corticosteroids). +4. Radiation.Maternal exposure to radiation during pregnancy may cause congenital cataracts. +IV. Foetal or infantile factors +1. Deficientoxygenation(anoxia) owing to placental haemorrhage. +2. Birth trauma, may cause cataract. +3. Metabolic disorders of the foetus or infant such as galactosemia, galactokinase deficiency and neonatal hypoglycemia. +4. Cataractsassociatedwithothercongenitalanoma-lies e.g., as seen in Lowe’s syndrome, myotonia dystrophica and congenital icthyosis. +5. Ocular diseases associated with developmental cataract include persistent hyperplastic primary vitreous (PHPV), aniridia anterior chamber cleavage syndrome retinopathy of prematurity, lenticonus posterior and microopthalmos. +6. Malnutrition in early infancy may also cause developmental cataract. + + +CLINICAL TYPES +Congenital and developmental cataracts have been variously classified. A simple morphological classification of congenital and developmental cataract is as under: +I. Congenital capsular cataracts 1. Anterior capsular cataract 2. Posterior capsular cataract +II. Polar cataracts +1. Anterior polar cataract 2. Posterior polar cataract +III. Congenital nuclear cataracts 1. Cataracta pulverulenta +2. Lamellar cataract +3. Sutural and axial cataracts – Floriform cataract +– Coralliform cataract +– Spear-shaped cataract +– Anterior axial embryonic cataract – Dendritic suture cataract +4. Total nuclear cataract +IV. Generalized cataracts 1. Coronary cataract 2. Blue dot cataract +3. Total congenital cataract +4. Congenital membranous cataract. + +I. Congenital capsular cataracts +1. Anterior capsular cataracts are nonaxial, stationary and visually insignificant. +2. Posterior capsular cataracts are rare and can be associated with persistent hyaloid artery remnants. +II. Polar cataracts +1. Anterior polar cataract +It involves the central part of the anterior capsule and the adjoining superficial-most cortex. It may arise in the following ways: +• Duetodelayeddevelopmentofanteriorchamber. In this case the opacity is congenital usually bilateral, stationary and visually insignificant. +• Duetocornealperforation.Such cataracts may also be acquired in infantile stage and follow contact of the lens capsule with the back of cornea, usually after perforation due to ophthalmia neonatorum or any other cause. +Morphological types +Anterior polar cataracts may occur as any of the following morphological patterns: +• Thickened white plaque in the centre of anterior capsule. +• Anteriorpyramidalcataract.In this the thickened capsular opacity is cone-shaped with its apex towards cornea. +184 Section II Diseases of Eye + + +• Reduplicated cataract (double cataract). Sometimes along with thickening of central point of anterior capsule, lens fibres lying immediately beneath it also become opaque and are subsequently separated from the capsule by laying of transparent fibres in between. The buried opacity is called ‘imprint’ and the two together constitute reduplicated cataract. +2. Posterior polar cataract +It is a very common lens anomaly and consists of a small circular circumscribed opacity involving the posterior pole. +Associations. Posterior polar cataract may be associated with: +• Persistent hyaloid artery remnants (Mittendorf dot), • Posterior lenticonus, and +• Persistent hyperplastic primary vitreous (PHPV). +Types. Posterior polar cataract occurs in two forms: • Stationary form and +• Progressive form which progresses after birth. It typically has an ‘onionwhorlappearance’(Fig. 9.6) +III. Congenital nuclear cataracts +1. Cataracta centralis pulverulenta +Cataracta centralis pulverulenta is an embryonic nuclear cataract. It has dominant genetic trait and occurs due to inhibition of the lens development at a very early stage and thus, involves the embryonic nucleus. The condition is bilateral and is characterised by a small rounded opacity lying exactly in the centre of the lens. The opacity has a powdery appearance (pulverulenta) and usually does not affect the vision. + +with visual impairment. It accounts for about 50% of the cases. +Etiology. It may be either genetic or environmental in origin. +■Genetic pattern is usually of familial autosomal dominant variety. +■Environmental form is associated with: • vitamin D deficiency, +• hypocalcemia +• sometimes maternal rubella infection contracted between 7th and 8th week of gestation may also cause lamellar cataract. +Characteristic features. Typically, this cataract occurs in a zone of foetal nucleus surrounding the embryonic nucleus (Fig. 9.7). +■The main mass of the lens internal and external to the zone of cataract is clear, except for small linear opacities like spokes of a wheel (riders) which may be seen towards the equator. +■Occasionally two such rings of opacity are seen. ■It is usually bilateral and frequently causes severe visual defects. +3. Sutural and axial cataracts +Sutural cataracts are comparatively of common occurrence and consist of a series of punctate + +2. Lamellar cataract +Lamellar or Zonular cataract refer to the developmental cataract in which the opacity +occupies a discrete zone in the lens. It is the most +common type of congenital cataract presenting A B + + + + + + + + + + + +C +Fig. 9.7 Lamellar cataract : A & B, diagrammatic depiction as seen by oblique illumination and in optical section with +Fig. 9.6 Posterior polar cataract the beam of the slit-lamp, respectively; C, clinical photograph +Chapter 9 Diseases of Lens 185 + +opacities scattered around the interior and posterior Y-sutures. Such cataracts are usually static, bilateral and do not have much effect on the vision. The individual opacities vary in size and shape and have different pattern and thus are named accordingly as under: +• Floriformcataract.Here the opacities are arranged like the petals of a flower. +• Coralliform cataract also known as fusiform spindle shaped axial cataract, is characterised by +an anterior posterior spindle- shaped opacity with +off shoots giving an appearance resembling a coral. A B • Spear-shapedcataract.The lenticular opacities are +in the form of scattered heaps of shining crystalline needles. +• Anterior axial embryonic cataract occurs as fine dot near the anterior Y-suture of fetal nucleus (Fig. 9.8). +• Dendriticsuturalcataractoccurs as fine dots along the dendritic sutures. +4. Total nuclear cataract +Total nuclear cataract. It usually involves the + +embryonic and fetal nucleus and sometimes infantile nucleus as well. It is characterized by a dense chalky white central opacity seriously impairing vision. The opacities are usually bilateral and non-progressive. +IV. Generalized cataracts +1. Coronary cataract +Coronary cataract (Fig. 9.9) is an extremely common form of developmental cataract occurring about puberty; thus involving either the adolescent nucleus or deeper layer of the cortex. The opacities are often many hundreds in number and have a regular radial distribution in the periphery of lens (corona of club-shaped opacities) encircling the central axis. Since, the opacities are situated peripherally, vision is + + + + + + + + + + + + + + +Fig. 9.8 Anterior axial embronic sutural cataract + + +C +Fig. 9.9 Coronary cataract: A & B as seen by oblique illumination and in optical section with the beam of the slit-lamp, respectively, C, clinical photograph + +usually unaffected. Sometimes the associated large punctate opacities may marginally reduce the vision. +2. Blue dot cataract +It is also called cataracta-punctata-caerulea. Perhaps this is the most common type of congenital cataract. It usually forms in the first two decades of life. The characteristic punctate opacities are in the form of rounded bluish dots situated in the peripheral part of adolescent nucleus and deeper layer of the cortex. Opacities are usually stationary and do not affect vision. However, large punctate opacities associated with coronary cataract may marginally reduce the vision. +3. Total congenital cataract +It is a common variety and may be unilateral or bilateral (Fig. 9.10). In many cases there may be hereditary character. Its other important cause is maternal rubella. + +Rubella Cataract +• Maternal Rubella infection acquired during first trimester (second or third month) may cause rubella cataract. +• Rubellacataract-typically, the child is born with a +186 Section II Diseases of Eye + + + + + + + + + + + + + + + +Fig. 9.10 Total congenital cataract + +‘pearly white’ nuclear cataract. It is a progressive type of cataract. +• Lens matter may remain soft or may even liquify (congenital Morgagnian cataract). +• Cataractousnucleusmayharbourthevirusupto two years of age. Therefore, removal of such a cataract is usually followed by a severe inflammatory reaction (uveitis or even endophthalmitis) probably due to liberation of retained viruses. +Note. Congenital rubella can be prevented by vaccination of the mother. Since, the rubella vaccine is toxic to foetus, it must therefore, be administered atleast three months before the pregnancy. Rubella Syndrome. Congenital rubella cataract may occur alone or as part of the classical rubella syndrome which consists of: +i. Ocular defects. Congenital cataract, salt and pepper chorioretinopathy, microphthalmos, cloudy cornea and poorly dilating pupil. +ii. Ear defects. Deafness due to destruction of organ of Corti +iii.Heartdefects.Patent ductus arteriosus, pulmonary stenosis and ventricular septal defects. +4. Congenital membranous cataract +Sometimes there may occur total or partial absorption of congenital cataract, leaving behind thin membranous cataract. Rarely, there is complete disappearance of all the lens fibres and only a fine transparent lens capsule remains behind. Such a patient may be misdiagnosed as having congenital aphakia. This is associated with Hallermann-Streiff-Francois Syndrome. +DIFFERENTIAL DIAGNOSIS +Congenital cataracts presenting with leukocoria need to be differentiated from various other conditions presenting with leukocoria such as retinoblastoma, retinopathy of prematurity, + +persistent hyperplastic primary vitreous (PHPV), etc. (also see page 306). +MANAGEMENT OF CONGENITAL AND DEVELOPMENTAL CATARACT +A. Clinico-investigative work up +A detailed clinico-investigative work up is most essential in the management of paediatric cataract. It should aim at knowing the prognostic factors and indications and timing of surgery. +1. Ocular examination should be carried out with special reference to: +• Density and morphology of cataract. Density is indicated by quality of red reflex seen on distant direct ophthalmoscopy before and after dilation of pupil. Cataract morphology may suggest underlying cause. +• Assessment of visual function is difficult in infants and small children. An idea may be made from the density and morphology of the cataract by oblique illumination examination and fundus examination. Special tests like fixation reflex, forced choice preferential looking test, visually evoked potential (VEP), optic-kinetic nystagmus (OKN) etc. also provide useful information. +• Associated ocular defects which need to be noted include microphthalmos, glaucoma, PHPV, foveal hypoplasia, optic nerve hypoplasia, and rubella retinopathy etc. +2. Laboratory investigations should be carried out to detect following systemic associations in non-hereditary cataracts: +■Intrauterine infections viz. toxoplasmosis, rubella, cytomegalo virus and herpes virus by TORCH test. ■Galactosemiaby urine test for reducing substances, red blood cell transferase and galacto kinase levels. ■Lowe’s syndrome by urine chromatography for +amino acids. +■Hyperglycemia by blood sugar level. ■Hypocalcemia by serum calcium and phosphate +levels and X-ray skull. +B. Prognostic factors +Prognostic factors which need to be noted are: • Density of cataract, +• Unilateral or bilateral cataract, • Time of presentation, +• Associated ocular defects, and • Associated systemic defects +C. Indications and timing of paediatric cataract surgery +1. Partialcataractsandsmallcentralcataractswhich are visually insignificant can safely be ignored and observed or may need non-surgical treatment with pupillary dilatation. +Chapter 9 Diseases of Lens 187 + + +2. Bilateraldensecataractsshould be removed early (within 6 weeks of birth) to prevent stimulus deprivation amblyopia. Second eye should be operated within a few days of the first eye. +3. Unilateral dense cataract should preferably be removed as early as possible (within days) after birth with optical correction in the first few weeks. However, it must be born in mind that visual prognosis in most of the unilateral cases is very poor even after timely operation, because correction of aphakia and prevention of amblyopia in infants is an uphill task. +D. Surgical procedures +Childhood cataracts (congenital, developmental as well as acquired) can be dealt with extra capsular cataract extraction technique involving anterior capsulorrhexis and irrigation aspiration of the lens matter (lens aspiration) or lensectomy. Lens aspiration can be performed either by manual SICS technique or by phacoemucification technique. Lens aspiration should be combined with primary posterior capsul-otomy in children below 6 years of age and also with anterior vitrectomy in all children below 2 years of age. Surgical technique of these procedures is described on page 206. +Note. The needlingoperation(which was performed in the past) is now obsolete because of high rates of complications. +E. Correction of paediatric aphakia +It is still an unsolved query. Presently, common views are as follows: +• Childrenabovetheageof2years can be corrected by implantation of posterior chamber intraocular lens during surgery. +• Childrenbelowtheageof2yearsshould preferably be treated by extended wear contact lens. Spectacles can be prescribed in bilateral cases. Later on secondary IOL implantation may be considered. +Note. Present trend is to do primary implantation at the earliest possible specially in unilateral cataract i.e., in all cases, because most surgeons have reported negative experiences in the compliance with glasses and contact lenses. +Paediatric IOL: size, design and power. The main concerns regarding the use of IOL in children are the growth of the eye, IOL power considerations, increased uveal reaction and long-term safety. Present recommendations are: +• Size of IOL above the age of 2 years may be standard 12 to 12.75 mm diameter for in the bag implantation. + +• DesignofIOLof choice at present is foldable IOLs made of hydrophobic acrylic material (e.g. Acrysof IOL, Alcon Lab, USA). Previously one-piece PMMA IOL with modified C-shaped haptics (preferably heparin coated) were recommended. However, PMMA IOLs are no more recommended because of the disadvantages of a bigger incision. The capsular and inflammatory responses remain a problem in children. +• Power of IOL. Most surgeons target emmetropia in older children (>8 years). In children between 2–8 years of age 10% undercorrection and below 2 years an undercorrection by 20% is recommended from the calculated biometric power to counter the myopic shift. +F. Correction of amblyopia +It is the central theme around which management of childhood cataract and aphakia revolves. In spite of best efforts, it continues to be the main cause of ultimate low vision in these children. (For management of amblyopia (see page 342). + +ACQUIRED CATARACT + +We have studied that congenital and developmental cataracts occur due to disturbance in the formation of the lens fibres, i.e., instead of clear, opaque lens fibres are produced. While, in acquired cataract, opacification occurs due to degeneration of the already formed normal fibres. A few common varieties of acquired cataract are described here. +AGE-RELATED CATARACT +‘Age-related cataract’ also called as senile cataract is the commonest type of acquired cataract affecting equally persons of either sex usually above the age of 50 years. The condition is usually bilateral, but almost always one eye is affected earlier than the other. +Morphologically, the senile cataract occurs in two forms, the cortical (soft cataract) and the nuclear (hard cataract). The cortical senile cataract may start as cuneiform (more commonly) or cupuliform— posterior subcapsular (PSC) cataract. +It is very common to find nuclear and cortical senile cataracts co-existing in the same eye; and for this reason it is difficult to give an accurate assessment of their relative frequency. In general, the predominant form can be given as cuneiform 70%, nuclear 25% and posterior subcapsular (cupuliform) 5%. +Etiology +Senile cataract is essentially an ageing process. Though its precise etiopathogenesis is not clear, the various factors implicated are as follows: +188 Section II Diseases of Eye + + +A. Risk factors +Risk factors affecting age of onset, type and maturation of senile cataract are as below: +1. Age. Age is the most important risk factor, i.e., why it is called age related cataract. As mentioned above it usually occurs after the age of 50 years. When it occur before 45 years of age, the term pre-senile cataract is used. By the age of 70 years, over 90% of the individuals develop senile cataract. +2. Sex. Without any doubt, the senile cataract affects both males as well as females. However, in many studies it is reported that prevalence of cataract is greater in females than males at all ages. +3. Heredity. It plays a considerable role in the incidence, age of onset and maturation of senile cataract in different families. +4. Ultraviolet irradiations. More exposure to UV irradiation from sunlight have been implicated for early onset and maturation of senile cataract in many epidemiological studies. +5. Dietary factors. Diet deficient in certain proteins, amino acids, vitamins (riboflavin, vitamin E, vitamin C), and essential elements have also been blamed for early onset and maturation of senile cataract. +6. Dehydrational crisis. An association with prior episode of severe dehydrational crisis (due to diarrhoea, cholera, etc.) and age of onset and maturation of cataract is also suggested. +7. Smoking has also been reported to have some effect on the age of onset of senile cataract. In numerous studies worldwide smoking has consistently been associated with an increase in the frequency of nuclear cataract. Smoking causes accumulation of pigmented molecules—3-hydroxykynurenine and chromophores, which lead to yellowing. Cyanates in smoke causes carbamylation and protein denaturation. +B. Causes of pre-senile cataract +The term pre-senile cataract is used when the cataractous changes similar to senile cataract occur before 50 years of age. Its common causes are: +1. Heredity. As mentioned above because of influence of heredity, the cataractous changes may occur at an earlier age in successive generations. +2. Diabetes mellitus. Age-related cataract occurs earlier in diabetics. Nuclear cataract is more common and tends to progress rapidly. +3. Myotonic dystrophy is associated with posterior subcapsular type of pre-senile cataract. Christmas tree cataract is typically seen in this condition. +4. Atopic dermatitis may be associated with + +pre-senile cataract (atopic cataract) in 10% of the cases. +C. Concept of syn- and co-cataractogenic factors +It has been conceptualised that cataract is the result of multiple subthreshold cataractogenic stresses acting in a concert. Age has been implicated as one of these cataractogenic stresses and that superimposition of other toxic stresses on the ageing lens may accelerate the rate of cataract formation. Conversely, the elimination of one or more cataractogenic stresses may delay the cataract formation. +D. Mechanism of loss of transparency +It is basically different in nuclear and cortical senile cataracts. +1. Cortical senile cataract. Its main biochemical features are decreased levels in the crystalline lens of total proteins, amino acids and potassium associated with increased concentration of sodium and marked hydration of the lens, followed by coagulation of lens proteins. The probable course of events leading to senile opacification of cortex is as shown in the Fig. 9.11. +2. Nuclear senile cataract. In this the usual degenerative changes are intensification of the age-related nuclear sclerosis associated with dehydration and compaction of the nucleus resulting in a hard cataract. It is accompanied by a significant increase in water insoluble proteins. However, the total protein content and distribution of cations remain normal. There may or may not be associated deposition of pigment urochrome and/or melanin derived from amino acids in the lens. + + + + + + + + + + + + + + + + + +Fig. 9.11 Flow chart depicting probable course of events involved in occurrence of cortical senile cataract +Chapter 9 Diseases of Lens 189 + + +Stages of Maturation +A. Maturation of the cortical type of senile cataract +1. Stage of lamellar separation. The earliest senile change is demarcation of cortical fibres owing to their separation by fluid. This phenomenon of lamellar separation can be demonstrated by slit-lamp examination only. These changes are reversible. +2. Stage of incipient cataract. In this stage, early detectable opacities with clear areas between them are seen. Two distinct types of senile cortical cataracts can be recognised at this stage: a.Cuneiformsenilecorticalcataract. It is characterised by wedge-shaped opacities with clear areas in between. These extend from equator towards centre and in early stages can only be demonstrated after dilatation of the pupil. They are first seen in the lower nasal quadrant. These opacities are present both in anterior and posterior cortex and their apices slowly progress towards the pupil. On oblique illumination these present a typical radial spoke-like pattern of greyish white opacities (Fig. 9.12). On distant direct ophthalmoscopy, these opacities appear as dark lines against the red fundal glow. +Since the cuneiform cataract starts at periphery and extends centrally, the visual disturbances are noted at a comparatively late stage. +b. Cupuliform senile cortical cataract. Here a saucer-shaped opacity develops just below the capsule usually in the central part of posterior cortex (posterior subcapsular cataract), which gradually extends outwards. There is usually a definite demarcation between the cataract and the surrounding clear cortex. Cupuliform cataract lies right in the pathway of the axial rays and thus causes an early loss of visual acuity. + +3. Immature senile cataract (ISC). In this stage, opacification progresses further. The cuneiform(Fig. 9.12) or cupuliform patterns can be recognised till the advanced stage of ISC when opacification becomes more diffuse and irregular. The lens appears greyish white (Fig. 9.13) but clear cortex is still present and so iris shadow is visible. +In some patients, at this stage, lens may become swollen due to continued hydration. This condition is called ‘intumescent cataract’. Intumescence may persist even in the next stage of maturation. Due to swollen lens anterior chamber becomes shallow. +4. Mature senile cataract (MSC). In this stage, opacification becomes complete, i.e., whole of the cortex is involved. Lens becomes pearly white in colour. Such a cataract is also labelled as ‘ripe cataract’ (Fig. 9.14). +5. Hypermature senile cataract (HMSC). When the mature cataract is left in situ, the stage of hypermaturity sets in. The hypermature cataract may occur in any of the two forms: +a. Morgagnian hypermature cataract. In some patients, after maturity the whole cortex liquefies + + + +Fig. 9.13 Immature senile cortical cataract + + + + + + + + + + + +A B +Fig. 9.12 Diagrammatic depiction of immature senile cataract (cuneiform type): A, as seen by oblique illumination; +B, in optical section with the beam of the slit-lamp Fig. 9.14 Mature senile cortical cataract +190 Section II Diseases of Eye + + + + + + + + + + + + +A + +Fig. 9.16 Early nuclear senile cataract + + + + + + + + + + + +B +Fig. 9.15 Morgagnian hypermature senile cataract: A, diagrammatic depiction; B, clinical photograph + + +and the lens is converted into a bag of milky fluid. The small brownish nucleus settles at the bottom, altering its position with change in the position of the head. Such a cataract is called Morgagnian cataract (Fig. 9.15). Sometimes in this stage, calcium deposits may also be seen on the lens capsule. +b. Sclerotic type hypermature cataract. Sometimes after the stage of maturity, the cortex becomes disintegrated and the lens becomes shrunken due to leakage of water. The anterior capsule is wrinkled and thickened due to proliferation + +of anterior cells and a dense white capsular cataract may be formed in the pupillary area. Due to shrinkage of lens, anterior chamber becomes deep and iris becomes tremulous (iridodonesis). +Maturation of nuclear senile cataract +Progressive nuclear sclerotic process renders the lens inelastic and hard, decreases its ability to accommodate and obstructs the light rays. These changes begin centrally (Fig. 9.16) and spread slowly peripherally almost up to the capsule when it becomes mature; however, a very thin layer of clear cortex may remain unaffected. +The nucleus may become diffusely cloudy (greyish) or tinted (yellow to black) due to deposition of pigments. In practice, the commonly observed pigmented nuclear cataracts are either amber, brown (cataractabrunescens)or black (cataractanigra)and rarely reddish (cataractarubra)in colour (Fig. 9.17). +Clinical features +Symptoms. An opacity of the lens may be present without causing any symptoms; and may be discovered on routine ocular examination. Common symptoms of cataract are as follows: +1. Glare. One of the earliest visual disturbance with + + + + + + + + + + + +A B C +Fig. 9.17 Nuclear cataract: A, Cataracta brunescens; B, Cataracta nigra; C Cataracta rubra +Chapter 9 Diseases of Lens 191 + + +the cataract is glare or intolerance of bright light; such as direct sunlight or the headlights of an oncoming motor vehicle. The amount of glare or dazzle will vary with the location and size of the opacity. +2. Uniocular polyopia (i.e., doubling or trebling of objects). It is also one of the early symptoms. It occurs due to irregular refraction by the lens owing to variable refractive index as a result of cataractous process. +3. Colouredhalos.These may be perceived by some patients owing to breaking of white light into coloured spectrum due to presence of water droplets in the lens. +4. Blackspots in front of eyes. Stationary black spots may be perceived by some patients. +5. Image blur, distortion of images and misty vision may occur in early stages of cataract. +6. Deterioration of vision. Visual deterioration due to senile cataract has some typical features. It is painless and gradually progressive in nature. +• Patientswithcentralopacities (e.g., cupuliform cataract i.e. posteriorsubcapsularcataract) have early loss of vision. These patients see better when pupil is dilated due to dim light in the evening (day blindness). +• In patients with peripheral opacities (e.g., cuneiform cataract) visual loss is delayed and the vision improves in bright light when pupil is contracted. +• Inpatientswithnuclearsclerosis, distant vision deteriorates due to progressive index myopia. + +Such patients may be able to read without presbyopic glasses. This improvement in near vision is referred to as ‘second sight’. +As opacification progresses, vision steadily diminishes, until only perception of light and accurate projectionoflightraysremains in the stage of mature cataract. +Signs. Following examination should be carried out to look for different signs of cataract shown in Table 9.1: +1. Visualacuitytesting.Depending upon the location and maturation of cataract, the visual acuity may range from 6/9 to just PL + (Table 9.1). +2. Oblique illumination examination. It reveals colour of the lens in papillary area which varies in different types of cataracts (Table 9.1). +3. Test for iris shadow. When an oblique beam of light is thrown on the pupil, a crescentric shadow of pupillary margin of the iris will be formed on the greyish opacity of the lens, as long as clear cortex is present between the opacity and the pupillary margin (Fig. 9.18). When lens is completely transparent or opaque, no iris shadow is formed. Hence, presence of iris shadow is a sign of immature cataract. +4. Distant direct ophthalmoscopic examination (for procedure seepage 586). A reddish yellow fundal glow is observed in the absence of any opacity in the media. Partial cataractous lens shows black shadow against the red glow in the area of cataract. Complete cataractous lens does not even reveal red glow (Table 9.1). + + + + +Table 9.1 Signs of senile cataract + + +Examination 1. Visual acuity +2. Colour of lens + + +3. Iris shadow +4. Distant direct ophthalmoscopy with dilated pupil +5. Slit-lamp examination + +Nuclear cataract 6/9 to PL+ +Grey, amber, brown, black or red +Not seen +Central dark area against red fundal glow + +Nuclear opacity clear cortex + +ISC +6/9 to CF+ Greyish white + + +Seen +Multiple dark areas against red fundal glow + +Areas of normal with cataractous cortex + +MSC +HM+ to PL+ +Pearly white with sinking brownish nucleus +Not seen +No red glow but white pupil +due to complete cataract +Complete cortex is cataractous + +HMSC (M) PL+ +Milky white + + +Not seen +No red glow milky white pupil + +Milky white cortex with sunken brown-ish nucleus + +HMSC (S) PL+ +Dirty white with hyper white spots + +Not seen +No red glow dirty white pupil + + +Shrunken cataractous lens with thickened anterior capsule + +ISC: Immature senile cataract, MSC: Mature senile cataract, HMSC (M) Hypermature senile cataract (Morgagnian), HMSC (S): Hypermature senile cataract (Sclerotic), PL: Perception of light, HM: Hand movements, CF: Counting finger +192 Section II Diseases of Eye + + + + + + + +A + + + + + +B +Fig. 9.18 Diagrammatic depiction of iris shadow in: immature cataract (A) and no iris shadow in mature cataract (B) + + +5. Slit-lamp examination should be performed with a fully-dilated pupil. The examination reveals complete morphology of opacity (site, size, shape, colour pattern and hardness of the nucleus). +Grading of nucleus hardness in a cataractous lens is important for setting the parameters of machine in phacoemulsification technique of cataract extraction. The hardness of the nucleus, depending upon its colour on slit-lamp examination, can be graded as shown in Table 9.2 and Fig. 9.19. +Differential diagnosis +1.Immature senile cataract (ISC) can be differentiated from the nuclear sclerosis without any cataract as shown in Table 9.3. +2. Mature senile cataract can be differentiated + + + + + + +Fig. 9.19 Slit-lamp biomicroscopic grading of nucleus hardness in cataractous lens + + +Table 9.3 Immature senile cataract versus nuclear sclerosis +ISC Nuclear sclerosis +1. Painless progressive loss 1. Painless progressive loss of vision of vision +2. Greyish colour of lens 2. Greyish colour of lens on oblique illumination +examination + + + +from retrolental causes of white pupillary reflex (leukocoria) as shown in Table 9.4. +Complications +1. Phacoanaphylactic uveitis. Lens proteins may leak into the anterior chamber in hypermature + +Table 9.2 Grading of nucleus hardness on slit-lamp biomicroscopy +Grade of Description of Colour of hardness hardness nucleus + +3. Iris shadow is present +4. Black spots against red glow are observed on distant direct ophthalmoscopy +5. Slit-lamp examination reveals area of cataractous cortex +6. Visual acuity does not improve on pin-hole testing + +3. Iris shadow is absent +4. No black spots are seen against red glow + + +5. Slit-lamp examination reveals clear lens with nuclear sclerosis +6. Visual acuity usually improves on pin-hole testing + + + +Grade I + +Grade II Grade III Grade IV +Grade V + +Soft + +Soft-medium Medium-hard Hard +Ultrahard (rock hard) + +White or greenish yellow +Yellowish Amber Brownish +Blackish + + +cataract. These proteins may act as antigen and induce antigen-antibody reaction leading to phacoanaphylactic uveitis. +2. Lens-induced glaucoma. It may occur by different mechanisms: +i. Phacomorphicglaucomais caused by intumescent (swollen and cataractous) lens. It is a type of +Chapter 9 Diseases of Lens 193 + +Table 9.4 Differences between mature senile cataract and leukocoria due to retrolental causes + +MSC + +1. White reflex in pupillary area +2. Size of pupil usually normal +3. Fourth Purkinje image is absent +4. Slit-lamp examination shows cataractous lens + +Leukocoria (due to retrolental causes) +1. White reflex in pupillary area +2. Pupil usually semidilated + +3. Fourth Purkinje image is present +4. Slit-lamp examination shows transparent lens with white reflex behind the lens + + + + + + + + + + + + +Fig. 9.20 Snow-flake (diabetic) cataract + + + +5. Ultrasonography normal 5. Ultrasonography reveals opacity in the vitreous cavity + + +secondary angle closure glaucoma. It is the most common type of lens induced glaucoma. +ii. Phacolyticglaucoma. Lens proteins are leaked into the anterior chamber in cases with Morgagnian type hypermature cataract. These proteins are engulfed by the macrophages. The swollen macrophages clog the trabecular meshwork leading to increase in IOP. Thus, the phacolytic glaucoma is a type of secondary open angle glaucoma (for details see page 248). +iii.Phacotopic glaucoma. Hypermature cataractous lens may subluxate/dislocate and cause glaucoma by blocking the pupil or angle of anterior chamber. +3. Subluxation or dislocation of lens. It may occur due to degeneration of zonules in hypermature stage. +TRAUMATIC CATARACT See page 430. +METABOLIC CATARACTS +These cataracts occur due to endocrine disorders and biochemical abnormalities. A few common varieties of metabolic cataracts are described here. +Diabetic cataract +Diabetes is associated with two types of cataracts: 1. Senile cataract in diabetics appears at an early age and progresses rapidly. +2. True diabetic cataract. The classical diabetic cataract is also called ‘snowflake cataract’ or ‘snowstorm cataract’. It is a rare condition, usually occurring in young adults due to osmotic over hydration of the lens. Osmotic over hydration of the lens occurs due to accumulation of sorbitol, when glucose is metabolized by NADPH+ dependent + + +aldose reductase. Initially, a large number of fluid vacuoles appear underneath the anterior and posterior capsules, which is soon followed by appearance of bilateral snowflake-like white opacities in the cortex (Fig. 9.20). Such opacities may resolve spontaneously or mature within a few days. +Galactosaemic cataract +It is associated with inborn error of galactose metabolism. Galactosaemia occurs in two forms: +1. Classical galactosaemia occurs due to deficiency of galactose–1 phosphate uridyl-transferase (GPUT); and +2. A related disorder occurs due to deficiency of galactokinase (GK). +Characteristic features. Galactosaemia is frequently associated with the development of bilateral cataract (oil droplet central lens opacities). The lens changes may be reversible and occurrence of cataract may be prevented, if milk and milk products are eliminated from the diet when diagnosed at an early stage. + +Hypocalcaemic (Tetanic) cataract +Cataractous changes may be associated with parathyroid tetany, which may occur due to atrophy or inadvertent removal (during thyroidectomy) of parathyroid glands. +■Multicolouredcrystals or small discrete white flecks of opacities are formed in the cortex which seldom mature. +■Zonularcataract, characterized by a thin opacified lamella deep in the infantile cortex is typically seen in infants with hypocalcemia. + +Cataract due to error of copper metabolism +Inborn error of copper metabolism results in Wilson’s disease (hepatolenticular degeneration). +194 Section II Diseases of Eye + + + + + + + + + + + + + + + +Fig. 9.21 Sunflower cataract + + +■‘Sunflower cataract’ characterised by yellowish brown dots (Fig. 9.21) may be observed rarely in such patients due to the deposition of cuprous oxide in the anterior lens capsule and subcapsular cortex in a stellate pattern. +■‘Kayser-Fleischer ring’ (KF ring) i.e., a golden ring due to deposition of copper in the peripheral part of Descemet’s membrane in the cornea, is a more commonly observed ocular feature of Wilson’s disease. +Cataract in Lowe’s syndrome +Lowe’s (Oculo-cerebral-renal) syndrome is a rare inborn error of amino acid metabolism. +• Ocular features include congenital cataract, glaucoma and blue sclera. +• Systemic features of this syndrome are mental retardation, dwarfism, osteomalacia, muscular hypotonia and frontal prominence. +COMPLICATED CATARACT +It refers to opacification of the lens secondary to some other intraocular disease. Some authors use the term secondary cataract for the complicated cataract. On the other hand, many authors use the term secondary cataract to denote after cataract. Therefore, to avoid confusion and controversy, preferably, the term secondary cataract should be discarded in general. +Etiology +The lens depends for its nutrition on intraocular fluids. Therefore, any condition in which the ocular circulation is disturbed or in which inflammatory toxins are formed, will disturb nutrition of the crystalline lens, resulting in development of complicated cataract. Some important ocular conditions giving rise to complicated cataract are listed here. + +1. Inflammatory conditions. These include uveal inflammations (like iridocyclitis, parsplanitis, choroiditis), hypopyon corneal ulcer and endophthalmitis. Anterior uveitis is the most common cause of complicated cataract. +2. Degenerativeconditionssuch as retinitis pigmentosa and other pigmentary retinal dystrophies and myopic chorioretinal degeneration. +3. Retinal detachment. Complicated cataract may occur in long-standing cases. +4. Glaucoma(primaryorsecondary)may sometimes result in complicated cataract. The underlying cause here is probably the embarrassment to the intraocular circulation, consequent to the raised pressure. +5. Intraocular tumours such as retinoblastoma or melanoma may give rise to complicated cataract in late stages. +Clinical features +Typically, the complicated cataract starts as posterior subcapsular cortical cataract (PSC). The opacity is irregular in outline and variable in density. In the beam of slit-lamp the opacities have: +• ‘Breadcrumb’ appearance. +• ‘Polychromaticluster’i.e., appearance of iridescent coloured particles of reds, greens and blue is a very characteristic sign (Rainbow cataract). +• Diffuseyellow-haze is seen in the adjoining cortex. • Slowly the opacity spreads in the rest of the cortex, and finally the entire lens becomes opaque, giving dirty white (Fig. 9.22) or chalky white appearance. +• Depositionofcalcium is common in the later stages. + +Drug-induced cataracts +Corticosteroid-induced cataract +Posterior subcapsular opacities are associated with the use of topical as well as systemic steroids. + + + + + + + + + + + + + + +Fig. 9.22 Complicated cataract with healed iridocyclitis +Chapter 9 Diseases of Lens 195 + + +Exact relationship between dose and duration of corticosteroid therapy with the development of cataract is still unclear. However, in general, prolonged use of steroids in high doses may result in cataract formation. Children are more susceptible than adults. +Therefore, it is recommended that all patients with diseases requiring prolonged corticosteroids therapy should be regularly examined on slit-lamp by an ophthalmologist. Further, intermittent regimes should be preferred over regular therapy and whenever possible steroids should be substituted by nonsteroidal anti-inflammatory drugs (NSAIDs). +Miotics-induced cataract +Anterior subcapsular granular type of cataract may be associated with long-term use of miotics, particularly long acting cholinesterase inhibitors such as echothiophate, demecarium bromide, disopropyl fluorophosphate (DFP). Removal of the drug may stop progression and occasionally may cause reversal of cataract. +Other drug-induced cataracts +Other drugs associated with fine toxic cataracts are amiodarone, chlorpromazine, busulphan, gold and allopurinol. +RADIATIONAL CATARACT +Exposure to almost all types of radiant energy is known to produce cataract by causing damage to the lens epithelium. Following types are known: +1. Infrared (heat) cataract +Prolonged exposure (over several years) to infra-red rays may cause discoid posterior subcapsular opacities and true exfoliation of the anterior capsule. It is typically seen in persons working in glass industries, so also called as ‘glass-blower’s or ‘glass-worker’s cataract’. +2. Irradiation cataract +Exposure to X-rays, g-rays or neutrons may be associated with irradiation cataract. There is usually a latent period ranging from 6 months to a few years between exposure and development of the cataract. People prone to get such cataracts are inadequately protected technicians, patients treated for malignant tumours and workers of atomic energy plants. +3. Ultraviolet radiation cataract +Long-term exposure to ultraviolet radiation has been linked with senile cataract in many studies. +ELECTRIC CATARACT +It is known to occur after passage of powerful electric current through the body. The cataract usually starts + +as punctate subcapsular opacities which mature rapidly. The source of current can be a live electricity wire or a flash of lightning. +SYNDERMATOTIC CATARACT +Lens opacities associated with cutaneous disease are termed syndermatotic cataracts. Such cataracts are bilateral and occur at a young age. +■Atopic dermatitis is the most common cutaneous disease associated with cataract (Atopic cataract). ■Otherskindisorders associated with cataract include poikiloderma, vasculare atrophicus, scleroderma and keratotis follicularis. + +MANAGEMENT OF CATARACT IN ADULTS + +Treatment of cataract essentially consists of its surgical removal. However, certain nonsurgical measures may be of help, in peculiar circumstances, till surgery is taken up. +A. NON-SURGICAL MEASURES +1. Treatment of cause of cataract. In acquired cataracts, thorough search should be made to find out the cause of cataract. Treatment of the causative disease, many a time, may stop progression and sometimes in early stages may cause even regression of cataractous changes and thus defer the surgical treatment. Some common examples include: +• Adequate control of diabetes mellitus, when discovered. +• Removal of cataractogenic drugs such as corticosteroids, phenothiazenes and strong miotics, may delay or prevent cataractogenesis. +• Removal of irradiation (infrared or X-rays) may also delay or prevent cataract formation. +• Early and adequate treatment of ocular diseases like uveitis may prevent occurrence of complicated cataract. +2. Measures to delay progression include: +• Topical preparations containing iodide salts of calcium and potassium are being prescribed in abundance in early stages of cataract (especially in senile cataract) in a bid to delay its progression. +• However, till date no conclusive results about their role are available. +• Role of vitamin E and aspirin in delaying the process of cataractogenesis is also mentioned. +3.Measures to improve vision in the presence of incipient and immature cataract may be of great solace to the patient. These include: +• Prescription of glasses refractive status, which +often changes with considerable rapidity in +196 Section II Diseases of Eye + + +patients with cataract, should be corrected at frequent intervals. +• Arrangement of illumination. Patients with peripheral opacities (pupillary area still free), may be instructed to use brilliant illumination. +• Conversely, in the presence of central opacities, a dull light placed beside and slightly behind the patient’s head will give the best result. +• Use of dark goggles in patients with central opacities is of great value and comfort when worn outdoors. +• Mydriatics. Patients with a small axial cataract, frequently may benefit from papillary dilatation. This allows the clear paraxial lens to participate in light transmission, image formation and focussing. Mydriatics such as 5% phenylephrine or 1% tropicamide; 1 drop b.i.d. in the affected eye may clarify vision. +B. SURGICAL MANAGEMENT +Indications +1. Visual improvement.This is by far the most common indication. When surgery should be advised for visual improvement varies from person to person depending upon the individual visual needs. So, an individual should be operated for cataract, when the visual handicap becomes a significant deterrent to the maintenance of his or her usual lifestyle and profession. +2. Medical indications. Sometimes patients may be comfortable from the visual point (due to useful vision from the other eye or otherwise) but may be advised cataract surgery due to medical grounds such as in the presence of: +• Lens-induced glaucoma, +• Phacoanaphylactic endophthalmitis and +• Retinal diseases like diabetic retinopathy or retinal detachment, treatment of which is being hampered by the presence of lens opacities. +3. Cosmetic indication. Sometimes patient with mature cataract may insist for cataract extraction (even with no hope of getting useful vision due to associated retinal or optic nerve disease), in order to obtain a black pupil. +Preoperative evaluation and workup +Once it has been decided to operate for cataract, a thorough preoperative evaluation should be carried out before contemplating surgery. This should include: +I. General medical examination of the patient to exclude the presence of systemic diseases especially: diabetes mellitus; + +• Hypertension +• Cardiac problems +• Obstructive lung disorders and +• Any potential source of infection in the body such as septic gums, urinary tract infection etc. +II. Ocular examination. A thorough examination of eyes including slit-lamp biomicroscopy is desirable in all cases. The following useful information is essential before the patient is considered for surgery: +1. Visual status assessment should include: +■Visual acuity should be noted unaided, best corrected and with pin hole testing. +■Perception of light (PL) must be noted. Absence of PL indicates nil visual prognosis. +■Projection of light rays (PR). It is a crude but an important and easy test for function of the peripheral retina. It is tested in a semi-dark room with the opposite eye covered. A thin beam of light is thrown in the patient’s eye from four directions (up, down, medial and lateral) and the patient is asked to look straight ahead and point out the direction from which the light seems to come. Inaccurate PR may be due to old retinal detachment, visual pathway defects, advanced glaucoma, large area of chorio-retinal atrophy and indicates poor visual prognosis. However, sometimes in dense cataract PR may be inaccurate with good visual prognosis. ■Potentialvisualacuitytests which may be required in the presence of opaque media include: +• Laser interferometry (LI), and +• Potential acuity meter (PAM) test. +2. Pupils should be examined to check for: ■Light reactions and RAPD, and +■Ability of the pupils to dilate adequately before surgery . +3. Anterior segment evaluation by slit-lamp biomicroscopy is must before cataract surgery. ■Cornea should be examined to note any scarring, endothelial status (guttata). In patients with suspicion of endothelial dystrophy, specular microscopy examination should be carried out for endothelial cell count and morphology. Normal cell count in elderly patients is 2000–2500 cell/mm2. Special care is needed in patients with cell counts below 1500 cells/mm2. +■Keratic precipitates (KPs) noted at the back of cornea suggest management of subtle uveitis before the cataract surgery. +■Cataractous lens should be evaluated for morphology and maturity of cataract and for grade of nuclear sclerosis (especially important for planning phacoemulsification surgery, See page 192) +Chapter 9 Diseases of Lens 197 + + +■Other signs to be particularly looked for include posterior synechiae, pseudoexfoliation, iridodonosis, pigments over the anterior lens capsule, and anterior chamber depth. +4. Intraocular pressure (IOP) should be measured in each case, preferably by applanation tonometry. Presence of a raised IOP needs a priority mana-gement. +5. Examination of lids, conjunctiva and lacrimal apparatus. Search for local source of infection should be made by ruling out conjunctival infections, meibomitis, blepharitis and lacrimal sac infection. Conjunctival swab culture and sensitivity should be carried out in doubtful cases. Lacrimal sac should receive special attention. Lacrimal syringing should be carried out orderly in patients with history of persistent watering from the eyes. In cases where chronic dacryocystitis is discovered, either DCR (dacryocystorhinostomy) or DCT (dacryocystectomy) operation should be performed, before the cataract surgery. +6. Fundus examination, wherever possible, should be carried out with special attention on macula, to rule out other causes of decreased vision. Indirect ophthalmoscopy may be useful in hazy media. +7. Macular function tests are important to predict the visual potential in patients with very dense cataracts where fundus examination is not possible a few simple macular functions tests are as below: +■Two-light discrimination test. The patient is asked to look through an opaque disc perforated with two pin-holes behind which a light is held. The holes are 2 inches apart and kept about 2 feet away from the eye. If the patient can perceive two lights, it indicates normal macular function. +■Maddox rod test.The patient is asked to look at a distant bright light through a Maddox rod. An accurate perception of red line indicates normal function. +■Colour perception. It indicates that some macular function is present and optic nerve is relatively normal. +■Entoptic visualisation. It is evaluated by rubbing a point source of light (such as bare lighted bulb of torch) against the closed eyelids. If the patient perceives the retinal vascular pattern in black outline, it is favourable indication of retinal function. Being subjective in nature, the importance of negative test can be considered if the patient can perceive the pattern with the opposite eye. +8. Objective test for evaluating retina are required if +some retinal pathology is suspected. These tests + +includes ultrasonic evaluation of posterior segment of the eye; electrophysiological studies such as ERG (electroretinogram), EOG (electrooculogram) and VER (visually evoked response); +9. Keratometry and biometry to calculate power of intraocular lens (IOL) to be implanted are performed in each case to be taken up for cataract surgery (For details see page 209). +Preoperative medications and preparations +1. Consent, with detailed information about the procedure, risks involved and outcome expected, should be obtained from each patient. +2. Scrub bath, care of hair and marking of the eye. Each patient should be instructed to have a scrub bath including face and hair wash with soap and water. Male patients must get their beard cleaned and hair trimmed. Female patients should comb their hair properly. The eye to be operated should be marked. 3. Preoperative antibiotics and disinfectants are required to prevent postoperative endophthalmitis: • Topical antibiotics such as fourth generation fluoroquinolone (0.3% moxifloxacin or 0.3% gatifloxacin) may be used QID for 3 days before surgery and every 15 minutes for 2 hours before +surgery to eradicate conjunctival bacterial flora. • Povidone-Iodine(10%) solutionshould be used to +paint the lids and facial skin preferably 2–3 hours before surgery. +• Povidone-Iodine (5%) solution as a single drop 10–30 minutes before surgery is one of the most effective measure to decrease the bacterial flora. +4. IOP loweringismust for conventional extracapsular cataract extraction (ECCE). A few surgeons also prefer to lower IOP in manual small incision cataract surgery (SICS) and phacoemulsification. It can be accomplished by mechanical pressure (digital massage or Honan balloon) and/or by IOP lowering drugs (I.V. mannitol or acetazolamide). +5. Mydriasis, sustained through out the procedure is required for successful completion of surgery. It can be obtained by: +• Topical tropicamide 1% (or cyclopentolate)+ Phenylephrine 2.5% should be instilled every 15 minutes 4–6 times before surgery. +• Topical cyclooxygenase inhibitor e.g. flurbiprofen 0.3% or, ketorolac 0.5%, or diclofenac 0.1% instilled 3 times a day before the surgery and every 15 minutes, 4 times immediately before the surgery helps in maintaining mydriasis during the procedure. +Anaesthesia +Cataract extraction can be performed under general or local anaesthesia. Local anaesthesia is preferred +198 Section II Diseases of Eye + + +whenever possible. Many surgeons prefer only topical anaesthesia for phacoemulsification (for details of anesthesia for cataract surgery see page 591). +Types and choice of surgical techniques +I. Intracapsular cataract extraction (ICCE) +In this technique, the entire cataractous lens along with the intact capsule is removed. Therefore, weak and degenerated zonules are a pre-requisite for this method. +Indications. ICCE has stood the test of time and had been widely employed for about 100 years over the world (1880-1980). Now (for the last 35 years) it has been almost entirely replaced by planned extracapsular techniques. +At present the onlyindicationofICCEis markedly subluxated and dislocated lens. +II. Extracapsular cataract extraction techniques +In these techniques, major portion of anterior capsule with epithelium, nucleus and cortex are removed; leaving behind the intact posterior capsule. Indications. Presently, extracapsular cataract extraction techniques are the surgery of choice for almost all types of adulthood as well as childhood cataracts unless contraindicated. +Contraindications. The only absolute contraindication for ECCE is markedly subluxated or dislocated lens. +Advantages of ECCE techniques over ICCE include: +1. ECCE is a universal operation and can be performed at all ages, except when zonules are not intact; whereas ICCE cannot be performed below 40 years of age. +2. Posterior chamber IOL can be implanted after ECCE, while it cannot be implanted after ICCE. +3. Postoperative vitreous related problems (such as herniation in anterior chamber, pupillary block and vitreous touch syndrome) associated with ICCE are not seen after ECCE. +4. Incidence of postoperative complications such as endophthalmitis, cystoid macular oedema and retinal detachment are much less after ECCE as compared to that after ICCE. +5. Postoperative astigmatism is less with ECCE techniques, as the incision is smaller. +6. Prognosis for subsequent glaucoma filtering or corneal transplantation (if required) is much improved with ECCE. +7. Incidence of secondary rubeosis in diabetics is reduced after ECCE. +Different techniques of extracapsular cataract extraction +The surgical techniques of ECCE presently in vogue are: • Conventional extracapsular cataract extraction +(ECCE), + +• Manual small incision cataract surgery (SICS), • Phacoemulsification. +Conventional ECCE versus SICS +Conventional large incision ECCE, though still being performed by some surgeons, has been largely replaced by small incision cataract surgery (SICS) and phacoemulsification techniques. +Merits of conventional ECCE over SICS +The only merit of conventional ECCE over SICS is that it is a simple technique to master with short learning curve. +Demerits of conventional ECCE over SICS include: • Long incision (10 to 12 mm). +• Multiple sutures are required. +• Open chamber surgery with high risk of vitreous prolapse, operative hard eye and expulsive choroidal haemorrhage. +• High incidence of postoperative astigmatism. +• Postoperative suture-related problems like irritation and suture abscess etc. +• Postoperative wound-related problems such as wound leak, shallowing of anterior chamber and iris prolapse. +• Needs suture removal, during which infection may occur. +Merits of manual SICS over phacoemulsification +1. Universal applicability i.e., all types of cataracts including hard cataracts (grade IV and V) can be operated by this technique. +2. Learning curve. This procedure is much easier to learn as compared to phacoemulsification. +3. Notmachinedependent.The biggest advantage of manual SICS is that it is not machine dependent and thus can be practised anywhere. +4. Lesssurgicalcomplications.Disastrous complic-ation like nuclear drop into vitreous cavity is much less than phacoemulsification technique. +5. Operatingtimein manual SICS is less than that of phocoemulsification, especially in hard cataract. Therefore, it is ideal for mass surgery. +6. Cost effective. With manual SICS, the expenses are vastly reduced as compared to considerable expenses in acquiring and maintaining phaco machine. There is no need to spend on consumable items like the phacotip, sleeves, tubing and probe. Further, in SICS nonfoldable (PMMA) IOLs are used which are much cheaper than the foldable IOLs. +Demerits of manual SICS over phacoemulsification +1. Conjunctival congestion persists for 5–7 days at the site of conjunctival flap. +Chapter 9 Diseases of Lens 199 + + +2. Mild tenderness sometime may be present owing to scleral incision. +3. Postoperativehyphemamay be noted sometimes. 4. Surgical induced astigmatism is more as the incision in SICS is large (about 6mm) as compared +to phacoemulsification (about 3.2 mm). +5. Delayed visual rehabilitation as compared to phacoemulsification. +Merits of phacoemulsification over manual SICS +1. Topical anaesthesia may be sufficient for phacoemulsification in expert hands. +2. Postoperative congestion is minimal after phacoemulsification, as phaco is usually performed through a clear corneal incision. +3. Small incision. The chief advantage of phacoe-mulsification over manual SICS is that it can be performed through a smaller (3.2 mm) incision. +4. Less corneal complications. Phacoemulsification can be performed in the posterior chamber without prolapsing the nucleus into the anterior chamber, thereby minimising the risk of corneal complications. +5. Visual rehabilitation is comparatively quicker in phacoemulsification as compared to manual SICS. +6. Postoperative astigmatism is comparatively less when foldable IOLs are implanted through a smaller incision (3.2 mm). +Demerits of phacoemulsification vis-a-vis manual SICS 1. Learning curve for phacoemulsification is more +painful both for the surgeons and patients. +2. Complications encountered during phacoem-ulsification like nuclear drop are unforgiving. +3. Machine dependent. This procedure is solely machine dependent and in the event of an unfortunate machine failure in the middle of surgery one has to shift to conventional ECCE. +4. High cost. Cost of this technique is very high because of expensive machine, accessories and maintenance. +5. Limitations. It is very difficult to deal with hard cataracts (grade IV and V) with this technique, and also there is high risk of serious corneal complications due to more use of phaco energy in such cases. +Conclusion. In spite of the demerits listed above the phacoemulsification has become the preferred method of cataract extraction world wide because the complication rate in the expert hands is minimal and the technique provides an almost quiet eye early postoperatively and an early visual rehabilitation. + +However, for the masses, especially in developing countries, the manual SICS offers the advantages of sutureless cataract surgery as a low cost alternative to phacoemulsification with the added advantages of having wider applicability and an easier learning curve. + +SURGICAL TECHNIQUES FOR CATARACT EXTRACTION + +INTRACAPSULAR CATARACT EXTRACTION + +Presently, the technique of intracapsular cataract extraction (ICCE) is obsolete and sparingly performed world wide. However, the surgical steps are described here as a mark of respect to the technique which has been widely employed for about 100 years over the world and is an important landmark in the history of cataract surgery. +Surgical steps of the ICCE technique are as follows: 1. Superior rectus (bridle) suture is passed to fix the eye in downward gaze (Fig. 9.23A). +2. Conjunctival flap (fornix based) is prepared to expose the limbus (Fig. 9.23B) and haemostasis is achieved by wet field or heat cautery. All surgeons do not make conjunctival flap. +3. Partial thickness groove or gutter is made through about two-thirds depth of anterior limbal area from 9.30 to 2.30 O’clock (150°) with the help of a razor blade knife (Fig. 9.23C). +4. Corneoscleral section. The anterior chamber is opened with the razor blade knife or with 3.2 mm keratome and section is completed using sclerocorneal scissors (Fig. 9.23D). +5. Iridectomy (Fig. 9.23E). A peripheral iridectomy may be performed by using iris forceps and de Wecker’s scissors to prevent postoperative pupil block glaucoma. +6. Methods of lens delivery. In ICCE, the lens can be delivered by any of the following methods: +i. Smith Indian method. Here the lens is delivered with tumbling technique by applying pressure on limbus at 6 O’clock position with lens expressor and counterpressure at 12 O’clock with the lens spatula. With this method lower pole is delivered first. +ii. Cryoextraction. In this technique, cornea is lifted cataracts. The surgical techniques of ECCE presently up, lens surface is dried with a swab, iris is in vogue for adulthood cataracts include: retracted up and tip of the cryoprobe is applied on the anterior surface of the lens in the upper quadrant. Freezing is activated +200 Section II Diseases of Eye + + + + + + + + + + + + +A B C + + + + + + + + + + +D E F + + + + + + + + + + + +G H I + +Fig. 9.23 Surgical steps of intracapsular cataract extraction with anterior chamber intraocular lens implantation:A, passing of superior rectus suture; B, fornix based conjunctival flap; C, partial thickness groove; D, completion of corneo-scleral section; E, peripheral iridectomy; F, cryolens extraction; G & H, insertion of Kelman multiflex intraocular lens in anterior chamber; I, corneo-scleral suturing + + +(–40°C) to create adhesions between the lens and the probe. The zonules are ruptured by gentle rotatory movements and the lens is then extracted out by sliding movements. In this technique, upper pole of the lens is delivered first (Fig. 9.23F). +iii. Capsule forceps method. The Arruga’s capsule holding forceps is introduced close into the anterior chamber and the anterior capsule of the lens is caught at 6 O’clock position. The lens is lifted slightly and its zonules are ruptured by gentle sideways movements. Then the lens is extracted with gentle + +sliding movements by the forceps assisted by a pressure at 6 O’clock position on the limbus by the lens expressor. +iv.Irisophakemethod.This technique is obsolete and thus not in much use. +v. Wire vectis method. It is employed in cases with subluxated or dislocated lens only. In this method, the loop of the wire vectis is slide gently below the subluxated lens, which is then lifted out of the eye. 7. Formation of anterior chamber. After the delivery of lens, iris is reposited into the anterior chamber with +Chapter 9 Diseases of Lens 201 + + +the help of iris repositor and chamber is formed by injecting sterile air or balanced salt solution. +8. Implantation of anterior chamber (ACIOL) (see Figs. 9.23 G and H). (For details see page 210). +9. Closure of incision is done with 5 to 7 interrupted sutures (8–0, 9–0 or 10–0 nylon) (Fig. 9.23I). +10. Conjunctival flap isreposited and secured by wet-field cautery. +11. Subconjunctival injection of dexamethasone 0.25 ml and gentamicin 0.5 ml is given. +12. Patching of eye is done with a pad and sticking plaster or a bandage is applied. + +SURGICAL TECHNIQUES OF EXTRA CAPSULAR CATARACT EXTRACTION FOR ADULTHOOD CATARACTS + +The surgical techniques of ECCE can be described separately for adulthood cataracts and childhood cataracts. The surgical techniques of ECCE presently in vogue for adulthood cataracts include: +• Conventional, extracapsular cataract extraction (ECCE), +• Manual small incision cataract surgery (SICS), and • Phacoemulsification. +CONVENTIONAL EXTRACAPSULAR CATARACT EXTRACTION +Surgical steps of conventional ECCE are: +1. Superior rectus (bridle) suture is passed to fix the eye in downward gaze (Fig. 9.23A). +2. Conjunctival flap (fornix based) is prepared to expose the limbus (Fig. 9.23B) and haemostasis is achieved by wet field cautery. Many surgeons do not make conjunctival flap. +3. Partial thickness groove or gutter is made through about two-thirds depth of anterior limbal area from 10 to 2 O’clock (120°) with the help of a razor blade knife (Fig. 9.23C). +4. Entry into anterior chamber. The anterior chamber is entered with the razor blade knife or with 3.2 mm keratome. +5. Injection of viscoelastic substance in anterior chamber. A viscoelastic substance such as 2% methylcellulose or 1 % sodium hyaluronate is injected into the anterior chamber. This maintains the anterior chamber and protects the endothelium (For details see page 458). +6. Anterior capsulotomy. It can be performed by any of the following methods: +i. Can-opener’s technique. In this an irrigating +cystitome (or simply a 26 gauge needle, bent at its tip) + +is introduced into the anterior chamber and multiple small radial cuts are made in the anterior capsule for 360° (Fig. 9.24A). +ii. Linear capsulotomy (Envelope technique). Here a straight incision is made in the anterior capsule (in the upper part) from 2–10 O’ clock position. The rest of the capsulotomy is completed in the end after removal of nucleus and cortex. +iii. Continuous circular capsulorrhexis (CCC). Recently, this is the most commonly performed procedure. In this the anterior capsule is torn in a circular fashion either with the help of an irrigating bent–needle cystitome or with a capsulorrhexis forceps (Fig. 9.26B). +7. Removal of anterior capsule. It is removed with the help of a Kelman-McPherson forceps (Fig. 9.24B). 8. Completion of corneoscleral section. It is completed from 10 to 2 O’clock position either with the help of corneoscleral section enlarging scissors or 5.2 mm blunt keratome (Fig. 9.24C). +9. Hydrodissection. After the anterior capsulotomy, the balanced salt solution (BSS) is injected under the peripheral part of the anterior capsule. This manoeuvre separates the corticonuclear mass from the capsule. +10. Removal of nucleus. After hydrodissection the nucleus can be removed by any of the following techniques: +i. Pressure and counterpressure method. In it the posterior pressure is applied at 12 O’clock position with corneal forceps or lens spatula and the nucleus is expressed out by counterpressure exerted at 6 O’clock position with a lens hook (Fig. 9.24D). +ii. Irrigating wire vectis technique. In this method, loop of an irrigating wire vectis is gently passed below the nucleus, which is then lifted out of the eye. +11. Aspiration of the cortex. The remaining cortex is aspirated out using a two-way irrigation and aspiration cannula (Fig. 9.24E). +12. Implantation of IOL. The PMMA posterior chamber IOL is implanted in the capsular bag after inflating the bag with viscoelastic substance (Figs. 9.24 G and H). +13. Closure of the incision is done by a total of 3 to 5 interrupted or continuous 10–0 nylon sutures (Fig. 9.24I). +14. Removal of viscoelastic substance. Before tying the last suture the viscoelastic material is aspirated out with 2 way cannula and anterior chamber is filled with BSS. +202 Section II Diseases of Eye + + + + + + + + + + + +A B C + + + + + + + + + + + +D E F + + + + + + + + + + + + +G H I + + +Fig. 9.24 Surgical steps of conventional extracapsular cataract extraction with posterior chamber intraocular lens implantation: A, anterior capsulotomy can-opener’s technique; B, removal of anterior capsule; C, completion of corneo-scleral section; D, removal of nucleus (pressure and counter-pressure method); E, aspiration of cortex; F, insertion of inferior haptic of posterior chamber IOL; G, insertion of superior haptic of PCIOL; H, dialing of the IOL; I, corneo-scleral suturing + + + +15. Conjunctival flap is reposited and secured by wet field cautery. +16. Subconjunctival injection of dexamethasone 0.25 ml and gentamicin 0.5 ml is given. +17. Patching of eye is done with a pad and sticking plaster or a bandage is applied. +MANUAL SMALL INCISION CATARACT SURGERY +Manual small incision cataract surgery (SICS) has become very popular because of its merits over + + +conventional ECCE as well as phacoemulsification technique highlighted earlier (see pages 198–199). In this technique ECCE with intraocular lens implantation is performed through a sutureless self-sealing valvular sclerocorneal tunnel incision. +Surgical steps of manual SICS +1. Superior rectus (bridle) suture is passed to fix the eye in downward gaze (Fig. 9.25A). This is specifically important in manual SICS where in addition to +Chapter 9 Diseases of Lens 203 + + +fixation of globe, it also provides a countertraction force during delivery of nucleus and epinucleus. Note. SICS can also be performed from temporal side, especially in patients with against the rule (ATR) astigmatism. In this situation, bridle suture is passed through the lateral rectus muscle and all the next steps are performed on the temporal quadrant. 2. Conjunctival flap and exposureof sclera (Fig. 9.25B). A small fornix based conjunctival flap is made with the help of sharp tipped scissors along the limbus from 10 to 2 O’clock positions. Conjunctiva and the Tenon’s capsule are dissected, separated from the underlying sclera and retracted to expose about 4 mm strip of sclera along the entire incision length. +3. Haemostasisis achieved by applying gentle and just adequate wet field cautery. +4. Sclerocorneal tunnel incision. A self-sealing sclerocorneal tunnel incision is made in manual SICS. It consists of following components: +i. External scleral incision. A one-third to half-thickness external scleral groove is made about 1.5 to 2 mm behind the limbus. It varies from 5.5 mm to 7.5 mm in length depending upon the hardness of nucleus. It may be straight, frown shaped or chevron in configuration (Fig. 9.25C). +ii. Sclerocorneal tunnel. It is made with the help of a crescent knife. It usually extends 1–1.5 mm into the clear cornea (Fig. 9.25D). +iii. Internalcornealincision.It is made with the help of a sharp 3.2 mm angled keratome (Fig. 9.25E). +5. Side-port entry of about 1.5 mm valvular corneal incision is made at 9 O’clock position (Fig. 9.25F). This helps in aspiration of the subincisional cortex and deepening the anterior chamber at the end of surgery. 6. Anterior capsulotomy.As described in conventional ECCE, the capsulotomy in manual SICS can be either a canopner, or envelope or CCC. However, a large sized CCC is preferred (Fig. 9.25G). +7. Hydrodissection. As described in ECCE hydro-dissection (Fig. 9.25H) is essential to separate corticonuclear mass from the posterior capsule in SICS. +8. Nuclear management. It consists of following manoeuvres: +i. Prolapse of nucleus out of the capsular bag into the anterior chamber is usually initiated during hydrodissection and completed by rotating the nucleus with Sinskey’s hook (Fig. 9.25I). +ii. Delivery of the nucleus outside through the corneoscleral tunnel can be done by any one of the following methods: +• Irrigating wire vectis method (Fig. 9.25J) + +• Blumenthal’s technique, +• Phacosandwitch technique, +• Phacofracture technique, and • Fishhook technique. +9. Aspiration of cortex. The remaining cortex is aspirated out using a two-way irrigation and aspiration cannula (Fig. 9.25K) from the main incision and/or side port entry. +10. IOL implantation. A posterior chamber IOL is implanted in the capsular bag after filling the bag with viscoelastic substance (Figs. 9.25L, M and N). 11.Removal of viscoelastic material is done thoroughly from the anterior chamber and capsular bag with the help of two-way irrigation aspiration cannula. Excessive left out viscoelastic material may cause secondary glaucoma. +12.Wound closure. The anterior chamber is deepened with balanced salt solution / Ringer’s lactate solution injected through side port entry. This leads to self sealing of the sclerocorneal tunnel incision due to valve effect. Rarely a single infinity suture may be required to seal the wound. The conjunctival flap is reposited back and is anchored with the help of wet field cautery (Fig. 9.25O). +PHACOEMULSIFICATION +Extracapsular cataract extraction by phaco-emulsification along with foldable posterior chamber intraocular lens implantation in the bag is the procedure of choice for cataract surgery. Phacoemulsification, differs from the conventional ECCE and manual SICS as follows: +1. Clear corneal incision required is very small (3 mm). Therefore, sutureless surgery is possible with self-sealing sclera corneal tunnel or clear corneal incision made with a 3 mm keratome (Fig. 9.26A). 2. Continuous curvilinear capsulorrhexis (CCC) of 4–6 mm is preferred over other methods of anterior capsulotomy (Fig. 9.26B). +3. Hydrodissection i.e., separation of capsule from the cortex by injecting fluid exactly between the two (Fig. 9.26C) is must for phacoemulsification and SICS. This procedure facilitates nucleus rotation and manipulation during phacoemulsification. Some surgeons also perform hydrodelineation (Fig. 9.26D). +4. Nucleus is emulsified and aspirated by phaco-emulsifier. Phacoemulsifier basically acts through a hollow 1 mm titanium needle which vibrates by piezoelectric crystal in its longitudinal axis at an ultrasonic speed of 40000 times a second and thus emulsifies the nucleus. Many different techniques +204 Section II Diseases of Eye + + + + + + + + + +A B C + + + + + + + + + +D E F + + + + + + + + +G H I + + + + + + + + +J K L + + + + + + + + + +M N O + +Fig. 9.25 Surgical steps of manual small incision cataract surgery (SICS): A, superior rectus bridle suture: B, conjunctival flap and exposure of sclera; C, external scleral incisions (straight, frown shaped, and chevron, respectively) part of tunnel incision; D, sclerocorneal tunnel with crescent knife; E, internal corneal incision; F, side port entry; G, large CCC; H, hydrodissection; I, prolapse of nucleus into anterior chamber; J, nucleus delivery with irrigating wire vectis; K, aspiration of cortex; L, insertion of inferior haptic of posterior chamber IOL; M, insertion of superior haptic of PCIOL; N, dialing of the IOL; O, reposition and anchoring of conjunctival flap +Chapter 9 Diseases of Lens 205 + + +are being used to accomplish nucleotomy. A few common names are: +• Chip and flip technique, +• Divide and conquer technique (Figs. 9.26E and F), • Stop and chop technique, and +• Direct Phaco chop technique. +5. Remaining cortical lens matter is aspirated with the help of an irrigation-aspiration technique (Fig. 9.26G). +6. IOL implantation. Foldable IOL implantation with the help of an injector (Fig. 9.26H) is most ideal with phacoemulsification technique (see page 210). However, phacoprofile (5.25 optic size) rigid (PMMA) IOLcan also be implanted after enlarging the incision. 7. Next steps i.e., removal of viscoelastic substance and wound closure are similar to that of SICS. +Microincision cataract surgery +Microincision cataract surgery (MICS) refers to the phacoemulsification techniques which can be performed through a microincision (<2 mm). These techniques offer almost no surgically induced astigmatism. Various MICS techniques have been developed. A few to mention are: +1. Microincision coaxial phacoemulsification (CO-MICS) performed through stab 2 mm incision with a dedicated phacomachine is essentially similar to standard coaxial phacoemulsification performed through 3 mm incision. + +2. Bimanual microphacoemulsification (BMICS) in essence uses separate hand piece for irrigation and phacoemulsification aspiration. The technique requires two limbal incisions of 1.2 × 1.4 mm made with a trapezoidal blade. +3. Phaconit is the term used by Prof. Amar Agarwal from India for the Bimanual Micro Phacodone with a Needle Incision Technique through an incision <1 mm in size. +Femtosecond laser assisted cataract surgery Femtosecond laser assisted cataract surgery (FLACS), is the best available procedure presently, FLACS is basically a microincision cataract surgery (MICS) or microphaco in which femtosecond laser (FSL) is used to perform certain steps: +Surgical steps with femtosecond laser are as below: +• Capsulorrhexis performend with FSL is more precise, accurate, controlled and centralised. +• Lens fragmentation with FSL allows reduction in phaco energy and intracameral manipulation resulting in improved safety and decreased complications. +• Clearcornealincisionfashioned with FSL offers the advantages of decreased leakage and added stability. +• Arcuatecornealincisions are created to tackle any co–existing astigmatism. +• Post femtosecond laser surgical steps. Patient is shifted under an operating microscope and following steps are performed: + + + + + + + + + + + +A B C D + + + + + + + + +E F G H + +Fig. 9.26 Surgical steps of phacoemulsification: A, clear corneal incision; B, continuous curvilinear capsulorrhexis; C, hydrodissection; D, hydrodelineation; E & F, nucleus emulsification by divide and conquer technique (four quadrant cracking); G, aspiration of cortex; H, implantation of foldable IOL with injector system +206 Section II Diseases of Eye + + +– Corneal incisions are opened up with fine iris repositor. +– Anterior chamber is filled with viscoelastic material. +– Capsulorrhexis flap is removed. +– Lens fragments are phacoaspirated, and +– Foldable IOL is implanted and in the capsular bag the procedure is completed. + +SURGICAL TECHNIQUES OF EXTRACAPSULAR CATARACT EXTRACTION FOR CHILDHOOD CATARACT + +Surgical techniques employed for childhood cataract are essentially of two types: +• Irrigation and aspiration of lens matter, and • Lensectomy +1. IRRIGATION AND ASPIRATION OF LENS MATTER +Irrigation and aspiration of lens matter is preferably done by corneoscleral tunnel techniques which include: +• Manual irrigation-aspiration technique, and • Phaco-aspiration technique. +The corneoscleral tunnel incision techniques (closed chamber surgery) as described for phacoemulsification is preferred over the conventional ECCE technique (open chamber surgery). +Surgical steps of irrigation and aspiration of lens matter by corneoscleral tunnel incision techniques are as follows: +1 to 5 initial steps upto making of side port entry are similar as described for manual SICS in adults except that size of the tunnel incision is 3–4 mm (page 203, Figs. 9.25A to F). +6. Anterior capsulorrhexis of about 5 mm size is made as described on page 201 (Fig. 9.26A). In children the anterior capsule is more elastic than in adults and therefore, the capsulorrhexis may be difficult due to tendency to run outwards. +7. Hydrodissection is performed to separate the capsule from the cortex by injecting fluid. (Fig. 9.26C). 8. Irrigation and aspiration of lens matter (which is soft in children) can be done by any of the following methods: +• Manuallywith a two-way irrigation and aspiration Simcoe cannula (Fig. 9.25K) or, +• With a phacoprobe (phaco-aspiration) (Fig. 9.26G). 9. Posterior capsulorrhexis of about 3–4 mm size is recommended in younger children to avoid the problem of posterior capsule opacification. + +10. Anterior vitrectomy of limited amount should be performed with a vitrector in very young children. 11.Implantation of IOLisdone in the capsular bag after inflating it with viscoelastic substance (Fig. 9.26H). Foldable acrylic IOLs are preferred in children. It has been postulated that acrylic IOLs induce less cellular reaction and are more adhesive to the capsular bag than PMMA IOLs. Some surgeons prefer to capture the lens optic through posterior capsulorrhexis. Note.Steps 9, 10 and 11 (the lens material choice and optic capture as described in step 11) are measures to prevent formation of after cataract, the incidence of which is very high in children. +12. Removal of viscoelastic material is done with the help of two-way cannula or irrigation—aspiration probe of phaco machine. +13. Intracameral antibiotics (preservative free moxifloxacin or vancomycin) use is reported to decrease post–operative bacterial endophthalmitis. 14. Wound closure. Though a well constructed corneoscleral tunnel often does not require a suture inadults.However, itis mandatorytoclose thewound in children to ensure wound stability and reduce postoperative astigmatism. The absorbable suture (10–0 vicryl) is adequate for closure of the wound keeping in mind the rapid healing characteristic and difficulty of removing sutures in children. +2. LENSECTOMY +In this operation, most of the lens including anterior and posterior capsule along with anterior vitreous are removed with the help of a vitreous cutter (Fig. 9.27). Childhood cataracts, both congenital/ developmental and acquired, being soft can be easily dealt with this procedure especially in very young children (less than 2 years of age) in which primary IOL implantation is not planned. Lensectomy in children is performed under general anaesthesia. Eitherparsplanaorlimbalapproach may be adopted. In pars plana approach, the lens is punctured at its equator and stirred with the help of a Ziegler’s or any other needle-knife introduced through the sclera and ciliary body, from a point about 3.5–4 mm behind the limbus. The cutter (ocutome) of the vitrectomy machine is introduced after enlarging the sclerotomy (Fig. 9.28) and lensectomy along with anterior vitrectomy is completed using cutting, irrigation and aspiration mechanisms. The aim of modern lensectomy is to leave in situ a peripheral rim of capsule as an alternative to complete lensectomy. +Secondary IOL implantation can be planned at a later date. +Chapter 9 + + + + + + + + + + + + + + + + + + +Fig. 9.27 Vitrectomy probe + +Diseases of Lens 207 + + + + + + + + + + + + + + + + + +Fig. 9.28 Pars plana lensectomy + + + +INTRAOCULAR LENS IMPLANTATION + +Presently, intraocular lens (IOL) implantation is the method of choice for correcting aphakia. Its advantages and disadvantages over spectacles and contact lenses are described in aphakia (see page 38). +The IOL implant history had its beginning on November 29, 1949, when Harold Ridley, a British ophthalmologist, performed his first case. Since then history of IOLs has always been exciting, often frustrating and finally rewarding and now highly developed. + +Types of Intraocular Lenses +During the last two decades a large number of different types and styles of lenses have been developed. +A. Based on the method of fixation in the eye, the major classes of IOLs are as follows: + +1. Anterior chamber IOL (Angle supported IOLs). These are not very popular due to comparatively higher incidence of bullous keratopathy. When indicated, ‘Kelman multiflex’ (Fig. 9.29A) type of ACIOL is used commonly. These lenses lie entirely in front of the iris and are supported in the angle of anterior chamber (Fig. 9.30). ACIOL can be inserted after ICCE or ECCE. Presently, AC-IOLs are used only in those cases where it is not possible to use the PC-IOL. +2. Iris-supported lenses. These lenses are fixed on the iris with the help of sutures, loops or claws. These lenses are also not very popular due to high incidence of postoperative complications. Example of iris supported lens is Singh and Worst’s iris claw lens (Figs. 9.29B and 9.31). +3. Posterior chamber lenses. PCIOLs rest entirely behind the iris (Fig. 9.32). They may be supported and fixed as below: + + + + + + + + + + + + + +Fig. 9.29 A, Anterior chamber IOL (Kelman multiflex); B, Singh and Worst’s iris claw lens; C, Posterior chamber IOL (modified C loop type); D, Posterior chamber IOL (four loop type) +208 Section II Diseases of Eye + + + + + + + + + + + + + + + + +Fig. 9.30 Pseudophakia with Kelman multiflex anterior chamber intraocular lens implant + +a. In the capsular bag fixation of PCIOL is the most ideal method. Commonly used models of PC-IOLs are modified C loop (Fig. 9.29C) and quadri loop (Fig. 9.29D). +b. In the ciliary sulcus fixation of PC-IOL is done in the absence of intact capsular bag but with adequate capsular support. +c. Scleral fixation of PC-IOL is done in the absence of capsular support. Broadly there are two types of techniques for scleral fixation of PC-IOL: +• Trans–scleral suture fixation of PC-IOL, and +• Trans–scleral sutureless fixation of PC-IOL (glued IOL). +d. Retro–iris fixation is the technique of implanting iris claw lens in the posterior chamber. +B. Depending on the material of manufacturing, three types of PCIOLs are available: +1. Rigid IOLs. The modern one piece rigid IOLs are made entirely from PMMA. + + + + + + + + + + + + + +A + +Fig. 9.31 Pseudophakia with iris claw intraocular lens implant + +2. Foldable IOLs, to be implanted through a small incision (3.2 mm) after phacoemulsification are made of silicone, acrylic, hydrogel and collamer. Thinner foldable IOLs can be implanted through 2–2.2 mm incision. Foldable IOLs are implanted with the help of an IOL injector (Fig. 9.26H) +3. Rollable IOLs are ultra-thin IOLs. These are implanted through 1 mm incision after microincision catarat surgery (MICS) technique. These are made of hydrogel. +C.Based on the focussing abilitythe IOLs are of following types: +1. Unifocal IOLs are the most commonly used ones having unifocal power (Fig. 9.33A). Depending upon the power of IOLs implanted, these can make the patient emmetropic, myopic or hypermetropic. +2. Multifocal lOLs have separate optics to focus for distance and near, so also known as simultaneous + + + + + + + + + + + + + + +B + +Fig. 9.32 Pseudophakia with posterior chamber intraocular lens: A, as seen on retroillumination with slit-lamp; B, diagrammatic depiction of PCIOL implanted in the capsular bag +Chapter 9 Diseases of Lens 209 + +vision lenses. These are of 2 types, either refractive or diffractive optics types (Fig. 9.33B). These are also called pseudoaccommodative IOLs. +3. Accommodative IOLs exhibit some anterior movement of optic to improve the near vision. Available models of accommodative IOLs are: +• Crystalens which is based on optic shift principle (Fig. 9.33C), and +• Synchrony lens which is based on dual optic mechanism. +D. Aphakic versus phakic refractive IOLs. In addition to the aphakic IOLs which are implanted after lens extraction, special phakic IOLs have been developed to correct the refractive errors. These are also called implantable collamer lenses (ICLs) and are of three types (For details see page 54). +E. Special function IOLs. These are developed +to provide some special function in addition to A correcting aphakia. Examples are: +1. Toric IOLs. These are designed to correct the associated astigmatism (Fig. 9.34A). +2. Aspheric IOLs. These have been designed to reduce spherical abberations. +3. Aniridia IOLs. These lenses are devised to cosmetically cover the defects of aniridia or partial iris loss in cases like trauma. In these lenses around the central optical part, there is a black diaphragm (Fig. 9.34B). +Indications of IOL implantation +Recent trend is to implant an IOL in each and every case being operated for cataract; unless it is +contraindicated. B + +Calculation of IOL power (Biometry) +The most common method of determining IOL power uses a regression formula called ‘SRK + +(Sanders, Retzlaff and Kraff) formula.’ The formula is: P = A—2.5L–0.9K, where: +P is the power of IOL, +• A is a constant which is specific for each lens type. • L is the axial length of the eyeball in mm, which is +determined by A-scan ultrasonography. +• K is average corneal curvature, which is determined by keratometry. +Equipment for biometry +1. A–scan ultrasonic biometer.The ultrasound machine equipped with A-scan and IOL power calculation software is called ‘Biometer’. +2. Optical biometers are non–contact optical devices based on the principle of partial coherence + + + + + + + +C +Fig. 9.33 Types of IOLs based on focusing mechanism: A, Unifocal; B, Multifocal; C, Accommodative (crystalens) + +interferometry (PCI). These are quick and more accurate devices. Commercially available optical biometers are: +• IOL Master Tm (Zeiss Humphrey system) and • Lenstar. +210 Section II Diseases of Eye + + + + + + + + + + + + + + + + +A B +Fig. 9.34 Special function IOLs: A, Toric IOL; B, Aniridia IOL + + + +Primary versus secondary IOL implantation Primary IOL implantationrefers to the use of IOL during surgery for cataract, while secondary IOL is implanted to correct aphakia in a previously operated eye. +Surgical technique of anterior chamber IOL implantation +Anterior chamber IOL implantation can be carried out after ICCE and after large posterior capsular rents with ECCE techniques. +• After completion of lens extraction, the pupil is constricted by injecting miotics (1% acetylcholine or pilocarpine without preservatives) into the anterior chamber. +• Anteriorchamberisfilled with 2% methylcellulose or 1% sodium hyaluronate (Healon). +• The IOL, held by a forceps, is gently slid into the anterior chamber. Interior haptic is pushed in the inferior angle at 6 O’clock position and upper haptic is pushed to engage in the upper angle (Figs 9.23G and H). +Technique of posterior chamber IOL implantation +Implantation of rigid intraocular lens. PCIOL is implanted after conventional ECCE and SICS and after enlarging the incision in phacoemulsification. After completion of ECCE, the capsular bag and anterior chamber are filled with 2% methylcellulose or 1% sodium hyaluronate. The PCIOL (Fig. 9.29C), is grasped by the optic with the help of IOL holding forceps. The inferior haptic and optic of IOL is gently inserted into the capsular bag behind the iris at 6 O’clock position (Fig. 9.24F). The superior haptic is grasped by its tip, and is gently pushed down + +and then released to slide in the upper part of the capsular bag behind the iris (Fig. 9.24G). The IOL is then dialled into the horizontal position (Fig. 9.24H). +Implantation of foldable IOLs is made either with the help of holder-folder forceps or the foldable IOL injector (Fig. 9.26H). +Scleral fixation of posterior chamber IOL is done as an alternative to anterior chamber IOL (ACIOL). Posterior chamber IOL can be fixated to the sclera in the ciliary sulcus region with the help of sutures or a biological glue (glued IOLs). + +POSTOPERATIVE MANAGEMENT AFTER CATARACT OPERATION + +1. Patient is asked to lie quietly upon the back for about 2–3 hours and advised to take nil orally. +2. Diclofenac sodium may be given for mild to moderate postoperative pain injection. +3. Next morning bandage/eye patch is removed and eye is inspected for any postoperative complication. +4. Antibiotic eyedrops are used for four times, 10-14 days. +5. Topical steroids (Prednisolone) eye drops 3 to 4 times a day are used for 6–8 weeks. +6. Topical ketorolac or any other NSAID eye drops 2 to 3 times/ day are used for 4 weeks. +7. Topical timolol (0.5%) eye drops twice daily are used for about 7–10 days. +8. Topical cycloplegic-mydriatic, e.g., homatropine eye drops may be used OD for 10–14 days. +Chapter 9 Diseases of Lens 211 + + +9. After 6–8 weeks of operation corneoscleral sutures are removed (when applied). Nowadays most surgeonsaredoingsuturelesscataractsurgery. +10. Final spectacles are prescribed after about 8 weeks of SICS operation and 3–4 weeks of phacoemulsification. + +COMPLICATIONS OF CATARACT SURGERY AND THEIR MANAGEMENT + +Nowadays cataract surgery is being performed largely by extracapsular cataract extraction technique. Therefore, complications encountered during these techniques are described in general. Wherever necessary a specific reference of the technique viz. conventional ECCE, manual SICS and phacoemulsification in relation to the particular complication is highlighted. Complications encountered during surgical management of cataract can be enumerated under the following heads: +(A) Preoperative complications (B) Operative complications +(C) Early postoperative complications +(D) Delayed (late) postoperative complications (E) IOL related complications +A. Preoperative complications +1. Anxiety. Some patients may develop anxiety, on the eve of operation due to fear and apprehension of operation. Anxiolytic drugs such as diazepam 2 to 5 mg at bed time usually alleviate such symptoms. 2. Nausea and gastritis. A few patients may develop nausea and gastritis due to preoperative medicines such as acetazolamide and/or glycerol. Oral antacids and omission of further dose of such medicines usually relieve the symptoms. +3. Irritative or allergic conjunctivitis may occur in some patients due to preoperative topical antibiotic drops. Postponing the operation for 2 days along with withdrawal of such drugs is required. +4. Corneal abrasion may develop due to inadvertent injury during Schiotz tonometry. Patching with antibiotic ointment for a day and postponement of operation for 2 days is required. +5. Complications due to local anaesthesia +• Retrobulbar haemorrhage may occur due to retrobulbar block. Immediate pressure bandage after instilling one drop of 2% pilocarpine and postponement of operation for a week is advised. Since, presently most cases are done under peribulbar or topical anaesthesia, so incidence of +retrobulbar haemorrhage has decreased drastically. + +• Oculocardiacreflex,which manifests as bradycardia and/or cardiac arrhythmia, has also been observed due to retrobulbar/peribulbar block. An intravenous injection of atropine is helpful. +• Perforation of globe may also occur sometimes. To prevent such catastrophy, gentle injection with blunt-tipped needle is recommended. Further, peribulbar anaesthesia may be preferred over retrobulbar block. +• Subconjunctival haemorrhage is a minor complication observed frequently, and does not need much attention. +• Spontaneous dislocation of lens in vitreous has also been reported (in patients with weak and degenerated zonules especially with hypermature cataract) during vigorous ocular massage after retrobulbar block. The operation should be postponed and further management is on the lines of posterior dislocation of lens (see page 217). +B. Operative complications +1. Superior rectus muscle laceration and/or haematoma, may occur while applying the bridle suture in conventional ECCE and SICS. Usually no treatment is required. +2. Excessive bleeding may be encountered during the preparation of conjunctival flap or during incision into the anterior chamber. Bleeding vessels may be gently cauterised. +3.Incision related complicationsdepend upon the type of cataract surgery being performed. +i. In conventional ECCE there may occur irregular incision. Irregular incision leading to defective coaptation of wound may occur due to blunt cutting instruments. +ii. InmanualSICSandphacoemulsificationfollowing complications may occur while making the self-sealing tunnel incision. +• Button holing of anterior wall of tunnel can occur because of superficial dissection of the scleral flap (Fig. 9.35B). As a remedy, abandon this dissection and re-enter at a deeper plane from the other side of the external incision. +• Premature entry into the anterior chamber can occur because of deep dissection (Fig. 9.35C). Once this is detected, dissection in that area should be stopped and a new dissection started at a lesser depth at the other end of the tunnel. +• Scleral disinsertion can occur due to very deep groove incision. In it there occurs complete separation of inferior sclera from the sclera superior to the incision (Fig. 9.35D). Scleral +212 Section II Diseases of Eye + + + + + + +A B C D +Fig. 9.35 Configuration of sclerocorneal tunnel incision: A, correct incision; B, buttonholing of anterior wall of the tunnel; C, premature entry into the anterior chamber; and D, scleral disinsertion + + +disinsertion needs to be managed by radial sutures. +4. Injury to the cornea (Descemet’s detachment), iris and lens may occur when anterior chamber is entered with a sharp-tipped instrument such as keratome or a piece of razor blade. A gentle handling with proper hypotony reduces the incidence of such inadvertent injuries. +5. Iris injury and iridodialysis (tear of iris from root) may occur inadvertently during intraocular manipulation. +6. Complications related to anterior capsulorrhexis +Continuous curvilinear capsulorrhexis (CCC) is the preferred technique for opening the anterior capsule for SICS and phacoemulsification. Following complications may occur: +■Escaping capsulorrhexis i.e., capsulorrhexis moves peripherally and may extend to the equator or posterior capsule. +■Small capsulorrhexis. It predisposes to posterior capsular tear and nuclear drop during hydrodissection. It also predisposes to occurrence of zonular dehiscence. Therefore, a small sized capsulorrhexis should always be enlarged by 2 or 3 relaxing incisions before proceeding further. +■Very large capsulorrhexis may cause problems for in the bag placement of IOL. ■Eccentriccapsulorrhexiscanlead to IOL decentration at a later stage. +7. Posterior capsular rupture (PCR). It is a dreaded complication during extracapsular cataract extraction. In manual SICS and phacoemulsification PCR is even more feared because it can lead to nuclear drop into the vitreous. The PCR can occur in following situations: +• During forceful hydrodissection, +• By direct injury with some instrument such as Sinskey’s hook, chopper or phacotip, and +• During cortex aspiration (accidental PCR). +8. Zonular dehiscence may occur in all techniques of ECCE but is especially common during nucleus prolapse into the anterior chamber in manual SICS. 9. Vitreous loss: It is the most serious complication which may occur following accidental rupture of + +posterior capsule during any technique of ECCE. Therefore, adequate measures as described below should be taken to prevent vitreous loss (especially useful in conventional ECCE). +■To decrease vitreous volume: Preoperative use of hyperosmotic agents like 20% mannitol or oral glycerol is suggested. +■To decrease aqueous volume: Preoperatively acetazolamide 500 mg orally should be used and adequate ocular massage should be carried out digitally after injecting local anaesthesia. ■Todecreaseorbitalvolume:Adequate ocular massage and orbital compression by use of superpinky, Honan’s ball, or 30 mm of Hg pressure by paediatric sphygmomanometer should be carried out. ■Betterocularakinesiaand anaesthesia decrease the chances of pressure from eye muscle. +■Minimising the external pressure on eyeball by not using eye speculum, reducing pull on bridle suture and overall gentle handling during surgery. +■Use of Flieringa ring to prevent collapse of sclera especially in highly myopic patients decreases the incidence of vitreous loss. +■WhenIOPishighin spite of all above measures and operation cannot be postponed, in that situation a planned posteriorsclerotomy with drainage of vitreous from pars plana will prevent rupture of the anterior hyaloid face and vitreous loss. Management of vitreous loss. Once the vitreous loss has occurred, the aim should be to clear it from the anterior chamber and incision site. This can be achieved by performing partial anterior vitrectomy with the use of automated vitrectors. +A meticulously performed partial anterior vitrectomy will reduce the incidence of postoperative problems associated with vitreous loss such as updrawn pupil, iris prolapse and vitreous touch syndrome. +10.Nucleus drop into the vitreous cavity. It occurs more frequently with phacoemulsification, less frequently with manual SICS and sparingly with conventional ECCE. It is a dreadful complication which occurs due to sudden and large PCR. +Chapter 9 Diseases of Lens 213 + + +Management. Once the nucleus has dropped into the vitreous cavity, no attempt should be made to fish it out. The case must be referred to vitreoretinal surgeon after a thorough anterior vitrectomy and cortical clean up. +11. Posterior loss of lens fragments into the vitreous cavity may occur after PCR or zonular dehiscence during phacoemulsification. It is potentially serious because it may result in glaucoma, chronic uveitis, chronic CME and even retinal detachment. Management. The case should be managed by vitreoretinal surgeon by performing pars plana vitrectomy and removal of nuclear fragments. +12. Expulsive choroidal haemorrhage. It is one of the most dramatic and serious complications of cataract surgery. It usually occurs in hypertensives and patients with arteriosclerotic changes. It may occur during operation or during immediate postoperative period. Its incidence was high in ICCE and conventional ECCE but has decreased markedly with valvular incision of manual SICS and phacoemulsification technique. +It is characterised by spontaneous gaping of the wound followed by expulsion of the lens, vitreous, retina, uvea and finally a gush of bright red blood. Although treatment is unsatisfactory, the surgeon should attempt to drain subchoroidal blood by performing an equatorial sclerotomy. Most of the time eye is lost so evisceration operation has to be performed. + +C. Early postoperative complications +1. Hyphaema. Collection of blood in the anterior chamber may occur from conjunctival or scleral vessels and rarely from the root of the iris. \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_8.txt b/notes/A K Khurana - Comprehensive Ophthalmology_8.txt new file mode 100644 index 0000000000000000000000000000000000000000..8929a48ca0fb8849e617a8ae15ff3884d7ca6ff8 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_8.txt @@ -0,0 +1,1599 @@ +Treatment. Most hyphaemas absorb spontaneously and thus need no treatment. Sometimes hyphaema may be large and associated with rise in IOP. In such cases, IOP should be lowered by acetazolamide and hyperosmotic agents. If the blood does not get absorbed in a week’s time, then a paracentesis should be done to drain the blood. +2. Iris prolapse. It is usually caused by inadequate suturing of the incision after ICCE and conventional ECCE and occurs during first or second postoperative day. This complication is not known with manual SICS and phacoemulsification technique. +Management.A small prolapse of less than 24 hours duration may be reposited back and wound sutured. A large prolapse of long duration needs abscission and suturing of wound. +3. Striate keratopathy. Characterised by mild corneal oedema with Descemet’s folds is a + +common complication observed during immediate postoperative period. This occurs due to endothelial damage during surgery. +Management. Mild striate keratopathy usually disappears spontaneously within a week. Moderate to severe keratopathy may be treated by instillation of hypertonic saline drops (5% sodium chloride) along with steroids. +4. Flat (shallow or nonformed) anterior chamber. It has become a relatively rare complication due to improved wound closure. It may occur due to wound leak, ciliochoroidal detachment or pupil block. +i. Flatanteriorchamberwithwoundleakis associated with hypotony. It is diagnosed by Seidel’s test. In this test, a drop of fluorescein is instilled into the lower fornix and patient is asked to blink to spread the dye evenly. The incision is then examined with slit-lamp using cobalt-blue filter. At the site of leakage, fluorescein will be diluted by aqueous. In most cases wound leak is cured within 4 days with pressure bandage and oral acetazolamide. If the condition persists, injection of air in the anterior chamber and resuturing of the leaking wound should be carried out. +ii. Ciliochoroidal detachment. It may or may not be associated with wound leak. Detached ciliochoroid presents as a convex brownish mass in the involved quadrant with shallow anterior chamber. In most cases, choroidal detachment is cured within 4 days with pressure bandage and use of oral acetazolamide. If the condition persists, suprachoroidal drainage with injection of air in the anterior chamber is indicated. iii.Pupilblockduetovitreousbulge(after ICCE or due to adhesions with IOL more common with ACIOLs) leads to formation of iris bombe and shallowing of anterior chamber. If the condition persists for 5–7 days, permanent peripheral anterior synechiae (PAS) may be formed leading to secondary angle closure glaucoma. +• Pupil block is managed initially with mydriatic, hyperosmotic agents (e.g., 20% mannitol) and acetazolamide.Ifnotrelieved,thenlaserorsurgical peripheral iridectomy should be performed to bypass the pupillary block. +5. Postoperative anterior uveitis can be induced by instrumental trauma, undue handling of uveal tissue, reaction to residual cortex or chemical reaction induced by viscoelastics, pilocarpine etc. Managementincludes more aggressive use of topical steroids, cycloplegics and NSAIDs. Rarely systemic +214 Section II Diseases of Eye + + +steroids may be required in cases with severe fibrinous reaction. +6. Toxic anterior segment syndrome (TASS) (see page 171) +7. Bacterial endophthalmitis. This is one of the most dreaded complications with an incidence of 0.2 to 0.5%. The principal sources of infection are contaminated solutions, instruments, surgeon’s hands, patient’s own flora from conjunctiva, eyelids and airborne bacteria. +Symptoms and signs of bacterial endophthalmitis are generally present between 48 and 72 hours after surgery and include: ocular pain, diminshed vision, lid oedema, conjunctival chemosis and marked circumciliary congestion, corneal oedema, exudates in pupillary area, hypopyon and diminished or absent red pupillary glow. +Management. It is an emergency and should be managed energetically (see page 171). +D. Late postoperative complications +These complications may occur after weeks, months or years of cataract surgery. +1. Cystoid macular oedema (CME). Collection of fluid in the form of cystic loculi in the Henle’s layer of macula is a frequent complication of cataract surgery. However, in most cases it is clinically insignificant, does not produce any visual problem and undergoes spontaneous regression. In few cases, a significant CME typically produces visual diminution one to three months after cataract extraction. On funduscopy it gives honeycomb appearance. On fluorescein angiography it depicts typical flower petal pattern (see Fig. 12.25A) due to leakage of dye from perifoveal capillaries. +• Etiopathogenesis. In most cases it is associated with vitreous incarceration in the wound and mild iritis. Role of some prostaglandins is being widely considered in its etiopathogenesis. +• Prevention. Therefore, immediate preoperative and postoperative use of antiprostaglandins (indomethacin or flurbiprofen or ketorolac) eyedrops is recommended as prophylaxis of CME. Treatment. In cases of CME with vitreous incarceration, anterior vitrectomy along with steroids and antiprostaglandins may improve visual acuity +and decrease the amount of discomfort. +2. Delayed chronic postoperative endophthalmitis is caused when an organism of low virulence (propionobacterium acne or staph epidermidis) becomes trapped within the capsular bag. It has an onset ranging from 4 weeks to years (mean 9 months) + +postoperatively and typically follows an uneventful cataract extraction with a PCIOL in the bag. Fungal endophthalmitis may occur rarely as delayed postoperative endophthalmitis. It is characterized by puff ball vitreous exudates. It needs to be treated by pars-plana vitrectomy and antifungal drugs administered intravitreally and orally. +3. Pseudophakic bullous keratopathy (PBK) is usually a continuation of postoperative corneal oedema produced by surgical or chemical insult to a healthy or compromised corneal endothelium. PBK is becoming a common indication of penetrating keratoplasty (PK). 4. Retinal detachment (RD). Incidence of retinal detachment is higher in aphakic patients as compared to phakics. It has been noted that retinal detachment is more common after ICCE than after ECCE and IOL implantation. Other risk factors for pseudophakic retinal detachment include vitreous loss during operation, associated myopia and lattice degeneration of the retina. +5. Epithelial ingrowth. Rarely conjunctival epithelial cells may invade the anterior chamber through a defect in the incision. This abnormal epithelial membrane slowly grows and lines the back of cornea and trabecular meshwork leading to intractable glaucoma. In late stages, the epithelial membrane extends on the iris and anterior part of the vitreous. 6. Fibrous downgrowth into the anterior chamber may occur very rarely when the cataract wound apposition is not perfect. It may cause secondary glaucoma, disorganisation of anterior segment and ultimately phthisis bulbi. +7. After cataract. It is also known as ‘secondary cataract’. It is the opacity which persists or develops after extracapsular lens extraction. +Causes. (i) Residual opaque lens matter may persist as after cataract when it is imprisoned between the remains of the anterior and posterior capsule, surrounded by fibrin (following iritis) or blood (following hyphaema). (ii) Proliferative type of after cataract may develop from the left out anterior epithelial cells in the capsular bag. The proliferative hyaline bands may sweep across the whole posterior capsule. +Clinical types. After-cataract may present as thickened posterior capsule opacification (PCO), or dense membranous after cataract (Fig. 9.36A) or Soemmering’s ring which refers to a thick ring of after cataract formed behind the iris, enclosed between the two layers of capsule (Fig. 9.36B) or +Elschnig’spearls in which the vacuolated subcapsular +Chapter 9 Diseases of Lens 215 + + +epithelial cells are clustered like soap bubbles along the posterior capsule (Fig. 9.36C). + +Treatmentis as follows: +i. Thin membranous after cataract and thickened posterior capsule are best treated by YAG-laser capsulotomy or discission with cystitome or Zeigler’s knife. +ii. Dense membranous after cataract needs surgical membranectomy. +iii. Soemmering’s ring after cataract with clean central posterior capsule needs no treatment. +iv. Elschnig’s pearls involving the central part of the posterior capsule can be treated by YAG-laser capsulotomy or discission with cystitome. +8. Glaucoma-in-aphakia and pseudophakia (see page 251). +E. IOL-related complications +In addition to the complications of cataract surgery, following IOL-related complications may be seen: +1. Complications like cystoid macular oedema, corneal endothelial damage, uveitis and secondary glaucoma are seen more frequently with IOL implantation, especially with anterior chamber and iris supported IOLs. +UGH syndrome refers to concurrent occurrence of uveitis, glaucoma and hyphaema. It used to occur commonly with rigid anterior chamber IOLs, which are not used nowadays. +2. Malpositions of IOL (Fig. 9.37). These may be in the form of decentration, subluxation and dislocation. The fancy names attached to various malpositions of IOL are: +• Sunset syndrome (Inferior subluxation of IOL). +• Sunrise syndrome (Superior subluxation of IOL). • Lost lens syndrome refers to complete dislocation +of an IOL into the vitreous cavity. + +• Windshieldwipersyndrome.It results when a very small IOL is placed vertically in the sulcus. In this the superior loop moves to the left and right, with movements of the head. +3. Pupillary capture of the IOL may occur following postoperative iritis or proliferation of the remains of lens fibres. +4. Toxic anterior segment syndrome (TASS). It is the uveal inflammation excited by either the ethylene gas used for sterilising IOLs (in early cases) or by the lens material (in late cases). It is characterised by violent inflammation and need to be differentiated from endophthalmitis. + +DISPLACEMENTS OF LENS + +Displacements of the lens from its normal position (in patellar fossa) results from partial or complete rupture of the lens zonules. + +CLINICO-ETIOLOGICAL TYPES +I. Congenital displacements +These may occur in the following forms: +(a) Simple ectopia lentis.In this condition, displacement is bilaterally symmetrical and usually upwards. It is transmitted by autosomal dominant inheritance. +(b) Ectopia lentis et pupillae. It is an autosomal recessive disorder, characterised by displacement of the lens associated with slit-shaped pupil which is displaced in the opposite direction. Other associationsmay be cataract, glaucoma, axial myopia macrocornea, abnormal iris transillumination and retinal detachment. +(c) Ectopia lentis with systemic anomalies. Salient features of some common conditions, are as follows: 1. Marfan’s syndrome. It is an autosomal dominant mesodermal dysplasia. In this condition, lens is + + + + + + + + + + + + + +A B C +Fig. 9.36 Types of after-cataract: A, dense membranous; B, Soemmering’s ring; C, Elschnig’s pearls +216 Section II Diseases of Eye + + + + + + + + + + + + + + + +Fig. 9.37 Decentered IOL + + +displaced upwards and temporally (bilaterally symmetrical) (Fig. 9.38). +• Systemicanomaliesinclude arachnodactyly (spider fingers), long extremities, hyperextensibility of joints, high arched palate and dissecting aortic aneurysm. +2. Homocystinuria. It is an autosomal recessive, inborn error of metabolism. In it the lens is usually subluxated inferior and nasally. +• Systemicfeaturesare fair complexion, malar flush, mental retardation, fits and poor motor control. +• Diagnosisis established by detecting homocystine in urine by sodium nitro-prusside test. +3. Weill-Marchesani syndrome. It is condition of autosomal recessive mesodermal dysplasia. +• Ocular features are spherophakia, and forward subluxation of lens (Fig. 9.39) which may cause pupil block glaucoma. +• Systemic features are short stature, stubby fingers and mental retardation. + + + + + + + + + + + + + + + +Fig. 9.38 Subluxated IOL in Marfan’s syndrome + +4. Ehlers-Danlos syndrome. In it the ocular features are subluxation of lens and blue sclera. The systemic featuresinclude hyperextensibility of joints and loose skin with folds. +5.Hyperlysinaemia.It is an autsomal recessive inborne error of metabolism occurring due to deficiency of the enzyme lysin alphaketoglutarate reductase. It is an extremely rare condition occasionally associated with ectopia lentis. Systemic features include lax ligaments, hypotonic muscles, seizures and mental handicap. +6. Stickler syndrome. Ectopia lentis is occasionally associated in this condition (for details see page 290). 7.Sulphite oxidase deficiency.It is a very rare autosomal recessive disorder of sulphur metabolism. Ectopia lentis is a universal ocular feature. The systemic features include progressive muscular rigidity, decerebrate posture, and mental handicap. It is a fatal disease, death usually occurs before 5 years of age. +II. Traumatic displacement of the lens +It is usually associated with concussion injuries. Couchingis an iatrogenic posterior dislocation of lens performed as a treatment of cataract in older days. +III. Consecutive or spontaneous displacement +It results from intraocular diseases giving rise to me-chanical stretching, inflammatory disintegration or degeneration of the zonules. A few common condi-tions associated with consecutive displacements are: hypermature cataract, buphthalmos, high myopia, staphyloma, intraocular tumours and uveitis. +TOPOGRAPHICAL TYPES +Topographically, displacements of the lens may be classified as subluxation and luxationor dislocation. + + + + + + + + + + + + + + + + +Fig. 9.39 Spherophakia and forward subluxation of lens in Weill-Marchesani syndrome +Chapter 9 Diseases of Lens 217 + + +I. Subluxation +It is partial displacement in which lens is moved sideways (up, down, medially or laterally), but remains behind the pupil. It results from partial rupture or unequal stretching of the zonules (Figs. 9.38 and 9.40A). +Clinical features are as follows: +• Defectivevisionoccurs due to marked astigmatism or lenticular myopia. +• Uniocular diplopia may result from partial aphakia. +• Anterior chamber becomes deep and irregular. • Iridodonesis is usually present. +• Edgeofthesubluxatedlens is seen as dark crescent line on distant direct ophthalmoscopy. +• And as a shining (bright) golden crescent on slit-lamp examination, Phacodonesis, i.e., trimulousness of lens may be seen. +• Retinoscopy reveals hypermetropia in aphakic area and myopia (index) in phakic area. +• Fundus examination shows large optic disc through phakic area and small optic disc through aphakic area. +Complications of subluxated lens include: +• Complete dislocation, • Cataractous changes, • Uveitis, and +• Secondary glaucoma. +Management. Spectacles or contact lens correction for phakic or aphakic area (whichever is better) is helpful in many cases. Surgery is controversial and usually associated with high risk of retinal detachment. Lensectomy with anterior vitrectomy may be performed in desperate cases. + + +II. Dislocation or luxation of the lens +In it all the zonules are severed from the lens. A dislocated lens may be incarcerated into the pupil or present in the anterior chamber (Fig. 9.40B), the vitreous (Fig. 9.40C) (where it may be floating—lens nutans; or fixed to retina—lens fixata), sub-retinal space, subscleral space or extruded out of the globe, partially or completely. +Clinical featuresof posterior dislocation.These include: deep anterior chamber, aphakia in pupillary area, and iridodonesis. Ophthalmoscopic examination reveals lens in the vitreous cavity. +Clinical features of anterior dislocationare deep anterior chamber and presence of lens in the anterior chamber. Clear lens looks like an oil drop in the aqueous. Complications associated with dislocated lens are uveitis and secondary glaucoma. +Management is as below: +• A lens dislocated in the anterior chamber and that incarcerated in the pupil should be removed as early as possible. +• Adislocatedlensfromthevitreouscavity should be removed only if it is causing uveitis or glaucoma. From the vitreous cavity lens can be removed after total vitrectomy, either with the help of an insulated vitreous cryoprobe or by aspiration facility of vitrectomy probe (only soft cataract). + +CONGENITAL ANOMALIES OF THE LENS + +1. Colobomaoflens. It is seen as a notch in the lower quadrant of the equator (Fig. 9.41). It is usually unilateral and often hereditary. + + + + + + + + + + + + + + +A B C + +Fig. 9.40 Displacements of lens: A, subluxation; B, anterior dislocation; C, posterior dislocation +218 Section II Diseases of Eye + + + + + + + + + + + +A + +A + + + + + + + + + + +B +Fig. 9.42 Lenticonus anterior: A, Diagrammatic; B, Slit-lamp photograph + +B +Fig. 9.41 Coloboma of the lens: A, Diagrammatic depiction; B, Clinical photograph + + + + + +2. Congenital ectopia lentis (see lens displacement page 215). +3. Lenticonus. It refers to cone-shaped elevation of the anterior pole (lenticonus anterior, Fig. 9.42) or posterior pole (lenticonus posterior, Fig. 9.43) of the lens. Lenticonus anterior may occur in Alport’s syndrome and lenticonus posterior in Lowe’s syndrome. On distant direct ophthalmoscopy, both present as an oil globule lying in the centre of the red reflex. Slit-lamp examination confirms the diagnosis. +4. Congenital cataract. (see page 182). +5. Microspherophakia. In this condition, the lens is spherical in shape (instead of normal biconvex) and small in size (Fig. 9.39). Microspherophakia may occur as an isolated familial condition or as a feature of other syndromes e.g.,Weill-Marchesani or Marfan’s syndrome. + + + + + +A + + + + + + + + + + + +B +Fig. 9.43 Lenticonus posterior: A, Diagrammatic; B, Slit-lamp photograph +10 + +Glaucoma + + + +CHAPTER OUTLINE + +ANATOMY AND PHYSIOLOGY +Applied anatomy +• +• Applied physiology +GLAUCOMA: AN OVERVIEW +• Definition and classification of glaucoma Pathogenesis of glaucomatous ocular damage +• +CONGENITAL/DEVELOPMENTAL GLAUCOMAS Terminology +• +• +• +Primary congenital/developmental glaucoma Developmental glaucomas with associated anomalies +PRIMARY OPEN-ANGLE GLAUCOMA AND RELATED CONDITIONS + + + +ANATOMY AND PHYSIOLOGY +APPLIED ANATOMY +Pathophysiology of glaucoma revolves around the aqueous humour dynamics. The principal ocular structures concerned with it are ciliary body, angle of anterior chamber and the aqueous outflow system. +Ciliary body +It is the site of aqueous production. Applied aspects of its anatomy have been described on page 147. +Angle of anterior chamber +Angle of anterior chamber plays an important role in the process of aqueous drainage. It is formed by root of iris, anterior-most part of ciliary body, scleral spur, trabecular meshwork and Schwalbe’s line(prominent end of Descemet’s membrane of cornea) (Fig. 10.1). The angle width varies in different individuals and plays a vital role in the pathomechanism of different types of glaucoma. Clinically, the angle structures can be visualised by gonioscopic examination (see page 568). +Gonioscopic grading of the angle width. Various systems have been suggested to grade angle width. + +• Primary open-angle glaucoma Ocular hypertension +Normal tension glaucoma +• +• +PRIMARY ANGLE-CLOSURE DISEASE Epidemiology +• +• +• +• +• +• +• +Etiopathogenesis Classification +Clinical profile & management Primary angle-closure suspect Primary angle-closure +Primary angle-closure glaucoma SECONDARY GLAUCOMAS +SURGICAL PROCEDURES FOR GLAUCOMA + + + +ThemostcommonlyusedShaffer’ssystemofgrading the angle is given in Table 10.1 and is shown in Fig. 10.2. +Aqueous outflow system +It includes the trabecular meshwork, Schlemm’s canal, collector channels, aqueous veins and the episcleral veins (Fig. 10.3). +1. Trabecular meshwork. It is a sieve-like structure through which aqueous humour leaves the eye. It consists of three layers, which from inside out + + + + + + + + + + + + +Fig. 10.1 Section of the anterior ocular structures showing region of the anterior chamber +220 Section III Diseases of Eye + +Table 10.1 Shaffer’s system of grading the angle width + + +Grade Angle width 4 40° +3 30° 2 20° 1 10° S <10° +0 0° + +Configuration Wide open Open angle +Moderately narrow Very narrow +Slit angle +Closed + +Risk of closure Closure impossible Closure impossible Closure possible High risk of closure Closure imminent +Closed + +Structures visible on gonioscopy SL, TM, SS, CBB +SL, TM, SS SL, TM +SL only +No angle structures seen +None of the angle structures visible + + +SL = Schwalbe’s line, TM = Trabecular meshwork, SS = Scleral spur, CBB = Ciliary body band + + + + + + + + + + +A + + + + + +Fig. 10.3 The aqueous outflow system + + + + + + + +B + +Fig. 10.2 Diagrammatic depiction of various angle structures (SL, Schwalbe’s line; TM, trabecular meshwork; SS, scleral spur; CBB, ciliary body band: ROI root of iris) as seen in different grades of angle width (Schaffer’s grading system): A, gonioscopic view; B, configuration of the angle in cross section of the anterior chamber + +are uveal meshwork, corneoscleral meshwork and juxtacanalicular meshwork. +i. Uveal meshwork. It is the innermost part of trabecular meshwork and extends from the iris root and ciliary body to the Schwalbe’s line. The arrangement of uveal trabecular bands create openings of about 25m to 75m. +ii. Corneoscleral meshwork. It forms the larger middle portion which extends from the scleral spur to the lateral wall of the scleral sulcus. It consists of + +sheets of trabeculae that are perforated by elliptical openings which are smaller than those in the uveal meshwork (5m–50m). +iii.Juxtacanalicular (endothelial) meshwork. It forms the outermost portion of trabecular meshwork and consists of juxtacanalicular space (filled with ground substance) and cells. The juxtacanalicular cell cytoplasmic processes attach externally to the processes arising from the innerwall endothelium of Schlemm’s canal and internally to the processes arising from the cells of corneoscleral meshwork. Thus, this narrow part of trabeculum connects the corneoscleral meshwork with Schlemm’s canal. This part of trabecular meshwork mainly offers normal resistance to the aqueous outflow. +2. Schlemm’s canal. This is an endothelial lined oval channel present circumferentially in the scleral sulcus. The endothelial cells of its inner wall are irregular, spindle-shaped and contain giant vacuoles and or aqueous valve. The outer wall of the canal is lined by smooth flat cells and contains the openings of collector channels. +Chapter 10 Glaucoma 221 + + +3. Collector channels. These, also called intrascleral aqueous vessels, are about 25–35 in number and leave the Schlemm’s canal at oblique angles to terminate into episcleral veins in a laminated fashion. These intrascleral aqueous vessels can be divided into two systems (Fig. 10.3): +■Direct system. It is formed by the larger vessels (aqueous veins) which run a short intrascleral course and terminate directly into episcleral veins. ■Indirect system. It is formed by the smaller collector channels which form an intrascleral plexus before eventually going into episcleral veins. +APPLIED PHYSIOLOGY +The physiological processes concerned with the dynamics of aqueous humour are its production, drainage and maintenance of intraocular pressure. + +Aqueous Humour and its Production +Functions and composition of aqueous humour Volume. The aqueous humour is a clear watery fluid filling the anterior chamber (0.25 ml) and posterior chamber (0.06 ml) of the eyeball. +Functions of aqueous humour are: +• Maintenance of a proper intraocular pressure. +• Metabolic and nutritional role. It plays an important metabolic role by providing substrates (nutrition) and by removing metabolites from the avascular cornea and lens. +• Optical function. It maintains optical transparency. • Clearing function. Aqueous humour serves as a mechanism to clear blood, macrophages, remnants of lens matter and products of inflammation from anterior chamber. Thus, it takes the place of lymph +that is absent within the eyeball. +Refractive index of aqueous humour is 1.336. Composition. Constituents of normal aqueous humour are: +• Water 99.9% and solids 0.1% (given below). +• Proteins (colloid content). Because of blood aqueous barrier the protein content of aqueous humour (5–16 mg%) is much less than that of plasma (6–7 gm%). However, in inflammation of uvea (iridocyclitis) the blood-aqueous barrier is broken and the protein content of aqueous is increased (plasmoid aqueous). +• Amino acid constituent of aqueous humour is about 5 mg/kg water. +• Noncolloid constituents in millimols/kg water are glucose (6.0), urea (7), ascorbate (0.9), lactic acid (7.4), inositol (0.1), Na+ (144), K+ (4.5), Cl– (10), and HCO – (34). +3 + +• Oxygen is present in the aqueous humour in dissolved state. +Note. Thus, composition of aqueous is similar to plasma except that it has: +• High concentrations of bicarbonate, ascorbate, pyruvate and lactate; and +• Low concentration of protein, urea and glucose. +Aqueous humour: anterior chamber versus posterior chamber. The composition of aqeuous humour in anterior chamber differs from that of the aqueous humour in posterior chamber because of metabolic interchange. The main differences are: +• HCO3 in posterior chamber aqueous is higher than +– +in the anterior chamber. +• Cl– concentration in posterior chamber is lower than in the anterior chamber. +• Ascorbate concentration of posterior aqueous is slightly higher than that of anterior chamber aqueous. +Aqueous humour formation +Aqueous humour is derived from plasma within the capillary network of ciliary processes. The normal aqueous production rate is 2.3 ml/min. The three mechanisms diffusion, ultrafiltration and secretion (active transport) play a part in its production at different levels. The steps involved in the process of production are summarized below: +1. Ultrafiltration. First of all, by ultrafiltration, most of the plasma substances pass out from the capillary wall and loose connective tissue. Thus, the plasma filtrate (dialysate) accumulates behind the pigmented and nonpigmented epithelium of ciliary processes. +2. Secretion. First the dialysate from the plasma is transported into the pigment epithelium. Paired Na+/ +H+ and Cl–/HCO3– antiports actively transports Na+ +and Cl– from the stroma into the cells. Intercellular gap junctions also play critical rule. The tight junctions between the cells of the nonpigment epithelium create part of blood aqueous barrier. Certain substances are actively transported (secreted) across this barrier into the posterior chamber. The active transport is brought about by Na+-K+ activated ATPase pump, calcium and voltage gated ion channels and carbonic anhydrase enzyme system. Substances that are actively transported include sodium, chlorides, potassium, ascorbic acid, amino acids and bicarbonates. +3. Diffusion. Active transport of these substances across the nonpigmented ciliary epithelium results in an osmotic gradient leading to the movement of other plasma constituents into the posterior +222 Section III Diseases of Eye + + +chamber by ultrafiltration and diffusion. Sodium is primarily responsible for the movement of water into the posterior chamber. As the aqueous humour passes from the posterior chamber to Schlemm’s canal, there occurs sufficient diffusional exchange with the surrounding structures (ciliary body, iris lens, cornea and trabecular meshwork). As a result the anterior chamber aqueous resembles plasma more closely than does the posterior chamber aqueous humour. +Control of aqueous formation +The diurnal variation in intraocular pressure certainly indicates that some endogenous factors do influence the aqueous formation. The exact role of such factors is yet to be clearly understood. Vasopressin and adenyl-cyclase have been described to affect aqueous formation by influencing active transport of sodium. +Ultrafiltration and diffusion, which primarily operate against concentration gradient, the passive mechanisms of aqueous formation, are dependent on the level of blood pressure in the ciliary capillaries, the plasma osmotic pressure and the level of intraocular pressure. + +Drainage of Aqueous Humour +Aqueous humour flows from the posterior chamber into the anterior chamber through the pupil against slight physiologic resistance. From the anterior chamber the aqueous is drained out by two routes (Fig. 10.5): + +1. Trabecular (conventional) outflow +Trabecular meshwork is the main outlet for aqueous from the anterior chamber. Approximately 70–80% of the total aqueous is drained out via this route. +Free flow of aqueous occurs from trabecular meshwork up to inner wall of Schlemm’s canal which appears to provide some resistance to outflow. +Mechanism of aqueous transport across inner wall of Schlemm’s canal. +Various theories put forward to explain the flow of aqueous across the inner wall of Schlemm’s canal can be grouped as below: +I. Passive filter mechanisms. Earlier it was believed that from the juxtacanalicular space. The aqueous humour enters the Schlemm’s canal against slight resistance. Following mechanisms were postulated which are now discarded and have become a part of historical interest only: +• Leaky pores in endothelial cells forming the inner wall of Schlemm’s canal were proposed. + +• Contractile microfilaments in the endothelial cells were suggested by some workers. +• Sondermann’s channels were also suggested to be responsible for aqueous outflow the inner wall of Schlemm’s canal. +• Vacuolation theory. It was one of the most accepted view till recent past. According to it, transcellular spaces exist in the endothelial cells forming inner wall of Schlemm’s canal. These open as a system of vacuoles and pores, primarily in response to pressure, and transport the aqueous from the juxtacanalicular connective tissue to Schlemm’s canal (Fig. 10.4). +II. Aqueous outflow active pump mechanism. Aqueous flow through the aqueous outflow system has long been considered a passive filter mechanism against the pressure gradient. However, recently it has been reported that aqueous outflow system acts as a biomechanical pump. It has been proposed that: ■Aqueous outflow pump operates through oscillatory +pressure transients caused by the ocular pulse, blinking and eye movements. +• Trabecular meshwork actively moves outward and recoils back in response to the oscillatory pressure transients. Thus, trabecular meshwork flexibility is essential for the aqueous outflow pump mechanism. +• Aqueous valve mechanism has been reported to operate at the level of inner wall of Schlemm’s canal (SC). These valves are oriented circumferentially in SC and their lumen is continuous with the juxtacanalicular space. These valves allow one way passage of aqueous humour from the juxtacanalicular space to inside the SC and not vice–versa. +• Aqueous outflowpump system is a part of vascular circulatory loop. During cardiac diastole the IOP is slightly decreased due to less blood flow to the choroidal vasculature. As a consequence, the trabecular meshwork is retracted inward leading to a negative pressure inside the Schlemm’s canal and opening of the aqueous valves. This is followed by flow of aqueous inside the SC. +• Aqueous humour flow from SC to collector’s channels and episcleral venis. During cardiac systole the choroidal vasculature explansion leads to transient rise in IOP. The aqueous pulse wave distends the trabecular meshwork (TM) forcing it outward against the SC. As a consequence of this pressure push the aqueous valves close and aqueous from the SC is pushed through the collector channels in its outer wall into the aqueous veins. +Chapter 10 Glaucoma 223 + + + + + + + + + + + + + + + + + +A B + +Fig. 10.4 Vacuolation theory of aqueous transport across the inner wall of the Schlemm’s canal: 1. Nonvacuolated stage; 2. Stage of early infolding of basal surface of the endothelial cell; 3. Stage of macrovacuolar structure formation; 4. Stage of vacuolar transcellular channel formation; 5. Stage of occlusion of the basal infolding + + + +• From aqueous veins the aqueous is pushed into the episcleral veins by the same mechanism. The pressure gradient between IOP (16 mm of Hg ) and episcleral venous pressure (about 10 mm of Hg) also facilitates this unidirectional pulsatile flow of aqueous humour. +2. Uveoscleral (unconventional) outflow +It is responsible for about 20 to 30% of the total aqueous outflow. The aqueous enters the ciliary body through the iris root, ciliary body face and uveal trabecular meshwork. Aqueous passes across the ciliary body between the bundles of ciliary muscles into the suprachoroidal space and is drained by the venous circulation of the ciliary body, choroid and sclera. +The drainage of aqueous humour is summarized in the flowchart (Fig. 10.5). +Maintenance of Intraocular Pressure +The intraocular pressure (IOP) refers to the pressure exerted by intraocular fluids on the coats of the eyeball. The normal IOP varies between 10 and 21 mm of Hg (mean 16 + 2.5 mm of Hg). The normal level of IOP is essentially maintained by a dynamic equilibrium between the formation and outflow of the aqueous humour. Various factors influencing intraocular pressure can be grouped as under: +A. Local factors +1. Rate of aqueous formation influences IOP levels. The aqueous formation in turn depends upon + + + + + + + + + + + + + + + + + + + + + + +Fig. 10.5 Flow chart depicting drainage of aqueous humour +many factors such as permeability of ciliary capillaries and osmotic pressure of the blood. +2. Resistance to aqueous outflow (drainage). From clinical point of view, this is the most important factor. Most of the resistance to aqueous outflow is at the level of trabecular meshwork. +3. Increased episcleral venous pressure may result in rise of IOP. The Valsalva manoeuvre causes +224 Section III Diseases of Eye + + +temporary increase in episcleral venous pressure and rise in IOP. +4. Dilatation of pupil in patients with narrow anterior chamber angle may cause rise of IOP owing to a relative obstruction of the aqeuous drainage by the iris. +5. Refractive errors. Myopic individuals have higher IOP as compared to emmetropes and hypermetropes. Infact, IOP correlates with axial length. +B. General factors +1. Heredity. It influences IOP, possibly by multi-factorial modes. +2. Age. The mean IOP increases after the age of 40 years, possibly due to reduced facility of aqueous outflow. +3. Sex. IOP is equal between the sexes in ages 20–40 years. In older age groups increase in mean IOP with age is greater in females. +4. Diurnal variation of IOP. Usually, there is a tendency of higher IOP in the morning and lower in the late evening (Fig. 10.9). This has been related to diurnal variation in the levels of plasma cortisol. Normal eyes have a smaller fluctuation (<5 mm of Hg) than glaucomatous eyes (>8 mm of Hg). +5. Postural variations. IOPincreases when changing from the sitting to the supine position. +6. Seasonal variations. IOP is higher in winter months. +7. Blood pressure. As such it does not have long-term effect on IOP. However, prevalence of glaucoma is marginally more in hypertensives than the normotensives. +8. Osmotic pressure of blood. An increase in plasma osmolarity (as occurs after intravenous mannitol, oral glycerol or in patients with uraemia) is associated with a fall in IOP, while a reduction in plasma osmolarity (as occurs with water drinking provocative tests) is associated with a rise in IOP. +9. General anaesthetics and many other drugs also influence IOP, e.g., alcohol lowers IOP, tobacco smoking, caffeine and steroids may cause rise in IOP. In addition there are many antiglaucoma drugs which lower IOP. +10.Exercise. Strenous exercise lowersIOP transiently. + +GLAUCOMA: AN OVERVIEW +DEFINITION AND CLASSIFICATION OF GLAUCOMA +Definition +Glaucoma is not a single disease process but a group of disorders characterized by a progressive optic + +neuropathy resulting in a characterstic appearance of the optic disc and a specific pattern of irreversible visual field defects that are associated frequently but not invariably with raised intraocular pressure (IOP). Thus, IOP is the most common risk factor but not the only risk factor for development of glaucoma. Consequently the term ‘ocular hypertension’ is used for cases having constantly raised IOP without any associated glaucomatous damage. Conversely, the term normal or low tension glaucoma (NTG/LTG) is suggested for the typical cupping of the disc and/ or visual field defects associated with a normal or low IOP. +Classification +Clinico-etiologically glaucoma may be classified as follows: +A. Congenital/developmental glaucomas +1. Primary congenital glaucoma (without associated anomalies). +2. Developmental glaucoma (with associated anomalies). +B. Primary adult glaucomas +1. Primary open-angle glaucomas (POAG) 2. Primary angle-closure glaucoma (PACG) 3. Primary mixed mechanism glaucoma +C. Secondary glaucomas + +EPIDEMIOLOGY +Global prevalence of glaucoma +• 2% of those over the age of 40 years, and • 10% of those over 80 years of age. +POAG Versus PACG in different ethnic groups Ethnic group POAG : PACG ■Indian 1 : 1 ■Urban Chinese 1 : 2 ■Mongolian 1 : 3 ■European, African 5 : 1 +and Hispanic + +Glaucoma blindness • Global : 8.0% +• India : 12.8% +PATHOGENESIS OF GLAUCOMATOUS OCULAR DAMAGE +As mentioned in definition, all glaucomas (classified above and described later) are characterized by a progressive optic neuropathy. It has now been recognized that progressive optic neuropathy results from the death of retinal ganglion cells (RGCs) in a typical pattern which results in characteristic optic disc appearance and specific visual field defects. +Chapter 10 Glaucoma 225 + + +Pathogenesis of Retinal Ganglion Cell Death Retinal ganglion cell (RGC) death is initiated when some pathologic event blocks the transport of growth factors (neurotrophins) from the brain to the RGCs. The blockage of these neurotrophins initiate a damaging cascade, and the cell is unable to maintain its normal function. The RGCs losing their ability to maintain normal function undergo apoptosis and also trigger apoptosis of adjacent cells. Apoptosis is a genetically controlled cell suicide programme whereby irreversibly damaged cells die, and are subsequently engulfed by neighbouring cells, without eliciting any inflammatory response. +Retinal ganglion cell death is, of course, associated with loss of retinal nerve fibres. As the loss of nerve fibres extends beyond the normal physiological overlap of functional zones, the characteristic optic disc changes and specific visual field defects become apparent over the time. +Etiological factors +Factors involved in the etiology of retinal ganglion cell death and thus in the etiology of glaucomatous optic neuropathy can be grouped as below: +A. Primary insults +1. Raised intraocular pressure (Mechanical theory). Raised intraocular pressure causes mechanical stretch on the lamina cribrosa leading to axonal deformation and ischaemia by altering capillary blood flow. As a result of this, neurotrophins (growth factors) are not able to reach the retinal ganglion cell bodies in sufficient amount needed for their survival. 2. Pressure independent factors (Vascular insuffciency theory). Factors affecting vascular perfusion of optic nerve head in the absence of raised IOP have been implicated in the glaucomatous optic neuropathy in patients with normal tension glaucoma (NTG). However, these may be the additional factors in cases of raised IOP as well. These factors include: +i. Failure of autoregulatory mechanism of blood flow. The retina and optic nerve share a peculiar mechanism of autoregulation of blood flow with rest of the central nervous system. Once the autoregulatory mechanisms are compromised, blood flow may not be adequate beyond some critical range of IOP (which may be raised or in normal range). +ii. Vasospasm is another mechanism affecting vascular perfusion of optic nerve head. This hypothesis gets credence from the convincing association between NTG and vasospastic disorders (migranous headache and Raynaud’s phenomenon). + + +iii. Systemic hypotension, particularly nocturnal dips in patients with night time administration of antihypertensive drugs, has been implicated for low vascular perfusion of optic nerve head resulting in NTG and progression of damage in POAG. +iv. Other factors such as acute blood loss and abnormal coagulability profile have also been associated with NTG. +B. Secondary insults (Excitotoxicity theory) +Neuronal degeneration is believed to be driven by toxic factors such as glutamate (excitatory toxin), oxygen-free radicals, or nitric oxide which are released when RGCs undergo death due to primary insults. In this way, the secondary insult leads to continued damage-mediated apoptosis, even after the primary insult has been controlled. + +CONGENITAL/DEVELOPMENTAL GLAUCOMAS +TERMINOLOGY +The congenital glaucomas are a group of diverse disorders in which abnormal high intraocular pressure results due to developmental abnormalities of the angle of anterior chamber obstructing the drainage of aqueous humour. Sometimes, glaucoma may not occur until several years after birth; therefore, the term developmental glaucoma is preferred to describe such disorders. +Types +1.Primary developmental/congenital glaucoma. 2.Developmental glaucoma with associated +congenital ocular anomalies. +3.Developmental glaucoma with associated systemic anomalies. +PRIMARY CONGENITAL/DEVELOPMENTAL GLAUCOMA +Primary congenital glaucoma (PCG) refers to abnor-mally high IOP which results due to developmental anomaly of the angle of the anterior chamber, not associated with any other ocular or systemic anomaly. Depending upon the age of onset the developmental glaucomas are termed as follows: +1. Newborn glaucoma, also called as true congenital glaucoma, is labelled when IOP is raised during intrauterine life and child is born with ocular enlargement. It accounts for about 40% of cases. +2. Infantile glaucoma is labelled when the disease manifests prior to the child’s third birthday. It accounts for about 55% of cases. +3. Juvenile glaucoma is labelled in the rest 5% of cases who develop pressure rise after 3 years but before adulthood. Also known as Juvenile primary open +226 Section III Diseases of Eye + + +angle glaucoma(POAG) usually occurs between 10 to 35 years of age. About 35% of patients with juvenile POAG are myopes. The disease has a strong autosomal dominant inheritance . Some of the families suffering from juvenile POAG have a genetic anomaly on the long arm of chromosome 21. Buphthalmos. When the disease manifests prior to age of 3 years, the eyeball enlarges and so the term ‘buphthalmos’ (bull-like eyes) is used. As it results due to retention of aqueous humour (watery solution), the term ‘hydrophthalmos,’ has also been suggested. +Prevalence and genetic pattern +• Sporadic occurrence is seen in most cases (90%). • Autosomal recessive inheritance with incomplete +penetrance is seen in about 10% cases. +• Loci linked with PCG are 2p21(GLC3A), 1p36 (GLC3B) and 14q24 (GLC3C). +• Sex linkage is not common in inheritance although over 65% of the patients are boys. +• Bilateral occurrence is seen in 70% cases, though the involvement may be asymmetric. +• Prevalence of the disease is only 1 child in 10,000 births. +Pathogenesis +Maldevelopment, from neural crest derived cells, of trabeculum including the iridotrabecular junction (trabeculodysgenesis) is responsible for impaired aqueous outflow resulting in raised IOP. In primary congenital glaucoma, the trabeculodysgenesis is not associated with any other major ocular anomalies. Clinically, trabeculodysgenesis is characterized by absence of the angle recess with iris having a flat or concave direct insertion into the surface of trabeculum as follows: +■Flat iris insertion is more common than the concave iris insertion. In it the iris inserts flatly and abruptly into the thickened trabeculum either at or anterior to scleral spur (more often) or posterior to scleral spur. It is often possible to visualize a portion of ciliary body and scleral spur. +■Concave iris insertion is less common. In it the superficial iris tissue sweeps over the iridotrabecular junction and the trabeculum and, thus, obscures the scleral spur and ciliary body. +Clinical features +1. Lacrimation, photophobia and blepharospasm often occur together and form the classic triad of symptoms of congenital glaucoma. Often there is history of rubbing of the eyes. These are thought to be caused by irritation of corneal nerves, which occurs as a result of the elevated IOP. Photophobia is usually the initial sign, but is not enough by itself to arouse suspicion in most cases. + +2. Corneal signs. Corneal signs include its oedema, enlargement and Descemet’s breaks. +i. Corneal oedema. It is frequently the first sign which arouses suspicion. At first it is epithelial, but later there is stromal involvement and permanent opacities may occur. +ii. Corneal enlargement. It occurs alongwith enlargement of globe-buphthalmos (Fig. 10.6), especially when the onset is before the age of 3 years. Normal infant cornea measures 10.5 mm. A diameter of more than 13 mm confirms enlargement. Prognosis is usually poor in infants with corneal diameter of more than 16 mm. +iii. Tears and breaks in Descemet’s membrane (Haab’s striae). These occur because Descemet’s membrane is less elastic than the corneal stroma. Tears are usually peripheral, concentric with the limbus and appear as lines with double contour. +3. Sclera becomes thin and appears blue due to underlying uveal tissue. +4. Anterior chamber becomes deep. +5. Iris may show iridodonesis and atrophic patches in late stage. +6. Lens becomes flat due to stretching of zonules and may even subluxate backward. +7. Optic disc may show variable cupping and atrophy especially after third year. +8. IOP is raised which is neither marked nor acute. 9. Axial myopia may occur because of increase in axial length which may give rise to anisometropic amblyopia. +Examination (Evaluation) +A complete examination under general anaesthesia (EUA) should be performed on each child suspected of having congenital glaucoma. The examination should include following: +1. Measurement of IOP with Schiotz or preferably hand held Perkin’s applanation tonometer since scleral rigidity is very low in children. IOP measurement under GA is unpredictably altered. + + + + + + + + + + + + +Fig. 10.6 Corneal enlargement in a child with congenital glaucoma +Chapter 10 Glaucoma 227 + + +2. Measurement of corneal diameter by callipers. +3. Slit-lamp examination should be carried out with portable slit-lamp. +4. Ophthalmoscopy to evaluate optic disc. +5. Gonioscopic examination of angle of anterior chamber reveals trabeculodysgenesis with either flat or concave iris insertion as described in pathogenesis. +Differential diagnosis +It is to be considered for different presenting signs as follows: +1. Cloudy cornea. In unilateral cases, the commonest cause is trauma with rupture of Descemet’s membrane (forceps injury). In bilateral cases, causes may be trauma, mucopolysaccharidosis, interstitial keratitis and corneal endothelial dystrophy. +2. Large cornea due to buphthalmos should be differentiated from megalocornea, sclerocornea and high myopia. +3. Lacrimation in an infant is usually considered to be due to congenital nasolacrimal duct blockage and thus early diagnosis of congenital glaucoma may be missed. Other causes of watering in small child include corneal abrasion, Meesman’s corneal dystrophy and Reis-Buckler dystrophy. +4. Photophobia may be due to keratitis or uveitis. +5. Raised IOP in infants may also be associated with retinoblastoma, retinopathy of prematurity, persistent primary hyperplastic vitreous, traumatic glaucoma and secondary congenital glaucoma seen in rubella, aniridia and Sturge-Weber syndrome. +6. Optic disc changes need to be differentiated from congenital anomalies of the disc such as pit, coloboma, hypoplasia, tilted disc and large physiological cup. +Treatment +Medical treatment +Medications are not very effective and so treatment of congenital glaucoma is primarily surgical. However, IOP must be lowered by medical treatment with hyperosmotic agents, acetazolamide and beta-blockers till surgery is taken up. Miotics are not used in such cases because they paradoxically increase IOP. Alpha-2 agonist (brimonidine) causes CNS depression in children and is contraindicated. +Surgical procedures for congenital glaucoma +I. Incisional angle surgery, which can be performed by the internal approach (goniotomy) or by external approach (trabeculectomy). +1.Goniotomy(Fig. 10.7). In this procedure, a Barkan’s goniotomy knife is passed through the limbus on the temporal side. Under gonioscopic control the knife + + + + + + + + + + +A + + + + + + + + + + + +B + +Fig. 10.7 Technique of goniotomy: A, showing position of goniotomy knife in the angle under direct visualization; B, showing procedure of sweeping the knife in the angle + + +is passed across the anterior chamber to the nasal part of the angle. An incision is made in the angle approximately midway between root of the iris and Schwalbe’s ring through approximately 75°. The knife is then withdrawn. Although the procedure may have to be repeated, the eventual success rate is about 85%. 2.Trabeculotomy. This is useful when corneal clouding prevents visualization of the angle or in cases where goniotomy has failed. In this, canal of Schlemm is exposed at about 12 O’clock position by a vertical scleral incision after making a conjunctival flap and partial thickness scleral flap. The lower prong of Harm’s trabeculotome is passed along the Schlemm’s canal on one side and the upper prong is used as a guide (Fig. 10.8). Then the trabeculotome is rotated so as to break the inner wall over one quarter of the canal. This is then repeated on the other side. The main difficulty in this operation is localization of the Schlemm’s canal. +II. Filteration surgery is required in many cases: +1. Trabeculectomy with antimetabolites gives good results. +2. Combined trabeculotomy and trabeculectomy with antimetabolites has been accepted as the standard procedure. +III. Glaucoma drainage devices (GDD) are required in incalcitrant cases. +228 Section III Diseases of Eye + + + + + + + + + + + + + + + + + + + + +Fig. 10.8 Technique of trabeculotomy + +DEVELOPMENTAL GLAUCOMAS WITH ASSOCIATED OCULAR ANOMALIES +A wide variety of systemic and/or ocular anomalies have an associated raised IOP, usually due to developmental defects of the anterior chamber angle. Some of the associations are as follows: +I. Glaucoma associated with iridodysgenosis 1. Glaucoma associated with aniridia (50%) +2. Glaucoma associated with familial iris hypoplasia 3. Glaucoma associated with congenital ectropion +uvea +4. Glaucoma associated with congenital microcornea 5. Glaucoma associated with congenital nanop- +hthalmos + +II. Glaucoma associated with iridocorneal dysgenesis +These include: +1.Posterior embryotoxon characterized by a prominent Schwalbe’s ring. +2. Axenfeld-Rieger syndrome refers to the spectrum of following anomalies: +• Axenfeld anomaly is characterized by posterior embryotoxon with attachment of strands of peripheral iris tissue. +• Rieger anomaly is characterized by posterior embryotoxon, iris stomal hypoplasia, ectropion uveal corectopia, and full thickness iris defect. +• Rieger syndrome refers to Rieger anomaly associated with dental anomalies (hypodentia or microdential), facial anomalies (maxillary hypoplasia, broad nasal bridge, telecanthus and hypertelorism) and other anomalies + +(hypospadias, redundant paraumblical skin, and renal anomalies). +3. Peter’s anomalyis characterized by central corneal opacity with or without irido-corneal or lenticulo-corneal adhesions. It may have other ocular and some systemic associations as well. +4. Combined Reiger’s syndrome and Peters anomaly is characterized by features of the both described above. + +DEVELOPMENTAL GLAUCOMA WITH ASSOCIATED SYSTEMIC ANOMALIES +1. Glaucomaassociated with chromosal disorders such as trisomy 13–15 (trisomy D syndrome), trisomy 18 (Edward’s syndrome), trisomy 21 (Down’s syndrome) and Turner’s syndrome. +2. Glaucoma associated with ectopia lentis syndromes, which include Marfan’s syndrome, Weil-Marchesani syndrome and homocystinuria. +3. Glaucoma associated with phakomatosis is seen in Sturge-Weber syndrome (50% cases) and Von Recklinghausen’s neurofibromatosis (25% cases). 4.Glaucoma associated with metabolic syndromes such as:Lowe’s syndrome (oculo-cerebrorenal syndrome), Hurler’s syndrome (mucopolysaccharidosis) and Zellweger syndrome (hepato-cerebral renal syndrome). + +PRIMARY OPEN-ANGLE GLAUCOMA AND RELATED CONDITIONS + + +PRIMARY OPEN-ANGLE GLAUCOMA + +As the name implies, it is a type of primary glaucoma, where there is no obvious systemic or ocular cause of rise in the intraocular pressure. Primary open-angle glaucoma (POAG), also known as chronic simple glaucoma of adult onset, is typically characterised by: +• Slowly progressive raised intraocular pressure (>21 mm Hg recorded on at least few occasions) associated with, +• Open normal appearing anterior chamber angle, • Characteristic optic disc cupping, and +• Specific visual field defects. + +ETIOPATHOGENESIS +Etiopathogenesis of POAG is not known exactly. +Some of the known facts are as follows: +Chapter 10 Glaucoma 229 + + +A. Predisposing and risk factors. These include the following: +1. Intraocular pressure (IOP), is the most important risk factor for development of POAG. +2. Family history (Heredity). The approximate risk of getting disease is 10% in the siblings, and 4% in the offspring of patients with POAG. POAG has a polygenic inheritance, approximately two dozen loci have been identified for POAG out of which only following three genes have been coloned: +• Myocilin C (MYOC), +• Optineurin (OPTN), and +• WD repeat domain 36 (WDR 36) +3. Age. The risk increases with increasing age. The POAG is more commonly seen in elders between 5th and 7th decades. +4. Race. POAG is significantly more common, develops earlier and is more severe in black people than in white. +5. Myopes are more predisposed than the normals. 6. Central corneal thickness (CCT). A thinner CCT, +apart from causing underestimation of IOP by applanation tonometer, is being considered as an independent risk factor for POAG. +7. Diabetics have a higher prevalence of POAG than nondiabetics. +8. Cigarette smoking is also thought to increase its risk. +9. High blood pressure is not the cause of rise in IOP, however, the prevalence of POAG is more in hypertensives than the normotensives. Most meaningful blood pressure variable related to glaucoma is diastolic perfusion pressure (diastolic blood pressure–IOP). A diastolic perfusion pressure of <55 mm Hg is an important risk factor for glaucoma. +10. Thyrotoxicosis is also not the cause of rise in IOP, but the prevalence of POAG is more in patients suffering from Graves’ ophthalmic disease than the normals. +11. Corticosteroid responsiveness. Patients with POAG and their offspring and sibilings are more likely to respond to 6 weeks topical steroid therapy with a significant rise of IOP. +B. Pathogenesis of rise in IOP. It is certain that rise in IOP occurs due to decrease in the aqueous outflow facility. Recently it has been proposed that reduced aqueous outflow facility occurs due to failure of aqueous outflow pump mechanism owing to trabecular meshwork stiffening and apposition of Schlemm’s canal wall. Such changes are caused by: • Thickening and sclerosis of trabecular meshwork +with faulty collagen tissue. + + +• Narrowing of intertrabecular spaces. +• Deposition of amorphous material in the juxtacanalicular space. +• Collapse of Schlemm’s canal and absence of giant vacuoles in the cells lining it. +The exact cause of these changes is uncertain. Detection of increased gammaglobulin and plasma cells in trabecular meshwork on immunohisto-chemistry and positive antinuclear antibody reaction in some cases support an immunogenic mechanism in POAG. + +C. Pathogenesis of optic neuropathy. (see page 224) + +EPIDEMIOLOGY OF POAG +POAG affects about 1 in 100 of the general population (of either sex) above the age of 40 years. It forms about one-third cases of all glaucomas. Prevalence of POAG varies in different populations is as below: +Ethnic group POAG : PACG • Europeans, Africans and 5 : 1 +Hispanics +• Mongolian 1 : 3 • Urban Chinese 1 : 2 • Indian 1 : 1 +CLINICAL FEATURES Symptoms +1. Asymptomatic. The disease is insidious and usually asymptomatic, until it has caused a significant loss of visual field. Therefore, periodic eye examination is required after middle age. +2. Headache and eye ache of mild intensity may be experienced in the course of the disease. +3. Scotoma (defect in the visual field) may be noticed occasionally by some observant patients. +4. Difficulty in reading and close work, often persistently increasing, is experienced by most patients. This occurs due to increasing accommodative failure as a result of constant pressure on the ciliary muscle and its nerve supply. Therefore, patients usually complain of, frequent changes in presbyopic glasses. +5. Delayed dark adaptation may develop, a disability which becomes increasingly disturbing in the late stages. +6. Significant loss of vision and blindness is the end result of untreated cases of POAG. +Signs +I. Anterior segment signs +Ocular examination including slit-lamp biomicroscopy may reveal normal anterior segment. In late stages, pupil reflex becomes sluggish and +230 Section III Diseases of Eye + + +corneamayshowslight haze. A low(<555mm)central corneal thickness (CCT) is a significant risk factor for POAG. +II. lntraocular-pressure changes +In the initial stages, the IOP may not be raised permanently, but there is an exaggeration of the normal diurnal variation. Therefore, repeated observations of IOP (every 3–4 hour), for 24 hours is required during this stage (Diurnal variation test). In most patients, IOP falls during the evening, contrary to what happens in angle-closure glaucoma. Different patterns of diurnal variation of IOP shown in Fig. 10.9 are: +• Morning rise in IOP–20% of cases • Afternoon rise in IOP–25% of cases • Biphasic rise in IOP–55% of cases +A variation in IOP of over 5 mm Hg (Schiotz) is suspicious and over 8 mm of Hg is diagnostic of glaucoma. In later stages, IOP is permanently raised above 21 mm of Hg and ranges between 30 and 45 mm of Hg. +III. Optic disc changes +Optic disc changes, usually observed on routine fundus examination, provide an important clue for suspecting POAG. These are typically progressive, asymmetric and present a variety of characteristic clinical patterns. It is essential, therefore, to record the appearance of the nerve head in such a way that will accurately reveal subtle glaucomatous changes over the course of follow-up evaluation. Examination techniques. Careful fundus examination should be performed to detect optic disc changes. Best technique is to have a stereoscopic view of the optic disc with contact or noncontact lenses on slit-lamp biomicroscopic examination. Non-contact lenses (+ 78D or + 90D) are more convenient and are thus widely used. +Recording and documentation techniquesinclude serial hand drawings, photography and photogrammetry. Confocal scanning laser topography (CSLT), i.e., Heidelberg retinal tomograph (HRT) is an accurate and sensitive method for this purpose. Other advanced imaging techniques include optical coherence tomography (OCT) and scanning laser polarimetry, i.e., nerve fibre analyser (NFA). Glaucomatous changes in the optic disc can be described as early changes, advanced changes and glaucomatous optic atrophy. Figs. 10.10A and B show normal disc configuration. +(a) Early glaucomatous changes (Figs. 10.10C and D) should be suspected to exist if fundus examination reveals one or more of the following signs: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 10.9 Patterns of diurnal variations of IOP: A, normal slight morning rise; B, morning rise seen in 20% cases of POAG; C, afternoon rise seen in 25% cases of POAG; D, biphasic variation seen in 55% cases of POAG + + +1. Vertically oval cup due to selective loss of neural rim tissue in the inferior and superior poles. +2. Asymmetry of the cups. A difference of more than 0.2 between two eyes is significant. +3. Large cup, i.e., 0.6 or more (normal cup size is 0.3 to 0.4) may occur due to concentric expansion. +4. Splinter haemorrhages present on or near the optic disc margin. +5. Pallor areas on the disc. +Chapter 10 Glaucoma 231 + + + + + + + + + + + + + + + + + + +C + + + + + + + +A + + + + + + + + + +B D +Fig. 10.10 Normal optic disc (A, diagrammatic depiction; B, fundus photograph) and optic disc showing early glaucomatous changes (C, diagrammatic depiction; D, fundus photograph) + + +6. Atrophy of retinal nerve fibre layer which may be seen with red free light. +(b) Advanced glaucomatous changes in the optic +disc include: +1. Marked cupping (cup size 0.7 to 0.9), excavation may even reach the disc margin, the sides are steep and not shelving (c.f. deep physiological cup) (Figs. 10.11A and B) which are well-delineated on OCT examination (Fig. 10.11C). +2. Thinning of neuroretinal rim which occurs in advanced cases is seen as a crescentric shadow adjacent to the disc margin. Normally, the thickest to thinnest parts of the neuroretinal rim of the optic disc are inferior, superior, nasal and temporal (ISNT rule). Any variation from this + + +helps to detect glaucoma. Notching of the rim specially up to disc margin is pathognomic. +3. Nasal shifting of retinal vessels which have the appearance of being broken off at the margin is an important sign (Bayonetting sign). When the edges overhang, the course of the vessels as they climb the sides of the cup is hidden. +4. Pulsations of the retinal arterioles may be seen at the disc margin (a pathognomic sign of glaucoma), when IOP is very high. +5. Lamellar dot sign the pores in the lamina cribrosa are slit-shaped and are visible up to the margin of the disc. +(c) Glaucomatous optic atrophy. As the damage progresses, all the neural tissue of the disc is +232 Section III Diseases of Eye + + +destroyed and the optic nerve head appears white and deeply excavated (Figs. 10.11C and D). Pathophysiology of disc changes. Both mechanical and vascular factors play a role in the cupping of the disc. +Mechanical effect of raised IOP forces the lamina cribrosa backwards and squeezes the nerve fibres within its meshes to disturb axoplasmic flow. Vascular factors contribute in ischaemic atrophy of the nerve fibres without corresponding increase of + +supporting glial tissue. As a result, large caverns or lacunae are formed (cavernous optic atrophy). +IV. Visual field defects +Visual field defects appear only after about 40% of axons have been damaged and subsequently the field defects usually run parallel to the changes at the optic nerve head and continue to progress if IOP is not controlled. These can be described as early and late field defects. +Anatomical basis of field defects. For better under-standing of the actual field defects, it is mandatory to have a knowledge of their anatomical basis. + + + + + + + + + + + + + + + + +A + + + + + + + + +D + + + +B + + + + + + + + + + +C E +Fig. 10.11 Optic disc showing advanced glaucomatous changes: A, diagramatic depiction; B, fundus photograph; C, OCT picture; D and E, diagrammatic depiction and fundus photograph of glaucomotous optic atrophy +Chapter 10 Glaucoma 233 + + +A.Distribution of retinal nerve fibres (Fig. 10.12). 1.Fibres from nasal half of the retina come directly +to the optic disc as superior and inferior radiating fibres (SRF and IRF). +2.Those from the macular area come horizontally as papillomacular bundle (PMB). +3.Fibres from the temporal retina arch above and below the macula and papillomacular bundle as superior and inferior arcuate fibres with a horizontal raphe in between (SAF and IAF). +B. Arrangement of nerve fibres within optic nerve head (Fig. 10.13): Those from the peripheral part of the retina lie deep in the retina but occupy the most peripheral (superficial) part of the optic disc. While fibres originating closer to the nerve head lie superficially in the retina and occupy a more central (deep) portion of the disc. +The arcuate nerve fibres occupy the superior and inferior temporal portions of optic nerve head and are most sensitive to glaucomatous damage; accounting for the early loss in the corresponding regions of the visual field. Macular fibres are most resistant to the glaucomatous damage and explain the retention of the central vision till end. + + + + + + + + + + + + + + + + + + +Fig. 10.12 Distribution of retinal nerve fibres + + + + + + + + +Fig. 10.13 Arrangement of nerve fibres within optic nerve head + +Nomenclature of glaucomatous field defects. Visual field defects in glaucoma are initially observed in Bjerrum’s area (10–25 degree from fixation) and correlate with optic disc changes. The natural history of the progressive glaucomatous field loss, more or less, takes the following sequence: +1. Isopter contraction. It refers to mild generalised constriction of central as well as peripheral field. It is the earliest visual field defect occurring in glaucoma. However, it is of limited diagnostic value, as it may also occur in many other conditions. +2. Baring of blind spot. It is also considered to be an early glaucomatous change, but is very nonspecific and thus of limited diagnostic value. Baring of the blind spot means exclusion of the blind spot from the central field due to inward curve of the outer boundary of 30° central field (Fig. 10.14A). +3. Small wing-shaped paracentral scotoma (Fig. 10.14B). It is the earliest clinically significant field defect. It may appear either below or above the blind spot in Bjerrum’s area (an arcuate area extending above and below the blind spot between 10° and 20° of fixation point). +4. Seidel’s scotoma. With the passage of time paracentral scotoma joins the blind spot to form a sickle-shaped scotoma known as Seidel’s scotoma (Fig. 10.14C). +5. Arcuate or Bjerrum’s scotoma. It is formed at a later stage by the extension of Seidel’s scotoma in an area either above or below the fixation point to reach the horizontal line (Fig. 10.14D). Damage to the adjacent fibres causes a peripheral breakthrough. +6. Ring or double arcuate scotoma. It develops when the two arcuate scotomas join together (Fig. 10.14E). 7. Roenne’s central nasal step. It is created when the two arcuate scotomas run in different arcs and meet to form a sharp right-angled defect at the horizontal meridian (Fig. 10.14E). +8.Peripheral field defects.These appear sometimes at an early stage and sometimes only late in the disease. The peripheral nasal step of Roenne’s results from unequal contraction of the peripheral isopter. +9. Advanced glaucomatous field defects. The visual field loss gradually spreads centrally as well as peripherally, and eventually only a small island of central vision (tubular vision) and an accompanying temporal island are left. With the continued damage, these islands of vision also progressively diminish in size until the tiny central island is totally extinguished. The temporal island of the vision is more resistant and is lost in the end leaving the patient with no light perception. +Diagnosis of glaucoma field defects on HFA single field printout. Glaucomatous field defects should always +234 Section III Diseases of Eye + + + + + + + + + + +A + + + + + + + + + +B + + + + + + + + + +C + + + + + + + + + +D + + + + + + + + + +E + +Fig. 10.14 Field defects in POAG: A, baring of blind spot; B, superior paracentral scotoma; C, Seidel’s scotoma; D, Bjerrum’s scotoma; E, double arcuate scotoma and Roenne’s central nasal step + +be interpreted in conjunction with clinical features (IOP and optic disc changes). Further, before final interpretation, the fields must be tested twice, as there is often a significant improvement in the field when plotted second time (because patients become more familiar with the machine and test process). +Criteria to grade glaucomatous, field defects. The criteria to label early, moderate and severe glaucomatous field defect from the HFA central 30-2 test, single printout is depicted in Table 10.2. +Assessing visual field progression in glaucoma. Progression in visual defects can be judged by any of the following methods: +• Comparing individual single field printouts obtained over a period of time. +• Overview printout, in which up to 16 previously tested visual fields can be shown in a single printout without any stastical interpretation. +• Progression analysis software (G PA in HFA machines and Peritrend in Octopus perimeter) is now available for stastical analysis of progression in the visual field defects. +• Visual field index (VFI), is a new measure which uses regression to offer a trend-based analysis of the speed of visual field loss. In it a scale of 0 to 100, i.e., complete loss of the field to normal full field is generate to grade the field loss. +Note. For proper understanding of Table 10.2, evaluation of the Humphrey single field printout described on page 515 should be revised. +Ocular associations +POAG may sometimes be associated with high myopia, Fuchs’ endothelial dystrophy, retinitis pigmentosa, central retinal vein occlusion and primary retinal detachment. +INVESTIGATIONS +1. Tonometry. Applanation tonometry should be preferred over Schiotz tonometry (see page 509). +2. Central corneal thickness (CCT) measurement is essential in the workup for glaucoma since a thinner cornea underestimates and a thicker cornea overestimates the IOP on applanation tonometry. A low CCT (<545 microns) is an independent risk factor for conversion of ocular hypertension to POAG. It has been suggested that a correction factor should be applied to the IOP readings in patients with CCT less than 545 microns and more than 600 microns. +3. Diurnal variation test is especially useful in detection of early cases (see page 230). +Chapter 10 Glaucoma 235 + + +Table 10.2 Criteria to diagnose early, moderate and severe glaucomatous field defects from HFA: 30-2-test. + +Sr. Parameter Criteria for glaucomatous field defects + +no. +1. Mean deviation (MD) +2. Corrected pattern standard deviation (CPSD) +3. Pattern deviation plot +Points depressed below the p < 5% +Points depressed below the p < 1% +4. Glaucoma Hemifield Test (GHT) +5. Sensitivity in central 5 degree (Raw data or Numeric value in dB) + +Early defects <–6 dB +Depressed to p < 5% + + +<18 (25%) + +<10 + +Outside normal limits + +No point <15 dB + +Moderate defects – 6 dB – 12 dB +Depressed to p < 5% + + +<37 (50%) + +<20 + +Outside normal limits + +One hemifield may have point with sensitivity <15 dB + +No point has 0 dB + +Severe defects > – 12 dB +Depressed to the p < 5% + + +>37 (>50%) + +>20 + +Outside normal limits + +Both hemifield have points with sensitivity <15 dB +Any point has 0 dB + + + +4. Gonioscopy.It reveals a wide open angle of anterior chamber. Its primary importance in POAG is to rule out other forms of glaucoma (For details, see pages 219 and 568). +5. Documentation of optic disc changes is of utmost importance (see page 230). +6. Slit-lamp examination of anterior segment to rule out causes of secondary open-angle glaucoma. +7. Perimetry to detect the visual field defects. +8. Nerve fibre layer analyzer (NFLA) is a recently introduced device which helps in detecting the glaucomatous damage to the retinal nerve fibres before the appearance of actual visual field changes and/or optic disc changes. +9. Provocative tests are required in border-line cases. The test commonly performed is water drinking test. Other provocative tests not frequently performed include combined water drinking and tonography, bulbar pressure test, prescoline test and caffeine test. +Water drinking test. It is based on the theory that glaucomatous eyes have a greater response to water drinking. In it after an 8 hours fast, baseline IOP is noted and the patient is asked to drink one litre of water, following which IOP is noted every 15 minutes for 1 hour. The maximum rise in IOP occurs in 15–30 minutes and returns to baseline level after 60 minutes in both normal and the glaucomatous eyes. A rise of 8 mm of Hg or more is said to be diagnostic of POAG. +DIAGNOSIS +Depending upon the level of intraocular pressure (IOP), glaucomatous cupping of the optic disc and + +the visual field changes (Fig. 10.15) the patients are assigned to one of the following diagnostic entities: 1. Primary open-angle glaucoma (POAG). Characteristically POAG is labelled when raised IOP (>21 mm of Hg) is associated with definite glaucomatous optic disc cupping and visual field changes. +However, patients with raised IOP and either typical field defects or disc changes are also labelled as having POAG. +2. Ocular hypertension. This term is used when a patient has an IOP constantly more than 21 mm of + + + + + + + + + + + + + + + + + + + +Fig. 10.15 Triad of abnormalities in disc, field and intra-ocular pressure (IOP) for the diagnosis of glaucoma +236 Section III Diseases of Eye + + +Hg but no optic disc and visual field changes (for details, see page 238). +3. Normal tension glaucoma (NTG) or low tension glaucoma (LTG) is diagnosed when typical glaucomatous disc cupping with or without visual field changes is associated with an intraocular pressure constantly below 21 mm of Hg (for details, see page 239). +MANAGEMENT General considerations +Baseline evaluation and grading of severity of glaucoma The aim of treatment is to lower intraocular pressure to a level where (further) visual loss does not occur. The management thus requires careful and regular periodic supervision by an ophthalmologist. Therefore, it is important to perform a good baseline examination with which future progress can be compared. +Baseline data should include: visual acuity, slit-lamp examination of anterior segment, tonometry (preferably with applanation tonometer); measurement of central corneal thickness, optic disc evaluation (preferably with fundus photography), gonioscopy and visual field charting. +Grading. American Academy of Ophthalmology (AAO) grades severity of glaucoma damage into mild, moderate and severe (Table 10.3). +Therapeutic choices ■Medical therapy, +■Argon or diode laser trabeculoplasty, and ■Filteration surgery. +A. Medical therapy +The initial therapy of POAG is still medical, with surgery as the last resort. +Antiglaucoma drugsavailable are described in detail on pages 449–453. +Basic principles of medical therapy of POAG +1. Identification of target pressure. From the baseline evaluation data a ‘target pressure’ (below which + +Table 10.3 Severity of glaucoma damage + +Degree Description +Mild Characteristic optic-nerve abnormalities are consistent with glaucoma but with normal visual field. +Moderate Visual-field abnormalities in one hemi-field and not within 5 degrees of fixation. +Severe Visual-field abnormalities in both hemi-fields and within 5 degrees of fixation. + +Source : AAO 2000a + + +glaucomatous damage is not likely to progress) should be identified for each patient. The target pressure is identified taking into account the severity of existing damage, the level of IOP, age, and general health of the patient. Although, it is not possible to predict the safe level of IOP, however, progression is uncommon if IOP is maintained at less than 16 to 18 mm of Hg in patients having mild to moderate damage. Lower target pressures (12–14 mm Hg) are required in patients with severe damage. +2. Single drug therapy.One topically instilled antiglaucoma drug should be chosen after due consideration to the patient’s personal and medical factors. If the initial drug chosen is ineffective or intolerable, it should be replaced by the drug of second choice. +3. Combination therapy. If one drug is not sufficient to control IOP then a combination therapy with two or more drugs should be tried. +4. Monitoring of therapy by disc changes and field changes and tonometry is most essential on regular follow-up. In the event of progress of glaucomatous damage the target pressure is reset at a lower level. +Treatment regimes +There are no clear-cut prescribed treatment regimens for medical therapy of POAG. However, at present considerations are as follows: +I. Single drug therapy. Antiglaucoma drugs used are: 1. Prostaglandin analogues. These decrease the IOP by increasing the uveo-scleral outflow of aqueous. Presently, a prostaglandin analogue is being considered the drug of first choice for the treatment of POAG (provided patient can afford to buy it). Further, these form a very good adjunctive drug to beta-blockers, dorzolamide and even pilocarpine when additional therapy is indicated. The available preparations include: +• Latanoprost (0.005%) to be used HS, • Travoprost (0.004%) to be used HS, +• Bimatoprost (0.03%, a prostamide) to be used HS, and +• Unoprostone (0.15%) to be used BID. +2. Topical beta-blockers are being recommended as the first drug of choice for medical therapy of POAG in poor and average income patients. These lower IOP by reducing the aqueous secretion due to their effect on beta-2 receptors in the ciliary processes. +Preparations. In terms of effectiveness, there is little difference between various beta-blockers. However, each offers a slight advantage over the other, which may help in choosing the particular medication as follows: +Chapter 10 Glaucoma 237 + + +• Timolol maleate, a non-selective beta-blocker (0.25, 0.5%: 1–2 times/day), is most popular as initial therapy. However, it should not be used in patients having associated bronchial asthma and/ or heart blocks. +• Betaxolol (0.25%: 2 times/day). Being a selective beta-1 blocker it is preferred as initial therapy in patients with asthma and other pulmonary problems. +• Levobunolol (0.25, 0.5%: 1–2 times/day). Its action lasts the longest and so is more reliable for once a day use than timolol. +• Carteolol (1%: 1–2 times/day). It raises triglycerides and lowers high density lipoproteins the least. Therefore, it is the best choice in patients with POAG having associated hyperlipidemias or atherosclerotic cardiovascular disease. +3. Adrenergic drugs. Role in POAG is as follows: +i. Epinephrine hydrochloride (0.5, 1, 2%: 1–2 times/ day) and dipivefrin hydrochloride (0.1%: 1–2 times/ day). These drugs lower the IOP by increasing aqueous outflow by stimulating alpha receptors in the aqueous outflow system. These are characterized by a high allergic reaction rate. Their long-term use has also been recognized as a risk factor for failure of filtration glaucoma surgery. For these reasons, epinephrine compounds are no longer being used as first line or second line drug. However, dipivefrine may be combined with beta-blockers in patients where other drugs are contraindicated. +ii. Brimonidine (0.2% : 2 times/day). It is a selective alpha-2-adrenergic agonist and lowers IOP by decreasing aqueous production and also by increasing uveo-scleral outflow. Because of increased allergic reactions and tachyphylaxis rates it is not considered the drug of first choice in POAG. It is used as second drug of choice and also for combination therapy with other drugs. +4. Dorzolamide (2%: 2–3 times/day) or Brizolamide (1%, BD). These are topical carbonic anhydrase inhibitors which lower IOP by decreasing aqueous production by altering ion transport along the ciliary process epithelium. These have replaced pilocarpine as the second line of drug and even as an adjunct drug. +5. Pilocarpine (1, 2, 4%: 3–4 times/day). It is a very effective drug and had remained as the sheet anchor in the medical management of POAG for a long time. However, presently it is not being preferredas the first drug of choice or even as second choice. It is because of the fact that in younger patients it causes problems due to spasm of accommodation and miosis. Most, + +but not all, older patients tolerate pilocarpine very well; however, axial lenticular opacities when present preclude its use in many such patients. Therefore, presently pilocarpine is being considered only as an adjunctive therapy where other combinations fail and as second choice in poor patients. ■Mechanism of action. Pilocarpine contracts longitudinal muscle of ciliary body and opens spaces in trabecular meshwork, thereby mechanically increasing aqueous outflow. +II. Combination topical therapy. If one drug is not effective, then a combination of two drugs—one drug which decreases aqueous production (timolol or other betablocker, or brimonidine or dorzolamide) and other drug which increase aqueous outflow (latanoprost or brimonidine or pilocarpine) may be used. +III. Role of oral carbonic anhydrase inhibitors in POAG. Acetazolamide and methazolamide are not recommended for long-term use because of their side-effects. However, acetazolamide 250 mg-tds may be added to control IOP for short term. IV.Hyperosmotic agentslike mannitol 1–2 gm/kg body weight may be used initially when patients present with very high IOP ( >30 mm Hg). +V. Neuroprotective agents. Neuroprotection is an IOP independent method of treating the retinal ganglion cells (RGCs) that are damaged in glaucoma. Some currently available neuroprotective agents have shown effects in vitro and in animal models, however, results in human clinical trials are either lacking or inconclusive. +B. Laser trabeculoplasty +Laser trabeculoplasty can be done using argon laser (ALT), or diode laser (DLT) and selective laser trabeculoplasty (SLT). +It should be considered in patients where IOP is uncontrolled despite maximal tolerated medical therapy. It can also be considered as primary therapy where there is non-compliance to medical therapy. +Technique and role of argon (ALT) or diode laser trabeculoplasty (DLT) inPOAG. It has an additive effect to medical therapy. Its hypotensive effect is caused by increasing outflow facility, possibly by producing collagen shrinkage on the inner aspect of the trabecular meshwork and opening the intratrabecular spaces. It has been shown to lower IOP by 8–10 mm of Hg in patients on medical therapy and by 12–16 mm in patients who are not receiving medical treatment. Treatment regime usually employed consists of 50 spots on the anterior half of the trabecular meshwork over 180°. +238 Section III Diseases of Eye + + +Complications include: +■Transient acute rise of IOP, which can be prevented by pretreatment with apraclonidine (an alpha agonist) and/or acetazolamide; and +■Transient inflammation which can be lessened by use of topical steroids for 3–4 days. +■Other complications seen less commonly are haemorrhage, uveitis, peripheral anterior synechiae and reduced accommodation. +Selective laser trabeculoplasty (SLT),based on the principle of selective photothermolysis, targets selectively pigmented trabecular meshwork (TM) cells without causing thermal or collateral damage to non-pigmented cells or structures unlike ALT or DLT. SLT is performed using Q-switched frequency doubled 532 nm Nd:YAG laser with a pulse duration of 3 ms, a spot size of 400 microns and energy setting of 0.8 mJ. Pressure lowering effect of SLT is similar to ALT with the advantage of not causing scarring and damage to TM. Further, SLT can be used in patients treated with ALT. +C. Surgical therapy +Indications +1. Uncontrolled glaucoma despite maximal medical therapy and laser trabeculoplasty. +2. Noncompliance of medical therapy and non-availability of ALT/SLT. +3. Failure of medical therapy and unsuitable for ALT either due to lack of cooperation or inability to visualize the trabeculum. +4. Eyes with advanced disease, i.e., having very high IOP, advanced cupping and advanced field loss should be treated with filtration surgery as primary line of management. +Types of surgery +Surgical treatment of POAG primarily consists of a fistulizing (filtration) surgery which provides a new channel for aqueous outflow and successfully controls the IOP (below 21 mm of Hg). +• Trabeculectomy is the most frequently performed filtration surgery nowadays. +• Details of filtration operations are described on page 254. +OCULAR HYPERTENSION Definition +Ocular hypertension is labelled when a patient has an IOP constantly more than 21 mm of Hg but no optic disc and visual field changes. These patients should be carefully monitored by an ophthalmologist and should be treated as cases of POAG in the presence of high risk factors. + +Glaucoma suspect is defined as an adult having normal open angle on gonioscopy and anyone of the following signs in at least one eye: +• Elevated IOP, consistently more than 21 mm of Hg by applanation tonometry. +• Suspicious disc changes in the form of asymmetric cup–disc ratio (difference >0.2), notching, or narrowing of neuroretinal rim, or a disc haemorrhage. +• Visual fields consistent with glaucomatous damage. +Risk factors for development of POAG among individuals with ocular hypertension +High-risk factors for development of POAG reported by ocular hypertension study (OHTS) and European Glaucoma Prevention Study (EGPS) are; +• IOP consistently >30 mm Hg, +• Central corneal thickness <550 µm, +• Vertical cup disc ratio of more than 0.7, • Increased age, +• Increased pattern standard deviation (PSD) on Humphrey visual field test, and +• Disc haemorrhages i.e., splinter haemorrhages over or near the disc. + +Other reported risk factors are: +• Family history of glaucoma or known genetic predisposition. +• Fellow eye of the unilateral POAG. +• Other ocular conditions include suspicious disc appearance, myopia, positive diurnal variation, steroid responder, and low optic nerve perfusion pressure. +• Systemic risk factors include diabetes mellitus, sleep apnea, hypertension, cardiovascular disease, hypothyroidism, migranous headache and vasospasm. +Note. The risk of developing POAG cannot be predicted from a single risk factor. The multivariate analysis of the risk factors is more useful in predicting the development of POAG in glaucoma suspects. +Treatment +• Patients with high-risk factors should be treated on the lines of POAG (see page 236). The aim should be to reduce IOP by 20%. +• Patients with no high-risk factors should be annually followed by examination of optic disc, perimetry and record of IOP. Treatment is not required till glaucomatous damage is documented. +Chapter 10 Glaucoma 239 + + +NORMAL TENSION GLAUCOMA Definition and prevalence +The term normal tension glaucoma (NTG), also referred to as low tension glaucoma is labelled when typical glaucomatous disc changes and visual field defects are associated with an intraocular pressure (IOP) constantly below 21 mm of Hg. Characteristically, the angle of anterior chamber is open on gonioscopy and there is no secondary cause for glaucomatous disc changes. NTG accounts for 16% of all cases of POAG and its prevalence above the age of 40 years is 0.2%. +Etiopathogenesis +It is believed to result from chronic low vascular perfusion, which makes the optic nerve head susceptible to normal IOP. This view is supported by following associations which are more common in NTG than in POAG: +• Raynaud phenomenon, i.e., peripheral vascular spasm on cooling, +• Migraine, +• Nocturnal systemic hypotension and overtreated systemic hypertension. +• Reduced blood flow velocity in the ophthalmic artery (as revealed on transcranial Doppler ultrasonography). +Clinical features +Intraocular pressure (IOP) is consistently lower than 21 mm of Hg, but is usually on the higher side of normal range. +Optic disc changesare similar to POAG with following special features: +• Thinning of neuroretinal rim is more significant. • Splinter haemorrhages at disc are more frequent. • Peripapillary atrophic changes are more prevalent. Visual field defects are essentially similar to POAG, but tend to be more deeper, steeper, more localized and closure to fixation point. +Characteristic associations in the form of ocular vascular abnormalities and systemic vascular and hematological abnormalities (as mentioned in etiopathogenesis) may be detected. +Differential diagnosis +I. High pressure glaucomas +1. POAG. In early stages. POAG may present with normal IOP because of a wide diurnal variation. Diurnal variation test usually depicts IOP higher than 21 mm of Hg at some hours of the day in patients with POAG. +2. Glaucoma with intermittent rise in IOP, e.g., glaucomatocyclitic crisis and intermittent angle closure glaucoma. + + +3. Previous episodes of glaucoma which might have caused optic disc changes, field defects, and are now cured, e.g., corticosteroid induced glaucoma, uveitic glaucoma, and traumatic glaucoma. +II. Non-glaucomatous optic neuropathies +1. Congenital optic disc anomalies such as large optic disc pits or colobomas which may be mistaken for acquired glaucomatous damage. A careful examination should help in differentiation. +2. Acquired optic neuropathies such as compressive lesions of optic nerve, shock optic neuropathies, anterior ischemic optic neuropathy, traumatic optic neuropathy and optic neuropathy due to methyl alcohol poisioning. +Treatment +1. Medical treatment to lower IOP. The aim of the treatment is to lower IOP by 30%, i.e., to achieve IOP levels of about 12–14 mm of Hg. Some important facts about medical treatment of NTG are: +• Betaxolol may be considered the drug of choice because in addition to lowering IOP it also increases optic nerve blood flow. +• Other beta blockers and adrenergic drugs (such as dipivefrine) should better be avoided (as these cause nocturnal systemic hypotension and are likely to affect adversely the optic nerve perfusion). +• Drugs with neuroprotective effect like brimonidine may be preferred. +• Prostaglandin analogues, e.g., latanoprost tend to have a greater ocular hypotensive effect in eyes with normal IOP. +2. Trabeculectomymay be considered when progressive field loss occurs despite IOP in lower teens. +3. Systemic calcium channel blockers (e.g., nifedipine) may be useful in patients with confirmed peripheral vasospasm. +4. Monitoring of systemic blood pressure should be done for 24 hours. If nocturnal dip is detected, it may be necessary to avoid night dose of anti-hypertensive medication. + +PRIMARY ANGLE-CLOSURE DISEASE +TERMINOLOGY +Since in the new classification, described of ‘Association of International Glaucoma Societies’ (AIGS), in 2006, the word glaucoma is used only when the optic disc and visual field changes are present, so the term ‘primary angle closure disease’ should replace the term ‘primary angle closure glaucoma’. Primary angle closure disease, is characterised by apposition of peripheral iris against the trabecular +240 Section III Diseases of Eye + + +meshwork (TM) resulting in obstruction of aqueous outflow by closure of an already narrow angle of the anterior chamber. The condition is not associated with any other ocular and systemic abnormalities. +EPIDEMIOLOGY +Salient points regarding epidemiology of primary angle closure disease as per International Society of Geographical and Epidemiological Ophthalmology (ISGEO) are as below: +1. For every 10 occludable angles (PAC suspects) seen there is only one case of PACG. Thus, most occludable eyes do not get glaucoma; and so does not justify prophylactic Laser P.I. in all such cases. +2. Chronic PACG (asymptomatic) is more common than acute PACG (symptomatic) (3:1); meaning thereby that most patients do not know they have disease; justifying need for glaucoma screening. +3. There is great ethnic variability in the prevalence of PACG. The ratio of POAG versus PACG reported for different ethnic groups is as below: +Ethnic group POAG : PACG Europeans, and Africans +and Hispanics : 5 : 1 Urban Chinese : 1 : 2 Mongolian : 1 : 3 Indian : 1 : 1 +4.Major cause of world glaucoma blindness is PACG. + +ETIOPATHOGENESIS +Etiopathogenesis of primary angle closure disease can be discussed as below: +A. Predisposing risk factors B. Pathogenesis of rise in IOP +A. Predisposing risk factors I. Demographic risk factors +1.Age. PACG with pupillary block occurs with greatest frequency in 6th and 7th decades of life. +2.Gender. Male to Female ratio is 1:3. +3.Race. In Caucasians, PACG accounts for about 6% of all glaucomas and presents in sixth to seventh decade. It is more common in South-East Asians, Chinese and Eskimos but uncommon in Blacks. In Asians it presents in 5th to 6th decade and accounts for 50% of primary adult glaucomas in this ethnic group. +II. Anatomical and ocular risk factors +Eyes anatomically predisposed to develop primary angle-closure glaucoma (PACG) include: +• Hypermetropic eyes with shallow anterior chamber and short axial length. +• Eyes in which iris-lens diaphragm is placed anteriorly. + +• Eyes with narrow angle of anterior chamber, which may be due to small eyeball, relatively large size of the lens and smaller diameter of the cornea or bigger size of the ciliary body or more anterior insertion of the iris on the ciliary body. +• Plateau iris configuration. +• Heredity. Most cases of PACG with pupillary block are sporadic in nature. However, predisposing anatomical factors, i.e., shallow anterior chamber and narrow angles have been reported as more common in first degree relatives of the patients. +B. Pathomechanisms of ‘rise in intraocular’ pressure Three pathomechanisms implicated in the causation of rise in IOP of the eyes at risk of PACG are: ■Pupillary block mechanism, +■Plateau iris configuration and syndrome, and ■Phacomorphic mechanism. +1. Pupillary block mechanism +Pupillary block mechanism is responsible for causation of rise in IOP in most (70%) of the predis-posed patients. +Precipitating factors. In a predisposed patient with occludable angles the pupillary block causing angle closure is precipitated by the following factors: ■Physiological mydriasis e.g., while reading in dim illumination, watching television or cinema in a darkened room, during anxiety and emotional stress (sympathetic overactivity) +■Pharmacological mydriasis is well documented to precipitate an attack of acute angle closure. Medications other than topical mydriatics (e.g., phenylephrine, tropicamide, cyclopentolate, homatropine and atropine) reported to precipitate the attack include tranquilizers, bronchodilators, antidepressants, vasoconstrictors including common nasal decongestants, antimalaria agents and antispasmodics. +■Pharmacological miosis induced by drugs like echothiophate and pilocarpine is also reported to precipitate an attack of acute PAC. +■Valsalva manoevure is reported to precipitate angle closure in predisposed individuals. +Mechanism of rise in IOP after mydriasis.The probable sequence of events resulting in rise of IOP in an anatomically predisposed eye is as follows: +First of all due to the effect of precipitating factors there occurs mid dilatation of the pupil which increases the amount of apposition between iris and anteriorly placed lens with a considerable pressure resulting in relative pupil block (Fig. 10.16A). Consequently, the aqueous collects in the posterior chamber and pushes the peripheral flaccid +Chapter 10 Glaucoma 241 + + +iris anteriorly (Iris bombe) (Fig. 10.16B), resulting in appositional angle closure due to iridocorneal contact (Fig. 10.16C). Eventually, there occurs rise in IOP which is transient to begin with. But slowly the appositional angle closure is converted into synechial angle closure (due to formation of peripheral anterior synechiae) and an attack of rise in IOP may last long. +In some cases, a mechanical occlusion of the angle by the iris is sufficient to block the drainage of aqueous. For this reason, the instillation of atropine in an eye with a narrow angle is dangerous, since it may precipitate an attack of raised IOP. +Mechanism of rise in lOP after miosis. The drugs that constrict pupil are also reported to increase pupillary block. Further these drugs also contract the ciliary muscles allowing the zonules to relax and the lens to move forward. Because of this reason, it is advisable to avoid miotics such as pilocarpine in the prevention of PACG in predisposed eyes (e.g., fellow eye of patient with acute attack). +2. Plateau iris configuration and syndrome +This mechanism is responsible for few (10%) atypical cases of acute angle closure glaucoma. Acute angle closure glaucoma associated with plateau iris is atypical in the patients that have normal central + + + + + + + + +A + + + + + + +B + + + + + + + +C +Fig. 10.16 Mechanism of angle closure glaucoma: A, relative pupil block; B, iris bombe formation; C, appositional angle closure + +anterior chamber depth, flat iris plane and minimal pupillary block. It has also been referred in the literature as an angle closure glaucoma without pupillary block. The anterior chamber angle is closed by a pushing mechanism because of the anterior positioned ciliary processes displacing the peripheral iris anteriorly. Such a situation is called plateau iris configuration and iridotomy is sufficient to control IOP in such patients. Plateau iris syndrome is labeled when acute angle closure glaucoma occurs either spontaneously or after pharmacological dilation, in spite of patent iridotomy. Such eyes are treated with miotics and laser peripheral iridoplasty to produce thinning of the peripheral iris. +3. Phacomorphic mechanism +Phacomorphic mechanism has now been included as one of the three basic PACG mechanisms, along with pupillary block and plateau iris. The abnormal lens may contribute by either causing pupillary block or by pushing the peripheral iris forward into the angle structures. Though the term phacomorphic glaucoma refers to an acute secondary angle closure glaucoma caused by the intumescent or other lens morphological abnormalities; but now UBM and OCT studies have shown that phacomorphic mechanism may be responsible for initiating acute primary angle closure glaucoma in predisposed patients (having occludable angle). This also forms the base of lens extraction as a treatment modality for acute primary angle closure glaucoma. +Note. In addition to meticulous gonioscopic examination, the high resolution ultrasonic biomicroscopy (UBM) examination and Anterior Segment OCT (AS-OCT) are very useful in understanding the pathogenesis of primary angle closure disease. These investigations are particularly useful in the documentation of plateau iris configuration, plateau iris syndrome, phacomorphic mechanism and post peripheral iridectomy angle dynamics. Further, these investigations are also helpful in differentiating primary and secondary angle closure glaucoma. +CLASSIFICATION +ISGEO Classification +World glaucoma experts under the auspices of the “Association of International Glaucoma Societies” (AIGS), now termed as ‘International Society of Geographical and Epidemiological Ophthalmology’(ISGEO), in 2006 have proposed following 21st century consensus classification based on natural history(IOP measurements, gonioscopy, disc and visual field evaluation): +242 Section III Diseases of Eye + + +1.Primary Angle Closure Suspect (PACS), 2.Primary Angle Closure (PAC), and 3.Primary Angle Closure Glaucoma (PACG). +Note. In this newer classification the word glaucoma is used only when the optic disc changes and field changes are present. Further, this classification is based only on the signs and has not taken into consideration the presenting symptoms. +Traditional clinical classification +The old traditional clinical classification based on the clinical presenting symptoms is as below: +1.Latent primary angle-closure glaucoma, 2.Subacute (intermittent) primary angle-closure +glaucoma, +3.Acute primary angle-closure glaucoma, and 4.Chronic primary angle-closure glaucoma. +CLINICAL PROFILE AND MANAGEMENT Clinical profile of three stages of primary angle-closure disease described below is based on the integration of the new ISGEO classification (based on natural history) with traditional clinical classification (based on the presenting symptoms). + +I. Primary Angle-Closure Suspect +Primary angle-closure suspect (PACS), can be considered analogous to the term ‘latent primary angle-closure glaucoma’ of clinical classification. +Clinical features and diagnostic criteria Symptoms are absent in this stage. +Presenting situations for diagnosis include: +• Suspicious clinical signs on routine ocular examination in patients coming for some other complaints. +• Fellow eye of the patients presenting with acute attack of PAC. +• Glaucoma screening programme. +Suspicious clinical signs noted on routine ocular examination include: +1. Eclipse sign. Eclipse sign, which indicates decreased axial anterior chamber depth, can be elicited by shining a penlight across the anterior chamber from the temporal side and noting a shadow on the nasal side (Fig. 10.17). +2. Slit-lamp biomicroscopic signs include: +• Decreased axial anterior chamber depth, • Convex shaped iris lens diaphragm, and +• Close proximity of the iris to cornea in the periphery. +3. Van Herick slit-lamp grading of the angle may be used with a fair accuracy. Here, the peripheral anterior + + + + + + + + + + + +A + + + + + + + + + + +B +Fig. 10.17 Estimation of anterior chamber depth by oblique illumination: A, normal; B, shallow + + + +chamber depth (PACD) is compared to the adjacent corneal thickness (CT) and the presumed angle width is graded as follows (Fig. 10.18): +• Grade 4 (Wide open angle): PACD = 3/4 to 1 CT +• Grade 3 (Mild narrow angle): PACD = 1/4 to 1/2 CT • Grade 2 (Moderate narrow angle): PACD = 1/4 CT • Grade 1( Extremely narrow angle): PACD < 1/4 CT • Grade 0 (closed angle): PACD = Nil +Diagnostic tests recommended to confirm diagnosis include: +■IOP measurement, ■Gonioscopy, +■Ultrasonic biomicroscopy (UBM), ■Anterior segment OCT, +■Optic disc evaluation, and ■Visual field analysis. +Diagnostic criteria for PAC suspect: +■Gonioscopy should reveal irido-trabecular contact in greater than 270° angle and no peripheral anterior synechia (PAS absent). +■IOP should be normal. +■Optic disc should show no glaucomatous change. ■Visual fields should be normal. +Impression: The angle is at risk. +Chapter 10 Glaucoma 243 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 10.18 Van Herick method of slit-lamp grading of angle width: A, Grade IV; B, Grade III; C, Grade II; and D, Grade I, and E Grade 0. PACD = Peripheral anterior chamber depth; CT = Corneal thickeners + + +Management +Provocative tests designed to precipitate closure of the angle though not popular presently but can be performed in patients with PAC suspect. These tests + +may be performed in the ophthalmologist’s office, where it can be treated promptly. +1. Prone-darkroom test was considered the most popular and best physiological provocative test. In this test, baseline IOP is recorded and patient is made to lie prone in a darkroom for 1 hour. He must remain awake so that pupils remain dilated. After 1 hour, the IOP is again measured. An increase in IOP of more than 8 mm Hg is considered diagnostic of PAC suspect. +2. Mydriatic provocative test is usually not preferred nowadays because this is not physiological. In this test either a weak mydriatic (e.g., 0.5% tropicamide) or simultaneously a mydriatic and miotic (10% phenylephrine and 2% pilocarpine) are used to produce a mid-dilated pupil. A pressure rise of more than 8 mm Hg is considered positive. +Inferences from provocative tests are: +• Positive provocative test indicates that angle is capable of spontaneous closure. +• Negative provocative test in the presence of occludable angles on gonioscopy does not rule out a possibility of spontaneous closure. So, patient should be warned of possible symptoms of an acute attack of PAC. +Treatment comprise: +Prophylactic laser iridotomy is warranted if more than 270° of oppositional iridotrabecular contact is seen on gonioscopy in the fellow eye of all patients presenting with acute PAC or PACG in one eye. If untreated, the risk of conversion to PACG during the next 5 years is about 50%. +Periodic follow up. Patients with PAC suspect in both eyes need to be followed periodically and educated about the symptoms of the disease. + +II. Primary Angle-Closure +Eyes with primary angle closure (PAC) may be considered to comprise following entities of clinical classification: +• Subacute primary angle closure • Acute PAC +• Chronic PAC (asymptomatic). +Defining criteria for primary angle closure (PAC) +• Irido-trabecular contact noted on gonioscopy in greater than 270° angle, +• IOP elevated and/or peripheral anterior synechiae (PAS) present, +• Optic disc: Normal, and • Visual fields: Normal +Impression: Angle is abnormal either in function (elevated IOP) and/or structure (PAS +ve). +244 Section III Diseases of Eye + + +Subacute primary angle-closure +Subacute primary angle closure is characterized by an attack of transient rise of IOP (40–50 mm Hg) which may last for few minutes to 1–2 hours. Precipitating factor such an attack in a patient with PAC include: +■Physiological mydriasis e.g., while reading in dim illumination, watching television or cinema in a darkened room, or during anxiety (sympathetic overactivity); or +■Physiological shallowing of anterior chamber after lying in prone position. +■Pharmacological mydriasis following use of pupil dilating drugs for fundus examination. +Symptoms include: +■Episode of subacute PAC is marked by experience of unilateral transient blurring of vision, +■Coloured halos around light, headache, browache and eyeache on the affected side. +■Self-termination of the attack occurs possibly due to physiological miosis induced by bright light, sleep or otherwise. +■Recurrent attacks of such episodes are not uncommon. Between the recurrent attacks the eyes are free of symptoms. +Signs. Usually, during examination the eye is white and not congested. However, all the signs described above in the definition of primary angle-closure (PAC) should be elicited to table PAC. +Diagnosis is made from the defining criteria for PAC as above. +Differential diagnosis of coloured halos in PAC. Coloured halos during intermittent attacks of raised IOP in PAC occur due to accumulation of fluid in the corneal epithelium and alteration in the refractive + + +condition of the corneal lamellae. Patient typically gives history of seeing colours distributed as in the spectrum of rainbow (red being outside and violet innermost) while watching on a lighted bulb or the moon. +The coloured halos in glaucoma must be differentiated from those found in acute purulent conjunctivitis and early cataractous changes. In conjunctivits, halos can be eliminated by irrigating the discharge. The halos of glaucoma and immature cataract may be differentiated by Fincham’s test in which a stenopaeic slit is passed across the pupil. During this test, glaucomatous halo remains intact, while a halo due to cataract is broken up into segments (Fig. 10.19). +Treatment of choice is Peripheral laser iridotomy. + +Acute primary angle-closure +An attack of acute rise in IOP in patients with primary angle closure (PAC) may occur due to pupillary block causing sudden closure of the angle. It usually does not terminate of its own and thus if not treated lasts for many days. It is a sight threatening emergency. +Clinical features Symptoms include: +■Pain.Typically acute attack is characterised by sudden onset of very severe pain in the eye which radiates along the branches of 5th nerve. +■Nausea, vomiting and prostrations are frequently associated with pain. +■Rapidly progressive impairment of vision, redness, photophobia and lacrimation develop in all cases. ■Past history. About 5% patients give history of typical previous intermittent attacks of subacute angle-closure. + + + + + + + + + + + + + + + +A B C D E +Fig. 10.19 Emsley-Fincham stenopaeic-slit test demonstrating breaking up of halos due to immature cataract into different segments +Chapter 10 Glaucoma 245 + + +Signs include (Fig. 10.20): +• Lids may be oedematous, +• Conjunctiva is chemosed, and congested, (both conjunctival and ciliary vessels are congested), +• Cornea becomes oedematous and insensitive, +• Anterior chamber isvery shallow. Aqueous flare or cells may be seen in anterior chamber, +• Angle of anterior chamber is completely closed as seen on gonioscopy (Shaffer grade 0), +• Iris may be discoloured, +• Pupil is semidilated, vertically oval and fixed. It is non-reactive to both light and accommodation, +• IOP is markedly elevated, usually between 40 and 70 mm of Hg, +• Optic disc is oedematous and hyperaemic, +• Fellow eye shows shallow anterior chamber and occludable angle. +Diagnosis +Diagnosis of an attack of acute primary angle closure is usually obvious from the clinical features. However, a differential diagnosis may have to be considered: 1.From other causes of acute red eye. Acute primary +angle closure sometimes needs differentiation from other causes of inflammed red eye like acute conjunctivitis and acute iridocyclitis (see page 158 and Table 8.1). +2.From acute secondary glaucomas such as: +• Phacomorphic glaucoma (see page 248), +• Acute neovascular glaucoma (see page 250) and • Glaucomatocyclitic crisis (see page 169). +Management +Acute angle closure is a serious ocular emergency and needs to be managed aggressively as below: +• Immediate medical therapy to lower IOP, • Definitive treatment, +• Prophylaxis of the fellow eye, and + + + + + + + + + + + + + + +Fig. 10.20 Clinical photograph of a patient with acute congestive glaucoma. Note ciliary congestion, corneal oedema and mid-dilated pupil \ No newline at end of file diff --git a/notes/A K Khurana - Comprehensive Ophthalmology_9.txt b/notes/A K Khurana - Comprehensive Ophthalmology_9.txt new file mode 100644 index 0000000000000000000000000000000000000000..53a1e7376f5bcf54656ece431c7287d566793d22 --- /dev/null +++ b/notes/A K Khurana - Comprehensive Ophthalmology_9.txt @@ -0,0 +1,1599 @@ + +• Long-term glaucoma surveillance and IOP management of both eyes. +A. Immediate medical therapy to lower IOP +1. Systemic hyperosmotic agents are required initially if IOP is more than 40 mm Hg. +• Intravenous mannitol (1 gm/kg body weight) should be preferred in the presence of nausea and vomiting. +• Oral hyperosmotics, e.g., glycerol 1 gm/kg body weight of 50% solution in lemon juice may be given if well tolerated and not contraindicated (as in diabetes mellitus). +2. Systemic carbonic anhydrase inhibitors, e.g., acetazolamide 500 mg IV stat followed by 250 mg tablet 3 times a day. +3. Topical antiglaucoma drugs to be instilled immediately include: +• Beta-blocker, e.g., 0.5% timolol or 0.5% betaxolol • Alpha adrenergic agonists, e.g., brimonidine +0.1–0.2%. +• Prostaglandin analogue, e.g., latanoprost 0.005%. Role of miotic therapy: +• Pilocarpine 2% QID should be started after 1 hour of the commencement of the treatment, i.e., when IOP is lowered, as at higher IOP sphincter is ischaemic and unresponsive to pilocarpine. +Note. Intensive miotic therapy is not advised nowadays. Some glaucoma experts have given up the use of pilocarpine entirely in the management of acute PACG. +4. Analgesics and antiemetics may be required to alleviate the symptoms. +5. Compressive gonioscopy with a 4 mirror goniolens may help relieve pupil block and is essential to determine if the trabecular blockage is reversible. 6. Topical steroid, e.g., prednisolone acetate 1% or dexamethasone eye drops administered 3–4 times a day reduces the inflammation. +B. Definitive therapy +1. Laser peripheral iridotomy (LPI). Gonioscopy should be performed as soon as cornea becomes clear. Laser PI should be performed if PAS are seen in <270° angle. LPI re-establishes communication between posterior and anterior chamber, so it bypasses the pupillary block and immediately relieves the crowding of the angle. +• Laser peripheral iridotomy (with Nd:YAG laser or Argon Laser) should always be preferred over surgical PI. However, if lasers are not available surgical PI should be done (see page 253 for technique). +2. Filtration surgery, i.e., trabeculectomy should +246 Section III Diseases of Eye + + +be performed in cases where IOP is not controlled with the maximum medical therapy following an attack of acute PAC or when gonioscopy reveals PAS >270° angle and also when peripheral iridotomy is not effective. +• Mechanism: Filtration surgery provides an alternative to the angle for drainage of aqueous from anterior chamber into subconjunctival space. Surgical technique. (see page 254). +3. Clear lens extraction by phacoemulsification with intraocular lens implantation has recently been recommended by some workers, especially in the presence of phacomorphic etiology (diagnosed on UBM). +C. Prophylactic treatment in the normal fellow eye Prophylactic laser iridotomy (preferably) or surgical peripheral iridectomy should be performed on the fellow asymptomatic eye (PACS) as early as possible as chances of acute attack are 50% in such eyes. +D. Long-term glaucoma surveillance and IOP man-agement in both eyes +Long-term glaucoma surveillance and IOP management in both eyes of a patient with acute PAC is must to ultimately prevent glaucomatous blindness: ■Eyes treated with PI (both affected and fellow eye) may develop PACG at any time. So, it should be treated as and when required. +■Filtration surgery may fail anytime during the course and hence need to be repeated with antimetabolites. +Sequelae of acute PAC +Clinical status of the eye after an attack of acute PAC with or without treatment is considered a sequelae of acute PAC. It may be seen as following clinical settings: 1. Postsurgical acute PAC. This refers to the clinical status of the eye after laser peripheral iridotomy (PI) treatment for an attack of acute PAC. It may occur in two clinical settings: +i. With normalized IOP after successful laser PI, the eye usually quitens after sometime with or without marks of an acute attack (i.e., Vogt’s triad, see below). +ii. With raised IOP after unsuccessful laser PI, which needs to be treated by trabeculectomy operation. +2. Spontaneous angle reopening may occur very rarely in some cases and the attack of acute PAC may subside itself without treatment. +Treatment of choice for such cases is laser peripheral iridotomy. +3. Ciliary body shut down. It refers to temporary cessation of aqueous humour secretion due to ischaemic damage to the ciliary epithelium after an attack of acute PAC. + +Clinical features in this stage are similar to acute PAC except that the IOP is low and pain is markedly reduced. Subsequent recovery of ciliary function may lead to chronic elevation of IOP with cupping and visual field defects, i.e., PACG. + +Treatment includes: +• Topical steroid drops to reduce inflammation. +• Laser peripheral iridotomy should be performed when cornea becomes clear and IOP should be monitored. +• Trabeculectomy is required when IOP rises constantly. +4. Vogt’s triad. It may be seen in both treated and non-treated cases after an attack of acute PAC. It is characterized by: +• Glaukomflecken (anterior subcapsular lenticular opacity), +• Patches of iris atrophy, and +• Slightly dilated nonreacting pupil (due to sphincter atrophy). + +III. Primary Angle-Closure Glaucoma Primary angle closure glaucoma (PACG) can be considered analogous to the term ‘chronic primary angle closure glaucoma’ used in the clinical classification. +Pathogenesis +Primary angle-closure glaucoma (PACG) results from gradual synechial closure of the angle of anterior chamber. Untreated patients with PAC may over the period covert to PACG with or without history of subacute or acute attack of PAC. +Clinical features +PACG may clinically manifest as subacute, acute or chronic PACG. +Subacute and acute PACG clinically present as similar to subacute and acute PAC, respectively (see page 244); except that glaucomatous optic disc changes and visual field defects are always present in PACG. +Chronic PACG. Clinical features, given below, are similar to POAG except that angle closure is present: ■Intraocular pressure (IOP) remains constantly raised. +■Eyeballremains white (no congestion) and painless, except in post acute angle closure cases where the eye may be congested and irritable. +■Optic disc shows glaucomatous cupping. +■Visual field defects similar to POAG occur (see page 232). +■Gonioscopy reveals more than 270° of angle closure along with peripheral anterior synechiae (PAS). The +Chapter 10 Glaucoma 247 + + +gonioscopic findings provide the only differentiating feature between POAG and chronic PACG. +Diagnosis +Defining criteria for primary angle closure glaucoma (PACG) as per ISGEO classification is: +• Irido-trabecular contact is noted on gonioscopy in greater than 270° of angle, +• PAS are formed, • IOP is elevated, +• Optic disc shows glaucomatous damage, and +• Visual fields show typical glaucomatous defects. +Impression: Angle is abnormal in function (elevated IOP) and structure (PAS + ve) with optic neuropathy. Note. In circumstances where advanced PACG disease with compromised media prohibits disc and visual field testing, e.g., cataract or corneal disease, a coarser definition holds for PACG whereby an IOP > 24 mm Hg and visual acuity of < 3/60 or a history of prior glaucoma surgery, will suffice. +Treatment +• Laser iridotomy alone or alongwith medical therapy similar to POAG (see page 236) should be tried first. +• Trabeculectomy (filtration surgery) is needed when the above treatment fails to control IOP. +• Prophylactic laser iridotomy in fellow eye must also be performed. + +Absolute Primary Angle-closure Glaucoma Primary angle closure glaucoma, if untreated, gradually passes into the final phase of absolute glaucoma. +Clinical features +• Painful blind eye. The eye is painful, irritable and completely blind (no light perception). +• Perilimbal reddish blue zone, i.e., a slight ciliary flush around the cornea due to dilated anterior ciliary veins. +• Caput medusae, i.e., a few prominent and enlarged vessels are seen in long-standing cases. +• Cornea in early cases is clear but insensitive. Slowly it becomes hazy and may develop epithelial bullae (bullous keratopathy) or filaments (filamentary keratitis). +• Anterior chamber is very shallow. • Iris becomes atrophic. +• Pupil becomes fixed and dilated and gives a greenish hue. +• Optic disc shows glaucomatous optic atrophy. +• Intraocular pressure is high; eyeball becomes stony hard. + + +Management of absolute glaucoma +1. Retrobulbar alcohol injection: It may be given to relieve pain. First, 1 ml of 2% xylocaine is injected followed after about 5–10 minutes by 1 ml of 80% alcohol. It destroys the ciliary ganglion. +2. Destruction of secretory ciliary epithelium to lower the IOP may be carried out by cyclocryotherapy(seepage 256) or cyclodiathermy or cyclophotocoagulation. +3. Enucleation of eyeball. It may be considered when pain is not relieved by conservative methods. The frequency with which a painful blind eye with high IOP contains a malignant growth, justifies its removal. (For surgical technique of enucleation see page 308). +Complications +Absolute glaucoma, if not treated, following complications may occur due to prolonged high IOP: Corneal ulceration.It results from prolonged epithelial oedema and insensitivity. Sometimes, corneal ulcer may even perforate. +Staphyloma formation. As a result of continued high IOP, sclera becomes very thin and atrophic and ultimately bulges out either in the ciliary region (ciliary staphyloma) or equatorial region (equatorial staphyloma). +Atrophic bulbi. Ultimately the ciliary body degenerates, IOP falls and the eyeball shrinks. + +SECONDARY GLAUCOMAS + +Secondary glaucoma per se is not a disease entity, but a group of disorders in which rise of intraocular pressure is associated with some primary ocular or systemic disease. Therefore, clinical features comprise that of primary disease and that due to effects of raised intraocular pressure. +Classification + +A. Depending upon the mechanism of rise in IOP +1. Secondary open angle glaucomas in which aqueous outflow may be blocked by: +• Pretrabecular membrane, • Trabecular clogging, +• Oedema and scarring or +• Post-trabecular elevated episcleral venous pressure. +2. Secondary angle closure glaucomas which may or may not be associated with pupil block. +B. Depending upon the causative primary disease, secondary glaucomas are named as follows: +1. Lens-induced (phacogenic) glaucomas. +2. Inflammatory glaucoma (glaucoma due to intraocular inflammation). +248 Section III Diseases of Eye + + +3. Pigmentary glaucoma. 4. Neovascular glaucoma. +5. Glaucomas associated with iridocorneal endothelial syndromes. +6. Pseudoexfoliative glaucoma. +7. Glaucomas associated with intraocular haemorrhage. +8. Steroid-induced glaucoma. 9. Traumatic glaucoma. +10. Glaucoma-in-aphakia. +11. Glaucoma associated with intraocular tumours. + +LENS-INDUCED (PHACOGENIC) GLAUCOMAS In this group IOP is raised secondary to some disorder of the crystalline lens. Lens induced glaucoma can be classified as below: +Lens-induced secondary angle closure glaucoma • Phacomorphic glaucoma (due to swollen lens) +• Phacotopic glaucoma (due to anterior lens displacement). +Lens-induced secondary open angle glaucoma • Phacolytic glaucoma +• Lens particle glaucoma +• Phacoanaphylactic glaucoma. + +1. Phacomorphic Glaucoma +Causes. Phacomorphic glaucoma is an acute secondary angle-closure glaucoma caused by: ■Intumescent lensi.e., swollen cataractous lens due to rapid maturation of cataract or sometimes following traumatic rupture of capsule is the main cause of phacomorphic glaucoma. +■Anterior subluxation or dislocation of the lens and spherophakia (congenital small spherical lens) are causes of phacotopic (a variant of phacomorphic) glaucoma. +Pathogenesis. The swollen lens pushes the iris forward and oblitrates the angle resulting in secondary acute angle closure glaucoma. Further, the increased iridolenticular contact also causes potential pupillary block and iris bombe formation. +Clinical presentation. Phacomorphic glaucoma presents as acute congestive glaucoma with features almost similar to acute primary angle-closure (see page 244) except that the lens is always cataractous and swollen (Fig. 10.21). Demonstration of deep anterior chamber and open angle in the fellow eye helps in differentiating from the acute primary angle closure glaucoma. +Treatment should be immediate and consists of: +• Medical treatment to control IOP by IV mannitol, systemic acetazolamide and topical beta-blockers. + + + + + + + + + + + + + + + + + +Fig. 10.21 Phacomorphic glaucoma. Note ciliary congestion, dilated pupil and intumescent senile cataractous lens +• Laser iridotomy may be effective in breaking the angle-closure attack. +• Cataract extraction with implantation of PCIOL (which is the main treatment of phacomorphic glaucoma) should be performed once the eye becomes quiet. + +2. Phacolytic Glaucoma (Lens Protein Glaucoma) +Pathogenesis. It is a type of secondary open angle glaucoma, in which trabecular meshwork is clogged by the lens proteins, macrophages which have phagocytosed the lens proteins, and inflammatory debris. Leakage of the lens proteins occurs through an intact capsule in the hypermature (Morgagnian) cataractous lens. +Clinical features. The condition is characterised by: • Features of acute congestive glaucoma (see page +244) due to an acute rise of IOP in an eye having hypermature cataract. +• Anterior chamber may become deep and aqueous may contain fine white protein particles, which settle down as pseudohypopyon. +• Anterior chamber angle is open on gonioscopy. + +Management consists of: +• Medical therapy to lower the IOP (see page 236) followed by +• Extraction of the hypermature cataractous lens with PCIOL implantation. + +3. Lens Particle Glaucoma +Pathogenesis. It is a type of secondary open angle glaucoma, in which trabecular meshwork is blocked +Chapter 10 Glaucoma 249 + + +by the lens particles floating in the aqueous humour. It may occur due to lens particles left after accidental or planned extracapsular cataract extraction or following traumatic rupture of the lens. +Clinical features. Symptoms of acute rise in IOP (see page 243) associated with lens particles in the anterior chamber. +Management includes: +• Medical therapy to lower IOP (see page 236) and • Irrigation-aspiration of the lens particles from the +anterior chamber. + +4. Phacoantigenic Glaucoma +In this condition, there occurs fulminating acute inflammatory reaction due to antigen (lens protein)—antibody reaction. The mechanism of rise in IOP and its management is similar to that of acute inflammatory glaucoma. Typical finding is a granulomatous inflammation in the involved eye after it goes surgical trauma. +Pathogenesis. As in the case of lens particle glaucoma, there is usually a preceding disruption of lens capsule by extracapsular cataract extraction, penetrating injury, or leak of proteins from the capsule. Distinguishing feature is a latent period during which sensitization to the lens proteins occurs. IOP is then raised due to inflammatory reaction of the uveal tissue excited by the lens matter. Basically, it is also a type of secondary open angle glaucoma where trabecular meshwork is clogged by both inflammatory cells and the lens particles. +Management consists of: +• Medical therapy to lower IOP, +• Treatment of iridocyclitis with steroids and cycloplegics. +• Irrigation-aspiration of the lens matter from anterior chamber (if required) should always be done after proper control of inflammation. + +GLAUCOMAS DUE TO UVEITIS +The IOP can be raised by varied mechanisms in inflammations of the uveal tissue (iridocyclitis). Even in other ocular inflammations such as keratitis and scleritis, the rise in IOP is usually due to secondary involvement of the anterior uveal tract. +Types +I. Non-specific inflammatory glaucomas, and II. Specific hypertensive uveitis syndromes. + +I. Non-Specific Inflammatory Glaucoma Based on the mechanism of rise in IOP the inflammatory glaucoma can be: + +• Open-angle inflammatory glaucoma, and • Angle-closure inflammatory glaucoma. +1. Open-angle inflammatory glaucoma +Clinically, the open-angle inflammatory glaucoma may manifest as acute or chronic entity. +i. Acute open-angle inflammatory glaucoma Mechanisms of rise in IOP. The acute open-angle glaucoma occurs due to trabecular clogging (by inflammatory cells, exudates and turbid aqueous humour), trabecular oedema (due to associated trabeculitis), and prostaglandin-induced rise in IOP. Clinical features. It is characterized by features of acute iridocyclitis associated with raised IOP with open-angle of anterior chamber. IOP usually returns to normal after the acute episode of inflammation. Management. It includes treatment of iridocyclitis and medical therapy to lower IOP by use of hyperosmotic agents, acetazolamide and beta-blocker eye drops (timolol or betaxolol). +ii. Chronic open angle inflammatory glaucoma Mechanism of rise in IOP includes chronic trabeculitis, and trabecular scarring. +Clinical features include raised IOP, open angle, no active inflammation but signs of previous episode of uveitis are often present. Some chronic cases may also have signs of glaucomatous disc changes and field defects. +Treatment consist of: +■Medical therapy with topical beta-blockers, and/ or carbonic anhydrase inhibitors and alpha agonist may be useful. Preferably avoid pilocarpine and prostaglandin agonists. +■Trabeculectomy, under cover of steroids, may be tried, if medical treatment fails. The results are usually poorer than POAG, but can be improved by augmented trabeculectomy or tube procedures. ■Cyclodestructive procedures (e.g. cyclodiode) may need to be considered if surgical treatment fails. +2. Angle-closure inflammatory glaucoma +When uveitis is not treated, over the period PAS are formed causing synechiae angle closure. +Mechanisms of rise in IOP include: +■Secondary angle-closure with pupil block. Pupillary block due to annular synechiae or occlusio pupillae leads to iris bombe formation followed by angle closure. +■Secondary angle-closure without pupil block occurs due to organisation of the inflammatory debris in the angle, which on contraction pulls the iris over the trabeculum. It is followed by gradual and progressive synechial angle closure with eventual elevation ofIOP. +250 Section III Diseases of Eye + + +Clinical featuresinclude raised IOP, seclusio papillae, iris bombe, shallow anterior chamber. +Management includes prophylaxis and curative treatment. +1.Prophylaxis. Acute iridocyclitis should be treated energetically with local steroids and atropine to prevent formation of synechiae. +2.Curative treatment. It consists of medical therapy to lower IOP (miotics are contraindicated). Surgical or laser iridotomy may be useful in pupil block without angle closure. Filtration surgery may be performed (with guarded results) in the presence of angle closure. + +II. Specific Hypertensive Uveitis Syndromes These include: +■Fuchs’ uveitis syndrome (see page 169) and ■Glaucomatocyclitic crisis (see page 169). +PIGMENTARY GLAUCOMA +It is a type of secondary open-angle glaucoma wherein clogging up of the trabecular meshwork occurs by the pigment particles. About 50% of patients with the Pigment dispersion syndrome (PDS) develop glaucoma. +Pathogenesis. Exact mechanism of pigment shedding is not known. It is believed that, perhaps, pigment release is caused by mechanical rubbing of the posterior pigment layer of iris with the zonular fibrils. +Clinical features include: +• Young myopic males typically develop this glaucoma. +• Characteristic glaucomatous features are similar to primary open angle glaucoma (POAG), associated with. +• Deposition of pigment granules in the anterior segment structures such as iris, posterior surface of the cornea (Krukenberg’s spindle), trabecular meshwork, ciliary zonules and the crystalline lens. +• Gonioscopy shows pigment accumulation along the Schwalbe’s line especially inferiorly (Sampaolesi’s line). +• Iris transillumination shows radial slit-like transillumination defects in the mid periphery (pathognomic feature). +Treatment. It is exactly on the lines of primary open angle glaucoma. +NEOVASCULAR GLAUCOMA (NVG) +It is an intractable glaucoma which results due to formation of neovascular membrane involving the angle of anterior chamber. + +Etiology. It is usually associated with neov-ascularization of iris (rubeosis iridis). Neov-ascularization develops following retinal ischaemia, which is a common feature of: +• Proliferative diabetic retinopathy, • Central retinal vein occlusion, +• Sickle-cell retinopathy, and • Eales’ disease. +• Other rare causes are chronic intraocular inflammations, intraocular tumours, long-standing retinal detachment and central retinal artery occlusion. +Clinical profile. NVG occurs in three stages: +1.Pre-glaucomatous stage (stage of rubeosis iridis); 2.Open-angle glaucoma stage—due to formation of +a pretrabecular neovascular membrane; and 3.Secondary angle closure glaucoma—due to +goniosynechiae resulting from contracture of the neovascular membrane (zipper angle closure). + +Treatment of NVG is usually frustrating, includes: +• Panretinal photocoagulation may be carried out to prevent further neovascularization. +• Medical therapy and conventional filtration surgery are usually not effective in controlling the IOP. +• Glaucoma drainage device, i.e., artificial filtration shunt (Seton operation) may control the IOP. +GLAUCOMA ASSOCIATEDWITH INTRAOCULAR TUMOURS +Secondary glaucoma due to intraocular tumours such as malignant melanoma (of iris, choroid, ciliary body) and retinoblastoma may occur by one or more of the following mechanisms: +• Trabecular block due to clogging by tumour cells or direct invasion by tumour seedlings. +• Neovascularization of the angle. +• Venous stasis following obstruction of the vortex veins. +• Angle closure due to forward displacement of iris-lens diaphragm by increasing tumour mass. + +Treatment. Enucleation of the eyeball should be carried out as early as possible. + +PSEUDOEXFOLIATIVE GLAUCOMA (GLAUCOMA CAPSULARE) +Pseudoexfoliation syndrome (PES) is characterised by deposition of an amorphous grey dandruff-like material on the pupillary border, anterior lens surface, posterior surface of iris, zonules and ciliary processes. +• Exact source of the exfoliative material is still not known. +Chapter 10 Glaucoma 251 + + +• Secondary open-angle glaucoma is associated in about 50% of the cases. +• Exact mechanism of rise of IOP is also not clear. Trabecular blockage by the exfoliative material is considered as the probable cause. +• Clinically, the glaucoma behaves like POAG and is thus managed on the same lines. +GLAUCOMAS-IN-APHAKIA/PSEUDOPHAKIA It is the term used to replace the old term ‘aphakic glaucoma’. It implies association of glaucoma with aphakia or pseudophakia. It includes following conditions: +1.Raised IOP with deep anterior chamber in early postoperative period. It may be due to hyphaema, inflammation, retained cortical matter or vitreous filling the anterior chamber. +2.Secondary angle-closure glaucoma due to flat anterior chamber. It may occur following long-standing wound leak. +3.Secondary angle-closure glaucoma due to pupil block. It may occur following formation of annular synechiae or vitreous herniation. +4.Undiagnosed pre-existing primary open-angle glaucoma may be associated with aphakia. pseudophakia. +5.Steroid-induced glaucoma. It may develop in patients operated for cataract due to postoperative treatment with steroids. +6.Epithelial ingrowth may cause an intractable glaucoma in late postoperative period by invading the trabeculum and the anterior segment structures. +7.Aphakic/pseudophakic malignant glaucoma (see page 252). +STEROID-INDUCED GLAUCOMA +It is a type of secondary open-angle glaucoma which develops following topical, and sometimes systemic steroid therapy. +Etiopathogenesis. It has been postulated that the response of IOP to steroids is genetically determined. Roughly, 5% of general population is high steroid responder (develop marked rise of IOP after about 6 weeks of steroid therapy), 35% are moderate and 60% are non-responders. +Mechanism responsible for the obstruction to aqueous outflow is unknown. Following theories have been put forward: +■Glycosaminoglycans (GAG) theory. Corticosteroids inhibit the release of hydrolases (by stabilizing lysosomal membrane). Consequently, the GAGs present in the trabecular meshwork cannot depolymerize and they retain water in the + +extracellular space. This leads to narrowing of trabecular spaces and decrease in aqueous outflow. ■Endothelial cell theory.Under normal circumstances the endothelial cells lining the trabecular meshwork act as phagocytes and phagocytose the debris from the aqueous humour. Corticosteroids are known to suppress the phagocytic activity of endothelial cells leading to collection of debris in the trabecular meshwork and decreasing the aqueous outflow. ■Prostaglandin theory. Prostaglandin E and F (PGE and PGF) are known to increase the aqueous outflow facility. Corticosteroids can inhibit the synthesis of PGE and PGF leading to decrease in aqueous outflow facility and increase in IOP. Clinical features. Steroid-induced glaucoma typically resembles POAG (see page 229). It usually develops following weeks of topical therapy with strong steroids and months of therapy with weak steroids. Management. It can be prevented by a judicious use of steroids and a regular monitoring of IOP when steroid therapy is a must. +Treatment consists of: +• Discontinuation of steroids. IOP may normalise within 10 days to 4 weeks in 98% of cases. +• Medical therapy with 0.5% timolol maleate is effective during the normalisation period. +• Filtration surgery is required occasionally in intractable cases. +TRAUMATIC GLAUCOMA +A secondary glaucoma may complicate perforating as well as blunt injuries. +Mechanisms.Traumatic glaucoma may develop by one or more of the following mechanisms: +• Inflammatory glaucoma due to iridocyclitis (see page 249). +• Glaucoma due to intraocular haemorrhage (see page 252). +• Lens-induced glaucoma due to ruptured, swollen or dislocated lens (see page 248). +• Angle-closure due to peripheral anterior synechiae formation following perforating corneal injury producing adherant leucoma. +• Epithelial or fibrous in growth, may involve trabeculum. +• Angle recession (cleavage) glaucoma. Angle recession refers to rupture in the ciliary body face (between scleral spur and iris root). Unilateral open angle glaucoma usually occurs after years (may be 10 years) of blunt trauma. Angle recession is not the cause of glaucoma but just indicator of old trauma. Glaucoma occurs due to slowly-induced fibrosis of trabecular meshwork. +252 Section III Diseases of Eye + + +Management includes: +• Medical therapy with topical 0.5% timolol and oral acetazolamide, +• Treatment of associated causative mechanism (e.g., atropine and steroids for control of inflammation), and +• Surgical intervention according to the situation. + +CILIARY BLOCK GLAUCOMA +Ciliary block glaucoma (originally termed as malignant glaucoma) is a rare condition which may occur as a complication of any intraocular operation. It classically occurs in patients with primary angle closure glaucoma operated for peripheral iridectomy or filtration (e.g., trabeculectomy) surgery. It is characterised by a markedly raised IOP associated with shallow or absent anterior chamber. Mechanism of rise in IOP. It is believed that, rarely following intraocular operation, the tips of ciliary processes rotate forward and press against the equator of the lens in phakic eyes (cilio-lenticular block) or against the intraocular lens in pseudophakic eyes (cilio-IOL block) or against the anterior hyaloid phase of vitreous in aphakic eyes (cilio-vitreal block) and thus block the forward flow of aqueous humour, which is diverted posteriorly and collects as aqueous pockets in the vitreous (Fig. 10.22). As a consequence of this the iris lens diaphragm is pushed forward, IOP is raised and anterior chamber becomes flat. Clinical features. Patient develops severe pain and blurring of vision following any intraocular operation + + + + + + + + + + + + + + + + + + + + + +Fig. 10.22 Pockets of aqueous humour in the vitreous in patients with ciliary-block glaucoma + +(usually after peripheral iridectomy, filtering surgery or trabeculectomy in patients with primary angle-closure glaucoma). On examination the main features of the ciliary block glaucoma noted are: +• Persistent flat anterior chamber following any intraocular operation, +• Markedly raised IOP in early postoperative period, • Negative Seidel’s test and +• Unresponsiveness or even aggravation by miotics. • Malignant glaucoma may be phakic, aphakic or +pseudophakic. +Management includes: +Medical therapy consists of 1% atropine drops or ointment to dilate ciliary ring and break the cilio-lenticular or cilio-vitreal contact, acetazolamide 250 mg QID and 0.5% timolol maleate eyedrops to decrease aqueous production, and intravenous mannitol to cause deturgescence of the vitreous gel. YAG laser hyaloidotomycan be undertaken in aphakic and pseudophakic patients. If the condition does not respond to medical therapy in 4–5 days. +Surgical therapy in the form of pars plana vitrectomy with or without lensectomy (as the case may be) is required when the above measures fail. It is usually effective, but sometimes the condition tends to recur. +Note. It is important to note that the fellow eye is also prone to meet the same fate. +GLAUCOMAS ASSOCIATED WITH INTRAOCULAR HAEMORRHAGES +Intraocular haemorrhages include hyphaema and/ or vitreous haemorrhage due to multiple causes. These may be associated with following types of glaucomas: +1. Red cell glaucoma. It is associated with fresh traumatic hyphaema. It is caused by blockage of trabeculae by RBCs in patients with massive hyphaema (anterior chamber full of blood). It may be associated with pupil block due to blood clot. Blood staining of the cornea may develop, if the IOP is not lowered within a few days. +2. Haemolytic glaucoma. It is an acute secondary open angle glaucoma due to the obstruction (clogging) of the trabecular meshwork caused by macrophages laden with lysed RBC debris. +3. Ghost cell glaucoma. It is a type of secondary open angle glaucoma which occurs in aphakic or pseudophakic eyes with vitreous haemorrhage. After about 2 weeks of haemorrhage the RBCs degenerate, lose their pliability and become khaki-coloured cells (ghost cells) which pass from the vitreous into the anterior chamber, and block the pores of trabeculae leading to rise in IOP. +Chapter 10 Glaucoma 253 + + +4. Hemosiderotic glaucoma. It is a rare variety of secondary glaucoma occurring due to sclerotic changes in trabecular meshwork caused by the iron from the phagocytosed haemoglobin by the endothelial cells of trabeculum. +GLAUCOMAS ASSOCIATED WITH IRIDOCORNEAL ENDOTHELIAL SYNDROMES +Iridocorneal endothelial (ICE) syndromes include three clinical entities: +• Progressive iris atrophy, +• Chandler’s syndrome, and • Cogan-Reese syndrome. +Pathogenesis. The common feature of the ICE syndromes is the presence of abnormal corneal endothelial cells which proliferate to form an endothelial membrane in the angle of anterior chamber. Glaucoma is caused by secondary synechial angle-closure as a result of contraction of this endothelial membrane. +Clinical features. The ICE syndromes typically affect middle-aged women. The raised IOP is associ-ated with characteristic features of the causative condition. +■In ‘progressive iris atrophy,’ iris features predominate with marked corectopia, atrophy and hole formation. ■While in Chandler’s syndrome, changes in iris are mild to absent and the corneal oedema even at normal IOP predominates. +■Hallmark of Cogan-Reese syndrome is nodular or diffuse pigmented lesions of the iris (therefore also called as iris naevus syndrome) which may or may not be associated with corneal changes. +Treatment is usually frustating: +• Medical treatment is often ineffective, • Trabeculectomy operation usually fails, +• Glaucoma drainage device i.e., artificial filtration shunt may control the IOP. + +SURGICAL PROCEDURES FOR GLAUCOMA +PERIPHERAL IRIDECTOMY Indications +1.Treatment of all stages of primary angle-closure glaucoma. +2.Prophylaxis in the fellow eye. +Note. Laser iridotomy should always be preferred over surgical iridectomy. +Surgical technique (Fig. 10.23) +1.Incision. A 4 mm limbal or preferably corneal incision is made with the help of razor blade fragment. + + + + + + + + + +A B + + + + + + + + + + + +C D + +Fig. 10.23 Technique of peripheral iridectomy: A, anterior limbal incision to open the anterior chamber; B, prolapse of peripheral iris by pressure at the posterior lip of the incision; C, excision of the prolapsed knuckle of the iris by de Wecker’s scissors; D, suturing the wound + +2.Iris prolapsed. The posterior lip of the wound is depressed so that the iris prolapses. If the iris does not prolapse, it is grasped at the periphery with iris forceps. +3.Iridectomy. A small full thickness piece of iris is excised by de Wecker’s scissors. +4.Reposition of iris. Iris is reposited back into the anterior chamber by stroking the lips of the wound or with iris repositors. +5.Wound closure is done with one or two 10–0 nylon sutures with buried knots. +6.Subconjunctival injection of dexamethasone 0.25 ml and gentamicin 0.5 ml is given. +7.Patching of eye is done with a sterile eye pad and sticking plaster. +GONIOTOMY AND TRABECULOTOMY +These operations are indicated in congenital and developmental glaucomas (For details, see page 227) +FILTERING OPERATIONS +Filtering operations provide a new channel for aqueous outflow and successfully control the IOP (below 21 mm of Hg). Filtration operations can be grouped as below: +A. External filteration surgery +1. Free-filtering operations (Full thickness fistula). These are no longer performed nowadays, because +254 Section III Diseases of Eye + +of high rate of postoperative complications. Their names are mentioned only for historical interest. These operations included Elliot’s sclero-corneal trephining, punch sclerectomy, Scheie’s thermosclerostomy and iridencleisis. +2. Guarded filtering surgery (Partial thickness fistula e.g., trabeculectomy). +3. Non-penetrating filtration surgery e.g., deep sclerectomy and viscocanalostomy. +B. Internal filteration surgery A B Note. Salient features of few important filteration +operations are described here. + +A. External Filtration Surgery +Trabeculectomy +Trabeculectomy, first described by Carain in 1980 is the most frequently performed partial thickness filtering surgery till date. + +Indications +1.Primary angle-closure glaucoma with peripheral anterior synechial involving more than 270° angle or where PI and medical treatment fail. +2.Primary open-angle glaucoma not controlled with medical treatment. +3.Congenital and developmental glaucomas where trabeculotomy and goniotomy fail. +4.Secondary glaucomas where medical therapy is not effective. +Mechanisms of filtration +1.Anew channel (fistula) is created around the margin of scleral flap, through which aqueous flows from anterior chamber into the subconjunctival space. +2.If the tissue is dissected posterior to the scleral spur, a cyclodialysis may be produced leading to increased uveoscleral outflow. +3.When trabeculectomy was introduced, it was thought that aqueous flows through the cut ends of Schlemm’s canal. However, now it is established that this mechanism has a negligible role. +Surgical technique is as below: (Fig. 10.24) +1.Initial steps of anaesthesia, cleansing, draping, exposure of eyeball and fixation with superior rectus suture are similar to cataract operation (see page 201). +2.Conjunctival flap (Fig. 10.24A). A fornix-based or timbal-based conjunctival flap is fashioned and the underlying sclera is exposed. The Tenon’s capsule is cleared away using a Tooke’s knife, and haemostasis is achieved with cautery. +3.Scleral flap (Fig. 10.24B). A partial thickness (usually half) limbal-based scleral flap of 5 mm × 5 mm size is reflected down towards the cornea. + + + + +C D + +Fig. 10.24 Technique of trabeculectomy: A, fornix-based conjunctival flap; B & C, partial thickness scleral flap and excision of trabecular tissue; D, peripheral iridectomy and closure of sclera) flap; E, closure of conjunctival) flap + +4.Excision of trabecular tissue (Fig. 10.24B): A narrow strip (4 mm × 2 mm) of the exposed deeper sclera near the cornea containing the canal of Schlemm and trabecular meshwork is excised. +5.Peripheral iridectomy (Fig. 10.24C) is performed at 12 O’clock position with de Wecker’s scissors. 6.Closure. The scleral flap is replaced and 10-0 nylon +sutures are applied. Then the conjunctival flap is reposited and sutured with two interrupted sutures (in case of fornix based flap) or continuous suture (in case of limbal-based flap) (Fig. 10.24D). +7.Subconjunctival injections of dexamethasone and gentamicin are given. +8.Patching. Eye is patched with a sterile eye pad and sticking plaster or a bandage. +Complications +A few common complications are postoperative shallow anterior chamber, hyphaema, iritis, cataract due to accidental injury to the lens, and endophthalmitis (not very common). +Use of antimetabolites with trabeculectomy +It is recommended that antimetabolites should be used for wound modulation, when any of the following risk factors for the failure of conventional trabeculectomy are present: +Chapter 10 + +1.Previous failed filtration surgery. 2.Glaucoma in aphakia. +3.Certain secondary glaucomas e.g., inflammatory glaucoma, post-traumatic angle recession glaucoma, neovascular glaucoma and glaucomas associated with ICE syndrome. +4.Patients treated with topical antiglaucoma medications (particularly sympathomimetics) for over three years. +5.Chronic cicatrizing conjunctival inflammation. +Antimetabolite agents. Either 5-fluorouracil (5-FU) or mitomycin-C can be used. Mitomycin-C is only used at the time of surgery. A sponge soaked in 0.02% (2 mg in 10 ml) solution of mitomycin-C is placed at the site of filtration between the scleral and Tenon’s capsule for 2 minutes, followed by a thorough irrigation with balanced salt solution. + +Glaucoma 255 + + + + + + + + +A B + + + + + + + + + +C D + + + +Use of collagen implant with glaucoma filtration surgery has been recommended as an alternative to mitomycin–C for modulating wound healing in high risk cases mentioned above. Its effectively is similar to MMC and eliminates the complications associated with MMC. However, collagen matrix implant is more expensive. +Technique. Usually a 6 mm diameter and 1 mm thick implant is sutured over the scleral flap. +Sutureless trabeculectomy 1.Initial steps, and +2.Conjuctival flap fashioning is similar to conventional trabeculectomy. +3.Sclero-corneal valvular tunnel, 4 mm × 4 mm in size, is made by first making 4 mm partial thickness scleral groove about 2.5 mm away from the superior limbus with the help of a razor bladefragment (Fig. 10.25A). A 4 mm wide sclero-corneal tunnel which extends about 1.5 mm in the clear cornea is then made with the help of a crescent knife (Fig. 10.25B). 4.Entry into the anterior chamber is made with the +help of a sharp 3.2 mm angled keratome. 5.Punching of posterior lip of the anterior chamber +entry site. (Fig. 10.25C) is then performed with the help of a Kelly’s punch (see Fig. 26.61) to make a sclerostomy of about 2 mm × 2 mm in size. +6.Peripheral iridectomy (Fig. 10.25D) is performed at 12 O’clock position with the help of de Wecker’s or Vanna’s scissors. +7.Closure. Anterior chamber is filled with balanced salt solution (BSS) or air to close the valvular sclero-corneal tunnel incision. Conjunctival flap is reposited and anchored with wet-field cautery. + + + +Fig. 10.25 Sutureless trabeculectomy + +Non-penetrating filteration surgeries +Recently some techniques of non-penetrating filteration surgery (in which anterior chamber is not entered) have been advocated to reduce the incidence of postoperative endophthalmitis, overfiltration and hypotony. Main disadvantage of nonpenetrating filteration surgery is inferior IOP control as compared to conventional trabeculectomy. The two currently used procedures are: +1. Deep sclerectomy. In this procedure, after making a partial thickness scleral flap, (as in conventional trabeculectomy, Fig.10.24A), a second deep partial-thickness scleral flap is fashioned and excised leaving behind a thin membrane consisting of very thin sclera, trabeculum and Descemet’s membrane (through which aqueous diffuses out). The superficial scleral flap is loosly approximated and conjunctival incision is closed. +2. Viscocanalostomy. It is similar to deep sclerectomy, except that after excising the deeper scleral flap, high viscosity viscoelastic substance is injected into the Schlemm’s canal with a special cannula. + +B. Internal Filteration Surgeries +Internal filteration surgeries, also called as canal-based procedure, are newer techniques that restore filteration through Schlemm’s canal. These are designed to keep the normal anatomy and to be conjunctival bleb free; and thus reducing the risk of long-term endophthalmitis and ocular hypotomy. +256 Section III Diseases of Eye + + +These procedure includes: +1. Canaloplasty, i.e., dilatation and circumferential, traction of canal using 10–0 prolene suture. +2. Trabectome involves an ab interno microcautery that ablates the trabecular meshwork and inner wall of Schlemm’s canal. +3. iStent, is a titanium micro device that is placed inside the Schlemm’s canal. It allows the aqueous humor to flow directly into the canal bypassing the trabecular meshwork. +GLAUCOMA DRAINAGE DEVICE OPERATIONS Glaucoma drainage device or the so called glaucoma valve implants are plastic devices which allow aqueous outflow by creating a communication between the anterior chamber and sub-Tenon’s space. The operation using glaucoma valve implant is also known as Seton operation. +Glaucoma drainage device commonly used include Molteno (Fig. 10.26) Krupin-Denver and Ahmed glaucoma valve (AGV). +Indications of artificial drainage shunts include: • Neovascular glaucoma, +• Glaucoma with aniridia, and +• Intractable cases of primary and secondary glaucoma where even trabeculectomy with adjunct antimetabolite therapy fails. +Ex-PRESS glaucoma implant +Ex-PRESS glaucoma implant (mini shunt), is small stainless steel device, which is now implanted under the partial-thickness sclera flap as a modification of + + + + + + + + + + + + + + + + + + + + +Fig. 10.26 Artificial drainage shunt operation using Molteno implant + +trabeculectomy. It provides a more favorable safety and postoperative recovery profile than standard trabeculectomy. So, it is now alternative to glaucoma drainage valves such as AGV. +CYCLO-DESTRUCTIVE PROCEDURES +Cyclo-destructive procedures lower IOP by destroying part of the secretory ciliary epithelium thereby reducing aqueous secretion. +Indications. These procedures are used mainly in absolute glaucomas. + +Cyclo-destructive procedures in current use are: +• Cyclocryotherapy, +• Nd: Yag laser cyclodestruction, and • Diode laser cyclophotocoagulation. +Technique of cyclocryotherapy +1.Anaesthesia. Topical and peribulbar block anaesthesia is given. +2.Lids separation is done with eye speculum. 3.Cryoapplications. Cryo is applied with a retinal +probe placed 3 mm from the limbus. A freezing at – 80°C for 1 minute is done in an area of 180° of the globe (Fig. 10.27). +If ineffective, the procedure may be repeated in the same area after 3 weeks. If still ineffective, then the remaining 180° should be treated. +Mechanism. IOP is lowered due to destruction of the secretory ciliary epithelium. The cells are destroyed by intracellular freezing. + + + + + + + + + + + + + + + + + + + + +Fig. 10.27 Site of cyclocryopexy +11 + +Diseases of Vitreous + + + +Chapter Outline + +APPLIED ANATOMY Structure Attachments +DISORDERS OF THE VITREOUS Vitreous liquefaction +• +• +Vitreous detachments Vitreous opacities +• +• +• +• +• +Muscae volitantes +Persistent hyperplastic primary vitreous Inflammatory vitreous opacities +Vitreous aggregates and condensation with liquefaction Amyloid degeneration + + + +APPLIED ANATOMY + +Vitreous humour is an inert, transparent, jelly-like structure that fills the posterior four-fifth of the cavity of eyeball. Vitreous body is some what spherical posteriorly and has a cup-shaped depression (patellar fossa) anteriorly. Thus, it conforms to the contour of retina behind and lens infront. It is about 4 ml in volume and 4 gm in weight. +Functions. It is a hydrophilic gel that mainly serves the optical functions. In addition, it mechanically stabilizes the volume of the globe and is a pathway for nutrients to reach the lens and retina. Embryologically, this vitreous body is the secondary or definitive vitreous secreted by neuroectoderm of optic cup. During development, when this secondary vitreous fills the cavity,primary or primitive vitreous (mesenchymal in origin) along with hyaloid vessels is pushed anteriorly and ultimately disappear. Tertiary vitreous is developed from neuroectoderm in the ciliary region and is represented by the ciliary zonules. +Structure +The normal youthful vitreous gel is composed of a network of randomly-oriented collagen fibrils interspersed with numerous spheroidal macromolecules of hyaluronic acid. The collapse + +• Asteroid hyalosis Synchysis scintillans +Red cell opacities Tumour cell opacities +• +• +• +Vitreous haemorrhage vitreo-retinal degenerations +VITREcTOMY Techniques +• +• +Open-sky vitrectomy +Closed vitrectomy (Pars plana vitrectomy) +Vitreous substitutes + + + +of this structure with age or otherwise leads to conversion of the gel into sol. The vitreous body can be divided into two parts: the cortex and the medulla or nucleus (the main vitreous body) (Fig. 11.1). +1. Cortical vitreous. It lies adjacent to the retina posteriorly and ciliary body, zonules and lens anteriorly. The density of collagen fibrils is greater in this peripheral part. The condensation of these fibrils form a false anatomic membrane which is called as anterior hyaloid membrane anterior to ora serrata and posterior hyaloid membrane posterior to ora. The attachment of the anterior hyaloid membrane to the posterior lens surface is firm in young and weak in elders, whereas, posterior hyaloid membrane remains loosely attached to the internal limiting membrane of the retina throughout life. These membranes cannot be discerned in a normal eye unless the lens has been extracted and posterior vitreous detachment has occurred. +2. The main vitreous body (medulla or nucleus). It has a less dense fibrillar structure and is a true biological gel. It is here where liquefactions of the vitreous gel start first. Microscopically the vitreous body is homogenous, but exhibits wavy lines as of watered silk in the slit-lamp beams. Running down the centre of the vitreous body from the optic disc to the posterior pole of the lens is the hyaloid canal +258 Section iii Diseases of Eye + + + + + + + + + + + + + + + + + + + + + + + +Fig. 11.1 Gross anatomy of the vitreous + + + +(Cloquet’s canal) of doubtful existence in adults. Down this canal ran the hyaloid artery of the foetus. +Attachments +The part of the vitreous about 4 mm across the ora serrata is called as vitreous base, where the attachment of the vitreous is strongest. The other firm attachments are around the margins of the optic disc, foveal region and back of the crystalline lens by hyaloidocapsular ligament of Wiegert. + +DISORDERS OF THE VITREOUS + +VitreouS LiquefAction +Vitreous liquefaction (synchysis) is the most common degenerative change in the vitreous. +Causes of liquefaction include: +1. Age-related liquefaction is of common occurrence after the age of 50 years. +2. Degenerations such as myopic degeneration , and that associated with retinitis pigmentosa. +3. Post-inflammatory, particularly following uveitis. 4. Trauma to the vitreous which may be mechanical +(blunt as well as perforating). +5. Thermal effects on vitreous following diathermy, photocoagulation and cryocoagulation. +6. Radiation effects may also cause liquefaction. Clinical features. On slit-lamp biomicroscopy the vitreous liquefaction (synchysis) is characterised + +by the absence of normal fine fibrillar structure and visible pockets of liquefaction associated with appearance of coarse aggregate material which moves freely in free vitreous. Liquefaction is usually associated with collapse (synersis) and opacities in the vitreous, which may be seen subjectivelyas black floaters in front of the eye. +VitreouS DetAchmentS +1. Posterior vitreous detachment (PVD) +It refers to the separation of the cortical vitreous from the retina anywhere posterior to vitreous base (3–4 mm wide area of attachment of vitreous to the ora serrata). +PVD with vitreous liquefaction (synchysis) and collapse (synersis) is of common occurrence in majority of the normal subjects above the age of 65 years (Fig. 11.2). It occurs in eyes with senile liquefaction, developing a hole in the posterior hyaloid membrane. The synchytic fluid collects between the posterior hyaloid membrane and the internal limiting membrane of the retina, and leads to PVD up to the base along with collapse of the remaining vitreous gel (synersis). These changes occur more frequently in the aphakics than the phakics, and in the myopes than the emmetropes. +Clinical features +■Flashes of light and floaters are often associated with PVD. +Chapter 11 Diseases of Vitreous 259 + + + + + + + + + + + + + + + +Fig. 11.2 Posterior vitreous detachment with synchysis and synersis +■Biomicroscopic examination of the vitreous reveals: +• A collapsed vitreous (synersis)behind the lens and an optically clear space between the detached posterior hyaloid phase and the retina. +• A ring-like opacity (Weiss ring or Fuchs ring), representing a ring of attachment of vitreous to the optic disc, is pathognomic of PVD. +Complications of PVD +These include retinal breaks, vitreous haemorrhage, retinal haemorrhages and cystoid maculopathy. +Management +• Uncomplicated PVD requires no treatment. Just reassure but give ‘retinal detachment warning’, i.e., to report immediately on noticing an increase in floaters, or flashing lights or the appearance of persistent curtain or shadow in the field of vision. +• Retinal tear complicating PVD may need to be treated by laser photocoagulation. +• Vitreous haemorrhage complicating PVD needs to be managed (see page 260). +• Retinal detachment complicating PVD requires urgent treatment (see page 300). +2. Detachment of the vitreous base and the anterior vitreous +It may occur following blunt trauma. It may be associated with vitreous haemorrhage, anterior retinal dialysis and dislocation of crystalline lens. +VitreouS oPAcitieS +Since vitreous is a transparent structure, any relatively nontransparent structure present in it will form an opacity and cause symptoms of floaters. Common conditions associated with vitreous opacities are described below. +muscae volitantes +These are physiological opacities and represent the residues of primitive hyaloid vasculature. Patient + +perceives them as fine dots and filaments, which often drift in and out of the visual field, against a bright background (e.g., clear blue sky). + +Persistent hyperplastic primary vitreous (PhPV) +It results from failure of the primary vitreous structure to regress combined with the hypoplasia of the posterior portion of vascular meshwork. Clinical features. PHPV may be anterior or posterior, most often elements of both are present. Common features are: +■Leucocoria (whitish pupillary reflex) is the most common presenting feature of both anterior and posterior PHPV. +■Microphthalmia is often associated with PHPV. ■Tractional retinal detachment and retinal folds are features of posterior PHPV. +■Associated anomalies include congenital cataract, shallow anterior chamber, angle closure glaucoma, long ciliary processes and recurrent intraocular haemorrhage. +■PHPV is almost always unilateral. Bilateral cases are rare and may be associated with trisomy 13 (Patau syndrome), trisomy 22, Norries disease and Walkers Warburg syndrome. +Differential diagnosis needs to be made from other causes of leucocoria especially retinoblastoma, congenital cataract and retinopathy of prematurity. Computerised tomography (CT) scanning helps in diagnosis by presence of calcification in retinoblastoma. +Treatment consists of pars plana lensectomy and excision of the membranes with anterior vitrectomy provided the diagnosis is made early. Visual prognosis is often poor. + +inflammatory vitreous opacities +These consist of exudates poured into the vitreous in patients with anterior uveitis (iridocyclitis), posterior uveitis (choroiditis), pars planitis, pan uveitis and endophthalmitis. + +Vitreous aggregates and condensation with liquefaction +It is the commonest cause of vitreous opacities. Condensation of the collagen fibrillar network is a feature of the vitreous degeneration which may be senile, myopic, post-traumatic or post-inflammatory in origin. + +Amyloid degeneration +It is a rare condition in which amorphous amyloid material is deposited in the vitreous as a part of the generalised amyloidosis. These vitreous opacities are linear with footplate attachments to the retina and the posterior lens surface. +260 Section iii Diseases of Eye + + +Asteroid hyalosis +It is characterised by small, white rounded bodies suspended in the vitreous gel. These are formed due to accumulation of calcium-containing lipids. Asteroid hyalosis is a unilateral, asymptomatic condition usually seen in old patients with healthy vitreous. There is a genetic relationship between this condition, diabetes and hypercholesterolaemia. The genesis is unknown and there is no effective treatment. +Synchysis scintillans (cholestrolosis bulbi) +In this condition, vitreous is laden with small white angular and crystalline bodies formed of cholesterol. It affects the damaged eyes which have suffered from trauma, vitreous haemorrhage or inflammatory disease in the past. In this condition vitreous is liquid and so, the crystals sink to the bottom, but are stirred up with every movement to settle down again with every pause. This phenomenon appears as a beautiful shower of golden rain on ophthalmoscopic examination. Since, the condition occurs in a damaged eye, it may occur at any age. The condition is generally symptomless, and untreatable. +red cell opacities +These are caused by small vitreous haemorrhages or leftouts of the massive vitreous haemorrhage. +tumour cells opacities +These may be seen as free floating opacities in some patients with retino-blastoma, and reticulum cell sarcoma and intraocular lymphomas. +VitreouS hAemorrhAge +Vitreous haemorrhage usually occurs from the retinal vessels and may present as preretinal (sub-hyaloid) or an intragel haemorrhage. The intragel haemorrhage may involve anterior, middle, posterior or the whole vitreous body. +causes +Causes of vitreous haemorrhage are: +1. Retinal tear, PVD and RD may have associated vitreous haemorrhage. +2. Trauma to eye, which may be blunt or perforating (with or without retained intraocular foreign body) in nature. +3. Inflammatory diseases such as erosion of the vessels in acute chorioretinitis and periphlebitis retinae primary (Eales’ disease), or secondary to uveitis. +4. Vascular disorders, e.g., hypertensive retinopathy, and central retinal vein occlusion. +5. Metabolic diseases such as diabetic retinopathy. + + +6. Exudative age-related macular degeneration usually high CNVM, may have vitreous haemorrhage. +7. Blood dyscrasias, e.g., retinopathy of anaemia, leukaemias, polycythemias and sickle-cell retinopathy. +8. Bleeding disorders, e.g., purpura, haemophilia and scurvy. +9. Neoplasms. Vitreous haemorrhage may occur from rupture of vessels due to acute necrosis in tumours like retinoblastoma and malignant melanoma of choroid. +10. Other causes include Coat’s diseases, radiation retinopathy, retinal capillary aneurysm. +clinical features +Depending upon the location it is labeled as: • Anterior vitreous hemorrhage, +• Mid vitreous hemorrhage, +• Posterior vitreous hemorrhage, or • Total vitreous hemorrhage. +Symptoms +• Floaters of sudden onset occur when the vitreous haemorrhage is small. +• Sudden painless loss of vision occurs in massive vitreous haemorrhage. +Signs +• Distant direct ophthalmoscopy reveals black shadowsagainsttheredglowinsmallhaemorrhages and no red glow in a large haemorrhage. +• Direct and indirect ophthalmoscopy may show presence of blood in the vitreous cavity in small vitreous haemorrhage and non-visualization of fundus in large vitreous haemorrhage. +• Slit-lamp examination shows normal anterior segment and a reddish mass in the vitreous. +• Ultrasonography with B-scan is particularly helpful in diagnosing vitreous haemorrhage. +fate of vitreous haemorrhage +1. Complete absorption may occur without organization and the vitreous becomes clear within 4–8 weeks. +2. Organization of haemorrhage with formation of a yellowish-white debris occurs in persistent or recurrent bleeding. +3. Complications like vitreous liquefaction, degeneration and khaki cell glaucoma (in aphakia) may occur. +4. Retinitis proliferans may occur which may be complicated by tractional retinal detachment. +Chapter 11 Diseases of Vitreous 261 + + +treatment +1. Conservative treatment consists of bed rest and elevation of patient’s head. This will allow the blood to settle down. +2. Treatment of the cause. Once the blood settles down, indirect ophthalmoscopy should be performed to locate and further manage the causative lesion such as a retinal break, phlebitis, proliferative retinopathy, etc. +3. Vitrectomy by pars plana route should be considered to clear the vitreous, if the haemorrhage is not absorbed after 3 months. Early vitrectomy may be required when associated with retinal detachment. +Vitreo-retinAL DegenerAtionS See page 290. + +VITRECTOMY + +Vitrectomy, i.e., surgical removal of the vitreous is now a frequently performed procedure. Common terms used in relation to vitrectomy are: +• Anterior vitrectomy. It refers to removal of anterior part of the vitreous. +• Core vitrectomy. It refers to removal of the central bulk of the vitreous. It is usually indicated in endophthalmitis. +• Subtotal and total vitrectomy. In this almost whole of the vitreous is removed. +techniqueS open-sky vitrectomy +This technique is employed to perform only anterior vitrectomy. +Indications +• Vitreous loss during cataract extraction. • Aphakic keratoplasty. +• Anterior chamber reconstruction after perforating trauma with vitreous loss. +• Removal of subluxated and anteriorly dislocated lens. +Surgical technique +Open-sky vitrectomy is performed through the primary wound to manage the disturbed vitreous during cataract surgery or aphakic keratoplasty. It should be performed using an automated vitrectomy machine. However, if the vitrectomy machine is not available, it can be performed with the help of a triangular cellulose sponge and de Wecker’s scissors (sponge vitrectomy). +closed vitrectomy (pars plana vitrectomy) +Pars plana approach is employed to perform anterior vitrectomy, core vitrectomy, subtotal and total vitrectomy. + + +Indications +• Endophthalmitis with vitreous abscess. • Vitreous haemorrhage. +• Proliferative retinopathies such as those associated with diabetes, Eales’ disease, retinopathy of prematurity and retinitis proliferans. +• Complicated cases of retinal detachment such as those associated with giant retinal tears, retinal dialysis and massive vitreous traction. Presently, even simple cases of rhegmatogenous retinal detachment are managed with this technique. +• Removal of intraocular foreign bodies. +• Removal of dropped nucleus or intraocular lens from the vitreous cavity. +• Persistent primary hyperplastic vitreous. • Vitreous membranes and bands. +• Macular pathology like macular hole, and epiretinal membrane. +Surgical techniques +Pars plana vitrectomy is a highly sophisticated microsurgery which can be performed by using two type of systems: +1.One-port vitrectomy or full function system vitrectomy is nowadays not used. It employs a multifunction system that comprises vitreous infusion, suction, cutter and illumination (VISC), all in one. +2. Three-port pars plana vitrectomy or divided system approach isthemostcommonlyemployedtechnique in modern vitrectomy. In this technique three separate incisions are given in pars plana region. That is why the procedure is also called three-port 20 gauze pars plana vitrectomy. The cutting and aspiration functions are contained in one probe, illumination is provided by a separate fiberoptic probe and infusion is provided by a cannula introduced through the third pars plana incision (Fig. 11.3). +Advantagesof divided system approachinclude smaller instruments, easy handling, improved visualization, use of bimanual technique and adequate infusionby separate cannula. +23 and 25 gauge three-port vitrectomy techniques introduced recently are becoming increasingly popular alternatives to the standard 20 gauge vitrectomy. Their advantages include self-sealing sclerotomy sites, improved patient comfort, reduced postoperative inflammation and more rapid visual recovery. + +VitreouS SubStituteS +Vitreous substitutes or the so called tamponading agents are used in vitreoretinal surgery to: +262 Section iii Diseases of Eye + + + + + + + + + + + + + + + + + + + + + + + +Fig. 11.3 Three-port pars plana vitrectomy using divided system approach + +• Restore intraocular pressure, and • Provide intraocular tamponade. + +An ideal vitreous substitute should be: +• Having a high surface tension, • Optically clear, and +• Biologically inert. + +Currently used vitreous substitutes in the absence of an ideal substitute are: +1. Air is commonly used internal tamponade in uncomplicated cases. It is absorbed within 3 days. 2. Physiological solutions such as Ringer’s lactate or balanced salt solution (BSS) can be used as substitute after vitrectomy for endophthalmitis or uncomplicated vitreous haemorrhage. +3. Expanding gases are preferred over air in complex cases requiring prolonged intraocular tamponade. They are used as 40% mixture with air. Examples are: +• Sulphur hexafluoride (SF6). It doubles its volume and lasts for 10 days. +• Perfluoropropane (C3 F8). It quadruples its volume and lasts for 28 days. +4. Perfluorocarbon liquids (PFCLs) are heavy liquids which are mainly used: +• To remove dropped nucleus or IOL from the vitreous cavity, +• To unfold a giant retinal tear, and +• To stabilize the posterior retina during peeling of the epiretinal membrane. +Agents used are perfluoro-n-octane, per-fluoro-tributylamine, perfluorodecalin and perfluorophenanthrene. +5. Silicone oil allows more controlled retinal manipulation during operation and can be used for prolonged intraocular tamponade after retinal detachment surgery. +12 + +Diseases of Retina + + + +CHAPTER OUTLINE + +APPLIED ANATOMY +CONGENITAL AND DEVELOPMENTAL DISORDERS OF RETINA +INFLAMMATORY DISORDERS OF RETINA Retinitis +• +• +Retinal vasculitis +VASCULAR DISORDERS OF RETINA Retinal artery occlusions +• +• +• +• +• +• +• +• +Retinal vein occlusions Hypertensive retinopathy +Retinopathy in pregnancy induced hypertension Diabetic retinopathy +Sickle-cell retinopathy Retinopathy of prematurity Retinopathies of blood disorders + + + +APPLIED ANATOMY + +Retina, the innermost tunic of the eyeball, is a thin, delicate and transparent membrane. It is the most highly-developed tissue of the eye. It appears purplish-red due to the visual purple of the rods and underlying vascular choroid. +Gross Anatomy +Retina extends from the optic disc to the ora serrata with a surface area of about 266 mm2. Retina is thickest in the peripapillary region (0.56 mm) and thinnest at ora serrate (0.1 mm). Grossly, it can be divided into two distinct regions: posterior pole and peripheral retina separated by the so called retinal equator. +■Retinal equator is an imaginary line which is considered to lie in line with the exit of the four vena verticose. +Posterior pole refers to the area of retina posterior to the retinal equator. The posterior pole of the retina includes two distinct areas: the optic disc and macula lutea (Fig. 12.1). Posterior pole of the retina is best examined by slit-lamp indirect biomicroscopy using +78 D and +90 D lens and by direct ophthalmoscopy. + +• Primary retinal telangiectasia Ocular ischaemic syndrome +DYSTROPHIES AND DEGENERATIONS OF RETINA Retinal dystrophies +• +• +• +Retinal degenerations MACULAR DISORDERS +RETINAL DETACHMENT +• Rhegmetogenous Exudative Tractional +• +• +TUMOURS OF RETINA +• Retinoblastoma Enucleation Phacomatoses +• +• + + +Optic disc. It is a pink coloured, well-defined vertically oval area with average dimension of 1.76 mm horizontally and 1.88 mm vertically. It is placed 3.4 mm nasal to the fovea. At the optic disc all the retinal layers terminate except the nerve fibres (1–1.2 million), which pass through the lamina cribrosa to run into the optic nerve. The optic disc thus represents the beginning of the optic nerve and so is also referred to as optic nerve head. A depression seen in the disc is called the physiological cup. The central retinal artery and vein emerge through the centre of this cup. Because of absence of photoreceptors (rods and cones), the optic disc produces an absolute scotoma in the visual field called as physiological blind spot. +Macula lutea. It is also called the yellow spot. It is comparatively deeper red than the surrounding fundus and is situated at the posterior pole temporal to the optic disc. It is about 5.5 mm in diameter. Fovea centralis is the central depressed part of the macula. It is about 1.5 mm in diameter and is the most sensitive part of the retina. With lowest threshold for light and highest visual acuity, because it contains only cones, in its centre is a shining pit called foveola (0.35 mm diameter) which is situated about 2 disc diameters +264 Section 3 Diseases of Eye + + + + + + + + + + + + + + + +A + + + + + + + + + + + + + + + +B + + + + + + + + + + + + + + + + + + +C +Fig. 12.1 Gross anatomy of the retina: A, parts of retina in horizontal section at the level of fovea; B, diagrammatic fundus view; C, fundus photograph + +(3–4 mm) away from the temporal margin of the disc and about 1 mm below the horizontal meridian. The tiny depression in the centre of foveola is called umbo which is seen as shinning foveal reflex on fundus examination. An area about 0.8 mm in diameter (including foveola and some surrounding area) does not contain any retinal capillaries and is called foveal avascular zone (FAZ). Surrounding the fovea are the parafoveal and perifoveal areas. +Peripheral retina refers to the area bounded posteriorly by the retinal equator and anteriorly by the ora serrata. Peripheral retina is best examined with indirect ophthalmoscopy and by the use of Goldman three mirror contact lens. +Ora serrata.It is the serrated peripheral margin where the retina ends. Here the retina is firmly attached both to the vitreous and the choroid. The pars plana extends anteriorly from the ora serrata. +Microscopic structure +Retina consists of ten layers, arranged in two distinct functional components the pigment epithelium and the neurosensory retina with a potential space between the two. The neurosensory retina consists of three types of cells and their synapses (Fig. 12.2): 1. Pigment epithelium. It is the outermost layer of retina. It consists of a single layer of cells containing pigment. It is firmly adherent to the underlying basal lamina (Bruch’s membrane) of the choroid. Pigment epithelium provides metabolic support to the neurosensory retina and also acts as an antireflective layer. Interphotoreceptor matrix (IPM) is present in the potential space between pigment epithelium and the neurosensory retina and constitutes a strong binding mechanism between the two (by binding pigment epithelium to the photoreceptor). ■Constituent molecules of IPM include: Inter-photoreceptor retinal binding protein (IRBP), proteoglycan-glycosaminoglycans (sulphated and nonsulphated chondroitin and hyaluronic acid), fibronectin, sialoprotein associated with rods and cones (SPARC), intercellular adhesion molecules, hyaluronic acid receptor (CD44 antigen), and lysosomal enzymes (matrix metalloproteinases and tissue inhibitors of metalloproteinases, i.e., TIMP). 2. Layer of rods and cones. Rods and cones are the end organs of vision and are also known as photoreceptors. Layer of rods and cones contains only the outer segments of photoreceptor cells arranged in a palisade manner. There are about 120 millions rods and 6.5 millions cones. Rods contain a +Chapter 12 Diseases of Retina 265 + + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 12.2 Microscopic structure of the retina + + +photosensitive substance visual purple (rhodopsin) and subserve the peripheral vision and vision of low illumination (scotopic vision). Cones also contain a photosensitive substance and are primarily responsible for highly discriminatory central vision (photopic vision) and colour vision. +3. External limiting membrane. It is a fenestrated membrane, through which pass processes of the rods and cones. +4. Outer nuclear layer. It consists of nuclei of rods and cones. +5. Outer plexiform layer. It consists of connections of rod spherules and cone pedicles with the dendrites of bipolar cells and horizontal cells. +6. Inner nuclear layer. It mainly consists of cell bodies of bipolar cells. It also contains cell bodies of horizontal, amacrine and Muller’s cells and capillaries of central artery of retina. The bipolar cells constitute the first order neurons. +7. Inner plexiform layer. It essentially consists of connections between the axons of bipolar cells and dendrites of the ganglion cells, and processes of amacrine cells. +8. Ganglion cell layer. It mainly contains the cell + +bodies of ganglion cells (the second order neurons of visual pathway). There are two types of ganglion cells. The midget ganglion cells are present in the macular region and the dendrite of each such cell synapses with the axon of single bipolar cell. Polysynaptic ganglion cells lie predominantly in peripheral retina and each such cell may synapse with up to a hundred bipolar cells. +9. Nerve fibre layer (stratum opticum) consists of axons of the ganglion cells, which pass through the lamina cribrosa to form the optic nerve. For distribution and arrangement of retinal nerve fibres see Figures 10.12 and 10.13, respectively and page 233. +10. Internal limiting membrane. It is the innermost layer and separates the retina from vitreous. It is formed by the union of terminal expansions of the Muller’s fibres, and is essentially a basement membrane. +Structure of fovea centralis +In this area (Fig. 12.3), there are no rods, cones are tightly packed and other layers of retina are very thin. Its central part (foveola) largely consists of cones and their nuclei covered by a thin internal limiting +266 Section 3 Diseases of Eye + + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 12.3 Microscopic structure of the fovea centralis + +membrane. All other retinal layers are absent in this region. In the foveal region surrounding the foveola, the cone axons are arranged obliquely (Henle’s layer) to reach the margin of the fovea. +Functional divisions of retina +Functionally, retina can be divided into temporal retina and nasal retina by a line drawn vertically through the centre of fovea. Nerve fibres arising from temporal retina pass through the optic nerve and optic tract of the same side to terminate in the ipsilateral geniculate body while the nerve fibres originating from the nasal retina after passing through the optic nerve cross in the optic chiasma and travel through the contralateral optic tract to terminate in the contralateral geniculate body. Neurons of geniculate body constitutes the third order neurons in visual pathway. +Blood supply +Outer four layers of the retina, viz, pigment epithelium, layer of rods and cones, external limiting membrane and outer nuclear layer are avascular get their nutrition from the choroidal and vascular system formed by contribution from anterior ciliary arteries and posterior ciliary arteries. +Inner six layers of retina are vascular and get their supply from the central retinal artery, which is a + +branch of the ophthalmic artery. In some individuals cilioretinal artery (branch from posterior ciliary arteries) is present as a congenital variation and supplies the macular area. In such cases central vision is retained in the eventuality of central retinal artery occlusion (CRAO). +Central retinal artery emerges from centre of the physiological cup of the optic disc and divides into four branches, namely the superior-nasal, superior-temporal, inferior-nasal and inferior-temporal. These are end arteries, i.e., they do not anastomose with each other. However, anastomosis between the retinal vessels and ciliary system of vessels (short posterior ciliary arteries) does exist with the vessels which enter the optic nerve head from the arterial circle of Zinn or Haller. Branches of this circle invade lamina cribriosa and also send branches to the optic nerve head (optic disc) and the surrounding retina. The retinal veins. These follow the pattern of the retinal arteries. The central retinal vein drains into the cavernous sinus directly or through the superior ophthalmic vein. The only place where the retinal system anastomosis with ciliary system is in the region of lamina cribrosa. +Blood supply of optic nerve head (see page 311). + +CONGENITAL AND DEVELOPMENTAL DISORDERS OF RETINA + +Classification +1. Anomalies of the optic disc. These include crescents, sites inverses, congenital pigmentation, coloboma, drusen and hypoplasia of the optic disc. +2. Anomalies of the nerve fibres, e.g., medullated (opaque) nerve fibres. +3. Anomalies of vascular elements, such as persistent hyaloid artery and congenital tortuosity of retinal vessels. +4. Anomalies of the retina proper. These include albinism, congenital night blindness, congenital day blindness, Oguchi’s disease, congenital retinal cyst, congenital retinal detachment and coloboma of the fundus. +5. Congenital anomalies of the macula are aplasia, hypoplasia and coloboma. +A few important congenital disorders are described briefly. + +COLOBOMA OF THE OPTIC DISC +It results from the failure in closure of the embryonic fissure. It occurs in two forms. +Chapter 12 Diseases of Retina 267 + + + +Minor defect is more common and manifests as inferior crescent, usually in association with hypermetropic or astigmatic refractive error. +Fully-developed coloboma typically presents inferonasally as a very large whitish excavation, which apparently looks as the optic disc. The actual optic disc is seen as a linear horizontal pinkish band confined to a small superior wedge. Defective vision and superior visual field defect is usually associated. +DRUSEN OF THE OPTIC DISC +Drusens are intrapapillary refractile bodies, which usually lie deep beneath the surface of the disc tissue in childhood and emerge out by the early teens. Thus, in children they present as pseudo-papilloedema and by teens they can be recognised ophthalmoscopically as waxy pea-like irregular retractile bodies. +HYPOPLASIA OF OPTIC DISC +Hypoplasia of the optic nerve may occur as an isolated anomaly or in association with other anomalies of central nervous system. The condition is bilateral in 60% of cases. It is associated with maternal alcohol use, diabetes and intake of certain drugs in pregnancy. It forms a significant cause of blindness at birth in developed countries. Diagnosis of mild cases presents little difficulty. In typical cases the disc is small and surrounded by a yellowish and a pigmented ring; referred to as ‘double ring sign’. +MEDULLATED NERVE FIBRES +These, also known as opaque nerve fibres, represent myelination of nerve fibres of the retina. Normally, the medullation of optic nerve proceeds from brain downwards to the eyeball and stops at the level of lamina cribrosa. Occasionally, the process of myelination continues after birth for an invariable distance in the nerve fibre layer of retina beyond the optic disc. On ophthalmoscopic examination, these appear as a whitish patch with feathery margins, usually present adjoining the disc margin. The traversing retinal vessels are partially concealed by the opaque nerve fibres (Fig. 12.4). Such a lesion, characteristically, exhibits enlargement of blind spot on visual field charting. The medullary sheaths disappear in demyelinating disorders and optic atrophy (due to any cause) and thus no trace of this abnormality is left behind. +PERSISTENT HYALOID ARTERY +Congenital remnants of the hyaloid arterial system may persist in different forms. + + + + + + + + + + + + + + +Fig. 12.4 Opaque nerve fibres + +Bergmester’s papilla refers to the flake of glial tissue projecting from the optic disc. It is the commonest congenital anomaly of the hyaloid system. Vascular loop or a thread of obliterated vessel may sometimes be seen running forward into the vitreous. It may even be reaching up to the back of the lens. +Mittendorf dot represents remnant of the anterior end of hyaloid artery, attached to the posterior lens capsule. It is usually associated with a posterior polar cataract. + +INFLAMMATORY DISORDERS OF RETINA +These may present as retinitis (pure retinal inflammation), chorioretinitis (inflammation of retina and choroid), neuroretinitis (inflammation of optic disc and surrounding retina), or retinal vasculitis (inflammation of the retinal vessels). +RETINITIS +I. Nonspecific retinitis +It is caused by pyogenic organisms and may be either acute or subacute. +1. Acute purulent retinitis. It occurs as metastatic infection in patients with pyaemia. The infection usually involves the surrounding structures and soon converts into metastatic endophthalmitis or even panophthalmitis. +2. Subacute retinitis of Roth. It typically occurs in patients suffering from subacute bacterial endocarditis (SABE). It is characterised by multiple superficial retinal haemorrhages, involving posterior part of the fundus. Most of the haemorrhages have a white spot in the centre (Roth’s spots). Vision may be +268 Section 3 Diseases of Eye + + + +blurred due to involvement of the macular region or due to associated papillitis. +II. Specific retinitis +It may be bacterial (tuberculosis, leprosy, syphilis and actinomycosis), viral (cytomegalic inclusion disease, rubella, herpes zoster), mycotic, rickettsial or parasitic in origin. +Cytomegalovirus (CMV) retinitis (Fig. 12.5), zoster retinitis, progressive outer retinal necrosis (PORN) caused by an aggressive variant of varicella zoster virus, and acute retinal necrosis (ARN) caused by herpes simplex virus II (in patients under the age of 15 years) and by varicella zoster virus and herpes simplex virus-I (in older individuals) have become more conspicuous in patients with AIDS (HIV infection). +RETINAL VASCULITIS +Inflammation of the retinal vessels wall may be primary (Eales’ disease) or secondary to uveitis. +Eales’ disease +It is an idiopathic inflammation of the peripheral retinal veins. It is characterised by recurrent vitreous haemorrhage; so also referred to as primary vitreous haemorrhage. The disease is rare in Caucasians but is an important cause of visual morbidity in young Asian males. +Etiology. It is not known exactly. Many workers consider it to be a hypersensitivity reaction to tubercular proteins. +Clinical features. It is a bilateral disease, typically affecting young adult males (20–30 years). The common presenting symptoms are: + + + + + + + + + + + + + + + +Fig. 12.5 Fundus photograph showing typical cytomeg­ alovirus (CMV) retinitis in a patient with AIDS. Note white necrotic retinal associated with retina haemorrhages + +• Sudden appearance of floaters (blackspots) in front of the eye or +• Sudden painless loss of vision due to vitreous haemorrhage. The haemorrhage clears up but recurrences are very common. +Clinical course of the Eales’ disease can be described in four stages: +1. Stage of active inflammation (active retinal vasculitis) (Fig. 12.6). The affected peripheral veins are congested and perivascular exudates and sheathing are seen along their surface. Superficial haemorrhages ranging from flame-shaped to sheets of haemorrhages may be present near the affected veins. +2. Stage of ischaemia or vascular occlusion is characterized by obliteration of the involved vessels and development of areas of capillary non-perfusion (CNP) in the periphery as evidenced on fundus fluorescein angiography. +3. Stage of retinal neovascularization is marked by development of abnormal fragile vessels at the junction of perfused and non-perfused retina. Bleeding from these vessels leads to recurrent vitreous haemorrhage. +4. Stage of sequelae or advance stage of disease is characterized by development of complications such as proliferative vitreoretinopathy, fractional retinal detachment, rubeosis iridis and neovascular glaucoma. +Treatment of Eales’ disease comprises: +1. Medical treatment. Course of oral corticosteroids for extended periods is the mainstay of treatment + + + + + + + + + + + + + + + +Fig. 12.6 Fundus photograph of a patient with Eales’ disease (stage of inflammation). Note venous congestion, perivascular exudates and sheets of haemorrhages present near the affected veins +Chapter 12 Diseases of Retina 269 + + + +during stage of active inflammation. A course of antitubercular therapy has also been recommended in selective cases. +2. Laser photocoagulation of the retina either PRP or feeder vessel photocoagulation is indicated in stage of neovascularizion. +3. Vitreoretinal surgery is required for non-resolving vitreous haemorrhage and fractional retinal detachment. + +VASCULAR DISORDERS OF RETINA + +Common vascular disorders of retina include: retinal artery occlusions, retinal vein occlusions, diabetic retinopathy, hypertensive retinopathy, sickle cell retinopathy, retinopathy of prematurity and retinal telangiectasia. +RETINAL ARTERY OCCLUSIONS +Etiology +Occlusive disorders of retinal vessels are more common in patients suffering from hypertension and other cardiovascular diseases. Common causes of retinal artery occlusion are: +1. Emboli from the carotid artery and those of cardiac origin are the most common cause of CRAO. Three types of emboli are known: +• Cholesterol emboli (Hollenhorst plaque) are refractile and orange and seen at retinal vessel bifurcation. These arise from atheromas in the carotid artery. +• Calcium emboli are white in colour and arise from the cardiac valves. +• Platelet fibrin emboli are dull white in colour and arise from atheromas in the carotid artery. They may cause retinal ischaemic attacks (TIA). +2. Atherosclerosis-related thrombosis at the level of lamina cribrosa is another common cause of CRAO. 3. Retinal arteritis with obliteration (associated with giant cell arteritis) and periarteritis (associated with polyarteritis nodosa, systemic lupus erythematosus, Wegner’s granulomatosis and scleroderma) are other causes of CRAO. +4. Angiospasm is a rare cause of retinal artery occlusion. It is commonly associated with amaurosis. 5. Raised intraocular pressure may occasionally be associated with obstruction of retinal arteries, for example, due to tight encirclage in retinal detachment surgery. +6. Thrombophilic disorders such as inherited defects of anticoagulants may occasionally be associated with CRAO in young individuals. + +7. Other rare causes are retinal migraine, sickling haemoglobinopathies and hypercoagulation disorders such as oral contraceptives, polycythemia, and antiphospholipid syndrome. +Clinical features +Clinically retinal artery occlusion may present as central retinal artery occlusion (60%) or branch artery occlusion (35%) or cilioretinal artery occlusion (5%). It is more common in males than females. It is usually unilateral but rarely may be bilateral (1 to 2% cases). +1. Central retinal artery occlusion (CRAO) +It occurs due to obstruction at the level of lamina cribrosa. +Symptoms.Patient complains of sudden painless loss of vision occurring over seconds. Patient may give history of transient visual loss (amaurosis fugax) in the past. Signs of CRAO are as below: +1. Visual acuity is markedly reduced (<3/60 in 90% cases) except in a few cases with cilioretinal artery supplying the macula (Fig. 12.7). +2. Direct pupillary reflex is absent and relative afferent pupillary defect (RAPD) is positive. +3. Fundus examination shows (Fig. 12.7): +• Marked narrowing of retinal arteries and mild narrowing of retinal veins. +• Retina becomes milky white due to ischaemic oedema. In eyes with cilioretinal artery part of macula remains normal in colour (Fig. 12.7A). +• Cherry-red spot is seen in the center of macula due to vascular choroid shining through the thin retina in foveal region, in contrast to the surrounding pale retina (Fig. 12.7B). +• Cattle tracking, i.e., segmentation of blood column is seen in the retinal veins. +• Atrophic changes. In most cases retinal oedema resolves over a period of 4–6 weeks and atrophic changes in the form of grossly attenuated thread like arteries atrophic appearing retina and consecutive optic atrophy occur in long standing cases (see Fig. 12.12B) +4. Fundus fluorescein angiography(FFA) shows delay in arterial filing (cilioretinal artery when present will fill in early phase) and masking of choroidal vasculature due to retinal oedema. +2. Branch retinal artery occlusion (BRAO) +It usually occurs following lodgement of embolus at a bifurcation. Retina distal to occlusion becomes oedematous with narrowed arterioles (Fig. 12.8). Later on the involved area is atrophied leading to permanent sectoral visual field defect. +270 Section 3 Diseases of Eye + + + + + + + + + + + + + + + + + +A + + + + + + + + + + + + +B +Fig. 12.7 Fundus photograph showing marked retinal pallor in acute central retinal artery occlusion (CRAO): A, with sparing of the territory supplied by cilioretinal artery; and B, cherry­red spot in the absence of cilioretinal artery +Management +Treatment of central retinal artery occlusion is unsatisfactory, as retinal tissue cannot survive ischaemia for more than 90–100 minutes. +A. Aggressive treatment of acute episodes of CRAO should be done in all cases presenting within 24 hours of onset with following measures: +1. Immediate lowering of intraocular pressure may aid the arterial perfusion and also help in dislodging the embolus, measure include: +• Intermittent ocular massage, intravenous mannitol, • Paracentesis of anterior chamber has been +recommended for this purpose, and +• Intravenous acetazolamide 500mg should be given immediately. +2. Vasodilators and inhalation of a mixture of 5% carbon dioxide and 95% oxygen (practically patient should be asked to breathe in a polythene bag) may help by relieving element of angiospasm. + +Fig. 12.8 Superotemporal branch of retinal artery occlusion (BRAO). Note retinal pallor in superotemporal area and whitish emboli on the optic disc and in superior temporal branch of retinal artery + +3. Fibrinolytic therapy may be helpful in some cases. 4. Intravenous steroids are indicated in patients with giant cell arteritis. +5. Laser photodisruption of the embolus has been reported in selected cases to dislodge the embolus. +B. Work-up for associated systemic conditions should be carried out immediately after the emergency management of acute episodes and corrective measures instituted. +Complications +In some cases ‘neovascular glaucoma’ with incidence varying from 2% to 6%, may occur as a delayed complication of central retinal artery occlusion. +RETINAL VEIN OCCLUSIONS +Retinal vein occlusions are more common than the artery occlusions. These typically affect elderly patients in sixth or seventh decade of life. +Etiology +1. Pressure on the vein by an atherosclerotic retinal artery where the two share a common adventitia (e.g., just behind the lamina cribrosa and at arteriovenous crossings), secondarily induces thrombosis in the lumen of vein. +2. Hypertension and diabetes mellitus are common predisposing factors. +3. Hyperviscosity of blood as in polycythemia, hyperlipidemia, macroglobulinemia, leukemia, multiple myeloma, cryoglobulinemia. +4. Periphlebitis retinae which can be central or peripheral associated with sarcoidosis, syphillis, and SLE. +Chapter 12 Diseases of Retina 271 + + + +5. Raised intraocular pressure. Central retinal vein occlusion is more common in patients with primary open-angle glaucoma. +6. Local causes are orbital cellulitis, orbital tumors, facial erysipelas and cavernous sinus thrombosis. +Classification +1. Central retinal vein occlusion (CRVO). It may be non-ischaemic CRVO (venous stasis retinopathy) or ischaemic CRVO (haemorrhagic retinopathy). +2. Branch retinal vein occlusion (BRVO). + +Centeral Retinal Vein Occlusion +Non-ischaemic CRVO +Non-ischaemic CRVO (venous stasis retinopathy) is the most common clinical variety (75%). It is characterised by mild to moderate visual loss and no RAPD. +Early cases on fundus examination (Fig. 12.9) reveal mild venous congestion and tortuosity, a few superficial flame-shaped haemorrhages more in the peripheral than the posterior retina, mild papilloedema and mild or no macular oedema. +In late stages (after 6–9 months), there appears sheathing around the main veins, and a few cilioretinal collaterals around the disc. Retinal haemorrhages are partly absorbed. Macula may show chronic cystoid oedema in moderate cases or may be normal in mild cases. +Note. About 15% cases of non-ischaemic CRVO are converted to ischaemic CRVO in 4 months and about 30% in 3 years. +Ischaemic CRVO +Ischaemic CRVO (haemorrhagic retinopathy) refers to acute (sudden) complete occlusion of central retinal vein. It is characterised by marked sudden visual loss and RAPD. + + + + + + + + + + + + + + +Fig. 12.9 Central retinal vein occlusion (non­ischaemic) + +Early cases on fundus examination (Fig. 12.10) reveal: +• Massive engorgement, congestion and tortuousity of retinal veins, +• Massive retinal haemorrhages (almost whole fundus is full of haemorrhages giving a ‘splashed-tomato’ appearance), +• Numerous cotton wool spots (usually more than 6 to 10), +• Disc shows oedema and hyperaemia, +• Macular area is full of haemorrhages and is severely oedematous and +• Break through vitreous haemorrhage may be seen in some cases. +In late stages, marked sheathing around veins and collaterals is seen around the disc. +• Neovascularization may be seen at the disc (NVD) or in the periphery (NVE). +• Macula shows marked pigmentary changes and chronic cystoid oedema. +Pathognomonic features for ischaemic CRVO differentiating it from non-ischaemic CRVO are: +• Presence of relative afferent pupillary defect (RAPD), +• Visual field defects, and +• Reduced amplitude of b-wave of electroretinogram. Complications. Rubeosis iridis and neovascular glaucoma (NVG) occurs in about 20% cases within 3 months (so also called as 90 days glaucoma), a few cases develop vitreous haemorrhage and proliferative retinopathy. +Branch retinal vein occlusion (BRVO) +It is more common than the central retinal vein occlusion. It may occur as: +• Hemispheric occlusion due to occlusion in themain branch at the disc. + + + + + + + + + + + + + + +Fig. 12.10 Central retinal vein occlusion (ischaemic) +272 Section 3 Diseases of Eye + + + +• Quadrantic occlusion due to occlusion at the level of AV crossing, and +• Small branch occlusion either as macular branch occlusion or peripheral branch occlusion. + +Features of BRVO are as below: +■Retinal oedema and haemorrhages are limited to the area drained by the affected vein (Fig. 12.11). Vision is affected only when the macular area is involved. +■Secondary glaucoma occurs rarely in these cases. ■Chronic macular oedema and neovascularization may occur as complications of BRVO in about one third cases. + +Management of retinal vein occlusions A. Clinical evaluation and investigations +I. Ocular examination and investigations +Ocular examination should include: +• Visual acuity, at presentation and at every follow up, is a useful guide for the interventions required. +• IOP should be recorded and associated POAG should be ruled out. +• Undilated slit-lamp examination to detect neovascularization of iris (NVI). +• Gonioscopy to rule out neovascularization of angle (NVA). +• Fundus examination with direct and indirect ophthalmoscopy and with 90D slit-lamp examination. + +Ocular investigations should include: +• Goldmann perimetry and ERG evaluation is very important in differentiating between ischaemic and non-ischaemic CRVO. + + + + + + + + + + + + + + +Fig. 12.11 Superotemporal branch of retinal vein occlusion (BRVO) + +• Fundus fluorescein angiography (FFA) should be carried out (to assess state of retinal perfusion) after resolution of retinal haemorrhage. Usually areas of capillary non-perfusion (CNP) of more than 10 disc area are seen in ischaemic CRVO. +• Optical coherence tomography (OCT) is particularly useful for evaluation of macular oedema, sub-retinal fluid accumulation and development of epiretinal membrane (ERM). +II. Systemic examination and investigations +Systemic associations which need to be looked for are: • Hypertension, diabetes mellitus, heart diseases, +dyslipidaemia, +• Hypercoagulative conditions, and +• Homocysteinosis, especially in young patients. + +B. Differential diagnosis +Diabetic retinopathy is generally bilateral and CRVO is usually unilateral. +Ocular ischaemic syndrome (OIS) due to carotid occlusive disease has only dilated veins without tortuosity (in CRVO tortuosity is also seen) and retinal haemorrhages are typically seen in the mid periphery. +C. Treatment +I. Treatment of systemic and ocular associations such as hypertension, diabetes, hyperlipidaemias, hyperhomocysteinaemia, POAG, and other conditions is important in all cases. Smoking should be avoided. +II. Observation and monitoring is all that is required in patients with mild to moderate visual loss (VA better than 6/18), as the condition (especially non-ischaemic CRVO), in more than 50% cases of CRVO resolves with almost normal vision. +III.Ocular therapy, as described below, is required in patients presenting with marked visual loss (usually ischaemic CRVO) and those with progressive visual loss on observation. +1. Medical therapy, presently in vogue is: ■Intravitreal anti-VEGFs, e.g., 1.25 mg Bevacizumab (Avastin), or 0.3 mg Ranibizumab (Lucentis) are useful for the associated CME and neovascularization. ■Intravitreal triamcinolone (1 mg/0.1 ml) may be given for the associated CME. +Note. Repeated injections of anti-VEGFs, and triamcinolone may be required. +2. Laser therapy, recommended is as below: +■Grid laser is NOT recommended for macular oedema in CRVO. However, persistent CME in BRVO may be treated by grid laser. +Chapter 12 Diseases of Retina 273 + + + +■Panretinal photocoagulation (PRP) is generally not recommended as prophylaxis even in cases with marked ischaemia (except in patients not likely to comply with regular follow-up). PRP should be performed without delay in CRVO when neovascularization develops any where, i.e., in angle (NVA), iris (NVE), retina (NVE & NVD). PRP involves application of 1500–3000 burns (0.5–1.0 second), spaced one burn width apart using frequency doubling YAG laser or argon green laser. ■Scatter laser photocoagulation is recommended for neovascularization else where (NVE) in patients with BRVOs. +3. Surgical therapy may be required in the form of +1. Pars plana vitrectomy for treating the following complications associated with venous occlusions: • Persistent vitreous haemorrhage, +• Tractional retinal detachment, +• Epiretinal membrane (ERM), and +• Intractable neovascular glaucoma (NVG). +Note. PPV may be combined with endolaser PRP when required. +i. Pars plana placement of glaucoma drainage device (GDD) may also be required in patients with NVG. ii. Radical optic neurotomy, once proposed by transvitreal incision of the scleral ring (along with PPV) to surgically decompress CRV at the level of scleral outlet, has not proved useful. + +HYPERTENSIVE RETINOPATHY +Hypertensive retinopathy refers to fundus changes occurring in patients suffering from systemic hypertension. Although the term hypertensive retinopathy implies only retinal changes but in fact the clinical presentation includes changes of hypertensive: +• Retinopathy, +• Choroidopathy, and • Optic neuropathy. + +Pathogenesis +Three factors which play role in the pathogenesis of hypertensive retinopathy are vasoconstriction, arteriosclerosis and increased vascular permeability. 1. Vasoconstriction. Arteriolar narrowing is the primary response to raised blood pressure and is related to the severity of hypertension. +• Vasoconstriction of retinal arterioles occurs in pure form in young individuals, but is affected by the pre-existing involutional sclerosis in older patients. + +• Vasoconstriction of choroidal vessels causes choroidal and RPE ischaemia, which manifests as hypertensive choroidopathy. +• Vasoconstriction of peripapillary choroid leads to optic nerve head ischaemia, manifesting as hypertensive optic neuropathy. +2. Arteriosclerotic changeswhich manifest as changes in the arteriolar reflex and A-V nipping result from thickening of the vessel wall and are a reflection of the duration of hypertension. In older patients arteriosclerotic changes may pre-exist due to involutional sclerosis. +3. Increased vascular permeability results fromhypoxia and is responsible for haemorrhages, exudates, focal retinal oedema, macular oedema, focal intraretinal periarterial transudates (FIPTs), and disc oedema. +Clinical types +Clinically, the hypertensive fundus changes can be described as: +• Chronic hypertensive retinopathy, and +• Malignant or acute hypertensive retinopathy. +Chronic hypertensive retinopathy +Patients with chronic hypertensive retinopathy are usually asymptomatic. Clinical situations in which chronic hypertensive retinopathy occurs include: +1. Hypertension with involutionary (senile) sclerosis When hypertension occurs in elderly patients (after the age of 50 years) in the presence of involutionary sclerosis the fundus changes comprise augmented arteriosclerotic retinopathy. +2. Chronic hypertension with compensatory arteriolar sclerosis +This condition is seen in young patients with prolonged benign hypertension usually associated with benign nephrosclerosis. The young arterioles respond by proliferative and fibrous changes in the media (compensatory arteriolar sclerosis). Advanced fundus changes in these patients have been described as ‘albuminuric or renal retinopathy.’ +Fundus changes of chronic hypertensive retinopathy can be summarized as below (Fig. 12.12A to C): +1. Generalized arterial narrowing or attenuation, depending upon the severity of hypertension may be mild or marked, and consists of vasoconstrictive and sclerotic phases. +• Vasoconstrictive phase occurs due to diffuse vasospasm which manifests when a significant elevation of blood pressure has persisted for an appreciable period and is characterised by an increase in retinal arteriolar tone. +274 Section 3 Diseases of Eye + + + +• Sclerotic phase occurs due to intimal thickening, hypoplasia of tunica media, and hyaline degeneration; and is characterised by arteriolar narrowing associated with tortuosity. +2. Focal arteriolar narrowing is seen as areas of localized vasoconstriction on the disc and within ½ disc diameter of its margin zone. +3. Arteriovenous nickingis the hallmark of hypertensive retinopathy and occurs where arteriole crosses and compresses the vein, as the vessels share a common adventitious sheath. Also known as A-V crossing changes, these include: +• Salu’s sign, i.e., deflection of veins at the arteriovenous crossings, +• Bonnet sign, i.e., banking of veins distal to arteriovenous crossings, and +• Gunn sign, i.e., tapering of veins on either side of the crossings. +4. Arteriolar reflex changes. The normal light reflex of the retinal vasculature is formed by the reflection from the interface between the blood column and vessel wall. +• Bright and thin, linear blood reflex is seen normally over the surface of the arteriole in the young age and is predominantly because of blood column in the arteriole, since the vessel wall is by and large transparent. +• More diffuse and less bright reflex is seen due to thickening of vessel wall and represents changes of grade I and II hypertensive retinopathy. +• Copper wiring, i.e., reddish-brown reflex of the arterioles occurs due to progressive sclerosis and hyalinization, and is a sign of grade III retinopathy. +• Silver wiring i.e., opaque–white reflex of the arterioles occurs ultimately due to the continued sclerosis, and is seen in grade IV hypertensive retinopathy. +5. Superficial retinal haemorrhages (flame shaped) occur at the posterior pole due to disruption of the capillaries in the retinal nerve fibre layer. These haemorrhages disappear in 3 to 5 weeks. +6. Hard exudates are lipid deposits in the outer plexiform layer of retina which occur following leaky capillaries in severe hypertensive retinopathy. They appear as yellowish waxy spots with sharp margins. They are generally seen in posterior pole and may be arranged as macular-fan or macular-star. They are also temporary and may disappear in 3–6 weeks. 7. Cotton wool spots are fluffy white lesions and represent the areas of infarcts in the nerve fibre layer. These occur due to ischaemia caused by + +capillary obliterations in severe hypertensive retinopathy. Due to their cotton wool feathery appearance they are also termed as soft exudates (a misnomer in fact). +Malignant hypertensive retinopathy +Malignant hypertension is not a separate variety of hypertension, but is an expression of its rapid progression to a serious degree in a patient with relatively young arterioles undefended by fibrosis. +Fundus picture is characterised by changes of acute hypertensive retinopathy, choroidopathy and optic neuropathy (Fig. 12.12D): +I. Acute hypertensive retinopathy changes include: +• Marked arteriolar narrowing due to spasm of the arteriolar wall, in response to sudden rise in blood pressure. +• Superficial retinal haemorrhages, flame shaped, arranged in clusters, appear in the posterior pole area due to disruption of capillaries in the nerve fibre layer. +• Focal intraretinal periarteriolar transudates (FIPTs) are small, white, focal oval lesions occurring due to the deposition of macromolecules along the major arterioles. These result due to break down of blood-retinal barrier following dilatation of terminal arterioles as a result of sudden rise in blood pressure in malignant hypertension. +• Cotton wool spots are also more marked in malignant hypertensive retinopathy. +• Microaneurysms, shunt vessels and collaterals may also develop as a result of capillary obliterations. +II.Acute hypertensive choroidopathy changes include: • Acute focal retinal pigment epitheliopathy, characterised by focal white spots, occurs due to +acute ischaemic changes in choriocapillaries. +• Elschnig’s spots are small black spots surrounded by yellow halos, these are formed due to clumping and atrophy of the infarcted pigment epithelium (focal white spots) described above. +• Siegrist streaks are formed due to linear configuration of the pigment along the choroidal arterioles. These are formed due to fibrinoid necrosis associated with malignant hypertension. +• Serous neurosensory retinal detachment, which preferentially affects the macular area, may occur due to accumulation of fluid beneath the retina following breakdown of outer blood-retinal barrier owing to ischemic damage to the retinal pigment epithelium. It may also manifest as exudative bullous retinal detachment with shifting subretinal fluid. +Chapter 12 Diseases of Retina 275 + + + + + + + + + + + + + + +A B + + + + + + + + + + + + +C D +Fig. 12.12 Hypertensive retinopathy: A, grade I; B, grade II; C, grade III; D, grade IV + + + +III. Acute hypertensive optic neuropathy changes include: +• Disc oedema and hemorrhages on the disc and peripapillary retina which occur due to vasoconstriction of peripapillary choroidal vessels supplying the optic nerve head. The ischemia of the optic nerve head leads to stasis of axoplasmic flow, thus the lesion is a form of anterior ischaemic optic neuropathy. +• Disc pallor, of variable degree, may occur late in the course of disease. + +Staging of Hypertensive Retinopathy +Several classification schemes have been described to stage hypertensive retinopathy. No classification is clinically useful. A few popular classifications, are given below, just for their historical value. +Keith and Wagner classification +• Grade I. Mild generalized arteriolar attenuation, particularly of small branches, with broadening of the arteriolar light reflex and vein concealment (Fig. 12.12A). + + +• Grade II. Marked generalized narrowing and focal attenuation of arterioles associated with deflection of veins at arteriovenous crossings (Salus’ sign) (Fig. 12.12B). +• Grade III. Grade II changes plus copper-wiring of arterioles, banking of veins distal to arteriovenous crossings (Bonnet sign), tapering of veins on either side of the crossings (Gunn sign) and right-angle deflection of veins (Salu’s sign). Flame-shaped haemorrhages, cotton-wool spots and hard exudates are also present (Fig. 12.12C). +• Grade IV. All changes of grade III plus silver-wiring of arterioles and papilloedema (Fig. 12.12D). +Scheie classification +Staging of retinopathy changes is as follows: +• Stage 0. No visible retinal abnormalities +• Stage 1. Diffuse arteriolar narrowing; no focal constriction +• Stage 2. More pronounced arteriolar narrowing with focal constriction +276 Section 3 Diseases of Eye + + + +• Stage 3. Focal and diffuse narrowing, with retinal haemorrhages +• Stage 4. Retinal oedema, hard exudates, optic disc edema + +Grading of the light reflex changes resulting from arteriolosclerosis is as follows: +• Grade 0. Normal +• Grade 1. Broadening of light reflex with minimal arteriolovenous compression +• Grade 2. Light reflex changes and arteriovenous crossing changes more prominent +• Grade 3. Copper-wire appearance and more prominent arteriolovenous compression +• Grade 4. Silver-wire appearance and severe arteriolovenous crossing changes. +Wong and McIntosh classification +Mild retinopathy is characterised by one or more of the following signs: generalised arteriolar narrowing, focal arteriolar narrowing, AV nicking, arteriolar wall reflex broadening. There is weak associations with stroke, coronary heart disease and cardiovascular mortality. +Moderate retinopathy consists of mild retinopathy with one or more of the following signs: retinal haemorrhages (blot and dot or flame shaped) microaneurysms, cotton-wool spots, and hard exudates. There is strong association with stroke, congestive heart failure, renal dysfunction and cardiovascular mortality. +Accelerated retinopathy consists of moderate retinopathy signs plus optic disc swelling, may be associated with visual loss. Associated with mortality and renal failure. + +Management +Mild hypertensive retinopathy requires blood pressure control only. +Moderate hypertensive retinopathy patients (characterised by retinal haemorrhages, microaneurysms, and cotton-wool spots) in addition to blood pressure control benefit from further assessment of vascular risk factors (e.g., cholesterol levels) and, if indicated, risk reduction therapy (e.g., cholesterol lowering agents). +Accelerated hypertensive retinopathy characterized by bilateral disk swelling which may occur in conjunction with severe hypertension needing urgent antihypertensive management. In such instances, physicians should aim for a small stepwise control of blood pressure over a few hours, and avoid a sudden + +reduction in blood pressure which may reduce perfusion of optic nerve head and central nervous system (causing stroke). +Note. With adequate hypertension treatment, resolution of signs may occur over a period of up to a year. Thus follow-up of patients for a year may be needed. + +Retinopathy in Pregnancy-induced Hypertension +Pregnancy-induced hypertension (PIH), previously known as ‘toxaemia of pregnancy’, is a disease of unknown etiology characterised by raised blood pressure, proteinuria and generalised oedema. Retinal changes are liable to occur in this condition when blood pressure rises above 160/100 mm of Hg and are marked when blood pressure rises above 200/130 mm of Hg. +• Earliest changes consist of narrowing of nasal arterioles, followed by generalised narrowing. +• Severe persistent spasm of vessels causes retinal hypoxia characterised by appearance of ‘cotton wool spots’ and superficial haemorrhages. +• Further progression of retinopathy occurs rapidly if pregnancy is allowed to continue. +• Retinal oedema and exudation is usually marked and may be associated with ‘macular star’ or ‘flat macular detachment.’ Rarely, it may be complicated by bilateral exudative retinal detachment. +• Prognosis for retinal reattachment is good, as it occurs spontaneously within a few days of termination of pregnancy. +Management. Changes of retinopathy are reversible and disappear after the delivery, unless organic vascular disease is established. +• In preorganic stage when patient responds well to conservative treatment, the pregnancy may justifiably be continued under close observation. +• Advent of hypoxic retinopathy (cotton wool spots, retinal oedema and haemorrhages), however, should be considered an indication for termination of pregnancy; otherwise, permanent visual loss or even loss of life (of both mother and foetus) may occur. +DIABETIC RETINOPATHY +Diabetic retinopathy (DR) refers to retinal changes seen in patients with diabetes mellitus. With increase in the life expectancy of diabetics, the incidence of diabetic retinopathy (DR) has increased. Diabetic retinopathy is a leading cause of blindness. +Chapter 12 Diseases of Retina 277 + + + +Etiopathogenesis +Risk factors +1. Duration of diabetes is the most important determining factor. +• After 10 years, 20% of type I and 25% of type II diabetics develop retinopathy. +• After 20 years, 90% of type I and 60% of type II diabetics develop retinopathy. +• After 30 years, 95% of both type I and type II diabetics develop retinopathy. +Note. It is important to note that it is the duration of disease after the onset of puberty which acts as a risk factor. For example, the risk of retinopathy is roughly same for two 30 years old patients, of whom one developed DM at 12 years and other at the age of 4 years, because both have same duration of disease (18 years) after the onset of puberty (i.e. after the age of 12 years). +2. Age of onset of diabetes also act as a risk factor. The risk of retinopathy in a child with onset of diabetes at the age of 2 years is negligible for the first 10 years. After onset of puberty, age of onset is not a risk factor. 3. Sex. Incidence is more in females than males (4:3). 4. Poor metabolic control is less important than duration, but is nevertheless relevant to the development and progression of DR. +5. Heredity. It is transmitted as a recessive trait without sex linkage. The effect of heredity is more on the proliferative retinopathy. +6. Pregnancy may accelerate the changes of diabetic retinopathy. +7. Hypertension, when associated, may also accentuate the changes of diabetic retinopathy. +8. Other risk factors include smoking, obesity, anaemia and hyperlipidaemia. +Pathogenesis +Hypergylcemia, in uncontrolled diabetes mellitus, is the starting point for development of DR. Microangiopathy, affecting retinal pre-capillary arterioles, capillaries and venules, produced by hyperglycaemia is the basic pathology in diabetic retinopathy. +Mechanisms by which hyperglycemia produces microangiopathy include: +i. Cellular damage. Hyperglycaemia produces damage to the cells of retina, endothelial cells, loss of pericytes and thickning of basement membrane of capillaries by following effects: +• Sorbitol accumulation in the cells due to aldose reductase mediated glycolysis, + + +• Advanced glycation end (AGE) product accumulates in the cells due to non-enzymatic binding of several sugars to proteins, +• Activation of several protein kinase C isoforms, and • Excessive oxidative stress to the cells due to excess +of free radicals. +ii. Hematological and biochemical changes induced by hyperglycaemia which play role in the development of microangiopathy include: +• Platelet adhesiveness increase, • Blood viscosity increase, +• Red blood cells deformation and Rouleaux formation, +• Serum lipids altered abnormally, +• Leukostasis increase due to increased intracameral adhesion molecule-1-(ICAM-1) level expression, and +• Fibrinolysis increase. +Effects of microangiopathy producing DR include: +• Breakdown of blood-retinal barrier leads to retinal oedema, haemorrhages, and leakage of lipids (hard exudates). +• Weakened capillary wall produces micro-aneurysms, and haemorrhages. +• Microvascular occlusions produce ischaemia and its effects, and arteriovenous shunts, i.e., intra-retinal microvascular abnormalities (IRMAs). +Neovascularization of retina is induced by: +• Proangiogenic factors such as vasculoendothelial growth factors (VEGFs), platelet derived growth factor (PDGF), and hepatocyte growth factor (HGF) which are released as a result of ischaemia produced by microvascular occlusions. Release of angiogenic factors is also mediated by hyperglycemia-induced oxidative stress, activation of protein kinase C and cytokines. +• Deletion of anti–angiogenic factors such as en-dostatin, angiostatin, pigment epithelial derived factor (PEDF), thrombospondin-1 and platelet fac-tor 4, also play role in causing neovascularization. Speculated pathogenesis of DR based on the above described changes is summarized in a flowchart +(Fig 12.13). + +Classification of Diabetic Retinopathy Diabetic retinopathy has been variously classified. Presently followed classification is as follows: +I. Non-proliferative diabetic retinopathy (NPDR) • Mild NPDR +• Moderate NPDR • Severe NPDR +• Very severe NPDR +278 Section 3 Diseases of Eye + + + + + + + + + + + + + + + + + + + + + + + + +Fig. 12.13 Flowchart depicting pathogenesis of diabetic retinopathy + \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_1.txt b/notes/DC Dutta Obstetrics 10th Edition_1.txt new file mode 100644 index 0000000000000000000000000000000000000000..652dabbf1d42ed5ff79c09f117ac71d8d85c508e --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_1.txt @@ -0,0 +1,2027 @@ +_I l_i z Textbook of +OBSTETRICS +sanket munde is best friend of bharat huse + +Including Perinatology and Contraception +VIDEO LIST FOR THE KERNEL +9. + +Lecture Series Case Presentations + + +1. Informed Consent Dr Roshini P 2. FOGSI Dr Roshini P +Obstetrics History Taking and Physical Dr Roshini P Examination +3. +Bony Pelvis and Fetal Skull Dr Rajiv Kumar Saxena +4. +Pelvic Floor and its Clinical Significance Dr Rajiv Kumar Saxena +5. +6. WHO Labor Care Guide Dr Roshini P +7. Induction and Augmentation of Labor Dr Roshini P from Old to New +8. Artificial Rupture of Membranes (ARM) Dr Roshini P + +1. Anemia Complicating Pregnancy Dr Roshini P, Dr Rajiv Kumar Saxena +2. Pregnancy with History of Prior Dr Roshini P, Dr Rajiv Cesarean Delivery Kumar Saxena +Multiple Pregnancy Dr Roshini P, Dr Rajiv Kumar Saxena +3. +Rh Negative Pregnancy Dr Roshini P, Dr Rajiv Kumar Saxena +4. +5. Pre-eclampsia and Eclampsia Dr Roshini P, Dr Rajiv Kumar Saxena +6. Diabetes in Pregnancy Dr Roshini P, Dr Rajiv Kumar Saxena + +Animation Videos + + + +Mechanism of Normal Labor 10. Mal positions +11. Mal presentations +12. Cardiotocographic Assessment of Fetal Wellbeing +13. Assisted Vaginal Breech Delivery 14. External Cephalic Version + +15. Episiotomy-Selective Use Justified 16. Vacuum Extraction (OVD) + +17. Operative Vaginal Delivery: Forcep Delivery +18. Postpartum Hemorrhage +19. Drugs and Suture Material in Obstetrics + + +Dr Roshini P Dr Roshini P Dr Roshini P Dr Roshini P + +Dr Roshini P +Dr Rajiv Kumar Saxena +Dr Roshini P +Dr Rajiv Kumar Saxena +Dr Rajiv Kumar Saxena +Dr Roshini P +Dr Roshini P + +1. Fertilization, Implantation and Embryogenesis 2. Artificial Rupture of Membranes (ARM) +3. Normal Labor Episiotomy +4. +5. Third Stage of Labor +6. External Cephalic Version Breech Delivery +7. +8. Vacuum Extraction Forceps Delivery +9. +10. Cesarean Section +11. Postpartum Hemorrhage + +Presentations + +Analgesia and Anesthesia in Labor 2. Urinary Catheterization and its Care +1. +3. Surgical Site Infection Care + + + +20. Instruments in Obstetrics +21. Cesarean Delivery-the Past and Present + +22. Neonatal Resuscitation Protocol +23. Female Catheterization + +Dr Roshini P +Dr Rajiv Kumar Saxena +Dr Roshini P +Dr Roshini P + + +Important Topics + +1. Quick Revision Topics for Viva Voce and MCQ Based on Entrance Examinations (with PDF) +2. Self-Assessment Questions for Obstetric Long Case Discussions (PDF) +_I 1 _I z Textbook of + +OBSTETRICS + + +Including Perinatology and Contraception + +Tenth Edition + + +DCDUTTA MBBS, DGO, MO (CAL) +Professor and Head, Department of Obstetrics and Gynecology Nilratan Sircar Medical College and Hospital, Kolkata, India + +Edited by HIALAL KONAR +(HONS; GOLD MEDALIST) MBBS (CAL), MD (PGI), DNB +MNAMS, FACS (USA), FRCOG (LONDON) +Professor and Head, Department of Obstetrics and Gynecology KPC Medical College and Hospital, Kolkata, West Bengal, India +Formerly, Professor and Head, Department of Obstetrics and Gynecology +Agartala Government Medical College and Hospital; Tripura, Midnapore Medical College and Hospital, West Bengal University of Health Sciences, Kolkata, West Bengal, India Rotation Registrar in Obstetrics, Gynecology and Oncology Northern and Yorkshire Region, Newcastle-upon-Tyne, UK +Examiner: National-MBBS, DGO, MD and PhD of different Indian Universities National Board of Examination, New Delhi, India +International-Membership of the Royal College of Obstetricians and Gynecologists, London (MRCOG) and Royal College of Physicias of Ireland (MRCPI) +Vice-President: FOGSI; Indian Society of Perinatology and Reproductive Biology (ISOPARB) +Recipient, "Pride of FOGSI Award" and "FOGS! Achiever Award': for exemplary works towards upliftment of Women's Health in India FOGSI Representative to Asia Oceania Federation of Obstetricians and Gynecologists (AOFOG) Chairman, Indian College of Obstetricians and Gynecologists (ICOG-2013) + + + + + + + +JAYPEE BROTHERS MEDICAL PUBLISHERS The Health Sciences Publisher +New Delhi I London +1Jaypee Brothers Medical Publishers (P) Ltd. Headquarters +Jaypee Brothers Medical Publishers (P) Ltd EMCA House +23/23-B, Ansari Road, Daryaganj New Delhi - 110 002, India +Landline: +91-11-23272143, +91-11-23272703 +91-11-23282021, +91-11-23245672 +Email: jaypee@jaypeebrothers.com + +Corporate Ofice +Jaypee Brothers Medical Publishers (P) Ltd 4838/24, Ansari Road, Daryaganj +New Delhi 110 002, India Phone: +91-11-43574357 Fax: +91-11-43574314 +Email: jaypee@jaypeebrothers.com +Website: www.jaypeebrothers.com Website: www.jaypeedigital.com + +© 2023, Copyright reserved by Mrs Madhusri Konar + + + + + + + + + + + + + + + + + +Overseas Ofice J.P. Medical Ltd +83 Victoria Street, London SWl H 0HW (UK) +Phone: +44 20 3170 8910 Fax: +44 (0)20 3008 6180 Email: info@jpmedpub.com + +The views and opinions expressed in this book are solely those of the original contributor(s)/author(s) and do not necessarily represent those of editor(s) and publisher of the book. +All rights reserved. No part of this publication including videos, graphics, photographs, designs, flowcharts, boxes, tables, QR codes and its contents may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the publishers and author. +All brand names and product names used in this book are trade names, service marks, tradema!ks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. +Medical knowledge and practice change constantly. This book is designed to provide accurate, authoritative information about the subject matter in question. However, readers are advised to check the most current information available on procedures included and check information from the manufacturer of each product to be administered, to verify the recommended dose, formula, method and duration of administration, adverse effects and contraindications. It is the responsibility of the practitioner to take all appropriate safety precautions. Neither the publisher nor the author(s)/editor(s) assume any liability for any injury and/or damage to persons or property arising from or related to use of material in this book. +This book is sold on the understanding that the publisher is not engaged in providing professional medical services. If such advice or services are required, the services of a competent medical professional should be sought. +Every effort has been made where necessary to contact holders of copyright to obtain permission to reproduce copyright material. If any have been inadvertently overlooked, the publisher will be pleased to make the necessary arrangements at the first opportunity. +Inquiries for bulk sales may be solicited at: jaypee@jaypeebrothers.com extbook of Obstetrics +Ninth Edition: 2018 Tenth Edition: 2023 ISBN: 978-93-5465-902-7 +Printed at: Sam rat Offset Pvt. Ltd. + + + + + + + + + + + + + + + + + + + + + + + + + +Dedicated to +The students of obstetrics­ past and present + + +Contributors + + + + + +BB Hore MD +Former Professor and Head Calcutta Medical College, Kolkata Consultant Anesthetist +Kolkata, West Bengal, India + +Santanu Bag FRCPCH (UK) CCT Assistant Professor Consultant Neonatologist +Rama Krishna Mission Seva Pratisthan +and Vivekananda Institute of Medical Sciences Kolkata, West Bengal, India + + +Sir Sabaratnam Arulkumaran PhD DSc FRCOG FRCS Professor Emeritus +St George's University, London +Past President-FIGG, BMA and RCOG + + +Preface to the Tenth Edition + + + + +With great pleasure we release the tenth edition of Dutta's Textbook of Obstetrics. Obstetric care is evolving fast with the progress in science and technology. The tenth edition has come up much earlier to ensure the updated knowledge and practice for the students and practitioners. +It is more than forty years that Prof. DC Dutta, the visionary leader of education recognised the need for such a book primarily intended for the medical and nursing students, residents and the practising obstetricians. +The changes in the present edition are significant and are in accordance with the current guidelines of National Medical Commission (NMC). This edition has been updated as per the CBME curriculum. It carries the extensive use of imaging studies as it is the need of the day. The chapter outlines, good number of tables, boxes are incorporated for easy understanding and reproduction. +We are indebted to Sir, Professor Sabratnam Arulkumaran, for revising the chapters: Normal Labor (Ch. 13) and Intrapartum Fetal Monitoring (Ch. 39). We are grateful to Dr S Bag, FRCPCH (UK), CCT, Assistant Professor, Department of Neonatology, RKMSP and Vivekananda Institute of Medical Sciences (VIMS), Kolkata, for updating the chapters on perinatal care (Ch. 31, 32, 33). We sincerely acknowledge Prof. K Oswal and Dr K Mukherjee, Sonologists, for their generous support. We are indebted to Prof. BB Hore, for the revising the Ch. 34 (Analgesia and Anesthesia in Obstetrics) as before. My sincere thanks are to Dr Chandrachur Konar, Dr Roshni P and Dr Lisley Konar, for their all round support for this edition. +The uniqueness of this text lies in its presentation, which is simple, lucid and unambiguous. Summary tables, key points, algorithm and the flowcharts are for quick revision before exams. Uniformity of information in all the chapters is a special value. Contemporary guidelines of different professional and academic organizations, e.g., RCOG, ACOG, ICOG, WHO, FIGO, NICE, CDC, ESHRE, ASRM, FOGSI are incorporated. List of most frequently used abbreviations have been provided for easy navigation. This edition, in its fully colored format is profusely illustrated with more than 790 line drawings, sketches and photographs. +I had the opportunity of visiting many medical institutions in this country and abroad. The feedback that I have received form the teachers and students are invaluable. Many of the suggestions have been addressed in this edition. The editor always welcomes the views of the students and the teachers through online access to e-mail: h.kondr@gmail. com and websites: hiralalkonar.com and dcdutta.com. Regarding the video section, interested readers keen to know more could reach out at: drroshnip24@gmail.com. +Dutta's Textbook of Obstetrics has a long-standing association with its sister books: Textbook of Gynecology (8th Edition, 2020), Clinics in Obstetrics (1st Edition, 2022), Clinics in Gynecology (1st Edition, 2022) and Bedside Clinics and Viva Voice (7th Edition, 2020). +The online version of this comprehensive book has been prepared by a very young and talented team members (Dr Chandrachur Konar, Dr Roshini P and Prof. Rajiv Kumar Saxena). Online version is_ extensively available. It has the flexibility of using the text content and video materials for clinical and practical purposes. Its content will be revised and updated annually as necessary. +I do hope that this comprehensive textbook will continue to be of immense educational resource to the readers as ever. I am grateful to those who have taught me, most of all, the patients and my beloved students. +According to the author's desire, this book is dedicated to the students of obstetrics: past and present, who strive relentlessly to improve maternal and newborn health care wherever they work. + +J{ira[a[ l(onar +P-13, New CIT Road Kolkata-700014 India + + +Preface to the First Edition + + + + +Over the years, there was an absolute dearth of a single comprehensive textbook of obstetrics, worth to be prescribed to the students. Moreover, of the textbooks currently available, most have been written with an orientation for the developed countries. +Being constantly insisted and hard-pressed by my beloved students, I ultimately decided to write a compact, comprehensive and practically oriented textbook of obstetrics. It is an attempt to encourage the students to learn obstetrics in a comparatively easy way. The aim was to emphasize the simplicities rather than complexities of knowledge. The book is written in a clear and concise language and in author's own style, which holds the reader's interest. Controversies are avoided and the management of the obstetrical problems is being highlighted with the facilities available to most of the Third World countries. Extensive illustrations and flow charts (schemes) have been used as and when needed to add lucidity and clarity to the subject and to emphasize the practical nature of the book. +Although the book has been written primarily for the undergraduates, it should also prove to be useful to nurses (midwives), those aspiring for diploma and postgraduate degrees in obstetrics, and also to the practicing obstetricians. I, however, do not consider this book to be an ideal one but a humble attempt has been made to remove the bottlenecks, as far as possible, of the books available to the students at present. +Acknowledgments: Very little of what is worthwhile in this book could not have been brought to publication without the generous cooperation, advice and assistance of many of my colleagues, seniors and juniors. +Dr BN Chakravarty, MBBS, DGO, MO (CAL), FRCOG (Eng), Prof., Department of Obstetrics and Gynecology, Nilratan Sircar Medical College, Kolkata; Dr KM Gun, MBBS, DGO, MO (CAL), FRCOG (Eng), FRCS (Edin), FACS, Prof., Department of Obstetrics and Gynecology, Medical College, Kolkata; Dr Santosh Kr Paul, MBBS, DGO, MO (CAL), Reader, Department of Obstetrics and Gynecology, Nilratan Sircar Medical College, Kolkata; Dr B Hore, MBBS, DA, MS (CAL), Prof. and Head of the Department of Anesthesiology, North Bengal Medical College, Siliguri; Dr BC Lahari, MBBS, DGO, MO (CAL), FRCS (Edin), FRCOG (Eng), FACS (USA), FAMS (Ind), Prof., Department of Obstetrics and Gynecology, Medical College, Kolkata; Dr NN Roy Chowdhury, MBBS, DGO, MO (CAL), PhD, FRCS, FRCOG, FACS, FAMS, Prof., Department of Obstetrics and Gynecology, Medical College, Kolkata. +I have much pleasure in expressing my cordial appreciation to the house-surgeons, internees and students of Nilratan Sircar Medical College, Kolkata, for all the help they have rendered in preparation of the final drafts of the manuscripts, checking the proofs, and in compiling the Index. Without their constant encouragement and active assistance, this book could never have been published. +In preparing a textbook like this, I have utilized the knowledge of a number of stalwarts in my profession and consulted many books and publications. I wish to express my appreciation and gratitude to all of them, including the related authors and publishers. +As a teacher, I have learnt a lot from the students and, more so, while writing this book and, as such, I could not think of dedicating the book to anyone else but the students of obstetrics, for which I express my gratitude. + +Mahalaya f)C f)utta 8th September, 1983 +P-13, New CIT Road Kolkata-700014 India + + +Acknowledgments + + + + +The job of editing such a comprehensive text is stupendous and it could never be completed without the help and advice of many experts in the field. I have consulted many of my esteemed colleagues in the profession in this country and abroad, multitude of eminent authors, many current evidence-based studies, guidelines and recommendations. I do gratefully attribute my legacy to all the teachers, related authors and the publishers. +At the outset, I am indebted wholeheartedly for the support provided by Prof. BB Hore, Consultant Anesthetist, Sir Sabaratnam Arulkumaran, Emeritus Professor, and Dr Santanu Bag, Assistant Professor and Consultant Neonatologist, for their contributions of the respective topics. I am extremely grateful to Mrs Madhusri Konar, MA, BEd, for all her insightful secretarial accomplishments in support of the book. +I gratefully thank Shri Jitendar P Vij (Group Chairman), Mr Ankit Vij (Managing Director), Mr MS Mani (Group President), Dr Madhu Choudhary (Director-Educational Publishing), Ms Pooja Bhandari (Production Head), Ms Sunita Katia (Executive Assistant to Group Chairman and Publishing Manager), for their all-round support as and when needed. I also acknowledge the help of Dr Aditya Tayal (Team Leader-Development Editor), Mr Rajesh Sharma (Production Coordinator), Ms Seema Dogra (Cover Visualizer), Mr Laxmidhar Padhiary (Quality Controller), Mr Ajeet Rathor (Typesetter), Mr Akshay Thakur (Typesetter), Mr Manoj Pahuja (Senior Graphic Designer), and wish to thank all others of M/s Jaypee Brothers Medical Publishers (P) Ltd, New Delhi, India, who worked for this project. + +International Reviewers +I am especially indebted to all the international reviewers: Sir Sabaratnam Arulkumaran, PhD, DSc, FRCOG, FRCS, Prof. Emeritus, St George's University of London, Past President-FIGG, BMA and RCOG; Dr Michael P O'Connel, Royal College of Physicians, Dublin; Prof. Colm O'Herlihy, National Maternity Hospital, Dublin; Prof. Farhana Dewan; Prof. Kohinoor Begum, Bangladesh; Prof. Rokeya Begum, Bangladesh; Prof. Rowshan Ara Begum; Prof. Sabera Khatun, Bangladesh; Prof. S Nurjahan Bhuiyan, Bangladesh; Prof. PR Pant, Tribhuvan University Teaching Hospital (TUTH), Nepal. + +National Reviewers +I sincerely acknowledge the following teachers across this vast country for their valuable suggestions. Their comments and guidance have helped me enormously to shape this new edition. I hope that I have listed all of those who have contributed and apologize if any name has been left out inadvertently. +My sincere thanks are due to Prof. Gita B Banerjee, CRSS, Kolkata; Prof. Picklu Choudhury, RPH MCH, West Bengal; Prof. PK Biswas, CNMCH, Kolkata; Prof. Narayan Jana, CRSS, Kolkata, Prof. Habibullah, MGMC, Puducherry; Prof. Ashok Kumar, Delhi; Prof. Pranay Nath, Prof. Gita Guin, NSCBMC, Jabalpur; Prof. Tusar Kar, Cuttack; Prof. Bharati Mishra, Brahmapur, Odisha; Prof. Ava Rani Sinha, Mujaffarpur; Prof. Vinita Sharma, PGI, Chandigarh; Prof. Kiran Pandey, GSVMMCH, Kanpur; Prof. Sowjanya Kumari, Tirupati; Prof. Suyajna, VIMS, Bellary; Prof. Sampatkumari, Tamil Nadu; Prof. Muralidhar Pai, KMC, Manipal; Prof. Devinder, AFMC, New Delhi; Prof. Himadri Bal, DY Patil MCH, Pune; Prof. M Sarkar, EMCH, West Bengal; Prof. H Rahman, Gangtok; Prof. Deepa Masand, NIMS, Jaipur; Prof. Ajith, Kannur; Prof. Pratap Kumar, KMC, Manipal; Prof. Nilesh Dalal, MGMC, Indore; Prof. SS Gulati, SMC, Noida; Prof. Jaya Chaturvedi, AIIMS, Rishikesh; Dr Sujatha, AMC, Visakhapatnam; Prof. Savita C, BMC, Karnataka; Prof. RC Antaratan, Hubli; Prof. +Umdi, Belagavi, IMS; Prof. Dharma Vijay MN, MVJMC&RH; Prof. Anju Agarwal, KGMC, Lucknow; Prof. Wani Aditya, +BRD Medical College, Gorakhpur; Prof. MD Pant, KMC, Manipal; Prof. Pushpalata, AIIMS, Bhopal; Prof. Prativa Singh, AIIMS, Jodhpur; Prof. Nirja Bhatia, AIIMS, New Delhi; Prof. Beena Kumari R, GMC, Kattayam; Prof. Nirmala, GHC, Thiruvananthapuram; Prof. Sarina Gilvaz, JMMCH; Prof. Radhamani K, IMS, Amrita Institute of Medical Sciences; Prof. T Padmabvathi, Andhra MCH; Prof. Pradeep S, PESIMSR, Kuppam; Prof. S Vijaya, Madras MCH; Prof. K Kalaivani, Stanley MCH; Prof. Krishnapriya Banerjee, SMSMCH, Jaipur; Prof. Parmeet Kaur, GMC, Patiala; Prof. Lajya Devi Goyel, AIIMS, Bhatinda; Prof. Amrit Pal Kaur, GMC, Amritsar; Prof. Seema Grover Bhatty, GGSMCH, Faridkot; Prof. Ashoke Anand, Grant MC, Mumbai; Prof. NM Mayadeo, KEM Hospital; Prof. JK Deshmukh, GMC, Nagpur; Prof. Brig Aruna Menon, AFMC, Pune; Prof. Hemant Deshpande, DY Patil MCH, Pune; Prof. T Panchanadikar, BVPMC, Pune; Prof. AV Mehta, BJMCH, +Ahmedabad; Prof. Gokhale, GMC, Baroda; Prof. Haresh Dashi, GCS MCH, Ahmedabad; Emeritus Prof. Dr Habibullah, +MGMCH, Puducherry; Prof. Seetesh Ghose, Dean, MGM MCH; Prof. Gauri, JIPMER; Prof. Lata, JIPMER, Puducherry, +!I Acknowledgments +Prof. Manidip Pal, Kalyani KMC; Prof. Sarita Agarwal, Raipur; Prof. Tripti Nagaria, JNMCH, Raipur; Prof. Uma Pandey, BHU; Prof. BM Rakshit, MCH, Kolkata; AGMC, Shimla; Prof. Pranay Phukan, Dibrugarh; Prof. J Ray, GMCH, Agartala; Prof. Debutta, RG Kar MCH, Kolkata; Prof. T Maity; Prof. A Phadikar, NRSRCH; Prof. Anuradha Chatterjee, NBMCH; Dr Pallab Mistri, Associate Professor, CMC, Kolkata; Dr Arindam Halda1 Associate Professor, Raiganj MCH; Prof. S Biswas, IGMER, Kolkata; Prof. Malbika Mishra, JIMS, Budge Budge; Prof. S Barik, Haldia Medical College; Prof. Sasavati Sanyal Choudhary; Prof. Alakananda, GMCH, Guwahati; Prof. P Das, Guwahati MCH; Prof. Kavita Mandrella Bhatti, CMC, Ludhiana; Prof. Aparajita S D'Souza, ESIC MCH, Hyderabad; Prof. BS Meena, SMSMCH, Jaipur; Prof. Seema Hakim, AMU, Aligarh; Dr AK +Bhattacharya, Associate Profess01 Jorhat Medical College; Prof. HK Sharma, Jorhat MCH; Prof. Panchanan Das, GMCH, +Guwahati; Lt Col. Prof. Indrani Mukopopadhyay, AFMC; Dr Saumen Das Poddar, AFMC, and Col. Bidhan Ray, AFMC. +I sincerely thank Prof. Rajiv Saxena, Dr Chandrachur Konar, Dr (Mrs) Roshini P, and Dr Lisley Konar, for their untiring effort for the all-round support to this tenth edition of the book. +I express my sincere thanks to all the teachers and students of different medical institutes, midwifery institutes, and nursing colleges in India and abroad for their valued suggestions, new ideas and contribution of photographs. Their inputs have been invaluable and much appreciated. +Last but not least, I am grateful to all who have taught me, most of all the patients and my beloved students. +The editor always welcomes the views of the students and the teachers through online access to e-mail: h.kondr@ gmail.com; ratulkonar@gmail.com; and, websites: hiralalkonar.com and dcdutta.com. + +J{iraCa[ l(onar P-13, New CIT Road +Kolkata-700014 India + + + + + + + + + + + + + + + + + + + + + +1).(J.f),.: 1932UL oc + + + + +List of Video Contributors + + +Rajiv Kumar Saxena MBBS, MD Professor and Head +Department of Obstetrics and Gynecology +The Oxford Medical College, Hospital and Research Centre +Bengaluru, Karnataka, India + +Roshini p MBBS MS DNB Assistant Professor +Department of Obstetrics and Gynecology ESIC and PGIMSR +Bengaluru, Karnataka, India + + +Contents + + + +IJ 'Anatomy of Female Reproductive Organs +■ External Genitalia 1; • Mons Veneris 2; • Labia Majora 2; • Labia Minora 2; • Clitoris 2; • Vestibule 2; • Perineum 3; ■ Internal Genitalia 3; • Vagina 3; • Uterus 4; • FallopianTube 6; • Ovary 7; • Muscles and Fascia in Relation to the Pelvic Organs 9; • Pelvic Floor 9; • Perineum 1 O; • Pelvic Fascia 11; ■ Pelvic +CellularTissue 11; ■ Female Urethra 12; ■ Urinary Bladder 12; ■ Pelvic Ureter 12; ■ Breasts 13 +II Fu"! amentaJs of Reproduction 16 + +■ Gametogenesis 16; • Oogenesis 16; • Spermatogenesis 18; ■ Ovulation 18; ■ Fertilization 19; +• Morula 20; • Blastocyst 20; ■ Implantation 21; • Trophoblast 21; ■ Decidua 22; ■ Chorion and +Chorionic Villi 23; ■ Development of Inner Cell Mass 23 +11 lPl centa and Fetal Membranes 26 + +■ Placenta 26; • Development 26; • Placenta at Term 27; • Structures 27; ■ Placental Circulation 29; +■ Placental Aging 31; ■ Placental Function 32; ■ Fetal Membranes 34; ■ Amniotic Cavity and Amnion 34; +■ Amniotic Fluid 34; ■ Umbilical Cord 36 +II The Fetus 38 +■ Fetal Physiology 39; ■ Fetal Circulation 40; • Changes in the Fetal Circulation at Birth 41 II l hysiological Changes During regnancy + +■ Genital Organs 43; • Uterus 43; ■ Breasts 46; ■ Cutaneous Changes 46; ■ Weight Gain 47; ■ Body Water Metabolism 47; ■ Hematological Changes 48; ■ Cardiovascular System 49; ■ Metabolic Changes 50; +■ Systemic Changes 51 +II E.1docri ?Logy i R , tion to Repro udion 55 +■ Maturation of Graafian Follicles and Ovulation 55; ■ Maintenance of Corpus Luteum after Fertilization 55; ■ Placental Endocrinology 55; • Hormones of Placenta 55; • Protein Hormones 55; • Steroidal Hormones 57; • Diagnostic Value of Placental Hormones 58; ■ Changes in Endocrine Glands During Pregnancy 58; • Pituitary Gland 58; • Thyroid Gland 58; • Adrenal Cortex 59; • Parathyroid +Gland 59; • Pancreas 59; ■ Hormonal Influences Necessary for Maintenance of Lactation 59 +II I Diagnosis of regnancy 61 + +■ FirstTrimester (First 12 Weeks) 61; ■ Second Trimester (13-28 Weeks) 63; ■ LastTrimester (29-40 +Weeks) 65; ■ Differential Diagnosis of Pregnancy 66; ■ Chronological Appearance of Specific Symptoms and Signs of Pregnancy 66; ■ Signs of Previous Childbirth 66; ■ Estimation of Gestational Age and Prediction of +Expected Date of Delivery 67; ■ Estimation of Fetal Weight 67 +II The Fetus-in-Utero 69 + +■ Causes of Preponderance of Longitudinal Lie and Cephalic Presentation 71; ■ Methods of Obstetrical +Examination 71 +ll rFetal Skull and Maternal Pelvis 76 +■ Fetal Skull 76; ■ Pelvis 79; • False Pelvis 79; • True Pelvis 80; • Inlet 80; • Cavity 82; • Outlet 82; • Midpelvis 83; • Physiological Enlargement of Pelvis during Pregnancy and Labor 85 +al IComnteAnntstenatal Care, Preconceptional Counseling and Care ___ 86 ■ Procedure at the First Visit 86; • History Taking 86; • Examination 88; ■ Procedure at the Subsequent +Visits 90; ■ Antenatal Advice 90; ■ Minor Ailments in Pregnancy 92; ■ Values of Antenatal Care 93; ■ Preconceptional Counseling and Care 94 + +Antenatal Assessment of Fetal Wellbeing 95 + +■ Clinical Evaluation of Fetal Wellbeing at Antenatal Clinic 95; • First Visit 95; • Subsequent Visits 95; +• Special Investigations 96; • Early Pregnancy 96; ■ Antepartum Fetal Surveillance (Late Pregnancy) 96; ■ Other Investigations in Late Pregnancy 99 + +Prenatal Genetic Counseling, Screening and Diagnosis 102 + +■ Prenatal Genetic Screening 102; • Prenatal Diagnosis 104; ■ Invasive Procedures for Prenatal Diagnosis 104; • Chorionic Villus Sampling 104; • Amniocentesis 105; • Cordocentesis or Percutaneous Umbilical Blood Sampling 105; ■ Noninvasive Method of Prenatal Testing from Maternal Plasma/Blood 106; • Fetal DNA 106 + +Normal Labor: lntrapartum Care for a Positive Child Birth Experience (WHO) 108 + +■ Labor 108; • Onset 108; • Contractile System of the Myometrium 109; ■ Physiology of Normal Labor 111; ■ Events in First Stage of Labor 113; ■ Events in Second Stage of Labor 115; ■ Events in Third Stage of Labor 116; ■ Mechanism of Normal Labor 117; ■ Anatomy of Labor 120; ■ Clinical Course of First Stage of Labor 121; +■ Clinical Course of Second Stage of Labor 124; ■ Clinical Course ofThird Stage of Labor 125; • Place of Delivery 126; ■ Management of Normal Labor 126; ■ Management of First Stage of Labor 127; ■ Management +of Second Stage of Labor 129; • Immediate Care of the Newborn 131; ■ Management ofThird Stage of Labor 132; +• Active Management ofThird Stage of Labor (AMTSL) 132; • Labor Care Guide (WHO) 136 +IJ Normal Puerperium 139 + +■ Involution of the Uterus 139; ■ Involution of Other Pelvic Structures 140; • Lochia 141; ■ General Physiological Changes 141; ■ Lactation 142; • Physiology of Lactation 143; ■ Management of Normal Puerperium 144; ■ Management of Ailments 145; ■ Postnatal Care 147 + + +Nausea and Vomiting in Pregnancy + +■ Vomiting in Pregnancy 149; ■ Hyperemesis Gravidarum 149; +m + +Hemorrhage in Early Pregnancy + + +149 + +• Clinical Course 150; • Management 151 + +153 + + +■ Spontaneous Abortion (Miscarriage) 153; ■ Threatened Miscarriage 155; ■ Inevitable Miscarriage 156; ■ Complete Miscarriage 156; ■ Incomplete Miscarriage 157; ■ Missed Miscarriage 157; ■ Septic Abortion 158; • Management 159; ■ Recurrent Miscarriage 160; ■ Cervical Incompetence 162; +■ Induction of Abortion 166; ■ Medical Termination of Pregnancy (MTP) 166; • Methods ofTermination of Pregnancy 166; • Recommendations 167; • First Trimester Termination of Pregnancy 167; • Midtrimester Termination of Pregnancy 168; ■ Ectopic Pregnancy 170; • Tubal Pregnancy 170; • Acute Ectopic Pregnancy 172; • Unruptured Tubal Ectopic 172; • Diagnosis of Ectopic Pregnancy 173; ■ Management of Ectopic Pregnancy 174; • Interstitial 178; • Abdominal 178; • Ovarian 179; • Cornual 179; +• Cervical 180; • Pregnancy of Unknown Location 180; • Cesarean Scar Pregnancy 180; • Heterotopic Pregnancy 181; ■ Gestational Trophoblastic Diseases (GTD) 182; • Hydatidiform Mole 182; • Partial or Incomplete Mole 187; • Placental Site Trophoblastic Tumor (PSTT) 188; • Persistent Gestational Trophoblastic Disease 188 + +Multiple Pregnancy, Amniotic Fluid Disorders, Abnormalities of Placenta and Cord 190 + +■ Twins 190; • Diagnosis 192; • Complications 194; • Prognosis 196; • Complications of Monochorionic Twins 196; ■ Antenatal Management 197; ■ Management during Labor 198; ■ Triplets, Quadruplets, +etc. 200; ■ Amniotic Fluid Disorders 202; • Polyhydramnios 202; • Etiology 202; • Complications 203; +■ Management of Hydramnios 204; • Acute Polyhydramnios 205; • Oligohydramnios 205; ■ Abnormalities of Placenta and Cord 206; • Placental Abnormalities 206; • Cord Abnormalities 208 +Contents - .... +lJ 1:iypertensive Disorders inwPr nancy .. 209 ■ Pre-eclampsia (PE) 209; • Diagnostic Criteria 210; • Etiopathogenesis 210; • Pathophysiology 211; + +• Clinical Types 213; and Prevention 215; + +• Clinical Features 213; • Complications 215; • Screening Tests for Prediction • Prophylactic Measures for Prevention 216; • Management of Gestational + +Hypertension and Pre-eclampsia 217; ■ Acute Fulminant Pre-eclampsia 220; ■ Eclampsia 221; • Clinical Features 222; • Prognosis 222; • Management 222; ■ Chronic Hypertension in Pregnancy 226; +■ Essential Hypertension in Pregnancy 226; ■ Chronic Renal Diseases in Pregnancy 227; ■ Pregnancy after Renal Transplant 228 +m + +Antepartum Hemorrhage 230 + +■ Placenta Previa 230; • Etiology 230; • Clinical Features 232; • Differential Diagnosis 233; +• Complications 233; • Prognosis 235; • Management 235; ■ Practical Guide for Cesarean Delivery 238; ■ Practical Approach to Lower Segment CD for Placenta Previa 238; ■ Practical Guide to Lower Segment Approach for Placenta Previa Accreta 238; ■ Abruptio Placentae 239; • Clinical Features 241; +• Management 241; • Treatment in the Hospital 242; • Indeterminate Bleeding 244 +m + +Medical and Surgical Illnesses Complicating Pregnancy 246 + +■ Hematological Disorders in Pregnancy 246; • Anemia in Pregnancy 246; • Iron Deficiency Anemia 248; +• Megaloblastic Anemia 253; • Dimorphic Anemia 255; • Aplastic Anemia 255; • Hemoglobinopathies 255; • Sickle Cell Hemoglobinopathies 256; • Thalassemia Syndromes 257; • Platelet Disorders 257; ■ Heart Disease in Pregnancy 259; • General Management 260; • Management during Labor 261; • Specific Heart Disease during Pregnancy and the Management 262; ■ Diabetes Mellitus and Pregnancy 265; • Gestational Diabetes Mellitus (GDM) 265; • Overt Diabetes 267; ■ Thyroid Dysfunction and Pregnancy 273; ■ Jaundice in Pregnancy 275; ■ Viral Hepatitis 275; ■ Epilepsy in Pregnancy 277; ■ Asthma in Pregnancy 278; +■ Systemic Lupus Erythematosus (SLE) 280; ■ Tuberculosis in Pregnancy 280; ■ Syphilis in Pregnancy 281; +■ Parasitic and Protozoa! Infestations in Pregnancy 283; ■ Pyelonephritis in Pregnancy 284; • Asymptomatic Bacteriuria (ASB) 285; ■ Viral Infections in Pregnancy 286; ■ Human Immunodeficiency Virus (HIV) Infection and Acquired Immunodeficiency Syndrome (AIDS) 288; ■ COVID-19 in Pregnancy 291; ■ Surgical Illness during Pregnancy 291; ■ Acute Pain in Abdomen during Pregnancy 292; ■ Headache in Pregnancy 293; +■ Acute Fatty Liver in Pregnancy 293 +Bl !Gynecological Disorders in Pregnancy 294 ■ Abnormal Vaginal Discharge 294; ■ Congenital Malformation of the Uterus and Vagina 294; ■ Carcinoma Cervix with Pregnancy 295; • Treatment 295; ■ Leiomyomas with Pregnancy 296; • Treatment 296; +■ Ovarian Tumor in Pregnancy 296; ■ Retroverted Gravid Uterus 297; ■ Morbid Anatomic Changes 298; +• Treatment 298; ■ Genital Prolapse in Pregnancy 298; • Treatment 298 +m + +!Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetalpeath 300 + +■ Preterm Labor and Birth 300; • Etiology 300; • Management of Preterm Labor and Birth 302; +• Prevention of Preterm Labor 302; • Measures to Arrest Preterm Labor 302; ■ Management in Labor 302; ■ Prelabor Rupture of the Membranes (PROM) 304; • Management 305; ■ Prolonged and Post-term Pregnancy 306; • Diagnosis 307; • Management 308; ■ Intrauterine Fetal Death (IUFD) 31 O; +• Etiology 31 O; • Diagnosis 311; • Recommended Evaluation for a Stillbirth 311; • Management 311 +m . + +Complicated Pregnancy 314 + +■ Pregnancy with Prior Cesarean Delivery (CD) 314; • Integrity of the Scar 314; • Evidences of Scar Rupture (or Scar Dehiscence) during Labor 315; • Management of a Pregnancy with Prior CD 316; • Vaginal Birth after Previous (CD) 316; ■ Red Cell Alloimmunization 318; • Fetal Affection by the Rh Antibody 320; +■ Manifestations of Hemolytic Disease of the Fetus and Newborn (HDFN) 320; • Prevention of Rh-D Alloimmunization 321; ■ Antenatal Investigation Protocol of Rh-negative Mothers 323; ■ Plan of Delivery 324; • Prognosis 326; ■ Exchange Transfusion in the Newborn 326; ■ Grand Multipara 326; ■ Elderly Primigravida 327; ■ Bad Obstetric History (BOH) 328; • Investigations and Management 328; +■ Obesity in Pregnancy 329 +Im Contents + +, Contracted Pelvis 331 +■ Asymmetrical or Obliquely Contracted Pelvis 333; ■ Mechanism of Labor in Contracted Pelvis with Vertex Presentation 333; ■ Diagnosis of Contracted Pelvis 334; ■ Disproportion 336; • Diagnosis of Cephalopelvic Disproportion (CPD) at the Brim 336; ■ Effects of Contracted Pelvis on Pregnancy and Labor 337; ■ Management of Contracted Pelvis (Inlet Contraction) 338; ■ Trial Labor 338; ■ Midpelvic and Outlet Disproportion 339 + +Abnormal Uterine Action 340 +■ Uterine Inertia (Hypotonic Uterine Dysfunction) 341; ■ lncoordinate Uterine Action 342; ■ Precipitate Labor 344; ■ Tonic Uterine Contraction and Retraction 344 + +• Complicated Labor: Malposition, Malpresentation and Cord Prolapse 347 +■ Occiput Posterior (OP) Position 347; • Diagnosis 348; • Mechanism of Labor 349; • Course of Labor 351; • Management of Labor 351; • Arrested Occiput Posterior Position 352; ■ Deep Transverse Arrest (OTA) 353; ■ Manual Rotation for Occiput Posterior Position 353; ■ Breech Presentation 355; • Varieties 355; • Etiology of Breech Presentation 355; • Diagnosis of Breech Presentation 356; • Mechanism of Labor in Breech Presentation 356; • Complications of Vaginal Breech Delivery 358; • Antenatal Management 359; +• Management of Vaginal Breech Delivery 361; • Assisted Breech Delivery 361; • Management of Complicated Breech Delivery 365; ■ Face Presentation 367; • Mechanism of Labor 368; • Diagnosis 368; • Management 370; • Vaginal Delivery 370; ■ Brow Presentation 371; ■ Transverse Lie 371; +• Diagnosis 372; • Clinical Course of Labor 372; ■ Management of Shoulder Presentation 374; +■ Unstable Lie 374; ■ Compound Presentation 374; ■ Cord Prolapse 375; • Management 376 + +Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies 378 +■ Prolonged Labor 378; • Treatment 380; ■ Obstructed Labor 381; • Treatment 382; • Shoulder Dystocia 383; ■ Dystocia Caused by Fetal Anomalies 383; • Hydrocephalus 383; ■ Neural Tube Defects (NTD) 384; • Anencephaly 384; ■ ConjoinedTwins 385 + +Complications of the Third Stage of Labor 386 +■ Postpartum Hemorrhage (PPH) 386; ■ Primary Postpartum Hemorrhage 386; • Causes 386; • Prevention 387; • Management ofThird-stage Bleeding 388; • Steps of Manual Removal of Placenta 388; • Management ofTrue Postpartum Hemorrhage 389; • Actual Management 390; ■ Secondary Postpartum Hemorrhage 393; ■ Retained Placenta 394; • Management 394; ■ Inversion of the Uterus 396 + + +• Injuries to the Birth Canal +■ Vulva 398; ■ Perineum 398; • Management 398; ■ Vagina 399; ■ Cervix 400; ■ Rupture of the Uterus 401; • Etiology 402; • Pathology 403; • Diagnosis 404; ■ Visceral Injuries 405 + +• Abnormalities of the Puerperium + +398 +■ Pelvic Hematoma 400; • Management 405; + + +407 + +■ Puerperal Pyrexia 407; ■ Puerperal Sepsis 407; • Pathology 408; • Clinical Features 408; • Investigations of Puerperal Pyrexia 409; • Treatment 410; ■ Subinvolution 411; ■ Urinary Complications in Puerperium 411; ■ Breast Complications 412; ■ Puerperal VenousThrombosis 413; • Prophylaxis and Management 414; +■ Pulmonary Embolism 415; ■ Obstetric Palsies 416; ■ Puerperal Emergencies 416; ■ Psychiatric Disorders during Puerperium 417; ■ Psychological Response to Perinatal Deaths and Management 418 + +The Term Newborn Infant 419 +■ Physical Features of the Newborn 419; ■ Immediate Care of the Newborn 421; ■ Infant Feeding 422; • Breastfeeding 423; • Artificial Feeding 427; • Childhood Immunization Program 428 + +Low Birth Weight Baby 429 +■ Preterm Baby 430; • Complications of a Preterm Neonate 430; • Management 432; • Care of a Preterm Neonate 432; ■ Fetal Growth Restriction (FGR) 434; • Management 437 +m 'Diseas!S,£f the Fet;!S and the New orn Contents ■ Perinatal Asphyxia 441; • Fetal Respiration 441; • Clinical Features 442; • Management 443; +■ Respiratory Distress in the Newborn 445; ■ Transient Tachypnea of the Newborn(TTN) 448; ■ Meconium Aspiration Syndrome(MAS) 448; ■ Jaundice of the Newborn 449; • Management of Jaundice in the Newborn 451; ■ Hemolytic Disease of the Newborn 452; • ABO Group Incompatibility 452; ■ Bleeding +Disorders in the Newborn 453; ■ Anemia in the Newborn 453; ■ Seizures in the Newborn 454; ■ Birth Injuries of the Newborn 455; • Injuries to the Head 455; • lntracranial Hemorrhage 456; • Other Injuries 457; +■ Perinatal Infections 458; • Mode of Infection 458; • Ophthalmia Neonatorum 459; • Skin Infections 460; • Necrotizing Enterocolitis 461; • Mucocutaneous Candidiasis 461; ■ CongenitalMalformations and Prenatal Diagnosis 463; • Down's Syndrome (Trisomy 21) 463; ■ Surgical Emergencies 463; ■ Nonimmune Fetal Hydrops 465 +m + +IPharmacotherapeutics in Obstetrics 467 + +■ Oxytocics in Obstetrics 467; • Oxytocin 467; • Methods of Administration 468; • Ergot Derivatives 470; • Prostaglandins (PGs) 470; ■ AntihypertensiveTherapy 473; ■ Diuretics 473; ■ Tocolytic Agents 473; +■ Anticonvulsants 474; ■ Anticoagulants 474; ■ Maternal Drug Intake and Breastfeeding 475; ■ Fetal Hazards of Maternal Medication duringPregnancy 477; • Teratology andPrescribing in Pregnancy 477; +■ Analgesia and Anesthesia in Obstetrics 479; • Anatomical and Physiological Considerations 479; • Analgesia during Labor and Delivery 480; • Inhalation Methods 481; • Regional ( Neuraxial) Anesthesia 482; • Infiltration Analgesia 484; • General Anesthesia forCesarean Section 484 +m + +[1ndtiction ohabor 487 + + +■ Methods of Induction of Labor 488; • Medical Induction 488; • Surgical Induction 490; the Membranes (LRM) 491; • Stripping the Membranes 491; ■ Combined Method 492 + +jPopulation Dynamics and Control of Co, nception +m + +• Low Rupture of + + +496 + + +■ Control of Contraception 496; • Family Planning 496; • Contraception 497; ■ Methods of Contraceptions 497; • TemporaryMethods 497; • IntrauterineContraceptive Devices 497; ■ Steroidal Contraceptions 504; • Combined Oral Contraceptives (Pills) 504; • Centchroman (Chhaya/Saheli) 509; +• Progestogen-only Contraceptions 509; • Emergency Contraception (CE) 511; • Summary of Oral Contraceptives 512; ■ Drug Interaction and Hormonal Contraception 513; ■ Sterilization 513; +• Couple Counseling 513; • Male Sterilization 514; • Female Sterilization 515; ■ Barrier Methods 518; +• Condom(Male) 519; • FemaleCondom(Femidom) 519; • Diaphragm 519; • VaginalContraceptives 520; • Fertility Awareness Method 520; • Contraceptive Counseling andPrescription 521; • Prescription 521; +■ Ongoing Trials and Selective Availability 522; • Transcervical Sterilization 522 +m + +10perative Obstetrics 523 + +■ Dilatation and Evacuation ( D & E) 523; • One-stage Operation 523; • Two-stage Operation 524; • Management of Uterine Perforation 525; ■ Suction Evacuation 525; ■ Vacuum Aspiration 526; +■ Episiotomy 527; • Types 527; • Steps, Postoperative Care 528; • Complications 529; ■ Operative Vaginal Delivery 529; • Forceps 530; • Types of Forceps Operation 530; • Low Forceps Operation 532; Outlet Forceps Operation 535; Midforceps Operation 535; • Difficulties in Forceps Operation 535; +• Kiel land's Forceps 536; • Complications of Forceps Operation 537; ■ Ventouse 537; ■ Version 540; +• External Cephalic Version 540; • Internal Version 542; ■ Cesarean Delivery (CD) 542; • Indications 543; • Lower Segment CS 544; • PostoperativeCare 547; • Classical Cesarean Section 548; • Complications of +CS: lntraoperative, Postoperative 549; ■ Destructive Operations 550; • Craniotomy 550; • Cleidotomy 552; • Postoperative Care 552; ■ Symphysiotomy 552 +m + +Safe Motherhood, Epidemiology of O s.tetrics +554 + +■ Safe Motherhood 554; ■ Clinical Causes of Maternal Deaths 554; ■ Country Targets 555; ■ Sustainable Development Goals ( SDGs) 556; ■ Reproductive and Child Health ( RCH) Care 557; ■ Epidemiology of Obstetrics 558; • MaternalMortality 558; • Maternal Near Miss 561; • MaternalMorbidity 561; +• PerinatalMortality 561; • Important Causes of PerinatalMortality andMain Interventions 563; • Stillbirths 563; • Neonatal Deaths 563 +!I Contents +• Special Topics in Obstetrics 565 +■ lntrapartum Fetal Evaluation 565; • Methods of Fetal Evaluation 565; ■ Nonreassuring Fetal Status (NRFS) 570; • Management 570; ■ Shock in Obstetrics 572; • Pathophysiology 572; • General Changes 572; • Classification of Shock 574; ■ Management of Shock 575; • Endotoxic Shock 576; +■ Acute Kidney Injury (AKI) 578; • Causes 578; • Management in Obstetrics 579; ■ Blood Coagulation Disorders in Obstetrics 580; • Normal Blood Coagulation 582; • Pathology of Acquired Coagulopathy 582; +• Investigations 583; • Treatment 584; ■ High-risk Pregnancy 585; • Management of High-risk Cases 587; ■ Immunology in Obstetrics 588; ■ Critical Care in Obstetrics 590 + +' t Current Topics in Obstetrics 592 +■ Medical Ethics 592; ■ Effective Clinical Communication 592; ■ Pregnancy Following Assisted Reproductive Technology (ART) 593; ■ Antibiotic Prophylaxis in Cesarean Section 594; ■ Day-care Obstetrics 594; ■ Legal and Ethical Issues in Obstetric Practice 594; ■ The Preconception Counseling Prenatal Diagnostic Techniques 595; ■ Audit in Obstetrics 595; ■ Umbilical Cord Blood Stem Cells in Transplantation and Regenerative Medicine 596; • Stem Cells and Therapies in Obstetrics 596 + +Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests 598 +■ Ultrasound in Obstetrics 598; • Three-dimensional Ultrasonography 599; • FirstTrimester Ultrasonography 599; • Midtrimester Ultrasonography 601; • Third Trimester Ultrasonography 602; • lntrapartum Sonography 603; ■ Magnetic Resonance Imaging (MRI) 603; ■ Computed Tomography (CT) in Obstetrics 604; ■ Radiology in +Obstetrics 604; ■ Amniocentesis 605; ■ Guides to Clinical Tests 606; ■ Tests for Blood Coagulation Disorders 607; • Collection of Blood Sample 607; • Samples for Blood Sugar Estimation 608; ■ Cervical and Vaginal Cytology 608 + + +Practical Obstetrics +■ Obstetrics Instruments 609; ■ Drugs 620; ■ Specimens 622; + +609 +■ Imaging Studies 627; ■ Suture Materials 629 + + +Index 631 + + +Competency-Based NMC Curriculum + + + + + + + +OGl.1 Define and discuss birth rate, maternal mortality and morbidity +OGl.2 Define and discuss perinatal mortality and morbid-ity including perinatal and neonatal mortality and morbidity audit +OGl.3 Define and discuss still birth and abortion + +OG2.1 Describe and discuss the development and anato-my of the female reproductive tract, relationship to other pelvic organs, applied anatomy as related to obstetrics and gynecology +OG3.1 Describe the physiology of ovulation, menstrua-tion, fertilization, implantation and gametogenesis +OG4.1 Describe and discuss the basic embryology of fetus, factors influencing fetal growth and develop-ment, anatomy and physiology of placenta, and teratogenesis +OG5.1 Describe, discuss and identify pre-existing medical disorders and discuss their management; discuss evidence-based intrapartum care +OG5.2 Determine maternal high-risk factors and verify immunization status +OG6.1 Describe, discuss and demonstrate the clinical fea-tures of pregnancy, derive and discuss its differen-tial diagnosis, elaborate the principles underlying and interpret pregnancy tests. + +OG7.1 Describe and discuss the changes in the genital tract, cardiovascular system, respiratory, hemato-logy, renal and gastrointestinal system in pregnancy +OG8.1 Enumerate, describe and discuss the objectives of antenatal care, assessment of period of gestation; screening for high-risk factors. + +OG8.2 Elicit document and present an obstetric history including menstrual history, last menstrual period, previous obstetric history, comorbid conditions, past medical history and surgical history +OG8.3 Describe, demonstrate, document and perform an obstetrical examination including a general and abdominal examination and clinical monitoring of maternal and fetal wellbeing; +OG8.4 Describe and demonstrate clinical monitoring of maternal and fetal wellbeing + +OG8.5 Describe and demonstrate pelvic assessment in a model +OG8.7 Enumerate the indications for and types of vac-cination in pregnancy + + + + +y Lecture, Small group discussion + +y Lecture, Small group discussion + +y Lecture, Small group discussion +y Lecture, Small group discussion + + +y Lecture, seminars + +y Lecture, Small group discussion + + +y Lecture, Bedside clinics + +y Lecture, Bedside clinics + +y Lecture, Small group discussion, Bedside clinics + + +y Lecture, seminars + + +y Small group discus-sion, Bedside clinics, Lecture + +y Small group discus-sion, Bedside clinics, Lecture + +y Bed side clinic, DOAP session + + +y Bedside clinic, DOAP session, Small group discussion +y DOAP session + +y Lecture, Small group discussion + + +Chapter +Number 38 + +38 + + +16 22 +1 + + + +2 + +3 4 + + +20 39 + +10 +39 + +5 6 7 15 +41 + +5 + + +10 11 12 39 +8 10 +23 + +8 10 +11 + +10 11 + +9 24 +10 20 + +.. ' . 554-564 + +554-564 + + +153-166 310-313 +1-15 + + + +16-25 + +26-37 38-42 + + +246-293 565-591 + +93 +565-591 + +43-54 55-60 61-68 149-152 598-608 +43-54 + + +86-94 95-101 102-107 565-570 +69-75 86-94 +314-330 + +69-75 86-94 +95-101 + +86-94 95-101 + +79-85 331-339 +93 +246-293 + + + + + + + + + + + + + + + +©> + + + + + + + + + + + + + + + + + + + + + +©> + +@) + +@) @) + +, Ch P! ,:vi'½ ft +·Nu"!l>eraa.a + +11 Competency-Based NMC Curriculum + + +I • • I . I + +OG8,8 Enumerate the indications and describe the inves-tigations including the use of ultrasound in the initial assessment and monitoring in pregnancy + + + + + + + + +y Lecture, Small group discussion + +,-w, - +7 61-66 41 598-608 + + + +OG9.1 Classify, define and discuss the etiology and management of abortions including threatened, incomplete, inevitable, missed and septic +OG9.2 Describe the steps and observe/assist in the per-formance of an MTP evacuation +OG9.3 Discuss the etiology, clinical features, differential diagnosis of acute abdomen in early pregnancy (with a focus on ectopic pregnancy) and enumer-ate the principles of medical and surgical manage-ment +OG9.4 Discuss the clinical features, laboratory investiga-tions, ultrasonography, differential diagnosis, prin-ciples of management and follow up of gestational trophoblastic neoplasms +OG9.5 Describe the etiopathology, impact on maternal and fetal health and principles of management of hyperemesis gravidarum +OG10.1 Define, classify and describe the etiology, patho-genesis, clinical features, ultrasonography, differ-ential diagnosis and management of antepartum hemorrhage in pregnancy +OG11.1 Describe the etiopathology, clinical features; diag-nosis and investigations, complications, principles of management of multiple pregnancies +OG12.1 Define, classify and describe the etiology and pathophysiology, early detection, investigations; principles of management of hypertensive disor-ders of pregnancy and eclampsia, complications of eclampsia. +OG12.2 Define, classify and describe the etiology, patho-physiology, diagnosis, investigations, adverse effects on the mother and fetus and the manage-ment during pregnancy and labor, and complica-tions of anemia in pregnancy +OG12.3 Define, classify and describe the etiology, patho-physiology, diagnosis, investigations, criteria, adverse effects on the mother and fetus and the management during pregnancy and labor, and complications of diabetes in pregnancy +OG12.4 Define, classify and describe the etiology, patho-physiology, diagnosis, investigations, criteria, adverse effects on the mother and fetus and the management during pregnancy and labor, and complications of heart diseases in pregnancy +OG12.5 Describe the clinical features, detection, effect of pregnancy on the disease and impact of the +disease on pregnancy complications and manage-ment of urinary tract infections in pregnancy +OG12.6 Describe the clinical features, detection, effect of pregnancy on the disease and impact of the +disease on pregnancy complications and manage-ment of liver disease in pregnancy + +y Lecture, Small 16 group discussion + +y DOAP session, 16 Bedside clinic +y Lecture, Small 16 group discussion 20 + + + +y Lecture, Small 16 group discussion + + +y Lecture, Small 15 group discussion + +y Lecture, Small 16 group disussion, 19 Bedside clinic + +y Lecture, Small 17 group discussion, Bedside clinics + +y Lecture, Small 18 group discussion, Bedside clinics + + +y Lecture, Small 20 group discussion, Bedside clinics + + +y Lecture, Small 20 group discussion, Bedside clinics + + +y Lecture, Small 20 group discussion, Bedside clinics + + +y Lecture, Small 20 group discussion, Bedside clinics + +y Lecture, Small 20 group discussion, Bedside clinics + + +153-189 + + +166-169 + +153-189 292-293 + + + +182-189 + + + +149-152 + + +153-189 230-245 + + +190-208 + + +209-229 + + + + +246-293 + + + + +246-293 + + + + +246-293 + + + + +246-293 + + + +246-293 +Competency-Based NMC Curriculum !1 + +- Competency ,, C,-;; +< The student should be able to·<. < +r "fr + + +Teaching-Learning Methods + + +Chapter . u}nb_er .. + + +• -,, ~ ~ ' • +Pag Nu J,er +: - .,: ;:s\,t3 } • :;:•; c + + + +OG12.7 Describe and discuss screening, risk factors, man-agement of mother and newborn with HIV + +OG12.8 Describe the mechanism, prophylaxis, fetal compli-cations, diagnosis and management of isoimmuni-zation in pregnancy +OG13.1 Enumerate and discuss the physiology of normal labor, mechanism of labor in occipito-anterior presentation; monitoring of labor including par-togram; conduct of labor, pain relief; principles of induction and acceleration of labor; management of third stage of labor +OG13.2 Define, describe the causes, pathophysiology, diagnosis, investigations and management of pre-term labor, PROM and postdated pregnancy +OG13.3 Observe/assist in the performance of an artificial rupture of membranes +OG14.1 Enumerate and discuss the diameters of maternal pelvis and types + + +OG14.2 Discuss the mechanism of normal labor, define and describe obstructed labor, its clinical features; prevention; and management + +OG14.3 Describe and discuss rupture uterus, causes, diag-nosis and management + + +OG14.4 Describe and discuss the classification; diagnosis; management of abnormal labor + +OG15.1 Enumerate and describe the indications and steps of common obstetric procedures, technique and complications: Episiotomy, vacuum extraction; low forceps; cesarean section, assisted breech delivery; external cephalic version; cervical cerclage +OG15.2 Observe and assist in the performance of an episiotomy and demonstrate the correct suturing technique of an episiotomy in a simulated environ-ment. Observe/assist in operative obstetrics cases including-CS, forceps, vacuum extraction, and breech delivery +OG16.1 Enumerate and discuss causes, prevention, diag-nos is, management, appropriate use of blood and blood products in postpartum hemorrhage +OG16.2 Describe and discuss uterine inversion-causes, prevention, diagnosis and management. + +OG16.3 Describe and discuss causes, clinical features, diagnosis, investigations; monitoring of fetal well-being, including ultrasound and fetal Doppler; principles of management; prevention and coun-seling in intrauterine growth retardation +OG17.1 Describe and discuss the physiology of lactation + + +y Lecture, Small group discussion, Bedside clinics +y Lecture, Small group discussion, Bedside clinics + +y Lecture, +Small group discus-sion (with models/ videos/ AV aids, etc.) + + +y Lecture, +Small group discus-sion, Bedside clinics + +N DOAP session, Bedside clinic + +y Lecture, Small group discussion DOAP session, Bedside clinic +y Lecture, Small group discussion DOAP session, Bedside clinic +y Lecture, Small group discussion DOAP session, Bedside clinic +y Lecture, Small group discussion, Bedside clinics +y Lecture, Small group discussion, seminarsf + + +y DOAP session, Bedside clinic + + + + +y Lecture, Small group discussion, Bedside clinics + +y Lecture, Small group discussion, Bedside clinics +y Lecture, Small group discussion, Bedside clinics + + +y Lecture, Small group discussion + +20 246-293 + + +23 314-330 + + +13 108-138 26 347-377 27 378-385 479A85 +34 +35 487A95 + + +22 300-313 + + +35 487A95 + +9 79-85 24 33H39 + +13 108-138 24 33H39 25 340-346 27 378-385 +29 398-406 + + + +27 378-385 + + +26 +347-377 +523-553 +37 + + + +523-553 +37 + + + + +28 386-397 39 584-585 + +28 396-397 + + +33 441-466 + + + + +14 143-144 + + + +@) + + + +© + + + +@ @ + + + + + + + + + + +@) + + +© + + + +©> + + + + +@ +--11 Competency-Based NMC Curriculum +595 +Chapter,, -' ,·, : •, +"' ;?, +-- +r'}-Pouch of Douglas "-¥-- - - =-- Rectum +- +) +\ +t +- + + +Perinea! body + + + +Vagina - ---'_,--- - - -' + +Fig. 1.3: Midsagittal section of the female pelvis showing relative position of the pelvic organs. +Chapter 1: Anatomy of Female Reproductive Organs .. + + +MEASUREMENTS AND PARTS: The uterus measures about 8 cm long, 5 cm wide at the fundus and its walls are about 1.25 cm thick. Its weight varies from 50 to 80 g. It has got the following parts: +♦ Body or corpus ♦ Isthmus ♦ Cervix +(1) Body or corpus: The body is further divided into fundus-the part which lies above the openings of the uterine tubes. The body proper is triangular and lies between the openings of the tubes and the isthmus. The superolateral angles of the body of the uterus project outwards from the junction of the fundus and body and is called the cornua of the uterus. The uterine tube, round ligament and ligament of the ovary are attached to it. (2) Isthmus is a constricted part measuring about 0.5 cm, situated between the body and the cervix. It is limited above by the anatomical internal os and below by the histological internal os (Aschoff). Some consider isthmus as a part of the lower portion of the body of the uterus. (3) Cervix is cylindrical in shape and measures about 2.5 cm. It extends from the isthmus and ends at the external os which opens into the vagina after perforating its anterior wall. The part lying above the vagina is called supravaginal and that which lies within the vagina is +called the vaginal part (Fig. 1.4). +CAVITY: The cavity of the uterine body is triangular on coronal section with the base above and the apex below. It measures about 3.5 cm. There is no cavity in the fundus. The cervical canal is fusiform and measures about 2.5 cm. Thus, the normal length of the uterine cavity is usually 6.5-7cm. +RELATIONS +Anteriorly: Above the internal os, the body forms the posterior wall of the uterovesical pouch. Below the internal os, it is separated from the base of the bladder by loose areolar tissue. + + +Posteriorly: It is covered with peritoneum and forms the anterior wall of the pouch of Douglas containing coils of intestine. +Laterally: The double fold of peritoneum of the broad ligament are attached between which the uterine artery ascends up. Attachment of the Mackenrodt's ligament extends from the internal os down to the supravaginal cervix and lateral vaginal wall. About 1.5 cm away at the level of internal os, a little nearer on the left side is the crossing of the uterine arte1y and the ureter. The uterine artery crosses from above and in front of the ureter, soon before the ureter enters the ureteric tunnel (Fig. 1.5). + +STRUCTURES +Body: The wall consists of three layers from outside inwards: +l. Parametrium: It is the serous coat which invests the entire organ except on the lateral borders. The peritoneum is intimately adherent to the underlying muscles. +2. Myometrium: It consists of thick bundles of smooth muscle fibers held by connective tissues and are arranged in various directions. During pregnancy, however, three distinct layers can be identified-outer longitudinal, middle interlacing and the inner circular. +3. Endometrium: The mucus lining of the cavity is called endometrium. As there is no submucous layer, the endometrium is directly opposed to the muscle coat. It consists of lamina propria and surface epithelium. The surface epithelium is a single layer of ciliated columnar epithelium. The lamina propria contains stromal cells, endometrial glands, vessels and nerves. The glands are simple tubular and lined by mucus secreting non-ciliated columnar epithelium which penetrate the stroma and sometimes even enter the muscle coat. The endometrium is changed to decidua during pregnancy. + + + + + + +Anatomical internal os + + + + +lsthmu (0.5 cm + +Cervix (2 5 cm) + +_ + + +-- +-· +- + +A , J +i.-----\ \ + + ---Histological internal os + +Supravaginal portion + +Portia vaginalis +External os + + + + + +Azygos-----f arteries to +the vagina + + + + + + - - Descending +cervical branch + +Fig. 1.4: Coronal section showing different parts of uterus. Fig. 1.5: The relation of the ureter to the uterine artery. +Chapter 1: Anatomy of Female Reproductive Organs +~ + +Cervix-The cervix is composed mainly of fibrous con­ nective tissues. The smooth muscle fibers average 10-15%. Only the posterior surface has got peritoneal coat. Mucous coat lining the endocervix is simple columnar with basal nuclei and that lining the gland is non-ciliated secretory columnar cells. The vaginal part of the cervix is lined by stratified squamous epithelium. The squamocolumnar junction is situated at the external os. +SECRETION: The endometrial secretion is scanty and watery. Secretion of the cervical glands is alkaline and thick, rich in mucoprotein, fructose and sodium chloride. +PERITONEUM IN RELATION TO THE UTERUS: Traced anteriorly: The peritoneum covering the superior sur­ face of the bladder reflects over the anterior surface of the uterus at the level of the internal os. The pouch, so formed, is called uterovesical pouch. The peritoneum thereafter, is firmly attached to the anterior and post­ erior walls of the uterus and upper one-third of the posterior vaginal wall from where it is reflected over the rectum. The pouch, so formed, is called pouch of Douglas {Fig. 1.3). +Traced laterally: The adherent peritoneum of the anterior and posterior walls of the uterus is continuous laterally forming the broad ligament. Laterally, it extends to the lateral pelvic walls where the layers reflect to cover the anterior and posterior aspects of the pelvic cavity. On its superior free border, lies the Fallopian tube and on the posterior layer, the ovary is attached by mesovarium. The lateral one-fourth of the free border is called infundibulopelvic ligament. +BLOOD SUPPLY: Arterial supply: The blood supply is from the uterine arteries one on each side. The artery arises directly from the anterior division of the internal iliac or in common with superior vesical artery. The other sources are ovarian and vaginal arteries with which the uterine arteries anastomose. The internal supply of the uterus is shown in Figures 1.6A and B. + +Arcuate artery + + + +Veins: The venous channels correspond to the arterial course and drain into internal iliac veins. + +LYMPHATICS: Body: (1) From the fundus and upper part of the body of the uterus, the lymphatics drain into preaortic and lateral aortic groups of glands. (2) Cornu drains to superficial inguinal gland along the round ligament. (3) Lower part of the body drains into external iliac groups. +Cervix: On each side, the lymphatics drain into­ (1) external iliac, obturator lymph nodes either directly or through paracervical lymph nodes, (2) internal iliac groups and (3) sacral groups. + +NERVES: The nerve supply of the uterus is derived principally from the sympathetic system and partly from the parasympathetic system. Sympathetic components +are from T5 to T6 (motor) and T10 to L1 spinal segments (sensory). The somatic distribution of uterine pain is +that area of the abdomen supplied by T 10 to L8. The parasympathetic system is represented on either side by +the pelvic nerve which consists of both motor and sensory +fibers from S2,3,4 and ends in the ganglia of Frankenhauser. +The details are described in Ch. 34. +The cervix is insensitive to touch, heat and also +when it is grasped by any instrument. The uterus, too, is insensitive to handling and even to incision over its wall. +DEVELOPMENT: The uterus is developed from the fused vertical part of the two Miillerian ducts. + +I FALLOPIAN TUBE (Synonyms: Uterine tube, oviduct) +The uterine tubes are paired structures, measuring about 10 cm and are situated in the medial three-fourths of the upper free margin of the broad ligament. Each tube has got two openings, one communicating with the lateral angle of the uterine cavity called uterine opening and measures 1 mm in diameter, the other is on the lateral end of the tube, called pelvic opening or abdominal ostium and measures about 2 mm in diameter. + +Endometrium + + + +Basal artery \ Spiral artery UI + +Capillary plexus + +'I +Venous lake + + + + +Spiral artery + + +Radial artery Myometrium +Perimetnum + +Gland Basal artery +Uterine artery Uterine vein +rn + +Figs. 1.6A and B: (A) Showing pattern of basal and spiral arteries in the endometrium; (B) Internal blood supply of uterus. +Chapter 1: Anatomy of Female Reproductive Organs .. + + +PARTS: There are four parts. From medial to lateral are­ (1) intramural or interstitial lying in the uterine wall and measures 1.25 cm in length and 1 mm in diameter, (2) isthmus-almost straight and measures about 3-4 cm in length and 2 mm in diameter, (3) ampulla-tortuous part and measures about 5 cm in length which ends in, (4) wide infundibulum measuring about 1.25 cm long with a maximum diameter of6 mm. The abdominal ostium is surrounded by a number of radiating fimbriae (20-25), one of these is longer than the rest and is attached to the outer pole of the ovary called ovarian fimbria (Fig. I. 7). +STRUCTURES: It consists of three layers-(1) Serous: consists of peritoneum on all sides except along the line of attachment of mesosalpinx, (2) Muscular: arranged in two layers outer longitudinal and inner circular and (3) Mucous membrane has three different cell types and is thrown into longitudinal folds. The epithelium rests on a delicate vascular reticulum of connective tissue. Mucous membrane is lined by: (i) Columnar ciliated epithelial cells that are most predominant near the ovarian end of the tube. These cells compose 25% of the mucosa! cells, (ii) Secretory columnar cells are present at the isthmic segment and compose 60% of epithelial cells, (iii) Peg cells are found in between the above two cells. They are +the variant of secretory cells. + +FUNCTIONS: The important functions of the tubes are-(1) transport of the gametes and (2) to facilitate fertilization and survival of zygote through its secretion. +BLOOD SUPPLY: Arterial supply is from the uterine and ovarian. Venous drainage is through the pampiniform plexus into the ovarian veins. + +LYMPHATICS: The lymphatics run along the ovarian vessels to para-aortic nodes. \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_10.txt b/notes/DC Dutta Obstetrics 10th Edition_10.txt new file mode 100644 index 0000000000000000000000000000000000000000..708622b33c557f2f91de6fe3834a837aacbeb9c6 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_10.txt @@ -0,0 +1,2027 @@ +Corona viruses are the single stranded RNA virus that are associated with common colds. The incubation period is 2-16 (mean 5-6) days. +Virus appears to spread rapidly through respiratory fomite or fecal methods. Vertical transmission is possible. Fetal effects or neonatal transmission as yet not known. +Clinical presentation: Maternal: Majority develop cold/ flue like symptoms, at times cough, fever and shortages of breath. +Severe symptoms such as pneumonia, hypoxia (SpO2 <94%) are +observed with elderly or women with diabetes, chronic lung disease. Fetal: No increased risk of miscarriage, or congenital defects have been observed. +Management:• Social distancing• Self-isolation and to follow respective government guidance. • Diagnostic swabs to be arranged if indicated. • Face mask should be used. • Chest radiograph-X-ray and CT scan to be arranged (protecting the fetus) when needed. +Antenatal care: Antenatal consultation ideally should be through teleconferencing and video conferencing. Record keeping is important. Women with symptoms should defer consultation for 7 days symptoms. Antenatal ultrasound for fetal growth assessment should be done 14 days after resolution of acute illness. Corticosteroids for fetal lung maturation could be used. Attending maternity staff should use PPE for any woman suspected or confirmed to have COVID-19. +Intrapartum care: Fetal monitoring-needs continued care. Maternal monitoring needs pulse rate, BP, temperature (2-4 hourly. interval). Hourly oxygen saturation to be recorded to +keep SpO2 >94% (to tritate 02 therapy accordingly). Mode of +delivery is an individual basis, CD is done for obstetric indication. Following delivery women should be assessed for the risks of venous thromboembolism. LMWH administration may be needed. Mode of delivery-is not influenced by COVID-19 infection. Instrumental vaginal delivery for a woman who is hypoxic could be done. Personal protective equipment (PPE with FFP3 mask) for healthcare staff managing a woman with COVID-19 is essential. Spinal or epidural anesthesia be used to minimize the need of general anesthesia. +Neonatal care: Breastfeeding is allowed taking adequate precautions to limit viral spread. Preventive measures are: (a) Handwashing before touching the baby; (b) Avoiding coughing or sneezing with the baby; (c) Wearing face mask during breastfeeding. +COVID-vaccination in pregnancy beyond 13 weeks (first trimester) is safe (RCOG). +For further reading-author's book 'Clinics in Obstetrics', Ch. 58. + +SVRGICAL ILLNESS DURING PREGNANCY +Principles of general surgery during pregnancy: +• Tty to avoid major elective or semielective surgety till delivery. + +a Second trimester is the safest time for surgery as the risks of teratogenesis, miscarriage and preterm delivery are lowest. +a Diagnosis of acute abdomen is difficult in pregnant state. +■ Emergency surgery has to be done at any time during pregnancy. +■ Laparoscopic surgery can be performed safely during pregnancy. +11 Imaging abdominal organs is difficult in pregnancy due to the presence of gravid uterus. Non-ionizing imaging procedures e.g., USG or MRI is performed to minimize fetal irradiation. +■ Management of a pregnant woman with trauma should be done following initial stabilization of the mother and evaluation of the fetal. +■ Operation should be done by a senior surgeon with an expert anesthetist. An obstetrician should be involved for fetal moni­ toring. +11 Minimal handling of the uterus should be done. +■ Postoperatively, the patient is to be given pain relief for 48 hours. Use of tocolytics may be helpful. +■ Close obse1vation is mandatory for evidences of miscarriage or preterm labor. +■ Overall mortality and morbidity for surgery in pregnancy is similar to nonpregnant state. +ACUTE APPENDICITIS: Incidence is about 1 in 1,000 pregnancies. It is the most common nongynecological cause of acute abdomen requiring surgery. +Dificulties of diagnosis in pregnancy are due to-(a) Nausea and vomiting common in normal pregnancy are also the common symptoms of appendicitis, (b) Leukocytosis is common in normal pregnancy, (c) Appendix moves upwards and outwards as the uterus enlarges. So pain and tenderness may not be located in the right iliac fossa (McBurney's point) and (d) Diagnosis is often confused with disturbed ectopic pregnancy, pyelonephritis, twisted ovarian cyst, abruptio placentae and red degeneration of a fibroid, preterm labor. Rebound tenderness and muscle guarding are less reliable signs of peritonitis due to changed position of the appendix. +Effect of appendicitis on pregnancy-may lead to miscarriage, preterm delivery, increased perinatal mortality and maternal mortality. +Effect of pregnancy on appendicitis is adverse because of-(a) late diagnosis, (b) failure of localization due to displacement of the position (c) peritonitis is more common, especially, in last trimester (d) rupture. +The risks of maternal and fetal mortality from appendicitis in pregnancy is high especially when associated with perforations and rupture. Ultrasonography is commonly ,done. Appendiceal mur l thickening, periappendiceal fluid and a noncompressible tubal structure (6 mm or more) are suggestive. MRI may be used when ultrasound is inconclusive. +Treatment consists oflaparotomy at the earliest opportunity. Once the diagnosis is suspected, it is essential to operate rather than to wait until rupture and generalized peritonitis to develop. Muscle splitting incision should be made at the point of maxi­ mum tenderness. Uterine manipulation is avoided to minimize the risk of preterm labor. Laparoscopic appendicectomy can be done before 28 weeks of gestation. Intra operative fetal monitoring should be considered. + +TRAUMA IN PREGNANCY: Trauma in pregnancy may be due to blunt trauma, motor vehicle accident, fall or following domestic violence. Placental abruption is the common complication following minor as well as major abdominal blunt trauma. +ED Chapter 20: Medical and Surgical Illnesses Complicating Pregnancy + +Common types of penetrating trauma in pregnant women are due to road traffic accidents, gunshot or stab wounds. Complications are: Abortion, preterm birth, PPROM, uterine rupture, massive hemorrhage and still birth. Maternal death rates in penetrating trauma is two-thirds lower than in the non-gravid women. It is due to protective effects of the uterus to other abdominal organs. Fetal death is high (70%). +SYMPTOMATIC CHOLELITHIASIS: Incidence is about 1 in 2,000 pregnancies. It is the second most common nongynecological condition that needs surgery during pregnancy. Initial management is conservative. Elective endocystectomy is done in the second trimester or during puerperium. Deterioration of clinical condition despite medical therapy or recurrent biliary colic needs cholecystectomy regardless of trimester. Laparoscopic cholecystectomy can be done in the second trimester of pregnancy safely. +PEPTIC ULCER: It is rare during pregnancy to appear for the first time. The course of the disease is unpredictable. Perforation and hemorrhage are uncommon during pregnancy. Infection with Helicobacter pylori plays an important part in the pathogenesis. +TREATMENT: Directed to inhibit acid production (PPI), acid neutralization (antacids) and eradication of H. pylori infection (using clarithromycin and metronidazole). +ACUTE PANCREATITIS: It is difficult to diagnose during pregnancy because of the physiological increase of amylase value during the second and last trimester. Serum amylase is elevated to 1000 IU/L or more, serum lipase is elevated, serum calcium is usually low. Ultrasound is of diagnostic value. Preterm labor is more common. Once the diagnosis is made, the treatment should be conservative rather than surgical. Medical management includes IV fluids, gastric acid suppression, analgesia and nasogastric suction. Broad spectrum antibiotic should be started. +LAPAROSCOPY IN PREGNANCY: Laparoscopic surgery can be performed safely during pregnancy. Second trimester is the best time. Fetal risks and preterm labor are less as the uterine manipulation and the use of narcotics are less. +Guidelines of laparoscopic surgery during pregnancy (SAGES, 2008) +1. Obstetric consultation is essential for preoperative and postoperative management. +2. Laparoscopy is safe and effective when done selectively. It can be done safely during any trimester of pregnancy. + +T ·ble 20.1·1:"ca stsof acute pain in a_bd9meriduring pregna:icy. +· +I. Obstetrical" + +3. Patient should be in the left lateral decubitus with minimum reverse Trendelenburg. +4. Open technique (Hasson) for entering the abdominal cavity may be used. Optical trocar technique may be used with adjustment to fundal height. +5. Anti thrombotic prophylaxis are: use of pneumatic compres­ sion devices (intraoperative as well as postoperative) and early postoperative ambulation. +7. CO2 pneumoperitoneum is maintained at 10-15 mm Hg, +intra-abdominal pressure should be sufficient to allow adequate visualization. +8. Maternal end tidal CO2 should be maintained at 25-30 mm +Hg (capnography) to minimize maternal and fetal acidosis. +9. Fetal monitoring is to be continued and pneumoperiton­ eum is to be released if fetal distress arises. +10. Laparoscopic cholecystectomy, appendicectomy, nephrec-tomy are safe procedure in pregnant women. +MANAGEMENT OF ADNEXAL MASS IN PREGNANCY: Approximately 80% of adnexal masses in pregnancy are simple +in origin. Usually they are <5 cm in diameter and resolve spontaneously by the 16th week of gestation. Dermoid cysts are the most common ovarian cysts presenting in pregnancy which are detected after the 16th week and are more prone to torsion. +Detection of adnexal mass in pregnancy via USG ➔ patient presenting with acute abdomen➔ surgery; Asymptomatic, benign, simple cyst, <3 cm ➔ no intervention required; Asymptomatic, benign, complex cyst, >3 cm➔ rescan in 4 weeks; Asymptomatic cyst with features suggestive of cancer ➔ surgery. +Indications of surgery include: Acute abdomen; mass suspicious of cancer; rapidly growing masses; mass > 10 cm. + +ACUTE PAIN IN ABDOMEN DURING PREGNANCY + +Some amount of abdominal pain is common during pregnancy. One should be very careful to distinguish the pathological variety from the physiological one (Table 20.17). +A meticulous history coupled with systematic and thorough examinations (general, abdominal and vaginal) are mandato1y to arrive at a diagnosis on the real state of affairs. Many a times a delay in the diagnosis of a + + +II. Nonobstetrical + + + +Early +a Abortion. +a Disturbed ectopic. Hydatidiform mole. +• +a Acute. polyhydramnios. + + +Late +■ Abruptio placentae. Preterm labor. Labor pains. Rupture uterus. Polyhydramnios. +• +• +• +• +• +Acute fulminating pre-eclampsia. +• +• +Eclampsia. +HELLP syndrome. +■ Torsion of the uterus. + + +Medical +• Pyelitis . Pyelonephritis. +• +• +• +• +Pneumonia. Cystitis. Hepatitis. +■ Acute fatty liver. Peptic ulcer. +• + + +Surgical +■ Acute appendicitis. a Intestinal or gastric +perforation. +• +Intestinal obstruction. ■ Volvulus. +• +• +• +• +• +• +Rectus sheath hematoma. Cholecystitis. Choledocholithiasis. Biliary colic. +Renal or ureteric calculi. Malignant disease. + +Gynecological +a Torsion of ovarian cyst. +• +• +Red degeneration of fibroid. +Retention of urine due to retroverted gravid uterus, impacted fibroid or ovarian tumor. +Chapter 20: Medical and Surgical Illnesses Complicating Pregnancy &I + +nongestational cause terminates fatally. Consultation with a surgeon or a physician should be done whenever felt necessary. Laboratory tests, ultrasonography and MRI are helpful diagnostic parameters. However, their limitations and restrictions in pregnancy should be borne in mind. The physician should be conscious of the entity of disturbed tubal pregnancy in early months and rupture of the uterus, in the later months while dealing with acute abdomen in pregnancy. +Round ligament pain is observed in about 10-20% of women commonly in the second or early third trimester. Commonly seen in multigravidae. Pain is due to stretching of the round ligament. It is felt as stabbing or cramp like and it is worse during movement. The pain is localized over the area of round ligament. Often there is delay in diagnosis. +Management: Reassurance is helpful. Analgesics (paracetamol) may be needed at times. + +HEADACHE IN PREGNANCY (Box 20.8) + + +Primary: ■ Anemia. +11 Migraine. ■ Idiopathic intracranial ■ Tension headache. hypertension. Secondary: ■ Stroke. +■ Hypertension. 11 Arteriovenous malformation. ■ Subarachnoid hemorrhage. ■ Enlargement of a pituitary +• Drug-related, e.g., nifedipine, tumor. +medication overuse. ■ Bleeding into a pre-existing ■ Postdural tap. tumor. +11 Meningitis. ■ Cerebral metastasis of 11 Cerebral venous thrombosis. choriocarcinoma. + + +ascites, and reduced uteroplacental circulation and even fetal death. +Management: Maternal stabilization and prompt delivery is the goal of treatment. Patient needs intensive care supports and blood transfusions (whole blood, PRBCs, PFP, Cryoprecipitate or platelets) to correct anemia or DIC. Hypoglycemia is corrected with glucose infusion and albumin is given to combat hypoalbuminemia. +Other complications are: Pulmonary edema, pancreatitis (20%), diabetes insipidus (25%), seizures, hepatic encephalopathy, ascites, coagulopathy and hepatic failure. The complications need specific supportive care: lactulose for hepatic encephalopathy, hemodialysis for renal failure should be done. Most patients improve completely following few days of delivery. Liver functions tests come back to normal. Early diagnosis, appropriate supportive therapy and prompt delivery improves maternal outcome. Perinatal mortality is about 15%. Recurrence of AFL in subsequent pregnancy is rare. + +Difference betwe n -!ELL:1 syn r75% postpartum, +Thrombocy- Rare More common topenia +Abnormal Transaminitis Normal liver function. liver function +Acute kidney 3-15% • 30-80% in pregnacy-injury associated TTP. +• +76% End Stage Renal Failure (ESRF). +Coagulopathy 20% None +Elevated antithrombin and fibrinogen may be seen. +ADAMTS 13 Reduced level in Deficiency in TTP HELLP. +Complement Detected in HELLP Cause HUS abnormalities + +y +Gynecological Disorders +in Pregnancy + + + +CHAPTER + !l ❖ Abnormal Vaginal Discharge +.i:; +❖ Congenital Malformation of the Uterus and Vagina +❖ Carcinoma Cervix with Pregnancy ► Treatment + + + + + + +❖ Leiomyomas with Pregnancy ► Treatment +❖ Ovarian Tumor in Pregnancy +❖ Retroverted Gravid Uterus + + + + + + +❖ Morbid Anatomic Changes ► Treatment +❖ Genital Prolapse in Pregnancy +► Treatment + + + + +ABNORMAL VAGINAL DISCHARGE + +There is an increased cervical secretions and vaginal transudate during pregnancy due to increased vascularity and hyperestrogenic state. The discharge is thick, mucoid in nature and non-irritating. Microscopic examination reveals preponderance of cornified squamous cells with few pus cells. Except improvement in personal hygiene, +no treatment is required. + +TRICHOMONAS VAGINALIS: The infection is not increased during pregnancy. The clinical features remain the same as in nonpregnant state. Treatment consists of prescribing metronidazole (Flagyl) 200 mg thrice daily for 7 days. Metronidazole should be avoided in the first trimester. The husband should be treated simultaneously. +MONILIA VAGINITIS: Vaginitis due to Candida albicans is relatively more common than Trichomonas vaginalis. Its growth is favored by the high acidic pH of vaginal secretions and frequent presence of sugar in the urine during pregnancy. It is more prevalent in diabetic pregnancy. Treatment is by use of miconazole vaginal cream, one applicator full, high up in the vagina at bedtime for 7 nights. +CERVICAL ECTOPY (EROSION) +Hormonal ectopy: During pregnancy as a result of hyperestrinism, there is marked hyperplasia of the endocervical mucosa. This results in the downgrowth of the columnar epithelium to a variable extent beyond the external os replacing the squamous epithelium producing 'pregnancy ectopy'. It appears for the first time during pregnancy, circumoral in position and does not bleed to touch. The only symptom, if any, may be copious, nonirritating, mucoid discharge. Spontaneous regression occurs usually 6-8 weeks postpartum. Similar lesion may be observed in women taking oral contraceptives. + +CERVICAL POLYP: During pregnancy, there is increased vascularity and as a result any pre-existent pol p bleeds, confusing the diagnosis with threatened abortion in early months and constitutes extraplacental (local) cause of APH in later months. The diagnosis is confirmed by speculum examination. The polyp should be excised +as in the nonpregnant state and should be sent for histological examination. +ACQUIRED ABNORMALITY IN THE CERVIX: The cervix may be scarred following amputation during Fothergill's type of operation for prolapse, deep cauterization or diathermy. The cervix may fail to dilate during labor. Cesarean section may be needed in such a situation. +PREVIOUS HISTORY OF VAGINAL PLASTIC OPERATION: The patients with previous history of vaginal reconstructive operation should be delivered in hospital. Difficult repair for stress incontinence or vesicovaginal fistula indicates an elective cesarean section. + +CONGENITAL MALFORMATIONS OF THE UTERUS AND VAGINA +Severe degrees of congenital malformations of the uterus usually lead to infertility; the minor degree has got little effect on obstetric performance and usually escapes attention. It is the moderate degree of malformations that has got an adverse effect on pregnancy and labor. The diagnosis is made during-(a) abdominal inspection-fundal notching, (b) cesarean section, (c) manual removal or evacuation operation, (d) hysterosalpingography or hysteroscopy and (e) laparoscopy for infertility investigation. The adverse obstetric effects are: (1) Recurrent mid-trimester abortion; (2) Rupture pregnant rudimentary horn (cornual pregnancy); (3) Malpresentation-transverse, breech (common cause of recurrent malpresentations); ( 4) Abnormal uterine action­ uterine inertia or asymmetrical uterine contractions; (5) Preterm labor; (6) Fetal Growth Restriction (FGR); (7) Postpartum hemorrhage; (8) Retained placenta; (9) Increased incidence of operative interference; (10) Obstructed labor by the nonpregnant horn of a bicornuate uterus. + + +The common types of malformations are: (a) Arcuate; (b) Subseptate; (c) Bicornuate with equal horn or unequal horn (rudimentary). +Septate vagina hardly produces any difficulty during delivery, but a transverse septum or partial atresia may necessitate delivery by cesarean section. +TORSION OF GRAVID UTERUS: Minor degrees of torsion (rotation) along the longitudinal axis is quite common as evidenced during cesarean section. But major degrees of torsion ( 270°) of the gravid uterus producing symptoms is extremely rare. The cases are associated with the presence of a fibroid or a bicornuate uterus. The diagnosis is confused with disturbed ectopic pregnancy in early months or abruptio placentae in later months. The presenting features are of acute abdomen with shock. The uterus is tense and tender. Internal examination reveals spiralling of the vagina. Sonography or MRI is helpful for correct diagnosis. The diagnosis is confirmed usually on laparotomy. Uterus must be repositioned anatomically prior to making any incision on it. + +CARCINOMA CERVIX WITH PREGNANCY +INCIDENCE: The incidence of invasive carcinoma of the cervix is about 1 to 2 in 2000 pregnancies. +DIAGNOSIS +■ Asymptomatic cases: Cytologic screening and or concurrent HPV testing for all pregnant women is a routine during antenatal checkup. Cases showing dyskaryotic smears (squamous intraepithelial lesions) are subjected to colposcopic directed biopsy. +11 Symptomatic cases: In cases with bleeding during pregnancy either in the early months simulating threatened abortion or in the later months mimicking APH, the cervix should be inspected through a speculum at the earliest opportunity. If suspicion arises, a biopsy from the site of lesion confirms the diagnosis. +Pitfalls in diagnosis during pregnancy: Pregnancy should not limit evaluation of abnormal cervical cytology or evaluation of a cervical mass. Because of increased vascularity, softening of cervix and gestational hyperplasia of the cervical mucosa, the following problems may arise in diagnosis: (1) Indurated feel of malignancy may not be evident; (2) Benign lesions such as ectopy or polyp may bleed to touch; (3) False-negative cervical cytology is at increased risk in pregnancy; (4) During pregnancy cervix is hypervascular. Hemorrhage may be serious when outpatient biopsy is taken. Therapeutic conization for CIN lesions is either avoided in pregnancy or done in second trimester of pregnancy. +Disease spread is better assessed by MRI. Cystoscopy and sigmoidoscopy can be done. CT scanning is avoided in pregnancy. +EFFECTS OF PREGNANCY ON CARCINOMA CERVIX: The malignant process remains unaffected. There may be a rapid spread following vaginal delivery and induced abor­ tion. HPV vaccination is not recommended in pregnancy. + +Chapter 21: Gynecological Disorders in Pregnancy + +EFFECTS OF CARCINOMA ON PREGNANCY: There is increased incidence of: (1) miscarriage, (2) premature labor, (3) secondary cervical dystocia, (4) injury to the cervix and lower segment leading to traumatic PPH, (5) lochiometra and pyometra, and (6) uterine sepsis. +ABNORMAL CYTOLOGY IN PREGNANCY: Abnormal cytology detected on routine screening procedure during antenatal checkup is managed under the evaluation protocol on cervical smear. +Read more Dutta's Textbook of Gynecology, Ch. 23. +I TREATMENT +Abnormal Pap smear following: Colposcopy and biopsy. +CIN OR CARCINOMA IN SITU: The pregnancy should be followed up as usual with periodic cytologic and colposcopic evaluation. There is no contraindication to vaginal delivery. Definitive therapy on postpartum evaluation. +■ Microinvasive disease confirmed on cone biopsy ➔ conservative management until delivery when the cone margins are negative ➔ for definitive therapy ➔ postpartum evaluation. +■ Early invasive (stages IB, IIA): Treatment options depend on-gestational age, tumor stage, metastatic evaluation and maternal desire to continue pregnancy. +.. First trimester: Radical hysterectomy (with the fetus in uterus), pelvic lymphadenectomy and aortic node sampling are done. Oophoropexy at the time of hysterectomy may be done. Postoperative irradiation following evaluation of prognostic factors. +.. Second trimester: Management decisions are more difficult. +Options are: (i) Neoadjuvant chemotherapy (platinum based) ➔ continuation of pregnancy for 7-15 weeks (fetal maturation) ➔ classical cesarean delivery and radical hysterectomy, pelvic lymphadenectomy (risk of prematurity far outweighs the risk of chemotherapy); (ii) Abdominal hysterectomy or classical cesarean section ➔ radical surgery. Postoperative irradiation as on evaluation procedure. +a. Third trimester: Radical hysterectomy, pelvic lymphadenectomy after classical cesarean delivery. Dissection may be easy, but bleeding is often more in pregnancy. +■ Advanced invasive disease (Stages 11B, III, IV): First trimester-Chemotherapy and external beam irradiation ➔ spontaneous abortion (2-5 weeks) or uterine evacuation ➔ brachytherapy. +Second or third trimesters: Classical cesarean delivery ➔ neoadjuvant chemotherapy and irradiation (external beam and brachytherapy). +Prognosis: Stage for stage, the survival outcome of women with cervical cancer in pregnancy is no different when compared to the nonpregnant women. +·· ·ll Chapter 21: Gynecological Disorders in Pregnancy + +LABOR AND DELIVERY: Controversy is there with vaginal delivery. This is due to the risk of disease spread following cervical injury. Moreover the risk of vaginal bleeding is significant as the tissues are friable. There may be cervical dystocia also. Delivery by classical cesarean section is commonly done. This is followed by definitive therapy. + +LEIOMYOMAS WITH PREGNANCY +INCIDENCE: The incidence of fibroid in pregnancy is about 1 in 1,000 and it depends on population characteristics. +EFFECTS ON PREGNANCY: It depends on their location. (1) Most remain symptomatic; (2) Pressure symptoms due to impaction-(a) bladder-retention of urine and (b) rectum-constipation; (3) Miscarriage; (4) Malpresentation; (5) Non-engagement of the presenting part; (6) Preterm labor and prematurity; (7) Red degeneration; (8) Placental abruption. +EFFECTS ON LABOR: (1) May be unaffected; (2) Uterine inertia; (3) Dystocia due to: (a) cervical or broad ligament fibroid and (b) fibroid not pulled up above the presenting part during labor; (4) Obstructed labor; (5) Postpartum hemorrhage is due to atonicity or due to morbid adherent placenta; (6) Difficult cesarean section. +EFFECTS ON PUERPERIUM: (1) Subinvolution; (2) Sepsis is common when placenta is implanted over the myoma site which is a submucous or intramural type; (3) Secondary PPH; (4) Inversion of uterus; (5) Lochiometra and pyometra. +EFFECTS OF PREGNANCY ON FIBROID +1. Ultrasonography is of great value to document the +location, size and consistency of leiomyomas in a pregnant uterus. +2. Increases in size due to increased vascularity, edema and hypertrophy and hyperplasia of the fibromuscular tissues. The tumor feels soft. +3. Changes in position. +4. Changes in shape-becomes flattened. +5. Degenerative changes, especially red degeneration. 6. Torsion ofpedunculated subserous fibroid. +7. Infection and polypoidal changes are more in puerpe­ rium. +RED DEGENERATION: It predominantly occurs in a large fibroid during the second half of pregnancy or puerperium. The cause is not known but is actually a hemorrhagic infarction. Infection does not play any part. Naked eye appearance of the tumor shows dark red areas with cut section revealing raw-beef appearance often containing cystic spaces. The odor is often fishy. The color is due to the presence of hemolyzed red cells and hemoglobin. Microscopically, evidences of necrosis are present. Vessels are thrombosed, but extravasation +of blood is unlikely. +Clinical features: (1) Acute onset of focal pain over the tumor; (2) Malaise or even rise of temperature; (3) Rapid pulse; ( 4) Constipation; (5) Tenderness and rigidity over the tumor and + + +(6) Blood count shows leukocytosis. The diagnosis is confused with acute appendicitis or twisted ovarian tumor which often made only on laparotomy. +Treatment: Conservative treatment should be followed. Patient is put to bed. Ampicillin 500 mg capsule thrice daily for 7 days is given. Analgesic and sedative are frequently given. The symptoms usually clear off within 10 days. There is no need of laparotomyin majority of cases. Pedunculated subserous fibroid may, however, be removed. +Diagnosis: Sonography confirms the diagnosis with certainty. Color Doppler is helpful in some cases. MRI is more accurate for diagnosis and to know the dimensions, location and its relation to placental implantation. +I TREATMENT +The basic principle in the management of pregnancy complicated by a fibroid is conservative whenever possible. +DURING PREGNANCY +♦ Uncomplicated-usual antenatal care is followed. All cases are to be assessed at 38 weeks to formulate the method of delivery. +♦ Impaction in early months followed by retention of urine-the same management protocol as prescribed in retroverted gravid uterus is to be followed. +♦ Acute pain following red degeneration-medical management is usually done (mentioned earlier). +Place of elective cesarean section: (1) Cervical or broad ligament fibroid; (2) Associated complicating factors such as elderly primigravida or malpresentation. +DURING LABOR +♦ Fibroid situated above the presenting part usually results in uneventful vaginal delivery. +♦ Fibroid situated below the presenting part­ spontaneous vaginal delivery may occur. If it fails, cesarean section is to be done. +♦ Place of myomectomy: Myomectomy is generally restricted in pregnancy. Conservative management, analgesia, reassurance and supportive therapy is almost always adequate. Occasionally, surgery during pregnancy is indicated for torsion of an isolated pedunculated leiomyoma. Rarely, myomectomy is needed when it lies in the line of incision over the lower segment of the uterus during cesarean delivery. +♦ One should be alert for postpartum hemorrhage and retained placenta. The fibroid usually reverts to a smaller size during puerperium. + +OVARIAN TUMOR IN PREGNANCY +INCIDENCE: The incidence of ovarian tumor with pregnancy is about 1 in 2,000. Although serous cystadenoma is common even during pregnancy the incidence of germ cell tumor (dermoid) is increased two-fold during pregnancy compared to the nonpregnant state. This is because of its high prevalence during childbearing period +Chapter 21: Gynecological Disorders in Pregnancy ii and its detection due to increased complications during +pregnancy. Malignant duration tumor is extremely rare during pregnancy. +EFFECTS OF TUMOR +■ On pregnancy: There is increased chance of­ (1) impaction leading to retention of urine, (2) mechanical distress in presence of large tumor, (3) malpresentation, and (4) non-engagement of the head at term. +■ On labor: There is chance of obstructed labor if the tumor is impacted in the pelvis (Fig. 21.1). + + +EFFECTS ON THE TUMOR: All the complications that occur in the nonpregnant state are likely to occur with increased frequency except malignancy. +1. Ovarian masses relocate (change their location) in the abdomen as pregnancy advances. +2. Torsion of the pedicle-usually occurs during 8-10 weeks of pregnancy as the tumor is out of the pelvis and in the early puerperium because of lax abdominal wall. +3. Intracystic hemorrhage is due to increased vascularity. 4. Rupture following intracystic hemorrhage or due to +impaction in labor (Fig. 21.1). +5. Infection is more common following abortion and delivery. Physiological event of thrombosis invites sepsis. +DIAGNOSIS: Patient may remain asymptomatic or presents with the symptoms of-(a) retention of urine due to impaction of the tumor, (b) mechanical distress due to the large cyst and (c) acute abdomen due to complications of the tumor. Abdominal examination reveals the cystic swelling felt separated from the gravid uterus. In later months of pregnancy, confusion may arise. The patient is examined vaginally in head down Trendelenburg position to elicit the groove between the two swellings, e.g., gravid uterus and the ovarian tumor (Hingorani sign). Ultrasonography is useful to have the details of pregnancy and the ovarian tumor. MRI is very useful for some cases with more accurate information about the tumor, its nature and about the pregnancy profile. +Differential diagnosis includes pelvic kidney, uterine fibroids, colorectal or bladder tumors. +TREATMENT: The principle is to remove the tumor as soon as the diagnosis is made. +DURING PREGNANCY +■ Uncomplicated: The best time of elective operation is between 14th and 18th week, as the chance of abortion is less and access to the pedicle is easy. +■ Complicated: The tumor should be removed irrespective of the period of gestation. +When a malignant ovarian tumor is encountered at laparotomy, surgical procedure should be similar to that + + + + +Fig. 21.1: Impacted ovarian tumor in the pouch of Douglas, causing obstructed labor. Delivery was done by cesarean section. + +for nonpregnant state. Preoperative serum tumor markers are of limited value during pregnancy. +Adequate pain relief is ensured for 48 hours following surgery. +DURING LABOR: (1) If the tumor is well above the presenting part, a watchful expectancy hoping for vaginal delivery is followed; (2) If the tumor is impacted in the pelvis causing obstruction, cesarean section should be done followed by removal of the tumor in the same sitting. +DURING PUERPERIUM: On occasion, the diagnosis is made following delivery. Tumor details could be obtained with the use of USG and MRI. The tumor should be removed as early in puerperium as possible. Following operation the specimen is sent for histological examination. +OVARIAN CANCER: Overall incidence of ovarian cancer in pregnancy is about 1 in 30,000. Most ovarian tumors in pregnancy are either germ cell tumors or epithelial cancer of early stage and low-grade variety. Treatment in majority of cases is continuation of pregnancy and preservation of fertility. When the tumor is found malignant on laparotomy, surgical intervention should be similar to that of nonpregnant patient. Preoperative tumor markers like serum CA-125, -hCG and AFP levels increase in pregnancy. They have prognostic value to monitor the course of the disease. Pregnancy usually does not alter the prognosis of most ovarian cancers. Women with advanced epithelial tumors should be treated postoperatively with combination (platinum agent and paclitaxel) chemotherapy. + +RETROVERTED GRAVID UTERUS + +Retroverted uterus, either congenital or acquired, is considered as a normal variant of uterine position. Retroversion is either pre-existing or may be due to pregnancy. The incidence is about 10% during first trimester of pregnancy. +ll Chapter 21: Gynecological Disorders in Pregnancy MORBID ANATOMIC CHANGES IF LEFT UNTREATED + + +FAVORABLE: In the majority, spontaneous rectification occurs. As the uterus grows, the fundus rises spontaneously from the pelvis beyond 12 weeks. Thereafter, the pregnancy continues uneventfully. +UNFAVORABLE: In the minority, spontaneous rectification fails to occur between 12 and 16 weeks. The developing uterus gradually fills up the pelvic cavity and becomes incarcerated. The probable causes of incarceration are: (a) Projected sacral promontory; (b) Uterine adhesions; (c) Pelvic tumor and (d) Idiopathic (majority). +CHANGES FOLLOWING INCARCERATION +Changes in the uterus: (I) The cervix is pointed upwards and forwards and is placed even on the upper border of the symphysis pubis; (2) Rarely, the uterus continues to grow at the expense of the anterior wall called anterior sacculation while the thick posterior wall lies in the sacral hollow (Figs. 21.2A and B). +Chauges iu the urethra and bladder: Urethra-marked elongation along with the bladder base due to stretching of the anterior vaginal wall by the cervix. There is retention of urine. The causes of retention are: (1) Mechanical compression of the urethra by the cervix; (2) Edema on the bladder neck; (3) The woman passes small amount of urine with increased pressure (strain) even when the bladder is full (paradoxical incontinence). +Effects on pregnancy: (l) Miscarriage; (2) If pregnancy continues with anterior sacculation, there is increased chance of-(a) Malpresentation, (b) Non-engagement of the head, (c) Preterm delivery, prematurity and (d) Rupture of the uterus during labor. + +I TREATMENT +Diagnosis may be confirmed by ultrasonography or MRI. +BEFORE INCARCERATION: (1) Periodic checkup up to 12 weeks until the uterus becomes an abdominal organ; (2) She is advised to empty the bladder frequently and to lie in prone position as far as possible. +AFTER INCARCERATION: (1) To empty the bladder slowly by continuous drainage with a Foley's catheter; (2) To put the patient in bed and advise her to lie on her face or in Sim's position; (3) Urine is sent for culture and sensitivity test and urinary antiseptics-ampicillin 500 mg is given 8 hourly daily. With these simple regimes, the uterus is corrected spontaneously. +Ifspontaneous correction/ails: +11 In diagnosed cases of anterior sacculation of the uterus, delivery by cesarean section is the method of choice. One should be careful in delineating the anatomy to avoid the risk of inadvertent incision over the bladder, or anterior vaginal wall. Abdominal incision needs to be made above the umbilicus; uterus is to be delivered from the abdomen to restore the anatomy first and then to make the incision. + +GENITAL PROLAPSE IN PREGNANCY +Pregnancy is not uncommon in first-degree uterine prolapse with cystocele and rectocele. Pregnancy is, + + + + + + + + + + +Figs. 21.2A and B: (A) Direction of the cervix following incarceration; (BJ Anterior sacculation (sonography or MRI is needed to detect anatomical alterations). + +however, unlikely when the cervix remains outside the introitus and continuation of pregnancy in third degree prolapse is an extremely rare event. The incidence of prolapse is about 1 in 250 pregnancies. +EFFECTS ON PROLAPSE: There is aggravation of the morbid anatomical changes in prolapse such as marked hypertrophy and edema of the cervix; first degree becomes second degree; cystocele and rectocele become pronounced and there is aggravation of stress incontinence. These are marked during early pregnancy and the effects are due to the weight of the uterus and increased vascularity (Fig. 21.3). +■ Vaginal discharge may be copious and decubitus ulcer may develop when the cervix remains outside the introitus. +■ There is chance of incarceration, if the uterus fails to rise above the pelvis by 16th week of pregnancy. +EFFECTS +On p,·egnancy: There is an increased chance of: (1) Miscarriage; (2) Discomfort due to increased ailments; (3) Premature rupture of the membranes and (4) Chorioamnionitis. +■ During labor: There is an increased chance of: (1) Early rupture of the membranes; (2) Cervical dystocia; (3) Prolonged labor due to non-dilatation of cervix and obstruction due to sagging cystocele and rectocele and Operative interference. +■ During puerperium: (1) Subinvolution; (2) Uterine sepsis. + +I TREATMENT +DURING PREGNANCY: The symptoms are mostly pronounced in early pregnancy. +♦ If the cervix is outside the introitus-the cervix is to be replaced inside the vagina and is kept in position by a ring pessary. The pessary is to be kept until 18th-20th week of pregnancy when the body of the uterus will be sufficiently enlarged to sit on the brim of the pelvis. +If the pelvic floor is too much lax-the patient is to lie in bed with the foot end raised by about 20 cm. + + + + + + + + + + + + + + + + + + + +Fig. 21.3: Uterine prolapse in pregnancy with hugely edematous and hypertrophied cervix. + +To relieve edema and congestion of the prolapsed mass, it should be covered by gauze soaked with glycerine and acriflavine. The treatment is continued until 18th to 20th week of pregnancy till the prolapsed mass is reduced in size and replaced inside the vagina. Thereafter, the patient is allowed to walk about. +♦ If the cervix remains outside the introitus even in the later months, it is preferable to admit the patient at 36th week. + +Chapter 21: Gynecological Disorders in Pregnancy JD DURING LABOR +♦ The patient should be in bed, not only to prevent early rupture of the membranes but also to facilitate replacement of the prolapsed cervix inside the vagina. +♦ Intravaginal plugging soaked with glycerine and acriflavine not only helps in reduction of cervical edema but also facilitates its dilatation. +♦ Prophylactic antibiotic, in cases of premature rupture of the membranes or when the cerix remains outside, should be administered. +♦ Manual stretching of the cervix or pushing up the cystocele or rectocele past the presenting part during uterine contractions facilitates progressive descent of the head. +♦ If the head is deeply engaged with the cervix remaining thin and partially dilated, delivery may be facilitated by Diihrssen's incision at 2 o'clock and 10 o'clock positions followed by ventouse extraction or forceps application. +♦ If the head is high up and/or the cervix remains edematous, thick or undilated, cesarean section is a safe procedure. +PUERPERIUM: (1) The patient should lie flat on the bed; (2) If the mass remains outside, it should be covered with gauze soaked in glycerine and acriflavine; (3) If subinvolution is evident, a ring pessary may be put in until involution is completed; ( 4) Prophylactic antibiotic is administered; (5) Cause of prolapse is investigated and managed accordingly. + + +fi-11M-i +► Cervical cytology screening is a routine during antenatal checkup. Cases with moderate to severe dyskaryotic smear (H SIL) are evaluated with colposcopy and directed biopsy. Cases with CIN and CIS are followed up during pregnancy and reevaluated 6 weeks postpartum. +► Cone biopsy in pregnancy is preferably avoided because of the risks of bleeding, miscarriage and preterm labor. It is done in second trimester if needed. +► Fibroid may affect the course of a pregnancy labor and puerperium adversely depending upon its location, number and size. Pregnancy also affects the fibroid. There is increase in size and risks of degeneration and infection. +► Red degeneration in a large fibroid is observed during the second half of pregnancy and puerperium. Conservative management is recommended. Myomectomy in pregnancy is preferably avoided due to the risk of profuse hemorrhage during operation. +► The ovarian tumors, germ cell ovarian tumor (dermoid) common in pregnancy. Continuation of pregnancy and preservation of fertility is possible. +► Ovarian tumor can complicate the course of a pregnancy and labor. +► Detail of information of an ovarian tumor in pregnancy can best be obtained with MRI. It is safe in pregnancy. +► Removal of the tumor is best done effectively between 14th and 18th week. However, it should be removed at any time, irrespective of duration of gestation, if complicated. +► Spontaneous rectification of a retroverted gravid uterus occurs between 12 and 16 weeks, unless it is incarcerated. +► Patient with retroverted gravid uterus commonly presents with retention of urine and UTI. Pregnancy complications (malpresentation, rupture of uterus) may occur. +► Correction of UTI and continuous bladder drainage with a Foley's catheter help spontaneous correction of retroversion in majority of the cases. +► Increased vascularity during pregnancy results in aggravation of the morbid anatomical changes of the uterus and cervix (edema, hypertrophy, infection) when there is uterine prolapse in pregnancy. +► Principle of management for genital prolapse in pregnancy is to replace the cervix inside the vagina and it is kept in position by a ring pessary. +Preterm Labor and Birth, Preterm Rupture of the Membranes, +Prolonged Pregnancy, +Intrauterine Fetal Death +CHAPTER +• + + + +❖ Preterm Labor and Birth ❖ Management in Labor ❖ Intrauterine Fetal Death (IUFD) ► Etiology ❖ Prelabor Rupture of the Membranes ► Etiology +► Management of Preterm Labor and (PROM) ► Diagnosis +Birth ► Management ► Recommended Evaluation for a ► Prevention of Prete rm Labor ❖ Prolonged and Post-term Pregnancy Stillbirth +► Measures to Arrest Preterm ► Diagnosis ► Management Labor ► Management + + + +PRETERM LABOR AND BIRTH (Syn: Premature Labor) + +DEFINITION: Preterm Labor (PTL) is defined as one where the labor starts before the 37th completed week ( <259 days), counting from the first day of the last menstrual period. The lower limit of gestation is not uniformly defined; whereas in developed countries it has been brought down to 20 weeks, in Low and Middle Income (LMI) countries it is 26-28 weeks (Box 22.1). Preterm Birth (PTB) is the significant cause of perinatal morbidity and mortality. +Fetal lung maturation has four stages known as the glandular, canalicular, saccular, and alveolar periods. The glandular period occurs between 6 to 16 weeks of intrauterine life. During this period most of the lung components are formed, except for the alveoli. Hence, gaseous exchange is not possible at this stage. The alveoli develop in the canalicular period that occurs between 16 to 24 weeks. The saccular period is between 24 weeks to birth. It is during this period that the blood­ air barrier is established. There are two types of lung cells: +Type 1 pneumocytes that line the alveoli; and Type 2 pneumocytes that appear at 24 weeks are responsible for surfactant production. The lung epithelium is initially cuboidal, but progressively changes to squamous. Respiration and gas exchange are possible only when + + +Risk factors for pre-eclampsia +■ Extremely preterm: <28 weeks. +■ Very early preterm: 28 to <32 weeks. ■ Early preterm: 32 to <34 weeks. +n Late preterm: 34 to <37 weeks. + +this epithelium changes to squamous epithelium. This process begins at 26 weeks of fetal life. +INCIDENCE: The prevalence widely varies and ranges between 10 and 15%. + +ETIOLOGY +In about 50%, the cause of preterm labor is not known. Often it is multifactorial. The following are, however, related with increased incidence of preterm labor. +HIGH-RISK FACTORS ASSOCIATED WITH PTL +A. History: There is an increased incidence of preterm labor in cases such as: (1) Previous history of preterm delivery induced or spontaneous abortion; (2) Preg­ nancy following Assisted Reproductive Techniques (ART); (3) Asymptomatic bacteriuria or recurrent urinary tract infection; (4) Smoking habits; (5) Low socioeconomic and nutritional status; (6) Maternal stress; (7) Genetic-mother, born preterm, has high risk of delivering her baby preterm. +B. Complications in present pregnancy: May be due to maternal, fetal or placental. +■ Maternal: (a) Pregnancycomplications:Preeclamp­ sia, APH, multiple pregnancy, premature rupture of the membranes, polyhydramnios; (b) Uterine anom­ alies:Cervical incompetence, malformation of uterus; (c) Medical and surgical illness: Acute fever, acute pyelonephritis, bicornuate, septate, acute appendici­ tis, toxoplasmosis and abdominal operation. Chronic diseases: Hypertension, nephritis, diabetes, decom­ pensated heart lesion, severe anemia, Low Body Mass Index (LBMI), periodontal disease; (d) Genital tract infection: Bacterial vaginosis (4 fold rise), beta­ hemolytic Streptococcus, Bacteroides, Chlamydia and Mycoplasma. +Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death +■ + +Flowchart 22.1: Etiopathogenesis of preterm labor. + + +■ Activation of fetal H PA axis tcRH, tACTH, tcortisol + +■ Pathologic uterine enlargement (polyhydramnios, multiple pregnancy) +tMechanical stretch, tlL-8 tPGEJ20 +tMyometrial +tGap junction, tPG synthetase tTXA2 contractions + I +Leukotrienes +■ Membrane/decidua activation I.PG dehydrogenase +tcervical +Chorion, Amnion +and Decidua +tMMP, tECM degradation tProteases -, ripening -> +teen apoptosis tcollagenase +■ Preterm parturition syndrome tLeukocyte elastase tcervical +effacement +• Infection, • Vascular insult tcytokines IL-6 ■ Bacterial calonization (40%) +I +I +tTNF, tlL-1, 6, 8 MMPs: Matrix Metalloproteinase; ECM: Extracellular Matrix + + + + + + + + +Preterm labor and delivery + + + +■ Surgical complications: Cervical-conization, amputation, abdominal surgery during pregnancy. Fetal: Multiple pregnancy, congenital malformations and intrauterine death. +Placental: Infarction, thrombosis, placenta previa or abruption. +■ +C. Iatrogenic: Indicated preterm delivery due to medical (severe preeclampsia) or obstetric complications (APH). +D. Idiopathic: Majority-premature effacement of the cervix with irritable uterus and early engagement of the head are often associated. In the absence of any complicating factors. +Etiopathogenesis ofpreterm labor (Flowchart 22.1). +■ Clinical evaluation of a patient to make the diagnosis of PTL: (a) Uterine contractions-frequency, duration and intensity (firmness, tenderness).(b) Digital/ speculum examination of the cervix. (c) USG evaluation for fetal gestational age, estimated fetal weight, cervical length and dilatation. (d) Presence of show. (e) Tocodynamometery and CTG for uterine contraction and fetal wellbeing. +■ +Differential diagnosis: False labor-contractions dissipate (p. 111), no cervical change over time, fFN test negative, cervical length (TVS) ;:2.5 cm. +■ +General examination: Pulse, BP, temperature and FHR. +A. USG (TAS): Fetal size assessment, presentation, placental location, TVS for cervical length (a,2.5 cm), cervical effacement (80%) and dilatation ::2 cm: PTL-likely. +Laboratory studies: +B. Blood for CBC, urine-urinalysis culture and sensitivity. +C. Speculum examination: fFN, cervical swabs culture for Chlamydia, Group B Streptococcus (GBS), vaginal pooled fluid (if any). + + +D. Fetal fibronectin (fFN) testing: A positive test result is of less value, however a negative test predicts low risk for PTL. +E. Amniocentesis may be helpful to ascertain fetal lung maturity (L/S ratio) and to exclude chorioamnionitis (Ch. 12 and 41). +F. Serum electrolytes and glucose levels when tocolytic agents are to be used (p. 475). + +I PREDICTION AND DIAGNOSIS OF PTL +i. Presence of risk factors: Previous history of PTL, others (p. 300). +ii. Symptoms and signs (see above). +iii. Biomarkers: Fibronectin (fFN), Placenta Associated a-Macroglobulin-1 (PAMG-1); Insulin Like Growth Factor Binding Protein-1 (IGFBP-1) and p-hCG. +iv. Amniotic fluid (Table 22.1). +v. Serum markers: CRH, CRP and ALF. +vi. Regular uterine contractions with or without pain (;:4 every 20 minutes or >8 in 60 minutes) AND ♦ Cervical dilatation ;:2 cm OR ♦ Cervical effacement ;:80%. ♦ TVS: Cervical dilatation ::20 mm and positive fFN. ♦ Pelvic pressure, backache and/ or vaginal discharge or bleeding. Cervical length ;:30 mm, PTL is unlikely regardless of contraction frequency. +■ +vii. Fibronectin is a glycoprotein that binds the fetal membranes to the decidua. Normally it is found in the cervicovaginal discharge before 22 weeks and again after 37 weeks of pregnancy. Presence of fibronectin (>50 ng/ mL) in the cervicovaginal discharge between 24 and 34 weeks is a predictor of preterm labor. When the test is negative it reassures that delivery will not occur within next 7 days. +Etiopathogenesis: Preterm labor syndrome is a multitude etiopathological process. Factors involved are: • Intrauterine inflammation, infection, Fetal Inflammatory Response Syndrome (FIRS). • Endocrine abnormality +ID Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death Flowchart 22.2: Management of a preterm labor. + +Preterm labor MEMBR ANES INTACT, MATERNAL AND FETAL STATUS STABLE + + + +GA <34 weeks + +Cervical dilatation +l + + +GA >34 weeks +l + +• Assessment ♦ No tocolysis +♦ Antenatal corticosteroids ± + + + +2:3cm, 2:80% +effaced + + +<3cm +• Test for ff N +♦ USG TVS for Cervical +Length (CL), effacement, dilatation +! + + +Contraction +ceases +l +Continue pregnancy + + +Progresses to +active labor +l +Delivery + + + +CL <20 mm CL 20-30 mm CL 2:30 mm <80% effaced +PTL Test for fFN PTL unlikely +l +l +l +l +j +j + +I l +fFN (+) fFN H +! + +PTL likely PTL unlikely +I +i +♦ To observe for 9-10 hours +♦ No change in cervical dilatations +• Tocolysis (maximum 48 hours) and effacement +i +• Antibiotics (GBS prophylaxis) +• MgSO , if pregnancy <32 weeks +4 +♦ Antenatal corticosteroids • Follow-up in 10-14days + + + + + + + + + + + + +I GA = Gestational Age I + + + + +(progesterone receptors withdrawal in the myometrium). • Inflammatory markers ( amniotic fluid). • Spiral arterial thrombosis, atherosis. • Decidual necrosis and hemorrhage leading to activate parturition. + +MANAGEMENT OF PRETERM LABOR AND BIRTH +I + +The management includes: (l) To assess the gestational age (Flowchart 22.2); (2) Confirmation of diagnosis (discussed above); (3) To stop preterm labor, if not contraindicated; (4) Appropriate management of labor; (5) Effective neonatal care (Box 22.2). + +I PREVENTION OF PRETERM LABOR + +Primary: Only some of the risk factors for PTL are modifiable: +♦ Short cervix-progesterone supplementation may prolong pregnancy. +♦ Singleton gestations are less likely for PTL compared to multiple gestations. +♦ Single embryo transfer and multifetal pregnancy reduction can reduce PTL. +♦ Progesterone supplementation ± cervical cerclage in few cases can reduce PTB. + + += -c'-'.', • • '.2: Principl s_pf rna_nage ,ent _of_ 9'l n _with preterm labor.· Risk Factors for Pre-eclampsia +• •= -f:lt -""'"'•1:mlls;!>:®U, l '• • ' ,, ," +s. +Box 22 +■ Corticosteroids (betamethasone/dexamethasone) to the mother to reduce neonatal RDS, IVH, NEC, BPD and PDA. +11 Antenatal transfer of the mother with fetus in utero to a tertiary center equipped with NICU. +■ Tocolytic drugs to the mother for a short period unless contraindicated (p. 303). +■ Antibiotics to prevent neonatal infection with Group B Strepto­ coccus (GBS). +11 Magnesium sulfate (neuroprotector) to the mother to reduce +neonatal cerebral palsy when pregnancy is <32 weeks. +■ Careful intrapartum monitoring, minimal trauma, presence of a neonatologist and delayed cord clamping is done to give the benefit of higher hematocrit and circulating blood volume. +■ Vaginal delivery is preferred, unless otherwise indicated for cesarean birth. +■ MEASURES TO ARREST PRETE RM LABOR +The scope to arrest preterm labor is limited, as majority is associated with maternal and/or fetal complicating factors where the early expulsion of the fetus may be beneficial. Only in about 10-20%, where the fetus is not compromised, the maternal condition remains good and membranes are intact, the following regime may be used +to arrest preterm labor. +Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death - +♦ Bedrest-the patient is to lie preferably in left lateral position with some benefit. + +♦ Adequate hydration is maintained. +♦ Prophylactic antibiotic is given to prevent neonatal GBS infection. Ampicillin (IV), cefazoline (IV) or clindamycin may be used. + + +■ Severe pre-eclampsia ■ Cholestasis +11 Medical disorders (asthma, epilepsy) + + +■ Diabetes mellitus ■ Placental: APH +11 Fetal compromise multifetal pregnancies, FGR + + + +♦ Prophylactic cervical cerclage: +• History-indicated cerclage: Women with singleton pregnancies and history of three or more midtrimester miscarriages or previous preterm births <34 weeks should be offered a history-indicated cervical cerclage between 12-14 weeks. +• Ultrasound-indicated cerclage: Women with a singleton pregnancy and a history of spontaneous second trimester Joss or preterm birth may be offered serial sonographic assessment. She should be offered cerclage operation (between 16-24 weeks), if the cervix is short (<25mm). +• Transabdominal cerclage: In women with a previous unsuccessful transvaginal cerclage, insertion of a transabdominal cerclage may be considered (p. 165). +• Emergency cerclage: In women with a singleton pregnancy insertion of an emergency cerclage between 16-27+617 weeks may delay birth by an average of 34 days (p. 164). +♦ Tocolytic agents: Various drugs nifedipine, progesterone have been used to inhibit uterine contractions. Drugs that are used are described in Ch. 34. The tocolytic agents are used for short-term (1-3 days) only (RCOG). +Treatment outlines: PTL is a complex multifactorial etiology, no single regimen is effective. Prematurity results in increased neonatal death and disability and also high maternal morbidity. Individualized approach can improve the outcome. Antenatal corticosteroid therapy, control +of infection prophylaxis, MgSO4 for neuroprotection and +transfer in utero to a center with advanced neonatal care are the important measure. +The goals of treatment for PTL are: (I) To delay delivery for at least for 48 hours for glucocorticoid therapy to the mother to enhance fetal lung maturation and (2) In utero transfer of the patient to a unit with an advanced Neonatal Intensive Care Unit (NICU). +Contraindications of tocolytics: A. Maternal: Uncon­ trolled diabetes, thyrotoxicosis, severe hypertension, cardiac disease, hemorrhage in pregnancy, e.g., placenta previa or abruption. B. Fetal: Fetal distress, fetal death, congenital malformation and pregnancy ,:34 weeks. C. Others: Rupture of membranes, chorioamnionitis and cervical dilatation more than 4 cm. +♦ Neuroprotection: MgSO4 is used when pregnancy is +<32 weeks. Dose schedule of MgSO 4 and monitoring +are same as used for seizure prophylaxis of pre­ eclampsia ( 4 g IV over 3-5 minutes followed by an infusion of 1 g/hr). It is started within 4 hours of PTL and continued till delivery or up to 24 hours, whichever is earlier. + + +Fetal effects of MgSO4: Decrease in baseline fetal heart +rate (remains within the normal range) and decrease in FHR variability that may be absent or minimal. +Maternal effects: Warmth, flushing, drop in BP, nausea, vomiting, headache, muscle weakness, visual disturbances. +♦ Corticosteroid therapy: Maternal administration of corticosteroid is advocated where the pregnancy is less than 34 weeks. This helps in fetal lung maturation so that the incidence of RDS, IVH, NEC and PDA are minimized. This is beneficial when the delivery is delayed beyond 48 hours of the first dose. Benefit persists as long as 18 days. Either betamethasone (Betnesol) 12 mg IM 24 hours apart for two doses or dexamethasone 6 mg IM every 12 hours for 4 doses is given. Betamethasone is the steroid of choice (RCOG-2004). Both cross the placenta and have identical biological activity. Rescue therapy of corticosteroid should be given to a woman before 34 weeks, when her first course was given more than two weeks earlier (Box 22.3): +Risks of antenatal corticosteroid use: (a) Any preexisting injection, as the infection may flare-up; {b) Insulin-dependent diabetes mellitus where patients need insulin dose readjustment; (c) Transient reduction of fetal breathing and body movements; (d) Transient increase in WBC count for 48 hours. + +MANAGEMENT OF PRETERM LABOR + +The principles in management of preterm labor are: (1) To prevent birth asphyxia and development of RDS; (2) To prevent birth trauma. Duration of labor is usually short. +Preterm infants <34 weeks should be delivered in hospitals equipped with intensive neonatal care facilities. +■ Routine Cesarean Delivery (CD) is not recommended. CD is done with obstetric indicants (malpresentation, non-reassuring fetal status, prior CD). ■ Labor should be monitored with continuous EFM. Apgar scores are often low in preterm Low Birth Weight (LBW) infant. These infants need cord blood pH and blood gas analysis for further management in intensive neonatal care. During vaginal delive1y episiotomy may be needed. Second stage delay may be curtailed by forceps. +Immediate management of the preterm baby following birth. +ml Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death + +PROGNOSIS: Preterm labor and delivery of a low birth weight baby results in high perinatal mortality and morbidity. However, with NICU, the survival rate of the + + +baby weighing between 1,000 and 1,500 g is more than 80%. With the use of surfactant, survival rate of infants born at 28 weeks is about 80%. + + + +fi-Mil +► A preterm labor is one when labor starts after the period of viability (20-28 weeks) but before 259 days (<37 completed weeks) of pregnancy. +► High-risk factors for preterm labor are many. Etiopathology of preterm labor is complex. Infection, uterine enlargement and/or fetal stress can initiate the pathology. +► Risk of preterm labor increases as the length of the cervix decreases (<2.5 cm) and with progressive dilatation of the cervix. +► Presence of fetal fibronectin in the cervicovaginal discharge (>50 ng/ml) between 22 and 34 weeks of pregnancy is a good predictor of preterm labor. +► To arrest preterm labor and birth tocolytics may be used for a short-term basis. There are several contraindications for the use of tocolytics, especially with betamimetic drugs. +► Complications of a preterm infant are many and are inversely related to the gestational age and birth weight. +► Management of PTL is aimed to reduce perinatal morbidity and mortality. The principles of management are: +• To transfer the mother with the fetus in uteroto a hospital where special care baby unit is available.• To start glucocorticoid to the woman to reduce neonatal RDS and IVH. • To start antibiotic to prevent infection. • To start tocolytic medications to delay delivery at least for 48 hours. +► Pregnancy s32 weeks, to start Mg SO4 to the mother to reduce the risk of cerebral palsy (neuroprotector). +► Infants with late preterm birth (between 34 and 37 weeks) have improved survival rate when compared to infants with early preterm birth (<34 weeks) + + + +PRELABOR RUPTURE OF THE MEMBRANES (PROM) (Syn: Premature Rupture of Membranes) + +DEFINITION: Spontaneous rupture of the membranes any time beyond 24°17th week of pregnancy but before the onset of labor is called Prelabor Rupture of the Membranes (PROM). When rupture of membranes occur beyond 37th week but before the onset of labor, it is called term PROM and when it occurs before 37 completed weeks, it is called preterm PROM. Rupture of membranes for >24 hours before delivery is called prolonged rupture of membranes. + +or slow leak. This is often confused with incontinence of urine especially in later months. +1. Inspection of vaginal pads for any evidence of soakage. +2. Valsalva maneuver: Patient is asked for coughs and to see escape of liquor from the os. +3. Speculum (sterile) examination: Visual inspection of the cervix for degree of dilatation and effacement. Pool of liquor may be collected for fetal lung maturity tests. + + + +INCIDENCE: PROM occurs in approximately 10% of all pregnancies. + +4. Amnisure for the presence of placental a macro globu­ lin-I protein in vaginal fluid. + + + +PATHOGENESIS: In majority, the causes are not known. The possible clinical causes are as discussed in page. 300. The molecular changes in PROM are: (a) Increased apoptosis of fetal membrane cells; (b) Increased degradation of amniotic membrane collagens by specific proteases; (c) High levels of Matrix Metalloproteinase (MMP) family of enzymes ( collagenase, protease) to cause amniotic membrane collagen degradation and (d) Inflammation following infections with release of cytokines; IL-1 , TNF-a, leukocyte activation and proliferation. All these ultimately lead to: (a) Decreased tensile strength and (b) Increased friability of the membranes. + +Disorders associated with PROM +■ +■ +■ +■ +Maternal infection (UTI). Cevical insuficiency. Hydramnios. Nutritional deficit. +■ History of PROM in prior pregnancy. ■ Poor tensile strength of membrane. +DIAGNOSIS OF PROM: The only subjective symptom is escape of wate1y discharge per vaginam either in the form of a gush + +5. Pooling: Collection of amniotic fluid in the posterior fornix. +6. Nitrazine test: Paper turns blue with alkaline PH (7.0-7.25). +7. Ferning: Fern like pattern of crystallization with liquor. +8. Nile blue sulfate staining (0.1%) of the centrifused cells to see orange colored fetal cells. +9. Ultrasonography for fetal weight and AFI or MVP, NST, BPP is done. +10. Cases where PROM is highly suspicious: Amniocen­ tesis with injection of dilute solution of indigo carmine dye is done. PROM is confirmed if the vaginal pads are soaked with the blue dye after 15-30 minutes. +CLINICAL FEATURES: Amnionitis: Clinical diagnosis: (a) mater­ nal temperature 38°C, (b) uterine tenderness, (c) maternal pulse (>100 bpm) and FHR (>160 bpm) tachycardia, (d) foul smelling aniniotic fluid. +Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death !D + +INVESTIGATIONS: (a) Blood for WBC-raised, neutrophilic leukocytosis (>15,000 mm3), (b) Others (Table 22.1). +Complications of PROM: The risks are less when the rupture occurs near term than earlier in pregnancy. + +■ Maternal: +1. In term PROM labor starts in 80-90% of cases within 24 hours. PROM is one of the important causes ofpreterm labor and prematurity. + + +Table 22.1_: Diagnostic tests for chorioamnionitis. Test Abnormalfinding +Maternal WBC > 15000 cells/mm3 with a preponder-ance of neutrophils. +Amniotic fluid glucose sl0-15 mg/dl. +Amniotic fluid IL-6 ?.7.9 ng/ml. + +2. Chance of ascending infection is more if labor fails to start within 24 hours. Liquor gets infected {chorioamnionitis) and fetal infection supervenes (Ch. 30). +3. Cord prolapse, cord compression especially when associated with malpresentation. +4. Continuous escape of liquor for long duration may lead to dry labor (oligohydramnios). +5. Placental abruption and retained placenta. +Others are: Endometritis, maternal sepsis and even death. ■ Fetal complications: +1. Fetal pulmonary hypoplasia, especially in preterm PROM when associated with oligohydramnios. +2. Fetal distress due to umbilical cord compression, placental abruption. +3. Neonatal sepsis, RDS, pneumonitis, IVH and NEC in preterm PROM. + + + +Amniotic fluid leukocyte ?.1 reaction. esterase + +4. Perinatal morbidities (cerebral palsy) are high. +5. Fetal death (2%). + + + +Amniotic fluid Gram stain Any organism in an oil immersion field. +Amniotic fluid culture Growth of any aerobic or anaerobic pathogen. +(IL-6: lnterleukin-6; WBC: White Blood Cell Count) + + +■ MANAGEMENT (Flowchart 22.3) + +PRELIMINARIES: (1) Aseptic examination with a sterile speculum is done not only to confirm the diagnosis but also + + +Flowchart 22.3: Scheme for management of PROM. + + + + +• Maternal health assessment. +maturity +• • +Fetal: Gestational age, weight, pulmonary . Biophysical profile. + +PROM +♦ Septic work up (cervical swab, urine culture). I • Nonstress Test (NST). + + + +To monitor maternal pulse, temperature, fetal heart rate and to start • Prophylactic broad-spectrum antibiotics • Betamethasone + + +Evaluation for amnionitis, placental abruption, fetal death/distress or labor process. + + + +Absent + + +Pregnancy <24 weeks Pregnancy 24°17 to 33617 Pregnancy 34°'7 to 36617 weeks Pregnancy 37°17 weeks +l +Couple counseling • Couple counseling. • Antibiotics. +♦ Expectant management ♦ Expectant management. • Corticosteroid course. +(for membrane sealing). ♦ Antibiotics to +• Bed rest with washroom prolong latency. To wait for spontaneous To wait for +spontaneous +facilities OR +lnduction of labor ♦ ction (<32 weeks). ote- onset of labor for onset of labor for +MgSO +4 +- +neuropr +24-48 hours +! +! +24 hours +♦ Antibioitics. • Corticosteroid +• Corticosteroid ±. course. +• Serial USG for ♦ May need transfer in Fails +Fails +i +oligohydramnios utero to a center with NICU. +and pulmonary +hypoplasia. Induction of labor Induction of labor with oxytocin with oxytocin +(CD for obstetric indications) (CD for obstetric reasons) + +Present + + +Expeditious delivery +1 +1 + + +lntrapartum antibiotics (broad-spectrum) +1 + + +NICU (facilities) + +Neonatal survival outcome depends upon birth weight and gestational age at delivery. Increased birth weight and the advanced gestational age at delivery improves the perinatal outcome +Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death + + +to note the state of the cervix and to detect any cord prolapse; (2) Vaginal digital examination is generally avoided; (3) Patient is put to bed rest and sterile vulva! pad is applied to observe any further leakage. Once the diagnosis is confirmed, management depends on-(i) Gestational Age (GA) of the fetus; (ii) Whether the patient is in labor or not; (iii) Any evidence of sepsis and (iv) Prospect of fetal survival in that institution, if delivery occurs. Maternal pulse, temperature and fetal heart rate are monitored 4 hourly. +Indication of urgent delivery in a case with PROM +♦ Non-reassuring fetal status. ♦ Start oflabor process. +♦ Evidence of pulmonary maturity (amniotic fluid evaluation). ♦ Evidence of chorioamnionitis. +♦ Cesarean delivery done for obstetric indications. +USE OF ANTIBIOTICS: +♦ Ampicillin 2 g IV every 6 hours plus erythromycin 250 mg N every 6 hours after 48 hours (if undelivered) +♦ Amoxicillin 250 mg PO, TID plus erythromycin 250 mg PO TID. Antibiotics are continued for 7 days, for undelivered women. Women with GBS positive culture should get prophylaxis intrapartum. +Term (>37°17) PROM: If the patient is not in labor and there is no evidence of infection or fetal distress, she is observed + + +carefully in the hospital. Generally in 90% of cases spontaneous labor ensue within 24 hours. If labor does not start within the stipulated time or there are reasons not to wait, induction of labor with oxytocin is commenced forthwith. Cesarean section is performed with obstetric indications. +Preterm PROM (,;36617): The main concern is to balance the risk of infection in expectant management (while pregnancy is continued) versus the risk of prematurity in active intervention. Ideally the patient should be transferred with the 'fetus in utero' to an unit able to manage preterm neonates effectively (Flowchart 22.3). +■ 34 weeks: • Plan delivery, Labor induction (GBS prophylaxis) • Single course of corticosteroid +11 32-33617: • Expectant management (GBS prophylaxis) • Corticosteroid therapy • Antibiotics to prolong latency +■ 24-31617: • Expectant management • GBS prophylaxis +• Antibiotics to prolong latency • MgSO4 for neuropro­ +tection + +Use of corticosteroids to stimulate surfactant synthesis against RDS in preterm neonates is advised (Ch. 33). As such PROM alone may accelerate fetal lung maturation. However, combined use of antibiotics and corticosteroids has reduced the risks of neonatal RDS, IVH and NEC, BPD and PDA. + + + + + +► PROM is defined as the rupture of membranes anytime beyond 24 weeks of pregnancy but before the onset of labor. PROM may be term or preterm (PPROM) when it occurs before 37 completed weeks of pregnancy. +► Neonatal complications after PROM is inversely related to the gestational age at the time of PROM and at delivery. ► Fetal complications after PROM include infection and fetal distress due to umbilical cord compression. +► Neonatal complications are RDS, NEC, IVH, Bronchopulmonary Dysplasia (BPD), PDA, sepsis and pulmonary hypoplasia. +► Maternal complications of PROM are: Chorioamnionitis, placental abruption, sepsis and maternal death, the birth weight at delivery. +► Antenatal corticosteroid therapy after PROM reduces the risk of RDS, IVH and NEC. It does not increase the risk of maternal and neonatal sepsis. +► Antenatal antibiotic treatment in PROM can prolong pregnancy and reduce chorioamnionitis and endometritis. It also prevents neonatal sepsis, pneumonia and IVH. +► Major risk factors for PTL are: (1) History of prior PTB; (2) Multiple pregnancy and (3) Vaginal bleeding after the first trimester of pregnancy. +► A 7-day course of parenteral (first 48 hours) and oral antibiotic therapy is given. The commonly used antibiotics are erythromycin or amoxicillin-ampicillin. +► Antenatal corticosteroids and use of broad-spectrum antibiotics reduce the newborn complications and should be used. ► MgSO4 is used for neuroprotection. + + + +LATE-TERM AND POST-TERM PREGNANCY (Syn: Prolonged Pregnancy Postmaturity) + +DEFINITION: Literally, any pregnancy which has passed beyond the expected date of delivery, is called a prolonged or postdated pregnancy. But for clinical purposes, a pregnancy continuing beyond 2 weeks of the expected date of delivery (>294 days) is called postmaturity or post-term pregnancy (WHO). + +ESSENTIALS OF DIAGNOSIS: + +Classification of term pregnancy (ACOG-2013) +■ Late pre term: 34°17 weeks through 36617 weeks. ■ Early term: 37°17 weeks through 38617 weeks. +■ Full term: 39°17 weeks through 40617 weeks. +■ Late term: 41°17 weeks through 41617 weeks. ■ Post-term: 42°17 weeks and beyond. +Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death il + +INCIDENCE: The incidence of pregnancies continuing beyond 42 completed weeks (>294 days) ranges between 4 and 10%. Incidence varies as different criteria are used for gestational age dating (clinical and sonography). +ETIOLOGY: The cause of the prolongation of pregnancy remains obscure. But certain factors are related with postmaturity. +1. Wrong dates-due to inaccurate LMP (most common). +2. Biological variability (hereditary) may be seen in the family. +3. Maternal factors: Primiparity, previous prolonged pregnancy, sedentary habit, elderly multiparae. +4. Fetal factors: Congenital anomalies: Anencephaly ➔ abnormal fetal HPA axis and adrenal hypoplasia ➔ diminished fetal cortisol response. +5. Placental factors: Sulfatase deficiency➔ low estriol. +6. Genetic: Mother who herself was post-term has the high risk for post-term pregnancy. +I DIAGNOSIS +It is indeed difficult to diagnose postmaturity when the case is first seen beyond the expected date. The important dates to determine fetal gestational age are: (1) Date of LMP; (2) Timing of intercourse; (3) Early pregnancy ultrasound dating and ( 4) Date of embrotransfer. Every possible effort should be made with available resources to diagnose at least the maturity of the fetus, if not the postmaturity. The following are the useful clinical guides: + +1. Menstrual history: If the patient is sure about her date with previous history of regular cycles, it is a fairly reliable diagnostic aid in the calculation of the period of gestation. But in cases of mistaken LMP or pregnancy occurring during lactational amenorrhea, the previous well-documented antenatal records of first visit in first trimester, if available, are useful guides. +2. The accuracy of gestational age measured by CRL in the first trimester based on LMP is superior to LMP alone. +3. The suggested clinical findings when a pregnancy overruns the expected date by 2 weeks are: +♦ Weight record: Regular periodic weight checking reveals stationary or even falling weight. +♦ Girth of the abdomen: It diminishes gradually because of diminishing liquor. +♦ Obstetric palpation: As the liquor amnii diminishes, the uterus feels 'full of fetus' -a feature usually associated with postmaturity. +♦ Internal examination: While a ripe cervix is usually suggestive of fetal maturity, to find an unripe cervix does not exclude maturity. +INVESTIGATIONS: Aims are: • To confirm the fetal maturity o To detect placental insuficiency. +♦ Sonography: Estimation of gestational age by early (first trimester) ultrasound is more accurate than by LMP. This is mainly due to poor recall of LMP by most patients and secondly LMP is not a good predictor of ovulation. Physiological variations in the duration of the follicular phase result in overestimation of true gestational age (Flowchart 22.4). + + + + +The important dates to determine fetal gestational age are: • Date of LMP. +• Early ultrasound dating. • CRL in first trimester is +(Tlost accurate(± 5 days) to calculate EDD. +• He when CRL >84 mm. • Timing of intercourse. +• Date of embryo transfer: + + + +1st trimester + +• CRL (variation: ± 5 days). II is more accurate +compared to use of LMP alone. +• Date of embryo transfer. + +Flowchart 22.4: Assessment of fetal maturity. +DETERMINATION OF FETAL MATURITY + + +Clinical Investigations +■ LMP. +■ Auscultation of FHR (17-20 weeks). ■ Quickening. +■ Fundal height. +■ Feel of the head. Fetal surveillance for +Sonography +■ Amount of liquor. postdated pregnancy +■ Cervical condition. +1. Daily fetal movement counting­ decreased DFMCR warrants immediate BPP evaluation. +2. Nonstress test. +2nd trimester +3rd trimester +Amniotic fluid +volume +(diminished +3. Amniotic fluid volume. assessment twice a week +• HC +• BPD +• BPD • HC amniotic 4. Biophysical Profile (BPP) twice • FL •AC fluid index) 5. Big (>3.5 kg) or compromised +a week. +(variation: +± 7-10 days) +• FL +(variation: +± 2-3 weeks) +fetus needs CD. +6. Pregnancy >41 weeks: induction of labor with close fetal monitoring. + +• CRL Crown-Rump Leng'th • BPO : Biparietal Diameter +• AC Abdominal Circumference • ;tC : Head Circ1.1mference • FL Femur length +' +Chapter 22: Prete rm Labor and Birth, Preterrn Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death + + +♦ Amniocentesis: The biochemical and cytological parameters are helpful. This is an invasive method and has been mostly replaced by sonography. It is rarely needed. +Assessment of fetal wellbeing is done by twice weekly nonstress test, biophysical profile and ultrasonographic estimation of amniotic fluid volume. Oligohydramnios has been associated with abnormal fetal CTG, umbilical cord compression and meconiumstained liquor. Modified biophysical profile (NST and amniotic fluid volume) is commonly done. Amniotic fluid pocket <2 cm and AFI :;5 cm indicates induction of labor or delivery. Doppler velocimetry study of umbilical and middle cerebral arteries waveforms are informative. Absence of umbilical artery end-diastolic velocity indicates fetal jeopardy. + +CLINICAL CONCEPT: The following criteria have been used to establish the diagnosis of postmaturity retro­ spectively, i.e., after the birth of the baby. +• Baby-postmaturity syndrome: (1) Baby looks thin and old. The characteristic feature are: wrinkled skin, palms and the soles, wasting of muscles, less subcutaneous fat, post mature neonates are not growth restricted but they look alike. There is absence of vernix caseosa. Body and the cord are stained with greenish yellow color. Head is hard without much evidence of molding. Nails are protruding beyond the nail beds; (2) Weight often more than 3 kg and length is about 54 cm. Both are variable and even an IUGR baby may be born. +• Liquor amnii: Scanty and may be stained with meconium. +• Placenta: There is evidence of aging of the placenta manifested by excessive infarction, apoptosis and calcification. +• Cord: There is diminished quantity of Wharton's jelly which may precipitate cord compression. +COMPLICATIONS OF POST-TERM PREGNANCY: There is risk of placental insufficiency due to placental aging. This is manifested by placental calcification and infarction. Associated complications like hypertension and diabetes aggravates the pathology. It is noteworthy that the risk of stillbirth at 37 week is 1 in 1000 increasing to 3 in 1000 at 42 weeks. +FETAL: During pregnancy-There is diminished placental function, oligohydramnios and meconium stained liquor. These lead to fetal hypoxia, fetal distress and IUFD. +During labor-(I) Fetal hypoxia and acidosis; (2) Labor dysfunction; (3) Meconium aspiration; (4) Risks of cord compression due to oligohydramnios; (5) Shoulder dystocia; ( 6) Increased incidence of birth trauma due to big size baby and non-molding of head due to hardening + + +of skull bones and (7) Increased incidence of operative delivery. The main clinical significance of postterm pregnancy is dysmaturity or macrosomia. +Following birth-(1) Chemical pneumonitis, atelectasis and pulmonary hypertension are due to meconium aspiration; (2) Hypoxia (low Apgar scores) and respiratory failure; (3) Hypoglycemia and polycythemia; ( 4) Increased NICU admissions; (5) Increased neonatal convulsions due to Hypoxic Ischemic Encephalopathy (HIE); (6) Birth injuries. +Perinatal morbidity and mortality is calculated in terms of stillbirth. The risk of stillbirth is increased by about three-fold from 37 (0.4 per 1,000) to 43 weeks (11.5 per 1,000). +MATERNAL: Dysfunctional labor, prolonged labor, fetopelvic disproportion, birth injury (shoulder dystocia), oligohydramnios and cord compression effect. All these lead to increased perinatal mortality and morbidity. There is increas_ed morbidity, related to hazards of induction of labor, operative vaginal or cesarean delivery. Postmaturity per se does not put the mother at risk. + +I MANAGEMENT + +Prevention: The common cause is error in pregnancy dating. It can be reduced by-first trimester ultrasound to confirm the EDD. +Before formulating the management, one should be certain about the maturity of the fetus as previously described. Increased antenatal fetal surveillance is maintained. Perinatal morbidity and mortality are increased when pregnancy continues beyond 41 weeks. Induction of labor may be considered at or beyond 41 weeks. Timely delivery reduces the risk of stillbirth. Increased fetal surveillance (twice weekly) is maintained using NST, BPP when conservative management is done. For the formulation of management, the cases are grouped into (Flowchart 22.5): +♦ Uncomplicated ♦ Complicated + +UNCOMPLICATED GROUP: +Measures to assess the fetal risk of post-dated pregnancy: 11 Daily Fetal Movement Counting (DFMCR). +mi Nonstress Tests (NST). +11 USG measurement of amniotic fluid volume (twice a week). Oligohydramnios increases perinatal morbidity and mortality. +11 Biophysical Profile (BPP)-twice a week. +11 Induction and delivery is to be done with any evidence of fetal compromise. +♦ Selective induction: In this regime, the pregnancy may be allowed to continue till spontaneous onset of labor. Fetal surveillance is continued with modified biophysical profile twice a week. +Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death la. Flowchart 22.5: Scheme for the management of postmaturity. +I Fetal maturity ensured I +Fetal surveillance: • Nonstress test. +• Amniotic fluid volume estimation. • Biophysical profile. +• Doppler velocimetry study. + +I Uncomplicated I ■ Macrosomia +■ Hypertension +Complicated: +!Induction (7-10 days) ■ Fetal compromise +l +l +l +l +■ Late term or post-term +Inclination towards CD Cervix -ripe Cervix-unripe Cervix-favorable Cervix-unfavorable +i +l +. i +Stripping Vaginal ARM Cesarean Delivery (CD) +of the +l +I + +! +administration +membranes of PGE, gel (electronic fetal monitoring) +(6 h urly) +; +ARM Cervix-ripe ! l +iquo +L r-me +l conium +Liquor-clear +stained +ARM Oxytocin augmentation (if required) +I +! +. * ' l Expected vaginal delivery Liquor-clear Liquor-meconium stained +■ Amnioinfusion. +Oxytocin augmentation ■ Electronic fetal monitoring. (if required) +! +Abnormal CTG trace +Expected vaginal Scalp blood pH estimation +delivery (where facilities available) Estimation of Fetal Acidosis +! +pH: 7.25: Normal; +7.21-7.24: Borderline; +Nonreassuring fetal status Satisfactory fetal behavior +:,7.20: +Abnormal +(fetal acidosis) and progress of labor +I +I +! +Cesarean delivery Expected vaginal delivery CD = Cesarean Delivery + + + ++ Routine induction: The expectant attitude is extended for 7-10 days past the expected date and thereafter labor is induced. +• Induction: Induction of labor is mostly considered beyond 41 weeks of gestation. It reduces the rate of cesarean delivery and perinatal mortality. If the cervix is favorable (ripe), induction is to be done by stripping of the membranes or by low rupture of the membranes. +If the liquor is found clear, oxytocin infusion is added if +required. Careful fetal monitoring is mandatory. If the cervix is unripe (Bishop score <6) it is made favorable +by vaginal administration of PGE2 gel. This is followed +by low rupture of the membranes. Oxytocin infusion is added when required. + + +COMPLICATED GROUP: (Associated complicating factors) +• Elective cesarean section is advisable when postma­ turity is associated with high-risk factors like: elderly primigravidae, pre-eclampsia, Rh-incompatibility, fetal compromise or oligohydramnios. +CARE DURING LABOR: Whether spontaneous or induced, the labor may be prolonged because of a big baby and poor molding of the head. More analgesia is required for pain relief. Possibility of shoulder dystocia is to be kept in mind. Careful fetal monitoring with electronic fetal monitoring is to be done. If fetal distress appears, prompt delive1y either by cesarean section or by forceps/ventouse is to be done. +!I Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death + + + +► Any pregnancy continuing beyond 2 weeks (>294 days) of the expected date of delivery is called post-term pregnancy. +► Expected Date of Delivery (EDD) is best assessed by LMP-based ultrasonography in the first trimester (CRL measurement) rather than LMP alone. +► Late term and post-term pregnancies have got increased risk of perinatal morbidity and mortality, macrosomia, oligohydramnios, meconium stained liquor and maternal morbidity. +► Postmature pregnancy needs careful antenatal fetal surveillance. Perinatal mortality and morbidity increase as gestational age advances beyond the EDD. +► Fetal surveillance should include fetal kick counts, NST, amniotic fluid volume estimation, modified BPP at least twice a week. It is started at 41 weeks. +► Induction of labor is commonly done after 41 weeks. +> Either stripping of the membranes or PGE2 can be used for induction of labor in post-term pregnancy. + + + +INTRAUTERINE FETAL DEATH (IUFD) + +Literally, Intrauterine Fetal Death (IUFD) embraces all fetal deaths (after 22 weeks) weighing 500 g or more occurring both during pregnancy (antepartum death) or during labor (intrapartum). But death of a fetus weighing less than 500 g (before 22 weeks) has got a distinct etiology and is usually termed as abortion. Death during labor ends in delivery of a fresh stillborn and does not pose a problem for management. Thus for practical purpose, antepartum death occurring beyond the period of viability is termed as intrauterine death. It usually results in the delivery of a macerated fetus. There is a gradual decline in the incidence of IUD. Overall incidence is 6 per 1000 pregnancies ( 39.4°(). +• +Antiphospholipid Syndromes (APS) presence of Lupus Anti-coagulant (LA), Anticardiolipin Antibodies (ACA) ➔ decidual vasculopathy with fibrinoid necrosis, placental vascular atherosis and intervillous thrombosis➔ IUFD. +• +Thrombophilias: Factor V Leiden, protein C, protein . +II 5-deficiency, hyperhomocysteinemia. Mechanism of IUFD is similar to APS. +ll Post-term pregnancy■ Advanced maternal age >35 years . +• +B Systemic lupus erythematosus. +■ Thyroid dysfunction■ Obesity (BMI 2S). +■ Abnormal labor (prolonged or obstructed labor, ruptured uterus). + +8. Fetal (25-40%) + +II Chromosomal abnormalities. ■ Major structural anomalies. +B Infections (virus, bacteria, chorioamnionitis). ■ Rh-incompatibility. +ii Non-immune hydrops. B Growth restriction. +C. Placental (20-35%) +■ Antepartum hemorrhage: Both placenta previa and abruptio placentae can cause fetal death by producing acute placental insufficiency. +B Cord accident (prolapse, true knot, cord round the neck). II Twin to Twin Transfusion Syndrome (TTTS). +II Placental insufficiency. + +D. Iatrogenic +■ External cephalic version. +II Drugs (quinine beyond therapeutic doses. + +E. Idiopathic (25-35%) +■ Cause remains unknown even with thorough clinical examination and investigations. +Chapter 22: Preterm Labor and Birth, Prete rm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death + +I DIAGNOSIS + +Repeated examinations are often required to confirm the diagnosis. +SYMPTOMS: Absence of fetal movements which were previously noted by the patient. +SIGNS: Retrogression of the positive breast changes that occur during pregnancy is evident after variable period following death of the fetus. +Per abdomen +♦ Gradual retrogression of the fundal height and it becomes smaller than the period of gestation. +♦ Uterine tone is diminished and the uterus feels flaccid. Braxton-Hicks contraction is not easily felt. +♦ Fetal movements are not felt during palpation. +♦ Fetal heart sound is absent. Use of hand held Doppler is better than the stethoscope. +♦ Cardiotocography (CTG): Flat trace. +♦ Egg-shell crackling feel of the fetal head is a late feature. +INVESTIGATIONS FOR CONFIRMATION OF DIAGNOSIS +• Sonography: Earliest diagnosis is possible with sonography. The evidences are: (a) Lack of all fetal motions (including cardiac) during a 10-minute period of careful observation with a real-time sonography is a strong presumptive evidence of fetal death and (b) Oligohydramnios and collapsed cranial bones are the evidents (Fig. 22.1). +• Straight X-ray abdomen: Not done at present. The following features are found (hyperflexion of the spine, crowding of the ribs and gas show in the major vessels) either singly or in combination. + +BLOOD: To estimate the blood fibrinogen level and partial thromboplastin time periodically, when the fetus is retained for more than 2 weeks. + +RECOMMENDED EVALUATION FOR A STILLBIRTH + +Hematological examination: +Maternal laboratory test after stillbirth A. All mothers of stillborn infants: +• Complete blood count. +• Kleihauer-Betke or other test for fetal cells in the maternal circulation. +• Human parvovirus-B 19, IgG, IgM antibodies. • Lupus anticoagulant. • Anticardiolipin antibody. +• TSH • Syphilis • Glucose screening (oral GTT, HbA,c) B. Selected mothers of stillborn infants: +• Parental karyotypes • Indirect Coombs test +• Thrombophilia (screening) • Homocysteine (fasting) C. Infant-for malformations (skeletal X-ray). +D. Umbilical cord for entanglement, number of vessels. + + + + + + + + + + + + + + + + +Fig. 22.1: Double turns of tight cord round the neck. + +• Whole body photograph, imaging with MRI or radiograph (skeletal dysplasia). +• Placenta for meconium staining, malformations and the weight is to be recorded. Histology in selected cases. +E. Autopsy and chromosome studies are done for fetuses with anomalies and dysmorphic features. It is also done if there is history of recurrent stillbirths or if either parent is a carrier for balanced translocation. Fetal skin, cartilage (patella or costochondral junction), placental tissue block, blood are usually taken for aneuploidy and single gene disorder study. If fetal blood is not available. Amniotic fluid following amniocentesis can be used for cytogenic analysis. Microarry testing for genetic abnormalities to be done as it does not need live cells. +COMPLICATIONS +1. Psychological upset often becomes a problem. +2. Infection-as long as the membranes are intact, infection is unlikely but once the membranes rupture, infection, especially by gas forming organisms like Clostridium welchii may occur. The dead tissue favors their growth with disastrous consequences. +3. Blood coagulation disorders are rare-if the fetus is retained for more than 4 weeks (10-20%), there is a possibility of defibrination from 'silent' Disseminated Intravascular Coagulopathy (DIC). It is due to gradual absorption of thromboplastin, liberated from the dead placenta and decidua, into the maternal circulation. +4. During labor-uterine inertia, retained placenta and postpartum hemorrhage. + +I MANAGEMENT + +PREVENTION: The overall risk of recurrence of stillbirth varies between O and 8%. The conditions that run the risks of recurrence are: hereditary disorders, diabetes, +fJ Chapter 22: Preterm Labor and Birth, Preterm Rupture ofthe Membranes, Prolonged Pregnancy, Intrauterine Fetal Death + +hypertension, thrombophilias, placental abruption and fetal congenital malformations. While IUD cannot be totally prevented, the following guidelines may help to reduce its recurrence: +♦ Preconceptional counseling and care is essential to prevent its occurrence in the high-risk group. +♦ Prenatal diagnosis-CVS or amniocentesis in selected cases. +♦ To screen the 'at-risk mothers' during antenatal care. Careful assessment of fetal wellbeing and to +terminate pregnancy with the earliest evidences of fetal compromise. +Breaking the bad news to the mother and the family members is a difficult task.This is mainly due to the fear of being blamed for the poor outcome and for the medical/ legal problems. To listen to the patient and her family members actively and then to answer their concerns are important. It needs professional skill and communication abilities (Ch.40). +DELIVERY: Depending on gestational age, woman's physical and psychological health, she may be delivered + + +by either induction of labor or waiting for 7-10 days for spontaneous onset of labor and delivery(Flowchart 22.6). + +EXPECTANT AT TITUDE (noninterference): The patient and her relatives are likely to be upset psychologically but they should be assured of safety of noninterference. In about 80% of cases, spontaneous expulsion occurs within 7-10 days of death. Fibrinogen estimation +should be done twice weekly. + +REASONS FOR EARLY DELIVERY: (i) Reliable and early diagnosis could be made with real time ultrasonography; (ii) Prostaglandins are available for effective induction +and(iii) Complications could be avoided. + +INDICATIONS OF EARLY INTERFERENCE +■ Psychological upset of the patient- common. ■ Threat of uterine infection. +11 Tendency of prolongation of pregnancy beyond 7-10 days. +■ Falling fibrinogen level (rare). +■ Evidence ofROM, infection, bleeding. + + +Flowchart 22.6: Schemeofmanagement ofIUFD. + + +I Non-interference(7-1d0ays) +i +Refractory cases or cases where early +delivery is indicated y_chologic- --__ _ - -- + , +- +P +s +_ +- +a +l +co +m +m +on +. +• Riskof infection. +• Falling fibrinogen level. +• Retained more than 7-10days. +• Bleeding. • ROM. + + + + +Spontaneous expulsion (80%) +i +(within7-10days) + + +■Medicalinduction of labor 1 --- ! Misoprostol PGE, (vaginal) +I +■ Hospitaliz +ation I +- + + +CERVIX +FAVORAiBiLE + +Oxytocin infusion (IV) + + + + +Fails +l + +Repeatoxytocin with vaginal +prostaglandin supplementation + + +CERVIX NOT +FAVORABLE + +■ Combination of mifepristone (oral) +misoprostol (PGE,) (vaginal). +■PGE,vaginal 4hourly. +■PGE,gel lntracervical or PGE;tab vaginal/oral may have to be +repeated after 6-8hours. + +Fails +l + +Supplementation with +oxytocin infusion + + + +Delivery +! +• Evaluation for stillbirth +• Bereavement management +• Contraceptive advic if required +e +Chapter 22: Preterm Labor and Birth, Preterm Rupture of the Membranes, Prolonged Pregnancy, Intrauterine Fetal Death II + +Methods of delivery: The delivery should always be done by medical induction: +(a) A combination of mifepristone and a prostaglandin preparation is recommended as the first­ line choice for induction oflabor. A single dose (200 mg) +of oral mifepristone and misoprostol (PGE1) intravaginal 25 µg 4 hourly are safe, effective and of low cost. Induction +delivery interval was 8 hours. Mifepristone (600 mg daily for 2 days) alone can be used for induction also. +(b) Misoprostol (PGE1) 25-50 µg either vaginally or +orally is also found effective. Vaginal route use is more effective compared to oral route. Misoprostol may be repeated at every 4 hours. Misoprostol is preferred to oxytocin or PGE2 as it is safe, effective and cheap. +(c) Prostaglandins (PGE2): Vaginal administration +of prostaglandin (PGE2) gel or lipid pessary high in the posterior fornix is very effective for induction where the +cervix is unfavorable. This may have to be repeated after 6-8 hours. The procedure may be supplemented with oxytocin infusion. +(d) Oxytocin infusion: This is widely practised and effective in case where the cervix is favorable. To begin with, 5-10 units of oxytocin in 500 mL of Ringer's solution is administered through intravenous infusion drip. In case of failure, an escalating dose of oxytocin is used on the next day. To start with, a drip is set up 20 units of oxytocin in 500 mL of Ringer's solution and run 30 drops per minute (80 mU/minute). Oxytocin infusion may be used as a supplementary therapy when vaginal prostaglandins are used. One should exclude the possibility of secondary abdominal pregnancy, hemolytic SLE and autoimmune hemolysis if repeated attempts fail to start labor. +Induction of labor in women with previous LSCS: +PGE2 gel may be used safely in women with previous +one LSCS, but for women with previous two LSCS, risk (rupture uterus) is slightly more (2-3 times). The success rate of VBAC with 1 previous less and IUD is approximately 87% but rupture rate also increase at 2.4%. +Place of cesarean section in a case with IUD is limited. Previous cesarean section (two or more), major degree placenta previa and transverse lie are the rare conditions. + + +Process for storing and sending the placenta: Store the placenta at 4°C in a tightly sealed container; the placenta must not be frozen; formalin fixation is indicated. +Postpartum suppression of lactation: Cabergoline (dopamine agonist), single dose (1 mg), is found effective. It should not be given to women with pre-eclampsia or hypertension. +Bereavement management and puerperium: The medical team and the nursing staff should provide all the support and empathy for the bereaved couple. The couple should be explained in simple terms about the possible cause of fetal death. A psychologist or a counselor may see them to support. Recovery in postpartum ward is better avoided. For psychological uplift the woman needs counseling as the risk of depression is high. The couple is seen in the postpartum clinic after 6 weeks. The investigation reports are reviewed and counseling for future pregnancy is done. Advice on contraception is given. + +Indications for Placental Histological Examination. +■ Stillbirth (antepartum or intrapartum). 11 Late miscarriage. +■ Severe fetal distress requiring admission to NICU. 11 Prematurity. +■ Fetal growth restriction (birth weight <3rd centile). ■ FetaI hyd rops. +■ Maternal pyrexia (>38°C). + +Management of pregnancy after a still birth: ♦ Evolution of reports of prior still birth. +♦ To correct the abnormalities as detected (thyroid dysfunction, thrombophilia). +♦ Support and reassurance. ♦ Prenatal diagnosis. +♦ Evolution of pregnancy with frequent visit for: • Dating pregnancy (first trimester). +• Anatomic survey (second trimester). +• Growth profile. • Fetal surveillance. • Delivery at 38 weeks. +Prognosis for future pregnancy depends on the underlying cause. For woman without any underlying cause, risk of recurrence is about 1-2%. + + + + + +► Causes of IUFD may be-(a) Maternal (5-10%), (b) Fetal (24-40%), (c) Placental (20-35%), (d) Iatrogenic, and (e) Unexplained (2S-30%). +► Earliest diagnosis of IUFD is possible with USG. Absence of all fetal movements (including cardiac motion, using real time sonography) is a strong presumptive evidence of IUFD. +► Maternal complications of IUFD are: During pregnancy: (a) Psychological upset, (b) Infection, (c) DIC (rare), and (d) During labor: Uterine inertia, PPH. +Management of IUFD includes: +► Expectant: (a) Waiting for spontaneous onset oflabor (7-1 0 days) and delivery (80%), (b) Medical method of induction using mifepristone and prostaglandin (PGE/PGE) or using prostaglandin alone or with oxytocin IV (infusion). + + + +Complicated Pregnancy + + + + + + + + + +❖ Pregnancy with Prior Cesarean Delivery (CD) +► Integrity of the Scar +► Evidences of Scar Rupture (or Scar Dehiscence) during Labor +► Management of a Pregnancy with Prior CD +► Vaginal Birth after Previous (CD) + + +❖ Red Cell Alloimmunization +► Fetal Affection by the Rh Antibody ❖ Manifestations of Hemolytic Disease +of the Fetus and Newborn (HDFN) ► Prevention of Rh-D +Alloimmunization +❖ Antenatal Investigation Protocol of Rh-negative Mothers +❖ Plan of Delivery + +❖ Exchange Transfusion in the Newborn +► Prognosis +❖ Elderly Primigravida ❖ Grand Multipara +❖ Bad Obstetric History (BOH) +► Investigations and Management ❖ Obesity in Pregnancy + + + + +PREGNANCY WITH PRIOR CESAREAN DELIVERY +Rates of cesarean delivery have risen worldwide. Most of the countries have high CD rates. WHO has proposed the incidence between 10% and 15% as the optimum. The common reasons are: dystocia (most common), maternal request, failed induction of labor, fetal distress and others . +Presently these cases are considered for Trial of Labor After Cesarean (TO LAC). Instead of doing repeat cesarean delivery for all, TO LAC is encouraged for women with prior low transverse cesarean deliveries. +EFFECTS ON PREGNANCY AND LABOR: Cesarean delive1y has become relatively safe. The potential benefits are: reduction of traumatic vaginal injuries and possible pro­ tective effects on pelvic floor dysfunction. However, the following risks are likely to increase: (1) Hospital stay and recove1y time; (2) Maternal morbidity; (3) Neonatal respiratory morbidity; (4) Preterm birth; (5) Operative inter­ ventions; (6) Cesarean scar ectopic pregnancy; (7) Need of blood transfusion; (8) Operative interference and incidental organ injmy and associated morbidity; (9) Placenta previa in next pregnancy; (lO)Adherent placenta [Placenta Accreta Spectrum (PAS)) (Ch. 28) (11) Postpaitum hemorrhage; (12) Peripa1tum hysterectomy; and (13) Need of repeat cesarean delive1y in future deliveries. +EFFECTS ON THE SCAR: There is increased risk of scar rupture. Whereas the lower segment scar usually ruptures during labor, the classical or hysterotomy scar ruptures during late pregnancy and labor. The incidence of scar rupture is about 0.2-1.5% in the former and about 2-3% in the latter. +HEALING OF THE UTERINE WOUND: The uterine wound is healed by muscles and connective tissues, if the + +tissues are perfectly apposed. The factors for impaired healing of the uterine wound are: (I) Imperfect apposition of the cut margins; (2) presence of sepsis; (3) presence of hematoma in the wound; (4) poor general condition and (5) excessive stretching of the lower segment leading to diminished vascularity of the muscles. + +■ SOUND SCAR: LOWER SEGMENT OR CLASSICAL? + +The test of a sound scar is provided by its ability to withstand the strains of a future pregnancy and labor. In identical conditions, the lower segment scar is more sound than the classical scar because of the following factors (Table 23.1). + +INTEGRITY OF THE SCAR Classical or Hysterotomy Scar +As stated above, the scar following classical section or hysterotomy is weak. The scar is more likely to give way during late pregnancy and labor with increased risks to the mother and the fetus. As such, these cases should be delivered by elective cesarean section. + +Lower Segment Transverse Scar +It usually heals better compared to the classical scar. During the course of labor the integrity of the scar needs to be assessed. It is indeed difficult to predict whether the particular scar is sound or not. High index of suspicion is essential. Scar dehiscence means asymptomatic separation or thinning of the scar without involving the peritoneal coat and without any hemorrhage. Factors to consider for assessing the scar integrity: +Chapter 23: Complicated Pregnancy + +rT b1_;ii i i. ifferen es_b;,;,;teen low i j gment ;· ar a d ;, ;;1 1' r hysterotomy scar, 'ii -,, ::,:,· +' +' +,' +Lower segment scar Classical or hysterotomy scar + +Apposition + + + +State of uterus during healing +Stretching effect + + +Placental implantation in future pregnancy +Net effect +(p.548) + + +Thin cut margins facilitate perfect apposition without leaving any pocket, + + +This part of the uterus remains inert while healing process is going on, +The scar is made to stretch during future pregnancy and normal labor more along the line of scar. +Chance of weakening the scar by placental attachment is unlikely, + +(a) Scar is sound; (b) rupture may occur only during labor (0.2-1.5%). +Following rupture: Maternal death-less; + +Difficult to appose the thick muscle layer, Pockets are formed that contain blood, which is subsequently replaced by fibrous tissue, Formation of gutter on the inner surface is likely, as the decidua is more often than not excluded during suture (Figs. 23.lA and B), +This part of the uterus contracts and retracts so that the sutures become loose leading to imperfect healing, +The stretch is at right angles to the scar. + + +The placenta is more likely to implant on the scar and weakens it by trophoblastic penetration or herniation of the amniotic sac through the gutter (Figs. 23.1A and B), +(a) Scar is weak; (b) rupture may occur both during pregnancy and labor (4-9%), +Following rupture: Maternal death-5%; Perinatal death-6 in 8. + + + +Perinatal death-1 in 8. + + +Scar tissue +·::::;.J,; +❖ +, +: + +r +,, +... +. +.. +o +.J Decid a Amn1 t1c memb a +u r ne + +, ... •!❖!'f!t +:❖!-'. + + +Q) +13 :, +/) + + + + +Figs. 23.1A and B: Herniation of the amniotic sac through the gutter of classical scar. + +m Previous operative notes: +♦ Indication of cesarean section: (a) Placenta previa makes a scar weak due to: (i) imperfect apposition of tissues and (ii) thrombosis of the placental sinuses. (b) Following prolonged labor-increased chance of sepsis. +♦ Uterine closure technique (single or double layer). +♦ Technical difficulty in the primary operation leading to lateral extension or tears to involve the branches of uterine vessels or colporrhexis. +Pregnancy (present and past): (1) Inter delivery internal :,10 months is associated with higher risk of scar rupture. This is due to the less time for sound wound healing; (2) Pregnancy complication such as twins or polyhydramnios big baby, puts excess stretching effect on the scar; (3) Placenta previa in the present pregnancy weakens the scar and ( 4) More number of prior CD. +■ Evaluation of uterine scar with ultrasonography: Assessment of thickness of the lower uterine segment is done. However, no ideal thickness value has been observed. Thickness 4 mm is good (RCOG). Risks of + + + +rupture is high (9%) when the full thickness was less than2,3 mm. +■ Hysterography in interconceptional period: Hysterog­ raphy, 6 months after the operation, may reveal defect on the scar (wedge depression of more than 5 mm). + +EVIDENCES OF SCAR RUPTURE (OR SCAR DEHISCENCE) DURING LABOR +I + +There is no single clinical feature that can indicate uterine scar dehiscence or rupture (Fig. 29.5, p. 403). Presence of any of the following features should be taken into consideration (RCOG-2007): +■ Abnormal CTG-(abnormal FHR, bradycardia, variable and late decelerations)-most consistent finding (55-87%); 11 suprapubic pain if severe and especially persisting in between contractions; 11 shoulder tip pain or chest pain or sudden onset of shortness of breath; • acute onset of scar tenderness; ■ abnormal vaginal bleeding or hematuria; 11 cessation of uterine contractions that were previously adequate; 11 maternal tachycardia, hypotension or shock and II loss of station of the presenting part on vaginal examination. Of note, most ruptures are seen in labor at 4-5 cm of cervical dialatation. Early diagnosis of scar dehiscence or rupture needs prompt laparotomy and resuscitation to reduce mortality and morbidity in mother and infant. +PROGNOSIS: Previous history of classical cesarean section or hysterotomy makes the woman vulnerable to unpredictable rupture of the uterus. This may occur either late during pregnancy or during labor and when it does, the maternal mortality is to the extent of 5-30% and the perinatal mortality to 50-75%. Evidence is insufficient with regard to inverted T or J or low vertical incisions. Even a pregnancy with previous myomectomy (Lap/cavity breached) is to be considered as undergoing VBAC. +ED Chapter 23: Complicated Pregnancy + + +■ Prior nonrecurring indication like fetal distress (73%}. ■ Woman having prior vaginal delivery (87% success}. +a Fetal birth weight (estimated}-higher the fetal weight; lower is the success. +11 Prior vaginal delivery (87% success}. +11 Spontaneous onset of labor in the present pregnancy-higher success (80%}. +■ Women with prior successful VBAC (85-90%). +11 Cervical dilatation (on admission} >4 cm-higher (86%} the success. +■ Women with prior LSCS due to breech presentation-higher success (89%}. +11 Women who are obese and elderly-lower success. +11 Overall success rate is: 72-75% + + + +treatment; (2) To prevent inconvenience of the patient, if the labor pain starts earlier, especially where the communication to the hospital is a problem. ++ Cases with previous history of classical cesarean section or hysterotomy should be admitted at 36th week. The chance of such type of scar rupture is more during the last few weeks of pregnancy. ++ All cases suggestive of weak lower segment scar (mentioned earlier) are also to be admitted at 36th week. +Emergency admission: (1) Whenever labor starts; (2) any symptom suggestive of scar rupture such as acute pain in the abdomen, bleeding per vaginam and tenderness over +the scar and (3) associated obstetrical complications. + + + + +The risk of lower segment scar-rupture is low (0.2-1.5%) and even if it does occur, maternal death is much less and the perinatal mortality is about one in eight. +The prognosis is dependent on scrupulous selection of cases as regards to the method of delivery (Box 23.1). Placed in ideal circumstances, the prognosis of the Vaginal Birth After Cesarean (VBAC) section and that of repeat cesarean section group is almost identical so far as maternal and perinatal deaths are concerned. However, in circumstances where meticulous observation in labor is not possible, liberal repeat section is likely to offer better prognosis. + +MANAGEMENT OF A PREGNANCY WITH PRIOR CESAREAN DELIVERY + +The patient should be considered as 'high-risk' and as such regular antenatal checkup is mandatory. At each visit, enquiry is to be made about the pain or tenderness over the scar or any vaginal bleeding. +HOSPITALIZATION: Elective ++ Cases with previous history of lower segment operation should be admitted at 38th week because of: (1) To assess the case and to formulate the line of + +FORMULATION OF THE METHOD OF DELIVERY-VAGINAL OR ABDOMINAL? +Previous classical cesarean section or hysterotomy: The choice is elective, repeat section as soon as pregnancy reaches 38 weeks. +Previous lower segment operation: The dictum which is widely accepted in the formulation of line of treatment is 'mandatory hospital delivery and individualization of the case'. Overall assessment of the case has to be made with due consideration to: +♦ Indication of primary cesarean section: recurrent or nonrecurrent. +♦ Integrity of the scar as evaluated clinically and with sonography. +♦ Associated obstetric complications, if any. +♦ Number of previous cesarean section or any previous vaginal deliveries. +♦ Estimated weight of the baby. + +VAGINAL BIRTH AFTER PREVIOUS CESAREAN (VBAC) DELIVERY + +Trial of Labor After Cesarean (TOLAC) is successful in 70-80% of cases (RCOG-2007). Benefits of successful VBAC are many (Table 23.2). Maternal and perinatal + + + -,. -' 2,3:2: To A : J . fj a µth;1, s8 i:J:; - :1?:r:f: ::t ; {; :}·1:! ,:·, "-{ ::, : :, < ' i :r:;Z} ,; :; ,,, .if' \: ;\ ' 1 , ;} :, ; /; \l:; Risks of Elective Repeat Cesarean +i + +: +1 +Benefits of VBAC Section (ERCS) Complications of unsuccessful TOLAC + +m 72-75% chances of success. +■ 0.5% chance of rupture uterus. Chance of future vaginal births. +• +• +• +• +Decreased maternal morbidity (infection and others}. Reduced length of hospital stay. +Decreased need for blood transfusion. +II Decreased risk of abnormal placentation and need for successive cesarean delivery in next pregnancy. +■ Low risk of placenta accreta spectrum. II Infant: RDS (2-3%). + + +II Increased maternal morbidity. +II Increased length of hospital stay. II Increased risk of hemorrhage +and need for blood transfusion. Increased risk of abnormal placen-tation (placenta previa/accreta}. Hemorrhage and successive cesarean delivery in the next +• +• +pregnancy. +II Infant: Risk of RDS (4-5%). + +• Maternal: +Uterine wound dehiscence. +• +• +• +Uterine rupture (0.5-1 %} . Increased blood transfusion . +II Increased risks of hysterectomy due to uterine rupture. +• +Infections, increased maternal morbidity. Perinatal: Low Apgar score, admission to NICU, hypoxic ischemic encephalopathy +(HIE},• neonatal death,• rarely stillbirth. + +° + + + +♦ More the number (>2) of prior cesarean delivery. ♦ lnterpregnancy interval <24 months. +♦ Induced labor, especially with misoprostol. +♦ Augmentation of labor with high dose oxytocin. +♦ Women having single layer uterine closure in prior cesarean delivery compared to double layer closure. + +· Box 23.3: Selection criteria of cases for TOLAC (ACOG). +■ One (RCOG) or two (ACOG) previous lower segment transverse scar. +■ Nonrecurring indication for prior cesarean section. 11 Pelvis adequate for the fetus. +■ Continued labor monitoring possible. +■ Availability of resources (anesthesia, blood transfusion and theater) for emergency cesarean section within 30 minutes of decision. +■ Informed consent of the woman. ■ Success ofTOLAC-72-75%. + +mortality rates following Trial of Labor After Cesarean (TOLAC) are the same when compared for elective repeat cesarean births. +In suspected maturity, it is better to wait for the pains to start or membranes to rupture, whichever occurs earlier and then to do cesarean section. +Vaginal delivery: If the previous section was done for some nonrecurrent indication and the uterine + +Chapter 23: Complicated Pregnancy fl 'e8 0 23.4: C:0ntr ii'di ;tio s io'r TOLAC (indications for cesarean +delivery)., •. , · ,.. '. /· . .. ., · . , , . . • •, ·.. : -"- · • ·.: +. +■ Previous classical or invertedT-shaped uterine incision. +■ Previous more than two lower segment cesarean section. " Pelvis contracted or suspected CPD. +■ Presence of complications in pregnancy: Obstetric (pre­ eclampsia, malpresentation, placenta previa) or medical. +■ Resources limited for emergency cesarean delivery or patient refusal forTOLAC. +■ History of prior uterine rupture. +■ Cases admitted as emergency (Box 23.5). + + +scar is sound (Table 23.1), a vaginal delivery is to be planned. Women need to be counseled as with the current recommendation (ACOG-2004) by the team of obstetrician, anesthetist and the neonatologist. +Trial of labor (TO LAC) to attempt VBAC: The woman should be discussed the benefits and the risks. Proper case selection (Boxes 23.2 to 23.4) and continued monitoring are needed. Facilities for immediate cesarean delivery (Category I: <30 minutes) should be available when necessity arises (RCOG-2007). +MANAGEMENT OF TRIAL OF LABOR AFTER CESAREAN (TOLAC) FOR VAGINALBIRTH (Flowchart 23.1) +♦ Spontaneous onset oflabor is desired. +♦ Induction of labor with prostaglandins (PGs) increases the risk of uterine scar rupture. + + +Flowchart 23.1: Scheme of management of pregnancy with prior cesarean delivery. + +s x 23:s: Emergency d ission., MANAGEMENT +■ Symptoms suggestive of scar Regular antenatal supervision rupture (Table 23.3). Hospitalization +m Unusual abdominal pain. +■ Bleeding per vaginam. +■ Unusual tenderness Lower segment transverse scar Classical scar or hysterotomy scar +suprapubic area. +■ Associated obstetric or cases under Box 23.4. complication (PE) Admission at 38 weeks +j • +l +l +Assessment of the cases. Admission at 36 weeks. +• Formulation of method of delivery. +- -- - - - -------- ----, Elective repeat +cesarean section (ERCS) +■ Cases admitted ■ Vaginal delivery at 38 weeks (Box 23.4). +l +as given in p. 316. +as emergency (selection criteria) +(Box 23.5). (Box 23.3). +: +Table" +i +' +. ,I ' ,, ' 'f' +of rupture., +, • •, +l Management guidelines and risk :i.:i: Type' of uterine 0in°cisions' +Emergency repeat Incision type Rupture(%) +cesarean section +■ Progress unsatisfactory Labor progress satisfactory Unscarred uterus 0.02 +l +■ Evidence of scar tenderness. Low transverse 0.5-1.0 +Prophylactic forceps or Low vertical 0.8-1.1 +Cesarean section +ventouse in 2nd stage Previous two CS 1.5 +l +Exploration of the scar after expulsion Classical orT shaped 2.5 +of the placenta (not a routine) Previous rupture uterus 5 +JD Chapter 23: Complicated Pregnancy +♦ Mechanical methods (Foley's catheterization) is safe compared to PGs. +♦ An intravenous line is commenced with Ringer's solution. ♦ Blood sample is sent for Hb%, group and cross-matching. +♦ Labor monitoring-clinically (for scar dehiscence) and electronically for fetal behavior. Careful serial clinical assessment is needed to ensure adequate cervicometric progress of labor. +♦ Analgesia-epidural is not contraindicated. It neither delays the course of labor nor delays the diagnosis of scar rupture. +♦ Oxytocin for augmentation of labor may be used selectively and judiciously. Augmentation of labor increases the risk of uterine scar rupture and the risk of cesarean section. +♦ Continuous EFM is desirable. Presence of nonre­ assuring pattern, severe variable decelerations, + + + +prolonged decelerations or bradycardia warns uter­ ine rupture. +♦ Prophylactic forceps or ventouse to cut short the second stage is used (Flowchart 23.1). +♦ Routine exploration of the uterus: Most prefer not to explore the uterine scar as a routine. It is done in selected cases only when there is continued and excessive vaginal bleeding or maternal hypotension in spite of well-contracted uterus. Others prefer to do it as a routine. Two fingers are introduced to palpate the scar internally for detection of any asymptomatic scar rupture. However, asymptomatic scar rupture or dehiscence generally heals well. +STERILIZATION: There is increasing risk after each cesarean operation. Before the third time cesarean delive1y, the woman needs to be counseled and option may be obtained for sterilization operation. + + + + +Pregnancy with History of Prior Cesarean Delivery (CD) +► Complications in pregnancy and labor are increased. Healing of uterine wound is more perfect in lower segment cesarean section compared to the classical cesarean (Table 23.1 ). Incidence of lower segment scar rupture is (0.5-1 %) less compared to classical scar (2-5%) (Table 23.1 ). +► Assessment ofintegrity of the uterine scar is done from history (types of scar, number of prior CD, Inter delivery interval, uterine closure technique (two layer closure is preferred), investigation (USG) and clinical examination. Diagnosis of scar rupture (dehiscence) during labor is mainly clinical and is difficult. +► Woman with lower segment transverse scar should preferably be admitted electively at 38 weeks and that with classical scar at 36 weeks of pregnancy. +► To formulate the method of delivery (vaginal or abdominal) each case should be assessed on individual basis (Tables 23.1 and Box 23.3). Lower segment scar rupture may occur in labor, whereas classical scar rupture may occur both in pregnancy and labor (Table 23.1). +► Use of PGs (PGE1) for cervical ripening is contraindicated. +► Management of labor is important for successful TOLAC. Otherwise risks are high. +► Incidence of placenta previa with accreta increases from 11 % to 67% from previous one to four CS respectively. +► Labor should be monitored by continuous EFM. Presence of nonreassuring fetal heart pattern, significant variable deceleration or bradycardia indicates scar rupture. +► Cases that may be considered for TO LAC are: (a) Nonrecurrent indication of previous CS, (b) lower segment transverse scar, (c) pelvis adequate, availability of resources in the hospital round the clock and (d) informed consent of the women (Box 23.3). + + + +RED CELL ALLOIMMUNIZATION (Syn: Pregnancy in a Rh-Negative Woman) +NOMENCLATURE: Landsteiner and Weiner in the year 1940, discovered specific unknown antigen in the human red cells. As it was also present in the Rhesus monkeys, the antigen was named Rh. The individual having the antigen is called Rh-positive and in whom it is not present, is called Rh-negative. +INCIDENCE: The incidence of Rh-negative in the European and American Whites, is about 15-17%; it is very much insignificant in China (1%) and almost nil in Japan. About 60% of Rh-positive men are heterozygous and 40% are homozygous at the D locus. Overall a Rh-negative woman having the chance of Rh-positive fetus is 60%, irrespective of the father's genotype. In India, the incidence is about 5-10% (South India-5%, North lndia-10%) in hospital statistics. + +GENOTYPES: All pregnant patients should have ABO-Rh group and typing and also have serum antibody testing at the first antenatal visit repeated again at 28th antenatal week. The complete genetic make-up of the Rh blood group of an individual is its genotype. +D antigen is the most potent and accounts for almost all damages (95%) due to Rh blood groups, its presence or absence denotes an individual to be Rh-positive or Rh-negative respectively. An individual carrying D on both sets of antigens (DD) is called homozygous and when carrying D only (Dd) in one set, it is called heterozygous, the former constituting 65% and the latter 35%. Heterozygous persons are always classified as Rh-positive because Dis dominant to d. The common genotypes are CDe/cde, CDe/CDe and CDe/cDE. In the discussion that follows, Rh-positive is taken to mean D-positive and Rh-negative to mean its absence. +Chapter 23: Complicated Pregnancy ED · Flowchart 23.2: Mating of Rh-positive male with Rh-negative female and the resultant possible Rh-group of the baby. + + +Father +Homozygous +Rh +ve + + +Mother +Rh-ve + + +Father +Heterozygous +Rh +ve + + +Genotype d d + +Germ cells + + + +Fetal genotype + + +Fetal Rh typing + + +Dd +I ++ve + + +Dd +I ++ve + + +Dd dd +I +I + + ++ve -ve + + + + +GRANDMOTHER THEORY: Transfer of Rh-D positive red cells from mother to Rh-negative fetus may occur at the time of delivery. Such an individual in adulthood may produce anti-D antibodies even before her first pregnancy. This mechanism is called grandmother theory because the fetus in the current pregnancy is affected by maternal antibodies that were initially provoked by his/her grandmother's red blood cells. Nearly 25% of Rh-negative babies have been found to be immunized in this way. +Genetic expression: The genetic locus for the Rh antigen complex is on the short arm of chromosome 1. Rh Ce and RhD are the two distinct genes located within the Rh locus. Depending upon the presence of D antigen on one or both the chromosomes 1, it would be heterozygous or homozygous. When the normal RhD gene sequence on both the chromosomes 1 is absent, the subject is D negative. +The father's genotype to be tested, when Rh-negative wife becomes pregnant, to find out whether he is homozygous or heterozygous. This can predict whether all the subsequent babies are likely to be incompatible and liable to be affected or not. Flowchart 23.2 gives an idea about the genetic make-up of the offsprings due to mating of Rh-positive male with a Rh-negative female. +When the genotype of the father is heterozygous, half of his genes will be Rh-negative and compatible with a Rh-negative mother; the other half being Rh-positive will be incompatible, and the children will be Rh-positive (Dd) and liable to be affected. When the father's genotype is homozygous, all his genes will be incompatible with a Rh-negative mother and as such all the children will be Rh-positive (Dd) and may be affected by hemolytic disease. +Noninvasivefetal genotype fDNA) using maternal bloodfor D, C, c, E, eandKantigenscouldbedone(Ch.12, Table12.3). This test is done in the first instance for the relevant antigen when maternal red cell antibodies are present. +Other antibodies to the reel cell antigens: Lewis, I, M, and P can be detected during antibody screening. These antibodies are typically of IgM class. They do not cause HDFN as they do not cross the placenta. However, mainly three antibodies anti-RhD, anti-Rhc and anti-Kell (K-1) cause fetal hemolysis. Intrauterine transfusion may be needed. Dufy (Fya) and Kidd (JK•, JKb) antigen cause mild HDFN. + + +Alloimmunization is defined as a production of immune antibodies in an individual in response to foreign red cell antigen derived from another individual of the same species provided the first one lacks the antigen. It occurs in two stages: (1) sensitization and (2) immunization. This is in contrast to ABO groups, where there are naturally occurring isoimmune anti-A and anti-B antibodies. + +CAUSES OF ALLOIMMUNIZATION DUE TO FETOMATERNAL HEMORRHAGE +(1) As a result ofpreg11a11cy (Rh-negative woman bearing a Rh-positive fetus). Normally, the fetal red cells containing the Rh antigen rarely enter the maternal circulation. The following are the conditions where the risk of fetomaternal bleed is present: +A. Early pregnancy: • miscarriage, • MTP, • ectopic pregnancy, • hydatidiform mole. +B. Procedures: • genetic amniocentesis, • embryo reduction, • CVS, • cordocentesis. +C. Late pregnancy: • placenta previa with bleeding, • placental abruption, • IUFD, • external cephalic version, • abdominal trauma and the delivery of a Rh-D positive infant to a Rh-negative mother. This is much more (15-50%) likely to occur during third stage oflabor, • following cesarean section, • manual removal of placenta. +However, recent studies show a continuous fetomaternal bleed occurring throughout normal pregnancies (1%). +Immunization is unlikely to occur unless at least 0.1 mL offetal blood enters the maternal circulation. Not all 'at risk' Rh-negative women become alloimmunized. About 13% of Rh-negative women will become alloimmunized by a single Rh-incompatible pregnancy. Rh-sensitization due to antepartum fetomaternal hemorrhage is about 1-2% before delivery. Fetal Rh-antigens are present by 38th day after conception. Spontaneous first trimester abortion carries 3-4% risk and that of induced abortion about 5% risk of sensitization. Thus, affection of the baby due to Rh incompatibility is low considering the increased number of Rh-positive babies delivered to Rh-negative mothers. +(2) Transfusion of mismatched blood: In ABO group incompatibility, there are naturally occurring anti-A and anti-B isoagglutinins, which result in immediate adverse reaction. In case of Rh group, there is no such naturally occurring antibody and as such there is no immediate reaction but the red cells carrying the Rh antigen sensitize the immunologically competent cells in the body, provided the amount is suficiently large. This takes at +Bl Chapter 23: Complicated Pregnancy + +least I week. Following a subsequent exposure to the antigen, the cells are stimulated to produce more specific anti-D antibody. The women may suffer a severe hemolytic reaction to the subsequent mismatched transfusion. +Test for fetomaternal Condition Anti-D hemorrhage +Threatened miscarriage at 250IU(SO µg) Not required 12 weeks. +Routine Antenatal Anti-D 1500IU(300 Not required Prophylaxis (RAADP): Single µg) +dose at 28-30 weeks. +FFP and cryoprecipitate. Not required Not required +D positive platelet 250 IU (within Required transfusion. 6weeks) +> 1 unit of D positive blood Exchange Required transfusion. transfusion + +The reasons for low rate of affection in babies due to Rh alloimmunization: +m Low prevalence of incompatible red cell antigens. +il Insufficient placental transfer of fetal antigens or maternal antibodies. +■ The immune response of Rh-negative women to Rh-positive red cells are of three types: (a) Responder (60-70%), (b) Hyporesponder (10-20%), and (c) Nonresponder (20%). +■ Inborn inability to respond to the Rh antigen stimulus. 11 ABO incompatibility has a protective effect against the development of Rh sensitization. This protective effect is significant when the mother is type O and the father is type A, B or AB. The reasons are-(i) ABO incompatible fetal cells are cleared from the maternal circulation rapidly before they are trapped by the spleen and (ii) maternal anti-A or anti-B antibodies damage +the Rh-antigen so that it is no longer immunogenic. +11 Variable antigenic stimulus of the D antigen which depends on the Rh genotype of the fetal blood, e.g., CDe/cde genotype. +11 Volume of fetal blood entering into the maternal circulation (0.1 mL is considered as critical sensitizing volume). +11 A small percentage of women are hyper-responder as they are immunized with a small amount of red cells. +11 A small number (1-2.7%) of Rh-negative women express D-antigen on the red cell surface. These women do not need Rh IG as they are not alloimmunized. +11 About 16% of Rh-negative women who do not receive Rh JG, develop alloimmunization with delivery. of Rh-positive fetuses (2% at the time of delivery, 7% by postpartum 6 months and another 7% in subsequent pregnancy). +MECHANISM OF ANTIBODY FORMATION IN THE MOTHER: +If the ABO compatible (mother and fetus have the same ABO group or when the fetus is group 'O'), Rh-positive fetal red cells enter the mother's blood, they remain in the circulation for their remaining lifespan. Thereafter, they are removed from the + + +circulation by the reticuloendothelial tissues and are broken down with liberation of the antigen. The antibody production is related not only to the responsiveness of the reticuloendothelial system but also to the amount of Rh antigen liberated, therefore to the number of red cells that have entered the maternal blood. Because this takes a long time, immunization in a first pregnancy is unlikely. Detectable antibodies usually develop after 10-16 weeks following larger volume of fetomaternal bleed. But, if the fetomaternal bleed is less than 0.1 mL, the antibody may not be detected until boosted byfurther Rh stimulus. Antibodies once formed remain throughout life. + +TYPES OF ANTIBODIES: Two types of antibodies are formed: +(1) IgM: This type of antibody is the first to appear in the maternal circulation and agglutinates red cells containing D when suspended in saline. IgM being larger molecules cannot pass through the placental barrier and is not harmful to the fetus. +(2) IgG: It is also called incomplete or blocking antibody. It will agglutinate the red cells containing D only when suspended in 20% albumin. Because of its small molecular size, it can cross the placental barrier and cause damage to the fetus. It appears at a later period than does the IgM antibody. It is important to recognize the preponderance of one or the other type of antibody than the actual level of the titer. + +I FETAL AFFECTION BY THE Rh ANTIBODY + +The antibody formed in the maternal system (IgG) crosses the placental barrier and enters into the fetal circulation. The prevalence of D alloimmunization complicating pregnancy is about 0.5-0.9%. The antibody will not have any effect on Rh-negative fetus. If the fetus is Rh-positive, the antibody becomes attached to the antigen sites on the surface of the fetal erythrocytes. The affected cells are rapidly removed from the circulation by the reticuloendothelial system. Depending upon the degree of agglutination and destruction of the fetal red cells, various types of fetal hemolytic diseases appear. These are loosely termed as erythroblastosis fetalis, since many babies may have a large number of nucleated cells in the peripheral blood as a result of compensatory erythropoiesis in response to anemia due to any cause other than Rh factor. + +MANIFESTATIONS OF THE HEMOLYTIC DISEASE OF THE FETUS AND NEWBORN (HDFN) + +Clinical manifestations of the hemolytic disease of the fetus and newborn are: +♦ Hydrops fetalis +♦ Icterus gravis neonatorum +♦ Congenital anemia of the newborn + +HYDROPS FETALIS: This is the most serious form of Rh hemolytic disease (HDFN). Excessive destruction of the +Chapter 23: Complicated Pregnancy Si + + + + + + + + + + + +Fig. 23.2: Hydrops fetalis-stillborn edematous infant due to rhesus alloimmunization (HDFN). + +fetal red cells leads to severe anemia, tissue anoxemia and metabolic acidosis. These have got adverse effects on the fetal heart and brain and on the placenta. Hyperplasia of the placental tissue occurs in an effort to increase the transfer of oxygen but the available fetal red cells ( oxygen carrying cells) are progressively diminished due to hemolysis. As a result of fetal anoxemia, there is damage to the liver leading to hypoproteinemia which is responsible for generalized edema (hydrops fetalis) (Fig. 23.2), ascites and hydrothorax. Rh-positive male fetuses are more likely (13 times) to become hydropic and more likely (3 times) to die thanfemalefetuses. In hydrops, there is accumulation of extracellular fluid in at least two body compartments. Fetal death occurs sooner or later due to cardiac failure. The baby is either stillborn or macerated and even if born alive, dies soon after. Other nonimmune causes of hydrops fetalis are discussed in Ch. 33. +The following are the diagnostic features: 1. Mother is Rh-negative. +2. Serological examination reveals presence of Rh-antibody. 3. There may be presence of polyhydramnios. +4. Previous history of affection of a baby due to hemolytic disease. +5. Sonography (real time combined with pulse Doppler) to detect edema in the skin, scalp and pleural or pericardia! effusion and echogenic bowel. +6. USG may reveal-'Buddha' position of the fetus with a halo around the head due to edematous scalp. +7. The baby at birth looks pale and edematous with an enlarged abdomen due to ascites. There is enlargement of liver and spleen. +8. Placenta is large, pale and edematous with fluid oozing from it. The placental weight may be increased to about half or even almost equal to the fetal weight. There is undue persistence of Langhans layer with marked swelling of the villi. If the fetus is not hydropic, the placenta usually looks normal. +ICTERUS GRAVIS NEONATORUM: This clinical entity is the effect of lesser form of HDFN. The baby is born alive without evidences of jaundice but soon develops it within 24 hours of birth. + +While the fetus is in utero, there is destruction of fetal red cells with liberation of unconjugated bilirubin which is mostly excreted through the placenta into the maternal system. A portion of the bilirubin enters the amniotic fluid perhaps from the fetal lung or through the skin or across the surface of the placenta or cord. This is the reason why baby is not born with jaundice. But as soon as the umbilical cord is clamped, with continuing hemolysis, the bilirubin concentration is increased. Sooner or later the baby becomes jaundiced. The liver particularly of a premature baby fails to conjugate the excessive amount of bilirubin to make it soluble and nontoxic. +If the bilirubin rises to the critical level of 20 mg per 100 mL (340 µmol/L-normal 30 µmol/L), the bilirubin crosses the blood-brain barrier to damage the basal nuclei of the brain permanently producing the clinical manifestation of kernicterus. +CONGENITAL ANEMIA OF THE NEWBORN: This is the mildest form of the disease where hemolysis is going on slowly. Although the anemia develops slowly within first few weeks of life, the jaundice is not usually evident. The destruction of the red cells continues up to 6 weeks after which the antibodies are not available for hemolysis. The liver and spleen are enlarged, the sites of extramedullary erythropoiesis. +Affection of the mother: The impact of Rh incompatibility mainly +falls on the baby. The mother may also be affected somewhat. There is increased incidence of: (1) pre-eclampsia; (2) polyhydramnios; (3) big size baby with its hazards; (4) hypofibrinogenemia due to prolonged retention of dead fetus in uterus; (5) postpartum hemorrhage due to big placenta and blood coagulopathy; (6) 'maternal syndrome' -the salient features are generalized edema, proteinuria and pruritus due to cholestasis. These features are ominous indicating imminent fetal death in utero. +I PREVENTION OF Rh-D ALLOIMMUNIZATION +♦ To prevent active immunization +♦ To prevent or minimize fetomaternal bleed ♦ To avoid mismatched transfusion +TO PREVENT ACTIVE IMMUNIZATION: To prevent active immunization of Rh-negative yet unimmunized, Rh anti-D immunoglobulin (lgG) is administered intramuscularly to the mother following childbirth. The other conditions that the Rh anti-D immunoglobulin should be given are mentioned below. +Mode of action is antibody-mediated immune suppression (AMIS). The possible mechanisms are: (i) the anti-D antibody when injected, blocks the Rh-antigen of the fetal cells (Fig. 23.3); (ii) the intact antibody coated fetal red cells are removed from the maternal circulation by the spleen or lymph nodes; (iii) central inhibition-the fetal red cells, coated with anti-D antibodies interfere the production of IgG from the B cells. +When to administer anti-D immunoglobulin? It should be administered within 72 hours or +ED Chapter 23: Complicated Pregnancy + + + + + + + +Fig. 23.3: Anti-D immunoglobulin injected into the mother surrounds the fetal RBC (thick green circle) preventing the antigen sites (spikes) to form antibody. + +preferably earlier following delivery or abortion. It should be given provided the baby born is Rh-positive and the direct Coombs' test is negative. This reduces the alloimmunization rate by 90%. Use of anti-D immunoglobulin at 28 weeks gestation additionally reduces third trimester alloimmunization from the background risk o/2% to 0.1%. +Rh-IG may be given as late as 28 days after delivery to avoid sensitization when the schedule dose has been omitted inadvertently. Similarly, when theRh factor of the fetus cannot be determined, it should be administered without any harm. +Dose: The standard dose for anti-D immune globulin is 300 µg or 1500 IU IM to protect a women from fetal hemorrhage of up to 30 mL of fetal whole blood or 15 mL of fetal red cells. Nearly 40% of neonates born to D negative women are also D negative. Indirect Coombs test may be done to determine, if the dose of anti-D was adequate. A positive result indicates there is excess of anti D immunoglobulin in maternal serum to prove that the dose was adequate. Other tests are rosette-where D-positive cells are present in maternal serum. The quantitative estimation of fetal red cells in maternal circulation is done by acid elution or Kleihauer­ Betke test. Fetal erythrocytes with HbF are more resistant to acid elution than HbA. After exposure to acid, fetal erythrocytes appear red and adult erythrocytes appear as "ghosts". The fetal cells counted and are expressed as a percentage of adult cells. +Anti-D-gammaglobulin is administered intramus­ cularly to the mother 300 µg following delivery. All Rh-negative unsensitized women should receive 50 µg of Rh-immunoglobulin IM within 72 hours of induced or spontaneous abortion, ectopic or molar pregnancy or CVS in the first trimester. Pregnancies beyond 12 weeks +should have full dose 300 mg. +Calculation of the dose: Approximate volume of fetal blood entering into the maternal circulation is to be estimated by 'Kleihauer-Betke test' using acid elution technique to note the number of fetal red cells (dark red, refractile bodies) per 50 low power fields (Fig. 23.4). Adult RBCs appear as "Ghost''. If there are 80 fetal erythrocytes in 50 low power fields in maternal peripheral blood films, it represents a transplacental hemorrhage to the extent of 4 mL of fetal blood. More accurate tests are immunofluorescence and flow cytometry. If the volume of fetomaternal hemorrhage is greater than 30 mL whole blood, the dose ofRh-immune globulin calculated is 10 µg +for every 1 mL of fetal whole blood + + + +Anti-D prophylaxis during pregnancy: Jn spite of postpartum Rh-immunoglobulin prophylaxis, failure rate is about 1-2%. This is due to antepartum fetomaternal hemorrhage and sensitization (1-2%). If the woman is Rh-negative and has no antibody, she should have one dose of 300 µg Rh-immunoglobulin as prophylaxis at around 28 weeks (ACOG-1999) and again after birth (within 72 hours). This Routine Antenatal Anti D Prophylaxis (RAADP) reduces alloimmunization to further 0.1 %. +Half-life of Rh-IG is about 16-24 days. So women receiving Rh-IG at 28 weeks gestation, have very low titer ofRh-IG during labor at term. She should be given 300 µg ofRh-IG within 72 hours of delivery. + +Causes of Fetomaternal Hemorrhage, Alloimmunization and Indications for Anti-D lmmunoglobulin +a Miscarriage. ■ ECV. +■ Medical termination ■ Abdominal trauma. of pregnancy. ■ IUFD. +■ Genetic ■ After transfusion of Rh-D-positive +amniocentesis. blood. +■ Embryo reduction. ■ Weak D phenotype (weak Rh-positive). a Ectopic pregnancy. Weak Rh-positive individuals have +■ Hydatidiform mole. missing of one more of the D-antigen +■ Chorion villus epitopes. These individuals are alloim­ +biopsy. munized and develop severe HDFN. +■ Cordocentesis. ■ Delivery of an Rh-positive infant to +11 Placenta previa. Rh-negative mother: postpartum. + +TO PREVENT OR MINIMIZE FETOMATERNAL BLEED: +- Precautions during cesarean section: (i) to prevent blood spilling into the peritoneal cavity and (ii) manual removal of placenta should not be done as a routine. +- Prophylactic ergometrine with the delivery of the anterior shoulder should preferably be withheld, as it may facilitate more fetoplacental bleed. +- Amniocentesis should be done after sonographic localization of the placenta to prevent its injury. +- Forcible attempt to perform external version under anesthesia should be avoided. +- Manual removal of placenta should be done gently. + + + + + + + + + + + + + + + +Fig. 23.4: Peripheral smear showing dark fetal red cells and light­ colored maternal cells (arrows). Modified Kleihauer and Betke acid elution test. +Chapter 23: Complicated Pregnancy &I + +- To refrain from abdominal palpation as far as possible in abruptio placentae. +To avoid giving Rh-positive blood to one Rh-negative female from her birth to the menopause. +All such women including women with multiple pregnancy may need more than usual 300 µg of anti-D immunoglobulin. + +ANTENATAL INVESTIGATION PROTOCOL OF Rh-NEGATIVE MOTHERS + +Investigation of blood for Rh and ABO grouping becomes almost a routine during the first antenatal visit in first trimester. If the woman is found Rh-negative, Rh grouping of the husband is to be done to find out whether the pregnancy is a result of incompatible or compatible mating. If the husband is also Rh-negative, i.e., compatible mating, there is no problem so far as Rh factor is concerned. But if the husband is found to be Rh-positive, further investigations are to be carried out which aim at: +(i) To detect whether the woman has already been immunized to Rh antigen; (ii) To forecast the likely affection of the baby; (iii) To anticipate and formulate the line of management of a likely affected baby. + +OBSTETRIC HISTORY: (a) If the woman is a primigravida with no previous history of blood transfusion, it is quite unlikely that the baby will be affected; (b) In a parous woman, a detailed obstetric history has to be taken. The classic history of fetal affection in the form of stillbirth or neonatal death due to severe jaundice following one or two uneventful births is quite suggestive. History of prophylactic administration of anti-D immunoglobulin following abortion or delive1y should be enquired. +ANTIBODY DETECTION: In all cases of Rh-negative women irrespective of blood grouping and parity, IgG antibody is detected by Indirect Coombs' test. +11 If the test is found negative at 12th week, it is to be repeated at 20th, 28th and 36th week in a primigravida. In a multigravida, the test is to be repeated at monthly intervals up to 24 weeks and at every 2 weeks thereafter. If the test is found positive: The patient should be supervised in centers equipped to tackle with Rh problem (specialized fetal medicine unit). +- Genotype of the husband is to be determined. If he is found to be homozygous, the fetus is likely to be affected and in heterozygous, the fetus may be affected in 50% cases. In that case fetal blood group is determined by cffDNA analysis from maternal blood. If the fetus is found to be Rh(D) negative, no further tests are required and routine care is continued. +- Fetal Rh status: Cell-free-fetal DNA present in maternal plasma is genotyped to detect fetal blood group. PCR for Free Fetal DNA (ffDNA) is done by 10 + +weeks gestation. This method has mostly replaced amniocentesis or chorionic villous biopsy. +- When the fetus is Rh-D positive, quantitative estimation of IgG antibody at weekly intervals is carried out. Sudden marked rise in the titer from 1 : 8 to 1: 32 is very much suggestive of fetal affection. Some centers consider the titer of 1: 16 or antibody level more than 10 IU/mL as a critical one. Critical titer means anti-D antibody level that causes hydrops fetalis. One should make a cautious interpretation of the rise or fall in the titer. +11 Autoanalyzer measurement of antibody (specific anti-D) is a more accurate test. Antibodies to D and c are quantified whereas other antibodies are titrated. The safe level of antibody in the maternal serum is <4 IU/mL. Anti-D level >4 IU/mL but <15 IU/mL has mild risk for HDFN. Anti-D level >15 IU/mL can cause moderate to severe HDFN. Those with levels of <4 IU/mL should have antibody measurement monthly. Levels >10 IU/mL should also have weekly ultrasound assessment to detect MCA PSV and signs of fetal hydrops. Antibody levels do not always correlate with fetal affection. +■ Doppler ultrasound: USG is useful to assess the fetal gestational age and also to detect the early onset of fetal hydrops (scalp edema, ascites and pleural effusion). Presence of fetal hydrops suggests end stage of fetal anemia with hemoglobin concentration <8.0 g/dL and the hematocrit value <15% (Fig. 23.5). +Fetal anemia is associated with low blood viscosity and increased blood velocity. Using this principle, Doppler ultrasound study of MCA PSV can predict fetal anemia more accurately. MCA PSV > 1.5 MoM for the corresponding gestational age, predicts moderate to severe degree of fetal anemia. Serial measurement of MCA PSV Doppler +study has replaced amniocentesis for 'iOD450• This value +(between 24 and 35 weeks of gestation), is an indication for cordocentesis and intrauterine fetal transfusion. Currently, MCA PSV is the mainstay of fetal surveillance in a case with red cell alloimmunization. Measurement is done by placing the Doppler gate in the proximal part of the MCA. It can be started as early as 18 weeks and may be repeated at interval of 1-2 weeks or as clinically indicated. Most centers have replaced serial amniocentesis and OD450 with serial MCA PSV Doppler studies (Fig. 23.6). +Assessment of fetal anemia is more accurate by doing fetal blood sampling (FBS). Fetal hydrops develops when there is deficit of 7-10 g/dL of hemoglobin from the mean hemoglobin value of the corresponding gestational age. Fetal anemia is assessed with the use of Doppler ultrasound to study the PSV in the MCA of the fetus. Serial MCA Doppler study is needed in cases with red cell alloimunization. +Management of a Rh-negative woman affected by alloimmunization in previous pregnancy: MCA +ml Chapter 23: Complicated Pregnancy + + +tUraltnrassdouucnedr abMdaotmewrinnaaallll + + + + +An(tfearcioer) + + + +needs intrauterine transfusion. Repeat transfusion may be needed. Delivery is done with pulmonary maturity. +Methods of antenatal assessment of fetal wellbeing: +1. Serial ultrasonography may detect fetal hydrops and anemia. The important features are: polyhydramnios, placental thickness >4 cm, pericardia! or pleural effu­ sion, echogenic bowel, dilatation of cardiac chambers and enlargement of spleen and liver. +2. Cardiotocography: Sinusoidal and decelerative pattern are observed in an affected fetus. +3. Doppler flow velocity waveforms in the umbilical artery, middle cerebral artery, ductus venosus have been used to detect fetal anemia and acidosis. +4. Cordocentesis is done when there is elevated peak systolic MCA Doppler velocities (> 1.5 MoM). + + + + +Fig. 23.5: Measurement of Middle Cerebral Artery (MCA) Peak Systolic Velocity (PSV). Doppler gate is on the MCA immediate to its origin from internal carotid artery. Color Doppler is used. + +MCA PSV >1.5 multiples of the median (MoMs) for corresponding gestational age predicts moderate to severe fetal anemia. +Serial Doppler studies of MCA are the mainstay to assess fetal anemia in red cell alloimmunized pregnancy. + + +PLAN OF DELIVERY +♦ Unimmunized mothers ♦ Immunized mothers + + + + + + +Fig. 23.6: MCA Doppler ultrasound in IUGR at 24 weeks of gestation show how the brain-sparing effect has resulted in relatively high diastolic flow. + +Doppler surveillance should be initiated at 18 weeks and is repeated every 1-2 weeks. Treatment is based on MCA Doppler results. +A. Unaffected or mildly affected: Testing is repeated every 2 weeks and delivery is planned at term or near term. +B. Fetus moderately affected: MCA Doppler report nearing 1.5 MOM. Testing is repeated at every 1-2 weeks. Delivery may be organized before term, pulmonary maturity is accelerated by use of corticosteroids. +C. Fetus severely affected: MCA Doppler >1.5 MOM or has evidence of hydrops. +Ultrasound guided cordocentesis is done. FBS is done selectively in cases when MCA PSV is >1.5 MoM. Cordocentesis helps to detect fetal blood grouping, hematocrit, DCT, reticulocyte count and total bilirubin level. Fetal hematocrit value <15% is associated with hydrops. Intrauterine Fetal Transfusion (IUFT) is indicated when hematocrit is below 30%. +Cordocentesis, cord blood sampling and intrauterine transfusion are done between 18 and 35 weeks of gestation. Before 18 weeks access to umbilical vein is difficult. After 35 weeks, risk benefit ratio favors delivery. Fetal anemia, hydrops + +UNIMMUNIZED MOTHERS: In cases where there is no detectable antibody found during pregnancy, an expectant attitude is followed till term (Flowchart 23.3). Tendency of pregnancy to overrun the expected date should not be allowed. +IMMUNIZED MOTHERS: As mentioned previously, whenever there is evidence of hemolytic process in the fetus in utero, the patient should be shifted to an equipped center specialized to deal with Rh problems. An intensive neonatal care unit, arrangements for exchange transfusion and an expert neonatologist are the basic requirements to taclde the affected babies. +Delivery is to be done in all cases of immunized mothers with evidences of fetal hemolysis in utero. The following factors are to be considered as to when terminate the pregnancy: (i) Previous history of stillbirth with father being homozygous; (ii) sudden rise in maternal antibody titer; (iii) the optical density difference at 450 nm wavelength as plotted on Liley's chart and (iv) Doppler and ultrasound features of fetal affection. +In mild affection, the pregnancy may be continued up to 38 weeks and then termination is to be done. +In severe affection: It is reasonable to terminate the pregnancy around 34 weeks after maternal steroid administration. In every case of premature termination before 34 weeks, it is desirable to confirm the fetal lung maturation by measuring the L:S ratio in the amniotic fluid. In a specialized center where there is severe affection before 34 weeks, intrauterine fetal transfusion +Chapter 23: Complicated Pregnancy -Flowchart 23.3: Scheme of management of Rh-negative mother. +I Mother Rh D-negative, Father Rh D-positive + + + + + + + +t +No antibody +l + +l Homozygous➔ at risk pregnancy. +Genotype of the Father -[ Heterozygous➔ fetal Rh-D status (ffDNA testing from maternal plasma after 14 weeks)➔ positive. +l +• Serial antibody quantification. OR +• Indirect Coombs' test. + +j • +t +Antibody present +Supervision in a specialized fetal medicine unit. +• Antibody titration at weekly intervals. + + +• No history of FMH • History of previous -. Titer >1 :16 or Ab level >10 IU/mL. +• Parous women +• Primigravida +l +l +affection +l • Serial fetal MCA PSV Doppler study every +Repeat Indirect Repeat Indirect Coombs' 1-2 weeks from 20 weeks. Coombs' test at test at monthly intervals up • Serial ultrasonography every +36 weeks to 24 weeks and every 2-3 weeks from 20 weeks. 2 weeks thereafter. \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_11.txt b/notes/DC Dutta Obstetrics 10th Edition_11.txt new file mode 100644 index 0000000000000000000000000000000000000000..0f8236ff19b852c679d6cccd32f6e689defccdbc --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_11.txt @@ -0,0 +1,2027 @@ +l +l + + l • Rising antibody titer; MCA PSV >1.5 MoMs. +Pos +tive +Negative/ +Negative titer ,;16 i -----+ [+ USG ➔ abnormal [fetal ascites, hydrops. MCA - Middle Cerebral Artery PSV - Peak Systolic VE)loci\y +I +J Deliver at term I l MoM - Multiple of Median 'I +l +l +Yes No MCA PSV ?:1.5 +Cordocentesis for MCA PSV <1.5 MoM fetal Hematocrit (Hct) +l +• Hematocrit <30% Serial fetal MCA PSV at interval of 1-2 weeks +l +l + +Intrauterine fetal transfusion To start antenatal to raise the Hct to 50% fetal surveillance +l +(NST, BPP, Doppler +study of UA) +May have to be repeated at 32 weeks +till 35 weeks +l + +• Fetal lung maturity Delivery by term +l + +Delivery + +• No prophylactic ergometrine • Rapid cord clamping +• Cord blood examinations: Hb%, ABO and Rh grouping, hematocrit, reticulocyte count, Direct Coombs' test, +To be done +[ +serum bilirubin +• Management in a specialized fetal medicine unit. + + + +(intraperitoneal or intravascular) is done (p. 323) to continue pregnancy beyond 34 weeks. +Methods of delivery: (1) Amniotomy (low rupture of the membranes) is quite effective, if termination is done near term. Vaginal prostaglandin gel could be used to make the cervix ripe. +(2) Cesarean section: In cases when termination has to be done prematurely (say 34-37 weeks), the cervix will be + +unfavorable and considering the severity of affection and urgency of termination, cesarean section is a safe procedure. +CARE DURING DELIVERY: Vaginal delivery: (i) Careful fetal monitoring is to be done to detect at the earliest, evidences of distress; (ii) prophylactic ergometrine during second stage should be withheld; (iii) gentle handling of the uterus in the third stage and (iv) to take care of postpartum hemorrhage. +&I Chapter 23: Complicated Pregnancy + +Cesarean section: (i) To avoid spillage of blood into the peritoneal cavity and (ii) routine manual removal of placenta should be withheld. +Clamping the umbilical cord: In either methods, the cord is to be clamped as quickly as possible to minimize even minute amount of antibody to cross to the fetus from the mother. The cord should be kept long (15-20 cm) for exchange transfusion, if required. +Collection of cord blood for investigation: Cord blood sample is to be taken from the placental end of the cut cord. The cord should not be squeezed to prevent contamination with Wharton's jelly. About 5 mL of blood (2 mL oxalated and 3 mL clotted) should be collected for the following tests: +Clotted blood: ABO and Rh grouping, reticulocyte count, direct Coombs' test and serum bilirubin. +Oxalated blood: Hemoglobin estimation and blood smear for presence of immature RBC. +INTRAUTERINE FETAL TRANSFUSION (IUFT) +Significant advancement has been made in diagnosis ( cordocentesis, Doppler ultrasonography for MCA PSV) and therapy of rhesus alloimmunization. This can be carried out in a regional specialized center. It is indicated in selected cases where there is severe affection of the fetus in utero prior to 34 weeks. The advantages are: (i) correction of fetal anemia and improvement of oxygenation and (ii) improved fetal hepatic function. +A. Intravascular Transfusion (IVT): Severity offetal affection is best assessed by fetal hemoglobin and hematocrit levels as determined by cordocentesis. Generally a fetus whose hemoglobin deficit is 2 g/dL or more from the mean of a normal fetus of corresponding gestational age or hematocrit <30% should be transfused. Hydropic changes are observed when fetal hematocrit is less than 15%. +Procedure: Transfusion is generally made through umbilical cord vessel (vein) near its insertion into the placenta or intrahepatic part of the umbilical vein under real time ultrasound. A 20-gauge needle is used. Type and amount of blood: blood group 'O', Rh-negative packed cells (hematocrit 90%), cross matched with the mother, are to be transfused. The blood should preferably be freshly donated, cytomegalovirus negative, leuko reduced and irradiated (25 Gy). The quantity of blood is to be calculated. The volume to transfuse, is calculated multiplying the estimated fetal weight in gram by 0.02 for each 10% increase in hematocrit. Donor blood with hematocrit of78% is used. Hematocrit level is checked at intervals during the procedure to determine the volume. Goal is to achieve a hematocrit of 50%. Repeat transfusion is given after 2 weeks. The timing of repeat JUT is decided by the PSV in the MCA. Final JUT is not done beyond 35 weeks. Complications: Fetal injury, volume overload, preterm labor and fetomaternal hemorrhage are the common complications. Emergency CD is 1 %. Procedure-related perinatal loss is 2%. Fetal surveillance with ultrasound and continuous electronic fetal monitoring is performed at the post-transfusion phase. Betamethasone (24 mg in three divided doses) should be administered to the mother 24 hours before transfusion from 26 weeks onwards to enhance pulmonary maturity, in case delivery becomes necessary during +transfusion. Overall fetal survival rate is 97%. + +B. Intraperitoneal transfusion (IPT): Intraperitoneal transfusion is done either alone or combined with intravascular transfusion with severe and early onset hemolytic disease when umbilical vein is too narrow to be punctured by a needle. Principle: Blood is transfused in the fetal peritoneal cavity under ultrasound guidance. Fetal anemia is corrected when the transfused erythrocytes are taken up by the subdiaphragmatic lymphatics. It can be started at 18 weeks and repeated at intervals of 1-3 weeks up to 32-34 weeks. Pregnancy can thereafter be terminated. Overall neonatal survival is approximately 90-100% for nonhydropic fetuses about 70-80% for hydropic fetuses. + +OTHER THERAPIES +♦ Plasmapheresis has been tried to remove several liters of +maternal plasma with maternal anti-D antibodies. Maternal titer should be reduced by 50%. IVIG is then given. Perinatal survival rate is 69%. +♦ High-dose Intravenous Immunoglobulin (IVIG) is thought to block placental transport of (FC mediated) antibody or to destroy anti-D coated erythrocytes in fetal spleen and liver. A dose of 1,000 mg/kg IVIG weekly has been used. +♦ Delive1y at around 34-36 weeks leads to neonatal survival to about 100% with low long-term morbidity. +♦ Artificial insemination with Rh-negative donor semen, surrogate pregnancy or PGD (when father is heterozygous) may be the option. +I PROGNOSIS +So long as the Rh-D-negative mother remains unim­ munized against Rh-D-antigen, the fetus is unaffected with any hemolytic process. With alloimmunization of the mother, the prognosis of the baby depends on: (1) Genotype of the father; (2) genotype of the fetus; (3) maternal antibody level; (4) history of previous affection of the baby due to hemolytic disease and (5) availability of sophisticated diagnostic and therapeutic facilities for the affected babies (specialist fetal medicine care unit). +However, with use of intensive management protocols such as repeated fetal MCA Doppler study, amniocentesis, cordocentesis, intrauterine fetal transfusions (when necessary) the neonatal survival is 100%. An immunized mother who has anti-D level more than 400 JU/L, should be advised for anti-D donation. + +BREASTFEEDING: There is no contraindication of breastfeeding in immunized mothers, although trace amount of antibodies are excreted through the breast milk. + +EXCHANGE TRANSFUSION IN THE NEWBORN +Exchange transfusion is a life-saving procedure in severely affected Hemolytic Disease of the Fetus and Newborn (HDFN). With the advent of wider use of prophylactic anti-D immunoglobulin, less and less problem babies are born and through exchange transfusion, the incidence of kernicterus has also been reduced. + +INDICATIONS: Rh-positive with Direct Coombs' test positive babies having (Ch. 33): +■ Cord blood bilirubin level more than 4 mg/dL and hemo­ globin level is less than 11 g/dL. + + +II Rising rate of bilirubin is over 1 mg/dL/hour despite phototherapy. +Total bilirubin level 20 mg/dL or more. + +OBJECTIVES +ii To stop hemolysis, and bilirubin production. +To correct anemia and to improve congestive cardiac failure of the neonate. +■ To remove the circulatory antibodies. ■ To remove sensitized RBCs. +■ To eliminate the circulatory bilirubin. +II To stop hemolysis and bilirubin production. +While about 80-90% of the fetal blood is exchanged during the procedure, transfusion of Rh-negative blood cannot alter the Rh-factor of the baby's blood. The replacement temporarily helps to tide over the crisis from anemia and hyperbilirubinemia for about 2 weeks. Thereafter, the baby is quite capable to get rid of the maternal antibodies by producing sufficiently his own Rh-positive blood. +NATURE AND AMOUNT OF BLOOD TRANSFUSED +- Blood for exchange should be Rh-negative whole blood with the same blood ABO grouping to that of the baby, otherwise group 'O'. The blood should be cross matched with the mother's serum or with the infant's serum. +- The blood should be collected relatively fresh ( <7 days old). - The amount is about 160 mL/kg body weight of the baby. +ADJUVANT THERAPY +(1) Phototherapy: Phototherapy is to be continued for 24 hours. Phototherapy (blue or blue green light of 420-470 nm wavelength) degrades bilirubin by photo-oxidation and structural isomerization (lumibilirubin). Bilirubin is converted to less toxic polar isomer. These products are water soluble and therefore readily excreted in the bile and urine. Ultraviolet light should be screened out and the baby's eyes should be protected by dark glasses (Ch. 33). +(2) Photochemical reactions convert bilirubin to less toxic and water-soluble polar isomer or to lumirubin. +(3) Antibiotics should be administered for 3-5 days. + +ELDERLY PRIMIGRAVIDA + +Women having their first pregnancy at or above the age of 30 years (FIGO-35 years) are called elderly primigravidae. The age limit is arbitrary and is based on the fact that the outcome of the pregnancy is adversely affected beyond the specified age limit. There are two groups of patients: (1) one with high fecundity-a woman married late but conceives soon after and (2) one with low fecundity-woman married early but conceives long after marriage. The latter one is prognostically more unfavorable so far as the obstetric outcome is concerned after conception occurs following treatment of infertility (ovulation induction or assisted reproductive technology). These women require 5 mg of Jolie acid. Prophylaxis with 75-150 mg aspirin is required at >40 years along with other risk factors. Thromboprophylaxis may be advised. + +Chapter 23: Complicated Pregnancy ID COMPLICATIONS +During pregnancy: There is increased incidence of: +(1) miscarriage; (2) pre-eclampsia because of increased association of hypertension; (3) abruptio placentae because of pre-eclampsia and folic acid deficiency; (4) uterine fibroid; (5) medical complications related with advancing age such as pregnancy-induced hypertension, gestational diabetes and organic heart lesion, placental abruption or previa; (6) tendency of postmaturity and (7) intrauterine growth restriction. +During labor: There is increased incidence of: (1) preterm labor; (2) prolonged labor due to (a) uterine iner­ tia caused by anxiety or malposition (occipitoposterior); (b) impaired joint mobility and (c) inelasticity of the soft tissues of the birth canal; (3) maternal and fetal distress appears early; ( 4) increased cesarean delivery and (5) retained placenta due to uterine atony and increased asso­ ciation of fibroid. +Fetal risks: Preterm birth and prematurity either iatrogenic or spontaneous, IUGR, fetal congenital malformation ( aneuploidy ). +Puerperium: (1) Increased morbidity due to operative interference and (2) failing lactation. +PROGNOSIS: The maternal morbidity is high and the maternal mortality is slightly increased due to the increased complications and operative interference. The perinatal mortality is increased due to prematurity, increased congenital malformation (trisomy 21) and operative interference. +MANAGEMENT: Preconception counseling should be done. Considering the risks involved in pregnancy and labor, the patients are considered 'highrisk'. They require meticulous antenatal supervision, prenatal genetic screening and should have a mandatory hospital delivery. The following principles are to be followed: (1) result of induction is unsatisfactory and as such cesarean section is a preferred alternative; (2) prenatal diagnosis and sonography (targeted) are done to exclude fetal genetic or structural anomaly and (3) development of other complications should be viewed with concern. +Contraceptive advice is given depending on her eligibility criteria (Ch. 36). + +GRAND MULTIPARA + +A grand multipara relates to a pregnant mother who has got previous four or more viable births. The incidence has been gradually declining over the couple of decades due to acceptance of small family norm but it still constitutes to about one-tenth of the hospital population and accounts for one-third of the maternal deaths in the developing countries. +COMPLICATIONS: Pregnancy: There is increased incidence of: (1) miscarriage-spontaneous and induced; (2) inherent obstetric hazards such as: (a) malpresentation due to pendulous abdomen and increased pelvic inclination resulting from associated lordosis; (b) multiple pregnancy; (c) placenta previa; (3) medical disorders such as anemia (both iron deficiency and megaloblastic), hypertension with or without superimposed pre-eclampsia, cardiac disability, exaggerated +Chapter 23: Complicated Pregnancy + +manifestations of hemorrhoids and varicose veins, hiatus hernia, etc. and (4) prematurity. +Labor: There is increased incidence of: (I) cord prolapse due to malpresentation; (2) cephalopelvic disproportion due to-( a) increasing size of the fetus; {b) seconda1y contracted pelvis which is mostly related to ill-nourished mothers and (c) fo1ward projection of the sacrum due to subluxation of the sacroiliac joints, thereby diminishing the inlet conjugate; (3) obstructed labor due to malpresentation, malposition and CPD; ( 4) rupture uterus, if the obstruction remains undetected and left uncared for; (5) postpartum hemonhage due to atonic uterus or increased association of adherent placenta; (6) shock due to severe anemia, hemorrhage or unrecognized uterine rupture and (7) operative interference because of the complications. +Puerperium: (1) Increased morbidity due to sepsis, intranatal hazards; (2) subinvolution and (3) failing lactation. +MANAGEMENT: The cases are considered as 'high risk'. As such they require adequate antenatal care and should have a mandatory hospital delive1y. +During labor, the following guidelines are prescribed: (1) pelvic assessment should be done as a routine; (2) presentation and position are to be checked; (3) undue delay in progress should be viewed with concern and (4) to take prophylactic measures against PPH. +Contraceptive advice is given depending on her eligibility criteria (Ch. 36). + +BAD OBSTETRIC HISTORY (BOH) + +DEFINITION: The term Bad Obstetric History (BOH) is applied to a pregnant women where her present obstetric outcome is likely to be affected adversely by the nature of previous obstetric disaster. The previous pregnancy loss should be obstetrically related and as such mishaps to the baby due to some other reasons should not come under the purview of BOH (Read more Dutta's Clinics in Gynecology, Ch. 3). + +■ INVESTIGATIONS AND MANAGEMENT + +The principles are: (1) To find out the cause; (2) to rectify the abnormality, if possible and (3) continued monitoring till delivery. +Tofind out the etiologicalfactor: At the first antenatal visit, detailed in-depth relevant history should be taken in an attempt to find out the cause ofmishaps. In majority of cases, however, the cause remains undetermined. Common causes are: endocrine disorders (diabetes mellitus, thyroid disorders), antiphospholipid syndromes, inherited thrombophilias (factor V Leiden mutation, proteins C and S deficiency, hyperhomocysteinemia), structural abnormalities of the uterus and cervix (septate uterus, cervical incompetence) or maternal systemic disease (SLE). Previous history of congenital deformity of the baby, especially a neural tube defect should be excluded as there is likely chance of recurrence. +ANTIPHOSPHOLIPID SYNDROME (APS): Antiphospholipid antibodies (aPLs) including lupus anticoagulant (LA) and anti­ cardiolipin antibodies (aCL) and antibodies to 2-glycoprotein-l (P2GP-l) are to be estimated. They are the markers of adverse pregnancy outcome (Box 23.6). These antibodies are either IgG or IgM or both and bind to negatively charged phospholipids. + + +They prevent physiological changes in decidual vessels. There is inhibition in release of prostacyclin (vasodilator) from vascular endothelium with rise in the level of thromboxane (vasoconstrictor) from platelets. +Other pathological changes like placental vascular atherosis, intervillous and spiral arte1ythrombosis and decidual vasculopathy with fibrinoid necrosis lead to inadequate maternal blood supply to fetus. Common obstetric complications associated with antiphospholipid syndrome are: (a) recurrent fetal loss ('.10 weeks), preterm birth; {b) IUGR; (c) IUFD; {d) early onset severe pre-eclampsia; (e) HELLP syndrome; {f) placental abruption; {g) recurrent thrombotic events and (h) thrombocytopenia. +THROMBOPHILIAS: Some regulato1y proteins act as inhibitors in the coagulation cascade. Inherited or acquired deficiencies of these inhibitory proteins are collectively known as thrombophilias. Thrombophilias causes hypercoagulability of blood and are associated with many pregnancy complications. Some inherited thrombophilias (factor V Leiden mutation, antithrombin deficiency, prothrombin gene mutation, proteins C and S deficiency, hyperhomocysteinemia) increases the risk like severe pre-eclampsia, eclampsia, HELLP syndrome, IUGR, placental abruption, insufficiency and stillbirths. +HYPERHOMOCYSTEINEMIA, an autosomal recessive inheritance, is commonly due to mutation of the enzyme 5,10-methylene­ tetrahydrofolate reductase (MTHFR). In a normal pregnancy its plasma level is low. Fasting plasma level more than 12 µmol/L is diagnostic. Hyperhomocysteinemia causes thromboembolism due to inactivation of protein C. It causes increased fetal loss due to premature placental vascular atherosis. It also causes fetal neural tube defect. Routine Jolie acid supplementation should be given. +To treat the offendingfactor: When the responsible factor is detected, appropriate therapy can be directed so as to prevent repetition of the mishaps. A good example is to perform encerclage operation in recurrent mid-trimester abortion. Diabetes in + + + +♦ Clinical Criteria: Obstetric +• One or more unexplained deaths of a morphologically normal fetus 30, S mg folic acid along with Vitamin D is required; (3) Weight loss is not recommended in pregnancy; (4) For BMI >35 along with family history of PE and age above 40 years requires 150 mg aspirin prophylaxis; (S) VTE prophylaxis is required as per criteria; (6) NT scan, cffDNA and anomaly scan is less effective. So diagnostic test may be offered; (7) For BMI >35, SFH measurements are inaccurate. So screening for FGR is done with USG and Doppler studies; (8) Only BMI is not an indication for CS; (9) Planned IOL along with AMTSL is advocated; (10) Increased rate of Surgical Site Infections (SSI). Subcutaneous fat closure is done at >2 cm; (11) Patients undergoing bariatic surgery should wait for 12-18 months before conceiving. + +Read more Dutta's Clinics in Obstetrics, Ch. 8. + + +• + +Red Cell Alloimmunization (Pregnancy in an Rh-negative Woman) +► An Rh-negative woman means she is D-negative. Alloimmunization is mainly due to Rh D, Kell red cell antigens. ► In alloimmunization, it is the lgG antibodies that cross the placenta and damage the fetus. +► Degree of affection of the fetus depends upon the degree of destruction of the fetal red cells, by the antibodies. +► Alloimmunization is preventable by anti-D prophylaxis. It should be given to the mother within 72 hours or earlier following delivery. ► It is always better to give anti-D immunoglobulin, where there is any doubt about whether to give or not. +► Additional indications of anti-D immunoprophylaxis for Rh (D) negative women are: (i) miscarriage; (ii) ectopic pregnancy; (iii) MTP; (iv) chorionic villous sampling; (v) amniocentesis; (vi) fetal blood sampling; (vii) APH; (viii) external cephalic version; (ix) routine at 28 weeks; (x) after delivery; (xi) molar pregnancy and (xii) after abdominal trauma. + +Contd ... +Chapter 23: Complicated Pregnancy + +Contd... + +► Half-life of Rh-lG is 16 days. If delivery occurs in less than 3 weeks from administration of Rh-lG during antenatal period, a repeat dose is unnecessary. +► Nearly 16% of Rh-negative women who do not receive RhlG, develop RhD alloimmunization following delivery of Rh-D positive fetus. ► In presence of ABO incompatibility, RhD-alloimmunization is about 2% without prophylaxis. +► An Rh-negative woman may be immunologically; (a) responder, (b) hyporesponder or even (c) non-responder to Rh-positive red blood cells. +► Management of an alloimmunized pregnancy is done by: (a) maternal antibody titer assessment, (b) monitoring of fetal MCA peak systolic velocity, (c) amniotic fluid bilirubin study, (d) IUFT in few cases. +► About 40% of Rh-negative women carry Rh-negative fetuses. Antenatal anti-D prophylaxis (at 28 weeks) reduces alloimmunization rate to 0.1 %. +► 2-3 per 1000 D-negative women have FMH>30 ml and need additional anti-D immunoglobulin. +► Antenatal investigations include: Antibody detection (indirect Coombs'test), serial antibody measurement and serial ultrasonography. Doppler study for MCA PSV is noninvasive and can reduce the need of amniocentesis and fetal blood sampling by cordocentesis. +► Ultrasonography is helpful to identify an affected fetus and its severity. It is done at 1-3 weeks interval. Findings suggestive of fetal anemia are-skin edema, ascites, pleural or pericardia! effusions, increased placental thickness and others. Doppler ultrasound and cardiotocography are also informative and are noninvasive methods. +► Doppler blood flow study in the Middle Cerebral Artery (MCA) can predict fetal anemia. Peak systolic velocity in the fetal (MCA PSV) greater than 1.5 Multiples of the Median (MoMs) for the corresponding gestational age predicts moderate to severe fetal anemia. Currently serial MCA Doppler studies have replaced serial amniocentesis. +► Management of an Rh-negative woman should be in a tertiary center where facilities for intrauterine transfusion and exchange transfusion are available. Specialized fetal medicine unit should deal the Rh problems. lntravascular fetal intrauterine transfusions are the main stay of fetal therapy. Perinatal survival is>95%. +► HDFN depends on the degree of destruction of the fetal red cells by the transplacental maternal antibodies (lgG). HDFN may be: +► (a) congenital anemia of the newborn, (b) icterus gravis neonatorum or (c) hydrops fetalis. +► Fetal Rh status can be studied by ffDNA present in maternal plasma. This method has replaced CVS and amniocentesis which are invasive methods. +► Rh-immune globulin prophylaxis can be given to Rh-negative, nonimmune woman at 28 weeks of pregnancy. This is in addition to the dose given after delivery (300 µg within 72 hours of delivery). +► Anti-D level of>10 IU/ml but <15 IU/ml indicates moderate risk of HDFN. Anti-D level of>15 IU/ml can cause severe HDFN. Woman should be referred to a fetal medicine unit when the anti-D levels are>4 IU/ml. +► In Rh alloimmunization, fetomaternal hemorrhage may occur during the antenatal period but it occurs predominantly during the time of delivery. +► Development of antibody to the Rh D antigen and monoclonal anti-D blocking antibodies is currently being thought to improve the established anti-D response. This may be the future therapeutic option to prevent severe HDFN in Rh-alloimmunization. +► Hydrops fetalis is due to accumulation of extracellular fluid in two fetal compartments. It is the severe type of HDFN. +Women with Bad Obstetric History (BOH) +► Women with BOH need to be investigated for the underlying etiological factor(s). +► Common causes are: Endocrine disorders (diabetes mellitus, thyroid disorder), antiphosph.olipid syndromes, inherited thrombophilias, anomalies of the uterus and the cervix (septate uterus, cervical insufficiency), red cell alloimmunization or chromosomal abnormalities. +► BOH cases need to be managed based on specific pathology. + + + +Contracted Pelvis + + + + + + + + + +❖ Asymmetrical or Obliquely Contracted Pelvis +❖ Mechanism of Labor in Contracted Pelvis with Vertex Presentation +❖ Diagnosis of Contracted Pelvis + + +❖ Disproportion +► Diagnosis of Cephalopelvic Disproportion (CPD) at the Brim +❖ Effects of Contracted Pelvis on Pregnancy and Labor + +❖ Management of Contracted Pelvis (Inlet Contraction) +❖ Trial Labor +❖ Midpelvic and Outlet Disproportion + + + + +DEFINITION: It is indeed difficult to define precisely what constitutes a contracted pelvis. Anatomically, contracted pelvis is defined as the one where the essential diameters of one or more planes are shortened by 0.5 cm. But of more importance is the obstetric definition which states alteration in the size and/or shape of the pelvis of sufficient degree as to alter the normal mechanism of labor in an average-size baby. +VARIATIONS OF FEMALE PELVIS: The size and shape of the female pelvis differ so widely due to morphological factors such as developmental, sexual, racial and evolutionary + + +that it is indeed dificult to define what the features of a normal pelvis are. +However, on the basis of the shape of the inlet, the female pelvis is divided into four parent types (Figs. 24.IA to C and Table 24.1): +♦ Gynecoid (50%) ♦ Anthropoid (25%) + Android (20%) ♦ Platypelloid (5%) +But more commonly, intermediate forms with combination of features are found. They are termed as gyne-android or andro-gynecoid, etc. The first part of the nomenclature relates to features of the posterior segment + + + + + + + + + + + + + + + + + + + + + + + + +Round Long oval Triangular Flat Figs. 24.lA to C: Anatomical features of parent pelvic types: (A) Inlet; (B) Cavity; (C) Outlet. +&g Chapter 24: Contracted Pelvis + + ,,-:b ,; , ,,,,z, "/!,.>,i;,"'.,•'" r. . ,); ,w; -"'~;• il'&'•p, r1, i ;1 , 7ctyp '"" (Fig. ¥-lW. =I': ,: I\1.,¢ Gynecoid Anthropoid +-eiv es +s 2fiAto·c 11 R +;ra te-2.i.l :AnatomicalfeaturesoT a en + + + + l -, f, :{ • .,,;i Android +• '11111 + + + + , * fl 'e, J'>1>s 1·,, ·: ·I' "'f, t:·1:r " , Platypelloid +.: . · +1, +f{f l 111i +:<. + + + +Inlet + + + + + + + +<;avity + +Outlet + + +Shape. +Anterior and posterior segment. + +Sacrum. + + + +Sacrosciatic notch. Sidewalls. +lschial spines. Pubic arch. Subpubic angle. +Bituberous diameter. + + +Round. +Almost equal and spacious, + + +Sacral angle (SA) more than go0• Inclined backwards, Well curved from above down and side to side. +Wide and shallow. +Straight or slightly divergent. Not prominent. +Curved. Wide (85°). +Normal. + + +Anteroposteriorly oval, +Both increased with slight anterior narrowing. +SA more than go0• Inclined posteriorly. Long and narrow. Usual curve. +More wide and shallow. Straight or divergent. Not prominent. +Long and curved. Slightly narrow. +Normal or short. + + +Triangular. +Posterior segment short and anterior segment narrow. +Sacral angle less than go0• Inclined forwards and straight. + +Narrow and deep. Convergent. Prominent. +Long and straight. Narrow. +Short. + +Transversely oval. Both reduced-flat. + + +SA more than go0• Inclined posteriorly. Short and straight. + +Slightly narrow and small. Divergent. +Not prominent. Short and curved. +Very wide (more than go0). +Wide. + + + +and the second part relates to that of the anterior segment of the pelvis. All types of combinations are possible except anthropoid with platypelloid. Thus, there may be 14 types of parent pelves either in pure form or in combination (Tables 24.1 and 24.2). +It should be clear that the pelves which are not typically female are not necessarily contracted, although there may be deviation of normal mechanism of labor. However, slight contraction if associated with any of the three nongynecoid pelves has a more serious consequence because of the unfavorable shape. +ETIOLOGY OF CONTRACTED PELVIS: Gross degree of contracted pelvis is nowadays a rarity. Severe malnutrition, rickets, osteomalacia and bone tuberculosis affecting grossly the pelvic architecture are now rarely met in clinical practice. Instead, minor variation in size and/ or shape of the pelvis is commonly found which is often overlooked until complication arises. + + +CAUSES FOR DEFORMITY OF THE PELVIS +Rachitic flat pelvis (Fig. 24.2A), osteomalacic pelvis, Naegele's and Robet's pelvis, kyphotic and scoliotic pelvis (Fig. 24.28) results in contraction of one or more of the major diameters of the pelvis at the levels of the brim, cavity or the outlet. In all such situations, cesarean delivery is mostly the safe method of delivery. +1. Nutritional and environmental defects: • Minor variation: Common. +• Major: Rachitic and osteomalacic-rare. +2. Diseases or injuries affecting the bones of the pelvis­ fracture, tumors, tubercular arthritis; spine-kyphosis, scoliosis, spondylolisthesis, coccygeal deformity; lower limbs-poliomyelitis, hip joint disease. +3. Development defects: Naegele's pelvis, Robert's pelvis; high or low assimilation pelvis. +RACHITIC FLAT PELVIS: Changes occur in the bony pelvis due to weightbearing. The classic changes in the pelvic bones are shown. + + + + + + +Inlet ■ Position. + + +■ Diameter of engagement. +■ Engagement. + + +Cavity ■ Internal rotation. + + + +Outlet ■ Delivery. + + +Gynecoid + +Occipitolateral or oblique occipitoanterior. + +Transverse or oblique. +No difficulty Usual mechanism. + +Easy anterior rotation. + + +No difficulty. + + +Anthropoid + +Direct occipitoanterior or posterior. + +Anteroposterior. + +No difficulty except flexion is delayed, + +Non-rotation common. + + +More incidence of face-to-pubis delivery. + +Android + +Occipitolateral or oblique occipitoposterior. + +Transverse or oblique. +Delayed and difficult. + + +Difficult anterior rotation. Not occurs early above the ischial spines, chance of arrest. + +Difficult delivery with increased chance of perinea! injuries. + +Platype/loid +Occipitolateral. + + +Transverse. +Difficult by exaggerated parietal presentation. + +Anterior rotation usually occurs late in the perineum. + +No difficulty. +Chapter 24: Contracted Pelvis Im + + + + + + + + + + + + + + + + + + + + + + + + + + +Figs. 24.2A and B: (Al Reniform shape of the inlet in a rachitic flat pelvis; (Bl Scoliotic pelvis. + +Inlet: Sacral promontory is pushed downwards and forwards producing a "reniform" shape of the inlet with marked shortening of the anteroposterior diameter without affecting the transverse diameter, which is often increased. +Cavity: Sacrum is flat and tilted backwards. +Outlet: Body weight transmitted through the ischium in sitting position results in widening of the transverse diameter of the outlet and the pubic arch. + +OSTEOMALACIC PELVIS: The deformity is caused by softening of the pubic bones due to deficiency of calcium and vitamin D and lack of exposure to sunrays. The changes in the pelvic bones are: +♦ The promontory is pushed downwards and forwards and the lateral pelvic walls are pushed inwards causing the anterior wall to form a beak. The shape of the inlet thus becomes triradiate. + +ASYMMETRICAL OR OBLIQUELY CONTRACTED PELVIS + +It is seen in: (1) Naegele's pelvis, (2) scoliotic pelvis, (3) due to disease affecting one hip or sacroiliac joint, and (4) tumors or fracture affecting one side of the pelvic bones during growing age. ♦ Naegele's pelvis: This type of pelvis is extremely rare. It is produced due to arrested development of one ala of the sacrum. It may be: (i) congenital or (ii) acquired (osteitis of +sacroiliac joint). Method of delivery is by cesarean section. +Scoliosis involving only the lumbar region will cause deformity of the pelvis (Fig. 24.28). The acetabulum is pushed inwards on the weight-bearing side. Oblique asymmetry of the + +pelvis results in contraction of one of the oblique diameters. Cesarean section is the only safe method of delivery. +Robert's pelvis (transversely contracted pelvis): This is extremely rare. Ala of both the sides are absent and the sacrum is fused with the innominate bones. +Kyphotic pelvis: This pelvic deformity is secondary to the ky­ photic changes of the vertebral column either following tubercu­ losis or rickets. The deformities observed with lumbar kyphosis are: +The sacrum is tilted backwards in the upper part and forwards in the lower part. It is narrow and straight. The anteroposterior diameter of inlet is increased but is diminished at the outlet. Subpubic angle is narrow. Thus, the feature is an extreme funneling of the pelvis. Cesarean section is ideal. + +I PELVIC FRACTURES +Information regarding fracture pattern, malalignment or retained hardwares are obtained by radiologic imaging. X-ray pelvimetry combined with CT have greater accuracy. CT pelvimetry has fetal radiation effect ranging from 250 to 1500 mrad. MRI pelvimetry is superior and has no ionising radiation. MRI helps imaging of pelvis, fetal head, the soft tissues and maternal pelvic dimensions. Decision for cesarean delivery could be made in some cases. + +MECHANISM OF LABOR IN FLAT PELVIS WITH VERTEX PRESENTATION + +In the flat pelvis, the head finds difficulty in negotiating the brim and once it passes through the brim, there is no difficulty in the cavity or outlet {Figs. 24.3A to C). The head negotiates the brim by the following mechanism: ■ The head engages with the sagittal suture in the +transverse diameter. +■ Head remains deflexed and engagement is delayed. +11 If the anteroposterior diameter is too short, the occiput is mobilized to the same side to occupy the sacral bay. The biparietal diameter is thus placed in the sacrocotyloid diameter (9.5 cm or 8.5 cm) and the narrow bitemporal diameter is placed in the narrow conjugate. If lateral mobilization is n.ot possible, there is a chance of extension of the head leading to brow or face presentation. +11 Engagement occurs by exaggerated parietal presentation so that the super-subparietal diameter (8.5 cm), instead of the biparietal diameter (9.5 cm), passes through the pelvic brim. +■ Molding may be extreme and often there is an indentation or even a fracture of one parietal bone. However, the caput that forms is not big. +o Once the head negotiates the brim, there is no dificulty in the cavity and outlet and normal mechanism follows. +GENERALLY CONTRACTED PELVIS: In this type of pelvis the shape remains unaltered, but all the diameters in the +ED Chapter 24: Contracted Pelvis + + + + + + + + + + + +Figs. 24.3A to C: Mechanism of labor in flat pelvis: (A} Lateralization of occiput to the sacral bay; (B and C} Engagement of the head by exaggerated parietal presentation. + + +different planes-inlet, cavity and outlet-are shortened. There is dificulty from the beginning to the end. + +DIAGNOSIS OF CONTRACTED PELVIS + +Presence of fetopelvic disproportion due either to inadequate pelvis or big baby or more commonly a combination of the both. +Past History +Medical: Past history of fracture, rickets, tuberculosis of the pelvic joints or spines is to be enquired. +Obstetrical: While an uncomplicated, previous safe vaginal delivery of an average size baby reasonably excludes pelvic contraction, a history of prolonged labor followed by difficult instrumental delivery or cesarean delivery is suggestive of pelvic contraction. +Physical Examination +Stature: A small woman of less than 5 ft is likely to have a small pelvis. +Dystocia dystrophia syndrome: This syndrome is characterized by the following features: The patient is stockily built with bull neck, broad shoulders and short thighs. She is obese with a male distribution of hairs. They are usually subfertile, having dysmenorrhea, oligomenorrhea or irregular periods. There is increased incidence of pre-eclampsia and a tendency for postmaturity. Pelvis is of the android type. Occipitoposterior position is common. During labor, inertia is common and there is a tendency for deep transverse arrest or outlet dystocia leading to either increased incidence of difficult + +instrumental delivery or cesarean section. There is a chance of lactation failure. + +Abdominal Examination +Inspection: Pendulous abdomen, in primigravidae is suspicious of inlet contraction. +Obstetrical: In primigravidae, usually there is engage­ ment of the head before the onset of labor. +Assessment of the pelvis (pelvimetry): Assessment of the pelvis can be done by bimanual examination: clinical pelvimetry (mostly) or by imaging studies-radiopelvimetry, Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). +Clinical pelvimetry: This is commonly done. +Time: In vertex presentation, the assessment is done at any time beyond 37th week but better at the beginning of labor. Because of softening of the tissues, assessment can be done effectively during this time. Procedures: The patient has to empty the bladder. The pelvic examination is done with the patient in dorsal position taking aseptic preparations. +The following features are to be noted simultaneously: 1. State of the cervix. +2. To note the station of the presenting part in relation to ischial spines. +3. To test for cephalopelvic disproportion in nonengaged head (described later). +4. To note the resilience and elasticity of the perinea! muscles. +Steps: The internal examination should be gentle, thorough, methodical and purposeful (Figs. 24.4A to D). It should be + + + + + + + + + + + +m Figs. 24.4A to D: Clinical assessment of the pelvis. +Chapter 24: Contracted Pelvis ED + + + + + + + + + + + + + + + + + +Figs. 24.SA and B: Measurement of transverse diameter of the outlet and subpubic angle. + + +emphasized that the sterilized gloved fingers once taken out should not be 1·eintroduced. +Sacrum (Fig. 24.4A): The sacrum may be smooth, short and well curved, and the sacral promontory usually cannot be reached or the sacrum may be long or straight. +Sacrosciatic notch (Fig. 24.4B): The notch is sufficiently wide so that two fingers can be easily placed over the sacrospinous ligament covering the notch. The configuration of the notch denotes the capacity of the posterior segment of the pelvis and the sidewalls of the lower pelvis. +Ischial spines (Fig. 24.4C): Spines are usually smooth (everted) and difficult to palpate. They may be prominent and encroach to the cavity thereby diminishing the available space in the midpelvis. Iliopectineal lines (Fig. 24.4D): To note for any beaking +suggestive of narrow forepelvis ( android feature). +Sidewalls: Normally, they are parallel or divergent. They may be convergent. +Posterior surface of the symphysis pubis: It normally forms a smooth rounded curve. Presence of angulation or beaking suggests abnormality. +Sacrococcygeal joint: Its mobility and presence of hooked coccyx, if any, are noted. +Pubic arch: Normally, the pubic arch is rounded and should accommodate the palmar aspect of two fingers. Configuration of the arch is more important than pubic angle. +Diagonal conjugate: Procedure is described before on page 81. After the procedure, the fingers are now taken out. +Subpubic angle: The inferior pubic rami are defined and, in female, the angle roughly corresponds to the fully abducted thumb and index fingers. In narrow angle, it roughly corresponds to the fully abducted middle and index fingers (Fig. 24.5B). +Transverse Diameter of the Outlet (TDO): It is measured by placing the knuckles of the first interphalangeal joints or knuckles of the clinched fist between the two ischial tuberosities (Fig. 24.5A). Normally, it accommodates four knuckles. +Anteroposterior diameter of the outlet:The distance between the inferior margin of the symphysis pubis and the skin over the sacrococcygeal joint can be measured either with the method employed for diagonal conjugate or by external calipers. + +X-ray pelvimetry is of limited value in the diagnosis of pelvic contraction or cephalopelvic disproportion. However, X-ray pelvimetry is useful in cases with fractured pelvis and for the important diameters which are inaccessible to clinical examination (Table 24.3). +Hazards of X-ray pelvimetry includes radiation exposure to the mother and the fetus is about 0.1-0.3 cGy. +Computed tomography ( CT) involves less radiation exposure ( 44-425 millirad) and is easier to perform. Accuracy is greater than that of conventional X-ray pelvimetry. Three images (lateral, AP and axial slice) are taken. +Magnetic Resonance Imaging (MRI) is more accurate to assess the bony pelvis. It is also helpful to assess the fetal size and maternal soft tissues which are involved in dystocia. It has got no radiation risk, hence biologically safe. It is expensive, requires more time and availability is limited. +Intrapartum Ultrasonography (IUSG) is of immense value for the management of labor (WAPM-2022). IUSG provides accurate information in all the areas: (a) Pelvic dimensions (pelvimetry) (Fig. 24.6), (b) fetal presentation, (c) position, (d) descent during the course of labor and (e) degree of flexion of the fetal head (details in Ch. 40, 41). Ultrasonography is useful to measure the fetal head dimensions in the intrapartum phase (Fig. 24.8). + + + +Brim Midpelvis Outlet +■ Diagonal conjugate. ■ Sacrum. ■ Sidewalls. +■ Posterior surface ■ lschial ■ Sacrococcygeal of the symphysis spines. joint. +pubis. ■ lnterspinous ■ Subpubic arch. ■ lliopectineal line. diameter. ■ Subpubic angle. +■ Sacrosciatic notch. ■ Sacrosciatic ■ Transverse Diameter notch. of the Outlet (TDO) +■ Sidewalls. +ID Chapter 24: Contracted Pelvis Anatomical conjugate +Symphysi +/) +U- Obstetric +..-/'"-,.'- . • conjugate + + +Diagonal +conjugate + + + + +Occiput + + +Fig. 24.6: lntrapartum Ultrasonography (USG), to assess the pelvic dimensions and the engagement of fetal presenting part (head), + +DISPROPORTION +DEFINITION: Cephalopelvic disproportion is mainly due to abnormal fetal size or reduced pelvic capacity or more commonly a combination of the both. This causes dystocia in labor, The disparity in the relation between the head and the pelvis is called cephalopelvic disproportion. Disproportion may be either due to an average-size baby with a small pelvis or due to a big baby with normal-size pelvis or due to the combination of both the factors. Pelvic inlet contraction is considered when the obstetric conjugate is <10 cm or the greatest transverse diameter is <12 cm or diagonal conjugate is <11 cm. Marked asynclitim of the presenting head during the course of labor suggest inlet contraction. +Contracted midpelvis: Midpelvis is considered contracted when the sum of the interischial spinous and posterior sagittal diameters of the midpelvis (normal: 10. 0 + 5 = 15.0 cm) is 13.0 cm or less. +Contracted outlet is suspected when the interischial tuberous diameter is 8 cm or less. A contracted outlet is often associated with midpelvic contraction. Isolated outlet contraction is a rarity. Disproportion at the outlet may not give rise to severe dystocia, but may cause perinea! tears. The head, is pushed backwards as it cannot be accommodated beneath the symphysis pubis. +As the head is the largest part of the fetus, it is more important to know whether the greatest diameter of the head passes through the different planes of the pelvis. Thus, from the clinical point of view, identification of the cephalopelvic disproportion is more logical than to concentrate entirely on the measurements of a given pelvis, as the fetal head is the best pelvimeter. Thus, disproportion may be limited to one or more planes. Absence of cephalopelvic disproportion at the brim usually, but not always, negates its presence at the midpelvic plane. On the other hand, isolated outlet contraction without + + + +midpelvic contraction is a rarity. Thus, a thorough assessment of the pelvis and identification of the presence and degree of cephalopelvic disproportion are to be noted while evaluating a case of contracted pelvis, + +DIAGNOSIS OF CEPHALOPELVIC DISPROPORTION (CPD) AT THE BRIM + +The presence and degree of cephalopelvic disproportion at the brim can be ascertained by the following: +♦ Clinical-(a) Abdominal method; (b) Abdomino­ vaginal (Muller-Munro Kerr). +♦ Imaging pelvimetry (see above: Intrapartum Ultraso­ nography) +♦ Cephalometry: (a) Ultrasound; (b) Magnetic reso­ nance imaging; (c) X-ray. +Clinical: In multigravida, a previous history of spontaneous delivery of an average-size baby reasonably rules out contracted pelvis. But in a primigravida with nonengagement of the head even at labor, one should rule out disproportion. +Abdominal method: The patient is placed in dorsal position with the thighs slightly flexed and separated. The head is grasped by the left hand. Two fingers (index and middle) of the right hand are placed above the symphysis pubis keeping the inner surface of the fingers in line with the anterior surface of the symphysis pubis to note the degree of overlapping, if any, when the head is pushed downwards and backwards (Fig. 24.7). +Inferences: +♦ The head can be pushed down in the pelvis without overlapping of the parietal bone on the symphysis pubis-no disproportion. +♦ Head can be pushed down a little but there is slight overlapping of the parietal bone evidenced by touch on the undersurface of the fingers (overlapping by 0.5 cm or 1/4" which is the thickness of the symphysis pubis)­ moderate disproportion. + + + + + + + + + + + + + + + + +Fig. 24.7: Abdominal method of testing cephalopelvic disproportion. +Chapter 24: Contracted Pelvis ii + +♦ Head cannot be pushed down and instead the parietal bone overhangs the symphysis pubis displacing the fingers-severe disproportion. +The abdominal method can be used as a screening procedure. At times, it is difficult to elicit due to deflexed head, thick abdominal wall, irritable uterus and highfloating head. +Abdominovaginal method (Muller-Munro Kerr): This bimanual method is superior to the abdominal method as the pelvic assessment can be done simultaneously. Muller introduced the method by placing the vaginal finger tips at the level of ischial spines to note the descent of the head. Munro Kerr added placement of the thumb over the symphysis pubis to note the degree of overlapping (Fig. 24.8). +Lower bowel is emptied, preferably by enema. The patient is asked to empty the bladder. The patient is placed in lithotomy position and the internal examination is done taking all aseptic precautions. Two fingers of the right hand are introduced into the vagina with the fingertips placed at the level of ischial spines and thumb is placed over the symphysis pubis. The head is grasped by the left hand and is pushed in a downward and backward direction into the pelvis (Fig. 24.8). +Inferences: (1) The head can be pushed down up to the level of ischial spines and there is no overlapping of the parietal bone over the symphysis pubis-no disproportion; (2) The head can be pushed down a little but not up to the level of ischial spines and there is slight overlapping of the parietal bone-slight or moderate disproportion; (3) The head cannot be pushed down and instead the parietal bone overhangs the symphysis pubis displacing the thumb-severe disproportion. + + + + + + + + + + + + + + + + + + + + +Fig. 24.8: Transperineal sonography for assessment of progress of labor (Ch. 41, p. 603). + +Limitations of clinical assessment: (1) The method is only applicable to note the presence or absence of disproportion at the brim and not at all applicable to elicit midpelvic or outlet contraction; (2) The fetal head can be used as a pelvimeter to elicit only the contraction in the anteroposterior plane of the inlet but when the contraction affects the transverse diameter of the inlet, it is of less use. +Cephalometry: While a rough estimation of the size of the head can be assessed clinically, accurate measurement of the biparietal diameter would have been ideal to elicit its relation with the diameters of the planes of a given pelvis through which it has to pass. In this respect, ultrasonographic measurement of the biparietal diameter or Magnetic Resonance Imaging (MRI) gives superior information. The average biparietal diameter measures 9.4-9.8 cm at term. +Magnetic Resonance Imaging (MRI): MRI is useful to assess the pelvic capacity at different planes. It is equally informative to assess the fetal size, fetal head volume and pelvic soft tissues which are also important for successful vaginal delivery. +Deg1·ee of disproportion and contracted pelvis: Based on the clinical and supplemented by imaging pelvimetry, the following degrees of disproportion at the brim are evaluated: +(1) Severe disproportion: Where obstetric conjugate is <7.5 cm (3"). Such type is rare to see. +(2) Borderline: Where obstetric conjugate is between 9.5 cm and 10 cm. When both the anteroposterior diameter ( <10 cm) and the transverse diameter ( <12 cm) of the inlet are reduced, the risk of dystocia is higher than that when only one diameter is contracted. + +EFFECTS OF CONTRACTED PELVIS ON +· PREGNANCY AND LABOR + +Pregnancy: The general course of pregnancy is not much affected. However, the following may occur: (1) Abdomen becomes pendulous, especially in multigravida with lax abdominal wall; (2) Malpresentations are increased three to four times and so also increased frequency of unstable lie. +Labor: The course of events in labor is greatly modified depending upon the degree of pelvic contraction and presentation of the fetus: (1) There is increased incidence of early rupture of the membranes; (2) Incidence of cord prolapse is increased; (3) Cervical dilatation is slowed; (4) There is increased tendency of prolonged labor; (5) There is increased incidence of operative interference, postpartum hemorrhage and sepsis. +Maternal injuries: The injuries of the genital tract may occur spontaneously or following operative delivery. There is increased maternal morbidity and mortality (Ch. 29). +Im Chapter 24: Contracted Pelvis +Fetal hazards: Fetal risks are due to trauma and asphyxia. The net effect leads to increased perinatal mortality and morbidity. + +MANAGEMENT OF CONTRACTED PELVIS (INLET CONTRACTION) +The prerequisite in the formulation of the line of management of contracted inlet is to ascertain the degree of disproportion by clinical examination and supplemented by imaging pelvimetry (rarely done). Due consideration is given to the associated complicating factor, if any. +Minor degrees of inlet contraction usually does not give rise to much problem and the cases have spontaneous vaginal delivery at term. Both the minor and moderate degrees are to be dealt with by any one of the following: ♦ Induction of labor ♦ Elective cesarean section at term ♦ Trial labor. +Induction oflabor prior to EDC: Induction 2-3 weeks prior to the EDC may be considered only in cases with minor-to-moderate degrees of pelvic contraction. It is not favored nowadays. In any case, one should be certain about the fetal gestational age. +Elective cesarean section at term: This is commonly done. Elective cesarean section at term is indicated in-(1) major degree of inlet contraction, and also in (2) moderate degree ofinlet contraction associated with outlet contraction or complicating factors like elderly primigravida. Cases with certain maturity of the fetus, the operation is done in planned way after 38 completed weeks. + +TRIAL LABOR + +Definition: It is the conduction of spontaneous labor in a minor to moderate degree of cephalopelvic disproportion, in an institution under supervision with watchful expectancy, hoping for vaginal delivery, Eve1y arrangement should be made available for operative delivery, either vaginal or abdominal, if the condition so arises. +Aims: A trial labor aims at avoiding an unnecessary cesarean section and at delivering a healthy baby. +The phrase "trial" was used originally to test for pelvic adequacy but subsequently its use has been extended to test numerous factors other than the pelvic capacity. For example, the trial is conducted to test the integrity of the scar in a woman with prior cesarean delivery when she goes into labor. +Contraindications: (1) Associated midpelvic and outlet contraction; (2) Presence of complicating factors like elderly primigravida, malpresentation, postmaturity, post-cesarean pregnancy, pre-eclampsia, medical disorders such as heart disease, diabetes, tuberculosis, etc.; (3) Where facilities for cesarean section is not available round the clock. + + + +Conduction of trial labor: The management of a trial labor requires careful supervision and consideration. The following guidelines are prescribed: +11 The labor should ideally be spontaneous in onset. But in cases where the labor fails to start even on due date, induction of labor may be done. +■ Oral feeding remains suspended and hydration is maintained by intravenous drip. Adequate analgesia (epidural) is administered. +■ The progress of the labor is mapped with a partograph-(a) progressive descent of the head, and (b) progressive dilatation of the cervix. +To monitor the maternal health. Fetal monitoring is done clinically and/or using EFM. +11 If there is failure to progress due to inadequate uterine contraction, augmentation of labor may be done by amniotomy along with oxytocin infusion. On no account should the procedure be employed before the cervix is at least 3 cm (2 fingers) dilated. +'I After the membranes rupture, pelvic examination is to be done: (a) To exclude cord prolapse; (b) To note the color of liquor; (c) To assess the pelvis once more; (d) To note the condition of the cervix, including pressure of the presenting part on the cervix; (e) Use of electronic fetal monitoring (CTG). +Successful outcome depends on: (1) Degree of pelvic contraction; (2) Shape of the pelvis-flat pelvis is better than android or generally contracted pelvis; (3) Favorable vertex presentation-anterior parietal presentation with less parietal obliquity is favorable; ( 4) Intact membranes till full dilatation of cervix; (5) Effective uterine contractions, and (6) Emotional support to the woman. +Ufavorable features: +1. Appearance of abnormal uterine contraction. +2. Cervical dilatation less than 1 cm per hour in the active phase (protracted active phase). +3. Descent of fetal head less than 1 cm per hour (protracted active phase) in spite of regular uterine contractions. +4. Arrest of cervical dilatation and nondescent of fetal head in spite of oxytocin therapy. +5. Early rupture of the membranes. +6. Formation of caput and evidence of excessive molding. 7. Fetal distress. +How long is the trial to be continued? It is indeed difficult to set an arbitrary time limit which is applicable to all cases. One should individualize the case. So long as the progress is satisfactory (evidenced by descent of the head and progressive cervical dilatation) and the maternal and fetal condition remain good, trial may be continued safely. However, if any ominous feature appears, trial is to be terminated forthwith. Nowadays, there is a tendency to +Chapter 24: Contracted Pelvis Em\ + +shorten the duration of trial. In spite of adequate uterine contractions, if there is arrest of descent or dilatation of the cervix for a reasonable period (3-4 hours) in the active phase, labor is terminated by cesarean section. +Termination of trial labor: The methods of termination are any one of the following: +\l Spontaneous delivery with or without episiotomy (30%). +11 Forceps or ventouse (3O%)-dificult forceps delivery is to be avoided. +m Cesarean section ( 4O%)-judicious and timely decision for cesarean delivery is to be taken. However, in significant cases, the section is done even before full dilatation of the cervix, the indication being uterine inertia or fetal distress. +Successful trial: A trial is called successful, if a healthy baby is born vaginally, spontaneously or by forceps or ventouse with the mother in good condition. Delivery by cesarean section or delivery of a dead baby, spontaneously or by craniotomy, is called failure of trial labor. +Advantages of trial labor: (I) It eliminates unnecessary cesarean section electively decided upon; (2) It reduces the need of preterm induction of labor with its antecedent hazards; (3) A successful trial ensures the woman a good obstetric future. +Disadvantages of trial labor: (1) Test of dispropor­ tion remains unproven when cesarean delivery is done due to fetal distress or uterine dysfunction; (2) Increased +perinatal morbidity or mortality due to asphyxia or intracranial hemorrhage when the trial is prolonged and/ or ends in difficult delivery; (3) Increased maternal morbidity due to the effects of prolonged labor and/or operative delivery; (4) Increased psychological morbid­ ity when trial ends with a traumatic vaginal delivery or in cesarean delivery. + + +MIDPELVIC AND OUTLET DISPROPORTION + +In clinical assessment, it is dificult to determine where the midpelvis ends and outlet begins. Moreover, isolated outlet contraction without midpelvic contraction is a rarity. As such, in practice, the two problems are jointly considered as outlet contraction. Cephalopelvic disproportion at the outlet is defined as the one where the biparietal­ suboccipitobregmatic plane fails to pass through the bispinous and anteroposterior planes of the outlet. +Management: Unlike inlet disproportion, clinical diagnosis of midpelvic and outlet disproportion can only be made after the head sufficiently comes down into the pelvis. +(1) Elective cesarean section: Contraction of both the transverse and anteroposterior diameters of the midpelvic plane is dealt by elective cesarean section. +(2) To allow vaginal delivery: In otherwise uncomplicated cases with minor contraction, vaginal delivery It is allowed under supervision with watchful expectancy. Molding and adaptation of the head and "give way" of the pelvis may allow the head to pass through the contracted zone. Delivery is accomplished by forceps or ventouse with deep episiotomy to prevent perinea! injuries, especially with narrow pubic arch. Labor progress should +be mapped with a partograph to make an early diagnosis of dysfunctional labor due to disproportion. Oxytocin may be used to augment labor for adequate uterine contractions. +In active labor when the progress is slower than normal, it is called protracted labor and when there is complete cessation progress, it is called arrest disorder. +If there is no dilatation of cervix or descent of the fetal head after a period of2 hours in the active phase oflabor, cesarean delivery is the option. +CASES SEEN LATE IN LABOR is not an uncommon problem when the referral is delayed. The principles of management rest on: (i) Cesarean section to avoid dificult forceps; (ii) Forceps with deep episiotomy in a selected case. + + + + +► Female pelvis is classified on the basis of the shape of the inlet. The four parent types are: (1) Gynecoid (50%), (2) Anthropoid (25%), (3) Android (20%), and (4) Platypelloid (5%). +► The anatomic features of the parent pelvic types and their obstetric outcomes are different (Tables 24.1 and 24.2). ► Difficult labor (dystocia) due to grossly contracted pelvis is rare these days. +► Cephalopelvic Disproportion (CPD) may be due to an inadequate pelvis or a big baby or, more commonly, due to a combination of both. +► Assessment ofthe pelvis (pelvimetry) can be done by bimanual examination (clinical pelvimetry) or by imaging studies (not commonly done). +► Clinical pelvimetry is to be done in early labor. +► The parameters of assessment with clinical pelvimetry include the brim, mid-pelvis and the outlet (Table 24.3). +► Clinical methods used for the diagnosis of CPD are: (a) Abdominal method, (bl Abdominovaginal (Muller-Munro Kerr) method, (c) Imaging pelvimetry or cephalometry (not commonly done). +► Dystocia is more common in nulliparous women than in multiparous women. +► Trial of labor is the conduction of spontaneous labor in a woman with minor degree cephalopelvic disproportion. It should be in an institution and under supervision with partographic monitoring. +► Trial of labor is aimed at to reduce unnecessary cesarean section and to deliver a healthy baby. ► lntrapartum ultrasonography is an useful tool in the assessment of labor progress. + +♦ + + +Abnormal Uterine Action + + + + + + + + + +❖ Uterine Inertia (Hypotonic Uterine Dysfunction) + + +❖ lncoordinate Uterine Action ❖ Precipitate Labor + + +❖ Tonic Uterine Contraction and Retraction + + + + +Normal labor is characterized by coordinated uterine contractions (Fig. 25.2A) associated with progressive dilatation of the cervix and descent of the fetal head. Normal labor is associated with cervical dilatation more than or equal to 0.5-0.7 cm/hr in a nulliparous woman and 1.3 cm/hr for a multiparous woman. This results in successful vaginal delivery. Overall labor abnormalities occur in about 25% of the nulliparous women and 10% of multiparous women. Abnormal active phase of labor may be protraction or arrest disorder. The most common cause of protraction disorder is inadequate or abnormal uterine contractions. Any deviation of the normal pattern of uterine contractions (as mentioned in page 112) affecting the course of labor is designated as disordered or abnormal uterine action. +TYPES: The following are the different types (Flowchart 25.1). +ETIOLOGY: As the physiology of normal uterine contraction is not fully understood, the cause of its + +disordered action remains obscure. However, the following clinical conditions are often associated: (I) Primigravida specially age >35 years. (2) Premature rupture of membranes. (3) Induction of labor. (4) Prolonged pregnancy. (5) Obesity. (6) Cephalopelvic disproportion on injudicious use of oxytocics. (7) Malpresentation or malposition of the fetus. (8) Injudicious use of analgesics. (9) Emotional factor (anxiety, stress). (10) Chorioamnionitis. +Normal uterine contractions: Polarity of the uterus means when the upper segment contracts, the lower segment relaxes. Normally, there are two pacemakers, one is situated at each cornua of the uterus. The uterine pacemakers generate uterine contractions in a coordinated fashion. The properties of a normal uterine contraction wave are: (i) The intensity of contraction diminishes from the fundus to the lower pole of the uterus; (ii) The contraction wave starts from the pacemaker and propagates towards the lower uterine segment; (iii) The duration of contraction diminishes progressively as the wave moves away from the + + +Flowchart 25.1: Types of abnormal uterine action. + + + +Normal polarity Abnormal polarity (incoordinate uterine action) + + +Hypertonic dysfunction Hypotonic dysfunction (excessive contraction) (uterine inertia common) + +Obstruction Obstruction +(+) +(-) ! +Precipitate Tonic uterine labor contraction and +retraction (Sandi's ring) + + +Spastic lower segment (common) + + +Colicky uterus + + +Asymmetric Constriction Generalized uterine ring tonic +contraction contraction + + +Cervical dystocia + + +I Hypertonic uterus I I Ineffective uterine contraction I +Chapter 25: Abnormal Uterine Action ll, + +pacemaker. In dysfunctional labor, new pacemakers may come up anywhere in the uterus. +The uterine pacemaker is situated at the cornua of the uterus and this generates uterine contractions. Effective uterine contraction starts at the cornua and gradually sweeps downwards over the uterus (Figs. 25.IA to H). In a primary dysfunctional labor, uterine activity, instead of being governed by a single dominant pacemaker, is shifted to less efficient contractions due to emergence of other pacemaker foci. Oxytocin therapy may be effective in restoring the global and effective uterine contractions. +Overall rate of cervical dilatation (at each stage) from 4 cm to 6 cm varies from 0.6 cm to 1.7 cm/hour (Zhang-2022). This is slow but it accelerates after 6 cm of cervical dilatation at a rate of 2.2-2.4 cm/hour. +Primary dysfunctional labor is defined when the cervix dilates less than 1 cm/hr following a normal latent phase of labor (Fig. 27.1). It is the most common abnormality and mostly corrected by amniotomy and/ or oxytocin augmentation. Secondary arrest is defined when the cervical dilatation stops after the active phase of labor has started normally. Secondary arrest of dilatation may be due to: (a) Poor uterine contractions (myometrial fatigue), (b) Cessation of cervical dilatation despite strong uterine contractions (mechanical factors like disproportion and malpresentation). +Uterine activity (contraction) is measured by noting: (i) basal tone; (ii) active (peak) pressure; and (iii) + + +frequency. Assessment is usually done by-(i) Clinical palpation- (inaccurate); (ii) Tocodynamometer with external transducer; (iii) Intrauterine Pressure Catheter (IUPC) is used to measure intrauterine pressure during uterine contractions. Normal baseline tonus is between 5 mm Hg and 20 mm Hg. Minimum uterine pressure required to dilate the cervix is 15 mm Hg over the baseline. Normal uterine contractions in labor create an intrauterine pressure up to 60 mm Hg. Oxytocin is to be used when uterine contractions are inadequate. Oxytocin dose is to be escalated till the optimum uterine contractions (3-4 per 10 minutes) with a peak intrauterine pressure of50-60 mm Hg and a resting tone of 10-15 mm Hg is obtained. + +UTERINE INERTIA {HYPOTONIC UTERINE DYSFUNCTION) + +Uterine inertia is the common type of abnormal uterine contraction but is comparatively less serious. It may complicate any stage of labor. It may be present from the beginning of labor or may develop subsequently after a variable period of effective contractions. +UTERINE CONTRACTION: The intensity is diminished; duration is shortened; good relaxation in between contractions and the intervals are increased. General pattern of uterine contractions of labor is maintained (Figs. 25.IA to H) but intrauterine pressure during contraction is less than 25 mm Hg. + + + + + + + + + + + + + + + + + + + + + + + + + +Figs. 25.lA to H: Normal and abnormal patterns of uterine contractions (dark shade indicating strong contraction): (A) Normal uterine contractions with single dominant pacemaker focus; (B) Uterus with three separate pacemakers firing sequentially; (C) Normal uterine contraction; (Dl Uterine inertia; (El Colicky uterus; (Fl Spastic lower segment; (G) Asymmetrical contraction; (H) Cervical dystocia. +EI Chapter 25: Abnormal Uterine Action + + +DIAGNOSIS +1. Patient feels less pain during uterine contraction. +2. Hand placed over the uterus during uterine contraction reveals less hardening of the uterus. +3. Uterine wall is easily indentable at the acme of a pain. +4. Uterus becomes relaxed after the contraction, fetal parts are well palpable and fetal heart rate remains normal. +5. Internal examination reveals-(a) Poor dilatation of the cervix (normal rate of dilatation in primigravida should be at the rate of 1 cm/hr beyond 4 cm dilata­ tion); (b) Presence of cephalopelvic disproportion, malposition, deflexed head or malpresentation may be evident; (c) Membranes usually remain intact. +EFFECTS ON THE MOTHER AND FETUS: Maternal exhaus­ tion and/or fetal distress are unusual and appear late. +MANAGEMENT: Case is reassessed to exclude cepha­ lopelvic disproportion or malpresentation. +Place of cesarean section: (I) Presence of contracted pelvis; (2) Malpresentation; (3) Evidences of fetal or maternal distress. +Vaginal delivery-(A) General measures: +1. To keep up the morale of the patient. Maternal stress, +pain and anxiety appear to inhibit uterine contractions through release of endogenous catecholamines. +2. Posture of the woman is changed. Supine position is avoided. +3. To empty the bladder, catheterization may be needed. 4. To maintain hydration by infusion of Ringer's solution. 5. Adequate pain relief. + + +(B) Active measures: Acceleration of uterine contraction can be brought about by low rupture of the membranes followed by oxytocin drip. The drip rate is gradually increased until effective contractions are set up. The drip is to be continued till I hour after delivery. + +INCOORDINATE UTERINE ACTION +It usually appears in active stage of labor. The hypertonic state of the uterus arises from any of the conditions such as spastic lower uterine segment, colicky uterus, asymmetrical uterine contraction, constriction ring or generalized tonic contraction of the uterus and all these states are collectively called incoordinate uterine action. Increased frequency and/or duration of uterine contractions cause rise in baseline tone and thereby diminish circulation in the placental intervillous space. These contractions fail to make progressive cervical effacement and dilatation. Frequent contraction of low amplitude causes elevation of basal intrauterine pressure. There is often maternal discomfort. Amniotomy with or without oxytocin augmentation is usually done when the women in the active phase of labor. Conservative management is done if it occurs in the latent phase. Uterine tonus is elevated. Pain is present before, during and +after contractions. This results in fetal hypoxia in labor. Placental abruption is often associated with high baseline tone (>25 mm Hg). On CTG, the FHR shows reduced variability and late decelerations (Figs. 25.2B and C). Uterine hyperstimulation due to oxytocics (oxytocin, prostaglandins) are often associated with fetal tachycardia (fetal adrenergic activity) due to fetal stress. Constriction + + + + +12 (90) + +0) Contraction +I +_ +-+ +interval + +(60) + + +/) +/) +4 QJ (30) +· + +2 (15) + + +Pain +threshold + + +Basal tone + + +__ts:9 15io - . 20-1-20 +c +: +90 901 60-60 + + + +0 2 3 4 Time (minutes) + +Figs. 25.2A to C: (A) Normal uterine contractions showing peak pressure, contraction interval, pain threshold and rise of basal tone; (B) Hypertonic contractions with prolonged duration; (C) Hypertonic contractions with increased frequency-both B and C showing changes in the fetal heart rate (decelerations) on CTG. +Chapter 25: Abnormal Uterine Action ED + +ring, generalized tonic uterine contraction and cervical dystocia have got their own separate clinical entity and as such will be discussed separately. +SPASTIC LOWER SEGMENT-UTERINE CONTRACTION: +1. Fundal dominance is lacking and often there is reversed polarity (Figs. 25.IA to H). +2. The pacemakers do not work in rhythm. +3. The lower segment contractions are stronger. +4. Inadequate relaxation in between contractions. +5. Basal tone is raised above the critical level of 20 mm Hg (Fig. 25.2A). +Diagnosis: (1) The patient is in agony with unbearable pain referred to the back. There are evidences of dehydration and ketoacidosis; (2) Bladder is frequently distended and often there is retention of urine; distension of the stomach and bowels; (3) There are premature attempts to bear down; (4) Abdominal palpation reveals: (a) Uterus is tender and gentle manipulation excites hardening of the uterus with pain, (b) palpation of the fetal parts is dificult; (5) Fetal distress appears early; (6) Internal examination may reveal: ( a) Cervix which is thick, edematous hangs loosely like a curtain; not well applied to the presenting part, (b) Inappropriate dilatation of the cerix, (c) Absence of the membranes, (d) Meconium-stained liquor amnii may be there. +Effect on the fetus: Fetal distress appears early due to placental insuficiency caused by inadequate relaxation of the uterus. +Management: There is no place of oxytocin augmentation with this abnormality. Cesarean section is done in majority of cases. Prior correction of dehydration and ketoacidosis must be achieved by rapid infusion of Ringer's solution. +CONSTRICTION RING (Syn: Contraction ring, Schroeder's ring): It is one form of incoordinate uterine action where there is localized myometrial contraction forming a ring of circular muscle fibers of the uterus. It is usually situated at the junction of the upper and lower segment around a constricted part of the fetus usually around the neck in cephalic presentation (Fig. 25.3). It may appear in all the stages oflabor. It is usually reversible and complete. +The common causes are: (1) Injudicious admin­ istration of oxytocics; (2) premature rupture of the membranes; and (3) Premature attempt at instrumental delivery. +Diagnosis: Diagnosis is difficult. It is revealed during cesarean section in the first stage, during forceps application in the second stage and during manual removal in the third stage (hour-glass contraction). The ring is not felt per abdomen. Maternal condition is not much affected but the fetus is in jeopardy because of the hypertonic state. Uterus never ruptures. + +forceps delivery (second stage) or during normal removal of placenta (third stage) can be overcome by using deep anesthesia that relaxes the constriction ring. +CERVICAL DYSTOCIA: Progressive cervical dilatation needs an effective stretching force by the presenting part. Failure of cervical dilatation may be due to-(a) Inefficient uterine contractions, (b) Malpresentation, malposition (abnormal relationship between the cervix and the presenting part), (c) Spasm (contractions) of the cervix. Cervical dystocia may be primary or secondary. +Primary: Commonly observed during the-(i) First birth where the external os fails to dilate; (ii) Rigid cervix; (iii) Ineficient uterine contractions, and the others (as mentioned earlier). +Treatment: In presence of associated complications (malpresentation, malposition), cesarean section is preferred. If the head is suficiently low down with only thin rim of cervix left behind, the rim may be pushed up manually during contraction or traction is given by ventouse. In others, where the cervix is very much thinned out but only half dilated Diihrssen's incision at 2 and 10 o'clock positions followed by forceps or ventouse extraction is quite safe and effective. +SECONDARY CERVICAL DYSTOCIA: This type of cervical dystocia results usually due to excess scarring or rigidity of the cervix from the effect of previous operation or disease (Ch. 21). Others are: (i) Post-delivery; (ii) Postoperative scarring; (iii) Cervical cancer. +GENERALIZED TONIC CONTRACTION (Syn: Uterine tetany): In this condition, pronounced retraction occurs involving whole of the uterus up to the level of internal os. Thus, there is no physiological differentiation of the active upper segment and the passive lower segment of the uterus. The whole uterus undergoes a sort of tonic muscular spasm holding the fetus inside (active retention of the fetus) (Fig. 25.4). Usually there is no risk of rupture uterus. New pacemakers appear all over the uterus. + + + +Treatment: Delivery is usually done by cesarean section. The ring usually passes off by deepening the +plane of anesthesia otherwise the ring may have to be cut Fig. 25.3: Constriction ring. vertically to deliver the baby. The dificulties faced during + + + +Fig. 25.4: Generalized tonic contraction of the uterus. +JD Chapter 25: Abnormal Uterine Action +Causes: (i) Cephalopelvic disproportion; (ii) Obstruction; (iii) Injudicious use of oxytocics. +Clinical features: The patient is in prolonged labor having severe and continuous pain. Abdominal examination reveals the uterus to be somewhat smaller in size, tense and tender. Fetal parts are neither well defined, nor is the fetal heart sound audible. Vaginal examination reveals jammed head with big caput, dry and edematous vagina. + +Treatment +♦ Correction of dehydration and ketoacidosis-by rapid infusion of Ringer's solution. +♦ Antibiotic-to control infection. ♦ Adequate pain relief. +Hypercontractility (tachysystole) may be induced by oxytocics (>5 contractions in 10 min). It may occur in spontaneous or with stimulated labor. Persistent tachysystole with FHR abnormality can cause fetal hypoxia. It can be managed by tocolytics (terbutaline 0.25 mg SC). Oxytocin infusion should be stopped. +Cesarean delivery is done in majority of the cases, especially when obstruction is suspected. + +PRECIPITATE LABOR AND DELIVERY + +A labor is called precipitate when the combined duration of the first and second stage is less than 3 hours. Prevalence is about 2%. Short labors may be associated with: placental abruption and uterine tachysystole. It is common in multiparae and may be repetitive. Rapid expulsion is due to the combined effect of hyperactive uterine contractions associated with diminished soft tissue resistance. Labor is short as the rate of cervical dilatation is 5 cm/hr or more for the nulliparous women. +Maternal risks include: +1. Extensive laceration of the cervix, vagina and perineum (to the extent of complete perinea! tear). +2. PPH due to uterine hypotonia that develops subsequent to unusual vigorous contractions. +3. Inversion. +4. Uterine rupture. 5. Infection. +6. Amniotic fluid embolism. +The fetal/neonatal risks include: Intracranial stress and hemorrhage because of rapid expulsion without time for molding of the head. Apgar score is low due to tumultous uterine contractions and reduced fetal oxygenation. The baby may sustain serious injuries if delivery occurs in standing position; bleeding from the torn cord and direct hit on the skull, brachia! plexus injury are real hazards. +Treatment: The patient having previous history of precipitate labor should be hospitalized prior to labor. During labor, the uterine contraction may be suppressed + + + +by administering tocolytic agents. Delivery of the head should be controlled. Episiotomy should be done liberally. Elective induction of labor by low rupture of membranes and conduction of controlled delivery is helpful. Oxytocin augmentation should be avoided. + +TONIC UTERINE CONTRACTION AND RETRACTION (SYN: BANDL'S RING, PATHOLOGICAL RETRACTION RING) + +This type of uterine contraction is predominantly due to obstructed labor. +Pathological anatomy of the uterus: There is gradual increase in intensity, duration and frequency of uterine contraction. The relaxation phase becomes less and less; ultimately, a state of tonic contraction develops. Retraction, however, continues. The lower segment elongates and becomes progressively thinner to accommodate the fetus driven from the upper segment (Figs. 25.5A and B). A circular groove encircling the uterus is formed between the active upper segment and the distended lower segment, called pathological retraction ring (Bandl's ring). Due to pronounced retraction, there is fetal jeopardy or even death. +In primigravidae, further retraction ceases in response to obstruction and labor comes to a standstill-a state of uterine exhaustion. Contractions may recommence after a brief period of rest with renewed vigor. But in multiparae, retraction continues with progressive circumferential dilatation and thinning of the lower segment. There is progressive rise of the Bandl's ring, moving nearer and nearer to the umbilicus and, ultimately, the lower segment ruptures (Figs. 25.5A and B). + + + + + + + + + + + + + + + + + + +Figs. 25.SA and B: Pathogenesis of retraction ring {Bandl's ring): {A) Normal labor; {Bl Late obstruction. Note the circumferential dilatation and progressive stretching of the lower segment with corresponding thickening of the upper segment and rise in the level of retraction ring following obstruction. +Chapter 25: Abnormal Uterine Action ED w le. , 1:J;,£t ! f !: t !' !r,i !l?- !Ln . .Q t " r !i, UJ'fI!}9{ t: tJ !i*. f4%: !f lITl}?iFtilfl ) /J;. ;tJl!ti ; : \ \· :,';-,¥ ;t 'e :;; ;3 ' \f; - i , + +• +P +- +t +; + + +" + +. +: +; +. +, +, + +w + + +" +N +n +s +l +. + +< +l +l +! + +, +, + + +" +' + + + +- +; +i +} + +i + + + +f +P +! +& +" +i +m +i +J +H +, +t +- +: +1 +1 +. + +L +. +) + + +< +t +; +" +; +: +t +, +• +, +n +• +l +l +¾ +" + +Z +! +t +( +' + +l +" +' +- +J +! +f + +J +: +W +; +. +r +, +. + +. +i +: +t + + +t +! +' +H +1 +t +, +, +: +. +- +t +, +- +o +< + +, +; +; +w +r + +0 +; +' +¥ + +r +, +" +. +1 +f +. +. +' + + + + +, +, +J +" +7 +b +o +- +' +. +' +Y +, +i +, +n +; +: +r + +, +, +3 +' +i + +; +; +\ +< +1 +% +. +. +i +) +i +' + +; +' +J +. +J +; +s +' +< +{ +: +; +, +- +; +t +, +• +, +: +, +f + + + +t +k +" +' +: +f +" +' +' +; +f +; +r +i +' +. +i +o +" + +s +1 + +· +: +, +J +I + + + +Nature + +Cause Situation + + +Uterus + + + +Maternal condition +Abdominal examination + + + +Vaginal examination + + +End result + + +Principle of treatment + +Constriction ring +It is a manifestation of localized incoordinate uterine contraction. +Undue irritability of the uterus. +Usually at the junction of upper and lower segment but may occur in other places. Once formed, the position does not alter. +• +Upper segment contracts and retracts with relaxation in between; lower segment remains thick and loose (Fig. 25.3). +• +Polarity is abnormal. +Almost unaffected unless the labor is prolonged. + +a. Uterus feels normal and not tender. b. Fetal parts are easily felt. +c. Ring is not felt. +d. Round ligament is not felt. e. FHS is usually present. +a. Lower segment is not pressed by the presenting part. b. Ring is felt usually above the head. +c. Features of obstructed labor are absent. + +a. Maternal exhaustion is a late feature. b. Fetal hypoxia usually appears late. +c. Chance of uterine rupture is absent. +To relax the ring followed by delivery of the baby or to cut the ring during cesarean section. Cesarean delivery and to cut the ring, if needed. + +Retraction ring +It is an end result of tonic uterine contraction and retraction. + +Following obstructed labor. +Always situated at the junction of upper and lower segment The position progressively moves upwards. + +• Upper segment is tonically contracted with no relaxation. The wall becomes thicker; lower segment becomes distended and thinned out (Fig. 25.S). +• Polarity is normal. +Features of maternal exhaustion, sepsis appear early. + +a. Uterus is tense and tender. b. Not easily felt. +c. Ring is felt as a groove placed obliquely. d. Round ligaments are taut and tender. e. Usually absent. +a. Lower segment is very much pressed by the forcibly driven presenting part. +b. Ring cannot be felt vaginally. c. Features are present. +a. Maternal exhaustion and sepsis appear early. b. Fetal anoxia and even death are usually early. c. Rupture uterus in multigravidae is common. +Cesarean delivery after excluding rupture uterus. + + + +Clinical features: (I) Patient is in agony from continuous pain and discomfort and becomes restless; (2) Features of exhaustion and ketoacidosis are evident; +(3) Abdominal palpation reveals-(a) Upper segment is hard and tender, (b) Lower segment is distended and tender. For other features in Table 25.1. +Management: Prevention-Partographic management of labor, early diagnosis of malpresentation, disproportion and delivery by cesarean section can prevent this condition completely. +Treatment +■ Correction of dehydration and ketoacidosis by infusion of Ringer's solution (Flowchart 25.2). +■ Rupture of uterus is to be excluded. a Adequate pain relief. +11 Parenteral antibiotic is given (ceftriaxone 1 g N). !1 Cesarean delivery is done in majority of the cases. 11 Internal version is contraindicated. + +SUMMARY +Abnormal uterine action is due to development of abnormal polarity on the uterus. It may manifest as uterine inertia (common) or hypertonic dysfunction due to any + +mechanical factor ( obstruction). Hypertonic dysfunction may end in either formation of Bandl's ring or precipitate labor. Incoordinate uterine action (asymmetric uterine contractions, constriction ring and cervical dystocia) can affect the health of both the mother and the fetus adversely. It is important to detect AUA early and to institute management appropriately to reduce maternal and neonatal morbidity and mortality (Flowchart 25.2). +Preventive measures of dystocia due to abnormal uterine action: +1. Quality antenatal care, emotional support to be parturient and close monitoring of labor can reduce abnormal uterine action. +2. Induction of labor should be judicious, especially when the cervix is unfavorable. +3. Amniotomy in the latent phase or as a routine procedure is to be avoided. +4. During the course of labor, the woman should be given adequate moral support, rest and analgesic. Her hydration should be maintained. +5. Management of labor should be plotted partographi­ cally so that any deviation from the normal is detected and managed early. +Ii Chapter 25: Abnormal Uterine Action +! +Flowchart 25.2: Management of dysfunctional labor. + +NON-PROGRESS OF LABOR +■ Arrest in cervical dilatation. +■ Arrest in descent of fetal head. + + +Reassessment + + +Mother +■ Uterine contractions. +■ Pelvic adequacy by clinical pelvimetry. ■ Pain tolerance. +■ Evidence of any infection, dehydration. + + + + +Fetus +■ Estimated fetal weight. ■ FHR pattern. +■ Fetal presentation, position, station. ■ Liquor color. + + + +To correct dehydration, sepsis (start IV Ringer solution and antibiotics) + + +Evidence of • CPD +• Fetal distress • Big baby + +Cesarean delivery + + + +Progress satisfactory +l + +Vaginal delivery + + +Pelvis adequate, average weight fetus, with engaged head but inadequate uterine contractions. + + +• Start oxytocin. +• Amniotomy-if not done before. • Pain relief-epidural analgesia. +• Fetal monitoring (EFM preferred). + + +No progress of labor +l + + + +First stage + +cs + + +Second stage + +• cs +• Operative vaginal delivery by forceps or ventouse. + + + + + +► Abnormal uterine action is an important cause of abnormal labor. Abnormal uterine actions are due to many factors and are of different types. Slow progress of labor is commonly due to uterine inertia. +► Supine position during labor should be avoided. Left lateral tilt is preferable. +► In a primary dysfunctional labor, uterine contractions are less efficient as there is emergence of other pacemakers instead of a dominant single one. +► Oxytocin is often effective to correct the underlying pathology and to restore global uterine contractions. +► Uterine contractions are best assessed by measuring the intrauterine pressure. Manual assessment of uterine activity is inaccurate. It is the peak uterine contraction pressure that causes progress of labor (Fig. 25.2A). +► Constriction ring dystocia affects mainly the fetus whereas retraction ring dystocia affects both the fetus and the mother adversely. Rupture of uterus must be excluded in Band l's (retraction) ring dystocia. +► Cesarean deliveries for dystocia should not be done unless adequate uterine contractions have been achieved. +Complicated Labor: +Malposition, Malpresentation +and Cord Prolapse + + + + + + +❖ Occiput Posterior {OP) Position ► Diagnosis +► Mechanism of Labor ► Course of Labor +► Management of Labor +► Arrested Occiput Posterior Position ❖ Deep Transverse Arrest {DTA) +❖ Manual Rotation for Occiput Posterior Position +❖ Breech Presentation ► Varieties +► Etiology of Breech Presentation ► Diagnosis of Breech Presentation + + +► Mechanism of Labor in Breech Presentation +► Complications of Vaginal Breech Delivery +► Antenatal Management +► Management of Vaginal Breech Delivery +► Assisted Breech Delivery +► Management of Complicated Breech Delivery +❖ Face Presentation +► Mechanism of Labor ► Diagnosis + + +► Management +► Vaginal Delivery ❖ Brow Presentation ❖ Transverse Lie +► Diagnosis +► Clinical Course of Labor ❖ Management of Shoulder +Presentation ❖ Unstable Lie +❖ Compound Presentation ❖ Cord Prolapse +► Management + + + + +OCCIPUT POSTERIOR (OP) POSITION + +Malposition refers to any position of the vertex other than flexed occiput anterior one. +In a vertex presentation where the occiput is placed posteriorly over the sacroiliac joint or directly over the sacrum, it is called an occiput posterior position. When the occiput is placed over the right sacroiliac joint, the position is called Right Occiput Posterior (ROP), traditionally called third position of the vertex and when placed over the left sacroiliac joint, is called Left Occiput Posterior (LOP), traditionally called fourth position of the vertex (Figs. 26.IA and B) and when it points toward the sacrum, is called direct occiput posterior. All the three positions may be primary (present before the onset of labor) or secondary (developing after labor starts). + + + + + + + + + + + + + +Figs. 26.1A and B: {A) Right occiput posterior position; (Bl Left occiput posterior position. + +Occiput posterior is an abnormal position of the vertex rather than an abnormal presentation. In majority of cases (90%), anterior rotation of the occiput occurs and follows the course like that of an occiput anterior and moreover, in certain type of pelvis (anthropoid), it is a favorable position. But as the posterior position occasionally gives rise to dystocia, it is described along with malpresentation. +Incidence: At the onset of labor, the incidence is about 10% of all the vertex presentations. The incidence is expected to be more during late pregnancy and is much less in late second stage of labor. Right occiput posterior is five times more common than the left occiput posterior. Dextrorotation of the uterus and the presence of the sigmoid colon on the left disfavor LOP position. +Cause: In majority, the cause of the abnormal position is not clear. The following are the responsible factors: +♦ Shape of the pelvic inlet: The shape of the inlet significantly determines the position of the head at the onset of labor. In more than 50%, the occiput posterior position is associated with either an anthropoid or android pelvis. The wide occiput can comfortably be placed in the wider posterior segment of the pelvis. +♦ Fetal factors: Marked deflexion of the fetal head, too often favors posterior position of the vertex. The causes of deflexion are: (I) High pelvic inclination; (2) Attachment of the placenta on the anterior wall of the uterus-this favors the well-flexed fetus ovoid looking toward the anterior wall of the uterus, i.e., remains in dorsoposterior position. Thus, the convexities of +ll Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse + + + +--r, +l ', .. _,, ',,\ + + + + +, + +,,;.------- +.. ___ cw.. --.; ---... ,. +, +1 + + +; +_ +.. +.. +, -,,.•. +.. +,/ +...... ,,, +,," +/,, + + f!, - -,,) +_________,../ - -c: '•.;_________ _ +:_ + + + + + + +Figs. 26.2A and B: Abdominal contour in: (A) Anterior; (B) Posterior positions of vertex presentation. + + +the fetal and maternal spines are apposed, leading to tendency of extension of the fetal spines with persistent deflexed attitude of the head; (3) Primary brachycephaly-this shortens the length of the lever from the frontal to atlanto-occipital joint, and thereby diminishes the effective movement of flexion. +♦ Uterine factor: Abnormal uterine contraction, which may be the cause or effect, leads to persistent deflexion and occiput posterior position. +I DIAGNOSIS ABDOMINAL EXAMINATION +Inspection: The abdomen looks flat, below the umbilicus (Figs. 26.2A and B). +Umbilical grip: The findings are-(1) The fetal limbs are more easily felt near the midline on either side. (2) The fetal back is felt far away from the midline on the flank and often difficult to outline clearly. (3) The anterior shoulder lies far away from the midline. +Pelvic grips: The findings are-(l) The head is not engaged; (2) The cephalic prominence (sinciput) is not felt so prominent as found in well-flexed occiput anterior. In direct occiput posterior, the small sinciput is confused with breech. + +Auscultation: The maximum intensity of the fetal heart sounds is heard on the flank and often difficult to locate especially in LOP. However, in direct occiput posterior, the FHS is distinctly felt in the midline. +VAGINAL EXAMINATION +The findings in early labor are: (l) Elongated bag +of membranes which is likely to rupture during examination. (2) The sagittal suture occupies any of the oblique diameters of the pelvis. (3) Posterior fontanel is felt near the sacroiliac joint. ( 4) The anterior fontanel is felt more easily because of deflexion of the head and, at times, is felt at a lower level than the posterior one (Figs. 26.3A and B). +In late labor, the diagnosis is often difficult because of caput formation which obliterates the sutures and fontanels. In such cases, the ear is to be located and unfolded pinna points toward the occiput. Simultaneous assessment of the pelvis should be done. +Imaging: Ultrasonography is the gold standard for the diagnosis of OP in labor. Bedside USG is highly accurate (>99%) compared to clinical examination (80%). Fetal orbits face anteriorly to the left in right sinciput posterior position. Fetal cerebellum is seen anteriorly in occiput anterior position. USG is also helpful to know the descent, + + + + + + + + + + + + + + + +Figs. 26.3A and B: Diagnosis of the attitude of the head. (A) Occiput anterior-well-flexed head-posterior fontanel easily felt; (B) Occiput posterior-deflexed head-anterior fontanel easily felt. +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse ED + +attitude of the head and its relation to the pelvic walls (position). +I MECHANISM OF LABOR +The head engages through the right oblique diameter in ROP and left oblique diameter in LOP. The engaging transverse diameter of the head is biparietal (9.5 cm) and that of anteroposterior diameter is either suboccipitofrontal (10 cm) or occipitofrontal (11.5 cm). Because of deflexion, engagement is delayed. +IN FAVORABLE CIRCUMSTANCES (90%) +■ Flexion: Good uterine contractions result in good flexion of the head. Descent occurs until the head reaches the pelvic floor. +■ Internal rotation of the head: As the occiput is the leading part, it rotates 3/8th of a circle (135°) anteriorly to lie behind the symphysis pubis. As the neck cannot sustain such amount of torsion, the shoulders rotate about 2/8th of a circle to occupy the right oblique diameter in ROP and the left oblique in LOP with I/8th of a circle torsion of the neck still left behind. Thus, the rest of the mechanism is like that of right occiput anterior in ROP and that of left occiput anterior in LOP {Flowchart 26.1). +11 Further descent and delivery of the head occurs like that of occiput anterior position. +■ Restitution: There is movement of restitution to the extent of I/8th of a circle in the opposite direction of internal rotation of the head. + +■ External rotation: The external rotation of the head occurs through I/8th of a circle in the same direction of restitution as the shoulders rotate from the oblique to anteroposterior diameter of the pelvis {Fig. 26.4A). +11 Birth of the shoulders and trunk: The process of expulsion is the same as that of occiput anterior. +Alternative mechanism (uncommon) {Fig. 26.4B): If the +shoulders fail to follow the anterior rotation of the occiput, the neck sustains a torsion equal to 3/8th of a circle (135°) and the shoulders remain static in the left oblique diameter in ROP and in the right oblique diameter in LOP. In such cases, restitution occurs 3/8th of a circle and external rotation occurs through I/8th of a circle in the opposite direction of restitution. However, the mechanism is quite unlikely. +In unfavorable circumstances (nonrotation or ma/rotation)-10%. +In certain circumstances, the occiput fails to rotate as described previously (Fig. 26.5). The causes are deflexion of the head, weak uterine contraction, faulty shape of the pelvis such as flat sacrum, prominent ischial spines or convergent side walls and weak pelvic floor muscles. Big baby and immobility of the fetal trunk consequent to the drainage ofliquor amnii also contribute to faulty rotation. +■ Incomplete forward rotation: In this condition, the occiput rotates through I/8th of a circle anteriorly and the sagittal suture comes to lie in the bispinous diameter. Thereafter, further anterior rotation is unlikely and arrest in this position is called deep transverse arrest. + + +Flowchart 26.1: Scheme of mechanism of labor in occiput posterior position. + +Diameter of engagement: Oblique diameter +Engaging diameter of the head: Occipitofrontal-11.5 cm, or suboccipitofrontal-10 cm + + + +Favorable + +• Good uterine contraction. • Favorable pelvis. + +Unfavorable + +• Weak pains. +• Android or anthropoid pelvis. + + + + + + +D +E s +C +E +N +T + +Increasing flexion with engagement. Engagement delayed. + +Long anterior internal rotation of the occiput (318th of circle). Deflection persists. Simultaneous rotation of the anterior shoulder through +! +218th of circle. Descent up to pelvic floor. + +Delivery of the head by extension. +Mild deflexion. Moderate deflexion. +! +! +Restitution (118th circle). +! +Anterior rotation Nonrotation of +of occiput (118th circle). occiput. +i +External rotation (118th circle). +Deep Transverse Oblique posterior Arrest (OTA). arrest. + + + + + + + +Severe deflexion. +! + +Posterior rotation of occiput. +i + +Occipitosacral position. + + + +■ Spacious gynecoid or; ■ Anthropoid pelvis. +Face-to-pubis delivery. Arrest (occiputo-sacral arrest). +· IJ Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse + + + + + + + + + + + +Figs. 26.4A and B: Diagram to illustrate the rotation of the occiput in ROP (3rd) position: (A) Common; (Bl Uncommon. (1 = Internal rotation; 2 = Restitution; 3 = External rotation). + + +■ Nonrotation: Both the sinciput and the occiput touch the pelvic floor simultaneously due to moderate deflexion of the head resulting in nonrotation of the occiput. The sagittal suture lies in the oblique diameter. Further mechanism is unlikely and the condition is called oblique posterior arrest. +■ Malrotation: In extreme deflexion, the sinciput touches the pelvic floor first resulting in anterior rotation of the sinciput to I/8th of a circle and putting the occiput to the sacral hollow. This position is termed as occipitosacral position. This is, in the true sense, "Persistent Occiput Posterior" (POP) of the vertex. In favorable circumstances, i.e., with an average-size baby, good uterine contractions and an adequate pelvis such as an anthropoid or spacious gynecoid­ spontaneous delivery may occur as "face to pubis". In unfavorable circumstances, when arrest occurs, it is called occipitosacral arrest. + + + + + + + + +Right posterior +l + + +Mechanism of''face to pubis" delivery (Fig. 26.6) +■ Further descent occurs until the root of the nose hinges under the symphysis pubis. +■ Flexion occurs; releasing successively the brow, vertex and occiput out of the stretched perineum and then the face is born by extension. +■ Restitution: The head moves I/8th of a circle in the opposite direction of internal rotation thus turning the face to look toward the mother's left thigh in ROP and right thigh in LOP. +■ External rotation: The occiput further rotates to the same direction of restitution to I/8th of a circle placing finally the face looking directly toward the left thigh in ROP and the right thigh in LOP. +Persistent occiput posterior: In the true sense, it is an abnormal mechanism of the occiput posterior position where there is malrotation of the occiput posteriorly toward the sacral hollow (occipitosacral position). + + + + + + + + + +l +Unfavorable +i + + + + + + + + + + + +Long rotation +(3/8°) + + +Short anterior rotation Nonrotation +(1/8°) (OTA) + + +Short posterior rotation +(1/8°) + +Fig. 26.5: Diagrammatic representation showing favorable and unfavorable rotation of occiput posterior position. +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse &I + + + + + + + + + + + + + +Fig. 26.6: Face-to-pubis delivery with occipitofrontal diameter emerges out of the introitus. + +As previously mentioned, delivery may occur spontaneously as face-to-pubis but arrest may occur in this position and is called occipitosacral arrest. +In the wider sense, it also includes two other arrested positions of the occiput posterior, namely deep transverse arrest and oblique posterior arrest. +I COURSE OF LABOR +Unlike the occiput anterior, the course of events in labor is likely to be modified in occiput posterior position. The average duration of both the first and second stage of labor is increased. +First stage: There is a tendency to delay. +1. Engagement: Engagement is delayed due to: (i) Persistence of deflexion of the head thereby increasing the diameter of engagement [occipitofrontal-11.5 cm (4½")]. (ii) The driving force transmitted through the fetal axis is not in alignment with the axis of the inlet. +2. Membrane status: Deflexed head becomes ovoid and this cannot fit well to the spherical lower segment ➔ loss of ball valve action during uterine contraction ➔ early rupture of the membranes and drainage of liquor. +3. Uterine contraction: Because of ill-fitting of the deflexed head to the lower uterine segment, there is lack of stimulus for uterine contraction. This results in abnormal uterine contraction with slow dilatation of the cervix. Pressure on the rectum by the wide occiput results in premature desire of bearing-down effort even in the first stage. The patient, as a result, becomes exhausted. There is prolongation of the first stage. +Second stage: The second stage is often delayed due to long internal rotation or malrotation with, at times, arrest of the head. This may happen in android pelvis or in midpelvic contraction. If felt uncared for, arrest of the head may lead to obstructed labor. +Third stage: There is increased incidence of postpartum hemorrhage and trauma to the genital tract. +MODE OF DELIVERY +1. Long anterior rotation of the occiput: Spontaneous or assisted vaginal delivery usually occurs (90%). + +2. Short posterior rotation: Spontaneous or assisted vaginal delivery may occur as face-to-pubis. There is more chance of perineal injuries than with anterior vertex delivery. This is because: (a) wide biparietal diameter 9.5 cm (3¾") stretches the perineum, and (b) occipitofrontal diameter 11.5 cm (4½") emerges out of the introitus (Fig. 26.6). +3. Nonrotation or short anterior rotation: Spontaneous vaginal delivery is unlikely except in favorable circumstances. If left uncared for, the case presents features of prolonged and obstructed labor. Vaginal operative delivery in such cases may, at times, become risky producing trauma to the genital tract (complete perinea! tear) or injury to the fetal head. +Molding: The characteristic molding of the head observed in "face-to-pubis" delivery has been shown in Figure 9.5C. There is compression of the occipitofrontal diameter with elongation of the vault at right angle to it. The frontal bones are displaced beneath the parietal bones. This type of molding favors tentorial tear because of extreme elevation of falx cerebri. +Prognosis: There is increased maternal morbidity, incidental to prolonged labor and increased incidence of operative delivery (1 in 5). There is also increased perinatal morbidity and mortality (10%) due to asphyxia or trauma during vaginal operative delivery. However, it is to be remembered that in 4 out of 5 cases, there is usually no trouble and the fetus is delivered spontaneously. + +I MANAGEMENT OF LABOR +PRINCIPLES: The underlying principles in the management ofthe occiput posterior position are- +(1) Early diagnosis; (2) Strict vigilance with watchful expectancy hoping for descent and anterior rotation of the occiput; and (3) Judicious and timely interference, if necessary (Flowchart 26.2). +Diagnosis and evaluation: Fetal back on the flank with the FHS not being easily located, early rupture of the membranes should arouse suspicion. Internal examination is confirmatory (mentioned earlier). +Apart from the overall assessment of the case, the pelvic assessment is mandatory. Pelvic adequacy is assessed clinically. Inclination of the pelvis, configuration of the inlet, sacrum, ischial spines and the side walls are to be noted. +Early Cesarean Delivery (CD): Occiput posterior per se is not an indication of cesarean section. Pelvic inadequacy or its unfavorable configuration, along with obstetric complications such as, pre-eclampsia, elderly primigravida (>35 years), big baby usually need CD. +First stage: In otherwise uncomplicated cases, the labor is allowed to proceed in a manner similar to normal labor. The following are the special instructions: +ID Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse +Flowchart 26.I2M: AScNhAeGmEeMfEoNr TmOanFaOgeCmCeIPnUt ToPf OocScTipEuRtIOpRosPteOriSoIrTIpOoNsitI ion. + +■ Early diagnosis. +■ Careful monitoring ·of labor. +■ Judicious and timely interference. + +Watchful expectancy Early CS-not indicated per se ++ +l • +• Inadequate pelvis. +• Oxytocin augmentation if needed. To assess the case in early 2n+d stage. • (Apsres-oeccialatmedpscioam, bpilgicabtainbgy)f. actors Anterior rotation of POP +• +the occiput (90%) Assess +l +or +■ The pelvis +■ Cause of failure of anterior rotation or malrotation +Spontaneous ■ Feta I status +Venotor use Partial ante+rior rotation Nonro+tation Malro+tation Forceps delivery +! +! ! +I +DTIA Oblique posI terior arrest Occpiopsitiotisoancral Assisted delivery +Pelvis aidequate Pelvis inladequate +! + +• Ventouse-ideal. cs +i +Spontaneous +i +Arrest in descent. +t +Station of the head. +• Manual rotation and forceps application. • Forceps rotation and delivery-only by +expert with Kielland rotational forceps. face-to-pubis delivery (spacious gynecoid +i or anthropoid pelvis). ++ +i +i +I POP: Persistant OcciputorPosterior I Above the level of ischial spine. Below the spines. +OTA: Deep Transverse Ar est +i +cs Ventouse or forceps with liberal episiotomy. + + + ++ Anticipating prolonged labor, intravenous infusion line is sited and Ringer's solution drip is started. ++ Progress oflabor is judged by: (a) Progressive descent of the head; {b) rotation of the back and the anterior shoulder toward the midline; (c) increasing flexion of the head; (d) position of the sagittal suture on vaginal examination; and (e) cervical dilatation. ++ Weak pain, persistence of deflexion and nonrotation of the occiput are the triad too often coexistent. In such a situation, oxytocin infusion is started for augmentation of labor. ++ Indication of CS: (a) Arrest of labor (failure of rotation); {b) incoordinate uterine action; and (c) fetal distress. +Second stage: In majority, anterior rotation of the occiput is completed and the delivery is either spontaneous or can be accomplished by low forceps or ventouse. +In minority {unrotated and malrotated): Provided the fetal and maternal conditions permit, one should take a watchful expectancy for the anterior rotation of the occiput and descent of the head. In occipitosacral + +position, spontaneous delivery as face-to-pubis may occur. In such cases, proper conduction of delivery and liberal episiotomy should be done to prevent complete perinea} tear. +Third stage: Because of prolongation of labor, tendency of postpartum hemorrhage can be prevented by prophylactic intravenous ergometrine 0.25 mg with the delivery of the baby. Following vaginal operative delivery, meticulous inspection of the cervix and lower genital tract should be made to detect any injury. + +■ ARRESTED OCCIPUT POSTERIOR POSITION + +If there is failure to progress (arrest) in spite of good uterine contractions for about ½-1 hour after full dilatation of the cervix, interference is indicated. The case is once more to be assessed abdominally and vaginally before formulating the suitable method of interference. +Per abdomen: The following conditions are assessed: (1) Size of the baby; (2) Engagement of the head; (3) Amount ofliquor; (4) FHS. +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse Im + +Vaginal examination: The following conditions are to be noted-(!) Station of the head; (2) Position of the sagittal suture and the occiput; (3) Degree of deflexion of the head; ( 4) Degree of molding and ca put formation, (5) Assessment of the pelvis at and below the level of obstruction, i.e., ischial spines, side walls of the pelvis, sacrococcygeal plateau, pubic arch and transverse diameter of the outlet. +I. ARREST IN OCCIPUT TRANSVERSE OR OBLIQUE OCCIPUT POSTERIOR POSITION +1. Ventouse (vacuum extraction): It is suitable in cases where the pelvis is adequate and the nonrotation of the occiput is either due to weak contractions or lack of tone of pelvic floor muscles. The cup is placed more toward the occiput (flexion point) to promote flexion and the rotation is expected during its descent on traction. +2. Cesarean section: If the case is unsuitable for manual rotation, especially in the presence of mid-pelvic contraction, cesarean section is much safer even at this stage. +3. Alternative methods: +a. Manual rotation followed by forceps extraction: The objectives are first to rotate the head manually until the occiput is placed behind the symphysis pubis and secondly in that position forceps blades are applied. The pelvis should be adequate; the baby is of average size and there is good amount of liquor. +b. Forceps rotation and extraction: In the hands of experts, forceps rotation followed by extraction can be achieved by using Kielland rotational forceps. Its advantages over manual rotation are-(I) no chance of displacement of the head, (2) accidental cord prolapse is absent, and (3) rotation can be done at, above or below the level of obstruction- depending upon the type of pelvis. +II. OCCIPITOSACRAL ARREST +If the head is engaged and the occiput descends below the ischial spines, forceps application in unrotated head followed by extraction as face-to-pubis is an effective procedure. Liberal mediolateral episiotomy should be done. If the occiput remains at or above the level of ischial spines, cesarean section should be considered. + +DEEP TRANSVERSE ARREST (DTA) + +The head is deep into the cavity; the sagittal suture is placed in the transverse bispinous diameter and there is no progress in descent of the head even after ½-1 hour following full dilatation of the cervix. The arrest in occiput transverse position may be the end result of incomplete anterior rotation (I/8th of circle) of oblique + + +occiput posterior position, or it may be due to nonrotation of the commonly primary occiput transverse position of normal mechanism of labor. +Causes: (a) Faulty pelvic architecture such as prominent ischial spines, flat sacrum and convergent side walls, (b) Deflexion of the head, (c) Weak uterine contraction, (d) Laxity of the pelvic floor muscles. +Diagnosis: (a) The head is engaged, (b) The sagittal suture lies in the transverse bispinous diameter, (c) Anterior fontanel is palpable, (d) Faulty pelvic architecture may be detected. +Management: The fetal condition and pelvic assessment give the guide as to the line of management (mentioned earlier). +1. Vaginal delivery is found not safe (big baby and/or inadequate pelvis): Cesarean Delivery (CD). +2. Vaginal delivery is found safe (any of the methods may be employed): (1) Ventouse-excessive traction force should not be used. (2) Manual rotation and application of forceps. (3) Forceps rotation and delivery with Kielland in the hands of an expert. Operative vaginal delivery for DTA should only be performed by a skilled obstetrician. Otherwise cesarean delivery is preferred. + +MANUAL ROTATION FOR OCCIPUT POSTERIOR POSITION +The manual rotation can be accomplished with wholehand method or with half-hand method. +Steps: The patient is put under general anesthesia and in lithotomy position. Full surgical asepsis is maintained. Bladder is catheterized. Vaginal examination is done to identify the direction of the occiput. If a big caput has been formed, the direction of the unfolded pinna of the ear which points toward the occiput, can be taken for help. +WHOLE-HAND METHOD: Whole of the hand is introduced inside the vagina for rotation. +Step-I: Gripping ofthe head: In ROP or ROT the left hand and in LOP or LOT, the right hand is usually used. The corresponding hand is introduced into the vagina in a cone-shaped manner after separating the labia by two fingers of the other hand. In occiput transverse position, the four fingers are pushed in the sacral hollow to be placed over the posterior parietal bone and the thumb is placed over the anterior parietal bone. In oblique posterior position, the four fingers of partially supinated hand are placed over the occiput and the thumb is placed over the sinciput (Fig. 26.7). +Step-II: Rotation of the head: Slight disimpaction may be needed for good grip. By a movement of pro nation of the hand, the head is rotated to bring the occiput anterior along the shortest route. Simultaneously, the back of the fetus is rotated by the external hand from the flank to the midline (Fig. 26.7). This is an essential prerequisite for anterior rotation of the head. A little over +DI Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse + +,, +, I +' +' +" ' +/ -----'\::\ +'' +' +. +' " +' +' +' +\ + \'<··-------I ' \ ''-,-_',.'.. } +' +' +. +, +'' + + + + + + +Fig. 26.8: Half-hand method of manual rotation. + + + + +Fig. 26.7: Alternative method of gripping the head in ROP with the right hand. + +rotation is desirable anticipating slight recurrence of malposition before the application of forceps. +In the alternative method, the four fingers of the pronated right hand are placed over the sinciput and the thumb over the occiput in ROP (Fig. 26.7). The head is rotated by supination movement of the hand. +Step-III:Application of the forceps: Following rotation, when the right hand is placed on the left side of the pelvis, left blade of the forceps is introduced. When the left hand is used, it is placed on the right side of the pelvis after rotation, as such the right blade is to be introduced first and the left blade is then to be introduced underneath the right blade. While introducing the blades, it is preferable that an assistant fixes the head by suprapubic pressure in a manner of first pelvic grip. As it is a mid-forceps application, axis traction device should be used. +Difficulties and dangers: The dificulties are due to-( 1) Failure to grip the head adequately due to lack of space, (2) Failure to dislodge the head from the impacted position, (3) Inadequate anesthesia, ( 4) Wrong case selection. + +Dangers-the chief dangers are accidental slipping of the head above the pelvic brim and prolapse of the cord. It is better to perform CS in such a situation. +HALF-HAND METHOD: In this method, the four fingers and not the thumb are introduced into the vagina. Its advantages, over the whole-hand method are: (i) less space is required, and (ii) less chance to displacement of the head. +Steps: The rotation is done only by using the right hand. The four fingers are introduced into the vagina and tangential pressure is applied on the head at the level of diameter of engagement. Thus, the pressure is applied on the side and the parietal eminence of the head. In ROP or ROT positions, the fingers are placed anterior to the head and the pressure is applied by the ulnar border of the hand (Fig. 26.8). In LOP or LOT positions, the fingers are placed posteriorly and the pressure is applied by the radial border of the hand. The force is applied intermittently till the occiput is placed behind the symphysis pubis. + +Such maneuvers are only practiced by a skilled and experienced obstetrician. Simulated learning using mannequins and model pelvis with an experienced trainer is needed to acquire the skill. + + + + + +> Occiput Posterior (OP) is an abnormal position of the vertex and not an abnormal presentation. +► Common causes of OP are: Anthropoid or android pelvis, deflexion of fetal head and abnormal uterine contraction. +> In OP, engagement of head is delayed due to deflexion. In favorable circumstances (90%) occiput rotates anteriorly 3/8th of a circle and delivery occurs as in occiput anterior. +> Cases may develop other abnormal positions. +> Depending upon the extent of rotation of the occiput, three positions may develop: (a) Incomplete anterior rotation-deep transverse position; (b) Nonrotation-oblique occiput posterior position; (c) Malrotation-occiput sacral position. +► Depending upon the pelvic adequacy, degree of flexion and uterine contraction delivery may occur or there may be arrest of labor. +> Labor in OP position, expectant management is the policy, as most OP rotate anteriorly and baby is delivered spontaneously or by instruments (ventouse or forceps). +► Indications of cesarean delivery are: (a) Lack of progress (CPD, android pelvis, deflection of the head, weak pelvic floor failing to guide occiput anteriorly); (b) Fetal distress (FHR <100 or> 160 bpm, or irregular FHR or meconium-stained liquor; (c) Maternal distress (emotional instability, dehydration, high-colored urine, pulse>100 bpm). +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse ED + +BREECH PRESENTATION +In breech presentation, the lie is longitudinal and the podalic pole presents at the pelvic brim. It is the most common malpresentation. +Incidence: The incidence is about 20% at 28th week and drops to 16% at 32-34th week and to 3-4% at term. Thus in 3 out of 4, spontaneous correction into vertex presentation occurs by 34th week. The incidence is expected to be low in hospitals where high parity births are less and routine external cephalic version is done in antenatal period. I VARIETIES +There are two varieties of breech presentation (Figs. 26.9A to C): +♦ Complete ♦ Incomplete +Complete (flexed breech): The normal attitude of full flexion is maintained. Thighs are flexed at hips and legs at knees. The presenting part consists of two buttocks, external genitalia and two feet. It is commonly present in multiparae (10%). +Incomplete: This is due to varying degrees of extension of thighs or legs at the podalic pole. Three varieties are possible: +■ Breech with extended legs (Frank breech): In this condition, thighs are flexed on the trunk and legs are extended at the knee joints. The presenting part consists of the two buttocks and external genitalia only. It is commonly present in primigravidae, about 70%. The increased prevalence in primigravida is due to a tight abdominal wall, good uterine tone and early engagement of breech. +■ Footling presentation (25%): Both thighs and legs are partially extended bringing the legs to present at brim. More commonly seen in preterm deliveries. +■ Knee presentation: Thighs are extended but the knees are flexed, bringing the knees down to present at the brim. The latter two varieties are not common. + +Clinical varieties: In an attempt to find out the dangers inherent to breech, breech presentation is clinically classified as: +1. Uncomplicated: It is defined as one where there is no other associated obstetric complications apart from the breech, prematurity being excluded. +2. Complicated: When the presentation is associated with conditions which adversely influence the prognosis such as prematurity, twins, contracted pelvis, placenta previa, etc. It is called complicated breech. Extended legs, extended arms, cord prolapse or difficulty encountered during breech delivery should not be called complicated breech but are called complicated or abnormal breech delivery. + +I ETIOLOGY OF BREECH PRESENTATION + +There is higher incidence of breech in earlier weeks of pregnancy. Smaller size of the fetus and comparatively larger volume of amniotic fluid allow the fetus to undergo spontaneous version by kicking movements until by 36th week when the position becomes stabilized. The following are the known factors responsible for breech presentation. In a significant number of cases, the cause remains obscure. +♦ Prematurity: It is the most common cause of breech presentation. +♦ Factors preventing spontaneous version: (a) Breech with extended legs, (b) Twins, (c) Oligohydramnios, (d) Congenital malformation of the uterus such as septate or bicornuate uterus; (e) Short cord, relative or absolute, (f) Intrauterine death of the fetus. +♦ Favorable adaptation: (a) Hydrocephalus-big head can be well accommodated in the wide fundus, (b) Placenta previa, (c) Contracted pelvis, (d) Cornu­ fundal attachment of the placenta-minimizes the space of the fundus where the smaller head can be placed comfortably. + + + + + + + + + + + + + +/ + +rn +Figs. 26.9A to C: Varieties of breech presentation: (A) Breech with extended legs (frank breech); (Bl Flexed breech (complete breech); (C) Footling presentation. +ID Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse +♦ Undue mobility of the fetus: (a) Hydramnios, (b) ULTRASONOGRAPHY is most informative. (1) It confirms Multiparae with lax abdominal wall. the clinical diagnosis-especially in primigravidae with +♦ Fetal abnormality: Trisomies 13, 18, 21, anencephaly engaged frank breech or with tense abdominal wall and and myotonic dystrophy due to alteration of fetal irritable uterus; (2) It can detect fetal congenital abnor­ muscular tone and mobility. mality and also congenital anomalies of the uterus; (3) +Recurrent breech: On occasion, the breech presen­ Type of breech (complete or incomplete); (4) It meas­ +tation recurs in successive pregnancies. When it recurs ures biparietal diameter, gestational age and estimated +in three or more consecutive pregnancies, it is called weight of the fetus; (5) It also localizes the placenta; habitual or recurrent breech. The probable causes are (6) Assessment of liquor volume (important for ECV); congenital malformation of the uterus, septate or bicor­ (7) Attitude of the head (Fig. 26.10)-flexion or hyper­ nuate, and repeated cornu-fundal attachment of the extension (important for decision making at the time of placenta. In general; recurrence rate ranges between delivery). CT and MRI can be used to assess the pelvic +8-10%. capacity in addition to all the above-mentioned information. + +I DIAGNOSIS OF BREECH PRESENTATION ♦ Clinical ♦ Sonography +Clinical: The diagnostic features of a complete breech and a frank breech are given in a tabulated form (Table 26.1). + + + + +Per abdomen +Fundal ■ Head-suggested ■ Head. +grip by hard and globular ■ Irregular small parts of +mass. the feet may be felt by ■ Head is ballotable. the side of the head. +■ Head is nonballotable due to splinting action of the legs on the trunk. +Lateral ■ Fetal back is to one ■ Irregular parts are less grip side and the irregular felt on the side. +limbs to the other. +Pelvic ■ Breech-suggested ■ Small, hard and a grip by soft, broad and conical mass is felt. +irregular mass. ■ The breech is usually ■ Breech is usually not engaged. +engaged during preg­ +nancy. +FHS ■ Usually located at a ■ Located at a lower level higher level round in the midline due to about the umbilicus. early engagement of the +breech. +Per vaginam +During ■ Soft and irregular ■ Hard feel of the sacrum is +preg­ parts are felt through felt, often mistaken for the fornix. the head. +nancy +and +labor ■ Palpation of ischial ■ Palpation of ischial +tuberosities, sacrum tuberosities, anal +and the feet by the opening and sacrum and sides of the buttocks. they are felt in one line. +Chance 5% 0.5% (Note: In cephalic +of cord presentation, the chance lapse of cord prolapse is 0.4%). +pro­ +The foot felt is identified by the prominence of the heel and lesser mobility of the great toe. + +POSITIONS: Sacrum is the denominator of breech and there are four positions. In anterior positions, sacrum is directed toward iliopubic eminences and in posterior positions, sacrum is directed to sacroiliac joints. The positions are: (1) First position-Left Sacroanterior (LSA)-being the most common; (2) Second position­ Right Sacroanterior (RSA); (3) Third position-Right Sacroposterior (RSP); and ( 4) Fourth position-Left Sacroposterior (LSP). + +MECHANISM OF LABOR IN BREECH PRESENTATION + +SACROANTERIOR POSITION: In the mechanism of breech delivery, the principal movements occur at three places-buttocks, shoulders and the head. The first two successive parts to be born are bigger but more compressible while the head because of nonmolding due to rapid descent, presents difficulties. Each of the three components undergoes cardinal movements as those of normal mechanism. +Buttocks (Figs. 26.1 0A to H) +■ The diameter of engagement of the buttock is one of the oblique diameters of the inlet. The engaging diameter is bitrochanteric (10 cm or 4") with the sacrum directed toward the iliopubic eminence. When the diameter passes through the pelvic brim, the breech is engaged. +■ Descent of the buttocks occurs until the anterior buttock touches the pelvic floor. +■ Internal rotation of the anterior buttock occurs through I/8th of a circle placing it behind the symphysis pubis. +■ Further descent with lateral flexion of the trunk occurs until the anterior hip hinges under the symphysis pubis which is released first followed by the posterior hip. +■ Delivery of the trunk and the lower limbs follow. +■ Restitution occurs so that the buttocks occupy the original position as during engagement in oblique diameter. + +Shoulders (Figs. 26.1 0A to H) +■ Bisacromial diameter (12 cm or 4¾") engages in the same oblique diameter as that occupied by the buttocks at the brim soon after the delivery of the breech. +■ Descent occurs with internal rotation of the shoulders bringing the shoulders to lie in the anteroposterior diameter +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse ID + + + + + + + + + + + \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_12.txt b/notes/DC Dutta Obstetrics 10th Edition_12.txt new file mode 100644 index 0000000000000000000000000000000000000000..9c2de356c13252c02a72c1b8a087adfb42809560 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_12.txt @@ -0,0 +1,2027 @@ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Figs. 26.10A to H: Mechanism of labor in breech presentation: Right Sacroanterior (RSA). +• -·· Bl Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse + +of the pelvic outlet. The trunk simultaneously rotates externally through I/8th of a circle. +■ Delivery of the posterior shoulder followed by the anterior one is completed by anterior flex.ion of the delivered trunk. +■ Restitution and external rotation: Untwisting of the trunk occurs putting the anterior shoulder toward the right thigh in LSA and left thigh in RSA. External rotation of the shoulders occurs to the same direction because of internal rotation of the occiput through I/8th of a circle anteriorly. The fetal trunk is now positioned as dorsoanterior. +Head (Figs. 26.1 0A to H) +■ Engagement occurs either through the opposite oblique diameter as that occupied by the buttocks or through the transverse diameter. The engaging diameter of the head is suboccipitofrontal (10 cm). +■ Descent with increasing fle.ion occurs. +■ Internal rotation of the occiput occurs anteriorly, through I/8th or 2/8th of a circle placing the occiput behind the symphysis pubis. +■ Further descent occurs until the subocciput hinges under the symphysis pubis. +■ Head is born by flexion-chin, mouth, nose, forehead, vertex and occiput appearing successively. The expulsion of the head from the pelvic cavity depends entirely upon the bearing-down efforts and, not at all, on uterine contractions. +Sacroposterior position: In sacroposterior position, the mechanism is not substantially modified. The head has to rotate through 3/8th of a circle to bring the occiput behind the symphysis pubis. + +COMPLICATIONS OF VAGINAL BREECH DELIVERY + +MATERNAL: Labor is usually not prolonged. But because of increased frequency of operative delivery, including cesarean section, the morbidity is increased. The risks include trauma to the genital tract, operative vaginal delivery ( episiotomy, forceps), cesarean section, sepsis and anesthetic complications. As a consequence, maternal morbidity is slightly raised. Frank breech acts as an effective cervical dilator. Flexed breech, although, theoretically might cause delay in first stage, but rarely so because of its prevalence among multiparae. +FETAL: The fetal risk in terms of perinatal mortality is considerable in vaginal breech delivery. The corrected (excluding fetal abnormality) perinatal mortality ranges from 5 to 35 per 1,000 births. The overall perinatal mortality in breech still remains 9-25% compared with 1-2% for nonbreech deliveries. Perinatal death (excluding congenital abnormalities) is 3 to 5 times higher than the nonbreech presentations. The factors which significantly influence the fetal risk are-(a) skill of the obstetrician, (b) weight of the baby, ( c) position of the legs, and (d) type of pelvis. The fetal mortality is least in frank breech and maximum in footling presentation, where the chance of cord prolapse is also more. Gynecoid and anthropoid pelvis are favorable for the aftercoming head. The fetal risk in multipara is no less than that of + +primigravida. This is because of increased chance of cord prolapse associated with flexed breech. + +THE DANGERS TO THE BABY +l. Intrapartumfetal death, especially with preterm babies 2. Injury to head, brain and skull-(a) Intracranial hemorrhage: Compression followed by decompres­ +sion during delivery of the unmolded aftercoming head results in tear of the tentorium cerebelli and hemorrhage in the subarachnoid space. The risk is more with preterm babies, (b) Minute hemorrhages, (c) Fracture of the skull. +3. Birth asphyxia: It is due to: +a. Cord compression soon after the buttocks are +delivered and also when the head enters into the pelvis. A period of more than 10 minutes will produce asphyxia of varying degrees. +b. Retraction of the placental site. +c. Premature attempt at respiration (amniotic fluid, vaginal fluid) while the head is still inside. +d. Delayed delivery of the head. +e. Cord prolapse. It is less (0.5%) in frank breach. f. Prolonged labor. +4. Birth injuries (7%): The following injuries are inflicted during manipulative deliveries. It is 13 times more than the vertex presentation. +♦ Hematoma-over the sternomastoid or over the thighs. +♦ Fractures-the common sites are femur, humerus, clavicle, hip joint and odontoid process. There may be dislocation of the hip joint, mandible or 5th and 6th cer­ vical vertebrae and epiphyseal separation (Fig. 26.11). + + + + + + + + + + + + + + + + + + + + + +Fig. 26.11: Birth injury following assisted breech (frank) delivery showing dislocation of the left knee joint. +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse - + +• Visceral injuries include rupture of the liver, kidneys, suprarenal glands, lungs, arms and legs and hemorrhage in the testicles. +• Nerve-medullary coning, spinal cord injury, stretching of the cervical and brachial plexus to cause either Erb's or Klumpke's palsy. +• Long-term neurological damage. +Some of the injuries may prove fatal and contribute to perinatal mortality. Long-term (neurological) morbidity of the surviving infants should not be underestimated. +5. Congenital malformations are double compared to babies with cephalic presentation (congenital dislocation of the hip, hydrocephalus and anencephaly are common). + +TYPES OF PROCEDURE AND THE NEONATAL OUTCOME +1. Entrapment of the after coming head due to delivery of a breech fetus through the partially dieted cervix. +2. Nuchal arms due to breech traction cause delay in delivery of fetal head. There is increased birth asphyxia. +3. Deflection or hypertension of the head cause impaction of the occipital part of the head behind the symphysis pubis. This may lead to fracture of cervical vertebra, injury to spinal cord, medullary hemorrhage and perinatal mortality. +4. Hasty delivery or delay in delivery, both may result in birth asphyxia due to umbilical cord compression. There is excessive pressure on fetal body and the after coming fetal head. Breech delivery needs an experienced obstetrician to perform/ execute the maneuver with gentleness and skill. + +PREVENTION OF THE FETAL HAZARDS ++ The incidence of breech can be minimized by external cephalic version where possible. ++ If the version fails or is contraindicated, delivery is done by elective cesarean section. ++ Vaginal breech delivery should be conducted by a skilled obstetrician along with an organized team consisting of a skilled anesthetist and neonatologist. ++ Vaginal manipulative delivery should be done by a skilled person with utmost gentleness, especially during delivery of the head. +I ANTENATAL MANAGEMENT +Antenatal management in breech presentation consists of: ♦ Identification of the complicating factors related with +breech presentation. +♦ External cephalic version, if not contraindicated (Box 26.1). +♦ Formulation of the line of management, if the version fails or is contraindicated (Flowchart 26.3). +Identification of complicating factor: It can be detected by clinical examination, supplemented by sonography. Sonography is particularly useful to detect congenital malformations of the fetus, the precise location of the placental site and congenital anomalies of the uterus. + + ++ Antepartum hemorrhage (placenta previa or abruption)-big +risk of placental separation. ++ Fetal causes-hyperextension of the head, large fetus (>3.5 kg), +congenital abnormalities (major), dead fetus, fetal compromise (IUGR). ++ Multiple pregnancy. ++ Ruptured membranes-with drainage of liquor. ++ Known congenital malformation of the uterus. + Abnormal cardiotocography (nonstress test). ++ Contracted pelvis. ++ Previous cesarean delivery(> 1 )-risk of scar rupture (previous 1 +LSCS is not an contraindication for ECV). ++ Obstetric complications: Severe pre-eclampsia, obesity, elderly +primigravida, bad obstetric history (BOH), oligohydramnios. + Rhesus isoimmunization. +Breech with extended legs is not a contraindication for version + +External Cephalic Version (ECV): The success rate of version is about 65% (60% in multi and 40% in primigravida) {for technique-p. 540). Successful version reduces the risk of cesarean section. Prior sonography should be a routine. Fetal wellbeing should be monitored with Doppler or real time USG scanning. The procedure should be abandoned in case of any fetal distress or failure of multiple attempts (usually >4). After the procedure, FHR monitoring should be continued for 1 hour to ensure stability. Anti-D immune globulin to be given if the mother is Rh negative. Vaginal breech delivery had 5 fold higher mortality rate in comparison to cephalic presentation. +Time of version: ECV has been considered from 36 weeks in primi and 37 weeks in a multigravida. While version in the early weeks is easy but chance of reversion is more (spontaneous version in PG at >36 weeks: 8%. Spontaneous reversion to breech after successful ECV: 3%). Late version may be difficult because of increasing size of the fetus and diminishing volume of liquor amnii. However, the use of uterine relaxant (tocolysis) has made the version at later weeks less difficult. It minimizes chance of reversion and should fetal complications develop, it can be effectively tackled by cesarean section. Hypertonus or irritable uterus can be overcome with the use of tocolytic drugs (tocolytic drugs with doses-p. 475). Epidural analgesia may be used selectively. +Benefits of ECV are: (i) Reduction in the incidence of breech presentation at term, {ii) Reduction in the incidence of breech delivery (vaginal or cesarean) and the associated complications (vide above), (iii) Reduction in the incidence of cesarean delivery by 5%. +Predictors of success are: (i) Multigravida, (ii) Non­ engagement of breech, (iii) Tocolysis, (iv) Maternal weight <65 kg, (v) Posterior placenta, (vi) Complete breech, {vii) AFI >10, {vii) Average size baby. +Successful version is likely in cases of: (i) Complete breech, (ii) Nonengaged breech, (iii) Sacroanterior position (fetal back anteriorly), {iv) Adequate liquor, (v) Nonobese patient. +ID Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse +Flowchart 26.3: Scheme for management of breech presentation. +I Management of breech presentation I + + + + + + + + + + + + +i +Successful +l + +Delivery as vertex + + + + + + + ++ +Satisfactory labor progress +i +Assisted breech delivery + +I Antenat.al asses ment I +Fetal: Wellbeing, weight, attitude +I• +I +• Maternal: Health (obstetric and medical) and maternal pelvis (clinical) +! ! +External Cephalic Version (ECV) Elective cesarean section (238 weeks) To be done • Estimated fetal weight: >3.5 kg or <1.5 kg. +• Hyperextended head. +• Around 36 weeks or after. • Associated complications (obstetric and/or medical). +• In the labor suite. +• With ocolytics if needed. +• Pelvic inadequacy. +• Fetal tmonitoring (CTG).before • Absence lof expertise for idelivery. +• Antenata fetal comprom se. +• Patient request. +and after the procedure +• Fetal factors: Footling presentation, FGR (EFW <10th centile) Fails • 21 Prior CD. +i +! + +i l +Trial of vaginal Elective cesarean breech delivery delivery (238 weeks) +• Informed consent. +• Average fetal weight (2-3.5 kg). • Frank or complete breech. +• Flexed fetal head. • Adequate pelvis. +• Availability of an experienced obstetrician and a neonatologist. • Rapid CD is possible when needed. ++ +CS in labor (if breech not on perineum after 2 hours of full cervical dialatation) ■ Arrest of progress +■ Fetal distress (non-reassuring FHR) +■ Cord prolapse + + + +Causes of failure of version: (1) Breech with extended legs-early engagement of presenting part and difficult to flex the trunk because of splinting action of the limbs; (2) Scanty liquor or big size baby; (3) Mechanical-obesity, increased tone of the abdominal muscles and irritable uterus; ( 4) Short cord-either relative (common) or absolute; (5) Uterine malformations-septate or bicornuate. +Dangers of version: The dangers of version are: (1) premature onset of labor; (2) premature rupture of the membranes; (3) placental abruption and bleeding; (4) entanglement of the cord round the fetal part or formation of a true knot leading to impairment of fetal circulation and fetal death; (5) increased chance of fetomaternal bleed and alloimmunization; (6) Amniotic fluid embolism; and (7) Rupture of uterus. (8) A transient bradycardia is common (<3 minutes). If it persists >6 minutes ➔ CAT I CS. Immunoprophylaxis with anti-D gammaglobulin is to be administered in nonimmunized Rh-negative mother (Ch. 23). The perinatal mortality should not exceed beyond 1 %. A reactive cardiotocographic trace should be obtained after the procedure. +Management, if version fails or is contraindicated: The pregnancy is to be continued with usual checkup and, + +unexpectedly, one may find that spontaneous version has occurred. But if the breech persists, the assessment of the case is to be done with respect to-(1) age of the mother, especially in primigravidae; (2) associated complicating factors; (3) size of the baby; and (4) pelvic capacity. Clinical assessment of the pelvis should be done in all primigravidae and in selected multigravidae with previous history suggestive of pelvic inadequacy. CT or MRI may be the alternative. Ultrasonographic examination is the gold standard for decision making. Two methods of delivery can be planned. +♦ To perform an elective cesarean section (Table 26.2). ♦ To allow spontaneous labor to start and vaginal breech +delivery to occur. +♦ Induction of labor is not usually recommended (RCOG-2017). +Elective Cesarean Section (CS): Because of decrease in skill and experience of vaginal breech delivery and rise in perinatal mortality and morbidity, there is a trend to liberalize the use of cesarean section in breech (ACOG-2018). +The indications of CS in breech are: • Big baby (estimated fetal weight >3.5 kg), small baby ( <1.5 kg) estimated fetal weight <1.5 or >3.5 kg• hyperextension of the head (stargazing fetus) • footling presentation (risk of cord prolapse) • suspected pelvic contraction or +Chapter 26: Complicated Labor: Mal position, Mal presentation and Cord Prolapse + + +Table 26.2: Selection criteria for the route of breech 9_elivery. +Assisted Vaginal Breech +Delivery (AVDJ Cesarean Delivery (CD) +• Frank breech presentation. • Unfavorable factors-fetal: +■ Gestational age: >34 Unengaged podalic pole, +weeks. footing breech. +• Estimated fetal weight ■ Estimated fetal weight 2000-3500 g. In breech presentation, the podalic pole presents at the pelvic brim, and the lie is longitudinal. It is the most common malpresentation. > Types of breech presentation are: complete, frank, footling and knee presentation. +► Prematurity is the most common cause of breech presentation. +► Ultrasonography is the most informative besides confirmation of diagnosis. +► Dangers to the baby following vaginal breech delivery and high mortality are due to: Prematurity, congenital malformation, injury to the skull, intracranial hemorrhage, birth asphyxia due to prolonged labor, cord compression or cord prolapse, birth injury (rupture of liver, fracture of femur, cervical and brachiaI plexus injury). +► Management of breech presentation: External Cephalic Version (ECV) is done after 36 weeks of pregnancy if not contraindicated. ECV has many benefits in selected cases and is safe. Use of tocolytics and epidural anesthesia may increase the success rate. However, ECV has got complications also. +► Management of breech delivery is by-(a) elective cesarean section after 38 weeks or (b) vaginal delivery (assisted breech delivery), or (c) cesarean delivery in labor. Induction of labor is not recommended. +► Trial of labor (vaginal breech delivery) is considered for cases with-(a) fetal weight between 2.0 kg and 3.5 kg, (b) adequate pelvis, +► (c) frank or complete breech, (d) flexed or neutral head, (e) in presence of a skilled obstetrician, and with (f) detailed informed consent explaining the higher perinatal mortality and morbidity compared to cesarean delivery (ACOG-2018). Center should have the facilities for emergency cesarean delivery when needed. +► Routine cesarean section for breech presentation after delivery of the first twin in spontaneous labor is not recommended (RCOG-2017). > All doctors and midwives should develop the skills of vaginal breech delivery using simulators. + + + +FACE PRESENTATION + +Face is a rare variety of cephalic presentation where the presenting part is the face. The attitude of the fetus shows complete flexion of the limbs with extension of the spine. There is complete extension of the head so that the occiput is in contact with the back. The denominator is mentum. +Position: There are four positions of the face according to the relation of the chin to the left and right sacroiliac joints or to the right and left iliopubic eminences. Face presentation results most likely from complete extension of deflexed head of a vertex presentation. The numbering of the face positions is obtained as follows (Box 26.2). + +The most common position is Left Mentoanterior (LMA)-As the ROP position is 5 times more common than LOP and as the conversion of face occursfrom deflexed OP, LMA is the commonest. Overall anterior positions are more +frequent than the posterior one. +Incidence: Its frequency is about 1 in 500 births. Face presentation present during pregnancy (primary) is rare, while that developing after the onset of labor (secondary) is common. It occurs more frequently in multiparae (70%). +Etiology: The cause of extreme extension of the head is not clear in all the cases. The following are the factors, which are often associated. + + + + + +1st vertex (LOA) +2nd vertex (ROA) +3rd vertex (ROP) +4th vertex (LOP) + + +becomes +becomes +becomes +becomes + + +1st face➔ +2nd face➔ +3rd face➔ +4th face-> + + +Right Mentoposterior {RMP) +Left Mentoposterior (LMP) +Left Mentoanterior (LMA) +Right Mentoanterior (RMA) +&I Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse +Maternal: (1) Multiparity with pendulous abdomen; occurs. Arrest occurs in all these positions with average (2) Lateral obliquity of the uterus, especially, if it is size pelvis and fetal head. Unlike persistent occiput directed to the side toward which the occiput lies; posterior, where occasional face-to-pubis delivery occurs, (3) Contracted pelvis is associated in about 40% cases. Flat there is no possibility of spontaneous delivery in persistent pelvis favors face presentation; (4) Pelvic tumors. mentoposterior. This is because the relatively short neck +Fetal: (I) Congenital malformations (15%)-(a) cannot clear off the total length of the sacrum (12 cm). As +The most common one is anencephaly. The almost such the thorax is thrust in, resulting bregmaticosternal +nonexistent neck with absence of the cranium makes it diameter (18 cm or 7") to occupy the pelvis (Fig. 26.22). +easy to feel the facial structure even with semi-extended As a result, the labor becomes inevitably obstructed. +head, (b) Congenital goiter-prevalent in endemic areas, +I +(c) Dolichocephalic head with long anteroposterior DIAGNOSIS diameter, (d) Congenital bronchocele. (2) Twist of the +Antenatal diagnosis is rarely made. Diagnosis is made +cord several turns round the neck. (3) Increased tone of only during labor but in about half, the detection is made at the time of delivery. +the extensor group of neck muscles. +I MECHANISM OF LABOR ABDOMINAL FINDINGS +MENTOANTERIOR 60-80% (LMA OR RMA) Inspection: Because of "S11 -shaped spine, there is no +The principal movements are like those of corresponding visible bulging of the flanks. +occiput anterior position. The exceptions are increasing Palpation (Fig. 26.23): The diagnostic features in men­ extension instead of flexion and delivery by flexion instead toanterior and mentoposterior are described in Table 26.3. of extension of the head. +VAGINAL EXAMINATION +The diagnostic features are pal ating the mouth +oblique diameter-right in iLMA, ileft inaRMA, with the with hard alveolar margins, nose,pmalar eminences, glabella to the opposite sacroiliac joint. The engaging labor, because of high head and sausage-shaped bag of (3¾") in fully extended head or submentovertical 11.5 cm membranes, the parts are not clearly defined. In late labor, +is the +Engagement: The diameter of eng gement +mentum related to one il opub c eminence and the +supraorbital ridges and the mentum +In early +(Fig. 26.24). +is submentobregmatic 9.5 cm +diameter of the head +the parts are often obscured due to edema. It is often +because pof tlong edistance between the mentum and confused with breech presentation. +(4½ ") in ar ially xtended head. +Engagement is delayed +biparietal plane (7 cm). Descent with increasing extension The distinguishing features are: +occurs till the chin touches the pelvic floor. 1. The mouth and the malar eminences are not in a line; +Internal rotation: Internal rotation of the chin occurs but in breech, the anus and the ischial tuberosities are +in one line. +through 1/Bth of a circle anteriorly, placing the mentum +behind the symphysis pubis. Further descent occurs till 2. Sucking effect of mouth. the submentum hinges under the pubic arch. 3. Hard alveolar margins. + +Delivery of the head: The head is born by flexion delivering the chin, face, brow, vertex and lastly the occiput. The diameter distending the vulval outlet is submentovertical-11.5 cm ( 4½ "). Restitution occurs through I/8th of a circle opposite to the direction of internal rotation. External rotation occurs further I/8th of circle to the same side of restitution so that ultimately the face looks directly to the left thigh in LMA and right thigh in RMA. This follows delivery of the anterior shoulder followed by the posterior shoulder and the rest of the trunk by lateral flexion. +MENTOPOSTERIOR (20-25%) (RMP OR LMP) +The cardinal movements in the mechanism of mentopos­ terior positions are like those of occiput posterior position. The salient differentiating features are: +(1) In the mentoposterior position, anterior rotation of the mentum occurs in only 20-30% cases. +(2) In the rest (70-80%), incomplete anterior rotation, nonrotation or short posterior rotation of the mentum + + + + + + + + + + + + + + + + + + +Fig. 26.22: Head cannot extend further, nor flexion is possible. Bregmatic sternal diameter (18 cm or 7") cannot be accommodated in the pelvis resulting in obstructed labor. +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse ID :Ti!ble.26,-3:_Diagno tic features in fac presentation. + + + + + + + + + + + + + + + + + + + +Fig. 26.23: Chief features to be recognized on abdominal examination in face presentation. + + +Lateral grip + + + + + + +Pelvic grip + + + + + + +Auscultation + + +.Mentoanterior +1. Fetal limbs are felt anteriorly. +2. Back is on the flank and is difficult to palpate. +3. The chest is thrown anteriorly against the uterine wall and is often mistaken for back. +1. Head seems big and is not engaged. +2. Cephalic prominence is to the side toward which back lies. +3. Groove between the head and back is not so prominent. +FHS is distinctly audible anteriorly through the chest wall of the fetus toward the side of limbs. + +Mentoposterior +1. Back is felt to the front and better palpated only towards the podalic pole because of extension of spine. + +1. Same. + +2. Same. + + +3. The groove is prominent. + +FHS is not so distinct and is audible on the flank toward the side of limbs. + + + +4. Absence of meconium staining on the examination fingers. The mentum and the mouth should be clearly identified to exclude brow presentation and to identify the position. The examination should be conducted gently, as there is chance of injury to the eyes. Assessment of the pelvis should be done as a routine. +SONOGRAPHY: This should be done to confirm the diagnosis, to exclude bony congenital malformation of the fetus and to note the size of the baby. +CLINICAL COURSE: In spite of the fact that the engaging diameter of the head in flexed vertex and the extended face presentation is the same-9.5 cm (3¾"), the clinical course of the latter is adversely affected because of the following: + + + + + + + + + + + + + + + + + + +Fig. 26.24: Vaginal touch picture showing landmarks in mentoanterior position. + +11 Irregular face ill fits with the lower uterine segment. The poor ball valve action results in formation of elongated bag of membranes which is likely to rupture early. +■ Chance of cord prolapse is more. +■ Delay of labor, in all the stages, is common. The causes are-(a) weak uterine contractions, (b) absence of molding of the facial bones, (c) delayed engagement- the distance between the biparietal plane to chin is 7 cm and to occiput is only 3 cm (Figs. 26.25A and B), (d) late internal rotation, and (e) arrest and, at times, insuperable obstruction if mentoposterior fails to rotate anteriorly. +11 Chance of perineal damage is more because of a wide biparietal diameter-9.5 cm (3¾") stretches the perineum and submentovertical diameter 11.5 cm 4½") emerges out of the introitus (Fig. 26.26). +11 Postpartum hemorrhage is more likely due to atonic uterus and trauma following operative delivery. +PROGNOSIS: Maternal-in mentoanterior, the maternal risk is not much increased. However, there is increased morbidity due to operative delivery and vaginal manipulation. In neglected cases, the risks of impacted mentoposterior leading to obstructed labor and ruptured uterus are not uncommon. +Fetal-fetal prognosis is, however, adversely affected due to-(a) cord prolapse, (b) increased operative delivery, (c) cerebral congestion due to poor venous return from the head and neck, and (d) neonatal infection due to prolonged labor (40% ). +CAPUT AND MOLDING: Due to poor venous return from the head and neck, marked caput forms, distorting the entire face. The lips and the eyelids are markedly swollen +ID Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse +Y + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Figs. 26.25A and B: (A) Vertex presentation-head engaged; (Bl Face presentation-head not yet engaged. + +with considerable appearance of bruising. There is no compression of the facial bones but there is elongation of occipitofrontal diameter {Fig. 9.5). The extended attitude of the head, swelling of the face and the elongation of the head subside within a few days. + +I MANAGEMENT + +Overall assessment of the case is to be done to note­ ( I) pelvic adequacy ( clinical); (2) size of the baby; (3) associated complicating factors, if any, like elderly primigravidae, severe pre-eclampsia, postcesarean pregnancy and postmaturity; ( 4) congenital fetal malformation; and (5) position of the mentum. +Indications of elective or early cesarean section: (1) Contracted pelvis; (2) Big baby; (3) Associated complicating factors. + +Fig. 26.26: Submentovertical diameter (11.5 cm or 4 ,'') emerges out of the introitus. + +I VAGINAL DELIVERY MENTOANTERIOR +First stage: In uncomplicated cases, a wait and watch policy is adopted. Labor is conducted in the usual procedure and the special instructions, as laid down in occiput posterior positions, are to be followed. +Second stage: One should wait for spontaneous delivery to occur. Perineum should be protected with liberal mediolateral episiotomy. In case of delay, forceps delivery is done. +MENTOPOSTERIOR +First stage: In uncomplicated cases, vaginal delivery is allowed with strict vigilance hoping for spontaneous anterior rotation of the chin, +Second stage: (I) If anterior rotation of the chin occurs, spontaneous or forceps delivery with episiotomy is all that needed. (2) In incomplete or malrotation: Early decision for the method of delivery is to be taken soon after full dilatation of the cervix. The following methods may be employed to expedite the delivery. +■ Cesarean section is the preferred method and is commonly done these days. + +BROW PRESENTATION + +Brow is the rarest variety of cephalic presentation where the presenting part is the brow and the attitude of the head is short that of degree of extension necessary to produce face presentation, i.e., the head lies in between full flexion and full extension. The denominator is the forehead (frontum: Fr). +INCIDENCE: The incidence of brow is very rare, about 1 in 1,000 births. However, it may persist temporarily while a deflexed head tends to become extended to produce a face presentation. This happens especially in flat pelvis where the biparietal diameter is held in the sacrocotyloid diameter. +CAUSES: The causes of persistent brow are more or less the same as those of face presentation. The position is +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse DI + +commonly unstable and converts to either vertex or face presentation. +DIAGNOSIS: Antenatal diagnosis is rarely made. The findings are more or less like those of face presentation. The cephalic prominence and the groove between it and the back are less prominent (Fig. 26.27). The head feels very big and is non engaged. +Vaginal examination: During labor the position is to be confirmed on vaginal examination by palpating supraorbital ridges and anterior fontanel. If the anterior fontanel is on mother's left, with the sagittal suture in transverse pelvic diameter, it is left frontum transverse position. In late labor, the landmarks may be obscured by caput formation. +Sonography is confirmatory and also helps in excluding bony congenital malformation of the fetus. +MECHANISM OF LABOR: Diameter of engagement is through the oblique diameter with the brow anterior or posterior. As the engaging diameter of the head is mentovertical (14 cm), there is no mechanism of labor in an average-size baby with normal pelvis. However, if the baby is small and the pelvis is roomy with good uterine contractions, delivery can occur in mentoanterior brow position. The brow descends until it touches the pelvic floor. Internal rotation and descent occur till the root of the nose hinges under the symphysis pubis. The brow and the vertex are delivered by flexion followed by extension to deliver the face. The mechanism is more or less the same as face-to-pubis delivery. Usual restitution and external rotation occur. There is no mechanism in posterior brow position. + + + + + + + + + + + + + + + + + + + + + + +Fig. 26.27: Chief features to be recognized during abdominal examination in brow presentation. + +TRIAL OF LABOR: Brow presentation when transitory, trial of labor may be a possibility. Correction of brow with flexion to occiput presentation or complete extension to a face presentation occurs. In such a situation, though rare, trial of labor may be possible. +COURSE AND PROGNOSIS: In case of persistent brow presentation, there is the risk of obstructed labor. It is an important cause of rupture of uterus in multiparae. On occasions (10%), there may be spontaneous conversion of brow into face or vertex presentation. +MANAGEMENT +During pregnancy: If the presentation is diagnosed during pregnancy and there is no other contraindications for vaginal delivery, trial of labor may be appropriate. +Elective cesarean section: Cases with persistent brow presentation are delivered by elective cesarean section. During labor: (1) In uncomplicated cases, if spontane­ ous correction to either vertex or face fails to occur early in labor, cesarean section is the best method of delivery. +(2) Manual correction to face or vertex with full dilatation of cerix is contraindicated. + +TRANSVERSE LIE + +When the long axis of the fetus lies perpendicularly to the maternal spine or centralized uterine axis, it is called transverse lie. But more commonly, the fetal axis is placed at an acute angle or oblique to the maternal spine and is then called oblique lie. In either of the conditions, the shoulder usually presents over the cervical opening during labor and as such both are collectively called shoulder presentations. +POSITION: The position is determined by the direction of the back, which is the denominator. The position may be-(1) dorsoanterior, which is the most common (60%). The flexor surface of the fetus is better adapted to the convexity of the maternal spine (Figs. 26.28A and B); (2) dorsoposterior; (3) dorsosuperior; or (4) dorsoinferior. The last two are rare. In dorsoposterior, chance of fetal extension is common with increased risk of arm prolapse. According to the position of the head, the fetal + + + + + + + + + + + + +Figs. 26.28A and B: Positions of transverse lie: (A) Dorsoanterior; (B) Dorsoposterior. +ID Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse + +position is termed right or left, the left one being more common than the right. +INCIDENCE: The incidence is about 1 in 200 births. It is common in premature and macerated fetuses, 5 times more common in multiparae than primigravidae. Transverse lie in twin pregnancy is found in 40% of cases. +ETIOLOGY: The causes are-(1) Multiparity-lax and pendulous abdomen, imperfect uterine tone and extreme uterine obliquity are the responsible factors; (2) Prematurity-center of the gravity lies almost in the middle of the body; (3) Twins-it is more common for the second baby than the first one to be in transverse position; (4) Hydramnios; (5) Contracted pelvis; (6) Placenta previa; (7) Pelvic tumors; (8) Congenital malformation of the uterus-arcuate or subseptate; and (9) Intrauterine death. +I DIAGNOSIS ABDOMINAL EXAMINATION +Inspection: The uterus looks broader and often asymmetrical, not maintaining the pyriform shape. +Palpation: +♦ The fundal height is less than the period of amenorrhea. +♦ Fundal grip: Fetal pole (breech or head) is not palpable. +♦ Lateral grip: (a) Soft, broad and irregular breech is felt to one side of the midline and smooth, hard and globular head is felt on the other side. The head is usually placed at a lower level on one iliac fossa, (b) The back is felt anteriorly across the long axis in dorsoanterior or the irregular small parts are felt anteriorly in dorsoposterior. +♦ Pelvic grip: The lower pole of the uterus is found empty. This, however, is evident only during pregnancy but during labor, it may be occupied by the shoulder. +Auscultation: FHS is heard easily much below the umbilicus in dorsoanterior position. FHS is, however, located at a higher level and often indistinct in dorsoposterior position. +Ultrasonography: Ultrasound examination confirms the diagnosis when there is any doubt in abdominal or vaginal examination. Obese women may make clinical examination difficult. Difficulties of clinical examination are overcome with ultrasonography to make the diagnosis early and correctly. +VAGINAL EXAMINATION +During pregnancy, the presenting part is so high that it cannot be identified properly but one can feel some soft parts. +During labor: Elongated bag of the membranes can be felt if it does not rupture prematurely. The shoulder is + + + + + + + + + + + + + + + + +Fig. 26.29: Woman in labor with hand prolapse. + +identified by palpating the following parts-acromion process, the scapula, the clavicle and axilla (Fig. 26.29). The characteristic landmarks are the feeling of the ribs and intercostal spaces (grid iron feel). On occasion, the arm is found prolapsed. It should be remembered that the findings of a prolapsed arm is confined not only to transverse lie but it may also be associated with compound presentation. Frequently, a loop of cord may be found alongside the arm. +Determination of position: Thumb of the prolapsed hand, when supinated, points toward the head, the palm corresponds to the ventral aspect. The angle of the scapula, if felt, indicates the position of the back. The side to which the prolapsed arm belongs, can be determined by shaking hands with the fetus. If the right hand is required for this, the prolapsed arm belongs to right side and vice-versa. +I CLINICAL COURSE OF LABOR +There is no mechanism of labor in transverse lie and an average size baby fails to pass through an average size pelvis. If the lie remains uncorrected and the labor is left uncared, the following sequence of events may occur (Flowchart 26.4). +UNFAVORABLE EVENTS (COMMON): • There may be premature rupture of the membranes with escape of good amount of liquor because of absence of ball valve action of the presenting part. • The hand of the corresponding shoulder may be prolapsed with or without a loop of cord. • The cord may be prolapsed in isolation. • There is increased chance of ascending infection from the lower genital tract. • With increasing uterine contractions, the shoulder becomes wedged and impacted into the pelvis and the prolapsed arm becomes swollen and cyanosed. • Gradually features of obstructed labor supervene. +The pathological anatomy of the uterus is like that of tonic uterine contraction and retraction. There is formation of a pathological retraction ring (Fig. 26.30). +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse Im Flowchart 26.4: Clinical course of labor in transverse lie left uncared for. + +CLINICAL COURSE OF LABOR IN TRANSVERSE LIE + + +Unfavorable (common) Favorable (rare) + + +Early rupture of the membranes + + + +Prolapse of the hand +l +and/or -----➔ I Fetal death +• Drainage of liquor. +17 +• Intrauterine infection. +• Poor dilatation of the cervix. +Contraction of the upper segment ++ Stretching of the lower segment++ + + +Spontaneous correction +• Early labor • Baby small +l + +Version Rectification +! ! + +Breech Vertex + + +Spontaneous Spontaneous +expulsion evolution + +Baby +small or +macerated +Uterine contraction++ + +Double-up Expulsion of +fashion breech and trunk followed by head + + +Formation of Sandi's ring -➔ j Fetal death +■ Appearance of dehydration +I +________, +and exhaustion. j Maternal death +r +■ Ketoac1dos1s. ■ Sepsis. + + +Multigravid + +Rupture uterus + +Primigravid + +Uterine exhaustion + + +Maternal death + + + +Primigravidae, in response to obstruction, the uterus becomes inert and features of exhaustion and sepsis are only evident. + +Thick upper segment + + + + + + + + + + + + + + +Internal os + + + + + + +Fig. 26.30: Pathologic anatomy of the uterus in neglected shoulder presentation. + +In multiparae, the uterus reacts vigorously in response to obstruction and ultimately, the lower segment gives way as a result of marked thinning of its wall. +Neglected shoulder: By neglected shoulder, it means the series of complications that may arise out of shoulder presentation when the labor is left uncared. Such complications are impacted shoulder ➔ obstructed labor➔ rupture of uterus with clinical evidences of dehydration, ketoacidosis, shock and sepsis. These put the mother and the fetus at risk. +FAVORABLE EVENTS (RARE): These are the rare events: +(I) Spontaneous rectification or version: Where the fetal lie is changed spontaneously from transverse to longitudinal either as vertex (rectification) or as breech (version). This may occur in multiparae with a small size fetus in early labor where some amount of liquor is present. +(2) Spontaneous evaluation: With progressive uterine contractions the fetus may gradually be expelled with the following body parts successively as: breech, trunk followed by delivery of the head. +(3) Spontaneous expulsion: This extremely rare where a prematu_re (as in macerated) fetus is expelled at as doubled up +fashion with apposed chest and abdomen. +These events are very rare and occur only when the baby is premature or macerated. +PROGNOSIS: In a well-supervised pregnancy and labor, the maternal and the fetal outlook is not unfavorable with the increased use of cesarean section. However, increased +JI Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse + +maternal morbidity following early rupture of the membranes and increased operative delivery, is inevitable. +But in uncared pregnancy and labor, the outlook of the mother and the fetus is very much unpredictable. The maternal risk is increased due to dehydration, ketoacidosis, septicemia, ruptured uterus, hemorrhage, shock and peritonitis-sequences of neglected shoulder. Marked increase of fetal loss is due to cord prolapse, tonic contraction of the uterus, ruptured uterus and neonatal sepsis. The overall perinatal mortality is as high as 25-50%. + +MANAGEMENT OF SHOULDER PRESENTATION + +ANTENATAL: External cephalic version should be done in all cases beyond 36 weeks provided there is no contraindication. If the lie fails to stabilize even at 36th week, the case is to be managed as outlined in unstable lie (Flowchart 26.5). +If version fails or is contraindicated: +♦ The patient is to be admitted at 36th weeks, because risk of early rupture of the membranes and cord prolapse is very much there. Elective cesarean delivery (after 37 completed weeks) is the preferred method of delivery. +PATIENT SEEN IN LABOR: The principles in management are as outlined below: +EARLY LABOR +■ External cephalic version in selected cases: Provided there is good amount of liquor amnii and there is no contraindication. +■ Cesarean section is the preferred method of delivery if version fails or is contraindicated. Difficulties are faced during cesarean section as the lower uterine segment is poorly developed. A low transverse incision is commonly made. Otherwise uterine incision may be low vertical or T shaped. +■ Internal version and breech extraction is not recommended. The complications both to the mother and the fetus are high. +Intraoperative cephalic version is often successful when done after the use of anesthesia and uterine relaxation. + +Flowchart 26.5: Management of shoulder presentation (transverse lie). + +Admission at 36 weeks + + +External cephalic version (contraindication are) + + +LATE LABOR +■ Baby alive: Cesarean Delivery (CD) is to be done. Internal version: In modern obstetric practice, is not recommended except in the case of second twin. +■ Baby dead: Cesarean delivery, even in such cases, is much safer than evisceration (p. 552). + +UNSTABLE LIE + +This is a condition where the presentation of the fetus constantly changes even beyond 36th week of pregnancy when it should have been stabilized. +CAUSES: The causes are those which prevent the presenting part to remain fixed in the lower pole of the uterus. Such conditions are: (1) Grand multipara with lack of uterine tone and pendulous abdomen-the most common cause; (2) Hydramnios; (3) Contracted pelvis; (4) Placenta previa; (5) Pelvic tumor. +Complications: Cord entanglement is a possible risk. Risk of cord prolapse is there once the membranes rupture. Perinatal death is high. +MANAGEMENT: ANTENATAL: At each antenatal visit, the presentation and the lie are to be checked. If there is no contraindication, external version is to be done to correct the malpresentation. Hospitalization: The patient is to be admitted at 36th week. Premature or early rupture of the membranes with cord prolapse is the real danger with the lie remaining oblique. After admission, the investigation is directed to exclude placenta previa, contracted pelvis and assessment of liquor volume with the help of sonography. + +FORMULATION OF THE LINE OF TREATMENT +• Elective cesarean section is done in majority of the cases, especially in the presence of complicating factors like pre-eclampsia, placenta previa, contracted pelvis. +• Stabilizing induction of labor: External cephalic version is done (if not contraindicated) after 37 weeks ➔ oxytocin infusion is started to initiate effective uterine contractions. This is followed by low rupture of the membranes (amniotomy). Labor is monitored for successful vaginal delivery. This procedure may be done even after the spontaneous onset of labor. + +COMPOUND PRESENTATION (Syn: Complex Presentation) + +Compound presentation is the presence of a fetal extremity alongside the presenting part. Hand in cephalic presentation is most common. Hand in breech presentation is relatively rare. + + + + +Fails + + +Cesarean delivery + + +Successful + + +Delivery as vertex + +When a cephalic presentation is complicated by the presence of a hand or a foot or both alongside the head or presence of one or both hands by the side of the breech, it is called compound presentation. The most common one being the head with hand (Fig. 26.31) and +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse iD CORD PROLAPSE + + + + + + + + + + + + + + + + + + + + +Fig. 26.31: Compound presentation-head with hand. + +the rarest one being the presence of head, hand and a foot. The incidence is about 1 in 300 to 1 in 1000 deliveries. +ETIOLOGY: Conditions preventing engagement of the head can result in slipping of either upper or lower limbs by the side of the head. Prematurity (the most common), contracted pelvis, pelvic tumors, multiple pregnancy, high head with premature or early rupture of the membranes and hydramnios are the known etiological factors. +DIAGNOSIS: The diagnosis is not difficult when the cervical os is sufficiently dilated to feel the limb by the side of the presenting part, especially after rupture of the membranes. Premature or early rupture of the membranes occurs in about one-third of the cases. Cord prolapse is to be excluded because of its frequent association-I 0-15%. + +MANAGEMENT: Factors to he considered are-(1) Stage of labor; (2) Viability of the fetus; (3) Singleton or twins; (4) Pelvic adequacy; and (5) Associated cord prolapse. The fetal risks in compound presentation are birth trauma and cord prolapse. +Indication of cesarean section: Term singleton live fetus associated with pelvic inadequacy or cord prolapse should be safely delivered by cesarean section. +Expectant management: In a case with nonviable fetus, labor is allowed in anticipation to vaginal delivery. Vaginal delivery is also anticipated in a viable fetus with cephalic presentation with a prolapsed hand. These cases do not pose any dificulty as the hand moves upwards with the descent of the head into the birth canal. The proposed hand may be pushed upwards, after/during uterine contractions. However, labor process needs to be monitored very carefully (preferably by electronic fetal monitoring). Elevation of the prolapsed limb with descent of the presenting part usually talces place spontaneously. + +There are three clinical types of abnormal descent of the umbilical cord by the side of the presenting part. All these are placed under the heading cord prolapse. ++ Occult prolapse: The cord is placed by the side of the presenting part and is not felt by the fingers on internal examination. It could be seen on ultrasonography or during cesarean section. ++ Cord (funic) presentation: The cord is slipped down below the presenting part and is felt lying in the intact bag of membranes. ++ Cord prolapse: The cord is lying inside the vagina or outside the vulva following rupture of the membranes (Fig. 26.32). +INCIDENCE: Incidence varies widely from 0.5% (cephalic presentation) to 20% in transverse lie. It is mostly confined to parous women. +ETIOLOGY: Anything which interferes with perfect adaptation of the presenting part to the lower uterine segment, may favor cord prolapse. Too often, more than one factor operates. The following are the associated factors: (1) Malpresentations-the most common being transverse (5-10%) and breech (3%), especially with flexed legs or footling and compound (10%) presentation; (2) Contracted pelvis; (3) Prematurity; (4) Twins; (5) Hydramnios; (6) Placental factor-minor degree placenta previa with marginal insertion of the cord or long cord; (7) Prematurity; (8) Iatrogenic; (9) Procedure related-(a) low rupture of the membranes, (b) manual rotation of the head, (c) ECV, (d) IPV, (10) Stabilizing induction. + +DIAGNOSIS: Occult prolapse: It is difficult to diagnose. The possibility should be suspected if there is persistence of variable deceleration, bradycardia of fetal heart rate pattern detected on continuous electronic fetal monitoring. Intrapartum Ultrasonography (IUSG) is very informative (Ch. 24, p. 335 and 41, p. 603). Cord presentation: The diagnosis is made by feeling the + + + + + + + + + + + + + + + + +Fig. 26.32: Woman in labor with cord prolapse. +ID Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse + +pulsation of the cord through the intact membranes. Cord prolapse: The cord is palpated directly by the fingers and its pulsation can be felt if the fetus is alive. Cord pulsation may cease during uterine contraction which, however, returns after the contraction passes off. Temptation to pull down the loop for visualization or unnecessary handling is to be avoided to prevent vasospasm. Prompt USG Doppler study for cardiac function or auscultation for FHS to be done for fetal assessment. +PROGNOSIS: Umbilical cord prolapse results in cord compression. This happens as the cord lies between the presenting part and the pelvic inlet, cervix or the vaginal wall. Umbilical cord compression reduces fetal circulation. Depending on the duration and severity of compression, there is fetal hypoxia, brain damage or even death. Apart from cord compression, there is vasospasm of the cord vessels due to irritation and the temperature variance when the cord comes out. Perinatal mortality associated with all cases of overt umbilical cord prolapse is about 20%. Prognosis for intrapartum cord prolapse is improved. Overall prognosis depends on the gestational age, degree, duration and severity of cord compression. When the prolapsed cord occlusion has occurred for ".5 minutes or intermittent/partial occlusion has occurred over a prolonged period, fetal damage or death may occur. If the delivery is completed, within 10-30 minutes, the fetal mortality can be reduced to 5-10%. The overall perinatal mortality is about 15-50%. +Maternal: The maternal risks are incidental due to emergency operative delivery, especially through the vaginal route. Operative delivery involves the risk of anesthesia, blood loss and infection. +PREVENTION AND EARLY DETECTION: (1) Patient with malpresentation or poorly applied cephalic presentations + +should be considered as high risk for cord prolapse. (ii) USG examination may be helpful to determine fetal lie and cord position. (iii) ARM should be avoided until the presenting part is well applied to the cervix. (iv) Pelvic examination should be a routine to rule out cord prolapse following spontaneous rupture of membranes. (v) Careful needling of the membranes, and slow release of the amniotic fluid can be performed until the presenting part is fixed against the cervix. + +I MANAGEMENT +CORD PRESENTATION: The aim is to preserve the membranes and to expedite the delivery. +♦ Once the diagnosis is made, no attempt should be made to replace the cord, as it is not only ineffective but the membranes inevitably rupture leading to prolapse of the cord. +♦ If immediate vaginal delivery is not possible, cesarean section is the best method of delivery. During the time of preparing the patient for operative delivery, she is kept in exaggerated Sims position. +♦ A rare occasion is when a fetus with longitudinal lie, good uterine contractions, cervix nearly full dilated and without any evidence of fetal distress. +Patient should be placed in left lateral maternal position. Oxygen is administered and electronic fetal monitoring is started. With full dilatation of the cervix, delivery is completed by forceps. Alternatively Cat I CS is done. +CORD PROLAPSE: Management protocol is to be guided by: (1) Baby living or dead; (2) Viability of the baby; and (3) Degree of dilatation of the cervix (Flowchart 26.6). +BABY LIVING: I. Definitive treatment: • Cesarean delivery is the best treatment when the baby is suficiently + + +Flowchart 26.6: Scheme of management of cord prolapse. + +Cord prolapse + + +• Baby living or dead + +• Viability of the baby. +• Cervical dilatation. + + + + + + + + +Immediate Cesarean delivery +l +(treatment of choice) + + +Baby alive +I + + + +Immediate safe vaginal +delivery possible (normal CTG) + +Baby dead +■ Confirm with ultrasound. +■ Wait for spontaneous delivery. + +Immediate vaginal +delivery not possible + + +Resuscitation First aid Definite management + + +Vertex +Forceps or +ventouse. + + +Breech +Breech extraction in +expert hands only. + +■ Bladder filling. Cesarean Delivery (CD) +■ To lift the presenting part off the cord. +■ Posture-exaggerated and elevated Sims. +position or Trendelenburg or knee chest. +position-to refer to an equipped hospital. +Chapter 26: Complicated Labor: Malposition, Malpresentation and Cord Prolapse il + +mature and is alive. Just prior to making the abdominal incision, the fetal heart should be auscultated once more to avoid unnecessary section on a dead baby. +II. Immediate safe vaginal delivery is possible: • If the head is engaged, delivery is to be completed by forceps. Ventouse may not be ideal in such circumstances as it takes a longer time. • Vaginal delivery is allowed when the fetus is previable or dead. +III. Immediate safe vaginal delivery is not possible: First aid management: The aim is to pressure on the cord till such time when the patient is prepared for assisted delivery or reaches an equipped hospital. +♦ If an oxytocin infusion is on, this should be stopped. +At this time intravenous fluid and 02 by face mask is +given. +♦ Bladder filling is done to raise the presenting part off the compressed cord till such time that patient + + +has delivered (either by CS or vaginally). Bladder is filled with 400-750 mL of normal saline with a Foley's catheter, the balloon is inflated and the catheter is clamped. Bladder is emptied before cesarean delivery. +♦ To lift the presenting part off the cord, by the gloved fingers introduced into the vagina. The fingers should be placed inside the vagina till definitive treatment is instituted. +♦ Postural treatment-exaggerated and elevated Sims position with a pillow or wedge under the hip or thigh; Trendelenburg or knee-chest position has been traditionally mentioned but may be tiring and irksome to the patient. +♦ To replace the cord into the vagina to minimize vasospasm due to irritation. +BABY DEAD: Labor is allowed to proceed awaiting spontaneous delivery. +Prolonged Labor, Obstructed +Labor, Dystocia Caused by +CHAPTER ii Fetal Anomalies + + +I) ❖ Prolonged Labor +► Treatment +❖ Obstructed Labor ► Treatment + + +► Shoulder Dystocia +❖ Dystocia Caused by Fetal Anomalies +► Hydrocephalus + + +❖ Neural Tube Defects (NTD) ► Anencephaly +❖ Conjoined Twins + + + + +PROLONGED LABOR + +DEFINITION: The labor is said to be prolonged when the combined duration of the first and second stage is more than the arbitrary time limit of 18 hours. The prolongation may be due to protracted cervical dilatation in the first stage and/ or inadequate descent of the presenting part during the first or second stage of labor. But it recommends diagnosis of arrest of labor after 6 cm of dilatation. Generally, if a patient with membrane rupture remains at 2:6 cm dilatation for more than 4 hours in the setting of an adequate contraction pattern or for more than 6 hours with inadequate contraction pattern with oxytocin, the women is said to have active phase arrest of labor. Prolonged labor is not synonymous with ineficient uterine contraction. Inefficient uterine contraction can be a cause of prolonged labor, but labor may also be prolonged due to pelvic or fetal factor. +PROLONGED LATENT PHASE +Latent phase is the preparatory phase of the uterus and the cervix before the actual onset of labor. Mean duration of latent phase is about 8 hours in a primi and 4 hours in a multi. Whether prolonged latent phase has got any adverse effect on the mother or on the fetus, it is not clearly known. A latent phase that exceeds 20 hours in primigravidae or 14 hours in multiparae is called prolonged. +Prolonged latent phase may be worrisome to the patient but does not endanger the mother or the fetus. +Management: Expectant management is usually done unless there is any indication (for the fetus or the mother) for expediting the delivery. Rest and analgesic are usually given. When augmentation is decided, medical methods (oxytocin or prostaglandins) are preferred. Amniotomy is usually avoided. Prolonged latent phase is not an indication for any intervention or cesarean delivery. + +CAUSES OF PROLONGED LABOR: Any one or combination of the factors in labor could be responsible. +First stage: Failure to dilate the cervix is due to: +♦ Fault in power: Abnormal uterine contraction such as uterine inertia (common) or incoordinate uterine contraction. +♦ Fault in the passage: Contracted pelvis, cervical dystocia, pelvic tumor or even full bladder. +♦ Fault in the passenger: Mal position [ Occiput Posterior (OP)] and malpresentation (face, brow), congenital anomalies of the fetus (hydrocephalus). +Too often deflexed head, minor degrees of pelvic contraction and disordered uterine action have got sinister effects in causing non-dilatation of the cervix. +■ Others: Injudicious (early) administration of sedatives and analgesics before the active labor begins. +Second stage: Sluggish or nondescent of the presenting part in the second stage is due to: +♦ Fault in the power: (1) Uterine inertia; (2) Inability to bear down; (3) Regional (epidural) analgesia; (4) Constriction ring. +♦ Fault in the passage: (1) Cephalopelvic disproportion, android pelvis, contracted pelvis; (2) Undue resistance of the pelvic floor or perineum due to spasm or old scarring; (3) Soft tissue pelvic tumor. +♦ Fault in the passenger: (1) Malposition (occipitoposterior); (2) Malpresentation; (3) Big baby; (4) Congenital malformation of the baby. +DIAGNOSIS: Prolonged labor is not a diagnosis but it is the manifestation of an abnormality, the cause of which should be detected by a thorough abdominal and vaginal examination. During vaginal examination, if a finger is accommodated in between the cervix and the head during uterine contraction pelvic adequacy can be reasonably established. Intranatal imaging (USG or MRI) is of help in determining the fetal station and position as well as pelvic shape and size. +Chapter 27: Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies ED + +First stage: First stage of labor is considered prolonged when the duration is more than 12 hours. The rate of cervical dilatation is <0.5 cm/h in a primi and 0.5-1.3 cm/h in a multi. The rate of descent of the presenting part is 20 hr + + + + + +• <1.2 cm/hr • <1 cm/hr + +■ >3 hr ■ >2 hr • >1 hr + + +Multiparous + + +>14 hr + + + + + +• <1.5 cm/hr ■ <2 cm/hr + +■ >1 hr ■ >2 hr >1 hr +• + + +Nulliparous + + +• Supportive care: • Oxytocin or +amniotomy. +• CD not indicated. + + +• Expectant care. • CDforCPD. + +■ CDforCPD. +■ No CPD: Oxytocin. + +Multiparous + + +• Supportive care: +• Oxytocin or amniotomy. • CD not indicated. + + + +CD not indicated. + + +CD indications: +■ Ruptured membranes and no progress after 4 hours of adequate contractions. OR + + + +■ Failure of descent. No descent in deceleration phase or second stage. + +■ No progress after 6 hr of inadequate contractions despite oxytocin stimulation. + +[CD: Cesarean Delivery; CPD: Cephalopelvic Disproportion; (ACOG, Cohen)] +!J Chapter 27: Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies + 10 I TREATMENT + +8 +6 + +4 + +·2: 2 +0 +0 4 8 12 16 20 24 Duration of labor (hours) +Fig. 27.1: Partographic analysis of labor to detect types of prolonged labor-protracted latent phase, protracted active phase and secondary arrest. + +2 hours or more prior to full dilatation of the cervix. It is commonly due to malposition or CPD. +Second stage arrest: No progress (descent or rotation) when pushing for over 3 hours in nulliparous women and over 2 hours in multiparous women is called second stage arrest. One hour more is allowed if epidural anesthesia is used (ACOG). +Disorders of the second stage: It may be due to one or a combination of several underlying abnormalities like CPD, malposition (OP), malpresentation, inadequate uterine contradictions or asynclitism. +DANGERS: Fetal: The fetal risk is increased due to the combined effects of: +(1) Hypoxia due to diminished uteroplacental circulation, especially after rupture of the membranes; (2) Intrauterine infection, pneumonia; (3) Intracranial stress or hemorrhage following prolonged stay in the perineum and/or supermoulding of the head; (4) Increased operative delivery. Prolonged second stage of labor is often associated with variable and delayed decelerations. Scalp blood pH estimations show fetal acidosis (Ch. 39, p. 569). All these result in increased perinatal morbidity and mortality. +Maternal: There is increased incidence of: (1) distress; (2) chorioamnionitis; (3) Postpartum hemorrhage; (4) trauma to the genital tract-concealed (undue stretching of the perinea! muscles which may be the cause of prolapse at a later period) or revealed such as cervical tear, rupture uterus; (5) increased operative delivery (vaginal instrumental or difficult cesarean); (6) puerperal sepsis; (7) subinvolution. The sum effects of all these lead to increased maternal morbidity and also increased maternal deaths. + + +PREVENTION +■ Antenatal or early intranatal detection of the factors likely to produce prolonged labor (big baby, small women, malpresentation or position). +■ Use ofpartograph (Fig. 34.4) helps early detection. +■ Selective amniotomy and judicious augmentation of labor by low rupture of the membranes followed by oxytocin drip. +■ Change of posture in labor other than supine to increase uterine contractions, emotional support, presence of a labor companion, avoidance of dehydration in labor and use of adequate analgesia for pain relief. +■ Respectful maternity care is to be provided (Ch. 13). +ACTUAL TREATMENT: Careful evaluation is to be done to find out: (1) cause of prolonged labor; (2) effect on the mother; (3) effect on the fetus. In a nulliparous patient, inadequate uterine activity is the most common cause of primary dysfunctional labor. Whereas in a multiparous patient, cephalopelvic disproportion (due to malposition) is the most common cause. +Preliminaries: In an equipped labor ward, prolonged labor is unlikely to occur in modern obstetric practice. But in low resource settings, cases of prolonged labor with evidences of dehydration and ketoacidosis are admitted to the referral hospitals. Correction of dehydration and ketoacidosis (isotonic drinks reduce ketosis) should be made urgently by rapid intravenous infusion of Ringer's solution. +Definitive treatment: First stage delay: Vaginal examination is done to verify the fetal presentation, position and station. Clinical pelvimetry is done. If only uterine activity is suboptimal, (1) amniotomy and/ or oxytocin infusion is adequate; (2) effective pain relief is given by regional (epidural) analgesia. (3) cesarean section is done when vaginal delivery is unsafe (malpresentation, malposition, big baby or CPD). +Second-stage delay: Short period of expectant management is reasonable provided the FHR (electronic monitoring) is reassuring and vaginal delivery is imminent. Otherwise, appropriate assisted delivery, vaginal (forceps, ventouse) or abdominal (cesarean) should be done. Dficult instrumental delivery should be avoided. + + + + + +► Prolonged labor is defined when the combined duration of first and second stage of labor is more than 18 hours. +► Prolonged latent phase is defined when the duration is more than 20 hours in a primigravida. Normally, it lasts for 8 hours in a primigravida. Latent phase ends when the cervix is 5 cm or more dilated. +► Prolonged labor may be due to abnormality of any one or combination of the factors, e.g., passage (pelvis, cervix); passenger (fetal size, presentation, position, congenital malformation) and the power. +Contd... +Chapter 27: Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies +DI· •·· + +Contd... +> Mal presentation and ma Iposition are associated with poor adaptation of the presenting part to the cervix. This causes poor progress of labor. +> Detection of prolonged labor in the first stage or in the second stage can be made on careful clinical examination and using a partograph. +> In a primigravida, inadequate uterine contraction is the most common cause of primary dysfunctional labor. In a multigravida, cephalopelvic disproportion is the most common cause. +> In the active phase of labor, the cervix should dilate at least at the rate of 1 cm per hour. +> Dangers of prolonged labor are both to the mother and the fetus. Management is primarily aimed in prevention, early detection and appropriate intervention. +> Maternal supine position and dehydration in labor should be avoided. There should be adequate pain relief. +> Common causes of prolonged labor are abnormal uterine contractions, abnormal presentation and position of the fetus and cephalopelvic disproportion. +> Dangers of prolonged labor are: (Al Fetal: Hypoxia, intrauterine infection. (Bl Maternal: Chorioamnionitis, increased operative delivery and PPH. +> Protraction disorders are defined when the progress of labor is slower than normal, whereas arrest disorders are defined where there is complete cessation of progress. +> Combined disorder in active phase is defined as the arrest of dilatation of the cervix or descent of the fetal head occurring in a woman who has previously developed protracted labor. Women with combined disorder often have less favorable chance of vaginal delivery. Patient needs to be evaluated as regard uterine contractions, pelvic adequacy, fetal presentation, position, station and estimated fetal weight. + + +OBSTRUCTED LABOR + +DEFINITION: Obstructed labor is the one where, in spite of good uterine contractions, the progressive descent of the presenting part is arrested due to mechanical obstruction. This may result either due to factors in the fetus or in the birth canal or both, so that further progress is almost impossible without assistance. +INCIDENCE: In the developing countries, the prevalence is about 1-2% in the referral hospitals. + +CAUSES +♦ Fault in the passage: (1) Bony: Cephalopelvic disproportion and contracted pelvis are the common causes. Secondary contracted pelvis may be encountered in multiparous women. (2) Soft tissue obstructions: This includes cervical dystocia due to prolapse or previous operative scarring, cervical or broad ligament fibroid, impacted ovarian tumor or the nongravid horn of a bicornuate uterus below the presenting part. +♦ Fault in the passenger: (1) Transverse lie; (2) Brow presentation; (3) Congenital malformations of the fetus-hydrocephalus ( commonest), fetal ascites, double monsters; (4) Big baby, occipitoposterior position; (5) Compound presentation; (6) Locked twins. + +MORBID ANATOMICAL CHANGES +Uterus: The morbid anatomical changes in response to obstruction have already been described in relation to the formation of pathological retraction ring or Band!'s ring. +Bladder: The bladder becomes an abdominal organ and due to compression of urethra between the presenting part and symphysis pubis, the patient fails to empty the bladder. The transverse depression at the junction of the + +superior border of the bladder and the distended lower segment is often confused with the Bandl's ring. The bladder walls get traumatized, which may lead to blood­ stained urine, a common finding in obstructed labor. The base of the bladder and urethra, which are nipped in between the presenting part and symphysis pubis, may undergo pressure necrosis. The devitalized tissue becomes infected and later on may slough off resulting in the development of genitourinary fistula. + +EFFECTS ON THE MOTHER Immediate: +1. Exhaustion is due to a constant agonizing pain and anxiety. +2. Dehydration is due to increased muscular activity without adequate fluid intake. +3. Metabolic acidosis is due to accumulation of lactic acid and ketones. +4. Genital sepsis is an invariable accompaniment, especially after rupture of the membranes with repeated vaginal examination or attempted manipulation outside. +5. Injury to the genital tract includes rupture of the uterus which may be spontaneous in multiparae or may be traumatic following instrumental delivery. +6. Postpartum hemorrhage and shock may be due to isolated or combined effects of atonic uterus or genital tract trauma. All these lead to an increased maternal morbidity and mortality. The deaths are due to rupture of the uterus, shock and sepsis with metabolic changes. +Remote: Even if the patient survives, the following legacies may be left behind: (1) genitourinary fistula or rectovaginal fistula, (2) variable degree of vaginal atresia, (3) secondary amenorrhea following hysterectomy due to rupture or due to Sheehan's syndrome. +· E9 Chapter 27: Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies +! + +EFFECTS ON THE FETUS +1. Asphyxia results from tonic uterine contraction that interferes with the uteroplacental circulation or due to cord prolapse, especially in shoulder presentation. +2. Acidosis due to fetal hypoxia and maternal acidosis. +3. Intracranial hemorrhage is due to supermoulding of +the head leading to tentorial tear or due to traumatic delivery. +4. Infection: All these lead to increased perinatal loss. +CLINICAL FEATURES: The clinical features are like those mentioned in tonic uterine contraction and retraction (p. 345). + +I TREATMENT +PREVENTION +♦ Antenatal detection of the factors likely to produce pro­ longed labor (big baby, small women, malpresentation and position). +♦ Intranatal: Continuous labor monitoring, use of partograph and timely intervention of a prolonged labor due to mechanical factors can prevent obstructed labor. Failure in progress of labor in spite of good uterine contractions for a reasonable period (2-4 hours) is an impending sign of obstructed labor. +ACTUAL TREATMENT: The underlying principles are: (1) to relieve the obstruction at the earliest by a safe delivery procedure, (2) to combat dehydration and ketoacidosis, (3) to control sepsis. +Preliminaries: +1. Fluid-electrolyte balance and correction of dehydration and ketoacidosis are done by rapid infusion of Ringer's solution; at least 1 liter is to be given in running drip. At least 3 liters of fluid is required to correct clinical dehydration. +2. A vaginal swab is taken and sent for culture and sensitivity test. +3. Blood sample is sent for group and cross-matching and a bottle of blood should be at hand prior to any operative intervention. +4. Antibiotic: Ceftriaxone I g IV is administered. +5. IV infusion, metronidazole is given for anaerobic infection. +Obstetric management: Before proceeding for definitive operative treatment, rupture of the uterus must be excluded. A balanced decision should be taken about the best method of relieving the obstruction with least hazards to the mother. Frantic attempt to deliver a moribund baby by a method ignoring the risk involved to the mother is indeed bad obstetrics. There is no place of "wait and watch' neither is any scope of using oxytocin to stimulate uterine contraction. +Vaginal delivery: The baby is invariably dead in most of the neglected cases and destructive operation is the + + +best choice to relieve the obstruction. If, however, the head is low down and vaginal delivery is not risky, forceps extraction may be done in a living baby. There is no place of internal version in obstructed labor. After completion of the delivery and expulsion of the placenta, exploration of the uterus and the lower genital tract should be done to exclude uterine rupture or tear. +Cesarean section: If the case is detected early with good fetal condition, cesarean section gives the best result. But in late and neglected cases, even if the fetal heart sound is audible, desperate attempt to do a cesarean section to save the moribund baby more often leads to disastrous consequences. Not infrequently, the baby is either delivered stillborn or dies due to neonatal sepsis. The postoperative period of the mother also becomes stormy and, at times, ends fatally. +Symphysiotomy: The place of symphysiotomy has to be duly considered in the developing countries as an alternative to risky cesarean section. This can be done in a case of established obstruction due to outlet contraction with vertex presentation having good FHS. + +MACROSOMIA (generalized fetal enlargement): Fetal Macrosomia is defined when the birth weight exceeds certain percentiles for a given population. Empirically a newborn weight exceeding 4000 g is frequently used threshold to define macrosomia. +Risk factors for fetal macrosomia: +■ Hereditary, race. ■ Male baby. +■ Size of the parents. ■ Advanced maternal ■ Maternal obesity. age. +■ Poorly controlled GDM. ■ Previous history of ■ Post-maturity. macrosomic baby ■ Multiparty. delive1y. + +Diagnosis is suspected because of: (1) disproportionate increase in uterine size, (2) clinically, the fetus is felt big, (3) ultrasonographic measurements of fetal BPD, HC, FL and AC are done to predict the estimated fetal weight. Dangers involve both the fetus and the mother. Fetal hazards are: surprise dystocia due to cephalopelvic disproportion, shoulder dystocia (30%), brachia! plexus injury (2-15%), asphyxia, birth trauma, meconium aspiration and HIE. Overall, perinatal mortality and morbidity are high. +Maternal dangers include: Injmy to the maternal soft tissues [vagina, perineum, 3rd and 4th degree perinea! trauma (5%), uterine rupture], PPH (10%) and puerperal sepsis. Rate of CD is high (50%). Maternal morbidity is high. ■ Increased rate of maternal and perinatal morbidity. +■ Increased rate of cesarean delivery (>50%). ■ Risk of shoulder dystocia (30%). +■ PPH, perinea! laceration, infections are higher. +Management: (i) Prophylactic induction of labor (early) to reduce the risk of shoulder dystocia or (ii) Elective cesarean delivery; (a) especially in diabetic women with big baby to reduce perinatal hazards (shoulder dystocia); +Chapter 27: Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies ED + +(b) In women with previous history of shoulder dystocia as risk of recurrence is 10 times higher. +I SHOULDER DYSTOCIA +Definition: The term shoulder dystocia is defined to describe a wide range of additional obstetric maneuvers to deliver the shoulder of the fetus after the head has been born and gentle traction has failed. Shoulder dystocia occurs when either the anterior or the posterior (rare) fetal shoulder impacts on the maternal symphysis or on the sacral promontory respectively. Overall incidence varies between 0.2% and 1 %. +Riskfactors: Are not always present. (A) Prelabor: (1) History of previous shoulder dystocia, (2) Macrosomia (>4.5 kg), (3) Diabetes, (4) Obesity (BMI >30 kg/ m2), (5) Induced labor, (6) Multiparity; (B) Intrapartum: (7) Prolonged first stage or second stage of labor, (8) Secondary arrest of labor, (9) Postmaturity, (10) Oxytocin augmentation, (11) Anencephaly, (12) Mid-pelvic instrumental delive1y (more followingventouse than forceps), (13) Fetal ascites. Complications: (A) Neonatal: asphyxia, brachia! plexus injury (plexopathy) due to stretch, Erb (C5, C6), Klumpke palsy (CS, Tl), humerus fracture, clavicle or sternomastoid hematoma during delivery. Perinatal morbidity and mortality are high. (B) Maternal: PPH (11 %), cervical laceration, vaginal tear, perinea! tear (3rd and 4th degree), rupture of uterus, bladder, sacroiliac joint dislocation and morbidity. +Prevention of shoulder dystocia is not possible accurately even with antenatal ultrasonographic assessment. +Prediction: Shoulder dystocia neither could be predicted accurately nor could be prevented entirely. Prolonged first or second stage of labor, secondary arrest of labor (p. 379) and difficult mid-pelvic instrumental delivery are the important intrapartum observations to predict. +Diagnosis: (1) Definite recoil of the head back against the perineum (turtle neck sign); (2) Failure of spontaneous restitution of fetal head; (3) Fetal face becomes plethoric; (4) Failure of shoulder to descend. +Management principles: Extra help is to be called (a) To clear infant's mouth and nose, (b) Not to give traction over baby's head, (c) Never to apply fundal pressure as it causes further impaction of the shoulder (Fig. 27.2), (d) To perform wide mediolateral episiotomy as it provides space posteriorly, (e) To involve the anesthetist (as analgesia is ideal) and the pediatrician (for infant's resuscitation). +Considering the need of emergency management, shoulder dystocia drill should be practiced by the birth attendants. + + + + + + + + + + + + +Fig. 27.2: Fundal pressure should not be used as it causes further shoulder impaction. + +Management: The following maneuvers are commonly employed. There is no evidence that any method is superior to another in releasing the impacted shoulder or reducing the chance injury (ACOG-2002). +a Head and neck of the fetus should be grasped and taken posteriorly while suprapubic pressure is applied by an assistant slightly toward the side of fetal chest. This will reduce the bisacromial diameter and rotate the anterior shoulder toward the oblique diameter. This maneuver is simple as well as effective. It needs only one assistant. This procedure, when possible, may be done first (RCOG-2012). +11 McRoberts maneuver: Abduct the maternal thighs and sharply hyperflex them onto her abdomen. There is rotation of symphysis pubis upward and decrease in angle of pelvic inclination. This straightens the lumbosacral angle, rotates the maternal pelvis upward and increases the anterior-posterior diameter of the pelvis. This maneuver is effective and is successful in about 90% of cases. Suprapubic pressure may be used together. +■ Wood's maneuver: General anesthesia is administered. The posterior shoulder is rotated to anterior position {180°) by a corkscrew movement. This is done by inserting two fingers in the posterior vagina. Simultaneous suprapubic pressure is applied. This pushes the bisacromial diameter from the anteroposterior diameter to an oblique diameter. This helps easy entry of the bisacromial diameter into the pelvic inlet. Extraction of the posterior arm: The operator's hand is introduced into the vagina along the fetal posterior humerus in the sacral hollow. The arm is then swept across the chest and thereafter delivered by gentle traction. This procedure may cause either fracture clavicle or humerus or both. +11 "All Fours" position: Changing the mother on to all fours may increase the pelvic dimensions and allow the fetal position to shift. Downward traction on the posterior shoulder helps to free the impacted shoulder. This may be done for a mobile and slim woman in a community setting. +• Other techniques may be used when all the above maneuvers have failed: +II Deliberate fracture of the clavicle by finger pressure (fracture heals rapidly) or cleidotomy: One or both clavicles may be cut with scissors to reduce the shoulder girth. This is applicable to a living anencephalic baby as a first choice or in a dead fetus. +■ Zavanelli maneuver (pushing the fetus back to the uterus and delivering by cesarean section) or symphysiotomy is done rarely. +• AMTSL and examination for perinea! trauma to be done as a routine. +• All maternity staff should have shoulder dystocia training. Skill drills using mannequins in simulation improves management outcome when applied in real life. +,. All the maneuvers employed must be documented correctly to avoid litigation. + +DYSTOCIA CAUSED BY FETAL ANOMALIES ■ HYDROCEPHALUS +With the routine use of early pregnancy ultrasono­ graphy, most cases of fetal anomalies are diagnosed early. Termination of pregnancy is considered there after. Dystocia causes by major fetal anomalies are extremely rare these days. +ll Chapter 27: Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies +Management: With the routine use of early pregnancy sonography, most cases are diagnosed early and managed. For late cases: Principle is to decompress the hydrocephalic head in labor either in vertex or in breech presentation. This is also done during cesarean delivery before incising the uterus. Bladder is evacuated beforehand. Once the labor is established and the cervix is 3-4 cm dilated, decompression of the head is done by a sharp pointed scissors or with a wide bore (17 gauge) long needle. + + + + + + +Fig. 27.3: Ultrasonogram showing hydrocephalus with hugely dilated ventricles (both). + + + + + + + + + + + + + + + +Figs. 27.4A and B: (A) Anencephaly; (Bl USG showing anencephaly, with absence of fetal skull. The face is seen with prominent orbit. Courtesy: (A) Dr Mahesh Bharpilania; (B) Dr K Oswal. + +Excessive accumulation of cerebrospinal fluid (0.5-1.5 L) in the ventricles with consequent thinning of the brain tissue and enlargement of the cranium occurs in 1 in 2,000 deliveries (Figs. 27.3 and 27.4). It is associated with other congenital malformations (aneuploidy) in one-third of cases and neural tube defects. Recurrence rate is about 5%. Breech presentation occurs in about 30% cases. +Hydrocephalus may be caused by various genetic and environmental pathologies or due to some other CNS abnormalities. +Diagnosis: ■ Sonography (ventriculomegaly): There is enlargement of cerebral ventricles by CSF. The atrium normally measures between 5 and 10 mm from 15 weeks to term. When atrial width measures >15 mm, it is severe ventriculomegaly. The choroid plexus appears to dangle within the ventricle. The other findings are: (a) Cranial shadow is globular rather than normal ovoid, (b) Fontanels and sutures are wide, (c) Vault bones thinne1; (d) The lateral and third ventricles are dilated with marked thinning of the cerebral cortex, (e) Often the dilatation is due to stenosis of the aqueduct of Sylvius, agenesis of corpus callosum. ■ Internal examination during labor reveals: (a) gaping sutures and fontanels, and (b) crackling sensation on pressing the head. +In breech presentation, however, the diagnosis is not made until the aftercoming head is arrested at the brim. Presence of open spina bifida points strongly toward hydrocephalus. +Prognosis: Fetal outlook is extremely poor except in mild variety. + +In breech presentation, the arrested head can be decompressed by perforating the suboccipital region using a needle or a sharp pointed scissors under the guidance of two fingers of the left hand protecting the anterior vaginal wall. Decompression of the head (cephalocentesis) through the abdominal route using a large bore needle under ultrasound guidance may also be done. + +NEURAL TUBE DEFECTS (NTD} + +Anencephaly and spina bifida comprise 95% of NTD and the remaining 5% is encephalocele (Fig. 27.5). It is more common in lower socioeconomic group. Recurrence risk after one affected child is 4%. +I ANENCEPHALY +The incidence of anencephaly is about 1 in 1,000 births. The anomaly results from deficient development of the vault of the skull and brain tissue, but the facial portion is normal. The pituitaiy gland is often absent or hypoplastic. Typically, there is marked diminution of the size of the adrenal glands probably secondaiy to the absence of the pituitary gland. +About 70% of anencephalic fetuses are females. Genetic and environmental factors are probably involved (multifactoriai). +Diagnosis: In the first half of pregnancy, the diagnosis is made by elevated alpha-fetoprotein in amniotic fluid. Diagnosis with USG could be made as early as 10 weeks gestation. The findings around 10 weeks are: (a) absence of cranial vault, (b) angiomatous, brain tissue. Meningomyelocele­ extending from the base of the skull down to the neck, may be present along with axencephaly. Encephalocele is due to the protrusion of the meninges and the brain tissue through a defect in the cranium. A midline sac is often seen protruding through the skull (occiput) on ultrasonography. +Complications include: (1) Hydramnios (70%); ( 2) Malpresentation-face or breech; (3) Preterm labor, especially when associated with hydramnios; (4) Tendency of postmaturity; (5) Shoulder dystocia; (6) Obstructed labor if the head and shoulders try to engage together because of short neck. +Management: Mostly it is confirmed by early sonography before 20 weeks and termination of pregnancy is done. The uterus is most often refractory to oxytocin because of low level of estriol as a result of insufficient production of its precursor cortisol from fetal adrenals. Use of prostaglandin vaginal gel +(PGE2) has been proved to be effective in resistant cases. During +labor, there is tendency of delay. Shoulder dystocia should be managed by cleidotomy. +Prevention: Prepregnancy counseling is essential. Folic acid supplementation: beginning 1 month before conception to about 12 weeks of pregnancy has reduced the incidence ofNTD significantly (85%). A dose of 5 mg daily is recommended. Risk of recurrence is about 4% in subsequent pregnancy. +Chapter 27: Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies + + + + + + + + + + + + + + +Fig. 27.5: Encephalocele. Fig. 27.6: Sonography showing fetal ascites. + +Fig. 27.7: Huge fetal abdo­ minal enlargement due to ascites. + + + +ENLARGEMENT OF FETAL ABDOMEN +The enlargement of fetal abdomen sufficient to produce dystocia may be due to ascites, distended bladder or enlargement of kidney by a tumor or an umbilical hernia. Antenatal diagnosis can be made by sonography (Figs. 27.6 and 27.7) which shows an appearance resembling that of the "Buddha position''. In an unbooked case, the diagnosis is made when there is dificulty in delivery of the trunk following birth of the head. Confirmation is done by introducing the hand and palpating the hugely distended abdomen. The decompression of the abdomen is done by simple puncture with a wide bore needle which is soon followed by spontaneous delivery. +MONSTERS: The varieties of incomplete twinning result in development of groups of monsters. The condition is extremely rare and often causes surprise dystocia. + +CONJOINED TWINS + +Diagnosis: Ultrasonography: A thorough targeted USG is done. Diagnosis on ultrasonography: (i) Early in first trimester monochorionicity and monoamnioncity and a bifid fetal pole. 3D-USG and MRI may be used to + +confirm the diagnosis, (ii) a continuous external skin contour, (iii) body parts of twins (heads) are on the same level, (iv) no change in relative positions of twins on successive scans, (v) spines are in unusual close proximity and are extended, and (vi) single placenta. 3D USG, color Doppler, fetal echocardiography and MRI can determine the extent of the organ sharing and also can classify the type of conjoined twining (Fig. 17.8). +Management: Once the diagnosis is confirmed, pregnancy termination is an option. Patients need to be counseled as regards the prognosis depending on the degree of organ sharing between the fetuses. Multidisciplinary team approach is needed for management when pregnancy is continued. Survival rate in a well-selected case following separation has improved (80%). Cesarean section offers best chance of fetal survival as in few cases of conjoined twins can be surgically separated. It is commonly done when the diagnosis is made during pregnancy. +Destructive operation (evisceration and amputation of body parts) is an alternative when diagnosed in labor with dead fetuses. It is rarely done these days. + + + + + +OBSTRUCTED LABOR +► Obstructed labor is the arrest of descent of the presenting part despite good uterine contractions. This occurs due to mechanical obstruction. +► Common causes are: CPD, soft tissue obstruction (impacted ovarian tumor) or fetal malpresentation or position. +► Effects on the mother or the fetus are worse compared to prolonged labor. Perinatal and maternal morbidity and mortality are high. ► Actual management includes: To correct maternal dehydration, ketoacidosis, sepsis and to deliver the woman. Cesarean delivery is +commonly done when the fetal condition is good. +► Management is primarily aimed in prevention. The actual management is to relieve the obstruction and to deliver the fetus safely. ► Dystocia may also be due to macrosomia or due to fetal anomalies (hydrocephalus, anencephaly or conjoined twins. +► Shoulder dystocia (difficulties during delivery of the shoulders) may be due to several factors. Dangers are mainly to the fetus. Hazards could be minimized if management principles are strictly followed. McRoberts maneuver along with suprapubic pressure is found successful in about 90% of cases. +► Conjoined twins: 30 USG, color Doppler, fetal echocardiography and MRI can confirm the diagnosis and also can determine the extent of organ sharing. Multidisciplinary team approach is essential in the management. + + +Complications of the Third Stage of Labor + + + + + + + +CHAPTER OUTLINE '. +❖ Postpartum Hemorrhage (PPH) +❖ Primary Postpartum Hemorrhage ► Causes +► Prevention +► Management of Third-stage Bleeding + + +► Steps of Manual Removal of Placenta ► Management of True Postpartum +Hemorrhage +► Actual Management +❖ Secondary Postpartum Hemorrhage ❖ Retained Placenta + + +► Management +► Management of Unforeseen Complications during Manual Removal of Placenta +❖ Morbid Adherent Placenta ❖ Inversion of the Uterus + + + + +Of all the stages of labor, third stage is the most crucial one for the mother. Fatal complications may appear unexpectedly in an otherwise uneventful first or second stage. The following are the important complications: (1) Postpartum hemorrhage; (2) Retention of placenta; (3) Shock-hemorrhagic or non-hemorrhagic; (4) Pulmonary embolism either by amniotic fluid or by air; (5) Uterine inversion (rare). + +POSTPARTUM HEMORRHAGE (PPH) +DEFINITION: Quantitative definition is arbitrary and is related to the amount of blood loss in excess of 500 mL following birth of the baby (WHO). It may be useful for statistical purposes. As the effect of the blood loss is important rather than the amount of blood lost, the clinical definition, which is more practical, states, "any amount of bleeding from or into the genital tract following birth of the baby up to the end of the puerperium, which adversely affects the general condition of the patient evidenced by rise in pulse rate and falling blood pressure, is called postpartum hemorrhage". +Visual estimation of blood loss is inaccurate. Therefore, clinical signs and symptoms should be included in assessment of PPH (RCOG-2016). +Postpartum hemorrhage defined as the excessive bleeding following delivery (>500 mL in vaginal delivery or >1000 mL in cesarean delivery accompanied by signs and symptoms of hypovolemia (ACOG-2017). +The average blood loss following vaginal delivery, cesarean delivery and cesarean hysterectomy is 500 mL, 1000 mL and 1500 mL respectively. +Depending upon the amount of blood loss, PPH can be: • Minor ( lL) or • Severe (>2L). +INCIDENCE: The incidence widely varies mainly because of lack of uniformity in the criteria used in definition. The incidence is about 4-6% of all deliveries. + +TYPES: ■ Primary {early) 11 Secondary {late) Primary: Hemorrhage occurs within 24 hours +following the birth of the baby. In the majority, hemorrhage occurs within two hours following delivery. These are of two types: +■ Third-stage hemorrhage: Bleeding occurs before expulsion of placenta. +■ True postpartum hemorrhage: Bleeding occurs subsequent to expulsion of placenta (majority). +Secondary: Hemorrhage occurs beyond 24 hours and within puerperium, also called delayed or late puerperal hemorrhage. +Another classification of PPH has been proposed, wherein the volume loss is assessed in conjunction with clinical signs and symptoms (Ch. 39, Table 39.4). + +PRIMARY POSTPARTUM HEMORRHAGE I CAUSES +Four basic pathologies are expressed as the four Ts' (RCOG): Tone (atonicity), tissue (retained bits, blood clots), trauma (genital tract injury) and thrombin ( coagulopathy). +■ Atonic. 11 Traumatic. +■ Retained tissues. 11 Blood coagulopathy (thrombin). ■ Atonic uterus (80%): Atonicity of the uterus is the +commonest cause of postpartum hemorrhage. With the separation of the placenta, the uterine sinuses, which are torn, cannot be compressed effectively due to imperfect contraction and retraction of the uterine musculature and bleeding continues. The following are the conditions, which often interfere with the retraction of the uterus as a whole and of the placental site in particular. +♦ Grand multipara: Inadequate retraction and frequent adherent placenta contribute to it. Associated anemia may also probably play a role. +Chapter 28: Complications of the Third Stage of Labor ED + +♦ Overdistension of the uterus as in multiple pregnancy, hydramnios and big baby (>4 kg). Imperfect retraction and a large placental site are responsible for excessive bleeding. +♦ Malnutrition and anemia ( <9.0 g/dL): Even slight amount of blood loss may develop clinical manifestations of postpartum hemorrhage. +♦ Antepartum hemorrhage (both placenta previa and abruption}: The causes of excessive bleeding are mentioned in Ch. 19. +♦ Prolonged labor (>12 hours}: Poor retraction, infection (amnionitis), dehydration are important factors (tone). +♦ Anesthesia: Depth of anesthesia and the anesthetic agents (ether, halothane) may cause atonicity. +♦ Initiation or augmentation of delivery by oxytocin: Postdelivery uterine atonicity is likely unless the oxytocin is continued for at least one hour following delivery. +♦ Uterine fibroid causes imperfect retraction mechanically. +♦ Mismanaged third stage oflabor: This includes-Ca) Too rapid delivery of the baby preventing the uterine wall to contract so rapidly, (b) Premature attempt to deliver the placenta before it is separated, (c) Kneading and fiddling the uterus, (d) Pulling the cord. All these produce irregular uterine contractions leading to partial separation of placenta and hemorrhage, (e) Manual separation of the placenta increases blood loss during cesarean delivery. +♦ Placenta: Morbidly adherent (accreta, percreta), partially or completely separated and/or retained (due to constriction ring of uterus) cause PPH. +♦ Precipitate labor: In rapid delivery, separation of the placenta occurs following the birth of the baby. Bleeding continues before the onset of uterine retraction. Bleeding may be due to genital tract trauma also. +♦ Other causes of atonic hemorrhage are: +11 Obesity (BMI >35). +■ Previous history of PPH. 11 Age (>40years). +11 Drugs: Use of tocolytic drugs (ritodrine ), MgSO 4, nifedipine. +■ Traumatic (20%}: Trauma to the genital tract usually occurs following operative delivery; even after spontaneous delivery. Blood loss from the episiotomy wound is often underestimated. Similarly, blood loss in cesarean section amounting to 800-1000 mL is most often ignored. Trauma involves usually the cervix, vagina, perineum (episiotomy wound and lacerations), paraurethral region and rarely, rupture of the uterus occurs. The bleeding is usually revealed but can rarely be concealed (vulvovaginal or broad ligament hematoma). + +■ Retained tissues (5-10%): Bits of placenta, blood clots cause PPH due to imperfect uterine retraction. USG of an echogenic mass is suggestive of returned tissues. +■ Thrombin: Blood coagulation disorders, acquired or congenital, are less common causes of postpartum hemorrhage. The blood coagulopathy may be due to diminished procoagulants (washout phenomenon) or increased fibrinolytic activity. The firmly retracted uterus can usually prevent bleeding. The conditions where such disorders may occur are abruptio placentae, jaundice in pregnancy, thrombocytopenic purpura, severe pre-eclampsia, HELLP syndrome, amniotic fluid embolism or in IUD. Specific therapy following coagulation screen, including recombinant activated factor VII (rF VIia) may be given. +■ Combination of atonic and traumatic causes. +DIAGNOSIS AND CLINICAL EFFECTS: In the majority, the vaginal bleeding is visible outside, as a slow trickle. Rarely, the bleeding is totally concealed as either vulvovaginal or broad ligament hematoma. The effect of blood loss depends on-(a) Predelivery hemoglobin level, (b} degree of pregnancy-induced hypervolemia, and ( c) speed at which blood loss occurs. Alteration of pulse, blood pressure and pulse pressure appears only after class 2 hemorrhage (20-25% loss of blood volume). On occasion, blood loss is so rapid and brisk that death may occur within a few minutes. +State of uterus, as felt per abdomen, gives a reliable clue as regards the cause of bleeding. In traumatic hemorrhage, the uterus is found well contracted. In atonic hemorrhage, the uterus is found flabby and becomes hard on massaging. However, both the atonic and traumatic cause may coexist. Even following massive blood loss from the injured area, a state of low general condition can make the uterus atonic. +PROGNOSIS: Postpartum hemorrhage is one of the life­ threatening emergencies. It is one of the major causes of direct maternal deaths both in the developing and developed countries. Prevalence of malnutrition and anemia, inadequate antenatal and intranatal care and lack of blood transfusion facilities, substandard care are some of the important contributing factors. There is also increased morbidity. These include shock, transfusion reaction, puerperal sepsis, failing lactation, pulmonary embolism, thrombosis and thrombophlebitis. Late sequelae include Sheehan's syndrome (selective hypopituitarism) or rarely diabetes insipidus. + +I PREVENTION + +Postpartum hemorrhage cannot always be prevented. However, the incidence and especially its magnitude can be reduced substantially by assessing the risk factors and following the guidelines as mentioned below: + Chapter 28: Complications of the Third Stage of Labor + + +However, most cases of PPH have no identifiable risk factors. +■ Antenatal +♦ Improvement of the health status of the woman and to keep the hemoglobin level normal (>10 g/dL) so that the patient can withstand some amount of the blood loss. +♦ High-risk patients who are likely to develop postpartum hemorrhage (such as twins, hydramnios, grand multipara, APH, history of previous PPH, severe anemia) are to be screened and delivered in a well-equipped hospital. +♦ Blood grouping should be done for all women so that no time is wasted during emergency. +♦ Placental localization must be done in all women with previous cesarean delivery by USG or MRI to detect placenta accreta or percreta. +♦ All women with prior cesarean delivery must have their placental site determined by ultrasound/MRI to determine morbid adherent placenta. +♦ Women with morbid adherent placenta are at high risk of PPH. Such a case should be delivered by a senior obstetrician. Availability of blood and/or blood products must be ensured beforehand. Multidisciplinary team approach should be made in such a case. +■ Intranatal +♦ Active management of the third stage, for all women in labor should be a routine as it reduces PPH by 60%. +♦ Cases with induced or augmented labor by oxytocin, the infusion should be continued for at least one hour after the delivery. +♦ Women delivered by cesarean section, oxytocin 5 IU slow IV is to be given to reduce blood loss. Carbetocin (long-acting oxytocin) 100 mg IV (to be given over 1 minute), is very useful to prevent PPH. +♦ Exploration of the uterovaginal canal for evidence of trauma following difficult labor or instrumental delivery. +♦ Observation for about two hours after delivery to make sure that the uterus is hard and well contracted before sending her to ward. +♦ Expert obstetric anesthetist is needed when the delivery is conducted under general anesthesia. Local or epidural anesthesia is preferable to general anesthesia, in forceps, ventouse or breech delivery. +♦ During cesarean section spontaneous separation and delivery ofthe placenta reduces blood loss (30%). +♦ Examination of the placenta and membranes should be a routine to detect at the earliest any missing part. +All said and done, it is the intelligent anticipation, skilled supervision, prompt detection and effective institution of therapy that can prevent a normal case from undergoing disastrous consequences. + +I MANAGEMENT OF THIRD-STAGE BLEEDING + +The principles in the management are: +■ To empty the uterus of its contents (removal of placenta) and to make it contract. +■ To replace the blood. On occasion, patient may be in shock. In that case patient is managed for shock first. +■ To ensure effective hemostasis in traumatic bleeding. + + +STEPS OF MANAGEMENT +a Placental site bleeding 11 Traumatic bleeding Placental site bleeding +■ To palpate the fundus and massage the uterus to make it hard. The massage is to be done by placing four fingers behind the uterus and thumb in front. However, if bleeding continues even after the uterus becomes hard, suggests the presence of genital tract injury. +■ To start crystalloid solution (normal saline or Ringer's solution) with oxytocin (1 L with 20 units) at 60 drops per minute and to arrange for blood transfusion, if necessary. +■ Oxytocin 10 units IM or methergine 0.2 mg is given intravenously. Carbetocin, a longer acting oxytocin derivative is found (100 µg) as effective as oxytocin infusion. +■ To catheterize the bladder. +■ To give antibiotics (Ampicillin 2 g and metronidazole 500 mg IV}. +During this procedure, if features of placental separation are evident, expression of the placenta is to be done either by fundal pressure or controlled cord traction method. If the placenta is not separated, manual removal of placenta under general anesthesia is to be done (Flowchart 28.1). In case the patient is in shock, she is resuscitated first before undertaking manual removal. If the patient is delivered under general anesthesia, quick manual removal of the placenta solves the problem. In cases where oxytocin 10 units is given IM with the delivery of the anterior shoulder, manual removal is done promptly when two attempts of controlled cord traction fail. Placenta is normally separated and is delivered within 5 minutes of delivery of the baby in 50% of the cases and within 15 minutes in 90% of cases. +Management of traumatic bleeding: The uterovaginal canal is to be explored under general anesthesia after the placenta is expelled and hemostatic sutures are placed on the offending sites. + +STEPS OF MANUAL REMOVAL OF PLACENTA (MRP) + +Step-I: The operation is done under general anesthesia. In extreme urgency where anesthetist is not available, the operation may have to be done under deep sedation with 10 mg diazepam given intravenously. The patient is placed in lithotomy position. With all aseptic measures, the bladder is catheterized. +Step-II: One hand is introduced into the uterus after smearing with the antiseptic solution in cone-shaped manner following the cord, which is made taut by the other hand (Fig. 28.1 ). The fingers of the uterine hand should locate the margin of the placenta. +Step-III: Counterpressure on the uterine fundus is applied by the other hand placed over the abdomen. The abdominal hand should steady the fundus and guide the movements of the fingers inside the uterine cavity until the placenta is completely separated. +Step-IV: As soon as the placental margin is reached, the fingers are insinuated between the placenta and the uterine wall with the +Chapter 28: Complications of the Third Stage of Labor + +Flowchart 28.1: Scheme of management of third-stage hemorrhage (The Golden "1 hour"). + +I Management I +• Control the fundus, massage and make ii hard. +• Injection methergine 0.2 mg IV injection; carbetocin 100 19 IV. • To start normal saline drip with oxytocin and arrange for blood +transfusion. +• Catheterize the bladder. +! ! +Placenta separated Not separated +l + +Express the placenta out Manual removal under GA by controlled cord traction j +t +Traumatic hemorrhage should be tackled with sutures. + + + +back of the hand in contact with the uterine wall. The placenta is gradually separated with a sideways slicing movement of the fingers, until whole of the placenta is separated (Figs. 28.2A and B). +Step-V: When the placenta is completely separated, it is extracted by traction of the cord by the other hand. The uterine hand is still inside the uterus for exploration of the cavity to be sure that nothing is left behind. +Step-VI: Intravenous methergine 0.2 mg is given and the uterine hand is gradually removed while massaging the uterus by the external hand to make it hard. After the completion of manual removal, inspection of the cervicovaginal canal is to be made to exclude any injury. +Step-VII: The placenta and membranes are inspected for completeness and be sure that the uterus remains hard and contracted. Intravenous (IV) antibiotic is given at the time of Manual Removal of Placenta (MRP). +Difficulties: (1) Hour-glass contraction leading to dificulty in introducing the hand, (2) Morbid adherent placenta which may cause difficulty in getting to the plane of cleavage of placental separation. In such a case placenta is removed gently in fragments using an ovum forceps. +Complications: (1) Hemorrhage due to incomplete removal; (2) Shock; (3) Injury to the uterus; (4) Infection; (5) Inversion (rare); (6) Subinvolution; (7) Thrombophlebitis; (8) Embolism. In such + + + + + + + + + + + + + + +Fig. 28.1: Introduction of the hand into the uterus in a cone-shaped manner following the taut umbilical cord. + +cases, placenta is removed in fragments using an ovum forceps or a flushing curette. + +MANAGEMENT OF TRUE POSTPARTUM HEMORRHAGE + +PRINCIPLES: Simultaneous approach ■ Communication +11 Resuscitation Monitoring +11 Arrest of bleeding. +It is essential in all cases of major PPH (blood loss >1000 mL or clinical shock) (RCOG-2009). +The Golden "I hour" is the time at which resuscitation must be started to ensure best chance of survival. The probability of survival decreases sharply after the first hour if the patient is not effectively resuscitated. +■ Shock Index (SI) is used as a valuable guide in monitoring and general management of a woman with PPH. It is calculated: dividing the Heart Rate (HR) by + + + + + + + + + + + + + + + + +Figs. 28.2A and B: The placenta is separated by: (A) Keeping the back of the hand in contact with the uterine wall; (Bl With slicing movements of the hand. +Chapter 28: Complications of the Third Stage of Labor + + +■ Fall of Systolic Blood Pressure (SBP) by 30 mm Hg. ■ Rise in heart rate by 30 beats/minute. +■ Rise in respiratory rate >30 breaths/minute. ■ Drop of hemoglobin or hemato.crit by 30%. ■ Fall of urine output <30 ml/hr. +■ With these observations, the patient has lost at least 30% of her blood volume. She is in moderate shock leading to severe shock. + +SBP. The normal value is 0.5-0.7; however, with major hemorrhage it increases to 0.9-1.1. Change in SI is a better indicator to suggest early acute blood loss than the HR, SBP or DBP, when used alone. +MANAGEMENT +Immediate measures are to be taken by the attending house officer (doctor/midwife). +■ Call for extra help-involve the obstetric registrar (senior staff) on call. +■ Put in two large bore ( 14-gauge) intravenous cannulas. ■ Keep patient flat and warm. +■ Send blood for full blood count, group, cross-matching, diagnostic tests (RFT, LFT), coagulation screen, including fibrinogen and ask for 2 units (at least) of blood. +■ Infuse rapidly 2 liters of normal saline (crystalloids) or plasma substitutes like haemaccel (colloids), an urea­ linked gelatin, to re-expand the vascular bed. It does not interfere with cross-matching (Flowchart 28.2). +■ Give oxygen by mask 10-15 L/min. +■ Start 20-40 units of oxytocin in 1 L of normal saline IV at the rate of 20-40 drops per minute. Transfuse blood as soon as possible. +■ One midwife/rotating houseman should be assigned to monitor the following-(i) Pulse, (ii) Blood pressure, (iii) Temperature, (iv) Respiratory rate and oximeter (Box 28.1), (v) Type and amount offluids (blood, blood products) the patient has received, (vi) Urine output (continuous catheterization), (vii) Drugs-type, dose and time, (viii) Central venous pressure (when sited). +I ACTUAL MANAGEMENT + + + +missing cotyledon or piece of membranes. If the uterus fails to contract, proceed to the next step. +Step-II: The uterus is to be explored under general anesthesia. Simultaneous inspection of the cervix, vagina especially the paraurethral region is to be done to exclude coexistent bleeding sites from the injured area. In refractory cases: +■ Injection 15 methyl PGF2cr 250 µg IM in the deltoid +muscle every 15 minutes (up to maximum of 2 mg). OR +11 Misoprostol (PGE1) 1000 mg per rectum is effective. +■ Injection tranexamic acid 0.5 g or 1 g IV may be given in addition to oxytocin. +11 When uterine atony is due to tocolytic drugs, calcium gluconate (1 g IV slowly) should be given to neutralize the calcium blocking effect of these drugs. +Step-III: Uterine massage and bimanual compression. +Procedures: (a) The whole hand is introduced into the vagina in cone-shaped fashion after separating the labia with the fingers of the other hand, (b) The vaginal hand is clenched into a fist with the back of the hand directed posteriorly and the knuckles in the anterior fornix, ( c) The other hand is placed over the abdomen behind the uterus to make it anteverted, (d) The uterus is firmly squeezed between the two hands (Fig. 28.3). It may be necessary to continue the compression for a prolonged period until the tone of the uterus is regained. This is evidenced by absence of bleeding if the compression is released. +During the period, the resuscitative measures are to be continued. If, in spite of therapy, the uterus remains refractory and the bleeding continues, the possibility of blood coagulation disorders should be kept in mind and massive fresh whole blood transfusion should be given until specific measures can be employed. However, with oxytocics and blood transfusion, almost all cases respond well. Uterine contraction and retraction regain and + + + +♦ Atonic +♦ Retained tissues + + +♦ Traumatic +♦ Coagulopathy (p. 580) + +The first step is to control the fundus and to note the feel of the uterus. If the uterus is flabby, the bleeding is likely to be from the atonic uterus. If the uterus is firm and contracted, the bleeding is likely of traumatic origin. +Atonic uterus: Step-I: (a) Massage the uterus to make it hard and express the blood clot, (b) Methergine 0.2 mg is given intravenously, (c) Injection oxytocin drip is started (10 units in 500 mL of normal saline) at the rate of 40-60 drops per minute, (d) Foley catheter to keep bladder empty and to monitor urine output, (e) To examine the +expelled placenta and membranes, for evidence of Fig. 28.3: Bimanual compression of the uterus. +Chapter 28: Complications of the Third Stage of Labor ml Flowchart 28.2: Scheme of management of true PPH. +I Management of True PPH I + + + + + +Skill drill for PPH using mannequins for all labor attendants +I I + +Immediate measures +♦ Call for extra help (communication). +♦ Commence IV line with two wide bore cannulas. ++ Send blood for cross-matching tests, coagulations screening, including fibrinogen level and ask for 2 units of blood (at least). +♦ Rapidly infuse normal saline/haemaccel 2 liters till blood is available. • To catheterize the bladder. ++ Top monitor pulse, BP, temperature, output, oximeter every 15-30 minutes. ♦ Body fluid replacement are essential. +♦ Massive transfusion may be necessary. +♦ Volume replacement should be quick and balanced. Crystalloid (warmed and isotonic) up to 2 L; colloid up to 1-2 L; cross-matched blood; FFP: 4 units for every 6 units of PRBC. Platelets (if count 500 ml following birth of the baby. +► Common causes of PPH are (4Ts): (a) Atonic (80%), (b) Traumatic, (c) Retained tissues, and (d) Coagulopathy. +► Visual estimation of blood loss is inaccurate. Clinical assessment of maternal health should be done in assessment of PPH. +► Prediction and prevention of PPH may be possible to some extent, though most cases of PPH have no identifiable risk factor. +► The 'golden hour' is the time at which resuscitation must be started to ensure best chance of survival. The probability of survival decreases sharply after the first hour, if the patient is not effectively resuscitated. +► Full management protocol for major PPH (blood loss > 1 L) includes: (a) Communication, (b) Resuscitation, (c) Monitoring and investigations, and (d) Arrest of bleeding. +► Assessment of Shock Index (SI) and the'rule of 30', is the useful clinical guide to manage the patient. +► Volume replacement should be quick and balanced. Crystalloid (warmed and isotonic) up to 2 L; colloid up to 1-2 L; cross-matched blood; FFP 4 units for every 6 units of PRBC. Platelets (if count <50 x 109/L) and cryoprecipitate (if fibrinogen <1 g/L). +► Therapeutic goals is to maintain:• Hemoglobin >8 g/dl • Platelet count >50 x 109/L • Fibrinogen >2 g/L • APTT <1.5 times, the normal • Prothrombin Time (PT) <1.5 times normal. +► Blood transfusion is as soon as possible. When needed immediate transfusion with group 0, Rh-D negative and K negative is to be done. Routine use of r FVII a is not recommended. +► Cases with atonic PPH, the following pharmacological agents are most helpful. These are: oxytocin (IV/IM), ergometrine IV/IM; carboprost IM/intramyometrial or misoprostol P/R. Tranexamic acid 1 g IV is given (WHO), when other uterotonics have failed. It is repeated by 30 minutes, if needed. +► Injection tranexamic acid (0.5-1.0 g), in addition to oxytocin, may be given to a woman with PPH following cesarean delivery (RCOG-2016). +► The mechanical and conservative surgical measures are: Bimanual uterine compressions, balloon tamponade, hemostatic breast sutures, bilateral ligation of uterine arteries, bilateral ligation of anterior division of internal iliac arteries or selective arterial embolization. +► Stepwise uterine devascularization and internal iliac artery ligation include successive ligation of: (i) one uterine artery, (ii) both uterine arteries, (iii) low uterine artery (one and both), (iv) one and (v) both utero-ovarian arteries, and (vi) internal iliac artery ligation (Figs. 28.6 and 28.7). +► Hysterectomy is the last resort in a rare case. However, decision for hysterectomy should not be delayed. A second consultant may be involved in decision-making. +► lntraoperative cell salvage should be considered for emergency use associated with cesarean section. +► Multidisciplinary team approach for management of PPH should be made. All staff should receive training in the management of obstetric emergency including PPH. + + +RETAINED PLACENTA + +DEFINITION: The placenta is said to be retained when it is not expelled out even 30 minutes after the birth of the baby (WHO, 15 minutes). +CAUSES: There are three phases involved in the normal expulsion of placenta: (1) Separation through the spongy layer of the decidua; (2) Descent into the lower segment and vagina; (3) Finally its expulsion to outside. +Interference in any of these physiological processes, results in its retention. +■ Placenta completely separated but retained this is due to poor voluntary expulsive efforts. +■ Simple adherent placenta is due to uterine atonicity in cases of grand multipara, overdistension of uterus, prolonged labor and uterine malformation or due to bigger placental surface area. The commonest cause of retention of non-separated placenta is a tonic uterus. +■ Morbid adherent placenta-partial or rarely, complete. +■ Placenta incarcerated following partial or complete separation due to constriction ring (hourglass + +contraction), premature attempts to deliver the placenta before it is separated. +DIAGNOSIS: The diagnosis of retained placenta is made by an arbitrary time (15 minutes) spent following delivery of the baby. Features of placental separation are assessed (p. 125). The hourglass contraction or the nature of adherent placenta (simple or morbid) can only be diagnosed during manual removal. + +DANGERS: The risks involved in prolonged retention of placenta are: +(1) Hemorrhage. (2) Shock is due to-(a) blood loss, (b) at times unrelated to blood loss, especially when retained more than one hour. (3) Puerperal sepsis. ( 4) Risk of its recurrence in next pregnancy. +I MANAGEMENT +PERIOD OF WATCHFUL EXPECTANCY +■ During the period of arbitrary time limit of half an hour, the patient is to be watched carefully for evidence of any bleeding, revealed or concealed and to note the signs of separation of placenta. +Chapter 28: Complications of the Third Stage of Labor + +■ The bladder should be emptied using a rubber catheter. ■ Any bleeding during the period should be managed as +outlined in third-stage bleeding. +RETAINED PLACENTA: +♦ Separated ♦ Unseparated ♦ Complicated +Placenta is separated and retained-to express the placenta out by controlled cord traction. +Unseparated retained placenta (apparently uncom­ plicated): Manual removal of placenta is to be done under general anesthesia as described earlier. + + +PLACENTA ACCRETA SPECTRUM (PAS) (Syn: Placenta Adherenta) + +It is the rare disorder of placentation, in which the placental villi are directly anchored to the myometrium partially or completely without any intervening decidua. The probable cause is the absence of decidua basalis and poor development of fibrinoid layer. Overall incidence of placenta accreta or its variations is 1 in 800 deliveries. +Risk factors (Box 28.2): +The risk of placenta accreta with placenta previa in an unscarred uterus is about 3%. The risk rises sharply with increasing number of Cesarean Delivery (CD). Placenta previa with one prior CD, the risk of being accreta is about 8%; whereas with two, it is 17%; and it is 40% with prior three and 61% with four or more cesarean sections. +Diagnosis is mostly made with USG, using gray scale, power Doppler study, 3D images and with MRI. + + +■ Endometritis. ■ Adenomyosis. +■ Cesarean Delivery (CD). ■ Uterine curettages. ■ Manual Removal of Placenta (MRP). ■ IVF procedures. +■ Uterine Artery Embolization (UAE). ■ Myomectomy. a Endometrial resection. ■ Chemotherapy. + + + +MRI (added benefits over USG diagnosis of PAS USG) +■ Loss ofclear zone between the ■ lntraplacental bands placental bed and the myometrium. (T2-weighted images). +■ Thinning ofmyometrium (<1 mm) ■ Depth of myometrial +■ lntraplacental lacunae. invasion. +■ Loss of hyperechoic line between ■ Diagnosis of posterior uterine serosa and the bladder. placenta previa. +■ Placental bulge and/or exophytic ■ Women with obesity. mass-invading beyond the uterus +to the bladder. +■ Hypervascularity between myometrium and posterior wall of the bladder (Tornado vessels). + + + + +Fig. 28.8: Placenta increta. + +(Table 28.1): Unexplained rise of maternal serum aFP is observed with placenta accreta. Pathological confirmation includes-(a) absence of decidua basalis, (b) absence ofNitabuch's fibrinoid layer (accreta), and (c) varying degree of penetration of the villi into the muscle bundles (increta) (Fig. 28.8) or up to the serosal layer (percreta). Depending on the extent of invasion, grading of PAS has been made (Ch. 42, p. 628). In advanced cases (G3B), it invades the bladder wall and in G3C it invades the other pelvic organs. Levels of MSAFP is found raised. +The risks include hemorrhage, shock, infection and hysterectomy. +MANAGEMENT: ♦ Multidisciplinary team approach in management is to be done. Delivery is commonly done in a tertiary care hospital with the facilities of blood banks, interventional radiology and the presence of a pelvic surgeon. Cesarean delivery is done at 34-36 weeks of pregnancy. +In partial placenta accreta (focal) ➔ To remove the placental tissue as much as possible. Effective uterine contraction and hemostasis are achieved by oxytocic and if necessary, by intrauterine plugging. Sometimes bleeding areas are oversewn. If the uterus fails to contract, an early decision of hysterectomy have to be taken and this is preferable in multiparous women. +♦ In total placenta accreta, hysterectomy is indicated in parous women following cesarean delivery. Patients desiring to have a child, conservative attitude may be taken. This consists of incising the uterus above the placental attachment and clamping and cutting the umbilical cord as close to its base as possible and leaving behind the placenta, which is expected to be autolyzed in due course of time. Appropriate antibiotics should be given. Any attempt of placental separation risks massive hemorrhage and ends in hysterectomy in 100% of cases. Place of interventional radiology: Intraoperative placement of internal iliac arterial +Chapter 28: Complications of the Third Stage of Labor + +balloons or uterine artery embolization is done. Postoperative therapy with methotrexate has been done for conservation of the uterus. +♦ In a rare case, placenta accreta may invade the bladder (placenta percreta). In that case, it is better to avoid placental removal. It may need hysterectomy and partial cystectomy. +♦ Other options are: Wedge resection of the placental implantation site (partial myomectomy) is done. +■ Complications of uterine conservations are: Secondary hemorrhage, late hysterectomy (58%), fistula for­ mation, sepsis and death. +Follow up: Conservative surgery (uterus sparing) when done successfully, subsequent fertility is not affected. However risks are-recurrent PAS, uterine rupture, PPH and peripartum hysterectomy. + +INVERSION OF THE UTERUS + +It is an extremely rare but a life-threatening complication in third stage in which the uterus is turned inside out partially or completely. The incidence is about 1 in 20,000 deliveries. The obstetric inversion is almost always an acute one and usually complete. +Types of uterine inversion based on time of occurrence: (A) Acute: Within 24 hours of delivery. (B) Subacute: >24 hours but <4 weeks. (C) Chronic: >4 weeks postpartum. +Incidence is 1 in 2000 to 1 in 2500 deliveries. +VARIETIES (Figs. 28.9A to C) +■ First degree: There is dimpling of the fundus, which still remains above the level of internal os. +■ Second degree: The fundus passes through the cervix but lies inside the vagina. +Third degree (complete): The endometrium with or without the attached placenta is visible outside the vulva. The cervix and part of the vagina may also be involved in the process. +It may occur before or after separation of placenta. +ETIOLOGY: The inversion may be spontaneous or more commonly induced. +Spontaneous (40%): This is brought about by localized atony on the placental site over the fundus + + + +associated with sharp rise of intra-abdominal pressure as in coughing, sneezing or bearing down effort. Fundal attachment of the placenta (75%), short cord and placenta accreta, weakness of uterine wall at the placental site are often associated. +Iatrogenic: This is due to the mismanagement of third stage of labor. +■ Pulling the cord when the uterus is atonic, especially when combined with fundal pressure. +■ Fundal pressure while the uterus is relaxed-faulty technique in manual removal. +Common risk factors are uterine over enlargement, prolonged labor, fetal macrosomia, uterine malformations, morbid adherent placenta, short umbilical cord, tocolysis and manual removal of placenta. It is more common in women with collagen disease like Ehler-Danlos syndrome. +DANGERS: (I) Shock is extremely profound mainly of neurogenic origin due to-(a) tension on the nerves due to stretching of the infundibulopelvic ligament, (b) pressure on the ovaries as they are dragged with the fundus through the cervical ring, and (c) peritoneal irritation. +(2) Hemorrhage, especially after detachment of placenta; (3) Pulmonary embolism; ( 4) If left untreated, it may lead to-(a) infection, (b) uterine sloughing, and (c) a chronic one. +DIAGNOSIS: Symptoms: Acute lower abdominal pain with bearing down sensation. +Signs: (I) Varying degrees of shock is a constant feature; (2) Abdominal examination-(a) Cupping or dimpling of the fundal surface, (b) Bimanual examination not only helps to confirm the diagnosis but also the degree. In complete variety, a pear-shaped mass protrudes outside the vulva with the broad end pointing downward and looking reddish purple in color (Fig. 28.10), (c) Sonography can confirm the diagnosis when clinical examination is not clear. +PROGNOSIS: As it is commonly met in unfavorable surroundings, the prognosis is extremely gloomy. Even if the patient survives, infection, sloughing of the uterus and chronic inversion with ill health may occur. +PREVENTION: Not to employ any method to expel the placenta out when the uterus is relaxed. Pulling the cord + + +Depressed posterior wall + + +Partial inversion + + + + +rn +Figs. 28.9A to C: Inversion of the uterus: (A) First degree; (B) Second degree; (C) Third degree. +Chapter 28: Complications of the Third Stage of Labor ID + + + + + + + + + + + + + + + + + + + + + + +Fig. 28.10: Spontaneous acute and complete uterine inversion. Courtesy: Department of Obstetrics and Gynecology, NRS Medical College, Kolkota. + +simultaneously with fundal pressure should be avoided. Manual removal should be done in a manner, as it should be (p. 389). +MANAGEMENT: • Call for extra help • Before the shock develops, urgent manual replacement even without anesthesia, if it is not readily available, is the essence of treatment for a skilled accoucheur. +Principal steps: The patient is under general anesthesia: (1) To replace that part first, which is inverted last with the placenta attached to the uterus by steady firm pressure exerted by the fingers; (2) To apply counter-support by the other hand placed on the + +abdomen; (3) After replacement, the hand should remain inside the uterus until the uterus becomes +contracted by parenteral oxytocin or PGF2u; ( 4) +The placenta is to be removed manually only after the uterus becomes contracted. The placenta may, however, be removed prior to replacement-(a) to reduce the bulk which facilitates replacement or (h) if partially separated to minimize the blood loss; (5) Usual treatment of shock, including IV fluids and blood transfusion should be arranged simultaneously. +• After the shock develops +Principal Steps: (1) The treatment of shock should be instituted with an urgent normal saline infusion and blood transfusion; using wide-bore IV cannula. (2) The inverted fundus lies on the palm of the hand with the fingers placed near the uterocervical junction. When pressure is exerted on the fundus, it gradually returns into the vagina. The vagina is packed with antiseptic roller gauze; (3) Foot end of the bed is raised; (4) Replacement of the uterus using hydrostatic method (O'Sullivan's) under general anesthesia is to be done along with resuscitative measures. Hydrostatic method is quite effective and less shock-producing. +Hydrostatic method: The inverted uterus is replaced into the vagina. Warm sterile fluid (up to 5 liters) is gradually instilled into the vagina through a douche nozzle. The vaginal orifice is blocked by operator's palms supplemented by labial apposition around the palm by an assistant. Alternatively, a silicon cup (vacuum extraction cup) is placed into the vagina. The douche can be placed at a height of about 3 feet above the uterus. The water distends the vagina and the consequent increased intravaginal pressure leads to replacement of the uterus. +• Subacute stage: (1) To improve the general condition by blood transfusion; (2) Antibiotics are given to control sepsis; (3) Reposition of the uterus either manually or by hydrostatic method may be tried; (4) If fails, reposition may be done by abdominal operation (Haultain's operation). + + + +Injuries to the Birth Canal + + + + + + + + + +❖ Vulva +❖ Perineum +► Management ❖ Vagina + + +❖ Cervix +❖ Pelvic Hematoma +❖ Rupture of the Uterus ► Etiology + + +► Pathology ► Diagnosis +► Management ❖ Visceral Injuries + + + + +Maternal injuries following childbirth process are quite common and contribute significantly to maternal morbidity and even to death. Prevention, early detection and prompt and effective management not only minimize the morbidity but prevent many gynecological problems from developing later in life. + +VULVA + +Lacerations of the vulval skin posteriorly and the paraurethral tear on the inner aspect of the labia minora are the common sites. Paraurethral tear may be associated with brisk hemorrhage and should be repaired by interrupted catgut sutures, preferably after introduction of a rubber catheter into the bladder to prevent injury of the urethra. + +PERINEUM + +While minor injury is quite common, especially during first birth, gross injury (third and fourth degree) is invariably a result of mismanaged second stage oflabor. Overall risk is 1 % of all vaginal deliveries (Box 29.1). +CAUSES: Perinea! injury (mainly the third and fourth degree) results from (i) over-stretching and/or, (ii) rapid stretching of the perineum, especially when the perineum is inelastic (elderly primigravida, perinea! scar). +PREVENTION: Proper conduct in the second stage of labor taking due care of the perineum when it is likely to be damaged is essential. The prevention of the + + +■ Big baby (weight 4 kg}. ■ Scar in the perineum 11 Nulliparity. (perineorrhaphy, +■ Outlet contraction with narrow episiotomy} +pubic arch. ■ Face to pubis delivery. ■ Shoulder dystocia. ■ Midline episiotomy. +■ Forceps deliverywithoutepisiotomy. 11 Precipitate labor. + + +perinea! injuries in norm l delivery has been outlined on p. 130. Mediolateral episiotomy (at 60° angle) during crowning is to be used when maneuvers are planned. + +I MANAGEMENT +Recent tear should be repaired immediately following the delivery of the placenta. This reduces the chance of infection and minimizes the blood loss. In cases of delay beyond 24 hours, the repair is to be withheld. Antibiotics should be started to prevent infection. The complete tear should be repaired after 3 months if delayed beyond 24 hours. In case of any doubt to grade of 3rd degree tear, it is advisable to classfy to the higher degree rather than lower degree (Box 29.2). +Repair of complete perineal tear: +Step I: Patient is put in lithotomy position. Antiseptic cleaning of the local area is done. Repair may be done with local infiltration of 1 % lignocaine hydrochloride (10-15 mL) or with pudenda! block or preferably under regional or general anesthesia. +Step II: Dissection is not required as in an old complete perinea! tear. (a) The rectal and anal mucosa is first sutured from above downward. No. "3-0" vicryl, on an atraumatic needle with interrupted stitches with knots inside the lumen are used. (b) The rectal muscles, +. +• t f1Rf I ,. . . +.. +RA • +First degree: Injury to perinea! skin only. +Second degree: Injury to perineum involving perinea! body (muscles} but not involving the anal sphincter. +Third degree: Injury to perineum, involving the anal sphincter complex (both external and internal}: +■ 3a : <50% of EAS thickness torn. ■ 3b: >50% of EAS thickness torn. ■ 3c : Both EAS and IAS torn. +Fourth degree: Injury to perineum involving the anal sphincter +complex (EAS and IAS} and anal epithelium (Fig. 29.1 }. +Chapter 29: Injuries to the Birth Canal + + + +/ Rectal mucous membrane + + + ""--Perineal body + + + +); + + + +nal sphincter nal epithelium + + + +1st 2nd 3rd 4th degree + +Fig. 29.1: Diagrammatic representation showing different degrees of perinea! tear. + +including the pararectal fascia are then sutured by interrupted sutures using the same suture material. (c) The torn ends of the sphincter ani externus (EAS) are then exposed by Allis's tissue forceps. The sphincter is then reconstructed and it is supported by another layer of interrupted sutures. For repair of EAS either an overlapping or end-to-end approximation method can be used with similar outcome. IAS repair is done by End­ to-End approximation, with 3-0 PDS or 2-0 polyglactin. +Step III: Repair of perinea! muscle is done by interrupted sutures using No. "0" PDS or dexon or polyglactin {vicryl). Surgical knots are buried under the superficial muscles. +Step IV: The vaginal wall and the perinea! skin are apposed by interrupted sutures with vicryl rapide. +Suture material: For repair of EAS, monofilament sutures such as Polydioxanone (PDS) or polyglactin {vicryl) can be used. Repair of IAS is done with fine suture size such as 3-0 PDS and 2-0 vicryl as they cause less irritation and discomfort. +AFTER CARE: The aftercare of the repaired perinea! injuries is similar to that following episiotomy. Special care following repair of complete tear-(1) A low +residual diet consisting of milk, bread, egg, biscuits, fish, sweets, etc. is given from third day onward; (2) Lactulose 8 mL twice daily beginning on the second day +and increasing the dose to 15 mL on the third day is a satisfactory regime to soften the stool; (3) Any one of the broad-spectrum antibiotics (N cefuroxime 1.5 g) is used during the intraoperative and the postoperative period {Figs. 29.2A and B). Metronidazole 400 mg thrice daily is to be continued for 5-7 days to cover the anaerobic contamination of fecal matter. The woman is advised physiotherapy and pelvic floor exercises and she is reviewed again 6-12 weeks postpartum. In case of persistent incontinence of flatus and feces, endoanal USG and anorectal manometry should be considered to detect any residual defects (20-30%). Consultation with a colorectal surgeon may be needed. + + + +a + + +Figs. 29.2A and B: Methods of repair of the cervical tear with vertical mattress suture. + +PLAN FOR FUTURE DELIVERY: All women need to have institutional delivery following repair of obstetric sphincter injury. Vaginal delivery may be allowed in a selected case with or without episiotomy. Women having symptoms or with abnormal endoanal USG and/or manometry should be delivered by elective cesarean birth. Chance of recurrence is 5-7%. + +VAGINA + +Isolated vaginal tears or lacerations without involvement of the perineum or cervix are not uncommon. These are usually seen following instrumental or manipulative delivery. In such cases, the tears are extensive and often associated with brisk hemorrhage. +TREATMENT: Tears associated with brisk hemorrhage require exploration under general anesthesia with a good light. The tears are repaired by interrupted or continuous sutures using chromic catgut No. "0". In case of extensive lacerations, in addition to sutures, hemostasis may be achieved by intravaginal plugging by roller gauze, soaked with glycerin and acriflavine. The plug should be removed after 24 hours. Selective arterial embolization may also be done if bleeding persists. +COLPORRHEXIS: Tear the vault of the vagina or any of its wall is called colporrhexis. It may be primary where only the vault is involved or secondary when associated with cervical tear (common). It is said to be complete when the peritoneum is opened up. +Treatment: If the tear is limited to the vault close to the cervix, the repair is done from below. If, however, the cervical tear extends high up into the lower segment or major branches of uterine vessels are damaged, laparotomy is to be done simultaneously +-·"ID Chapter 29: Injuries to the Birth Canal +with resuscitative measures. Evacuation ofhematoma and arterial ligation may be needed. + + +CERVICAL INJURY + +Minor degree of cervical tear ( <0.5 cm) is invariable during first delivery and requires no treatment. Extensive cervical tear is rare. It is the commonest cause of traumatic postpartum hemorrhage. Left lateral tear is the most common. +CAUSES +11 Iatrogenic: Attempted forceps or ventouse delivery or breech extraction through incompletely dilated cervix. +11 Rigid cervix: This may be congenital or more commonly following scar from previous operations on the cervix like amputation, conization or presence of a lesion like carcinoma cervix. +11 Strong uterine contractions as in precipitate labor or extremely vascular cervix as in placenta previa. +11 Detachment: Detachment of the cervix may be annular which involved the entire circumference of the cervix. This occurs following prolonged labor in primary cervical dystocia. It may, however, involve only the anterior lip when it is nipped between the head and the symphysis pubis in association with the sacral os. In both varieties, the bleeding is minimal and healing occurs through epithelialization. +Rarely cervical tears extend upwards to reach the lower uterine segment and involve the uterine artery and its major branches. Severe laceration may cause broad ligament hematoma. +DIAGNOSIS: Excessive vaginal bleeding immediately following delivery in presence of a hard and contracted uterus-raises the suspicion of a traumatic bleeding. Exploration of the uterovaginal canal under good light not only confirms the diagnosis but also helps to know the extent of the tear. +COMPLICATIONS: +Early-(1) Deep cervical tears involving the major vessels lead to severe postpartum hemorrhage; (2) Broad ligament hematoma; (3) Pelvic cellulitis; ( 4) Thrombophlebitis. +Late-(!) Ectropion; (2) Cervical incompetence with midtrimester abortion. + +TREATMENT: Only deep cervical tear (>l cm) associated with bleeding should be repaired soon after delivery of the placenta. Repair should be done under general anesthesia, in lithotomy position with a good light (Fig. 29.3). The prerequisites are-Sims' posterior vaginal speculum, vaginal wall retractors, at least two sponge­ holding forceps and an assistant. +Procedures: The anterior and posterior margins of the torn cervix are grasped by the sponge-holding forceps. +Instead of giving traction to the forceps, it is better to + + + + + + + + + + + + + + +Fig. 29.3: Vulval hematoma following spontaneous delivery. + +push down the fundus gently by an assistant. This makes the tear more accessible for effective suturing. The apex is to be identified first and the first vertical mattress suture is placed just above the apex using polyglactin (vicryl) or chromic catgut No. "O" taking whole thickness of the cervix. The bleeding stops immediately. The rest of the tear is repaired by similar mattress sutures. Mattress suture is preferable as it prevents rolling in of the edges. A helpful guide for proper exposure in such a case is to start suture at the proximal end and using the suture for traction, more distal tear area is exposed until the apex is in view and is repaired. The cervical tears extending to the lower segment or vault with broad ligament hematoma are managed as outlined in ruptured uterus (p. 390). + +PELVIC HEMATOMA + +DEFINITION: Collection of blood anywhere in the area between the pelvic peritoneum and the perineal skin is called pelvic hematoma. +Vulvar hematoma m y be due to injury to the pudendal artery, Inferior Rectal Artery, or Perinea! arteries. Paravaginal hematomas are due to the injury of descending branch of uterine artery. +ANATOMICAL TYPES: Depending upon the location of the hematoma, whether below or above the levator ani, it is termed as: +♦ Infralevator hematoma-common ♦ Supralevator hematoma-rare +INFRALEVATOR HEMATOMA +The commonest one is the vulval hematoma. +Etiology: (I) Improper hemostasis during repair of vaginal or perinea! tears or episiotomy wound-(a) Failure of suturing the apex of the tear, (b) Failure to obliterate the dead space while suturing the vaginal walls; (2) Rupture of paravaginal venous plexus either spontaneously or following instrumental delivery. +Chapter 29: Injuries to the Birth Canal ll . + +Symptoms: (1) Persistent, severe pain on the vulvar or perinea! region; (2) There may be rectal tenesmus or bearing down efforts when extension occurs to the ischiorectal fossa. There may be even retention of urine. +Signs: (I) Variable degrees of hypovolemia shock may be evident; (2) Local examination reveals a tense swelling at the vulva which becomes dusky and purple in color and tender to touch (Fig. 29.3). +n·eatment: A small hematoma (<5 cm) may be treated conservatively with cold compress. Larger hematomas should be explored in the operation theater under general anesthesia. Simultaneous resuscitative measures are to be taken. The blood clots are to be scooped out and the bleeding points are to be secured. Usually, a generalized oozing surface is visible. The dead space is to be obliterated by deep mattress sutures and a closed suction drain may be kept in that place for 24 hours. A Foley catheter is inserted till the tissue edema subsides. Prophylactic antibiotic are to be administered. +SUPRALEVATOR HEMATOMA: Causes: (1) Extension of cervical laceration or primary colporrhexis (vault rupture); (2) Lower uterine segment rupture (Fig. 29.4); (3) Spontaneous rupture of paravaginal venous plexus adjacent to the vault. +Diagnosis: The diagnosis is usually late as pain is not of a conspicuous nature and so also the vaginal bleeding. Unexplained shock with features of internal hemorrhage following delivery raises the suspicion. Abdominal examination reveals a swelling above the inguinal ligament pushing the uterus to the contralateral side. Vaginal examination reveals-(a) occlusion of the vaginal canal by a bulge or (b) a boggy swelling felt + + + + + +Peritoneum + +Obturator +fascia +.. +. +- +.... .. _--------------. +.. +_ +_ +- +- + + + + + + +lnfrafascial + + +through the fornix. Rectal examination corroborates the presence of the boggy mass. It may extend between the leaves of the broad ligament. This is detected on abdominal palpation only. Imaging with USG or CT is useful. Ultrasonography or CT may be needed for exact localization of the hematoma. +Management: Usual treatment of shock is to be instituted and arrangement is made for laparotomy. The anterior leaf of the broad ligament peritoneum is incised and the blood clot is scooped out. The bleeding points, if visible, are to be secured and ligated. Random blind sutures should not be placed to prevent ureteric damage. If the oozing continues, one may have to tie +the anterior division of the internal iliac artery. Selective arterial (uterine) embolization may be done as an alternative. The presence of associated rupture uterus may modify the treatment as mentioned later in this chapter. +!li +' +i: .. +-t +- ': + +RUPTURE OF THE UTERUS + +DEFINITION: Disruption in the continuity •!] +of the all uterine layers ( endometrium, '. 'I +myometrium and serosa) any time beyond · . :i 20 weeks of pregnancy is called rupture !li +of the uterus. Small rupture to the wall of the uterus in early months is called perforation either instrumental or perforating hydatidiform mole. Rupture of a rudimentary pregnant horn has got a special clinical entity and is grouped in ectopic pregnancy. +INCIDENCE: The prevalence widely varies from 1 in 2,000 to 1 in 200 deliveries. There is a significant change in the etiology of rupture uterus. Currently there is decline in multiparity, traumatic rupture due to internal podalic version + + + + + +Round ligament + -----<;,-- Superior and inferior fascia of levator ani +muscle + +Supralevator +hematoma +IM/1--- Obturator internus + +--- + + + +lnfralevator +hematoma + + +Superior and inferior +fascia of urogenital diaphragm + + +Fig. 29.4: (Al Schematic diagram showing normal disposition of pelvic muscles, fascia and the spaces; (Bl Supralevator hematoma; (Cl lnfralevator hematoma (small). +l9 Chapter 29: Injuries to the Birth Canal + +and breech extraction, difficult forceps delive1y, obstructed labor, fetal abnormality (hydrocephalus). On the other hand there is rise in cesarean delivery, myomectomy, operative hysteroscopy, uterine curettage and perforation (most common instrument causing perforation is suction cannula: 50%. The anterior uterine wall is most commonly injured: 40%), sequential use of prostaglandins and oxytocin for induction of labor and abdominal trauma are the important ones. + +I ETIOLOGY + +The causes of rupture of the uterus are broadly divided into (Flowchart 29.1): +♦ Spontaneous rupture ♦ Scar rupture +♦ Iatrogenic rupture +SPONTANEOUS +During pregnancy: It is indeed rare for an apparently uninjured uterus to give way during pregnancy. The causes are: (1) Previous damage to the uterine walls following dilatation and curettage operation or manual removal of placenta; (2) Rarely in grand multiparae due to thin uterine walls; (3) Congenital malformation of the uterus (bicornuate variety) is a rare possibility; (4) In Couvelaire uterus. +Spontaneous rupture during pregnancy is usually complete, involves the upper segment and usually occurs in later months of pregnancy. On rare occasion, spontaneous rupture may occur even in early months. During labor: Spontaneous rupture which occurs predominantly in an otherwise intact uterus during labor is due to: +♦ Obstructive rupture: This is the end result of an +obstructed labor. It is less common these days. + + +♦ Nonobstructive rupture: Grand multiparae are usually affected. Weakening of the walls due to repeated previous births is the responsible factor. +OTHER CASES ARE: Cases with repair of previous uterine rupture, prior vigorus curettage (Ch. 23, p. 315). +SCAR RUPTURE: With the liberal use of primary cesarean section, scar rupture constitutes significantly to the overall incidence of uterine rupture. The incidence of lower segment scar rupture is about 1-2%, while that following classical one is 5-10 times higher. Uterine scar following hysterotomy behaves like that of a classical scar and is of high risk. +During pregnancy: Classical cesarean or hysterotomy scar is likely to give way during later months of pregnancy. The weakening of such scar is due to the stretching. Lower segment scar rarely ruptures during pregnancy. +During labor: The classical or hysterotomy scar or cornual resection for ectopic pregnancy is more vulnerable to rupture during labor. Although rare, lower segment scar predominantly ruptures during labor. +IATROGENIC OR TRAUMATIC +During pregnancy: (1) Injudicious administration of oxytocin; (2) Use of prostaglandins for induction of abortion or labor; (3) Forcible external version, especially under general anesthesia; ( 4) Trauma: Fall or blow on the abdomen. +During labor: (1) Internal podalic version; (2) Destructive operation; (3) Manual removal of placenta; ( 4) Application of forceps or breech extraction through incompletely dilated cervix; (5) Injudicious administra­ tion of oxytocin for augmentation of labor. + + +Flowchart 29.1: Scheme showing etiology of ruptured uterus. +I +I + +Ruptured uterus +I During p;egnancy I ! Durin1 labor + +Spontaneous Iatrogenic Spontaneous Iatrogenic +I +I +l l l + + +Intact uterus Scarred uterus Traumatic Oxytocics Traumatic Oxytocics +! +l +• Multiparae. ♦CS scar. • External cephalic ♦ Oxytocin. ■ Difficult forceps delivery. ■ Oxytocin. +■ Prostaglandins. +■ Internal version. +version. +♦ Congenital n • Hysterotomy scar. ♦ Fall or blow. • Prosta­s. ■ Manual removal of +glandin +malformatio +• Previous manual +placenta. +of uterus. removal. • Motor vehicle accident. +• Vigorous uterine ♦ Metroplasty. ♦ Internal podalic version ----'--- +! + -- +uterus +curettage. +(rare). +! +Scarred uterus +♦Trauma (blunt/sharp). +lntac +♦ Repair of previous \ ■ CS or hysterotomy scar. +uterine repture. +♦ ♦ +Non-obstructive Obstructive ■ Repair of previous rupture uterus. +Myomectomy scar. +■ +■ +Following obstructed labor. +■ Grand multipara. +■ Congenital malformation of uterus. ■ Pelvic tumor. ■ Cornual resection of ectopic pregnancy. +■ Metroplasty. +■ Rudimentary horn pregnancy. + + +I PATHOLOGY +TYPES: Pathologically, it is customary to distinguish between complete and incomplete rupture depending on whether the peritoneal coat is involved or not. So far from the treatment point of view, it matters little. In incomplete rupture, the peritoneum remains intact. +Incomplete rupture usually results from rupture of the lower segment scar (Fig. 29.5) or extension of a cervical tear into the lower segment with formation of a broad ligament hematoma. Complete rupture usually occurs following disruption of the scar in upper segment. It may also be due to spontaneous rupture of both obstructive and nonobstructive type. +SITES: Spontaneous nonobstructive rupture usually involves the upper segment and often involves the fundus. Whereas, in obstmctive type, the mpture involves the ante­ rior lower segment transversely and often extends upward along the lateral uterine wall. The margins are ragged and necrosed (Fig. 29.7). On occasion, the posterior wall may be involved due to friction with the sacral promontory. +Not infrequently, the tear extends downward to involve the cervix and the vaginal wall (colporrhexis). The bladder may be involved, at times. Rupture over the previous scar is almost always located at the site of the scar. The margins of the ruptured cesarean scar are usually clean and look fibrosed (Fig. 29.6). The rent over the lower segment scar may extend to one or both the sides to involve the major branches of uterine vessels. +The morbid pathology of traumatic rupture following destructive operation or internal version is almost similar to that met in spontaneous obstructive variety. This may, at times, be indistinguishable (Fig. 29. 7). + + + + + + + + + + + + + + + + +Fig. 29.5: lntraoperative photograph of cesarean delivery. Lower segment of the uterus is shown using the Doyen's retractor. Scar dehiscence is seen as there is: disruption of almost entire length of the scar (see arrow). Amniotic membrane is seen bulging out and it is intact. Bleeding is almost absent or minimal. + +Chapter 29: Injuries to the Birth Canal ID Dehiscence and scar rupture +Scar dehiscence (intact uterine serosa)-(a) disruption of part of scar and not the entire length, (b) fetal membranes remain intact (Table 29.1), (c) bleeding is almost nil or minimal (Fig. 29.5). +Scar rupture-(a) disruption of the entire length of the scar, (b) complete separation of all the uterine layers including serosa, (c) rupture of the membranes with, (d) varying amount of bleeding from the margins or from + + + + + + + + + + + + + + + + + + + + +Fig. 29.6: Lower segment scar rupture (arrow). The margins are found clean and scarred. There is omental adhesion on the upper segment. Total hysterectomy was done. +(Courtesy: Museum, Department of Obstetrics and Gynecology, NRSMCH, Kolkata) + + + + + + + + + + + + + + + + + + +Fig. 29.7: Rupture of uterus following obstructed labor. Rupture extends along the lateral border of the uterus. Margins are irregular, bruised and necrosed. Total hysterectomy has been done. +Im Chapter 29: Injuries to the Birth Canal + +its extension, (e) uterine cavity and peritoneal cavity become continuous. +FETUS AND PLACENTA: In incomplete rupture, both the fetus and placenta remain inside the uterine cavity or part of the fetus may occupy in between the layers of broad ligament. In complete rupture, the fetus with or without the placenta usually escapes out of the uterus. The uterus remains contracted. Blood loss is not much unless major vessels are affected. +PROGNOSIS: Fetal prognosis depends upon the degree of placental separation, severity of hemorrhage and hypovolemia. Lower segment scar rupture gives a comparatively better prognosis. But, rupture following obstructed labor either spontaneous or due to instrumentation causes maternal mortality of about 20% or more. The major causes of death are hemorrhage, shock and sepsis. Late sequelae include intestinal obstruction and scar rupture in subsequent pregnancies. +I DIAGNOSIS +Obstetrician should be conscious of the entity for an early diagnosis. +During Pregnancy: ♦ Scar rupture +♦ Spontaneous rupture ♦ Iatrogenic rupture +Scar rupture: Classical or hysterotomy-the patient complains of a dull abdominal pain over the scar area with slight vaginal bleeding. There is varying degrees of tenderness on uterine palpation. FHS may be irregular or absent. CTG tracings reveal variable or late deceleration (most consistent finding). The features may not be always dramatic in nature (silent phase). Sooner or later, the rupture becomes complete. There is a sense of something giving way accompanied by acute abdominal pain and collapse. The diagnosis is self-evident (Ch. 23, p. 315, VBAC). +Spontaneous rupture in uninjured uterus: The rupture is usually confined to the high parous women. The onset is usually acute but, sometimes, insidious. In acute types, the patient has acute abdominal pain with fainting attacks and may collapse. The diagnosis is established by the presence of features of hypovolemia, shock, acute tenderness on abdominal examination, palpation of superficial fetal parts, if the rupture is complete and absence of fetal heart rate. However, with insidious onset, the diagnosis is often confused with concealed placental abruption or rectus sheath hematoma. +Rupture following fall, blow or external version or use of oxytocics: There is the history of such an accident followed by acute pain abdomen and slight vaginal bleeding. Rapid pulse and tender uterus raise the suspicion of rupture. The confirmation is done + + +by laparotomy. This is too often confused with accidental hemorrhage. +During labor: +♦ Scar rupture +♦ Spontaneous obstructive rupture +♦ Spontaneous nonobstructive rupture ♦ Iatrogenic rupture +Scar rupture: Classical or hysterotomy scar rupture­ the features are the same as those occur during pregnancy. The onset is usually acute. +Lower segment scar rupture: The onset is insidious. There is no classical feature of lower segment scar rupture (p. 402). The confirmation is by laparotomy. It is called "silent rupture''. +Spontaneous obstructive rupture: This type of spontaneous rupture has got a distinct premonitory phase prior to rupture. +Phase of rupture: (1) There is a sense of something giving way at the height of uterine contraction; (2) The constant pain is changed to dull aching pain with cessation of uterine contractions; (3) General examination reveals features of exhaustion and shock; (4) Abdominal examination reveals-(i) superficial fetal parts, (ii) absence ofFHS, (iii) absence of uterine contour, and (iv) two separate swellings, one contracted uterus and the other-fetal ovoid; (5) Vaginal examination reveals­ (i) recession of the presenting part, and (ii) varying degrees of bleeding. +Spontaneous nonobstructive rupture: This is rare and solely confined to high parous women. The patient at the height of uterine contraction is suddenly seized with an agonizing bursting pain followed by a relief, with cessation of contractions. The diagnostic features of the catastrophe are-presence of shock, evidences of internal hemorrhage, tenderness over the uterus and varying amount of vaginal bleeding. +Rupture following manipulative or instrumental delivery: Sudden deterioration of the general condition of the patient + +Table 29.1: Differentiation'of Ute;ine Scar'Dehiscenc and Rupture. +Scar dehiscence (Fig. 29.5) Scar rupture (Fig. 29.6) ■ Occult scar separation (no pain). • Suprapubic pain. +■ Often diagnosed at laparotomy. • Bleeding PN, tachycardia . +• +■ Serous coat: Intact. Disrupted; clinically diagnosed. ■ Muscle layer partly separated. • Disruption of all the layers +of the uterus. II Hemorrhage from the margins • lntraperitoneal +absent/minimal. hemorrhage++. +■ Fetal health-often not • FHR abnormality: Bradycar-affected. dia, prolonged deceleration +(CTG). +• +t . +Fetal mortality +11 Maternal health not affected. • Maternal morbidity and maternity +tt. + + +with varying amount of vaginal bleeding following manipulative or instrumental delivery raises the suspicion. Shortening of the cord immediately following a difficult vaginal delivery is pathognomonic of uterine rupture, the placenta being extruded out into the abdominal cavity, through the rent in the uterus. + +I MANAGEMENT + +PROPHYLAXIS: The following guidelines are helpful to prevent or to detect at the earliest the diagnosis of rupture uterus: + +Chapter 29: Injuries to the Birth Canal ID Flowchart 29.2: Management of scar dehiscence +and rupture uterus. + +Management of Scar Dehiscence and Uterine Rupture + + +Urgent resuscitation and laparotomy. • IV crytalloids • Blood transfusion +• Injection ceftriaxone IV• Catheterization + + +Laparotomy + + + +• The at-risk mothers, likely to rupture, should have mandatory hospital delivery. These are-(a) Contracted pelvis, (b) Previous history of CD, hysterotomy or myomectomy, (c) Uncorrected transverse lie, (d) High parity. +• General anesthesia should not be used to give undue force in external version. +• Undue delay in the progress of labor in a multipara with previous uneventful delivery should be viewed with concern and the cause should be sought for. +• Judicious selection of cases with previous history of cesarean sections for vaginal delivery (VBAC). +• Judicious selection of cases for oxytocin infusion either for induction or augmentation oflabor. +• There is no place of internal podalic version in singleton fetus in present-day obstetrics. +• Attempted forceps delivery or breech extraction through incompletely dilated cervix should be avoided. +• Destructive vaginal operations should be performed by skilled personnel and exploration of the uterus should be done as a routine following delivery. +• Manual removal in morbid adherent placenta-should be done by a senior person. + +TREATMENT: • Resuscitation • Laparntomy +Depending upon the state of the clinical condition, either resuscitation is to be done followed by laparotomy or in acute conditions, resuscitation and laparotomy are to be done simultaneously. +LAPAROTOMY: Any of the three procedures (Flowchart 29.2) may be adopted following laparntomy: +♦ Hysterectomy: Hysterectomy is the surgery for ruptured uterus unless there is sufficient reason to preserve it. This is especially indicated in spontaneous obstructive rupture. It is preferable to perform a quick subtotal hysterectomy, rather than total hysterectomy (Read more Dutta's Clinics in Obstetrics, Ch. 53). Risk of injury to the ureters or bladder is thereby reduced. It takes less time. +• However, if the condition permits and/or there is colporrhexis, a total hysterectomy may be done. +♦ Repair: This is mostly applicable to a case with scar rupture where the margins are clean (Table 29.1). Repair is done by excision of the fibrous tissue at the margins. Remote prognosis during future pregnancy is very much unfavorable because of high risk of scar rupture. + + +Spontaneous Scar rupture/ +obstructive rupture scar dehiscence + +• Hysterectomy (sub-total) Delivery ➔ Repair of the scar preferred. ± bilateral tubal ligation +OR +• Total hysterectomy. Hysterectomy. + + +♦ Repair and sterilization: This is mostly done in patients with a clean cut scar rupture having desired number of children. +To tackle a broad ligament hematoma-To open up the anterior leaf of the broad ligament ➔ Scoop out the blood clot ➔ Secure the bleeding points ➔ Replaced by ligature, taking care not to injure the ureter. Failing to secure the bleeding points ➔ To tie the anterior division of the internal iliac artery. + +VISCERAL INJURIES + +BLADDER: Causes: Obstetrical injury to the bladder may be due to: +(A) Traumatic: (1) Instrumental vaginal delivery such as destructive operations or forceps delivery especially with Kielland; (2) Abdominal operation such as hysterectomy for rupture uterus or cesarean section. (B) Sloughing fistula: It results from prolonged compression effect on the bladder between the head and symphysis pubis in obstructed labor. +Diagnosis: (A) Traumatic-(}) Urine-dribbles out soon following the operative delivery. Blood-stained urine following cesarean section or hysterectomy is suggestive of bladder injury; (2) Margins are clean cut with oozing surfaces. (B) Sloughing fistula-(}) History of prolonged labor; (2) Dribbling of urine occurs after varying interval following delivery (5-7 days); (3) Margins devitalized and necrosed. +Management: Traumatic fistula: Immediate local repair is preferable, if the local tissues are healthy. +In unfavorable condition, a self-retaining catheter is introduced and to be kept for 10-14 days or even longer. Urinary antiseptics are prescribed. In a small size fistula, there may be spontaneous closure of the fistula. If it fails, repair is to be done after 3 months. +-· Im Chapter 29: Injuries to the Birth Canal +Sloughingfistula: Repair should not be attempted as the conditions are not ideal (vide supra), instead, a self­ retaining catheter is placed as outlined above. Repair is to be done after 3 months. +RECTUM: Rectal injury, other than that involved along with complete perinea! tear is rare in obstetrics. This is because, the middle-third of the rectum is protected by the curved sacral hollow and the upper third is protected by the peritoneal lining. Prolonged compression of the + + + + +rectum by the head in midpelvic contraction with a flat sacrum predisposes to ischemic necrosis of the anterior rectal wall and results in rectovaginal fistula. The repair in such cases should be postponed for at least 3 months. +URETHRA: Urethral injury may be traumatic resulting from instrumental delivery or during pubiotomy; may be ischemic sloughing, the mechanism of which is similar to that of bladder necrosis. The principles in management are similar to those of bladder injmy. + + + +-:fi•MIH +► Fourth degree perinea I (complete) tear involves tear of the posterior vaginal wall, perinea! body, anal sphincter complex with tear of the anal or rectal mucosa. Recent tear can be repaired immediately. +► Pelvic hematoma is commonly due to vulvar hematoma (infralevator). Large vulval hematoma should be explored in the operation theater. +► Rupture of uterus may be-(i) spontaneous, (ii) scar rupture or (iii) iatrogenic. Rupture of uterus may occur either during pregnancy or during labor. Diagnosis is difficult. One should be conscious of the entity. +► Management of rupture uterus is resuscitation and laparotomy. Subtotal hysterectomy is commonly done. Repair may be done in cases where margins are clean. Repair and sterilization is done when the woman has completed her family. +► Obstetric emergencies are often very frightening though rare. +► Obstetric emergency drill training should be regularly practiced by the labor ward team to face such emergencies. +► Rupture uterus, cord prolapse, PPH, shoulder dystocia, eclampsia, inversion uterus are some of the many obstetric emergencies. All these need prompt and appropriate management. +► All the staff should receive training in the management of obstetric emergency. +► Debriefing and to discuss the events in respect of rupture uterus and hemorrhage and hysterectomy should be done with the woman and the family members. + +Abnormalities of the +Puerperium + + +CHAPTER + + + +CHAPTER OUTLINE +❖ Puerperal Pyrexia ❖ Puerperal Sepsis +► Pathology +► Clinical Features +► Investigations of Puerperal Pyrexia +► Treatment + + +❖ Subim:iolution +❖ Urinary Complications in Puerperium ❖ Breast Complications +❖ Puerperal Venous Thrombosis ❖ Pulmonary Embolism +► Prophylaxis and Management ❖ Obstetric Palsies + + +❖ Puerperal Emergencies +❖ Psychiatric Disorders during Puerperium +❖ Psychological Response to Perinatal Deaths and Management + + + + +PUERPERAL PYREXIA +DEFINITION: A rise of temperature reaching !l !l +g +!l +l +100.4°F (38°C) or more (measured orally) on ii';.Cj two separate occasions and 24 hours apart (excluding first 24 hours) within first 10 days following delivery is called puerperal pyrexia. In some countries, postabortal fever is also included. +The pathology and prevention of childbirth fever (puerperal - pyrexia) are best known from the works of Ignaz Semmelweis, +working in Vienna in the nineteenth century. He faced dificulties +to establish his doctrine. Unfortunately, he died of an infection on his right hand that he contracted during an operation. + +PUERPERAL SEPSIS (Syn: Puerperal Infection) +DEFINITION: An infection of the genital tract which occurs as a complication of delivery is termed puerperal sepsis. Puerperal pyrexia is considered to be due to genital tract infection unless proved otherwise (Box 30.1). +There has been marked decline in puerperal sepsis during the past few years due to: (1) improved obstetric care; (2) availability of wider range of antibiotics. +Puerperal sepsis is commonly due to-(i) endome­ tritis, (ii) endomyometritis, or (iii) endoparametritis + + +■ Puerperal sepsis (genital tract infection). +11 Urinary tract infections: Cystitis, pyelonephritis. 11 Mastitis, breast abscess. +■ Wound infections: CS or episiotomy. +11 Pulmonary infections: Atelectasis, pneumonia. 11 Septic pelvic thrombophlebitis. +■ A recrudescence of malaria or pulmonary tuberculosis. ■ Others: Pharyngitis, gastroenteritis. + +or a combination of all these when it is called pelvic cellulitis. +Vaginal flora: The vaginal flora in late pregnancy and at the onset of labor consists of the following organisms: + +(1) Doderlein's bacillus (60-70%); (2) Candida albicans (25%); (3) Staphylococcus albus or aureus; (4) Streptococcus-anaerobic common; beta-hemolytic rare; (5) Escherichia coli and Bacteroides group; (6) Clostridium welchii on occasion. + +These organisms remain dormant and are harmless during normal delivery conducted in aseptic condition. +PREDISPOSING FACTORS OF PUERPERAL SEPSIS: The pathogenicity of the vaginal flora may be influenced by certain factors: (1) The cervicovaginal mucous membrane is damaged even in normal delivery; (2) The uterine surface (the placental site), is converted into an open wound by the cleavage of the decidua which takes place during the third stage of labor; and (3) The blood clots present at the placental site are excellent media for the growth of the bacteria. +Antepartum risk factors: (1) Anemia; (2) Preterm labor; (3) Premature rupture of the membranes; ( 4) Prolonged rupture of membrane (,: 18 hours); (5) Diabetes; (6) Immunocompromised (HIV). +Intrapartum risk factors: (1) Repeated vaginal examinations; (2) Traumatic vaginal delivery; (3) Hemorrhage-antepartum or postpartum; (4) Retained bits of placental tissue or membranes; (5) Prolonged labor; (6) Obstructed labor; (7) Cesarean delivery; (8) Dehydration and ketoacidosis during labor. +Due to the factors mentioned above, the organisms (Box 30.2) gain foothold either in the traumatized tissues +r---- + +·ID Chapter 30: Abnormalities of the Puerperium + + +11 Aerobic: +• Group A, beta hemolytic Streptococcus: Toxic shock syndrome; necrotizing fasciitis in episiotomy or CS wound. +• Group B, beta hemolytic Streptococcus: Neonatal septicemia, respiratory disease and meningitis, Methicillin-Resistant, S. aureus (MRSA)-severe infection (cellulitis), Methicillin­ Sensitive S. aureus (MSSA). +• Gram-negative: E coil, Klebsiella, Proteus, Pseudomonas. +o Gram variable: Gardnerel/a vaginitis. o Others: Chlamydia, Mycop/asma. +• Anaerobes: Cocci: Peptostreptococcus; Peptococcus. +■ Others: Bacteroides (Fragi/es, Bivims, Fusobacteria, Mobiluncus, Clostridia). + + + +lacerated wound are the favorable sites for bacterial growth and multiplication. The devitalized tissue, blood clots, foreign body (retained cotton swabs}, and surgical trauma favor polymicrobial growth, proliferation and spread of infection. This ultimately leads to metritis, parametritis and/ or cellulitis. +Uterus: Endomyometritis-the incidence varies from 1 % to 3% following vaginal delivery and about 10% following cesarean delivery. It is commonly polymicrobial. The decidua, especially over the placental site, is primarily affected. The risk factors for endometritis are mentioned before. +The necrosed decidua sloughs off. The discharge is offensive. A zone of leukocytic barrier prevents the infection to the deeper myometrium. Severe infection is rare nowadays. + +Most of the infections in the genital tract are polymicrobial with a mixture of aerobic and anaerobic organisms. + +of the uterovaginal canal or in the raw decidua left behind or in the blood clots, especially at the placental site. +MODE OF INFECTION: Puerperal sepsis is essentially a wound infection. Placental site (being a raw surface), lacerations of the genital tract or cesarean section wounds may be infected in the following ways: +11 Sources of infection: ♦ Endogenous where organisms are present in the genital tract before delivery. Anaerobic Streptococcus is the predominant pathogen. ♦ Autogenous where organisms present elsewhere (skin, throat) in the body and migrate to the genital organs by bloodstream or by the patient herself. Beta-hemolytic Streptococcus, E. coli, Staphylococcus are important. ♦ Exogenous where infection is contracted from sources outside the patient (from hospital or attendants). Beta-hemolytic Streptococcus, Staphylococcus and E. coli are important. +II PATHOLOGY + +The primary sites of infection are: (1) Perineum; (2) Vagina; (3) Cervix; (4) Uterus. The infection is either localized to the site or spreads to distant sites. The lacerations on the perineum, vagina and the cervix are often infected by the organisms due to the presence of blood clots or dead space. The wounds become red, swollen and there is associated seropurulent discharge. There may be disruption of the wound if repaired before control of infection. Diabetes, obesity, immunocompromised state (HIV) are the other high­ risk factors for wound infection. +I PATHOGENESIS + +Endogenous Bacterial colonization +Bacterial infection (aerobic, anaerobic +Exogenous and others) + +Endometrium (placental implantation site), cervical lacerated wound, vaginal wound (episiotomy) or perinea! + +SPREAD OF INFECTION +■ Pelvic cellulitis (parametritis) is due to spread of infection to the pelvic cellular tissues by direct or by lymphatic or hematogenous routes. The infection causes exudation and formation of an indurated mass usually c'onfined to one side of the uterus. The uterus in that case is pushed to the contralateral side. +II Peritonitis is common following infection (metritis) after cesarean delivery. There may be necrosis of uterine incision wound and dehiscence. Patient presents with bowel distension and a dynamic ileus. +11 Salpingitis may be interstitial (due to lymphatic spread) or perisalpingitis (following pelvic peritonitis). Endosalpingitis (tubal mucosa) is uncommon. +11 Pelvic abscess following pelvic peritonitis may be due to spread of infection. Rarely, there may be generalized peritonitis. With a dynamic ileus pelvic abscess has become rare (100.4°F} and pulse rate (>90); (2) Lochial discharge becomes offensive and copious; (3) The uterus is subinvoluted and tender. +Severe: (I) The onset is acute with high· rise of temperature, often with chills and rigor; (2) Pulse rate is rapid, out of proportion to temperature; (3) Often there is breathlessness, coughs, abdominal pain and dysuria; (4) Lochia may be scanty and odorless; (5) Uterus may be subinvoluted, tender and softer. There may be associated wound infection (perineum, episiotomy wound or the cervix}. +SPREADING INFECTION (EXTRAUTERINE SPREAD) is evident by presence of pelvic tenderness (pelvic peritonitis), pelvic cellulitis with tenderness on the fornix (parametritis), bulging fluctuant mass in the pouch of Douglas (pelvic abscess). Rare presentations are: abdominal tenderness (general peritonitis}, pelvic thrombophlebitis or septicemia or even septic shock. +Parametrial phlegmon: Rarely parametritis (parametrial cellulitis) occurs following cesarean delivery. lnduration develops within the layers of broad ligament (phlegmon). The cellulitis may spread along the natural planes of the broad ligament cleavage. This may spread to the pelvic side wall, rectovaginal septum and around the cervix. It takes longer time (7-10 days) to resolve with the use of broad-spectrum antibiotics. Suppuration of a parametrial phlegmon is rare. The abscess may manifest as a fluctuant mass in the POD or as psoas abscess or may point above the inguinal ligament. Drainage of abscess may be done by culdocentesis or percutaneous drainage under CT guidance. +Toxic shock syndrome is often manifested by fever, headache, nausea, vomiting, diarrhea and erythematous skin rash. Major organ dysfunction (renal failure, hepatic dysfunction, DIC) have been observed. Etiologically staphylococcal exotoxin (Staphylococcus aureus) has been found to activate T cells to create a "Cytokine storm''. Maternal mortality is high unless promptly treated. Supportive therapy and antibiotics are used to prevent the capillary endothelial injury. +Septicemia: (I) There is high rise of temperature usually associated with rigor. Pulse rate is usually rapid even after the temperature settles down to normal; (2) Blood culture is positive, (3) Symptoms and signs of metastatic infection in the lungs, meninges or joints may appear. +Bacteremia, endotoxic or septic shock is due to release of bacterial endotoxin (lipopolysaccharide) causing circulatory inadequacy and tissue hypoperfusion. It is manifested by hypotension, oliguria and adult respiratory distress syn­ drome. + +Chapter 30: Abnormalities of the Puerperium - . +II INVESTIGATIONS OF PUERPERAL PYREXIA + +The underlying principles in investigations are: (I) To locate the site of infection; (2) To identify the organisms; (3) To assess the severity of the disease. +A case of puerperal pyrexia is considered to be due to genital sepsis unless proved otherwise. The investigations should also be directed to find out any extragenital source of infection to account for the fever as well. +History: Antenatal, intranatal and postnatal history of any high-risk factor for infection like anemia, prolonged rupture of membranes or prolonged labor are to be taken. +Clinical examination includes thorough general, physical and systemic examinations. Abdominal and pelvic examinations are done to note the involution of genital organs and locate the specific site of infection. Legs should be examined for thrombophlebitis or thrombosis. +Investigations include: (I) High vaginal and +endocervical swabs for culture in aerobic and anaerobic media and sensitivity test to antibiotics; (2) "Clean catch" midstream specimen of urine for analysis and culture including sensitivity test; (3) Blood for total and differential white cell count, hemoglobin estimation and lactate measurement. A low platelet count may indicate septicemia or DIC. Thick blood film should be examined for malarial parasites; (4) Blood culture, if fever is associated with chills and rigor. Other specific investigations as per the clinical condition are needed; (5) Serum urea, creatinine and electrolytes may be done in a selected case to have a baseline record in the event that renal failure develops later in the course of the disease or laparotomy is needed. (6) Pelvic ultrasound is helpful­ (i) to detect any retained bits of conception within the uterus, (ii) to locate any abscess within the pelvis, (iii) to collect samples (pus or fluid} from the pelvis for culture and sensitivity, and (iv) for color flow Doppler study to detect venous thrombosis. Use of CT and MRI is needed, especially when diagnosis is in doubt or there is pelvic vein thrombosis; (7) Chest X-ray (CXR) should be taken in cases with suspected pulmonary Koch's lesion and also to detect any lung pathology like collapse and atelectasis (following inhalation anesthesia). + +I PROPHYLAXIS +Puerperal sepsis is to a great extent preventable provided certain measures are undertaken before, during, and following labor. +Antenatal prophylaxis includes improvement of nutritional status (to raise hemoglobin level} of the pregnant woman and eradication of any septic focus (skin, throat, tonsils} in the body. +Intranatal prophylaxis includes-(a) Full surgical asepsis during delivery, (b) Screening for Group B +· i - Chapter 30: Abnormalities of the Puerperium + + +Streptococcus in a high-risk patient. Prophylactic use of antibiotic is not recommended as a routine, (c) Prophylactic use of antibiotic at the time of cesarean section has significantly reduced the incidence of wound infection, endometritis, urinary tract infection and other serious infections. +Postpartum prophylaxis includes aseptic precautions for at least 1 week, following delivery until the open wounds in the uterus, perineum and vagina are healed up. Too many visitors are restricted. Sterilized sanitary pads are to be used. Infected babies and mothers should be in isolated room. +I TREATMENT + +General care: (i) Isolation of the patient is preferred, especially when hemolytic Streptococcus is obtained on culture, (ii) Adequate fluid and calorie are maintained by intravenous infusion (N), (iii} Anemia is corrected by oral iron or if needed by blood transfusion, (iv) An indwelling catheter is used to relieve any urine retention due to pelvic abscess. It also helps to record urinary output, (v) A chart is maintained by recording pulse, respiration, temperature, lochial discharge, and fluid intake and output, (vi) Antibiotics: Ideal antibiotic regimen should depend on the culture and sensitivity report. Pending the report, empirical therapy with gentamicin (2 mg/kg IV loading dose, followed by 1.5 mg/kg IV every 8 hours) and clindamycin (900 mg IV every 8 hours) should be started. Metronidazole 0.5 g N is given at 8 hours interval to control the anaerobic group. The treatment is continued +until the infection is controlled for at least 7-10 days. +CHOICE OF ANTIBIOTIC REGIMENS: Severe sepsis. A combination of either piperacillin-tazobactam or carbapenem plus clindamycin has broadest range of antimicrobial coverage. Women with MRSA infection should be treated with vancomycin or teicoplanin. +Surgical treatment: There is little role of major surgery in the treatment of puerperal sepsis. +11 Perineal wound-management of episiotomy wound +infection and dehiscence. • Antibiotics-Iv. +• Removal of sutures and wound dressing. +• Wound debridement-under analgesia/anesthesia. • Repeated sitz bath. +• Wound dressing and debridement till healthy granulation tissue develops. +• Secondary wound repair with nonabsorbable suture. • Removal of sutures after 10-12 days. +a Retained uterine products with a diameter of 3 cm or less may be disregarded and left alone. Otherwise, surgical evacuation after antibiotic coverage for 24 hours should be done to avoid the risk of septicemia. Cases with septic pelvic thrombophlebitis are treated with N heparin for 7-10 days. + + +■ Pelvic abscess should be drained by colpotomy under ultrasound guidance. +■ Wound dehiscence: Dehiscence of episiotomy or abdominal wound following cesarean section is managed by scrubbing the wound twice daily, debridement of all necrotic tissue and then closing the wound with secondary suture. Appropriate antimicrobials are used following culture and sensitivity. +11 Laparotomy has got limited indications: Maintenance of electrolyte balance by intravenous fluids along with appropriate antibiotic therapy usually controls the peritonitis. However, in unresponsive peritonitis, laparotomy is indicated. Even if no palpable pathology is found, drainage of pus may be effective. Hysterectomy is indicated in cases with rupture or perforation, having multiple abscesses, gangrenous uterus or gas gangrene infection. Ruptured tuboovarian abscess should be removed. +11 Necrotizing fasciitis (Fig. 30.1) is rare but fatal complication of wound infection (abdominal, perinea!, vaginal), involving muscle and fascia. Risk factors are diabetes, obesity and hypertension. Infection is caused by Group A beta-hemolytic Streptococcus and often it is polymicrobial. Tissue necrosis is the significant pathology. Treatment includes: Rehydration, wound scrubbing, debridement of all necrotic tissues, and use of high-dose broad-spectrum (N) antibiotics. +Indications of intensive care unit management: (1) Hypotension; (2) Oliguria; (3) Raised serum creatinine; (4) Raised serum lactate ('.4 mmol/L); (5) Thrombocytopenia; (6) ARDS; (7) Hypothermia. +11 Management of bacteremic or septic shock includes-fluid and electrolyte balance (to monitor CVP), respiratory supports (to maintain arterial P02 and PC02}, circulatory support (dopamine or + + + + + + + + + + + + + + + + +Fig. 30.1: Necrotizing fasciitis involving the skin, subcutaneous tissues, rectus sheath and the muscles (myofasciitis) in a cesarean section wound. + + + +Chapter 30: Abnormalities of the Puerperium IIIL· w + + +dobutamine), infection control (intensive antibiotic therapy, surgical removal of septic foci) and specific management (as hemodialysis for renal failure). + +SUBINVOLUTION + +DEFINITION: When the involution is impaired or retarded, it is called subinvolution. The uterus is the most common organ affected in subinvolution. As it is the most accessible organ to be measured per abdomen, the uterine involution is considered clinically as an index to assess subinvolution. +CAUSES: Predisposing factors are-(1) Grand multi­ parity; (2) Overdistension of uterus as in twins and hydramnios; (3) Maternal ill-health; (4) Cesarean section; (5) Prolapse of the uterus; (6) Retroversion after the uterus becomes pelvic organ; (7) Uterine fibroid. +Aggravating factors are: (1) Retained products of conception; (2) Uterine sepsis (endometritis). +SYMPTOMS: The condition may be asymptomatic. The predominant symptoms are: (1) abnormal lochial discharge, either excessive or prolonged; (2) irregular or at times, excessive uterine bleeding; (3) irregular cramp-like pain in cases of retained products or rise of temperature in sepsis. +SIGNS: (1) The uterine height is greater than the normal for the particular day of puerperium. Normal puerperal uterus may be displaced by a full bladder or a loaded rectum. It feels boggy and softer; (2) Presence of features responsible for subinvolution may be evident. +MANAGEMENT: Mere size of the uterus is not important and provided there is absence of features, such as excessive lochia or irregular bleeding or sepsis, the size of the uterus can be safely ignored. Appropriate therapy is to be instituted only when subinvolution is found to be a mere sign of some local pathology: (1) Antibiotics in endometritis; (2) Exploration of the uterus in retained products; (3) Pessary in prolapse or retroversion. Methergine, so often prescribed to enhance the involution process, is of little value in prophylaxis. + +URINARY COMPLICATIONS IN PUERPERIUM + +URINARY TRACT INFECTION: It is one of the common causes of puerperal pyrexia, the incidence being 1-5% of all deliveries. The infection may be the consequence of any of the following: (1) Recurrence of previous cystitis or pyelitis; (2) Asymptomatic bacteriuria becomes overt; (3) Infection contracted for the first time during puerperium is due to-(a) effect of frequent catheterization, either during labor or in early puerperium to relieve retention of urine, (b) stasis of urine during early puerperium due to lack of bladder tone and less desire to pass urine. + +The organisms responsible are-E. coli, Klebsiella, Proteus and S. aureus. The clinical features, diagnosis and management have been described. +RETENTION OF URINE: This is a common complication in early puerperium. The causes are-(1) Bruising and edema of the bladder neck; (2) Reflex pain from the perinea! injury; (3) Unaccustomed position. +Postpartum Urinary Retention (PUR) is common after childbirth, depending on the type of delivery. Risk factors for PUR include: Epidural analgesia, prolonged first or second stage of labor, instrumental delivery, episiotomy, primiparous women, physiological changes such as increased progesterone levels. +Treatment: If simple measure fails to initiate micturition within 6 hours of delivery, an indwelling catheter is to be kept in situ for about 48 hours. This not only empties the bladder but helps in regaining the normal bladder tone and sensation of fullness. Following removal of catheter, the amount of residual urine is to be measured. If it is found to be more than 100 mL, continuous drainage is resumed. Appropriate urinary antiseptics should be administered for about 5-7 days. +INCONTINENCE OF URINE: This is not a common symptom following birth. The incontinence may be: (I) overflow incontinence; (2) stress incontinence; (3) true incontinence. Overflow incontinence following retention of urine should first be excluded before proceeding to differentiate between the other two. Stress incontinence usually manifests in late puerperium, whereas true incontinence in the form of genitourinary fistula usually appears soon following delivery or within first week of puerperium. Diagnosis of stress incontinence is established by noting the escape of urine through the urethral opening during stress. The exact nature of urinary fistula is established by noting the fistula site by examining the patient in Sims' position, using Sims' speculum or by three-swab test, if the fistula is tiny. +SUPPRESSION OF URINE: One should differentiate suppression from retention of urine. If the 24 hours urine excretion is less than 400 mL or less, suppression of urine (oliguria) is diagnosed; the cause is to be sought for and appropriate management is instituted. + +Physiological changes in pregnancy. +Change Clinical effects +50-60% increase in renal blood flow and Increased urinary glomerular filtration rate. frequency +Dilatation of urinary collecting system and Increased risk of UTI ureters. +Bladder and urethra elevated and stretched Urinary incontinence with reduced tone and sensation. and retention. +·fl Chapter 30: Abnormalities of the Puerperium + +Physiological changes in the puerperium. +Change Clinical effects +Fluid shift from extravascular space to Increased urinary intravascular space, renin-angiotensin- output alodesterone system activity (Ch. 5, p. 46). +Bladder wall becomes edematous, hyperemic; Urinary retention compression of urethra, reduced bladder tone +and sensation. +Atony of pelvic floor muscles Urinary incontinence +Dilatation of urinary collecting system and Increased risk of ureters secondary to smooth muscle relaxation UTI. +or compression of ureters by enlarged uterus + +BREAST COMPLICATIONS + +The common breast complications in puerperium are: (1) Breast engorgement; (2) Cracked and retracted nipple leading to difficulty in breastfeeding; (3) Mastitis and breast abscess; (4) Lactation failure. Breast engorgement and infection are responsible for puerperal pyrexia. +I BREAST ENGORGEMENT + +Cause: Breast engorgement is due to exaggerated normal venous and lymphatic engorgement of the breasts which precedes lactation. This, in turn, prevents escape of milk from the lacteal system. The primiparous patient and the patient with inelastic breasts are likely to be involved. +Onset: It usually manifests after the milk secretion starts (third or fourth day postpartum). +Symptoms include: (a) Considerable pain and feeling of tenseness or heaviness in both the breasts; (b) Generalized malaise or even transient rise of temperature; and (c) Painful breastfeeding. +Prevention includes: (i) To avoid prelacteal feeds, (ii) To initiate breastfeeding early and unrestricted, {iii) Exclusive breastfeeding on demand, {iv) Feeding in correct position, (v) Correct latch on. +TI·eatment: (1) To support the breasts with a binder or brassiere; (2) Frequent suckling; (3) Manual expression of any remaining milk after each feed; (4) To administer analgesics for pain; (5) The baby should be put to the breast regularly at frequent intervals; (6) In a severe case, gentle use of a breast pump may be helpful. This will reduce the tension in the breast without causing excess milk production. +I CRACKED AND RETRACTED NIPPLE + +Cracked nipple: The nipple may become painful due to-(1) Loss of surface epithelium with the formation of a raw area on the nipple; or (2) Due to a fissure situated either at the tip or the base of the nipple. These two conditions frequently coexist and are referred to as cracked nipple. It is caused by-(a) unclean hygiene + +resulting in formation of a crust over the nipple, (b) retracted nipple, and (c) trauma from baby's mouth due to incorrect attachment to the breast, (d) infection with Candida albicans and S. aureus is often present. The condition may remain asymptomatic but becomes painful when the infant sucks. When infected, the infection may spread to the deeper tissue producing mastitis. Prophylaxis includes local cleanliness during pregnancy and in the puerperium before and after each breastfeeding to prevent crust formation over the nipple. Treatment: Correct attachment (latch on) will provide immediate relief from pain and rapid healing. Fresh human milk and saliva have got healing properties. Purified lanolin with the mother's milk is applied three or four times a day to hasten healing. When it is severe, mother should use a breast pump and the infant is fed with the expressed milk. Inflamed nipple and areola may be due to thrush also. Miconazole lotion is applied over the nipple as well as in the baby's mouth if there is oral thrush. If it fails to heal up, rest is given to the affected nipple using a breast pump while the nipples heal. Nipple shields (thin latex) can be used. The persistence of a nipple ulcer, in spite of therapy mentioned, needs biopsy to exclude malignancy. +Retracted and flat nipple: It is commonly met in primigravidae. It is usually acquired. Babies are able to attach to the breast correctly and are able to suck adequately. In difficult cases, manual expression of milk can initiate lactation. Gradually, breast tissue becomes soft and more protractile, so that feeding is possible. +I ACUTE MASTITIS + +The incidence of mastitis is 2-20% in lactating and less than 1 % in non-lactating women. The common organisms involved are S. aureus (MRSA), Staphylococcus epidermidis and Streptococcus viridans. Risk factors for mastitis are poor nursing, maternal fatigue and cracked nipple. +Mode of infection: There are two different types of mastitis depending upon the site of infection. (1) Infection that involves the breast parenchymal tissues leading to cellulitis. The lacteal system remains unaffected; (2) Infection gains access through the lactiferous duct leading to development of primary mammary adenitis. The source of organisms is the infant's nose and throat. +Noninfective mastitis may be due to milk stasis (plugged duct). Feeding from the affected breast solves the problem. +Onset: In superficial cellulitis, the onset is acute during first 2-4 weeks postpartum. However, acute mastitis may occur even several weeks after the delivery. +Clinical features: Symptoms include-(a) +Generalized malaise and headache, nausea, vomiting, +Chapter 30: Abnormalities of the Puerperium 11 + +(b) Fever (>38.5°C or more) with chills, (c) Severe pain and tender swelling in one quadrant of the breast and {d) Indurated. Signs include-{a) Presence of toxic features, and {b) Presence of a swelling on the breast. The overlying skin is red, hot and flushed and feels tense and tender. +Diagnosis: Microscopic examination of breast milk, showing leukocytes more than 106 /mL and bacterial count more than 103 /mL, supports the diagnosis of mastitis. +Complications: Due to variable destruction of breast tissues, it leads to the formation of a breast abscess. +PROPHYLAXIS: Thorough handwashing before each feed, cleaning the nipples before and after each feed, and keeping them dry, reduce the nosocomial infection rates. +Management: (a) Breast support, (b) Plenty of oral fluids, (c) Breastfeeding is continued with good attachment. Nursing is initiated on the uninfected side first to establish let down, (d) The infected side is emptied manually with each feed, (e) Dicloxacillin (penicillinase­ resistant penicillin) is the drug of choice. A dose of 500 mg every 6 hours orally is started till the sensitivity report available. Erythromycin or clindamycin is an alternative to patients who are allergic to penicillin. Antibiotic therapy is continued for 10-14 days, (f) Analgesics (ibuprofen) are given for pain, (g) Milk flow is maintained by breastfeeding the infant. This prevents proliferation of Staphylococcus in the stagnant milk. The ingested Staphylococcus will be digested without any harm. +BREAST ENGORGEMENT: Bilateral generalized tenderness of breasts is seen on 2 to 4 days postpartum. Low grade fever is often associated. It is due to interstitial edema or accumulation of excess of milk. It is treated with worm compress followed by expression (by hand or pump) of milk. Continued breast feeding is helpful. +BREAST ABSCESS: Features are-(1) Flushed breasts not responding to antibiotics promptly; (2) Brawny edema of the overlying skin; (3) Marked tenderness with fluctuation; (4) Swinging temperature. +Breast abscess is to be drained under general anesthesia by a deep radial incision extending from near the areolar margin to prevent injury of the lactiferous ducts. Incision perpendicular to the lactiferous ducts increases the risk of fistula formation and ductal occlusion. Finger exploration is done to break up the walls of the loculi. The cavity is loosely packed with gauze which should be replaced after 24 hours by a smaller pack. The procedure is continued till it heals up. The abscess can also be drained by serial percutaneous needle aspiration under ultrasound guidance. +Breastfeeding is continued in the uninvolved side. The infected breast is mechanically pumped every 2 hours and with eve1y let down. Recurrence risk is about 10%. Once cellulitis has resolved, breastfeeding from the involved side may be resumed. +Antibiotics to be continued depending upon the culture report of pus. +Breast pain may be due to engorgement, infection ( C. albicans), nipple trauma, clogged milk, mastitis or occasionally with latching on or let down reflex. + + +Management: Appropriate nursing technique, posi­ tioning and breast care can reduce pain significantly when it is due to nipple trauma, engorgement or mastitis. Use of miconazole oral lotion or gel to both the nipples and into infant's mouth thrice daily for 2 weeks is helpful. +INADEQUATE MILK PRODUCTION: The normal volume of milk produced at the end offirst postpartum week is 550 mL/ day. By 2-3 weeks it is increased fom 80 about 800 mL/day. Production peaks at 1.5-2.0 L/day. The causes of inadequate milk production are: (1) Infrequent suckling; (2) Depression or anxiety state in the puerperium; (3) Reluctance or apprehension to nursing; (4) Ill­ development of the nipples; (5) Painful breast lesion; (6) Endogenous suppression of prolactin (retained placental bits); {7) Prolactin inhibition (ergot preparations diuretics, pyridoxine); (8) Previous breast surgery; (9) Insulin resistance; (10) High androgen levels. +r +Treatment: For maintenance of effective lactation in an otherwise healthy individual, the following guidelines are helpful. ++ Antenatal: (1) To counsel the mother regarding the advantages of nursing her baby with breast milk; (2) To take care of any breast abnormality, especially a retracted nipple and to maintain adequate breast hygiene, since 36 weeks of pregnancy. ++ Puerperium: (1) To encourage adequate fluid intake; (2) To nurse the baby regularly; (3) Painful local lesion is to be treated; ( 4) Metoclopramide, intranasal oxytocin and sulpiride (selective dopamine antagonist) have been found to increase milk production. They act by stimulating prolactin secretion. Metoclopramide given in a dose of 10 mg thrice daily is found helpful. + +PUERPERAL VENOUS THROMBOSIS (VT) AND PULMONARY EMBOLISM (PE) +Approximately 80% of VTEs in pregnancy are due to DVT and 20% are PE. Pregnant women 4-5 times are more likely to have VTE. About 50% of all DVT and VTEs occur in antepartum period. +Basic pathology for venous thrombosis are-(i) Vascular stasis, (ii) Hypercoagulability of blood (pregnancy), and (iii) Vascular endothelial trauma (Virchow's triad 1856). Other pregnancy­ specific risk factors are as mentioned below: +Venous thromboembolic diseases include: +♦ Deep vein thrombosis (iiiofemoral-70% ). +♦ Thrombophlebitis (superficial and deep veins). ♦ Pulmonary embolus (PE). +Pathophysiology: (1) In a normal pregnancy there is rise in concentration of coagulation factors I, II, VII, VIII, IX, X, XII (20-100%). Plasma fibrinolytic inhibitors are produced by the placenta and the level of protein S is markedly (40%) decreased; (2) Alteration in blood constituents-increased number of young platelets and their adhesiveness; (3) Venous stasis is increased due to compression of gravid uterus to the inferior vena cava and iliac veins. This stasis causes damage to endothelial cells. +Thrombophilias are hypercoagulable states in pregnancy that increase the risk of venous thrombosis. It may be inherited +······II Chapter 30: Abnormalities of the Puerperium + +or acquired. Inherited thrombophilias are the genetic conditions associated with the deficiencies of antithrombin III, protein C, protein S and prothrombin gene mutation. Others are factor V Leiden mutation and hyperhomocysteinemia. Acquired thrombophilias are due to the presence lupus anticoagulant and antiphospholipid antibodies. +Risk factors for VTE-(1) High l'isk: Previous VTE, thrombophilia; (2) Intermediate risk: (a) Heart disease, (b) SLE, (c) Surgical procedures (LSCS); (3) Low risk: Presence of less than three from any of these risk factors mentioned: (a) age >35 years, (b) Obesity (BMI >35), (c) Parity 3, (d) Immobility, (e) +Dehydration, (f) Hyperemesis, (g) Multiple pregnancy. +Note: Low risk factors more than three make the patient as intermediate risk. +DEEP VEIN THROMBOSIS: Diagnosis: Clinical diagnosis is unreliable. In majority, it remains asymptomatic. +Symptoms include pain in the calf muscles, tenderness, edema legs and rise in skin temperature. On examination asymmetric leg edema ( difference in circumference between the affected and the normal leg more than 2 cm) is significant (Fig. 30.2). A positive Roman's sign-pain in the calf on dorsiflexion of the foot may be present ( <15%). +Investigations: The following biophysical tests are employed to confirm the diagnosis: +1. Venous duplex imaging, including compression. +2. Ultrasound, color and spectral Doppler sonography is the gold standard and the noninvasive diagnostic method. +3. MRI is done when iliac vein thrombosis is suspected and compression USG results are negative or equivocal. It has sensitivity of 100% and specitivity of99%. +4. D-dimer test is sensitive but nonspecific for DVT. +5 . Doppler ultrasound to detect the changes in the velocity of blood flow in the femoral vein by noting the alteration of the characteristic "whoosh" sound which is audible from a patent's vein. Venous Ultrasonography (VUS): It is done by placing the transducer over the femoral vein and then gradually it is moved to the great saphenous vein, the popliteal vein and to its branches with the deep veins of the calf. + + + + + + + + + + + + + + + + +Fig. 30.2: Deep vein thrombosis of the lower limb (right) showing massive edema of both the legs and the thighs. Compression ultrasonography was positive. + + +6. Magnetic Resonance Imaging (MRI) is found superior to VUS and equivalent to contrast venography in the diagnosis ofDVT. MRI is helpful to detect thrombosis in pelvic, iliac or femoral veins. The sensitivity and specificity of MRI in the diagnosis ofDVT are 100% and the accuracy is 99%. +7. D-dimer assays: D-dimer is a product of degradation of fibrin by plasmin. Testing for D-dimer is not preformed for acute episode ofVTE in pregnancy. +SEPTIC PELVIC THROMBOPHLEBITIS (SPT): Postpartum thrombophlebitis originates in the thrombosed veins at the placental site by organisms such as anaerobic streptococci or Bacteroides fragilis). When localized in the pelvis, it is called pelvic thrombophlebitis. There is no specific clinical feature of pelvic thrombophlebitis, but it should be suspected in cases where the pyrexia continues for more than a week in spite of antibiotic therapy. It is a diagnosis of exclusion. +Extrapelvic spread: (1) Through the right ovarian vein into inferior vena cava and thence to the lungs; (2) Through the left ovarian vein to the left renal vein and thence to the left kidney; (3) Retrograde extension to iliofemoral veins to produce the clinicopathological entity of "phlegmasia alba dolens" or white leg. It is rare these days. +Clinical features: (1) It usually develops on the second week of puerperium; (2) Mild pyrexia is common prior to the dramatic local manifestations. At times, the fever may be high with chills and rigor; (3) Evidences of constitutional disturbances such as headache, malaise and rising pulse rate or features of toxemia may be present; ( 4) The affected leg is swollen, painful, white and cold. The pain is due to arterial spasm as a result of irritation from the nearby thrombosed vein; (5) Blood count shows polymorphonuclear leukocytosis. The diagnosis may be made by venous ultrasound, Computed Tomography (CT) scan or by Magnetic Resonance Imaging (MRI). + +PROPHYLAXIS AND MANAGEMENT FOR VENOUS THROMBOEMBOLISM (VTE) IN PREGNANCY AND PUERPERIUM + +Preventive measui-es include: +■ Prevention of trauma, sepsis, anemia in pregnancy and labor. Dehydration during delivery should be avoided. +■ Use of elastic compression stocking and intermittent pneumatic compression devices during surgery. +■ Leg exercises, early ambulation are encouraged following operative delivery. +Women at risk of venous thromboembolism during pregnancy have been grouped into different categories depending on the presence ofriskfactors (see above). Thromboprophylaxis to such a woman depends on the specific risk factor and the category. +(1) A low-riskwoman has no personal or family history ofVTE and is heterozygous for factor V Leiden mutation. Such a woman needs no thromboprophylaxis, early mobilization and adequate hydration to be maintained. (2) A high-risk woman (prothombin gene mutation) needs Low-Molecular-Weight Heparin (LMWH) prophylaxis throughout pregnancy and postpartum 6 weeks. (3) Intermediate risk women with three or more risk factors are considered for antenatal prophylaxis with LMWH up to 7 days of puerperium. + + +Management: (1) The patient is put to bedrest with the foot end raised above the heart level. (2) Pain on the affected area may be relieved with analgesics. (3) Appropriate antibiotics are to be administered. (4) Anticoagulants-Ca) Weight adjusted LMWH is used for the treatment ofVTE. Advantages of LMWH are: Less bleeding complications, less thrombocytopenia and osteoporosis, longer plasma half-life and more predictable dosed response. Monitoring of LMWH is peak plasma anti-factor Xa activity. Use of LMWH for the prevention and treatment ofVTE in pregnancy is recommended. (b) Heparin 15,000 units are administered intravenously, followed by 10,000 units 4-6 hourly for 4-6 injections when the blood coagulation is likely to be depressed to the therapeutic level. Risk of major bleeding withUFH is about 2%. +Heparin is continued for at least 7-10 days or even longer if thrombosis is severe. Prolongation of activated partial thromboplastin time (APTT) to 1.5-2.5 times indicates effective and safe anticoagulation. Serum heparin level should be of 0.1-0.2U/mL. +(c) A drug of coumarin series-warfarin is commonly used orally with an overlap of at least 3 days with heparin. The initial daily single dose of 7 mg for 2 days is adequate for induction. Subsequent maintenance dose depends upon international normalized ratio (INR) which should be within the range of 2.0-3.0. The daily maintenance dose of warfarin is usually 5-9 mg, to be taken at the same time each day. The anticoagulant therapy should be continued till all evidences of the disease have disappeared which generally take 3-6 months. The anticoagulant (warfarin, LMWH or unfractionated heparin) is safe for breastfeeding. (5) As soon as the pain subsides, gentle movement is allowed on bed by the end of first week. High quality elastic stockings are fitted on the affected leg before mobilization. (6) Inferior vena cava filters are used for patients with recurrent pulmonary embolism or where anticoagulant therapy is contraindicated.Vena cava may be completely ligated by teflon clips. (7) Fibrinolytic agents like streptokinase produce rapid resolution of pulmonary emboli. (8) Venous thrombectomy is needed for massive iliofemoral vein thrombosis or for massive pulmonary embolus. +ii PULMONARY EMBOLISM (PE) + +Pulmonary Embolism (PE) is the lead cause of maternal deaths (20%) in many parts of the world. The clinical features depend on the size of the embolus and on the preceding health status of the patient. The classical symptoms of massive pulmonary embolism are sudden collapse with acute chest pain and air hunger. Death usually occurs within short time from shock and vagal inhibition. +The important signs and symptoms of pulmonary embolism are: Sudden tachypnea (>20 breaths/min), dyspnea, pleuritic chest pain, cough, tachycardia (>100 bpm), hemoptysis and rise in temperature more than 37°C. +DIAGNOSIS: +♦ X-ray of the chest shows diminished vascular marking in areas of infarction, elevation of the dome of the diaphragm and often pleural effusion. I t is useful to rule out pneumonia, pulmonary infiltrates and atelectasis. +♦ ECG: ECG is abnormal in 41 % of women with acute PE. The most common abnormalities are: Twave inversion (21%); + +Chapter 30: Abnormalities of the Puerperium + +Sl Q3 T3 pattern (15%) and right bundle branch block (18% during pregnancy and 4.2% in the puerperium). ABG analysis is of limited diagnostic value. +♦ Arterial blood gas: PO2 more than 85 mm Hg on room air is reassuring but does not rule out PE. More than 50% of +pregnant women with a documented PE have a normal alveolar-arterial gradient. +♦ D-Dimer: A negative D -dimer value may rule out the diagnosis of PE. It has a high negative predictive value. +♦ Doppler ultrasound can identify a DVT. When the test is positive for DVT, anticoagulation therapy should be started. +♦ Lung scans(ventilation/perfusion scan orV/Q scan): Perfusion scan will detect areas of diminished blood flow whereas a reduction in perfusion with maintenance of ventilation indicates pulmonary embolism. V/Q scanning is the method of choice for patients with suspected PE and with normal chest radiograph. High probabilityV/Q scan suggests PE. +♦ Magnetic Resonance Imaging (MRI) can be used in pregnancy as the risk of ionizing radiation is absent. +♦ Pulmonary angiography is the gold standard to the diagnosis but has got high risks of complications. Mortality rate is 0.5% and overall complication rate is 3%. +♦ Computed Tomographic (pulmonary) Angiography (CTA) is the recommended imaging in pregnant women with suspected PE. The CTA is cost effective and has lower dose radiation effect to the fetus than a V/Q scan. Multidetector CTA allows visualization of finer pulmonary vascular detail. It has higher diagnostic accuracy. +Radiation exposure: Two-view chest radiograph is <0.001 rad V/Q scan-fetal radiation is 0.064-0.08 rads compared with CTA (0.0003-0.0131 rad). Pulmonary angiography provides about 0.2 to 0.4 rad with femoral approach and <0.05 rad with brachia! approach. +In V/Q and CTPA, the absolute risk is very small. The radiation dose to the fetus at any stage of pregnancy: CXR: Less than 0.01 mSv(millisievert); CTPA: 0.1 mGy(milligray);V/Q Scanning: 0.5 mCy (milligray) +♦ Magnetic Resonance Angiography (MRA) with IV gadolinium: It has got sensitivity of 100% and specificity of 95% in the diagnosis of PE. +Management: Prophylaxis (as mentioned on p. 414). +Active treatment includes: (1) Resuscitation-cardiac massage, oxygen therapy, intravenous heparin (UFH) bolus dose of 10,000 IU and morphine 15 mg (IV) are started. Heparin remains the mainstay of therapy for VTE. Therapeutic doses of LMWH [enoxaparin 1 mg/kg subcutaneous (SC) twice daily] may be used. Antifactor Xa levels of 0.6-1U /mL are to be maintained. Heparin therapy (IV) should be continued for 5-10 days until patient improves clinically. Thereafter, it is changed to SC injections. Anticoagulation may need to be continued for 6 weeks to 6 months depending upon the case. Heparin level is maintained at 0.2-0.4 U/mL or the Activated Partial Thromboplastin Time (APTT) about twice the normal (1.5-2.5 times). (2) IV fluid support is continued and blood pressure is maintained, if needed by dopamine or adrenaline. (3) Tachycardia is counteracted by digitalis. (4) Recurrent attacks of pulmonary embolism necessitate surgical treatment like embolectomy, placement of inferior caval filter or ligation of inferior vena cava and ovarian veins. Surgical treatment +is done following pulmonary angiography. +Chapter 30: Abnormalities of the Puerperium + +Indications of inferior vena cava filters are: (a) absolute contraindication to medical anticoagulation, {b) failure of anticoagulation, (c) heparin-induced thrombocytopenia, {d) allergy to UFH or LWH. +Contraindications of heparin therapy are: +♦ Women with active antenatal or postpartum bleeding. ♦ Risk of major hemorrhage (placenta previa). +♦ Coagulopathy. • Thrombocytopenia. ♦ Allergic to UFH or LWH. +Contraception for women with a history of VTE: Due to thrombogenic potential of estrogenic-containing contraception, progestin only or nonhormonal methods are recommended. +Natural family planning, condoms, POP, LNG-IUCD, copper IUD, tubectomy are the options. + +OBSTETRIC PALSIES +(Syn: Postpartum Traumatic Neuritis) + +The commonest form of obstetric palsy encountered in puerperium is foot drop. It is usually unilateral and appears shortly after delivery or during first day postpartum or so. It is thought to be due to stretching of the lumbosacral trunk by the prolapsed intervertebral disk between L5 and SI. Backward rotation of the sacrum during labor may also be a contributing factor. Direct pressure either by the fetal head or by forceps blade on the lumbosacral cord or sacral plexus as a causative factor is no longer tenable. +The condition is usually mild and may pass unnoticed unless there is disability. Neurological examination reveals lower motor neuron type of lesion with flaccidity and wasting of the muscles. Post-traumatic neuropathies: In some cases, there may be foot drops. This is due to the injury oflumbosacral trunk, sciatic nerve or common peroneal nerve. The common peroneal nerve may compressed when the legs are placed in stirrups for a long time. Management of the damaged lumbosacral nerve roots is the same as that of the prolapsed intervertebral disk in consultation with an orthopedist. + + + +abruptio placentae, mismatched blood transfusion or eclampsia; (8) Decreased milk supply. +(c) Delayed: (1) Secondary postpartum hemorrhage; (2) Thromboembolic manifestation-pulmonary embolism; (3) Septic thrombophlebitis; (4) Psychosis; (5) Postpartum cardiomyopathy; (6) Postpartum hemolytic uremic syndrome. +Sudden postpartum collapse is a life threatening event. It may be due to (Table 30.1): +■ Hemorrhagic or 11 Non-hemorrhagic conditions. + +I CHORIOAMNIONITIS + +It is the infection of amniotic fluid, amnionitic membranes with or without infection of the fetus. It is seen in term pregnancy (2-5%). It is more common with preterm delivery and/or PROM. The infection may be evident clinically or may remain sub-clinical. +The common organisms are: Prevotella specis, E. Coli, anerobes, bacteroides, group B streptococci. +Risk factors are: Long duration of rupture of membranes, multiple vaginal examination, pre-existing infections in the genital tract. +Diagnosis: Clinical presentation: ■ Rise in maternal temperature +11 Tachycardia: Both maternal and fetal, 11 Uterine tenderness and +11 Vaginal leakage of amniotic fluid-thick and turbid. +Investigations: Commonly done are: (A) Complete hemo­ gram (polymorphonuclear leukocytosis); (B) Amniotic fluid (obtained following abdominal amniocentesis) + +Table 30.1: Common causes of sudden postpartum collapse. + + + +Paraplegia due to epidural hematoma or abscess (arachnoiditis) following regional anesthesia is extremely rare. +During labor: Lateral femoral cutaneous nerve neuropathies are also common. Nerve injuries with transverse cesarean incision include the iliohypogastric or the ilioinguinal nerves. Injury leads to loss of sensation over the area supplied. + + +Obstetric complications. + + + +Medical + +11 Massive postpartum hemorrhage. 11 Amniotic fluid embolism. +11 Acute inversion of the uterus. 11 Septic shock. +11 Severe pre-eclampsia and eclampsia. +• Cardiac: + + + + +PUERPERAL EMERGENCIES + +There are many acute complications that may occur during the puerperium. The majority of the alarming complications, however, arise immediately following delivery. The late complications are relatively less risky. The acute complications are: +(a) Immediate: (1) Postpartum hemorrhage, (2) Shock-hypovolemic, endotoxic or idiopathic, (3) Post­ partum eclampsia, ( 4) Pulmonary embolism- liquor amnii or air, (5) Inversion of the uterus. +(b) Early (within one week): (1) Acute retention of urine; (2) Urinary tract infection; (3) Puerperal sepsis; ( 4) Breast engorgement; (5) Mastitis and breast abscess; (6) Pulmonary infection (atelectasis); (7) Anuria following + +disorders in 11 Myocardial infarction. pregnancy. 11 Cardiomyopathy. +11 Cardiac arrhythmias. +11 Pulmonary: ■ Embolism. +■ Acute respiratory failure (pulmonary edema). +Neurological. ■ Cerebral hemorrhages. +■ Cerebral venous thrombosis. Metabolic • Hypo-/hyperglycemia. disorders. Hypo-/hyperkalemia. +• +Anesthetic ■ High spinal (diaphragmatic paralysis). causes: ■ Mendelson's syndrome. +■ Intravenous use of local anesthetic drug. +Anaphylaxis. ■ Drug toxicity. +Read more Dutta's Clinics in Obstetrics, Ch. 38 +Chapter 30: Abnormalities of the Puerperium - +Table 30.2: Complications of chorioamnionitis. Complications of chorioamnionitis: Table 30.2. + +Maternal + + + +Fetal/neonatal (5-10%): + + +■ Febrile morbidity due to infections (10%); ■ Operative interventions (CD); ■ Wound infection; ■ Dysfunctional labor; ■ Pelvic abscess (rare); ■ Sepsis +■ Bacteremia; ■ Sepsis; ■ Pneumonia; ■ Meningitis; ■ Respiratory distress syndrome; ■ lntraventricular hemorrhage; ■ Necrotizing enterocolitis; ■ IUFD; ■ Mortality (1-4%) + + +Management: Combination of ampicillin (2 g every 6 hours) and gentamicin 3 mg/kg eve1y 8 hours for 5-7 days is given. For anaerobic coverage either Clindamycin or Metronidozole is administered. +Neonatal prognosis: Short term outcomes: Broncho pulmonary dysplasia, sepsis and intraventricular hemorrhage are more with preterm neonate. + + + +• Gram stain and culture to slow organisms, and growth of pathogens (gold standard); (C) Amniotic fluid glucose <10-15 mg/dL; (D) Amniotic fluid IL-6 > 7.9 ng/mL; (F) Amniotic fluid leukocyte esterase >1 + reaction (Table 22.1). + +Long-term outcomes: RDS, periventricular leukomalacia and cerebral palsy. Fetal inflammatory response syndrome (SIRS) is mainly due to excess production of cytokines. + + + +MENTAL HEALTH AND PSYCHIATRIC DISORDERS DURING PREGNANCY AND PUERPERIUM + + +In the first 3 months after delivery, the incidence of mental illness is high. Overall incidence is about 15-20%. +HIGH-RISK FACTORS FOR POSTPARTUM DEPRESSIVE DISORDERS (PPDD) +♦ Past history: Psychiatric illness, puerperal psychiatric illness. +♦ Family history: Major psychiatric illness, marital conflict, poor social situation. +♦ Present pregnancy: Young age, cesarean delivery, difficult labor, neonatal complications. +♦ Others: Unmet expectations (fetal loss). +♦ Postpartum Depression (PPD) most common complication of child birth. +Others: Unmet expectations (fetal loss, financial problems). +Diagnostic criteria for PPD: Depressed mood, sleep changes (insomnia), lack of energy, loss of interest, hopelessness, guilt. May change to Major Depressive Disorder (MDD) (Edinburgh Postnatal Depression Scale score ::13). +Pharmacotherapy is indicated if depression is moderate to severe (suicidal ideation). Selective Serotonin Reuptake Inhibitors (SSRls) are preferred in such a case. +■ Bipolar Affective Disorders (BPAD): It is a severe mood disorder characterized by periods of depression and periods of abnormally elevated mood. Genetic involvement is stronger in BPAD than MDD. Patients with confirmed or suspected BPAD should be referred to a psychiatrist for evolution. +■ Perinatal Mood and Anxiety Disorders (PMADs) are highly prevalent during pregnancy and postpartum period. +Treatment: SSRI and Cognitive Behavioral Therapy. Gabapentin can offer immediate relief. + + +■ Obsessive-Compulsive Disorder ( OCD) in pregnancy and puerperium +• OCD is not uncommon in pregnancy and postpartum period. +• Obsessions are repetitive, intrusive, less wanted thoughts and can be directed toward the fetus or the infant. Thoughts may be the fear of loss or death, fear of infections. Patient recognizes obsessions as irrational but unable to control them. Delusion is a false belief but the patient firmly believes it is true, despite the evidence to the contrary. +Treatment: Patient should be referred to psychiatrist evaluation. In such a situation temporary separation and nursing supervision are needed. +Pregnancy and puerperium in a woman with primary psychiatric disorders +11 Women with psychiatric disorders are at elevated risks of Cesarean Delivery (CD), placental abruption, preterm delivery, PPROM, hemorrhage, FGR, fetal distress and even fetal death. +■ For most medications plasma level will drop by 50% during pregnancy and will rise in puerperium. Dose adjustment is needed in pregnancy and puerperium. +■ Transfer of all psychotropic medications occurs through the placenta and the breast milk. Physicians must be conversant of the drug dose information with the latest version of recommendations and monitoring the women with serum level of the drug when needed. +Commonly used drugs are: +• SSRI: Escitalopram; sertraline, fluoxetine. +• Tricyclic antidepressants: Amitriptyline, imipra-mine, duloxetine. +• Antipsychotics: Olanzapine, lithium, carbamazepine. +Treatment: Psychotherapy is the preferred treatment option for mild to moderate episodes of anxiety or +Chapter 30: Abnormalities of the Puerperium + +depression. Antidepressant medication is started when the episode is considered severe. +■ Electroconvulsive Therapy (ECT) for ve1y severe cases of depression, or mixed states. +■ Psychological: Psychotherapy including Congenic Behavioral Therapy (CBT) and Interpersonal Psychotherapy (IPT) is for Mild/Moderate Perinatal Mood and Anxiety (PMAD). + +PSYCHOLOGICAL RESPONSE TO PERINATAL DEATHS AND MANAGEMENT + +Most perinatal events are joyful. But when a fetal or neonatal death occurs, special attention must be given + + + +to the grieving patient and her family. Perinatal grieving may also be due to unexpected hysterectomy, birth of a malformed or critically ill infant. Prolonged separation from a critically ill newborn can also provoke grief reaction. Physician, nurse and attending staff must understand the patient's reaction. The common maternal somatic symptoms are: insomnia, fatigue and sighing respirations, feeling of guilt, hostility and anger. +Management of perinatal grieving: Facilitating the grieving process with consolation, support and sympathy is important. Others are: supporting the couple in seeing or holding or taking photographs of the infant; autopsy requests, planning investigations, follow-up visit and plan for subsequent pregnancy. + + + + + +► The common causes of puerperal pyrexia are: (i) Puerperal sepsis, (ii) Urinary tract infection, (iii) Mastitis, (iv) Infection of the cesarean section wound, (v) Pulmonary infection, (vi) Septic thrombophlebitis, (vii) Recrudescence of malaria, tuberculosis or (viii) Unknown. +► The common causes of puerperal sepsis are the infections in the genital tract. This includes: (i) Endometritis, (ii) Endomyometritis, or (iii) Episiotomy wound infection. +► Pathogens commonly responsible for female genital infections are: (A) Aero bes (gram-positive-streptococci and staphylococci, gram­ negative-E. coli, Klebsiel/a or gram-variable-Gardnere//a). (B) Anaerobes (peptostreptococci, Fusobacterium, Clostridium) and (C) Others (Mycoplasma, Chlamydia). +► Common causes of subinvolution are: (a) Excess enlargement of the uterus (twins), (b) Anemia, (c) Retained bits of tissues, (d) Endometritis. +► Common breast complications in the puerperium are: (a) Breast engorgement, (b) Cracked and retracted nipple, (c) Mastitis and breast abscess. +► Puerperal emergencies are often immediate (third-stage complications). There may be some complications that are relatively delayed but acute and alarming. These are-(i) Mastitis and breast abscess, (ii) thromboembolism, (iii) Psychiatric disorders, and (iv) Postpartum cardiomyopathy. +► Workup for Women with Suspected Pulmonary Em bolus +► D-dimer, CXR, VUS, V/Q scan, CTPA are to be done depending upon individual woman's signs and symptoms. Woman with positive observation in VUS, CXR, V/Q scan and CTPA need therapy. Anticoagulation is started in the absence of contraindications. +► Risk factors for VTE are: (a) Previous VTE, (b) Heart disease, (c) SLE, (d) Surgical procedure (LSCS), (e) Obesity, (f) Immobility. +► Thromboprophylaxis against VTE for women with intermediate-risk and high-risk factors are: LMWH throughout pregnancy and postpartum 7 days to 6 weeks, respectively. + + +The Term Newborn Infant + + + + + + + + +CHAPTER OUTLINE +❖ Physical Features of the Newborn ❖ Immediate Care of the Newborn + + +❖ Infant Feeding +► Breastfeeding + + +► Artificial Feeding +► Childhood Immunization Program + + + + +DEFINITION: A healthy infant born at term (between 38 weeks and 42 weeks) should have an average birth weight for the country ( usually exceeds 2,500 g), cries immediately following birth, establishes independent rhythmic respiration and quickly adapts to the changed environment. +The weight is variable from country to country but usually exceeds 2,500 g. In India, the weight varies between 2.7 kg and 3.1 kg with a mean of 2.9 kg (Fig. 31.1). The length (crown to foot) is 50-52 cm. The length is a more reliable criterion of gestational age than the weight. Occipitofrontal circumference measures about 32-37 cm and the biparietal diameter measures about 9.5 cm. + +PHYSICAL FEATURES OF THE NEWBORN +The newborn must be examined thoroughly within 24 hours of birth. Before the actual examination, the important maternal and perinatal history should be reviewed. Maternal history ( age, parity, medical disorders, etc.), pregnancy problems-present + + +and past (drugs, IUFD, pre-eclampsia, IUGR, prematurity), labor and delivery history (duration, anesthesia, duration of PROM, Apgar score) should be obtained. Assessment of gestational age is done (Table 31.1). +A. Examination of vital signs: +a. Temperature is recorded and the site (e.g., rectal, oral or axillary) is mentioned. +b. Respiration: Normal, 30-60 breaths/min. May need screening with pulse oximetry (>95% and :;3% difference between right hand and foot). +c. Pulse: Normal, 100-160 beats per min (bpm) and when asleep, it is around 70-80 bpm. +d. Blood pressure: Normal range 45-60/25-40 mm Hg. BP is directly related to gestational age and birth weight of the infant. +B. General examination: +1. Skin color: It is the single most important parameter of cardiorespiratory function. +a. Pallor may be due to anemia, birth asphyxia, or shock. + + + + + + + + + + + + + + + + + + + +Fig. 31.1: A healthy term baby weighing 3.3 kg. +[l Chapte, 31 ,The Teem Newbom Infant +Table 31.1: Assessment of gestational age at birth. + +Character +Sole creases + + +<36weeks +1-2 transverse creases on anterior 1 /3rd of sole. + + +37-3Bweeks +Multiple creases on anterior 2/3rd of sole. + + +>39weeks +Entire sole covered with creases. + +Breast nodule 2mm. 4mm. 7mm. + +Scalp hair Ear lobe +Testes and scrotum + + +Fine, wooly, fuzzy. No cartilage. +Testes partially descended, scrotum small and few rugae. + + +Fine, wooly, fuzzy. +Moderate amount of cartilage. - + + +Coarse, silky. +Stiff earlobe, thick cartilage. +Testes fully descended, scrotum normal size, prominent rugae. + + + +b. Cyanosis: +♦ Cental cyanosis (bluish skin, including the tongue and lips) is caused by low oxygen saturation. It may be due to congenital heart or lung disease. Desaturation of hemoglobin should be >3-5 g/dL. +r +♦ Peripheral cyanosis (bluish skin with pink lips and tongue) may be due to drugs (nitrates or nitrites) or hereditary. It is often associated with +methemoglobinemia (hemoglobin oxidizes from ferrous to ferric form). +♦ Acrocyanosis (bluish hands and feet only) may be normal immediately following birth. It may be due to cold stress. +c. Plethora is commonly seen in infants with polycythemia. It may be seen in an overheated or over­ oxygenated infant. Hematocrit value may be done. +d. Jaundice: Bilirubin level >5 mg/ dL. +e. Extensive bruising may be due to difficult or traumatic delivery. +2. Skin rashes: +a. Milia seen on the nose, cheeks and forehead are due to plugged sweat glands. +b. Mongolian spots are bluish, often large, commonly seen on the back, buttocks or thighs. Usually present in Blacks and Asians (90%). They disappear by 4 years of age. +c. Erythema toxicum: These are papular lesions with an erythematous base. Commonly seen after 48 hours of birth. They resolve spontaneously. +d. Diaper rash usually the skinfolds are involved. It appears as erythematous plaques and the edges are well demarcated. It is a form of irritant contact dermatitis. It may be infected with Candida albicans. +3. Head: Fontanels: +a. Large fontanels are associated with hypothyroi­ dism, osteogenesis imperfecta or chromosomal anomalies (Down syndrome). Bulging fontanel may be due to increased intracranial pressure, meningitis or hydrocephalus. Depressed fontanels are seen with dehydration. A small fontanel may be due to hyperthyroidism, microcephaly or craniosynostosis. +b. Caput succedaneum should be differentiated from cephalhematoma. + +c. Molding seen with prolonged labor. Usually molding subsides within 5 days. +d. Cephalhematoma is due to subperiosteal hemorrhage resulting from a traumatic delivery. It never extends beyond the suture line. X-ray and CT scans should be taken to exclude skull fracture. Hematocrit and bilirubin levels should be estimated. Aspiration of hematoma is rarely needed as they often resolve in 4-6 weeks of time. +e. Raised intracranial pressure is diagnosed by the following signs: (i) Bulging anterior fontanel; (ii) Separation of suture lines; (iii) Paralysis of upward gaze; (iv) Prominent veins of the scalp. +Craniosynostosis is the premature closure of one or more of sutures of the skull. On palpation, a bony ridge is felt over the suture line and the cranial bones cannot be moved. X-ray studies of the skull should be done. +4. Neck: It is checked for movements, goiter, thyroglossal cysts, sternomastoid hematoma (sternomastoid tumor) or short neck, webbed neck (Turner's syndrome). +5. Face and mouth: Face is looked for hypertelorism (eyes widely separated) or low-set ears (trisomy 9, 18, triploidy) or facial nerve injury. Mouth is checked for clefts (palate, lips), natal teeth, lingual frenulum (tongue tie), macroglossia (Beckwith syndrome) or oral thrush. Thrush is treated with nystatin suspension. +6. Eyes are examined for congenital cataract, Brushfield's spots in the iris (Down's syndrome) or subconjunctival hemorrhage (traumatic delivery) and conjunctivitis. +7. Chest is examined for any asymmetry (tension pneumothorax), tachypnea, grunting, intercostal retractions (respiratory distress), pectus excavatum and the breath sounds. The newborn's breasts may be enlarged (normal 1 cm in diameter) due to maternal estrogen. The white discharge from nipple is common known as "Witch's milk''. +8. Heart is examined for rate (normal 120-160 bpm), rhythm, the quality of heart sounds and presence of any murmur. Murmurs may be associated with VSD, PDA, ASD, transposition of great vessels, tetralogy of Fallot, coarctation of aorta and others. Fetal echocardiography at 18-20 weeks of gestation can make the antenatal diagnosis in utero. Fetal cardiac intervention in utero is a new and promising method of treatment. +Chapter 31:TheTerm Newborn Infant ID + +9. Abdomen is examined for any defect, e.g., omphalocele, hepatomegaly (sepsis), splenomegaly (CMV, rubella infection) or any other mass. A scaphoid abdomen may be due to diaphragmatic hernia. +10. Umbilicus is examined for any discharge, redness or infection. A greenish-yellow colored cord suggests meconium staining (fetal distress). Single umbilical arte,y (more in twin births) indicates genetic (trisomy 18) and congenital anomalies (40%), and FGR. +11. Genitalia should be examined carefully before gender assignment. Male is examined for penis (normal >2 cm), testes within the scrotum, any hydrocele or hypospadias. Prepuce is normally long and phimosis is present. Female is examined for any clitorial enlargement (maternal drug), fused labia with clitorial enlargement (adrenal hyperplasia). Blood-stained vaginal discharge may be due to maternal estrogen withdrawal. Normally labia majora cover the labia minora and clitoris. +12. Anus and rectum are checked to rule out imperforation and their position. Meconium should be passed within 48 hours of birth. +13. Extremities, spine and joints are examined for syndactyly (fusion of digits), polydactyly, Simian crease (Down's syndrome), talipes equinovarus, hip dislocation ( Ortolani and Barlow maneuvers). +14. Nervous system is examined for any irritability, abno­ rmal muscle tone, reflexes, cranial and peripheral nerves (Erb's paralysi). Neurological development is dependent on gestational age. The reflexes including Moro reflex are present at birth. +15. Hematological findings: Blood volume soon after birth is about 80 mL/kg body weight if immediate cord clamping is carried out. RBC-6-8 million/cu mm, Hb%-18-20 g%, WBC-10,000-17,000/cu mm, platelets-3,50,000/cu mm, nucleated red cells 500/ cu mm, sedimentation rate is elevated. Clotting power may be poor because of deficient vitamin K which is necessary for the production of prothrombin from the liver. Reticulocyte count ranges from 3% to 7%. In a healthy term infant, hemoglobin values reach a nadir of 11 g/dL at 8-12 weeks of birth. This is known as physiological anemia of infancy. In preterm infants, the decline (7-9 g/dL) is more at 4-8 weeks. +REFLEX BEHAVIORS: +(A) Muscle tone: Hypotonia (floppiness) or hypertonia (increased resistance) is examined. +(B) Reflexes: +1. Rooting reflex: Stroke the corner of the cheek with a finger and the infant will turn in that direction and open her mouth. +2. Glabellar reflex: To tap gently over the forehead and the eyes will blink. +3. Grasp reflex (palmar grasp): Place a finger in the open palm of the infant's hand and the infant will grasp the finger. + +4. Moro reflex: The infant is supported from behind the upper back with one hand and then the baby is allowed to drop back l cm but not on the mattress. The baby will symmetrically abduct, extend the arms and fingers. This is followed by flexion and adduction of the arms. Asymmetry may signify a fractured clavicle, hemiparesis or brachia! plexus injury. An absent Moro reflex may signify CNS pathology. +5. Sucking and swallowing reflexes: A normal infant starts sucking when something (nipple and the areola) touches the palate. Baby swallows when the mouth is filled with milk. +(C) Gestational age (Table 31.1) + +IMMEDIATE CARE OF THE NEWBORN +♦ Care at birth ♦ Care in nursery CARE AT BIRTH: This has already been described on p. 131. +CARE IN NURSERY: +Admission in nurse1y: All healthy newborns are kept in the delive1y room with their mother to promote immediate breastfeeding and early bonding. Common indications for admission of the newborn in the nursery are: prematurity, respiratory distress, poor perfusion or presence of pallor or +cyanosis, malformation and need for 02 therapy. +Routine nursery care: The newborn is examined systematically and assessment of the gestational age is done. +Infant's weight, Pronto-occipital Circumference (FOC) and length are recorded. On these bases, the newborn is classified as Average for Gestational Age (AGA), Small for Gestational Age (SGA) or Large for Gestational Age (LGA). +The newborn must be kept under a neutral thermal condition. This is defined as the external temperature range where metabolic rate and oxygen consumption are at minimum. The normal skin temperature in the neonate is 36.0-36.5°C (96.8-97.7°F). Normal core (rectal) temperature is 36.5-37.5°C (97.7-99.5°F). Axillary temperature may be 0.5-l.0°C lower. +Mechanisms of heat loss are: (i) Radiation, (ii) Conduction from the infant to the surface in direct contact, (iii) Convection from the infant to the surrounding area, and (iv) Evaporation of water from the skin. +Consequences of excessive heat loss: (i) Compensatmy heat production through increase in metabolic rate, (ii) Insufficient oxygen supply ➔ Hypoxia ➔ Anaerobic metabolism, (iii) Hypoglycemia, (iv) Metabolic acidosis, (v) Apnea; and (vi) Pulmona1y hypertension. +Consequences of hypothermia are: (a) DIC, (b) Pulmonary hemorrhage, (c) Shock, (d) IVH, (e) Increased mortality. +The measures to prevent heat loss are: (i) Place the baby under a preheated (36.5°C) radiant warmer (servo­ control) immediately following delivery, (ii) Dry baby +L ··ID Chapter 31:TheTerm Newborn Infant + +immediately after birth, (iii) Cover baby (including the head) with a pre-warm towel, (iv) Put baby close to mother's breast (Kangaroo mother care), (v) Wrap the mother and baby together, and (vi) Commence early breastfeeding. +Kangaroo Mother Care (KMC) is the care for preterm and LBW infants. It includes: +a. Kangaroo position: Skin-to-skin contact between the mother and the infant in a vertical position. +b. Kangaroo nutrition: Exclusive breastfeeding. +c. Kangaroo discharge and follow-up: Early discharge from neonatal unit. +Benefits: Protects the baby against cold stress and hypothalamia and it increases milk production in mothers for exclusive breastfeeding. + +DAILY OBSERVATION AND CARE +Rooming-in: Soon after birth, if mother is fit, baby is kept in a cot by the bedside of mother. This establishes mother-child relationship. Mother also learns the art of baby care. +Baby bath: Routine bath is delayed until the baby is able to maintain the body temperature and has started breastfeeding. The excess vernix, blood or meconium are wiped off from the skin using sterile moist swabs and then make the skin dry by using a soft towel. The water for baby bath should be at body temperature (>97.5°F} and a separate bathtub should be earmarked for each baby. +Umbilical cord care: It is kept exposed to air and allowed to dry to promote early detachment. Topical antiseptics or antibiotics such as triple dye or neosporin powder may be applied to reduce bacterial colonization. +Routine medications: A single intramuscular dose +of 0.5-1 mg of vitamin K1 (phytonadione) is given to all newborns within 6 hours of birth. This prevents vitamin K +deficient bleeding. +Eyes are kept clean with cotton wool soaked with sterile normal saline as a prophylaxis against ophthalmia neonatorum (Chlamydia, Gonococcus). Erythromycin ointment (0.5%) bilaterally in the conjunctiva! sac or tetracycline (1%} ointment may be used. +Immunization and vaccines: Hepatitis B vaccine is given at birth. Other vaccine information is given to the parents. +Screening of the newborn: Commonly done screen­ ing tests are: (A) Glucose screening and detecting hypoglycemia, especially for infants of diabetic mothers, SGA and LGA infants; (B) Bilirubin screening; (C) Other metabolic screen depending on need (e.g., galactosemia). +Assessment of vital signs: Respiratory rate, heart rate, axillaiy temperature are recorded eve1y 6-8 hours in the baby's chart. Each of urine and stool output is recorded. Most of the newborns pass urine by 24 hours and meconium by 48 hours of life. Daily weights are recorded. + + +Weight loss in excess of 7% is often due to inadequate calorie intake. +Feedings: The frequency, duration and volume of each feed is important for newborn's growth and development. The infant should be put to breast as soon as possible after delive1y in the delive1y room. Feeding is allowed on demand (demand feeding). Usually, it is 8-12 times per day. +Discharge: Each infant is evaluated carefully to decide the optimal time of discharge. Considering the huge number of institutional deliveries in a developing country set up, early discharge of mother and infant may be done to avoid overcrowding in the postnatal ward and in the nurse1y. +The following infants may be discharged by 48 hours of age: Vaginal delivery, gestational age >38 weeks, singleton birth, birth weight-AGA, normal vital signs, passed urine and stool, initial immunization done, successful feedings and normal on physical examination. +Follow-up: Follow-up ofnewborns should be organized depending upon the risks of feeding problems, infections, hyperbilirubinemia or other issues. During follow-up, the newborn is assessed for weight, hydration, infection and for any new problem. Parental education and immunization schedule are discussed. +INFANT GROWTH ASSESSMENT: Serial measurement of weight, length and head circumference allow for evaluation of infant growth. +WEIGHT: There is weight loss of 7-10% in the first week of life. Weight gain generally begins by the second week. Average daily weight gain is 20-30 g/day. The infant should be weighed daily. +LENGTH: Normal weekly length gain is 0.8-1.0 cm for first 8-12 weeks. +HEAD CIRCUMFERENCE: Intrauterine growth is 0.5-0.8 cm/week. + +INFANT FEEDING +The rate of growth of the infants during the first 6 months of life is greater and faster than any other period of life. Its weight is doubled by the age of 5 months and tripled by the end of one year. Keeping this in mind, the baby should be nursed adequately (both quantitatively and qualitatively) which allows easy digestion and absorption. +NUTRITIONAL REQUIREMENTS IN THE NEONATE +■ The infant should get sufficient fluid: Fluid intake should be 150-175 mL/kg body weight per day. +■ The infant should get adequate calorie: A term healthy infant needs 100-110 kcal/kg of body weight per day. Low birth weight infant needs about 105-130 kcal/kg/day. Each 30 mL (1 oz) of breast milk gives 20 calories. Calorie needs are primarily dependent on oxygen consumption. + + +■ The food should have a balanced composition of protein (2-4 g/kg/ day), fat ( 4-6 g/kg/ day), carbo­ hydrate (10-15 g/kg/day), minerals and vitamins and it should be easily digestible. +TYPES OF FEEDING: +♦ Breastfeeding ♦ Artificial feeding +I BREASTFEEDING +The two vital considerations for the infants in tropical +countries are breastfeeding and avoidance of infection. Artificial feeding may be required in a ve1y rare situation, but where the mothers have an inadequate knowledge of the technical details of artificial feeding, gastroenteritis and malnutrition of the neonates are inevitable consequences. All the babies, regardless of the type of delive1y, should be given early and exclusive breastfeeding up to 6 months of age. Exclusive breastfeeding means giving nothing orally other than colostrum and breast milk. Medicines and vitamins are allowed. +Breastfeeding is the "Gold standard" for infant feeding. There are several areas of biological superiority of breastfeeding and breast milk over artificial (formula) milk. Obstetricians and midwives should educate the mother during prenatal and postnatal care for the usefulness of breastfeeding. +BABY-FRIENDLY HOSPITAL INITIATIVE: Baby-friendly hospital initiative with ten steps to successful breastfeeding (WHO/UNICEF 1992: Protecting, promoting and supporting breastfeeding). + +These are: (i) There must be a written breastfeeding policy; (ii) All healthcare staff must be trained to implement this policy; (iii) All pregnant women must be informed about the benefits of breastfeeding; (iv) Mothers should be helped to initiate breastfeeding within half an hour of birth; (v) Mothers are shown the best way to breastfeed; (vi) Unless medically indicated, the newborn should be given no food or drink other than breast milk; (vii) To practice 'rooming-in' by allowing mothers and babies to remain together 24 hours a day; (viii) To encourage demand breastfeeding; (ix) No artificial teats to babies should be given; and (x) Breastfeeding support groups are established and mothers are referred to them on discharge. + +A baby-friendly hospital should also provide other preventive health cares, e.g., infant immunization, rehydration salts against diarrheal dehydration and child's growth and development surveillance. +ADVANTAGES OF BREASTFEEDING +A. Composition: Breast milk is an ideal food with easy digestion and low osmotic load. +♦ Carbohydrate: Mainly lactose, stimulates growth of intestinal flora, produces organic acids needed for synthesis of vitamin B. + +Chapter 31:TheTerm Newborn Infant + +♦ Fat: Smaller fat globules, better emulsified and digested. +♦ Protein: Rich in lactalbumin and lactoglobulin, less in casein. +♦ Minerals: Low osmotic load (K+, Ca2+, Na+, c1-), less burden on the kidney. +B. Protection against infection and deficiency states: +1. Vitamin D promotes bone growth, protects the baby against rickets +2. Leukocytes, lactoperoxidase prevent growth of infective agents +3. Lysozyme, lactoferrin, interferon protect against infection +4. Long-chain omega-3 fatty acids essential for neurological development +5. Immunoglobulins IgA (secretory), IgM, IgG protect against infection +6. Supply of nutrients and vitamins. +C. Breast milk is a readily available food to the newborn at body temperature and without any cost. +D. Breastfeeding acts as a natural contraception to the mother. Criteria for LAM inculde: ■ Continuous amenorrhea; ■ Exclusive breastfeeding; ■ Night nursing. +E. Additional advantages are: (i) It has laxative action; (ii) No risk of allergy; (iii) Psychological benefit of mother-child bonding; (iv) Helps involution of the uterus; and (v) Lessens the incidence of sore buttocks, gastrointestinal infection and atopic eczema. The incidence of scurvy and rickets is significantly reduced. +Long-term risks of exclusive artificial (bottle) feeding: (a) Type I diabetes; (b) Sudden infant death; (c) Adult type 2 diabetes; (d) Childhood obesity; (e) Adult obesity; (f) Crohn's disease; (g) Ulcerative colitis; (h) Atopic dermatitis; and (i) Reduced Intelligence Quotient (IQ). + +PREPARATIONS FOR BREASTFEEDING: • Counseling for the need of early feeding ( 10/day), • No supplemental feeding, unless medically indicated. • To educate appropriate way to get the baby good latch on to the breast with comfortable position. • Massaging the breasts, expression of the colostrum and maintenance of cleanliness should be carried out during the last four weeks of pregnancy. + +MANAGEMENT OF BREASTFEEDING: The modern practice is to reduce nipple cleansing to a minimum and to wash the breasts once daily. A clean, soft, supporting brassiere should be worn. The mother should wash her hands prior to feeding. Mother and the baby should be in a comfortable position during feeding (Fig. 31.3). Frequent feedings, 8-12 feeds/24 hours are encouraged. +First feed: In the absence of anatomical or medical complications, a healthy baby is put to the breast +L.. Chapte,31,TheTe,m Newborn lofaot +t · . +. +I +! + + +I I + + + + + + + + + +Figs. 31.2A and B: Technique of breastfeeding: (A) Poor attachment; (Bl Good attachment. + + +immediately or at most 6 times) becomes scanty and high colored; and (5) Test feeding is the only reliable method of diagnosis (vide infra). +Management: The deficient amount of milk should be substituted by artificial milk. The required deficit of 24 hours as calculated from test feeding is to be divided by the number of feeds to be given in 24 hours. The amount of deficit for each feed, so calculated, should be given after each feed. As soon as sufficient milk comes to the breast, the supplementary feed is withdrawn. + +CARE OF THE BREASTS: Daily washing of the breasts with clean water is essential. The nipple should be cleaned with clean water before and after each feed. Brassieres are to be worn for support and comfort. + +FEEDING DIFFICULTIES DUE TO NIPPLE ABNORMALITIES Breast engorgement usually occurs on day 3-5 postpartum. There is copious milk production. Breasts are swollen and hard. There is dificulty to latch on for the infant. Treatment options are: (i) Gentle hand expression of milk to make the breasts soft so that the infant can latch on; (ii) Application of moist heat and cold compress to relieve edema; (iii) Gentle breast massage during feeding or milk expression; and (iv) Pain relief to reduce inflammation (ibuprofen). + +Long nipples may cause poor feeding due to improper latch on to the nipple without the areola. Mother has to help the baby to draw the areola also. +Short nipples usually cause no problem. Mother is reassured. +Inverted and flat nipples attachment to the breasts is possible and babies are able to feed adequately. In difficult cases, lactation is initiated by expression. Baby is then attached to breast as breast tissue becomes soft and protractile gradually. It can be corrected by suction with a syringe or breast pump. +Expression of breast milk or artificial removal of breast milk is not generally needed where breastfeeding is normal. The indications of expressing breast milk are: (i) Where +the baby is separated from the mother due to prematurity or illness; (ii) Where there are dificulties in breastfeeding as in attaching the baby to the breast, e.g., cleft palate; (iii) When the mother is separated from the baby because of work; and (iv) Colostrum should always be expressed and given to the babies if they cannot suck properly. +Methods of milk expression: (a) Breast milk expression is needed when mother and her baby are separated for a longer period (6-8 hours). The breast is massaged in a spiral fashion starting at the top and moving towards the areola. It is done in a comfortable environment. Mechanical, or electric breast pump is of help when breast feeding appears to be difficult or impossible. Breast pump may be helpful for flat or inverted nipples. It increases the level of prolactin that helps to maintain lactation for longer period. It can be practiced anywhere and costs nothing, (b) Breast pumps may be electrical or manual. +Donor breast milk: Historically, it has been used for centuries. Currently, its use is limited. Transmission of infection (HIV, CMV, hepatitis B, TB) is the concern for its safety. If the donor breast milk or milk banks are used, donor screening, pasteurization of milk and parental counseling are recommended. +Breast milk can be stored frozen at - 20°C for up to 6 +months, refrigerated at <4°C for 96 hours and at room temperature ( <25°C) for 4 hours. Fresh, unrefrigerated milk can be used within 4 hours of expression. Frozen milk should be thawed in a waterless warmer or in a container of tepid (not hot) water. Microwave thawing should not be done. +METHODS OF INITIATION OF LACTATION: The following methods may be employed with varying success to establish lactation after it has been temporarily withheld. +For the baby: (I) To discontinue bottle feedings; (2) To put the baby to the breast at frequent intervals; (3) Baby should suck in a well-attached manner. +For the mothers: (I) To encourage plenty of fluid (1 L extra) and milk intake; (2) Drugs like metoclopramide or oxytocin (nasal spray) are of help. +Chapter 31: The Term Newborn Infant ID· Table 31.3: Composition of human and cow milk. + + +Human +Cow milk + +Lactose (g/100 mL) 7 +4.5 + + +Fat (g/100 mL) 3.5 +3.5 + + +Protein (g/100 mL) 1.2 +3.4 + + +Sodium (mmo//L) Water 7 89 +22 88 + + +Calories (kcal/100 mL) 75 +67 + + + +I FORMULA MILK +When the infant is fed by any preparation other than human milk, it is called formula feeding. As artificial feeding is commonly accomplished by using a bottle, it is often called as bottle feeding. But an artificial feeding can be given without a bottle. +Indications +- Contraindications to breastfeeding either temporary or permanent (mentioned earlier). +- Changing lifestyle of women or pressurised under changed socioeconomic conditions (expressed breast milk may be an alternative). +FOOD USED: There is no perfect substitute for breast milk. Most formula milk products use cow milk or soyabean constituents as a substrate. Minerals, vitamins, proteins, carbohydrates and fats are added to pasteurized bovine milk for the nutritional needs. Palm or coconut based oils are added to make artificial formula milk appear creamy. Compared to human milk, formula milk has major differences in the validity of proteins, carbohydrates, minerals, vitamins and fats. Breast milk promotes optimal somatic growth, cognitive development and metabolic need. +Composition: The principal compositions of the breast milk and the cow milk are given in Table 31.3. +Qualitative differences between human and cow milk: The sugar in both is lactose. Breast milk is sweeter due to its high lactose concentration. The fat globules in cow milk are coarser and hence difficult to digest. The caseinogen (protein) in cow milk causes indigestion. Sodium content in cow milk is about four times higher. +Humanization of cow milk: It is indeed impossible to change the composition of the cow milk to that of human milk, no matter how the amounts of protein, fat, carbohydrate and minerals are altered. As such, so called humanization of the cow milk is an inappropriate usage. +• Quantitative changes in the constituents can be done by dilution followed by addition. One part of milk is added to one part of water. To bring about readjustment, about 4% of sugar and 2% of fat are to be added to the diluted cow milk. The sugar can be added as cane sugar or glucose in the proportion of a quarter of teaspoonful to each ounce of milk. The fat is added as cream (30-60%). However, in the tropical countries, addition of cream may be omitted. +• The qualitative alteration is principally directed to change in the caseinogen to make it easily digestible by boiling. + + +Sterilization: Sterilization of the milk should be done by boiling followed by rapid cooling or pasteurized by heating to 160°F (73°C) for 20 minutes followed by rapid cooling. +Container: Babies may be fed either by spoon from the bowl (katori) or by feeding bottle. It is easy to clean the former. The feeding bottle and the teat should be cleaned prior to and after each feeding. The rubber teat and the bottle should be boiled after each feeding. Spoon feeding is always preferred to bottle feeding to avoid nipple confusion. +PRINCIPLES TO FOLLOW IN BOTTLE FEEDING +♦ The baby is to be held in comfortable position during feeding. +• The hole of the teat should be of such size that 20-30 drops of milk are suckled by the baby per minute. +♦ Burping of the baby should be done in the middle and at the end of each feed. +♦ Not more than 20 minutes should be spent for each feed. +• All utensils, including the bottle and teat are to be cleaned before and after each feed and to be sterilized by boiling. +SUCCESSFUL FEEDING: The most satisfactory guide to successful feeding is the regular weight gain of the baby after 10 days which should be at the rate of 25-30 grams per day up to 3 months. If the baby fails to attain the weight gain evidenced by weekly weighing or appears unsatisfied, the feeding is to be increased until the baby gains weight. Figure 31.4 shows the normal weight chart. + +12 11 +10 ,- +/ +9 +8 Overweight - lJonlilal "' 7 ,,v _-- +- + +,-- +-- +v +Ol +.S +:c 6 +/ + 5 I/V +/ +/ +3 ,. Underwei@ht +2 +1 +0 0 1 2 3 4 5 6 7 8 9 10 11 12 Months +Fig. 31.4: Normal weight chart. +ID Chapter 31:TheTerm Newborn Infant + +WEANING: It is the process during which the baby gets accustomed to food other than its mother's milk. This period extends from 6th month to 1 year. The infant requires-110-125 calories/kg body weight per day and its fluid requirement is about 150-175 mL/kg body weight per day. During the period of 3-4 months, the baby may weigh as much as 5-5.5 kg and as such, its demand is more. The breast milk cannot supply the necessary baby's need and as such additional foods are required by 6 months of age. Semisolid foods such as rice, dal, boiled fish, egg are gradually incorporated in the tropical countries. These also prevent the baby from becoming anemic. Breastfeeding supports the development of neurological and immunological system up to 4-6 years of age. The dangers of the weaning period are: (a) Nutritional disturbances, (b) Weaning diarrhea due to altered composition of the food or contaminated with +[· : ' , ,. , ,. '. . . .... .. c<,o • . .., ... ··•,: At birth : BCG, OPV, Hepatitis B· 1 (BD). +"•Ja 11i.t.1• +. +. +.. ... +_ +• +• +• +6 weeks : DTwP/DTaP-1, IPV-1, Hib-1, Hep B-2, Rotavirus-1, PCV-1. +• +10 weeks : DTwP/DTaP-2, IPV-2, Hib-2, Hep B-3, Rotavirus-2, PCV-2. +• +14 weeks : DTwP/DTaP-3, IPV-3, Hib-3, Hep B-4, Rotavirus-3, PCV-3. +• 6 months Influenza (IIV)-1. 7 months : Influenza (IIV)-2. +• +• +• +• +6-9 months : Typhoid conjugate vaccine. 9 months : MMR-1 +12 months : Hepatitis A + +pathogens, and ( c) Psychological trauma to the baby when weaning is abrupt. + +CHILDHOOD IMMUNIZATION PROGRAM (BOX 31.1) + +Vaccines for high-risk children (under special circum­ stances) +1. Influenza vaccine +2. Meningococcal vaccine +3. Japanese encephalitis vaccine 4. Cholera vaccine +5. Rabies vaccine +6. Yellow fever vaccine +7. Pneumococcal Polysaccharide Vaccine (PPSV 23) + + +• BCG Bacillus Calmette- • DTwP: Diphtheria, Tetanus, Guerin . Whole cell Pertussis. +• Hep B: Hepatitis B • IPV Injectable Polio • DTaP Diphtheria, Tetanus, Vaccine. +Acellular Pertussis. • B, Booster 1 +• Hib Haemophilus • B2 Booster 2 +influenzae type B. • Td Tetanus, low dose • MMR Measles, Mumps, Diphtheria. +Rubella. • PCV Pneumococcal +• TdaP Tetanus, low dose Conjugate Vaccine. +Diphtheria, low dose • RV Rotavirus Vaccine. +Acellular Pertussis. +• OPV Oral Poliovirus Vaccine. + + +Comments: BCG: before discharge; OPV: as soon as possible after birth; Hep B should be administered within 24 hours of birth; DTwP or DTaP may be administered in primary immunization; IPV: 6-10-14 weeks is the recommended schedule. If IPV, as part of a hexavalent combination vaccine, is unaffordable, the infant should be sent to a government facility for primary immunization as per UIP schedule; RV1: 2-dose schedule, all other rotavirus brands: 3-dose schedule. An additional 4th dose of Hep B vaccine is safe and is permitted as a component of a combination vaccine. Uniform dose of 0.5 ml for DCGI approved brands. To be repeated every year, in pre-monsoon period, till 5 year of age. As of available date, there is no recommendation for a booster dose. Single dose for live attenuated vaccine. + +'£i1-mm +► Assessment of gestational age of a newborn at birth is done by careful clinical examination of: ear lobe, breast nodule, sole creases, scalp hair, and genitalia. +► Baby-friendly hospital initiative with ten steps is aimed to successful breastfeeding. +► Breastfeeding is the 'Gold standard' for infant feeding. Advantages to the newborn (better growth and neurodevelopment, less allergy, protection against infection) are many. +► Advantages of breastfeeding to the mother are: faster postpartum involution, less insulin resistance, less diabetes mellitus, less breast cancer, better infant-mother bonding and less cost. +► Contact with the breast within half to one hour of birth increases duration of breastfeeding. +► Correct position of nursing the infant and correct latch on are essential for efficient milk transfer. It also reduces breast pain and nipple injury. +► Childhood immunization is done according to IAP recommendations. +► Exclusive breastfeeding provides contraceptive protection in 98% of women up to 6 months after delivery. + + +Low Birth Weight Baby + + + + + + + + +. CHAPTER OUTLINE +❖ Preterm Baby +► Complications of a Preterm Neonate + + +► Management +► Care of a Preterm Neonate + + +❖ Fetal Growth Restriction (FGR) ► Management + + + + +Failure of a fetus to reach the optimum growth potential makes pregnancy a high risk one. Survival outcome of an infant depends both on the gestational age and birth weight. Fetal Growth Restriction (FGR) is the second leading cause of perinatal mortality next to prematurity. Overall perinatal mortality rates of FGR is as high as 120 per 1000 for all cases of FGR. Optimal fetal growth and development depends on: (A) Transfer of nutrients like glucose, amino acids and free fatty acids and (B) Oxygen delivery by the placental circulation for utilization of the nutrients. +Normal fetal growth involves sequential phases of cellular hyperplasia, hyperplasia and hypertrophy and finally cell hypertrophy. +Fetal growth dynamics when lead to reduced cell number, cell size or the both, IUGR is the outcome. +Growth has been classified by absolute birth weight {Fig. 32. I). +■ Low Birth Weight {LBW): • Very Low Birth Weight {VLBW); • Extremely Low Birth {ELBW). + +WEIGHT PERCENTILES +4600 "'•"",----,,-,----,,---,---,,-,-., Large for 4400 · : gestational 4200 ·. age + +3800 +· 1 +3600+r--t-t-++---t-t-++-+-t-+-z Appropriate +for +3400 +:t--t-t +- +++-+ +- +t-t +- +++ + +- +1ff:- +- +3200t-t--!-t-+-+-+-!-t-+-t-+,,-f- gestational +3000t----t-++-+-!-t-+--t. age + + + + + + +t"-t-+-1-t-+-+-+--t-+-+-;1 Small for +--+-+-1-+-!--+-+-1-+-!-+--l-l gestational +Term age + +0 313 6 37 383940 41 42 43 +Gestational age (week) +Fig. 32.1: Graph showing-correlation of birth weight and gestational age in percentile. + +■ Macrosomia +Currently birth weight has been classified in terms of small for gestational age (Table 32.1). +• Very Small for Gestational Age (VSGA). +• Small for Gestational Age (SGA). • Average Gestational Age (AGA). • Large for Gestational Age (LGA). +■ Preterm: Preterm Birth (PTB) is defined as the one when birth occurs before completion of 37 menstrual weeks of gestation regardless of birth weight. The growth potential may be normal and appropriate for the gestational period (10th to 90th percentile). +■ Small for Gestational Age {SGA): About 70% of infants with a birth weight below the 10th percentile are found normally grown. They are constitutionally small and not at any increased risk for adverse outcome. They present at the end of the normal spectrum for growth. The remaining 30% are truly growth restricted. These neonates are at increased risk for perinatal morbidity and mortality. The percentile cut-off values to define IUGR is a matter of debate. +The identification of these two distinct clinical entities is important from both prognostic and management points of view. + +INCIDENCE: The incidence of low birth weight is generally highest in those countries where the mean birth weight is low and as such varies from about + +Table 32.1: Fetal growth classifications. +Fetal growth classification based on birth weight +ELBW VLBW LBW Macrosomia <1000g <1500 g <2500 g >4000g Fetal growth according to birth weight percentile +VSGA SGA AGA LGA +<3rd <10th Between 10th >90th percentile percentile and 90th percentile +percentile +r-·= I +£ i- Chapter 32: Low Birth Weight Baby +5-40% of live births. In India, about one third of the infants weigh less than 2500 g. The factors influencing the low birth weight of the baby, apart from the preterm birth period, are socioeconomic status and intrauterine environment. Ethnic background and genetic control are also important. Thus, it is logical to correlate birth weight and gestational age with risks of neonatal morbidity and mortality of the individual countries or population groups. + + +PRETERM BABY +(Syn: Prematurity, Premature Baby) + +DEFINITION: A baby born before 37 completed weeks of gestation calculating from the first day of last menstrual period is arbitrarily defined as preterm baby. Babies born before 37 completed weeks usually weigh 2,500 g or less. However, in less than 5%, the babies may weigh more than 2,500 g even when born before 37 completed weeks. Preterm baby's weight corresponds to average weight (above 10th percentile) for its gestational age. +INCIDENCE: Preterm baby constitutes two-thirds of low birth weight babies. The incidence of low birth weight baby is about 30-40% in the low resource countries, as such the incidence of preterm baby is about 20-25%. In the high resource settings the incidence of preterm baby is less than 10%. + + + + + + + + + + + + + + +Fig. 32.2: Neonatal intensive care unit management of a preterm newborn weighing 1.1 kg. +Courtesy: Neonatal Care Unit-NRS Medical College and Hospital, Kolkata. + + +Plasma Biological Placental Mater- + + + +ETIOLOGY: Discussed in preterm labor (Ch. 22). + +Antenatal +corticosteroids + + +half-life +(minutes) + + +half-life +(hours) + + +transfer (%) + + +nal: fetal +ratio + + + +MANIFESTATIONS OF PREMATURITY: The clinical mani­ festations differ with the degree of prematurity. +Anatomical: The weight is 2,500 g or less and the length is usually less than 44 cm. The head and abdomen are relatively large; the skull bones are soft with wide sutures and posterior fontanel. The head circumference disproportionately exceeds that of the chest (Normally, the head circumference is greater than the chest circumference at birth and the difference is about 1.5 cm). Pinnae of ears are soft and flat. The eyes are kept closed {Fig. 32.2). +The skin is thin, red and shiny, due to lack of subcutaneous fat and covered by plentiful lanugo and vernix caseosa. Muscle tone is poor. Plantar deep creases are not visible before 34 weeks. The testicles are undescended; the labia minora are exposed because the labia majora are not in contact. There is a tendency of herniation. The nails are not grown right up to the finger tips (Table 31.1, p. 420). + +I COMPLICATIONS OF A PRETERM NEONATE +More preterm the infant is, higher the risk of disabili­ ties. Risk stratification of preterm infants according to gestational age are: <30 weeks-severe risk: between 30-32 weeks moderate risks and 33-34 weeks mild risks. Administration of antenatal corticosteroids ( <34 weeks) magnesium sulfate ( <32 weeks) showed improved outcome. + + +Dexamethasone 200-300 Long-acting 50 2:1 (36-54) +Betamethasone 300+ Long-acting 33 3:1 (36-54) + +Preterm infants are at risk of many complications due to immaturity of various organs and also for the cause of preterm birth. Late preterm infants {born between 34 and 37 weeks) though they appear equivalent to term infants, they have some short-term difficulties. +■ Asphyxia: The babies are often asphyxiated because of anatomical and functional immaturity. Even minor degree of anoxia may produce subserosal hemorrhages, especially in the heart, lungs and liver. In addition, it may produce intense congestion of the choroid plexus leading to Intraventricular Hemorrhage (IVH). +■ Hypothermia: A low birth weight baby has reduced subcutaneous as well as brown fat and increased surface area. Very often the newborn fails to maintain the thermoneutral range of temperature. +■ Pulmonary syndrome (23%): This includes: (a) Pulmonary edema; {b) Intra-alveolar hemorrhage; (c) Idiopathic Respiratory Distress Syndrome (RDS); {d) Bronchopulmonary dysplasia. The first two are +Chapter 32: Low Birth Weight Baby + +the effects of hypoxia; RDS is one of the major causes ■ Apnea and Sudden Infant Death Syndrome (SIDS) is of death in preterm babies born before 34 weeks. due to immaturity of the autonomic nervous system. The deficient lung surfactant is the principal factor The risks of bradycardia, apnea and SIDS are increased. +responsible for pulmonary atelectasis leading to ■ Retinopathy of prematurity is a multifactorial disorder hypoxia and acidosis. Surfactant therapy is effective in of the retina caused by abnormal neovascularization. reducing RDS. It is an important cause of blindness for the children +■ Development of the respiratory tract begins on day 22 under 6 years. The cause is mostly related to the and continues to form the trachea, lungs, bronchi, and liberal administration of high concentration of oxygen alveoli. It has five stages: Emb,yonic, Pseudoglandular, above 40% for a prolonged period (1-2 days) following Canalicular, Saccular, and Alveolar stage: • Embryonic birth. Persistent hypoxia is an important cause. The stage: 3-6 weeks;• Pseudoglandular stage: 5-17 weeks; blindness is due to the formation of an opaque • Canalicular stage: 16-25 weeks; • Saccular stage: 24 membrane behind the lens. +weeks to birth;• Alveolar stage: 36 weeks onwards. ■ Length of hospital stay: Increased length of hospital 11 Cerebral hemorrhage: The causes are: Soft skull stay, especially for the neonates who are early preterm +bones allow dangerous degree of moulding leading to ( <32 weeks). +subarachnoid hemorrhage. The severity of hemorrhage +PROGNOSIS: +The chance of survival is directly related +is assessed by neuroimaging studies, Cranial to the birth weight. A baby weighing more than 1500 g limited to germinal matrix; Grade-2: Intraventricular is most likely (95%) to survive. With intensive neonatal hemorrhage; Grade-3: Hemorrhage with ventricular is to the extent of 80%. With gestational age <23 weeks, mortality is >97%. The deaths are due to complications +Ultrasound (CUS) or MRI. Grade-I: Hemorrhage is +care, the survival rate of the baby weighing 751-1000 g +dilatation and Grade-4: Parenchymal damage. The +lesions with degeneration and cystic changes are +known as Periventricular Leukomalacia (PVL). This as mentioned (Table 32.2). Most of the deaths {two­ correlates with cerebral palsy. +thirds) occur within 48 hours. +11 Hypoglycemia (blood glucose <40 mg/dL) is observed LONG-TERM PROGNOSIS: Major handicaps (cerebral +in about 15% of infants due to lack of glycogen stores palsy), hearing loss, chronic lung disease and poor in the liver. Cold stress, hyperinsulinemia and poor growth are observed. Infants <2500 g are more likely to +feeding, are the other causes. suffer Attention Deficit Hyperactivity Disorder (ADHD) +{Table 32.2). +1. J/ea,:t.Jailu,:e-lt-may-be-precipitated-by-asphy.xia-wit,-------- --------------- +rapid development of pulmonary edema, which, in +turn, impairs pulmonary aeration. There may be patent Table 32.2: Complications of low birth weight infants. ductus arteriosus. System Early Longterm + +11 Oliguria, anuria: As the immature kidneys are unable to handle water, solute and acid loads. Normal urine output on D-2 is 1-2 mL/kg/h. After that it increases to 3.0-5.0 mL/kg/hr. +■ Infection: As the transfer of protective immunoglob­ ulins from the mother to a preterm baby is less, the incidence of infection is increased by 3-10 folds. +■ Jaundice: Because of hepatic immaturity, the bilirubin produced by the excessive hemolysis cannot be conjugated adequately. This leads to rise in unconjugated bilirubin which is responsible for exaggerated physiological jaundice. +■ Patent Ductus Arteriosus (PDA): Persistent PDA is inversely related to gestational age. Incidence of PDA is about 70% in infants with birth weight <1000 g. Overhydration should be avoided. +11 Dehydration and acidemia due to immature renal function may occur abruptly. +■ Anemia: Lack of stored iron, hypofunction of the bone marrow and excessive hemolysis all contribute to anemia. Blood transfusion is often needed in LBW +infants. + +■ Cardiac + + + +• Pulmonary + + +• Renal + + + +• Endocrino-logical + +■ CNS + + + + +■ Eye + + ++ Cardiogenic shock. + Hypotension. ++ PDA ++ Pulmonary hypertension. ++ RDS + HMD ++ Pulmonary hemorrhage. ++ Acute tubular necrosis. ++ Electrolyte imbalance. ++ Oliguria ++ Adrenal hemorrhage. + Cortisol deficiency. ++ Hypoglycemia. +IVH, Germinal Matrix Hemorrhage (GMH), PVL. + + +Retinopathy of prematurity. + + ++ Pulmonary hypertension. ++ Hypertension in adult life. + ++ Chronic lung disease. ♦ BPD + + ++ Hypertension in adult life. + + + ++ Increased insulin resistance. ++ Diabetes. ++ CP ++ Epilepsy. ++ Neurodevelopmental delay. ++ ADHD. ++ Blindness + Myopia ++ Strabismus +=ID Chapter 32: Low Birth Weight Baby +Very Preterm (VPT) babies (born before 32 weeks of gestational age) have special medical needs. These neonates run the higher risks of morbidities and mortality. Many of these neonates are saved with advanced neonatal care. An increased risk for long-term complications are: neurodevelopmental impairment, cerebral palsy, learning disabilities, visual and hearing impairments and attention deficit disorders. Furthermore these infants revealed reduced cognition and motor performances. +I MANAGEMENT +♦ Prevention of prematurity. +♦ Management of preterm labor. ♦ Care of preterm neonate. +The prevention of prematurity and the management of preterm labor have been discussed (p. 302). + +L _! RE OF A PRETERM --------- --IMMEDIATE MANAGEMENT FOLLOWING BIRTH +NEONATE +-- +♦ Delayed Cord Clamping (DCC) by at least 60 seconds. +♦ The cord length is kept long (about 8-10 cm) in case exchange transfusion is required. +♦ The air passage should be cleared of mucus promptly and gently using a mucus sucker. +♦ Adequate oxygenation through mask or nasal catheter in concentration not exceeding 35%. +♦ The baby should be wrapped, including head in a sterile warm towel (normal temperature 36.5-37.50C). Hypothermia and its sequelae: Hypoxia➔ Hypoglycemia➔ Anaerobic metabolism➔ Metabolic acidosis. +♦ Aqueous solution of vitamin K I mg is to be injected intramuscularly to prevent hemorrhagic manifestations. +INTENSIVE CARE PROTOCOL: Preterm babies are functionally immature and 'special care' is needed for their survival. Those requiring 'special care' are judged by: (i) Inability to suckle the breast and to swallow, (ii) Incapacity to regulate the temperature within limited range from 96-99°F (35.6-37 .2°C}, (iii) Inability to control the cardiorespiratory function without cyanotic attacks. +The principles of special care are: +- Delayed cord clamping (DCC) by 60 seconds has significant reduction in mortality for preterm infants. +- To maintain a relatively stable thermoneutral condition-keep delivery room warm, wrap the baby with a warm towel (plastic wrap), keep LBW neonate with mother-skin-to-sldn contact (Kangaro care). +- Adequate humidification to counterbalance increased insensible water loss. +- Oxygen therapy and respiratory support. - To prevent infection. +- To maintain nutrition and close monitoring. + + + +To maintain body temperature: As the premature babies are extremely thermolabile, they can easily develop hyperpyrexia or +hypothermia. The axillary temperature should be between36.0°C +and36.5°C. +The ELBW babies are best placed in prewarmed double­ walled incubators where temperature and humidity can be better stabilized. Alternatively, the baby could be managed under radiant warmer with protective plastic covers. The skin temperature should be maintained at36-36.5°C with surrounding humidity 80%. +Slow warming should be done for infants who become hypothermic. +Fluid, electrolyte balance and nutrition: Initially IV fluid dextrose solution is used to maintain blood glucose levels of >45-50 mg/dL. ELBW infants need more energy to protect against growth immaturity, hypothermia, anemia and infection. Daily requirement is 110-120 Kcal/kg/day. Parenteral Nutrition (PN) is needed in infants weighing <1500 g at birth. PN using a standard solution is given at the rate of 60 mL/kg/ day. It provides proteins, lipids and carbohydrates. +Respira tory support: Oxygen concentration is adjusted so as to keep saturation level of 90-95% for all babies <32 weeks. Many infants may need initial sup­ port with either Positive Pressure Ventilation (PPV} or Continuous Positive Airway Pressure (CPAP). The early use of CPAP with surfactant therapy in extremely preterm infants ( <32 weeks} reduces the risk of Bronchopulmo­ nary Dysplasia (BPD), atelectasis or death. +Indications of mechanical ventilation and surfactant +therapy are: (a) Rise in 02 need even after maximal +pressure (>8 cm H2O} with CPAP and (b) recurrent apnea. Surfactant therapy: For infants with RDS who are +ventilated with mean ailways pressure of at least 7 cm H2O and have an inspired oxygen concentration (FiO2} of >0.35. +The first dose is given as soon as possible after birth and intubation. However, CPAP is the initial therapy. +Caffeine citrate is used as prophylaxis, soon after +admission. Early (<2 days) caffeine therapy is associated with better neurodevelopmental outcome in infants born <30 weeks gestation. +Desirable level of arterial blood gas values should be: +(i) PaO2 55-65 mm Hg, (ii) PaCO2 35-45 mm Hg, and +(iii) pH 7.35-7.45 and pulse oximeter reading should be 90-95% oxygen saturation. +Hyperbilirubinemia: Serum bilirubin should be maintained <10 mg/dL. Infant may need phototherapy or exchange transfusion. +Ifection: The main sites of infection are respiratory tract, gastrointestinal tract, skin and the umbilicus. The incidence is as high as 70% in VLBW infants ( <1000 g). +Group B Streptococcus (GBS) is a common pathogen. In India, multidrug resistant, Acinetobacter baumannii and Klebsiella has fatality rate of 59%. Prophylactic antibiotic (ampicillin and amikacin) are commonly used pending culture results. +Chapter 32: Low Birth Weight Baby Im + +The common antibiotics used are ampicillin 100 mg/ kg per day and amikacin 10-15 mg/kg per day to be given intravenously in two divided doses for 5-7 days. GBS is an important pathogen. +Nutrition: Preterm infants are often unable to suck and swallow. Enteral feeding may be possible depending on gestation age and vigor. Babies may require gavage feeding or parenteral nutrition. Human milk is the first choice of nutrition for all low birth weight babies. Colostrum, foremilk, hindmilk and preterm milk help faster growth of the baby. +Commencement: Early feeding within ½-1 hour of birth is now widely recommended. It eliminates hypoglycemia, lowers serum bilirubin and neurological sequelae. +Intervals: Depending upon the birth weight, the interval of feeding ranges from hourly in extreme prematurity to 3 hourly feeds in babies born after 36 weeks. +Methods: The methods used depend on the size and vigor of the infant and his ability to suck and swallow. Thus, while a LBW infant with vigor can be put to the breast right from the beginning, the smaller one should be fed by any of the following methods: +♦ Tube (Gavage) +♦ Pipette, dropper, katori and spoon ♦ Bottle +♦ Intravenous +General guidelines are to start intravenous fluids to a baby weighing <1200 g ( <30 weeks) and gradually to initiate tube (gavage) feeding after 1-3 days and spoon after 2-4 weeks and thereafter breastfeeding after some more time. Baby weighing 1200-1800 g (30-34 weeks) may be started with tube feeding and gradually to move onto spoon and breastfeeding. Whereas babies weighing >1800 g (>34 weeks) generally have no dificulty to start with breastfeeding. +II Tube or Gavage: A fine polythene tube of about 0.5 mm internal diameter is used. It should be passed through the nose down to esophagus. Expressed breast milk is started with a small volume and is gradually built up. It may be safely continued for about 7 days. Calculated amount of fluid is delivered with a syringe by gravitation (gavage feeding). +II Pipette, droppe,; katori and spoon: This is used where the baby can swallow but fails to suck. +II Bottle: It is used when the baby can suck and swallow but cannot manage to express the milk out from the breast. +■ Intravenous fluid therapy: Neonates within the incubator or under radiant heaters have 10% increased fluid requirement to counterbalance the increased insensible water loss. +Fluid requirement varies from 60-80 mL/kg/day of 10% dextrose water or breast milk 10-20 mL/kg/day on first day and to increase by 15 mL/kg/day. Amount should be 10% more, if phototherapy is used. Monitoring of fluid is done by measuring + +body weight, urine output, its specific gravity and serum sodium level. +Calorie requirement: It is a paradox that the premature +infants require more calories than their mature counterpart because of relatively greater loss of heat from the body swface. The calorie intake of 60 calories per kg per day on 7th day is to be stepped up gradually to 100 on 14th day and about 120-150 on 21st day. +Food volume: To meet the calorie requirements, the amount of milk to be given is slowly but progressively increased. Requirement on 1st day is 80 mL/kg. Gradually increased by 15 mL/kg/day to reach 200 mL/kg/day by 8th to 10th day. This is expected to be achieved by 2 weeks. +Additional supplements: All premature babies should receive additional supplement of vitamins and minerals which should be started after 2 weeks. The daily requirement consists of vitamin A 2500 IU, vitamin D 400 JU, vitamin C 50 mg, folic +acid 65 1g and vitamin B1 0.5 mg. Supplementation of calcium and phosphate are also essential. In addition, iron supplement +should be given in the second or third week. A liquid preparation containing 2-4 mg/kg/day of elemental iron is given in two divided doses. Intravenous gamma globulin therapy (400 mg/kg/ dose) may be given to prevent infections in selected cases. For ve1y low birth weight ( <1200 g) babies parenteral nutrition with amino acids and lipids along with dextrose and multivitamins are given. The single most important factor is high standard of nursing. +FAVORABLE SIGNS OF PROGRESS: The following are the favorable signs: (1) The color of the skin remains pink all the time; (2) Smooth and regular breathing; (3) Increasing vigor evidenced by-(a) movements of the limbs, and (b) cry; ( 4) Progressive gain in weight. Baby loses 1-2% weight every day for the first 5-7 days. Thereafter, baby gains 1-1.5% of birth weight daily. Baby regains birth weight by 10-14 days. +WHEN TO DISCHARGE? The premature babies are discharged: (1) When they attain sufficient weight; (2) Attain good vigor; (3) Able to suckle the breast successfully. +ADVICES ON DISCHARGE: If possible, the supervision is to be continued at home by public health nurses or health visitors. Parental education is given for care of the baby at home. The following advices are given on discharge: +- Advice about feeding schedule. +- Prescribe a suitable multivitamin and oral iron preparation as mentioned earlier. +- To attend the well-baby clinic for subsequent check-up, immunization and guidance. +FOLLOW-UP VISIT: Assessment is done for infant's general health, weight, hydration and degree of jaundice. Immunization schedule is verified. Any new problem needs to be identified. Pattern of feeding and its adequacy are explored. Screening test, if any, to be done. Guidance for infant care is given to the mother. +ml Chapter 32: Low Birth Weight Baby + +FETAL GROWTH RESTRICTION (FGR) Syn: Intrauterine Growth Restriction (IUGR), +chronic placental insufficiency DEFINITION: FGR is a syndrome where fetus @. !] + •f + --.!j +fails to reach its growth potential due to several underlying disorders related to maternal, fetal +l +or placental. Small for Gestational Age (SGA) !J:\ .,.ii is defined as an estimated fetal weight below the 10th per­ centile for the gestational age. ■ Fetal Growth Restriction (FGR) is defined on a combination of measures of fetal +size percentile and Doppler abnormalities. FGR may be with early onset (<32 weeks) or late onset (z:32 weeks). Growth restriction can occur in preterm, term or post­ term babies. Fetal weight estimation: Hadlock (based on HC, AC and FL) equation is used. +INCIDENCE: FGR comprises about one-third of low birth weight babies. In high income group countries, its overall incidence is about 2-8%. The incidence among the term babies is about 5% and that among the post-term babies is about 15%. +NOMENCLATURE: SGA fetuses constitute 70% of the babies with birth weight <10th centile. These fetuses fulfill the growth potential and are not growth restricted. They are constitutionally small but otherwise normal. They have no increased obstetric or neonatal risks. They grow parallel to the lower centile throughout the pregnancy. These babies are small due to constitutional reasons and said as 'small mother small baby'. On the other hand, early onset of pathological cessation of growth may produce a baby with typical features ofFGR. Sonographic Estimated Fetal Weight (SEFW) is determined (population specific) and the cut off value <10 percentile is more appropriate to define the FGR. This group (30%) is of higher perinatal risk. +TYPES: Based on the clinical evaluation and ultrasound examination, the small fetuses are divided into: +1. Fetuses who are small and healthy. The birth weight is less than 10th centile for their gestational age. They are small for gestational age. They have normal + + +Table 32.3: Features of early onset and late onset growth restricted fetuses. +Early onset: 20% Late onset: 80% +Uniformly small Head larger than abdomen. +Pondera! index (birth weight/Crown-heel Low length3)-normal. +HC:AC and Elevated. FL: AC ratios-normal. +Etiology: Chronic placental ■ Genetic syndromes (5%), aneuploidy, insufficiency- +triploidy, trisomy 13, 18. extrinsic to fetus, +■ Infection-intrinsic to fetus. constilunally small. ■ Early onset severe hypertension. +Definition for fetal growth restriction +Early-onset FGR (<32 weeks) Late-onset FGR (!:32 weeks) +■ EFW or AC <3rd percentile. • EFW or AC <3rd percentile OR OR +UA with AREDV. ■ !:2 of the following three OR criteria: \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_14.txt b/notes/DC Dutta Obstetrics 10th Edition_14.txt new file mode 100644 index 0000000000000000000000000000000000000000..7472cc27d01adf29e405012ff322449d9e565b9c --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_14.txt @@ -0,0 +1,2027 @@ +■ EFW or AC <10th percentile, a. EFW or AC <10th +combined with one or more of percentile. +the following: b. EFW or AC crossing +a. UA Pl >95th percentile percentiles; > 2 quartiles b. UtA Pl >95th percentile +on growth percentiles. +c. CPR <5th percentile or +(EFW: estimated fetal weight) UA Pl >95th percentile. +FIG0-2021 + +(AERDV: Absent End Diastolic Velocity; UA: Umbilical Artery; UtA: Uterine Artery) + + +Ponderal index, normal subcutaneous fat and usually have uneventful neonatal course. +2. Fetuses whose growth is restricted by pathological process (true FGR). Depending upon the time of onset, relative size of their head, abdomen and femur, the fetuses are subdivided into: (a) Early onset or symmet­ rical, or (b) Late onset or asymmetrical (Fig. 32.3 and Table 32.3). +Early onset (symmetrical) 20%: The fetus is affected from +the noxious effect very early in the phase of cellular hyperplasia. +The total cell number is less. This form of growth restriction is + + + + + + + + + + + + + + +Fig. 32.3: Pregnancy complicated with chronic hypertension, delivered by CS at 38 weeks. The baby weighed 1.9 kg with features of asymmetrical FGR. Physical features (wrinkled skin, scaphoid abdomen, head circumference > abdominal circumference) give the baby an "old-man look''. +Chapter 32: Low Birth Weight Baby lmL -- + +most often caused by structural or chromosomal abnormalities or congenital infection (TORCH) or early onset severe hypertension. The pathological process is intrinsic to the fetus and involves all the organs including the head (Table 32.3). +Late onset (asymmetrical) 80%: The fetus is affected in later months during the phase of cellular hypertrophy. The total cell number remains the same but size is smaller than normal. The pathological processes that too often result in asymmetric growth retardation, are maternal diseases extrinsic to the fetus. These diseases alter the fetal size by reducing uteroplacental blood flow or by restricting the oxygen and nutrient transfer or by reducing the placental size. + +ETIOLOGY: The causes of fetal growth restriction can be divided into four groups: + +■ Maternal ■ Fetal 11 Placental ■ Unknown + +■ Maternal factors: +• Constitutional: Small women, slim, maternal genetic and racial background. +■ Others: • Age >40 years; • Maternal BMI ( <20 or >35}; • IVF singleton pregnancy; • Nullipar­ ity; • Poor weight gain during pregnancy; • Anemia, malnutrition; • Hypoxemia (lung disease}; • Smok­ ing, alcohol, drugs; • Previous pre-eclampsia, SGA, stillbirth; • Pregnancy interval <6 or 60 months. +■ Placental factors: • Poor uterine blood flow (maternal vascular malperfusion; • Infarction (5%}, abruption, mosaicism; • Diabetes with vascular disease; • Antiphospholipid syndrome; • Placental inflammation ( villitis). +11 Umbilical cord factors: • Increased cord length; • Single umbilical artery; • Velamentous cord inser­ tion; • Cord knot (true). +11 Fetal factors: +• Genetic (chromosomal, aneuploidy, microdeletion duplications, single site mutations. +• Structural anomalies +• Congenital infection (CMY, TORCH} • Terato gen exposure (drugs) +• Multiple pregnancy +■ Toxins: Alcohol, smoking, cocaine, heroin, drugs. 11 Unknown ( 40%) +Predictivefactorsfor FGR: +A. Maternal: • Elderly (>35 years) • Underweight • Severe anemia, hemoglobinopathies. +B. Medical: Hypertension, SLE, IBS, APLS, DM (long standing), CKD. +C. Obstetric: Previous pregnancy affected by FGR, pre-eclampsia D. Biochemical markers: +• Low PLGF; • Low PAPPA; • High APP +E. USG based markers: +• UtA: PI >95 percentile; • UtA notching (bilateral); +• Single umbilical arte1y; • Velamentous cord insertion; • Abnormal placental morphology. + + +F. Summary of risk factors at booking assessment (first trimester): Minor riskfactors: Maternal age 35 years; IVF singleton pregnancy; Nulliparity; BMI <20 or >35; Previous pre-eclampsia; Pregnancy interval <6 or >60 months. Major riskfactors: Maternal age >40 years; Paternal SGA; Previous SGA baby; Previous stillbirth; Maternal SGA; Chronic hypertension; Diabetes with vascular disease; Renal impairment; Antiphospholipid syndrome; Heavy bleeding similar to menses and PAPP-A <0.4 MoM. +Pathophysiology: Basic pathology in small for gestational age is due to reduced availability of nutrients in the mother or its reduced transfer by the placenta to the fetus. It may also be due to reduced utilization by the fetus. Brain cell size as well as cell numbers are reduced. Liver glycogen content is reduced. There is oligohydramnios as the renal and pulmona1y contribution to amniotic fluid is diminished due to reduction in blood flow to these organs. The SGAfetus is at risk of intrauterine hypoxia and acidosis, which, if severe, may lead to intrauterine fetal death. + +PREDICTION AND DIAGNOSIS: Significant improvements have been made by clinical and biophysical methods in prediction (see above) and diagnosis of a growth restricted fetus. + +CLINICAL: +Detailed history for the risk factors: +■ Clinical palpation of the uterus for the fundal height, liquor volume and fetal mass may be used for screening. It is simple, safe and inexpensive. But it is less sensitive. +11 Symphysis Fundal Height (SFH} measurement in centimeters closely correlates with gestational age after 24 weeks. A lag of 3 cm or more suggests growth restriction. It is a fairly sensitive parameter (30-85%). Serial measurement is important. +■ Maternal weight gain remains stationary or, at times, falling during the second-half of pregnancy. +■ Measurement of the abdominal girth showing statio­ nary or falling values. +Biophysical: 11 USG examination is done to confirm the clinical evaluation of gestational age. USG is extremely useful for structural anomalies, soft markers and related infections (CMV, rubella, toxoplasma). Sonographic predictive values that are commonly used are: +♦ Head Circumference (HC) and Abdominal Circumference (AC) ratios: In a normally growing fetus the HC/ AC ratio exceeds 1.0 before 32 weeks. It is approximately 1.0 at 32 to 34 weeks. After 34 weeks, it falls below 1.0. If the fetus is affected by asymmetric FGR, the HC remains larger. The HC/ AC is then elevated. In symmetric FGR, both the HC and AC are reduced. The HC/ AC ratio remains normal. Using HC/ AC ratio, 85% of FGR fetuses are detected. Transcerebellar diameter correlates well with the gestational age. +♦ AC is the single most sensitive parameter to detect FGR (Fig. 42.51A). Serial measurements of AC and estimation of fetal weight are more diagnostic to fetal growth restriction. +Im Chapter 32: Low Birth Weight Baby + +♦ Femur Length (FL) is not affected in asymmetric FGR. The FL/AC ratio is 22 at all gestational ages from 21 weeks to term. FL/AC ratio greater than 23.5 suggests FGR. +♦ Amniotic fluid volume: Amniotic fluid pocket 32 weeks). Decision for early delive1y may increase the risk of neonatal deaths due to complications, on the other hand, delay in delivery may increase the risk of IUFD. +General: At present, there is no proven therapy for preventing growth restriction once it is established. However, the following may be tried with some success: +1. Rest, especially in left lateral position; +2. Improve nutritional status by balanced diet: 300 extra calories per day are to be taken; +3. To institute appropriate therapy for the associated complicating factors likely to produce growth restriction; +4. Avoidance of smoking, tobacco and alcohol; +5. Maternal hyperoxygenation at the rate of 2.5 L/min by nasal prong, for short-term prolongation of pregnancy; +6. Low-dose aspirin (75-150 mg daily) since 12 weeks may be helpful in very selected cases with history of + +thrombotic disease, hypertension, pre-eclampsia, or recurrent FGR; +7. Maternal hyperalimentation by amino acids can improve fetal growth if it was due to maternal malnutri­ tion. Maternal hyperalimentation is only helpful when IUGR is due maternal malnutrition. It is not helpful when placental function is deficient; +8. Maternal circulatory volume expansion may be helpful in improving placental perfusion. +Antepartum evaluation: Serial evaluations of fetal growth and assessment of wellbeing should be done once the diagnosis is made (Flowchart 32.1). +■ Ultrasound examination should be done at an interval +of 1-2 weeks for the assessment of BPD, HC/AC, fetal weight and AFI for high risk fetus (based on history, biochemistry, UtA Doppler or single SFH measurement <10th centile or serial measurements indicative of FGR). +■ Fetal wellbeing is assessed by • Kick count, • NST, • Biophysical profile, • Amniotic fluid volume • Monitoring • CTG • Monitoring frequency: CTG/ NST twice weekly. +11 Doppler ultrasound parameters are to be studied. +At present, there is no effective treatment to improve FGR. There is no proven treatment for FGR. Phosphodiesterase type-5 inhibitors (sildenafil citrate) was used to release NO for vasodilatation. It did not improve the result. Vascular Endothelial Growth Factor, gene therapy is underway for improving local vasodilatation and angiogenesis. Timing of delivery is a critical issue. This is to balance the risk of prematurity against the risk of continued pregnancy. Unless carefully judged, continued pregnancy may end in IUFD or organ damage due to hypoxia. +TIMING OF DELIVERY: The factors to be considered are: (1) Presence of fetal abnormality; (2) Duration of pregnancy; (3) Onset ofFGR; (4) Associated complicating factor; (5) Underlying pathology (if known); (6) Results of antenatal fetal surveillance; and (7) Availability of neonatal intensive care unit (NICU). +Optimum time of delivery for a growth-restricted fetus may be between 34 weeks and 37 weeks depending upon the presence of any additional risk factor(s) (e.g., oligohydramnios, pre-eclampsia, abnormal Doppler study). +■ Pregnancy near to 37 weeks-uncomplicated mild FGR: Fortunately, the majority fall in this group. Usual treatment as outlined above to improve the placental function may be employed. Pregnancy is continued at least 37 weeks. Thereafter delivery is done. +■ Cases with mild SGA (estimated fetal weight: 3rd to 9th percentile) with normal Doppler studies: ➔ Delivery by +·Im Chapter 32: Low Birth Weight Baby +Flowchart 32.1: Management protocol for fetal growth restriction (FGR). + + + + + + + + + +>­ +J: +0. +<( +:: +!) +0 +z + +0 J) + +I CLINICAL EVALUATION I +• Antenatal assessment of risk factors (age >35 years, oligohydramnios, hypertension, renal disease) +• SFH: Measurement at each antenatal visit after 24 weeks • A discrepancy of >3 cm (in the absence of obesity, multiple +pregnancy, fibroid uterus) or single SFH <10th centile +i +USG diagnosis +-A Fetal biometry(• BPD • HC • AC • FL). +-A Single OR EFW, AC <10th centile. +-A Serial measurements indicative of FGR. Medical management ++ Increased rest. + Folic acid. +■ To exclude congenital anomalies, genetic + Increased fluid intake. +syndromes and infections + Low-dose aspirin (selective). +■ To treat underlying pathology (if known) + To treat underlying pathology(if any). ! +Fetal surveillance + +Management summary of FGR based on Doppler study: ++ ·Early onset FGR cases are more difficult in management compared to late oriset FGR. ++ UA Doppler is the only parameter that provides both diagnostic and prognostic information in the management. +-♦ Once FGR (estimated fetal weight <10th centile) is identified, UA.PI, MCA ■ DFMCR, • CTG, NST Pl, CPR should be measured. Stages(severity) of hypoxia can be determined +■ BPP • Amniotic fluid liy ch_anges with the UA and. DV Doppler +. +volume(DVP) • Uterine Artery Doppler Pl (UtA Pl) when abnormal, one can predict poor outcome in a growth restricted fetus. +• Progression of UA Doppler patterns from reduced to absent and further to reversed end-diastolic flow, correlates with worsening severity of fetal hypoxia and acidosis, ending with fetal death (Box 32.1). +· .♦ Growth-restricted fetuses with EFW <3rd centile, have much higher risk of adverse perinatal outcome compared to fetuses with EFW <10th centile. +• Ductus Venosus (DV) Doppler is strongest single parameter to predict fetal acidemia when there is absent or reversed flow velocities. With this, +Timing of delivery +· delivery is recommended at any gestational age after completion of corticosteroid therapy. +<37 weeks 37 weeks➔ delivery ♦ All Doppler signs should be confirmed at least twice at 12 hours apart. -- + +------------------ +------ +-- +! + +if Umbilical Artery (UA), u Doppler Study +­ +c +i +Repeat study at +(Pl/RI > +2 SD) +:, +i +. + interval of 10-14 days End -dIastolIc ve oc1ty (EDV) +. +I . +:: * + • USG (AC, EFW) (10-14 days] Present EDV Absent or reversed EDV Absent or reversed +o. + + +• Doppler (UA, MCA, CPR, DV) (AREDV) (AREDV) +! +Normal +l +c Repeat study + abnormal +• USG (AC, EFW) weekly Doppler study DV Doppler +• Doppler study: Twice weekly • UA • MCA • CPR • DV (Daily) (DV A-wave: +l +(UA, MCA, CPR, DV) Absent/reversed) +Delivery by 37-39 weeks +I +Persistent Persistent lPresent + +Delivery by 34 /7 weeks Delivery by 30°" weeks 26-30 weeks +Delivery by +1 1 +! +• TO ADMINISTER CORTICOSTEROID BEFORE • Mgso. WHEN <32 WEEKS • AVAILABILITY OF NICU FACILITIES PRETERM (<34 WEEKS) DELIV ERY +(SEFW: Sonographic Estimated Fetal Weight) + + +?:37 weeks. Until then monitoring to be continued with CTG, NST, BPP (fortnightly) or by Doppler, +■ Cases with FGR with early Doppler changes/or with oligohydramnios, P ➔ delivery by 34-37 weeks: until this continued monitoring with CTG, NST, BPP (weekly) and UA Doppler (twice weekly). +E +■ FGR with UA, AEDV with abnormal CTG, NST, EPP (Box 32.1) delivery➔ by 32 weeks. +11 Cases of FGR with UA REDV; ➔ Delivery by 30 weeks. ■ Cases of FGR with abnormal DV ➔ Doppler: delivery +by 26-30 weeks (Box 32.1). +■ Administration of antenatal corticosteroid in FGR to be used. +11 Absolute indications for delivery: Irrespective of gestational age are: CTG/NST abnormalities: Reduced variability, repetitive late deceleration, severe PE with end-organ damage. +11 When delivery is to be done before 32 weeks, magnesium sulfate should be given (additional) to the mother for fetal and neonatal neuroprotection. + +Chapter 32: Low Birth Weight Baby - ., + + + +Fetal circulation: +■ UA : !-EDV (UA Pl f) (fetal hypoxia) 1, +■ MCA: fDiastolic flow (MCA Pl l-) 1, +Hypoxic response: Blood flow redistribution -1, +■ UA : Absent flow (AEDFV) 1, +o MCA: fPSV 1, +II UA Reverse flow (fetal hypoxia) 1, +II DV Absent/Reversed flow (hypoxia/acidemia) 1, +■ UV Pulsatile flow (acidemia) +(UA: Umbilical Artery; MCA: Middle Cerebral Artery; DV: Ductus Venosus; +UV: Umbilical Vein; AEDFV: Absent End Diastolic Flow Velocity) + + + +11 Fetuses with aneuploidy or congenital infection have poor outcome irrespective of gestational age and timing of delivery. +Mode of delivery: FGR alone is not an indication of Cesarean Delivery (CD). 11 Indications for CD are: (a) Early onset FGR, (b) with UA, AEDV, REDV or changes in DVand (c) abnormal CTG, NST, BPE +11 Delivery should be in centers with intensive neonatal care facilities. +11 Low rupture of the membranes followed by oxytocin is employed in cases with pregnancy beyond 34 weeks with favorable cervix and the head is deep in the pelvis. +■ Placenta should be sent histopathological examination for counseling the future pregnancies. + +IMMEDIATE CARE OF THE BABY AFTER BIRTH +■ A pediatrician should be present at the time of delivery. +■ The same precautions as outlined in the preterm delivery are to be taken to prevent the complications. +Intensive care protocols: Special precaution is to be taken to prevent and treat complications (p. 421). +POSTPARTUM FOLLOW UP AND COUNSELLING FOR FUTURE PREGNANCIES: To educate women about the preventive strategies to decrease the risk in future pregnancy. Infant follow up, counseling the woman regarding the importance of diet, weight, cessation of smoking, use of aspirin, monitoring of BP and fetal growth during the next pregnancy. + + + + +► A low birth weight infant is one whose birth weight is less than 2500 g irrespective of gestational age. It is a major cause of perinatal morbidity and mortality (Table 32.2). +► Fetal Growth Restriction (FGR) is defined when baby's birth weight is below the 10th percentile of the average for gestational age FGR is a major cause of perinatal morbidity and mortality. +► Etiology of FGR is many. Symmetrical (early onset) FGR infants face more complications and have got poor prognosis compared to asymmetrical (late onset) ones. +► Serial measurement of Symphysis Fundal Height (SFH) should be done at each antenatal visit from 24 weeks onwards. It can predict the FGR well. +► When SFH revealed slow or static fetal growth, the woman should have ultrasound evaluation of fetal growth. USG diagnosis of FGR is made from four biometric measures: (1) BPD, (2) HC, (3) AC, and (4) FL. The estimated fetal weight can be derived from these va I ues. +► When sonographic estimated fetal weight is <10th centile (FGR), fetal genetic syndrome (aneuploidy), infections and placental insufficiency are to be ruled out. +► The terms FGR and SGA used interchangeably to define small fetuses whose birth weight is below the 10th centile. FGR indicates a pathologically small fetus whereas SGA indicates a fetus below the specific cut-off value but otherwise normal. +► Further evaluation for FGR is done with UA and MCA Doppler and the CPR. Normal study report with all these parameters, even on repeat examination after 14 days, suggests a SGA (constitutionally small) fetus. +Contd... +!1 Chapter 32: Low Birth Weight Baby Contd... +·1 +► Amniotic fluid volume assessment should be done measuring the Single Deepest Vertical Pocket. +► With ultrasound evidence of FGR, the woman should be referred to a fetal medicine unit for fetal anatomy survey and uterine artery Doppler study. Serological screening may be done when congenital infection is suspected +► Antiplatelet agent (aspirin) is given in cases with pre-eclampsia or high-risk factors. +► Management of FGR depends on its time of onset, severity and duration of pregnancy. Serial assessment of fetal growth and surveillance is needed. Timing of delivery is based on the fetal surveillance of fetal hypoxia and acidemia. +► In high-risk women, use of Umbilical Artery Doppler Velocity (UADV) study is the primary surveillance tool for a growth restricted fetus (RCOG). It reduces perinatal morbidity and mortality. +► When UADV indices are abnormal (Pl or RI >2 SDs above the mean for gestational age) ➔ Repeat surveillance is done. +► A growth-restricted fetus is previable when delivery is done before 28 weeks of gestation. Interventions need to be undertaken in consideration with maternal health (severe pre-eclampsia). +► Optimum time for delivery for a woman with FGR is between 34 and 37 weeks. +► Presence of recurrent late decelerations in CTG, oligohydramnios, BPP score <6 and reversal of DV Doppler A-wave, suggest maximum risk of fetal acidemia and death. +► Woman with FGR showing AREDV in the umbilical artery-needs to be delivered (cesarean section). Absolute indications of delivery are: CTG/NST abnormalities and abnormal DV Doppler. +► Delivery for FGR should be organized in a center with NICU facilities. +► The neonatal morbidities in FGR are: Birth asphyxia, meconium aspiration, hypothermia and others. ► FGR can cause short-term as well as long-term morbidities (Table 32.2). +► No single parameter is of absolute value to assess the severity of fetal hypoxemia and acidemia. Multiple parameters are involved as below: +(a) CTG: Repetitive late decelerations +(b) USG: Olighydromnios is studied to make the decision of delivery +(c) BPP score <6. (d) DV Doppler >3 SDs with reversal of DV A-wave. (e) Reversed/absent UA Doppler velocity. +► Doppler changes in fetal circulation are directly correlated with progressive fetal hypoxia and acidemia. + +- + + + + + +C H A P T E R !11:•: +'! +J + +Diseases of the Fetus and the Newborn + + + +CHAPTER OUTLINE . !] . ": ❖ Perinatal Asphyxia +► Fetal Respiration ► Clinical Features ► Management +❖ Respiratory Distress in the Newborn ► Idiopathic Respiratory Distress +Syndrome +❖ Transient Tachypnea of the Newborn (TTN) +❖ Meconium Aspiration Syndrome (MAS) +❖ Jaundice of the Newborn + + +► Management of Jaundice in the Newborn +❖ Hemolytic Disease of the Newborn ► ABO Group Incompatibility +❖ Bleeding Disorders in the Newborn +❖ Anemia in the Newborn ❖ Seizures in the Newborn +❖ Birth Injuries of the Newborn ► Injuries to the Head +► lntracranial Hemorrhage ► Other Injuries + + +❖ Perinatal Infections ► Modes of Infection +► Ophthalmia Neonatorum ► Skin Infections +► Necrotizing Enterocolitis +► Mucocutaneous Candidiasis ❖ Congenital Malformations and +Prenatal Diagnosis +► Down's Syndrome (Trisomy 21) ❖ Surgical Emergencies +❖ Nonimmune Fetal Hydrops + + + + +PERINATAL ASPHYXIA +DEFINITION: Perinatal asphyxia refers to a condition during pregnancy and labor in which impaired placental gaseous exchange leads to fetal hypoxemia, acidosis and hypercarbia. +The essential neonatal features for the diagnosis are: (i) Persistent bradycardia ( 7.20, it is unlikely that intrapartum hypoxia, is the cause of neonatal encephalopathy. (4) Need for positive pressure ventilation. (5) Seizures within 12-24 hours of birth. (6) Suppressed background pattern on EEG. +According to the parameters denoted by Apgar (Dr Virginia Apgar-1953), a scoring procedure has been designed for simple understanding of the clinical state. Long-term neurological correlation is obtained at the 5-minute score which is of more value. In cases where the score remains significantly depressed at 5 minutes, it should be evaluated again after 15 minutes. This scoring +Chapter 33: Diseases of the Fetus and the Newborn ID +L + +Table 33.1: Apgar scoring. +Parameters Score +Signs 0 1 +Respiratory Absent Slow, irregular effort +Heart rate Absent <100 bpm +Muscle tone Flaccid Flexion of extremities. +Reflex irritability No response Grimace + + + + +2 +Good, crying + +>100 bpm +Active body movements. +Cough or sneeze + +3. Delayed cord clamping (until 60-90 sec) to support transfusion (placental to fetal). +4. Intrapartum fetal close clinical monitoring for early detection of fetal distress and delivery. +5. Intrapartum use of electronic fetal monitoring and scalp blood pH assessment when indicated. +6. Judicious use of anesthetic agents and sedatives during labor. +7. Avoidance of dificult or traumatic delivery. 8. Management in the delivery room. + + + +Color Blue, pale Body pink, Complete pink extremities blue. +• Total score= 1 O; • No depression = 8-1 O; • Mild depression = 5-7; • Moderate depression= 3-4; • Severe depression= 0-2 + +is done in a newborn baby at 1 minute, 5 minutes and 15 minutes and can be tabulated as follows (Table 33.1). +The etiology of ?:90% of cases of Cerebral Palsy (CP) remains unknown. Apgar score alone should not be taken as an evidence of neurological damage. Cord blood pH can assess fetal oxygenation status better. +Normal range of arterial blood gas values for a term +newborn are: Pa02 50-95 mm Hg; PaC02 35-45 mm Hg; HC03 24-26 mEq/L and pH 7.35-7.45. +Clinical sequelae of birth asphyxia: The variable clinical signs of CNS injury with HIE are: hypoxia, seizures, apnea, respiratory failure, hypotension, NEC, thrombocytopenia, metabolic acidosis and hypoglycemia. Initial response is hyperapnea and hypertension ➔ primary apnea ➔ gasping attempt to breathe ➔ (if unresolved) ➔ secondary apnea ➔ bradycardia and shock ➔ diminished cerebral blood flow ➔ cerebral hemorrhage ➔ hypoxic ischemic encephalopathy (HIE) ➔ (if severe)➔ either death or disability (if the baby survives). +Neonatal diagnosis: A full array EEG (a EEG) is used to select babies for cooling to detect subclinical seizure activity and as long-term prognostication. CT is used to detect cerebral edema, hemorrhage and the eventual HI brain injury. MRI (Tl and T2 weighted) are the best modality to detect the severity and extent of irreversible HI brain injury. Diffusion weighted imaging (DWI), proton Magnetic Resonance Spectroscopy (MRS) and Magnetic Resonance (MR) angio- or venography may be useful for cases with suspected sinus venous thrombosis or vascular anomalies. +Cranial Ultrasonography ( CUS)-detect edema, intracranial hemorrhage, but it is insensitive to detect HI brain injury. +Common patterns of brain injury seen on MRI are: Infarction, intraventricular and intraparenchymal hemor­ rhage, or metabolic encephalopathies. +I MANAGEMENT +Management of perinatal asphyxia can be divided into two areas: +■ Preventive II Definitive +PREVENTIVE +1. Antenatal detection of high-risk factors. +2. Antenatal administration of corticosteroids to the mother when preterm delivery (<34 weeks) is antici­ pated. + + +DEFINITIVE: • Delayed cord clamping (until 60-90 sec). Apgar rating-classically, the evaluation of the cardiopulmonaiy status in the newborn has been assessed at 1 minute and 5 minutes after birth. But in certain circumstances, it is inappropriate to delay resuscitative efforts until the 1 minute Apgar score is obtained (Flowchart 33.1). However, most infants born with Apgar scores of7-10 are essentially normal (Figs. 33.2A to F). +11 Neonatal heart rate <100/min for >2 min in the first 5 min after birth increases the mortality by 4-5 folds. EFM monitoring in high-risk cases is needed. Pulse oximetry with saturation gradually rising from 60% to 90% over first 10 min is satisfactory when heart rate is within the normal range. Presence of bradycardia +(<100/min) and lower SpO2 ( <80%) in the first 5 min +is associated with death or intracranial hemorrhage. This is especially in preterm neonates. +11 Spontaneously breathing babies, need to stabilize +with CPAP of at least 6 cm H2O via with mask or +nasal prongs. +11 Oxygen for resuscitation should be given, using a +blended air/oxygen. Initial FiO2 of 0.30 for babies +<28 weeks gestation and 0.21 for 32 weeks and above. +FiO2 adjustment of up or down should be guided by +pulse ornetry. +11 Intubation should be reserved for babies not respond­ ing to positive pressure ventilation via face mask. +11 Babies requiring intubation for stabilization should be given surfactant. +11 Plastic bags or occlusive wrapping under warmers should be used during stabilization in the delivery suite for babies <28 weeks. +11 In preterm babies receiving oxygen the saturation target should be between 90 and 94%. The alarm limits should be set to 89 and 95%. +11 CPAP involves delivering gas ideally heated and humi­ dified with a measurable and controllable pressure. +11 CP AP with early rescue surfactant is considered optimal for babies with RDS. +m Babies at risk of RDS ( <30 weeks, who do not need intubation), should be started with CPAP. +11 Heated humidified HFNC are increasingly used as an alternative to CPAP. +11 Short binasal prongs or mask with a starting pressure of about 6-8 cm HzO could be initiated. +Im Chapter 33: Diseases of the Fetus and the Newborn +Flowchart 33.1: Resuscitation of the newborn in the delivery room. + + +Ventilatory resuscitation: + +► Dry the infant, to place under the radiant heater. +► Place the infant with head in midline position neck with slight extension. +► Suction of mouth, oropharynx with a suction bulb. +► Assess the infant's condition: Respira­ tory effort (apnea or regular breathing) and heart rate. +► Infants with regular breathing and heart rate >100 bpm need no further +intervention; if cyanotic, provide 02 supplementation. + +► Infants HR <100 bpm, apnea or irregular respiration: Bag and mask +ventilation (100% 02) to be given. A soft mask that seals around the mouth +and nose is to be used. +► Most neonates can be effectively managed with a bag and face mask. If no improvement by another 30-40 seconds-intubation and proceeded. +► Monitoring equipment is pulse oxi­ meter (enhanced) ECG; Medications: Normal saline, epinephrine. +Chest compression: The sternum is compressed about one-third the diameter of the chest at a regular rate of 90 compressions/min while ventilating (PPV) the infant at 30 breaths/min (3:1). The HR is checked periodically and chest compression is discontinued when the HR is >60 bpm. The thumbs are placed together over the lower third of the sternum. The palms encircle the torso and support the back. +Medications: Epinephrine: 0.1-0.3 ml/ kg in 1:10,000 dilution is given IV or endotracheal, when there is persistent bradycardia [<60 bpm despite adequate +ventilation with 100% 02 (30 sec), chest compression (60 sec)] until the HR >60 +bpm. It may be repeated at every 3 to 5 minutes. +Volume expansion: Indications: Neonates with acute bleeding, pallor, or shock. Immediate infusion of normal saline boluses is needed. 10 ml/kg can be given through an umbilical venous catheter over +5-10 min. + + +Antenatal counseling +Team briefing and equipment check + +Birth + +Infant stays with mother for routine +Term gestation? care: warm and maintain normal Good tone? 1--- temperature, position airway, check +Yes +Breathing or crying? secretions if needed, dry. +Ongoing evaluation +No + +Warm, dry, stimulate, position airway, suction only if required. + +Apnea or gasping? No Labored breathing or +HR below 100/minute? persistent cyanosis? Yes Yes +PPV Position and clear airway, SpO,, +SpO2 monitor more supplementary O, as +Consider ECG mionitor needed consider CPAP. + +HR below 100/minute? Post-resuscitation care +Yes Team debriefing. + +Check chest movement +Ventilation corrective steps if needed +Targeted preductal SpO +ETT or laryngeal mask if needed. after birth 2 +1 minute 60-65% +6 +0/ +t +HR b +e low minue? 2 minutes 65-70% Yes 3 minutes 70-75% +Intubate if not already done. 4 minutes · 75-80% +Chest compressions +80-85% +5 minutes +Coordinate with PPV. +100% 02 10 minutes 85-95% +ECG monitor +Consider emergency UVC. Delivery room resuscitation protocol +following American Heart Association, +__ +t +_ +- +-, +No +r- +- - +H +R +b +- _ _ +__ +- +6 +0 + - +/ +- +i +elow m nue? _ American Academy of Pediatrics +and National Neonatology Forum +YesL +J (NNF), India. + +IV epinephrine +if HR persistently below 60/minute Consider hypovolemia. Consider pneumothorax. + + +Airway management Thermoregulations +• Bulb suction ♦ Radiant warmer, caps. +• Suction catheter ♦ Warm blankets. +♦ Stethoscope • Plastic wrap for covering the baby. +♦ Ventilation ♦ Temperature probe. +♦ Bag and mask +• Oral airways Gastric decompression • 0 source ♦ Orogastric tube +2 +• Laryngoscope ♦ Suction +• Endotracheal Tubes (ETT). ♦ Personal Protection Equipment ♦ Um bilical Vein Catheter (UVC). (PPE). +Chapter 33: Diseases of the Fetus and the Newborn l@;J1 . + + + + + + + + + + + + + + + + + + + + + +Figs. 33.2A to F: Top: (1) Infant resuscitation bag and mask (Ambu bag), (2) Short binasal prongs. Bottom: Use of face mask: (A) Correct; (B and C) Incorrect; (D) Correct positioning (neck slightly extended); (E) Chest compression (thumb method); (Fl A neonate of 27 weeks under endotracheal tube ventilation, umbilical venous catheter, due to RDS, in a NICU. + + +■ During weaning HFNC can be used as an alternative to CPAP for some babies. +11 Mechanical Ventilation (MV) may be needed in babies with RDS when other methods of respirat01y support have failed. +■ Targeted tidal volume ventilation is preferred as it reduces lung injmy. +■ Caffeine is often used to facilitate weaning from MV. 11 A short tapering course of low dose dexamethasone +could be used to facilitate extubation for babies on MVfor l-2weeks. +11 Inhaled budesonide is considered for infants at very high risk of Bronchopulmonaiy Dysplasia (BPD). +Other Supportive Cases +11 Core temperature-to be maintained between 36.5 and37.5C. +° +11 IV fluids 7 0-80mL/kg/day-in a humidified incubator. Fluids need to be tailored for an individual baby. +■ Parenteral nutrition is needed from birth. +11 Early feeding with mother's milk should be started, once the baby is hemodynamically stable. +■ Hemoglobin level should be at normal limit. ■ Antibiotics need to be started as indicated. + +Drugs used for resuscitation: Drugs are needed for a persistent HR <6 0 bpm even after ventilation and chest compression. Drug of choice is epinephrine. Other drugs are given as needed (Flowchart 33.1). + +PROGNOSIS: The prognosis is dependent on: (I) Gestational age; (2) Duration and intensity of hypoxia and acidosis as evidenced by Apgar score and blood + +pH-higher the Apgar score, normal the pH, better is the prognosis; (3) Facilities for immediate and competent management of a compromised baby. Most survivors of perinatal asphyxia do not have any major sequelae. Factors for sequelae are: (i) Apgar score of 0-3 at 20 minutes of age; (ii) Presence of multiorgan failure (oliguria >24 hours of life); (iii) Severity of the neonatal neurological syndrome. Severe HIE carries mortality about80%, and (iv) Presence of neonatal seizure. +COMPLICATIONS: Immediate: (a) Cardiovascular­ hypotension, cardiac failure; (b) Renal-acute cortical necrosis, renal failure; (c) Liver function-compromised; (d) Gastrointestinal-ulcers and necrotizing enterocol­ itis; (e) Lungs-persistent pulmonaiy hypertension; (f) Brain-cerebral edema, seizures, irritability, poor tone. +Delayed: (a) Retarded mental and physical growth; (b) Epilepsy-up to 30% in severe asphyxia; (c) Minimal brain dysfunction. + +RESPIRATORY DISTRESS IN THE NEWBORN (Syn: Hyaline Membrane Disease) + +Increased alveolar fluid content, inadequate clearance of lung fluid, lack or inhibition of surfactant function, or reduced surface area for gas exchange is the basic pathology for respirat01y distress. The important clinical causes are shown in Table 33.2. +Respiratory distress syndrome is defined as the +persistence of arterial 02 tension (PaO2) <50 mm Hg and +central cyanosis in room air. Supplemental oxygen supply +is required to maintain PaO2 >50 mm Hg or pulse oximeter +saturation >85%. +Chapter 33: Diseases of the Fetus and the Newborn + + +Table 33.2: Causes of respiratory distress. Pulmonary. +♦ Hyaline Membrane Disease (HMD) or RDS ♦ Meconium aspiration ++ Clear fluid aspiration + Pulmonary hypoplasia +♦ Bronchopulmonary dysplasia + Bronchopneumonia +♦ Airway obstruction ♦ Transient tachypnea ♦ Pneumothorax +♦ Pulmonary edema + + +Cardiovascular +♦ Congenital heart disease +Aortic stenosis, coarctation of aorta. Cyanotic-transposition of great vessels. - Tetralogy of Fallot. +- PDA - VSD ++ Heart failure +♦ Persistent Pulmonary Hypertension of Newborn (PPHN). + + +Noncardiopulmonary +♦ Metabolic acidosis +♦ Hypo-or hyperthermia ♦ Hypoglycemia ++ Asphyxia +♦ Drugs (pethidine) ♦ Birth trauma +♦ lntracranial injury + + + +INCIDENCE: It ranges from 75% at around 28 weeks to 52% at 30 weeks of gestation. Use of exogenous surfactant has significantly reduced the risk of neonatal death by <10%. +PATHOGENESIS: The primary cause is inadequate pulmonary surfactant (Flowchart 33.2). Deficiency of surfactant in the lung alveoli increases alveolar surface tension. It is seen within first 24 hours of birth. Surfactant is a surface active material. It is produced by alveolar epithelial cells called type II pneumocytes at 24-28 weeks gestation. Antenatal corticosteroids enhances but fetal hyperinsulinemia delays surfactant synthesis. Other factors that enhance maturity of type II cells are: chronic stress, PIH, FGR, twins and placental insuficiency. There is poor lung compliance, reduction in ventilation-perfusion ratio and progressive atelectasis. Hyaline Membrane Disease (HMD) is further complicated by the weak respiratory muscles of the newborn. +The consequent finding is widespread atelectasis. A homogeneous eosinophilic membrane (Fig. 33.3) (hyaline membrane) plastering the alveolar ducts and terminal bronchioles is found. +Factors that affect lung maturation: +1. Maternal diabetes: Uncontrolled maternal diabetes is associated with enhanced increased production of fetal insulin. Insulin inhibits production of surfactant phospholipids. +2. Labor: Causes endogenous production of maternal glucocorticoids. This enhances sodium resorption by the epithelial sodium channels. Preterm babies, delivered by cesarean section have a higher incidence of RDS. + +3. Male infants have higher risk of RDS as fetal androgens inhibits surfactant synthesis. +Blood biochemical changes: The infant develops both +metabolic and respiratory acidosis. Pa02 <50 mm Hg and +PC02 may rise to even 80 mm Hg in a severe case. Normal blood gas values are: Arterial 02 tension +of 50-70 mm Hg, arterial CO2 tension of 45-60 mm Hg, +pH at or above 7.25. Arterial 02 saturation at 88-95%. +Hypocalcemia and hypoglycemia can cause respiratory distress and tachypnea. +OTHER INVESTIGATIONS: ♦ Sepsis workup: CBC, Absolute Neutrophil Count (ANC), band cell, micro-ESR, CRP, blood culture are done to detect early onset of sepsis (Group B Streptococcus). ♦ Blood glucose, calcium levels. ♦ Serum electrolyte levels. ♦ Echocardiography to exclude PDA, congenital heart disease. +CLINICAL FEATURES: RDS is commonly found in preterm infant, <34 weeks of gestation. It develops soon after the birth. +(1) Respiratory rate (tachypnea). (2) Rib retractions­ to maximize the negative inspiratory pressure. This results in subcostal, intercostal and suprasternal retractions. (3) Grunting is due to exhalation active exhalation against a partially closed glottis. ( 4) Hypoxia. (5) Tachypnea. (6) Nasal flaring to reduce the resistance of air flow. (7) Silverman-Andersen scoring-higher the score (2:5), more is the work of breathing and higher is the need of respiratory support. (8) Central cyanosis. +Chest X-ray shows uniform reticulogranular pattern known as ground-glass mottling (Fig. 33.3) due to + + +Flowchart 33.2: Etiopathological causes of respiratory distress syndrome. + + + +Neonates +♦ Preterm (<34 mm). ♦ Diabetic mother. +• Cesarean delivery. • Hypothermic. +• Hypovolemic. • Genetic factor. +• Multiple pregnancy. + Male baby. + + + +-.1 Deficient I +I +I +surfactant + +I + +Eitopathology + +Collapse of alveoli + + + +' Atelectasis + + +I + + + +I + + +Hypoxemia and acidosis (metabolic and respiratory)➔ Increased pulmonary vascular resistance➔ hypoperfusion. +➔ alveolar epithelial damage. +➔ increased capillary permeability. +➔ leakage of plasma into alveolar spaces. ➔ combines with cellular debris to form +characteristic hyaline membrane change. + + +Recovery phase: Regeneration of alveolar cells and type II cells. There is increase in surfactant activity. +Chapter 33: Diseases of the Fetus and the Newborn flb . + + + + + + + + + + + + + + + +Fig. 33.3: Hyaline membrane atelectasis. + +extensive atelectatic process. Homogeneus white lung with contrast "black" bronchi is the typical appearance. +DIFFERENTIAL DIAGNOSIS: (1) Aspiration pneumonia (liquor amnii or meconium); (2) Transient tachypnea of newborn (TTN); (3) Pneumothorax; (4) Diaphragmatic hernia; (5) Congenital heart disease. +PREVENTION: (1) Administration of betamethasone (12 mg) to the mother two doses IM 24 hours apart, especially before 34 weeks. Cortisol acts on type II pneumocytes to stimulate phospholipid synthesis. Benefits are obtained after 24 hours of therapy and continue for 7 days. Fetal hyperinsulinism blocks cortisol action; (2) Assessment of lung maturity before premature induction of labor and to delay the induction as much as possible without any risk to the fetus; (3) Prevent fetal hypoxia in diabetic mothers. +Decreased risk factors are: +♦ Vaginal delive1y ♦ Corticosteroid therapy • Thyroid hormones +♦ Prolonged rupture of membranes ♦ Female baby. +TREATMENT +Pl"inciples of management in HMD are: (i) Prevent hypoxia and acidosis; (ii) Maintain fluid and electrolyte balance; (iii) Prevent atelectasis and pulmonary edema; and (iv) Avoid lung injury (barotrauma) and infection. +Management: The key principles are to establish and maintain Functional Residual Capacity (FRC) at the earliest. The role of pulmonaiy surfactant in the alveoli and the bronchioles is to maintain a low surface tension. +■ The baby should be placed in neonatal intensive care unit and nursed in a warm incubator with high humidity (neutral thermal condition). Air passage is cleaned periodically through endotracheal suction. +■ Adequate warmed and humidified oxygen therapy in concentration of 35-40% under positive pressure is to be administered through endotracheal tube to relieve +hypoxia and acidosis. If the arterial oxygen tension (PO2) cannot be maintained above 50 mm Hg, application of + +Continuous Positive Airway Pressure (CPAP) at 5-8 cm of water is indicated. Warm humidified air oxygen mixture is critical for the health of the respirat01y epithelium. +■ Correction of hypovolemia with albumin or other colloid solution. +■ Treatment of anemia, electrolyte imbalance if any and prevention of infection. +■ Frequent monitoring of the arterial PO2, PCO2, pH and +base excess are to be determined to diagnose metabolic +and respiratory acidosis. Higher than necessary FiO2 +may cause lung injury and retinopathy of prematurity. ■ Acidosis should be corrected by adequate ventilation +and oxygenation. +■ Continuous Positive Airway Pressure (CPAP) helps the infants with RDS to maintain FRC: Nasal (NCPAP) or nasopharyngeal (NPCPAP) is used early to delay or prevent the need for mechanical ventilation and tracheal intubation. +■ Surfactant replacement therapy has significantly improved the outcome of the infants with RDS. Surfactant is composed chiefly of phospholipids 80% and protein 10%. It is produced and stored in the characteristic lamellar bodies of type II pneumocyte. Reduction of surface tension and stabilization of alveolar air-water interface is its basic function. Surfactants of human, bovine (Survanta), porcine (Curosurf) or Calf (Infasurf) or synthetic preparations (Exosurf) have been used. Prophylactic surfactant replacement has reduced the risk of Bronchopulmonary Dysplasia (BPD), Chronic Lung Disease (CLD) and Deaths. Natural surfactants are the treatment of choice. Mechanical ventilation is less often needed when the technique 'Intubate-Surfactant-Extubate to CPAP' is done. Prophylactic therapy is given (within 15 minutes of birth) in very premature infants. Direct tracheal instillation is done +through a feeding tube. Oxygen tension (PaO2) is adequately +maintained. With the use of antenatal corticosteroids, early initiation of CPAP and the use of surfactant, the survival outcome even for smallest infant has improved significantly. Early rescue (within 2 hours of age) is preferable rather than delayed treatment. Surfactant reduces the need of intubation and mechanical ventilation (MV). Administration: commonly tracheal intubation and bolus administration is done. Less Invasive Surfactant Administration (LISA), is done using a special catheter either by direct or by video­ laryngoscopy. It reduces the need of MV. Complication: Pulmonary hemorrhage, air leak are rare complications of surfactant therapy. + +Surfactant Preparation and Dose Schedule +■ Surfactant may be used for RDS complicated with pneumonia or +■ In babies with pulmonary hemorrhage. + +Surfactant use and preparations +Generic name Trader name Source Dose (volume) +Beractant Survant Bovine 100 mg/kg/dose (4 ml/kg) Bovactant Aveofact Bovine 50 mg/kg/dose (1.2 ml/kg) +Poractant Curosurf Porcine 100-200 mg/kg/dose (1.25-2.5 ml/kg +f' -­ +l + +t - Chapter 33: Diseases of the Fetus and the Newborn + + +Table 33.3:The sequelae of perinatal asphyxia. System Manifestations +Acute Long-term +Cardiac ■ Cardiogenic shock. Papillary muscle dysfunction. +• +CNS ■ Cerebral edema. ■ Cerebral Palsy (CP). ■ Seizures. Epilepsy. +• +■ Hemorrhage. ■ Mental retardation ■ HIE. (most CP, however, +is not related to birth asphyxia). +Pulmonary ■ Aspiration syndromes. ■ Chronic lung Pulmonary hemorrhage . disease (following +• +■ HMO. HMO). +Renal ■ Acute tubular necrosis, ■ Retinopathy of +oliguria. prematurity. Adrenal • Hemorrhage . +GI system ■ Necrotizing enterocolitis. +Metabolic ■ Hypoglycemia. Hematologic • DIC, thrombocytopenia . + +■ Mechanical ventilation-Indications are: Babies with poor +respiratory effort, recurrent apnea with severe RDS (high Fi02 need, high CO2 despite optimal CPAP and surfactant). +■ Antibiotic therapy against common neonatal infections should be started initially. +COMPLICATIONS: Acute complications of RDS include­ (i) Infection; (ii) Air leak (pneumothorax); (iii) Pneumo­ mediastinum; (iv) Persistent patent ductus arteriosus. Other complications are: (a) Intraventricular hemorrhage, (b) chronic lung disease (CLD), (c) bronchopulmonary dysplasia (BPD), (d) intracranial hemorrhage, (e) retin­ opathy of prematurity, (f) pulmonary hemorrhage, (g) barotrauma-pneumothorax, (h) retrolental fibroplasia; and (i) neurological abnormalities (Table 33.3). +PROGNOSIS: With the widespread use of antenatal corticosteroids, early use of CPAP and exogenous surfactant, presently cases of RDS has been reduced significantly to few hours. RDS infants born 2:32 weeks of gestational and without other complications resolves +completely without any long-term pulmonary squealae. + +TRANSIENT TACHYPNEA OF THE NEWBORN (TTN) +Tachypnea of the newborn (TTN) is a self-limiting type of respiratmy distress due to delayed clearance of lung fluid. It is commonly seen in the preterm and less commonly in term newborns. It develops shortly after birth and usually resolves within 3-5 days. +TTN-the incidence of TTN is 0.3% of the term and 1 % of the preterm deliveries. +Physiology of pregnancy and labor: During preg­ nancy, fetal pulmonary epithelium actively secretes + +fluid into the alveoli. With the onset of labor and stress, fetal hormones and catecholamines (glucocorticoids, thyroid hormones, adrenaline) are released. This opens up the sodium channel mechanism for active absorption of sodium. During labor, there is rise in intrapulmonaiy pressure with uterine contractions and opening up of sodium channels. This results in shift of alveolar fluids from the alveoli to the interstitium. The fluid in the interstitium is slowly absorbed by the lymphatics and blood vessels. +Pathology of TTN +A. Absence of catecholamine surge: Infants born by +Elective CS are not exposed to the stress of labor. These infants run the high risk ofTTN. +B. Uterine contractions during labor increase the intra­ pulmonary pressure. This causes eflux of lung fluid via trachea. This is absent in the neonate born by cesarean delive,y. +C. Birth through the vagina increases the transpulmo­ nary and intra-abdominal pressure of the neonate. This increased pressure forces the lung fluid out through the nose and mouth. This squeeze effect is absent in elective cesarean delivery. +D. Relative deficiency of phosphatidylglycerol and surfactant at birth in these neonates is also seen. +E. Genetic predisposition is also associated. + +Risk factors for TTN: +a. Cesarean delive1y b. Preterm infant c. Male baby d. Breech delive1y +e. Multiple gestation f. Infant of a diabetic mother g. Birth asphyxia h. Instrumental delive1y +i. Macrosomia. ( forceps/ventouse) +Clinical presentation: • Tachypnea (breaths >60 per minute), • grunting, • nasal flaring, • ribs retraction, cyanosis (rarely), chest radiograph may show 'double lung point', due to difference of lung echo between upper and lower lung areas. +Management: Prevention: +(a) To perform elective CS after 38 completed weeks, (b) antenatal betamethasone use. +Actual management: +■ a. Oxygenation: With hood or nasal cannula, +b. Nasal Continuous Positive Airway Pressure (NCPAP), when oxygen need is >30%, +c. Intubation (rarely) when oxygen need >40%. ■ Neutral thermal condition to maintain. +■ Feeding: Oral when respiratory rate is <60 breaths per minute otherwise with nasogastric tube. +♦ N nutrition when RR is >80 breaths per minute. ■ Prognosis: Excellent, it usually lasts for 2-5 days. +II MECONI UM ASPIRATION SYNDROME (MAS) Meconium Aspiration Syndrome (MAS) usually occurs in term or post-term babies who are small for gestational age (IUGR). +Chapter 33: Diseases of the Fetus and the Newborn aa· + +Overall incidence of Meconium-Stained Amniotic Fluid (MSAF) varies between 10% and 15%. Chronic placental insufficiency leads to intrauterine hypoxia with passage of meconium. The meconium-stained liquor may be aspirated by the fetus-in-utero or during first breath. Pathophysiology includes: (a) airway obstruction, lung atelectasis causing hypoxia and increased pulmonary vascular resistance (PVR); (b) chemical pneumonitis; (c) pulmonary inflammation due to release of cytokines. This causes airway edema and hypoxia; (d) surfactant dysfunction; and (e) development of Persistent Pulmonary Hypertension (PPHN). Not all the infants with meconium aspiration will develop MAS. Features of respiratory distress develop immediately after birth in only 5-10% infants. The infant manifests with tachypnea, nasal flaring, intercostal retractions and cyanosis. +Diagnosis is mainly based on: (a) Aspiration of meconium from the trachea at birth; (b) Signs of respiratory distress; (c) Radiologically hyperinflated lung fields, flattened diaphragm with coarse and patchy infiltration; and (d) Cyanosis. +Management +♦ Careful intrapartum monitoring; +♦ Amnioinfusion in oligohydramnios-may reduce cord compression, grasping and intrapartum aspiration. +♦ Maintenance of: (a) thennoneutral environment; (b) blood; to correct metabolic abnormalities (glucose, calcium); (c) circulatory support (normal saline or whole blood). +♦ Liberal oxygen supply and monitoring of SpO2• +♦ Depending on the severity, infant may need assisted ventila-tion and/or CPAP and often associated with PPHN. +♦ Antibiotic coverage, as meconium invites infection. +♦ In a severe case arterial blood gas analysis should be done. ♦ Surfactant therapy is beneficial; corticosteroid not routinely used. Inhaled Nitric Oxide (iNO) and Extracorporeal Membrane Oxygenation (ECMO) may be needed in cases +with refractory respiratory failure. +♦ General management includes correction of hypoxia, acidosis, hypoglycemia and hypocalcemia. Mechanical +ventilation is required where PO2 is less than 50 mm Hg and PCO2 is above 50 mm Hg. Complications like air leak +(pneumothorax), PPHN, bronchopulmonary dysplasia or chronic lung diseases are common. New modalities of therapy have reduced mortality to <5%. +Prognosis: MAS may be associated with neurodevelopmental delay, cerebral palsy and mental retardation. Infants need long-term follow-up. + +JAUNDICE OF THE NEWBORN +Yellow discoloration of the skin and the mucosa is caused by accumulation of excess of bilirubin in the tissue and plasma (serum bilirubin level should be in excess 7 mg/dL). A value >15 mg/dLis considered severe. About 80% of term newborn and most of preterm newborns develop clinical jaundice. +Bilirubin source and metabolism: RBC hemoglobin ➔ +breakdown in RE system➔ biliverdin, CO2 (excreted by lungs) +and iron (reutilized). Biliverdin is reduced to bilirubin by the enzyme biliverdin reductase. I g hemoglobin produces 35 mg of bilirubin. Bilirubin bound to serum albumin is transported to the liver cells➔ carried to the smooth endoplasmic reticulum by cytoplasmic ligandin (Y protein). Unconjugated (indirect) bilirubin is converted to Conjugated (direct) Bilirubin (CB) + + +by Uridine Diphosphoglucoronate Glucoronosyl Transferase (UGTIAI). CB excreted in GI tract, is eliminated by stool. When CB is acted upon by J3 glucuronidase, it is converted to UCB which is reabsorbed back to the liver (enterohepatic circulation) for reconjugation. Sulfonamides, and free fatty acids can displace bilirubin from albumin. Phenobarbitone can induce the enzyme UGPG-GT and catalyze the conjugation process. Conjugated bilirubin is water soluble and nontoxic. Unconjugated bilirubin is toxic and causes neuronal dysfunction and +death. + +I CAUSES OF NEONATAL JAUNDICE ♦ Physiological ♦ Nonphysiological +PHYSIOLOGICAL: The jaundice usually appears on 2nd and 3rd day and disappears by 7th-10th day, a little later in premature neonates. In a term infant, the level may be 3-5 mg/dL on 3rd day. A rise of unconjugated serum bilirubin to 12 mg/dL is in the physiological range. In a preterm infant the peak level of 12-15 mg/dL in the 1st week may be without any abnormality. +Causes of excessive bilirubin production are: +1. Increased red cell volume per kg and increased red cell destruction due to shorter lifespan (90 days compared to 120 days in adult) in the neonate. +2. Transient decreased conjugation of bilirubin due to decreased UGPG-GT activity. +3. Increased enterohepatic circulation due to decreased gut motility and high level of intestinal p glucuronidase. +4. Decreased hepatic excretion of bilirubin; and +5. Decreased liver cell uptake of bilirubin due to decreased ligandin (transport protein). + +Labor and Delivery +(a) Birth trauma; (b) Oxytocin use; (c) Infants with hypoxic ischemic insult; (d) Delayed cord clamping. +Treatment: No specific treatment is required. The baby is given more frequent feeds. In premature babies, careful observation is required and evidences of rising bilirubin near critical level need exchange transfusion. However, use of phenobarbitone or phototherapy is quite useful in such cases. + +PATHOLOGICAL +CAUSES OF SEVERE NEONATAL HYPERBILIRUBINEMIA +A. Excessive red cell hemolysis +i. Hemolytic disease of the newborn: +• Fetomaternal blood group incompatibilities: Rh (most common), ABO (rare), immunization against Kell antigen (rarest). +• Increased red cell fragility-congenital sphero­ cytosis. +• Deficient red cell enzyme-Glucose-6-Phosphate Dehydrogenase (G6PD deficiency and drugs). +ii. Sepsis: Intrauterine (Toxoplasma, Rubella), neonatal (E. coli) omphalitis. +Im Chapter 33: Diseases of the Fetus and the Newborn +iii. Blood extravasation ( cephalhematoma, intraven­ tricular hemorrhage). + +B. Defective conjugation of bilirubin and clearance +i. Congenital deficiency of glucuronyl transferase • Preterm babies with impaired liver function. +• Crigler-Najjar syndrome (Autosomal Recessive), • Gilbert syndrome (Autosomal Dominant), +C. Breast milk jaundice: The activity of the enzyme-glucuronyl transferase is inhibited by a specific steroid 3a, 20 ­ pregnanediol and increased fatty acids of breast milk. The bilirubin level rises fom the 7th day after birth to a maximum of 20-30 mgldL by 14th day. Jaundice is usually mild and it takes a time (4-12 weeks) to disappear. It rarely causes kernicterus. It requires no treatment. If the bilirubin level is more, temporary withdrawal of breastfeeding cures jaundice. Breast milk jaundice may recur in 70% offuture pregnancies. Breastfeeding jaundice is due to decreased intake of milk that leads to increased enterohepatic circulation. +r +D. Metabolic and endocrine disorders: Galactosemia, hypo­ thyroidism (unconjugated hyperbilirubinemia). +Galactosemia: There is heredita1y deficiency of an enzyme­ galactose-1-phosphate uridyl transferase which converts galactose derived from the milk into glucose-1-phosphate. As a result there is increased accumulation of galactose that leads to periportal fibrosis and cirrhosis of liver. The biliary canaliculi are blocked by inspissated bile and obstructive jaundice results. Baby develops jaundice, hepatomegaly and feeding intolerance. A reducing substance (lactose) is detected in the urine by clinistix. Breastfeeding is contraindicated because of high lactose content. Lactose-free milk feeding should be recommended. +E. Increased enterohepatic circulation of unconjugated bilirubin: Duodenal atresia, pyloric stenosis, less frequent feeding. +F. Substances and disorders that affect binding of bilirubin to albumin: Aspirin, sulfonamides, fatty acids and asphyxia, acidosis, sepsis, or hypothermia increases free unconjugated bilirubin level. +G. Miscellaneous: • Congenital obstruction (atresia or stricture of biliary canaliculi), • asphyxia, • polycythe­ mia and • thalassemia. +I HYPERBILIRUBINEMIA OF THE NEWBORN +When the bilirubin (unconjugated) level rises more than the arbitrary cut-off point of 12 mg/dL, in a term infant the condition is called 'hyperbilirubinemia of the newborn'. The face and chest of the infant are usually stained yellow at this level of serum bilirubin (Box 33.2). Conjugated hyper­ bilirubinemia is never normal or physiologic. +■ Unconjugated: Hemolytic disease due to Rh (common) or ABO (rare) incompatibility, increased red cell fragility (spherocytosis), prematurity, glucose-6-phosphate­ dehydrogenase deficiency, sepsis, iatrogenic (drugs), breast milk jaundice, cephalhematoma, hemoglo­ binopathy, infant of diabetic mother, hypothyroidism, idiopathic neonatal hepatitis. + + +■ Jaundice appearing within 24 hours of birth. +■ Bilirubin level increasing at the rate of >5 mg/dl/day or >0.2 mg/dl/hour. +■ Conjugated bilirubin >2 mg/dl. ■ Clinical jaundice persisting > 1 +week in a term infant or >2 weeks in a preterm infant. +■ Jaundice requiring phototherapy. +■ Sick baby. + +Table 33,4: Dermal icterus zone and serum bilirubin level. +Derma/zone Blirubin (mgldL) 1 5 +2 10 +3 12 Fig. 33.4: Dermal icterus +4 15 zone and serum bilirubin (indirect) level in a term +> +15 +5 +infant (Kramer-1969). + +■ Conjugated: Neonatal hepatitis, bacterial infection, intra­ uterine TORCH infection, trisomy 21, 18; galactosemia, cystic fibrosis, biliary atresia, drugs (anticonvulsants), panhypopituitarism, etc. + +Management of Hyperbilirubinemia in Newborn Infant >35 Weeks of Gestation (AAP) (Box 33.3) + + +■ Lower gestational age (<37 weeks). +■ Jaundice in the first 24 hour after birth. +■ Pre-discharge Transcutaneous Bilirubin (TcB) or Total Serum Bilirubin (TSB) concentration close to the phototherapy threshold (Fig. 33.5). +■ Hemolysis from any cause (based on a rapid rate of increase in the TSB orTcB of >0.3 mg/dl per hour in the first 24 hour or >0.2 mg/dl per hour thereafter). +■ Phototherapy before discharge. ■ Previous sibling with jaundice. +■ Family history of inherited red blood cell disorders, including (G6PD) deficiency. +■ Scalp hematoma or significant bruising. ■ Macrosomic infant of a diabetic mother. + +DIAGNOSIS OF NEONATAL HYPERBILIRUBINEMIA +A. Clinical: Evaluation of jaundice is done by blanching the skin with digital pressure. Visual inspection is not a reliable indicator of serum TB level. Severe hyperbilirubinemia (TB >25 mg/dL) is associated with the increased risk ofBilirubin Induced Neurologic Dysfunction (BIND). Clinical jaundice in a neonate indicates serum bilirubin of more than 5 mg/dL. Cephalocaudal progression of dermal icterus is a useful clinical tool (Fig. 33.4). +Dermal icterus zone and serum bilirubin (indirect) level in a term infant (Kramer-1969) (Table 33.4). +Chapter 33: Diseases of the Fetus and the Newborn + + + + + + + + + + + + + + + + + + + + + + + + + + +A thorough physical examination of the infant is done. Abnormal neurologic signs are: lethargy, poor feeding, vomiting, hypotonia and seizures. +B. Laboratory studies: +Serum bilirubin level > 12 mg/ dL, requires further +investigations. +1. Blood group (ABO, Rh) status-mother and infant. Antibody screen of the mother. +2. Direct Coombs' test (infant)-for alloimmunization disorder. Positive➔ Antibody study (Rh, ABO, Kell). +3. Total bilirubin, conjugated bilirubin and unconjugated bilirubin. +4. Complete hemogram including reticulocyte count: +• Hemolytic anemia: ,I, Hb%, t reticulocyte count, presence of nucleated red cells. +• Sepsis: WBC count (total and differential) I,, neutrophil I,, band cell, micro ESRt, CRPt. +♦ Polycythemia: Hematocrit (>65%) t. +• Hereditary spherocytosis: Peripheral blood film t reticulocyte count. +5. Serum albumin to detect total bilirubin binding sites and to assess the need of albumin infusion. +6. Other laboratory tests: +♦ Urine for reducing substance (galactosemia), culture for infection. +♦ Hemoglobin electrophoresis. ♦ Osmotic fragility tests. +♦ Thyroid and liver function tests. ♦ G6PD screening. +♦ LFT (AST, ALT, PT). +C. Ultrasonography or MRI to detect intestinal obstruction, intraventricular hemorrhage and tumor. +COMPLICATION (unconjugated)-kernicterus is the important complication which is more often fatal, if not promptly detected and adequately treated. + +II KERNICTERUS +Kernicterus is the chronic and permanent squealae of bilirubin toxicity that develop during the first year of the age. The other signs are: +♦ Choreoathetoid cerebral palsy with neuromotor impairment. ♦ Sensory neural hearing loss. +♦ Limitation of upward gaze and ♦ Dental enamel dysplasia +Basal ganglia, cerebellum, cranial nerve nuclei, hippocampus, brainstem nuclei and anterior horn cells of the spinal cord are commonly affected. The critical level of bilirubin causing kernicterus in a term infant is more than 20 mg/dL (340 µmol/L). Bilirubin enters the brain in free (unbound) form (Box 33.4). Risk of bilirubin encephalopathy is unlikely, if the total bilirubin level is <20 mg/dL. +Hypoxia, acidosis, hypoglycemia, hypothermia, sepsis or prematurity enhance the pathogenesis so affection may occur even at a low level ofbilirubin. Excess rise of conjugated bilirubin cannot produce kernicterus. +It is clinically characterized by lethargy, hypotonia, poor feeding and loss of neonatal reflexes, and oculogyric crisis. + + +■ Gestational age <38 weeks. Risk increases with degree of prematurity. +■ Serum albumin <3.0 g/dl. +■ Hemolytic conditions (Rh-ABO disease, G6PD deficiency, others). ■ Sepsis. + +MANAGEMENT OF JAUNDICE IN THE NEWBORN +I + +Objective of management is prevention of encephalo­ pathy or severe hyperbilirubinemia of the newborn +l9 Chapter 33: Diseases of the Fetus and the Newborn + +(>25 mg/dL in a term, baby). Three methods of treatment are used to reduce the level of unconjugated bilirubin: (1) Phototherapy; (2) Exchange transfusion. +1. Phototherapy: It is best when used in moderate cases where the bilirubin level rises above 12 mg%. Total Serum Bilirubin (TSB) or Transcutaneus Bilirubin (TcB) to be measured. Phototherapy is discontinued when serum bilirubin level is <13 mg/dL in term and <11 mg/dL in preterm neonates. A rebound increase in serum bilirubin may occur once phototherapy is stopped. Adequate hydration of the neonate has to be maintained. Special blue lamps with an output of 460-490 nm wavelengths are the most effective. Double phototherapy ( overhead light-plus light from below or fiberoptic blanket) is twice as effective as single phototherapy. +Bilirubin (indirect) absorbs light maximally at that range and undergoes photoisomerization and is converted to less toxic polar isomer (4Z, 15E) which is excreted into the bile. Phototherapy also converts bilirubin to lumibilirubin by structural isomerization. Lumibilirubin is excreted in the bile and urine without conjugation. +Light sources: Blue Light-Emitting Diodes (LEDs) are the optimum in the absorption spectrum of bilirubin. These are available as either overhead or underneath devices and can be placed closer to the infant. Sunlight also lower the TB level effectively. Risks are due to ultraviolet light and skin burn. Monitoring: TB is to be measured to monitor the response to therapy. TB decreases during the first 4-6 hours of exposure. Urine output, weight record are maintained. Breastfeeding is continued. +Phototherapy should be started early, exposing the maximum surface area and shielding the eyes. It may be continuous or interrupted for breastfeeding. Phototherapy causes increased insensible fluid loss of the neonate. Oral hydration with frequent breast milk is encouraged. IV fluid therapy or nasogastric feeding may be needed. Fiberoptic blankets protect the infants. Adverse effects ofphototherapy are: Watery diarrhea, skin rashes, dehydration, bronze baby syndrome (dark brown discoloration of the skin), low calcium levels and retinal damage. +Treatment decision (phototherapy) depends on the Total Serum Bilirubin levels (TSB). +Presence of risk factors (Box 33.4) lower the threshold for phototherapy {Fig. 33.5). All infants should be visually assessed for jaundice at least every 12 hours following delivery. TSB or TcB should be measured as soon as possible especially those with high-risk factors (Box 33.4). There is a good correlation between TcB and TSB concentration for infants >35 weeks. TcB is noninvasive. It measures bilirubin levels by comparing the wavelengths of lights directed into the skin of the neonate and those reflected back. TSB generally remains within 3 mg/dL of the TcB. TSB should be measured if the TcB exceeds or is within 3 mg/dL of the phototherapy treatment threshold or if the TcB is >15 mg/dL. Phototherapy decreases bilirubin concentrations. Intensive phototherapy is recommended at the total serum bilirubin thresholds {Fig. 33.5). Phototherapy treatment thresholds take + + + +■ When there is progressive rise of bilirubin (> 1 mg/dl/hour) in spite of phototherapy. +■ Rate of bilirubin rise >0.5 mg/dl/hour despite phototherapy when Hb is between 11-13 g/dl. +■ To improve anemia and congestive cardiac failure of the neonate. + +the gestational age and also other high risk factors for neurotoxicity (Fig. 33.5). Infants under phototherapy should have the tests for hemoglobin, hematocrit to detect any anemia. G6PD activity should be measured when TSB increases despite intensive phototherapy. Phototherapy is discontinued when there is fall of TSB by at least 2 mg/dL below the hour specific threshold. Infant should be followed after phototherapy to detect any rebound hyperbilirubinemia. +Escalation of care: Exchange transfusion is needed when there is rapid rise of serum bilirubin. The escalation of care threshold is 2 mg/dL below the exchange transfusion threshold. Intravenous Immune Globulin (IVIG-0.5 to 1 g/kg over 2 hours) is given for infants with isoimmune (Rh or ABO incompatibility) hemolytic disease. Urgent exchange transfusion is done when TSB rises despite phototherapy or is within 2-3 mg/dL of the threshold recommended for ET. +2. Exchange Transfusion (ET) is done to remove bilirubin when intensive phototherapy fails to prevent rising bilirubin or neurologic signs suggesting bilirubin toxicity (Box 33.5). Double-volume exchange replaces 85% of circulating red blood cells and reduces bilirubin level by 50%. +In nonimmune hyperbilirubinemia blood is typed and cross-matched with the infant. Two-volume exchange is usually done. If the newborn's blood volume is 80 mL/kg, then 160 mL/kg of blood is used for exchange transfusion. Complications of exchange transfusion: • Air embo­ lism, • thrombosis, • hypervolemia, RDS, hypothermia, acidosis, infection, hyperkalemia, hypocalcemia, hypo­ glycemia, cardiac arrhythmias, thrombocytopenia, coagulopathies and necrotizing enterocolitis. + +HEMOLYTIC DISEASE OF THE NEWBORN + +Hemolytic Disease of the Newborn (HDN) is due to hemolysis of the fetal red blood cells (RBCs) due to passively acquired maternal antibodies. Hemolysis is manifested by a: • Decreased hematocrit, • Increased reticulocyte count and • Increased bilirubin level. The common causes are shown in Table 33.5. + +I __ABO GROUP INCOMPATIBILITY___ _ +Principle: The mother with blood group O has got naturally occurring anti-A and anti-B agglutinins. These antibodies are mainly IgM and do not cross the placenta. If the fetus happens to be blood group A or B corresponding to that of the father, the + + +Table 33.S: Common causes of HDN. +A.Immune B. Inherited RBC C.Acquired hemolysis disorders heriolysis +■ Rh • RBC membrane • Infection: incompatibility defects bacterial, viral, +■ ABO incom- (spherocytosis, parasitic (rubella, patibility elliptocytosis) syphilis) +■ Other blood ■ Metabolic: G6PD ■ DIC +group deficiency ■ Acute transfusion incompatibility ■ Systemic diseases hemolysis +(C, E, Kell, Dufy) (galactosemia) ■ Vitamin E ■ M<1ternal diseases ■ Hemoglobinopathies deficiency +(lupus); drugs (a-and -thalas- ■ Drugs (vitamin K, semia syndrome) nitrofurantoin) +Management is to treat this underlying primary disorder, simple transfusion, exchange transfusion and nutritional support (Fe, folate, vitamin E). + +immune antibodies are formed in response to the entry of A or B antigen bearing fetal red cells, into the maternal circulation. As these are mainly IgG, they can cross across the placenta into the fetal circulation and cause a variable amount of hemolysis due to antigen-antibody reaction. Although 15% of the babies have got ABO blood group incompatibility, only in 34 weeks gestation are 14-20 g/dL with an average value of 17 g/dL. +DEFINITION: Central venous hemoglobin level <13 g/dL in an infant of >34 weeks gestation is considered anemia. +PATHOPHYSIOLOGY: Anemia in the newborn infant may be due to any one of the three pathologies: +a. Physiologic anemia of infancy is due to shorter lifespan of RBCs and less erythropoietin production. +b. Loss of RBCs (hemorrhagic anemia). +c. Destruction of RBCs (hemolytic anemia); or +d. Under-production of RBCs (hypoplastic anemia). + +CAUSES: (1) Hemorrhagic anemia: +A. Obstetric causes: (a) Abruptio placentae; (b) Placenta pre­ via; (c) Traumatic rupture of umbilical cord; (d) Obstetric trauma (dificult delive1y with visceral or intracranial hemor­ rhage); (e) Twin-twin transfusion; (f) Delivery of the baby by cesarean section after cutting through the placenta in anterior +,·­ +! + - +"' +·L_J__ Chapter 33: Diseases of the Fetus and the Newborn + + +placenta previa; (g) Ruptured vasa previa; (h) Excessive feto­ maternal bleed; {i) Anemia of prematurity; {j) Hereditaty RBC disorders-hemoglobinopathies. +B. Neonatal causes: (a) Caput succedaneum; {b) Cephal­ hematoma; (c) Intracranial hemorrhage; ( d) Visceral hemorrhage (spleen, kidneys and adrenals); (e) DIC; (f) Thrombocytopenia; and (g) Hemorrhage due to deficient vitamin K dependent factors (II, VII, IX and X). +(2) Hemolytic anemia (p. 452). +(3) Under-production of RBCs: (a) Congenital hypoplastic anemia, {b) Leukemia, and (c) Infections (rubella, syphilis). +Diagnosis: (1) History: (a) Family history of bleeding and (b) Maternal medications (phenytoin, warfarin); (2) Clinical examination (jaundice, splenomegaly, skin bruises); and (3) Laboratory tests: Complete blood count, RBC indices, blood smeat; reticulocyte count, Kleihauer Betke test, coagulation profile, intrinsic RBC defect, TORCH study and ultrasound of abdomen and head. + +TREATMENT: Treatment of anemia in neonates, involves treatment of the underlying primaty disorder along with blood transfusion, exchange transfusion and nutritional support. (1) Replacement transfusion in neonates with hemorrhagic anemia (hematocrit <35%); (2) Oral iron in suspension (2-4 mg elemental iron/ kg) and folic acid 50 µg/day vitamin E 25 JU/day have to be continued for a longer period; (3) Recombinant human etythropoietin (rh-EPO) for anemia of prematurity; (4) Exchange transfusion-in neonates with: {i) hemolytic or hemorrhagic anemia with raised CVP, (ii) Rh incompatibility. Treatment of selected disorders (e.g., consumption coagulopathy, immune thrombocytopenia). +Prognosis depends on the basic underlying pathology and its severity. + +SEIZURES IN THE NEWBORN +A seizure is a paroxysmal manifestation of neurological dysfunction (i.e., behaviors, motor or autonomic function). Overall incidence ranges from 1 to 5 per 1,000 live births. Pathophysiology: The basic mechanism is excessive depolarization ( excitation) of neurons within the CNS. Three possible reasons for excessive depolarization are proposed: +A. Failure of sodium-potassium pump operation; +B. Relative excess of excitato1y neurotransmitter compared to the inhibitory ones; +C. Relative deficiency of inhibit01y neurotransmitters. + +Neonatal convulsion is usually a visible manifes­ tation of some underlying pathology (Table 33.6). Rarely, a baby may have convulsion where the cause can­ not be detected. The common causes of convulsion in the newborn are shown in Table 33.6. +Risk factors: (a) Prematurity, (b) Birth weight <2.5 kg, (c) Maternal age 2:40 years, (d) Traumatic delivery (forceps). +Common clinical seizure patterns are: (a) Focal clonic (b) Focal tonic (c) Myoclonic and (d) Automatic seizures. +DIAGNOSIS +History: Details of delivery, Apgar score at birth, birth weight, gestational age, breastfeeding or not, maternal drug history, family history of seizures, inborn errors of metabolism, withdrawal of narcotic drugs. + +INVESTIGATIONS: Laboratory studies +• Full blood count • Blood, urine and CSF cultures. • Serum IgM and IgG-specific TORCH titers. +• Blood biochemical-estimation for glucose, ammonia, calcium, magnesium, bilirubin and electrolytes, if needed. +• Blood gas levels to detect acidosis and hypoxia. +Imaging studies: EEG, ultrasonography and CT scan of the head-to detect intraventricular and/or subarachnoid hemorrhage. They are also useful to detect any congenital malformation. MRI-congenital abnormalities (lissencephaly, IVH, HIE). +EEG diagnosis: Continuous Electroencephalogram (CEEG): >3 hours of monitoring is considered the gold standard for the diagnosis of neonatal seizures. +TREATMENT: The principles of treatment are: (1) To control convulsions; (2) To stabilize the vital functions; (3) To treat the underlying pathology; and (4) To maintain supportive therapy­ nutrition, ventilation, cardiac output, serum electrolytes and pH. Neurologic consultation should be done. +To control convulsions: Intravenous administration of phenobarbitone 20 mg/kg body weight slowly over a period of 20 minutes is effective. A maintenance dose of3-4 mg/kg bodyweight per day administered orally or IV for at least a period of2 weeks or even longer. In resistant cases IV phenytoin (dilantin), 15-20 mg/ kg at the rate of 1 mg/kg/min is administered. Maintenance dose of3-4 mg/kg/day is divided 12 hourly. Fosphenytoin is preferred. +Many anticonvulsants (phenytoin, valproic acid, vigabatrin) increased the rate of apoptotic neuronal cell death. The drugs topiramate, levetiracetam do not have this effects. + + +Table 33.6: Etiological factors for neonatal seizures. + + +Traumatic +♦ Perinatal asphyxia. ♦ Hypoxic-lschemic +Encephalopathy (HIE). ♦ lntracranial +hemorrhage (subarachnoid, peri-or intraventricular or +subdural). + + +Metabolic +♦ Hypoglycemia ♦ Kernicterus +♦ Hypocalcemia ♦ Hypercalcemia ♦ Hyponatremia +♦ Hypomagnesemia +♦ Pyridoxine dependence + +Inborn error of metabolism +♦ Pyridoxine-dependent seizure. +♦ Mitochondrial disorders. +♦ Aminoacidopathies +♦ Organic acidurias + + +Infective +♦ High fever +♦ CNS infection due to: +• Group B Strepyococcus +• E.coli +• TORCH infection +• Tetanus + + +Iatrogenic +♦ Narcotic withdrawal +♦ Drug toxicity theophylline +♦ Respiratory +stimulants + +Others (congenital) +♦ Cerebral malformation. +♦ Neonatal epileptic syndromes. +♦ Chromosomal syndromes. +♦ Unknown + + +Levetiracetam, loading dose 20-50 mg/kg. IV bolus and maintenance dose: 20-80 mg/kg/day. Twice daily dosing is commonly used. +To treat the underlying pathology: Hypoglycemia: Glucose infusion, 2 mL/kg of 10% glucose, through an intravenous line is given over 2-3 minutes. Blood glucose should be maintained at 70-100 mg/dL. +Hypomagnesemia: Magnesium sulfate (0.4-0.8 mg/kg) is given 1V every 12 hours until magnesium level is normal. +Infection: Appropriate antibiotic therapy following complete septic work-up. +Hypocalcemia: Intravenous administration of 2 mL/kg of 10% calcium gluconate taken over 5 minutes. This is to be followed by oral calcium 40-50 mg/kg/day for few days. +Pyridoxine deficiency: Intravenous administration of 100 mg pyridoxine is effective. +Prognosis varies with the etiology. Convulsions due to transient or metabolic disorders (hypocalcemia) have an excellent prognosis whereas seizures secondary to congenital malformations, HIE, have poor outcome. The overall mortality rate has decreased but neurological sequelae (neurodevelopmental impairment, CP, epilepsy) are still around 30-40%. + +BIRTH INJURIES OF THE FETUS AND NEWBORN +Birth injury is an impairment of the infant's body function or structure due to adverse influences that occurred at birth. Injmy commonly occurs during labor or delive1y. Antenatal injuries may be due to amniocentesis and intrauterine transfusion and intrapartum injury may occur following fetal scalp electrodes and intrapartum monitoring. Birth injuries may be severe enough to cause neonatal deaths, stillbirths or number of morbidities (Box 33.6 and Table 33. 7). + +Chapter 33: Diseases of the Fetus and the Newborn + + +■ Prolonged or obstructed labor. ■ Fetal macrosomia. +■ Cephalopelvic disproportion. " Very low birth weight infant +11 Vaginal breech delivery (breech). +a Instrumental delivery (forceps or ventouse). 11 Difficult labor. +11 Shoulder dystocia. +■ Inadequate maternal pelvis. 11 Oligohydramnios. +11 Fetal anomalies. ■ Precipitate labor. +11 Manipulative delivery (IPV). + +Table 33.7: Birth injuries. +Types of +injury Organ(s) affected +Soft tissue Skin: Lacerations, abrasions, fat necrosis, petechiae. Muscle Sternocleidomastoid. +Nerve Facial nerve, brachia! plexus, Duchenne Erb (C5, C6), +Klumpke (C7, C8, T1), spinal cord, phrenic nerve (C3, C4 or +C5), Homer's syndrome, recurrent laryngeal nerve. Eye Hemorrhages: Subconjunctiva, vitreous, retina. +Viscera Rupture of liver, adrenal gland, spleen testicular injury. +Scalp Laceration, abscess, hemorrhage, caput succedaneum. Dislocation Hip, shoulder, cervical vertebrae. +Skull Cephalhematoma, subgaleal hematoma, fractures. +lntracranial Hemorrhages: lntraventricular, subdural, subarachnoid. + + + +I INJURIES TO THE HEAD Bones + +Fractures: Mandible, clavicle, humerus, femur, skull and nasal bones. + + + +CEPHALHEMATOMA: It is a collection of blood in between the pericranium and the flat bone (subperiosteal) of the skull, usually unilateral and over a parietal bone (Fig. 33.6). It is due to rupture of a small emissary vein from the skull and may be associated with fracture of the skull bone. This may be caused by forceps delivery but may also be met with following a normal labor. Ventouse application does not increase the incidence of cephalhematoma. It is never present at birth but gradually develops after 12-24 hours. The swelling is limited by the suture lines of the skull as the pericranium is fixed to the margins of the bone (Fig. 33.6). It is circumscribed, soft, fluctuant and incompressible. There may be underlying fracture of the skull. It can cause hyperbilirubinemia when extensive, and the infant may need blood transfusion. MRI scan should be done if neurologic symptoms are present. The condition may be confused with caput succedaneum or meningocele. Meningocele always lies over a suture line or fontanel and there is impulse on crying. Management: Observation is done. The blood is absorbed in course + +Injuries may involve: (i) Soft tissue (most common) and/or (ii) Bones (rare) + + + +Faix cerebelli + + + + + + +Tentorium +cerebelli + + + + + + +Fig. 33.5: Excessive molding of the head with marked elongation of the mentovertical diameter resulting in tear of the tentorium cerebelli. +El Chapter 33: Diseases of the Fetus and the Newborn +of time (6-8 weeks) leaving an entirely normal skull. +Prognosis is good. Rarely, suppuration occurs. No active treatment is necessary. Prevention of infection and avoidance of trauma are important. Anemia and hyperbilirubinemia should be treated. +Subgaleal hematoma is the hemorrhage under the scalp aponeurosis. It may occur following vacuum or forceps delivery. The hematoma can spread across the entire calvarium over the suture lines unlike cephal-hematoma. It may be progressive and needs frequent reassessment. Clinically, it is noted as a fluctuant swelling with insidious onset. Rarely rapidly progressive to cause shock even. +Management: The infant needs to be observed care­ fully for signs of hypokalemia. Blood transfusion may be need.ed. Head circumference monitoring, phototherapy for any hyperbilirubinemia may be needed. Surgical +drainage rarely indicated. +SCALP INJURIES: Minor in1uries of the scalp such as abrasion in forceps delivery (tip of the blades), incised wound inflicted during cesarean section, scalp-electrode placement or episiotomy may be met with. On occasion, the incised wound may cause brisk hemorrhage and requires stitches. The wound should be dressed with an antiseptic solution like 2% mercurochrome. +Fracture skull: Fracture of the vault of the skull (frontal or anterior part of the parietal bone) may be of linear or depressed type. Fractures are due to the effect of a dificult forceps delivery. +The fracture may be associated with cephalhematoma, extradural or subdural hemorrhage or a hematoma or brain contusions. Linear fracture if uncomplicated is usually symptomless. Depressed fracture may occasionally cause pressure effect. Neurological manifestations may occur later on due to effect of compression. Treatment is conservative in symptomless cases. Neurosurgical consultation should be obtained in presence of symptoms and X-ray or MRI studies are needed. The depressed bone has to be elevated or subdural hematoma may have to be aspirated or drained surgically. + +i lNTRACRANIAL HEMORRHAGE ♦ Traumatic +♦ Anoxic +♦ Primary hemorrhagic disease (p. 453) +Intracranial Hemorrhage {ICH) may be-(a) external to the brain (epidural, subdural or subarachnoid spaces); {b) in the parenchyma of brain (cerebrum or cerebellum); and (c) into the ventricles from subependymal germinal matrix or choroid plexus. +Ve1y common is subdural hemorrhage (70%), then subarachnoid (20%) ➔ intracerebral (20%) ➔ intraventricular and epidural hemorrhage. The most common ICH in preterm infants is bleeding from the germinal matrix and that may result in intraventricular or periventricular hemorrhage. +Traumatic +■ In Epidural Hemorrhage (EH) blood collects between inner skull and the dura mater. It is rare in newborn. Usually associated with fracture skull bone following dificult instrumental delivery (described earlier). EH does not always + + + + + + +need surgical intervention. It needs monitoring with serial imaging. +■ Subdural Hemorrhage (SDH) is the accumulation of blood between the dura and arachnoid membrane. +♦ Slight hemorrhage may occur following: (i) fracture of skull bone; {ii) rupture of the inferior sagittal sinus; or (iii) ruptme of small veins leaving the c01tex. The hemorrhage, so occurring, produces hematoma which may remain stationa1y or increase in size. Neurological symptoms may appear acutely or may have insidious onset, like vomiting, irritability and failure to gain weight. Hydrocephalus and mental retardation may be a late sequelae. +♦ Massive hemorrhage: Massive subdural hemorrhage usually results from-(1) Tear of the tentorium cerebelli thereby opening up the straight sinus or rupture of the vein of Galen or its tributaries; (2) Injury to the superior sagittal sinus. Clinical presentation: Nuchal rigidity, coma, apnea, bulging fontanel (increased intracranial pressure) nonreactive pupils, seizures may be present. +Meehani,m oftento,iol tea, +Causes: {i) Excessive moulding in deflexed vertex I.": +with gross disproportion; (ii) Rapid compression of • the head during delivery of the aftercoming head of • breech or in precipitate labor; and {iii) Forcible forceps traction following wrong application ofthe blades (other than biparietal diameter). +!] .,. +Clinical features: The hemorrhage may be fatal and the baby is delivered stillborn or with severe respiratory depression. In lesser affection, the baby recovers from the respiratory depression. Gradually, the features of cerebral irritation appear, such as, frequent high-pitch cry, neck retraction, incoordinate ocular movements, convulsion, vomiting and bulging of the anterior fontanel. +Subarachnoid Hemorrhage (SAH) is an accumulation of blood between the arachnoid and the pia mater. It is due to the rupture of small vessels due to birth trauma or birth asphyxia. It may be idiopathic and significant at times. The symptoms may appear late (1 week). Clinical presentations are: seizures, irritability and lethargy with focal neurological signs. +Anoxic damage may be: (A) Cerebral intraparenchymal hemorrhage (IPH) or (B) Intraventricular hemorrhage (IVH)/ Germinal Matrix Hemorrhage (GMH). +Fu, Hemonhage due to Ano>ia +Diagnosis is made invariably by neuroimaging ,- +studies: Real time portable Cranial Ultrasonography ., · . + +!J, · +(CUS) is the procedure of choice in the term +newborn. IVH is diagnosed by head CT or CUS. MRI is also helpful. Risk factors for GMH/IVH: Extreme prematurity (32 weeks), and birth asphyxia. PVH, IVH and PVL are the most common neurologic complications of prematurity. GMH/IVH originates from the fragile involuting vessels of the subependymal germinal +matrix. +PREVENTION: Comprehensive antenatal and intranatal care is the key to success in the reduction of intracranial injuries. +Antenatal measures to prevent IVH/GMH +1. Tocolysis with indomethacin should be avoided. +2. In utero transfer of preterm labor to a center with NICU. +3. Cesarean delivery before active phase of labor in preterm infants. + + +4. Antenatal steroids can reduce the risk by threefold. +5. To prevent or to detect at the earliest, intrauterine fetal asphyxia by intensive fetal monitoring. +6. To avoid traumatic vaginal delivery in preference to cesarean section. Difficult forceps should be avoided. +7. Administration of vitamin K I mg intramuscularly soon after birth in susceptible babies. +Postnatal prevention: Avoid birth asphyxia, fluctuation of blood pressure and correct acid-base abnormalities. Surfactant therapy is found helpful. +INVESTIGATIONS +1. Cranial Ultrasonography (CUS) is used to detect intraventricular hemorrhage; +2. Doppler ultrasonography can detect any change in cerebral circulation; +3. CT scan is useful to detect cortical neuronal injury; +4. Magnetic Resonance Imaging (MRI) is the best for Cerebral Intraparenchymal Hemorrhage (IPH). In addition MR angiography/venography may be useful to demonstrate a vascular anomaly, arterial embolus or sinus venous thrombosis. MRI is superior than CT, CUS to establish the etiology of IPH, to determine the long term prognosis of the newborn (Fig. 33.7); and +5. CSF-elevated RBCs, WBCs and protein. + +MANAGEMENT: Prnvention: Antenatal glucocorticoids reduce GMH/IVH. +Supportive care: To maintain normal circulatory volume, cerebral perfusion, serum electrolytes and blood gases. Packed red blood cells transfusion may be needed where IVH is large. Thrombocytopenia and coagulation parameters should be corrected, seizures should be treated. + + + + + + + + + + + + + + + + + + + + + + + +Fig. 33.7: MRI of brain showing massive areas of hypoxic and ischemic injury (arrows). + +Chapter 33: Diseases of the Fetus and the Newborn + +TREATMENT +■ Follow-up with serial neuroimaging Cranial Ultrasound (CUS and MRI) to detect any progressive hydrocephalus. +■ Anticonvulsant: Any of the following may be useful­ (a) Phenobarbitone; (b) Phenytoin; (c) Levetiracetam. +■ Subdural hematoma: (a) Subdural tap-aspiration of the blood through lateral angles of the anterior fontanel may be required which may have to be repeated; (b) Open surgical evacuation-serial CT is indicated before surgical interven­ tion. The infant should be monitored for any hydrocephalus. Surgical removal of the clot including the capsule may have to be done to prevent development of neurological sequelae; and (c) Rarely, subdural-peritoneal shunting may be needed. Neurosurgeon is consulted. +PROGNOSIS: Prognosis of GMH/IVH depends on the severity of IVH, brain lesions, birth weight and gestational age of the infant. The surviving infants usually behave normally in later life. There is, however, some correlation with mental retardation and neurological disorders. Epilepsy may develop later in life. +Management of IPH: Acute management is similar to SDH and SAH. Any large IPH with severe neurologic compromise, needs prompt neurosurgical intervention. A large IPH when associated with IVH or SAH, should be observed at a regular interval. Long-term prognosis largely relates to the location, size of the IPH and the gestational age of the newborn. Major cerebellar IPH in preterm newborns may result severe cognitive and motor disability. +I OTHER INJURIES +SKIN AND SUBCUTANEOUS TISSUES: Bruises and lacerations on the face are usually caused by forceps blades. Scalpel cut or laceration injury may occur during cesarean section. They usually occur on the buttocks, scalp or thigh. Small cut heals spontaneously. Laceration injury may need repair by stitches with 7-0 nylon. Healing is usually rapid. + +MUSCLES +■ Sternocleidomastoid (SCM) injury (congenital torticollis) is characterized by a well-circumscribed immobile mass in the midpoint of the SCM. The head tilts towards the involved side. The patient cannot move the head normally. +■ Sternomastoid hematoma usually appears about 7-10 days after birth and is usually situated at the midposition of the muscle. It is caused by rupture of the muscle fibers and blood vessels, followed by a hematoma and cicatricial contraction. It may be associated with difficult breech delivery or attempted delivery following shoulder dystocia or excessive lateral flexion of the neck even during normal delivery. There is transient torticollis and it is wise not to massage. Treatment is conservative. Stretching of the involved muscle should be done several times a day. Recovery is rapid (3-4 months) in majority of cases. Surgery is needed if it persists after 6 months of physical therapy. +NERVE INJURIES: Facial (cervical nerve VII) palsy (peripheral): The facial ne1ve remains unprotected after its exit through the stylomastoid foramen. It is involved by direct pressure of the forceps blades or by hemorrhage and edema around the nerve. It may even be involved in spontaneous delivery when too much pressure is applied on the ramus of the mandible where +Im Chapter 33: Diseases of the Fetus and the Newborn + +the nerve crosses superficially. Diagnosis is made by noting the eye of the affected side which remains open and eyelids are immobile. On c1ying, the angle of the mouth is drawn over to the unaffected side. No nasolabial fold is present. Sucking remains unaffected. Treatment aims at protecting the eye, which remains open even during sleep, with synthetic tears (1 % methyl cellulose drops). The condition usually disappears within 2-3 weeks unless complicated by intracranial damage (Figs. 33.8A and B). +■ Brachial plexus palsy: Either the nerve roots or the trunk of the brachia! plexus are involved. The damage of the nerve is due to stretching (common) or effusion or hemorrhage inside the sheath. Tearing of the fibers is rare. +The cause is undue traction on the neck during attempted delivery of the shoulder. The affection is due to hyperextension of neck to one side with forcible digital extension and abduction of the arm in an attempt to deliver the shoulders. The risk factors are: macrosomia, shoulder dystocia, instrumental delivery. Unilateral involvement is common. Two clinical types are met depending upon the nerve root involved. Rarely, both types are present together. +Management: Early mobilization and referral to a specialist team if not improved by 1 month. +■ Duchenne-Erb's palsy: This is the most common type when the 5th and 6th and rarely the 7th cervical nerve roots are involved. The resulting paralysis causes the arm to lie on the side (adducted) with extension of the elbow, pronation of the forearm and flexion of the wrist (Waiter's tip). Winging of the scapula is common. Moro reflex is absent. There may be associated ipsilateral phrenic nerve (diaphragmatic) paralysis (C3, 4, 5). +■ Iaumpke's palsy: This type of palsy is due to the affection of the lower cords of the plexus involving 7th and 8th cervical or even the first thoracic nerve roots. There is paralysis of the muscles of the forearm. The arm is flexed at the elbow and the wrist is extended. The forearm is supinated and a claw­ like deformity of the hand is observed. When thefirst thoracic nerve is involved, there may be ipsilateral ptosis with small pupil due to sympathetic nerve involvement (Homer's syndrome). Treatment consists of immobilization and prevention of contractures. Physical therapy and passive movements are advocated. Full recovery takes weeks or even months. Severe injmy may produce permanent disability (Figs. 33.8A and B). Bony injmy should be excluded with radiography. +Prognosis is usually good, if it is due to stretching. But if it is due to hemorrhage or avulsion, the deformity may be permanent. +■ Brachial plexus injury: The incidence is about 0.1-0.2% of shoulder dystocia, even in normal delivery, macrosomia, + + + + + + + + + + +., +Figs. 33.SA and B: (A) Facial palsy; (Bl Erb's palsy. + +malpresentation and instrumental deliveries. The entire arm is flaccid. All reflexes are absent. +■ Phrenic nerve injury (C3, 4 or 5) causes paralysis of the ipsilateral diaphragm. This is due to excessive stretching of the neck at birth. Risk factors are: Breech or dficult forceps delivery. Infants present with respiratory distress, cyanosis and tachypnea. Diagnosis is made by USG showing paradoxical movement of the diaphragm. +Treatment is supportive. Continuous Positive Airway Pressure (CPAP) or mechanical ventilation may be needed. Recovery is usually completed in 1-3 months of time. +FRACTURES +♦ Skull bone-(p. 455) +♦ Spines-fracture of the odontoid process or fracture dislocation of the fifth-sixth cervical vertebrae may occur due to acute bending of the spine while delivering the aftercoming head or in shoulder dystocia. The result is instantaneous death of the baby due to compression on the medulla. +♦ Long bones-bones commonly involved in fractures are-the humerus, the clavicle and the femu,: These occur in breech delivery. Fractures are usually of greenstick type but may be complete. Rapid union occurs with callus formation. Deformity is a rarity even where the bone ends are not in good alignment. +n·eatment: Fracture femur and humerus are treated by immobilization (splinting). X-ray studies are done. Closed reduction and casting are needed when bones are displaced. Limb motion is restricted. Healing with callus formation occurs over 2-4 weeks. Usually there is complete recovery. +DISLOCATIONS: The common sites of dislocations of joints are shoulder, hip, jaw and fifth-sixth cervical vertebrae. Confirmation is done by radiology or ultrasonography and the help of an orthopedic surgeon should be sought. +VISCERAL INJURIES: Liver, kidneys, adrenals or lungs are commonly injured mainly during breech delive,y. The most common result of the injury is intraperitoneal hemorrhage. Severe hemorrhage is fatal. In minor hemorrhage, the baby presents features of blood loss in addition to the disturbed function of the organ involved. Treatment is directed: (1) To correct hypovolemia, anemia and coagulation disorders; (2) Specific management-surgical or otherwise, to tackle the injured viscera. + +PERINATAL INFECTIONS +Perinatal infection is still one of the leading causes of neonatal death. The neonates are more susceptible to infection as they are deficient in natural immunity and acquired immunity. Preterm infants are at high-risk for perinatal infections (Box 33.7). Neonates who survive from sepsis often suffer from severe neurological as well as severe parenchymal lung diseases. Early Onset Sepsis (EOS) occurs within first 3 days oflife. + +I MODE OF INFECTION +♦ Antenatal ♦ Intranatal ♦ Postnatal +ANTENATAL: Transplacental: Maternal infection that can affect the fetus through transplacental route are predominantly +Chapter 33: Diseases of the Fetus and the Newborn ID + + + +♦ Rupture of membranes> 18 hours. +♦ Maternal intrapartum fever> 100.4°F. ♦ Low birth weight infant (<2,500 g). +♦ Early preterm infant (<34 weeks). ♦ Chorioamnionitis. ++ Male infants. +♦ Mother with Group B f3-hemolytic streptococcal (GBS) colonization. +♦ Repeated vaginal examination in labor. ♦ Invasive procedures of monitoring. + +the viruses. They are rubella, cytomegalovirus, herpes virus, HIV, chickenpox and hepatitis-B and C, COVID virus. Other infections are syphilis, toxoplasmosis and tuberculosis. +Amnionitis: Amnionitis following premature rupture of the membranes can affect the baby following aspiration or ingestion of infected amniotic fluid. + +INTRANATAL +■ Aspiration of infected liquor or meconium following early rupture of the membranes or repeated internal examination. +■ While the fetus is passing through the infected birth passage-(a) eyes are infected-ophthalmia neonatorum, or (b) oral thrush with Candida albicans. +■ Improper asepsis while caring the umbilical cord. +POSTNATAL: Nosocomial infections-(i) Transmission due to human contact-infected mother, relatives or staff of the nurse1y; (ii) Cross-infection from an infected baby in the nurse1y; (iii) Infection through feeding, bathing, clothing or airborne; and (iv) Infection in the environment of neonatal intensive care unit (NICU) or invasive monitoring. +Clinical presentation of early-onset neonatal sepsis (EOS): It is abrupt and 90% infants become symptomatic by 24 hours of age. Tachypnea, grunting, lethargy, hypotension, cyanosis, jaundice, vomiting, diarrhea and RDS are the common symptoms. Other less common presentations are: DIC, meningitis and Persistent Pulmonary Hypertension of the Newborn (PPHN). Infections with A. baumannii can cause: septicemia, pneumonia, meningitis, UTI and soft tissue infection. Poor perfusion, irritability and DIC with petechiae can occur in more severe sepsis. There may be hypothermia (preterm), or hyperthermia (term) infants. +Common pathogens are: Acenetobacter species, gram-negative: A. Baumannii (multidrug resistant). ESKAPE organisms are: Enterococcus faeciam, S. aureus, K. pneumoniae, A. baumannii, Pseudonona aeruginosa. These organism efficiently evade the effects of antibiotics. +Others are: Group B Streptococcus (GBS), Staphylo­ coccus aureus, E. coli, Klebsiella, Haemophilus, Enterobacter, B. fragilis and Citrobacter, Pseudomonas, fungus ( Candida) and anaerobes. The infection is acquired during intrapartum period from the genital tract. The infant is colonized with pathogen in the perinatal period. + +The prima,y sites of colonization are: skin, nasophaiynx, orophaiynx, conjunctiva and the umbilical cord. +DIAGNOSIS: Laboratory evaluation includes: Complete Blood Count (CBC), platelet count, blood and urine culture and acute phase reactants. An elevated WBC (>40,000) count with polymorphonuclear cells or a depressed total WBC ( <5,000) and absolute neutropenia ( <1,500) are commonly found. Coagulation profile (PT, PTT, INR), LP for CSF cell count, protein, glucose are to be done. C-Reactive Protein (CRP) remains elevated with inflammation and decline rapidly with resolution. Serial tests are needed. +Imaging studies: Chest X-ray and renal ultrasound are needed depending upon the presentation. +PREVENTION OF NEONATAL INFECTION: GBS prophylaxis can reduce EOS significantly. Empiric antibiotic therapy with broad coverage (P lactam and Aminoglycoside) are started. Emergence of Multidrug-Resistant (MDR) Organisms (MDROs) need therapy with Piperacillin­ Tazobactum and gentamicin. +TREATMENT: Antibiotic therapy (Table 33.8)-Aceneto­ bacter sepsis is treated with carbapenem (imipenem or meropenem). Resistant cases are treated with polymyxin antibiotics. Other antibiotics are: Colistin, Tigecycline and Rifampicin. Broad spectra are given to cover the gram-positive and gram-negative organisms as well as the anaerobes. Immunotherapy with IV Immunoglobulin (IVIG), monoclonal antibodies, Granulocyte Colony Stimulating Factor (GM-CSF) are used as an adjuvant to the antibiotics. Till date the benefits are limited. +SUPPORTIVE TREATMENT FOR SEPSIS: Mechanical venti-lation, surfactant therapy for pneumonia and RDS, pressor drugs for hypotension and anticonvulsants for seizures are to be maintained. Echocardiography may be helpful in selected cases ( cyanotic infant, pulmonary hypertension). +COMMON SITES OF INFECTION +n·ivial but may be serious: (i) Eyes-ophthalmia neonatorum; (ii) Skin; (iii) Umbilicus; (iv) Oral thrush. +Severe systemic: (i) Respiratory tract; (ii) Septicemia; (iii) Meningitis; (iv) Intra-abdominal infection. + +OPHTHALMIA NEONATORUM (CONJUNCTIVITIS) +Ophthalmia neonatorum is defined as inflammation of conjunctiva during first month of life. +CAUSES: The common causative agents are: (i) Chlamydia trachomatis (oculogenitalis); (ii) Other bacterial causes: (a) Gonococcus (rare), Staphylococcus, Pseudomonas, (b) Chemical­ silver nitrate, (c) Viral-herpes simplex (type II). +MODE OF INFECTION: Infection occurs mostly during delive1y by contaminated vaginal discharge. It is more likely in face or breech delive,y. During neonatal period, there may be direct contamination from other sites of infection or by chemical. +Im Chapter 33: Diseases of the Fetus and the Newborn Table 33.8: Antibiotics used to treat neonatal sepsis. + +Drug Ampicillin Amikacin Gentamicin +Cefotaxime + + +Nature Bactericidal Bactericidal Bactericidal +Bactericidal + + +Bacterial coverage +Both gram +ve and gram -ve Primarily gram -ve +Primarily gram -ve +Mainly gram -ve + + +Daily dose Route 150 mg/kg/q 12 h IV/IM 15 mg/kg/q 24 h -do-3-4 mg/kg/q 24 h -do- +50 mg/kg/q 12 h -do- + + +Side effects +Diarrhea, skin rash, nausea, vomiting. Nephrotoxicity, ototoxicity. Ototoxicity, nephrotoxicity. +Hypersensitivity, thrombophlebitis, +diarrhea. + +Organism GBS +Escherichia coli CONS +Klebsiella, Serratia + + + +Cefuroxime + +Ceftriaxone + + +Bactericidal + +Bactericidal + + +Both gram +ve and gram -ve + +-do- + + +50 mg/kg/q 12 h -do- + +50 mg/kg/q 12 h -do- + + +Generally free from toxicity, +hypersensitivity (rarely). +Diarrhea, eosinophilia, skin rash, +neutropenia. + + +Enterobacter + +Listeria + +Meropenem Bactericidal A+vereoabnicd agnrdaman-aveerobic gram 20 mg/kg/q 12 h -do- tDhiarorrmhbeao,clyetuokpoepneina,iaa,naphylaxis. Enterobacter + +Piperacillin/ +tazobactam + +Bactericidal Mainly gram +ve gram -ve 2 g + 250 mg (Tazo) q 12 IV +hourly (see infusion guide) + +Allergic rash, anemia, candidiasis, fever, Pseudomonas +diarrhea. + + + +Vaneomycin Bactericidal eMnotsetrogcraomcci+avneearonbdics + +15 mg/kg/day IV or 12 Allergy +hours + + +Allergy, ototoxicity, nephrotoxicity, +thrombophlebitis. + + +MRSA + +(IM: Intramuscular; IV: Intravenous; q 12 h: every 12 hours; q 24th: every 24 hours; CONS: Coagulase Negative Staphylococci; MRSA: Methicillin-Resistant Staphylococcus aureus; ESBL: Extended-Spectrum j3 Lactamase) + + +The clinical picture varies and the discharge may be watery, mucopurulent to frank purulent in one or both eyes. The eyelids may be sticky or markedly swollen. Cornea may be involved in severe cases. +Prognosis is favorable to most cases. +PREVENTION: Any suspicious vaginal discharge during the antenatal period should be treated and the most meticulous obstetric asepsis is maintained at birth. The newborn baby's closed lids should be thoroughly cleansed and dried. +INVESTIGATIONS: The discharge is taken for-(a) Gram stain smear; (b) Culture and sensitivity; (c) Scraping material from lower conjunctiva for Giemsa staining and also culture in suspected chlamydial infection; and (d) Culture in special viral media for suspected herpes simplex infection. +TREATMENT: Prophylaxis: Erythromycin or gentamicin ophthal­ mic drops, ointment is effective without any complication. +(a) Gonococcal: Infant is isolated during the first 24 hours of treatment. Eyes are irrigated with sterile isotonic saline eve1y 1-2 hours until clear. In severe and culture positive cases, systemic ceftriaxone 25-50 mg/kg/IV/IM or cefotaxime 100 mg/ kg is given IM/IV. Single dose in infant without dissemination or for 7 days when there is dissemination, is usually given. +(b) Chlamydia: Elythromycin suspension 40 mg/kg daily orally divided into 4 doses for 14 days is given to prevent systemic infection. Topical treatment alone is ineffective. +(c) Herpes simplex: The infant is isolated. Systemic therapy with acyclovir 20 mg/kg eve1y 8 hours for 2 weeks is given IV. Topical use of 3% vidarabine or 0.1% iododeoxyuridine ointment 5 times a day for 10 days is used. +Ophthalmologist should be consulted for any severe infection. +I SKIN INFECTIONS +Newborn's skin infections may manifest as skin rashes, pustulosis or cellulitis. The causative organisms are: Gram-positive, Gram­ negative and anaerobic organisms. Staphylococcus aureus is the predominant one. Common sites of infections are: face, axilla, + +groin, scalp and periumbilical area. Colonization of the newborn skin occurs during birth from vaginal flora as well as from the environment (nosocomial, cross-infection from the carriers). +Localized infections are often due to traumatized skin. The common sites are: venipuncture or scalp electrode. +PUSTULOSIS-is usually caused by S. aureus. Rarely, it may be epidemic, and results in septicemia or pyemia. Some skin lesions may be bullous or scalded. +Treatment of S. aureus pustulosis depends on the severity of infections and condition of the infant. Mild infections may be treated with topical mupirocin and oral therapy with amoxycillin/ or cephalexin. More extensive lesions require therapy with nafcillin or oxacillin MRSA infection need to be treated by Vancomycin. +v. +Cellulitis-usually occurs at a traumatic skin site (see above). It is usually treated with local antibiotic ointment (bacitracin). In severe infections or in a premature infant, Complete Blood Count (CBC) and, blood culture are to be obtained. Systemic antibiotic (oxacillin or nafcillin and gentamicin) IV is given. +Epidemic outbreaks due to nosocomial acquisition of S. aureus in newborn nurseries or NICU need intensive surveillance of the staff members and the newborns with culture. + +UMBILICAL SEPSIS (OMPHALITIS) +It is not uncommon for mild umbilical sepsis to occur. The causative organisms include both gram-positive and gram­ negative organisms. The infection is manifested by serous or seropurulent umbilical discharge which may be offensive. The base of the cord stump looks moist and the periumbilical skin becomes red and swollen. There is delay in falling off of the cord. Systemic manifestations include pyrexia and features of toxemia or jaundice in severe infection. +SPREAD OF INFECTION: (1) Periumbilical cellulitis with suppuration; (2) Thrombophlebitis of the umbilical vein with extension of the infection to the liver producing hepatitis or pyemic liver abscess; (3) Peritonitis; and (4) Necrotizing fasciitis. +PREVENTION: Antiseptic and aseptic precaution should be taken right from the time of cutting the cord to the time of complete +Chapter 33: Diseases of the Fetus and the Newborn ID + +epithelialization of the area after falling of the cord. The care of the umbilical cord as mentioned in Ch. 31 should be followed. +CURATIVE: Treatment: Complete septic work up (CBC, blood and umbilical swab culture) is done. Antibiotic therapy with Nafcillin and Gentamicin or Oxacillin or Piperacillin/ Tazobactam may be used depending upon the severity of infection. The wound is dressed like any surgical wound with spirit and antiseptic powder. +TETANUS NEONATORUM: It is rare nowadays. The infection is caused by the neurotoxin of Clostridium tetani and the portal of entty is through the umbilical cord. The features are evident within 5-15 days after birth. +The striking features are: Inability to suck associated with marked trismus followed by rigidity of the body with opisthotonus, pyrexia and convulsions. +Prevention includes immunization of the mother during pregnancy with tetanus toxoid. Babies born in safe conditions without previous immunization of the mother, should be given 1,500 IU of antitetanus serum intramuscularly soon after birth. +Curative treatment includes: (l) The baby should be isolated in the infectious disease hospital; (2) Tetanus immune globulin (human) 500 IU is given intramuscularly; (3) Antibiotics, particularly Penicillin G should be given (100,000 units/kg/day divided every 4-6 hours for 7-10 days); (4) Sedation and muscle relaxants to be given; (5) Endotracheal intubation and mechanical ventilation may be needed; (6) Nutrition is to be maintained by intragastric feeding. (7) MG to be given ifTIG is not available. The infant after recovety should be given standard tetanus immunization. Prognosis: Mortality is up to 60-80%. +I NECROTIZING ENTEROCOLITIS +NEC is an acute ischemic and inflammatory injury of the distal small and often proximal large intestine. Surgical pathology revealed segmental coagulative necrosis of mucosa, intramural gas (pneumatosis) and sloughing of mucosa. Incidence: An estimated 0.3 per 1000 live births. +Risk factors: (a) Premature infants; (b) Perinatal asphyxia; (c) Hypotension; (d) Polycythemia; (e) Umbilical cord catheter­ related thromboembolism; (f) Septicemia due to E.coli, Klebsiella, Pseudomonas; (g) Exchange transfusion; and (h) Congenital heart disease; (i) Bacterial dysbiosis. +Pathophysiology: There is ischemic and/ or toxic damage to the mucous membrane of the gut commonly in the ileocecal region. It is associated with bacterial proliferation and gas formation. There is excessive and inappropriate intestinal inflammatory response. Inflammatory mediators (platelet activating factors, endotoxins, TNF, inflammatory mediators, interleukins) are present. Gradually, there is ischemic necrosis of the muscular wall of the gut, gangrene ultimately leads to perforation and peritonitis. +Diagnosis: Systemic signs: Respiratory distress, bradycardia, hypotension, acidosis, oliguria are present. Abdominal signs: dystonia, vomiting, hematochezia or ascites, feeding intolerance, acidosis, oliguria, bleeding diathesis, abdominal distension and tenderness. Laboratory findings are of less value, +Imaging studies: X -ray abdomen reveals abdominal gas pattern with dilated loops. Pneumatosis intestinalis is the hallmark of diagnosis. Ultrasonography, including Doppler, can detect + +gas bubbles in liver parenchyma, portal venous system, bowel necrosis and perforation. Grossly bloody stool is common in NEC. Thrombocytopenia, metabolic acidosis and hyponatremia are the triad of signs to confirm the diagnosis. +Prevention: Human (mother's) milk can prevent NEC. Probiotics and nutrients enhance the growth of beneficial microbes. Prolonged use of antibiotics should be avoided. +TREATMENT: (i) Respiratory system: Supplemental 02 and mechanical ventilation may be needed; (ii) Support to the +cardiovascular system: Circulatory volume, blood pressure, arterial blood gas, tissue perfusion. +Nutrition-(i) Discontinuation of oral feeding and to start nasogastric suction; (ii) Total parenteral nutrition; (iii) Laboratory monitoring for arterial blood gas, serum electrolytes, blood glucose,. platelet count, acid-base balance and septic work up are done; (iv) Antibiotics-Vancomycin, Piperacillin/ Tazobactam, Gentamycin and Metronidazole; (v) Bowel resection in the case of perforation. Prognosis: Mortality is up to 40% when associated with pe1foration. Overall mortality is about 10-12%. +Prevention of NEC: Prevention of preterm birth is the key factor. Others are: (i) Antenatal Corticosteroid for GI maturation (ii) Exclusive feeding with human milk. (iii) Enterally fed probiotics to normalize intestinal microflora colonization (Lactobacillus GG) and (iv) Nutritional supplements: (a) Poly unsaturated fatty acids (PUPA), (b) growth factors: Transforming Growth Factor Beta (TGFB). + +I MUCOCUTANEOUS CANDIDIASIS +ORAL THRUSH: Infection of the buccal mucous membranes and the tongue by the fungus Candida albicans is not uncommon, especially in bottle-fed babies. Contamination by the organisms occurs from the feeding bottle, pacifiers, nurse's hand, mother's nipple and infected vagina. The fungus grows on the mucous membrane and produces milky white elevated patches resembling milk curd, which cannot be easily wiped off. Rarely, the fungal infection may spread down to involve the gastrointestinal or respiratoty tract. +It usually appears in the late first week or during the 2nd week. The infant refuses to take feeds. Constitutional upset is unusual but becomes evident in extraoral spread to the respiratory tract. The typical patches are visible on the mouth and an attempt to remove the patch leaves behind a raw oozing surface. Spots on the edges of the tongue are diagnostic, as suckling would remove the milk curd from that region. +PROGNOSIS: If effectively treated, cure is vety prompt; but, in neglected cases, especially with alimentaty or respiratoty tract involvement, rapid deterioration occurs. +PREVENTION: Maternal fungal infection in the vagina is to be adequately treated before delivety. Utensils, including feeding bottles and teats, are to be properly cleansed before and after each feed. + +TREATMENT: Nystatin oral suspension (100,000 U/mL), 1 mL is applied to each side of the mouth 4 times a day for about 2-3 weeks. Fluconazole 6 mg/kg IV or orally once followed by 3 mg/kg IV/PO each day can be used for severe oral candidiasis. Systemic fluconazole is highly effective in treating chronic candidiasis in the immune compromised host. Infants with chronic, severe thus should be evaluated for immune deficiency. +ID Chapter 33: Diseases of the Fetus and the Newborn + +Mother with superficial or ductal candidiasis in the breast, should be treated concurrently. Term infant can continue breast feeding during treatment. Infants with chronic thrush refractory to usual treatment should be investigated for immunodeficiency. Diaper candidal dermatitis is treated with topical 2% nystatin ointment, 2% miconazole ointment or I% clotrimazole cream. Intestinal colonization should be treated with oral nystatin at the same time. + +TERATOLOGY AND MAJOR MALFORMATIONS + +The incidence of major congenital malformations is about 2-5% at birth, a lower incidence of 1 in 500, is however, reported from the hospital statistics of India. Developmental defects are mainly from the genetic (25-30%), environmental or unknown causes (65%). Drug exposure accounts for only 2-5% of birth defects. In general population the incidence of major malformations is about 2-5%. Defects in the central nervous system account for about 50% of malformations. + +ETIOLOGY: The causes are not fully understood and are grouped as follows (Flowchart 33.3). +When a fetus is exposed to a teratogenic agent, the resultant effect will depend on the duration of gestation and the genetic susceptibility of the fetus. Calculating from the first day of LMP (D 31 to D 71 is the critical period of organ development). +GENETICS: The defect is inherited through the genes in the ovum or sperm. Single gene disorders either Autosomal or X-linked, which may be Dominant or Recessive. +ENVIRONMENTAL: The fetal affection due to a given teratogen will depend on the dose administered, the gestational age at exposure and the maternal and fetal immune response to the agent. The fetus is, infact, potentially susceptible to some teratogenic effecteven after the completion of morphogenesis. The net effect may be death, malformation, growth retardation or functional disorder. +■ Advancing maternal age increases the incidence of Down's syndrome to the extent of 1 in 100 births at the age of 40 + + +years. Increasing parity is associated with high incidence of malformations. +■ The adverse effects of drugs (Fig. 33.3) on the preimplantation and postimplantation phase remain unpredictable. However, wa,Jarin, lithium, dilantin, antifolic acid group of drugs have got established risks on the growing conceptus. The malformation effects of the various drugs are mentioned in Ch. 34 (p. 478). +■ Infections-maternal Rubella, Cytomegalovirus, Toxoplasma either latent or overt in the first trimester, produces congeni­ tal malformation of the fetus. The correlation with other maternal infections are described in Ch. 20. +■ Irradiation is a potential danger to the fetus, especially in early emb1yonic phase. Irradiation of gonads of either parent may result in mutation of genes. Maximal ionizing radiation currently thought to be safe for the human emb1yo and fetus at any stage of gestation (as stated by the National Committee on Radiation Protection) is 5 rads. It is safer to limit its use, especially during first trimester. +Radiation can cause fetal morbidity (FGR, genetic muta­ tions, neurologic abnormalities, mental retardation, childhood leukemia) and mortality. Radiation risks are high with radiation after the first 2 weeks postconception and within the first trimester (period of organogenesis). Exposure >15 rad during second and third trimester or >5 rad in the first trimester needs patient counseling. +■ Terntogenicity: Diagnostic range of radiation exposure (less than 5 rad) is not associated with any significant congenital malformation either in human or in animal. +II Oncogenicity: Dividing cells, particularly in the first trimester are more sensitive to injury from radiation. Diagnostic radiation with fetal exposure is associated with an increased risk of malignancy. +■ Genetic damage: No radiation-induced transmissible gene mutations have been seen in humans. +II Intrauterine death: Low-dose radiation (1-5 rad) is not associated with any fetal death. + + +Flowchart 33.3: Causes of congenital abnormalities. + + +CAUSES + +Chromosomal (6%) Single gene Infections (2%) Maternal Drugs and +• Trisomy-21 disorder •Rubella illness (5%) Environmental +(Down's (5%) •Cytomegalo- • Diabetes (2-3%) +syndrome) virus • Epilepsy ■Warfarin +• Trisomy-18 •Varicella ■ Lithium +(Edward's • Parvovirus ■ Dilantin +syndrome) +•Trisomy-13 • Toxoplasma ■ACE inhibitors +■Radiation +(Palau's ■Alcohol +syndrome) ■Hypoxia + + +Autosomal X-linked disorders ■ Recessive-5% +■ Dominant-rare + +Dominant (70%) Recessive (20%) •Hemophilia +• Achondroplasia • Cystic fibrosis • Duchenne muscular dystrophy • Marfan's syndrome • Galactosemia •Color blindness +• Neurofibromatosis • Sickle cell anemia • Fragile X syndrome + + + +Multifactorial (20%) ■ Neural lube defects +■Congenital heart +defects +■ Cleft palate and cleft lip +■ Teratogenicity +■ Oncogenicity +■ Genetic damage +■ Intrauterine death + + + + + + + + +Idiopathic (60%) + + +To Defer Conception +with the following drugs: +1. Deferasirox or Deferiprone: to stop before 3 months. Desferrioxamine may be started after +20 weeks of pregnancy. +2. Methotrexate, Mycophenolate: to stop before 3 months. +3. Rituximab: to stop before 6 months. +4. ACE inhibitors, Angiotensin receptor antagonists and Warfarin: to be changed during pregnancy. +Chapter 33: Diseases of the Fetus and the Newborn ml + +■ Maternal malnutrition, metabolic and endocrinal disorders like uncontrolled diabetes, and epilepsy are related with increased incidence of fetal malformations. + +MULTI FACTORIAL: Most of the malformations probably result from delicate and complex interactions between genetic, infections and altered environmental factors, the nature of which remains obscure. The malformation may affect a single organ and a particular sex. +I DOWN'S SYNDROME (TRISOMY 21) +Trisomy 21 is the most frequent Autosomal (chromosomal) syndrome. The defect is due to: +(1) Inclusion of an additional chromosome, trisomy 21 (95%)-47 instead of 46 chromosomes. Triplication may be caused either by the presence of an entire additional chromosome 21 or the addition of only band q 22. +(2) Chromosomal translocation defect (14 : 21) (rare)­ especially occurring in young mothers. There is transfer of a segment of one chromosome to a different site of the same chromosome or to a different chromosome. There is 30% chance of recurrence in translocation defect. +Incidence: The overall incidence is 1 in 600. The incidence rises with advancing age of the mother, reaching a peak of about 1 in 25 by the age of 45 years. +Diagnosis of the affected baby: +■ Exracardiac: Craniofacial abnormalities include small ears (100%), brachycephaly, upwards and outwards slanting of the eyes with epicanthic folds; short upper lip with small mouth and macroglossia (Fig. 33.9). The hands are short and broad with a single palmar crease (30%). There is increased association of omphalocele, cataracts and esophageal atresia, duodenal atresia and imperforate anus. The affected baby is mentally retarded. +Cardiac features (40-50% ): Complete Atrioventricular Canal (CAVC), VSD most common, others are: TOF, ASD, PDA. +Hypotonia may cause breathing difficulties, poor swallowing and aspiration. Joint hyperextensibility is observed. +Expectation of life is reduced. In adult age they often develop leukemia. Male infertility is the rule. In female, puberty may be delayed and may be fertile. +■ Confirmation is established by chromosomal analysis (ka1yo­ type) using bone marrow aspiration or leukocyte culture. + +Genetic counseling in subsequent pregnancy. The risk of rec-urrence due to trisomy 21 is 1 %. That of translocation is higher. Prenatal diagnosis is possible. + +CONGENITAL MALFORMATIONS IN NEWBORN AND THE SURGICAL EMERGENCIES + +♦ Imperforate anus ♦ Esophageal atresia ♦ Meconium ileus ♦ Exomphalos +♦ Diaphragmatic hernia ♦ Duodenal atresia +IMPERFORATE ANUS: It is more prevalent in males than females. Two types are met with: +A. High imperforate anus; where rectum ends above the pubo­ rectalis sling (80-90%). There may be associated rectourinary fistula in males or rectovaginal fistula in females (95%). +B. Low imperforate anus where rectum has traversed the puborectalis sling. This variant may be associated with or without perinea! fistula. +Diagnosis is made by: (1) Absence of meconium passage; (2) Absence of anal opening; (3) Failure to pass a rectal thermometer rubber catheter or lubricated little finger; (4) A cystogram may show a fistula and document the level of distal rectum. This is also defined by ultrasonography. (5) Imaging study (X-ray, USG) of the lumbosacral spine and urinary tract should be done to exclude any other abnormality in this area. +Management +1. Cruciate incision (perinea! anoplasty) is made on the membrane in case of the simple membranous obstruction which is evidenced by marked bulging over the anal pit when the baby cries; +2. In high imperforate anus, colostomy is done and pull through operation is done at a later date (Table 33.9). A temporary colostomy may be necessary in neonates without a perinea! fistula. Primary repair without a colostomy is now being performed at many centers. +ESOPHAGEAL ATRESIA: The esophagus ends blindly about 12 cm from the nares. Babies born to mothers having hydramnios should be checked carefully at birth to exclude this abnormality. Simultaneous distal Tracheoesophageal Fistula (TEF) too often (85%) coexists. Excessive salivation, increasing respiratmy distress and even a small amount of fluid by mouth causing + +Table 33.9: Age for elective surgical procedures. + + + + + + + + + + + + + + + +tf + +Fig. 33.9: Baby with Down's syndrome. + + +Malformation Cleft lip +Cleft palate Umbilical hernia Inguinal hernia + +Hydrocele Undescended testicle +Patent ductus arteriosus Coarctation of aorta + +Hypospadias (other than glandular) + +Optima/age +6 weeks to 6 months. 9-12 months. +After 1 year, if required. +As early the infant's general condition permits. +After 1 year. +Between 1 and 2 years of age. At birth. +3-4 years or soon after the infant has been medically stabilized. +6-18 months. +r. Chapter 33: Diseases of the Fetus and the Newborn +cough and cyanosis point strongly towards the entity. Distal TEF causes reflux of gastric contents into the tracheobronchial tree causing chemical pneumonitis and pneumonia. Diagnosis is made by failure to pass a nasogastric tube down through the esophagus. Confirmation is done by radiography with prior insertion of a radiopaque catheter into the esophagus. +Management: (1) Withhold fluids by mouth; (2) Frequent suctioning to prevent aspiration; (3) Place the baby in relatively upright position (45°) to prevent reflux; ( 4) Broad spectrum antibiotic should be administered; (5) Placement of a gastrostomy tube; (6) Ligation of tracheoesophageal fistula and esophageal anastomosis by thoracotomy or thoracoscopy are the principal steps of the operation. +MECONIUM ILEUS: It is a manifestation of fibrocystic disease of the pancreas(90%). Deficiency of the pancreatic enzyme makes the meconium in the intestine inspissated which, in turn, obstructs the lumen of the lower ileum. Diagnosis is based on clinical manifestations of small gut obstruction. Sweat test: A patient with cystic fibrosis is found to lose large quantities of sodium in the sweat. Blood sample for DNA analysis to screen for cystic fibrosis is done. Straight radiographic pictures of the abdomen reveal the solid nature of the meconium with a granular appearance. Rectal mucosa! biopsy may have to be done to demonstrate the absence of ganglion cells in Hirschsprung disease. Contrast enema (meglumine diatrizoate) can be both diagnostic and therapeutic. Surgery includes resection and anastomosis of the gut containing the inspissated meconium followed by treatment with pancreatic enzymes and vitamins. Surgical therapy: Surge1y may be done open, laparoscopic and transanal. Different methods are: Staged repair with colostomy, one stage pull through or delayed I-stage repair when the infant has gained (double) weight. Prenatal diagnosis with DNA probes is possible from chorionic villus +sampling. +EXOMPHALOS (OMPHALOCELE): It is a congenital herniation of the abdominal contents (usually small gut) through the defect in the abdominal wall at the base of the umbilical cord. The anterior abdominal wall is defective in its entire thickness. Associated congenital anomalies occur in about + + + + + + + + + + + + + + + +Fig. 33.10: USG: Stomach, liver and small intestine are in the left side of the thoracic cavity, fetal heart is pushed to the right. Mediastinal shift is present. + + + + + + +30-40% of infants (chromosomal abnormalities, CDH, cardiac defects). Omphalocele differs from that of gastroschisis by the following anatomic features: (a) A protective membrane encloses the abdominal contents, {b) Contents of umbilical cord course individually over the sac and come out at the apex. Every effort should be made to protect the membranes from rupture. Cesarean delive1y may prevent rupture of this sac. A moist sterile saline dressing should be applied and arrangement is made for immediate surgical closure, if possible, in one stage ( <5 cm opening) or in two stages. Prenatal diagnosis with ultrasound is possible. +CONGENITAL DIAPHRAGMATIC HERNIA (CDH): Incidence is about 1 in 4,000 live births. Congenital diaphragmatic hernia occurs where the abdominal contents herniate through a defect in the diaphragm (patent pleuroperitoneal canal) into the thorax. It usually occurs on the left side through foramen of Bochdalek {95%). CDH following delive1y: infants may develop (A) Pulmonary parenchymal insufficiency due to hypoplastic lungs, and {B) Pulmonaiy hypertension of the newborn. Symptoms include: acute respirato1y distress with marked cyanosis which may be relieved by holding the baby in an upright position. Signs include: unequal movements of the thorax, absent breath sounds on the affected side with scaphoid abdomen. In left-sided CDH, apical impulse is shifted to the right and heart sounds are better heard over the right side of chest. USG chest reveals gas shadow of small bowel in the thorax and mediastinal shift away from the affected side (Figs. 33.10 to 33.12). It may be associated with trisomies (13, 18) and 45XO. Prenatal diagnosis with ultrasound is possible around 16 to 18 weeks. +Management-supportive care: Intubation and PPV is to be initiated immediately. Replacement of surfactant is helpful. +1. Cases diagnosed antenatally may be managed with delive1y by EXIT procedure. Multidisciplinary team (obstetricians, anesthesiologist, surgeon, neonatologists) management is started since delivery with intubation and ventilation. +2. Correction of acidosis; blood gas levels should be monitored. 3. Extracorporeal membrane oxygenation is used for neonates +with respiratory failure due to pulmonary hypoplasia; + + + + + + + + + + + + + + + + + +Fig. 33.11: USG with Doppler study: Stomach, liver in the left side of the thoracic cavity, fetal heart is pushed to the right. +Courtesy: Professor K Ghosh of IOFM. +Chapter 33: Diseases of the Fetus and the Newborn - + + + + + + + + + + + + + +Fig. 33.12: Large left-sided pleural effusion (arrow) in a fetus with extrapulmonary sequestration (nonimmune hydrops). + +4. Surgical repair is done either through the abdomen or the chest, with reduction of intestines into the abdominal cavity. Open surgical procedures have better outcomes. + +♦ Other congenital abnormalities (5%): Diaphragmatic hernia, renal abnormality, cystic hygroma. +♦ Hematological (10%): Beta-thalassemia, Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, leukemia. +♦ Infections (6-7%}: Parvovirus, rubella, toxoplasma, syphilis, cytomegalovirus, hepatitis. +♦ Placenta and umbilical cord pathology (5%): Twin-to-twin transfusion, chorioangioma, umbilical vein thrombosis, TRAP. +♦ Maternal diseases (5%): Uncontrolled diabetes, severe anemia, thyrotoxicosis. +♦ Urinal tract malformations (2%): Urethral obstruction. Prune belly syndrome. +♦ Lymphatic dysplasia (7%): Lymphatic dysplasia +♦ Miscellaneous (4%): CNS malformations, skeletal abnormali­ ties, lysosomal disorders. +♦ Idiopathic (18%) + +5. Intrauterine fetal surgery has been done in few cases to Pathology: Pathology depends on the etiological factor. +prevent pulmonary hypoplasia. However, ultimate pathology is development of severe Prognosis is largely related to severity of pulmonary anemia, hypoproteinemia ( decreased colloid osmotic +hypoplasia and associated structural malformations ( congenital pressure), asphyxia, increased capilla1y permeability and +heart disease). heart failure. DUODENAL ATRESIA: In atresia, the lumen is completely +Prenatal diagnosis is made with high +Investigations: +obstructed s whereas in stenosis, it is narrowed. Duodenal resolution ultrasound scan, Doppler flow study, echocar­ +atresia: +It +i often associated (70%) with other malformations, +diography and cordocentesis. +Down syndrome (33%), CV and GI anomalies. Prenatally it +is diagnosed by ultrasonography. Vomiting is a prominent 1. Maternal blood for complete blood count, ABO feature, the vomitus being copious and bile stained (atresia is and Rh group, red cell antibody titers, hemoglobin usually below the Ampulla of Vater). The upper abdomen may electrophoresis, VDRL, Kleihauer test, glucose +be distended and following the passage of meconium ( usually tolerance test, G6PD deficiency and serological tests for +white), no further stools are passed. infections. Doppler study for fetal anemia measuring +Plain X-ray of the abdomen or USG in upright position MCA peak velocity. +shows the typical 'double-bubble appearance' -gas in fundus of stomach and in the vault of the proximal half of duodenum with +2. +Ultrasound-detailed scan +of the fetus for echocardiog­ +raphy, structural lesions +(Fig. 33.12), +and Doppler flow +no air in the small or large bowel. Prenatal diagnosis is made with studies (MCA) is most important for diagnosis and fol­ Management: (1) Withhold fluids by mouth; (2) Parenteral low up. +ultrasound. +for chromosomal, biochemical and +3. +Amniocentesi·s +replacement of fluids and electrolytes; (3) Prompt corrective +surgery of duodenojejunostomy by open or MIS techniques. enzyme studies. +4. Cordocentesis for study of chromosomal and single NONIMMUNE FETAL HYDROPS gene disorders, enzymes, plasma proteins, blood gases +Nonimmune Fetal Hydrops (NIFH) is defined !] !] and antibodies, hemoglobin electrophoresis, PCR, DNA +studies. +as the accumulation of extracellular fluid :- · =- · +n +· +!l +■ .. +5. +Neonatal: +Chromosomal study, placental examination, +autopsy study if there is stillborn. +in tissues and serous cavities in conditions ,.,T:• • +other than Rh incompatibility. It is usually 1,ia +associated with increased skin thickness (>5 mm), Management: It is directed according to the cause due to generalized subcutaneous edema in the fetus, and severity of the pathology. Termination of pregnancy placental enlargement, pericardial effusion, pleural may be an option when the parents desire, especially in effusion and/or ascites in at least two fetal body presence of chromosomal or structural abnormality. compartments. With complete prevention of Rh problem, Transplacental therapy for fetal dysrhythmias could be more than 75% of the fetal hydrops are related to NIFH. made by administering digoxin orally to the mother. + +Causes: +♦ Chromosomal abnormality (12%): Trisomies (13, 18, 21), Turner syndrome, triploidy, aneuploidy. +♦ Cardiovascular (20%): Congenital heart block, supraven­ tricular tachycardia, structural major cardiac abnormality (hypoplastic left heart). + +Direct fetal therapy may be done by intraperitoneal, intramuscular or intravascular ( umbilical vein) routes. Fetal transfusion may be given through umbilical vein or peritoneal cavity to improve anemia. Drainage of pleural fluid, pericardia! fluid or ascitic fluid under ultrasound guidance may be needed. +ID Chapter 33: Diseases of the Fetus and the Newborn + +Obstetric management: +1. Laser photocoagulation for twin-twin transfusion. +2. Intrauterine paracentesis or thoracocentesis prior to delivery is helpful for easy delivery and for neonatal resuscitation. +3. Place of cesarean section depends on obstetric reasons. + +4. Antenatal corticosteroid therapy is to be given when delivery is planned preterm. +5. Intensive neonatal care including ventilator support is needed. +Prognosis: Perinatal mortality is high (50-100%), especially in presence of a structural and/ or chromo­ somal abnormality. + + + + + +► Perinatal asphyxia is a significant cause of perinatal death (50%). +► The essential requirements for extrauterine independent survival are the formation of thin air blood barrier and the production of surfactant by the type two alveolar cells. +► Surfactant reduces surface tension and prevents alveolar collapse. +► Several hormones (glucocorticoids, thyroid hormones, TRH) and growth factors are needed for lung maturation and pulmonary phospholipid development. Glucocorticoids are the most essential hormone. +► Resuscitation of the newborn in the delivery room are done following the protocol of AAP and NNF, India. +► Important causes of respiratory distress in the newborn are many. RDS is mainly due to deficient pulmonary surfactant. Antenatal betamethasone accelerates pulmonary surfactant synthesis. +► Antenatal corticosteroid therapy has the following benefits: (a) Acceleration fetal lung maturation, (b) Reduction of RDS in preterm infants, (c) Reduction of ICH and NEC, and (d) Decrease in neonatal mortality. +► Common causes of neonatal hypoglycemia are: preterm and IUGR infants, perinatal hypoxia, RDS, and neonatal hyperinsulinism (infant of a diabetic mother). +► The neonatal hyperbilirubinemia is principally due to: (a) Increased red cell mass with decreased red cell survival, and (2) decreased hepatic intake and conjugation of bilirubin, (3) decreased excretion of bilirubin. +► The major concern with neonatal hyperbilirubinemia is the development of kernicterus. The critical level of bilirubin to cause kernicterus in a term infant is >20 mg/dl (340 tmol/L). +► Causes of seizures in newborn may be traumatic, metabolic, infective, iatrogenic and others. +► Birth injuries of the newborn may involve the soft tissues (skin, nerves) and/or the bones (clavicle). +► Risk factors for neonatal infections are: Rupture of membranes> 18 hours, maternal fever, prematurity, repeated vaginal examinations in labor. +► Mode of infection may be antenatal, intranatal or postnatal. Common pathogens are Group B Streptococcus (GBS), Staphylococcus aureus, E.coli, Klebsiel/a also anaerobes. +► Causes of Nonimmune Fetal Hydrops (NIFH) are many. +► Ultimate pathology of NIFH is development of severe anemia, hypoproteinemia, asphyxia and heart failure. + +Pharmacotherapeutics +in Obstetrics + + +CHAPTER + + + +CHAPTER OUTLINE +❖ Oxytocics in Obstetrics ► Oxytocin +► Methods of Administration ► Ergot Derivatives +► Prostaglandins (PGs) +❖ Antihypertensive Therapy ❖ Diuretics +❖ Tocolytic Agents ❖ Anticonvulsants + + +❖ Anticoagulants +❖ Maternal Drug Intake and Breastfeeding +❖ Fetal Hazards of Maternal Medication during Pregnancy +► Teratology and Prescribing in Pregnancy +❖ Analgesia and Anesthesia in Obstetrics + + +► Anatomical and Physiological Considerations +► Analgesia during Labor and Delivery +► Inhalation Methods +► Regional (Neuraxial) Anesthesia ► Infiltration Analgesia +► General Anesthesia for Cesarean Section + + + + +OXYTOCICS IN OBSTETRICS +DEFINITION: Oxytocics (ecbolics) are the drugs of varying chemical nature that have the power to excite contractions of the uterine muscles. Amongst the large number of drugs belonging to this group, the following are the important ones and are extensively used in clinical practice. +♦ Oytocin ♦ Ergot derivatives ♦ Prostaglandins + +I OXYTOCIN +PHARMACOLOGY: Oxytocin is a nonapeptide. In 1950, de Vigneaud and coworkers were awarded Nobel Prize for their work on structure of oxytocin. It is synthesized in the supraoptic and paraventricular nuclei of the hypothalamus. By nerve axons, it is transported from the hypothalamus to the posterior pituitary where it is stored and eventually released. +Oxytocin has a half-life of 3-4 minutes and a duration of action is approximately 20 minutes. It is rapidly metabolized and degraded by oxytocinase. +MODE OF ACTION: Myometrial oxytocin receptor concentration increases maximum (100-200 fold) during labor. Oxytocin acts through G-protein coupled receptor and voltage-mediated calcium channels to initiate myometrial contractions. It stimu­ lates amniotic and decidual prostaglandin production. Bound intracellular calcium is eventually mobilized from the sarcoplasmic reticulum to activate the contractile protein. The uterine contractions are physiological, i.e., causing fundal contraction with relaxation of the cervix. Oxytocin and vasopressin have a similar structure, and the oxytocin receptor has equal affinity for +oxytocin and ADH. V1 receptors have a higher affinity for ADH but high doses of oxytocin induce similar action. + +PREPARATIONS USED: (i) Synthetic oxytocin (Syntocinon­ Sandoz or Pitocin-Parke-Davis) is widely used. It has only got oxytocic effect without any vasopressor action. The syntocinon is available in ampoules containing 5 IU/mL: Pitocin 5 IU/mL. (ii) Syntometrine (Sandoz)-a combination of syntocinon 5 units and ergometrine 0.5 mg. (iii) Desamino-oxytocin-it is not inactivated by oxytocinase and is 50-100 times more effective than oxytocin. It is used as buccal tablets containing 50 IU. (iv) Oxytocin nasal solution contains 40 units/mL. +EFFECTIVENESS: In the first trimester, the uterus is almost refractory to oxytocin. In the second trimester, relative refractoriness persists, and, as such, oxytocin can only supplement other abortifacient agents in induction of abortion. In later months of pregnancy and during labor in particular, it is highly sensitive to oxytocin even in small doses. Oxytocin loses its effectiveness unless preserved at the correct temperature (between 15°C and 30°C). +INDICATIONS: Oxytocin may be conveniently used in preg­ nancy, labor or puerperium. The indications are grouped as follows: +♦ Therapeutic ♦ Diagnostic +THERAPEUTIC +■ Pregnancy ■ Labor ■ Puerperium +Pregnancy ■ Early: +• To accelerate abortion-inevitable or missed. • To expedite expulsion of hydatidiform mole. +• To stop bleeding following evacuation of the uterus. • Used as an adjunct to induction of abortion along +with other abortifacient agents (PGE1 or PGEz). +&J Chapter 34: Pharmacotherapeutics in Obstetrics + +■ Late: +• To induce labor. +• To ripen the cervix before induction. • Augmentation of labor. +• Uterine inertia. +Labor: +■ Active management of third stage of labor. +■ Following expulsion of placenta as an alternative to ergometrine. +Puerperium: To minimize blood loss and to control postpartum hemorrhage. + +DIAGNOSTIC +■ Contraction Stress Test (CST)-p. 469 ■ Oxytocin Sensitivity Test ( OST)-p. 469 +I SIDE EFFECTS AND DANGERS OF OXYTOCIN +The dangers are particularly noticed when the drug is administered late in pregnancy or during labor (Table 34.1). +♦ Maternal ♦ Fetal +MATERNAL +■ Nausea, vomiting, arrhythmias +■ Uterine hyperstimulation (overactivity)-is a +frequently observed side effect. There may be excessive duration of uterine contraction (hypertonia) or increased frequency (>6 in 10 min time) of contractions (tachysystole). It is often associated with abnormal FHRpattern (p. 342, Fig. 25.2). +■ Uterine rupture-may be seen with violent uterine contractions. High-risk cases are: Grand multipara, malpresentation, contracted pelvis, prior uterine scar (cesarean) and excessive oxytocin use. +■ Water intoxication is due to its antidiuretic function when used in high dose (30-40 mIU/min). Water intoxication is manifested by hyponatremia, confusion, coma, convulsions and congestive cardiac failure. It is prevented by strict fluid intake and output record, use of crystalloid solution and by avoiding high-dose oxytocin for a long time. +■ Hypotension: Bolus IV injections of oxytocin cause hypotension, especially when patient is hypovolemic or with a heart disease. Occasionally, it may produce angina! pain. + +Table 34.1: Contraindications of Oxytocin. +Pregnancy Labor Anytime +Grand multipara All the contraindi- Hypovolemic cations in pregnancy. state. +Contracted pelvis Obstructed labor. Cardiac disease +History of cesarean lncoordinate uterine section or hysterotomy contraction. +Malpresentation Fetal distress. + + +■ Antidiuresis: Antidiuretic effect is observed when oxytocin infusion rate is high ( 40-50 mIU/min) and continued for a long time. +(Rare: Anaphylactoid reactions, amniotic fluid embo­ lism). +FETAL: Fetal distress, fetal hypoxia or even fetal death may occur due to uterine hyperstimulation. Uterine hypertonia or tachysystole causes reduced placental blood flow. + +ROUTES OF ADMINISTRATION +■ Controlled intravenous infusion is the widely used method. +■ 5-10 units IV or IM after the birth of the baby as an alternative to ergometrine. +■ Intramuscular-the preparation used is syntometrine. ■ Buccal tablets or nasal spray-limited use on trial basis. +I METHODS OF ADMINISTRATION OF OXYTOCIN ♦ Controlled intravenous infusion +♦ Intramuscular +CONTROLLED INTRAVENOUS INFUSION: Oxytocin infu­ sion should be ideally by infusion pump. Fluid load should be minimum. It is started at low dose rates (1-2 mIU/min) and increased gradually. +♦ For induction of labor ♦ For augmentation of labor +For induction of labor +Principles: (1) Because of safety, the oxytocin should be started with a low dose and is escalated at an interval of 20-30 minutes where there is no response. When the optimal response is achieved (uterine contraction sustained for about 45 seconds and numbering 3 contractions in 10 minutes), the administration of the particular concentration in mIU/minute is to be continued. This is called oxytocin titration technique; (2) The objective of oxytocin administration is not only to initiate effective uterine contractions but also to maintain the normal pattern of uterine activity till delive1y and at least 30-60 minutes beyond that. +Calculation of the infused dose: Nowadays the infusion is expressed in terms of milliunits per minute. This can give an accurate idea about the exact amount administered per minute irrespective of the concentration of the solution. +Regulation of the drip: The drip is regulated by­ (1) Manually, counting the drops per minute commonly practiced; (2) Oxytocin infusion pump which automati­ cally controls the amount offluid to be infused. +Convenient regime: Because of wide variation in response, it is a sound practice to start with a low dose (1-2 mIU/min) and to escalate by 1-2 mIU/min at every 20 min intervals up to 8 mIU/min. The patient should preferably lie on one side or in semi-Fowler's position to minimize vena caval compression. + +' +- +• , +M + +Table 34.2: Calculation of the dose delivered in milliunits (mlU) and its correlation with drop rate per minute. +Units ofoxytocin mixed in Drops per minute 500 ml Ringer solution +(15 drops= 1 ml) +15 +30 +60 +(1 unit= 1000 milliunits) +(m/UJ In terms of mlU/minute + +Chapter 34: Pharmacotherapeutics in Obstetrics - \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_15.txt b/notes/DC Dutta Obstetrics 10th Edition_15.txt new file mode 100644 index 0000000000000000000000000000000000000000..03720ca8ca24ebfad188e7e8fc97caa724b7d1e0 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_15.txt @@ -0,0 +1,2027 @@ + + +Abdominal wall + +terine wall + +1 2 4 8 2 4 8 16 8 16 32 64 + + +Ta bl e 34.3:The convenient regime.,'-<.:' 't,,,. , •,, ,-- .1 '""" • ,,; *,;.;,,.,,;;,., +Solution Escalating drop rate at Dose· of oxytocin used intervals of20-30 minutes +., · , .... , :·,. _, .·.« /,'· · -c··• +w +· +j +1 +, -• +s + <',.,\ C c; < , '/,, ',.CC'fttl ,-2,," +To start with 1 unit 500 ml 15-30-60 Ringer solution +If no response-2 units -do- -do-If still no response-8 units -do- -do- + +High-dose oxytocin begins with 4 mIU/min and increased 4 mIU/min at eve,y 20-30 min interval. It is mainly used for augmentation of labor and in active management of labor. Risks of uterine hyperstimulation and fetal heart irregularities are more with high-dose regime. +In majority of cases, a dose of 4 to 8 mill/min (2 units in 500 mL Ringer solution with drop rate of 20-30/min) is enough to achieve the objective. Conditions where fluid overload is to be avoided, infusion with high concentration and reduced drop rate is preferred (Tables 34.2 and 34.3). Use of infusion pump with variable speed can avoid excess volume infusion. +For augmentation of labor +Oxytocin infusion is used during labor in uterine inertia +or for augmentation of labor or in the active management of labor for details, p. 489. The procedure consists of low rupture of the membranes followed by oxytocin infusion when the liquor is clear. Fetopelvic disproportion must be ruled out beforehand. +Observation during oxytocin infusion +11 Rate of flow of infusion by counting the drops per minute or monitoring the pump. +■ Uterine contractions-number of contractions per 10 min duration and period of relaxation are noted. 'Fingertip' palpation for the ton us of the uterus in between contractions (Fig. 34.I) may be done where gadgets are not available. +■ Peak intrauterine pressure of 50-60 mm Hg with a resting tone 10-15 mm Hg is optimum when intrauter­ ine pressure monitoring is used (Fig. 25.2). +11 FHR monitoring is done by auscultation at every 15 minutes interval or by continuous EFM. +■ Assessment of progress of labor (descent of the head and rate of cervical dilatation). + + + + +Fig. 34.1: To note the uterine tonus. + +Indications ofstopping the infusion +1. Nature of uterine contractions-(a) Abnormal uterine contractions occurring frequently (every 2 minutes +or less) or lasting more than 60 sec ( tachysystole). (b) Increased tonus in between contractions. +2. Evidences of fetal distress. +3. Appearance of untoward maternal symptoms. +Carbetocin is a longer acting oxytocin derivative. It is effective to control atonic PPHfollowing cesarean delive,y. It is given slow IV per dose. +Pharmacological properties of carbetocin are similar to myt.ocin. It has a longer biological half-life (40 minutes). Its onset of action is 2 minutes. after IV or IM administration. It causes sustained uterine contraction and is stable at room temperature. It is given IV, slowly over 1 minute. Each mL of vial contains carbetocin 100 ftg. +Contraindication of use: Pregnancy, labor before delivery of the baby, induction/augmentation of labor, renal, hepatic, cardiovascular disorders, epilepsy and drug hypersensitivity. + +I._Q _ GNOSTIC USE OF OXYTOCIN ♦ Contraction Stress Test ( CST) +♦ Oxytocin Sensitivity Test ( OST) + +CONTRACTION STRESS TEST (CST) (Syn: Oxytocin challenge test) +It is an invasive method to assess the fetal wellbeing during pregnancy. When there is alteration in FHR in response to uterine contractions, induced by oxytocin, it suggests fetal hypoxia. This test is not commonly done these days (Box 34.1). +Principles: The test is based on determination of the respirato,y function of the fetoplacental unit during induced contractions when the blood flow through the unit is curtailed. The objective is to detect the degree of fetal compromise so that a suitable time can be selected to terminate the pregnancy. +Candidates for CST: (1) Intrauterine Growth Restriction, (2) Postmaturity, (3) Hypertensive disorders of pregnancy, ( 4) Diabetes. +Chapter 34: Pharmacotherapeutics in Obstetrics + +Table 34.4: Composition of different Ergot preparations. + +■ Positive: Persistent late deceleration of FHR with 50% ormore of uterine contractions. +■ Negative: No late or significant variable deceleration. ■ Suspicious: Intermittent late or variable decelerations. +11 Unsatisfactory: <3 contractions per 1 Ominutes or an unpredictable tracing. +■ Tachysysto/e: Decelerations with contractions lasting >90 seconds or occurringmore frequently than every 2minutes. + + +Preparations +Ergometrine (ergonovine) +Methergine (methylergonovine) +Syntometrine (Sandoz) + + +Ampoules 0.25-0.5mg + +0.125-0.250 mg + +0.5 mg-ergometrine + +5 units-syntocinon + +Tablet 0.5-1mg + +0.125-0.5mg + + + +Contraindications: (i) Compromised fetus, (ii) Previous history of cesarean section, (iii) Complications likely to produce preterm labor, (iv) APH, (v) multiple pregnancy. +Procedure: The oxytocin infusion is started in the same manner as mentioned earlier. The initial rate of infusion is 1 mIU/minute which is stepped up at intervals of20 minutes until the effective uterine contractions are established. The alteration of the FHR during contractions is recorded by electronic monitoring. Alternatively, clinical monitoring can effectively be performed using hand to palpate the hardening of the uterus during contraction and auscultation of FHR during contraction and for 1 minute thereafter. It takes at least 1-2 hours to perform the test. +Importance: A negative test is associated with good fetal outcome. Whereas a positive CST is associated with increased incidence of IUD, fetal distress in labor and low Apgar score. But there is 50% chance of false-positive results and as such positive test cases are subjected to other methods of evaluation [biophysical profile and Doppler studies for the wellbeing of the fetus. Suspicious CST should have a repeat test in 24 hours. +I ERGOT DERIVATIVES +Out of many ergot derivatives, two are used extensively as oxytocics. These are: +♦ Ergometrine (Ergonovine in USA) +♦ Methergine (Methyl-ergonovine in USA) +CHEMISTRY: Ergometrine is an alkaloid isolated by Dudley and Moir in 1935 from Ergot, a fungus Claviceps purpurea that develops commonly in cereals like 1ye, wheat, etc. The alkaloids are detoxified in the liver and eliminated in the urine. Methergine is a semisynthetic product derived from lysergic acid (Table 34.4). + +MODE OF ACTION: Ergometrine acts directly on the myometrium. It excites uterine contractions which come so frequently one after the other with increasing intensity that the uterus passes into a state of spasm without any relaxation in between. +EFFECTIVENESS: Keeping the physiological functions in mind, it should not be used in the induction of abortion or labor. On the contra1y, it is highly effective in hemostasis-to stop bleeding from the uterine sinuses, either following delivery or abortion. Methergine is somewhat slower in producing uterine response taking 96 seconds in contrast to 55 seconds by ergometrine when administered intravenously (Table 34.5). +MODE OF ADMINISTRATION: Ergometrine and methergine can be used parenterally or orally. As it produces tetanic uterine contractions, the preparation should only be used either in the late second stage of labor ( after the + + +delivery of the anterior shoulder) or following delivery of the baby. Syntometrine should always be administered intramuscularly. +SIDE EFFECTS AND HAZARDS +1. Common side effects are nausea and vomiting. +2. Because of its vasoconstrictive action, it may precipitate rise of blood pressure, myocardial infarction, stroke and bronchospasm. +3. Repeated use may lead to gangrene of the toes due to its vasoconstrictive effect. +4. Repeated use in puerperium may interfere with lactation by lowering prolactin level. +CONTRAINDICATIONS: Table 34.6. +USES OF ERGOMETRINE/METHERGINE +CAUTIONS: Ergometrine should not be used during preg­ nancy, first stage of labor, second stage prior to crowning of the head (Table 34.6). +COMMENTS: As a hemostatic in uterine hemorrhage following expulsion of the fetus irrespective of duration of pregnancy, ergometrine or methergine is the drug of choice (Table 34.7). On the contrary, oxytocin is predominantly used to initiate uterine contractions (induction) and to accelerate uterine contractions in labor (augmentation). I PROSTAGLANDINS (PGs) +Prostaglandins are the derivatives of prostanoic acid from which they derive their names. They have the property of acting as "local hormones''. They were first described and named by Von Euler in 1935. +Chemistry: Prostaglandins are 20-carbon carboxylic acids with a cyclopentane ring which are formed from pol unsaturated fatty acids. Ofthe many varieties ofprostaglandins (Table 34.8) +y + +Table.34:5: Comparative stucly ·oi"onset'ana ,i:luratidn°of action' of +i + d fMrent:oxytocics. :,; > - ' ,',. " ,,_-,. '.' ,., '·, +1 +: +, +:i' - : +Syntocinon on puerperal +Routes Ergometrine Methergine Syntometrine uterus +Onset of action +IV 45-60 sec l½ min Not to be used 30 sec +IM 6-7min ?min 21h min 2½min Oral 10min 10min - - +Duration of action +3 hr 3 hr 3 hr 8 min +Chapter 34: Pharmacotherapeutics in Obstetrics il Table 34.6: Place of ergometrine/methergine in Obstetrics. +Indications Contraindications +A. Prophylactic 1. Suspected multiple pregnancy: If given accidentally following the delivery of the first baby, the Active management of third second baby is compromised by the tetanic contractions of the uterus. +stage of labor as prophylaxis 2. Organic cardiac diseases: Results in sudden squeezing of blood from the uterine circulation into the +to excess bleeding following systemic circulation causing overload of the right heart and failure. +3. Severe pre-eclampsia and eclampsia: Sudden rise of blood pressure or development of fits (eclampsia). 1---------------1 4. Rh-negative mother: More risk of fetomaternal microtransfusion. +delivery +B. Therapeutic 5. Heart disease (cardiac failure). +To stop the atonic uterine 6. Severe hypertensive disorders: Because of its vasoconstrictive effect, it may cause transient bleeding; following delivery, hypertension or cardiac failure. Oxytocin is a better alternative in such cases. +abortion or expulsion of 7. Presence of sepsis. +hydatidiform mole 8. Labor induction or during the course of labor (first and second stage). +9. Vascular disease. + + +Table 34.7: Comparati'.e study of Ergot d rivatives a'n :oxytocin. : . , + + +Mode of action + +Onset of action Duration Clinical uses + + + +Hazards + + +Contraindication + +Ergot derivatives +Acts directly on the myometrium producing tetanic contraction with complete loss of polarity. +Comparatively slower. Long sustained. +■ To stop hemorrhage following delivery, abortion or +expulsion of H mole. +• Prophylactic use in third stage to hasten separation of placenta and to minimize blood loss. +• Nausea and vomiting, +• Rise in blood pressure, stroke. Rarely gangrene of the toe, +• +See above + +Oxytocin +Acts on the physiological uterine contractile system. Law of polarity is maintained. +Faster in action. +Short lived. +• In the induction of labor. +■ To augment uterine contraction during labor. +■ To stop postpartum or postabortal hemorrhage +along with ergometrine or in isolation. • Uterine hyperstimulation. +■ Antidiuretic effect, uterine rupture. ■ Anginal pain or rarely hypotension. +Table 34.1 + + + +Table 34.8: Pharmacoki,netic properties of PGE1 and routes of use.'-Routes Onset of action (min) Peak(min) Duration (min) +Oral 8 (fastest to act) 60 120 (shortest duration) +Sublingual 11 60 180 Vaginal 20 120 240 +Rectal 100 120-180 240 (longest action) + + +PGEJI PGE2 and PGF2a are exclusively used in clinical practice. +The subscript numeral after the letter indicates the degree of unsaturation. Inactivation is done in lungs and liver. +Source: Prostaglandins are synthesized from one of the ess­ ential fatty acids; arachidonic acid, which is widely distributed throughout the body. In the female, these are identified in men­ strual fluid, endometrium, decidua and amniotic membrane. +Prostaglandins (PGs) in obstetrics: Increased biosynthesis of PGs of E and F series in the uterus is a prerequisite for labor in both term and preterm. PGs are paracrine/autocrine hormones as they act on locally at their site of production. Their half-life in the peripheral circulation is about 1-2 minutes. Decidua is the main +source of PGF2a, fetal membranes (amnion) produce PGE2 and the myometrium mainly produce PGI2. + +In vivo, PGF20 promotes myometrial contractility. PGE2 +induces labor with cervical effacement and dilatation. It shortens induction to delivery interval. PGs promote myometrial contraction irrespective of the duration of gestation, whereas oxytocin acts predominantly on the uterus at term or in labor. This has helped the widespread use of PGs to effect first trimester medical termination of pregnancy and also for induction of labor at term. Side effects of PGs are less when used vaginally. Local +application of PGE2 gel is the gold standard for cervical +ripening (Table 34.9). + + + +10 + + + +Prostanoic acid +USE IN OBSTETRICS +■ Induction of abortion (MTP and missed abortion. ■ Termination of molar pregnancy. +■ Induction of labor. +■ Cervical ripening prior to induction of abortion or labor. +Chapter 34: Pharmacotherapeutics in Obstetrics + + +Table 34.9: Prostaglandins in Obstetrics. Advantages +■ Powerful oxytocic effect, irrespective of duration of gestation. +■ · Induction of labor (PGE1, PGEJ In cases with-(a) low pre-induction score; (b) IUFD. +■ Used in induction of abortion (PGE1) with success ■ It has got no antidiuretic effect (cf oxytocin). +■ PGE1 (misoprostol) can be used for augmentation of labor. + + +Disadvantages and side effects +■ It is costly compared to oxytocin. +■ Nausea, vomiting, diarrhea, pyrexia, bronchospasm, tachycardia and chills. +■ Cervical laceration may occur (PGF al when used as an abortifacient. ■ Tachysystole (hyperstimulation) of the uterus, may occur during +2 +induction and may continue for a variable period. +■ Risk of uterine rupture in cases with previous scar. + + + +■ Augmentation (acceleration) of labor. +■ Management of atonic postpartum hemorrhage. ■ Medical management of tubal ectopic pregnancy. +CONTRAINDICATIONS +♦ Hypersensitivity to the compound. ♦ Uterine scar. +♦ Active cardiac, pulmonary, renal or hepatic disease; +hypotension (PGE2). +♦ Bronchial asthma (PGF20). +MECHANISM OF ACTION: Both PGE2 and PGF20 have got +an oxytocic effect on the pregnant uterus when used in appropriate dose. The probable mechanism of action is change in myometrial cell membrane permeability and/ or alteration of membrane-bound Ca++. PGs also sensitize +the myometrium to oxytocin. PGE2 is at least 5 times more potent than PGF2a. PGF2a acts predominantly on +the myometrium, while PGE2 acts mainly on the cervix +due to its collagenolytic property. PGE2 causes dissolu­ +tion of collagen bundles and increases submucosal water content of the cervix. +Preparations +Prostaglandin E2 is widely used because it is less toxic and +more effective than PGF2a. It is, however, more costly. +Vaginal tablet: Contains 3 mg dinoprostone (Prostin E2). +Instilled in the posterior fornix followed by 3 mg after 6-8 hours maximum dose of 6 mg. +Vaginal pessary ( with retrieval device process) releasing dino­ prostone approximately 10 mg over 24 hours. It is removed when cervical ripening is adequate. Dose not to be repeated. +Prostin E2 (Dinoprostone) gel-500 pg into the cervical canal, +below the level of internal os or 1-2 mg in the posterior fornix +(Fig. 34.2); may be repeated after 6 hours. Prostin E2 gel and tablet +are not bioequivalent. + + + + + + + + + + +Fig. 34.2: Dinoprostone gel in disposable syringe with catheter. + + +Parenteral: (a) PGE2 (IV)-Prostin E2 containing 1 mg/mL, +(b} PGF2a-Prostin F2a (Dinoprost tromethamine) containing 5 mg/mL, (c) Methyl analogue of PGF2a (Carboprost containing +250 pg/mL). +PGE2 is effective for induction of labor causing cervical effacement and dilatation. It reduces the need of oxytocin +use and cesarean delivery. PGE2 preparations are rela­ tively expensive and require refrigeration as it is unstable +at room temperature. +Methyl ester of PGE1 (misoprostol}: It is rapidly +absorbed and is more effective than oxytocin or dinoprostone for induction oflabor. +Misoprostol (PGE1} (Table 34.8) has been used for +cervical ripening. Primarily it has been used for peptic ulcer disease. Transvaginal misoprostol is used for induction of labor. Oral misoprostol can be used as it is convenient to the patient. It is given 25-50 µg eve1y 3-6 hours by oral or +vaginal route. Low doses of oral PGE1 ( dissolving 200 µg +tablet in 200 mL tap water) 2-25 µg in solution is safe. It is to be repeated at interval of 2 hours. Buccal or sublingual misoprostol is also used for induction of labor and vaginal delive1y. Oxytocin when needed may be added after 4 hours. Misoprostol has been found to be as effective as +PGE2 for cervical ripening and induction of labor. To date, +no evidence of teratogenic or carcinogenic effects has been +observed. PGE1 is effective in the management of AMTSL +and in the management of atonic PPH. +Advantages of PGE1 over PGE2: Misoprostol is cheap, +stable at room temperature, long shelf-life, easily admin­ istered ( oral, vaginal or rectal) (Table 34.8) and has less side effects. Induction delive1y interval is short. Need of oxytocin augmentation is less. Failure of induction is less. +Risks: Incidence of tachysystole (hyperstimulation), fetal heart rate changes and meconium passage are high. Rupture of uterus, though rare, has also been observed. It should not be used for cases with previous cesarean birth because the risk of rupture is high. Misoprostol is not yet approved for use in pregnancy by FDA. Use of misoprostol for induction of abortion has been discussed on p. 166. +Tachysystole: Contractions more than 5 in 10 minutes time averaged over a 30 minutes window. It may occur in spontaneously or stimulated labor. FHR changes may or may not be present. +Contraindications: Pre-eclampsia, eclampsia, epilepsy. +Chapter 34: Pharmacotherapeutics in Obstetrics - . + + +SELECTION OF OXYTOCICS IN OBSTETRICS: All the oxy­ tocics have got their place. +♦ To arrest hemorrhage following delivery (PPH) or abortion, ergot preparation (methergine, ergometrine) is the life-saving drug. In refractory cases of atonic +PPH, PGF2a (IM/intramyometrial) or PGE1 (misopro­ +stol) 1,000 1g (rectal) is an effective choice. +♦ PGE1 is used in the active management of third stage of +labor. +♦ For induction of labor-either prostaglandins or oxytocin can be used. With favorable pre-induction cervical score, there is ve1y little to choose between + +oxytocin and prostaglandin, but when the score is unfavorable as in IUD, shorter period of gestation or in elderly primigravida, prostaglandins have got a distinct advantage over oxytocin. Misoprostol has +certain advantages over PGE2• +♦ In augmentation or acceleration of labor, oxytocin +is still the drug of choice although prostaglandins are equally effective. +♦ For induction of abortion-prostaglandins (misopros­ +tol-PGE1) has got a distinct advantage over oxytocin. +Oxytocin may supplement the effects of PGs in the pro­ cess. + + + + + +► Oxytocics are the drugs used to stimulate uterine contractions. +► Oxytocin can be used in pregnancy, labor and puerperium. Contraindications and dangers of oxytocin use must be carefully assessed. +► Oxytocin is given by controlled intravenous infusion. During infusion, the woman must be monitored carefully. Oxytocin must be preserved between 2°C and 8°C to be effective. +► Methergine (ergot derivative) can be used orally or parenterally. It differs with oxytocin in its action (Table 34.5). Indications, contraindications and hazards of ergot derivatives must be assessed. +► Prostaglandins are widely used in Obstetrics. They have many advantages. Of the different preparations, PGE2, PGF 20, and PGE1 are commonly used. Prostaglandins (PGE2, PGE1) have some advantages over oxytocin in medical induction of labor. +► Carbetocin is used to prevent PPH due to uterine atony after cesarean delivery. + + +ANTIHYPERTENSIVE THERAPY + +Antihypertensive drugs are essential for women with severe preeclampsia (BP 160/110 mm Hg) to protect the mother from eclampsia, cerebral hemorrhage, cardiac failure and placental abruption (Table 34.10). Aim is to reduce BP to a mean less than 125 mm Hg. Their benefit in mild or moderate hypertension is not yet known. If there is any risk of target organ damage (kidney) antihypertensives are given to maintain BP :;140 mm Hg. systolic. The following are the drugs with their pharmacological property and clinical use (Table 34.10). ■ In pre-eclampsia and eclampsia (Tables 34.10 and +34.11). +■ Chronic hypertension. + +DIURETICS +The diuretics are used in the following conditions during pregnancy: +♦ Pregnancy-induced hypertension with pathological edema. ♦ Eclampsia with pulmonary edema. +♦ Severe anemia in pregnancy with heart failure. ♦ Prior to blood transfusion in severe anemia. +♦ As an adjunct to certain antihypertensive drugs such as hydralazine or diazoxide. +COMMON PREPARATIONS USED: Frusemide (loop diuretic)­ dose-40 mg tablet daily following breakfast for 5 days a week. In acute conditions, the drug is administered parenterally in doses of 40-120 mg daily. Mode of action: It directly prevents reabsorption of sodium and potassium mainly from the loop of Henle. + +Hazards-(a) Maternal complications include-weakness, fatigue, muscle cramps, hypokalemia and postural hypoten­ sion. These can be corrected by potassium supplement during therapy. (b) Fetal-in pre-eclampsia, its routine use should be restricted, as it is likely to cause further reduction of maternal plasma volume, which is already lowered. This may result in diminished placental perfusion leading to fetal compromise. Other hazards include thrombocytopenia and hyponatremia. +Thiazide diuretic is often used in conjunction with other antihypertensives. It is safe in pregnancy. +Dose: 12.5 mg twice daily maximum up to 50 mg daily may be used. Side effects are: Maternal and fetal hyponatremia, acute pancreatitis, rise in uric acid levels, and neonatal thrombocyto­ penia. In a diabetic patient, it may cause hype1glycemia. +Spironolactone potentiates thiazide or loop diuretics by antagonizing aldosterone. It is a potassium-sparing diuretic. It is contraindicated in hyperkalemia. Drospirenone is an analog of spironolactone. It has antiandrogenic and antimineralocorticoid properties. The dose used in COCs is usually not associated with hyperkalemia. + +TOCOLYTIC AGENTS + +Preterm labor and delivery can be delayed by drugs in order to improve the perinatal outcome. Short-term delay of 48 hours allows the use of corticosteroids that can reduce the perinatal mortality and serious morbidity signi­ ficantly. The commonly used drugs are: Betamimetics, prostaglandin synthetase inhibitors, magnesium sulfate, calcium channel blockers, oxytocin receptor antagonists, nitric oxide donors and progesterone. +&I Chapter 34: Pharmacotherapeutics in Obstetrics Table 34.1 0: Anti hypertensive drugs. +Contraindications + +Drugs Labetalol + + + + + + +Nifedipine + + +Mechanism of action +Combined a and p adrenergic blocking agent. + + + + + +Direct arteriolar vasodilatation by inhibition + + +Doses +■ Orally-100 mg tid may be increased up to 2,400 mg daily +■ IV infusion (hypertensive crisis) 20-40 mg IV every 10-15 min until desired effect, maximum up to 220mg. +Orally-5-1 O mg tid maximum dose + + +Side effects +■ Tremors, headache, asthma, congestive cardiac failure. May cause neonatal bradycardia. +• + + + + +Flushing, hypotension, headache, tachycardia, + + +and precautions +• Hepatic disorders. +■ Asthma, congestive cardiac failure. + + + + + +Simultaneous use of magnesium sulfate could be + + + + +Hydralazine + + + + + + +Methyl dopa + + + + + +Sodium nitro-prusside + +of slow inward calcium 60-120 mg/day. channels in vascular +smooth muscle. +Acts by peripheral ■ Orally-100 mg/day in vasodilatation as it relaxes four divided doses +• +the arterial smooth muscle. IV 5-1O mg every 20 min Orally, it is weak and should maximum 20 mg. +be combined with meth-yldopa or p blockers. It increases the cardiac out-put and renal blood flow. +Central and peripheral ■ Orally-250 mg bid-antiadrenergic action. may be increased to 1 g Effective and safe for both qid depending upon the the mother and the fetus. response. + + + +Direct vasodilator (arterial IV infusion-0.25-8 µg/ and venous). kg/min. + + +inhibition of labor. hazardous due to synergistic effect. +• Maternal-hypotension, Because of variable sodium tachycardia, arrhythmia, retention, diuretics should be palpitation, lupus-like used. To control arrhythmias, +syndrome, fluid retention. propranolol may be +■ Fetal-reasonably safe. administered intravenously. ■ Neonatal +thrombocytopenia. +• Maternal-postural • Hepatic disorders, psychic hypotension, hemolytic patients, congestive +anemia, sodium retention, cardiac failure. excessive sedation. Postpartum (risk of Coombs' test may be depression). positive. +• +• +Fetal-intestinal ileus . +• Maternal-nausea, Drug of last resort for acute vomiting, severe hypertension. Should be hypotension. used in critical care unit for Fetal toxicity due to very short time (10minutes). metabolites-cyanide and +• +thiocyanate. + + + +Nitroglycerin Relaxes mainly the venous but also arterial smooth muscle (vasodilatory effect). + + +Given as IV infusion-5 µg/ min to be increased at every 3- 5 min up to 100 µg/min. + + +Tachycardia, headache, methemoglobinemia. + + +Used in hypertensive crisis for short time only. Contraindicated in hypertensive encephalopathy as it increases blood flow and intracranial pressure. + + + +ACE inhibitors/ angiotensin-11 receptor blockers (AARB) + + +ACE inhibitors: Inhibit formation of angiotensin-11 from angiotensin-1. +ARB-block angiotensin-11 receptors. + +■ Captopril orally-6.25 mg bid. +■ Telmisartan-orally 20-40 mg a day. + + +■ Maternal-hypotension, headache, asthenia, arrhythmias. +• +Fetal-oligohydramnios, IUGR, fetal renal tubular dysgenesis, neonatal renal failure, pulmonary hypoplasia. + + +Should be avoided in pregnancy. +Suitable for chronic hypertension in nonpregnant state or post pa rtu m. + + + + +DRUGS: The commonly used drugs are given in Table 34.12. + +ANTICONVULSANTS + +Convulsion in pregnancy is largely due to eclampsia. Other common causes are-epilepsy, meningitis, cerebral malaria and cerebral tumors, and metabolic causes. Eclampsia should be considered first unless proved otherwise by history, +examination and investigations. + + +The commonly used drugs are given in the tabulated form (Table 34.13). + +ANTICOAGULANTS +Anticoagulants are used in pregnancy to prevent thromboembolic problems. Cardiac disease, venous thrombosis and antiphospholipid syndrome are some of the indications. The commonly used drugs are discussed here (Table 34.14). Venous Thromboembolism (VTE) + + +Table 34.11: Drugs to treat Hypertensive emergencies in pregnancy (Table 34.9). +Treatment of severe hypertension +as emergency Side effects/precautions +Labetalol IV: 10-20 mg over 2 min; Asthma, CCF, heart disease. 20-80 mg every 20-30 min. +Hydralazine: IV 5 mg over 2 min. ■ Tachycardia Headaches +• +Nifedipine: 10 mg PO, repeat in 30 • Tachycardia min. Palpitations +• +Long-term treatment of hypertension: +• +• +• +Labetalol 100 mg BID PO Nifedipine 10 mg BID PO Hydralazine 10 mg BID PO ■ Thiazide 12 .5 mg BD PO +Other drugs Vasodilators: ■ Nitroglycerin +• Sodium nitroprusside ACE inhibitors (postpartum) Captopril. +Seizure prophylaxis: MgSO4; 4 g IV loading dose, followed by 2 g IV +per hour infusion. + +Chapter 34: Pharmacotherapeutics in Obstetrics + +encompasses Deep Vein Thrombosis (DVT} and Pulmonaty Embolism (PE}. Pregnant women are 4-5 times more likely to suffer VTE than the nonpregnant women. Pregnancy is a hypercoagulable state. The high-risk factors for VTE are: hypertension, diabetes, obesity, lupus, prolonged immobilization and thrombophilias. Commonly used LMWH in pregnancy are-enoxaparin, tinzaparin and deltaparin {Table 34.14). + +MATERNAL DRUG INTAKE AND BREASTFEEDING +Maternal drug intake during nursing may have adverse effect not only on lactation but also on the baby through the ingested breast milk. Any drug ingested by a nursing mother may be present in her breast milk, but its concentrations are usually low compared to blood levels in the mother. Usually such low levels are not of any clinical significance to the infant (Boxes 34.2 to 34.4 and Tables 34.12 to 34.16). + + +Table 34.12: Tocolytic agents. + +Drugs +Calcium channel blockers: +■ Nifedipine ■ Nicardipine ■ Verapamil +Magnesium sulfate for PTL: <32 weeks. Neuroprotection against cerebral palsy + + + +lndomethacin: Cyclo-oxygenase inhibitor (Sulindac another +NSAID is also used as it has less placental transfer) + + +Mechanism of action +Nifedipine blocks the entry of calcium inside the cell. It is equally effective to MgSO4 + + +It acts by competitive inhibition to calcium ion at the motor end plate reducing calcium influx ++ Increased cerebral perfusion + + +Reduces synthesis of PGs, thereby reduces intracellular free ca++, activation of MLCK and uterine contractions. (PGs cause in free intracellular ca++ and activation of MLCK) +t + + +Doses +Oral (not sublingual) +10-20 mg every 3-6 hours + + + +Loading dose 4-6 g IV +(10-20% solution) over 20-30 min followed by an infusion of 1-2 g/hr ➔ to continue tocolysis for 12 hours after the contractions have stopped. + +Loading dose 50 mg PO or PR followed by 25 mg every +6 hours for 48 hours + + +Side effects and precautions +■ Maternal: Nausea, headache, flushing hypotension and tachycardia. +Combined therapy with p mimetics or MgSO4 +should be avoided. +■ Fetal/neonatal:Tachycardia. +MgS04 is relatively safe. +■ Common maternal side effects are flushing, perspiration, headache and muscle weakness. +■ Fetal side effects: Decrease in FHR variability ■ Dose monitoring. +Contraindications: Myasthenia gravis and impaired renal function. +Maternal:Heartburn, asthma, GI bleeding, thrombo­ cytopenia, renal injury, platelet dysfunction. Contraindications: Hepatic disease, active peptic ulcer, coagulation disorders. +Fetal and neonatal side effects: +(i) Constriction of the ductus arteriosus (due to +inhibition of synthesis of PGl2 and PGEil, (ii) Oligohydramnios. +(iii) Neonatal pulmonary hypertension; (iv) IUGR. + + + +Betamimetics: ■ Terbutaline • Ritodrine +■ lsoxsuprine (effective for 48 hours to allow time for steroids and antibiotics to work) + + +Activation of the intracellular Ritodrine is given by IV enzymes (adenylate cyclase, infusion, 50 µg/min and is cAMP, protein kinase), reduces increased by 50 µg every 10 intracellular free calcium (Ca++ min until contractions cease. ,.,.) and inhibits activation of Infusion is continued for about MLCK (,.,.J ➔ 12 hours after the contractions Reduced interaction of cease. +actin and myosin ➔ smooth Terbutaline has longer half­ +muscle relaxation. P2 receptor life and has fewer side effects. stimulation causes smooth Subcutaneous injection of0.25 +muscle relaxation mg every 3-4 hours is given. + + +Side effects of p mimetics are more when used parenterally, +Maternal: Headache, palpitation, tachycardia, pulmonary edema, hypotension, cardiac failure, hyperglycemia, ARDS, hyperinsulinemia, lactic acidemia, hypokalemia and even death. Fetal:Tachycardia, heart failure, IUFD. Neonatal: Hypoglycemia and intraventricular hemorrhage. +Contraindications: maternal cardiac disease, diabetes. + + + +Oxytocin antagonists: Atosiban (between: +24 and 32 weeks) + + +Oxytocin analogue (antagonist) that blocks myometrial oxytocin receptors. It inhibits intracellular calcium release, release of PGS and thereby inhibits myometrial contractions. + + +IV infusion 300 1g/min Nausea, vomiting, chest pain (rarely). Initial bolus may be needed. + + + + +Contd... +ZI Chapter 34: Pharmacotherapeutics in Obstetrics + + +Contd... Drugs +Nitric Oxide (NO) Donors: Glyceryl Trinitrate (GTN) + + +Mechanism of action +Smooth muscle relaxant + + +Doses +Patches + + +Side effects and precautions +• May cause cervical ripening . Headache. +• +• +Hypotension . + + + +Table 34.13: Ahticonvulsants. +Drugs Mode of actions Doses Side effects + +Magnesium It decreases the Repeat injections are given only if knee jerks are sulfate acetylcholine present, urine output >30 ml/hr and respiration rate (also) release from the > 16/min. Therapeutic level of serum Mg is 4-7 mEq/L. +nerve endings and reduces the motor end plate sensitivity to acetylcholine. + + +Mg5O4 is relatively safe and is the drug of +choice. Muscular paresis (diminished knee jerks), respiratory failure. Renal function is to be monitored. It does not affect the duration of labor. Antidote: Calcium Gluconate. +Fetal effects are usually absent. It is contraindi-cated in patients with myasthenia gravis. + + + +Diazepam + + + + +Phenytoin + + +Central muscle relaxant and anticonvulsant. + + +Centrally acting anticonvulsant (for other anticonvul-sant drugs. + + +Initially, 20-40 mg IV slowly to be followed by an infusion ■ Mother: Hypotension, apnea, cardiac arrest. containing 500 ml of dextrose with 40 mg of diazepam, ■ Fetus: Respiratory depressant effect which the drip rate being 30 drops/min or adjusted as per need. may last for even 3 weeks after delivery. Status epilepticus: 10-20 mg IV slowly, may be followed Hypotonia, hypothermia in newborn. +by IV infusion to a maximum of 3 mg/kg over 24 hours. +Epilepsy: 300-400 mg daily orally in divided doses. Maternal: Hypotension, cardiac arrhythmias, and Status epilepticus: 18 mg/kg slow IV (SO mg/min); phlebitis at the injection site. +maintenance dose of about 100 mg is given at an interval Fetal hydantoin syndrome (when used in first of 6-8 hours. BP and ECG monitoring should be done. trimester) is observed in 5-10% offspring. This may be due to the disease itself due to drug +metabolism and deficient folate level. For the abnormalities. + + + +Table 34.14: Anticoagulants. '· +Drugs Mode of action Doses (weight adjusted dose) Side effects +Heparin Inhibits factor Xa 5,000-10,000 IU to be administered parenterally. Maternal: Hemorrhage, urticaria with long- +• +Unfractionated and thrombin. DVT and Pulmonary Embolism: Loading dose term use thrombocytopenia, osteopenia, Heparin (UFH) Increases factor 5,000 units IV followed by continuous infusion hyperkalemia. +Antidote: Prat- Xa inhibitor of 18 units/kg/hr Protamine sulfate reverses the action of UFH. amine sulfate Pregnancy: 5,000-10,000 SC every Fetal: It does not cross the placenta and not +12 hours (with monitoring). secreted in the breast milk. It is not teratogenic. +• Low-Molecular-Weight Heparin (LMWH) are as effective and safe as Unfractionated Heparin. It has longer half-life and once daily dose is convenient. Standard doses need not require monitoring. It has higher activity against factor Xa. LMWH heparins have better bioavailability. Commonly used LMWH in pregnancy are: Enoxaparin, Tinzaparin and Deltaparin. Heparin-induced thrombocytopenia and osteoporosis are less. Dose of Enoxaparin: 1 mg/kg twice daily SC. +■ Contraindications of Heparins are: (1) Known bleeding disorders (hemophilias); (2) APH, PPH; (3) Thrombocytopenia (<75 x 109/L); +(4) Severe renal (creatinine clearence <30 ml per min.) and liver disorders (PT above normal); (5) Uncontrolled hypertension BP >200 min Hg or> 120 mm Hg diastolic; (6) Recent stroke. + +Warfarin Interferes with synthesis of vitamin K dependent factors (II, VII, IX,X) + + +5-10 mg orally daily for initial 2 days then 3-9 mg daily (taken at the same time each day) depending upon the prothrombin time and INR. +(INR-2.0-3.0) + + +Maternal: Hemorrhage +Fetal: Warfarin embryopathy (5%) nasal, mid-face hypoplasia, bone stipplings, optic atrophy, mental retardation, microcephaly, chondrodysplasia punctata. Women with mechanical heart valves, warfarin is preferred. To avoid in first trimester. + +(Read more Dutta's Clinics in Obstetrics, Ch. 31) + +. . +■ Chemical properties of the drug. +• Molecular weight. +■ Degree of protein binding. ■ Degree of ionic dissociation. + + + + +■ Lipid solubility. ■ Tissue pH. +■ Drug concentration in maternal blood. +■ Duration of exposure time. + + + + ++ Benefits of medication must outweigh the risks. ++ Select drugs that are most widely tested and with short half-life. + Monitor the infant during the course of therapy. +Nonionized, low molecular weight, lipid-soluble compounds are usually excreted through breast milk. + + + +■ Cytotoxic drugs (cyclosporine, doxorubicin, cyclophosphamide): Might cause immune suppression. +■ Drugs of abuse: Cocaine, heroin, marijuana. +■ Radioactive compounds: 1311, Technetium - 99 m. +■ Drugs, whose effects on nursing infants are unknown but may be of concern: Amiodarone (hypothyroidism), Sertraline. Benefits of breastfeeding are to be weighed against the negative effects. +Medical complications during pregnancy and lactation are best managed without any drug whenever possible. Risk and benefit ratio of any drug is to be weighted before a drug is to be used. Therapy may be deferred whenever possible till the first trimester is over. + + + +■ Codeine phosphate. +■ Nitrofurantoin in babies with G6PD deficiency or <8 days old. +■ ACE ls other than enalapril. ■ Diuretics. +■ Angiotensin receptor blockers. ■ Phenobarbital, primidone. +■ Sertraline. ■ Fluoxetine. + + +Table 34.15: Effects of various medications on Lactation and Neonates. +Maternal medications Effects on lactation and the neonate +Oral pill (combined) Suppression of lactation. Bromocriptine -do- +Ergot Vomiting, diarrhea, convulsions in infants Progesterone-only pill It is ideal for breastfeeding mother. +Metronidazole (single- No adverse effects have been reported dose regimen) Temporary cessation of lactation +(12-24 hours) is advised. +Antithyroid drugs (PTU) Can continue with supervision of infant. +Warfarin: Safe in therapeutic doses. Prophylactic vitamin K to the infant +ACE inhibitors, 13 blockers Generally no adverse effects. +Cytotoxic agents Risk of immune suppression. Risks may outweigh the benefits depending on individual drug. +Lithium Lethargy, hypotonia, poor feeding. +Narcotics, sedatives and Generally no adverse effects. anticonvulsants +Tetracycline Tooth staining, delayed bone growth. + + +However, milk concentrations of some drugs (e.g., iodides) may exceed those in the maternal plasma so that therapeutic doses in the mother may cause toxicity +to the infant (Table 34.13). Common side effects from maternal medication on breastfed infants are: diarrhea (antibiotics), irritability (antihistaminics), drowsiness (sedatives, antidepressants, antiepileptics). +Benefits of breastfeeding are well known. The risk of drug exposure to the neonate must be weighed against these benefits. If the drug amount is 1-2% of the mother, usually no adverse effects are noted. Short-term effects + +Chapter 34: Pharmacotherapeutics in Obstetrics + +of most drugs on breastfed infants are little. Benefits of breastfeeding must be weighed against the theoretical effects of small amount of drug. + +FETAL HAZARDS OF MATERNAL MEDICATION DURING PREGNANCY +I TERATOLOGY AND PRESCRIBING IN PREGNANCY Fetotoxic agents or the known teratogens are: (A) +Viruses (Rubella, CMV); (B) Environmental (Radiation); (C) Chemicals (alcohol, mercury); (D) Drugs (warfarin, isotretinoin). Depending on the timing of exposure, the felotoxic effect may cause-(A) miscarriage, (B) structural malformations, (C) fetal demise, growth restriction or neurobehavioral abnormalities. +Approximately, 25% of human development defects are genetic in origin, 2-3% are due to drug exposure and about 65% are either unknown orfom combination of genetic and environmental factors. +r +Mechanism of teratogenicity: The actual mechanism is unknown. Teratogens may affect through the following ways: 1. Folic acid deficiency leads to deficient methionine production and RNA, DNA synthesis. Folic acid is essential for normal meiosis and mitosis. Periconceptional folate +deficiency leads to neural tube defects, cleft lips and palate. +2. Epoxides or arena oxides are the oxidative inter-metabolites of many drugs like hydantoin and carbamazepine. These intermediaty metabolites have carcinogenic and teratogenic effects unless they are detoxified by fetal epoxide hydrolase. +3. Environment and genes: Abnormalities that are multifactorial depend on the ultimate interaction between the environment and fetal gene mutation. Genotype of the embryo and their susceptibility to teratogens (valproic acid) are the important determinants. FDA has categorized the drugs and medications according to the risks (Table 34.17). Embtyonic period (2nd to 8th weeks) is most vulnerable. Homozygous gene mutations are associated with more anomalies. +4. Maternal disease and drugs (epilepsy and anticonvulsants) have an increased risk of fetal anomalies (Table 34.13). Pater­ nal exposure to drugs or mutagens (polycyclic hydrocarbons) can cause gene mutation and chromosomal abnormality in sperm. FDA has categorized the drugs and medications according to the risks in human fetus (Table 34.15). +5. Homeobox genes are groups of regulatory genes that control the expression of other genes involved in the normal development of growth and differentiation. Teratogens like retinoic acid can dysregulate these genes to cause abnormal gene expression. +TIMING OF TERATOGEN EXPOSURE AND THE HAZARDS +■ Before D 31: Teratogen produces an all or none effect. The conceptus either does not survive or survives without anomalies. In early conception, only few cells are there. So any damage at that phase is irreparable and is lethal. +■ D 31-D 71 is the critical period for organ formation. Effects of teratogen depend on the following factors: {i) Amount of the drug reaching the fetus, (ii) Gestational age at the time of exposure, (iii) Duration of exposure. +,ll Chapter 34: Pharmacotherapeutics in Obstetrics +Table 34.16: Fetal or neonatal affections caused by various maternal medications. + +Maternal medications Cytotoxic drugs + +Medroxy progesterone acetate Lithium + +Anticonvulsants ■ Phenytoin +■ Valproate + +■ Carbamazepine Aspirin + + +Cocaine Antimalarials Corticosteroids + +Aminoglycosides Anxiolytics Quinolones +Methotrexate, antimetabolities Nitrofurantoin +Metronidazole +Cimetidine, omeprazole, ranitidine Retinoids (isotretinoin) +Efavirenz Acyclovir +ACE inhibitors Vitamin A (large dose) All live viral vaccines Narcotics +Smoking (nicotine, CO, and other polycyclic hydrocarbons) + +Fetal or neonatal affection and comment +First trimester:Teratogenic major malformation, single agent 10-17% and combination agent up to 25%; abortion; 2nd and 3rd trimester: FGR, IUFD, myelosuppression. +Hypospadias, masculinization of the female offspring. +Cardiovascular (Ebstein's) anomalies, fetal diabetes insipidus, polyhydramnios, neonatal goiter, hypotonia and cyanosis, prenatal diagnosis with echocardiography needed. + +■ Benefits of treatment outweigh the risks to the fetus. Polytherapy should be avoided. +■ Fetal hydantoin syndrome. It includes-microcephaly, IUGR, mental retardation, craniofacial abnormalities, hypertelorism, hypoplasia of the nails and distal phalanges. +• +Increased risk of neural tube defects, ASD, cleft palate, polydactyly, hypospadias, craniosynostosis. +High doses in the last few weeks cause premature closure of ductus arteriosus, persistent pulmonary hypertension and kernicterus in newborn. Risk of prolonged pregnancy and maternal bleeding due to platelet dysfunction is there. +Congenital anomalies (cardiac, CNS), miscarriage, placental abruption, microcephaly. +Chloroquine, quinine-no evidence of fetal toxicity in therapeutic doses; benefits outweigh the risk. +High doses (>10 mg prednisolone daily) may produce fetal and neonatal adrenal suppression. Prolonged systemic use may cause IUGR. +Nephrotoxicity, ototoxicity in preterm infants. +Neonatal withdrawal, hypotonia, cyanosis, floppy infant syndrome. Arthropathy in animal studies. No malformation was noted. Craniofascial, axial skeletal, gastrointestinal malformation. +Hemolysis in newborn with G6PD deficiency, if used at term. No congenital defects noted. No evidence of teratogenic risk. High-dose regimens should not be used. +No known teratogenic risk. +Severe CNS, CVS, endocrine dysfunction, mental retardation. Thought to be teratogenic, risks of NTD. +No increased risk of malformation. +1st trimester: CVS/CNS malformation; others. May be teratogenic. +Potentially dangerous to the fetus. +Maternal: Miscarriage, FGR. Fetal: Depression of CNS-apnea, bradycardia and hypothermia. +Placental abruption, placenta previa, prematurity and IUGR increased. + +Selective serotonin reuptake inhibitors (SSRIS): +Sertaline: Omphalocele, atrial, ventricular septal defects. Paroxetine: 1' Congenital cardiac malformation, anencephaly, omphalocele. +Anticoagulants (p. 474), antihypertensives (p. 473), antithyroids (p. 273) diuretics (p. 473). Antiemetics (p. 152), -mimetics (p. 475) and oral contraceptives (p. 477) are mentioned earlier. + +Table 34.17: FDA risk categories for drugs and medications: FDA drug bulletin (1994). + +Category A B + +C + +D + +X + +Definitions +Adequate and Well-controlled Studies (AWS) in pregnant women have failed to demonstrate a fetal risk in all trimesters. +No evidence of risk in humans: AWS in pregnant women have not shown any increased risk of fetal malformation despite adverse findings in animals. The chance of fetal harm is remote but remains a possibility. +Risk cannot be ruled out. Adequate, well-controlled human studies are lacking. Animal studies have shown a risk to the fetus or are lacking as well. Potential benefit may outweigh the risk. +Positive evidence of risk: Studies in humans have demonstrated fetal risk. Potential benefits from the use of the drug (life-threatening situation) may outweigh the potential risk. +Contraindicated in pregnancy: Proven fetal risks clearly outweigh any possible benefit. Drugs in this group are: Alcohol, ACE inhibitors, lithium, methotrexate, valproic acid, mifepristone, danazol, isotretinoin, radioactive iodine and others. + +Teratogen information databases: Organization ofTeratology Information Services (OTIS): http:## www.otispregnancy.org./www.fda.gov. +Chapter 34: Pharmacotherapeutics in Obstetrics IDL + + +Last menstrual period Conception (14 days) +to parturition +(280 days) Heart, central +/ nervous system +(31 days) / + + + + +Brain +growth Palate, ear +(71 days) + + + +Fig. 34.3: Gestational age and teratogenicity. + +■ After D 71 development of other organs continues. Diethyl­ stilbestrol (DES)-related uterine anomalies occur with exposure around 20 weeks (Fig. 34.3). +Brain continues to develop throughout pregnancy and neo­ natal period. Fetal alcohol syndrome occurs in late pregnancy. +Placental transfer of drugs: Most drugs cross the placental barrier by simple difusion. The factors responsible for transfer are-(i) Molecular weight (molecular weight >1,000 Da do not cross the placenta), (ii) Protein binding, (iii) Concentration of free drug, (iv) Lipid solubility, (v) Degree of ionization and tissue pH, {vi) Uteroplacental blood flow, and {vii) Placental surface area. The rate of drug transfer across the placenta is increased in late pregnancy. + + +This is due to: (i) Increased unbound drug available for transfer, (ii) Increased uteroplacental blood flow, {iii) Increased placental surface area, {iv) Decreased thickness of the placental membranes. +Keeping these in mind, the following guidelines are formulated: +■ If the benefit outweighs the potential risks, only then can the particular drug be used with prior counseling. +■ Only well-tested and reputed drugs are to be prescribed and, that too, using the minimum therapeutic dosage for the shortest possible duration. +ALCOHOL: Heavy drinkers ('.3 oz) have major risk to the fetus (6%). Fetal Alcohol Syndrome {FAS) is defined as the presence of at least one characteristic from each of the following three categories: +1. Growth restriction before and/or after birth. +2. Facial anomalies: Small palpebral fissures, indistinct or absent philtrum, epicanthic folds, flattened nasal bridge, short length of nose, thin upper lip, low set and unparallel ears and retarded midfacial development. +3. CNS dysfunction: Microcephaly, mental retardation, abnormal neurobehavioral development (attention deficit with hyperactivity). + +PATERNALLY MEDICATED DRUGS AFFECTING HUMAN PROGENY: Adverse effects on human progeny has been observed in the form of miscarriage, congenital malformations, low birth weight and increased perinatal loss when the father has been exposed to lead, anesthetic agents, smoking or caffeine ingestion. These agents probably alter the morphology of the spermatozoa or cause some changes in the composition of the semen. + + + +ANALGESIA AND ANESTHESIA IN OBSTETRICS + + +Relief of pain during labor and delivery is an essential part in good obstetric care. Choice of anesthesia depends upon the patient's conditions and the associate disorders. Anesthetic complications may cause death. Anesthesia following full meal may cause death due to vomiting and aspiration of gastric contents. Maternal risk factors for anesthesia are: Short stature, short neck, marked obesity, severe pre-eclampsia, bleeding disorders, placenta previa, medical disorders, like cardiac, respiratory and neurological diseases. + +ANATOMICAL AND PHYSIOLOGICAL CONSIDERATIONS + +NERVE SUPPLY OF THE GENITAL TRACT: Uterus is under both nervous and hormonal control. Hypothalamus controls the uterine activity through the reticular formation which balances the effects of the two autonomic divisions. +Motor nerve supply: The uterus receives both sympathetic and parasympathetic nerve fibers. The sympathetic nerve fibers arise from lower thoracic and upper lumbar segments of the spinal cord. The parasympathetic fibers arise from sacral 2, 3 and 4 segments of the spinal cord {Fig. 34.4). +The preganglionic fibers of the sympathetic nerves arising from the spinal cord pass through the ganglia of the sympath­ etic trunk to aorticorenal plexus where they synapse. The aorticorenal plexus continues as the superior hypogastric plexus or + +presacral nerve and passes over the bifurcation of aorta and divides into right and left hypogastric nerves. Each hypogastric nerve joins the pelvic parasympathetic nerve of the corresponding side and forms the pelvic plexus (right and left) or inferior hypogastric plexus. The pelvic plexus then continues along the course of the uterine artery as paracervical plexus on each side of the cervix. +Sensory pathway: Sensory stimuli from the uterine body are transmitted through the pelvic, superior hypogastric and aorticorenal plexus to the 10th, 11th and 12th dorsal and the first lumbar segments of the spinal cord. Sensory stimuli from cervix pass through the pelvic plexus along the pelvic parasympathetic nerves to sacral segments 2, 3 and 4 of the spinal cord. Sensory stimuli from upper vagina pass to 2, 3 and 4 sacral parasympathetic segments and from lower vagina pass through the pudenda! nerve. The perineum receives both motor and sensory innervation from sacral roots 2, 3 and 4 through the pudenda! nerve. The branches of ilioinguinal and genital branch of genitofemoral nerves supply the labia majora and also carry the impulses from the perineum. +NERVOUS CONTROL OF UTERINE ACTIVITY: Regarding motor innervation of the uterus, the sympathetic nerves rather than the parasympathetic have the influences over the uterine activity. +HORMONAL CONTROL: It is generally agreed that intact nerve supply is not essential for the initiation and progress of labor. Total spinal block does not inhibit uterine activity, provided +·· ~"!J Chapter 34: Pharmacotherapeutics in Obstetrics Pain pathways in labor +[ + +I + + +1st stag, { + + +Lumbar +epidural block + + + +2od stag,{ + + + +Caudal epidural block + + +Paarffaesryemntpfaibtheerstic + + +Pudenda! block Paracervical block + +Fig. 34.4: Diagrammatic representation of the pain pathways during labor and the methods of their interruption. +-c + +Flowchart 34.1: Stress of labor and body response. +• + +Physical (pain of surgery, trauma) + . Stress J--. Hypothalamus • Psychological + + + +I+ P1tu1tary --+ [ tGH, tTSH, 1'endorph1n, tprolactin +-+_. + Adrenal Cortex Medulla ' tcortisol tNorepinephrine +tADH, 1'ACTH +L +tAldosterone tEpinephrine tGlucagon + +• Hyperventilation +• Respiratory alkalosis FETAL +r +• tGlucose Acidosis +---+ • tFFA t-----+ Hypoxia +• Metabolic acidosis +• I-Placental flow + + + + + +blood pressure is not allowed to fall, and normal vaginal delivery can occur in the paraplegic patient. It is believed that some hormones are essential for the control of uterine activity. Oxytocin, a hormone derived from posterior pituitaty, maintains the uterine activity during labor. Progesterone is the pregnancy-stabilizing hormone. Labor commences when it is withdrawn. Adrenaline with its beta activity inhibits the contraction of uterus, while its alpha activity excites it {Flowchart 34.1). +I ANALGESIA DURING LABOR AND DELIVERY +Pain during labor results from a combination of uterine contractions and cervical dilatation. During cesarean delivery incision is usually made around the Tl 2 dermatome and anesthesia is requiredfrom the level ofT4 to block the peritoneal discomfort. Labor pain is experienced by most women with satisfaction at the end of a successful labor. Antenatal (mothercraft) classes, sympathetic care and encouraging environment during labor can reduce the need of analgesia. Drugs have an important part to play in the relief of labor pain but it must not be supposed that they are of greater importance than proper preparation and training for childbirth. The intensity of labor pain depends on the intensity and duration of uterine contractions, degree of dilatation of cervix, distension of perinea! tissue, parity and the pain threshold of the subject. The most distressing time during +the whole labor is just prior to full dilatation of the cervix. + + +■ The ideal procedure should produce efficient relief of pain but should neither depress the respiration of the fetus nor depress the uterine activity causing prolonged labor. +■ The drug must be nontoxic and safe for both mother and fetus. But it is regretted that no such agent is available at present that fulfills all these conditions. Every case of labor does not require analgesia and only sympathetic explanation may be all that is required (Table 34.18). + +PSYCHOPROPHYLAXIS (Syn: Natural childbirth): It is psychological method of antenatal preparation designed to prevent or at least to minimize pain and dificulty during labor. For most women, labor is a time of apprehension, fear and agony. As a result of suitable antenatal preparation, majority of women have labor that is easy and painless. +Relaxation and motivation can reduce the fear and appre­ hension to a great extent. Patient is taught about the physiology of pregnancy and labor in antenatal (mothercraft) classes. Relaxation exercises are practiced. Husband or the partner is also involved in the management. His presence in labor would encourage the bearing down efforts. Need of analgesia would be less. +TRANSCUTANEOUS ELECTRIC NERVE STIMULATION (TENS): It is a noninvasive procedure and is preferred by many women +Chapter 34: Pharmacotherapeutics in Obstetrics ml Table 34.18: Analgesia during Labor and Delivery. + +Methods of pain relief +Nonpharmacologic analgesics • Psychoprophylaxis. +• +• Continuous support (Doula). • Acupuncture. +• Transcutaneous (TENS). +• +Sedatives, analgesics and anesthetics • Patient-Controlled Analgesia (PCA). +• Neuroaxial analgesic and anesthetic. • Inhalation agent. +• General anesthesia. + +Commonly used sedatives and analgesics in labor +Drugs Usual doses Frequency +Pethidine 50-100 mg IM 4 hours Fentanyl 50-100 µg IV 1 hour Nalbuphine 10 mg (IV/IM) 3 hours Morphine 5-l0mg IM 4 hours Meperidine 25-50mg (IV/IM) 4 hours +Remifentanil 0.15-0.5 tg/kg used for PCA 2-3minutes + + +Neonatal half-life (approx) +13-20 hours 5 hours +4 hours +7 hours + + + +during labor. Electrodes are placed over the level of Tl0-Ll and S2-4. Current strength can be adjusted according to pain. It works by inhibiting transmitter release through interneuron level. However, no change in pain score was observed when TENS was switched on. +I SEDATIVES AND ANALGESICS +The following factors are important to control the dose of sedatives and analgesics: +1. Pain threshold: The threshold of pain varies from patient to patient. Some patients experience severe pain though the uterine contractions are relatively weak. In such cases, it is preferable to control the pain adequately. +2. Parity: The multiparous women need less analgesia due to added relaxation of the birth canal and rapid delivery. +3. Maturity of the fetus: Minimal doses of drugs are indicated while the fetus is thought to be premature to avoid neonatal asphyxia. +For the purpose of selecting a general analgesic drug, labor has been divided arbitrarily into two phases. The first phase corresponds up to 8 cm dilatation of the cervix in primigravidae and 6 cm in case of multipara. The second phase corresponds to dilatation of the cervix beyond the above limits up to delivery. The first phase is controlled by sedatives and analgesics, and the second phase is controlled by inhalation agents. The idea is to avoid the risk of delive1y of a depressed baby. +OPIOID ANALGESICS-Pethidine: For a long time, pethidine has been used as an analgesic in labor. It has got strong sedative, eupharic but less analgesic efficacy. It is generally used in the early first stage of labor and indicated when the discomfort of labor merges into regular, frequent and painful contractions. The initial dose is 100 mg (1.5 mg/kg body weight) IM and repeated as the effect of the first dose begins to wane, without waiting for the re-establishment of labor pain. +The side effects of pethidine to the mother are nausea, vomiting, delayed gastric emptying. Ranitidine should be +given to inhibit gastric acid production, and emetic effect is counteracted by metoclopramide (10 mg IM). Pethidine crosses the placenta and accumulates in fetal tissues. It reduces baseline variability, depresses respiration and suckling of the newborn when administered before delivery. +Meperidine: Compared to morphine, analgesic effect is one- tenth. It is used 25-50 mg (1-3 mg/kg IM) or a PCA pump 15 mg every 10 minutes. Repeated use or PCA in labor, infants may need naloxone at delivery. Maximum placental transfer and neonatal depression occur 2-3 hours of use. It is not used for + +peripartum analgesia. There is reduced or loss ofFHR variability or neonatal respiratory depression. Side effects: Tachycardia, delayed gastric emptying. +Fentanyl is a fast onset short-acting synthetic opioid and is equipotent to pethidine. It has less neonatal effects and less maternal nausea and vomiting. It needs frequent dosing. It can be used as PCA. +Remifentanil: It is an ultrashort-acting synthetic opioid. It is metabolized by plasma esterase. Metabolites are not active. It is used as PCA. Sedation and hypoventilation with oxygen desaturations may occur. Respiratory monitoring is needed. Placental transfer occurs. It is rapidly metabolized in neonates. Patients may be given supplemental oxygen. Side effects: Nausea, vomiting, decreasedFHR variability, respiratory, depression. +Benzodiazepines (diazepam): Sedatives like phenothiazines and benzodiazepines have no analgesic property. Benzodiazepines cause maternal amnesia, reduced baseline fetal heat variability and neonatal hypothermia. +Combination of narcotics and antiemetics: Narcotics may be used in combination with promethazine, metoclopramide or ondansetron. The advantages claimed that the combination potentiates the action of narcotic, produces less respiratory depression and prevents vomiting. +Nalbuphin and butorphanol are mixed agonist and antagonist. Therefore with an equianalgesic dose, respiratory depression is less. +Narcotic antagonists are used to reverse the respiratory depression induced by opioid narcotics. Naloxone is given to mother 0.4 mg IV in labor. It may have to be repeated. It is given to the newborn 10 µg/kg IM or IV and is repeated if necessary when the infant is born with narcotic depression. Naloxone is given to a newborn born of a narcotic addicted mother, with proper ventilation arrangement only otherwise withdrawal symptoms are precipitated. +I INHALATION METHODS +Premixed nitrous oxide and oxygen: Cylinders contain 50% nitrous oxide and 50% oxygen mixture. Entonox apparatus has been approved for use by midwives. This agent is used in the second phase (from 8 cm dilatation of cervix to delivery). It can be self-administered using a mask. Entonox is most commonly used inhalation agent during labor in the UK. Hyperventilation, dizziness and hypocapnia are the side effects. The woman is to take slow and deep breaths before the onset of contractions +and to stop when the contractions are over. Inhaled N20 is safe for the mother and the fetus. It is also used for repair of +ID Chapter 34: Pharmacotherapeutics in Obstetrics +Table 34.19: Commonly used Local Anesthetic agents in Obstetrics. + +Drugs Lignocaine Bupivacaine +Ropivacaine + + +Usual doses Onset 7 mg/kg Rapid 3 mg/kg Slow +15 mg/kg Slow + + +Duration 60-90min 90-150min +90-150min + + +Use in obstetrics +Local or pudenda! block for instrumental delivery. Epidural or spinal for cesarean delivery. +Continuous epidural infusion for labor pain. + +Toxicity-central nervous system: Depression, dizziness, tinnitus, metallic taste, numbness of tongue, slurred speech, muscle fasciculation. Rarely generalized convulsions and loss of consciousness. +Cardiovascular toxicity: Hypotension, cardiac arrhythmias and fetal distress due to impaired placental circulation. + + +short painful procedures as perinea! tear or manual removal of placenta. The woman should be monitored with pulse oximetry (Table 34.19). +I REGIONAL (NEURAXIAL) ANESTHESIA +When complete relief of pain is needed throughout labor, neuroaxial anesthesia is the safest and simplest method for procuring it. +Continuous lumbar epidural analgesia: A lumbar puncture +is made between L2 and L3 with the epidural needle (Tuohy needle). When the epidural space is ensured, a plastic catheter +is passed through the epidural needle for continuous epidural analgesia. A local anesthetic agent (0.5% bupivacaine) is injected into the epidural space. Full dose is given after a test dose when there is no toxicity. For complete analgesia, a block from TIO to the S5 dermatomes is needed. For cesarean delivery, a block from T4 to Sl is needed. Repeated doses (top ups) of 4-5 mL of 0.5% bupivacaine or 1 % Jignocaine are used to maintain analgesia. Maternal hydration should be adequate with normal saline or Ringer's solution (crystalloid) infusion prior to commencing the blockade. The patient's hydration blood pressure, pulse and the fetal heart rate should be recorded at 15 minutes interval. The woman is kept in semilateral position to avoid aortocaval compression. +Neuroaxial analgesia and anesthesia (Table 34.20) [epidural, spinal or a Combination of Spinal Epidural (CSE)]: It provides the most adequate analgesia to control pain during labor as well as anesthesia during delivery either for vaginal or cesarean section. +Blockade of sympathetic fibers improve the labor pain. The sensation of pressure, motor function of the perineum and the lower extremities are spared. Patient is able to move about in bed and feel the pressure of the presenting part on the perineum. +For maintenance of epidural analgesia, dilute local anesthetic is combined with an opioid (fentanyl). Patient-Controlled Epidural Analgesia (PCEA), may be adjusted according to the need of analgesia and anesthesia. A small gauge pencil point spinal needle is passed through the epidural needle before the catheter is passed. + + +This Combined Spinal-Epidural ( CSE) method, can provide more rapid onset of analgesia administering a small dose of opioid or a local anesthetic. CSE has better pain scores during first stage of labor. Parturients can ambulate during labor ( walking epidural) as there is no blockade with motor function. Drug dose used in spinal is smaller compared to epidural analgesia. Risks of high spinal block are avoided. FHR monitoring should be continued for any women in labor with either epidural or in the spinal or combined spinal epidural analgesia (CSE). +Epidural analgesia is especially beneficial in cases like pregnancy-induced hypertension, breech presentation, twin pregnancy and pretenn labor. It is commonly used to relieve pain in all cases of-(a) spontaneous vaginal delivery, {b) outlet forceps delivery, (c) low operative vaginal delivery (forceps/ ventouse). Previous cesarean section is not a contraindication (Box 34.5). Epidural analgesia when used, there is no change in duration ofirst stage of labo,: But second stage of labor appears to be prolonged by 15-30 minutes. This might lead to fequent need of instrumental delivery like forceps or ventouse (Box 34.5). +r +Paracervical nerve block was used earlier for relief of pain in the first stage of labor. Considering the potential adverse fetal effects, use of paracervical block is contraindicated. It is no longer considered safe in obstetrics. +Pudendal nerve block: It is a safe and simple method of analgesia during delive1y. Pudenda/ nerve block does not relieve the pain of labor but affords perinea/ analgesia and relaxation. Pudendal nerve block is mostly used for forceps and vaginal breech delivery. Simultaneous perinea/ and vulva/ infiltration is needed to block the perinea/ branch of the posterior cutaneous nerve of the thigh and the labial branches of the ilioinguinal and genitofemoral nerves (vide supra). This method of analgesia is associated with Jess danger, both for mother and baby than general anesthesia (Fig. 34.5). +Pudenda] nerve (S2-S4) covers most part of the perineum. Other cutaneous nerves to be infiltrated are: inferior rectal nerve, +posterior femoral cutaneous nerve (S1-S3) covering anterior to the fourchette bilaterally. This nerve must be blocked separately. +Other two nerves are: ilioinguinal nerve (L1) and genital branch +of genitofemoral nerve (L1 and L2) (Fig. 34.6). + + + +Table 34.20: Neuraxial Anesthesia. Advantages +■ No difficulties of intubation. +■ Most effective mode of pain relief. ■ No risk of aspiration. +■ Analgesia during labor and anesthesia for delivery (vaginal/cesarean) and postoperative period. +■ Reduced catecholamine release and decreased systemic response to surgery. ■ Allows mother newborn contact soon following delivery. +■ The patient is awake and can enjoy the birth time. + + +Side effects/disadvantages +■ Women may not prefer to be awake during operation. ■ Inadequate analgesia due to poor block. +■ Hypotension may occur. ■ Neurologic injury. +■ Postdural puncture, headache. ■ High neuraxial block. +■ Local anesthetic toxicity. ■ Infection, meningitis. +Chapter 34: Pharmacotherapeutics in Obstetrics ID r= .,;.,. ,,,, "'"''" EpJ, = c n ·- .,e - ''!z'-'? {"•c"" 't"&,:¥mw...l f,;k3? 'l-" ..''>1'#, if'-ff1 -°"• '"•- --;. ,.1 '-:J ·::.1":· i . . ,,. ... +I +.. +' +- + .. - , + H aJg sia: +'£ Jf:¼ J.1JJ.:} !.'1 h\:: +f i + i .. l; }>::_1•:ti- +} +t.• +:-. OX +34.5: +Contraindications of Epidural Analgesia Complications of Epidural Analgesia +• +• +• +• +• +Maternal coagulopathy or anticoagulant therapy. ♦ Hypotension due to sympathetic blockade (vasodilatation). Parturient Supine hypotension. should be well hydrated with (IL) crystalloid solution beforehand (left Hypovolemia lateral change or vasopressure, phenylephrine, may be used). +Neurological diseases. ♦ Pain at the insertion site. Back pain. +Spinal deformity or chronic low back pain. ♦ Postspinal headache due to leakage of cerebrospinal fluid through +the needle hole in the dura. +CoPatient hemodynamically unstable (APH, placenta accreta) . ♦ Total spinalidue to inadvertent administration of the drug in the +ntraindications to Neuraxial Anesthesia +• +• +• +• +• +subarachno d space. +Patient with sepsis. ♦ Injury to nerves, convulsions, pyrexia. Increased intracranial pressure, space-occupying brain lesion . ♦ Ineffective analgesia. +Cardiac disease. ♦ Infection (meningitis). +Acute deterioration of fetal condition. +For a healthy patient, choice primarily rests on the anesthetist (Boxes 34.6 and 34.7). Most consider spinal block is the easier, quicker to perform and also safe. After spinal or epidural catheter removal, start thromboprophylaxis after 4 hours. + +Genitofemoral + + + +--- ---- Sacrospinous +ligament + +'----'L. lschial spine + +Pudenda! +nerve + +,, +, • +llioinguinal --- ,•·-,," ·· +. +nerve +Branches of pudenda! +nerve +lschial +tube rosily + + +>Ii'" • ' +. +·- ,-,,--. . + + + + + + +lschial spine + + +Fig. 34.5: Method of transvaginal pudenda! block anesthesia. Note the relation of the pudenda I nerve to the ischial spine in the inset. + +Technique: The pudenda! nerve may be blocked by either the transvaginal or the transperineal route. +Transvaginal route: Transvaginal route is commonly preferred. A 20 mL syringe, one 15 cm (6") 22-gauge spinal needle and about 20 mL of 1 % lignocaine hydrochloride are required. The index and middle fingers of one hand are introduced into the vagina, the fingertips are placed on the tip of the ischial spine of one side. The needle is passed along the groove of the fingers and guided to pierce the vaginal wall on the apex of ischial spine and thereafter to push a little to pierce the sacrospinous ligament just above the ischial spine tip. After aspirating to exclude blood, about 10 mL of the solution is injected. The similar procedure is adopted to block the nerve of the other side by changing the hands (Fig. 34.6). +Complications: Hematoma formation, infection and rarely intravascular injection or allergic reaction. Toxicity may affect: (A) CNS: Excitation, ringing in the ears and convulsions. (B) Cardiovascular: Tachycardia, hypotension, arrhythmias, convulsions, even cardiac arrest. +Spinal anesthesia: Spinal anesthesia is obtained by injection of local anesthetic agent into the subarachnoid space. It has less +procedure time and high success rate. Spinal anesthesia can be employed to alleviate the pain of delive,y and during the third stage of labor. For normal delivery or for outlet forceps with episiotomy, + +Fig. 34.6: Methods of pudenda! and labial-perinea! block for episiotomy during outlet forceps/ventouse application. + +ventouse delivery, block should extend from TIO (umbilicus) to SI. For cesarean delivery, level of sensory block should be up to T4 dermatome. Hyperbaric bupivacaine (5-10 mg) or lignocaine (25-50 mg) is used. Addition of fentanyl (to enhance the onset of block) or morphine (to improve pain control) may be done. Brief or minimal spinal anesthesia is far safer than prolonged spinal anesthesia Box 34.6. The advantages of spinal anesthesia are: (a) less fetalhypoxia unless there is hypotension, and (b) minimal blood loss. The technique is not difficult and no inhalation anesthesia is required. Postspinal headache occurs in 5-10% of patients. + +Postdural headache. +■ Puncture of the dura occurs in 0.5-2.5% of epidurals. +■ If accidental dural puncture occurs, there is a 70-80% chance of a postdural puncture headache. +■ The headache is usually in the fronto-occipital regions and radiates to the neck. It is worse on standing and develops 24-48 hours post-puncture. +■ Conservative management includes hydration and simple analgesics. +■ Untreated, the headache typically lasts for 7-10 days but can last up to 6 weeks. +■ Epidural blood patch has a 60-90% cure rate. +Chapter 34: Pharmacotherapeutics in Obstetrics + + + ++ Hypotension due to blocking of sympathetic fibers leading to vasodilatation and low cardiac output. ++ Respiratory depression may occur due to paralysis of respiratory +-q. +muscles (high spinal) including diaphragm (C3 ++ Failed block, chemical meningitis, epidural abscess. ++ Total spinal-due to excessive dose or improper positioning. ++ Postspinal headache-due to low or high CSF pressure and leakage of CSF. ++ Infection-meningitis, maternal fever. + Transient or permanent paralysis. ++ Toxic reaction of local anesthetic drugs. + Paralysis and nerve injury. ++ Nausea and vomiting are not uncommon. + Urinary retention (bladder dysfunction). ++ Nonrassuring fetal status-bradycardia. ++ Increased rates of forceps/ventouse delivery. + + +■ Maternal cardiac disease: Congenital, valvular, cardiomyopathy, PAH. +■ Neuromuscular disease: CNS disease, spinal surgery. ■ Obesity. +■ Obstructive sleep apnea. +■ Hematologic disease: Immune thrombocytopenia. +■ Obstetric complications: Placenta previa, accreta (PAS). + +Spinal anesthesia can be obtained by injecting the drug into the subarachnoid space of the third or fourth lumbar interspace with the patient lying on her side with a slight head up-tilt. The blood pressure and respiratory rate should be recorded every 3 minutes for the first 10 minutes and every 5 minutes thereafter. Oxygen should be given for respiratory depression and hypotension. Sometimes, vasopressor drugs may be required if a marked fall in blood pressure occurs. It is used during vaginal delivery, forceps, ventouse and cesarean delivery. +High (total) spinal: The level of anesthesia rises danger­ ously high up to the cervical level of C3-C5. This may be due to the miscalculated dose of the drug or inadvertent sub arachnoid injection of an epidural block. Management needs quick assessment of the true level of anesthesia. If diaphragm is paralyzed assisted ventilation and endotracheal intubation is necessary. Intralipid (lipid solution) IV is very effective therapy to combat the cardiotoxic effects. Postdural headache is often due to puncture of the dura with a large bore needle. It is more severe in upright than in supine position. It usually subsides with analgesics as caffeine (cerebral vasoconstrictor). Epidural blood patch is very effective. +Combined Spinal-Epidural Analgesia (CSE): An introducer needle is first placed in the epidural space. A small gauge spinal needle is introduced through the epidural needle into the subarachnoid space (needle through needle technique). A single bolus of 1 mL 0.25% bupivacaine with 25 µg fentanyl is injected into the subarachnoid space. The spinal needle is then withdrawn. An epidural catheter is thus sited for repeated doses of anesthetic drug. The method gives rapid and effective analgesia during labor and cesarean delivery. Continuous Spinal Epidural (CSE) Analgesia can provide more rapid onset analgesia with a small dose of opioid or a local anesthetic or a combination. CSE can + +Table 34.21: General Anesthesia for Cesarean delivery. Advantages Disadvantages +Patient is not aware of the Intubation causes hyper-operation. tension and tachycardia. +Total pain relief Intubation at times is difficult or impossible +No apprehension or anxiety of delivery Aspiration of gastric contents + +decrease the risks of high spinal and motor block. It allows women to move (walking epidural) during labor. +Advantages: Regional analgesia provides excellent pain control during labor and delivety. Its increased use in labor and for vaginal and cesarean delivety has led to significant reduction in maternal morbidity and mortality. + +I INFILTRATION ANALGESIA (TABLE 34.19) +Perinea! infiltration: For episiotomy-perineal infiltration anesthesia is extensively used prior to episiotomy. A 10 mL syringe, with a fine needle and about 8-10 mL 1% lignocaine hydrochloride (xylocaine) are required. The perineum on the proposed episiotomy site is infiltrated in a fanwise manner (Fig. 34.6) starting from the middle of the fourchette. Each time prior to infiltration, aspiration to exclude blood is mandatory. Episiotomy is to be done about 2-5 minutes following infiltration. +For outlet forceps or ventouse-Perineal and labial infiltration: The combined perinea! and labial infiltration is effective in outlet forceps operation or ventouse traction. A 20 mL syri­ nge, a long fine needle and about 20 mL of 1 % lignocaine hydrochloride are required. The needle is inserted just posterior to the introitus. About 10 mL of the solution is infiltrated in a fan­ wise manner on both sides of the midline (as for episiotomy). The needle is then directed anteriorly along each side of the vulva as far as the anterior-third to block the genital branch of the genitofemoral and ilioinguinal nerve. Five milliliter is required to block each side (Fig. 34.6). +Local abdominal for cesarean delivery: This method is rarely used where regional block is patchy or inadequate. Technique: The skin is infiltrated along the line of incision with diluted solution of lignocaine (2%) with normal saline. The subcutaneous fatty layet; muscle, rectus sheath layers are infiltrated as the layers are seen during operation. The operation should be done slowly for the drug to become effective. +PATIENT-CONTROLLED ANALGESIA (PCA): Narcotics are administered by mother herself from a pump at continuous or intermittent demand rate through intravenous route. Total dose is limited as there is a lockout inte1val. This offers better pain control than high doses given at a long intetval by the midwife. Maternal satisfaction is high with this method. Drugs commonly used are fentanyl, meperidine or remifentanil. +I GENERAL ANESTHESIA FOR CESAREAN SECTION The following are the important considerations of general anesthesia for cesarean section: +■ Cesarean section may have to be done either as an elective or emergency procedure. +Chapter 34: Pharmacotherapeutics in Obstetrics .... A + + +■ Ryle's tube aspiration of gastric contents is to be done, especially when the stomach contains food materials. +■ A large number of drugs pass through the placental barrier and may depress the baby. +■ Uterine contractility may be diminished by volatile anesthetic agents like ether and halothane. +■ Halothane and isoflurane cause cardiac depression, hepatic dysfunction and hypotension. +■ Hypoxia and hypercapnia may occur. +■ Time interval from uterine incision to delive1y is related directly to fetal acidosis and hypoxia. +■ Longer the exposure to general anesthetic before delivery, the more depressed is the Apgar score. +Risk factors for high gastric aspiration in pregnancy: +(a) Gravid uterus increases intra-abdominal pressure and the intragastric pressure. +(b) The gastroesophageal sphincter is distorted and is less competent. +(c) Increased progesterone levels in pregnancy-(i) delays gastric emptying, (ii) relaxes gastroesophageal sphincter. +Aspiration of gastric contents with a pH <2.5 cause +pulmonary hemorrhage, inflammation and edema. Pa02 +decrease significantly due to lung injury (Table 34.21). Preoperative preparations: These safety measures should be +taken to prevent complications of general anesthesia. +■ Preoperative medication with sedatives or narcotics is not required as they cause respiratmy depression of the fetus. +■ Fasting of about 6 hours is preferable for an elective surgery. 11 High-risk women in labor should preferably not be allowed +to eat. +■ Ryle's tube aspiration of gastric contents is to be done when the stomach contains food materials. +■ H2-blocker (Ranitidine 150 mg orally) should be given night before (elective procedure). H2 receptor blocking agent and metoclopramide are to be given IM, especially to women with +high risks (obesity). +■ Non-particulate antacid (0.3 molar sodium citrate 30 mL) is given orally before transferring the patient to theater to neutralize the existing gastric acid. +• While on the theater table, left lateral tilt of the woman is main­ tained with a wedge on the back. This is to avoid aortocaval compression as it is detrimental to both mother and fetus. +■ Metoclopramide (10 mg IV) is given after minimum 3 minutes of preoxygenation to decrease gastric volume and to increase the tone of lower esophageal sphincter. + +■ Intubation with adequate cricoid pressure following induction should be done. +11 Uterine incision: Delivery (U-D) interval is more predictive of neonatal status (Apgar score). Prolonged U-D interval of more than 3 minutes results in lower Apgar scores and neonatal acidosis. +■ Awake extubation should be a routine. +Preoxygenation with 100% oxygen is administered by tight mask fit for more than 3 minutes. Induction of anesthesia is done with the injection of thiopentone sodium 200-250 mg (4 mg/kg) as a 2.5% solution intravenously. +Muscle relaxants: Succinylcholine is commonly used immediately after the induction drug to facilitate intubation. It is a short-acting muscle relaxant with rapid onset of action. +Intubation: An assistant is asked to apply cricoid pressure as soon as the consciousness is lost. Intubation is done with a cuffed endotracheal tube and the cuff is inflated. Presence of obesity, severe edema, neck abnormalities, short stature or airway abnormalities make intubation difficult. +Anesthesia is maintained with 50% nitrous oxide, 50% oxygen and a trace (0.5%) of halothane. Relaxation is maintained with nondepolarizing muscle relaxant (vecuronium bromide 4 mg or atracurium 25 mg). After delivery of the baby, the nitrous oxide concentration should be increased to 70% and narcotics are injected intravenously to supplement anesthesia. Opioids injection oxytocin is given IV to stimulate uterine contraception. +Complications of general anesthesia: Aspiration of gastric contents (Mendelson' s syndrome) is a serious and life-threatening one. Delayed gastric emptying due to high level of serum progesterone, decreased motility and maternal apprehension during labor is the predisposing factor. The complication is due to aspiration of gastric acid contents (pH <2.5) with the development of chemical pneumonitis, lung damage, atelectasis and bronchopneumonia. Right lower lobe is commonly involved as the aspirated food material reaches the lung parenchyma through the right bronchus. Clinical presentation: Tachycardia, tachypnea, bronchospasm, rhonchi, rales, cyanosis, decreased +PaO2 and hypotension. X-ray chest reveals right lower lobe involvement. +Management: Immediate suctioning of oropharynx and nasopharynx is done to remove the inhaled fluid. Bronchoscopy may be needed if there is any large particulate matter. Continuous positive pressure ventilation to maintain arterial oxygen saturation of 95% is done. Pulse oximeter is a useful guide. Antibiotics are administered when infection is evident. Role of corticosteroid is doubtful. +Other complications of general anesthesia are: (i) Failure in intubation and ventilation, (ii) Nausea, vomiting and sore throat. + + + '·*iH +► Commonly used antihypertensives in pregnancy are: Labetalol, hydralazine and nifedipine. Methyldopa, hydralazine, labetalol, nitroglycerine and sodium nitroprusside are used for hypertensive crisis. ACE inhibitors should be avoided in pregnancy. +► Commonly used tocolytics are: Calcium channel blockers, magnesium sulfate, oxytocin antagonists and nitric oxide donors, betamimetics (terbutaline, ritodrine, isoxsuprine), indomethacin. +► Tocolytics are used to delay preterm labor for a short-term period (48 hours). Delay in delivery for 48 hours is for corticosteroids to work and to allow intrauterine transfer of the fetus to a center equipped with NICU facilities. Side effects and the precautions of use must be known. +► Anticonvulsants used in pregnancy are: Magnesium sulfate, diazepam and phenytoin. Mg5O4 is the drug of choice in eclampsia. +► While breastfeeding, the benefits of breast milk must be weighed against the risk drug exposure to the neonate. Information as regards +some commonly used drugs are available (Table 34.15). +Contd... +II Chapter 34: Pharmacotherapeutics in Obstetrics Contd... +► Teratogens exert their effects through different mechanisms. The hazards of drugs depend upon the placental transfer of drugs and the period of gestation. Information as regards some commonly used drugs are available (Table 34.16). +► Opioid analgesics are commonly used in labor. They work primarily as a sedative. Of the inhalation methods, premixed nitrous oxide and oxygen are commonly used. +► Epidural analgesia is the safe, effective and simple method of regional anesthesia. One must know the contraindications and complications of its use. In Obstetrics, it is especially beneficial for some cases (Box 34.5 and Table 34.20). +► Pudenda! block is good for perinea! analgesia and is used for forceps and vaginal breech delivery. ► Spinal anesthesia has some advantages but it should be used carefully to avoid the side effects. +► Complications of general anesthesia could be reduced when few preoperative safety measures are taken. +► Mendelson's syndrome is a serious complication of general anesthesia. This can be prevented when the safety measures are taken beforehand. +► Epidural analgesia prolongs the second stage of labor by 20-30 minutes without any adverse effects to the fetus and the neonate. ► Neuraxial analgesia in cases with preeclampsia is beneficial. General anesthesia worsens hypertension during laryngoscopy and intubation. ► Breastfeeding is not affected with the use of neuraxial or opioid analgesia or general anesthesia. +► Opioid analgesics have adverse effects for the women, the fetus and the neonate. Risks or respiratory depressions are for the both. +► Labor is a stressful process. This is associated with adverse metabolic response due to the pain. Analgesia in labor can reduce the stress. ► Epidural analgesia-increases the duration of second stage of labor by 20-30 minutes and the rate of instrumental vaginal delivery +(forceps or ventouse). It does not increase the rate of cesarean delivery. +► General anesthesia is less commonly used these days. Intubation may be at times difficult or failed. Aspiration of gastric contents is a cause for maternal mortality. + + +Induction of Labor + + + + + + + + +CHAPTER OUTLINE +❖ Methods of Induction of Labor ► Medical Induction +► Surgical Induction + + +► Low Rupture of the Membranes ❖ Combined Method (LRM) +► Stripping the Membranes + + + + +Induction of Labor (IOL) means initiation of uterine contractions ( after the period of viability) by any method (medical, surgical or combined) for the purpose of vaginal delivery. The patient and the family members are informed about the benefits, potential complications and the possibility of cesarean deliveiy. Overall induction rate is I 0%. Augmentation of labor is the process of stimulation of uterine contractions (both in frequency and intensity) that are already present but found to be inadequate. +PURPOSE OF INDUCTION OF LABOR: When the risks of continuation of pregnancy either to the mother or to the fetus is more, induction is indicated (Boxes 35.1 to 35.3). Before induction, one must ensure the gestational age as well as pulmonary maturity of the fetus. Rarely, preterm induction may have to be done. The incidence of stillbirth increases with prolonged pregnancy; while at 37 weeks it is I in 1000, increasing to 3-5 in 1000 at 42 weeks and beyond. For women >40 years, the incidence at 39-40 weeks is 2 in 1000. +Elective induction of labor means initiation of labor at term pregnancy without any acceptable medical or obstetric indication. It is done for the convenience of the patient, obstetrician or the hospital. Unless for a selective + + +■ Pre-eclampsia, eclampsia (hypertensive disorders in pregnancy). ■ Maternal medical complications: +• Diabetes mellitus. +• Chronic renal disease. +• Cholestasis of pregnancy. • Postmaturity. +a Abruptio placentae. +■ Fetal Growth Restriction (FGR). ■ Rh-isoimmunization. +11 Premature rupture of membranes. +11 Fetus with a major congenital anomaly. • Intrauterine death of the fetus. +■ Oligohydramnios, polyhydramnios. +11 Unstable lie-after correction into longitudinal lie. +• Maternal request (not routine)/advanced maternal age. + +patient (e.g., who has history of rapid labor) the social indications should not be recommended. The major risks are iatrogenic prematurity and increased cesarean delivery for failed induction (Table 35.1). + +_ ,• • •-., ,•, 1. --;,i., , f•r.- • ,> ( ,,.: , +f +. +' +: +' +. +o +C +o +n +t +r +a +i +n +d +i +.Bo 35.2: tCi!!iO!) qf'lndi,is.t 9"! f_L o. :;:7.f,6, ♦ To estimate feta I favorable) {Table 35.3). weight: clinical and +■ Perform clinical pelvimetry to assess USG. +pelvic adequacy. + Ensure fetal lung ■ Adequate counseling about the risks, maturation status. +benefits and alternatives of IOL with ♦ Ensure fetal +the woman and the family members. presentation and lie ■ Counseling for the need of cesarean + Confirm fetal well­ +delivery in case of failure of induction. being. + +PARAMETERS TO ASSESS PRIOR TO INDUCTION OF LABOR: When induction is considered for fetal interest, one must ensure the gestational age and maturity (pulmonary) of the fetus. However, induction for maternal interest may compel to ignore the fetus (Table 35.2). +Cervical ripening is a series of complex biochemical changes in the cervix which is mediated by the hormones. There is alteration of both cervical collagen and ground substance. Ultimately, the cervix becomes soft and pliable (Table 35.4). + +METHODS OF INDUCTION OF LABOR + +♦ Medical ♦ Surgical ♦ Combined I MEDICAL INDUCTION +DRUGS USED +♦ Prostaglandins PGE2, PGE1 ♦ Oxytocin ♦ Mifepristone Prostaglandins (Table 35.6): Act locally (autocrine +and paracrine hormones) on the contiguous cells. PGE2 +and PGF2a-both cause myometrial contraction. But +PGE2 is primarily important for cervical ripening +whereas PGF2a for myometrial contraction. PGE2 has greater collagenolytic properties and also sensitizes the +myometrium to oxytocin. Intracervical application of + +Table 35.3: Predictive factors for successful Induction of Labor. +Period of gestation Pregnancy at term or post-term-more the success. +Preinduction score Bishop score 6 is favorable. Dilatation of the cervix is most important. +Sensitivity of the uterus Positive oxytocin sensitivity test is favorable. +Cervical ripening Favorable in multiparous and in cases with PROM. +Presence of Fetal Fibronectin Favorable for successful IOL. {fFN) in vaginal swab (>50 ng/ +ml) +Other positive factors Maternal height >5', normal BMI, EFW <3 kg. + +dinoprostone (PGE2-0.5 mg) gel is the gold standard for cervical ripening. It may be repeated after 6 hours for 3 +or 4 doses if required. The woman should be in bed for 30 minutes following application and is monitored for uterine activity and fetal heart rate. Side effects are few. +PGE2 (tablet, gel or controlled release pessary) should be used as the first-line agent (NICE). +Misoprostol (PGE1) is currently being used either +transvaginally or orally for induction of labor (ACOG, 2003). Oral use of misoprostol is less effective than vaginal administration. A dose of 25 µg vaginally every 4 hours is found either superior or similarly effective to that of +PGE2 for cervical ripening and labor induction. With the above dose schedule, the risk of uterine hyperstimulation, +meconium-stained liquor and fetal heart irregularities are reduced. Total 6-8 doses are used. Buccal and sublingual use of misoprostol can avoid the first pass hepatic circulation and can maintain the serum bioavailability similar to that of vaginal use. Side effects are: Tachysystole, meconium passage and possibly uterine rupture (Boxes 35.4 and 35.5). It is contraindicated in woman with previous cesarean birth. + + + +Table 35.4: Methods of Cervical Ripening. Pharmacological methods +Oxytocin Prostaglandins {PGs) +■ Dinoprostone {PGEJ Gel, tablet, controlled release pessary +■ Misoprostol (PGE1):Tablets +Progesterone-receptor antagonists: Mifepristone (RU 486) +Relaxin: A protein hormone from corpus luteum, dissolutes cervical connective tissue. + +Hyaluronic acid +Estrogen + + +Nonpharmacological methods +A. Mechanical methods: ■ Mechanical dilators +■ Foley catheter {single balloon) ■ Transcervical (30 ml) balloon +catheter +■ Osmotic (hygroscopic) dilators, Laminaria tents (natural) or Dilapan (synthetic) +■ Extra-amniotic Saline Infusion (EASI) +B. Surgical methods: +■ Sweeping of membranes +■ Amniotomy (artificial rupture of membranes) + + +Advantages of Foley catheter for labor induction +♦ Lower risk of uterine tachysystole and FHR changes. ♦ Reduced risk of cesarean delivery. +♦ Induction to delivery interval, is the same when compared to PGE gel. +2 +♦ Less stringent monitoring. ♦ Low cost. +♦ More suitable for women at risk (eclampsia, FGR). ♦ Easier to store. +♦ Can be used in scarred uterus. +♦ Used with Extra-amniotic Saline Infusion {EASI), improved results, .I- infection rate. + +Use (off-label) of misoprostol (PGE1) for cervical ripening is safe and effective (ACOG-2003) +Chapter 35: Induction of Labor Im ••Box ?;S:,Maflageme:i.t of ,c"'"T"'f .-,. .:'-',,.;. . = - tl l' , "'•:i '>• r• '>;u_"r:'S','. ,,,,d.')l' + =-tv..,.•.. {=.,•f' !"' l: ":.- - +, +., +omp[i a 11msf !9.Y!!ng +l !l i_op +9f Lab.% +2 + +♦ Oxytocin: +• Water intoxication. • Hypotension. • Uterine tachysystole. • FHR changes. +♦ ARM +• Cord prolapse. • Infection. • Chorioamnionitis. • Bleeding. +• Sweeping of membranes +• Vaginal bleeding. • PROM. ♦ Misoprostol +• Tachysystole. • FHR changes. +• Meconium-stained liquor. • Uterine rupture. ♦ Foley catheter +• Vaginal bleeding. • Febrile morbidity. ♦ Mechanical dilators +• Maternal and neonatal infections. ♦ Any method +• Placental abruption. • FHR changes. • Cesarean delivery. + +Comments: With favorable preinduction cervical score (Table 35.5), there is very little to choose but where the score is poor, prostaglandin has got a distinct advantage over oxytocin (Table 35.6). +Oxytocin is an endogenous uterotonic that stimulates uterine contractions. Oxytocin receptors present in the myometrium are more in the fundus than in the cervix. + + +♦ Oxytocin infusion: To decrease/stop. ♦ Hypotension: Infuse IV crystalloids. +♦ Uterine tachysystole with category II or Ill. FHR changes. Injection terbutaline 0.25 mg SC. +♦ Additional measures: • Left lateral position. +• 02 inhalation. +• IV infusion-crystalloids. +♦ Delivery by cesarean section (when no improvement). + +Receptor concentrations increase during pregnancy and in labor (cf. prostaglandins). Oxytocin acts by­ (a) receptor mediation; (b)voltage-mediated calcium channels; and (c) prostaglandin production. Because of short half-life (3-4 minutes) plasma levels fall rapidly when intravenous infusion is stopped. Oxytocin is effective for induction of labor when the cervix is ripe. It is less effective as a cervical ripening agent. Regimen of use: Low dose: between 1.0 and <4 mU/min. High dose: Between 4 and 6 mU/min. Dose is increased in eve1y 20-30 min. +Mifepristone (progesterone receptor antagonists) blocks both progesterone and glucocorticoid receptors. RU 486, 200 mg vaginally daily for 2 days has been found to ripen the cervix and to induce labor. + + +,Ta_ble 35.S: Bishop's (Edward Harry Bi hop) preinduction' ;i I "Zo;in /syste (modified). ,_ Score + +Parameters +Cervix +• Dilatation (cm) • *Effacement (%) • Consistency +• Position +Head: Station + + +0 + +Closed 0-30 Firm +Posterior +-3 + + +1 + +1-2 40-50 +Medium Midline +-2 + + +2 3 + +3-4 5+ +60-70 ?!80 Soft - +Anterior - +-1,0 + 1,+2 + +Total score= 13; Favorable score= 6-13; Unfavorable score= 0-5 +* Cervical length (cm) >4 2-4 1-2 <1 * Modification (1991) replaces effacement(%) with cervical length in cm. + +Table 35.6: Merits and demerits of Oxyt cin d Pro;tagiandins in medic I lnd ction'of Labor. + + +Cost Stability +Administration Effectiveness + + + +Side effects + + +Systemic side effects +Antidiuretic Hormone (ADH) effect + +Oxytocin Cheaper +Needs refrigeration Intravenous (IV) infusion +Less with: +• +• +" +Low Bishop score. IUFD +Lesser weeks of pregnancy. +Uterine hyperstimulation mainly with high dose (ceases following stoppage of infusion). +Less; water intoxication. +In high dose + +Prostaglandins (PGE ' PGE1) PGE2 costly, PGE1 less costly. +PGE2 needs refrigeration; PGE1 is stable at room temperature. lntravaginally or orally. +More effective in those cases as it has got more collagenolytic properties and it also sensitizes the myometrium to oxytocin . + + +Low-dose schedule has got minimal side effects. Tachysystole (rare)-(may need injection terbutaline 0.2 mg SC). +Vaginal route use has got minimal side effects. +No such +Im Chapter 35: Induction of Labor +Table 35.7: Methods of induction of labor and the common clinical conditions. + +Medical methods +■ Intrauterine fetal death. +■ Premature rupture of membranes. +■ In combination with surgical induction (ARM). + + +Surgical methods +■ Abruptio placentae. ■ Chronic hydramnios. +■ Severe pre-eclampsia/eclampsia. +■ In combination with medical induction. +■ To place scalp electrode for electronic fetal monitoring. + + +Combined methods +■ To shorten the induction-delivery interval (commonly done). Medical methods followed by surgical or surgical methods followed by medical. + + + + + + + + + + + + + + + + + +Fig. 35.1: Artificial rupture of the membranes (ARM) using amnihook. + +Mechanical methods are effective. Advantages are­ low cost, low risk of tachysystole (Table 35.4). +Disadvantages: Infection. +I SURGICAL INDUCTION METHODS (Table 35.7) +■ Artificial {low) Rupture of the Membranes (ARM/ LRM) {Fig. 35.1). +■ Stripping the membranes + +Low Rupture of the Membranes (LRM) +Mechanism of onset of labor: May be related with-(a) stretching of the cervix; (b) separation of the membranes (liberation of prostaglandins); and (c) reduction of amniotic fluid volume. + +Effectiveness depends on: (l) State of the cervix; (2) Station of the presenting part. Induction delivery interval is shorter when amniotomy is combined with oxytocin than when either method is used singly. +Advantages of amniotomy: (a) High success rate; (b) Chance to observe the amniotic fluid for blood or meconium; (c) Access to use fetal scalp electrode or intrauterine pressure catheter or for fetal scalp blood sampling. Early amniotomy at 1-2 cm or late amniotomy at 5 cm cervical dilatation is used for inductions or augmentation of labor. +Limitation: It cannot be employed in an unfavorable cervix (long, firm cervix with os closed). The cervix should be at least one finger dilated (Table 35.8). +Indications: Table 35.7. +Contraindications: Intrauterine fetal death, maternal AIDS, genital active herpes infection. +Immediate beneficial effectsofARM +♦ Lowering of the blood pressure in pre-eclampsia-eclampsia. +♦ Relief of maternal distress in hydramnios. ♦ Control of bleeding in APH. +♦ Arrest of progress in abruptio placentae and initiation of labor. +♦ Shortens the duration of labor. +These benefits are to be weighed against the risks invo­ lved in the indications for which the method is adopted. +HAZARDS OF ARM +♦ Once the procedure is adopted, there is no scope of +retreating from the decision of delivery. + + +Table 35.8: Merits and demerits of Oxytocin and Low Rupture of the Membranes (amniotomy) as an isolated method. + + +Exclusive indications + +Oxytocin ' +IUD + + +Amniotomy (LRM) +■ APH +■ Hydramnios +■ Severe pre-eclampsia/eclampsia + + + +Prerequisites + +Effectiveness + +Special benefits + + +Hazards + + +Can be employed irrespective of the state of the cervix and the station of the head. +Quite satisfactory and the procedure can be repeated at intervals. +Reversibility of the decision + + +P. 468, Table 35.6 + + +The cervical canal must be at least one finger dilated and the head should preferably be engaged. +If the procedure fails to initiate labor within 4 hours, should be supplemented by oxytocin, if required. +(a) Observation of liquor for blood or meconium stain, (b) Access to uterine cavity for the use of-(i) fetal scalp electrode-electronic monitoring, (ii) fetal scalp blood sampling, (iii) intrauterine pressure catheter. +P.490 +Chapter 35: Induction of Labor + +♦ Chance of umbilical cord prolapse-the risk is low with engaged head. + +♦ Amnionitis-it is the infection of the chorion, amnion and the amniotic fluid (chorioamnionitis). Aseptic procedure reduces the risk. +Induction delivery interval is reduced with proper sele­ ction of cases with favorable Bishop's score. +♦ Accidental injury to the placenta, cervix or uterus, fetal parts or vasa previa. Care taken during rupture of the membranes minimizes the problem. +♦ Liquor amnii embolism (rare). +I LOW RUPTURE OF THE MEMBRANES (LRM) +It is widely practiced nowadays with high degree of success. The membranes below the presenting part overlying the internal os are ruptured to drain some amount of amniotic fluid. + +Contraindications: +i. Woman with HN infection. +ii. Woman with Group B Streptococcus infection. +iii. It is preferably avoided in chronic hydramnios, as there is risk of sudden massive liquor drainage. +Sudden uterine decompression may precipitate early placental separation (abruption). In such a case controlled ARM is done. +Procedures: Preliminaries: It is an indoor procedure. The patient is asked to empty her bladder. The procedure may be conducted in the labor ward or in the operation theater if the risk of cord prolapse is high. +Actual steps (Fig. 35.2): +■ FHR status is monitored before and after the procedure. ■ The patient is in lithotomy position. +11 Surgical asepsis to be taken. +■ Two fingers are introduced into the vagina smeared with antiseptic ointment. The index finger is passed through the cervical canal beyond the internal os. The membranes are swept­ free from the lower segment as far as reached by the finger. +■ With one or two fingers still in the cervical canal with the palmar surface upwards, a long Kocher's forceps + + + + + + + + + + + + + + +Fig. 35.2: Methods of low rupture of membranes by Kocher's artery forceps. + + + + + +a + +, + +., +. +, +,, +·""' + +m +Figs. 35.3A and B: (A) Kocher's artery forceps; (Bl Showing the tip of the Kocher's forceps. + +(Figs. 35.3A and B) with the blades closed or an amnion hook is introduced along the palmar aspect of the fingers up to the membranes, +■ The blades are opened to seize the membranes and are torn by twisting movements. Amnihook is used to scratch over the membranes. This is followed by visible escape of amniotic fluid, +If the head is not engaged, an assistant should push the head to fix it to the brim of the pelvis to prevent cord prolapse. If the head is deeply engaged and the drainage ofliquor is insignificant, gentle pushing of the head up, facilitates escape of desired amount of amniotic fluid. +After the membranes rupture, the following are to be assessed: +■ a. Color of the amniotic fluid; b. Status of the cervix; +c. Station of the head; +d. Detection of cord prolapse, if any; +e. FHR pattern is again checked. In high-risk cases, scalp electrode for fetal monitoring is applied. +■ A sterile vulva! pad is placed. Prophylactic antibiotic may be prescribed. +■ Monitoring the progress (Box 35.6). Hazards: See above. +I STRIPPING THE MEMBRANES +Stripping (sweeping) of the membranes means digital separation of the chorioamniotic membranes from the wall of the cervix and lower uterine segment. It is thought to work by release of endogenous prostaglandins from the membranes and decidua. Manual exploration of the cerix triggers Ferguson reflex which promotes oxytocin release from maternal pituitary. Sweeping of the membranes is done prior to ARM. It is simple, safe and beneficial for induction of labor. + + + +♦ Patient should be in bed. +♦ Monitoring of uterine contractions. +♦ Monitoring of fetal heart rate. ♦ Monitoring of drug use (Oxytocin dose increment/repeat dose for PGs). +Im Chapter 35: Induction of Labor +As an isolated procedure, stripping the membranes off from its attachment from the lower segment is an effective procedure for induction provided cervical score is favorable. It is used as a preliminary step prior to rupture of the membranes. It is also used to make the cervix ripe. +Criteria to be fulfilled for membrane stripping are: (a) The fetal head must be well applied to the cervix; (b) The cervix should be dilated so as to allow the introduction of the examiner's finger. +Comments: Each method has got its limitations and hazards. For induction of labor, each case should be judged on individual basis. +Mechanical: Dilators-act by release of endogenous prostaglandins from the membranes and maternal decidua to induce labor and cervical ripening. Hygroscopic dilators, e.g., laminaria (desiccated seaweed), lamicel (magnesium sulfate in polyvinyl alcohol) act by absorption of water. They swell and forcibly dilate the cervix. Mechanical dilators are as safe +and effective as PGE2 in cervical ripening. +Cervical balloon catheter causes cervical ripening with release of the interleukins (IL-6, IL-8), Matrix Metalloproteinase (MMP-8) and hyaluronic acid synthetase. Balloon volumes may be low (30 mL) or high (60-80 mL). + + + +Transcervical balloon catheter (Foley catheter) and extra-amniotic saline infusion are effective for cervical ripening (Fig 45.4). + +COMBINED METHOD + +The combined medical and surgical methods are commonly used to increase the efficacy of induction by reducing the induction-delivery interval. The oxytocin infusion is started either prior to or following rupture of the membranes depending mainly upon the state of the cervix and head brim relation (Flowchart 35.1). With the head nonengaged, it is preferable to induce with prostaglandin gel or to start oxytocin infusion followed by ARM. The advantages of the combined methods are: +1. More effective than any single procedure; +2. Shortens the induction-delivery interval and thereby-(a) minimizes the risk of infection, and (b) lessens the period of observation. + +ACTIVE MANAGEMENT OF LABOR (Syn: Augmentation of Labor) +Active management of labor was introduced by O'Driscoll and his colleagues in 1968 at National Maternity Hospital, Dublin. The term "Active" refers to the active involvement + + +Flowchart 35.1: Scheme for induction of labor. + +Induction of labor + + +Medical Surgical + + +Exclusive indication IUFD. + + +ex-favorable. + + +Oxytocin +or prostaglandin E/E1 + +Prostaglandin E,, E/oxytocin. + + +ex-unfavorable. + + +Prostaglandins more effective. + + +Amniotomy (LRM) + +♦ APH +♦ Severe pre-eclampsia • Eclampsia + +Special advantages +• Observation of the amniotic fluid for blood or meconium. ♦ Use of scalp electrode for fetal monitoring. +• Fetal scalp blood sample. +• Use of intrauterine pressure catheter. + + +Combined (common) + + + +ex-unfavorable + +Vaginal prostaglandin E2 gel/E/oxytocin infusion + +ex-favorable + +Amniotomy + Oxytocin + + +Cervix-ripe + +Amniotomy + Oxytocin +Chapter 35: Induction of Labor Im Amnion Chorion + + + + + + +-'-1...--fl-- Extra-amniotic +saline + + + +Fig. 35.5: Electronic fetal monitor with abdominal transducers. + +Table 35.9: Advantages and contraindications of Active Management of Labor. +Advantages Contraindications + + + +Fig. 35.4: Extra-amniotic Saline Infusion (EASI) through a Foley catheter that is placed through the cervix. The 30-ml balloon is inflated with saline and pulled snugly against the internal os. Room-temperature normal saline is infused through the catheter port. + +of the consultant obstetrician in the management of primigravid labor. +■ Active management applies exclusively to primigravi­ das with singleton pregnancy and cephalic presentation who are in spontaneous labor and with clear liquor. +■ Husband or the partner is present during the course of labor. +■ Partograph is maintained to record the progress of labor (Fig. 35.6). +The essential components of Active Management of Labor (AMOL): +■ Antenatal classes to explain the purpose and the procedure of AMOL (prenatal education) +■ Woman is admitted in the labor ward only after the diagnosis of labor (regular painful uterine contractions with cervical effacement) +■ One-to-one nursing care with partographic monitor­ ing oflabor (Fig. 35.6) +■ Amniotomy (ARM) with confirmation of active labor +■ Oxytocin augmentation if cervical dilatation is slower in the active phase (>5 cm dilatation) of labor. +■ Epidural analgesia if needed for pain relief. +■ Fetal monitoring by intermittent auscultation or by continuous electronic monitoring (Fig. 35.5) +■ Active involvement of the consultant obstetrician. +■ The duration of active first stage (from 5 cm to 10 cm) usually is S.12 hours in a primi and 10 hours in a multi. +The key to active management involves strict vigilance (one-to-one care), active and informed intervention + +• Less chance of dysfunctional labor ■ Early (<5 cm dilatation) + Maintains maternal and fetal amniotomy and +wellbeing oxytocin augmentation. • Shortens the duration of labor ■ Presence of obstetric +(<12 hours) complication. +♦ Fetal hypoxia can be detected ■ Any medical interven­ early tions when cervical ++ Low incidence of cesarean birth dilatation <5 cm. ♦ Less analgesia ■ Presence of fetal • Less maternal anxiety due to compromise +support of the caregiver and ■ Multigravia (not a prenatal education routine) + +in time. The incidence of operative delivery is not increased and less analgesia is required (Table 35.9). +Aim: To expedite delivery within 12 hours without increasing maternal morbidity and perinatal hazards. +Active management of labor: Objective is-(a) early detection of any delay in labor; (b) diagnose its cause; and (c) initiate management. +Emotional support in labor: Stress and anxiety during labor can make labor prolonged. Presence of a support­ ive companion during labor (husband/female relative of choice) reduces the duration of labor, need of analge­ sics and oxytocin augmentation. Such social support is a low-cost useful inte1vention. Stress-induced high levels of endogenous adrenaline is thought to inhibit uterine con­ tractions via stimulation of uterine muscle beta receptors +(Ch. 13, p.109). +Limitations of Active Management of Labor: It is employed only in selected cases and in selected centers where intensive intrapartum monitoring by trained personnel is possible. It requires more staff involvement in the antenatal clinic and labor ward. + +PARTOGRAPH +Partograph is the graphic representation of !] - •· +· +· +. + + +l] +!] · : +the progress of labor in terms of women's §1, +cervical dilatation and descent of the fetal presenting part, against time (Philpott and +1B Chapter 35: Induction of Labor +WHO LABOR CARE GUIDE + +Section 1 + + +Name +Ruptured membranes (Date + +Parity Labor onset Active labor diagnosis [Date +Time ] Risk factors + + +1-- -+m-,--,--+--+--+--++---+-+-I -1 -11 1-- -----1 + 10 11 12 I + .---------ACTIVE FIRST STAGE--------- - SECOND STAGE -- + + +Section 2 + +Companion N +Painrelief N +Oral fluid N +Posture SP + +Baseline <110, ..160 deceFleHrRation +FHR +l +Section 3 Amniotic fluid M+++, B +Fetal position P,T +Caput +++ + + + + +Section 4 + + + + + + + +Section 5 + + + + + + +Section 6 + + + + + +Section 7 + +Moulding +++ + +Pulse <60, .. 120 +fi +Systolic BP <80,i.140 +Diastolic BP +,90 +Temperature"( i.37.S +<35.0, +I cootractions / P++,A++ I I I I I I I I I I I I I I! I! I! I! I! I! I 10 +Urine +Contrctioos +perlOmin +Duration of +2 5 +s:, +> +<20, >60 +I: I: I I: I: I +9 • 1h In active first stage, plot 'X' to +Cervix record cervical dilatation. Alert +8 z.2.Sh +IP lXI +trlggered when lag time for + 7 , lh currentcervlcal dllatation is +} 1;1111111111111se : !:::: ; p;. t f -l te z Oxytocin (U/1., drops/min) +e +o +■ +6 , Sh +5 ,6h + + +Medicine +!e 1-------,1---t--t--+--+--+--+--+-t--+--+--+---, IJ .... ·-··-· +1111111·1 +11 +1··r····1 +I I I I I I IITn + +IV fluids + +INSTRUCTIONS: CIRClE ANY OBSERVATIOU MEETING THE CRITERIA IN THE 'ALERT' COLUMN,ALERTTHE SEtllOR MIDWIFE OR DOCTOR ANO RECORD THE ASSESSMENT ANO ACTION TAKEN. IF LABOR EXHtlDS BEYOND 12HOURS, PLEASE CONTINUE ON A NEW LABOR CARE GUIDE. +Abbreviations: Y -Yes, II -/lo, D -i!dined, U -Unkno1m, SP -Supine, MO-Mobile, E - Early, L - Late, V -Variable, I -lnmt. C -Clear, M -Meconi um, B -Blod, A-Anterio!, P -Posterio!, T -Transverse. P+ - Protein, A+ -Acetone + + +Fig. 35.6: Partograph (modified WHO) representing graphically the important observations in labor. WHO Labor Care Guide with the sections of: Patient's details, supportive care, baby, woman, labor progress, medications and shared decision making. + + +Castle, 1972). Regular recording of important clinical parameters has been maintained covering the wellbeing of the woman and baby. +The components of a partograph are {Fig. 35.6): Labor Care Guide (WHO) has made the important changes: + + +■ Active phase of labor starts from 5 cm of cervical dilatation (earlier 4 cm). Fixed 1 cm/hour 'alert' line and the corresponding 'action line' has been changed with evidence-based time limits at each cm of cervical dilatation during active first stage of +Chapter 35: Induction of Labor Im~-­ + +labor. It allows the variability in the rates of progress of labor between women. The lines have been removed but the parameters remain the same. +• A companion of choice for all women throughout labor and child birth is recommended. +• Duration and frequency of uterine contractions are recorded. The strength of uterine contractions is no longer recorded, as it is difficult to quantify clinically. +■ The parameters are highlighted when there is deviations from expected observations of any labor. The corre­ sponding response is recorded by the care provider. +■ There is increased uterine contractions in intensity and duration in the second stage labor. The combined propulsive and maternal voluntary expulsive effort make the second stage a more critical time. This stage needs more vigilance and intensified monitoring for both the mother and her baby. +■ In the 'assessment; the care giver has to record the overall assessment. The care plan is formulated in discussion with the woman. In the 'plan' section, the care plan is documented. +■ Labor Care Guide (WHO) is designed for an individual woman's care. This is aimed for positive child birth experience. + +Plotting ofpartograph-P. 494. +Recordings as regard to areas: ■ Women ■ Baby +■ Labor progress ■ Medications ■ Shared decision making. +Assessment: • Fetus: FHR every 30 minutes and every 15 minutes in second stage. • Woman: Pulse; BP, temperature, urine output every hour; uterine contractions (frequency) per 10 min (:52, >5) and duration (<20 sec, >60 sec). +Labor progress:• Cervix [dilatation (cm) with hour] (plot X}; descent (Plot O}; • Medication: oxytocin; analgesic, IV fluid and • Shared decision making following assessment and plan. +Advantages of a partograph: (i) A single sheet of paper can provide details of necessary information at a glance; {ii) No need to record labor events repeatedly; {iii) It can predict deviation from normal progress of labor early. So, appropriate steps could be taken in time; {iv) It facilitates handover procedure; (v) Introduction of partograph in the management of labor (WHO, 1994) has reduced the incidence of prolonged labor and cesarean section rate. There is improvement in maternal morbidity, perinatal morbidity and mortality. + + + + + +► Theobald and associates in 1948 described the use of oxytocin for labor induction, +> Currently, there is rise in the incidence of induction of labor globally (US: 23.4%, UK: 21 %, Asian countries 12.1 %, Sri Lanka: 35.5%) +> Induction of labor means initiation of uterine contractions (after fetal viability) for the purpose of vaginal delivery, Augmentation +is the process of stimulation of uterine contraction that are already present but found to be inadequate. +> Induction of labor should be done when benefits of delivery to either the mother or the baby outweigh the risks of pregnancy +continuation. +> Indications and contraindications must be carefully judged to avoid the dangers of induction of labor, +> Methods of cervical ripening are many, Bishop's preinduction cervical score (Table 35.5) can predict the success of induction, +Score Methods of induction may be medical, surgical or combined, depending upon the individual case, Each method has got its merits and demerits (Tables 35.6 to 35.8). +> Cervical remodeling (ripening) is achieved by collagen breakdown and rearrangement. There is also changes in the glycosamino­ +glycans, increased hyaluronic acid and production of cytokines and white blood cell infiltration, ► There is rise in the number of nonindicated induction of labor (induction on maternal request), +> Induction of labor with sweeping of the membranes is effective, Combined use of amniotomy (ARM) and IV oxytocin is more +effective than ARM alone, +► Foley catheter, a non-pharmacological method, has many advantages for labor induction. Risks of uterine tachysystole, fetal heart rate changes, cesarean delivery are low (Table 35.4). +> Active management of labor needs some criteria to be fulfilled, It has many advantages, Contraindications are to be maintained, > Partograph is a composite graphical record of labor events (maternal and fetal) entered against time on a single sheet of paper (Fig. 35.7), It has many advantages. It can predict deviation from normal progress of labor early so that early steps could be taken. +► Recommendations on intrapartum care for a positive child birth experience (WHO) are to be followed. + +Population Dynamics and +Control of Conception + + + + + + +CHAPTER OUTLINE +❖ Control of Contraception ► Family Planning +► Contraception +❖ Methods of Contraceptions ► Temporary Methods +► Intrauterine Contraceptive Devices ❖ Steroidal Contraceptions +► Combined Oral Contraceptives (Pills) +► Centchroman (Chhaya/Saheli) +► Progestogen-only Contraceptions + + +► Emergency Contraception (EC) +► Summary of Oral Contraceptives ❖ Drug Interaction and Hormonal +Contraception ❖ Sterilization +► Couple Counseling ► Male Sterilization +► Female Sterilization ❖ Barrier Methods +► Condom (Male) +► Female Condom (Femidom) + + +► Diaphragm +► Vaginal Contraceptives +► Fertility Awareness Method +► Contraceptive Counseling and Prescription +► Sterilization Counseling ► Prescription +❖ Ongoing Trials and Selective Availability +► Transcervical Sterilization + + + +I INTRODUCTION +Rapid population growth (96% in LMIC countries) is a critical issue worldwide. Family planning methods save women's lives preventing unintended pregnancies. Slower population growth conserves resources, improves health and living standards. +Benefits of fertility control are interrelated. Benefits are improved quality of life, better health, less physical and emotional stress of life, better education, job, and economic opportunities. Benefits are enjoyed by the couple, the child­ ren, other family members, the community and the Country. +Contraception and fertility control are not synony­ mous. Fertility control includes both fertility inhibition (contraception) and fertility stimulation. While the fertility stimulation is related to the problem of the infertile couples, the term contraception includes all measures, temporary or permanent, designed to prevent pregnancy due to the coital act. +Ideal contraceptive methods should be highly (100%) effective, acceptable, safe, reversible, cheap, having non-contraceptive benefits, simple to use and requiring minimal motivation, maintenance and supervision. + +CONTROL OF CONCEPTION I FAMILY PLANNING +AIMS: The aims of family welfare planning are: (1) To bring down population growth, so as to ensure a better standard of living; (2) From economic and social point of view-the already existing population of nearly + + +l, 705 million, there is deficiency in basic needs of food, clean water, clothing, housing, education and proper health care. Spacing of birth and small family norm will improve the health of the mothers and their children so that a healthier society can emerge; (3) To reduce the maternal and infant mortality rates; (4) To prevent pregnancies that are too early, too frequent and too many and the number of unsafe abortions. + +OBJECTIVES Conception control: +a To bring down the birth rate to a realistic minimum during a given period of time. The term 'eligible couple' is applied to couples with wives in the reproductive age group of 15-45 years and who require the use of some sort of family planning method. In India Total Fertility Rate (TFR) currently is 2.4 and target is to reduce it to 2. +■ To bring about certain social changes like: (a) To educate and motivate the sexually active and fertile couple to accept the small family norm; (b) To increase the literacy rate, especially amongst women in rural areas; (c) To raise the marriageable age of both boys and girls. Low age of marriage not only contributes to the increased birth rate but adversely affects the health of the woman. In 1978, the Indian Parliament approved the Bill fixing the minimum age of marriage at 21 years for men and 18 years for women; (d) To maximize the access of good quality, wide variety, client-oriented family planning services and to fulfill the unmet need of contraception. + + +I CONTRACEPTION +Contraception and fertility control are not synonymous. Fertility control includes both fertility inhibition ( contraception) and fertility stimulation. While the fertility stimulation is related to the problem of the infertile couples, the term contraception includes all measures, temporary or permanent, designed to prevent pregnancy due to the coital act. + +Chapter 36: Population Dynamics and Control of Conception la Withdrawal Others (2%) +method (5%) +Rhythm---­ +method (3%) Female sterilization (24%) +Male condom +(21%) Male sterilization (24%) + + + +Ideal contraceptive methods should be highly (100%) effective, acceptive, safe, reversible, cheap, having non­ contraceptive benefits, simple to use and requiring minimal motivation, maintenance and supervision. + + +IUD (17%) Pills (16%) \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_16.txt b/notes/DC Dutta Obstetrics 10th Edition_16.txt new file mode 100644 index 0000000000000000000000000000000000000000..aa06dedbeaa79656fc397b1993b08dff94c4ca35 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_16.txt @@ -0,0 +1,2027 @@ + + + +CONTRACEPTIVE EFFECTIVENESS: The failure rate of any contraceptive is calculated in terms of pregnancy rate per Hundred Women Years (HWY) of use. It is calculated according to the following formula (Pearl index): +Pregnancy failure rate/HWY +_ Number of accidental pregnancies x 1,200* Number of patients observed x months of use +• 1,200 = number of months in 100 years +Example: If 100 couples have used a method for a period of 2 years and have resulted in 20 pregnancies, the +1200 +24 +20 +X +100 +. +pregnancy rate 1s calculated to be: ---- == 10 X +When the pregnancy rate is below 10, the effectiveness of the particular method is considered to be high. If it is more than 20, it is said to be low. The following are the effectiveness of the commonly used contraceptive methods. + +METHODS OF CONTRACEPTIONS +The various methods of contraception are schematically depicted here (Flowchart 36.1 and Fig. 36.1). +Contraception is a preventive issue. Nearly 55% of all Indian women are using a contraceptive method. There are several noncontraceptive benefits of contraceptives. The preferred method of contraception for a women may change over for phases of life. "Tiers of effectiveness" of contraceptive methods are based on pregnancy rates with their perfect use and typical use (Table 36.1). +The Medical Eligibility Criteria (MEC) provides the guidance for safe use of contraceptives for any woman with medical comorbidities (Table 36.2). + +Flowchart 36.1: Methods of Contraception. +Methods of Contraception + +Implants (2%) +Fig. 36.1: Methods of Contraception used by women of reproductive age (15-49 years); Worldwide. +Source: United Nations-data booklet of World Contraceptive Use 2019. +I TEMPORARY METHODS +Temporary methods are commonly used to postpone or to space births. However, these methods are also frequently being used by the couples even though they desire no more children. + +INTRAUTERINE CONTRACEPTIVE DEVICES (IUCDS) + +The Intrauterine Contraceptive Devices (IUCDs) have been used worldwide. It is a safe, effective and reversible method of contraception. The efficacy of IUCDs are comparable with surgical sterilization. +There has been a significant improvement in its design and content. The idea is to obtain maximum eficacy without increasing the adverse effects. The device is classified as open, when it has got no circumscribed aperture of more than 5 mm so that a loop of intestine or omentum cannot enter and become strangulated if, accidentally, the device perforates through the uterus into the peritoneal cavity. Cu-T, Multiload 375 are examples of open devices. The device may be medicated (bioactive) by incorporating a metal copper, in devices like Cu-T 380A, Multiload-375 (Figs. 36.2A to C) or it may be hormonally active (LNG-IUS). +Types of IUCDs: The copper T-380A is commonly used. The amount of copper that comes out of the device on daily basis amounts to less than that ingested in the normal diet. +Hormone-containing IUDs either releasing progester­ one (progestasert) or levonorgestrel (LNG-IUS) has also been introduced. Nowadays, the following medicated IUDs are in use: + ++ Cu-T 380A. + LNG-IUS. + +• Barrier methods (p. 518). +• Natural contraception. +• Intrauterine contraceptive. devices (IUCDs). +• Steroidal contraception. + + + +Female • Tubal +occlusion. + + + +Male +• Vasectomy. + +• Multiload 375. • Skyla. +Description of the devices (Figs. 36.2A to CJ +Cu-T 380A: It is a medicated device containing copper. +It carries 380 mm2 of copper in total. The vertical stem +ID Chapter 36: Population Dynamics and Control of Conception + + + + +(FirstTier} Most Effective IUCD: Intrauterine devices +Levonorgestrel system 0.1 0.1 T 380A copper 0.6 0.8 Levonorgestrel implants 0.05 0.05 Sterilization: +Female 0.5 0.5 Male 0.1 0.15 +(Second Tier} Very Effective +Combination pill 0.3 9 Vaginal ring 0.3 9 Patch 0.3 9 DMPA 0.2 6 Progestin-only pill 0.3 9 (Third Tier} Effective Condom +Male 2 18 Female 5 21 +Diaphragm with 6 12 spermicides 12 +Fertility-awareness +Standard days 5 Two days 4 Ovulation 3 Symptothermal +0.4 +(FourthTier} Least Effective +Spermicides 18 28 Sponge +Parous women 20 24 + + + +The stem of the device is made of polyethylene frame. These two threads are used for detection and removal of the device. In spite of copper being radiopaque, additional barium sulfate is incorporated in the device. The device is replaced every 10 years. However, this Cu-T 380A device has been used to prevent pregnancy for 20 years. Women desiring for continued contraception, the existing device can be removed at the end of the schedule time and a new device can be inserted during the same time. Apart from the use of Cu-T as a contraceptive (both LARC and Emergence Contraceptive), it is used following synecolysis to prevent recurrent adhesion formation. Devices containing less than 300 mm2 of copper have higher failure rate. +Multiload Cu-375: The device is available in a sterilized sealed packet with an applicator. There is no introducer and no plunger. It has 375 mm2 surface area of copper wire wound around its vertical stem. Replacement is every 5 years (Fig. 36.2A). +Levonorgestrel-intrauterine system (LNG-IUS) (Fig. 36.2B): This is a T -shaped device, with polydimethyl­ siloxane membrane around the stem which acts as a steroid reservoir. Total amount of levonorgestrel is 52 mg and is released at the rate 20 µg/ day. This device is to be replaced every 7 years though approved for 5 years. Its eficacy is comparable to sterilization operation. It has many noncontraceptive benefits also. +■ LNG-IUD 19.5 mg (Kyleena) initially releases 17.5 µg LNG daily. It is effective for 5 years. +■ LNG-IUD 13.5 mg (Skyla) initially releases 14 µg LNG daily for 3 years (Fig. 36.2D). +■ The 19.5 mg and 13.5 mg LNG-IUD are smaller in size (28 mm x 30 mm). These two are approved for small size uterus. These are more suitable for nulliparous women. + + + +Nulliparous women 9 12 No Category +Withdrawal 4 22 No contraception 85 85 +Lactational amenorrhea 2 +Failure rate is less when methods are used correctly and consistently. (IUCD: Intrauterine Contraceptive Devices; CU-T: Copper-T; LNG: Levonorgestrel; DMPA: Depot Medroxyprogesterone Acetate; NET: Norethisterone) + + +Table 36.2: MEC for contraceptive use (WHO/EPP/CDC}. Category Use +1 No restriction of method and use. +2 Advantages of method use outweigh the risks. 3 Method risks of use outweigh the advantages. 4 Method possess unacceptably high health risk. + +is wrapped with 314 mm2 of fine copper and each arm has a 33 mm2 copper bracelet. The sum of these is 380 mm2. Two strings extend from the base of the stem. + + +Lower dose LNG-IUDs cause lesser rates of amenorrhea than the 52 mg LNG-IUD. The trailing strings attached to each device are: Tan for Mirena and Skyla; Blue for Lileta and Kyleena. Skyla and Lietta are approved for 3 years. Skyla and Kyleena have a silver ring at the junction of their stem and arms. + +Nonhormonal intrauterine devices: Cu-T 380A. +The Cu IUD is also the most effective form of postpartum contraception (see below). + +Mode of action +Mechanism of antifertility effect of all the IUDs is not yet clear. They act predominantly in the uterine cavity and do not inhibit ovulation. They have both pre- and post­ fertilization effects to its eficacy and thus they are effective +immediatelyfollowing insertion. Probable factors are: +■ Biochemical and histological changes in the endometrium: There is a nonspecific inflammatory reaction along with biochemical changes in the endometrium. This accumulates throughout the +r Chapter 36: Population Dynamics and Control of Conception JI + + + + + +E +E +N ") + + + + + + + + + +m Multiload 375 ll + + +Cu-T 380A Levonorgestrel containing intrauterine system +ti (LNG-I US) +Figs. 36.2A to D: Commonly used intrauterine devices. + + +m Skyla + + + +uterine lumen, cervical canal and the fallopian tubes. This affects the function and viability of the gametes. Thus, it prevents fertilization, reduces chance of zygote formation and implantation. Lysosomal disintegration from the macrophages attached to the device liberates prostaglandins, which are toxic to spermatozoa. Macrophages cause phagocytosis of spermatozoa. +■ Endometrial inflammatory response decreases sperm transport and impedes the ability of sperm to fertilize the ovum. +■ Copper devices: Ionized copper has got an additional local antifertility effect by preventing blastocyst implantation thro ugh enzymatic interference. Copper initiates the release of cytokines which are cytotoxic. Serum copper level is not increased. The copper ion impedes sperm transport and viability in the cervical mucus. These actions of IUD, prevent sperm to reach the tubes. So there is no fertilization. +■ Levonorgestrel-IUS {Mirena): It induces strong and uniform suppression of endometrium. Cervical mucus becomes very thick and scantly. It impedes sperm motility and access to the upper genital tract. Anovulation and insufficient luteal phase activity has also been mentioned. PGN also reduce tubal motility. Serum progesterone level is not increased. The LNG has little +effect on the HPO axis. The serum E2 concentration are +not reduced and hence; ovulation occurs (Anovulation is more with 52 mg Vs 13.5 LNG-IUS). +The risk ofVTE is nil with the Cu IUCD; little with the LNGIUS. + +Contraindications for Insertion of IUCD +■ Pregnancy or suspected pregnancy. ■ Undiagnosed genital tract bleeding. +■ Acute pelvic infection current or within 3 months. + +■ Distortion of the shape of the uterine cavity as in fibroid or congenital uterine malformation. +■ Severe dysmenorrhea. +■ Known or suspected uterine or cervical neoplasia. +■ Postpartum or postabortal endometritis in last 3 months or infected abortion. +■ Sexually Transmitted Infections (STis): Current or within 3 months. +■ Trophoblastic disease. +■ Significant immunosuppression. + +Additionally for Cu-T are: +■ Wilson disease. ■ Copper allergy. + +For LnG-IUS are: +■ Hepatic tumor or hepatocellular disease (active). ■ Current breast cancer. +■ Severe arterial disease. + +Time of Insertion +■ Interval (when the insertion is made in the intercon­ ceptional period beyond 6 weeks following childbirth or abortion): It is preferable to insert 2-3 days after the period is over. But it can be inserted any time during the cycle, provided she is not pregnant. It can be safely inserted even during menstrual phase which has certain advantages (open cervical canal, distended uterine cavity, less cramp). However, during lactational amenorrhea, it can be inserted at any time. +■ Postabortal: Immediately following termination of pregnancy by suction evacuation or D and E, or following spontaneous abortion. The additional advantage of preventing uterine synechia can help in motivation for insertion. +mJ Chapter 36: Population Dynamics and Control of Conception + + + + + + + + + + +a + +'J + + + + +:Q +I] Figs. 36.3A to F: Withdrawal technique of insertion of CuT- . (Cl Uterocervical length is measured. + + + +■ Cu-T 380A can be used as an emergency contraception up to 5 days following unprotected coitus. +Immediate postpartum: +■ Post-placental within 10 minutes after expulsion of placenta following vaginal delivery. +■ Intracesarean insertion during cesarean delivery, after removal of the placenta and before closure of the uterine incision. +■ Within 48 hours (MEC-1) after delivery before the patient is discharged from the hospital. +■ Extended postpartum/interval (between 48 hours to 4weeks: MEC-3) anytime after 4weeks (MEC-1). +■ Advantages are: (a) Safe and highly effective; (b) immediate action; (c) Long-term protection; (d) Special benefit to women having limited access or no access to postpartum care; (e) Immediate return to fertility after removal; (f) No need of frequent visits and no further cost; (g) High continuation rates and user satisfaction. Howeve1 the expulsion rate is high. +Criteria to exclude pregnancy: She has not had intercourse since her last normal menses; there is correct and consistant use of a reliable method of contraception; within the first 7 days of a normal menstrual period; not breastfeeding and is <4 weeks postpartum; fully breastfeeding, amenorrhoic, and <6 months postpartum; within 7 days post-abortion or miscarriage. +A negative pregnancy test, is reliable only if ?.3 weeks since the last episode of UPS!. + +Methods of Insertion (Figs. 36.3 to 36.6) +■ Cu-T 200 ■ Cu-T 380A (paragard) + +Preliminaries +(1) History-taking and examinations (general and pelvic) to exclude any contraindication of insertion. (2) Patient is informed about the various problems, the device is shown to her and consent is obtained. (3) The insertion is done in the outpatient department, taking aseptic precautions without sedation or anesthesia. To reduce cramping pain ibuprofen [nonsteroidal anti-inflammatory drug (NSAID)] may be given (200-400 mg) 30 minutes before insertion. (4) Placement of the device inside the inserter-the device is taken out from the sealed packet. The thread, the vertical stem and then the horizontal stem folded to the vertical stem are introduced through the distal end of the inserter. The device is now ready for introduction. "no touch" insertion method is preferred (see below). + +Actual steps +(1) The patient empties her bladder and is placed in lithotomy position. Uterine size and position are ascertained by pelvic examination. (2) Posterior vaginal speculum is introduced and the vagina and cervix are cleansed by antiseptic lotion. + + +LNG-IUD + + +Inserter tube + + + + + + + + +..r---- Slider + +Handle + + + + +Fig. 36.4: Technique of insertion of multiload IUCD. Fig. 36.5: Insertion method of LNG-IUS. +Chapter 36: Population Dynamics and Control of Conception JI' + + + + + + + + + + + +Fig. 36.6: LNG-IUS insertion device. Different parts of the device are shown. + + +(3) The anterior lip of the cervix is grasped by Allis forceps. A sound is passed through the cervical canal to note the position of the uterus and the length of the uterine cavity. The appropriate length of the inserter is adjusted depending on the length of the uterine cavity. (4) The inserter with the device placed inside is then introduced through the cervical canal right up to the fundus and after positioning it by the guard, the inserter is withdrawn keeping the plunger in position. Thus, the device is not pushed out of the tube but held in place by the plunger while the inserter is withdrawn (withdrawal technique in Figure 36.3). (5) The excess of the nylon thread beyond 2-3 cm from the external os is cut. Then the Allis forceps and the posterior vaginal speculum are taken off. 'No-touch' insertion technique includes: (i) Loading the IUD in the inserter without opening the sterile package. The loaded inserter is now taken out of the package without touching the distal end. (ii) Not to touch the vaginal wall and the speculum while introducing the loaded IUD inserter through the cervical canal. +■ Multiload Cu-375: The applicator with the device is just to be taken out of the sealed packet in a 'no-touch' method and the same is pushed through the cervical canal up to the fundus of the uterus. The applicator is then withdrawn (Fig. 36.4). +■ LNG-IUS: The details of insertion are to be followed as in the instruction package (Fig. 36.5). + +Principal steps +The initial steps are the same as in Cu-T 380A. +Sterile package is opened up. The arms of the device should be kept horizontal. The slider is pushed up, to draw the IUCD within the insertion tube. +■ The uterocervical length is measured by the uterine sound. +■ The flange on the inserter tube is positioned from the IUCD tip according to this uterocervical length. +■ The inserter tube with the device is gently inserted within the uterus, until the flange is at 1.5-2 cm from the external os. +■ The arms of the device are then released by pulling the slider back to the raised white line on the handle. To hold this position for about 20-30 seconds to allow the arms to open fully. +■ The inserter is then gently guided into the uterine cavity until its flange touches the cervix (Fig. 36.6). +■ The device is released by holding the inserter firmly in position and pulling the slider back all the way. Fundal placement is ideal. +■ The threads are released automatically. The inserter is then removed slowly. + +■ The threads are then trimmed preserving 3 cm length outside the cervix (same as in Cu-T 380A). + +Instructions to the patient +The possible symptoms of pain and slight vaginal bleeding should be explained. The patient should be advised to feel the thread periodically by the finger. The patient is checked after 1 month and then annually. + +Complications Immediate +■ Cramp-like pain: It is transient but, at times, severe and usually lasts for half to 1 hour. It is relieved by analgesic (ibuprofen) taking before insertion or antispasmodic drugs. +■ Syncopal attack: Pain and syncopal attack are more often found in nulliparous or when the device is large enough to distend the uterine cavity. This could be problematic in patients with cardiac disease. +■ Partial or complete perforation: It is due to faulty tech­ nique of insertion but liable to be met within lactational period when the uterus remains small and soft. + +Remote +■ Pain: The pain is more or less proportionate to the degree of myometrial distension. A proper size of the device may minimize the pain. +■ Abnormal menstrual bleeding: The excessive bleeding involves increased menstrual blood loss, prolongation of duration of period and intermenstrual bleeding. The patient may become anemic especially who is already anemic. Iron supplement is advocated. Tranexamic acid may be given for short-term relief. +Menstrual loss is much less with the use of third­ generation IUDs {p. 503). +Women using LNG-IUS have less (60%) blood loss. Nearly 50% of women develop amenorrhea and 25% have oligomenorrhea after 24 months of use. +■ Pelvic Inflammatory Disease (PID): The risk of developing PID with the use of current devices, is not increased. Modern IUDs have monofilament (not braided) strings that do not increase the risk of infection. Asymptomatic, low risk women do not need additional screening prior to IUD insertion (ACOG-2017). Infections with gonorrhea, Chlamydia and rarely with actinomyces are seen. Women at risk of STis should be screened either before or at the time of IUD insertion (CDC-2015). Women with existing infection like purulent vaginal discharge, adnexal tenderness or cervical +! . ,.mg Chapter 36: Population Dynamics and Control of Conception + + +motion tenderness, laboratory testing should be done and IUCD insertion is delayed. Newer IUDs reduce the risk. Women with IUCD in situ, diagnosed with pelvic infection, removal of IUCD is advised if there is no response to treatment even after 72 hours. +Pain, Abnormal Uterine Bleeding (AUB) and PID are the main factors related to its discontinuation (10-15%). +■ Spontaneous expulsion: Usually occurs within the first month +following insertion, more commonly during the period, at times, unnoticed by the patient. Failure to palpate the thread which could be felt before, is an urgent ground to report to the physician. The expulsion rate is about 5%. The rate is, however, more following postabortal or puerperal insertions. The expulsion rate is markedly reduced in the successive years. The newer IUDs have got less expulsion rate. +■ Perforation of the uterus: It is rare and the incidence is about 1 in 1,000 insertions most commonly seen in breastfeeding women. Most perforations occur at the time of insertion but migration may also occur following initial partial perforation with subsequent myometrial contractions. It is, however, less common when the device is introduced by the withdrawal technique. +■ Diagnosis of uterine perforation: (1) Nonvisibility of the threads through the external os and the appearance of pelvic symptoms after a long asymptomatic period are suspicious. (2) Negative findings on exploration of the uterine cavity by a probe is suggestive. (3) Ultrasonography can detect the IUD in abdominal cavity and is better than radiography. (4) Plain X-ray, anteroposterior and lateral view, following introduction of a radiopaque probe (uterine sound) into the uterine cavity, is conclusive. (5) The device is found away from the opaque shadow placed in the uterine cavity, if it has perforated the uterine wall (Fig. 36.7). Management of missing thread is discussed below. + + + + + + + + + + + + + + + + +Fig. 36.7: Plain X-ray of the pelvis with an uterine sound placed inside the uterine cavity-the displaced Intrauterine Contraceptive Device (IUCD) seems inside the uterine cavity with Anteroposterior (AP) view. Lateral view is needed for confirmation. +(Courtesy: Dr Swati Shirodkar, Head, Department of Obstetrics and Gynecology, MGM Medical College, Aurangabad) + + +Copper Device +A copper-bearing device induces an intense local inflam­ matory reaction with adhesions with the surrounding structures. Thus, as soon as the diagnosis is made, it is to be removed by laparoscopy or laparotomy. + +Pregnancy +The pregnancy rate with the device in situ is rare. Lowest pregnancy rates are observed with Cu-T 380A (0.8-HWY) and LNG-IUS (0.2-HWY). When pregnancy occurs with a device in situ, there is risk of ectopic pregnancy (0.02%). IUD can thus prevent a uterine but not an ectopic pregnancy. +Third generation of IUDs like Cu-T 380A and LNG­ IUS give some amount of protection against an ectopic pregnancy. IUCDs do not increase the viral shedding or reduce the antiretroviral therapy efficacy (ACOG, 2012). +■ Management of a pregnant woman with device in situ: If the thread is visible through the cervix it is best to remove the device. This will minimize complications like miscarriage, preterm labor, sepsis, placenta previa, abruption, cesarean delivery, low birth weight baby, including malformations. However, if the thread is not visible, it is better to counsel the patient about the risks involved in continuing pregnancy. Pelvic ultrasound must be carried out to locate the pregnancy. When the pregnancy is undesired, manual vacuum aspiration can be done to remove the pregnancy and the device. The device is expected to be expelled spontaneously with the delivery of the placenta. +Indications for removal of IUDs +♦ Persistent excessive regular or irregular uterine bleeding. ♦ Flaring-up of salpingitis. +♦ Perforation of the uterus. +♦ IUD has come out of place (partial expulsion). ♦ Pregnancy occurring with the device in situ. +♦ Woman desirous of a baby. ♦ Missing thread. +♦ One year after menopause. +♦ When effective lifespan of the device is over. +IUD removal is simple and can be done at any time. It is done by pulling the strings gently and slowly with forceps. +■ Missing threads: The thread may not be visible through the cervical os due to-(a) Thread coiled inside; (b) Thread torn through; (c) Device expelled outside unnoticed by the patient; (d) Device perforated the uterine wall and is lying in the peritoneal cavity, and (e) Device pulled up by the growing uterus in pregnancy. +Methods of identfication +Pregnancy is to be excluded first. Alternate contraceptive advice is given: +♦ Ultrasonography (TVS and TAS) can detect the IUD either within the uterine cavity or in the peritoneal cavity (if perforated) {Fig. 36.8). 3-D TVS is more informative. +Chapter 36: Population Dynamics and Control of Conception m·-- · + + + + + + + + + + + + + + + + + +Fig. 36.8: Ultrasonogram showing the Cu-T inside the uterine cavity, Thread was missing in this case. + +When sonography is inconclusive of the device is not seen within the uterus, a plain X-ray of the abdomen and pelvis is to be done. Imaging with CT or MRI is rarely needed. +♦ Hysteroscopy can be used for direct visualization of the uterine cavity and it could be removed simultaneously (Fig. 36.9), +♦ Sounding the uterine cavity may be done by a probe. +♦ If negative, plain X-ray is done after introducing a radio­ opaque probe (uterine sound) into the uterine cavity. This will not only reveal the presence or absence of the device but also its existence outside in the abdominal cavity, +Removal +♦ Device inside the uterine cavity: It can be removed by any of the following methods. +• With a specially designed blunt hook (Dutta's Textbook Gynecology, Ch. 38, Fig. 38.41, p. 544), +• Hysteroscopically under direct vision (Fig. 36.9). • Uterine curette. +• Artery forceps. +♦ Outside the uterus but inside the abdominal cavity: (a) Laparoscopy; (b) Laparotomy (rarely). + + + + + + + + + + + + + + + + +Fig. 36.9: Hysteroscopic view of IUCD in uterine cavity, The threads are coiled inside. + +Advantages +■ Inexpensive: Cu-T distributed free of cost through Government channel. +■ Simplicity in techniques of insertion and most cost effective of all methods, +■ Prolonged contraceptive protection after insertion (5-10 years) and suitable for the rural population of developing Countries. +■ Systemic side effects are nil. Suitable for hypertensives, breast­ feeding women and epileptics. +■ Reversibility to fertility is prompt after removal; failure rate-0.1-2/HWY, +■ Risk of ectopic pregnancy is significantly reduced (Cu-T 380A and LNG-IUS: 0.02 HWY). +■ Risk of PIO is reduced, anemia is improved. +■ Noncontraceptive benefits, especially with LNG-IUD: +• Significant reduction in menstrual blood loss, menorrhagia, dysmenorrhea, and premenstrual tension syndrome (PMS), +• It can be used in the treatment of endometrial hyperplasia, adenomyosis, endometriosis, and uterine leiomyomas. +■ Safety and advantages of LNG-IUS: +• Use is associated with reduction in the risk of endometrial and cervical carcinoma, +• LNG-IUS-can be used as a fertility sparing treatment in early stage endometrial carcinoma. +• Safe and as effective as an alternative to sterilization method, +• Higher level of user satisfaction. +• It can be used as an alternative to hysterectomy for menor­ rhagia, Dysfunctional Uterine Bleeding (DUB). +• It provides excellent benefits of Hormone Replacement Therapy (HRT) when used over the transition years of repro­ duction to perimenopause. +■ Disadvantages of third generation of IUDs • Expensive (LNG-IUS). +• Amenorrhea (5%). +• Malpositioning with long duration of use may cause pregnancy (failure) or expulsion, + +Advantages of third generation ofIUDs +Cu-T 380A, multiload-375 and levonorgestrel-IUS. +♦ Higher efficacy with lowest pregnancy rate (less than one per 100 women every year). +♦ Used as LARC with longer duration of action (5-10 years). +♦ Low expulsion rate and fewer indications for medical removal (Box36.l). +Long-Acting Reversible Contraceptions (LARC) are designed to be used for at least I year. LARC methods are cost effective compared to shorter acting methods, Commonly 2 types of IUD are available: (a) Nonhormonal and (b) Hormonal. There are four types of LNG-IUD which are used: LNG-IUD 52 mg (Mirena and Lileta): Both measure 32 mm x 32 mm and initially release 20 pg LNG daily. Mirena is approved for 5 years and the Liletta is approved for 6 years but both are likely to be effective for 7 years. Non-contraceptive benefits are also there, WHO has grouped methods into efficacy tiers (Table 36.2), Intrauterine devices and the implants are found to in the top tier. These are also known as for Long-Acting Reversible Contraception (LARC) (Read more Dutta's Clinics in Gynecology, Ch. 29). +-ml Chapter 36: Population Dynamics and Control of Conception + +SUMMARY OF IUD +Intrauterine contraceptive device is a safe and widely acceptable reversible method of contraception for spacing of births. Amongst +many, either a copper impregnated device like Cu-T, Multiload 375 or a hormone-releasing device like LNG-IUS is commonly used. Its mode of action: It produces nonspecific biochemical and histological changes in the endometrium and ionized copper has got spermolytic and gametotoxic effects. LNG-I US induces uniform suppression of endometrium and produces very scanty cervical mucus. Both copper and LNG-IUS can be offered to young or nulliparous women. Symptomatic women with IUCDs should be treated with an antibiotic regimen (CDC, 2015) till she is symptom free. Otherwise the device should be removed (<72 hours). The device can be introduced in the interval period or following abortion or following childbirth. The introduction is an outdoor procedure and can be done even by a trained paramedical personnel without anesthesia. The technique employed is 'withdrawal' in Cu-T. The +immediate complications include cramp-like pains or even syncopal attacks. The delayed complications include pelvic pain, menstrual irregularities, expulsion of the IUD or even perforation of the uterus. Complications are much less with third generation of IUDs. The indications of its removal are missing threads, persistent pelvic pain, menorrhagia, pregnancy, displacement of the device and flaring up of pelvic infection. Multiload 375 is replaced after 5 years, Cu-T 380A after 10 years and LNG-IUS after 5 years. The failure rate is about 0.5-2 per HWY. Devices Jess than 300 mm2 of copper have higher failure rate. Copper device can also be used as postcoital contraception and following synechiolysis. + + + + +► Modes of antifertility effects of IUCDs are: (a) Nonspecific inflammatory reaction along with biochemical (gametotoxic) changes in the endometrium; (b) Copper devices release ionized copper that prevents blastocyst implantation; (c) LNG-IUS-suppresses endometrium, as it makes cervical mucus scanty. +► The introduction of IUCDs (Cu-T, multiload) is an OPD procedure without anesthesia taking full aseptic precautions. 'no touch' insertion technique is preferred. +► Intrauterine Contraceptive Devices (IUCDs): (a) This is an effective method of contraception with failure rate of 0.5-2 HWY; (b) It is also the most effective method of emergency contraception; (c) It can be used by nulliparous women; (d) IUCDs containing <300 mm2 copper have higher failure rate; (e) Irregular and heavy bleeding may be the side effects and the reason for removal; (f) Third generation IUCDs have higher efficacy and reduced side effects; (g) Risks of ectopic pregnancy is also reduced. +► The contraindications to insertion of IUD are: PID, suspected pregnancy, DUB or suspicious cervix. The failure (pregnancy) rate is about 0.5-2 HWY. There is risk of ectopic pregnancy 1-2%. Third generation IUDs have minimal side effects and lowest pregnancy rate. +► Immediate complications of IUDs include pain, syncopal attack, and uterine perforation. Remote complications include-pain, abnormal uterine bleeding, pelvic infection, spontaneous expulsion or even perforation of the uterus. +► Indications of removal of IUD are-excessive uterine bleeding, flaring up of pelvic infection, uterine perforation, pregnancy, missing thread, and patient desirous of a baby. +► There are many reasons for missing threads and management depends on whether it is within the uterine cavity or within the peritoneal cavity. +► Apart from contraception, the IUD is used as an emergency contraception and following synechiolysis. +► The replacement time for Cu-T 2008 is 4 years, multiload 250-3 years, Cu-T 380A-1 O years, multiload 375-5 years and LNG-IUS is 5 years. +► LnG-IUS has got many noncontraceptive health benefits. It is a very safe and effective method for prolonged use. + + +STEROIDAL CONTRACEPTIONS + +Enovid (norethynodrel 10 mg and mestranol 0.15 mg) was used in the first contraceptive field trial in Puerto Rico in 1956 by Pincus and his colleagues. Currently, 30 µg dose of estrogen has been reduced to 20 µg or even 10 µg to minimize the side effects of estrogen without reducing the efficacy. Types of steroidal contraceptives have been discussed in Flowchart 36.2. + +COMBINED HORMONAL CONTRACEPTIVES (CHC) + +The combined oral hormonal contraceptives (pills) is the most effective reversible method of contraception. Other forms of CHC include:• Combined Vaginal Ring (CVR) [Releasing EE: 15 mcg/day + etonogestrel: 120 mcg/day] and• Combined Transdermal Patch (CTP) [Releasing EE: 40 mcg/day + norelgestromin: 203 mcg/day]. The contraceptive efficacy + +and side effect of all CHC's are similar. In the combination pill, the commonly used progestins are either levonorgestrel, or norethisterone, or desogestrel and the estrogens are principally confined to either ethinylestradiol or mestranol (3-methyl ether of ethinylestradiol). Currently, 'lipid friendly' third-generation progestins, namely desogestrel, gestodene, norgestimate are available. Some of the preparations available in the market are mentioned in Table 36.3. Only Mala-N is distributed through Government channel free of cost (Fig. 36.10). +Fourth generation: Drospirenone which is an analog of spironolactone is used as progestin. It has antiandrogenic and antimineralocorticoid action. It causes retention of K+ (hyperkalemia) and reduces water retention. So drospirenone should not be used in patients with renal, adrenal or hepatic dysfunction. +Serum potassium should be monitored when the women is on any other drug to cause potassium retention (NSAIDs, ACE inhibi­ tors, potassium sparingdiuretics, heparin, aldosterone antagonists). + + + + + + +I + + + + + + +• Oral + +Chapter 36: Population Dynamics and Control of Conception ED -­ Flowchart 36.2: Types of steroidal contraceptives. + +STEROIDAL CONTRACEPTIVES +I +I +• +I +• +• +l +I +I • I Parenteral I • Device I I Patch I +I +I +I +lnjectables Implant Transdermal +• DMPA • lmplanon. (nestorone) +• NET-EN • Norplant-II. +• Combined (ones a • LNG rod. +month injection) + + + +• +Combined preparations • Monophasic. +• Biphasic. • Triphasic. +• Emergency (postcoital). + +• +Single preparations +• Progestin-only pill +(minipill). +• Estrogen only +(emergency). + + + + +I + +• +IUD +(LNG-I US) + + + + +I + + + + Vaginal ring • LNG ring. +• Combined (estrogen and +progesterone) ring. + + + + +I + +• +Transcervical • Essure + + + + +I + + +(DMPA: Depot Medroxyprogesterone Acetate; NET-EN: Norethisterone Enanthate; LNG: Levonorgestrel; LNG-IUS: Levonorgestrel-lntrauterine System; IUD: Intrauterine Devices) + +TABLE 36.3: Some of the oral contraceptives and their composition. + + +Commercial names +1. Mala-n (Government of India) 2. Mala-D +3. Loette (Wyeth) +4. Yasmin (Schering) + + +Progestins (mg) Levonorgestrel (0.15) Levonorgestrel (0.15) Desogestrel (0.15) +Drospirenone 3 mg + +Composition +Estrogen (µg) Ethinyl estradiol (30) -do- +Ethinyl estradiol (20) +Ethinyl estradiol (30) + + +No. of tablets +21 + 7 iron tablets 21 + 7 iron tablets 2 +21 + +Depending on the amount of Ethinyl Estradiol (E) and the types of progestin (P) used. Pills are defined as: 1st generation-with E 50 Lg or more; 2nd generation-with E 20-35 µg and Pas levonorgestrel or norgestimate (active metabolite: Norelgestromin); 3rd generation-with E 20-30 Lg and Pas desogestrel (active metabolite: Etonogestrel) or gestodene; 4th generation-E as third generation, with Pas drospirenone, dienogest or nomegestrol. Low dose pills have E less than SO mcg. + + + + + + + + + + + + + +Fig. 36.10: Some commonly used oral contraceptives. + + +Mode of Action +The probable mechanisms of contraception are: +■ Inhibition of ovulation: Both the hormones synergistically act on the Hypothalamopituitary (HP) axis. Estrogen suppresses GnRH, Follicle-Stimulating Hormone (FSH) and prevents follicular growth and progestins suppress Luteinizing Hormone (LH) and prevent ovulation. The release of Gonadotropin-Releasing Hormones (GnRH) from the + + +hypothalamus is prevented through a negative feedback mechanism. There is thus no peak (pulsatile) release of FSH and LH from the anterior pituitary. So follicular growth is either not initiated or if initiated, recruitment does not occw: There is no ovulation. +■ Producing static endometrial hypoplasia: There is stromal edema, decidual reaction and regression of the glands making endometrium nonreceptive to the embryo. +ll Chapter 36: Population Dynamics and Control of Conception + +■ Alteration of the character of the cervical mucus (thick, viscid, and scanty) so as to prevent sperm penetration. +■ Probably interferes with tubal motility and alters tubal transport. Thus, even though accidental breakthrough ovulation occurs, the other mechanisms prevent conception. +Estrogen inhibits FSH rise and prevents follicular growth It is also useful for better cycle control and to prevent breakthrough bleeding. +Progestin: Anovulatory effect is primarily by inhibiting LH surge. It is also helpful to counteract the adverse effects of estrogen on the endometrium (endometrial hyperplasia and heavy withdrawal bleeding). It is also responsible for changes in the cervical mucus (vide supra). + +Selection of the Patient +History and general examination should be thorough, taking special care to screen cases for contraindications (headache, migraine). Examination of the breasts for any nodules, weight, and blood pressure are to be noted. +Pelvic examination to exclude cervical pathology, is mandatory. Pregnancy must be excluded. +Cervical cytology (HPV screening) to exclude abnormal cells, preferably to be done. Thus, any woman of reproductive age group without any systemic disease and contraindications listed, is a suitable candidate for combined pill therapy (Table 36.4). Growth and development of the pubertal and sexually active girls are not affected by the use of 'pill'. + +How to Prescribe a Pill? +Patient instruction: New users should normally start their pill packet on day one of their cycle. One tablet is to be taken daily preferably at bed time for consecutive 21 days. It is continued for 21 days and then has a 7 days break, with this routine, there is contraceptive protection fom thefirst pill. Next pack should be +r + + +started on the eighth day, irrespective of bleeding (same day of the week, the pill finished). Thus, a simple regime of "3 weeks on and 1 week off" is to be followed. Packing of 28 tablets, there should be no break between packs. Seven of the pills are dummies and contain either iron or vitamin preparations. However, a woman can start the pill up to day 5 of the bleeding. In that case, she is advised to use a condom for the next 7 days. The pill should be started on the day after abortion. Following childbirth in nonlactating woman, it is started after 3 weeks, and in lactating woman, it is to be withheld for 6 months (p. 509). +Follow-up: The patient should be followed up based on her symptoms. The patient above the age 35 should be checked more frequently. +Missed pills: Normally, there is return of pituita1y and ovarian follicular activity during the Pill-Free Interval (PFJ) of 7 days. Breakthrough ovulation may occur in about 20% cases during this time. Lengthening of Hormone Free Interval (HFI) due to omissions, malabsorption, or vomiting either at the start or at +the end of a packet, increases the risk of breakthrough ovulation and, therefore, pregnancy. + +Management +When a woman forgets to take one pill (late up to 24 hours), she should take the missed pill at once and continue the rest as schedule. There is nothing to worry. +When she misses two pills or more she should take the most recent missed pill immediately and then continue the rest as scheduled. Extra precaution has to be taken for next 7 days either by using a condom or by avoiding sex. Alternatively, a new pack can be started and a barrier method to be used additionally for a week. Failure of withdrawal bleeding during the pill free interval, pregnancy should be excluded with medical tests. CHCs are not teratogenic when taken accidentally in early pregnancy. + + +Table 36.4: Medical Eligibility Criteria for contraceptive use (WHO/FRM/FPP) (p. 498, Table 36.2). Combined Oral Contraceptives (COCs) +Indications of COCs Contraindications of COCs + +No restriction of use (WHO Category-1) +• Age: Menarche to 40 years. • Postabortion. +• Anemia (iron deficiency, malaria). +• HIV or AIDS (additional to condom use). • GTN following normal hCG level. +• History of ectopic pregnancy. +• Endometriosis, uterine fibroid, ovarian or endometrial cancer. +• Dysmenorrhea, DUB. +• Pelvic inflammatory disease. • Epilepsy. +• Thyroid disease. • Varicose veins. • Tuberculosis. +• Benign breast disease. + + +Relative (WHO Category-2 and 3) +A. WHO Category-2 (advantages outweigh the risks): +• Age ;,40 years. +• Smoker <35 years. • History of jaundice. • Mild hypertension. • Gallbladder disease. • Diabetes. +• Sickle cell disease. • Headache. +• Cancer cervix or CIN. +B. WHO Category-3 (risks outweigh the advantages): +• Unexplained vaginal bleeding. • Hyperlipidemia. +• Liver tumors (benign). +• Breastfeeding (postpartum 6 weeks to 6 months). +• Heavy smoker (> 20 cigarettes/day). • Past breast cancer. + + +Absolute (WHO Category-4) +A. Circulatory diseases (past or present): • Arterial or venous thrombosis. +• Severe hypertension. • History of stroke. +• Heart disease: Valvular, ischemic. • Diabetes with vascular +complications. +• Migraine with focal neurologic symptoms (aura). +B. Diseases of the liver: +• Active liver disease, jaundice. • Liver adenoma, carcinoma. +C. Others: +• Pregnancy +• Breastfeeding (postpartum 6 weeks). • Major surgery or prolonged +immobilization. +• Estrogen-dependent neoplasms, e.g., breast cancer. + +(GTN: Gestational Trophoblastic Neoplasia; CIN: Cervical lntraepithelial Neoplasia; HIV: Human Immunodeficiency Virus; AIDS: Acquired Immunodeficiency Syndrome; hCG: Human Chorionic Gonadotropin; DUB: Dysfunctional Uterine Bleeding) +Chapter 36: Population Dynamics and Control of Conception Ea + +Drug Interactions +Effectiveness of some drugs (aspirin, oral anticoagulants, oral hypoglycemics, lamotrigine) are decreased and that for some other drugs (beta blockers, corticosteroids, diazepam, aminophylline) are increased by oral contraceptives(details on p. 513). + +Additional Contraception +To ensure 100% efficacy, additional mechanical contraceptives (usually condom) are to be used in the following circumstances: +■ When broad-spectrum antibiotics like ampicillin, ciprofloxacin, tetracycline, doxycycline are used-as they impair the absorption of ethinyl estradiol. +■ When enzyme-inducing drugs are used, e.g., ( a) Barbiturates; (b) All antiepileptic drugs except sodium valproate and clon­ azepam; (c) Rifampicin; (d) Ketoconazole; (e) Griseofulvin; (f) Protease inhibitor (ritonavir); and (g) Nevirapine-under such circumstances, high dose preparations (ethinyl estra­ diol of 50 1g or more) are to be used to counter-balance the increased liver metabolism. +The indications for withdrawal of the pill are-(a) Severe migraine; (b) Visual or speech disturbances; (c) Sudden chest pain; (d) Unexplained fainting attack or acute vertigo; (e) Severe cramps and pains in legs; (f) Excessive weight gain; (g) Severe depression; (h) Prior to surgery (it should be withheld for at least 6 weeks to minimize postoperative vascular complications), and (i) Patient wanting pregnancy. + +Continuous Cycle and Extended Use of COCs +Extended cycle or continuous regimens: Contain 84 days of active pills followed by 7 days of Hormone Free Interval (HFI). Withdrawal bleeding is only four times a year. Any monophasic pill may be used in this manner. Failure rate is also Jess. This generally decreases or eliminates withdrawal bleeding. Extended use preparations also improve menorrhagia, dysmenorrhea, endometriosis and chronic pelvic pain. +Return of fertility: The suppressive effects on H-P-O axis disappear quickly following stoppage of low dose COCs. Normal endocrine function returns. Ovulation returns within 3 months of withdrawal of the drug in 90% cases. Women who conceive inadvertently while taking COCs, there is no risks of fetal congenital malformations. +Withdrawal bleeding: It is bleeding that is seen during the hormone free interval, whereas bleeding that occurs during the time when active pills are being taken is called breakthrough bleeding. Breakthrough bleeding is due to insufficient estrogen to support the endometrium. +How Long can the Pill be Continued? +Potential benefits of pills are greater when compared to risks, in a well-selected individual. A woman who does not smoke and has no other risk factor for cardiovascular disease, may continue the pill (with careful monitoring) until the age of 50 years. This offers the dual advantages of effective contraception and HRT. However, for spacing of births, use of 3 to 5 years is considered enough and safe. + +General and Metabolic Effects of COCs +The combined preparations containing estrogen and progestin have got a wide range of metabolic activities which affect almost all the systems of the body. The changes are almost similar to + + +those of pregnancy and almost completely revert back to normal after the drug is withdrawn. The effects are related either to the estrogen (OGN) or to the progestin (PGN) or to both (OGN + PGN) of the compounds. + +Health Benefits of Combined Oral Contraceptives (COCs) +■ Contraceptive benefits: (a) Protection against unwanted pregnancy(failure rate-0.1 per 100 women years); (b) Con­ venient to use; (c) Not intercourse related; (d) Reversibility; and (e) Improving maternal and child health care. +■ Noncontraceptive health benefits: Improvement of menstrual abnormalities-(1) Regulation of menstrual cycle (Box 36.2); (2) Reduction of dysmenorrhea (40%); (3) Reduction of menorrhagia (50%); (4) Reduction of PMS; (5) Reduction of Mittelschmerz syndrome; (6) Protection against iron-deficiency anemia. Protection against health disorders; (7) PIO (thick cervical mucus); (8) Ectopic pregnancy; (9) Endometriosis; (10) Fibroid uterus; (11) Hirsutism, acne and PCOD; (12) Functional ovarian cysts; (13) Benign breast disease; (14) Osteopenia and postmenopausal osteoporotic fractures; (15) Autoimmune disorders of thyroid; (16) Rheumatoid arthritis; (17) Increases bone mineral density. Prevention of malignancies; (18) Endometrial cancer (50%); (19) Epithelial ovarian cancer (50%); (20) Colorectal cancer(40%). +Adverse Effects of COCs Minor Complications +The minor complications or ailments are: +■ Nausea, vomiting, headache (OGN) and leg cramps (PGN): These are transient and often subside following continuous use for 2-3 cycles. +■ Mastalgia (OGN + PGN): Heaviness or even tenderness in the breast is often transient. +■ Weight gain (PGN): Though progestins have got an anabolic effect due to its chemical relation to testosterone, use of low­ dose COCs does not cause any increase in weight. +■ Chloasma (OGN) and acne (PGN): These are annoying for cosmetic reasons. Low-dose oral contraceptives improves acne as levonorgestrel preparations are less androgenic. +■ Menstrual abnormalities: Breakthrough Bleeding (BTB): It is commonly due to subthreshold blood level of hormones. Other causes of breakthrough bleeding in pill takers are: (a) Disturbance of drug absorption-diarrhea, vomiting; (b) Use of enzyme inducing drugs (mentioned earlier), missing pills, use of low dose pills; (c) Pregnancy complications (miscarriage); (d) Diseases-cervical ectopy or carcinoma. Usually, it settles after 3-4 cycles when + + + +Health benefits of COCs ■ Highly effective. +■ Good cycle control. +■ Well-tolerated in majority. +■ Additional health benefits are many. +■ Low-dose pill with 'lipid friendly' progestins further reduces the risk. +■ Extended regimens are available. ■ Return of fertility rate is prompt. +Failure rate-0.1 (HWY) +r-ED Chapter 36: Population Dynamics and Control of Conception there is no other specific cause for BTB. Exogenous estrogen (conjugated estrogen 1.25 mg or estradiol 2 mg) given daily for 7 days can control the bleeding. Doubling up the active pills for 2-3 days, or until bleeding stops, is helpful. A pill containing higher dose of estrogen, with different progestin could be helpful. BTB is not associated with any increased failure rate. CVR has better cycle control. Hypomenorrhea (PGN): It is of little significance although disturbing to the patient. It is due to the local endometrial changes. Menorrhagia (OGN): It is usually pre-existing and use of compounds with progestin preponderance is helpful. Amenorrhea (OGN or PGN): Postpill amenorrhea of more than 6 months duration occurs in less than 1 % cases. The association is casual not causal. It is usually more in women with pre-existing functional menstrual disorders. Spontaneous resumption of menstruation occurs in 6 months for majority of cases. A refractory case (>6 months) should be investigated as a case of secondary amenorrhea. +. +" +11 Libido (PGN): Libido may be diminished probably due to d1yness of the vagina. More often, it may either remain static or, at times, may even increase due to loss of fear of pregnancy. +■ Leukorrhea: It may be due to excessive cervical mucus secretion (OGN) or due to increased preponderance of monilial infection (OGN + PGN). +Major Complications +■ Depression: Low-dose estrogen preparations are not associated with depression. +11 Hypertension (OGN): Current low dose COCs rarely cause significant hypertension. Pre-existing hypertension is likely to be aggravated. Changes are seen only in systolic but not in diastolic blood pressure. The effect on blood pressure is thought to involve the renin-angiotensin system. There is marked increase in plasma angiotensinogen. The changes, however, reverse back to normal 3-6 months after stoppage of pill. +■ Vascular complications (OGN): +(A) Venous Thromboembolism (VTE): The overall risk is to the extent of 3-4 times more than the non-users. Pre­ existing hypertension, diabetes, obesity thrombophilias (inherited or acquired) and elderly patient (over 35, especially with smoking habits) are some of the important risk factors. Ethinyl estradiol used with a dose of 20 µg in the pill markedly reduce the incidence. Current studies estimate the annual number of nonfatal VTE per 100,000 users as: no COC use= 4, second-generation COC= 10, COC-containing desogestrel and gestodene = 30, pregnancy= >100. The absolute risk is very small compared to pregnancy. The most important risk factor is genetic thrombophilia {factor V Leiden mutation). This is rare in Asians (0.4%) compared to Caucasian (5%). Lowest risk of VTE is with COC containing LNG/NET/Norgestimate. Increased rate ofVTE is seen with other CHC like CTP/CVR. +(B) Arterial thrombosis: The high-risk factors for myocar­ dial infarction and stroke (ischemic and hemorrhagic) are hypertension, smoking habit, age over 35 and diabetes. Women with multiple risk factors for cardiovascular disease generally should not use COCs. +■ Cholestatic jaundice: Susceptibility is increased in women with previous history of idiopathic recurrent jaundice in pregnancy or hepatitis. + + + + + + +■ Neoplastic risks and the benefits: Combined Oral Contraceptives (COCs) reduce the risk of epithelial ovarian (50% ..I-) and endometrial (50% .I-) carcinoma. This protective effect persists for 10-15 years even after stopping the method following a use of 6 months to 1 year. There is reduction in colorectal carcinoma (20%). +Breast cancer: COCs use increases the risk of breast cancer by 25% and the risk disappears after cessation of use. The absolute risk is low. However COC can be prescribed to women with a family history of breast cance,: +Cervical cancer: COC increase the risk of cancer cervix with increasing duration of use (>5 years). It is no longer a risk factor after 10 years of stopping. Adenocarcinoma of the cervix is more compared to squamous cell. However, pill users should have regular HPV-DNA and cervical cytology screening. No increased risk ofhepatocellular adenomas have been found with low dose preparations. It gives protection against benign cystic breast disease and cystic ovaries. +■ Death: Risk of death for a woman using COCs is about 1.5/100,000. It is significantly low. +General and Metabolic Effects +Carbohydrate (PGN): Progestins impair glucose tolerance promoting insulin resistance and hyperglycemia. This was observed in preparations containing 150 µg or more levonorgestrel. Low-dose COCs have no effect on insulin, HbAlC, and fasting glucose levels. Protein (OGN): Estrogen has got some stimulatory effect on the hepatic secretion of many proteins. Fibrinogen and other clotting factors level rise in direct proportion to the estrogen. This may cause thrombosis. The level of sex hormone-binding globulin (SHBG) is increased. Lipid (OGN): Plasma lipids and lipoproteins are increased. Total cholesterol and triglycerides are increased. Low dose estrogen increases High-Density Lipoprotein (HDL) cholesterol and decreases Low-Density Lipoprotein (LDL) cholesterol thereby exerts its protective effect against atherosclerosis. Progestins, howeve,; decrease HDL cholesterol and increase LDL cholesterol thereby promote heart disease. Preparations with more selective, lipid friendly, and third generation progestins namely desogestrel, gestodene or norgestimate, HDL level is somewhat elevated. However, most changes are within the normal range +and not clinically relevant. Vitamins and minerals: Vitamin B6, B12, folic acid, calcium, manganese, zinc, and ascorbic acid levels are decreased while vitamins A and K levels are increased. +Effects on Organs +■ Hypothalamopituitary axis: Both FSH and LH levels remain low as found in early proliferative phase and remain throughout the cycle at such static low level. +■ Ovary: Ovarian function remains quiescent with occasional evidence of breakthrough ovulation. There is evidence of fibrosis, progressive wastage of unripe ova with advancing age without evidence of corpus luteum. The endogenous hormones remain static at a low level. +■ Endometrium (PGN): Stromal edema, decidual reaction and glandular exhaustion out of depletion of glycogen are more or less constant findings. +■ Cervix (PGN + OGN): Increased glandular hyperplasia and downgrowth of the endocervical epithelium beyond the squamocolumnar junction gives the appearance of an ectopy. Relative risk of cervical cancer with COC use is 1.1. It may + + +be due to the persistent exposure of the pill users to HPV infection or due to their more sexual activity. +■ Uterus (OGN): Uterus may be slightly enlarged. Low-dose COCs do not usually increase the size of a pre-existing fibroid. COCs can reduce the amount of menstrual bleeding. +■ Vagina (PGN): Cytohormonal study reflects the picture of early luteal phase. +■ Other organs: (a) Liver: The liver functions are depressed; (b) Gastrointestinal Tract (GIT): There is increased incidence of mesenteric vein thrombosis; (c) Urinary: There is increased incidence of urinary tract infection but is probably related to increase in sexual activity. +Effects on Reproduction +■ Risk to fetus: When COC is taken during early pregnancy inadvertently there is no greater risk of significant congenital anomaly. Risk of congenital abnormality in general is 2-3%. +■ Lactation (OGN + PGN): Lactation is probably affected by a reduction in the milk production and also by alteration of the quality of the milk (reduction of protein and fat content). Moreover, significant amount of the steroids are ingested by the infant, the effects are as yet unknown. Mini-pill is a better alternative for the breastfeeders. +Types of Oral Contraceptive Formulations +In multiphasic preparation, minimum doses are provided for contraceptive effect in the early part of the cycle and slightly higher doses later in the cycle to prevent breakthrough bleeding. It is an attempt to minimize undesirable side effects of lipid metabolism. +1. (a) Monophasic (fixed dose): Combined pills (COCs). +(b) Multiphasic (different dose combinations) with different tablet color): It may be biphasic, triphasic or four phasic. +The theoretic advantage of phasic preparations has little impact on clinical response. +2. OC formulations and regimens: Most covers 28 days ( 4 weeks). Many combinations are-21 days (3 weeks) followed by 7 days hormone-free interval (HF!). +Most products contain spacer pills (iron) in the HF!. Bleeding usually occurs during the HFI (or 3-4 days). Some preparation contains active tablets for 24 days and HF! is 4 days. They are more effective than 21 days pill. +I CENTCHROMAN (SAHELI) +Female: Ormeloxifene is a research product of Central Drug Research Institute (CDRI) of Lucknow, India. It is a nonsteroidal compound with potent antiestrogenic and weak-estrogenic properties. !tis taken orally (30 mg) twice a week for first 3 months then once a week. It works primarily by preventing implantation of fertilized ovum. It creates asynchrony between developing zygote and the endometrium causing implantation failure. It does not inhibit ovulation. + +Chapter 36: Population Dynamics and Control of Conception + +Side effects are a few. It is avoided in polycystic ovarian disease, cervical cell hyperplasia, with liver (jaundice) and kidney diseases, and in tuberculosis. There may be a tendency of oligomenorrhea. The failure rate is about 1-4 per 100 women years of use. Failure rate is less with increased doses. It is devoid of any significant adverse metabolic and hormonal effect. This may also be used as safely by the lactating women and an emergency contraceptive. It is highly safe, effective and a reversible method. It has no teratogenic effect and return of fertility is immediate. It is sold against prescription only and not over the counter. +Noncontraceptive use: Because of its potent antiestrogenic activity, centchroman is being currently tried in the management of DUB, endometrial hyperplasia, endometriosis and breast cancer. It is used as HRT, because of its weak estrogenic property. +However; risk of VTE is lower compared to pregnancy and puerperium. + +SUMMARY OF CHC +(1) Women with weight >90 kg may have less efficacy of CHC; (2) Women with bariatic surgery may have less efficacy of CHC; +(3) Additional contraceptive is not required when non-enzyme induing drugs are used; (4) Users of CHC have slight absolute risk of VTE. Risk reduces after 1 year of use; (5) BP, BMI to be checked prior starting CHC. Pelvic/breast examination is not required; (6) Annual review is advised; (7) CHC is stopped 4 weeks before surgery; (8) Can be used till 50 years of age; (9) It is contraindicated in personal history of VTE, known thrombophilic, major surgery with prolonged immobilization +t +(MEC-4). + +I PROGESTOGEN-ONLY CONTRACEPTIONS +Progestogen-only contraception includes: ■ Oral:POPs +11 Parenterals: DMPA, NET-EN, Implants (Implanon) ■ LNG-IUS. +Progestin-only Pill (POP/Minipill) +Progestin-only pill is devoid of any estrogen compound. It contains very low dose of a progestin in any one of the following forms-levonorgestrel 75 µg, norethisterone 350 µg, desogestrel 75 tg, lynestrenol 500 tg or norgestrel 30 µg. It has to be taken daily around same time each day from the first day of the cycle with no pill free interval. Mechanism of action:It works mainly by making cervical mucus thick and viscous, thereby prevents sperm penetration. Endometrium becomes atrophic, so blastocyst implantation is also hindered. This cervical effect is apparent by 2 days of startingPOP. But as it is short lived ( <24 hours), daily prescription of POP is given. In about 2% of cases, ovulation is inhibited and 50% women ovulate normally. +How to prescribe a minipill?: Thefirst pill has to be taken on the first day of the cycle and then continuously. It has to be taken regularly and at the same time ofthe day. There must be no break between the packs. Delay in intake for more than 3 hours (i.e., >27 hours late; c.f DSG in next page), the woman should have the missed pill immediately and the next one as scheduled. Extra +precaution has to be taken for next 2 days. +Advantages: (a) Side effects attributed to estrogen in the combined pill are totally eliminated; (b) No adverse effect on lactation and hence can be suitably prescribed in lactating women and as such it +f +r +f + +l -----ED Chapter 36: Population Dynamics and Control of Conception + +is often called 'Lactation Pill'; (c) Easy to take as there is no'Onand Off' regime; (d) It may be prescribed in patient having (medical disorders) hypertension, fibroid, diabetes, epilepsy, smoking, and hist01y of thromboembolism, HIV positive women; (e) Reduces the risk of PID and endometrial cancer. Disadvantages: (a) There may be acne, mastalgia, headache, breakthrough bleeding (Can be controlled by adding estrogen supplementation), or at times amenorrhea in about 20-30% cases; (b) All the side effects, attributed to progestins may be evident; (c) Simple cysts of the ovary may be seen, but they do not require any surge1y; (d) Ectopic pregnancy: 1 in 10; (e) Failure rate is about 0.3-2 per 100 women years of use. Failure is more in young compared to women over 40. Women using drugs that induce liver microsomal enzymes to alter metabolism should avoid this method of contraception. +Contraindications: (a) Pregnancy; (b) Unexplained vaginal bleeding; (c) Recent breast cancer; (d) Arterial disease; (e) Thromboembolic disease; (f) Women taking antiseizure drugs. + +SUMMARY OF POP +(1) If used consistently and correctly, POP are >90% effective; (2) Desogestrel (DSG) Pills inhibit Ovulation in 97% of cycles (c.f. LNG) and have a 12-hour window for missed pills (i.e., 36 hours of missed pills) (c.f. LNG); (3) Return to fertility is immediate after stopping. + +Injectable Progestins +The preparations commonly used are Depo Medroxy Progesterone Acetate (DMPA) and Norethisterone Enanthate (NET-EN). Both are administered intramuscularly (deltoid or gluteus muscle) within 5 days of the cycle. The injection should be deep, Z-tract technique and the site not to be massaged. DMPA in a dose of 150 mg every three months (WHO, 4 months) or 300 mg every six months; +NET-EN in a dose of 200 mg given at two monthly intervals. + + + + + + + + +Medroxyprogesteroneace­ tate (SAYAnA PRESS): Injection 104 mg/0.6S ml. It is available as a pre-filled single dose injec­ tor. The injector needs to be activated by pushing the nee­ dle shield firmly towards the port, before use. The medicine appears white and uniform. The suspension is to be shaken vig­ orously just before use. It is given by SC injection into the anterior thigh or abdomen every 3 months (12-14 weeks). It is administered by a health­ care professional or by the woman herself. + +Depo-SubQ provera 104 (Uniject) contains 104 mg of DMPA. It is given subcutaneously over the anterior thigh or abdomen at + + +every 90 days. It suppresses ovulation for 3 months as it is absorbed more slowly. +Mechanism of action: (a) Inhibition of ovulation-by suppressing the midcycle LH peak; (b) Cervical mucus becomes thick and viscid thereby prevents sperm penetration. As this effect takes approximately 7 days (c.f POP), additional contraception for 1st 7 days is required; (c) Endometrium is atrophic preventing blastocyst implantation. +Advantages: (a) It eliminates regular medication as imposed by oral pill; (b) It can be used safely during lactation. It probably increases the milk secretion without altering its composition; (c) No estrogen-related side effects; (d) Menstrual symptoms, e.g., menorrhagia, dysmenorrhea are reduced; (e) Protective against endometrial cancer; (f) Can be used as an interim contraception before vasectomy becomes effective; (g) Reduction in PID, endometriosis, ectopic pregnancy and ovarian cancer. The noncontraceptive benefits are DMPA reduces the risk of-salpingitis, endometrial cancer; iron deficiency anemia, sickle cell problems, and endometriosis. +Disadvantages: Failure rate for DMPA-(0-0.3) (HWY). There is chance of irregular bleeding ( a COC can be used for 3 months) and occasional phase of amenorrhea. Return offertility fter their discontinuation is usually delayed for several months (6-12 months). However, with NET-EN the return of fertility is quicke,: Loss of bone mineral density (reversible) has been observed with Jong-term use of depot provera. It is suitable for adolescents and the perimenopausal women. However, most bone Jost is restored within 5 years of stoppage. Overweight, insulin-resistant women may develop diabetes. Other side effects are depression, weight gain, and headache. +Contraindications: Women with high-risk factors for osteo­ porosis, breast cancer, and the others are same as in POP. + +SUMMARY OF INJECTABLE PROGESTINS +(1) Both DMPA and NET-EN are Long Acting PGN's. Amenorrhea is common and thus helpful for women with history of HMB; (2) It is a contraception of choice for women with Sickle Cell Disesase; (3) Weight gain is a common complaint; (4) The injection of DMPA can be administered upto 4 months (i.e., 16 weeks); (5) The efficacy is not affected with concurrent use of enzyme inducing drugs. + +Implant +Nexplanon is a progestin-only delivery system containing 3 ketodesogestrel (etonogestrel). It is a long-term (up to 3 years) reversible contraception (Fig. 36.11). It consists of a single closed capsule (made of ethylene vinyl acetate copolymer 40 mm x 2 mm) and contains 68 mg of Etonogestrel (ENG). It releases the hormone about 60 µg, gradually reduced to 30 µg per day over 3 years. Imp/anon does not cause decrease in bone mineral density. +Mechanism of action: It inhibits ovulation in 90% of the cycles for the first year. It has got its supplementary effect on endometrium (atrophy) and cervical mucus (thick) as well. +Insertion: The capsule is inserted subdermally, in the inner aspect of the nondominant arm, 6-8 cm above the elbow fold. It is inserted between biceps and triceps muscles. Preloaded sterile applicator is available. No incision is required. Removal is done by making a 2 mm incision at the tip of the implant and pushing the rod until it pops out. It is done under local anesthetic. +Chapter 36: Population Dynamics and Control of Conception Jlt. + + + + + + + +Fig. 36.11: Single implant rod-implanon. + + +It is ideally inserted within D-5 of a menstrual cycle, immediately after abortion and 3 weeks after postpartum. +Removal: lmplanon should be removed within 3 years of insertion. Loss of contraceptive action is immediate. +Advantages are the same as with DMPA. Others are­ (a) Highly effective for long-term use and rapidly reversible; (b) Suited for women who have completed their family but do not desire permanent sterilization; (c) Improvement of anemia; (d) Reduced seizure frequency in some women with epilepsy; (e) Reduced frequency of pain crises rises in women with sickle cell disease. Efficacy of Nexplanon is extremely high with Pearl indices of 0.01. This safe and effective method is considered as 'reversible sterilization'. Risks: Infection, nerve injmy, migration or incorrect placement. Drawbacks: frequent irregular menstrual bleeding, spotting and amenorrhea are common. Dificulty in removal is felt occasionally. Nexplanon can be imaged (X-ray, USG, MRI); if not palpable during removal. Contraindications are similar to POP. +Norplant-II (Jade/le) +Two rods of 4 cm long with diameter of 2.5 mm is used. Each rod contains 75 mg of levonorgestrel. It releases 50 µg of levonorgestrel per day. Contraceptive efficacy is similar to combined pills. Failure rate is 0.06 per 100 women years. It is used for 3 years. The rods are easier to insert and remove. +Long-Acting Reversible Contraception (LARC) needs only one time motivation for long-term use. There is no risk of user error once it is placed in the body. LARCs are highly effective and immediately reversible with rapid return offertility after its removal. Contraindications of LARCs are very few. It is recommended for the lactating women. It can be used in the postpartum or postabortal period. It has high continuation rate and user satisfaction. It is offered as first line contraception (ACOG, 2009). The common LARC methods are: Copper-T 380A, LNG-IUS, Implants (Nexplanon). + +SUMMARY OF IMPLANT +(1) No or little risk ofVTE, Stroke or Ml; (2) Infrequent bleeding is the main cause of menstrual symptoms. A COC may be advised to counter the menstrual issues during implant use. About 1 in 5 women have amenorrhea; (3) Enzyme inducing drugs affect the efficacy of implants during use and till 28 days after stopping. So additional contraception is advised. + +EMERGENCY CONTRACEPTION (SYN: POSTCOITAL CONTRACEPTION) +■ Hormones ■ IUD +■ Antiprogesterone ■ Others +Indications of emergency contraception: Unprotected inter­ course, condom rupture, missed pill, delay in taking POP for more than 3 hours (12 hours with DSG POP), sexual assault or rape and + + +first time intercourse, as known to be always unplanned. In the days immediately prior to ovulation and on the day of ovulation itself, pregnancy risk following a single episode of Unprotected Sexual Intercourse (UPSI) has been estimated to be up 30%. + +Indications +1. After UPSI on any day of natural cycle. +2. UPSI from D-21 after child birth (unless criteria for lacational amenorrhoea are met). +3. UPSI from D-5 after abortion, miscarriage, ectopic pregnancy or uterine evacuation of GTD. +Methods: (1) Cu IUCD-(most effective); (2) Ulipristal acetate (UPA-EC-2nd most effective); (3) LNG (3rd most effective) (Table 36.5). +Cu IUCD: It is toxic to sperms and ova, inhibits fertilization and also prevents implantation. It is inserted within 5 days of first UPSI in a cycle. It has both pre- and post-fertilization inhibition. Pregnancy rate <0.1 %. +Copper IUD: It is the gold standard method to be offered to all women for EC. +Advantage: It can be kept in place for 10 years if desired as a regular method of contraception. +Ulipristal acetate as an EC is superior to levonorgestrel. It is a progesterone receptor modulator. A single dose 30 mg, to be taken orally as soon as possible or within 120 hours of coitus. It acts by suppressing follicular and endometrial growth. It delays ovulation and inhibits implantation. Overall pregnancy rate after UPA EC is 1-2%. It should neither be prescribed in women with severe hepatic dysfunction nor with severe asthma. +Levonorgestrel (E. pills) 0.75 mg, two doses given at 12 hours interval, is very successful and without any side effects. The two tablets (1.50 mg) can be taken as a single dose also (Fig. 36.12). The first dose should be taken within 72 hours (most effective) may be taken up to 120 hours. This drug is successful in 85% cases. However LNG cannot act once LH surge has happened. +No fetal adverse effect has been observed when there is failure of emergency contraception. However, induced abortion should be offered to the patient, if the method fails. +Mode of action: The exact mechanism of action remains unclear. The following are the possibilities: +■ Ovulation is either prevented or delayed when the drug is taken in the beginning of the cycle. +■ Fertilization is interfered. +■ Implantation is prevented (except E. pills) as the endome­ trium is rendered unfavorable. +■ Interferes with the function of corpus luteum or may cause luteolysis. +Drawbacks: Nausea and vomiting are much more intense with estrogen use. Antiemetic (meclizine) should be prescribed. +'---""-· -Ei Chapter 36: Population Dynamics and Control of Conception Table 36.5: Emergency contraceptives . + +Method/ +drug Dose Timing of use + + +Failure rate + +Individual: Obese/Enzyme +inducing drugs(+) Breast feeding Contraindication + + + +Cu IUCD - + +UPA 30mg + + +Up to 120hours of UPSI or within 5 <0.1% days of ovulation; whichever is later. +Up to 120hours of UPSI 1-2% + + +Ideal + +Less effective + + +Uterine perforation +No breastfeeding upto 1 week + + +- + +Asthma, glucocorticoid use + + + +LNG 1.5 mg Up to 72hours of UPSI (ineffective after 96hours of UPSI) + + +0.6-2.6% Double the dose (3mg) Nil effect [Less effective) + +Concurrent use of UPA and LNG to be avoided. + + + + + +LEVONORGESTREL TABLETS 1.P. +ezy•pill + +M• +An Oral Emergency Conlroceptive for Women +-ft +m'l"'a.-1il- +Fig. 36.12: Levonorgestrel (LNG) pill. + +Postcoital contraception is only employed as an emergency measure and is not effective if used as a regular method of contraception. +Yuzpe method (combined hormonal regimen) is equally effective. Two tablets of ovral (0.25 mg levonorgestrel and 50 µg ethinyl estradiol) should be taken as early as possible after coitus (<72 hours) and two more tablets are to be taken 12 hours later. +Oral antiemetic (10 mg metoclopramide) may be taken 1 hour before each dose to reduce the problem of nausea and vomiting. + +Anti progesterone +Antiprogesterone (RU 486-mifepristone) binds competitively to progesterone receptors and nullifies the effect of endogenous progesterone. +Dose: A single dose of 100 mg is to be taken within 5 days of intercourse. Implantation is prevented due to its antiprogesterone effect. Pregnancy rate is 0-0. 6%. + +I SUMMARY OF ORAL CONTRACEPTIVES +■ Combined Hormonal Contraceptive (CHC) ■ Triphasic pill +■ Emergency (postcoital) contraception + +■ Minipill +■ Conventional combined preparations: The widely used oral contraceptives consist of tablets containing estrogen and progestin compounds. It is the most effective and reversible method of contraception. Each tablet usually contains 30 mg of ethinyl estradiol and 1 mg of norethisterone or 0.3 mg norgestrel. It has got trigger action-(a) inhibition of ovulation, (b) production of static endometrial hypoplasia, and (c) alteration of the character of the cervical mucus. Its use is absolutely contraindicated in cases with circulatory diseases, liver diseases, severe migraine, and estrogen­ dependent tumor. The pill should be started from the day one of a cycle and continued as '3 weeks on and 1 week off' regime. Periodic check-up is essential, especially when prescribed in women above the age of 35. The pill should be withdrawn if complications arise such as severe migraine, chest pain, visual disturbances, etc. +The beneficial effects are relief of dysmenorrhea, premenstrual tension, endometriosis, acne, hirsutism, and lesser chance of ectopic and PID. It gives protection against ovarian and endometrial carcinomas. +The minor side effects are nausea, vomiting, breakthrough bleeding, mastalgia, leg cramp, weight gain, hypomenorrhea or amenorrhea. The major complications are rare and include depression, hypertension and thromboembolic manifestations. The failure rate is about 0.1 per HWY. +11 Triphasic pill: It has got lesser amount of steroids than the conventional monophasic tablets. There is lesser effect on lipid metabolism. +■ Emergency: Following unprotected or accidental exposure any of these methods can be used: (1) CU IUCD is most effective. (2) UPA second most effective. (3) LNG is third most effective (Table 36.5). +11 Minipill: The pill contains low doses of progestin-norgestrel 30 mg, levonorgestrel 75 µg or desogestrel 75 µg. It should be taken daily and can be safely prescribed during lactation. It is best suited where estrogen is contraindicated. + + + + +► Medical eligibility criteria (WHO) for the use of any method of contraception is categorized as: ( 1) No restriction for use of the method; (2) Advantages of using the method generally outweigh the theoretical or proven risks, (3) Theoretical or proven risks usually outweigh the advantages of using the method, (4) Health risks are unacceptable if the contraceptive method is used. +► Combined Oral Contraceptives (COCs) are very reliable apart from their many other health benefits. +► Mechanism of action of COCs are: (a) Inhibition of ovulation by suppression of FSH and LH, (bl Making endometrium nonreceptive for implantation (endometrial hypoplasia), (c) Making cervical mucus thick, viscid and scanty, and (d) Probably alters tubal motility. +► Absolute contraindications of oral pills, major side effects and indications of withdrawal of pills have been discussed. +Contd... +Chapter 36: Population Dynamics and Control of Conception + +Contd... +► The newer low-dose pills with more specific and 'lipid friendly' progestins reduce the health risk further. +► Drospirenone containing COC is useful in treating PMS, PMDD. It should not be used in women with renal, adrenal or hepatic dysfunction. +► A woman who does not smoke and has no other risk factor for cardiovascular disease, may continue the pill (with careful monitoring) until the age of 50. +► Combined oral contraceptives: (a) Contain estrogen and progestin compounds; (b) Third-generation progesterone may increase the risk of VTE; (c) Current users of COCs have an increased risk of breast cancer (RR 1.24); (d) With perfect use, failure rate is 0.1 per 100 WY; (e) It is contraindicated in women with arterial or venous disease. +► Progestogen-only contraceptions +(a) Does not inhibit ovulation completely; (b) Irregular vaginal bleeding is often associated and it may be the reason for discontinuation; (c) LNG-IUS may cause amenorrhea due to endometrial atrophy. DMPA should be used in adolescents and perimenopausal women after consideration of other methods. Importantly, most bone mass loss during DMPA use is restored within 5 years after its discontinuation; (d) DMPA does not increase the risk of cardiovascular disease but is associated with decreased BMD. +► Low-dose progestin pill (minipill) is advantageous in lactating women, as it has got no adverse effect on breast milk. It can be used as a suitable alternative where estrogen is contraindicated. +► Overall safety of DMPA is clearly greater than COC. Norplant and implanon are safe and effective for long-term use. Both are considered as 'reversible sterilization'. +► Long acting reversible contraceptives ((arcs) include: LNG-IUS, CU IUD, progesterone only injectables and implant. Pregnancy rates are extremely low with LARCs. These are user independent methods. The women need to do nothing until the method has expired. +► Emergency contraception includes hormones, IUD and antiprogesterone (RU 486). Within 72 hours, hormonal preparations are effective; within 5 days, IUD is effective and Ru 486 should be taken within day 27 of cycle irrespective of the day and number of intercourse. +► Centchroman in a nonsteroidal antiestrogenic compound used as once a week contraceptive pill. It acts by preventing the implantation of the fertilized ovum. It has many benefits. + + + +DRUG INTERACTION WITH HORMONAL CONTRACEPTION + +Pharmacokinetic of drug interactions: It is observed when one drug alters the absorption, distribution, metabolism or excretion of another drug, and changes its bioavailability. The pharmacokinetic interactions of a drug that induces hepatic cytochrome P 450 enzymes, increase the clearance of contraceptive hormones. This results in reduced contraceptive effectiveness of many hormonal contraceptives. These are: all Combined Hormonal Contraceptives (CHC), all POPs, etonogestrel implant and oral emergency contraceptions. (Importantly, contraceptive effectiveness of the progestogen-only injection, locally acting levonorgesterel releasing intrauterine systems and the copper IUDs are not apparently affected by the enzyme inducing drug). On the other hand, pharmacokinetic interactions that inhibit cytochrome P450 could result in increased exposure of contraceptive hormones. There is potentially increased risks and side effects. Risk of thrombosis is increased in the case of elevated serum levels of ethinylestradiol. CHC induce glucuronidation of lamotrigine and reduces lamotrigine exposures. This reduces the seizure control. +Other Clinical Scenarios +■ Unless the antibiotic is an enzyme inducer or it causes vomiting or diarrhea, no additional contraceptive precaution is needed. +■ Combined Hormonal Contraceptives (CHC): Combined pill, patch or vaginal ring-effectiveness could be reduced with the use of enzyme inducing drug. Alternative effective method is to be used. +■ DMPA: No effect on contraceptive effectiveness. No need of extra precaution. +■ LNG-IUS: No effect on contraceptive effectiveness. No need of extra precaution. + +■ CU-IUD: No effect on contraceptive effectiveness. It is most effective as emergency contraception. +■ LNG-EC: Effectiveness could be reduced. Cu-IUD is most effective. +■ UPA-EC: Effectiveness could be reduced. Cu-IUD is most effective. +■ IMP, DMPA, LNG-IUS, Cu-IUD: In the event of vomiting or diarrhea. No need of additional precaution. + +STERILIZATION +Permanent method of contraception is done either for the male or female. Sterilization is a highly effective and safe method. In contrast to other methods, which are reversible or temporary, sterilization should be considered permanent. If a women who have tubal sterilization, wish to conceive, IVF can be used otherwise tubal reconstructive surgery is the alternative. For the male, anastomosis of vas deferens could be done. The operation done on male is vasectomy and that on the female is tubal occlusion, or tubectomy. + +I PRESTERILIZATION COUNSELING + +It includes a discussion of the following issues: (a) Desire of the individual partner (male/female); (b) Procedure selection; (c) Failure rate; (d) Risks and side effects; (e) Issue ofreversibility. Reversal is more likely to be successful after laparoscopic clips compared to laparotomy procedures. However, the risks of ectopic pregnancy is there; and (f) Options for alternative long active (equally effective) reversible methods (Implants, Cu-T 380A) should be given. +Pre sterilization Information and advice: +■ This covers both verbal and written information. II It is done with both the partners together. +ED Chapter 36: Population Dynamics and Control of Conception + +■ Include information with other methods including LARCs. ■ Includes information about failure rate and complications. + +Surgery +Advantages of vasectomy over tubectomy: (a) Can be done in the clinic under local anesthesia; (b) No entry to peritoneal cavity; (c) Less time needed (20 minutes); (d) Complications are less; (e) No hospital admission or stay; (f) Highly effective; (g) Minimum side effects; (h) Low cost; and (i) Simple to perform. + +I MALE STERILIZATION Vasectomy (Fig. 36.13) +It is a permanent sterilization operation done in the male where a segment of vas deferens of both the sides are resected and the cut ends are ligated. +Advantages: (a) The operative technique is simple and can be performed by one with minimal training; (b) The operation can be done as an outdoor procedure or in a mass camp even in remote villages; (c) Complications-immediate or late are fewer; (d) Failure rate is minimal-0.15% and there is a fair chance of success of reversal anastomosis operation (70-80%); ( e) The overall cost is minimal in terms of equipment, hospital stay and doctor's training. +Drawbacks: (a) Additional contraceptive protection is needed for about 2-3 months following operations, i.e., till the semen becomes free of sperm; (b) Frigidity or impotency when occurs is mostly psychological. +Selection of candidates: Sexually active and psychologically adjusted husband having the desired number of children is an ideal one. + +No-scalpel Vasectomy +No-Scalpel Vasectomy (NSV) is commonly done at present in India. It was popularized by Dr Li Shun Qiang of China in 1991. +Technique +Written consent of the person is taken following counseling. The operation is done as an outdoor procedure or in the camp. The local area is shaved and cleaned with povidone-iodine lotion. Full surgical asepsis has to be maintained during operation. Procedure is done under local anesthetic. + + +The vasa is palpated with three fingers of the left hand; index and thumb in front and the middle behind. This is done at the level midway between the top of the testis and the base of the penis. The vasa is grasped with a ringed clump applied perpendicularly on the skin overlying the vasa. The skin is punctured with the sharp pointed end of the medial blade of dissecting forceps. The puncture point is enlarged by spreading the tissues (dartos muscle and spermatic fascia) inserting both the tips of the dissecting forceps. The vasa is elevated with the dissecting forceps and in hold with the ringed clamp. At least 1 cm of length ofvasa is made free and mobilized. The vasa is ligated at two places 1 cm apart by No. '00' chromic catgut and the segment of the vasa in between the ligatures is resected out. Division of the vasa should be accompanied by fascia! interposition or diathermy. This reduces the failure rate. Hemostasis is secured. No skin suturing is needed. Wound dressing is done and a small pressure bandage is applied. The same procedure is repeated on the other side. A scrotal suspensory bandage is worn. The patient is allowed to go home after half an hour. Histological examination of the excised segment of the vasa should be done for confirmation if the surgeon is in any doubt. +Advices +Antibiotic (injection penidure LA 6 IM) is administered as a routine and an analgesic is prescribed. Heavy work or cycling is restricted for about 2 weeks, while usual activities can be resumed forthwith. For check-up, the patient should report back after 1 week, or earlier, if complication arises. Additional contraceptive should be used for 3-4 months. +NSV takes less time, helps faster recovery due to less tissue injury. Complications are significantly less. However, it needs training on the part of the surgeon. +Precaution +The man does not become sterile soon after the operation as the semen is stored in the distal part of the vasa channels for a varying period of about 3 months. It requires about 20 ejaculations to empty the stored semen. Semen should be examined either by one test after 16 weeks or by two tests at 12 and 16 weeks after vasectomy and if the two consecutive semen analyses show absence of spermatozoa, the man is declared as sterile. Till then, additional contraceptive (condom or DMPA to wife) should be advised. + + + + +'\_ olding the vas with the +._ +\t',, , ' +ringed clamp at 90° t: +' + +. +Local anesthetic infiltration , + +Complications +Complications of NSV are significantly less. +■ Immediate: (a) Wound sepsis which may lead to scrotal cellulitis or abscess; (b) Scrotal hematoma. +■ Remote: (a) Frigidity or impotency: It is mostly psychological in origin; (b) Sperm granuloma is due to inflammatory reaction to sperm leakage. This can be prevented by cauterization or fulguration of the cut ends; (c) Chronic intrascrotal pain and discomfort (post-vasectomy syndrome) may be due to scar tissue formation, or tubular distension of the epididymis; (d) There is no increase in testicular cancer or heart disease. Risk of prostate cancer is considered to have no causal association; (e) Spontaneous recanalization (1 in 2,000) is rare. + + + + +-Inserting both 1 -Dissecting +the tips of the ., forceps is +dissecting forceps·--;_--- opened to strip + +to dissect tissues the sheath +Fig. 36.13: Method of No-Scalpel Vasectomy (NSV) operation. + +Other Methods to Block the Vasa +■ Electrocoagulation may be used to encourage scar tissue formation. +■ Fascia! interposition following ligation, excision, and cautery. This is done to prevent recanalization. + +I FEMALE STERILIZATION +Occlusion of the fallopian tubes in some form is the underlying principle to achieve female sterilization. It is the most popular method of terminal contraception all over the world. +Indications +1. Family planning purposes: This is the principal indication in most of the developing countries. +2. Socioeconomic: An individual is adopted to accept the method after having the desired number of children. +3. Medicosurgical indications (female partner): (a) Medical diseases such as heart disease, diabetes, chronic renal disease, hypertension are likely to worsen, if repeated pregnancies occur; (b) During third time repeat cesarean section or following repair of prolapse to avoid complications. +4. Risk-reducing salpingectomy: As a preventive measure against serous ovarian and peritoneal cancer. +Time of Operation +1. During puerperium {puerperal): If the patient is otherwise healthy, the operation can be done 24-48 hours following delivery. Its chief advantage is technical simplicity. Hospital stay and rest at home following delivery are enough to help the patient to recover simultaneously from the two events, i.e., delivery and operation. +2. Interval: The operation is done beyond 3 months following delivery or abortion. The ideal time of operation is following the menstrual period in the proliferative phase. +3. Concurrent with Medical Termination of Pregnancy {MTP) and at the time of cesarean section: Sterilization is performed along with termination of pregnancy. This is mostly done, especially in the urban centers. +4. Concurrent with cesarean delivery with prior consent. +Methods of Female Sterilization +Occlusion by resection of a segment of both the fallopian tubes (commonly called tubectomy) is the widely accepted procedure. Currently, occlusion of the tubes with rings or clips or electrocoagulation using a laparoscope is gaining popularity. Hysterectomy during the childbearing period has got an incidental sterilization effect but should not be done for sterilization purpose. +Tubectomy +It is an operation where resection of a segment of both the fallopian tubes is done to achieve permanent sterilization. The approach maybe: +■ Abdominal II Vaginal +Abdominal +11 Conventional 11 Minilaparotomy + +Conventional (Laparotomy) +Steps +II Anesthesia: The operation can be done under general or spinal or local anesthesia. In mass camp, local anesthesia is preferable. In case of local anesthesia, premedication with injection morphine 15 mg or injection pethidine 100 mg with phenergan 50 mg IM is to be administered at + +Chapter 36: Population Dynamics and Control of Conception + +least 30-45 minutes prior to surgery. The incisional area is infiltrated with 1 % lignocaine. +II Incision: In puerperal cases, where the uterus is felt per abdomen, the incision is made two fingers breadth (l") below the fundal height and in interval cases, the incision is made 2 fingers' breadth above the symphysis pubis. The incision may be either midline or paramedian or transverse. The abdomen is opened by the usual procedure. +II Delivery of the tube: The index finger is introduced through the incision. The finger is passed across the posterior surface of the uterus and then to the posterior leaf of the broad ligament from where the tube is hooked out. The tube is identified by the fimbrial end and mesosalpinx containing utero-ovarian anastomotic vessels. + +Techniques (Figs. 36.14A to F) +11 Pomeroy's: A loop is made by holding the tube by an Allis forceps in such a way that the major part of the loop consists mainly of isthmus and part of the ampullary part of the tube (at the junction of proximal and middle third). Through an avascular area in the mesosalpinx, a needle threaded with No. 'O' chromic catgut is passed and both the limbs of the loop are firmly tied together. About 1-1.5 cm of the segment of the loop distal to the ligature is excised. The tube is so excised as to leave behind about 1.5 cm of intact tube adjacent to uterus. Segment of the loop removed is to be inspected to be sure that the wall has not been partially resected and to send it for histology. The same procedure is repeated on the other side. Because of the absorption of the absorbable ligature, the cut ends become independently sealed off and are separated after a few weeks. Advantages: It is easy, safe, and very effective in spite of the simplicity of the technique. The failure rate is 0.1-0.5%. The cut ends become independently sealed off and retract widely from each other {Fig. 30.14C). +11 Uchida technique: A saline solution is injected subserosally in the midportion of the tube to create a bleb. The serous coat is incised along the antimesenteric border to expose the muscular tube. The tube is ligated with No. 'O' chromic catgut on either side and about 3-5 cm of the tube is resected offThe ligated proximal stump is allowed to retract beneath the serous coat. The serous coat is closed with a fine suture in such a way that the proximal stump is buried but the distal stump is open to the peritoneal cavity. No failure in this method has been observed so fa,: +II Irving method: The tube is ligated on either side and midportion of the tube (between the ties) is excised. The free medial end of the tube is then turned back and buried into the posterior uterine wall creating a myometrial tunnel {Fig. 36.14D). +II Madlener technique (Fig. 36.l4E): It is the easiest method. The loop of the tube is crushed with an artery forceps. The crushed area is tied with black silk. The loop is not excised. The failure rate is very high to the extent of 7% and hence, it is abandoned in preference to the Pomeroy's technique. +II Kroener method of fimbriectomy is not a common procedure (Fig. 36.l4F). +The abdomen is closed in layers. Antibiotics are given routinely in the postoperative period. The abdominal stitches are removed on the 5th day and the patient is discharged. However, if the patient has satisfactory postoperative progress, she may be discharged after 48 hours. The stitches may be removed in the outpatient department. +Ii Chapter 36: Population Dynamics and Control of Conception + + + + + + + + + + + + + + + + + + + + + + +Figs. 36.14A to F: Steps of tubectomy by Pomeroy's method: (A) A segment of the fallopian tube is lifted up; (B) The loop is ligated with chromic catgut and is cut (about 1 .5 cm); (C) End result of the operation-note wide separation; (D) Irving procedure: The medial cut end is buried in the myometrium posteriorly and the distal cut end is buried in the mesosalpinx; (E) Madlener procedure; (F) Kroener procedure: The ampullary end of the tube is ligated and resected. + + +Minilaparotomy (Mini-Lap) +When the tubectomy is done through a small abdominal incision along with some device, the procedure is called mini-Lap. It has been popularized by Uchida of Japan ever since 1961. + +Steps +(1) Anesthesia: Always under local anesthesia: (2) Plan of incision: As described in conventional method but the incision should be 1/2" - 3/4"; (3) Especially designed retractor may be introduced after the abdomen is opened; ( 4) Uterus is elevated or pushed to one side or the other by the elevator that has already been introduced transvaginally into the uterine cavity. This helps manipulation of the tube in bringing it close to the incisional area, when it is seized by artery forceps; (5) The appropriate technique oftubectomyis performed on one side and then repeated on the other side; (6) The peritoneum is closed by purse string suture. Once conversant with the technique, it can be performed with satisfaction to the patient. It also benefits the organization (turnover of the patient per bed is more than that in the conventional +method). The patient is usually discharged within 24-48 hours. +Vaginal ligation: Tubectomy through the vaginal route may be done along with vaginal plastic operation or in isolation. When done in isolation, the approach to the tube is through posterior colpotomy. Surgeon needs additional skill of vaginal surgery. Interval cases (uterus <12 weeks) are most suited. It is done under general or spinal anesthesia. It takes longer time. Laparotomy may sometimes be needed due to difficulties. +Complications: Hemorrhage, broad ligament hematoma, and rarely rectal injury. Dyspareunia may be a late complication +Advantage: Short hospital stay is convenient in obese women. Its limitation and relative merits and demerits are given in Table36.6. + + +Laparoscopic Sterilization +Laparoscopy is the commonly employed method of endoscopic sterilization (Fig.36.15). It is gradually becoming more popular­ especially, in the camps (Fig.36.16). The procedure is mostly done under local anesthesia. The operation is done in the interval period, concurrent with vaginal termination of pregnancy or 6 weeks following delivery. It should not be done within 6 weeks of delivery. +The procedure can be done either with single or double puncture technique. The tubes are occluded either by a silastic ring (silicone rubber with 5% barium sulfate) devised by Fallope or by Filshie clip is made of titanium lined with silicone rubber. Only 4 mm of the tube is destroyed. Failure rate is 0.1 %. Hulka­ Clemens spring clip is also used. Electrosurgical methods: Desicates the tissue by heating. Unipolar or bipolar method of tubal coagulation is used. Bipolar cautery is safer than unipolar one but it has higherfailure rates (2.1 %}. Laser photocoagulation is not popular because of high recanalization rate. +Principal Steps (Single Puncture Technique) +Premedication: Pethidine hydrochloride 75-100 mg with phenergan 25 mg and atropine sulfate 0.65 mg are given intramuscularly about half an hour prior to operation. +Local anesthesia: Taking usual aseptic precautions about 10 mL of 1 % lignocaine hydrochloride is to be infiltrated at the puncture site (just below the umbilicus) down up to the peritoneum. +Position of the patient: The patient is placed in lithotomy position. The operating table is tilted to approximately <15° of Trendelenburg position. Usual aseptic precaution is taken as in abdominal and vaginal operations. The bladder should be fully emptied by a metal catheter. Pelvic examination is +Chapter 36: Population Dynamics and Control of Conception + +Table 36.6: Mini-Lap vis-a-vis laparoscopic sterilization. +Features Mini-Lap Laparoscopic sterilization , + +Principle +Personnel + + +Resection of portion of the tube. +Any medical personnel with surgical skill. + +Using biopolar cautery sialistic band (Fallopering) or Filshle clip. +Should only be performed by persons with special training. + +Selection of time Any time-puerperium, interval (with MTP). Should not be done within 6 weeks of delivery or with enlarged uterus. + +Contraindication + +Complication life-threatening +Hospital stay Failure rate +Reversibility + + +Practically none. Can be done in conditions contraindicated for laparoscopy. +Minimal but usually not. + +3-4 days (long stay). 0.1-0.3%. +Difficult due to adhesions and reduced remnant tubal length. + +Lung lesions, organic heart diseases, intra-abdominal adhesions, extreme obesity. +Minimal but at times fatal. + +3-4 hours (short stay). 0.2-0.6%. +Easier and effective. Only 4 mm of the tube is destroyed with the Filshie clip. + +(MTP: Medical Termination of Pregnancy) + + + + + + + + + + + + + +Fig. 36.15: Laparoscopic tubal sterilization by Filshie clip. Filshie (GM Filshie) clip is made of titanium and the inner surfaces are lined with silicone. It is easier to apply and damage to the tube is less. + + + + + + + + + + + + + + + + +Fig. 36.16: Laparoscopic instruments for tubal sterilization. + +done methodically. A uterine manipulator is introduced through the cervical canal for manipulation for visualization of tubes and uterus at a later step. +Producing pneumoperitoneum: A small skin incision (1.25 cm) is made just below the umbilicus. The Veress needle is introduced through the incision with 45° angulation into the peritoneal cavity. The abdomen is inflated with about 2 liters of gas (carbon dioxide or nitrous oxide or room air or oxygen). Choice of gas depends upon the method of sterilization. + +Introduction of the trocar and laparoscope with ring-loaed applicator: Two silastic rings are loaded one after the other on the applicator with the help of a loader and pusher. The tr9car with cannula is introduced through the incision previously made with a twisting movement. The trocar is removed and the laparoscope together with ring applicator is inserted through the cannula (Fig. 36.15). +The ring loaded applicator approaches one side of the tube and grasps at the junction of the proximal and middle third of the tube. A loop of the tube (2.5 cm) is lifted up, drawn into the cylinder of the applicator and the ring is slipped into the base of the loop under direct vision. The procedure is to be repeated on the other side (Fig. 36.15). +Removal of the laparoscope: After viewing that the rings are properly placed in position, the tubal loops looking white and there is no intraperitoneal bleeding, the laparoscope is removed. The gas or air is deflated from the abdominal cavity. The abdominal wound is sutured by a single chromic catgut suture. +Risk reducing salpingectomy: Bilateral total salpingectomy is recommended as it reduces the risk of ovarian cancer (endometrioid and serous types) up to 34 % (SGO, 2013). This is especially beneficial for high-risk women (BRCA 1 or BRCA 2 mutation). +Comments on Methods of Female Sterilization +In the LMIC, mini-lap remains the mainstay in the National Family Planning Programme (NFPP) as a method of permanent sterilization. It is safe, has wider applicability, is less expensive and has got a less failure rate compared to laparoscopic sterilization. However, for a quick turnover in an organized mass camp, laparoscopic sterilization offers a promising success (Table 36.7). +Hazards of Tubal Sterilization +Immediate: These are related to general anesthesia and to the particular method used in sterilization. The related complications have already been discussed (Tables 36.6 and 36. 7). +Remote: (a) Specific for the approach; (b) Related to the sterilization. +ll The remote complications specific for the approach of the operation, abdominal or vaginal have already been described. +II The complications related to sterilization can be grouped into: (a) General complications: These include occasional obesity, psychological upset; (b) Gynecological: (i) Chronic pelvic pain, (ii) +! +t +t +[ + + +-Ei Chapter 36: Population Dynamics and Control of Conception Table 36.7: Female sterilization. +Abdominal approach Vaginal approach + + + +Surgeon + +Time of operation + +Contraindication Anesthesia +Complication during operation +Duration of operation +Complications: Immediate Late +Hospital stay + + +Can be performed by any one conversant with surgery. +Can be done at any time, puerperal or interval. +Practically-nil, uterus <12 weeks size. Can be done under local anesthesia. Easy to tackle. + +Shorter time. +Few +Wound infection, peritonitis-rare. lncisional hernia, failure rate-less. +Longer-5-6 days. +Shorter with mini-lap (24-48 hours). + +Can be done only by a surgeon conversant with vaginal plastic operation. + +Interval period is most suited. May be done in other times, provided the uterus is smaller than 12 weeks. +Associated to mass, uterus-> 12 weeks. General or spinal anesthesia is usually needed. +Difficult at times and laparotomy may be necessary. + +Longer time. +Few +Hemorrhage, revealed or broad ligament hematoma, injury to the rectum. Dyspareunia, failure rate-more. +Shorter-24-48 hours. + + + +Congestive dysmenorrhea, (iii) Menstrual abnormalities in the form of menorrhagia, hypomenorrhea or irregular periods. Pelvic pain, menorrhagia along with cystic ovaries constitute a post-ligation syndrome. It may be vascular in origin. However, the incidence can be minimized, if the blood vessels adjacent to the mesosalpinx are not unduly disturbed; (iv) Alteration in libido. +Failure Rate +The overall failure rate in tubal sterilization is about 0. 7%, the Pomeroy's technique being the lowest 0.1-0.5%, in contrast to the Madlener's, being 1.5-7%. The failure rate is increased when it is done during hysterotomy or during cesarean section. Failure rates of laparoscopic sterilization depend upon the individual method (electrocoagulation-unipolar 0. 75%, bipolar 2.1 %, Fa/lope ring 1. 7%, Filshie clip 0.1 %}. Failure may be due to fistula formation +or due to spontaneous reanastomosis. + + +Mortality following tubal sterilization is estimated to be 72 per 100,000 for all methods. Laparoscopic procedures carried the mortality rate of 5-10 per 100,000 compared to 7 per 100,000 for puerperal ligations. + +Reversibility +Informed consent must be obtained after adequate counseling. Couple must understand the permanency of the procedure, its occasional failure rate, the risks and side effects, and its alternatives. Unfortunately, regret is not uncommon. Microsurgical techniques give excellent result for tubal reanastomosis. Pregnancy rates after reversal are high (80%) following use of clips and rings. Reversal of vasectomy with restoration of vasa patency is possible up to 90% of cases. But pregnancy rate is low (50%}. + + + + +► Sterilization is the permanent method of surgical contraception. In male, it is vasectomy and that in female, it is tubectomy. ► No Scalpel Vasectomy (NSV) is commonly done in India. +► Tubectomy could be done by abdominal (common) or by vaginal route. Abdominally, it is done by conventional laparotomy or by minilaparotomy procedure. Pomeroy's method is commonly done. +► A man is not sterilized immediately after vasectomy. As such, additional condom should be advised for at least 3 months. +► No Scalpel Vasectomy (NSV) is done under local anesthetic making a tiny puncture over the stretched skin of the vasa. It has fewer complications. Both the NSV and scalpel vasectomy (SV) are safe. +► Globally, tubal sterilization is the most common method (20%) of contraception followed by IUDs (15%), oral contraceptives (8%) and condoms (5%). +► Counseling for sterilization should be done with all information. +► Female sterilization operation can be done during puerperium (puerperal), in interval period or concurrent with MTP or cesarean delivery. Hysteroscopic methods of sterilization include insertion of quinacrine pellet and essure (microcoil). +► Reversal of sterilization is not always successful. This should be counseled to the couple before sterilization operation. ► Apart from conventional or mini-lap abdominal method, laparoscopic sterilization is very popular and effective. +► Contraceptive prescription should be on an individual basis. In an individual, the method may vary according to her phase of reproductive life. Teenage girls, older women and sex workers should also be protected. + + +BARRIER METHODS +These methods prevent sperm deposition in the vagina or prevent sperm penetration through the cervical canal. The objective is achieved by mechanical barriers and by chemical means which produce sperm immobilization, or by combined means. The following are used. + +TYPES OF BARRIER METHODS + +11 Mechanical Male: Condom +Female: Condom, diaphragm, cervical cap ■ Chemical (vaginal contraceptives) +Creams: Delfen (nonoxynol-9, 12.5%) +Chapter 36: Population Dynamics and Control of Conception Ba\-· + +Foam tablets: Aerosol foams, Sponge (today) ll Combination +Combined use of mechanical and chemical methods + +I CONDOM (MALE) + +Condoms are made of polyurethane (lamb skin) or latex. Polyurethane condoms are thinner and suitable to those who are sensitive to latex rubber. It is the most widely practiced method used by the male. In India, one particular brand (latex) is widely marketed as 'Nirodh'. The eficacy of condoms can be augmented by improving the quality of the products and by adding spermicidal agents during its use. Protection against Sexually Transmitted Disease (STD) is an additional advantage. Occasionally, the partner may be allergic to latex. It should neither be too tight or too loose. A reservoir should be left at the tip to retain the ejaculate. Adequate lubrication should be used. Women who are at high risk of HIV infection, should not use monoxynol-9 spermicides as thus may increase the risk of HIV transmission. +The method is suitable for couples who want to space their families and who have contraindications to the use of oral contraceptive or IUD. These are also suitable to those who have infrequent sexual intercourse. + +I FEMALE CONDOM (FEMIDOM) (FIG. 36.17A) + +It is a sheath made of polyurethane which lines the vagina and also the external genitalia. It is 17 cm in length with one flexible + +polyurethane ring at each end. Inner ring at the closed end is smaller compared to the outer ring. Inner ring is inserted at the apex of the vagina and the outer ring remains outside. It gives protection against ST!s Cytomegalovirus (CMV} [HIV, Hepatitis B Virus (HBV)} and pelvic injlammato,y disease. It is expensive. Multiple uses can be made with washing, drying, and with lubrication. Failure rate is about 5-21/HWY. + +Use of Condom +(a) As an elective contraceptive method; (b) As an interim form of contraception during pill use, following vasectomy operation (see later) and if an IUD is thought lost until a new IUD can be fitted; (c) During the treatment of trichomonal vaginitis of the wife, the husband should use it during the course of treatment irrespective of contraceptive practice; (d) Immunological infertility-male partner to use for 3 months. For other noncontraceptive benefits (Table 36.8). + +I DIAPHRAGM (TABLE 36.9 AND FIG. 36.17B) +It is an intravaginal device made of a silicone cup with flexible metal or spring ring at the margin. Its diameter varies from 5 cm to 10 cm. It requires a medical or paramedical personnel to measure the size of the device. The largest size should be used without any discomfort or undue pressure. Caya (FDA approved) is a single dose diaphragm that does not require fitting by a medical person. Failure rate: Typical use 13-17%; perfect use 4-8%. Diaphragm and cervical cap may also reduce the risk of + + + + + + + + + + + + + +Figs. 36.17A to C: (A) Female condom; (8) Commonly used conventional contraceptive (diaphragm); (C) Vaginal contraceptive (nonoxynol-9, 12.5%). + + +Table 36.8: Condom. · +Advantages + + +. , , . _., , · • , · , . Disadvantages + + + +• Cheaper with no contraindications. • No side effects. +• Easy to carry, simple to use and disposable. +• Protection against sexually transmitted diseases, e.g., gonorrhea, Chlamydia, HPV and HIV. +• Protection against pelvic inflammatory diseases. • Reduces the incidence of tubal infertility and +ectopic pregnancy. +• Protection against cervical cell abnormalities. • Useful where the coital act is infrequent and +irregular. + +• May accidentally break or slip off during coitus. • Inadequate sexual pleasure. +• Allergic reaction (Latex). +• To discard after one coital act. +( +H +_ +W +Y +) +I + I +a +r +i e +ra +te +f-;-/u___----,-s _ + + + +NIRODH +111• Ltwi.aledt1ms , +@fd> ,u +u +. +!/!·. +1;:l + + +Precautions: (a) To use a fresh condom for every act of coitus. (b) To cover the penis with condom prior to genital contact. (c) Create a reservoir at the tip. (d) To withdraw while the penis is still erect. (e) To grasp the base of the condom during withdrawal. +=--'mJ Chapter 36: Population Dynamics and Control of Conception + +Table 36.9: Diaphragm. + +Advantages +• Cheap. +• Can be used repeatedly for a long time. • Reduces PID/STls to some extent. +• Protects against cervical precancer and cancer. + + +Disadvantages +• Diaphragm now come in two sizes, nulliparous and parous. There is no need of pelvic examination for fitting. +• Risk of vaginal irritation, abrasion and urinary tract infection are there. +• Not suitable for women with uterine prolapse. + +Failure rate-16 (HWY). (PIO: Pelvic Inflammatory Disease; STls: Sexually Transmitted Diseases) + + +cervical cancer. It should completely cover the cervix. As it cannot effectively prevent ascent of the sperms alongside the margin of the device, additional chemical spermicidal agent should be placed on the superior surface of the device during insertion, so that it remains in contact with the cervix. The device is introduced up to 3 hours before intercourse and is to be kept for at least 8 hours after the last coital act. Ill-fitting and accidental displacement during intercourse increase the failure rate. +I VAGINAL CONTRACEPTIVES (FIG. 36.17C) Spermicides +Spermicides are available as vaginal foams, gels, creams, tablets, and suppositories. Usually, they contain surfactants like nonoxynol-9, octoxynol or benzalkonium chloride. The cream or jelly is introduced high in the vagina with the help of the applicator soon before coitus. The duration of maximum effectiveness is usually not more than one hour. Foam tablets (1-2) are to be introduced high in the vagina at least 5 minutes prior to intercourse. In isolation, it is not effective (18-29 HWY), but enhances the efficacy of condom or diaphragm when used along with it. There may be occasional local allergic manifestations either in the vagina or vulva. +Spermicide-microbicide combination supports the natural defense maintaining the acidic pH and acts as antimicrobial also. They are controlled by the female. These agents are protective against STis including HIV. The agents containing surfactant, destroy the sperm membrane and also the outer envelops of the virus and bacteria. + +Vaginal Contraceptive Sponge (Today) +It is made of polyurethane impregnated with 1 g of nonoxynol-9 as a spermicide. Nonoxynol-9 acts as a surfactant which either immobilizes or kills sperm. It releases spermicide during coitus, absorbs ejaculate and blocks the entrance to the cervical canal. The sponge should not be removed for 6 hours after intercourse. Its failure rate (WY) is about-parous women: 32-20, nulliparous 16-9. Moreover, it produces lesions in the genital tract when used frequently. Those lesions are associated with increased risk of HIV transmission. Sponge should not be used during mens or puerperium. + +I FERTILITY AWARENESS METHOD (TABLE 36.10) + +Fertility awareness method requires partner's cooperation. The woman should know the fertile time of her menstrual cycle. + +Rhythm Method +This is the only method approved by the Roman Catholic Church. The method is based on identification of the fertile period of a cycle and to abstain from sexual intercourse during that period. + + +Table 36.10: Fertility awareness Methods (rhythm method). Advantages Disadvantages +• No cost. • Difficult to calculate the safe • Lack of side effects. period reliably. +• The period of abstinence is • Needs several months determined by calculating training to use these +the length of the woman's methods. +previous menstrual cycles. • Compulsory abstinence from Three assumptions are sexual act during certain considered: (al Human periods. +ovum can be fertilized • Not applicable during for about 24 hours after lactational amenorrhea ovulation; (bl Sperm can or when the periods are +fertilize 3-5 day after coitus; irregular. +I +I +(cl Ovulation usually occurs +12-16 days before the onset Failure rate-20-30 (HWY) of menstruation. + +This requires partner's cooperation. The methods to determine tlie approximate time of ovulation and the fertile period include­ (a) Recording of previous menstrual cycles (calendar rhythm); (b) Noting the basal body temperature chart (temperature rhythm); (c) Noting excessive mucoid vaginal discharge (mucus rhythm). The users of the calendar method obtain the period of abstinence from calculations based on the previous twelve menstrual cycle records. The first unsafe day is obtained by subtracting 20 days from the length of the shortest cycle and last unsafe day by deducting 10 days from the longest cycle. Users of temperature rhythm require abstinence until the third day of the rise of temperature. Users of mucus rhythm require abstinence on all days of noticeable mucus and for 3 days thereafter. + +Coitus lnterruptus (Withdrawal) (Table 36.11) +It is the oldest and probably the most widely accepted contracep­ tive method used by man. It necessitates withdrawal of penis shortly before ejaculation. It requires sufficient self-control by the man so that withdrawal of penis precede ejaculation. + +Table 36.11: Coitus interruptus. Advantages Disadvantages +• No appliance • Requires sufficient self-control by the man is required. • The woman may develop anxiety neurosis, +• No cost. vaginismus or pelvic congestion. • Chance of pregnancy is more: +o Precoital secretion may contain sperm. o Accidental chance of sperm. +I +I +Failure rate-20 (HWY) +When the woman is exclusively breastfeeding, a contraceptive method should be used in the 3rd postpartum month and with partial or no breastfeeding, she should use it in the 3rd postpartum week. +Emergency contraception should be used from 21 day postpartum. + + +Breastfeeding, Lactational Amenorrhea (LAM) +Prolonged and exclusive (6 months) breastfeeding offer a natural protection against pregnancy. The criteria for successful of LAM are: Continuous amenorrhea and exclusive breastfeeding up to 6 months. Night nursing is highly protective. More effective in women who are amenorrheic than those who + +Chapter 36: Population Dynamics and Control of Conception + +are menstruating. The risk of pregnancy to a woman who is exclusively breastfeeding for 6 months and amenorrheic is less than 2% in the first 6 months. Otherwise, the failure rate is high (1-10%). Thus during breastfeeding, additional contraceptive support should be given by condom, IUCD or injectable steroids where available, to provide complete contraception. + + +CONTRACEPTIVE COUNSELING AND PRESCRIPTION + + +Pregnancy carries an overall maternal mortality around 400 per 100,000 total births in the developing countries (India 167 /100,000 LB) and the same in the developed countries is less than 10. Whereas annual number of deaths per 100,000 exposed to pill is 1.3 and with that of IUDs is 1. The same from tubal sterilization is 1.2 and vasectomy is 0.1. The risks of death from automobile driving is 1 in 6,000 per year. Contraception usually carries less risk compared to pregnancy. Importantly, benefits of contraceptive use outweigh the risks of pregnancy. +No single universally acceptable method has yet been discovered. The individual should have the liberty to choose any of the currently available well-tested method, which may even vary at each phase in her reproductive life. If one compares the risks and benefits of any contraceptive, it is observed that more deaths occur as a result of unplanned pregnancies than from the hazards of any modern contraceptive method (excluding 'pill' users over 35 who smoke). +Important factors for the selection of any contJ·aceptive method for an individual are-relative safety, effectiveness, side effects, and willingness to use the method correctly and consistently. The other fac­ tors to consider are the frequency of coitus, the need oflactation and prevention ofSTis. Acceptability is probably the most critical factor in the effectiveness of a contraceptive method. Couple (client) should be helped to make an informed choice. A clear account of the risks and the benefits for an individual method is given. Regular follow-up and compliance with the instructions are to be ensured. It is also essential that an informed (verbal) consent is obtained and recorded. + +I PRESCRIPTION + +Conventional contraceptives can be safely prescribed during the entire reproductive period as elective choice or as an alternative to 'pill' or IUD if they are contraindicated or unacceptable to the couple. As such only the advice regarding the use of 'pill' or IUD during different phases of reproductive life is discussed. + +Adolescent Girls +Low-dose combined pills are most effective for the sexually active adolescents. It is the contraceptive of choice. However, DMPA or norplant may be an alternative when accepted. There is no concern about their future reproductive endocrinologic function or the epiphyseal closure in postmenarchal girls. + +Newly Married Couple +A highly effective and acceptable contraceptive like DMPA, or POPs, could be prescribed. IUD may not be prescribed. As such COCs are recommended provided there is no contraindication. Apart from effective contraception 'COCs' have got many noncontraceptive benefits as well. + +Spacing of Births +■ Postabortal ■ Postpartum ■ Interval + + +♦ It should be noted that Emergency Contraception is required from 21 days postpartum. +Postabortal +The contraceptive practice should be started within 5 days following the abortion/ectopic management/GTD treatment process is completed. DMPA, POPs or COCs could be a choice. IUD is an alternative. +Postpartum +■ Nonlactating ■ Lactating +Non lactating +Contraceptive practice should be started after 3 weeks. 'POP' is good; IUD is an equally effective alternative. Injectable DMPA could be used as it is devoid of any estrogen-related side effects (DMPA theoretically risk of VTE if used within 6 weeks of delivery; MEC-2). Implanon (etonogestrel) may be prescribed. +t + +Lactating +In fully lactating women (5-6 feeds and spending about 60 minutes in 24 hours), the contraceptive practice may be safely withheld for 6 weeks postpartum. For doubtful adverse effects of steroids on lactation and on the babies through the ingested milk, 'pill' is better withheld. Minipill (POP) or injectable steroid (DMPA) is ideal. Alternatively, IUD can be inserted. +Interval +Below the age of 35 years, she can have her choice to either 'pill' or IUD following adequate counseling. In women above the age of 35, especially who are smokers, IUD should be inserted in preference to 'pill'. Injectables (DMPA) or implant (Implanon) is the other alternative. +To stop future pregnancies: The decision to advise permanent sterilization should be judiciously given, especially to the under­ privileged women in the face of high perinatal and infant mortality rate. The cases are to be individualized. However, a two-child formula is usually recommended and as such, a couple having two children who have been fully immunized can have permanent sterilization (husband or wife). If the couple is not motivated to undergo the sterilization operation, any of the temporary methods is to be prescribed till the end of the reproductive period of the wife. Women who have completed their family but do not desire for permanent sterilization, may use IUD (CU-T 380A) or implant if accepted. + +Older Women +Contraception should be prescribed to avoid unplanned pregnancy. Low dose pills can be continued till menopause ( with monitoring) in the low-risk group. Progestin-only pill, injectable progestin (DMPA), LNG-IUS are the other alternatives. Barrier methods and vaginal spermicides can be used either as a primary or back-up method. Usually, fertility is reduced after 40 years ofage. +Chapter 36: Population Dynamics and Control of Conception + +Age for stopping contraception. +Type of contraception 40-50 years >SO years +Non hormonal Stop after 2 years Stop after 1 year of of amenorrhoea. amenorrhoea. +CHC May be continued Stop by SO years. till SO years. May switch to non +hormonal methods or IMP/POP/LNG IUS. +DMPA May be continued May switch to other till 50 years. methods +IMP/POP/LNG IUS May be continued Can stop by 55 years. till 50 years. + +Women at risk of STis need dual protection against preg­ nancy and STis. They should use condom with spermicides or use another contraceptive (DMPA, COC, or POP), method in conjunction with condom. +Women using enzyme inducers are advised to take COCs having more than usual dosage or other method of contraception (DMPA, IUDs). Emergency contraception (postcoital contraception) when required as emergency, POP, IUD can be used. + +ONGOING TRIALS AND SELECTIVE AVAILABILITY +The following are used on trial basis or are available in selected countries: +■ Combined Injectable Contraceptives (CICs): Both estrogen and progestin are combined in these monthly injectables. Preparations available are: DMPA 25 mg with estradiol cypionate 5 mg (Cyclofem) and NET-EN 50 mg with estradiol valerate 5 mg (Mesigyna). It is given within first 5 days of menstruation. Next injection should be on the same date of each month ( 4-week schedule). Fertility return is quick. +Drawbacks: (a) Irregular or prolonged menstrual bleeding; (b) Not suitable for nursing mothers. It is has been currently withdrawn from the market. +■ Transdermal patch: Patch contains 0.75 1g ethynyl estradiol and 6 mg norelgestromin. When used as a cream to the skin. It provides effective contraception. Patch delivers 150 1g norgestinate (progestin) and 20 1g ethinylestradiol daily. It has an area of 20 cm2 (4.5 x 4.5 cm). The patch is used weekly for 3 weeks and one week off for withdrawal bleeding. It is well-tolerated, safe and effective. + + + +Advantages: It avoids hepatic first pass metabolic effects and maintains steady serum hormone levels. +Drawbacks: Patch detachment, skin reaction and high failure in overweight women (>90 kg). It is applied over the buttocks, upper and outer arm, or lower abdomen but not over the breasts. Failure rate is 1.2 per 100 women years. Patch failure rate is high in woman weighing >90 kg. Patch may increase the risk ofVTE. +■ Vaginal ring: Containing levonorgestrel covered by silastic tubing has been introduced. They are 5 and 6 cm in diameter. The vaginal ring delivers levonorgestrel (20 1g/day) to maintain a constant blood level like norplant. The rings are replaced by 90 days. Pregnancy rate is 3 per 100 women. This method is under woman's control. +■ Combined ring (Nuva ring): Soft, flexible transparent ethylene vinyl ring releases ethinyl estradiol (15 1g) and etonogestrel (metabolite of desogestrel) 120 1g daily over a period of 21 days. The ring is inserted on the first day of menses and is worn for 3 weeks. The ring must be reinserted within the next 3 hours, if removed for any reason, vaginal route use avoids GI absorption, first pass liver metabolism and has lowest systemic estrogenic side effects. It is then removed and after 1 week (after the withdrawal bleed) a new ring is inserted. It acts by inhibiting ovulation. Pearl index is 0.65 and cycle control is good. The ring (54 mm diameter and 4 mm thick) is inserted within 5 days of menses. Side effects are, headache, leukorrhea, vaginitis, and expulsion. +I TRANSCERVICAL STERILIZATION +Essure is a 4 cm long, 2 mm diameter, microcoil (spring­ like device) made of nickel-titanium steel alloy coil within which lie polyethylene terephthalate fibers. It is inserted into each fallopian tube transcervically using a hystero­ scope. The tube is blocked permanently when scar tissue grows into the device. To ensure proper placement and total occlusion of essure a hysterosalpingogram is done three months after. Its success rate is similar to surgical sterilization ( 45°. +Fetal head is engaged. Head is 1/5 palpable per abdomen but station is above +2 cm but not above the ischial spines (Figs. 37.10A to C}. +Head is not engaged. This type is not included in classification. + + + +application as it has got a negligible compression effect on the cranium. +Pelvic application: When the blades of the forceps are applied on the lateral pelvic walls ignoring the position of the head, it is called pelvic application. If the head remains unrotated, this type of application puts serious compression effect on the cranium and thus must be +avoided. + +I LOW FORCEPS OPERATION +Preliminaries: Same as those mentioned (Table 37.4). The following are especially emphasized: +■ Anesthesia: Pudenda/ block supplemented by perineal and labial infiltration with 1 % lignocaine hydrochloride is quite effective in producing local anesthesia. A perineal block may be sufficient (regional block is required for a rotational birth). + + +Table 37 .4: Prerequisites for operative vaginal delivery (forceps or vacuum application} (SOGC-2004, RANCZOG-2002). + +Fetal and Maternal Criteria +• Fetal head engaged (head 51/5 Bladder must be emptied +• +palpable per abdomen}. a Adequate maternal analgesia (regional ■ The cervix must be fully dilated block for mid-cavity or pudenda! block} ■ The membranes must be ruptured ■ Informed consent (verbal or written} with +• +Fetal head position is exactly known. prior clear explanation a Caput and moulding not more than +2. +■ Pelvis deemed adequate. + + +Others +■ Experienced operator. ■ Aseptic techniques. +■ Back-up plan and facilities in case of failure. +• +Presence of a neonatologist. +■ Willingness to abandon the procedure when difficulties faced. + + + +Pelvic +brim + +Head +-1 , -2 station + + +Head at +station "O" + + + +Rotated head +at station +5 + + + + + + + + + + + + + + + + +lschial +spine + +Path of +fetal head + + + + +Centimeters from ischial spine +(approx) + + +Forceps may be only choice +a. Aftercoming head of breech delivery. b. Preterm delivery <34 weeks. +c. Mentoanterior face delivery. d. Suspected coagulopathy, +thrombocytopenia. +e. Situation where maternal pushing is absent. + +Fig. 37.9: Different types of forceps operations (ACOG-2000). +Chapter 37: Operative Obstetrics mJL + + + + + + + + + + + + + +Figs. 37.10A to C: (A) Engaged head with lower pole below the level of ischial spine appropriate for instrumental vaginal delivery; (B) Supermoulding of the head due to brim contraction with the lower pole at the ischial spines, yet not engaged, misleading the station of head; (C) Excessive moulding and caput formation often mislead the actual level of head in the pelvis. Abdominal palpation is essential before instrumental vaginal delivery. + + +■ Catheterization +■ Internal examination to assess: (a) State of the cerix, {b) Membranes status, (c) Presentation and position of the head, {d) Assessment of the pelvic outlet (sacro­ coccygeal plateau, TDO and subpubic arch). +■ Episiotomy: It is usually done during traction when the perineum becomes bulged and thinned out by the advancing head. +STEPS: The operation consists of the following steps: ■ Identification of the blades and their application ■ Locking of the blades +■ Traction +■ Removal of the blades. + +Step I: Identification and application of the blades +The identification of the blades is to be made after articulation as mentioned earlier (Fig. 37.11). The left or lower blade is to be introduced flrst. +The four fingers of the semi-supinated right hand are inserted along the left lateral vaginal wall, the palmar surface of the fingers rest against the side of the head (Figs. 37.12A to F). The fingers are used to guide the blade during application and to protect the vaginal wall. The handle of the left blade is taken lightly by three fingers of the left hand-index, middle and thumb in a pen-holding manner and is held vertically almost parallel to the right inguinal ligament. The fenestrated portion of the blade is placed on the right palm with the tip (toe) pointing upwards. The right thumb is placed at the junction of the blade and the shank (heel). +The blade is introduced between the guiding internal fingers and the fetal head, manipulated by the thumb. As the blade is pushed up and up, the handle is carried downwards and backwards, traversing wide arc of a circle towards the left until the shank is to lie straight on the perineum. Utmost gentleness is required while introducing the blade. No assistant is usually required to hold the handle in low forceps operation. When correctly applied, the blade should be over the parietal eminence, the shank should be in contact with the perineum and the superior surface of the handle should be directed upwards. + + + + + + + + + +-----Left +blade + + + + + + + + + + + + + + +Fig. 37.11: Identification of forceps blades. Articulated forceps are held in front of the perineum in a position that they are expected to assume after application. This practice is known as "ghosting". + + +Introduction of the right blade: The two fingers of the left hand are now introduced into the right lateral wall of the vagina alongside the baby's head. The right blade is introduced in the same manner as with left one but holding it with the right hand. +Step II: Locking of the blades +Proper application of blades is confirmed by-(a) Blades should be in bimalar and biparietal placement; (b) Posterior fontanel should be one fingerbreath above theplane of the shanks and midway between the blades (Fig. 37.12D); (c) Lambdoid suture should be equidistant from the upper edge of each blade (Fig. 37.13); (d) The sagittal suture should be perpendicular to the +mJ Chapter 37: Operative Obstetrics + + + + + + + + + + + + + + + + + + + + + + + + + + +Ii +Figs. 37.12A to F: Steps of low forceps operation: (A) Introduction of the left blade; (Bl The handle lying flat on the perineum after introduction; (C) Introduction of the right blade; (D) Showing perfect apposition and locking of the blades; (El Bimalar, biparietal placement of blades and position of the fingers during traction; (Fl Change in the grip in the final stage of delivery. + + +plane of the shanks (Fig. 37.12E) and (e) The blade fenestrations should barely be palpated (Fig. 37.128). +Minor difficulty in locking can be corrected by depressing the handles on the perineum. In case of major difficulty, the blades are to be removed, the causes are to be sought for (vide infra) and the blades are to be reinserted. The handles should never be forced to lock them. +Step III and IV: Traction and removal of blades +Before traction is applied, correct application of the blades is to be ensured. Correct application is evidenced by: (a) Easy locking, (b) The blades are equidistant from the lambdoid suture (Fig. 37.13), (c) Firm gripping of the head on the biparietal diameter-as judged by a few tentative pulls. +Principles: Steady but intermittent traction should be given with uterine contraction. Preferably it should coincide with maternal pushing efforts. Howevet; in outlet forceps, the only resistance to overcome is the perineum and the coccyx. +Gripping of the articulated forceps during traction: The traction is given by gripping the handle, placing the middle finger in between the shanks with the ring and index fingers on either side on the finger guard. During the final stage of traction, the four fingers are placed in between the shanks and the thumb which is placed on the undersurface of the handles and exerts the necessary force. +Direction of the pull: The direction of the pull corresponds to the axis of the birth canal (Fig. 37.14). In low forceps operation depending upon the station of the head, the direction of the + +pull is downwards and backwards until the head comes to the perineum. The pull is then directed horizontally straight towards the operator till the head is almost crowned. The direction of pull is gradually changed to upwards and forwards, towards the mother's abdomen to deliver the head by extension. The blades are removed one after the other, the right one first. + + + + + + + + + + + + + + + + + +Fig. 37.13: (a) The blades are equidistant from the lambdoid suture indicating correct application (Biparietal Bimalar application); (b) Sagittal suture is in the midline of both the blades. +Chapter 37: Operative Obstetrics &Dt. +♦ General anesthesia is preferable. + + + + + + + + + + + + + + +Fig. 37.14: Showing direction of traction along the axis of the birth canal-(1) Downwards and backwards; (2) Straight horizontal pull; (3) Upwards and forwards. + +Following the birth of the head, usual procedures are to be taken as in normal delivery. Routine injection oxytocin 10 IU, MIM or intravenous methergine 0.2 mg is to be administered with the delivery of the baby. Episiotomy is repaired in the usual method. Lacerations on the vaginal walls or perineum are to be excluded. + +Forceps traction should begin with uterine contraction. It should concise preferably with maternal pushing efforts. Descent should occur with each pull. Fetal heart rate should be monitored. Failure of descent after two or to three pulls following correctly applied forceps by an experienced operators, operative vaginal delivery should be abandoned in favor of cesarean delivery. "Sequential use ofvacuum" may be done very cautiously (it is not a routine). + +I OUTLET FORCEPS OPERATION +Wrigley's forceps are used exclusively in outlet forceps operation. Perinea! and vulval infiltration with 1 % lignocaine is enough for local anesthesia. The blades are introduced as in the low forceps operation with long curved forceps except that two fingers are to be introduced into the vagina for the application of the left blade. Traction is given holding the articulated forceps with the fingers placed in between the shanks and the thumb on the undersurface of the handles {Fig. 37.12F). The direction of the pull is straight horizontal and then upwards and forwards. + +I MIDFORCEPS OPERATION +The most common indication of midforceps operation is following manual rotation of the head in malrotated occipitoposterior position. The commonly used forceps is long curved one with or without axis traction device. Kielland is useful in the hands of an expert. + +Procedures +♦ Midforceps delivery should be done by a skilled obstetrician. + +♦ Introduction of the blades: The introduction of the blades is to be done with prior correction of the malrotation. +(a) Without axis traction device: The blades are introduced as in the low forceps operation. An assistant is required to hold the left handle after its introduction. {b) With axis-traction device: While applying the left blade, the traction-rod already attached to the blade is held backwards. During introduction of the right blade, the traction-rod must be held forwards otherwise it will prevent locking of the blades. +♦ Traction: (a) Without axis traction device: The direction of pull is first downwards and backwards, then horizontal or straight pull and finally upwards and fo1wards. (b) With axis-traction device: The traction handle is to be attached to the traction-rods. During traction, the traction-rods should remain parallel with the shanks. When the base of the occiput comes under the symphysis pubis, the traction-rods are to be removed. + +I DIFFICULTIES IN FORCEPS OPERATION +The difficulties are encountered mainly due to faulty assessment of the case before the operative delivery is undertaken. However, there is hardly any difficulty in low forceps operation. +During application of the blades: The causes are: (1) Incompletely dilated cervix; (2) Unrotated or nonengaged head. +Dificulty in locking: The causes are: (1) Application in unrotated head, (2) improper insertion of the blade (not far enough in), (3) failure to depress the handle against the perineum, and ( 4) entanglement of the cord or fetal parts inside the blades. +Dificulty in traction: The causes of failure to deliver with traction are: +1. Undiagnosed occipitoposterior position 2. Faulty cephalic application +3. Wrong direction of traction 4. Mild pelvic contraction +5. Constriction ring. +Slipping of the blades: The causes are: +1. The blades are not introduced far enough. +2. Faulty application in occipitoposterior position. +The blades should be equidistant from the sinciput and occiput. +FORCEPS IN OCCIPITOSACRAL POSITION: Usual application of the blades as like that of occipitoanterior position is made. The blades should lie equidistant from the sinciput and occiput, otherwise the blades may slip during traction. Horizontal traction is given until the root of the nose is under the symphysis pubis. The direction is +II Chapter 37: Operative Obstetrics + +changed to upwards and forwards to deliver the occiput. By a downward movement of the instrument, the nose and chin are delivered. +FORCEPS IN FACE PRESENTATION: Forceps delivery is only reserved for mentoanterior position. The blades are applied as in occipitoanterior position. But the handles should be kept well forward to avoid grasping of the neck by the tips of the blade. Traction is made like that of occipitoanterior to bring the chin well below and then round the symphysis pubis. +APPLICATION OF FORCEPS TO THE AFTERCOMING HEAD: The method has been described on p. 363. +I KIELLAND'S FORCEPS +The forceps was designed and named after Kielland (Kjelland) of N01way (Rotational forceps, 1916). In the hands of an expert, it is a useful and preferred instrument. Its advantages over the widely used long curved forceps are: +1. It can be used with advantages in unrotated vertex or face presentation; +2. Facilitates grasping and correction of asynclitic head because of its sliding lock (Figs. 37.15A and B). +IDENTIFICATION OF THE BLADES: The articulated blades are to be held in front of the vulva in a position to be taken up when applied to the head. The concavity of the slight pelvic curve should correspond to the side towards which the occiput lies. The blades are named anterior and posterior. The anterior blade is to be introduced first. +METHODS OF APPLICATION: There are three methods: 1. Classical (obsolete) +2. Wandering 3. Direct +Indications of rotational forceps are few. It is commonly used in deep transverse arrest with asynclitism of the fetal head. Wandering method is popular. The anterior (superior) blade is applied first. The blade is inserted along the side wall of the pelvis and then wandered by swinging it round the fetal face to its anterior position. The posterior blade is inserted directly under guidance of the right hand placed between the head and the hollow of the sacrum. The forceps handles are depressed down and the handle tips are brought into alignment to correct the asynclitism. The occiput is rotated anteriorly. Slight upward dislodgement of the head may facilitate rotation. The position is rechecked and traction is applied. Sitting on a low foot stool or kneeling is convenient for the operator. +LIMITATIONS: Because of complexity in the technique of its appli­ cation, one should be sufficiently trained before independent use. + + + +■ Eclampsia, severe pre-eclampsia. ■ Heart disease. +■ Previous history of cesarean section. ■ Postmaturity. +■ Low birth weight baby. +■ To curtail the painful second stage. ■ Patients under epidural analgesia. + +COMPLICATIONS: Fetal: Facial bruising, laceration, facial nerve palsy, skull fractures, intracranial hemorrhage. Maternal: Perinea! sulcus tear, complete perinea! tear. Deep mediolateral episiotomy is mandatory. +Piper forceps is a specialized forceps used to assist the deli­ ve1y of the aftercoming head of breech. It has a cephalic curve, English lock, reverse pelvic curve, long parallel shanks that permit the baby's body to rest against it during head delive1y. Snanks are long and parallel. +PROPHYLACTIC FORCEPS (ELECTIVE): This type of forceps operation was named after De Lee (1920). It refers to forceps delivery only to shorten the second stage of labor when maternal and/ or fetal complications are anticipated (Box 37.3). +It prevents possible fetal cerebral injury due to pres­ sure on the perineum and spares the mother from the strain of bearing down efforts. Prophylactic forceps should not be applied until the criteria of low forceps are fulfilled. +TRIAL FORCEPS: It is a tentative attempt of forceps delivery in a case of suspected midpelvic contraction with a preamble declaration of abandoning it in favor of cesarean section if moderate traction fails to overcome the resistance (Box 37.4). The procedure should be conducted in an operation theater keeping everything ready for cesarean section. The conduct of trial forceps requires great deal of skill and judgment. If moderate traction leads to progressive descent of the fetal head, the delivery is completed vaginally, if not cesarean section is done immediately. Many unnecessary cesarean sections or dificult vaginal deliveries can thus be avoided. + + +■ Maternal obesity (BMI 30). +■ Clinically big baby (weight 3 kg). ■ Occipitoposterior position. +■ Mid-cavity delivery. +■ When 1 /5th fetal head palpable per abdomen. + + + + + + + + + + +Figs. 37.15A and B: (A} Kielland's forceps; (B} Piper forceps. +Chapter 37: Operative Obstetrics ii +I COMPLICATIONS OF FORCEPS OPERATION + +■ Incompletely dilated cervix. ■ Short maternal height. +■ Unrotated occipitoposterior position. ■ Cephalopelvic disproportion. +■ Unrecognized malpresentation (brow) or hydrocephalus. ■ Constriction ring. +■ Clinically big baby ( 4 kg). ■ Maternal BMI 30. +■ In a case with mid-cavity delivery. + + +Table 37 .S: Complications of Forceps Operation. Maternal Fetal Immediate Immediate +■ Injury: Vaginal laceration or sulcus tear, ■ Facial and scalp +cervical tear, extension of episiotomy to lacerations. +involve the vaginal vault, Obstetric Anal ■ lntracranial +Sphincter Injury (OASI) 10%. hemorrhage +■ Nerve injury: Femoral (L2, 3, 4), (rupture of the lumbosacral trunk (L4, 5) with midforceps great vein of +delivery. Galen). +■ Postpartum hemorrhage may be-(i) ■ Asphyxia +■ Cephalhematoma +(more with +vacuum), facial +palsy, skull +fractures, cervical +Traumatic or (ii) Atonic, requiring blood +transfusion or (iii) Both, may cause shock. ■ Anesthetic complications (following local +or general anesthesia). +■ Puerperal sepsis and maternal morbidity spine injury +■ +Risk of VTE (score 1). (rotational forceps). +■ Jaundice Remote Remote +Painful perinea! scars, Dyspareunia, Low Cerebral or spastic backache, Genital prolapse, Stress Urinary palsy due to residual Incontinence, Urinary retention and Anal cerebral injury (rare). +Sphincter Dysfunction. + +FAILED FORCEPS: When a deliberate attempt in vaginal delivery with forceps has failed to expedite the process, it is called failed forceps. It is often due to poor clinical judgment and skill. Failure in the operative delivery may be due to improper application (Box 37.5). +Prevention: It is a preventable condition. Only through skill and judgment, proper selection of the case ideal for forceps can be identified. Even if applied in wrong cases, one should resist the temptation to give forcible traction in an attempt to hide the mistake. +Management +1. To assess the effect on the mother and the fetus. +2. To start a Ringer's solution drip and to arrange for blood transfusion, if required. +3. To administer parenteral antibiotic. 4. To exclude rupture of the uterus. +5. The procedure is abandoned and delivery is done by cesarean section. +6. Laparotomy should be done in a case with rupture of uterus. + + +The complications of the forceps operation are mostly related to the faulty technique and to the indication for which the forceps are applied rather than the instrument. The complications are grouped into (Table 37.5): +♦ Maternal ♦ Fetal + +VENTOUSE + +Ventouse is an instrumental device designed to assist delivery by creating a vacuum between the cup and the fetal scalp. The pulling force is dragging the cranium while, in forceps, the pulling force is directly transmitted to the base of the skull. +INSTRUMENTS: Ever since Tage Malmstrom, in 1953, introduced and popularized its use, various modifications of the instruments are now available. Each, however, consists of the following basic components {Figs. 37.16A to C): +Metal cups were initially used. Soft cups (Bell-shaped), silicone cup [silicone rubber or disposable plastic (Mityvac)} cups have better adherence to the fetal scalp. These cups could be folded and introduced into the vagina without much discomfort. Silastic cup causes less scalp trauma and there is no chignon formation. The mushroom shaped cups are a hybrid of stainless steel and plastic devices {KIWI Omnicup). This cup can be placed on the flexion point in an asynchitic head {OP position). It is safe, effective and is useful for rotational delive1y (Table 37.6). +The cup is connected to a pump through a thick-walled rubber tube by which air is evacuated. Vacuum is created by a hand pump or by electric pump. The parts of the device are: +1. Suction cups with four sizes (30 mm, 40 mm, 50 mm and60mm). +2. A vacuum generator. +3. Traction tubings {Figs. 37.16A to C). +INDICATIONS of ventouse delivery are the same as those of forceps (Table 37 .2). + +PROCEDURE +Preliminaries: The procedures to be taken are mentioned on p. 525. Pudenda! block or perinea! infiltration with 1 % lignocaine is sufficient. It may be applied even without anesthesia especially in parous women. The instrument should be assembled and the vacuum is tested prior to its application. +Step I: Application of the cup: The largest possible cup is to be selected. The cup is introduced after retraction of the perineum with two fingers of the other hand. The cup is placed against the fetal head nearer the occiput (flexion point) with the 'knob' of the cup pointing towards the occiput. Flexion or pivot point is an imaginary site located midsagittally about 6 cm from the center of the anterior fontanel or about 3 cm in front of the posterior fontanel. Traction over this flexion point either by ventouse or forceps facilitates flexion and presents +Chapter 37: Operative Obstetrics + + +- Manometer +(kg/cm2) + + + + + +Pump + + + + + +t1 +Figs. 37.16A to C: (A) Malmstrom device; (BJ Mityvac pump with tube and soft cup; (CJ Kiwi vacuum devices with the flexible stem and hand-held pumps pressure gauze device. + + +Table 37 .6: Advantages of individual Instrument (Forceps or Ventouse) delivery, one over the other. + + +Agvantages of ventouse over forceps +■ It can be used in unrotated or malrotated head (OP, OT position). It helps in autorotation. +■ It is not a space-occupying device like the forceps blades. ■ Traction force is less (10 kg) compared to forceps. +■ It is comfortable and has lower rates of maternal trauma and genital tract lacerations. +■ Analgesia need is less. Pudenda! block with perinea! infiltration is adequate but for forceps regional or general +anesthesia is often needed. +■ Reduced maternal pelvic floor injuries and is advocated as the instrument of first choice. +■ Perinea! injury (3rd and 4th degree tears) are less compared to forceps. +■ Postpartum maternal discomfort (pain) are less compared to forceps. +■ Easier to learn comparing to forceps. +■ Simplicity of use in delivery makes it convenient to the operator (suitable for trained midwives). + + +Advantages of forceps over ventouse +♦ In cases, where moderate traction is required, forceps will be more effective compared to ventouse. +♦ Forceps operation can quickly expedite the delivery in case of fetal distress where ventouse will be unsuitable as it takes longer time. ++ It is safer at any gestational age baby (even <36 weeks). The fetal head remains inside the protective cage. +♦ It can be employed in anterior face or in aftercoming head of breech presentation where ventouse is contraindicated. ++ Lesser neonatal scalp trauma, retinal hemorrhage, jaundice or cephalhematoma compared to ventouse. ++ Higher rate of successful vaginal delivery as ventouse has got higher failure rates than forceps. +♦ Cup detachment (pop-off) occurs when the vacuum is not maintained in ventouse. No such problems once forceps blades are correctly applied. +♦ Different types of forceps are available for outlet, mid-cavity or rotational delivery. Traction force is more (about 20 kg for a primary and about 13 kg in a multigravida). + + + + +the smaller diameter to the pelvis (Fig. 37.17). The knob indicates the degree of rotation. Betadine (antiseptic) solution is applied to the rim of the malstrom metal cup. +A rapid negative pressure (compared to stepwise increment) of 0.2 kg/cm2 is induced by the pump slowly, taking at least 2 minutes. A check is made using the fingers round the cup to ensure that no cervical or vaginal tissue is trapped inside the cup. Alternatively the pressure is gradually raised at the rate of 0.1 kg/cm2 per minute (76 mm Hg) until the effective vacuum of 0.8 kg/cm2 (608 mm Hg) is achieved in about 10 minutes time. Negative pressure can be created within 2 minutes without any adverse effects. The scalp is sucked into the cup and an artificial caputsuccedaneum (chignon) is produced. The chignon usually disappears within few hours. +Step II: Traction-Practical guides are (Figs. 37.18A to C): + +♦ Traction is released in between uterine contractions and maternal pushing efforts. +♦ Traction should be made using one hand along the axis of the birth canal. The fingers of the other hand are to be placed against the cup to note the correct angle of traction, rotation and advancement of the head. +♦ Operative vaginal delivery (forceps/ventouse) should be abandoned where there is no descent of the presenting part with each pull or when delivery is not imminent after three pulls (3) with correctly applied instruments by an experienced operator. +♦ Traction between contractions should be avoided. Traction in the absence of maternal pushing needs increased force and increases the risk of cup detachment. It is advised to complete the delivery in 3 to 4 uterine contractions. + + + +♦ Traction must be at right angle to the cup. +♦ Traction should be synchronous with the uterine contractions. + + +♦ Twisting or Rocking the vacuum cup to facilitate descent of the fetal head is not recommended as it increases the +Chapter 37: Operative Obstetrics ED .... + + + + + + --- -Anterior fontanel + +a Any presentation other than vertex (face, brow, breech). +■ Preterm fetus (<32 weeks) chance of cephalhematoma, intracra­ nial hemorrhage, subg/ea/ hemorrhage or neonatal jaundice. +11 Suspected fetal coagulation disorder. +■ Suspected fetal macrosomia (:.4 kg). + + + + + + +:: +-;-- - --t- Flexion or pivot point + +■ Unengaged fetal head. +11 Obvious CPD. +■ Prerequisites for operative vaginal delivery not fulfilled (Table + + + + +3cm ■ + +37.4). +Fetus having an acute bleeding diathesis (hemophilia). + +<-- 9' -- Posterior 11 Patient's refusal; ■ Inexperienced operator. fontanel + +Fig. 37.17: Ventouse cup should be placed on the flexion or pivot point (Figs. 37.18A to C). + +risk of scalp laceration, intracranial hemorrhage and cup detachment. +♦ Correct application and traction and to maintain descent flexion and autorotation. +♦ Vacuum delivery: Completed by: 3 pulls (3 additional to ease head out of the perineum); Discontinue after: 2 pop off's. +♦ Repeated detachment (POP-offs) of the cup (:.2) during traction indicates evaluation of the site of application, direction of pull, maternal pelvis (Boxes 37.6 and 37.7). +♦ As soon as the head is delivered, the vacuum is reduced by opening the screw-release valve and the cup is then detached. +The delivery is then completed in the normal way. + +COMPLICATIONS: Neonate: 1. Superficial scalp abrasion. 2. Sloughing of the scalp. +3. Cephalhematoma-due to rupture of emissary veins beneath the periosteum. Usually, it resolves by 1 or 2 weeks. +4. Subaponeurotic (subgalea]) hemorrhage (not limited by suture line as it is not subperiosteal). +5. Intracranial hemorrhage (rare). +6. Retinal hemorrhage (no long-term effect). 7. Jaundice: +■ Vacuum extraction is considered a trial and may fail at +achieving vaginal birth. +■ Maternal (Obstetric) Anal Sphincter (OASI) perinea!, +vaginal, injury are less compared to forceps (19-12%). + + + + + + + + + + + +Silicon cup Suction cup (hybrid) 'Chignon' (schematic) 'Chignon' (dotted line) + + + + + + + + + + + +Figs. 37.18A to C: Application of vacuum extractor (A to C) indicating the directions of traction at different stations of the fetal head. Traction over this flexion or pivot point either by ventouse or forceps promotes flexion and presents smaller diameter to the pelvis (Fig. 37 .17). +ID Chapter 37: Operative Obstetrics +Maternal: The injuries are uncommon but may be due to inclusion of the soft tissues, such as the cervix or vaginal wall inside the cup. However, failure rate is high. The sequential use of ventouse and forceps increases the risk of trauma both to the mother and the neonate. Outlet forceps may be used following failure ofventouse. +SUMMARY: Ventouse is an instrument designed to assist delive1y by creating vacuum between it and fetal scalp. The instrument, as deviced by Malmstrom, consists of: +1. Suction cup. +2. Vacuum generator. +3. Traction tubing device. +Silicon cups are found more convenient. The indications are same as those of forceps except that it cannot be employed in face or after coming head of breech. Vacuum: Causes lower rates of maternal trauma and genital tract lacerations, but causes more neonatal scalp trauma and cephalhematoma compared to forceps. Both the instruments (ventouse and forceps) are not inherently dangerous. The operator must have knowledge, experience and skill to use and also the willingness to abandon the procedure when felt difficult. All operative vaginal delivery procedures should be considered as a trial. +The rate of Obstetric Anal Sphincter Injury (OAS!) may be higher in forceps delivery. The risk of fetal injury associated with instrumental vaginal delivery is instrument specific. The sequential use of ventouse and forceps increases the risk of injury both to the mother and the neonate. This should be avoided. +Benefits and risks of operative vaginal delivery +Benefits: Most women desire a vaginal delivery. Safe and effective use of instrumental delivery fulfills women's desire and satisfaction. Many women (79%) have subsequent spontaneous vaginal delivery compared with women delivered by cesarean section (39%). +Maternal risks: +1. Perinea! trauma: Third or fourth degree perinea! injury is associated with primiparity, macrosomia, shoulder dystocia, prolonged pregnancy and operative vaginal delivery. +2. Urinary retention: Risk of retention is present. A post void residual should be documented. An indwelling catheter for 6-12 hours to relief retention especially following epidural is a good practice. +3. Urinary incontinence: Compared to spontaneous, vaginal delivery, urinary incontinence is not high following forceps or venture delivery. +4. Fecal incontinence: Operative vaginal delivery is associated with increased risk of perinea! injury (third and fourth degree lacerations). Long-term data as regard fecal incontinence is debated. +5. Infection: A single prophylactic dose of amoxicillin and clavulanic acid is recommended. Good standards of hygiene and asepsis is maintained. +Fetal risks: Forceps, Ventouse. +Vacuum: Retinal hemorrhages (twice to that of forceps). Forceps protects against neurologic injury. + + + + +VERSION +DEFINITION: It is a manipulative procedure designed to change the lie or to bring the comparatively favorable pole to the lower pole of the uterus. +TYPES: According to the methods employed: +♦ Spontaneous ♦ External ♦ Internal ♦ Bipolar +Spontaneous: Version process occurs spontaneously. The incidence of spontaneous version in breech presentation is nearly 55% after 32 weeks and about 8% after 36 weeks. It is more common in multiparous women. +External: The maneuver is done solely by external manipulation. +Internal: The conversion is done principally by one hand introducing into the uterus and by the other hand on the abdomen. +Bipolar (Braxton-Hicks): The conversion is done introducing one or two fingers through the cervix and by the other hand on the abdomen. +Manipulations are done through the abdominal wall. When an oblique or transverse lie is changed into longitudinal lie and the presentation is made cephalic it is called External Cephalic Version. When the manipulations are made inside the uterine cavity to make a breech presentation it is known as Internal Podalic Version. +I EXTERNAL CEPHALIC VERSION External Cephalic Version (ECV) is done to bring the favorable cephalic pole in the lower pole of the uterus. +INDICATIONS +♦ Breech presentation ♦ Transverse lie +Selection of time, contraindication, difficulties and complications have already been described. +The advantages of ECV at term are: (i) By this time spontaneous version will occur in many cases; (ii) If any complications occur during ECV, prompt delivery could +be done by cesarean section as the baby is at term. Success rate of BCV in general is 60%. Use of tocolytics (ritodrine) increases the success rate. +Benefits of ECV: (i) Reduces the incidence of breech presentation at term and of breech delivery, (ii) Reduces the number of cesarean delivery by 50%, (iii) Reduces maternal morbidity due to cesarean or vaginal breech delivery, and (iv) Reduces the fetal hazards of vaginal breech delive1y. + +PROCEDURES: In breech presentation-the maneuver is carried out at 36 weeks in primi and 37 weeks in a multigravida in the labor delivery complex. Tocolytic drug (terbutaline-0.25 mg SC), if required, can be +Chapter 37: Operative Obstetrics + + + + + + + + + + + + +rn + + + + + + + + + + + + +!J +Figs. 37.19A to D: Steps of External Cephalic Version (breech-LSA): (A) Mobilization of the buttocks to the iliac fossa towards the back using both hands; (Bl Rotation of the trunk holding the poles and maintaining flexion of the trunk; (C) Change of hands to prevent crossing after the lie becomes transverse; (D) The lie becomes longitudinal with the cephalic pole being brought to the lower pole of the uterus. + + +administered. Real-time ultrasound examination is done to confirm the diagnosis and adequacy of amniotic fluid volume. Uterine anomalies to be ruled out. A reactive NST should precede the maneuver. +Preliminaries: Informed consent is taken. The patient is asked to empty her bladder. She is to lie on her back with the shoulders slightly raised and the thighs slightly flexed. Abdomen is fully exposed. The presentation, position of the back and limbs are checked and FHR is auscultated. +Actual steps: 'Forward roll' movement. +Step I (Figs. 37.19A to D): The breech is mobilized using both hands to one iliac fossa towards which the back of the fetus lies. The podalic pole is grasped by the right hand in a manner like that of Pawlik's grip while the head is grasped by the left hand. +Step II: The pressure (firm but not forcible) is now exerted to the head and the breech in the opposite directions to keep the trunk well flexed which facilitates version. The pressure should be intermittent to push the head down towards the pelvis and the breech towards the fundus until the lie becomes transverse. The FHR is once more to be checked. + +Fetal wellbeing is monitored intermittentity with Doppler or real-time ultrasound scanning. The procedure is abandoned in case of any significant fetal distress. The procedure is not to be attempted more then 4 times. + +Tocolysis (ritodrine or terbutatine may be used). Epidural analgesia has also been used. Moxibuston (Chinese medicine) increases fetal movements and promote spontaneous version to breech. +Step III: The hand is now changed one after the other to hold the fetal poles to prevent crossing of the hand. The intermittent pressure is exerted till the head is brought to the lower pole of the uterus. +A reactive NST should be obtained after completing the procedure. There may be undue bradycardia due to head compression which is expected to settle down by 10 minutes. If, however, fetal bradycardia persists, the possibility of cord entanglement should be kept in mind and in such cases reversion may have to be considered. The patient is to be observed for about 30 minutes: (I) To allow the FHR to settle down to normal; and (2) To note for any vaginal bleeding or evidence of premature rupture of the membranes. + +INSTRUCTIONS: (1) The patient is advised for follow-up to check the corrected position; (2) To report to the physician if there is vaginal bleeding or escape of liquor amnii or labor starts and (3) Rh-negative nonimmunized women must be protected by intramuscular administration of 100 µg anti-D gammaglobulin. +EXTERNAL VERSION IN TRANSVERSE LIE: The version is much easier than in breech. The association of placenta + -=·· Ei Chapter 37: Operative Obstetrics + +previa or congenital malformation of the uterus should be excluded. +EXTERNAL PODALIC VERSION: The external podalic version may be done in cases when the external cephalic version fails in transverse lie in case of the second baby of twins. + +I INTERNAL VERSION +Internal version is always a podalic version and is almost always completed with the extraction of the fetus. +INDICATIONS: Internal version is hardly indicated in a singleton pregnancy in present day obstetric practice. Its only indication being the transverse lie in case of the second baby of twins. +However, it may be employed in singleton pregnancy to expedite delivery in adverse conditions where the cesarean section facilities are lacking. Such conditions are: (1) Transverse lie with cervix fully dilated, and (2) Cord prolapse with cervix fully dilated with transverse lie or head high up and the baby is alive. +CONDITIONS TO BE FULFILLED: (I) The cervix must be fully dilated, (2) Liquor amnii must be adequate for intrauterine fetal manipulation, and (3) Fetus must be living. +CONTRAINDICATION: It must not be attempted in negle­ cted obstructed labor even if the baby is living. + +PROCEDURES: Assessment of the lie, presentation and FHR is made by an experienced obstetrician by abdominal palpation, vaginal examination and/or transabdominal ultrasound examination. Close (continuous) FHR monitoring is essential. The steps are to be followed as mentioned earlier. Internal version should be done under general or epidural anesthesia. Actual steps (Figs. 37.20A and B): +Step I: Patient is placed in dorsal lithotomy position. Antiseptic cleaning, drapings and catheterization are done. Introduction of the hand-if the podalic pole of the fetus is on the left side of the mother, the right hand is to be introduced and vice versa. The hand is to be introduced in a cone-shaped manner. It is then pushed up into the uterine cavity keeping the back of the hand against the uterine wall until the hand reaches the podalic pole. +Step II: The hand is to pass up to the breech and then along the thigh until a foot is grasped. The identification of the foot is done by palpation of the heel. It is advantageous to grasp the first foot which one encounters. +Step Ill: While the leg is brought down by a steady traction, the cephalic pole is pushed up using the external hand. +Step IV: After one leg is brought down, there is no difficulty to deliver the other leg. The delivery is usually completed with breech extraction during uterine contractions. +Step V: Routine exploration of the uterovaginal canal to exclude rupture of the uterus or any other injury. + +COMPLICATIONS: Maternal risk includes placental abruption, rupture of the uterus and increased morbidity. The fetal risk includes asphyxia, cord prolapse and + + + + + + + + + + + + + + + + + + + + + + + + + + +Figs. 37.20A and B: Principal steps of Internal Podalic Version: (A) To introduce the right hand to grasp the upper leg in dorsoanterior position with the head lying on the right iliac fossa; (Bl To give traction on the leg gripping in a cigarette holding fashion, the other hand pushes up the head externally. + +intracranial hemorrhage apart from all hazards of breech delivery leading to a high perinatal mortality of about 50%. + +CESAREAN DELIVERY (CD) +DEFINITION: It is an operative procedure !l !l whereby the fetuses after the end of 28th +_ +_ +weeks are delivered through an incision +!I +on the abdominal and uterine walls. This ' · excludes delivery through an abdominal incision where the fetus lying free in the abdominal cavity following uterine rupture or in secondary abdominal pregnancy. The first operation performed on a patient is referred to as a primary cesarean section. When the operation is performed in subsequent pregnancies, it is called repeat cesarean section. +Nomenclature and history: Amidst controversy, it appears that the operation derives its name from the notification 'lex Cesarea' -a Roman law promulgated in 715 BC which was continued even during Caesar's reign. The law provided either an abdominal delivery in a dying woman with a hope to get a live baby or to perform postmortem abdominal delivery for separate burial. The operation does not derive its name from the birth of Caesar, as his mother lived long time after his birth. The other explanation is that the word cesarean is derived from the Latin +Chapter 37: Operative Obstetrics + + + +♦ Rising incidence of primary cesarean delivery. ++ Identification of at-risk fetuses before term (FGR). ++ Identification of high-risk pregnancy (hypertension). + Wider use of repeat CS withoutTOLAC. ++ Rising rates of induction of labor and failure of induction. ++ Decline in operative vaginal (forceps, vacuum) delivery. + + ++ Decline in assisted vaginal breech delivery (malpresentation). ++ Increased number of women with age >35 years and associated medical complications (diabetes, heart disease). ++ Wider use of electronic fetal monitoring and increased diagnosis of fetal distress. ++ Fear of litigation in obstetric practice (medicolegal issue). ++ Cesarean delivery on maternal request. + + + +Verb 'Cedere' which means 'to cut'. French obstetrician, Francois Mauriceau first reported cesarean section in 1668. In 1876, Porro performed subtotal hysterectomy. It was Max Sanger in 1882, who first sutured the uterine walls. In 1907, Frank described the extraperitoneal operation. Kronig in 1912, introduced lower segment vertical incision and it was popularized by De _Lee (1922). Although Kehrer in 1881 did the transverse lower segment operation for the first time, Munro Kerr in 1926 not only reintroduced the present technique of lower segment operation +but also popularized it. + +INCIDENCE: The incidence of cesarean section is steadily rising. During the last decade there has been two-to­ threefold rise in the incidence from the initial rate of about 10%. The incidence of CD between 10% and 15% is optimum for maternal and perinatal health (WHO). Apart from increased safety of the operation due to improved anesthesia, availability of blood transfusion and antibiotics, the other responsible factors are (Box 37.8). +I INDICATIONS +Indications for cesarean delivery: Cesarean delivery is done when delivery is indicated but labor contraindicated or not inducible ( central placenta previa) and/ or vaginal delivery is found unsafe for the fetus and/ or mother. + + +The indications are broadly divided into two categories (Box 37.9). +♦ Absolute ♦ Relative (common) + +TIME OF OPERATION ♦ Elective +♦ Emergency (Category l, 2 and 3) +Elective: When the operation is done at a prearranged time during pregnancy to ensure the best quality of obstetrics, anesthesia, neonatal resuscitation and nursing services. +Time +a. Maturity is certain: The operation is done about 1 week prior to the expected date of confinement. +b. Maturity is uncertain: Ultrasound assessment in first or second trimesters if available is corroborated. Amniocentesis for L:S ratio is used to ensure fetal maturity. Otherwise spontaneous onset of labor is awaited and then CS is done. +Factors reducing CS rate: (a) Support during labor; (b) Induction of labor at 40 weeks or more; (c) Main­ taining partograph; (d) No CTG for low risk women; (e) Membrane sweeping. + + + +Absolute indications (labo rContra indic ated) Relative indications +Vaginal delivery is not possible. Cesarean is needed even with a Vaginal delivery may be possible but risks to the mother and/or baby dead fetus. are high +Indications are few: (More often multiple factors may be responsible). ■ Central placenta previa + Cephalopelvic disproportion (relative). +■ Contracted pelvis or cephalopelvic disproportion (absolute) + Previous cesarean delivery-{a) When primary CS was due to +,. Pelvic mass causing obstruction (cervical or broad ligament recurrent indication (contracted pelvis), (b) Previous two CS, +fibroid) {c) Features of scar dehiscence, (d) Previous classical CS. ++ Non-reassuring FHR (fetal distress). +Advanced carcinoma cervix +■ Vaginal obstruction (atresia, stenosis) +11 + Dystocia may be due to (three Ps) relatively large fetus (passenger), +small pelvis (passage) or inefficient uterine contractions (power) +m +o +n +_ +, +_ +· +_ +_ +_ +a +t +_ +_ +_ +_ +_ +c +t +i +_ +o +_ +_ +_ +_ +e +_ +_ +_ +,_com_ __ ndic _ ions__fcsare _an_se __on _______ , + Antepartum hemorrhage: (a) Placenta previa and (b) Abruptio +_ +Primigravidae: placentae. +1. Failed induction ♦ Malpresentation: Breech, shoulder (transverse lie), brow. +2. Fetal distress (nonreassuring fetal FHR) ♦ Failed surgical induction of labor, failure to progress in labor. 3. Cephalopelvic Disproportion (CPD) ♦ Bad obstetric history-with recurrent fetal loss. +4. Dystocia (dysfunctional labor), nonprogress of labor ♦ Hypertensive disorders: {a) Severe pre-eclampsia, (b) Eclampsia- +5. Malposition and malpresentation (occipitoposterior, breech). uncontrolled fits even with antiseizure therapy. +6. On maternal request + Medical-gynecological disorders: {a) Diabetes (uncontrolled), heart +disease (coarctation of aorta, Marfan's syndrome); (bl Mechanical obstruction due to benign or malignant pelvic tumors (carcinoma +Mutigravidae: +1. Previous cesarean delivery +2. Antepartum hemorrhage (placenta previa, placental abruption) cervix), or following repair of vesicovaginal fistula. 3. Malpresentation (breech, transverse lie) +• On maternal request +········&I Chapter 37: Operative Obstetrics + +Benefits and risks of elective operation: Reduction in perinatal morbidity and mortality as there is no hazard from labor and delivery process. Maternal benefits: No pelvic floor dysfunction (Table 37.7). +Maternal risks are: Longer recovery time and hospital stay. Risks of placenta previa and hysterectomy are more in subsequent delivery. +Category of CS (NICE): Emergency: When the operation is to be done due to an acute obstetric emergency (fetal distress). A time interval of 30 minutes between the decision and delivery is taken as reasonable. +Category 1: When there is immediate threat to the +life of the woman or the fetus. Decision delivery interval should be 30 minutes. +Category 2: When there is maternal or fetal compro­ mise which is not immediately life-threatening. CS should be done within 75 minutes of making decision. +Category 3: There is no maternal or fetal compromise but needs early delivery. +Category 4: Delive1y is planned to suit the woman, family members and the hospital staff. Planned CS after 39 weeks to J, RDS; if <39 weeks, steroid therapy is given. + +TYPES OF OPERATIONS ♦ Lower segment +♦ Classical or upper segment +Lower Segment Cesarean Section (LSCS): In this operation, the extraction of the baby is done through an incision made in the lower segment through a transperitoneal approach. It is the only method practiced in present-day obstetrics and unless specified, cesarean section means lower segment operation. The operation done through an extraperitoneal approach to the lower segment in infected cases is obsolete. +Classical: In this operation, the baby is extracted through an incision made in the upper segment of the uterus. Its indications in present day obstetrics are very much limited and the operation is only done under forced circumstances, such as: +♦ Lower segment approach is difficult: (1) Dense adhesions due to previous abdominal operation; (2) Severe contracted pelvis (osteomalacic or rachitic) with pendulous abdomen. + +♦ Lower segment approach is risky: (1) Big fibroid on the lower segment-blood loss is more and contemplating myomectomy may end in hysterectomy; (2) Carcinoma cervix-to prevent dissemination of the growth and postoperative sepsis; (3) Repair of high WF; (4) Complete anterior placenta previa with engorged vessels in the lower segment-risk of hemorrhage. +♦ Periml'tem cesarean section: It is done to have a live baby (rare). Perimortem section is an extreme emergency procedure. Classical section is done in a woman who has suffered a cardiac arrest. The infant may survive if delivery is done within 5 minutes of maternal death. + +■ LOWER SEGMENT CESAREAN SECTION + +PREOPERATIVE PREPARATION +Informed written permission for the procedure, anesthesia and blood transfusion is obtained. +■ Abdomen is scrubbed with soap. Hair may be clipped. ■ No premedicative sedative is given. +■ Nonparticulate antacid (0.3 molar sodium citrate, 30 mL) is given orally before transferring the patient to theater. It is given to neutralize the existing gastric acid. +■ Ranitidine (H2 blocker) 150 mg is given orally night before (elective procedure) and it is repeated (50 mg IM or IV) 1 hour before the surgery to raise the gastric pH. +■ The stomach should be emptied, if necessary, by a stomach tube (emergency procedure). +■ Metoclopramide (10 mg IV) is given to increase the tone of the lower esophageal sphincter as well as to reduce the stomach contents. It is administered after about 3 minutes of preoxygenation in the theater. +■ Intraoperative: Catheterization is not mandatory. If done, may be removed after the operation. +■ FHS should be checked once more at this stage. +■ Neonatologist should be present. +■ Cross-match blood when above average blood loss (placenta previa, prior multiple cesarean delivery) is anticipated. +■ Prophylactic antibiotic is given (IV) one hour before making the skin incision. It reduces postopoerative + + + +Table 37 .7: Benefits and risks of Cesarean Delivery. Benefits +■ .. Traumatic injury to the genital tract. ■ .. Perinatal morbidity and mortality. +■ .. Anxiety and stress of labor and the time. ■ .. Injury to the pelvic floor muscles resulting +.. prolapse .. fecal or urinary incontinence. ■ .. Postpartum hemorrhage. + + +Risks +■ t Hospital stay. +t +■ Maternal morbidity. +■ t Need of blood transfusion. +■ t Risk of thromboembolism. +■ t Neonatal respiratory distress (RDS). +■ t Risk of placenta accreta syndrome (PAS) need for cesarean +delivery and need for hysterectomy. + + +endomyometritis and wound infection. Single dose therapy with first generation cephalosporin (cefazolin) or ampicillin is effective. +■ Thromboprophylaxis (depending on risk factors): To use mechanical graduated compression stockings or a pneumatic compression device during and after CD. +♦ IV cannula: Sited to administer fluids (Ringer's solution). +♦ Position of the patient: The patient is placed in the dorsal position with a lateral tilt to minimize vena caval compression. A 15° lateral tilt to her left using a wedge till delivery of the baby should be done. +♦ Anesthesia: It may be spinal, epidural or general. However, choice of the patient and urgency of delivery are also considered. +♦ Antiseptic painting: The abdomen is painted with 7.5% povidone-iodine solution or with chlorhexidine alcohol and is properly draped (nonadhesive) with sterile towels. +♦ Incision on the abdomen: The surgeon may choose either a vertical or a transverse skin incision. Vertical incision may be infraumbilical midline or parame­ dian. Transverse incision, modified Pfannenstiel is made 3 cm above the symphysis pubis. Transverse incision has certain benefits (Table 37.8). The rectus sheath is incised, the rectus muscles are retracted laterally. The posterior rectus sheath and peritoneum are now dissected. It can be done bluntly using fingers to enter the peritoneal cavity. This avoids any injury to the underlying bowels. Otherwise, peritoneum is opened up at a higher level to avoid bladder injury. Peritoneal cavity is opened. + +Chapter 37: Operative Obstetrics + +The Doyen's retractor (Fig. 42.14) is introduced. Introduction of Doyen's retractor and approach to the lower segment is done. +Uterine incision (Figs. 37.22A to E) +Peritoneal incision: The loose peritoneum of the uterovesical pouch is cut transversely across the lower segment with convexity downwards at about 1.25 cm (0.5'') below its firm attachment to the uterus. No dissection for bladder flap is done. +(a) Muscle incision (Figs. 37.22A to C): The most commonly used incision (90%) is low transverse. Advantages are: • ease of operation (Table 37.9); • no bladder dissection, • less blood loss, • easy to repair, • less adhesion formation, • less risk of scar rupture when trial (TOLAC) of labor is given for subsequent delivery. +(b) A small transverse incision is made in the midline by a scalpel until the membranes of the gestation sac are exposed. Two index fingers are then inserted through the small incision down to the membranes and the muscles of the lower segment are split transversely across the fibers. This method minimizes the blood loss but requires experience. Alternatively, the incision may be extended on either side using a curved scissors to make it a curved one of about 10 cm (4") in length, the concavity is directed upwards. +Other types of uterine incisions are (Figs. 37.21A to E): (a) Lower vertical-it may be extended upwards when needed. (b) Classical incision (upper segment). (c) 'J' incision-upward vertical extension of the initial transverse incision. (d) Inverted 'T' incision-upward extension from the mid-transverse incision. Indications of vertical uterine incision: (i) Lower segment poorly developed (26-28 weeks). (ii) Fetus with transverse lie with dorso inferio1; (iii) Anteriorly located myoma obstructing lower uterine segment, (v) When the placenta is anterior and previa and/or accreta. +Delivery of the head (Figs. 37.22D and E): The membranes are ruptured if still intact. The amniotic fluid is sucked out by + + +Table 37.8:Transverse abdominal incision (modified Pfannenstiel Incision). + +Advantages +■ Postoperative comfort is more. +■ Less interferance with postoperative respirations. +■ Fundus of the uterus can be better palpated during immediate postoperative period. +u Less chance of wound dehiscence. ■ Less chance of incisional hernia. +■ Cosmetic value. + +Disadvantages +■ Takes a little longer time and as such unsuitable in acute emergency situation. +■ Blood loss is slightly more. +■ Requires competency during repeat section. u Unsuitable for classical operation. + + + + + + + + + + + + +m +Figs. 37.21A to E: Uterine incisions for cesarean section; (A) Lower segments transverse; {B) Lower segment vertical; {C) 'J' incision; (D) Classical incision; (E) Inverted 'T' incision. +- Chapter 37: Operative Obstetrics + +Table 37.9: Merits and demerits of lower segment transverse over lower segment vertical incision. + +Parameters Extension of incision + +Bladder dissection Uterine closure Muscle apposition Reperitonization +lntraoperative bleeding Subsequent adhesions +Risk of scar rupture + + +Lower segment transverse +■ May occur to involve the +uterine vessels +• Minimal ■ Easy +■ Good +■ Complete ■ Less +■ Less +■ 0.S-1.0% + + +Lower segment vertical +• +May occur to involve the upper segment or downward the bladder. + +• More when extends inferiorly. ■ Difficult +■ Often imperfect ■ Often imperfect ■ More +■ More +■ 0.8-2% (risk of scar rupture in cases with Tor J shaped incision is 2-6%). + +Lower segment transverse incision: Wound healing is perfect and the scar is sound. This is due to: (a) Perfect muscle apposition; (b) Less wound hematoma; (c) Less gutter formation; and (d) Wound remains quiescent during healing. The risk of scar rupture is less. Choice of suture materials are +given in Ch. 42; p. 629. + + +continuous suction. The Doyen's retractor is removed. The head is delivered by hooking the head with the fingers which are carefully insinuated between the lower uterine flap and the head until the palm is placed below the head. The head is delivered by elevation and flexion using the palm to act as a fulcrum. As the head is drawn to the incision line, the assistant is to apply + + +pressure on the fundus. The head can also be delivered using one blade of Wrigley's forceps or ventouse. +Delivery of the trunk: After the delivery of the head and shoulders, intravenous oxytocin 10 units or methergine 0.2 mg is to be administered. The rest of the body is delivered slowly and the baby is placed in a tray placed in between the mother's thighs. + + + + + + + + + + + + + + + + +Fundal pressure + + +Fundal pressure + + + + + + + + + + +Ii +Figs. 37.22A to F: Steps of LSCS: (A) The loose peritoneum on the lower segment is cut transversely; (Bl A short incision is made +in the midline down to the membranes; (C) The incision of the lower segment is being enlarged using index finger of both hands; (D) Sagittal section showing insinuation of the fingers between the lower uterine flap and the fetal head until the posterior surface is reached; (E) Methods of delivery of the head; (F) Placenta is being delivered. +Chapter 37: Operative Obstetrics + + + + + + + + + + + + + + + +D +Figs. 37.22G to I: Steps of LSCS: (G) Inserting the continuous vicryl or chromic catgut (No. 'O') suture taking deeper muscles excluding +the decidua; (H) Similar method of continuous suture taking superficial muscles and fascia down to the first layer of suture; (I) Continuous peritoneal catgut suture (optional). + + +Delayed clamping of the cord (60-90 sec) is done. The cord is cut in between two clamps and the baby is handed over to the pediatrician. The Doyen's retractor is reintroduced. +The optimum interval between uterine incision and deli­ very should be less than 90 seconds. Interval >90 seconds are associated with poor Apgar scores. There is reflex uterine vasoconstriction following uterine incision and manipulation. IV oxytocin 10 JU in 500 mL crystalloid is given after the baby is delivered as a measure to prevent PPH. +Removal of the placenta and membranes (Figs. 37.22F): By this time, the placenta is separated spontaneously. The placenta is extracted by gentle traction on the cord with simultaneous pushing of the uterus towards the umbilicus per abdomen using the left hand (controlled cord traction). Routine manualremoval should not be done. Advantages of spontaneous placental separation are: Less blood loss and less risk of endometritis. The membranes are carefully removed preferably intact and even a small piece, if attached to the decidua should be removed using a dry gauze. Dilatation of the internal os is not required. Exploration of the uterine cavity is desirable. +Suture ofthe uterine wound (Figs. 37.22G to I): The suture of the uterine wound is done with the uterus keeping in the abdomen. Some, howeve1 prefer to eventrate the uterus prior to suture. The margins of the wound are picked up by Allis tissue forceps or Green-Armytage hemostatic clamps (four are required, one each for angle and one for each margin). The uterine incision is sutured in two layers. +Uterine suture: Commonly double layer closure is done. Single layer closure may done if the patient has completed her child bearing (concurrently bilateral tubal ligation is done). +First layer: The first stitch is placed on the far side in the lateral angle of the uterine incision and is tied. The suture material is No. 'O' chromic catgut or vicryl and the needle is round bodied. A continuous running suture taking deeper muscles excluding or including the decidua (very difficult to exclude) ensures effective apposition of the tissues; the stitch is ultimately tied after the suture includes the near end of the angle. +Second layer: A similar continuous suture is placed taking the superficial muscles and adjacent fascia overlapping the first layer + + +of suture. Uterine muscles may be closed using a continuous single layer stitch taking full thickness muscle and less decidua. +Double layer closure has reduced risk of scar rupture in subsequent pregnancy. +Nonclosure of visceral and parietal peritoneum is preferred. +Concluding part: The mops if placed inside are removed and the number verified. Peritoneal toileting is done and the blood clots are removed meticulously. The tubes and ovaries are examined. Doyen's retractor is removed. After being satisfied that the uterus is well contracted, the abdomen is closed in layers. The subcutaneousfat tissue is closed separately when the thickness is ?.2 cm. The skin may be closed using absorbable interrupted stitches or using a delayed absorbable subcuticular stitch or by metal staplers. The vagina is cleansed of blood clots and a sterile vulva! pad is placed. +I POSTOPERATIVE CARE First 24 hours: (Day O) +■ Observation for the first 6-8 hours is important. Periodic checkup of pulse, BP, amount of vaginal bleeding and behavior of the uterus (in low transverse incision) is done and recorded. +11 Fluid: Sodium chloride (0.9%) or Ringer's lactate drip is continued until at least 2.0-2.5 L of the solutions are infused. Blood transfusion is helpful in anemic mothers for a speedy postoperative recovery. Blood transfusion is required if the blood loss is more than average during the operation (average blood loss in cesarean section is approximately 0.5-1.0 L). +11 Oxytocics: Injection oxytocin 5 units IM or N (slow) or methergine 0.2 mg IM is given and may be repeated. +11 Prophylactic antibiotics ( cephalosporins, metroni­ dazole) for all cesarean delivery is given for 2-4 doses. Therapeutic antibiotic is given when indicated. +■ Analgesics in the form of pethidine hydrochloride 75-100 mg is administered and may have to be repeated. +ll Chapter 37: Operative Obstetrics + +Table 37.10: Merits and demerits of lower segment operation over classical. +Lower segment (transverse) Classical + +Techniques + + + + +Postopera-tive + + + + + + +Wound healing + + + + +During future pregnancy + + +■ Technically slight difficult. ■ Blood loss is less. +■ The wall is thin and as such apposition is perfect. ■ Perfect peritonization is possible. +■ Technical difficulty in placenta previa or transverse lie. +• Hemorrhage and shock-less. +■ Peritonitis is less even in infected uterus because of perfect peritonization and, if occurs, localized to pelvis. +■ Peritoneal adhesions and intestinal obstructions are less. ■ Convalescence is better. +■ Morbidity and mortality are much lower. + +The scar is better healed because of: +■ Perfect muscle apposition due to thin margins. ■ Minimal wound hematoma. +■ The wound remains quiescent during healing process. ■ Chance of gutter formation is unlikely. + + +Scar rupture is less 0.5-1.5% + +■ Technically easy. ■ Blood loss is least. +■ The wall is thick and apposition of the margins is imperfect. ■ Not possible. +■ Comparatively safer in such circumstances. +■ More +■ Chance of peritonitis is more in presence of uterine sepsis. ■ More because of imperfect peritonization. +■ Relatively delayed. +■ Morbidity and mortality are high. + +The scar is weak because of: +■ Imperfect muscle apposition because of thick margins. ■ More wound hematoma formation. +■ The wound is in a state of tension due to contraction and relaxation of the upper segment. As a result, the knots may slip or the sutures may become loose. +■ Chance of gutter formation on the inner aspect is more. +More risk of scar rupture 4-9% + + + + +■ Ambulation: The patient can sit on the bed or even get out of bed to evacuate the bladder, provided the general condition permits. She is encouraged to move her legs and ankles and to breathe deeply to minimize leg vein thrombosis and pulmonary embolism. +■ Thrombophophylaxis: Based on risk factors. +■ Baby is put to the breast for feeding after 3-4 hours or sooner, when mother is stable and relieved of pain. +Day 1: Oral feeding in the form of plain or electrolyte water or black tea may be given. Active bowel sounds are observed by the end of the day. +Day 2: Light solid diet of the patient's choice is given. Bowel care: 3-4 teaspoons of lactulose is given at bed time, if the bowels do not move spontaneously. +Day 5 or day 6: The abdominal skin stitches are to be removed on the D-5 (in transverse) or D-6 (in longitudinal). +Discharge: The patient is discharged on the day following removal of the stitches, if otherwise fit. Usual advices like those following vaginal delive1y are given. Depending on postoperative recovery and availability of care at home, patient may be discharged as early as third to as late as fifth postoperative days. + +I CLASSICAL CESAREAN SECTION +Indications: (a) Placenta previa; (b) Transverse lie; ( c) Preterm delivery where lower segment is poorly formed; (d) Dense adhesions limiting access to LUS; (e) + +Planned caserean hysterectomy; (f) PAS; (g) Perimortem CS. Uterine wound is closed in three layers. +This is relatively easy to perform (Table 37.10). Abdominal incision is always longitudinal (paramedian) and about 15 cm (6") in length, I/3rd of which extends above the umbilicus. A longitudinal incision of about 12.5 cm (5") is made on the midline of the anterior wall of the uterus starting from below the fundus. The incision is deepened along its entire length until the membranes are exposed which are punctured. In about 40% cases, the placenta is encountered. In such cases, fingers are slipped between the placenta and the uterine wall until the membranes are reached. The baby is delivered commonly as breech extraction. Intravenous oxytocin 5 IU IV (slow) or methergine 0.2 mg is administered following delive1y of the baby. The uterus is eventrated. The placenta is extracted by traction on the cord or removed manually. +Suture of the uterine incision: The uterus is sutured in three layers: +1. A continuous suture is placed with chromic catgut No. 'O' or vicryl taking deep muscles excluding the decidua. +2. A second layer of interrupted sutures (1 cm apart) using chromic catgut No. 'l' or vicryl taking the entire depth of superficial muscles down to the first layer of suture. +3. The third layer of continuous suture taking the serious coat with the adjacent muscles using chromic catgut No. 'O' and round-bodied needle. +The uterus is returned back into the abdominal cavity. Packings are removed; peritoneal toileting is done and the abdomen is closed in layers. + + +I COMPLICATIONS OF CESAREAN SECTION + +The complications are related either due to the: ■ Operations (inherent hazards), or due to +■ Anesthesia: The complications are grouped into: ♦ Maternal ♦ Fetal +The maternal complications may be: ■ Intraoperative +■ Postoperative + +I INTRAOPERATIVE COMPLICATIONS +♦ Extension of uterine incision to one or both the sides. This may involve the uterine vessels to cause severe hemorrhage, may lead to broad ligament hematoma formation. +♦ Uterine lacerations at the lower uterine incision-may extend laterally or inferiorly into the vagina. +♦ Bladder injury-is rare in a primary CS but may occur in a repeat procedure. Should a bladder injury occur, repair is done with a two-layer closure with 2-0 chromic catgut. Continuous bladder drainage is then maintained for 7-10 days. +♦ Ureteral injury is rare (1 in 1,000 procedures). Injury occurs during control of bleeding from lateral extensions. +♦ Gastrointestinal tract injury is rare unless there is prior pelvic/abdominal adhesions. +♦ Hemorrhage may be due to uterine atony or uterine lacerations. Medical management should be started. Surgical management is done where there are wound lacerations. Blood transfusion is needed. +♦ Morbid adherent placenta (placenta accreta) is commonly seen in cases with placenta previa who had prior cesarean delivery. Total hysterectomy (cesarean) is often needed for such a case to control hemorrhage. +I POSTOPERATIVE COMPLICATIONS MATERNAL: ♦ Immediate ♦ Remote +IMMEDIATE +■ Postpartum hemorrhage: The blood loss in cesarean section is more often underestimated. It is mostly related to uterine atony but blood coagulation disorders may rarely occur. +■ Shock: While most often it is related to the blood loss, it may occur when the operation is done following prolonged labor without correcting pre-existing dehydration and ketoacidosis. +■ Anesthetic hazards: These are mostly associated in emergency operations. The hazards are related to general anesthesia: aspiration of the gastric contents. The result may be aspiration atelectasis or aspiration pneumonitis (Mendelson's syndrome). Others are: (neuroaxial) Hypotension and spinal headache. + +Chapter 37: Operative Obstetrics gr· +■ Infections: The common sites are uterus ( endomyo­ metritis ), urinary tract, abdominal wound, peritoneal cavity (peritonitis) and lungs. Septic pelvic thrombo­ phlebitis may be associated with endometritis. Risk factors for infection are: Prolonged duration of labor and that of rupture of membranes, repeated number of vaginal examinations. Prophylactic antibiotics reduce the risk significantly. +■ Intestinal obstruction: The obstruction may be mech­ anical due to adhesions or bands, or paralytic ileus following peritonitis. +■ Deep vein thrombosis and thromboembolic disorders are more likely to occur following cesarean section than vaginal delivery. Septic thrombophlebitis is also a known complication. +■ Wound complications: Abdominal wound sepsis is quite common. The complications which are detected on removal of the skin stitches are: (1) sanguineous or frank pus, (2) hematoma, (3) dehiscence (peritoneal coat intact), ( 4) burst abdomen (involving the peritoneal coat), and (5) rarely necrotizing fasciitis. +■ Secondary postpartum hemorrhage. + +REMOTE COMPLICATIONS +■ Gynecological ■ General surgical ■ Future pregnancy +Gynecological: Menstrual excess or irregularities, chronic pelvic pain or backache. +General surgical: Incisional hernia, intestinal obstruction due to adhesions and bands. +Future pregnancy: There is risk of scar rupture. + +FETAL COMPLICATIONS: Iatrogenic prematurity and development of RDS is not uncommon following cesarean delivery. This is seen when fetal maturity is uncertain. Accidental scalpel injury to the baby may occur. + +MATERNAL AND PERINATAL MORTALITY: Maternal: Overall maternal mortality ranges between 6 to 22 per 100,000 procedure. But with adverse patient profile and suboptimal circumstances which are often interrelated, the maternal mortality ranges from 0.1 to 1%. The causes of death are: +1. Hemorrhage and shock. 2. Anesthetic hazards. +3. Infection. +4. Thromboembolic disorders. +Fetal: The perinatal mortality ranges from 5 to 10% and the deaths are mostly related to emergency operations and the complicating factors for which the operations are done. The causes of death are: (I) Asphyxia may be pre-existing, (2) RDS, (3) Pre-maturity, (4) Infection, (5) Intracranial hemorrhage-attempting breech delivery through a small incision. +:.. &J Chapter 37: Operative Obstetrics +i +Table 37 .11: Measures to reduce cesarean births. + +Cases with: +(AJ Fetal distress +♦ To confirm fetal acidosis by fetal scalp blood sampling +♦ Scalp stimulation as a means of assessing fetal acid-base status +(BJ vaginal birth aftercesarean section ♦ In selected cases VBAC is successful (CJ Amnioinfusion +♦ Management of cases with variable or early FHR deceleration due to oligohydramnios, meconium-stained liquor +♦ Amnioinfusion for repetitive variable fetal heart decelerations + + + + + +(PP: Primiparous; MP: Multiparous) + + +Safe prevention of cesarean delivery (ACOG-2014J + +Labor: Normal and dsystocia +1. Latent phase >20 hours in PP women and>14 hours in MP women is not dystocia and not an indication of CD. +2. First stage of labor +(a) Active phase of labor starts at 5 cm cervical dilatation. Before 5 cm dilatation CD is not indicated for dystocia. +(b) Active phase arrest is diagnosed at or beyond 5 cm with rupture membranes and failure of progress for 4 hours of adequate uterine contractions or 6 hours of oxytocin administration due to inadequate uterine activity. +3. Second stage of labor: Second stage to continue if maternal and fetal conditions permit: +(a) In MP women: 2 hours pushing and 3 hours in the second stage. (b) In PP women: 3 hours pushing and 4 hours in the second stage. Long duration may be appropriate in situations: epidural analgesia, malposition as long as progress is documented. (c) To perform other alternatives to CD: operative vaginal delivery in the second stage (forcesps/ventouse). +(d) Manual rotation in cases with OP and operative vaginal delivery. +4. Induction of labor to be considered at or after 39 weeks. It is done for a well selected case. 5. Breech presentation: Practice of ECV, assisted vaginal breech delivery-in selected cases. 6. Twin gestation: First twin is cephalic-vaginal delivery is an option. +7. Destructive operations: Craniotomy in a selected case of obstructed labor with hydrocephalus, dead or moribund fetus. + + + +Complications of cesarean section could be reduced to a great extent when the measures to reduce cesarean section are adopted (Table 37.11). +Extraperitoneal cesarean section was practiced in the past in cases with severe infection. Lower segment is approached extraperitoneally by dissecting through the space of Retzius. Currently, with the availability of potent antimicrobial agents, this is rarely performed. +Cesa1·ean hysterectomy: Cesarean hysterectomy refers to an operation where cesarean section is followed by removal of the uterus. The common condi­ tions are: +1. Morbid adherent placenta. +2. Atonic uterus and uncontrolled postpartum hemorrhage. +3. Big fibroid (parous women). +4. Extensive lacerations due to extension of tears with broad ligament hematoma. +5. Grossly infected uterus. 6. Ruptured uterus. +Peripartum hysterectomy is the surgical removal of the uterus either at the time of cesarean delivery or in the immediate postpartum period (even following vaginal delivery). Subtotal hysterectomy is commonly done as an emergency (unplanned) procedure. Benefits of subtotal hysterectomy are: Less operating time, less blood loss, less risk of injury to other organs (bladder, ureter) and less postoperative morbidity. +Pel"imortem cesarean delivery refers to the cesarean delivery of a woman who is expected to die within next few +moments or has just died. It is done within 4-5 minutes of start of Cardiopulmonary Resuscitation (CPR) when + + +the fetus is alive. Irreversible brain damage occurs by 4 to 6 minutes. The gravid uterus reduces venous returns and hence reduces cardiac output (CO) by 60% secondary to compression. So urgent delivery of the fetus and placenta improves venous return and CO. This also facilitates chest compression and improves ventilation. Maternal and fetal survival is 50%. Read more Dutta's Clinics in Obstetrics, Ch. 56. + +DESTRUCTIVE OPERATIONS +The destructive operations are designed to diminish the bulk of the fetus so as to facilitate easy delivery through the birth canal. In modern obstetric practice, virtually there is hardly any place for destructive operations. Neglected obstetrics requiring destructive operations are completely preventable. These procedures are difficult and may be dangerous too unless the operator is sufficiently skilled. Unfortunately, one may have to perform such operations while working in the unorganized sector. Some commonly performed operations are discussed here. There are four types of operations: +1. Craniotomy 2. Evisceration 3. Decapitation 4. Cleidotomy +I CRANIOTOMY +DEFINITION: It is an operation to make a perforation on the fetal head, to evacuate the contents followed by extraction of the fetus. +INDICATIONS +■ Cephalic presentation producing obstructed labor with dead fetus: This is the most common indication +Chapter 37: Operative Obstetrics + +Pressure by assistant +,r + + + + + + + + + + + + + + + + +Figs. 37.23A and B: (A) Perforation of the head while an assistant fixes the head suprapubically; (B) Separation of the blades by compression of the handle (for better display, the fingers of the left hand are removed). + + +of craniotomy in the referral hospitals of the developing Countries. +■ Hydrocephalus even in a living fetus: This is applicable both for the forecoming and the aftercoming head. +■ Interlocking head of twins. +CONDITIONS TO BE FULFILLED: (1) The cervix must be fully dilated, and (2) Baby must be dead (hydrocephalus being excluded). +CONTRAINDICATIONS: (i) The operation should not be done when the pelvis is severely contracted so as to shorten the true conjugate to less than 7.5 cm (3"). In such condition, the baby cannot be delivered, as the bimastoid diameter (base of the skull) of7.5 cm cannot be compressed. (ii) Rupture of the uterus where laparotomy is essential. +PROCEDURES: Preliminaries: The preliminary prepara­ tions are the same as mentioned above. The operation is to be done under general anesthesia. +Actual steps +Step I: The two fingers (index and middle) are introduced into the vagina and the finger tips are to be placed on proposed site of perforation. However, when the suture line cannot be defined because of big caput, the perforation should be done through the dependent part. +Sites of perforation: Vertex: On the parietal bone either side of the sagittal suture. Suture is avoided to prevent collapse of the bone thereby preventing escape of the brain matter. Face: Through the orbit or hard palate. Brow: Through the frontal bone. +Step II: The Oldham's perforator (Fig. 42.33) with the blades closed is introduced under the palmar aspect of the fingers protecting the anterior vaginal wall and the adjacent bladder (as shown in Figures 37.23A and B) until the tip reaches the proposed site of perforation. +Step Ill: By rotating movements, the skull is perforated. During this step, an assistant is asked to steady the head per abdomen in a manner of first pelvic grip. After the skull is perforated, + +the instrument is thrust up to the shoulders and the handles are approximated so as to allow separation of the sharp blades for about 2.5 cm. +The blades are again apposed by separating the handles. The instrument is brought out keeping the tip of the blades still inside the cranium. The instrument is rotated at right angle and then again thrust in up to the shoulders. The handles are once more to be compressed so as to separate the blades for about 2.5 cm. The perforated area now looks like a cross. The instrument with the blades closed is then thrust in beyond the guard to churn the brain matter. The instrument with the blades closed is brought out under the guidance of the two fingers still placed inside the vagina. +Alternative to Oldham' s perforator, similar procedure could be performed using a sharp-pointed Mayo's scissors. +Step IV: With the fingers, brain matter is evacuated. The idea is to make the skull collapse as much as possible. +Step V: When the skull is found sufficiently compressed, the extraction of the fetus is achieved either by using a cranioclast or by two giant volsella (Fig. 42.34). Giant volsella are used to hold the incised skull and scalp margins. +Step VI: The traction is now exerted in the same direction as like that mentioned in forceps operation. +Step VII: After the delivery ofthe placenta, the uterovaginal canal must be explored as a routine for evidence of rupture uterus or any tear. +Injection methergine 0.2 mg is to be given intravenously with the delivery of the anterior shoulder. The rest of the delivery is completed as in normal delivery. +Forceps versus craniotomy in a dead fetus: If the delivery of the uncompressed head can be accomplished without much force with consequent injuries to the mother, forceps delivery is preferred. But if it is found difficult and damaging to the mother, craniotomy is safer. +I DECAPITATION +DEFINITION: It is a destructive operation whereby the fetal head is severed from the trunk and the delivery is completed with the extraction of the trunk and that of the decapitated head per vaginam. +Chapter 37: Operative Obstetrics + +INDICATIONS: (1) Neglected shoulder presentation with dead fetus where neck is easily accessible; (2) Inter-locking head of twins. It is rarely done these days. It is rarely done in current obstetric practice. +I EVISCERATION +The operation consists of removal of thoracic and abdominal contents piecemeal through an opening on the thoracic or abdominal cavity at the most accessible site. The object is to diminish the bulk of the fetus which facilitates its extraction. If difficulty arises, the spine may have to be divided (spondylectomy) with embtyotomy scissors. It is rarely done in current obstetrics practice. + +I CLEIDOTOMY +The operation consists of reduction in the bulk of the shoulder girdle by division of one or both the clavicles. +The operation is done only in dead fetus (anencephaly excluded) with shoulder dystocia. The clavicles are divided by the embryotomy scissors or long straight scissors introduced under the guidance of left two fingers placed inside the vagina. + +POSTOPERATIVE CARE FOLLOWING DESTRUCTIVE OPERATIONS + +♦ Exploration of the uterovaginal canal must be done to exclude rupture of the uterus or lacerations on the vagina or any genital injury. +♦ A self-retaining (Foley's) catheter is put inside, especially following craniotomy for a period of 3-5 days or until the bladder tone is regained. +♦ Dextrose saline drip is to be continued till dehydration is corrected. Blood transfusion may be given, if required. +♦ Ceftriaxone 1 g IV infusion is given twice daily. + + + +COMPLICATIONS: (1) Injury to the uterovaginal canal; (2) Rupture of uterus; (3) Postpartum hemorrhage-atonic or traumatic; (4) Shock-due to blood loss and/or dehydration; (5) puerperal sepsis; (6) Subinvolution; (7) Injuty to the adjacent viscera-bladder-vesicovaginal fistula or rarely to rectal wall leading to rectovaginal fistula; and (8) Prolonged ill health. + +SYMPHYSIOTOMY +Symphysiotomy is the operation designed to enlarge the pelvic capacity by dividing the symphysis pubis. In the tropical countries, its place has to be duly considered in the perspective of wide prevalence of obstructed labor cases which are rushed to the referral hospitals in a bad shape. +The cases are judiciously selected and symphysiotomy may be done as an alternative to risky cesarean section when there is a likelihood of scar rupture in subsequent labors. Moreover, symphysiotomy produces permanent enlargement of the pelvis, as such future dystocia will be unlikely. The operation should be done in established obstruction and not when it is only anticipated. The conditions to be fulfilled are: (1) The pelvis should not be severely contracted; isolated outlet contraction is ideal, (2) Vertex must be presenting, and (3) the FHS must be present. +The operation consists of dividing the symphysis pubis strictly in the midline from above downwards until the arcuate ligament is cut. The fingers of the left hand in the vagina displace the urethra, while catheter is in, to one side. The baby is delivered spontaneously with liberal episiot­ omy or by traction-ventouse (preferable) or forceps. +Complications: Retropubic pain, osteitis pubis, stress urinary incontinence and rarely vesicovaginal fistula. + + + + + +► The operation, 'Dilatation and Evacuation' (D & E) consists of dilatation of the cervical canal and Evacuation of the Retained Products of Conception (ERPC) from the uterine cavity. +► Indications of D & E are many; of which, incomplete abortion is most common. +► In suction evacuation (S & E) operation, the products of conception are sucked out from the uterus with the use of a cannula fitted to a suction apparatus. +► Indications of S & E are many; of which, MTP during first trimester is most common. +► _End point of suction is important to understand. This reduces the complications of the operation. +► Vacuum aspiration either as manual (MVA) or electric (EVA) is highly effective (98-100%) for MTP up to 12 weeks of pregnancy. +► Episiotomy is a planned incision over the perineum and the posterior vaginal wall to enlarge the space for safe delivery. It is done in a selective case only. +► Of the different types, mediolateral and median types are commonly done. Both have got relative merits and demerits. ► The procedure, repair and the postoperative care of episiotomy are important to minimize its complications. +► Obstetric forceps are used to extract the fetal head thereby to deliver the fetus. However, forceps has got other functions also. ► Of the different types of forceps delivery, outlet and low forceps deliveries are commonly done (Table 37.3). +► Both the forceps and ventouse are safe instruments. Operator should determine the superiority of one instrument over the others (Table 37.6) for an individual patient. +► Maternal and fetal criteria must be carefully assessed to determine the indications of forceps/ventouse delivery. +► Prerequisites for application of forceps/ventouse, must be fulfilled to avoid the difficulties and the failure of the procedure. The prerequisites for application of forceps or vacuum are the same. +Contd... +Chapter 37: Operative Obstetrics + +Contd... +> There should be descent of the fetal head with each pull while doing forceps/ventouse delivery. When there is no descent after the third pull, the procedure should be abandoned. +> Prophylactic forceps delivery is done to shorten the second stage when maternal and/or fetal complications are anticipated (Box 37.3). +> Trial forceps and failed forceps have different clinical criteria. The causes are different (Box 37.4). +► Correct assessment of criteria and application of the instrument (bimalar, biparietal placement for forceps and for ventouse cup on or close to the flexion point) is essential for successful delivery and to minimize the complications. +► Sequential use of different instruments to deliver the baby, increase the risk of complications to both the neonate and the mother. ► In trial labor as well as in failed forceps delivery, the operator should have the willingness to abandon the procedure in case of +difficulty and should go for immediate cesarean delivery. This reduces the rates of morbidity and mortality both for the neonate and the mother. +► The outcomes of midcavity forceps delivery have been compared with cesarean delivery. There is no increase in the risks of neonatal adverse outcome in terms of birth trauma, Apgar score and NICU admission. +> Factors for rising cesarean section (CS) are many including the CS on maternal request (Box 37.8). +> Indications of CS are mostly relative (CPD) and absolute indications are a few. Based on time, CS may be done either as an elective or an emergency procedure. +► Common indications of CS are: Failed induction of labor, fetal distress, previous cesarean delivery, antepartum hemorrhage, ma Iposition or malpresentation and cephalopelvic disproportion (Box 37.9). +> Lower segment CS is commonly done with low transverse abdominal incision. There are merits and demerits of lower segment transverse versus classical uterine incision (Table 37 .1 O). +► Complications of cesarean section may be: (a) Due to operation itself or (b) Due to anesthesia. +> Maternal complications may be: (a) lntraoperative or (b) Postoperative (552). Visceral injury (bladder), hemorrhage, anesthetic hazards (aspiration), wound sepsis are the important complications. +► Prophylactic antibiotics during CS are used to reduce the frequency of sepsis. First dose to the mother is given one hour before the skin incision is made. +► Forceps has little or no effect on subsequent urinary incontinence. +► The risk of the fetal injury with vacuum delivery are cephalohematoma, subgaleal and retinal hemorrhages; forceps delivery are: injury to the scalp and the face, facial bruising). +► Different destructive operations are: Craniotomy, evisceration, decapitation and cleidotomy. In modern obstetrics, there is hardly any place for destructive operations. +> Safe prevention of CD include: ECV; assisted vaginal breech delivery in selected cases, avoiding CD in latent phase and in first stage labor before 6 cm dilatation and for second stage (Table 37 .11 ). + +Safe Motherhood, Epidemiology of Obstetrics + + +CHAPTER + + + +CHAPTER OUTLINE +❖ Safe Motherhood +❖ Clinical Causes of Maternal Deaths ❖ Country Targets +❖ Ending Preventable Maternal Mortality +❖ Sustainable Development Goals (SDGs) + + +❖ Reproductive and Child Health (RCH) Care +► RCH Interventions +❖ Epidemiology of Obstetrics ► Maternal Mortality +► Maternal Near Miss + + +► Maternal Morbidity ► Perinatal Mortality +► Important Causes of Perinatal Mortality and Main Interventions +► Stillbirths +► Neonatal Deaths + + + + +SAFE MOTHERHOOD +In an attempt to reduce maternal deaths in the low and middle income countries, the WHO in 1987 conceived the idea of 'Safe Motherhood Initiative' at a conference in Nairobi, Kenya. It is a global effort to reduce the maternal deaths by at least half by 2000 AD, and was extended to 2015 now extended further to 2030. +Maternal and child health promotion is one of the key commitments in the WHO constitution. Ending Preventable Material Mortality (EPMM) is the world's most critical challenges (WHO). +Maternal death: As estimated 30,300 maternal deaths in 2015 yields an overall global Maternal Mortality Ratio (MMR) 216/100,000 live births for 183 countries. Global targets are to increase equity in maternal mortality between countries. The steps are: +a. By 2030 all countries should reduce maternal mortality (MMR) by at least two thirds of their 2010 baseline level. +b. The average global target of MMR is less than 70/100,000 Live Birth (LB) by 2030. +c. The supplementary national target is that no country should have a MMR greater than 140/100,000 LB (a number twice the global target) by 2030. +About 99% of the estimated total maternal deaths occurred in the developing regions. Majority (80%) of these deaths are preventable. +In the developed regions, the MMR is 12 (range 11-14) per 100,000 live births. The lifetime risk of dying from pregnancy related complication for a woman of developing region is one in 150 compared to one in 4900 in the developed regions. This reflects the huge difference in national commitment. + +Safe Motherhood Initiative (SMI) is a global effort and it is designed to operate through partners: (a) Government agencies, (b) Non-government agencies, and (c) Other groups and individuals. Worldwide MMR has fallen from 342 in the year 2000 to 211 in 2017 (WHO). +The MMR in India has declined by about 70% from 398/100,000 LB (in 1997-98) to 99/100,000 (90-108) in 2020 (Table 38.1). +Worldwide MMR has fallen from 342/100,000 in 2000 to 211/100,000 (about 40% of the absolute decline was derived from fewer maternal deaths in India). +Experts from WHO, UNFPA, UNICEF, IPPFF, the World Bank Group, UNPD regions, the population council and other national and international agencies concerned with safe motherhood concluded that it is possible to reduce maternal mortality significantly with limited investment and effective policy interventions (Table 38.2). According to national and international human rights treaties (1948) safe motherhood is considered a human rights issue. Therefore, it is + + +Table 38.1: Goals ancj targets to reduce maternal deaths: Global and in India. +Organization Year Target of MMR reduction Target year +Sustainable 2015 • MMR reduction 2030 Development QO per 100,000 LB +Goals • Neonatal Mortality Rate (NMR) +■ NMR <12 per 1000 LB +MMR in India (SRSJ Worldwide MMR +1997-1998 2020 2000(WHO) 2017 398 99 342 211 +Reduction in MMR (70%) +Chapter 38: Safe Motherhood, Epidemiology of Obstetrics - ·--- + + +Table 38.2: National Sociodemographic Goals (2030) (SDG) National Population Policy, National Health Mission (NHM). +Parameters 2030 Total fertility rate <2.1 Maternal mortality ratio (per 100,000 live births) <70 Infant mortality <12 Antenatal care (%) 100 Institutional deliveries (%) 80 Deliveries by skilled personnel(%) 100 + +considered that maternal death is the reflection of 'social disadvantage' not merely a 'health disadvantage'. +Basic facts underlying the clinical causes of maternal deaths are: +♦ Social inequalities and discrimination on grounds of gender, age and marital status, are considered the major determinants of maternal mortality. In low resource countries, girls and women face the following difficulties such as: (i) Limited access to economic resources, (ii) Less opportunity for basic education, (iii) Less opportunity in decision making as regard their own health and reproduction, (iv) Unplanned childbirth that are too early, too frequently, too many or too late, and (v) Less utilization of essential obstetric services. +♦ Poor nutrition contributes to poor maternal health and results in poor pregnancy outcome. +♦ Less utilization of available resources. +♦ Lack of skilled attendant during the time of delivery, appropriate referral system, Emergency Obstetric Care (EmOC), sex education, family planning and safe abortion services are the important areas. +Country targets to increase equity in maternal mortality +The global MMR <70 by 2030 target may not necessarily apply to individual countries. However, regardless of its + +baseline MMR, each country should accelerate efforts in achieving the global target (Figs. 38.IA and B). +11 Countries with baseline MMR <420 in 2010 (the majority worldwide) should reduce its MMR by at least two thirds by 2030 (Fig. 38.IA). +11 Countries with baseline MMR >420 in 2010 should not have an MMR greater than 140 by 2030 (Fig. 38.IB). +11 Countries with baseline MMR <10 in 2010 should aim to achieve equity in MMR for vulnerable populations at the subnational level. +11 A special target for all countries in addition to reducing their national average MMR, is to reduce the extremes of between-country inequity. +■ Countries with the highest MMRs (MMR >420) need to reduce their MMR at an Annual Rate of Reduction (ARR) greater than 5.5%. Countries with the lowest MMRs (MMR <10) that may find it difficult to achieve a two-thirds reduction from baseline. Such countries need to achieve within-country equity in maternal survival in subpopulations with higher risk of maternal death. +In an attempt to improve the maternal mortality situation in India, all the states have been categorized into groups: (A) Empowered Action Group (EAG and Assam): The states in this group are Bihar, Jharkhand, MP, Chhattisgarh, Odisha, Rajasthan, Uttar Pradesh, Uttarakhand and Assam. (B) Southern states: Andhra Pradesh, Karnataka, Kerala, Tamil Nadu, and (C) Other states: The remaining states and the union territories. Government of India pointed out three types of delays that results in an increase in maternal mortality and morbidity. +1. Delay-I: Delay in recognizing the problem and deciding to seek care (lack of birth preparedness). +2. Delay-II: Delay in reaching the health facility (due to nonavailability of transport referral facility (lack of complication readiness). + + + + + + +<: +/) + +Q) + + +0 0 +0 + +0 +(D +.. '. +2 +2 + +600 + +500 + +400 + +300 + +200 + +100 + +0 1990 + + +Country 3 + +Reduction >2/3 \ (ARR-5.5%) +' + +' ' ' +' +- +- ' ' '100 +- +- +, +70 +- - - --so +- +19 + +2000 2010 2020 2030 + + +Country C +/) 1000 +ii \ +Q) 800 \ +£ +0 +0 600 \ +' +' +' +' +- +- +0 +\ +' +' +- +' +400 +(D +.. '- '- +'. 200 ':_ 140 +2 +2 - -70 +0 +1990 2000 2010 2020 2030 + +APR annual rate of reduction (WHO) + + +Figs. 38.lA and B: (A} Countries with baseline MMR <420; (Bl Countries with baseline MMR >420. +·m1 Chapter 38: Safe Motherhood, Epidemiology of Obstetrics + +3. Delay-III: Delay in receiving treatment at the center [(due to unequipped health facility, lack of trained personnel, medicines, blood, etc., (lack of facilities readiness)]. +Decline has been observed in all the delays. +WHO published five strategies towards Ending Preventable Maternal Mortality (EPMM). +1. Addressing inequities in access to and quality of sexual, reproductive, maternal and newborn health care (Ethiopia, Vietnam). +2. Ensuring universal health coverage for comprehen­ sive sexual, reproductive, maternal and newborn health care (Rwanda, Bangladesh). +3. Addressing all causes of maternal mortality, reproductive and maternal morbidities, and related disabilities (Nepal, Maldives). +4. Strengthening health systems to respond to the needs and priorities of women and girls (Indonesia, Cambodia). +5. Ensuring accountability to improve quality of care and equity (Mangolia, India). +Name of the countries that have made significant reductions in maternal mortality are mentioned within the parenthesis. +Other areas that need to improvement to achieve this target: +WHO stresses on the need for good quality data collection. Each count1y need Civil Registration and Vital Statistics (CRVS) systems. Under reporting need to be avoided. Actual number and the cause of deaths can help to make correct strategies to reduce maternal deaths. +Strategic framework and program implementation: 1. Empowering women, girls and communities. +2. Protecting and supporting the mother-baby care. +3. Ensuring country ownership, leadership and supportive legal, technical and financial frameworks. + +Abortion (8%) +Embolism (3%) + + +4. Applying a human rights framework to ensure that high-quality reproductive, maternal and newborn health care is available, accessible and acceptable to all who need it (WHO-2015). +Lifetime risk is defined as the probability of dying of a woman in her reproductive age (15-49 years), due to causes in pregnancy, childbirth or within 6 weeks of childbirth. In India, presently, it is 0.3%. +OBSTETRIC CARE AND THE SOCIETY: Obstetric care is by and large a preventive medicine. Social obstetrics is defined as the obstetric care of a community that can be provided in the perspective of its social, economic, environmental and cultural background. + +SUSTAINABLE DEVELOPMENT GOALS (SDGs) +The United Nations General Assembly adopted the new development agenda in September 2015. The 2030 agenda comprises 17 Sustainable Development Goals (SDGs) (Fig. 38.3). It integrates all three main dimensions of developments (economic, social and environmental). Health is placed in the central position of 2030 agenda with one comprehensive goal SDG3. SDG3 includes 13 targets covering all major health topics. These include: reproductive, maternal, newborn and child health care, infectious diseases, Noncommunicable Diseases (NCDs), mental health, road traffic injuries, UHC and environmental health consequences. There are 26 proposed indicators. The indicators for SGD targets 3.1 and 3.2, include maternal and under-five mortality. Sole objective is to achieve the SDG target of MMR 70 per 100,000 live births by 2030. + +The global annual rate of reduction of MMR should be 5.5% at least. Globally, under-five mortality rate, at present, is 42.5 per 1000 live births. SDG target of under­ five mortality in 2030 is 25 per 1000 live births. SDG target of neonatal deaths in 2030 is 12 per 1000 live births. + + + +Indirect-.,,, (28%) + + +Hemorrhage (27%) + +Other--­ direct (10%) + + + +Sepsis (11 %) Hypertension, eclampsia (14%) +Fig. 38.2: Important causes of maternal deaths. Fig. 38.3: Sustainable development goals (SDG-3). +Source: Global causes of maternal death: a WHO systematic analysis. Lancet Glob Heal. 2014;2:323-33. +Chapter 38: Safe Motherhood, Epidemiology of Obstetrics + + +Table 38.3: Selected SDG targets and proposed indicators. +Type of SDG +indicator target Proposed indicators by 2030 +Impact ■ Reduce maternal mortality to +3.1 +3.2 <70/100,000 LB +3.7 +■ Reduce neonatal mortality to 12/1000 LB +■ Ensure universal access to sexual and +reproductive health care including family planning information and education. lnte-gration of reproductive health into national +strategies and programs +Coverage 3.1 ■ Birth attended by skilled health 3.7 professional +3.8 ■ Family planning coverage +■ UHC: RMNCH (family planning, antenatal +and delivery care, full immunization coverage, health-seeking behavior for +suspected child pneumonia + + +Selected SDG targets and proposed indicators linked to reproductive, maternal, newborn and child health by type of indicator is shown in Table 38.3. +The key five strategies towards Ending Preventable Maternal Mortality (EPMM) by 2030 are: +■ To address inequities (WHO 2015) in access to and quality of sexual, reproductive, maternal and newborn healthcare services. +■ To ensure universal and comprehensive healthcare for sexual, reproductive, maternal and newborn health. +■ To address all causes of maternal mortality, morbidities and related disabilities. +■ To strengthen health system for the needs and priorities of women and girls. +■ To ensure accountability to improve quality care and equity. +There is a wide variation between rich and poor countries and between urban and rural areas. Poor women get either inadequate care or no care at all. + +REPRODUCTIVE AND CHILD HEALTH {RCH) CARE +(a) Safe motherhood: Risk assessment is not once only but a continued procedure throughout and the woman is referred to a higher level of care when needed (Table 38.4). +(bl Adolescent and reproductive health: 20% of the total population in India are adolescent (age group of 10-19 years), of which half are either sexually active or married. Problems to overcome are: (i) Early motherhood-risk of the mother and her newborn, (ii) Undernutrition and anemia, (iii) Psychological immaturity and vulnerability, (iv) Consequences of unprotected sex-unwanted pregnancy, unsafe abortion, Sexually Transmitted Infections (STis) and Reproductive Tract Infections (RTis). + +(c) Reproductive Tract Infections (RTls) and Sexually Transmitted Infections (STls): RTis are mainly due to unsafe abortion, uncleaned delivery, poor menstrual hygiene and unhygienic IUD insertion. All these are avoidable by proper preventive and curative measures under the RCH program. +(d) Others: RCH II, skilled birth attendant and uni­ versal immunization to children: In India, RCH II highlights the following areas-(i) Community Need Assessment Approach ( CNAA), (ii) Up gradation of facilities at First Referral Unit (FRU) for comprehensive emergency obstetric and newborn care at the subdistrict levels, (iii) Permission for skilled birth attendant to administer certain life-saving drugs and to perform certain life-saving interventions under specified situations (see below). +Life-saving drugs are: Misoprostol [prevention of Postpartum Hemorrhage (PPH)], injection Oxytocin (man­ +agement of PPH), injection MgS04 (eclampsia), ampicillin, metronidazole (infection) are the life-saving interventions + + + + +Table 38.4: Measures for safe motherhood. + +Antenatal care +Essential obstetric care: +• +• +Early registration of pregnancy (<12 weeks) +Minimum 4 antenatal visits (WHO). (1st visit: 12-14 weeks; 2nd visit: 14-26 weeks; 3rd visit: +28-34 weeks and 4th visit: 36-40 weeks) Identification of high-risk factors Provision of prompt referral +• +• +• +• +• +Essential newborn care +Early and exclusive breastfeeding +Immunization with tetanus toxoid and +supplementary lron-Folic Acid (IFA) therapy +daily for at least 100 days after the first trimester + + + + +tntranatal care +• Institutional deliveries +in 80% cases and 100% +deliveries by skilled persons +Postnatal care +• +Support to restore the health of mother and care of the +newborn +• +Family planning services +to prevent unplanned +pregnancy +• +• +Safe abortion services +Breastfeeding-early and +exclusive + +I +Essential newborn Comprehensive EmOC +care (at FRUs under NHM scheme) +• +• +Clean delivery ■ Vacuum extractions +Resuscitation at ■ Anesthetic services +• +birth Blood transfusion facilities +■ Prevention of ■ Cesarean delivery +hypothermia ■ Manual removal of placenta +• +Prevention of ■ Suction evacuation (MVA) ■ Safe abortion services +infection +Ten +baby-friendly +■ hospital initiatives ■ Contraceptive services Referral of sick ■ Sterilization operations +(IUCDs) +• +newborn +■ Referral and transport +facilities +t +r +° +p +:. + + + +BJ Chapter 38: Safe Motherhood, Epidemiology of Obstetrics + + + +are: Digital removal of products of conception (incomplete abortion with bleeding, active management of 3rd stage of labor, maintaining a partograph [early diagnosis of pro­ longed and obstructed labor need a skilled person. +Emergency Obstetric Care (EmOC) is life-saving, as the time between onset of an emergency during delivery and start of treatment is very crucial. +Emergency obstetric care has a major role to improve maternal mortality. Many women died in the facilities when obstetric complications were faced as emergency and unanticipated. +The reduction of maternal deaths suggest successful initiatives by the government and stakeholders through the Safe Motherhood Programme (1992). Reproductive and Child Health Programme (1997), National Health Mission (2005), Janani and Sishu Suraksha Karyakram (JSSK-2017). +The comprehensive EmOC that has to be provided at FRUs are: anesthetic service, vacuum delivery, blood transfusion facilities, cesarean delivery, manual removal of placenta, safe abortion services, contraceptive services, including sterilization and facilities of referral with transport. + +EPIDEMIOLOGY OF OBSTETRICS +The sensitive index of the quality of the healthcare delivery system of a country as a whole or in part, is reflected by its maternal and perinatal mortality rates (Table 38.5). Fertility regulation, safe abortion procedure, quality antenatal care, presence of skilled birth attendant (SBA), have been recognized as the key elements to reduce maternal and perinatal deaths in the low resource settings. + +I MATERNAL MORTALITY +DEFINITION OF MATERNAL DEATHS: Death of a woman while pregnant or within 42 days of the termination of pregnancy irrespective of the duration and the site of pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes. + +MATERNAL MORTALITY RATIO (MMR): The MMR is expressed in terms of such maternal deaths per 100,000 live births. In most of the developed countries, the + +MMR varies from 11-14 per 100,000 live births. In the developing countries, it varies from 27-546 with India having 99 per 100,000 live births. Good quality data is essential to identify the trends and the cause of maternal deaths. It is also useful to prevent future deaths. The tools for quality data collection are: +■ Confidential Enquiry into Maternal Death (CEMD) established in England and Wales since 1952. +■ Maternal Deaths Surveillance and Response (MDSR) established in India, Congo, Nigeria and few other countries. +■ Digital innovations using mobile devices. This is used to connect front line health workers to the national health systems. + +MAGNITUDE OF THE PROBLEM: One woman in 150 die of pregnancy-related complications in Low Income Countries (LIC) compared to one in 4,900 High Income Countries (HIC). Here lies the major discrepancies in global health. It is further estimated that for one maternal death at least 16 more suffer from severe morbidities. +MATERNAL MORTALITY RATE: Indicates the number of maternal deaths divided by the number of women of reproductive age (15-49). It is expressed per 100,000 women of reproductive age per year. In India, it is about 120 as compared to 0.5 in the United States. +The term reproductive mortality is used currently to include maternal mortality and mortality from the use of contraceptives. + +CLASSIFICATIONS +♦ Direct ♦ Indirect ♦ Non-obstetric +■ Direct obstetric deaths (75%) are those resulting from complications of pregnancy, delivery or their management. Such conditions are abortion, ectopic gestation, pre-eclampsia-eclampsia, antepartum and postpartum hemorrhage and puerperal sepsis (Table 38.6). Suicidal death is considered as a direct death. +■ Indirect deaths (25%) include conditions present before or developed during pregnancy but aggravated by the physiological effects of pregnancy and strain of labor. These are anemia, cardiac disease, diabetes, thyroid disease, etc., of which, anemia is the most important single cause in the developing countries. + + + +,Table 38,5: Maternal mortalitxestimates (WHO, UNICEF, UNFPA, World Bank) .. ' .; .. . : Maternal mortality ratios in the HIC +SWEDEN USA UNITED KINGDOM SINGAPORE 3 23.8 9.7 (2016-17) 10 +I I I +I +I I +Maternal mortality ratios in South-East Asia +I I I I +I +I I +I +SRI LANKA THAILAND INDIA2020 CHINA BANGLADESH +30 20 99 56 178 + + + + +I +I + +I +I + + +' • > /.,'" +, , + +JAPAN 6 + +NEPAL +258 +Chapter 38: Safe Motherhood, Epidemiology of Obstetrics + + +Table 38.6: Important causes of maternal deaths and main interventions. Causes +Hemorrhage: Mostly due to postpartum hemorrhage. Other causes are: (i) Antepartum hemorrhage (abruptio placentae, placenta previa), +(ii) Retained placenta, (iii) Abortion complications and ectopic pregnancy. Hemorrhage is more dangerous when the woman is anemic. + + +Infection is associated with labor and puerperium. Infections from premature rupture of membranes, prolonged and obstructed labor are still frequent in the developing world. +Hypertension during pregnancy pre-eclampsia, eclampsia +Unsafe abortion + + + + +Obstructed labor-due to cephalopelvic disproportion, abnormal lie or malpresentation. +Anemia is an indirect cause of death. About 50% of pregnant women worldwide suffer from anemia. Anemia is commonly due to dietary deficiency (nutrition, iron, folic acid, iodine and other micronutrients) or infections. +Other indirect causes: Viral hepatitis is endemic in India with high mortality. Death is mostly in the last trimester due to hepatic coma and coagulation failure and postpartum hemorrhage. + + +Percentage 20-25 + + + + +15-20 + + +12-15 + +10-13 + + + + +8 + +15-20 + + +5-10 + + +Proven interventions +■ Treat anemia in pregnancy Skilled attendants at birth +• +■ Prevent/treat hemorrhage ■ Use oxytocics in time +• +Replace fluid loss +■ Transfusion of blood, if severe hemorrhage +■ Skilled attendants at birth +■ Clean practices (three cleans) during delivery ■ Antibiotics-if infection is evident +• Early detection ■ Appropriate referral +■ Antiseizure prophylaxis/treatment with MgSO4 +■ Skilled attendant +a Access to family planning and safe abortion services +■ Antibiotics after evacuation ■ Postabortion care +• Use of partograph ■ Detection in time Refer for operative delivery +• +• Routine iron-folic acid supplementation ■ Treat hookworm, malaria, HIV, etc. +■ Admit when Hb 5,7 g/dl +■ Safe drinking water ■ Immunization +■ Appropriate referral and supportive care + +80% of these deaths can be prevented through actions that are effective and affordable in developing country settings (WHO, UNICEF and +UNFPA-2001 ). + + +Viral hepatitis, when endemic, contributes significantly to maternal deaths. +■ Non-obstetric or fortuitous deaths: Accidents, typhoid and other infectious diseases. + +FACTORS ASSOCIATED WITH MATERNAL MORTALITY +Age: In women aged 35 years or above, the risk is 3-4 times higher. +Parity: The risk is slightly more in primigravida but it is 3 times greater in para 5 or above where postpartum hemorrhage, malpresentations and ruptured uterus are more common. The risk is lowest in the second pregnancy. +Socioeconomic status: Mortality ratios are higher in women belonging to low socioeconomic strata. +Antenatal care: The women of lower socioeconomic status, are the high-risk women as often they do not avail the benefits of antenatal care. +Substandard care: When the care provided is below the generally accepted level, available at those circumstances. Shortage of resources (staff) or back up facilities (laboratory) is also included. +In the Low and Middle Income Countries (LMIC), avoidable social factors are palpably evident. These are related to: (a) Ignorance, teenage pregnancy or prejudice, (b) Unregulated fertility and unsafe abortion, (c) Poor socioeconomic condition, (d) Inadequate maternity + +services, (e) Underutilization of the existing services, (f) Lack of communication and referral facilities. These are most often interrelated and are responsible for increased number of preventable deaths. +Important causes of maternal death (Fig. 38.2): Whereas in the organized sector (HIC)-hypertensive disorders, hemorrhage and pulmonary embolism are the main causes, in the LMIC-hemorrhage, sepsis and hypertensive disorders and unsafe abortion are the main causes (Table 38.6). +STEPS TO REDUCE MATERNAL MORTALITY +Actions may vary in respect of an individual country. The government must make maternal mortality a priority public health issue and periodically evaluate the programs in an effort to prevent or minimize maternal deaths. Specific actions are discussed under the following groups: +A. Health Sector Actions +■ Basic antenatal, intranatal and postnatal care (see RCH interventions). Risk assessment is a continued procedure throughout and is not once only. +■ A skilled birth attendant should be present at every birth. Functioning refel'ral system is essential for integration of domiciliary and institutional services. +■ Emergency Obstetric Care (EmOC) is to be provided at the First Referral Unit (FRU). +iJ Chapter 38: Safe Motherhood, Epidemiology of Obstetrics + +• Good quality obstetric services at the referral centers are to be ensured. Facilities for blood transfusion, laparotomy and cesarean section must be available at the FRU level. +■ Prevention of unwanted pregnancy and unsafe abortion. All couples and individuals should have access to effective, client-oriented and confidential family planning services. +■ Frequent joint consultation among specialists in the management of medical disorders in pregnancy, particularly anemia, viral hepatitis, and hypertension. +• Maternal mortality conferences and audit to evaluate the cause of death and the avoidable factors. +■ Periodic refresher courses for continuing education of obstetricians, general practitioners, midwives and ancillary staff and to highlight the preventable factors. +B. Community, Society and Family Actions: Wide range of groups (women's groups), healthcare professionals, religious leaders can help the woman to obtain the essential obstetric care. +C. National Health Mission (NHM) Action Plan is to: ■ Strengthen all First Referred Units (FRUs). +11 Provide basic and comprehensive Emergency Obstetric Care (EmOc) and essential newborn care (see below). +■ Janani Shishu Suraksha Karyakram (JSSK) under the umbrella of NHM is to implement the interventions in all the states and Union Territories (UTs) with a special focus on Low-Performing States (LPS) that they have low institutional deliveries (Uttar Pradesh, Uttarakhand, Bihar, Jharkhand, Madhya Pradesh, Chhattisgarh, Assam, Rajasthan, Odisha, Jammu and Kashmir). The remaining states have been named as high performing states. +D. Skilled birth attendant +Skilled Birth Attendant (SBA) is defined as an accredited health professional (doctor, midwife or nurse) who has been educated and trained to achieve proficiency in the skills, needed to manage normal (uncomplicated) pregnancies, childbirth and the immediate postnatal period and in the identification, management and referral of complications in women and newborns. Besides doctors, SBAs include Auxiliary Nurse Midwives (ANMs), Lady Health Visitors (LHVs) and Staff Nurse (SNs), SBAs are trained and made competent to take certain life-saving measures. +E. Accredited Social Health Activist (ASHA) +ASHA is a female (preferably a daughter-in-law) accre­ dited social health worker of 25-45 years age. She is to work in a village with population >1,000 under the NRHM scheme. She is trained over a period of 3-4 weeks for the work. + + +11 She acts as a link person among the beneficiary at the village level with the ANMs, LHVs, doctors at the FRU (Government). +■ She arranges escort to the pregnant woman, sick child and provide DOTs, ORS, IFA tablets for the needful. +11 She works along with Anganwadi Workers (AWWs) and TRBAs to provide service under JSSYK. +F. 1. Empowered Action Group (including Assam). 2. Other states: +EAGA states-Uttar Pradesh, Uttarakhand, Bihar, Jharkhand, Madhya Pradesh, Chhattisgarh, Rajasthan, Odisha and Assam. +EAGA states in India currently is the location of over 60% of maternal deaths. These EAGA states and the rural and tribal areas need special strategies and intervention to improve the maternal deaths and to react the national goal and SDG. +Conclusion: +11 EAGA states and the rural and tribal areas are the regions for majority of maternal deaths (60%). These areas need special strategies and specific intervention. +11 Educational programs and motivation for women about the benefits of planned delivery at health facilities. +11 All the EAGA states need continuing reliable estimation of maternal deaths for review. This is needed for any strategic change and appropriate intervention. +11 Prioritizing specific improvement in maternal health outcomes in EAGA states are needed. +11 It is expected that each state in India achieves the 2030 goals with prioritization and need specific intervention. +Most deaths: Occurring in EAGA states (63%) and among women aged between 20 and 29 years (58%). + +MATERNAL HEALTH BEYOND 2030 I NATIONAL HEALTH POLICY (GOl-2017) +The National Health Policy 2017, aims the attainment of highest possible level of health and wellbeing for all at all ages through preventive and primitive healthcare system. +The policy principles are: +1. Professionalism, Integrity and Ethics: NHP demands high professional standard. Integrity and ethics are to be maintained. +2. Equity: Inequity to be reduced. This is to reduce disparity on the ground of gender, poverty, caste, disability or other forms of social and geographical barriers. +3. Affordability: The costs of care should be made affordable for all. +4. Universality: Prevention of exclusions on social, economic or on any other grounds. +Chapter 38: Safe Motherhood, Epidemiology of Obstetrics ml + +5. Patient centered and quality of care: Gender sensitive, effective, safe, and convenient healthcare services to be provided with dignity and confidentiality. +6. Accountability: Financial and performance account­ ability, transparency in decision making, and elimination of corruption in healthcare systems are essential. It is applicable both in public and private care. +I MATERNAL NEAR MISS +A woman who experienced a severe !] +complication and she nearly died, but she ■- ' • ,cj survived the severe health condition during pregnancy, childbirth or postpartum is !J considered as maternal near miss or Severe Acute Maternal Morbidity (SAMM). Maternal near miss is defined as: 'A woman who nearly died but survived a complication that occurred during pregnancy, childbirth or within 42 days of termination of pregnancy' (WHO). MNM incidence ratio (MNMIR) refers to the number of maternal near miss cases per 1000 live births (MNMIR = MNM/1000 LB). + +Potentially life-threatening conditions commonly seen in obstetrics are: +II Hypertensive disorders: Sever pre-eclampsia, eclampsia. +■ Hemorrhagic disorders: Placenta previa, placental abruption and postpartum hemorrhage. +■ Other systemic disorders: Septic shock and others. Specific defining criteria for MNM (SAMM) are: +■ Clinical criteria: • Acute cyanosis • Loss of Consciousness (LC) lasting >12 hours, gasping • LC and absence of pulse/heart beat • Respiratory rate >40 breaths/min or <6/min stroke • Disseminated Intravascular Coagulation (DIC). +■ Laboratory-based criteria: • Oxygen saturation <90% +for >60 minutes • PaOz1FiO2 <200 mm Hg • Serum +creatinine 3.5 mg/dL • Serum bilirubin 6.0 mg/dL • pH <7.1 • Lactate >5 • Acute thrombocytopenia (<50,000 platelets/ cu mm). +■ Interventions-based criteria: • Use of vasoactive drugs (dopamine, epinephrine), • Hysterectomy following infection/hemorrhage • Transfusion >5 units blood • Dialysis for acute renal failure • Cardiopulmona1y resuscitation. +OR: Any single criteria that signifies cardiorespiratory collapse indicated with heart ( •) symbol is accepted. +Read more Dutta's Clinics in Obstetrics, Ch. 16. +I MATERNAL MORBIDITY +It has been estimated that for one maternal death at least 15 more suffer from severe morbidities. +Definition: Obstetric morbidity originates from any +cause related to pregnancy or its management any time + + +during antepartum, intrapartum and postpartum period usually up to 42 days after confinement. The parameters of maternal morbidity are: +1. Fever more than 100.4°F or 38°C and continuing more than 24 hours. +2. Blood pressure more than 140/90 mm of Hg. 3. Recurrent vaginal bleeding. +4. Hb% less than 10.5 g irrespective of gestational period. 5. Asymptomatic bacteriuria of pregnancy. + +Classifications +I. Direct obstetric morbidity: +• Temporary • Permanent (chronic) II. Indirect obstetric morbidity +Direct-Temporary: Antepartum Hemorrhage (APH), Postpartum Hemorrhage (PPH), eclampsia, obstructed labor, rupture uterus, sepsis, ectopic pregnancy, molar pregnancy, etc. +Chronic: Vesicovaginal Fistula (VVF), Rectovaginal Fistula (RVF), dyspareunia, Current Procedural Termino­ logy (CPT), prolapse, secondary infertility, obstetric palsy, Sheehan's syndrome, etc. +Indirect: These conditions are only expressions of aggravated previous existing diseases like malaria, hepatitis, tuberculosis, anemia, etc., by the changes in the various systems during pregnancy. +Reproductive morbidity is used in a broader sense to include-(a) Obstetric morbidity, (b) Gynecological morbidity, and (c) Contraceptive morbidity. +I PERINATAL MORTALITY +Perinatal mortality is defined as deaths among fetuses weighing 1000 g or more at birth (28 weeks of gestation) who die before or during delivery or within the first 7 days of delivery. The perinatal mortality rate is expressed in terms of such deaths per 1000 total births. The perinatal mortality rate closely reflects both the standards of medical care and effectiveness of social and public health measures. According to the WHO, the limit of viability is brought down to a fetus weighing 500 g (gestational age 22 weeks) or body length (25 cm crown-heel) or more. However, for international comparisons, only deaths of fetuses or infants weighing 1000 g at birth should be included as in the Low and Middle Income Countries (LMIC) many such deaths are under-reported. +Perinatal deaths could be reduced by at least 50% worldwide if key interventions are applied for the newborn. The perinatal mortality is less than 10 per 1000 total births in the developed countries while it is much higher in the developing countries (26/1000 in India). The major health problem in the LMIC arises from the synergistic effect of infection and preterm birth combined with non-utilization of obstetric care. +ED Chapter 38: Safe Motherhood, Epidemiology of Obstetrics + +Majority of fetal deaths (70-90%) occur before the onset of labor. The important causes of antepartum deaths are: (a) Chronic hypoxia (30%), (b) Pregnancy complications (30%), (c) Congenital malformations (15%), (d) Infection (5%), and (e) Unexplained (20%). +PREDISPOSING FACTORS OF PERINATAL MORTALITY +Many factors influence the perinatal survival and these are briefly discussed below (Table 38.7): +■ Epidemiological: Age-elderly (>35 years), teenagers, parity above 5, low socioeconomic condition, poor maternal nutritional status-all adversely affect the pregnancy outcome. +■ Medical disorders: Anemia (Hb <8 g/dL), +hypertensive disorders, diabetes mellitus, acute fever (malaria) and infection (HIV) are often associated. Perinatal deaths increase due to hypoxia, hypothermia, IUGR, prematurity, infections and congenital malformations. +■ Obstetric complications: (a) Antepartum hemor­ rhage particularly abruptio placentae is responsible for about 10% of perinatal deaths due to severe hypoxia, (b) Pre-eclampsia-eclampsia is associated with high perinatal loss either due to placental insufficiency or preterm delivery (c) Rh isoimmunization, (d) Preterm labor, (e) Cervical incompetence­ premature effacement and dilatation of cervix <34 weeks is responsible for significant perinatal deaths from prematurity. +■ Complications of labor: Dystocia from disproportion, malpresentation, abnormal uterine action, premature rupture of membranes may result in asphyxia, amnionitis and birth injuries contributing to perinatal deaths. +■ Fetoplacentalfactors: +• Multiple pregnancy most often leads to preterm delivery and the related complications. +• Intrauterine growth restriction and low-birth­ weight babies: Low weight babies are more vulnerable to biochemical, neurological and respiratory complications resulting in high perinatal deaths. + +• Preterm labor and preterm rupture of the mem­ branes are the known leading causes of prematurity. +• Congenital malformation and chromosomal abnormalities are responsible for 15% of perinatal deaths, the lethal malformations are mostly related to nervous, cardiovascular or gastrointestinal system. With prenatal diagnosis, it is reduced significantly. +■ Unexplained: About 20% of stillbirths have no obvious fetal, placental, maternal or obstetric causes. +PREVENTION: As every mother has the right to con­ clude her pregnancy safely so also has the baby got a right to be born alive safe and healthy. As such, utilization of obstetric service only around delivery, may not minimize perinatal deaths appreciably. Simultaneous demographic and social changes are essential. The following measures are helpful in reducing the perinatal mortality. +■ Prepregnancy health care and counseling. +■ Ge1ietic counseling in high-risk cases and prenatal diagnosis to detect genetic, chromosomal or structural abnormalities are essential. +■ Regular antenatal care, with advice regarding health, diet and rest. +■ Detection and management of medical disorders in pregnancy: Anemia, diabetes, infections and pre­ eclampsia-eclampsia. Immunization against tetanus should be done as a routine. +■ Screening of high-risk patients as with high parity, extremes of age, and twins, etc. and their mandatory hospital delivery. Risk approach to RCH care is essential. +■ Careful monitoring in labor to detect hypoxia early and avoidance of traumatic vaginal delivery. +■ Skilled birth attendant-to minimize sepsis, at least three cleans are to be maintained. +■ Provision of referral neonatal service, especially to look after the preterm and LBW babies. +■ Healthcare education of the mother about the care of the newborn. Early and exclusive breastfeeding, prevention of hypothermia. + + +Table 38.7: Important causes of neonatal mortality and the main interventions. +Causes Percentage Proven interventions + +Prematurity and low birth weight 48.1 Birth asphyxia and birth trauma 12.9 + + +Neonatal pneumonia 12.0 Other noncommunicable disease 7.1 +Sepsis 5.4 Congenital malformation 4.0 Others 10.5 + + +♦ Maternal immunization against tetanus ♦ Warmth +♦ Screening for infections + +♦ Skilled attendants at birth ♦ Warmth +♦ Prevention of obstetric complications and management +♦ Infection control +♦ Breastfeeding + + ++ Clean delivery (three cleans) +♦ Early and exclusive breastfeeding +♦ Early recognition and management of infections +♦ Detection and management of obstetric complications + + ++ Warmth +♦ Referral to special care unit + + + +CLASSIFICATION OF PRETERM NEWBORN +♦ Extremely preterm: <28 weeks +♦ Very early preterm: 28 to 31 weeks ♦ Early preterm: 32 to 33617 weeks +♦ Late preterm: 34 to 36617 weeks + +CLASSIFICATION OF TERM NEWBORN ♦ Early term: 37°17 weeks through +38617 weeks +♦ Full term: 39°17 weeks through 40617weeks +° +♦ Late term: 41 17 weeks through 4 617 weeks +1 +♦ Post-term: 42°17 weeks and beyond + + + +Conception + + + + + + + + + + +o 2 12 +t + +1st +Conception trimester + +Chapter 38: Safe Motherhood, Epidemiology of Obstetrics ED Birth + +500 1000 2500 3250 4000 Weight of the fetus (g) +• + + +I I +I +I +0 1 +l +3 4 +..--------.--.',.._ Weeks after +birth + + + + +20 22 28 37 40 42 44 Weeks of +t gestation +2nd trimester 3rd trimester Birth + +Fig. 38.4: Perinatal nomenclature. + + + +IMPORTANT CAUSES OF PERINATAL MORTALITY AND MAIN INTERVENTIONS +■ Educating the community to utilize the available maternity and child healthcare services. Family plan­ ning services can prevent unwanted pregnancies. +■ Autopsy studies of all perinatal deaths. +■ Continued study of perinatal mortality problems by demographic studies, regular clinically allied interdepartmental meetings and pathological research. +Perinatal morbidity: It implies major illness of the neonate from birth to first 4 weeks of life. Important causes of morbidity are due to: (a) Prematurity and low birth weight, (b) Birth asphyxia and birth trauma, (c) Congenital malformations. +I STILLBIRTHS +A stillbirth is the birth of a newborn after 28th com­ pleted week ( weighing 1000 g or more) when the baby does not breathe or show any sign of life after delivery (Fig. 38.4). Such deaths include antepartum deaths (macerated) and intrapartum deaths (fresh stillbirths). Stillbirths rate is the number of such deaths per 1000 total births (live and stillbirth) (Table 38.7 and 38.8). I NEONATAL DEATHS +Neonatal death is the death of the infant within 28 days after birth. Neonatal mortality rate is the number of + + +such deaths per 1000 live births. Majority of the deaths occur within 48 hours of birth. +Causes: The causes of death within 7 days are almost always obstetrically related (Table 38.7) and as such stillbirths and neonatal deaths within 7 days are grouped together as perinatal deaths. About two-thirds of the neonatal deaths are related to prematurity. +HEALTH PROGRAMS IN MATERNAL AND CHILD HEALTH CARE (Government of India) +1. Reproductive and Child Health (RCH) +2. Janani Sishu Suraksha Karyakaram (JSSK) 2011. 3. LaQShya: Labor room quality +4. Anemia Mukt Bharat to reduce anemia to <32% (NIPl-2018). +Improvement in initiative:To ensure Respectful Maternity Care (RMC)-2017. + +NATIONAL DIGITAL HEALTH MISSION (NDHM) +Objective: It is to create a digital echo system that supports universal health coverage with the use of a national health ID for every citizen.There are six building blocks to it-(a) Health data (personal health records) with the use of NDHM registry, (b) Health ID, (c) Health registries-to provide information about doctors, nurses, ASHAs and others, (d) Health claims (through e-claim form), (e) Health Data Analytics for health information providers, (f) Use ofTelemedicine and e-Pharmacy Network. +Aims of the Care +1. To reduce maternal and newborn mortality and morbidity. + + +Table 38.8:_ Important causes of stillbirths and min' 1nte_rventions: .. ' . . . + +Causes +Birth asphyxia and trauma +Pregnancy complications (placental abruption, hypertension, diabetes mellitus) +Fetal congenital malformations and chromosomal anomalies Infections +Causes unknown + + +Proven interventions +Skilled attendants at birth. Effective management of obstetric complications Prepregnancy care, effective management of pregnancy complications. + +Preconceptional genetic counseling, prenatal diagnosis Effective care during pregnancy and labor. Clean delivery. +(Ch. 22, Box 22.4) +&I Chapter 38: Safe Motherhood, Epidemiology of Obstetrics + +2. To improve quality of care: +(a) Intrapartum care; (b) Postpartum care; (c) Timely referral; (d) Improve communication +3. National rural health message (NRHM 2005-12). Read more Dutta's Bedside Clinics and Viva-Voce in Obstetrics and Gynecology (p. 348) +4. National Digital Health Mission (NDHM) +Training for skill development in obstetrics +The special areas that need development of skill for improving the outcomes in obstetrics are: +1. Operative vaginal delivery: Instrumental deliveries (forceps/ventouse) (p. 530) + +2. Assisted vaginal breech delive1y (p. 361) 3. Shoulder dystocia-management (p. 383) +4. Internal podalic version and breech extraction (p. 542) 5. Cesarean delivery (p. 542) +6. Communication skill (p. 592) 7. Breaking the bad news (p. 593) +Method of skill development: +A. Use of simulations-in the form of mannequins or computer generated programmes are of help. +B. Different training programs and courses are available for this purpose in many medical institutions/ organizations including ICOG, FOGSI, in India. + + + + + +> Safe motherhood is a global effort to achieve the SDG target of MMR 70 per 100,000 live births, by 2030. +> Lifetime risk of dying from pregnancy related complications for a woman of UC regions is 1 in 150, compared to 1 in 4,900 in the developed regions in India, presently, it is 0.3%. +> The 2030 agenda comprises 17 Sustainable Development Goals (SDGs). It integrates all three main dimensions of developments (economic, social and environmental). +> National sociodemographic goals for 2015 and international commitment are to improve maternal and newborn health. RCH care is an integrated and composite care to improve the health of the women and children in India. +> Maternal death is expressed (MMR) per 100,000 live births. Maternal deaths are classified into-(a) Direct, (b) Indirect and (c) Fortuitous deaths. In India, MMR presently is 130 per 100,000 live births (2014-2016). +> Important causes of maternal deaths are: (i) Hemorrhage (20-25%), (ii) Hypertension (15-20%), (iii) Infection (11%), (iv) Unsafe abortion (8%), (v) Obstructed labor (9%), (vi) Anemia (15-20%), and (vii) Other indirect (viral hepatitis) causes (5-10%) (p. 556). +> Maternal Near Miss is a condition when a woman who nearly died but survived from a severe health condition, during pregnancy, childbirth or within 6 weeks of puerperium. For diagnosis, patient should meet 3 criteria-(1) Clinical (symptoms/signs); (2) Investigation; (3) Intervention. +> There are several proved interventions that can prevent maternal deaths. Steps to reduce maternal mortality are a coordinated long­ term effort (Table 38.6). +> Maternal morbidity (obstetric morbidity) develops from any cause related to pregnancy, childbirth or puerperium. Nearly 15 more women suffer from severe morbidity, when there is one maternal death. +> Perinatal mortality is expressed per 1000 total births. Important causes of PNM are: (i) Infection (33%), (ii) Birth asphyxia and trauma (28%), (iii) Preterm birth and/or LBW (24%), and (iv) Congenital malformation (15%). +> Important causes of stillbirths are: Birth asphyxia and trauma (30%), pregnancy complications (30%) and others. +> The SDGs '2030 agenda proposed to reduce maternal mortality to <70/100,000 LB and to reduce neonatal mortality to 12/1000 LB. No country should have an MMR higher than 140 deaths per 100,000 live births (twice the global target). +> The key strategies towards Ending Preventable Maternal Mortality (EPMM) by 2030 (WHO 2015) are: to address inequalities, to ensure universal and comprehensive health care, to ensure accountability and the others. +> Specific interventions to prevent maternal deaths are: Preventing and managing the complications of pregnancy, to end poverty and inequalities and the others. + + +Special Topics in Obstetrics + + + + + + + + +CHAPTER OUTLINE +❖ lntrapartum Fetal Evaluation ► Methods of Fetal Evaluation +❖ Nonreassuring Fetal Status +(NRFS) +► Management +❖ Shock in Obstetrics +► Classification +► Pathophysiology ► General Changes + + +► Hypovolemic Shock ► Endotoxic Shock \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_18.txt b/notes/DC Dutta Obstetrics 10th Edition_18.txt new file mode 100644 index 0000000000000000000000000000000000000000..0d3e2252dc37e53584c964c26cb0fb835fca90e7 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_18.txt @@ -0,0 +1,2027 @@ +❖ Management of Shock +❖ Acute Kidney Injury (AKI) +► Causes +► Management in Obstetrics +❖ Blood Coagulation Disorders in Obstetrics +► Normal Blood Coagulation + + +► Pathology of Acquired Coagulopathy ► Investigations +► Treatment +❖ High-risk Pregnancy +► Screening of High-risk Cases +► Management of High-risk Cases ❖ Immunology in Obstetrics +❖ Critical Care in Obstetrics + + + + +INTRAPARTUM FETAL EVALUATION + +By deflnUion, Int,apa,tum Fetal Evaluation (IFM) means to watch the fetal condition • · during labor. The goal of IFM is to detect +- +!I +hypoxia in labor and to initiate management ■ .... depending upon the severity of hypoxia. Severe hypoxia in labor when associated with metabolic acidosis can cause fetal organ damage or fetal death. +In between contractions the intraluminal pressure within the spiral artery (85 mm Hg) is higher than the intramyometrial pressure (10 mm Hg) to maintain the uteroplacental blood flow. During peak uterine contractions, myometrial pressure (120 mm Hg) exceeds the arterial pressure (90 mm Hg) causing +temporary halting of 02 delivery to the fetus through the placenta. Depending upon the intensity and duration of +contraction, fetal hypoxia may develop. +The objective of intrapartum fetal monitoring is to prevent fetal organ injury that may be caused by intrapartum fetal hypoxia. +Even in a normal labor, the baby is subjected to stress due to: +1. Uterine contractions temporarily curtailing the uteroplacental circulation. +2. Cord compression with contractions can cause intermit­ tent interruption of blood flow and may cause hypoxia. +Factors for the release of oxygen from hemoglobin are (factors for shift of oxyhemoglobin saturation curve to the right): (a) increased levels of 2,3-diphosphoglycerate (DPG) concentration, (b) production of lactic acid +(decreased pH), (c) increased partial pressure of CO2 +(pC02). + +Fetal defense mechanism to hypoxia +■ t 02 extraction by the tissues. +■ !- Non-essential activity(!- fetal movement). +11 t Sympathoadrenal activity(catecholamines). ■ t Glycogenolysis. +11 t Anaerobic metabolism (tK+, tlactate). +■ t Redistribution of blood flow (heart, brain). ■ t Use of bicarbonate to stabilize pH. +11 Metabolic acidosis. +■ Persistent acidemia, hypotension. +■ Multiorgan hypoperfusion (heart, brain, adrenals). +■ Cellular dysfunction; ion shifts, !- enzyme function, t free radicals. +■ Cell injuty, organ damage ➔ fetal death. I METHODS OF FETAL MONITORING +A. Clinical B. Biophysical C. Biochemical +A. CLINICAL: To note the FHR-intermittent Auscultation of FHR using an ordinary stethoscope or a fetoscope or a handheld Doppler can be done to note its rate and rhythm. FHR should be recorded at every 30 minutes interval initially followed by 15 min intervals in the first stage and at about 5 min intervals in the second stage. The auscultation should be made for 60 sec par­ ticularly before and immediately following a uterine contraction. +Normal fetal heart rate is at an average of 140 beats per minute(bpm) in between contractions with a variation between 100 and 160 per min (FIGO ACOG: 110-160 bpm). There may be slowing of FHR during a contraction (vagal stimulation) which, however, comes back to normal +when the contraction passes off. +!J Chapter 39: Special Topics in Obstetrics +Table 39.1: Causes of fetal tachycardia and bradycardia lasting for> 1 O minutes. + +Causes of fetal tachycardia (FHR >160 bpm) +11 Drugs to mother: +(i) -sympathomimetic agents used to inhibit preterm labor (isoxsuprine, ritodrine); (ii) Vagolytic: atropine. +■ Maternal: Metabolic acidemia, hyperthyroidism. ■ Infection-both maternal and fetal. +11 Anemia-both maternal and fetal. ■ Fetal hypoxia. + + +Causes offetal bradycardia (FHR <: 110 bpm) +♦ Fetal hypoxia, acidosis. ♦ Fetal sepsis, anomalies. +♦ Drugs to mother, e.g., pethidine, antihypertensives (methyldopa, +propranolol), Mg504• +• Use of local anesthetic drugs, epidural analgesia. +♦ Fetal heart conduction defect (SLE). +♦ Maternal: Hypoglycemia, hypothermia. + + + +Limitations of clinical methods +1. As it is a periodic observation, any transient significant abnormality in between observations is likely to be overlooked; +2. Inherent human error; +3. Difficult, at times, to count the FHR during uterine contractions or in case of obesity or hydramnios. +Evidences of distress +1. An increase in FHR to over 160/min (tachycardia +lasting for >10 minutes) or a decrease in rate to less than 100/min (bradycardia) (Table 39.1); +2. FHR takes a long time to come back to its normal rate after the contraction passes off; +3. Fetal heart rate irregularity. +Meconium in the liquor amnii: Meconium in the liquor amnii is a potential sign of fetal hypoxia. It acts as a toxin, if the fetus aspirates this particulate matter. Pathogenesis: Hypoxia ➔(t) vagal response ➔ (t) peristaltic activity and relaxation of the anal sphincter ➔ passage of meconium. The vicious circle is: Placental insuficiency ➔ oligohydramnios ➔ cord compression ➔ hypoxia ➔ thick meconium ➔ gasping breath ➔ meconium aspiration. Meconium staining of the liquor as observed following rupture of the membranes gives a crude idea of intrauterine fetal jeopardy. It is observed in about 10-20% of labors. Presence of meconium and nonreassuring FUR pattern necessitates urgent intervention. On the other hand, reassuring FUR pattern and thin meconium can be managed expectantly. +Intermittent auscultation is recommended to monitor the fetus for a woman in labor without any complications. +B. (i) BIOPHYSICAL-Ultrasound: Doppler effect is used to detect Fetal Heart Rate (FHR) from cardiac motion and major fetal vessels. This observation has to be rechecked when an abnormality is detected. +(ii) CONTINUOUS ELECTRONIC FETAL MONITORING (EFM) Indications of continuous EFM are: +a. Maternal conditions: Hypertension diabetes, previous cesarean delivery, induced labor, APH, PROM, thick MSL, pyrexia (38°C on 2 ocassions, 2 hours apart), fresh bleeding in labor, oxytocin use for labor augmentation. +b. Fetal conditions: Small fetus (FGR), oligohydramnios, multiple pregnancy, abnormal FHR on auscultation. + +Two methods are applied: ♦ External: From maternal abdominal wall-noninvasive; ♦ Internal: Directly from the fetus-invasive. +Maternal position: Maternal lateral recumbent position or half sitting are preferable. +External (Fig. 35.4): Continuous tracing of FHR can be obtained using ultrasound Doppler effect. The transducers are placed on the maternal abdomen, one over thefundus and the other at a site where the fetal heart sound is best audible. Frequency of uterine contractions and uterine pressure are recorded simultaneously by tocodynamometer. +Internal: Fetal ECG tracing is made by applying a spiral pointed scalp electrode to the fetal scalp after rupturing the membranes (Fig. 39.1). Intrauterine pressure could be simultaneously measured by passing a catheter inside the uterine cavity. +CTG could be done with portable sensors that transmit signals wirelessly to a remote fetal monitor (telemetry). This allows the mother to move freely. Paper speed is 1 cm/min. +Internal scalp electrode should not be used in cases with active genital herpes infection, HIV or in a very preterm fetus ( <:32 weeks). +Categorization of FHR according to RCOG, NICE is as in Table 39.2. National Institute of Child and Human Development (2008), ACOG (2009); Three-tier FHR interpretation system. + + + + + + + + + + + + + + + + +Fig. 39.1: Scalp electrodes. +Chapter 39: Special Topics in Obstetrics + + +Table 39.2: Categorization of Fetal Heart Rate (FHR) features (RCOG, NICE). +-Baseline Variability +Feature (bpm) (bpm) Deceleration +Normal/ 110-160 >5-25 None or early or variable decelerations with no reassuring concerning features for <1 O min. + + + + +Accelerations +Present + +Categorization of CTG Traces +Based on four features (baseline FHR, variability, decelerations, accelerations) +Normal: All four features are reassuring. + + + +Non-reassuring + + + + +Abnormal + +100-109 OR +161-180 + + + +<100 OR +>180 + +<5 for 30 to 50 min. +OR +>25 for 15-25 min. + +<5 for >50 min OR >25 for >25 min OR sinusoidal pattern> 10 min. + + +Variable decelerations: +• +Dropping from baseline by s60 bpm, +recovering by s60 seconds OR >60 bpm, +recovering >60 seconds OR late decelerations. Present up to 30 minutes. +• +■ Occurring o:50% of contractions. +■ Nonreassuring variable decelerations (as +above) present even 30 min after conservative +measures OR +■ Late decelerations >30 min with >50% of +contractions OR +■ Bradycardia or a single prolonged deceleration lasting o:3 minutes. + + + + +Absence of accelerations with an otherwise normal CTG is of uncertain significance. + + +Suspicious: One nonreassuring and the rest are reassuring. + + + +Pathological: Two or more features nonreassuring OR one or more abnormal categories. + + + +Category I: Normal (baseline rate 110-160 bpm; FHR variability-moderate; no late, variable or prolonged deceleration; early deceleration±; acceleration±. +Category II: Indeterminate-all tracings not categorized as category I or III. +Category III: Abnormal (either absent baseline FHR variability and any one of the following: recurrent late/ variable decelerations, bradycardia at least for 10 min or sinusoidal pattern for at least 20 min). +Advantages of EFM over clinical monitoring ♦ Accurate monitoring of uterine contractions. +♦ Significant improvement of perinatal mortality. +♦ Can detect hypoxia early and can explain the mechanism of hypoxia and its specific treatment. +♦ Improvement of intrapartum fetal death by threefold. ♦ It is an important record for medicolegal purpose. +Drawbacks: +,. Interpretation is affected by intra- and interobserver error. +■ Due to error of interpretation (false positive) cesarean section rate (63%) and operative vaginal delivery (15%) are high. +■ Instruments are expensive and trained personnel are required to interpret a trace. +■ Mother has to be confined in bed unless portable sensors are used. +Fetal behavior states: (a) Deep sleep (no eye movements) up to 50 minutes, {b) active sleep (rapid eye movements) (c) wakefulness. All these are hall mark fetal neurological responsiveness and absence of hypoxia/ acidosis. Deep sleep is associated with stable base line, accelerations (rare) and borderline variability. Active sleep is associated with moderate number of accelerations and normal variability. Active wakefulness is rarer and + +represented by a good number of accelerations and normal variability. + +INTERPRETATION OF A CARDIOTOCOGRA PHY (CTG) +♦ Accelerations and normal baseline variability (5-25 bpm) denote a healthy fetus. +♦ Absence of accelerations is of unknown significance. +♦ Absence of accelerations, reduced baseline variability of <5 bpm for >50 minutes denotes a hypoxic fetus. +♦ Decreased baseline variability may be due to fetal sleep, infection, hypoxia, anomalies or due to maternal medications. +♦ Repeated late decelerations increase the risk of low Apgar score and hypoxemia. +♦ Reduced baseline variability, with late or variable deceleration lasting 3 minutes, increases the risk of hypoxia. +♦ Interpretation of the CTG should always be made in the context of clinical picture. +Baseline FHR is the mean level of FHR excluding accelerations and decelerations. It is expressed in beats per minute (bpm). Normal baseline FHR is 100-160 bpm. +Baseline variability is the oscillation of baseline FHR excluding the accelerations and decelerations. Variability is the reflex of normal cardiac behavior in response to sympathetic and parasympathetic nerve input. However, parasympathetic (vagus) has the dominant role in modulating variability. Baseline variability may be: +(A) Absent (B) Minimal ( <5 bpm) (C) Moderate (6-25 bpm) (D) Marked (>25 bpm) +Reduced baseline variability is observed in many conditions (Table 39.3). +Acceleration: Transient increase in FHR by 15 bpm or more lastingfor at least 15 seconds. Prolonged acceleration +Chapter 39: Special Topics in Obstetrics +• + +Table 39.3: Factors to cause FHR changes. +Factors to cause diminished fetal heart variability Factors (maternal/fetal) to alter FHR not related to oxygenation + +Maternal medications +■ Pethidine +■ Tranquilizers +■ Corticosteroids +■ Hypoxia, acidosis • Atropine +" General anesthesia + + +Fetal conditions • Prematurity +■ Sleep cycle Hypoxia Anemia +• +• +• +• +Metabolic acidemia Infection +" Congenital malformation + + +Factor(s) +• Infections Prematurity Fetal anemia Fetal sleep Heart block +• +• +• +• + +Alteration in FHR +■ Tachycardia, tvariability. ■ Tachycardia, tvariability. +■ Sinusoidal pattern, tachycardia. tvariability, taccelerations. +• +■ ,,variability, bradycardia. + + + +lasts ?.2 min but <10 min. When it lasts ?.10 min, it is called baseline change. Acceleration denotes an intact neurohormonal and cardiovascular activity and therefore, a healthy fetus (Fig. 39.2). +Deceleration: Transient decrease in FHR below the baseline by 15 bpm or more and lasting ?.15 seconds (Fig. 39.3). +Three basic types of deceleration are observed and are called early, late and variable (Fig. 39.3). +■ Early deceleration (Type I Dips), uniform, repetitive periodic slowing of FHR and, in most cases, the onset, nadir and recovery of deceleration coincides with the beginning, peak and ending of uterine contraction respectively. It is due to head compression (vagal nerve activation) (Fig. 39.3). It is usually benign (no hypoxia) in nature. +■ Late deceleration (Type II Dips), uniform, U shaped with reduced variability within the deceleration segment and with repetitive periodic slowing of FHR. It begins >20 sec after the onset of the uterine contraction. Usually, the onset, nadir and recove1y of the deceleration occur after the start, peak and end of the uterine contraction respectively. Nadir occurs 20 seconds after the peak of the contraction (acme) and FHR returns to normal after the contraction is over. It suggests uteroplacental insufficiency (Fig. 39.4) and fetal hypoxia (50%). + + + + + + + + + + + + + + + + + + + + + +a: + +I +LL + + +2©0 + +180+·· +160 +. ·1-4© /-It- +H/0 + +1©0 +80 + +60 +CGBI 100 CG46 +B" +-,- +6p +PHuOIsNO 4p .... TOCO +- +21,! +-,- +TOCO 0 +Fig. 39.2: Reactive trace with acceleration. + +160 deceleration::: II Variable 140 +Ill +I +Early +: +shape +120 100 + + + +■ Causes of late deceleration: +i. Placental pathology (postmaturity, hypertension, diabetes, placental abruption); +ii. Excessive uterine contractions; + + + +Fig. 39.3: Graphic representation showing various types of decelerations in relation to uterine contractions. + + + + +•• • ·754·1a· • • • • • • • • • • • • ;40• • • • • ·754;9 •• 75420 240 . 0 2-10 +1-80 80 mo +1-50 -50 150 1-20 +90 +90 +60 60 +30 0 30~ +.00 mo +mo +" +ZS .s 50 50 50 ff ff +0 0 0 +I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Ill I Ill I I I I I I I I I I I I I I I I I I I I I I I I I I Il I I I I I + + +Admission CTG is a CTG trace done for a woman on admission in the labor ward. Admission CTG is poor in predicting fetal compromises in labor. Routine admission CTG testing is not recommended in low-risk women. + +Fig. 39.4: Persistent late deceleration with loss of variability. + + +iii. Injudicious use of oxytocin; +iv. Regional anesthesia (spinal or epidural). +■ Variable deceleration: It is the intermittent periodic slowing (variable) of FHR (V shaped) with rapid onset and recovery (Fig. 39.3). Decelerations are variable in all respect of size, shape, depth, duration and timing to the uterine contractions. When it is 'U' shaped with reduced variability and/or duration c:3 minutes, it suggests fetal hypoxia/acidosis. It is thought to indicate cord compression and may disappear with the change in position of the patient. It is the most common type. Accelerations often precede and follow the deceleration. It is called shoulders. Concerning character of a variable deceleration: (a) Lasting >60s, (b) No shouldering, (c) Reduced baseline variability, (d) Faliure to return to baseline; biphasic (W) shape. Prolonged deceleration is the abrupt decrease in +FHR (c:15 bpm) to levels below the baseline and it lasts >3 min but <10 min. Commonly seen following: Placental abruption, Uterine rupture, Cord prolapse, Uterine hyperstimulation and Epidural top-up. It indicates +hypoxia and acidosis and require emergent intervention. Prolonged deceleration: it indicates fetal hypoxia/acidosis and require emergent intervention. Fetal pH drop by 0.01/min. If it lasts c:10 min, it is a baseline change. +Lag period: It is the time taken for the FHR to reach the nadir (the lowest point of the FHR dip) from the apex of the preceding uterine contraction (Fig. 39.3). In deceleration lag period is c:30 seconds. +Sinusoidal pattern: It resembles a sine wave (3-5 cycles/min). It has a stable baseline FHR with fixed or absent baseline variability (:55) lasting c:30 min. Accelerations are absent. It is often associated with fetal anemia, fetomaternal hemorrhage, vasa previa, fetal hypoxia (acidosis) (Fig. 39.5). It may occur when narcotics are given to mother. Such FHR showing 'sawtoothed' pattern are called pseudosinusoidal as the fetus is well-oxygenated. It is observed in fetomaternal hemorrhage, twin to twin transfusion syndrome, ruptured vasa previa and +hydrops fetalis. +Pseudosinusoidal pattern: It is more jagged "saw tooth" pattern rather than the smooth sine-wave form. +....... +28352 +• ••••••••••••••••• 2s"J° Y ••••••••••••••••••• "iiis·.' +s +4 +21Jl 21Jl +21() 1() +8Jl +tBJl +,s_o iJ;_o +:20 +90 90 60 0 +0 +00 .00 +1-5 25 +0- +1 111 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I +Fig. 39.5: Sinusoidal pattern showing absence of baseline variability. + +Chapter 39: Special Topics in Obstetrics + +It seldom exceeds 30 minutes. It is often observed after analgesic/sedative drugs. At times it is difficult to distin­ guish from true sinusoidal pattern except the short duration. +C. INDUCED FETAL STIMULATION AND FHR ACCELERA­ TIONS: Any FHR acceleration spontaneous or induced, indicates the absence of fetal acidosis. +Vibroacoustic Stimulation (VAS) of the fetus is done using an electronic larynx placed on the maternal abdomen. Presence of FHR accelerations indicates normal blood pH. +Fetal scalp stimulation by gentle digital stroke is done before scalp blood pH test. Presence of FHR accelerations is associated with normal scalp blood pH. +Halogen light stimulation is used. FHR accelerations suggests normal pH. Positive response. +Place of auscultation of fetal heart sound versus EFM: Intermittent auscultation is an effective method for evaluation of fetal wellbeing. It is as effective as EFM. In the high-risk patient, auscultation should be done at every 15 minutes in the first stage and at every 5 minutes +in the second stage. In the low-risk group, or in the absence of adequate staff, it may be done at an interval of 30 minutes in the first stage and at every 15 minutes in the second stage. Auscultation should be done for a period of 60 seconds after a uterine contraction. When any audible abnormality is heard, continuous auscultation or conversion to EFM is recommended. +Fetuses with abnormal FHR pattern on auscultation should have EFM to detect any nonreassuring patterns. +D. BIOCHEMICAL: Fetal scalp Blood Sampling (FBS): To corroborate the significance of fetal CTG abnormality due to hypoxia. Saling, in 1962, demonstrated a simple and quick method to obtain fetal blood samples from the scalp to detect the fetal blood pH. Fetal scalp blood pH <7.20 is abnormal and indicates fetal acidosis and urgent delivery, pH between 7.21 and 7.25 is borderline and needs to be repeated within 30 minutes. pH >7.25 is reassuring and labor progress is monitored. pH to be repeated after 30 minutes to detect any changes. It has high specificity. The positive predictive value of a low scalp pH in identifying a newborn with hypoxic ischemic encephalopathy is low. If the CTG (after resuscitation effects) remain unchanged, a second FBS is indicated. FBS can be done for a maximum of 4 times. Lactate levels of the fetus are often correlated with FBS values: <4.1: Normal; >4.9: Abnormal; 4.2-4.9: Boderline. Currently it is not used in many institutions. +Procedures: Mother is in left lateral position. An illuminated plastic cone is inserted through the dilated cervix ( 4-5 cm) against the fetal head. An incision of 2 mm depth is made with a lancet. Blood is collected (35 µL may be adequate for analysis with most pH monitors) with a long capilla1y tube for pH and base excess estimation. +mJ Chapter 39: Special Topics in Obstetrics +Indications: (i) Nonreassuring CTG in labor, (ii) Bio­ chemical assessment of fetal hypoxia. +Contraindications: +i. When delivery is urgently indicated or spontaneous delivery is imminent. +ii. Maternal infection (HIV, hepatitis or herpes simplex virus). +iii. Fetal coagulation disorders. iv. Prematurity ( <34 weeks). +v. Cervical dialation of 4 cm. +Risks involved are: • Fetal bleeding from the incision site and maternal injury. • False prediction is about 10%. +E. FETAL ELECTROCARDIOGRAM (ECG) analysis has been done with ST segment and T wave analysis (STAN) or with T/QRS ratio. An increase in T-wave amplitude occurs in hypoxia. Each fetus has its own baseline T/QRS. A normal fetus has a T/QRS <0.25. A significant increase in T/QRS or more than two consecutive biphasic ST in fetal ECG complexes, combined with a nonreassuring FHR tracings (CTG), indicates fetal metabolic acidosis. Fetal ECG analysis (ST-segment analysis) when combined with CTG, reduces operative delivery rates compared to CTG alone. Limitations: Not used for fetus <36 weeks. Cannot be used alone for decision making. +F. Umbilical arterial cord (or neonatal) blood samples with pH <7.0 and base deficit of >12 mmol indicates profound metabolic acidemia and multiple organ dysfunction. Intrapartum umbilical artery Doppler study was poor to predict umbilical artery acidosis. A positive test increases the cesarean delivery rates. There is a correlation between NRFS and neonatal depression, but it is not related with the long-term neurologic sequelae. +G. Fetal pulse oximetry is no longer used as its accuracy is uncertain. + +NONREASSURING FETAL STATUS (NRFS) + +DEFINITION: Fetal distress is an ill-defined !) !·) term, used to express intrauterine fetal jeopardy, a result of intrauterine fetal .Ea;;i hypoxia. Nonreassuring Fetal Status !] (NRFS) is characterized by tachycardia or bradycardia, reduced FHR variability, decelerations and absence of + + + +accelerations (spontaneous or elicited). It must be emphasized that hypoxia and acidosis is the ultimate result of the many causes of intrauterine fetal compromise (Box39.l). +FHR patterns in labor are dynamic and can change rapidly from normal to abnormal and vice versa. Because of this uncertainty about the diagnosis of fetal distress, terminologies used are 'Reassuring' and 'Nonreassuring'. +Nonreassuring fetal heart rate pattern is associated with fetal hypoxia, acidosis and, therefore, called fetal distress (Box 39.1). Features to rule out metabolic acidosis are: (a) Presence of accelerations, (b) moderate variability, and (c) scalp blood pH >7.25. +Fetal condition at birth is assessed by blood gas values of the umbilical artery. Normal (mean) values are: pH +7.27, PC02 50; Hco- 23, base excess -3.6. The correlation +3 +between the FHR and long-term neurological sequelae is poor. In many cases, asphyxia occurs prior to labor. + +MANAGEMENT OF NONREASSURING FETAL STATUS (NRFS) + +Ideally, management should be specific to the cause ofNRFS. +NONSURGICAL: Management is aimed to reverse the abnormality (hypoxia) by noninvasive procedures. +■ Lateral positioning avoids compression of vena cava and aorta by the gravid uterus. This increases cardiac output and uteroplacental perfusion. This also reduces umbilical cord compression. +11 Change in maternal position also reduces cord compression. +■ Oxygen is administered (6-8 L/min) for short periods +to the mother with face mask to improve fetal Sa02• +■ Correction of dehydration by IV fluids (crystalloids) improves intravascular volume and uterine perfusion. +■ Correction of maternal hypotension (following epidural analgesia) with immediate infusion of 1 liter of crystalloid (Ringer's solution). +■ Stoppage of oxytocin to improve fetal oxygenation. Fetal hypoxia may be due to strong and sustained uterine contractions. With reassuring FHR and in absence of fetal acidemia, oxytocin may be restarted. + + + + +A.Acute: +I. During pregnancy-less common +♦ Placental separation in placenta previa or abruptio placentae + Following external cephalic version due to cord entangle- +ment +♦ During oxytocin induction + Diabetes ++ Hypertension + +II. During labor-common ++ Uterine tachysystole following oxytocin for augmentation of labor. + Placental abruption. ++ Uterine rupture or scar dehiscence. + Cord prolapse. ++ Injudicious administration of oxytocin, analgesics and anesthetic agents. ++ Maternal hypotension-as in epidural analgesia. + +B. Chronic: The various clinical conditions which are responsible for chronic placental insufficiency and IUGR, are also linked with chronic fetal distress. +Chapter 39: Special Topics in Obstetrics JI:---­ 11 Remove prostaglandins (vaginal pessa1y). patients need to be evaluated (continuous or intermittent) +11 Tocolytic (Injection terbutaline 0.25 mg SC) is given as required to exclude acidosis. Labor progress is to be when uterus is hypertonus and there is nonreassuring monitored, vaginal delivery could be done safely. +FHR. Tocolytics increase oxygen to the fetus. B. Persistence of nonreassuring pattern or the fetus • To avoid sustained pushing in the second stage of labor. becoming acidotic, patient needs immediate delivery. • Amnioinfusion can be given for NRFS. SURGICAL: Cesarean delivery should be done with a +Amnioinfusion is the process to increase the intraute­ 15° lateral tilt till the baby is delivered. Thirty minutes +rine fluid volume with warm normal saline (500 mL). ( Cat I) has been accepted as the gold standard for +Other indications of amnioinfusion: decision to delivery interval in cases of confirmed fetal +Pediatrician should be present. +compromise. +a. Oligohydramnios and cord compression, Limitation of cardiotocography: (a) Inter- and intra­ observer disagreement. (b) Criteria forinterpretation of +b. To dilute or to wash out meconium, +c. To improve variable or prolonged decelerations, +d. To reduce fetal gasping which is the result of hypoxia CTG are in identification of deceleration and evaluation due to cord compression. suspicious and pathological tracings. ( d) Suspicious and pathological tracings have a limited capacity to predict +of variability. (c) Disagreements are more with the +Advantages of amnioinjusion: +Reduces cord compres­ +sion, meconium aspiration, and improves Apgar score. It +also reduces cesarean section rate. +metabolic acidosis and hypoxic neurologic injury. Thus Routine prophylactic use of amnioinfusion for meco­ CTG has low specificity and low positive predictive value. +Continuous monitoring with CTG is not recommended +nium stained liquor is not recommended (ACOG). for all women in labor. Benefits of CTG in monitoring in If the fetal heart rate pattern remains nonreassuring, labor was reduction in neonatal seizures (50%}. Only a further tests are performed to rule out fetal acidosis. small proportion of perinatal deaths and cerebral palsies Tests are: (i) To detect FHR accelerations (CTG)­ are caused by intrapartum hypoxia/acidosis. On the other spontaneous or induced ( digital fetal scalp stimulation), hand continuous CTG was associated with 63% increase (ii) Scalp blood pH, (iii) Fetal ECG/ST-segment analysis in cesarean delivery and 15% increase in instrumental (STAN), combined with CTG. Above supportive measures vaginal delivery. Unnecessary obstetric intervention due +are continued and the women is revaluated. to poor CTG in interpretation confer more risks for the A. Conversion of NRFS to a reassuring pattern (RFS) and mother and the newborn. Computer analyses of CTG without any evidence of metabolic acidosis (presence of are more precise but has not improved the prediction of +accelerations, variability and scalp blood pH > 7 .25): these neonatal outcome. r:f:.,n +► lntrapartum fetal monitoring is done to evaluate the oxygenation of a fetus during labor. The sole objective is to take appropriate steps +in time so that fetal hypoxic injury is prevented. +► Continuous EFM (CTG) in labor reduces neonatal seizures by 50%. +► EFM, scalp pH and ST analysis are used to detect intrapartum fetal hypoxia. +► Methods of intrapartum monitoring includes: (1) Clinical monitoring: (a) intermittent auscultation, (bl color of the liquor (meconium). (2) Biophysical: (a) CTG, (bl induced fetal stimulation (acoustic, fetal scalp). (3) Doppler velocimetry for UA. (4) Combined fetal CTG & ECG. (5) Biochemical: (a) Fetal blood sampling (pH), (b) Lactate estimation. +► Intermittent auscultation is an effective method. Fetuses with abnormal FHR pattern on auscultation should have EFM. +► EFM has few limitations. Normal CTG indicates a healthy fetus, whereas abnormal FHR pattern in CTG does not always indicate +fetal asphyxia. Limitations are: • Inter- and intra-observer disagreement of CTG report, • Different CTG interpretation criteria, • Limited knowledge about the pathophysiology of fetal hypoxia. +► Presence of accelerations and normal variability denote a healthy fetus. +► False positive rate of EFM for predicting fetal hypoxia is high. CTG has low specificity and low positive predictive value to detect fetal acidosis. +► Loss of variability, loss of acceleration and presence of bradycardia indicate fetal compromise. +► Decelerations that occur with 50% of uterine contractions in a 20 minute window are defined as recurrent decelerations. ► Presence of accelerations of the FHR either spontaneous or induced (VAS stimulation), indicates absence of fetal acidosis. +► EFM is most reliable when FHR pattern is reassuring (category-I) and when there is fetal acidosis (category-Ill). It is most unreliable when tracings are equivocal (category-II). +► High-risk labor should be monitored continuously. Use of continuous EFM is associated with an increased rate ofoperative interventions (vacuum/forceps-15%, or cesarean delivery-63%). Only a small proportion of perinatal deaths and CP are caused by intrapartum hypoxia and/or acidosis. +► Nonsurgical measures are used to improve or reverse hypoxia. +► Persistent hypoxia or presence of metabolic acidosis needs expeditious delivery of the baby to prevent neurological injury and organ damage. +► Amnioinfusion for variable decelerations may reduce the rate of cesarean section. +fD Chapter 39: Special Topics in Obstetrics SHOCK IN OBSTETRICS +DEFINITION: Shock is defined as a state of +- +!l !l +cj + + +circulatory inadequacy with poor tissue ·' perfusion resulting in generalized cellular hypoxia. Circulatory inadequacy is due +to a disparity between the circulating blood volume and the capacity of the circulatory bed. The net effect of this disparity is inadequate exchange of oxygen and carbon dioxide between the intra- and extravascular compartments. The stagnation of carbon dioxide and other metabolites in the tissue leads to metabolic acidosis, cellular dysfunction and death. The series of changes +observed in shock and their clinical manifestations, are therefore, dependent on two sets of changes: (a) Circulatory inadequacy at the 'filtration' level (microvascular compartment), (b) Cellular damage and ultimately death. +Anatomy of microvascular circulation: Microvascular circulation consists of circulation of blood through a tuft of capillaries with a feeding arteriole and a draining venule at either end of the capillary bed. The flow of blood within the capillary bed is controlled by 2 sphincters-one at the arteriolar end and the other at the venular end. They are known as pre- and postcapillary sphincters. In addition to the tuft of capillaries, there is a direct communication between the arteriole and the +venule and this communicating trunk bypasses the capillary bed. This is known as metarteriole shunt or 'thorougllfare channel'. When the sphincters are closed, the metarteriole shunt operates to divert blood for supply to the vital organs, like brain, heart and kidney. The basic pattern of microcirculation is schematically represented in Figure 39.6. + +I PATHOPHYSIOLOGY OF SHOCK + +Pathophysiological changes in obstetric shock are predominantly associated with: (a) general changes due to hypovolemia, and (b) specific changes due to liberation of endotoxin. +Hypotension stimulates release of neuroendocrine mediators like Adrenocorticotropic Hormone (ACTH), Growth Hormone (GH), endorphin, cortisol and + + +Arteriole + +·., 7 l +l +_ True I l +: +-,_ +capillary: : Metarteriole : +I +I +I +I +: Thoroughfare +_________ J chan: nel __ -1.- U- I +I +I +capillary I +I +I +___________________ J + + + +Fig. 39.6: Schematic diagram of a microcirculatory unit. + + + +glucagon (Flowchart 39.1). There is also sympathoadrenal response. Presence of endotoxin (lipopolysaccharide), in septic shock activates the leukocytes through complement system. There is release of inflammatory mediators such +as proteases, superoxide (02), hydroxyl (OH-) radicals, cytokines, prostaglandins and many cytotoxic enzymes. +These interfere with the function of a number of enzyme systems and increase capillary permeability. Cytokines such as Interleukins (ILS) and Tumor Necrosis Factor (TNF) interact by autocrine and paracrine mechanism to cause cellular or organ dysfunction. In presence of hypoxia, sepsis and acidosis, lysosomal enzymes which are cytotoxic, are released. They can cause myocardial depression and coronary vasoconstriction. +Prostacyclin is a vasodilator and inhibits platelet aggregation. +Thromboxane A2 causes pulmonary vasoconstriction and platelet aggregation. Leukotrienes cause vasoconstriction, platelet +activation and increased vascular permeability. Endothelium­ Derived Relaxing Factor (EDRF) which is identified as Nitric Oxide (NO) is found to produce sustained vasodilatation and hypotension. Thrombosis is increased due to inhibition of antithrombin III. Thrombocytopenia is common. +In pregnancy prostaglandins and nitric oxide, upregulated by estradiol are implicated in physiological adaptation required to support the developing fetus. This may make pregnant women more susceptible to abrupt hypotension due to infection. The women suffers the risk of tissue hypoxia and organ dysfunction. +Metabolic changes: Hepatic glycogenolysis due to increased level of glucagon, catecholamine and cortisol leads to hyperglycemia. There is diminished peripheral utilization of glucose due to increased level of insulin antagonists like cortisol and growth hormone. Inadequate oxygen supply to tissue initiates anaerobic metabolism. Consequently, there is metabolic acidosis, production of lactic acid and H+ ions. Sodium pump fails to operate. Finally, the lysosomal enzymes are released. These lead to cell death. + +GENERAL CHANGES IN SHOCK (WITH SPECIAL REFERENCE TO HYPOVOLEMIC SHOCK) + +The changes are in four phases. The first two phases are reversible; the third one probably correctable and the fourth is irreversible: +♦ First phase: Sympathetic impulses and the level of circulating catecholamines increase in response to hypovolemia, cardiogenic or neurogenic stimulus. +♦ Second phase: As a result of excessive sympathetic stimulus, there is constriction of the pre- and postcapillary sphincters, resulting in inadequate venous return leading to diminished cardiac output, clinical manifestations of which are hypotension and tachycardia. +Compensatory mechanisms that operate at this stage to maintain the blood pressure, has been discussed in the (Flowchart 39.1). +These mechanisms attempt to correct hypovolemia, improve cardiac output and the perfusion of vital organs. +Chapter 39: Special Topics in Obstetrics + +Flowchart 39.1: Pathogenesis of Septic Shock. + +INFECTION (sepsis syndrome) +i +(Septic abortion, septic peritonitis, pyelonephritis, chorioamnionitis/endometritis/Necrotizing fascitis) + +Gram-negative (70-80%) Gram-positive (20-30%) + +(Aerobic and anaerobic) + +Endotoxin (lipopolysaccharide acid} + +• • 0 • N utrophils • Monocytes +• +• +.. +. +. +- +l + + +Exotoxin (lipoteichoic acid) +• Macrophages • Endothelial cells (j. + + +Systemic inflammatory response (SIR) +lI +l + + +• Endogenous mediators • Autocrine and paracrine action +I +1 l 1 +• Cytokines, chemokines (T cells, B cells).• Platelet activating factor. • Endothelin-1. +• Proinflammatory: IL 1, IL 6, IL 8, • Prostaglandins (PGE , PGl , TXA )- • Cytotoxic enzymes. +2 +2 2 +IL 12, TNFa, interferon. • p endorphins. • Complements C3a, C5b. + Anti-inflammatory: IL4, IL 10, TGFp. • lnterferon-y. • Nitric oxide. +i l ! +Myocardial effects Vascular effects ■ Coagulation cascade activation. +■ Cardiomyocyte death. ■ Vasodilatation. ■ Vasoconstriction. +■ Myocardial contraction!-. ■ Maldistribution of blood flow. ■ Fibrin deposition. +■ Cardiomyopathy. ■ lntravascular thrombosis. ■ Microthrombi formation. +■ LV ejection fraction i. ■ Endothelial cell injury. ■ ARDS. ■ Thrombocytopenia. +■ Cardiac output ,I._ ■ Hypotension. ■ Tissue hypoperfusion. ■ DIC. ■ tcapillary permeability. +1---------_, + +----------- I Irreversible phase +-,+1 +I +l +Persistent hypotension Metabolic acidosis Severe myocardial depression + + +Multiorgan Dysfunction Syndrome (MODS) + + + +At this stage replacement of blood volume (transfusion) and control of hemorrhage are usually effective in restoring the normal circulatory balance and tissue perfusion. +♦ Third phase: Prolonged anoxia of the tissues will lead to excessive production of lactic acid (acidosis). Lactic acid and anoxia cause relaxation of the precapillary sphincters but not the postcapillary sphincters. In addition, +thromboxane A2 and leukotrienes (endogenous mediators) cause damage to the endothelial cells of the capillaries of the +microcirculatory bed. These lead to formation of thrombus within the capillaries (diffuse intravascular coagulation) and increased capillary permeability. +♦ Fourth phase: Consequent to persistent constriction of the postcapillary sphincter, blood remains stagnant within the capillary bed. Fluid from the capillaries leaks into the tissue spaces due to increased permeability. All fluids administered intravenously will go into the interstitial spaces and circulatory blood volume cannot be restored. Clinically, this is the stage of irreversible shock. There is severe loss of systemic vascular resistance, severe + + +myocardial depression ( I, cardiac output), unresponsive hypotension and ultimately multiple organ system failure. +Systemic Inflammatory Response Syndrome (SIRS) is manifested by two or more of the following conditions: (1) Temperature >38°C or <36°C, (2) HR >90 bpm, (3) Respiratory rate >24/min, or (4) Serum lactate >l mmol/L, (5) WBC >12000/ µLor leukopenia: <4000/µL or more than 10% immature forms. +I CHANGES IN ENDOTOXIC SHOCK + +Endotoxic shock usually follows infection with gram­ negative organisms (75-80%). The most common organism involved is Escherichia coli (50%). Other organisms occasionally responsible for endotoxic shock are, Pseudomonas aeruginosa, Klebsiella, Proteus, Bacteroides and Aerobacter aerogenes. Gram-positive organisms (Staphylococcus, Streptococcus), anaerobes (Bacteroides +fragilis), Clostridium group are less common (20%). +Pathophysiology of endotoxic shock has been discussed before (Flowchart 39.1). Bacterial endotoxin +•=-· ml Chapter 39: Special Topics in Obstetrics + +causes selective vasospasm at the postcapillary end. Blood is pooled in the capillary bed. There is inhibition of myocardial function and cellular damage through complex biochemical changes (vide supra). +The patient in early septic shock feels warm due to vasodilatation. This is called warm shock. In the late phase, the patient feels cold due to vasoconstriction (sympathetic squeeze). This is called cold shock or late shock. Patient's skin becomes cold, clammy and ashen gray. +The various biochemical and pathological changes observed in endotoxic shock are: (i) Diffuse intravascular coagulation, (ii) Increased capillary permeability, (iii) Metabolic acidosis, (iv) Release of nitric oxide (NO) superoxide (0 -) and hydroxyl (OH-) radicals, (v) Failure of sodium pump operation, (vi) Water and electrolyte imbalance, (vii) Lowered pH, (viii) Altered enzyme function, (ix) ion shift and (x) Excessive and uncontrolled Systemic Inflammatory Response (SIR) can lead to cellular and tissue disfunction, injury and even death. Organ changes depend on the degree of hypoperfusion and extent of the underlying pathology: (a) Kidney­ Patchy and massive cortical necrosis leading to oliguria, anuria and azotemia. Persistent hypotension leads +2 +to acute tubular necrosis and ultimately renal failure. (b) Liver-Hepatocellular necrosis and degeneration ultimately leading to hepatic failure. (c) GI tract­ Hypoxic mucosa! injury increases systemic sepsis by translocation of intraluminal microbes. Congestion, hemorrhage and ulceration are responsible for hematemesis. (d) Lungs-Congestion or atelectasis leads to tachypnea or dyspnea, progressive hypoxemia and reduced pulmonary compliance. ARDS results from increased capillary permeability and thickening +of the alveolar capillary membranes. Arterial Pa02 is +low ( <65 mm Hg). Mechanical ventilation is needed. (e) Coagulopathy (DIC)-It is due to diffuse endothelial injury, microvascular thrombosis and thrombocytopenia. (f) Adrenal insuficiency is due to Critical Illness-Related Corticosteroid Insufficiency ( CIR CI). CIR CI causes hypotension which is refractory to fluid replacement. Vasopressor therapy is needed. (g) Heart-Cardiac output decreases depending on the degree of hypotension, hypoperfusion and vasoconstriction. Myocardial ischemia ➔ cardiac dysfunction ➔ dysrhythmias ➔ cardiac failure ➔t Left Ventricular End-Diastolic Pressure (LVEDP) ➔ pulmonary edema ➔ tissue hypoxia (h) Ultimately, multiple organ failure develops. Endotoxins have got special affinity for kidneys and lungs for reasons which are +not very clear. +I CLASSIFICATION OF SHOCK +Based on our understanding of the basic pathophysiology of shock and its clinical correlation; shock may be classified as follows +(Box39.2): + + + +1. Hypovolemic shock: (i) Hemorrhagic or (ii) Nonhemorrhagic. Hemorrhagic shock: Associated with postpartum or postabortal hemorrhage, ectopic pregnancy, placenta previa, abruptio placentae. +• Shock associated with disseminated intravascular coagulation. Nonhemorrhagic shock: +• Fluid loss shock-associated with excessive vomiting, diarrhea, diuresis or too rapid removal of amniotic fluid. +• Supine hypotensive syndrome. +2. Septic shock (endotoxic shock): Hypotension (systolic BP <90 mm Hg) is due to sepsis resulting in cellular and organ system dysfunction. +3. Cardiogenic shock: +• Myocardial infarction. +• Cardiac arrest (asystole or ventricular fibrillation). • Cardiac tamponade. +Characterized by I, systolic pressure(<80 mm Hg), ,I, cardiac index ( < 1.8 L/min/m2) and left ventricular filling pressure(> 18 mm Hg). +t +4. Extracardiac shock: Massive pulmonary embolism, amniotic +fluid embolism, anaphylaxis, drug overdose. +• Chemical injury: Aspiration of gastrointestinal contents during general anesthesia (Mendelson's syndrome). +• Drug-induced: Associated with spinal anesthesia. + +CLINICAL FEATURES OF SHOCK: Clinical features of shock depend on the basic etiological factors and, consequently, the sequence of pathological changes occurring within the microvascular unit. In early stages, the features of hypovolemic and septic shock are different. In the irreversible (late) phase, the clinical features are the same as the final pathology is multiple organ failure. It canies mortality of 30-100%. +Hemorrhagic Shock +■ Early phase (com11ensatory phase): In the early phase, there is mild vasoconstriction and with the compensatory mechanism operating, the patient has relatively normal blood pressure but tachycardia. This phase can be easily managed by volume replacement. +■ Intermediate phase (reversible phase): If the early phase remains untreated, the patient passes into the state of +hypotension. Patient progressively becomes pale; tachycardia persists and due to intense vasoconstriction, the periphery becomes cold and there may be sweating. Due to diversion of blood to vital organs, the patient remains conscious and the urine output is within normal limits. Still with adequate +management, the shock state can be reversed. +■ Late stage (irreversible): Hypotension continues and cannot be reversed by fluid replacement (CIRCI). Extremities become cold and clammy because of vasoconstriction due to sympathetic stimulation. Metabolic acidosis, coagulopathy and thrombocytopenia are associated. Practically, imperceptible low volume pulse, oliguria, mental confusion is observed. Patient is in MODS. Treatment of any kind is practically useless in this phase and mortality varies between 3% and 100%. +NEUROGENIC SHOCK: The basic pathological factors in both hemorrhagic and neurogenic shock are more or less the same except for the fact that hemorrhagic shock is hypovolemic and neurogenic shock, initially is +Chapter 39: Special Topics in Obstetrics &BL + + +normovolemic, though this becomes hypovolemic in the later phase due to pooling and stagnation of blood in the microvascular capillaries. +ENDOTOXIC SHOCK: Clinically it is manifested with temperature changes, >38°C or <36°C, bounding pulse, heart rate >100 beats per min, respirato1y rate >20/min, WBC >12000/mm3 or <4000/mm3. Pathophysiology of septic shock has been described on p. 576. +SEPSIS-3: ltis defined as the septic shock with the need of vasopressor drug to maintain a mean arterial pressure (MAP 65 mm Hg). In the absence of hypovolemia and serum lactate >2 mmol/L. + +MANAGEMENT OF SHOCK I HEMORRHAGIC SHOCK +Basic management of hemorrhagic shock is to stop the bleeding and replace the volume which has been lost (Tables 39.4 and 39.5). Prompt diagnosis and immediate resuscitation is essential failing which multiple organ failure develops. +■ Restore circulating volume (infusion and transfusion): Blood should be transfused, especially in hemorrhagic shock as soon as it is available. Crystalloids: Normal saline has to be infused (20-30 mL/kg) initially for immediate volume replacement. Crystalloids are the primary choice. Colloids: Polygelatin solutions (Hemaccel, Gelofusion) are iso-osmotic with plasma. They do not interfere with the coagulation system. They promote osmotic diuresis. Human albumin solutions ( 4.5%)-are less used for volume replacement. +■ Maintenance of cardiac efficiency: When a large volume of fluid or blood is to be administered, the + +Table 39.4: Classification of obstetric hemorrhage based O[l th' mo r't, +e +' +of blood loss (volume deficit), considering a woman weighing 60 kg·i with a blood volume of 6lat 30 weeks of gestation (Be!)edetti-2002),'. +Blood loss (mLJ (%) Clinical +Class of blood volume presentation Management +0 <500: ( < 10%) Nil Normal loss +1 900 ml: (15%) No alteration Observation, replacement ± +2 1200-1 500 ml: ■ tPulse Immediate +(20-25%) ■ !-BP volume +■ tRespiratory repalcement + +rate Uterotonics ■ !-Urine output +3 1800-2000 ml: ■ t PR Urgent active +(30-35%) ■ -!-BP managemet Volume 90 and MAP ':60 mm +Hg, CVP 12-15 cm H2O and pulmonaiy capillary wedge +pressure 14-18 mm Hg. +■ Administration of oxygen to avoid metabolic acidosis: In the initial phase, administration of oxygen by nasal cannula at a rate of 6-8 liters per minute is started. Oxygen delivery should be continued to +maintain 02 saturation >94%. PaCO2 30-35 mm Hg and +pH >7.35. Endotracheal intubation and mechanical ventilation may be needed for patients with septic shock. Indications of mechanical ventilation are: (a) Severe tachypnea (RR >40/min), (b) altered +mental status, (c) persistent hypoxemia, despite 02 supplementation. +■ Pharmacological agents: Use of vasopressor drugs should be kept to a minimum, since peripheral vasoconstriction is already present. The role of vasoactive drugs, inotropes and corticosteroids in shock has been discussed in detail in connection with management of endotoxic shock. +■ Control of hemorrhage: Specific surgical and medical treatment for control of hemorrhage should start along with the general management of shock. The specific management of each variety of obstetric hemorrhage has been outlined in the related chapters. + +Table 0 39.5:·c1assificati fo(h.emorrhagic shod (based on total +' +, +blood volume 6 L). ' ' +Parameter Class I Class II Class Ill Class IV Blood volume s15 15-30 30-40 >40 loss%(ml) (<750) (750-1500) (1500-2000) (>2000) +Heart rate No Tachycardia Moderate Marked (bpm) change tachycardia tachycardia +Blood Normal Normal Decreased Decreased pressure +Respirations Normal Tachypnea Tachypnea Marked tachypnea +Mean arterial Normal Mildly <60mm Hg Decreased pressure decreased +Cardiac Normal Mildly Reduced Markedly output reduced reduced +Systemic Normal Increased Increased Increased vascular resistance +Urine output >30 20-30 5-15 Anuric (ml/hr) +Mental status Normal Anxious Confused Obtunded +ZI Chapter 39: Special Topics in Obstetrics + +Monitoring: Clinical parameters like skin temperature, visible peripheral veins can be helpful to assess the degree of tissue perfusion. Urine output (>30 mL/hr) is a useful guide. Arterial blood pressure is a poor indicator to assess tissue perfusion. Invasive monitoring may not be needed in a straight fo1ward case. In a critically ill patient, however, measurement of Central Venous Pressure (CVP), to assess the adequacy of patient's circulating volume and the contractile state of the myocardium, is essential. Pulse oximeter and blood gas analysis are useful to assess tissue perfusion. Measurement of left atrial pressure (pulmonary arte1y occlusion pressure) by 'Swan-Ganz' catheters could be done in selected cases. +I ENDOTOXIC SHOCK +Investigations to organize in a patient with !] •· !] septic shock: CBC, hematocrit, coagulation +- +!] +profile, (platelet count, serum fibrinogen, +FDPs, PT, APTT), liver enzymes and renal +function tests, chest radiograph, USG, CT or MRI may be needed (for localizing pelvic pathology or pelvic abscess, pneumonia or ARDs), and also ECG monitoring to detect signs of arrhythmias or ischemia. +Biomarkers: In evaluation of obstetric sepsis, the important blood biomarkers predominantly used are: WBC count, C-Reactive Protein (CRP), Procalcitonin (PCT) and lactate. WBC and CRP are nonspecific, but PCT appears to be more specific for bacterial infection. A venous lactate >2 mmol/L suggest critical care input and a level >4 mmol/L needs the support of vasopressors, monitoring of Central Venous Pressure (CVP) and oxygen saturation. +Principles of management are: (a) To correct the hemodynamic instability due to sepsis (endotoxin), (b) appropriate supportive care, and (c) to treat and to remove the source of sepsis. +Two wide bore cannulas are sited. Foley's catheter is inserted. Oxygenation with (face mask) is to be given. Mechanical ventilation may be needed in a severe case. +Goal ofhemodynamic resuscitation is to maintain (a) Mean arterial pressure > 70 mm of Hg, (b) CVP 10 to 12 cm HzO, (c) Urine output 0.5 mL/kg/hour, (d) Central venous oxygen saturation > 70%. +This includes administration of oxygen, antibiotics, intravenous fluids, adjustment of acid-base balance, steroids, inotropes, prevention and treatment of intra­ vascular coagulation and toxic myocarditis, administration of oxygen and elimination of the source of infection. +■ Antibiotics: Endotoxic shock is most commonly due to gram-negative organisms. The choice of antibiotic will depend upon the sensitivity test but before the report is available, broad-spectrum antibiotics co-vering gram-positive, gram-negative and anaerobic organisms should be started. Ampicillin (2G IV every + + +6 hours), gentamicin (2 mg/kg N loading dose followed by 1.5 mg/kg N every 8 hours) and metronidazole (500 mg IV every 8 hours) is a good combination to start with. Alternative regimen is to give N teicoplain 12 mg/ kg 12 hourly for 3 does, then 10 mg/kg/24 hourly + IV clindamycin 1.2 g 6 hourly+ N gentamycin 5 mg/kg. +■ Intravenous fluids and electrolytes: Septic shock associated with hemorrhagic hypotension should be treated by liberal infusion and blood transfusion. Isotonic c1ystalloid (normal saline) should be given. The amount of fluid to be administered can be precisely assessed by monitoring the pulse, BP, urine output and recording the central venous pressure. Oliguria with high specific gravity is an indication for fluid administration. Impairment of renal function contraindicates administration of electrolytes. Estimation of blood electrolytes (Na, K, bicarbonate) is needed. +■ Correction of acidosis: Acidosis and hypoxemia depress myocardial contractility. Bicarbonate should be administered to correct persistent metabolic acidosis (pH <7.2) only. A reasonable first dose would be 50-100 mEq (60-110 mL of 7.5%) of sodium bicarbonate solution. Further doses will depend on the clinical state of the patient and blood gas analysis result. +■ Vasopressors: Inotropic agent is started in a critically ill patient when there is hypotension (MAP <60 mm Hg) and impaired perfusion of vital organs despite adequate volume replacement, inotropes should be used. Noradvenaline is the first line treatment because of its eficacy. A sepsis related scoring system to identify the critically ill obstetric patient has been made (Table 39.6) and for convenience a quick scoring system has also been made (Table 39.7). Noradrenaline and +dobutamine have both inotropic and vasoconstrictive +effects. Dobutamine W1 and p2 adrenergic) is used in +cardiogenic shock. Noradrenaline (5-15 microgram/ +min) is used. Adrenaline is a very potent a and p agonist and is sometimes used in patients who do not respond to other drugs, especially in septic shock. Levosimendan is a novel inotropic agent. It has vasodilater and anti­ inflammatory effects. +Vasodilator therapy: In selected cases (MAP >70 mm Hg) afterload reduction may improve stroke volume and reduce ventricular wall tension. Sodium nitroprusside and nitroglycerin could be used for that purpose. This is done under continuous hemodynamic monitoring. +Diuretic therapy: To reduce fluid overload (preload) and pulmona1y edema, diuretics should be used. Frusemide is the drug of choice. +■ Corticosteroids: Patients with severe sepsis develop systemic inflammatory response syndrome or relative adrenal insufficiency (CIRCI). Corticosteroids could be used as anti-inflammatory agents to improve the outcome. The dose recommended in septic shock +Chapter 39: Special Topics in Obstetrics + + +Table 39.6: Obstetrically modified SOFA score. +A sepsis-related scoring system to identify the critically ill obstetric patient +Score +System parameter 0 1 2 +Respiration: PaO/Fi02 >400 300to <400 <300 +Coagulation: Platelets (x >150 100-150 <100 105/L) +Liver: Bilirubin (µmol/L) <20 20-32 <32 +Cardiovascular (CVS): Mean >70 <70 Vasopressors arterial pressure (mm Hg) required +Central nervous system Alert Rousable by Rousable by voice pain +Renal: Creatinine (µmol/L) <90 91-120 >120 + + +is 50 mg of hydrocortisone per kg body weight in +divided doses for 7 days. The advantages claimed are: (i) exerts an anti-inflammatory effect at the cellular level, (ii) stabilizes lysosomal membrane, (iii) counteracts anaerobic oxidative mechanism, +(iv) exerts positive inotropic effect to improve cardiac efficiency, (v) improves regional blood flow (micro­ circulation). However its absolute benefits are debated. +■ Treatment of dffuse intravascular coagulation: When there is low fibrinogen level, reduced platelet count and increased fibrin degradation products, heparin therapy should be considered. As a prophylactic measure, heparin 5000 JU subcutaneous or intravenous route at 8 hourly interval can be given safely. Alternatively, fresh frozen plasma or Packed Red Blood Cells (PRBC) transfusion could be done. +■ Treatment of myocarditis: Myocarditis most often is associated with septic hypotension. There is no specific treatment apart from the treatment of endotoxemia. In cases with congestive cardiac failure or features of atrial fibrillation or flutter, digitalis may be administered. + +Table 39.7: Obstetrically modified qSOFA score. +Rapid clinical assessment before investigations to identify the critically ill obstetric patient +A score ,2 is associated with an increased risk of mortality +Score Parameter 0 1 Systolic BP (mm Hg) '.90 <90 +Respiratory rate <25 breaths/ >25 breaths/minute minute +Altered mentation Alert Not alert +■ SOFA (Sequential) or qSOFA (Quick Sequential) Sepsis-Related Organ +Failure Assessment. +• +PaO = Partial Pressure of Inspired Oxygen . +2 +2 +■ FiO = Fraction of Inspired Oxygen. +• Society of obstetric medicine, ANZ guidelines for the investigation + + +the retained products of conception or hysterectomy for a case with septic abortion or puerperal sepsis should be done without delay. Removal of the source of infection may make the patient hemodynamically stable. +■ Intensive insulin therapy is done in patients with severe sepsis and septic shock to maintain normal blood glucose level. These patients often develop hyperglycemia, which further increases the risk of septicemia and death. +H -blockers: Antacids to reduce the stress ulcer of gastric mucosa either by oral or H2-blocking agents (IV) are used. +2 +Nutritional support is maintained as Total Parenteral Nutrition (TPN). Usually, 20-30 kcal/kg/day is equally distributed between fat and carbohydrate. Serum electrolytes, BUN, glucose, creatinine should be monitored on a regular basis. +Admission to ICU: Selected patients need ICU admission. + + + +■ Surgical management: Surgical intervention should be done to eliminate the source of infection. Evacuation of + + +Morbidity from sepsis in pregnancy has been scored to decide the need for ICU admission (Tables 39.6 to 39.8). + + +Table 39.8: Sepsis in obstetrics score (SOS)-a model to identify risk of morbity from sepsis and need for admission in ICU. + +Variable +Score +4 +Temp( C) >40.90 SBP(mm Hg) +° +HR(bpm) >179 RR (breaths/minute) >49 +SpO2 (%) +Leukocytes (number/µL) >39.9 +Immature neutrophils (%) +Lactic acid (mmol/L) + + ++3 +39-40.9 + +150-179 +35-49 + + ++2 + + + +130-149 + + + +25-39.9 2'10% +::4 + + ++1 ++38.5-38.9 + +120-129 25-34 + +17-24.9 + +Value +0(normal) +36-38.4 >90 +sl 19 12-24 ::92 +5.7-16.9 +<10% +<4 + + ++1 +34-35.9 + + + +10-11 90-91 +3-5.6 + + ++2 +32-33.9 70-90 + +6-9 + +1-2.9 + + ++3 +4 30-31.9 <30 +<70 + +:55 85-89 s85 +sl + +Patients with an SOS score 2c6 are more likely to be admitted to intensive care. [Albright et. al. (2014)]. +(SBP: Systolic Blood Pressure in mm Hg; HR: Heart Rate; bpm: beats per minute; RR: Respiratory Rate). +mJ Chapter 39: Special Topics in Obstetrics +ACUTE KIDNEY INJURY {AKI) (Syn: Acute Renal Failure in Obstetrics) +I + +DEFINITION: Acute kidney injury (failure) is !] J!] + ® + ti +■ ·· -- +clinically accepted as a condition in which the urine volume falls below 400 mL in 24 hours, the minimum amount necessary for +the excretion of the normal solute load. Currently AKI is considered as the fall in urine output below <0.5 mL/kg/ hr for 6 hours. There is associated rise in serum creatinine ::0.3 mg/dL from the baseline or rise in serum creatinine 2 times the normal (I.I mg/dL). Oliguria is the term given to the clinical condition. Anul'ia is the absence of excretion of urine in 12 hours. +Acute Kidney Injury (AKI) is manifested with the sudden impairment in kidney function resulting in retention of waste products (BUN) and potassium. There is abnormal fluid and electrolyte balance with loss of body acid-base equilibrium. +Effects of AKI on pregnancy are: Miscarriage, low birth weight, IUGR, preterm labor and still birth. ARF carries high maternal mortality therefore it needs to be prevented and treated aggressively. +Acute renal failure: (a) Urine output <400 mL/24 hours, (b) Rise in serum creatinine (at least 1.5 fold) and BUN. Prerenal failure: Patient is hypovolemic and hypo­ tensive. Laboratory tests: Serum BUN to creatinine >20, urinary sodium <20 mEq/L and FENa 1% ). +Renal causes of failure may be due to: (a) Glomerular, (b) tubular, (c) interstitial, and (d) vascular. In all these causes FEN a is >l %. In all glomerular causes urine analysis revealed: REC, casts and protein. +Bl CAUSES OF ACUTE KIDNEY INJURY (AKI) +Causes are broadly classified into: (A) Causes unrelated to the pregnant state and (B) Causes peculiar to the + + + +pregnant state. The second group may be divided into three categories: (1) Prerenal ARF, (2) Intrinsic renal ARF, and (3) Postrenal ARF (Table 39.9). +Prerenal ARF is due to hypovolemia and/or low cardiac output resulting in renal hypoperfusion. +PATHOLOGY OF ARF: Prerenal is the most common form of AKI (ARF). It is due to mild-to-moderate degree of renal hypoperfusion. Mild and even moderate ischemia with acute tubular necrosis are reversible. In severe ischemia, renal cortical tissue is damaged and this pathology is irreversible. + +CHARACTERISTICS OF THE RENAL AND SPLANCHNIC CIRCULATION: Under normal conditions it is strongly auto regulated, but in emergency situations the generalized intense sympathetic vasoconstriction overrides the renal auto regulatory mechanism; With gentle falls in BP, the renal auto regulatory mechanism is maintained; The renal venous pO2 is high because this tissue is normally over-perfused for its metabolic needs. + +ACUTE TUBULAR NECROSIS: It is the most common pathology in obstetrics. Acute tabular necrosis is due to several causes such as: ischemic insult; shock, surgery, toxins, drugs (aminoglycosides ), NSAIDS. Urinary sodium is >25 mEq/L and FENa is >l. The lesion begins in Henle's loop, especially in the intermediate zone, involving particularly the ascending limb and distal convoluted tubules and is fully developed after 48 hours. + +ACUTE CORTICAL NECROSIS: It is relatively uncommon and seen in abruptio placentae and endotoxic shock following gram-negative septicemia. Usually diffuse ischemic necrosis occurs all over the cortex. The glomerular afferent vessels are end arteries and thus the damage that occurs in the segment of the nephron supplied by these arteries is irreversible, hence the ultimate fatality. This condition is best diagnosed by Contrast Enhanced CT Scan (CECT) as the 'rim sign'. + +CLINICAL FEATURES: When anuria is reversible, the clinical condition can be divided into four phases: +♦ Incipient phase ♦ Phase of anuria +♦ Phase of diuresis ♦ Phase of recovery + + + +Table 39.9: Cau;es of acut kidney injury (failure) in-'pregnancy' (prere- a1'.? , :_ , ;;; :' \) -, :;:., ) : ' = s: ,, J - +- ' " ' ' - < • +;: + + +0 '. > o- l y" . • ', +c +I +_, ' +J + +Early pregnancy Late pregnancy and labor Other causes in pregnancy +■ Acute and massive hemorrhage: ■ Acute and massive hemorrhage: Postpartum ■ Mismatched blood transfusion. Abortion, ectopic pregnancy, hemorrhage, placenta previa, traumatic ■ Thrombotic microangiopathy. hydatidiform mole. delivery, obstetric shock. Hemolytic Uremic Syndrome (HUS) . +• +• +■ Severe dehydration: Hyperemesis ■ Abruptio placentae:The pathological basis of Renal: Renal disease, DIC, hypoperfusion, gravidarum, acute pyelonephritis. ARF are: (a) Hypovolemia; (b) DIC. ischemia, toxins, obstetric pathology +superimposed on pre-existing renal disease +(interstitial nephritis), (interstitial nephritis, SLE). ■ Septic abortion: Septicemia, • Severe pre-eclampsia, eclampsia, HELLP ■ Postrenal (obstructive): Accidental ligature +endotoxic shock, hypotension. syndrome. of the ureters during cesarean section, +■ Acute Fatty Liver of Pregnancy (AFLP). hysterectomy for rupture of uterus (rare). • Urosepsis, nephritis (pre-existing) . ■ Severe infection: Chorioamnionitis, pyelonephritis. ■ Drugs: NSAIDs, aminoglycosides. + + +Table 39.10: Criteria, for differentiation between prerenal and renal causes of dysfunction. + +Chapter 39: Special Topics in Obstetrics - + +Endogenous protein catabolism + + + +Criteria +Urine specific gravity. +Urine osmolality (mOsm/kg}. +Urine sodium (mmol/L}. + + +Pre-renal Renal >1.0020 <1.010 >500 <350 +<10 >20 + + + +INCIPIENT PHASE: The phase is short-lasting. There is marked diminution in urinaty output. +PHASE OF ANURIA: This phase lasts from a few hours to as long as 3 weeks. A urinaty output is less than 30 mL/hours. Initially, the patient remains alert and looks well. There is rise in serum BUN and potassium levels. Gradually the patient develops anorexia, vomiting and diarrhea. +Blood biochemical changes: There is gradual rise in the concentration of plasma urea, potassium, creatinine and phosphate as a result of endogenous protein catabolism (Table 39.10). The rise in plasma potassium is aggravated by the retention of hydrogen ions which are forced into the cells in exchange of intracellular potassium ions. The plasma concentration of bicarbonate diminishes. Acidosis occurs due to shifting of hydrogen ions intracellularly. Simultaneously, there is rise of phosphate which leads to lowering in plasma calcium. The fall in calcium and rise in potassium level have got a combined adverse effect on the cardiac function which may cause death. A simultaneous rise of plasma magnesium potentiates the harmful effect of rising plasma potassium. +INVESTIGATIONS +■ Blood: Leukocytosis may be evident and is a better index of infection than the rise of temperature. +■ Urine: Physical examination shows scanty and dark­ colored urine. Specific gravity is 1020 or more in prerenal causes and 1010 or less in renal causes. Protein is present in va1ying amounts. Presence of casts and red cells on microscopic examination suggests glomerular pathology. +■ Blood biochemical findings (Fig. 39. 7): Urine sodium concentration is <10 mmol/L in prerenal and >20 mmol/L in renal causes. Urine osmolality is more than 500 mOsmol/L in prerenal and less than 350 mOsmol/L in renal causes. Urine: Plasma creatinine ratio is >40 in prerenal ARF and <20 in intrinsic renal causes. +There is raised sodium (normal 136-145 mEq/L); potassium (normal 3.5-5 mEq/L); and urea level (normal 20-25 mg%). Standard bicarbonate level falls resulting in acidosis (normal 24-32 mEq/L). Arterial blood gases are done to detect acidosis (Table 41.11). +■ ECG-for evidence of rise in plasma potassiwn: Serial electrocardiographic tracing is important. The findings are: (a) Gross peak of the 'T' waves, (b) Absence of 'P' waves, (c) Prolonged 'QRS' complex to 0.2 seconds. +PHASE OF EARLY DIURESIS: In this phase, tubular function (reabsorption) is delayed. The only favorable feature + + + + +(-} +--{ Bicarbonate pH-I, Urea Potassium Phosphate +l +Acidosis Magnesium Potentiates1 Lowers +- -> +plasma +Cardiotoxic __ calcium + +Fig. 39.7: Effects of acute renal failure of blood biochemical changes. + +is the increased excretion of dilute urine. But the rise of potassium, sodium, creatinine (BUN) and chloride continues and the specific gravity of the urine is still low. + +THE PHASE OF LATE DIURESIS: The phase is as hazardous as the previous one. The causes of diuresis are: +1. Osmotic diuresis due to high blood urea, +2. Functional inadequacy of tubular reabsorption, +3. Release of surplus fluid and electrolytes, particularly sodium and potassium. +CLINICAL FEATURES: Clinical features and complications are anorexia, nausea, vomiting, cardiac arrhythmia, anemia, thrombocytopenia, metabolic acidosis and electrolyte imbalance (hyponatremia, hyperkalemia, hypermagnesemia, hyperphosphatemia). +PHASE OF RECOVERY: Tubular epithelium regenerates and tubular function is re-established along with the establishment of glomerular activity. The concentration of the electrolytes either in the plasma or in the urine gradually returns to normal values and so also the specific gravity of the urine. It may take about 1 year for restoration of full function. + +MANAGEMENT OF AKI IN OBSTETRICS (Prerenal) + +Prevention of ARF +■ Decline in the number of septic abortion cases with liberalization of MTP plans and medical methods of abortion. +■ Selection of high risk cases and judicious termination of cases with severe pre-eclampsia and hypertension in pregnancy. +■ Appropriate management of cases with abruptio placentae. +ED Chapter 39: Special Topics in Obstetrics + +■ Early volume replacement and intervention in cases with hemorrhage in pregnancy, labor and postpartum. +■ Facilities of blood transfusion. +TREATMENT: The first thing is to exclude retention of urine (obstruction). The possibility of inadvertent injury to the ureters during surgery should also be excluded by ultrasonographic study. +ACTUAL MANAGEMENT: Emergency management inclu­ des correction of causes of acute renal failure ( obstetric hemorrhage). +■ Surgical measures: Correction obstetric sepsis, hypovolemia or uterine bleeding. Patient may need dilatation and curettage, laparotomy for hysterectomy to remove the source of sepsis. +■ Medical measures: Fluid and electrolyte balance to be restored. Fluid intake is calculated from urinary output, loss of fluid from other sources (e.g., diarrhea, vomiting, insensible loss of about 500 mL/day along with correction of fever. Intake output record is to be maintained carefully. Hyperkalemia is controlled with the use of glucose and insulin. Diet should be with optimum calories containing carbohydrates, low proteins and electrolytes. Patient may need parenteral therapy due to nausea and vomiting. Antibiotics without renal toxicity should be given, if needed to control sepsis. +PLACE OF DIALYSIS: +Dialysis is no longer a last resort. The following are the accepted indications (Table 39.11): +Hemodialysis in pregnancy often causes wide fluctuation of blood pressure. Continuous EFM should be continued during dialysis. Dialysates containing glucose and bicarbonate are preferred to avoid loss of bicarbonate. Patient must have at least 70 g of protein and 1 .5 g of calcium daily. Hematocrit should be above 25%. Packed red cell transfusion or Iron (IV) may be given. Risk of preterm labor is high as progesterone is removed during dialysis. Parenteral progesterone therapy is advocated in patients with dialysis. Maternal complications are placental abruption, heart failure and sepsis. Women need more frequent dialysis. +POSTPARTUM RENAL FAILURE (Ch. 30, p. 416) (postpartum hemolytic uremic syndrome) +It is a clinical condition of acute irreversible renal failure occurring within the first 6 weeks postpartum. + +Table 39.11: Indications of dialysis. , +Criteria for dialysis in antepartum Serum levels cases with continuing pregnar,cy +■ Potassium 6.5 mEq/L In such a case dialysis is instituted ■ Sodium sl 30 mEq/L earlier considering fetal wellbeing. +• Bicarbonate s 13 mEq/L No specific criteria have been +firmly established. One criteria is Daily increments of 30 mg/dl rise of BUN >60 mg/dl. +BUN ,,120 mg/dl or +■ +Blood urea 150 mg/dl + + +The exact cause is still obscure. Thrombocytopenic Purpura-Hemolytic Uremic Syndrome (TTP-HUS)-is an unexplained combination of thrombocytopenia and microangiopathic hemolytic anemia. Renal failure is caused by microangiopathy. The pantad findings of TTP-HUS are: (a) Microangiopathic hemolytic anemia; (b) Thrombocytopenia; (c) Neurologic abnormalities (headache, confusion, fever, seizures); (d) Fever and (e) Renal dysfunction. The mortality of TTP is high (90%). The optimal therapy for TTP-HUS is delivery. Plasma­ pheresis has improved survival (80%). + +OBSTRUCTIVE RENAL FAILURE: Obstructive anuria due to ureteric ligation should be dealt with promptly. If the general condition permits, delegation or implantation of the ureters into the bladder can be carried out after prior confirmation by cystoscopy and ureteric catheterization. If the general condition is too poor, bilateral nephrostomy is the life-saving procedure. +In obstetrics, overall mortality due to ARF is about 15% and slightly high in sepsis-related ARF. Renal parenchymal injury is associated with high mortality. Prognosis of the fetus is unfavorable and mortality is about50%. +!]m!] + +., + +BLOOD COAGULATION DISORDERS IN OBSTETRICS + +Disseminated Intravascular Coagulation +(DIC), is a clinicopathologic syndrome . .. '-•: characterized by widespread intravascular +fibrin deposition in response to excessive .t +blood protease activity that overcomes the natural anticoagulant mechanism. +The commonly used terminology: Consumptive coagulopathy, where there is actual consumption of procoagulants within the vascular system. Activation of fibroholytic system is the other cause of defibrination syndrome. +The plasmin activity usually declines until after deli­ very. The plate count either remains static or there is a slight fall (15%) in pregnancy. +Control of blood loss from the vessels depends on the following: +■ Muscular contraction ++ Vascular contraction ( vasoconstriction) ++ Myometrial contraction (adjacent to the vessels) ■ Tissue pressure +■ Platelet functions +■ Blood coagulation mechanism (Fig. 39.8) +Physiological changes: Procoagulant factors markedly increased in pregnancy are I, VII, VIII, IX and X. Factors either unchanged or mildly increased are II, V and XII. Factors that decline are XI and XIII. +Chapter 39: Special Topics in Obstetrics :I Xll➔Xlla + +( Intrinsic pathway ) ( Extrinsic pathway ) + +Ca2• §}--v11 +XI Xia Tissue +Thromboplastin + +VIia/tissue factor + +IX IXa + + + +/ + +VIII ----+ VIiia + +PL + +Common pathway +I +I + + + +- - ----- x + +Va------ V + + + + +Prothrombin (II) + + +Thcomr (Ila) + +aPTTIPT + + + Fibrinogen +n + + +Cross-linked fibrin clot + + + + +FOP, +0-dimers +Plasmin +l + +Plasminogen + + +Fibrin polymer + + +Xllla + +Plasminogen activator inhibitors (EACA) + +Fibrin monomer + + + + +Fibrinolysis + + + +Plasminogen activator (urokinase) + + +Fig. 39.8: Coagulation cascade and laboratory assessment of clotting factor deficiency­ activated Partial Thromboplastin Time (aPTT ), Prothrombin Time (PT) and Thrombin Time (TT). + + +The plasmin activity usually declines until after delive1y. The platelet count either remains static or there is a slight fall (15%) in pregnancy. + + +Table 39.12: Complications and trigger factors for DIC. +Release of Release of Endothelial injury thromboplastin phospholipids + + + +Initiation of pathological coagulation: There is release of tissue factor from the damaged subendethelial layer of the blood vessels. Cytokines are released from the endothelium. The cascade of coagulation and fibrinolysis {Fig. 39.8) is initiated. Ultimately the coagulation factors and platelets are depleted to manifest the fetuses of consumptive coagulopathy. Obstetric complications that trigger consumptive coagulopathy are many (Table 39.12). + + +♦ Pre-eclampsia, eclampsia, HELLP syndrome. +♦ Sepsis syndrome • Septic abortion +• Chorioamnionitis • Pyelonephritis +♦ Hypovolemia. + + +♦ Amniotic fluid embolism. +♦ Dead fetus syndrome. +♦ Abruptio placentae. ♦ Hydatidiform mole. ♦ Cesarean section. +♦ Intra-amniotic hypertonic saline. +♦ Shock. + + +♦ Fetomaternal bleed. +♦ Incompatible blood transfusion. +♦ Hemolysis. ♦ Septicemia. +--·· ED Chapter 39: Special Topics in Obstetrics +I NORMAL BLOOD COAGULATION + +Normal intravascular blood coagulation is linked with three different interrelated systems. + +These are: +• Coagulation system +• Coagulation inhibitory system • Fibrinolytic system. +Pathological disturbance of one or more of the systems leads to intravascular coagulation or a tendency to bleed. + +COAGULATION MECHANISM: The complex system of blood coagulation, 'Enzyme cascade theory' involves two different pathways, viz. intrinsic and extrinsic. Both are initiated by different stimuli and ultimately they culminate into a common pathway for final conversion of inert prothrombin to thrombin. + +COAGULATION INHIBITORY SYSTEM: There are a number of naturally occurring anticoagulants in blood, to counterbalance the hypercoagulable state in pregnancy. Antithrombin III (AT III) is a main physiological inhibitor of thrombin and factor Xa. Protein C combined with protein S and thrombomodulin inactivates factors V and VIII. Their deficiency is associated with recurrent thromboembolism. + +PLASMA FIBRINOLYTIC SYSTEM: Tissue plasminogen is activated to plasmin by tissue activators ( urokinase, streptokinase). In turn, plasmin lyses fibrinogen and Fibrin-to-fibrin Degradation Products (FDP). Serum FDPs are detected by immunoassays as D-dimers. Blood coagulation and fibrinolysis work side-by-side to maintain hemostasis and patency of microcirculation. There are several plasminogen inhibitors like Epsilon Aminocaproic Acid (EACA) and tranexamic acid (AMCA). +I PHYSIOLOGICAL CHANGES IN PREGNANCY +During pregnancy, there is increase in concentration of clotting factors II, V, VII, VIII, IX, X and XII. Plasma + + + + +fibrinogen level is significantly increased. There is a small decrease in platelet count, due to low-grade intravascular coagulation. Plasma fibrinolytic activity is suppressed during pregnancy and labor. It returns to normal within 1 hour of delive1y of the placenta. This is due to liberation of plasminogen inhibitor from the placenta (Fig. 39.8). + +PATHOLOGICAL CONDITIONS OF ACQUIRED COAGULOPATHY + +Initiation of pathological coagulation: There is release of tissue factor from the damaged subendothelial layer of the blood vessels. Cytokines are released from the endothelium. The cascade of coagulation and fibrinolysis (Fig. 39.8) is initiated. Ultimately the coagulation factors and platelets are consumed (depleted) to manifest the features of consumptive coagulopathy. +Obstetric complications and trigger factors for DIC are many (Table 39.12). All these clinical conditions may trigger the delicate hemostatic mechanism either by endothelial injury or by release of thromboplastin and phospholipids. It is always a secondary phenomenon and never primary. Because of the hypercoagulable state in pregnancy, presence of any provocative factor can easily upset the normal balance culminating into Disseminated Intravascular Coagulopathy (DIC). It is sometimes called 'defibrination syndrome' but because other constituent factors, besides fibrin, are also consumed, a better nomenclature would be 'consumptive coagulopathy'. The blood fibrinogen level of 100 mg/ dL is arbitrarily considered to be a critical level. +Chronic DIC is a compensated state commonly observed in a case with dead fetus syndrome. Plasma levels of FDP, D-dimers are raised, aPTT, PT and fibrinogen are within the normal range. There may be mild thrombocytopenia and red cell fragmentation (Flowchart 39.2). + + +Flowchart 39.2: Pathophysiology of DIC. + +Interaction between coagulation and fibrinolytic pathways +l +Widespread intravascular thrombin generation + +l Deposition of Secondary fibrinolysis +fibrin in microcirculation +l +l +l + +lschemic tissue damage Vessel Diffuse FOP(+) +patency bleeding D-dimer (1') + +Multiorgan dysfunction + +j Multiorgan failure (kidney) I + +l l +RBC damage Consumption of and platelets and +hemolysis cMg"'' factorn +T +j Diffuse bleeding I + + +I MECHANISM OF ACQUIRED COAGULOPATHY ABRUPTIO PLACENTAE: Mechanism +■ Massive retroplacental clot: Not only the fibrinogen along with other procoagulants is consumed in the clot but after the clot retraction, the serum component is absorbed into the circulation, thereby further reducing the circulatmy procoagulant. + +Chapter 39: Special Topics in Obstetrics ED RETAINED DEAD FETUS: There is gradual fall in fibrinogen +level. It usually becomes evident following retention of the dead fetus for more than 4 weeks. There is gradual absorption of thromboplastin liberated either from the placenta or from amniotic fluid or decidua. This results in consumption not only of fibrinogen but also the Factor VIII and platelets. In response to DIC, there +is enhanced fibrinolytic activity which, in turn, reduces + + + +■ Thromboplastin liberated from the clot, damaged decidua and uterine musculature enters into the circulation and produces DIC. +■ Because of precipitating shock, synthesis of the essential coagulation factors fails to occur promptly. + +the fibrinogen level further. +SALINE INDUCED ABORTION (MTP): Thromboplastin is released from the placenta, fetus and the decidua due to necrobiotic effect. It gains access into the circulation and causes defibrination. + + + +■ Fibrinolysis (activation of plasmin): It serves as a protective mechanism to dissolve the fibrin clot so as to restore patency in the microcirculation. +■ Level of Fibrin Degradation Products (FDP) is raised. It inhibits myometrial contraction. +■ Pre-eclampsia, eclampsia and HELLP syndrome: Endothelial injmy is the underlying pathology. It results in thrombocytopenia and rise in fibrin degradation products. +AMNIOTIC FLUID EMBOLISM +Mechanism: Liquor amnii is forced into the maternal circulation either through a rent in the membranes or placenta. Thromboplastin-rich liquor amnii containing the debris, blocks the pulmonary arteries and triggers the complex coagulation mechanism leading to DIC. There is massive fibrin deposition distributed throughout the entire pulmonary vascular tree. If the patient survives from the severe cardiopulmonary embarrassment which stimulates thromboembolic phenomenon, there will be severe clotting defect with profuse bleeding per vaginam or through the venepuncture sites due to consumption of coagulation factors. +From the damaged endothelium of the pulmonary arteries, massive fibrinolytic activators are produced which excite the fibrinolytic system converting the plasminogen to plasmin, which in turn, produces lysis of fibrin, fibrinogen and even the Factor V and Factor VIII. Thus, there is secondary fibrinolysis on top of primary fibrinogen depletion arising out of DIC. +ENDOTOXEMIA-Mechanism: (I) Hypercoagulable state in pregnancy adversely reacts with endotoxin and leads to DIC. There is release of thromboplastin into maternal circulation from the placenta, fetus and decidua. There is extensive DIC and deposition of fibrin in the renal vascular system. (2) In obstetric sepsis , the endothelium of the capillaries in the microcirculation is damaged due to anoxia. There is activation of coagulation system. (3) Increased production of activators from the damaged capillary endothelium triggers the fibrinolytic activity and causes defibrination (fibrinolysis). + +CESAREAN SECTION: Primary defibrination following cesarean section may be due to: (1) Entry of thromboplastin or amniotic fluid into the circulation through the open vessels on the uterine wound, (2) Excess production of plasminogen activators from the injured uterine site. +CLINICAL MANIFESTATIONS: The manifestations of blood coagulation disorder are evidenced by hemorrhage from various sites. +Before delivery: There are signs of bruising, prolonged bleeding at the injection sites (venepuncture or intramuscular), gum or nose bleeding or hemorrhage from catheterization the gastrointestinal tract and persistent hypotension. +After delivery: Apart from the manifestations already described, there is postpartum hemorrhage (traumatic bleeding being excluded). The hemorrhage usually occurs 1-2 hours following delivery. There may be bleeding from the suture sites (episiotomy wound) or hematoma formation in the abdominal wound following cesarean section or formation of a vulva! hematoma following vaginal delive1y. +I INVESTIGATIONS +Bedside tests, to evaluate the blood coagulation disorders can give useful information to the diagnosis. Detailed laborato1y investigations are needed for the diagnosis. +Bedside tests that may be done are: (1) Bleeding time, (2) Coagulation time, (3) Clot observation test, (4) Peripheral smear, (5) Circulatory fibrinolysis test. +Clot observation test (Weiner): It is a useful bedside test. It can be repeated at 2-4 hours intervals. 5 mL of venous blood is placed in a 15 mL dry test tube and kept at 37°C. Usually, blood clot forms within 6-12 minutes. This test provides a rough idea of blood fibrinogen level. If the clotting time is less than 6 minutes, fibrinogen level is more than 150 mg%. If no clot forms within 30 minutes, the fibrinogen level is probably less than 100 mg%. +Peripheral blood smear: Peripheral blood smear when stained with Wright's stain may be of help. {i) If less than four platelets per high-power field are seen, +ml Chapter 39: Special Topics in Obstetrics + +thrombocytopenia is diagnosed. Thrombocytopenia is a feature of DIC but not of fibrinolytic process. (ii) RBC morphology-in DIC, the cell shape will be 'helmet shaped' or fragmented whereas in fibrinolytic process, the cell morphology will be normal. +Essential laboratory tests to know the specific defects in the coagulation mechanisms are: (1) Platelet count, (2) Activated partial thromboplastin time (intrinsic coagulation), (3) Prothrombin time (extrinsic coagulation) (4) Thrombin time, (5) Fibrinogen estimation, (6) Fibrin degradation products (FDP), (7) D-dimer. +Measurement of FDP is an indirect evidence of fibrinolysis. The determination of a low platelet count is of far more diagnostic significance than the finding of a raised FDP level. The most valuable and rapid clotting screen is thrombin time, where thrombin is added to citrated plasma. Thrombin time of normal plasma is 10-15 seconds. Thrombin time is prolonged where fibrinogen is depleted. Normal values of blood coagulation profile are given in page 608. +Thromboelastometry and thromboelastography are used as adjuncts to other laboratory tests. +I TREATMENT +PREVENTIVE: Blood coagulation disorders in obstetrics of suficient magnitude to cause hemostatic failure, have been reduced to a great extent. The responsible factors in prevention are the changes in the trends of obstetric management: +■ Abruptio placentae: (a) Massive blood transfusion, (b) To expedite early delivery by low rupture of the membranes supplemented by oxytocin drip, (c) Libera­ lization of cesarean section. +■ Intrauterine death: (a) Early delivery, (b) Availability of potent oxytocics (prostaglandins) to empty the uterus (p. 313). +■ Better understanding of the pathophysiology of shock and early institution of treatment. Early restoration of blood loss to treat hypovolemia and replacement of the procoagulants. +■ Severe pre-eclampsia, eclampsia and HELLP syn­ drome have been substantially reduced by effective care and judicious timing of delivery. +■ Emptying the uterus and controlling the infection early with antibiotics in cases with sepsis syndrome. +■ Avoiding instillation of hypertonic saline for induction of abortion. +Adjuvant therapies (vitamin K): The vitamin K­ dependent factors II, VII, IX, X are consumed in DIC. 5-10 mg of injection vitamin K given (IM), can help to replenish these procoagulants. + +CURATIVE: The management goal is to identify and to correct the underlying pathology with priority. Women + + +with severe DIC are treated for hemodynamic parameters, respiratory support and surgical intervention when needed. In most cases, delivery of the fetus brings the resolution of coagulopathy. The other part of the management is to achieve a platelet count >50,000/µL and a fibrinogen level > 100 mg/dL. +ACTUAL MANAGEMENT +■ Volume replacement +■ Blood component therapy ■ Heparin +■ Fibrinolytic inhibitors +• Volume replacement by crystalloids (Ringer's solution) or by colloids (hemaccel or gelofusine or human albumin 5%) will reduce the amount of whole blood needed to restore the blood volume. The crystalloids remain in the vascular compartment less compared to colloids. Dextran should be avoided as they adversely affect platelet function and blood cross­ matching tests. Two large bore N catheters are sited. +• Whole blood transfusion is given to replenish not only the fibrinogen but also the other procoagulants. 500 mL of fresh blood raises the blood volume, the fibrinogen level approximately by 12.5 mg/100 mL rise in hematocrit by 3-4% and adds 10,000-15,000 platelets/mm3• Whole blood is less commonly used in present day obstetrics practice. +• Fresh-Frozen Plasma (FFP) is extracted from whole blood. It contains all the clotting factors including fibrinogen. It is commonly used in cases with consumptive and dilutional coagulopathy. However, it is not used as volume expander. It is usually given for women with fibrinogen level <150 mg/dL or with abnormal PT or a PTT. One unit of FFP (250 mL) raises the fibrinogen by 5-10 mg/dL. FFP needs to be ABO or Rh compatible. Shelf life is 12 months. +• Cryoprecipitate and fibrinogen concentrate: It is obtained from thawed FFP. It is rich in fibrinogen, factor VIII, von Willebrand's factor, and XIII. Cryoprecipitate provides less volume (40 mL) compared to FFP (250 mL). So it should not be used for volume replacement. Each 10-15 mL of cryoprecipitate contains 200 mg of fibrinogen and no platelets. Shelf life is 12 months. +• Platelet concentrates may be given to a patient with very low platelet count ( <50,000/mL) and persistent bleeding. Platelets should be given rapidly over 10 minutes. It should be ABO and Rh specific. Transfusion of a single unit of platelets is expected to raise the count between 5,000 and 10,000/mL. In case of sensitization Rh-immunoglobulin 300 µg is given. Several units (5-10 units) of platelet concentrates are to be transfused, as one unit (50 mL) raises the platelet count by 7,500/mL. +Single donor concentrates are preferred as the +Chapter 39: Special Topics in Obstetrics - + + +immunogenic and antigenic risks are low. Shelf life is 5 days. ++ Packed Red Blood Cells (PRBC) are most effective to improve oxygen-carrying capacity. Oxygen-carrying capacity is reduced when hemoglobin level is <8 g/dL even in an euvolemic patient. Transfusion reactions are less compared to whole blood transfusion. Each unit contains about 300 mL (250 mL RBC and 50 mL of plasma). One unit of PRBC will raise the hemoglobin by 1 g/ dL and hematocrit by 3%. PRBC has less fibrinogen, no platelets. It must be ABO compatible. Shelf life of red cells is 35 days. ++ Massive transfusion protocols: The commonly used protocol is: 5 units of PRBCs, 3 units of FFP and 1 unit of platelet concentrate (5:3:1). Cryoprecipitate may be added to this regimen. ++ Recombinant-activated Factors VIIA (rFVIIA): (60-100 µg/kg IV) can reverse DIC within 10 minutes as it is a precursor for extrinsic clotting cascade which is replaced. It also activates platelets and the coagulation cascade. It has rapid bioavailability (10-40 minutes) but the half-life is short (2 hours). rFVIIA is not effective when plasma fibrinogen level is <50 mg/ dL and platelet count is <30,000/mL. ++ Autotransfusion is the collection of blood from the operative field (blood salvage), filter the blood and then transfusing the red cells back to the patient. The device for autotransfusion is called cell saver. The advantages are: less risks of infectious disease transmission and immunological reactions. Cell salvage and autologous blood storage for transfusion has not been found useful. ++ Alternative oxygen carriers or artificial hemoglobin solutions have short intravascular half-life. Recent meta-analysis has revealed a significant risk of mortality and myocardial infarction. +Heparin: It should be used when the vascular compartment remains intact. In acute condition such as amniotic fluid embolism, intravenous heparin 5000 units repeated 4-6 hours intervals is useful to stop DIC and may be lifesaving. In retained dead fetus, there is progressive but slow defibrination due to DIC. In such cases, the process can be arrested by intravenous heparin. In acute DIC, heparin may aggravate bleeding. +Fibrinolytic inhibitors: Place of fibrinolytic inhibitors is very limited. Fibrinolysis may be a protective phenomenon. Commonly available antifibrinolytic agents are-(1) EACA-inhibits plasminogen and plasmin, (2) Trasylol-inhibits plasmin, (3) Aprotinin-nonspecific enzyme inhibitor. Fibrinolytic inhibitors are mainly indicated in postpartum hemorrhage following traumatic hemorrhage or abruptio placentae in spite of a firm and contracted uterus and when blood fibrinogen level is 200 mg% or more. However, these drugs can increase the risk of thrombosis. + + +Conclusion: Prompt restoration of blood volume and replacement coagulation factors is an important step in the management of coagulation disorders in obstetrics. Management of the triggering factor ( e.g., immediate delive1y in a case of abruptio placentae) should be done along with. This will improve the hemostatic competence in vast majority of cases. With adequate perfusion of vital organs, there is accelerated synthesis of procoagulants, also especially by the liver. Treatment with c1ystalloids only, may lead to dilutional coagulopathy due to depletion of platelets and clotting factors. +Whole blood-restores blood volume and fibrinogen and increases hematocrit by 3-4%. FFP-restores blood volume and fibrinogen. +Risks of blood transfusion: The adverse reactions are: (A) Immune-mediated reactions: (a) Febrile, (b) Allergic, (c) Anaphylactic, (d) Hemolytic, and (e) Transfusion related lung injmy (TRALI), which is an immune-mediated condition and causes ARDS. (B) Transfusion-related infections: Virus (HBV, HCV, CMV, HIV), parasites (malaria), bacteria. (C) Others: (a) Fluid overload, (b) Hypothermia, (c) Electrolyte imbalance (Kt, Cat), and (d) Acidosis. + +HIGH-RISK PREGNANCY +ASSESSMENT OF PREGNANCY AT RISK: High-Risk Pregnancy (HRP) is one in which the mother, fetus or the newborn is/or may possibly be at increased risk of morbidity +or mortality before, during or after delive1y. Factors for increased risks are many (Box 39.3 and Table 39.13). The important causes of maternal deaths are: hypertensive disorders, hemorrhage, sepsis and the medical disorders. + + +A. Maternal: Diabetes, hypertension, cardiac, endocrine (thyroid), preterm labor. +B. Fetal: Structural anomalies; chromosomal abnormalities; genetic syndromes; multiple gestation and infection. +C. Maternal-fetal: Preterm birth, PPROM, cervical insufficiency, stillbirth; IUGR; abnormalities of placentation; pre-eclampsia. + + +Table 39.13: Assessment of high-risk factors in l bor. General physical examination Pelvic examination +■ Height: Below 150 cm, particularly ■ Uterine size­ below 145 cm in our country. disproportionately +■ Weight: Overweight or smaller or bigger. underweight ■ Genital prolapse. Body mass index (BMI): Weight/ ■ Lacerations or +(height)2 BMI: 20-24 is accepted as dilatation of the cervix. normal. ■ Associated tumors. +• High blood pressure. ■ Infected labor. +a Anemia ■ Liquor meconium ■ Cardiac or pulmonary disease. stained. +■ Orthopedic problems. ■ Pelvic inadequacy. +li Chapter 39: Special Topics in Obstetrics + +The important causes of infant deaths (since birth to 1 year of age) are: preterm birth, prematurity related conditions, sepsis and congenital malformations. +EXAMINATION +Risk assessment starts with a good history taking and examination. Investigations are then organized for management (Table 39.14). +Maternal age: Extremes of maternal age increase the risks of maternal or fetal morbidity and mortality. Adolescents are at increased risk of pre-eclampsia, IUGR, women with increasing age are at higher risk for pre-eclampsia, diabetes, cesarean delive1y, placenta previa, accreta (PAS). +The risk of fetal aneuploidy increases with increasing maternal age. These women are offered prenatal screening which includes: serum analyte testing, cell free DNA, ultrasound and/or invasive testing following counseling. +Type of conception: Pregnancy in a women following spontaneous conception need to be differentiated from Assisted Reproductive Technology (ART). Risks of pregnancy following ART are: Increased preterm birth, multifetal gestation, low birth weight, congenital anomalies and increased perinatal mortality. +Past medical and surgical history: Past medical and surgical disorders can complicate the course of present pregnancy affecting both the mother and the fetus (Table 12.2, p. 104). +Family history: Detailed information is helpful to determine the risks of inheritable disease (diabetes, thalassemia, cystic fibrosis). +Past-obstetric history: (a) Woman with recurrent miscarriages, needs investigation following 2 losses. (b) Previous still birth. (c) Rh alloimmunization. (d) Previous infant with genetic disorder. +Physical examination: (Ch. 10). Antenatal management: +■ First trimester screening: Nuchal Translucency (NT) +° +is measured between 11 17 and 13617 weeks, combined + +with maternal serum free -hCG and Pregnancy Associated Plasma Protein A (PAPP-A). Increased NT is associated with higher risks of cardiac defects, diaphragmatic hernia, fetal skeletal dysplasia and other genetic syndromes. Patients with an abnormal screening result is offered invasive testing like CVS for +earlier confirmation of aneuploidy. +■ Second trimester screening: "Quad screen" can detect fetuses with NTD and certain chromosomal abnormalities (Trisomy 21). Integrated aneuploidy screening is suggested. +■ Cell free DNA for aneuploidy screening-for trisomy 21, 18 and 13. Detection rate of >98% with false-positive rate of 0.2-0.5%. +■ Detection of preterm labor is commonly done by: (a) measurement of cervical length by TVS and {b) fetal fibronectin detection in cervicovaginal discharge. +■ Screening for gestational diabetes. +■ Assessment of fetal wellbeing: Ultrasonography is commonly used. Real-time sonography with 2 dimensional (2D) image to demonstrate fetal anatomy, fetal growth, weight, movements and liquor volume. Three-dimensional sonogrpahy 3D and 4-D have many other advantages. Fetal Doppler study, biophysical profile (BPP), fetal echocardiogram are of specialized study for other information. +■ Sonographic markers of aneuploidy screening are identified. +■ Invasive tests for prenatal diagnosis are: (a) Chori­ onic villus sampling {b) Amniocentesis and (c) Fetal blood sampling. +■ Antenatal fetal wellbeing: (a) Fetal movement assessment; {b) Nonstress test; (c) Biophysical profile (BPP); {d) Modified biophysical profile; (e) Growth profile and (f) Doppler studies. +11 Intrapartum management: +(A) Fetal heart rate monitoring-clinical and electronic fetal monitoring (EFM) (Box 39.4). +(B) VAS, (C) Fetal scalp blood sampling and fetal ECG. + + +Table 39.14: High-risk factors in pregnancy. +Reproductive history Medical disorders in pregnancy Previous surgery + +■ Two or more previous miscarriages or Diseases +previous induced abortion. These cases ■ Pulmonary disease-tuberculosis run the risk of further abortion or preterm ■ Renal disease (pyelonephritis) delivery. ■ Thyroid disorders +■ Previous stillbirth, neonatal death or birth ■ Psychiatric illness of babies with congenital abnormality. ■ Cardiac disease +■ Previous preterm labor or birth of an IUGR ■ Epilepsy +or macrosomic baby. ■ Viral hepatitis +■ Grand multiparity ■ Pre-eclampsia, eclampsia ■ Previous cesarean section or hysterotomy. ■ Anemia +■ Third-stage abnormalities (PPH)-this has ■ Infections in pregnancy (malaria, HIV) a particular tendency to recur. +■ Previous infant with Rh-isoimmunization or ABO incompatibility. + + +■ Myomectomy. +■ Repair of complete perinea! tear. ■ Repair of vesicovaginal fistula. +■ Repair of stress incontinence. +■ In all these conditions, fetal or maternal outcome or both may be affected. +Family history +■ Socioeconomic status-patients belonging to low socioeconomic status have a higher incidence of anemia, preterm labor, growth-retarded babies. +■ Family history of diabetes, hypertension or multi-pie pregnancy and congenital malformation. + + + +COMPLICATIONS OF PREGNANCY AND LABOR: The cases should be reassessed during late pregnancy and labor (Box 39.5). Attention is given to detect the risks that may develop during labor. Some important points to consider are: +■ Patient having induction or acceleration of labor. 11 Patients having no antenatal care. +■ Presence of anemia, pre-eclampsia or eclampsia. 11 Premature or prolonged rupture of membranes. 11 Chorioamnionitis. +■ Meconium-stained liquor. +■ Abnormal presentation and position. +■ Disproportion, floating head in labor. +■ Multiple pregnancy. ■ Preterm labor. +■ Abnormal fetal heart rate. +■ Patients with prolonged or obstructed labor. +■ Rupture uterus. + +Intrapartum complications: ■ Intrapartum fetal distress +■ Delivery under general anesthesia ■ Dificult forceps or breech delivery ■ Failed forceps +■ Postpartum hemorrhage or retained placenta +■ Prolonged interval from the diagnosis of fetal distress to delivery. Interval more than 30 minutes since the recognition of fetal distress to delivery, the mortality increases three-folds. +POSTPARTUM COMPLICATIONS: An uneventful labor may suddenly turn into an abnormal one in the form of PPH, retained placenta, shock or uterine inversion or sepsis. The condition of the neonate should be assessed after delivery. The following categories of neonates are at high risk (Box 39.6). + +I MANAGEMENT OF HIGH-RISK CASES +For improvement of obstetric results, the high-risk cases should be identified and given additional antenatal, intranatal and neonatal care. But, in general, they need not be admitted to specialized centers and their care can be left to properly trained midwives and medical officers in health centers, or general practitioners. A simple checklist should be prepared for them to fill + + + +■ Cases with uteroplacental insufficiency. ■ IUGR. +■ Hypertension. +■ Antepartum hemorrhage. ■ Prolonged pregnancy. +■ Extremes of maternal age: <15, >30 years. +■ Previous stillbirth. +■ Multiple pregnancy. +■ Diabetes mellitus. +11 Alloimmunization in pregnancy. +■ Polyhydramnios/oligohydramnios. +■ Hematological disorders in pregnancy. + +Chapter 39: Special Topics in Obstetrics il-- + + +A. Hemorrhage D. Hypertensive disorders • APH • Severe pre-eclampsia. • PPH • Eclampsia. +Nearly 75% of obstetric patients • HELLP syndrome. admitted in ICU are postpartum. +B. Sepsis syndrome E. Cardiopulmonary +• Postabortal. • Heart disease in +• Pregnancy (chorioamnionitis, pregnancy. +pyelonephritis). • Thromboembolism. C. Trauma F. Puerperal sepsis + + +■ Apgar score below 7. ■ Convulsions. +■ Hypoglycemia. ■ Neonatal infection. +11 Anemia. ■ Respiratory distress syndrome. ■ Birth weight <2.5 kg or ■ Persistent cyanosis. +>4kg. ■ Jaundice. +■ Major congenital +abnormalities. + +up; arrangement should be made for early examination of the high-risk cases. The health centers or the clinics should have periodic specialist cover from teaching or nonteaching hospitals, as well as district and subdivisional hospitals. The general practitioner or medical officer of health centers, in collaboration with the specialists, will decide what type of cases (with a comparatively lower risk) can be managed at the health centers. Cases with a significantly higher risk should be referred to specialized referral centers. Cases from rural areas may be kept at maternity waiting homes close to the referral centers. The organizational aspect may be summarized as follows: +■ Strengthen midwifery skills, community participation and referral (transport) system. +■ Proper training of residents, nursing personnel and community health workers. +■ Arranging periodic seminars, refresher courses with participation of workers involved in the care of these cases. +■ Concentration of cases in specialized centers for management. +■ Availability of perinatal laboratory for necessary investigations; availability of a good pediatric service for the neonates. +Folic acid ( 4 mg/day) therapy should be started in the prepregnant state and is continued throughout the pregnancy. Early in pregnancy after the initial clinical examination, routine and special laboratory investigations should be undertaken. +Assessment of maternal and fetal wellbeing: This should be done at each antenatal visit according to the guidelines given in the appropriate chapter; maternal complications should be looked for and treated, if necessary. +MANAGEMENT OF LABOR: It is evident that elective cesa­ rean section is necessary in a high-risk case. Some cases +Chapter 39: Special Topics in Obstetrics + +may need induction of labor after 37-38 completed weeks of gestation. Those cases who go into labor spontaneously or after induction, need close monitoring during labor for the assessment of progress of labor or for any evidence of the fetal hypoxia (Box 39.4). +If there is any evidence of fetal hypoxia in the first stage or labor: going to be prolonged, cesarean section is necessaiy. The condition of the neonate is assessed immediately after delive1y. Many of these babies need expert neonatal care. Delive1y is conducted in an institute with equipped neonatal care unit. + +IMMUNOLOGY IN OBSTETRICS +Many obstetric problems are now explained with the complexity of immunology. In this chapter a short review of the selected areas will be made highlighting the imm­ unological explanations. +BASIC IMMUNOLOGY OF PREGNANCY: One tissue that is repeatedly grafted and repeatedly tolerated is the fetus. The mysterious mechanism of the immune system that prevents rejection offetus remains unknown to the immunobiologists. The immune system is generally divided into two arms: +(i) Innate, and (ii) Adaptive. +The innate immune system is the: (a) First line of host defense against infection. (b) It works fast once it recognizes the pathogens. (c) It cannot identify the self vs nonself (nonspecific). (d) It involves complement system. The immune cells involved are: phagocytic (neutrophils, monocytes and macrophages) cells, natural killer cells (NK cells), eosinophils and basophils. The immune responses are by the release of cytokines (TNFa, IL-1, IL-6) and chemokines (IL-8, MIP-la, MCP-1). The phagocytic cells ingest and digest microorganisms with lysosomal enzyme. The NK cells can recognize and distinguish between normal cells and cells infected with a virus or tumor (self or nonself) through the expression of MHC Class I antigens. The NK cells destroy cells that are deficient in HLA Class I molecules. +Adaptive immune system: (a) It works as a second line defense against infection; (b) It has delayed response; (c) It can discriminate 'self' from 'nonself'; (d) It prevents re-infection through 'immunological memory'. It is contributed mainly by two types of cells. Lymphocytes (B and T lymphocytes) and antigen-presenting cells (APC). T lymphocytes are classified into T-helper (Th) and T cytotoxic (Tc) cells. Th cells have two subtypes-Th-I and Th-2. Th-1 cells activate macrophages and are involved in cell-mediated immunity. Th-2 cells activate B-cell differentiation and are involved in humoral immunity. When pathogens (viruses) replicate inside the cells and are inaccessible to antibodies, are destroyed by T cells. +Major Histocompatibility Complex (MHC) is a complex of genes with multiple loci. It is located on the chromosome 6. MHC encodes two types of membrane proteins. Those are known as Human Leukocyte Antigens (HLA) Class I and Class II. The process of graft rejection + + + +generally involves recognition of foreign MHC molecules by host TI hymphocytes. +(1) IMMUNOLOGY IN PREGNANCY +• Pregnancy is not an immunodeficient state. Women are able to respond to both humoral and cell-mediated immunity against the paternal antigen. +• Specific types of NK cells (large granular lymphocytes) are present in the decidua mainly at the site of implantation. These NK cells (uterine NK cells) are different from blood NK cells. These U-NK cells control the trophoblast proliferation, invasion when they interact with the trophoblast HLA Class I molecule. The U-NK cells depend on progesterone for survival. U-NK cells contribute to maternal tolerance of the fetus and maintenance of pregnancy. NK cells share many antigenic and functional similarities to 'T' cells. There is high (30%) proportion of NK cells in fetal circulation (13 weeks). Due to their high number, early presence and the ability to kill cells, it is likely that these NK cells are very important in fetal innate immune system. +Uterine macrophages are the major source of nitric oxide and prostaglandins. +• Trophoblast cells are derived from the fetal tissue and invade the decidua. These trophoblast cells (placenta) form the interface between the fetus and the mother. Thus the placenta forms an efficient barrier against the transmission of immunocompetent cells between the fetus and the mother. +• The trophoblast covering the chorionic villi (villous trophoblasts) comes in contact with the maternal blood in the intervillous space and interacts with maternal systemic immune response. It does not express HLA Class I or Class II molecules. +• The trophoblast in contact with the decidua (extravil­ lous trophoblast) expresses HLA Class I molecules but not HLA Class II molecule. This interacts with maternal local uterine immune response. +• Placenta presents no immunocompetent cells due to lack of HLA antigens. Placenta acts as an efficient immunological barrier. +• During pregnancy, maternal immune response is shifted (immunomodulation) from Th-1 (cell mediated) to Th-2 (humoral mediated) type. Th-2 type response is beneficial due to the production of anti-inflammatory cytokines. Immunomodulation results in improvement of woman with rheumatoid arthritis in pregnancy. +• During pregnancy there is production of antibodies of paternal antigens. These are anti-HLA antibodies and antibodies against sensitized T cells. These antibodies have no major effect on pregnancy outcome. +• Immunological mechanisms involved in pregnancy are not the same as that of organ transplantation. Immunological tolerance through complement and cytokines regulation is protective for pregnancy. +Chapter 39: Special Topics in Obstetrics ED + +Other Postulations +■ Maternal fetal cell trafficking and microchimerism: Maternal tolerance of fetus is due to bidirectional cell trafficking between the mother and fetus. Cell­ Free Fetal DNA (Cff DNA) and also infant fetal cells are detected in maternal circulation during entire pregnancy. The existence of two-cell populations in a single person is known as microchimerism. It is likely that microchimerism may have beneficial effects. +■ Immunosuppressive factors that operate in preg­ nancy are: estradiol, progesterone, hCG and prolactin. Fetal tolerance is probably due to the presence of alpha fetoprotein. A number of pregnancy associated glyco­ +proteins, e.g., a2 macroglobulin and placental interferon +have immunosuppressive properties. Amniotic fluid is rich in immunosuppressive phospholipids. +Immune Tolerance +• Immune tolerance of normal pregnancy at the maternal-fetal interface is maintained by the interaction of HLA-G with uterine NK cells. This effect predominates in a normal pregnancy. +• The levels of complements and cytokines (proinflam­ matory factors) are often raised during pregnancy. Inhibition of such complements and cytokines by the placenta reduces the immune-mediated pregnancy complications. +In a normal pregnancy, there is suppression of Th-1 and activation ofTh-2 cytokine response. In cases with preterm labor, Th-1 cytokine profile is activated. +■ Inhibition of complement activation contributes to fetal tolerance. +■ Fetal red blood cells (CD 71+) produce an enzyme arginase. CD 71+ cells appear to protect the neonate from excessive inflammation. +■ Influx of T cells into the fetal membranes may cause loss of fetomaternal tolerance. Development of chorioammonitis due to influx T cells (TL-1 , IL-6, TNFa)results in preterm labor and fetal death. +(2) ABO HEMOLYTIC DISEASE OF THE NEWBORN: Jaundice in newborn within 24 hours of birth may be due to ABO isoimmunization of the mother. The incidence is higher in group 'O' mothers carrying group A fetuses. +(3) Rh-lSOIMMUNIZATION: Though entry of fetal blood in maternal circulation can take place at any time during pregnancy, fetomaternal bleed is common in the third trimester, particularly during separation of the placenta. 0.1 mL of Rh-positive fetal blood is sufficient to bring about immunization in Rh-negative mother. Immunization. +(4) PRE-ECLAMPSIA/ECLAMPSIA: In pre-eclampsia, the abnormal immunological response develops in two stages: +A. Abnormal placentation and spiral artery remode­ ling: This is due to decreased placental HLA-G expression. HLA-G has a major role in placentation and blood flow + +development as observed in a normal pregnancy. There is failure of extravillous trophoblasts invasion and spiral arte1y remodeling. This is due to failure of interaction of extravillous trophoblasts with uterine NK cells and HLA-C receptors. +B. Pre-eclampsia is associated with widespread systemic inflammation and endothelial dysfunction. The immune dysfunction in pre-eclampsia are as follows: +• There is decrease in regulatoryT cells both in number and function. ++ There is insufficient shift from Th-1 to Th-2 as opposed to normal pregnancy. +• There is a higher level of cytokine abnormalities with increased concentration ofTNFa, IL-6, IL-1 , IL-8 and lower concentration ofIL-10. +(S) SPORADIC AND RECURRENT MISCARRIAGE:There are some observations suggesting an immunological interaction in cases with sporadic and recurrent miscarriages. +• Cytokines are immune molecules. Th-1 cells produce proinflammatory cytokines whereasTh-2 cells produce anti-inflammatory cytoldnes. In a normal pregnancy there is a shift of Th-1 response to Th-2 response. Progesterone has an immunomodulatory role to induce a pregnancy protective shift from Th-1 cytokine response to more favorable Th-2 cytokine response. ++ Women with recurrent miscarriage produce low levels ofTh-2 cytokines (IL-4 and IL-10). ++ Women with recurrent miscarriage have a decreased population of NK cells in the decidua. This indicates an altered immune environment within the decidua. +• NK cells differ from T and B lymphocytes cells. NK cells do not have clonally distributed receptors for foreign antigens and can lyse target cells without prior sensitization. +■ Cord blood transplantation: Fetal blood contains a high number of hematopoietic stem cells as well na·ive T cells and NK cells. For this, cord blood is an ideal source of cells for hematopoietic cell transplantation. +■ Solid organ transplantation in pregnancy: This is long-term persistence of fetal cells in the mother and the maternal cells in her pregnancy. +• Coexistence of two cell population in a single per­ son has been observed. This is referred to as Microchimerism (MC). A pregnant woman with solid organ transplantation has at least three sources of MC (fetal MC, maternal MC and the donor allograft). Uterine transplantation has now been performed. +• Maternal T cells and B cells through regulation (T REG cells and B REG cells) suppress the antigen specific immune response. In pregnancy there is expansion of +T REG cells (>100 fold). B REG cell expansion occurs in early pregnancy with rise in hCG. Combined together these help in pregnancy (maternal-fetal) tolerance and +continuation. +f mJ Chapter 39: Special Topics in Obstetrics +(6) ANTIPHOSPHOLIPID SYNDROME (p. 161,328,435): In SLE antiphospholipid antibodies, e.g., lupus anticoag­ +ulant 2 glycoprotein, and anticardiolipin are important. These antibodies act by dysregulation of coagulation +pathways. This causes thrombosis of uteroplacental vessels and poor placental perfusion. Obstetric complications are due to this pathology. +(7) MATERNAL AUTOIMMUNE DISEASE AND FETUS +• Incidence of neonatal thyrotoxicosis is higher in babies born of a thyrotoxic mother. +• A baby born to a mother with ITP will, in all probability, suffer from the same disease through transplacental transfer of antiplatelet antibodies. ++ Myasthenia gravis also has some such relationship due to transplacental transfer of acetylcholine-blocking factor. +Babies born of mothers suffering from systemic lupus e1ythematosus often develop congenital heart block due to transplacental transmission of anti-Ro and anti-LA (anti-SS-A and anti-SS-B) antibodies. SLE patients, very often, have exacerbation of disease activity during pregnancy or in the early postpartum phase. All the diseases listed in this group manifest transiently in the newborn. + +CRITICAL CARE IN OBSTETRICS + +Overall, 1-3% obstetric patients are admitted in Intensive Care Unit (ICU). Among these patients, the risk of death ranges from 2% to 11%. + +Selection Criteria of Obstetric Women for ICU Admission +ICU admission should be restricted to a critically ill woman who is likely to be benefited (Box 39.7). +Some institutes have their own guidelines for transfer to ICU (ACOG). Antenatal transfer to ICU rather than with newborn transfer is preferred except in a situation, where maternal transport is unsafe or impossible. + + + + + + + +Table 39, 1 S: Arterial Blood Gases (ABG) during nonpregnant state and pregnancy. +ABG variables Nonpregnant state Pregnancy pH 7.35-7.43 7.40-7.47 +PaC02 (mm Hg) 37-40 27-34 Pa02 (mm Hg) 94 101-106 HC03-(mEq/L) 22-26 17-18 Base deficit (mEq/L) 1 3 + +cardiologists, pulmonologists, intensivists, respiratory therapists, pharmacists and nurses. Obstetric critical care unit involves obstetricians, obstetric nurses and neonatologists. +There are three levels of adult critical care (ACOG). +Level 1: Highest level of care: Severely ill patients are managed with the involvement of multidisciplinary team members. +Level 2: Intermediate care or High Dependency care Units (HDU): This is the post-ICU step down unit. These are within the labor ward. Care is provided by the obstetricians and nurses who are experienced. +Level 3: Other intensive care units: For patients requiring long-term ventilator support. +Arterial Blood Gases (ABGs) values during nonpregnant state and pregnancy varies (Table 39.15). It is important while managing a woman during pregnancy in ICU. + +OBJECTIVE PARAMETERS (SELECTED) FOR ADMISSION OF A PATIENT (NON-PREGNANT) IN AN ICU + +Laboratory values and physiologic parameters are changed in pregnancy. Hemodynamic changes in a normal nonpregnant and pregnant women at term are significant: These values are important while managing an obstetric patient in ICU (Box 39.7). Cardiovascular changes and respiratory system changes are important. Use of pulmonaiy artery catheter (Swan-Ganz) is used, + +The essential requirements for transfer are: continu­ ous pulse oximet1y monitoring, ECG monitoring, venous access, and confirmed position of endotracheal tube when a woman is under mechanical ventilation. + +Organization of a Critical Care Unit +A qualified intensive care physician is to manage ICU, though it is not mandatory. However, it is observed that high-intensity ICU physician staffing is associated with lower ICU mortality and decreased hospital stay, when compared with low-intensity ICU physician staffing. +Critical care unit involves multidisciplinary appro­ ach: The team members involve physicians, anesthetists, + +A. Vital signs +• Heart rate (HR) <40 bpm +or >1 SO bpm. +• BP <80 mm Hg systolic or > 120 mm Hg diastolic. +• Mean arterial pressure <60 mm Hg. +• Respiratory rate > 35 breaths/minute. +B. Physical findings • Anuria +• Coma +• Uncontrolled seizures • Cardiac arrest +• Cyanosis + +C. Laboratory values +• Serum Na+ <110 or > 170 +mEq/L. +• Serum K+ <2 or >7 mEq/L. • Pa0 <50 mm Hg. +2 +• pH <7.1 or >7.7. + + + +D. Imaging studies +• CT/MRI: Cerebral +hemorrhage. +• Electrocardiography: Complete and heart block, complex arrhythmia, CCF. + + +especially in cases with severe pre-eclampsia, eclampsia, respiratory distress syndrome and amniotic fluid embolism. +Pulmonary artery catheter values: Normally, pulmonary capillary wedge pressure (mm Hg) at term pregnancy is 7.5 ( +18% rise from nonpregnant state) and CVP is 3.6 mm Hg (-2%). There is fall in systemic vascular resistance (-21 % ) and pulmonary vascular resistance (-35%) at term pregnancy compared to a nonpregnant +adult. It is an invasive procedure. +Indications of invasive hemodynamic monitoring (ACOG) +11 Shock (septic, hemorrhagic, cardiogenic). 11 Pulmonary edema. +■ Severe PIH with persistent oliguria. ■ ARDS. +■ Severe cardiac disease. +Causes of acute lung injury and ARDS in obstetrics +■ Pre-eclampsia-eclampsia. +■ Obstetric sepsis (septic abortion, chorioamnionitis, pyelonephritis, puerperal sepsis (Box 39.8). +■ Massive hemorrhage [shock, Transfusion Related Lung Injury (TRALI)]. +■ Tocolytic therapy. + +Decision Making and Patient Care in ICU +For a pregnant woman, ICU team members should plan for management including delivery which may be needed long before the EDD. Safe delivery of a woman needs consideration of period of gestation (fetal survival), place and mode of delivery (vaginal or cesarean). Vaginal delive1y or operative vaginal delive1y (forceps, ventouse) after at least 34 weeks of gestation within the ICU set up when possible is always beneficial. Cesarean delivery in the ICU is often faced with the problem of space for anesthesia, operative facilities, neonatal resuscitation arrangements and the risk of infection. Cesarean delive1y in ICU may have to be done where transport of patient is not possible or for perimortem procedures. + +Chapter 39: Special Topics in Obstetrics + + +■ CNS: Confusion, altered sensorium. +■ CVS: Tachycardia, hypotension, warm or cool peripherals. 11 Respiratory: Tachypnea, hypoxia. +11 Renal: Oliguria, anuria. +11 GI: Abnormal LFTs, jaundice, nausea, vomiting. +■ Metabolic: +• Lactic acidosis. +• Hypo-/hyperglycemia. • Hypocalcemia. +11 Hematology: +• Abnormal WBC count. +• Reduced platelets, fibrinogen, DIC. +• Increased D-dimer. ■ Skin: +• Hyperthermia. • Hypothermia. + +Fetal Care in ICU +11 Fetal gestational age assessment is essential to estimate the approximate fetal survival rate following delivery. Effects of obstetric medications need to be carefully judged in terms of risks and benefits. +■ Drug-related side effects that may arise are: beta ago­ nists (tachycardia), indomethacin (platelet dysfunction, reduced renal perfusion), beta blockers (IUGR). Bene­ fits of antenatal corticosteroids are established and it is to be given in the event ofpreterm delive1y ( <34 weeks). +■ Maternal drugs (sedatives), acidemia, hypoxia, blood pH, may alter the CTG tracings. Correction of mater­ nal hypoxia, acidemia may improve fetal condition. Howeve1; fetal interest comes second and essential med­ ications should not be withheld to the pregnant woman. +Place of perimortem cesarean delivery: There is no such clear guideline regarding this issue. However, it is observed that cesarean delivery should be considered for both maternal and fetal benefits about 5 minutes within a pregnant woman has experienced total cardiopulmona1y arrest in the third trimester. + + + + +► Women with multisystem pathology need improved care with technology and expertise of critical care obstetrics. +► Common indications for admission in ICU (based on objective parameters) are: Need of cardiac, circulatory, pulmonary or multiorgan support arising out of obstetric complications (hemorrhage, hypertensive disorders or sepsis). +► The comparative values of hemodynamic changes in nonpregnant and pregnant women at term are important in the management. Pulmonary artery catheterization are of immense value in the management. +► Critical care unit management involves multidisciplinary approach. High-intensity ICU staffing can reduce ICU mortality and decrease hospital stay. Obstetrician, intensivist, specialty nurses, and neonatologists are involved. +► Acute Respiratory Distress Syndrome (ARDS) may be due to pneumonia, sepsis, pre-eclampsia, embolism or drugs. Vigorous antimicrobial therapy, oxygen delivery (early intubation and ventilation for woman with respiratory failure) and support of circulatory volume (IV crystalloids and blood) are essential considerations. +► Fetal care in ICU needs consideration of fetal gestational age, drug-related side effects, and timing, place and mode of delivery. ► Benefit of antenatal corticosteroids in the event of preterm delivery (<34 weeks) is established and should be used. +► Nearly 7S% of obstetric ICU patients admitted are postpartum. +► Hemorrhage, hypertension and sepsis are the most common causes of admission in obstetric ICU. +► Necessary medications should not be withheld to a pregnant woman because of fetal concerns. So also necessary imaging studies. However, attempts should be made to limit fetal exposure (drugs/radiation) as much as possible. +► For antimicrobial therapy-Read more Dutta's Clinics in Obstetrics, Ch. 71 and Clinics in Gynecology, Ch. 59. + + +Current Topics in Obstetrics + + + +CHAPTER + + + +CHAPTER OUTLINE +❖ Medical Ethics +❖ Effective Clinical Communication ❖ Pregnancy Following Assisted +Reproductive Technology (ART) +❖ Antibiotic Prophylaxis in Cesarean Section + + +❖ Day-care Obstetrics +❖ Legal and Ethical Issues in Obstetric Practice +❖ Audit in Obstetrics +❖ The Preconception Counseling Prenatal Diagnostic Techniques + + +❖ Umbilical Cord Blood Stem Cells in Transplantation and Regenerative Medicine +► Stem Cells and Therapies in Obstetrics + + + +I MEDICAL ETHICS +The word ethics (derived form the Greek word 'ethos'), means custom, habit, character or disposition. +Ethics consists of moral principles which are concerned with individuals and society. It is a system which helps us to tell right from wrong, good from bad and gives practical guidance to our lives. +Principles of medical ethics: +(1) Respect for autonomy; (2) Nonmaleficence; (3) Beneficence and ( 4) Justice, are the four principles of medical ethics (Tom Beauchamp and James Childress-1985). Along with these, confidentiality and truth-telling are also included. Medical ethics is meant to profit and defend human dignity and patient's rights and it is a set of norms, values and principles to avoid harm. +Need for ethics: To have norms which everyone should follow both as an individual and as a society, otherwise it will end up in chaos. +■ Beneficence: It is a moral obligation to act for the benefit of others, e.g., holding the hand of a dying person. +■ Nonmaleficence: There is an obligation not to infilict harm on others "primum non nocere" (first, do no harm). +■ Autonomy: It involves respecting patient's view, allowing or enabling them to make their own decision-it is a shared decision +■ Justice: According to health care, ethics is divided into three categories (Gillon-1994): distributive justice, rights based justice and legal justice. +Distributive justice means fair distribution of scarce resources, rights based justice is respect for people's rights and legal justice means respect for morally acceptable laws. +Alperovitch (2009) described two more elements: Equality and Equity. There should be equal access to the treatment and the patients should be treated equally. +It is vital that healthcare professionals must have knowledge and training about ethics and its challenges so that the patients receive the best care. Role of healthcare ethics will change in future and will gain increased importance. + + +EFFECTIVE CLINICAL COMMUNICATION + +To have a good patient-physician relationship, effective communication is the cornerstone. Students need to develop communication strategies and the skill throughout the medical course. Nowadays, effective clinical communication skill is considered as the utmost important and it is also to be assessed. +Steps for effective clinical communication are: (1) To greet and to introduce one self; (2) Initiate the reason for discussion; (3) Building the relationship; ( 4) Providing information; (5) Explaining the risks; (6) To assist with decision making; (7) Closing the consultation. +Decision making with patients is guided both by the ethics of beneficence and the ethics of respect to autonomy. +Simple consent: Where clinical management poses no significant risk to the patient ( measurement of BP). +Informed consent: Where clinical management entails clinically significant risks, including the risk of mortality , disability or sufferings. +Example: (A) To give information regarding: Instrumental (forceps/ventouse) vaginal delivery to cut short the delay in second stage of labor. +Steps involved +1. First greet and introduce yourself: Establish the reason for consultation. +2. Building the relationship: Assess the woman's and her attenders knowledge for about the forceps/ventouse delivery. Establish their ideas about this, their expectations and their concerns. +3. Providing informations: Frame an organized consultation. Give a clear information about the use and benefits of instrumental vaginal delivery. It should be in simple words. Medical terminology is to be avoided as much as possible. Use visual aids (when needed). Explain the procedure to relieve her apprehension: For example, to avoid pain, appropriate analgesic will be given during the procedure. There is no need of general anesthesia. There would not be much need of straining as the instrument will help her during the procedure. It also reduces the time for the baby under stress. + + +Instrumental delivery facilitates early ambulation and less hospital stay. She can go home within 2-3 days. +4. Explaining the risk: +• A small cut is made at the birth passage. It is repaired at the end. It heals soon. +• Analgesics (oral) are sufficient enough to take care of her pain following delivery. +5. Assist with decision-making: +• Time should be given to the woman to respond on the information provided. +• Encourage her. Help her to make the decision. +6. Closing the consultation +• Invite some more questions from them. • Discuss and agree to her plan. +• Get signature. +• Thank the patient. +(B) Breaking the bad news: For example, Intrauterine Fetal Death (IUFD) +1. Initiating session: +• Introduce yourself. +• Provide a comfortable room for all. +• Establish rapport with her and her spouse/accompanying person. +2. Assess whether they already have any information about the condition: +• Assess what is their concern, ideas and their expectations. • Briefly tell them what has happened in simple words. +3. Delivering bad news +• Give the news in simple straightforward manner. +• Give reason for patient's condition (intrauterine death). • Give some time to the patient to process the information. • Show empathy. +4. Explore the patient's initial emotions +• Allow the woman to express her initial emotions. • Try and identify her emotions. +• Recognize how the patient feels after hearing the news. • Show concern. +5. Giving information +• Find out whether the patient needs some more information. • Provide clear explanation (visual aid) +• Offer other medical options/additional investigations +6. Assist in taking decision +• Give enough time to the patient to reflect on the information provided. +• Assist in arriving at her plan (shared decision). +7. Inviting further questions +• Invite some more questions from them. Discuss and agree to the plan. +8. Closing the consultation: +• Inform the patient about the plan of subsequent management. +• Discuss about the patient's support and follow-up. • Get the signature. +• Thank them. + +Chapter 40: Current Topics in Obstetrics ml + + +■ Gestational Diabetes Mellitus (GDM-20%). +11 Gestational hypertension, pre-eclampsia (2%). 11 Complications related to multiple pregnancy. +■ Hemorrhage (placenta previa, placenta accreta, abruption). ■ Cesarean delivery. +• Admission to Intensive Care Unit (ICU-33%). + + + +11 Genetic and chromosomal abnormalities (Trisomy 21). ■ Structural malformations (7%). +■ Fetal Growth Restrictions (FGR). +11 Low birth weight babies (<2500 g). ■ Stillbirth. +■ Preterm births (11 %, spontaneous and indicated). ■ Increased perinatal mortality (2-3 fold). + +babies have been conceived through IVF. Assisted Reproductive Technology (ART) is now an established procedure in the management of couples with infertility. It is proved to be an effective and relatively safe procedure. The number of babies born from ART worldwide has increased significantly since 1980s. However ART has got certain risks associated (Boxes40.1 and40.2). +Conceptions following ART are at increased risk of maternal and fetal complications (Boxes 40.1 and 40.2). Early pregnancy complications are few (Table 40.1). A special care is needed when such a woman is seen in the antenatal clinic. Such woman need to be seen by a senior obstetrician. +Management issues: Risk assessment of individual woman is needed. Prenatal screening procedures are to be done. Pregnancy monitoring with standard surveillance procedure is recommended. Individual woman may be benefitted with aspirin, progesterone (recurrent miscarriage). Heavier women with recurrent miscarriage, antiphospholipid syndrome are benefitted with LMWH/heparin therapy. +Multifetal gestation following ART is high (20 times) compared to spontaneous conception. Risk of monozygotic twins (mono chorionic monoamniotic twins) appears to be higher (3%) following Elective Single Embryo Transfer (ESET) than in natural conceptions (0.4%). Risk of ectopic and heterotopic pregnancy is increased following ART treatment. Maternal risk factors such as smoking, PID, endometriosis, impaired tubal function further increase the risk. ART related factors (alterations of hormonal micro environment following controlled ovarian stimulations), embryo quality, multiple embryo transfer and embryo transfer techniques are also associated with increased risk. +ART and cancer risk in women: No increased risk for breast, ovarian or endometrial cancer has been associated. Possible increased risk of ovarian borderline tumor has been noted. + + +Table 40.1: Conception following ART and the early pregnancy complications. +Condition Risk + + + +PREGNANCY FOLLOWING ASSISTED REPRODUCTIVE TECHNOLOGY + +■ Miscarriage 15-20% +■ Ectopic pregnancy 2-8% + + + + +More than 3 million babies are born following ART procedures since the birth of the first baby in 1978. Overall 1-5% of the + +■ Ovarian Hyperstimulation Syndrome (OHSS) 3-8% +Woman need counselling before and after ART procedure +Chapter 40: Current Topics in Obstetrics + +Early menopause: No significant association between the women of ART cycles and menopause has been observed. +Venous Thromboembolism (VTE): ART doubles the risk of VTE during pregnancy. Risk is high in the first trimester (four fold). Presence of additional risk factor indicates prophylactic anticoagulation therapy (LMWH). Additional risk factors are: BM! >30 kg/m2, age >35 years, Parity ?3, estrogen provoked VTE, thrombophilia and multiple pregnancy. + +ANTIBIOTIC PROPHYLAXIS IN CESAREAN SECTION + +Prophylactic use of antibiotics effectively reduces postoperative infectious morbidity and hospital stay both for the mother and the neonate. Postoperative morbidity like fever, endometritis, wound infection, peritonitis, and also pelvic abscess can significantly +be reduced. However, an institution, where infection rate is high, should primarily improve the surgical and aseptic technique. Emergency cesarean section is associated with higher rate of infection than the elective procedure. Similarly, cases with prolonged rupture of membranes and in prolonged labor are at higher risk of infection. +Infective agents are mostly polymicrobial, including gram­ positive, gram-negative aerobes and anaerobes. Generally, antibiotics with broad-spectrum activity are better. Single dose therapy of ceftriaxone (1 g), cefuroxime (1.5 g) or co-amoxiclav (1.2 g) by intravenous route is a reasonable choice. Shorter courses of 1-3 doses may be given. This can reduce the cost compared to a full 7 days course. First dose to the mother is given 60 minutes before the skin incision is made. Ideally, the antibiotic infusion should be timed so that a bactericidal serum level is reached by the time skin incision is made. It is recommended that prophylactic antibiotic should be administered within 60 minutes of the start of the cesarean delivery. When this is not possible, it should be started as soon as possible (ACOG). This avoids antibiotic exposure to the baby. Bacteriology pattern and antibiotic sensitivity need to be monitored regularly by the microbiology laboratory. Antibiotic prophylaxis has no deleterious effects on the mother or the neonate. + +DAY-CARE OBSTETRICS + +It is designed to provide inpatient care to a pregnant woman, on an outpatient basis throughout the day. It is a new concept. This is similar to today's care surgery, as done for minor operations. +DEVELOPMENT OF A DAY-CARE UNIT: Significant number of antenatal inpatient load is due to pregnancies complicated by hypertension. Objective is to provide rest, risk assessment and treatment to avoid any complication. When such a patient is seen in the day-care unit, repeated blood pressure measurement is done. Examination of urine for protein, blood for uric acid and platelets, and LFT are also done. Fetal wellbeing is assessed by clinical examination and also with cardiotocography and ultrasonography for liquor volume and fetal weight. Finally, the patient's risk is assessed and management is done accordingly. +Similarly, women with diminished fetal movements could be assessed in a day-care unit. She could be assessed with all parameters of histoty, clinical examination (fetal growth, liquor volume, auscultation of FHR), ultrasonographic study (BPP), + + + +and Doppler flow study of umbilical artery and ductus venosus depending upon the case. +PROCEDURES FOR RISK EVALUATION IN DAY-CARE OBSTETRICS +♦ It requires an organized setup with quick access to laboratory and other monitoring parameters. +♦ It is essential that an experienced obstetrician should assess the pregnant women in a day-care unit. +♦ A high-risk patient should be admitted from the day-care unit for subsequent management. +♦ A moderate-risk patient could be seen for repeat day-care assessment. +♦ A low-risk patient without any maternal or fetal compromise is referred back to routine care. +Advantages: (a) This acts as a safety net for assessment of obstetric complaints, (b) Reduces inpatient overcrowding and workload, especially in a busy hospital, (c) Reduces the stress of the woman due to separation from the family, ( d) It reduces concomitant costs. + +LEGAL AND ETHICAL ISSUES IN OBSTETRIC PRACTICE +Currently, there is growing concern in the relationship of caregiver (Doctor) and the care-receiver (Client) in medical practice, in terms of mutual trust and understanding. This is due to great expectations of the society with progressive technological advancement. Medicolegal problems in obstetric practice are, therefore, rising both in the developed and in the developing world. +The doctor owes to his patient a duty of care. Care and attention must be according to the established norms available at that time and place. When the doctor fails to exercise that duty properly, he/she is found to be negligent. The failure to perform the proper duty to patient care may be due to his incompetence or malpractice or mere negligence. The failure to provide a standard care may again be either by acts of omission or commission. +Adverse outcomes of medical care are often due to: (i) System errors (inadequate staff, physician or operating room, etc.) or (ii) Healthcare personnel's error. +Once the act of substandard care due to system error, negligence, malpractice or incompetence is proved in the court of law, the plaintiff has to be compensated. +COMMON AREAS OF LEGAL THREAT IN OBSTETRICS: There are certain areas where claims are frequent and, sometimes, ve1y high. These are in the field of: (a) Perinatal inju1y, (b) Maternal injuty or (c) Both. +a. Perinatal injury: (I) Stillbirth and neonatal death, (2) Brain damage to a baby, (3) Injury following vaginal breech delive1y, (4) Operative vaginal delivery. +b. Maternal injw)': (I) Maternal trauma, (2) Maternal death, (3) Episiotomy, (4) Forgotten packs in abdominal cavity or within the vagina. +c. Both: (l) Instrumental delivery, (2) Operative delivery, (3) Anesthesia. +MEASURES TO MINIMIZE THE MEDICOLEGAL PROBLEMS +a. Communication-must be made in a clear and understandable way to the client (patient) and the relatives about the management decision. +Chapter 40: Current Topics in Obstetrics ED +I + +b. Informed and written consent-must be taken before any agreed management decision or investigations. +c. Legal and ethical: +♦ Her consent must be following a clear understanding of the proposed procedures or therapy, its risks to herself and her fetus, the alternatives, success rates and the likely problems or complications. +♦ Obstetrician should not perform any procedure that is refused by the pregnant woman. Surgery without consent is an assault. +♦ The physician must provide information to the parents in relation to genetic counseling and prenatal diagnosis. +♦ Patient's privacy and autonomy must be protected. No information, obtained in genetic counseling and screening, should be disclosed to any third party without the patient's authorization. +♦ Where conflicts arise, the doctor should seek help of and advice from other professional colleagues. +d. Proper documentation of facts in the patient's file clearly and legibly in respect of date and time. +e. Strict adherence to established management protocol (evidence based) is essential. When there is any deviation, it must be documented showing suficient reasons. +f. Careful record maintenance in institution as it may be required later on. +g. Adequate training and supervision of juniors, especially involved in labor ward patient care. Seniors must be available for consultation or direct involvement as and when asked for. +h. Consultation with another physician in the specialty when any difficulty is faced as regards the patient care. +i. Regular audit and meetings-should be done to update the knowledge of all the staff involved in patient care. Audit will help to improve the quality of care. + +PRECONCEPTION COUNSELING, PRENATAL DIAGNOSTIC TECHNIQUES (PCPNDT) +Objectives +1. The Act provides the prohibition of sex selection/determi­ nation before or after conception and prevent the misuse of prenatal diagnostic technique for sex selective abortions. +2. It regulates the use of prenatal diagnostic techniques, like ultrasound and amniocentesis by allowing them only to detect: (a) Chromosomal abnormalities, (b) Genetic abnormalities, (c) Metabolic disorders, {d) Certain congenital malformations, (e) Hemoglobinopathies, (f) Sex-linked disorders, {g) Any other abnormalities or diseases as may be specified by the central supervis01y board. +3. The techniques must be conducted by qualified persons only. +4. Every center/institute conducting these tests must be registered under the Act. +5. Every center/institute must display a notice delineating that sex determination/selection is prohibited under law. + +Salient Features of the Act +■ Absolute prohibition of sex determination/selection and no communication can be made about the sex of the fetus in any manner. + +11 A copy of the Act and rules must be available in the center/ institute. +■ Signage board in English and in the local language must be displayed indicating the fetal sex is not disclosed in the clinic. +■ Prohibition of sale of equipments/machines, etc., to anyone who is not registered under the act. + +Penalities +Ii If any person acts contrary to the prohibitions listed above he/she will be punished with imprisonment which may extend to 3 years and fine which may extend to'( 10,000.00. +11 Any subsequent conviction entails, imprisonment which may extend to 5 years and fine which may extend to'( 50,000.00. +■ In case of a registered medical practitioner, his/her name shall be reported by the Appropriate Authority to the State Medical Council concerned for taking necessary action including suspension of the registration and for the removal of his name from the register of the council on conviction for the period of five years for the first offence and permanently for the subsequent offence. +■ Any person who puts an advertisement for prenatal and preconception sex determination facilities in any form, can be imprisoned for up to 3 years and fined no,000.00. +11 The Act mandates compulsory registration of all diagnostic laboratories, all genetic counselling centers, genetic laboratories, genetic clinics and ultrasound clinics. + +AUDIT IN OBSTETRICS + +Progress in clinical care cannot be achieved without a change. Many outdated practices in clinical medicine should be removed for betterment. Audit (clinical review) is an effective tool to indicate that change is essential. +DEFINITION: Audit is defined as the systematic and critical analysis of the quality of medical care. Objective of carrying out an audit is to improve the quality of clinical care. It is done by changing and strengthening many aspects of hospital practice and administration. Audit should not be confused with research, which involves new experiments, investigations and treatment. +Audit could be medical where scrutiny is done over the medical aspect of the work performed by the doctors. It could be clinical, where scrutiny is done over the work done by all health professionals including the doctors. + +STRUCTURING AN AUDIT: Audit has to be structured beforehand. It should be based on available resources including personnel and finance. Important aspect to organize an obstetric audit is motivation of all doctors, midwives and other health professionals. Proper documentation of facts and figures must be there. Audit should be kept confidential and is considered as an educational tool. +EXAMPLE: Subject-'Hypertensive pregnant women must have their Blood Pressure (BP) checked at least 4-6 hours interval'. With this subject a standard (best practice) has to be adopted. The indicators are: BP measurement, hypertensive pregnant women and the time, so staff and equipment (resources) should be made available. A target is set up to include maximum number (95%) of the patients in the study. Monitoring methods should be strictly followed. The components are documentation and data collection. There must be an individual (Registrar/ Senior Resident/Lecturer) assigned for canying out the audit. +Chapter 40: Current Topics in Obstetrics + + + Accept a standard (best practice) + + + + + +Implement Analyze the change existing practice +J + + + +Compare +the existing practice with the standard + +Fig. 40.1: Audit cycle. + +Finally, this existing practice is critically analyzed, interpreted and then compared with the standard. Use of computers is helpful in data processing. Once the problems are identified and solved, better clinical care would emerge (Fig. 40.1). +AUDIT CYCLE +Importance of Carrying Out an Audit +1. A well-structured and efficient audit is based on scientific evidences with facts and figures. +2. It can replace the out-of-date clinical practice with the better one. +3. It can remove the disbelieving and agnostic attitudes between hospital management and professionals and also amongst the professionals. +4. It improves awareness between doctors and patients. 5. It is an efficient educational tool. +LIMITATIONS: Unless the audit is a simple one, it requires a lot of time, staff commitment and technology. + +UMBILICAL CORD BLOOD STEM CELLS IN TRANSPLANTATION AND REGENERATIVE MEDICINE + +Cord blood collection is done from the ex-utero separated placenta following delivery. Umbilical cord blood banking of Stem Cells (SC), gives benefit to treat many diseases. Allogeneic Hematopoietic Stem Cells (HSC) derived from umbilical cord blood have been used in the treatment of more than 70 indications. The common indications are: (1) Malignancies of the hematopoietic and lymphatic systems, (2) Metabolic disorders, (3) Immunodeficiencies, (4) Tumors, (5) Hemoglobinopathies, and (6) Genetic disorders. +Advantages of umbilical cord blood: (a) It is more readily available than bone marrow, (b) Better tolerated than bone marrow due to its immunological immaturity, (c) It is as effective and safe when compared to bone marrow. Fresh (not previously frozen) cord blood is a promising source of non-hematopoietic stem cells. Allogeneic stem cells from cord blood are best suited for the therapeutic use in regenerative medicine. +Common uses in regenerative medicine: (a) Myocardial infarction, (b) Heart valve replacement, (c) Diabetes mellitus, (d) Neurological disorders (stroke, Parkinson's disease, Alzheimer's disease, spinal cord injuries). With the current state + + + +of knowledge, it is not essential to store the umbilical cord blood in private blood bank, for donor's own use. +In summary, the uses of umbilical cord blood are: +■ The allogeneic hematopoietic stem cells from umbilical cord blood are used in the treatment of hematopoietic disorders (childhood leukemia). +■ Autologous hematopoietic stem cells from cord blood are unsuitable for the treatment of hematopoietic disorders. +a Non-hematopoietic stem cells can be produced from fresh (not previously cryopreserved) allogeneic cord blood donations. These non-hematopoietic stem cells are used in regenerative medicine. +■ Current state of knowledge suggests if a child needs transplant, it is better to use the blood of a healthy allogeneic donor. +♦ Allogeneic: Donor and recipient of a transplant are not identical (they may be related or not related) +♦ Autologous: Donor and recipient are identical. +I STEM CELLS AND THERAPIES IN OBSTETRICS + +Reproductive tissues are the important source of stem cells (progenitor cells). Stem cells have the potential to be used in the field of regenerative medicine. A stem cell has the ability to renew (reproduce) itself for long periods. +Potentials for the use of stem cells in regenerative medicine 1. Treatment of inherited genetic disorders +2. Treatment of hematological diseases. Properties of stem cells +a. Ability to self-renew (undergoing numerous cell divisions) maintaining the undifferentiated state. +b. Multipotency: Capacity to differentiate into a mature cell type. +Sources of stem cells +(A) Embryonic tissues, (B) Fetal tissues, (C) Extrafetal tissues, (D) Adult gonads. +A. Emb1yonic tissues: Inner Cell Mass (ICM) of the blastocyst, embryo and yolk sac. +B. Fetal stem cells: Human Fetal Hematopoietic Stem Cells (hf HSC) are primarily obtained from bone marrow and liver. Virtually, eve1y part of the developing fetus has higher proliferative capacity. These cells have higher amount of telomerase activity and have longer telomeres compared to their adult counterparts. Moreover, these tissues can differentiate efficiently into neuronal, muscle and osteogenic lineages. +Primitive hf MSC are transduced by integrating vectors and they do not express HLA-Il. They can be used for ex vivo gene therapy as well as postnatal bone tissue engineering. +C. Extrafetal tissues: Amniotic membranes, placenta, trophoblasts, amniotic fluid cells, all contain progenitor cells. These Mesenchymal Stem Cells (MSC) can differentiate into most cell types of mesodermal lineages. +Stem cell sample collection and banking +Currently, the use of stem cells in regenerative medicine is regulated through institutional regulatory boards. +■ Umbilical Cord Blood (UCB) collection and banking is an established source of HSC and MSC. This is used for + + +treatment of hematological diseases like leukemia and bone marrow failure. +■ Fetal tissues can be obtained following medical termination of pregnancy. Stem cells from fetal tissues can be harvested. Intrauterine transplantation of Human Fetal Mesenchymal Stem Cells (hfMSC), collected from liver, can be used for the treatment of hemoglobinopathies. +Intrauterine Stem Cell Transplantation (IUSCT) can be used to correct genetic disorders (monogenic diseases) (Box 40.3). +Use ofhfMSC has been explored for diseases having mesen­ chymal origin (Box 40.3). hf MSC undergoes site-specific differentiation and contributes to repair tissues in such diseases (muscular dystrophy, osteogenesis imperfecta). +Allogeneic transplantation of HSC in the treatment of mono genie disorder has certain advantages. It has high tolerance and less rejection rate as it is done before the onset offetal immune maturity (first trimester). +Autologous stem cells from fetal cord blood sampling or fetal liver biopsy in early pregnancy is done and the cells are harvested. An ex-vivo gene transfer may be done thereafter. This also reduces the risk of immune rejection. Howevet; fetal HSC in first trimester has favorable engraftment kinetics. + +Chapter 40: Current Topics in Obstetrics + + + +■ Hemoglobinopathies (a thalassemia, thalassemia, sickle cell anemia). +■ Mucopolysaccharidoses (MPS). ■ Inherited immune deficiencies. ■ Osteogenesis imperfecta. + +In the first trimester, fetal hematopoietic stem cells are highly proliferative and they circulate in significant numbers. Therefore, these cells are the important source of autologous HSC. +Fetal mesenchymal stem cells can be bioengineered and used for the disease of bone, skin, liver and heart. +The potential to use stem cells for the fabrication of tissues or organ implants may prove helpful in the treatment of several diseases like genetic, immunodeficiency syndromes, urinary incontinence, infertility and structural repair. +However, till date, it is essential to understand its known lim­ itations, putative benefits and the unknown risks. Until there is sufficient evidence on the efficacy of therapy, each case should be considered on an individual basis. +Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests + +CHAPTER + + + +CHAPTER OUTLINE +❖ Ultrasound in Obstetrics ► Three-dimensional +Ultrasonography +► First Trimester, Midtrimester and Third Trimester + + +❖ Magnetic Resonance Imaging (MRI) ❖ Computed Tomography (CT) in +Obstetrics +❖ Radiology in Obstetrics ❖ Amniocentesis + + +❖ Guides to Clinical Tests +❖ Tests for Blood Coagulation Disorders ► Collection of Blood Sample +► Samples for Blood Sugar Estimation ❖ Cervical and Vaginal Cytology + + + + +Imaging in obstetrics is indicated for the purpose of diagnosis and/or therapy to the fetus or the mother. Most (USG and MRI) of the imaging studies are harmless. The primaty imaging modality in obstetrics are 2-dimensional, 3- and 4-Dimensional (3D/4D). Magnetic Resonance Imaging (MRI) are used in situations where enhanced imaging are needed. Use of Computed Tomography (CT) and radiology in Obstetrics are limited because of safety issue. +PRINCIPLES OF DIAGNOSTIC IMAGING IN OBSTETRICS ++ Ultrasound is the most commonly used imaging tool in obstetrics. ++ MRI is useful for high soft tissue contrast and acquisition of images. Study of fetal neuroanatomy is best done with MRI. +• USG and MRI, both are safe in all the trimesters of pregnancy. +• There is no documented harmful effects to the fetus from diagnostic ultrasound and MRI (p. 629). + +ULTRASOUND IN OBSTETRICS +The ultrasound is a sound wave beyond the human audible range of frequency greater than 2 MHz ( cycles per second). SONAR stands for 'Sound, Navigation and Ranging'. The clinical application of ultrasound in obstetrics was introduced and popularized by Ian Donald in Glasgow in 1958. +Ultrasound is produced by the vibration of a synthetic piezoelectric crystal in response to a rapidly altering electrical potential situated in the transducer of an ultrasound machine probe. The transducer converts electrical energy to mechanical energy ( ultrasound) and vice versa. The commonly used frequency range in obstetrics is 3-5 MHz for abdominal transducers and 5-7 MHz for vaginal transducers. When the frequency + +(number of ultrasound waves per second) increases there is improvement in image resolution but due to rapid wave attenuation, deeper structures are not properly visualized. This is due to poor penetration. In medical imaging, the transducer both sends and receives ultrasound waves (pulse echosonography). Sound travels through the tissues of the body at 1,540 meters per second. +The echo strength (strength of the reflected sound) depends mainly on the following four factors: (a) acoustic impedance mismatch (e.g., soft tissue-bone interface causes maximum ultrasound reflection producing bright echogenic structure), (b) the angle at which the ultrasound beam strikes a reflecting interface (more the ultrasound beam is perpendicular to the reflector, more echogenic the structure), (c) the strength of the ultrasound, and ( d) size of the reflector (fetal femur is more echogenic whereas renal pelvises scatter the ultrasound to give speckle). +In clinical practice, standard ultrasound images are: +■ B-mode (brightness mode display)-two-dimensional (2D) images (width and brightness) are obtained. +■ M-mode is used to study the moving organs, e.g., fetal heart. This results in a wavy pattern in the presence of motion. +■ Color Doppler and pulse wave ultrasound ( Christian J Doppler-1942) is based on the principle of Doppler frequency shift. Doppler ultrasound is used to measure the speed at which blood is moving within a vessel. The most common fetal arterial Dopplers measured are: umbilical artery, middle cerebral artery. The most common fetal venous Doppler is the ductus venosus. Umbilical artery Dopplers are a reflection of the placental circulation. Ductus venosus Dopplers reflect cardiac compliance and cardiac after load. This may increase with the pathology of the placenta. The Doppler shifted audible signals can be converted +Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests ED to visual signals and are known as Flow Velocity +Waveform (FVW). + +Safety of ultrasound: The effects of ultrasound on tissues are: temperature elevation, formation of microbubbles and cavitation. However, there is no clear evidence till date that diagnostic ultrasound examination during pregnancy is harmful. Ultrasound should be done with shortest duration possible to avoid unnecessary exposure, especially with the Doppler. + +The choice of the probe generally depends on the structure to be studied and its distance from the probe. Early pregnancy study is done best by using TV probe, whereas fetal study in third trimester is best done with transabdominal imaging. + +Transvaginal Ultrasound (TVS) is superior to transabdominal ultrasound for early pregnancy evaluation (when uterus is within the pelvis). There is very little attenuation of sound waves because the distance between the probe and the concepts is very close. This makes tissue resolution better. + + +■ Intrauterine pregnancy. +■ Suspected ectopic pregnancy. +■ Vaginal bleeding (in all trimesters). ■ Fetal anomalies (anencephaly). +■ Suspected molar pregnancy. ■ Gestational age. +■ Multiple pregnancy (chorionicity). ■ To confirm cardiac activity. +■ Screening of aneuploidy. +■ Evaluation of pelvic/adnexal masses (all trimesters). + +Table 41.1: Fetal features on Transvaginal Sonography (TVS) for dating in pregnancy. +Mean Sac Diameter (MSDJ Findings +6mm Yolk sac. +12mm Embryo with cardiac activity. +Embryo CRL 2:4 mm Cardiac activity. +GS should increase by 1.1 mm in diameter per day. +Gestational age and embryonic structures are identified by Transvaginal Sonography (TVS). + + + +I 3D/4D ULTRASONOGRAPHY +3D can produce more life-like images of the fetus in utero. The ultrasound beam is swept in two orthogonal planes to capture a block or volume of echoes (depending on the required volume), which are digitally stored. This volume of echoes can be resliced in any plane. Reconstruction of a 3D image from a subvolume of images can be made using computer software. 3D images have multiple advantages: +a. Complex structure can be viewed in a single image, e.g., no need of mental reconstruction to define a defect. + +Menstrual age(weeks) +4 + +5 5.5 6 +7 + +8 +9 + + +CRL(mm) - + +-- +5 10 + +16 +24 + + +Fetal structures +Choriodecidual thickness, chorionic sac. +Gestation sac. +Yolk sac. +Fetal pole, cardiac activity. +Lower limb buds, midgut herniation (physiological). +Upper limb buds, stomach. +Spine, choroid plexus. + + + +b. The stored volume tissue (organ) can be reviewed at any plane later on without needing the patient. This helps to get second opinion if required. +c. Prenatal diagnosis of certain anomalies is improved. +d. Lifelike photos of 3D images improves antenatal parental bonding. +e. It calculates tissue and fluid volumes, e.g., fetal lung volume measurement could be done to predict pulmonary hypoplasia. +f. This is also an important teaching tool. +I FIRST TRIMESTER ULTRASONOGRAPHY +Common indications are mentioned (Box 41.1). +An Intrauterine Gestational Sac (GS) is visible by Transvaginal Sonography (TVS) by +as early as 5 weeks of pregnancy (Table 41.1). Yolk sac is seen by 5.5 weeks and the fetal pole is seen by 6 weeks of pregnancy (Fig. 42.46). Definite diagnosis of intrauterine pregnancy is possible as early as 29-35 days of menstrual age (Table 41.1). True gestational sac (GS) is eccentric in position within the endometrium of fundus or body of + + +the uterus. Double decidua sign of the gestational sac is due to the interface between the decidua and the chorion which appears as two distinct layers of the wall of the gestation sac. Presence of yolk sac or fetal pole within the gestation sac confirms pregnancy. True gestational sac size increases 1 mm/day. Pseudogestational sac or pseudosac is irregular in outline, usually centrally located in the uterus, has no double decidua sign and the sac remains empty. The rate of early ( <12 weeks) pregnancy loss (miscarriage) diminishes steeply with the progressive appearance of fetal structures (e.g., with only GS = 11.5% and with emb1yo >10 mm= 0-5%). Fetal anatomy and viability (Table 41.1). +Gestational age for dating in pregnancy: Ultrasound examination is the best method to estimate the gestational age dating (Table 41.1). The error with LMP is due to late ovulation (>14 days after LMP). CRL (Fig. 41.lA) is most accurate with an error of 2.1 days in the first trimester. Biparietal Diameter (BPD), Femur Length (FL), Head Circumference (HC) and Abdominal Circumference (AC) are commonly used for dating thereafter. Transcerebellar Diameter (TCD) is an accurate predictor of gestational +t__ GD Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests +r + + + + + + + + + + + + + + + +Figs. 41.1A to C: (A) Sonograph (TVS) demonstrating crown-rump length (between crosses) of an 8-week fetus. Yolk sac is seen in the near field (arrow); (B) Sonograph showing femur length; (C) Biparietal diameter at the level of cavum septum pellucidum. + + +age when measured between 14 weeks and 28 weeks. IVF pregnancy is dated by the date of embryo transfer minus 14 days to get LMP and to calculate EDD by Naegele's rule. +An ultrasound can show the number of gestational sacs, number of yolk sacs and the number of fetal poles with cardiac activity. The presence and absence of dividing membranes between the fetuses can be seen. This is characterized by T sign or lambda sign or twin peak sign. + +Ultrasound markers for fetal anomalies +USG can detect the soft markers that can be associated with aneuploidy. For soft markers of fetal aneuploidy. +Nuchal translucency (Fig. 41.2): Increased fetal nuchal skin thickness (in the first trimester) >3 mm by TVS is a strong marker for chromosomal anomalies (trisomy 21, 18, 13, triploidy and Turner's syndrome). +Other indications: +Multiple pregnancy: Identification of two gestational sacs indicates twin birth in 52-63% of case. Anemb1yonic pregnancy (blighted ovum). + + \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_19.txt b/notes/DC Dutta Obstetrics 10th Edition_19.txt new file mode 100644 index 0000000000000000000000000000000000000000..646439bfa2f7b57da82ae6a1411e45ff91067b17 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_19.txt @@ -0,0 +1,2027 @@ + + + + + + + + + + + + + + +Fig. 41.2: Longitudinal view of a 12-week fetus with a thickened nuchal translucency (arrow). Fetuses with increased nuchal thickness need genetic screening. + +Ectopic pregnancy: TVS can detect 90% of tubal ectopic pregnancy. The double decidual sac sign differ­ entiates normal pregnancy from pseudogestational sac of an ectopic pregnancy. Presence of echogenic fluid in the pouch of Douglas (blood) suggests probable presence of ectopic pregnancy. Color Doppler helps to identify the echogenic ring (ring-of-fire) of an ectopic gestational sac outside the uterine cavity. Diagnosis of hydatidiform mole. +Early pregnancy failure: These are the sonography based evidences to predict the stoppage of fetal growth and development. The clinical terminologies used, "threatened", missed or "blighted ovum" are of little value. Overall 75% of all pregnancies will fail. 30% are lost before implantation, 30% during implantation and 15% after implantation (Box 41.2). + +SECOND AND THIRD TRIMESTER ULTRASONOGRAPHY (Box 41.3) +Anatomy: Fetal anatomic evaluation as recommended is done after 18 weeks. However, majority of the anomalies can be seen as early 14 weeks (TVS). Follow-up USG may be needed after 20 weeks especially for the brain, and/ or the heart (Table 41.2). +Aneuploidy screening: Multiple second-trimester sonographic findings are associated with aneuploidy. These "markers" of aneuploidy have been identified. These are findings that are not structural malformations, but when seen, they may be associated with an increased risk of aneuploidy. The presence of single or multiple markers adjusts the patient's age-related risk of aneuploidy based on the particular markers present. + + + +■ CRL >7 mm and no cardiac motion. ■ MSD >25 mm and no embryo. +■ A collapsing sac with irregularly marginated amnion. ■ Presence of yolk sac calcification. +■ Fetal HR <80 bpm in an embryo with CRL 5 mm. +Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests + + + + ++ Gestational age. ++ Cervical insufficiency. ++ Suspected multiple pregnancy. ++ Liquor volume (poly/oligohydramnios). + Placenta previa/abruption. ++ Suspected uterine malformation. ++ Cases with Premature Rupture of Membranes (PROM). ♦ Fetal Growth (FGR). ++ Fetal presentation (breech, face). + Fetal wellbeing (BPP) assessment. + Screening fetal anomalies. ++ As an adjunct to: Amniocentesis, Chorionic Villus Sampling (CVS), cordocentesis, fetal therapy, External Cephalic Version (ECV). ++ Uterine size: Either > dates or < dates. + + +Table 41.2: AIUM guidelines for the fetal anatomical ultrasound. +Head, face Cerebellum, choroid plexus, cisterna magna, lateral and neck cerebral ventricles, midline falx, cavum septum +pellucidum, upper lip, nuchal fold. +Chest 4-chamber view of the heart, outflow tracts of the heart if feasible. +Abdomen Stomach, kidneys, bladder, umbilical cord insertion (fetal abdomen) umbilical cord vessel number. +Spine Cervical, thoracic, lumbar and sacral. Extremities Legs and arms, presence or absence. +Sex Medically indicated only in multiple gestation. + +Such sonographic findings include many (few mentioned below), but are not limited to: +■ Nasal bone. +■ Choroid plexus cysts. +■ Echogenic intracardiac focus. ■ Pyelectasis. +■ Echogenic bowel. +■ Shortened femur or humerus. ■ Increased nuchal fold. + +Given the high sensitivity and specificity of cell-free DNA testing, these second trimester markers are not used in patients who have had negative cell-free DNA testing as part of aneuploidy risk assessment. + + + + + + + + +Fig. 41.3: Level for the measurement of Head Circumference (HC) and Biparietal Diameter (BPD). + +actual fetal weight using fetal biometric data (BPD, HC, AC and FL). The availability of the estimate is± 16-20%. +■ Gestational age assessment: Nearly 20% of pregnant women are uncertain about the last menstrual period. In the second trimester, optimum time for most accurate assessment of gestational age is between 14 weeks and 20 weeks. The parameters used are Biparietal Diameter (BPD), Head Circumference (HC) (Fig. 41.lC), Abdom­ inal Circumference (AC) and the Femur Length (FL) (Fig. 41.IB). The fetal head is imaged in a transverse axial section at the level falx cerebri, cavum septum pellucidum and the thalamic nuclei {Figs. 41.2 and 41.3). BPD {Fig. 41.lC) is recorded from outer skull edge of the proximal skull to the inner edge on the distal skull. Femur length is measured when the beam from the transducer is perpendicular to the shaft. AC is measured preferably at the level of the junction of the left and right portal veins, umbilical vein and as round as possible {Fig. 41.4). AC is the single most sensitive parameter for assessment offetal growth. +Averaging the measurements of BPD, HC, AC and FL the variation of estimated gestational age to true gestational age, is shown in Table 41.3. +Important observations on ultrasonography are: +A. Cranial abnormalities (Fig. 41.5)-(i) Obliteration of cisterna magna. {ii) Compression or flattening of the posterior cerebellar surface making a crescentic appear­ ance {banana sign). {iii) Concave deformity of the frontal bones {lemon sign) in NTD. {iv) Absence of calvarium­ anencephaly. (v) Hydrocephaly may be suspected when the HC or BPD is enlarged {Fig. 27.3). Ventriculomegaly is + + + +MIDTRIMESTER ULTRASONOGRAPHY (Box 41.3) + + +AC rtal vein + + + +■ Fetal growth-is calculated on the basis of an accurate gestational age and is expressed in percentiles. Normal fetal weight should be between the 10th and 90th percentiles. Weight less than 10th percentile is considered Small for Gestational Age (SGA). Whereas more than 90th percentile is large for gestational age. On the basis of biometric data, computer software can calculate fetal weight using formula. Hadlock formula which is commonly used, is sensitive to 7.5% of the + + +Liver + + + +Stomach Spine + + +X +Fig. 41.4: Level for fetal Abdominal Circumference (AC). +r + +GD Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests +Table 41.3: Correlation of Gestational Age (GA) with USG based fetal 0 THIRD TRIMESTER ULTRASONOGRAPHY parameters. Discrepancy between USG oAbllttahine eindfionrmthairtidotnriomf esestceorn. d trimester sonography can be +GA weeks +Fetal parameters +and menstrual age +■ A detailed anatomical survey should be done now +<86/7 CRL ± 5 days pevlaesnticifdtwhaerfpisrmeviisoudsiagsunrovseeyd winatshinsotrrimmaels. tAerc.hondro­ 1 6/ CRL ± 7 days ■ Estimated Fetal Weight (EFW) is determined from the +3 +7 +9017 - +16°17 - 21617 BPD, HC, AC, FL ± 10 days average of three readings for each of the following: FL, +28 0/7 BPD, FL, HC, AC ± 21 days AC and BPD. AC is most important. Sonographic EFW has an error risk of 15-20%. + +Scalloping of frontal bones +(lemon sign) +Flattening +of cerebellar hemispheres +(banana sign) + +Fig. 41.5: Cranial abnormalities associated with open spina bifida and Arnold-Chiari malformation. + +diagnosed when the width of the lateral ventricle is >10 mm and the choroid plexus is seen dangling. +B. Fetal face-for cleft lip or palate. +Omphalocele and gastroschisis are rare (1 in 4,000 live births) abdominal wall defects. They should be differen­ tiated (Table 41.4): Hydrops fetalis and hydatidiform mole. +Umbilical cord: Single Umbilical Artery (SUA) is associated with a higher rate of fetal anomalies (30-70%). The major anomalies observed are: Cardiac, CNS, and kidneys. Umbilical cord insertion: Velamentous insertion, and vasa previa can be diagnosed with Doppler ultrasound. +Assessment of amniotic fluid: AFI >25 cm constitutes polyhydramnios. Largest vertical pocket >8 cm and is considered as polyhydramnios. +Fetal weight: Hadlock formula. Commonly uses four variables: BPD, HC, AC and FL. The absolute error for birth weight prediction is about 8-10%. Ultrasound and clinical examinations have similar accuracy for predicting birth weight. +Doppler: Ch. 32. + +Table 41.4: Differentiation of abdominal wall defects. Gastroschisis Omphalocele +■ Paraumbilical defect. ■ Usually midline defect. + +Growth profile (Fig. 41.6): (i) In late IUGR, the HC is maintained but the AC falls off around 30 weeks. The HC:AC ratio is, therefore, elevated. (ii) In symmetric IUGR, both the HC and AC are affected early. Therefore, HC:AC ratio remains normal. +Evaluation of fetal wellbeing is done for fetal surveillance to identify the fetuses at risk of IUGR, IUFD or severe morbidity. This may allow interventions early (delivery) to prevent complications. The two principal methods of fetal surveillance are: the assessment of BPP, and Doppler USG. +Placental evaluation is done by its location and relationship to the internal os. Placenta accreta is diagnosed on USG: 11 Lack of sonolucent area between the placenta and the myometrium. ■ Lakes of turbulent venous flow within the placenta adjacent to the involved myometrium II Retroplacental thinning and ■ Loss or interruption of the white line (interface) between the bladder and the uterine serosa ■ Hypervascularity of the interface between the bladder and uterine serosa on color Doppler. 11 Antenatal diagnosis of placenta accreta is helpful to make planned delive1y ensuring appropriate resources. + +cm Asymmetrical IUGR 36 Head circumference +34 +32 (mean± 2SD) +30 cm +28 38 26 36 24 +34 +32 +30 +22 20 +18 28 +16 26 +14 24 +12 22 +10 (mean± 2SD) 20 +8 + + + +■ Usually on the right side of the cord insertion. +■ Herniated small bowel loops floating free in amniotic fluid. +■ Not covered by any membrane. +■ Not associated with chromosomal anomaly. +■ Prognosis-good. + + +■ Cord insertion is on the herniated mass. +■ Hernia contains intestines, liver or both. +■ Covered by a membrane (peritoneum and amnion). +■ Associated chromosomal anomaly 40-60%. +■ Prognosis-often poor. + + +1.1 1.0 0.9 +162024 28 323640 6 ratio is +HC/AC +14 16 18 2022 24 2628 3032 34 3638 40 elevated Gestation (weeks) +Fig. 41.6: Ultrasonographic growth profile in a case of late onset IUGR shows Head Circumference (HC) is maintained but Abdominal Circumference (AC) falls off around 30 weeks. The HC/AC ratio is elevated. +Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests Im + +■ Maternal evaluation: Assessment of cervical length by TVS for preterm delivery and cervical insufficiency. +■ Doppler evaluation of maternal and fetal vessels. • Uterine artery • Umbilical artery • Middle Cerebral Artery (MCA) • Uterine artery notching, low end diastolic velocity, high impedance are the predictors of pre-eclampsia and Fetal Growth Restriction (FGR). + + +majora or at the level of fourchette. Bladder should be emptied before scanning (Fig.24.8). USG gel could be placed directly over the skin. Real-time sound waves are used with a low frequency ( <4 MHz) wide sector convex transducer. The probe is covered with a sterile examination gloves. Sterile gel (single use container) is also used (Figs. 41.7A to C). + + + +■ Ductus venosus Doppler study is done to predict fetal acidemia in cases with FGR. +INTRAPARTUM ULTRASONOGRAPHY (IUSG) has been observed to be immensely valuable for the management of labor (WAPM-2022). IUSG provides accurate information as regard the assessment of pelvic dimensions (pelvimetry), fetal presentation with dimensions of the presenting part, position, descent during the course of labor including the degree of flexion. +Unlike clinical pelvic examination, IUSG is neither painful nor has the risks of introducing infection. IUSG has the additional benefits of diagnosing fetal compromises, anomalies, placenta previa especially in those unsupervised cases, seen first time in labor. +IUSG is useful to measure accurately the subpubic angle, confirmation of fetal presentation (face, brow, breech), position, attitude, engagement, station of the presenting part, Head-Perinea! Distance (HPD), including the presence of caput or mouldings. +Measurement of Occiput-Spine Angle (OSA)-represent the degree of head flexion (Fig. 41.7B). Similarly Chin to Chest Angle (CCA) is also used (Fig. 41.7C) to assess fetal head flexion. Measurement of the Angle of Progression (AoP) has been correlated to the station of the presenting part and the success of delivery. AoP is the angle subtended between the long axis of the pubic bone and a line from the lowest edge of the pubic bone drawn tangential to the deepest bony part of the fetal skull. AoP measured 110 and 120 degrees to the digital assessment correlates to the level of ischial spine (station zero). +IUSG could be done by Transabdominal (TAS) (Fig. 41. 7 A) or by Transperineal (TPS) method (Fig. 24.8). In TPS, the transducer is placed between the labia + + +MAGNETIC RESONANCE IMAGING (MRI) +MRI is useful to obtain high soft-tissue contrast and acquisition of images in axial, sagittal and coronal planes. Powerful magnets are used to alter temporarily the static tissue proteins (mainly hydrogen protons). Radiowaves are used to deflect the magnetic vector. The hydrogen protons return to their normal state once the radiofrequency source is turned off. During this phase, they emit radiowaves of different frequencies which are received by radio coils wrapped around the body part. An image is constructed from these pulse sequences using their location and characteristics. +MRI is devoid of any ionizing radiation and found to have no fetal harmful effect at any gestational age with 1.5 tesla strength. +The gadolinium contrast MRI in pregnancy should be used with caution as gadolinium crosses the placenta. It is a category C drug (p. 478) and should be avoided in first trimester. Rapid sequence MRI is preferable to conventional MRI as the exposure is brief. MRI is preferable to CT scanning during pregnancy as MRI is devoid of ionizing radiation (Table 41.5). +Abnormal fetal neuroanatomy especially ventri• culomegaly is the most common indication for a fetal MRI. MRI is used for evaluation of other fetal anomalities such as genitourinary, gastrointestinal (Fig. 41.8B and C), cardiac and muscle skeletal anomalies. MRI is superior to USG as oligohydramnios in genitourinary anomalies is often associated. Morbid adherent placenta (accreta, increta or percreta) where USG findings are equivocal (or for a posterior placenta where USG has limited information). +MRI is used as an adjunct to fetal therapy. Fetal abnormalities are outlined preoperatively because of its + + + + + + + + + + + + + +rn +Figs. 41.7A to C: lntrapartum ultrasonography: (A) Transducer is placed trans over the pubic bone; (B) Measurement of Occiput and Spine Angle (OSA); (C) Measurement of Chest to Chin Angle (CCA). +ml Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests + + + + + + + + + + + + + +Figs. 41.SA to C: (A) Ultrasonographic image of central placenta previa; (B) Central placenta previa: MRI sagittal (T2) image showing fetal head, brain, eyeball, and the placenta (P). Myometrial signal is preserved; (C) MRI of the abdomen and pelvis of a fetus at 33.3 weeks (sagittal image-T2). Attachment of the umbilical cord to the placenta is seen. +(P: Placenta; E: Eye ball; C: Cervix; AF: Amniotic Fluid; B: fetal Brain; S: Spine; LL: Lower Limb) + + +precision in diagnosis (Figs. 41.8A to C). MRI is helpful before laser ablation of Twin-to-twin Transfusion Syndrome (TTTS) and also before the surgical procedures of spina bifida, sacrococcygeal teratoma and neck surge1y. +Contraindications of use are: Internal cardiac pace­ maker, implanted defibrillator, implants or other metals in the body. + +COMPUTED TOMOGRAPHY (CT) IN OBSTETRICS +CT imaging is done by obtaining a spiral 360° images that are processed in multiple planes. Multidetector CT (MDCT) is now used. MDCT has got increased dosimetry compared to traditional CT. Due to its radiation risks, use of CT should be avoided in all trimesters of pregnancy unless absolutely essential. Fetal dose during CT pelvimetry varies between 0.25 rad and 1.5 rad. CT pelvimet1y may be obtained with little or no exposure to the fetus. Chest CT scan is done in cases with suspected pulmona1y embolism and cranial CT scan is done in cases with eclampsia with neurological features. + +RADIOLOGY IN OBSTETRICS +With the advent of ultrasonography, Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) the importance of radiology is declining. Currently, there are ve1y few conditions where radiology may be of help + + +during pregnancy. Risk of radiation is the main concern (Table 41.6). + +Table 41.5: Indications of MRI in obstetrics. Maternal Fetal +■ Cerebral vascular flow study ■ Fetal anatomy survey. +(eclampsia) and detection of ■ Fetal biometry. +thrombosis. ■ Fetal weight estimation +■ Angiography. (superior to sonography). +■ Evaluation of maternal ■ Evaluation of complex +tumors. abnormalities (brain, chest, ■ Evaluation of placenta previa genitourinary system). +accreta (Fig. 28.8), posterior ■ As a complement to placenta previa. sonography. + + +Table 41.6: Absorbed radiation by the fetus in different diagnostic radiation procedures. +Procedure Dose(cGyJ Abdominal X-ray 0.1-0.3 Pelvic X-ray 0.5-1.1 Chest X-ray <0.001 Abdominal CT 0.4-0.8 Chest CT 0.002-0.02 Abdominopelvic CT 2.5-3.5 Ventilation scan 0.007-0.05 +PET scan 1-1.5 + + +--6-m,a +► Before any imaging in obstetrics, benefits and safety of different modalities (USG, MRI, CT, radiology) must be carefully considered. ► Ultrasonography is the preferred modality of initial imaging for evaluation of a pregnant woman with abdominal pain. +► Ultrasound is the most valuable diagnostic tool in pregnancy and is safe when used appropriately. +► Benefits of USG in all the trimesters of pregnancy are many (Table 41.1). Gestational age is accurately determined in the first half of pregnancy and fetal anomalies are determined. +► The optimal timing for a single USG examination is at 18-20 weeks. ► MRI has got some added benefits to USG. +Contd... +Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests rm Contd. .. +► MRI is safe in pregnancy; however, it is a good practice to avoid MRI during pregnancy, particularly for elective studies or in the first trimester (ACOG). +► MRI is devoid of any ionizing radiation. +► IV gadolinium is contraindicated in pregnancy. It should be used only if absolutely essential. +► CT of the fetus should be avoided in all the trimesters of pregnancy as the main concern is carcinogenesis. Risks of teratogenesis is less. CT pulmonary angiogram is the preferred modality for imaging of suspected pulmonary embolism. +► Use of radiology in obstetrics is very limited. +► Exposure or radiation > 15 rad during second or third trimester or >5 rad in first trimester is hazardous. Patient needs to be counseled for elective termination of pregnancy. + + + +AMNIOCENTESIS +DEFINITION: Amniocentesis is the deliberate puncture of the amniotic fluid sac per abdomen. +INDICATIONS: + Diagnostic + Therapeutic + +DIAGNOSTIC +■ Early months (15-20 weeks): Genetic amniocentesis antenatal diagnosis of chromosomal and genetic disorders: (i) Sex-linked disorders. (ii) Kmyotyping. (iii) Inborn errors of metabolism. (iv) Neural tube defects. +■ Later months: +i. Fetal maturity. +ii. Degree of fetal hemolysis in Rh-sensitized mother-spectrophotometric analysis of amniotic fluid and deviation bulge of the optical density at 450 nm is obtained. +iii. Meconium staining of liquor-an evidence of fetal distress. +THERAPEUTIC +■ First half +1. Induction of abortion by instillation of chemicals such as hypertonic saline, urea or prostaglandins. +2. Repeated decompression of the uterus in acute hydramnios. + +2. The abdominal wall is prepared aseptically and draped. +3. The proposed site of puncture is infiltrated with 2 mL of 1 % lignocaine. +A 20- or 22-gauge spinal needle with stylet in about 4" in length is inserted into the amniotic cavity under real-time sonographic control (Fig. 41.8B). Injury to the placenta, umbilical cord and fetus is to be avoided. Continuous visualization of the needle under USG guidance reduces the risks of injmy, bloody or dty tap and need of multiple insertion. The stilette is withdrawn and few drops ofliquor are discarded. Initial 1-2 mL of fluid is either used for Alpha-Fetoprotein (AFP) or is discarded as it is contaminated with maternal cells. Rest is used for fetal karyotyping. About 30 mL of fluid is collected in a test tube for diagnostic purposes. Fetal cardiac motion is to be seen after the procedure. Patient is asked to report for any uterine cramps, vaginal bleeding or leakage of liquor. + +PRECAUTIONS +i. Prior sonographic localization of placenta is desirable to prevent bloody tap and fetomaternal bleeding. +ii. Prophylactic administration of 100 microgram of anti-D immunoglobulin in Rh-negative nonimmunized mother. Hazards are reduced significantly when it is done 'under direct ultrasound control' compared to the blind procedure (Fig. 41.9). + + + +■ Second half +1. Decompression of uterus in unresponsive cases of chronic hydramnios producing distress or to stabil­ ize the lie when it is not axial prior to induction. +2. To give intrauterine fetal transfusion in severe hemolysis following Rh-isoimmunization. +3. Amnioinfusion: Infusion of warm normal saline into the amniotic cavity is done transabdominally or transcervically to increase the volume of amniotic fluid. +Indications of amnioinfusion: A. Oligohydramnios: +i. To prevent fetal lung hypoplasia +ii. To minimize umbilical cord compression during labor. +B. To dilute meconium-stained amniotic fluid. + + +Ultrasound transducer + + + + + +wall + + +PROCEDURE +1. After emptying the bladder, the patient remains in +dorsal position. Fig. 41.9: Amniocentesis-direct ultrasound control. +Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests + + +COMPLICATIONS OF AMNIOCENTESIS A. Maternal complications: +1. Infection (rare). +2. Hemorrhage (placental or uterine injury). 3. Premature rupture of the membranes. +4. Premature labor. +5. Maternal alloimmunization in Rh-negative cases. +B. Fetal complications: +1. Fetal loss (1 in 400 procedures). 2. Trauma (rare). +3. Fetomaternal hemorrhage (rare). +4. Oligohydramnios due to leakage of amniotic fluid and that may lead to: +i. Fetal lung hypoplasia. ii. Respiratory distress. +5. Antiretroviral treatment should be optimized to aim for an undetectable viral load prior to amniocentesis or CVS. +Amniocentesis should be avoided for HIV-positive women and noninvasive tests [Nuchal Translucency (NT), Maternal Serum Alpha Fetoprotein (MSAFP), anatomic USG] are preferred. However, in women with HBV, HCV may be done with counseling. The mother to child transmission is low. +Early amniocentesis (11-14 weeks) notto be done for genetic indications as the cell culture failure rate is high. Less fluid is withdrawn. Rates of complications are high. + +GUIDES TO CLINICAL TESTS I EXAMINATION OF URINE +TESTS THAT ARE DONE: + + +Experiment: (a) 5 mL of Benedict's reagent is taken in a test tube and is heated to boiling. (b) Add 8-10 drops of urine to it. ( c) Boil the mixture vigorously for 2 minutes and allow it to cool. +Interpretation: Presence of reducing substance is indicated by change of color in the precipitate. Approximate glucose concentration in urine is as follows: Pale green: 0-100 mg%; Green: 100-500 mg%; Greenish yellow: 500-1,000 mg%; Yellowish orange: 1,000-2,000 mg%; Brick red: >2,000 mg%. +Dipsticks (Diastix): These reagent strips provide quick, specific, simple qualitative and semiquantitative color tests to detect the presence of glucose in urine. They do not react with other reducing substances found in urine. The strip is of absorbent cellulose, one end of which is impregnated with buffered mixture of glucose oxidase and peroxidase. +Procedure: Dip the test end of the reagent strip in urine and take it out immediately. Now observe the color of the test end exactly 1 minute later. If there is change in color of the test end, the test is positive. The instructions of the manufacturers are to be followed strictly. The dipsticks available may only be used for glucose or may cover other urinary constituents (Multistix). +Urine dipstick test is based on the detection of leukocyte esterase and nitrites in a freshly collected sample of urine. Positive dipstick test (change in color) indicates infection (Fig. 41.10). +Test for Acetone: ♦ Rothera's test (Tables 41. 7 and 41.8) ♦ Ketostix +Ketostix: The reagent strips provide quick, simple standardized color test for detection of ketone bodies in urine. The strip is impregnated with a buffered mixture of sodium nitroprusside and glycine. + + + +1. Physical +4. Bacteriological + + +2. Biochemical +5. Immunological + + +3. Microscopical +6. Hormonal. + +COLLECTION OF URINE: For items 1, 2 and 3, first morning urine is collected in a clean container. But for bacteriological examination, 'clean-catch' midstream urine is collected in a sterile container. Alternatively, a catheter sample may be taken. +Tests for Protein: • Qualitative (Table 41. 7) • Quantitative + +Qualitative: (i) Heat and acetic acid test. (ii) Dipsticks. Report: Protein-absent, trace (+ ), ( ++ ), or (+++) +Dipsticks (Albustix): These reagent strips provide quick and simple standardized color tests to detect protein. The dipsticks available may be specific for albumin or may cover other urinary constituents like pH, acetone, glucose and specific gravity (multistix). Procedure: Dip the test end of the reagent strip in urine and take it out immediately. Now compare any change of color of the test end with the color chart supplied by the manufacturer. If the test end turns green or blue, the test is positive. +Interpretation: Trace= 0.1 g/L; 1 + = 0.3 g/L; 2 + = 1.0 g/L; 3 + = 3.0 g/L; 4 + = 10.0 g/L. +Test for Sugar: • Benedict's test ♦ Dipsticks +Qualitative: Benedict's test + + +Fig. 41.10: Uro-dip reagent strips: For rapid determination of urobilinogen, glucose, bilirubin, ketones, specific gravity, blood, pH, protein, nitrite and leukocytes and ascorbic acid in urine. + + +Table 41.7: Heat and acetic acid test. +Experiment Observation Inference +■ Three-fourth of a test tube is ■ A cloudy ■ Presence of filled with urine. The tube is precipitate is protein or held obliquely and the upper formed. phosphate. part of the urine is heated. +■ Add few drops of 5% acetic ■ The cloudiness ■ Presence of acid to it. persists or protein. +increases. +Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests ., + +Table 41.8: Rothera's test. Table 41.1 0: Collection of bloo9 samples for laboratory tests. + +Experiment Observation Inference +■ Take 5 ml of urine in a test tube. A reddish- Presence Add ammonium sulfate to make it purple ring of saturated. appears at acetone. +■ To it, mix 3-4 drops of freshly prepared the junction sodium nitroprusside solution (or a few of the two crystals of sodium nitroprusside). Then liquids overlay with 1 ml of concentrated (A brown ammonium hydroxide and allow it to ring is of no stand for 1-2minutes. significance). + +Procedure: Dip the test end of the reagent strip in fresh specimen. Compare the color of the test end with the supplied color chart as per the instructions of manufacturer. + + +Test Hb/o/PCV +ABO and Rh-group +VDRL +Direct or indirect Coombs' test +Prothrombin time + +Fibrinogen Platelet +EDP + + +Method of collection of blood in test tube or vial +EDTAvial +Plain (clotted) and 3.8% sodium citrate solution +Plain (clotted) Plain (clotted) + +0.5 ml of 3.8% sodium citrate solution +EDTAvial EDTAvial +Special tube supplied with kits + + +Amount of blood +2ml +2ml +Few drops +2ml 2ml + +4.5 ml + +2ml +2ml + + + +TESTS FOR BLOOD COAGULATION DISORDERS +Bedside tests are discussed in Chapter 39. Only the laboratory tests for blood coagulopathy are mentioned here. +LABORATORY TESTS (Table 41.9) +■ Prothrombin Time (PT): Quick's prothrombin time assay measures the time required for clotting by the extrinsic pathway and is carried out by adding tissue thromboplastin to plasma. Normal value is 11-17 seconds. In coagulation failure, the time is prolonged. +Procedure: Blood is to be sent in a vial containing 3.8% of sodium citrate solution in proportion of 9:1 (0.5 mL sodium citrate and 4.5 mL blood). +■ Estimation of fibrinogen: Blood sample is to be collected in Ethylenediaminetetra-Acetic Acid (EDTA) vial. Critical level is considered to be 100 mg% (plasma). +■ Platelets: Blood is to be sent in EDTA vial containing diso­ dium or dipotassium salt of ethylenediaminetetraacetic acid powder. A count less than 70,000 per mm3 is usually found in Disseminated Intravascular Coagulation (DIC). Thrombo­ cytopenia is characteristic of intravascular coagulation but it is not found in a pure fibrinolytic syndrome. +■ Fibrin Degradation Products (FDPs) is estimated by latex agglutination test. Blood sample is to be sent in a special + + +Test Value +1. Bleeding time (Duke's method) 1-3 min (Ivy's method) 1-9min +2. Coagulation time +(Wright's tube method) 3-7 min (Lee and White method) 4-9min +3. Clot observation test (Weiner's) 6-12 min Clot retraction time 30 min +4. +5. Fibrindex or thrombin test Formation of a clot within 1 min +6. Prothrombin time 8.5-13.1 sec Thrombin time 16-17 sec +7. +8. Platelet count 1.5-4 lac/mm3 Fibrinogen 300-600 mg% +9. +10. D-dimer (breakdown product of fibrin) 0.1-1.8 (µg/ml) + +ECLT Citrate solution 4.5 ml D-dimer EDTAvial 2ml Blood glucose Oxalate-fluoride 2ml Blood culture Glucose broth media 50 ml 5 ml Urea, NPN, creatinine Plain (clotted) 5 ml Bilirubin Plain (clotted) 3 ml Plasma protein EDTA vial 3 ml + +tube. In normal pregnancy, it is usually absent. In DIC, its presence to the extent of 80 µg/mL is significant. +■ D-dimer is a specific component of fibrin breakdown. It is detected by latex agglutination method. The latex beads are coated with monoclonal antibodies. Level more than 200 mg/ mL is found in DIC. Blood sample is to be collected as that of fibrinogen. +I COLLECTION OF BLOOD SAMPLE MATERIAL: Table 41.10. +EDTA/Glucose vials containing recommended quantity of anticoagulants are available. +CORD BLOOD SAMPLES (Table 41.11 ): Cord blood sample should be collected from the placental end of the severed cord. It should not be squeezed out, otherwise Wharton's jelly may contaminate the blood, which may vitiate the result. To get a true picture, the sample should be taken by opening the Kocher's forceps from the placental end of the cord as early as possible. Samples are taken especially of babies born of Rh-negative mothers. 10 mL of cord blood should be collected in a heparinized tube. Alternatively, about 5 mL of blood (2 mL EDTA and 3 mL clotted) should be collected for the following tests: +■ Clotted blood: ABO and Rh grouping, direct Coombs' test and serum bilirubin. +■ EDTA blood: Hemoglobin estimation and blood smear for the presence of immature RBC. +Alkali denaturation test (Singer's test): Blood to be sent-2 mL blood is to be collected from the vagina in an EDTA vial. +Detection of fetal red cells in the maternal blood (in case of Rh-isoimmunization). +I : Chapter 41: Imaging in Obstetrics (USG, MRI, CT, Radiology), Amniocentesis and Guides to Clinical Tests + + +Table 41.11: Laboratory tests and the blood values. +Arterial blood and gas values in pregnancy- Coagulation parameters in normal pregnancy (3rd trimester at normal altitude) (3rd trimester) + + +Newborn umbilical cord blood at delivery (umbilical artery) + + + +Test Arterial pH +Arterial PO, (mm Hg) 02 saturation (%) + +Arterial PCO2 (mm Hg) + +Sodium bicarbonate (mEq/L) + + +Value +7.44 ±0.04 85± 5 96± 1 + +29.7 ± 2.8 + +22.0± 2.1 + + +Test INR +PTT (sec) +Antithrombin Ill (77-122% of normal 22-39 mg/dl) +Protein C (%) (71-142% of increased functional activity) +Protein S (%) + + +Value 0.87±0.07 27.5±2.8 102.8±13.5 + +94.9±25.5 + +51.7±17.9 +(70-120% of normal) + + +Test +Hb (g/dl) Hematocrit (%) pH + +PCO2 (mm Hg) + +PO (mm Hg) +2 +Base deficit (mmol/L) + +Value 15.3-17.2 45.2-50.9 7.06-7.36 + +27.8-68.3 + +9.8-41.2 0.5 - 15.3 + + + + +Modified Kleihauer-Betke acid elution test (Fig. 23.4) +Blood to be sent: A blood film is drawn over a dry slide from maternal blood. The slide is fixed by immersing it in a solution of ethanol (80%) for 3 minutes and after drying in air, it is to be sent to the laboratmy. Alternatively-2 mL of maternal venous blood may be sent to laborato1y in an EDTA vial. + +I SAMPLES FOR BLOOD SUGAR ESTIMATION +GLUCOSE TOLERANCE TEST: Procedure-Patient should be on normal carbohydrate diet for 3 days prior to the test. Patient should not eat after dinner and no breakfast is given. In the morning, urine is collected before commencement of the test. A fasting (12 hours) venous blood sample is taken and then the patient is given 100 g (or 75 g) of glucose in 250 mL of water flavored with lemon or orange. Further venous blood samples are collected at an hour intervals for 3 hours. The patient should be at rest during the period. Urinary samples are taken at 1 hour, 2 hours and 3 hours. 2 mL venous blood is taken in a oxalate-fluoride vial. Sodium fluoride is used to destroy glycolytic enzyme. If the test is to be delayed, the blood should be stored in a refrigerator. The concentration of glucose in plasma or serum is typically about 15% greater than that in whole blood (true glucose estimated by glucose oxidase-peroxidase method). +DEXTROSTIX: These reagent strips provide a rapid, convenient, specific and semiquantitative method for approximating blood glucose level. The strip is composed of a firm plastic, one end of which is impregnated with chromogen system which turns into oxidized chromogen, based on the action of the enzyme, glucose oxidase. +Procedure: Dip the entire test end of the reagent strip in a large drop of blood from fingertip. Just after 60 seconds, wash off the blood quickly with a sharp stream of water or to wipe off the blood with a tissue. Read the result within 1-2 seconds after washing, by comparing with the color chart supplied by the manufacturer. The results are provided directly in mg of glucose per 100 mL of blood. Other test values in pregnancy are also mentioned in Tables 41.12 to 41.14. + +CERVICAL CYTOLOGY/HPV SCREENING +Cervical cytology/HPV screening is done as a routine protocol to every woman attending the antenatal clinic especially those who have not been screened before. + + +Table 41.12: Liver and pancreatic function tests. Parameter Value (term) AST 4-36 {IU/L) ALT 2-30 {IU/L) Total bilirubin 0.1-1.1 mg/dl LDH 80-500 U/L Amylase 10-100 IU/L Lipase 20-150 IU/L + +Table 41.13: Osmolarity, electrolytes, BUN (term) Parameter Value +Osmolarity 270-285 (mOsm/kg) Na+ 124-140 (mEq/L) +K+ 3.4-5.5 (mEq/L) +HCO3 17-25 (mEq/L) Urea 4-15 (mg/dl) +Creatinine 0.5-1.1 (mg/dl) Uric acid 2.0-4 (mg/dl) + + +Table 41.14: Pulmonary function tests (term pregnancy). +Parameter Value +Respiratory rate 15/min (unchanged) +Total Lung Capacity (VC + RV) 4.0 (L)l, 5% +Vital Capacity (VC) 4.1 (L) (unchanged) +Tidal Volume (TV) 700 (mL)t 30-40% +Residual Volume (RV) 1000 (mL)l, by 20-25% +lnspiratory Capacity (IC) 2.9 (L) t by 5-10% +Functional Residual Capacity (ERV+ RV) 1,350 (ml) J,20% + +■ Cervical: As a routine to detect any squamous cell abnor­ malities (atypical squamous cells) +■ Vaginal: Cytohormonal study to know the progesterone status (rarely done nowadays). + + +Practical Obstetrics + + + + + + +• OBSTETRIC INSTRUMENTS • PROCESSING OF INSTRUMENTS • DRUGS • SPECIMENS • IMAGING STUDIES • SUTURE MATERIALS + + +Fig. 42.1: CLINICAL THERMOMETER +Celsius temperature scale (°C) is SI-derived unit and is known as Celsius after the name of the scientist +who introduced it. Conversion of Fahrenheit to +1 +1 +1 ' ,,I +111 11 ' +1 +I'1111·1 1 :· I, ,I ,i '!' "''' ::·" · ·: +1 +I +I + +Celsius-subtract 32, multiply by 5 and then divide by Conversion of Celsius to Fahrenheit-multiply by +divide by 5 and then add +9. +9, +32. + + + + +Freezing 95 96 97 98 +3 : I I I I I I \ I I I I I I I I + +Fahrenheit scale +99 100 101 102 103 104 105 +1 1 1 1 I 1 1 1 1 r 1 1 1 I 1 11 I 1 1 1 1 I 1 1 1 r 1 1 1 I 1 1 1 + + +106 Boiling + + + : + + + +35 36 + +■ OBSTETRIC INSTRUMENTS + + +37 40 41 +38 +39 +Celsius scale + +Fig. 42.2 SIMPLE RUBBER CATHETER +Description: It is made of rubber. It has different sizes. Slit openings, usually two (one on either side) are present close to the tip. +Sterilization: Boiling +Uses: It is used to empty the bladder in cases with retention of urine: (A) during-(a) Pregnancy (retroverted gravid uterus). (b) Labor-(i) when the woman fails to pass urine by herself, (ii) before and after any operative interventions (forceps delivery), destructive operations. (c) Postpartum-(i) during management of postpartum hemorrhage, (ii) retained placenta. (B) Other uses-(a) as a tourniquet, (b) to administer 02 when nasal catheter is not available, (c) as a mucus sucker-when it is attached to a mechanical or electric sucker. +Self-assessment: (i) Length of female urethra (p. 12). (ii) Causes of retention of urine during pregnancy, labor and puerperium. Retroverted gravid uterus, compression by the fetal head (in late first or in the second stage of labor), in puerperium due to pain. (iii) Why a metal catheter is not used in obstetrics? Ans: To avoid trauma to the soft and vascular urethra. + + +Steps of catheterisation: (1) Patient to lie down in dorsal position with thighs abducted; (2) Strict aseptic procedure: wearing gloves, using sterile savlon swabs; (3) The labias are separated using the left index finger and the thumb; (4) External urinary meatus is cleaned using the swabs from above down (one swab for once only); (5) The sterile rubber catheter is hold in the right hand using the index finger and the thumb, cm away from the tip. In no touch manner, the tip of the catheter is projected and introduced through the external urinary meatus into the bladder. Urine is seen to come out through the other end (Read more Dutta's Textbook of Gynecology, Figs. 9.13A and B). +2-3 +GD Chapter 42: Practical Obstetrics Fig. 42.3: FOLEY'S CATHETER +Description: It is made of silicon rubber. The catheter tip has two slit openings, one on either side for drainage of urine. The other end goes to the urinary bag to collect urine. The catheter has two channels within. One for urine drainage and the other is used to push water that inflates the catheter bulb. This inflated bulb makes the catheter self retaining. The catheters are of different sizes. The commonly used catheters in female are: 14F, 16F or 18F. These are disposable. +Uses: It is used for continuous drainage of bladder in cases +with: (i) Eclampsia. (ii) Retroverted gravid uterus. (iii) To give rest to the bladder following any destructive operation and/or in a case with suspected bladder injury. It is usually kept for 7-10 days. (iv) In the management of atonic PPH. (v) To control atonic PPH. The catheter is inserted within the uterine cavity and the catheter balloon is inflated with normal saline. The balloon provides a tamponade to the uterine surface. The catheter drains the blood from the uterine cavity if there is any. Others: (vi) For induction of labor as a mechanical method (p. 492). (vii) Cases with obstructed labor to evacuate and to give rest to the bladder. (viii) Amnioinfusion (p. 550). +Self-assessment: (i) Indications of continuous bladder drainage (p. 298, 552). (ii) Causes of atonic PPH (p. 392). + + +Fig. 42.4: SIMS' DOUBLE-BLADED POSTERIOR VAGINAL SPECULUM +Description and identification: This double-bladed speculum has a groove in the handle. This groove is in continuity at either end with the concave inner surface of the blade. The purpose of the groove is to allow drainage of blood, urine (in a case ofVVF), or to collect such samples for tests. +The blades are of unequal breadth to facilitate introduc­ tion into the vagina depending upon the space available (narrow blade in nulliparous and the wider blade in parous women). It is used in obstetrics: (l) To inspect the +cervix and vagina and to detect any injury following delive1y. (2) To clean the vagina following delivery. (3) To inspect the cervix and vagina to exclude any local cause for bleeding in APH ( Cusco' s speculum preferred). ( 4) During D and E operation. +Self-assessment: (i) Common sites of traumatic PPH (p. 393). (ii) Diagnosis of traumatic PPH (p. 386). (iii) Indications of D + E (p. 523). (iv) What are the local (extraplacental) causes of APH (p. 230). (v) What is Sims' position and what is Sims' triad? Read more Dutta's Textbook of Gynecology (p. 85, 353). + + +Fig. 42.5: CUSCO'S BIVALVE SELF-RETAINING VAGINAL SPECULUM +Description and identification: It has two blades joined by screws to allow the blades to open and close. The blades are concave inside. The handles are designed to open and close the blades with a separate rod and screw system. This makes the blades self-retaining during examination. It does not need an assistant to hold it. +Uses: +(i) To visualize the cervix and vaginal fornices for any local cause (polyp, ectopy) of APH. +(ii) To inspect the cervix and to prepare cervical smear for cytology screening. +(iii) To detect leakage of liqor from the cervical os in a case of suspected PROM. +Chapter 42: Practical Obstetrics Ii Fig. 42.6: MULTIPLE TOOTHED VULSELLUM +It is used to catch hold of the anterior lip of the cervix in (a) D + E operation, (b) suction evacuation. As it produces trauma to the soft and vascular cervix, Allis tissue forceps may be used instead. + + + + + + + +Fig. 42.7: ALLIS TISSUE FORCEPS +Uses: (1) To catch hold of the anterior lip of the cervix in D + E operation. (2) To hold the apex of the episiotomy wound during repair. (3) To catch hold of the margins of the peritoneum, rectus sheath, vaginal mucosa during repair. (4) To catch hold of the torn ends of the sphincter ani externus prior to suture in repair of complete perinea! tear. (5) To catch hold of the margins and angles of the uterine flaps in LSCS after the delivery of the baby as an alternative to Green-Armytage hemostatic clamp. +Self-assessment: (i) Episiotomy-p. 527. (ii) What are the obstetric causes of perinea! tear? (p. 398). (iii) What are the different degrees of perinea! tear? (p. 398). (iv) When and how a recent perinea! tear is repaired? (p. 398). + + + +Fig. 42.8: LONG STRAIGHT HEMOSTATIC FORCEPS +This is not commonly used in obstetrics. It can be used to clamp the pedicle while removing the uterus as in rupture uterus. The umbilical cord may be clamped as an alternative to Kocher's. +Self-assessment: (i) What are the causes of rupture uterus? (p. 402). (ii) How to suspect scar dehiscence? (p. 315, 403). (iii) How a case of rupture uterus is managed? (p. 405). + + + +Fig. 42.9: KOCHER'S HEMOSTATIC FORCEPS +Description and identification: This instrument has a tooth at the end of one blade and a groove on the other so as to have a firm grip. The handles have the catch. +Uses: (1) To clamp the umbilical cord-for better grip and effective crushing effect to occlude the vessels. (2) In low rupture of the membranes as surgical induction oflabor or augmentation of labor (Figs. 35.2, 35.3). (3) Can be used as a hemostatic and pedicle clamp during hysterectomy. +Self-assessment: (i) Structures of umbilical +cord (p. 36), (ii) Significance of single umbilical artery (p. 208). (iii) Indications of induction of labor (p. 487). (iv) Indications of surgical induction of labor (p. 490, Table 35. 7), (v) Dangers of induction of labor (medical and surgical) (p. 487). (vi) What is the pre-induction cervical scoring system? (p. 487). (vii) What immediate attention we should pay following ARM? (p. 491). +ag Chapter 42: Practical Obstetrics +Fig. 42.10: LONG STRAIGHT SCISSORS +Uses: It is commonly used to cut the (i} umbilical cord, (ii) to make episiotomy, (iii) to cut suture materials as in cesarean section. +Self-assessment: (i) When the umbilical cord should be clamped and cut? (p. 132). (ii) What are the indications of early cord clamping and cutting? (p. 132). (iii) At what distance from the umbilicus, the cord is clamped and cut? (p. 132). + + + + +Fig. 42.11: UTERINE SOUND +It is an olive pointed, graduated, malleable, metallic uterine sound. As it is malleable, its curvature could be changed to adapt the position of the uterus and for ease of introduction. +Uses: (i} To know the position of the uterus and the length of the uterine cavity prior to dilatation of the cervix in +D + E operation. (ii} To sound the uterine cavity to detect any foreign body (IUCD}. (iii) It acts as a first dilator of the cervical canal. +Self-assessment: (i) What are the instruments required for D + E or suction evacuation? (p. 522, 524). (ii) What are the important steps of S + E or D + E? (p. 523, 524, 525). (iii) What are the complications of S + E or D + E operation? (p. 525). + + + + +Figs. 42.12A and B: CERVICAL DILATORS: HAWKIN­ AMBLER (Fig. 42.12A) AND DAS OR HEGAR'S DILATORS (Fig. 42.12B) +Hawkin-Ambler: It is a single-ended metallic cervical dilator. It has got 16 sizes, the smallest one being 3/6 and the largest one being 18/21. The number is arbitrary in the scale of Hawkin-Ambler. The smaller one denotes measurement at the tip and the larger one measures the maximum diameter at the base in mm. +Das or Hegar's dilator is a double-ended one. The mini- +mum size is 1/2 and the maximum size is 11/12. The number represents the diameter in mm. Both the sides are used with the lower number first. +Use: It is used in dilatation of the cervical canal prior to evacuation operation. +Degree of dilatation required: (i} Incomplete abortion-sufficient to introduce the index finger (usually 16/19). (ii} In suction evacuation-one size smaller than the size of the suction cannula. (iii) In MTP by D + E-sufficient dilatation to introduce ovum forceps (usually 9/12). +Self-assessment: (i) How to know the end point of suction procedure? (p. 526). (ii) What is the management protocol when there is uterine perforation? (p. 525), (iii) What are the indications of laparotomy following perforation? +Ans. Laparoscopy is helpful to assess the situation. (i} Lateral uterine wall injury with intraperitoneal hemorrhage or broad ligament hematoma. (ii} Suspected injury to bowel and/ or omentum. (iii) Deterioration of vital signs during the period of observation. (iv) Perforation prior to complete evacuation. +Chapter 42: Practical Obstetrics GD Fig. 42.13: FLUSHING CURETTE +It is a blunt curette used in the operation of D + E. Previously, it was used to flush the uterine cavity with lukewarm antiseptic solution-passing through the communicating channel. +Self-assessment: Questions are similar as in Figures 42.11 and42.l2. + + +Fig. 42.14: DOYEN'S RETRACTOR +Description: It is a long metallic instrument with a stout handle at one end. The other end has a wide retracting blade (fan-shaped and curved). It needs an assistant to hold and to retract. +Uses: It is used to retract the abdominal wall as well as the bladder for proper exposure of lower uterine segment during LSCS. It is to be introduced after opening the abdomen; to be temporarily taken off while the baby is +delivered, to be reintroduced after delivery of the baby and finally to be removed after toileting the peritoneal cavity. +Self-assessment: (i) Types of CS (p. 544). (ii) Common indications of LSCS (p. 543). (iii) Principal steps of LSCS (p. 545). (iv) Merits and demerits of LSCS over classical (p. 548). (v) Complications of CS (p. 549). (vi) Measures to reduce cesarean delivery (p. 550). + + +Fig. 42.15: SPONGE-HOLDING FORCEPS +Description: It is a long metallic instrument (steel). It has two ends. (A) One end is the handle with rachet and catch. (B) The other end is ring-shaped with transverse serrations inside for better grip. +Uses: (I) To clean the vulva, vagina and perineum prior to and following delivery. (2) Antiseptic painting of the abdominal wall prior to cesarean section. (3) To catch hold of the membranes if it threatens to tear during delivery of the placenta. (4) To catch hold of the cervix +(2 pairs are needed) for inspection in suspected cervical tear. (5) To catch hold of the cervix during encerclage operation. +Self-assessment: (i) What antiseptic solutions are commonly used to clean the vulva and vagina prior to and following delivery? (p. 127) (ii) How the antiseptic painting of the abdominal wall is done before CS and what antiseptic solution is commonly used? (p. 545) (iii) What happens if bits of placental tissue or membranes are left behind? (p. 393) (iv) How a cervical tear is repaired? (p. 400). + + +Fig. 42.16: OVUM FORCEPS +Description and identification: It is a long metallic (steel) instrument with two ends and a shaft. The handle has no catch and the blades are slightly bent and fenestrated. Absence of catch minimizes uterine injury, if accidentally caught. It prevents crushing of the conceptus. It is to be introduced with the blades closed, to open up inside the uterine cavity, to grasp the products and to take out the +instrument with a slight rotato1y movement. The rotat01y movements not only facilitate detachment of the products from the uterine wall but also minimize the injury of the uterine wall, if accidentally grasped. It may be confused with sponge-holding forceps but it has no catch moreover the blades of sponge forceps are serrated. +Self-assessment: (i) How to differentiate it from a sponge- holding forceps? (ii) How the absence of catch made it advantageous? (iii) What are the indications of its use? (p. 524). It is used to remove the products of conception in D&E operation and to remove the bits of placenta and the membranes. +GD Chapter 42: Practical Obstetrics +Fig. 42.17: KELL Y'S LONG FORCEPS +Description: This is long metallic instrument. It has a smooth curve close to the blades. The handle has no ca­ tch. The blades are fenestrated with transverse serrations on its inner surface. +Uses: (1) Postplacental (following delivery of the plac­ enta), insertion of IUCD (Cu-T 380 A) in the puerperal uterus (p. 500). (2) As an alternative to ovum forceps for removal of retained placental bits and membranes. +This instrument has got advantages: (1) The length +enables it to place the IUCD at the fundus of the puerperal uterus. (2) The transverse serration provides good grip to the IUCD. (3) Absence of catch protects the IUCD from crushing. + + +Fig. 42.18: UTERINE CURETTE +Description and identification: It is a long metallic instrument with a small fenestrated end at each side. The shaft is there in the middle. +It may be sharp at both ends or sharp at one end and blunt at the other. Its common use in obstetrics is in the operation of D + C for incomplete abortion. In D + E operation, the curettage is done by blunt curette as the uterine wall is very soft. It can also be used in D + C opera­ tion one week following evacuation of hydatidiform mole. +Self-assessment: (i) Questions as in Figures 42.11, 42.12, 42.13, 42.15 and 42.16. {ii) Place of curettage following evacuation ofH. mole (p. 187). {iii) Drawbacks of vigorous curettage. {iv) What is the post-abortion care? (p. 524) + + +Fig. 42.19: UTERINE DRESSING FORCEPS +The instrument is most often confused with laminaria tent introducing forceps. The blades are transversely serrated; while in the latter, there is a groove on either blade. +Uses: (a) To swab the uterine cavity following D + E with small-gauze pieces, (b) To dilate the cervix in lochiometra +or pyometra. (c) It can be used to introduce Laminaria tents. + + +Fig. 42.20: LAMINARIA TENT AND THE TENT INTRODUCING FORCEPS WITH LAMINARIA TENT +The instrument is almost similar to uterine dressing forceps. There is a groove on either blade to catch the laminaria tent. +Laminaria tent: It is dehydrated, compressed, Chinese +sea-weeds. It is sterilized by keeping it in absolute alcohol at least for 24 hours. Usually, more than one tent is to be introduced to prevent dumbling of the ends. It produces slow dilatation of the cervical canal, as it swells up due to hygroscopic action (Fig. 37.1). +Isabgol tents (Isogel): It is dried granules prepared from the husks of" certain mucilaginous tropical seeds". +Self-assessment: (i) Steps of introduction of tents (p. 524). {ii) What are the other alternatives of tent used for slow dilatation of the cervix? (p. 524). +Chapter 42: Practical Obstetrics Ii Fig. 42.21: MANUAL VACUUM ASPIRATION (MVA ) +SYRINGE +Use: This is used for evacuation of the uterus by creating a vacuum. It is used up to 12 weeks of pregnancy for medical termination. +Other uses: Evacuation of the uterus in cases-(i) menstrual regulation, (ii) incomplete/missed abortion (up to 12 weeks}, (iii) molar pregnancy (up to 12 +weeks), blighted ovum, and in cases for (iv) endometrial +A. Valve button; B. Cap; C. Hinged valve with valve liner inside; Advantages of MVA: (i) It is simple, (ii) safe, (iii) can be D. Collar stop; E. Cylinder; F. Plunger; 0. Ring; H. Plunger handle. done as an outpatient basis, (iv) with local anesthesia, (v) +sampling/biopsy. +effective (98%}, (vi) less traumatic, and (vii) it takes less time (10-15 min). +Self-assessment: (i) Methods of termination of pregnancy in the first trimester (p. 166). (ii) Complications of MVA (p. 526). (iii) How can one ensure that the procedure is completed? (p. 526). (iv) What are the precautions that we should take? (p. 526). + + +Fig. 42.22: PLASTIC SUCTION CANNULA (KARMAN'S TYPE) +These are of different sizes (4, 5, 61 71 81 9, 10 and 12 mm). Appropriate size of the cannula (diameter in mm) needed for a particular case, is same to the duration of pregnancy in weeks. In general, the size of the pregnant uterus (weeks} and the size of the cannula (mm) are: 4-6 weeks size with 4-7 mm cannula; 7-9 weeks size with 5-10 mm cannula and for 9-12 weeks with 8-12 mm size cannula. The plastic cannula has got advantages over the metallic one-as it causes less damage to the uterine wall and the product sucked out is visible. The vacuum must be broken before it is withdrawn. It is used for S + E and MVA. Cannulas are used for S + E when attached with MVA syringe. +Self-assessment: (i) How the size of the cannula is determined? (p. 525). (ii) During S + E procedure, how the cannula is to be moved? (p. 525). (iii) How much suction pressure is generally used? (p. 525). + + +Fig. 42.23: LONG-CURVED OBSTETRIC FORCEPS (Ch. 37, p. 530) +It is commonly used in low forceps operation. Self-assessment: (i) Different types of +obstetric forceps. (ii) Different parts and the curvatures. (iii) Identification of blades. (iv) Types of forceps application. (v) Functions of the obstetric forceps. (vi) Common indications of forceps delivery. (vii) Conditions to be fulfilled before application of forceps. (viii) Steps of forceps application. (ix) Direction of pull during delivery, +(Fig. 37.14). (x) Complications of forceps delivery. (xi) Indications of elective (prophylactic) forceps delivery. (xii) Trial of forceps. {xiii) What is a failed forceps? +ED Chapter 42: Practical Obstetrics +Fig. 42.24: SHORT-CURVED OBSTETRIC FORCEPS (WRIGLEY'S FORCEPS) (Ch. 37, p. 531) It can only be used as outlet forceps for extraction of the head. +Sef-assessment: (i) Difference with long-curved forceps. (ii) Define outlet forceps. (iii) What is the direction of pull? + + + + + + + +Fig. 42.25: KIELLAND'S FORCEPS (Ch. 37, p.536) +It is usually used as rotation forceps in deep transverse arrest of occipitoposterior position +of the head or in unrotated vertex or face presentation. +Self-assessment: (i) Identification of blades (p. 536). (ii) Special advantages over the long-curved forceps (p. 531). (iii) Methods of application (p. 536). (iv) Hazards of its use (p. 536). + + + +Fig. 42.26: FORCEPS' AXIS TRACTION DEVICES +It includes axis traction rods (right and left) and handle. The rods are assembled in the blades of long-curved obstetric forceps prior to introduction and lastly the handle is attached to the rods. The devices are required where much forces are necessary for traction as in mid-forceps operation. These are less commonly used now. +Self-assessment: (i) Identification of traction rods. (ii) Indications of use. + + + + +Fig. 42.27: EPISIOTOMY SCISSORS (Ch. 37, p. 527) +It is bent on edge. The blade with blunt tip goes inside the vagina. +Self-assessment: Common indications of +episiotomy (p. 527). (ii) Should episiotomy be made in all cases? (p. 527). (iii) Types of episiotomy (p. 527). (v) Complications of episiotomy (p. 529). +Chapter 42: Practical Obstetrics am Figs. 42.28A and B: VENTOUSE CUP WITH TRACTION DEVICE (Ch. 37, p. 537) +Use: It is used in the operation of vacuum extraction of the head. The cup is to be fitted to the scalp of the forecoming head by producing" chignon" with the help of vacuum. The cup has got various sizes (p. 537). +Self-assessment: (i) Indications of its use (p. 537). (ii) Advantages over forceps (p. 538). (iii) Conditions to be fulfilled for its application (p. 539). (iv) Methods of its use (p. 537). (v) Hazards ofVentouse delivery (p. 540). (vi) Advantages of a silastic cup over the metallic one (p. 538). (vii) What is flexion point? Ans. p. 537. + + + + + + + + + + +Figs. 42.28A and B: Ventouse cup: (Al Metal; (Bl Silastic. + + +Fig. 42.29: GREEN-ARMYTAGE HEMOSTATIC FORCEPS +Description: It is a long metallic instrument. The handle has rachet and catch system. The other end is broad and has transverse serrations. This end is for holding the tissues. +This forceps is used in lower segment cesarean section. Total four forceps are ordinarily required-one for each angle and one for each flap. Its functions are hemostasis and to catch hold of the margins so that they are not missed during suture. It cannot be used in classical cesarean sec-tion. Alternative to this, Allis tissue forceps may be used. +Self-assessment: (i) Factors for rise in CS rate (p. 543). (ii) Methods of suturing the uterine wound (p. 547). (iii) Criteria forVBAC (p. 316). (iv) Intraoperative complications of CS (p. 549). + + +Figs. 42.30A and B: MUCUS SUCKER +(A) Disposable, (B) Rubber-It is used to suck out the mucus from the naso-oropharynx following delivery of the head of the baby. To be of value, the mucus should be sucked prior to the attempt of respiration, othe1wise the tracheobronchial tree may be occluded leading to inad­ equate pulmonary aeration and development of asphyxia neonatorum. The metal sucker requires a sterile simple rubber catheter to be fitted at one end and a sterile piece of gauze to the other end. Currently, electric or the disposable sucker is being used. +Self-assessment: (i) Immediate care of the newborn (p. 131). (ii) Management of the cord round the neck (p. 131). (iii) Causes of asphyxia neonatorum (p. 441). (iv) How Apgar scoring is done? (p. 443). (v) How do you manage an asphyxiated neonate? (p. 443). + + + + + +Figs. 42.30A and B: (Al Mucus sucker­ disposable; (Bl Mucus sucker-rubber. +ml Chapter 42: Practical Obstetrics +Fig. 42.31: CORD-CLAMP (DISPOSABLE) +It is made of plastic and is supplied in a sterile pack. The serrated surface and the lock make its grip firm. It occludes the umbilical vessels effectively. The cord clamp is to be kept in place until it falls off together with the detached stump of umbilical cord. +Self-assessment: (i) What is the purpose of the cord­ clamp that is applied on the maternal end? (p. 132). (ii) What are the different abnormalities of cord attachment? (p. 208). (iii) What is the significance when the cord is unduly long or short? (p. 208). + + + + + + +Fig. 42.32: PINARD'S STETHOSCOPE +Use: It should be held firmly at right angle to the point on the abdominal wall. The ear must be firmly closed +to the aural end. It should not be touched by hand while listening. +Self-assessment: (i) Earliest at what weeks, FHS could be detected with a stethoscope? (p. 64). (ii) What are the different sites where maximum intensity of FHS is obtained in relation to fetal presentation and position? (p. 74). (iii) What are the clinical conditions where FHS may not be audible? (p. 66, 73, 74). + + + +Fig. 42.33: PERFORATOR (OLDHAM'S) +The instrument is required in craniotomy to perforate the skull bone for decompression of the fetal head. Self-assessment: (i) Indications of craniotomy (p. 550). (ii) Contraindications of craniotomy (p. 550). +(iii) Conditions to be fulfilled prior to craniotomy (p. 550). (iv) What specific postoperative care is essential in such a case? (p. 552). (v) Important steps of the operation (p. 551). (vi) Procedure to do after delivery of the placenta (p. 552). (vii) Complications of destructive operations (p. 552). + + +Fig. 42.34: GIANT VULSELLUM +It is used in destructive operation, especially in evis­ ceration to have a good grip of the fetal parts for giving traction. +Self-assessment: (i) Indications of use. (ii) What is meant by neglected shoulder presentation? (p. 373). (iii) Mention the postoperative care following any destructive operation (p. 552). +Chapter 42: Practical Obstetrics GD Fig. 42.35: TROLLEY WITH INSTRUMENTS PREPARED FOR CESAREAN SECTION OPERATION +Instruments are (from left to right and top to bottom): + +(1) Mops (large swabs). (2) Electrodiathermy set. +(3a) Suction tube with cannula. (3b) Baby suction catheter. +(4) Towel clips. (5) Kidney dish. + + +(10) Obstetric Forceps (Wrigley's). (11) Doyen's retractor. +(12) Kocher's clamps. (13) Long artery forceps. +(14) Allis tissue forceps (long variety). + +(18) Artery forceps (short variety). (19) Dissecting forceps-toothed +and non-toothed. +(20) Scissors (straight and curved variety). +(21) Knives (two). + +(6) Gauze pieces. (15) Green-Armytage forceps. (22) Bowl with povidone-iodine +(7) + +Lanes tissue forceps. (8) Needle holders. +(9) Empty bowl. + + +(16) Littlewood's forceps. (17) Allis tissue forceps (short +variety). + +lotion. +(23) Sponge-holding forceps (two). (24) Suture packets. + + + + + + + + + + + + + + + + + + + + + + + +■ PROCESSING OF INSTRUMENTS +A. Disinfection is done by any one of the methods: Immersing instruments in-0 boiling water for 20 minutes, f) 2% glutaraldehyde (cidex) solution for 20 minutes, or O 0.5% chlorine solution for 20 minutes (0.5% of chlorine solution is made by adding 3 teaspoons (15 g) of bleaching powder in one liter of water). +B. Cleaning: Instruments are disassembled and washed on all surfaces in running (preferably warm) water. The cannulas should be flushed repeatedly. +C. Sterilization: Either by: 0 Autoclaving at 121 °C (250°F), under pressure of 15 lbs/in2 (106 kPa) for 30 minutes or 9 Immersing in 2% glutaraldehyde (cidex) solution for 10 hours. +mJ Chapter 42: Practical Obstetrics +Figs. 42.36A and B: DOPPLER (ULTRASOUND) FETAL MONITOR-(A) DEVICE AND (B) IN USE +Self-assessment: (i) Earliest at what weeks the FHS could be detected with a Doppler? (p. 64). (ii) What are the other alternatives when FHS is not audible with a stethoscope? Ans. (a) Doppler (p. 566). (b) CTG (p. 567). (c) Ultrasound for cardiac motion (p. 64). (iii) What are the advantages ofEFM over the clinical? (p. 567). (iv) What are the causes of fetal bradycardia? (p. 566). (v) What are the characteristics of an abnormal CTG? (p. 568). (vi) What other tests could be done when a CTG is abnormal? (p. 568). (vii) What is meant by non-reassuring fetal status (fetal distress)? (p. 570). + + + + + + + + + + + + + + + + + + + + +■DRUGS +Fig. 42.37: OXYTOCICS: OXYTOCIN, METHERGINE, MISOPROSTOL (PGE1 ); CARBOPROST (PGF2a), PROSTIN (PGE2) Self-assessment: (i) What are oxytocics? Ans. P. 467. (ii) Indications of use (p. 467). (iii) Contraindications of use (p. 395,467). (iv) How the different oxytocics differ in the action? Ans. P. 467,470. (v) What are the merits and demerits of oxytocin and prostaglandins when used for medical induction of labor? Ans. P. 488. + + +Fig. 42.38: MAGNESIUM SULFATE (MgS04) +Q. What are the monitoring parameters of MgSO,/ Ans. 1. Respiratory rate: >12/min +2. Urine output: >30 mL/hour +3. Presence of deep tendon reflexes (patellar reflex) 4. Serum level of magnesium should be < 10 mEq/L +Q. What are the toxicities ofMgSO4 ? Ans. 1. Respirato1y depression +2. Neuromuscular paralysis 3. Renal suppression + +Chapter 42: Practical Obstetrics ml + + + + + + + + + + +3. Pulmonary: Respiratory paralysis. + + + +Q. What are the precautions of use and management of magnesium toxicity? +Ans. 1. Periodic measuring of plasma magnesium level in selected cases besides clinical monitoring (see above). Knee jerk reflex to be tested before each dose of magnesium sulfate. Repeat dose should be withheld when knee jerks are absent. +2. Management: Life-threatening hypermagnesemia: +A. Calcium gluconate 1 g IV (10 mL-10%). B. Fluid loading and forced diuresis. +3. Magnesium is contraindicated in patients with-(a) heart block, and (b) myasthenia gravis. +Q. What are the side effects/toxicity of magnesium sulfate? +Ans. 1. Cardiovascular: +A. Hypotension. B. Heart block. +C. Circulatory collapse. +2. CNS: Depressed reflexes; flaccid paralysis. + + +4. Metabolic hypocalcemia. 5. Others: Flushing, sweating. +Magnesium toxicity resulting in maternal death is rare. +MgSO 4 is the drug of choice to treat eclampsia and +prevent subsequent convulsions in eclampsia. Recurrence offits following MgSO4 therapy only 10%. +In these cases, bolus of 2 g of magnesium sulfate can be given IV over 3-5 minutes. +Magnesium toxicity should be considered in those women who do not regain consciousness. Compared to the other drugs (diazepam, phenytoin and lytic cocktail) +MgSO4 was associated with significantly lower rate of +recurrent seizures (9.4% versus 23.1%) and lower rate of maternal death (3% versus 4.8%). + + +Intravenous administration of Mg50 : For IV use, concentration of Mg50 should not exceed 20%. One part of 50% Mg50 is diluted with 1.5 parts of water for injection to make it 20%. It is then given IV slowly. +4 +4 +4 + + + +Fig. 42.39: MIFEPRISTONE +It is a synthetic steroid with anti progesterone and anti glu­ cocorticoid activity. Half life is 25-30 hours. +Action: If blocks both the progesterone and glucocor­ ticoid receptors leading to decidua necrosis. Other functions are: Increased production of prostaglandins (PGs), increased uterine sensitisation to PG receptors and cervical ripening. Lower doses of PGs and PG analogous are required to induce delivery. +Indication: (a) Cervical ripening before MTP up to 24 hours. (b) Labor induction in IUFD. +Dose: 200 mg PO followed 48 hours later by misopros­ tol. +Contraindications: Chronic adrenal failure, suspected ectopic pregnancy, severe asthma and acute porphyrias. +MISOPROSTOL (PGE1)-Ch. 34, p. 472 +Halflife: 20-40 min. Side effects: Nausea, diarrhea, vomiting, dizziness, fever and chills. +ID Chapter 42: Practical Obstetrics SPECIMENS +■ +Figs. 42.40A and B: PLACENTA: NORMAL-(A) MATERNAL SURFACE AND (B) FETAL SURFACE + +Important features on maternal surface are: 0 Rough and shaggy look with remnants of decidua. 0, Areas of cotyledons limited by the fissures. 0 The margin is continued with chorion and amnion (membranes). +Features on the fetal surface are: 0 Smooth and shining look. 0, Covered with amnion. 0 Umbilical cord attached at/ or near the center. «D Branching of umbilical vessels are visible underneath the amion as they radiate from the umbilical cord insertion. +At term about 80% of placenta is of fetal origin. +The human placenta is a discoid, deciduate, hemochorial and labyrinthine organ (Ch. 3, p. 26) . + + + + + + + + + + + + + + + + +Figs. 42.40A and B: Normal placenta: (Al Maternal surface of the placenta; (Bl Fetal surface of the placenta. + + + +Figs. 42.41 A and B: PLACENTA SUCCENTURIA TA +A. Maternal surface: One or more sometimes more small lobes of placenta are connected to the main lobe. +B. Fetal surface: Leash of blood vessels transverse through the membranes from the main lobe to be small lobe (see arrow). +Clinical significance: Once the succenturiate lobe is retained inside the uterus following delivery, it may cause­ (a) PPH; (b) Subinvolution; (c) Sepsis (Ch. 17, p. 206). Read more Dutta's Clinics in Obstetrics, Ch. 7. +Treatment: Manual removal of the lobe under anesthesia. + + + + + + + + + + + + + +Figs. 42.41A and B: Placenta succenturiata: (Al Maternal surface and (Bl fetal surface showing the communicating vessels (arrow). Courtesy: Dr D Debanshi, Consultant Obstetrician and Gynecologist. +Chapter 42: Practical Obstetrics mJ Fig. 42.42: RUPTURE UTERUS +It is a specimen of gravid uterus showing ragged, irregular, blackish necrosed margin along the lateral wall ofthe uterus. Cervix is not seen. It is a specimen of rupture uterus. Subtotal hysterectomy with conservation of ovaries had been done. +Self-assessment: (i) What are the common causes of rupture uterus? Ans. P. 402. (ii) Differentiation of scar dehiscence from scar rupture (p. 402). (iii) How the diagnosis of rupture uterus (spontaneous as well as scar) is made? Ans. p. 402. (iv) How do you manage a case ofrupture uterus? Ans. Resuscitation and laparotomy. Laparotomy ➔ hysterectomy (commonly subtotal). Repair ofuterus may be done in selected cases with scar rupture. Repair and bilateral tubal ligation may also be done (p. 405). + + +Fig. 42.42: Rupture uterus. + + +Fig. 42.43: UN RUPTURED TUBAL ECTOPIC PREGNANCY +Laparoscopic panoramic view of an unruptured tubal ectopic pregnancy. Ectopic pregnancy is seen at the region of ampulla of the tube (right). +Self-assessment: (i) How a case of acute (ruptured) tubal ectopic pregnancy is diagnosed? (p. 172). (ii) How a case of unruptured tubal ectopic pregnancy is diagnosed? (p. 172) (estimation ofserum -hCG, TVS and laparoscopy). (iii) Management of acute tubal ectopic pregnancy (p. 173). (iv) Management of an unruptured tubal pregnancy (p. 174). + + +■ IMAGING STUDIES (USG PLATES) +Figs. 42.44A and B: ULTRASONOGRAM: HYDATIDIFORM MOLE +Sef-assessment: (i) How a case ofmolar pregnancy commonly presents? Ans. P. 182. (ii) What are the complications ofa molar pregnancy? Ans. Hemorrhage, shock, pre-eclampsia, sepsis, acute pulmonary insuficiency and rarely coagulation failure. The late complications are: development of persistent trophoblastic neoplasia and choriocarcinoma (p. 182). (iii) How do you manage a case ofhydatidiform mole? Ans. p. 185. Principles ofmanagement are: (a) Supportive therapy (blood transfusion), (b) Suction evacuation ofthe uterus, and (c) follow-up (p. 185). + + + + + + + + + + + + + + + +Figs. 42.44A and B: (A} Showing grape-like vesicles of varying sizes. These are the tissues of molar pregnancy (see the arrows}; (B} An ultrasonogram showing snowstorm appearance of a molar pregnancy. +ml Chapter 42: Practical Obstetrics +Fig. 42.45: ULTRASONOGRAM: GESTATIONAL SAC +Presence of an intrauterine gestational sac is a reliable evidence of intrauterine pregnancy. The sac is eccentri­ cally located. The gestation sac could be seen as early as 4.5-5 weeks with the use of TVS. The normal gestational sac appears round in the early stages; and, gradually, it becomes oval in shape. The gestational sac is filled with chorionic sac fluid which is more echogenic than the amniotic fluid as it contains more protein materials. A gestational sac diameter ,:16 mm without an emb1yo is a strong sign of early pregnancy failure. Abnormal size of the gestational sac is an indication of abnormal outcome. + +Clinical Importance of GS +0 TVS with color flow Doppler study is helpful to identify a normal pregnancy. 8 It can differentiate a normal pregnancy from a failed intrauterine pregnancy. 0 It can diagnose ectopic pregnancy (extrauterine). 0 Fetal gestational age can be estimated measuring the Mean Gestational Sac Diameter (MSD ). 0 Abnormal size of the gestational sac is an indicator of abnormal outcome. + +Fig. 42.46: ULTRASONOGRAM: YOLK SAC AND FETAL POLE +Yolk sac is the first structure seen normally within the Gestational Sac (GS). Yolk sac is seen using TAS when the Mean GS Diameter (MSD) is 10-15 mm and using TVS, with MSD of 8 mm. + +Clinical Importance of the Presence of Yolk Sac +(1) It can differentiate an early intrauterine GS from a pseudosac. (2) It is diagnostic of intrauterine pregnancy. (3) It plays an important role of embryonic development by transfer of nutrients. ( 4) Fetal angiogenesis starts in the wall of the yolk sac in the 5th week. (5) Fetal hematopoie­ sis occurs first in the yolk sac. (6) Primitive gut is formed from the dorsal wall of the yolk sac. +The number of yolk sacs and the number of amniotic sacs are the same. The number of yolk sacs is helpful to determine amnionicity of a multifetal pregnancy. In Monochorionic, Monoamniotic (MCMA) twin pregnancy there are: (a) Two emb1yos, (b) One chorionic sac, (c) One amniotic sac and (d) One yolk sac. + +Fig. 42.47: UL TRASONOGRAM: CROWN RUMP LENGTH (CRL) +Gestational sac is visualized between 4.5 and 5 weeks of menstrual age. MSD is about 5 mm at 5 weeks. At 5.5 weeks, the yolk sac appears. At 6 weeks, an embryo first appears adjacent to the yolk sac (Fig. 42.46). A CRL length when correctly measured in the first trimester is accurate to measure the fetal gestational age to ±5-7 days. The fetal measurement from the top of the head (see calipers) to the end point of the bottom (excluding the limbs) is called CRL. Currently, late first trimester sonography (11-13 weeks) is considered to be the ideal time for screening for aneuploidy, when combined with maternal serum screening and fetal nuchal translucency (p. 601). +Chapter 42: Practical Obstetrics Im Fig. 42.48: EMBRYONIC CARDIAC ACTIVITY +Using TVS, an embryo can be identified almost always with an MSD of 16-18 mm. The tubular embryonic heart begins to beat at 36-37 days ges­ tational age. In general, cardiac activity can be visualized in normal embryos of greater than 5 mm CRL. Normal embryonic cardiac activity is > 100 beats per minute. Absent cardiac activity in emb1yos is the most important factor in predicting poor pregnancy outcome. +TVS: Emb1yonic color flow Doppler study showing cardiac activity of a normally growing fetus. FHR is 177/min. + + + + + +Fig. 42.49: Bl PARIETAL DIAMETER AND HEAD CIRCUMFERENCE +It is an ultrasonogram showing the fetal head. In this view, the biparietal diameter (BPD) and the head circumference (HC) had been measured as a part of fetal biometiy (p. 601). +Self-assessment: (i) What is the importance of BPD measurement? Ans. BPD is most accurate for assessment of fetal gestational age from 14 to 24 weeks (variation ± 8 days). (ii) How BPD is measured? Ans. It is measured from outer edge of proximal skull to the inner edge of the distal skull. It is measured at the level of thalami and cavum septum pellucidum (Fig. 41.4). (iii) What is the importance of HC? Ans. Head shape dolichocephaly (flattened) or rounded (brachycephaly) is known. HC is more reliable than +BPD. (iv) What other fetal parameters are measured to determine fetal gestational age? Ans. Femur Length (FL) and Abdominal Circumference (AC). AC is measured at the level of fetal stomach and umbilical vein (Fig. 42.51A and B). + + + +Fig. 42.50: UL TRASONOGRAM SHOWING TWO FETAL HEADS IN TWIN PREGNANCY +Self-assessment: (i) How the diagnosis of twin pregnancy can be made clinically? Ans. P. 192. (ii) What other information can be obtained from sonography besides the confirmation of diagno­ sis? Ans. P. 193. (iii) What are the complications (maternal and fetal) of twin pregnancy? Ans. P. 193. (iv) Outline the management of twin pregnancy in labor. Ans. P. 198. +Im Chapter 42: Practical Obstetrics +Fig.42.51 A: UL TRA5ONOGRAM: ABDOMINAL CIRCUMFERENCE (AC) +AC is measured as an axial image of the fetal abdomen at the level of the stomach and intrahepatic portion of the umbilical vein at the junction of the portal vein. It should be as round as possible, outlining the outer surface of the skin around the abdomen. AC is used to assess the gestational age and fetal weight in second and third trimesters. Composite age formula includes BPD, HC, FL and AC. +Fig.42.51 B: ULTRASONOGRAM: Fias. 42.51A and B: (Al USG (AC): (Bl USG (Fll. FEMUR LENGTH (FL) +Sonographic length of femur is measured between the ossified diaphysis. Composite age and weight formula includes BPD, HC, FL and AC. + + +Figs. 42.52A to C: ABNORMALITIES OF THE UMBILICAL CORD AND THE FETAL RESPONSE Case history: +Mrs AG, 37 years, Pl + 0 + 0 + 1, previous cesarean delivery at 37+3 weeks gestation, a booked case, was seen for reduced fetal movements. Her kick chart revealed a significant drop of fetal movements from the earlier records. USG study revealed normal parameters. CTG tracings as seen in Figure 42.52A. + + + + + + + + + + + +rJ +Chapter 42: Practical Obstetrics 18 Observation with CTG: ■ Baseline fetal heart rate 140 bpm, ■ Variability - -- ' +/ +·­ +.. +/) :,. \ - "' -- ,..,Jc-. +- ._, ---"--' +.... -, ...... , + + + + +Medulla + + + +Mature corpus luteum + + +Corpus luteum (early) + +Fig. 1.9: Histological structure of the ovary. + + +Cortex: It consists of stromal cells which are thickened beneath the germinal epithelium to form tunica albuginea. During reproductive period (i.e., from puberty to menopause) the cortex is studded with numerous follicular structures, called the functional units of the ovary, in various phases of their development. These are related to sex hormone production and ovulation. The structures include-primordial follicles, maturing follicles, Graafian follicles and corpus luteum. Atresia of + + +the structures results in formation of atretic follicles or corpus albicans {Fig. 1.9). +Medulla: It consists of loose connective tissues, few unstriped muscles, blood vessels and nerves. There is a small collection of cells called 'hilus cells' which are homologous to the interstitial cells of the testes. +BLOOD SUPPLY: Arterial supply is from the ovarian artery, a branch of the abdominal aorta. Venous drainage is through pampiniform plexus, to form the ovarian +r Chapter 1: Anatomy of Female Reproductive Organs .. + +veins which drain into inferior vena cava on the right side and left renal vein on the left side. Part of the venous blood from the placental site drains into the ovarian veins and thus may become the site of throm­ bophlebitis in puerperium. +LYMPHATICS: Through the ovarian vessels drain to the para-aortic lymph nodes. +NERVE SUPPLY: Sympathetic supply comes down along the ovarian arte1y from T 10 segment. Ovaries are sensitive to manual squeezing. +DEVELOPMENT: The ovary is developed from the cortex of the undifferentiated genital ridges by about 9th week; the primary germ cells reaching the site migrating from the dorsal end of yolk sac. + +MUSCLES AND FASCIA IN RELATION TO THE PELVIC ORGANS + +The most important muscle supporting the pelvic organs is the levator ani which forms the pelvic floor. The small muscles of the perineum also have got some contribution. +il PEL VIC FLOOR (Synonym: Pelvic diaphragm) + +Pelvic floor is a muscular partition which separates the pelvic cavity from the anatomical perineum. It consists of three sets of muscles on either side­ pubococcygeus, iliococcygeus and ischiococcygeus and these are collectively called levator ani. Its upper surface is concave and slopes downwards, backwards and medially and is covered by parietal layer of pelvic fascia. The inferior surface is convex and is covered by anal fascia. + +The muscle with the covering fascia is called the pelvic diaphragm. + +ORIGIN: Each levator ani arises from the back of the pubic rami, from the condensed fascia covering the obturator internus (white line) and from the inner surface of the ischial spine. + +INSERTION: From this extensive origin, the fibers pass, backwards and medially to be inserted in the midline from before backwards to the vagina (lateral and posterior walls), perinea! body and anococcygeal raphe, lateral borders of the coccyx and lower part of the sacrum (Fig. 1.10). + +GAPS: There are two gaps in the midline-(1) The anterior one is called hiatus urogenitalis which is bridged by the muscles and fascia of urogenital triangle and pierced by the urethra and vagina. (2) The posterior one is called hiatus rectalis, transmitting the rectum. + +STRUCTURES IN RELATION TO PELVIC FLOOR +The superior surface is related with the following: +(I) Pelvic organs from anterior to posterior are bladder, vagina, uterus and rectum. (2) Pelvic cellular tissues between the pelvic peritoneum and upper surface of the levator ani which fill all the available spaces. (3) Ureter lies on the floor in relation to the lateral vaginal fornix. The uterine artery lies above and the vaginal artery lies below it. (4) Pelvic nerves. +The inferior surface is related to the anatomical perineum. + +NERVE SUPPLY: It is supplied by the 4th sacral nerve, inferior rectal nerve and a perinea! branch of pudenda! nerve s2,3,4' + + + +Pubis---------""-"'" i;; + +Urogenital diaphragm -·---- -,,-5$ + + +! ' + + + +Anus + +Anococcygeal raphe + +Vagina Pubovaginalis White line of pelvis +Puborectalis Obturator internus +Pubococcygeus + +lschiococcygeus + + +Piriformis + + + + +Sacrum +Fig. 1.10: Levator ani muscles viewed from above. +Chapter 1: Anatomy of Female Reproductive Organs + +FUNCTIONS: (1) To support the pelvic organs-the pubovaginalis which forms a 'U' shaped sling, supports the vagina which in turn supports the other pelvic organs-bladder and uterus. Weakness or tear of this sling during parturition is responsible for prolapse of the organs concerned. (2) To maintain intra-abdominal pressure by reflexly responding to its changes. (3) Facilitates anterior internal rotation of the presenting part when it presses on the pelvic floor. ( 4) Puborectalis plays an ancillaiy role to the action of the external anal sphincter. (5) Ischiococcygeus helps to stabilize the sacroiliac and sacrococcygeal joints. (6) To steady the perineal body. +PELVIC FLOOR DURING PREGNANCY AND PARTURITION: During pregnancy levator muscles undergo hypertrophy, become less rigid and more distensible. Due to water retention, it swells up and sags down. In the second stage, the pubovaginalis and puborectalis relax and the levator ani is drawn up over the advancing presenting part in the second stage. Failure of the levator ani to relax at the crucial moment may lead to extensive damage of the pelvic structures. The effect of such a displacement is to elongate the birth canal which is composed solely of soft parts below the bony outlet. The soft canal has got deep lateral and posterior walls and its axis is in continuation with the axis of the bony pelvis. +I PERINEUM +ANATOMICAL PERINEUM: Anatomically, the perineum is bounded above by the inferior surface of the pelvic floor, below by the skin between the buttocks and thighs. Laterally, it is bounded by the ischiopubic ramus, ischial + + + +tuberosities and sacrotuberous ligaments and posteriorly, by the coccyx. The diamond-shaped space of the bony pelvic outlet is divided into two triangular spaces with the common base formed by the free border of the urogenital diaphragm. The anterior triangle is called the urogenital triangle which fills up the gap of the hiatus urogenitalis and is important from the obstetric point of view. The posterior one is called the anal triangle. +Urogenital triangle: It is pierced by the terminal part of the vagina and the urethra. The small perineal muscles are situated in two compartments formed by the ill-defined fascia. The compartments are superficial and deep perineal pouch. The superficial pouch is formed by the deep layer of the superficial perineal fascia ( Calles fascia) and inferior layer of the urogenital diaphragm (perineal membrane). The contents are (Fig. 1.2) superficial transverse perinei (paired), bulbospongiosus covering the bulb of the vestibule, ischiocavernosus (paired) covering the crura of the clitoris and the Bartholin's gland (paired). The deep perineal pouch is formed by the inferior and superior layer of the urogenital diaphragm-together called urogenital diaphragm or triangular ligament. Between the layers there is a potential space of about 1.25 cm. The contents are the following muscles­ deep transverse perinei (paired) and sphincter urethrae membranacea. Both the pouches contain vessels and nerves (Fig. l.ll). +Anal triangle: It has got no obstetric importance. It contains the terminal part of the anal canal with sphincter ani externus, anococcygeal body, ischiorectal fossa, blood vessels, nerves and lymphatics. + + + + +Peritoneum + +Supralevator space + + + +Obturator muscle + +Vagina + + +Bulbocavernosus + +Superficial perinea! pouch + +Levator ani + +Superior and inferior layer of urogenital diaphragm + + +lschiocavernosus + + +Deep perinea! pouch + + + ;;---- Calles fascia + +'-f--sa----- Bartholin's gland +1 +I + + ------- - -- Labium minus +I + + +Fig. 1.11: Schematic diagram showing the pelvic muscles, fascia and cellular tissue as seen from the front. + + +OBSTETRICAL PERINEUM: (Synonyms: Perinea[ body, central point of the perineum). The pyramidal-shaped tissue where the pelvic floor and the perinea! muscles and fascia meet in between the vagina and the anal canal is called the obstetrical perineum. It measures about 4 cm x 4 cm with the base covered by the perinea! skin and the apex is pointed and is continuous with the rectovaginal septum. + +The musculofascial structures involved are: +• Fasciae-(1) Two layers of superficial perinea! fascia­ superficial fatty layer and deeper layer called Colles fascia. (2) Inferior and superior layer of urogenital diaphragm, together called triangular ligament. +• Muscles-(1) Superficial and deep transverse perinei (paired). (2) Bulbospongiosus. (3) Levator ani pubo­ coccygeus part (paired), situated at the junction of the upper two-thirds and lower one-third of the vagina. (4) Sphincter ani extern us (few fibers). +Importance: (1) It helps to support the levator ani which is placed above it. (2) By supporting the posterior vaginal wall, it indirectly supports the anterior vaginal wall, bladder and the uterus. (3) It is vulnerable to injury during childbirth. (4) Deliberate cutting of the structures during delivery is called episiotomy. +I PELVIC FASCIA + +For descriptive purpose, the pelvic fascia is grouped under the heading that covers the pelvic wall, the pelvic floor and the pelvic viscera. +Fascia on the pelvic wall: It is very tough and memb­ ranous. It covers the obturator internus and piriformis and gets attached to the margins of the bone. The pelvic + + + +Retropubic space + +Chapter 1: Anatomy of Female Reproductive Organs + +nerves lie external to the fascia but the vessels lie internal to it. +Fascia on the pelvic floor: It is not tough but loose. The superior and the inferior surfaces are covered by the parietal layer of the pelvic fascia which runs down from the white line to merge with the visceral layer of the pelvic fascia covering the anal canal (Fig. l.ll). +Fascia covering the pelvic viscera: The fascia is not condensed and often contains loose areolar tissue to allow distension of the organs. + +PELVIC CELLULAR TISSUE + +It lies between the pelvic peritoneum and the pelvic floor and fills up all the available empty spaces. It contains fatty and connective tissues and unstriated muscle fibers. Its distribution around the vaginal vault, supravaginal part of the cervix and into the layers of the broad ligament is called parametrium. Condensation occurs especially near the cervicovaginal junction to form ligaments which extend from the viscera to the pelvic walls on either side. These are Mackenrodt's ligaments, uterosacral ligaments and vesicocervical ligaments (fascia). All these constitute important supports of the uterus to keep it in position {Fig. 1.12). +Importance: (I) To support the pelvic organs. (2) To form protective sheath for the blood vessels and the terminal part of the ureter. (3) Infection spreads along the track, so formed, outside the pelvis to the perinephric region along the ureter, to the buttock along the gluteal vessels, to the thigh along the external iliac vessels and to the groin along the round ligament. (4) Marked hypertrophy occurs during pregnancy to widen up the spaces. + + + +Paravesical fascia + + + + +Vesicouterine space ,. J Paravesical space +\ +Cervix +Rectouterine space !) +Pararectal space + +Bladder + +Pubocervical fascia + +Paracervical fascia + + + +Cardinal ligament + + +Uterosacral ligament + + +Rectum +Fascia around rectum + + + + +Fig. 1.12: The main supporting ligaments of the uterus viewed from above. +Chapter 1: Anatomy of Female Reproductive Organs + +FEMALE URETHRA + +The female urethra extends from the neck of the bladder to the external urethral meatus which opens into the vestibule about 2.5 cm below the clitoris. It measures about 4 cm and has a diameter of 6 mm. Its upper half is separated from the anterior vaginal wall by loose areolar tissue and the lower half is firmly embedded in its wall. Numerous tubular glands called paraurethral glands open into the lumen through ducts. Of these, two are larger called Skene's ducts which open either on the posterior wall just inside the external meatus or into the vestibule. These glands are the sites for harboring infection and occasional development of benign adenoma or malignant changes. While piercing the deep perinea! pouch it is surrounded by sphincter urethrae membranacea which +acts as an external sphincter. +STRUCTURES: Mucous membrane in the distal one­ third is lined by stratified squamous epithelium but in the proximal two-thirds it becomes stratified transitional epithelium. Submucous coat is vascular. Muscle coat is arranged as inner longitudinal and outer circular. +BLOOD SUPPLY: Arterial supply: Proximal parts are supplied by the inferior vesical branch and the distal part by a branch of internal pudenda! artery. The veins drain into vesical plexus and into internal pudenda! veins. +LYMPHATICS: Ear the meatus, the lymphatics drain into superficial inguinal glands and the rest drain into internal and external iliac group of glands. +NERVE SUPPLY: It is supplied by the pudenda! nerve. +DEVELOPMENT: The urethra is developed from the vesicourethral portion of the cloaca. + +URINARY BLADDER + +The bladder is a hollow muscular organ with consi­ derable power of distension. Its capacity is about 450 mL (15 oz) but can retain as much as 3-4 liters of urine. When distended it is ovoid in shape. It has got-(1) an apex, (2) superior surface, (3) base, ( 4) two inferolateral surfaces and (5) neck, which is continuous with the urethra. The base and the neck remain fixed even when the bladder is distended. +RELATIONS: The superior surface is related with the peritoneum of the uterovesical pouch. The base is related with the supravaginal cervix and the anterior fornix. The ureters, after crossing the pelvic floor at the sides of the cervix, enter the bladder on its lateral angles. In the interior of bladder, the triangular area marked by three openings-two ureteric and one urethral, is called the trigone. The inferolateral surfaces are related with the space of Retzius. The neck rests on the superior layer of the urogenital diaphragm. + + + +STRUCTURES: From outside inwards-(1) Outer-visceral layer of the pelvic fascia. (2) Muscle layer composed of muscles running in various directions. Near the internal urethral opening the circular muscle fibers provide involuntary sphincter. (3) Mucous coat is lined by transitional epithelium with no gland. There is no submucous coat. + +BLOOD SUPPLY: The blood supply is through superior and inferior vesical arteries. The veins drain into vesical and vaginal plexus and thence to internal iliac veins. + +LYMPHATICS: Lymphatics drain into external and internal iliac lymph nodes. + +NERVE SUPPLY: The sympathetic supply is from the pelvic plexus and the parasympathetic via the pelvic plexus from +the nervi erigentes (S2,3 4). The parasympathetic produces +, +contraction of the detrusor muscles and relaxation of the internal sphincter (nerve of evacuation). Sympathetic conveys afferent painful stimuli of overdistension. + +DEVELOPMENT: The urinaiy bladder is developed from the upper part of the urogenital sinus. + +PELVIC URETER + +It extends from the crossing of the ureter over the pelvic brim up to its opening into the bladder. It measures about 13 cm in length and has a diameter of 5 mm. Ureter is retroperitoneal in course. +COURSE AND RELATIONS: The ureter enters the pelvis in front of the bifurcation of the common iliac artery over the sacroiliac joint behind the root of the mesentery on the right side and the apex of the mesosigmoid on the left side. As it courses downwards in contact with the peritoneum, it lies anterior to the internal iliac arte1y and behind the ovaiy and forms the posterior boundary of ovarian fossa (Fig. 1.8). On reaching the ischial spine, it lies over the pelvic floor and as it courses fo1wards and medially on the base of the broad ligament, it is crossed by the uterine artery anteriorly (Fig. 1.5). Soon, it enters into the ureteric tunnel and lies close to the supravaginal part of the cervix, about 1.5 cm lateral to it. After traversing a short distance on the anterior fornix of the vagina, it courses into the wall of the bladder obliquely for about 2 cm by piercing the lateral angle before it opens into the base of the trigone. In the pelvic portion, the ureter is comparatively constricted-(a) where it crosses the pelvic brim, (b) where crossed by the uterine artery and (c) in the intravesical part. +STRUCTURES: From outside inwards-(1) Fibers derived from the visceral layer of the pelvic fascia. (2) Muscle coat consisting of three layers-outer and inner longitudinal and intermediate circular. (3) Mucous layer lined by transitional epithelium. +Chapter 1: Anatomy of Female Reproductive Organs la + +BLOOD SUPPLY: It has got segmental supply from nearly all the visceral branches of the anterior division of the internal iliac ( uterine, vaginal, vesical, middle rectal) and superior gluteal arteries. The venous drainage corresponds to the arteries. +LYMPHATICS: The lymphatics from the lower part drain into the external and internal iliac lymph nodes and the upper part into the lumbar lymph nodes. +NERVE SUPPLY: Sympathetic supply is from the hypogastric and pelvic plexus; parasympathetic from the sacral plexus. +DEVELOPMENT: It is developed as an ureteric bud from the caudal end of the mesonephric duct. + +BREASTS + +The breasts are large, modified sebaceous glands. The breasts are bilateral and in female constitute accessory reproductive organs as the glands are concerned with lactation following childbirth. +The shape of the breast varies in women and also in different periods of life. But the size of the base of the breast is fairly constant. It usually extends from the second to sixth rib in the midclavicular line. It lies in the subcutaneous tissue over the fascia covering the pectoralis major or even beyond that to lie over the serratus anterior and external oblique. A lateral projection of the breast towards the axilla is known as axillary tail of Spence. It lies in the axillary fossa, sometimes deep to the deep fascia. The breast weighs 200-300 g during the childbearing age. + + +STRUCTURES (Non-lactating breasts): The areola is placed about the center of the breast and is pigmented. It is about 2.5 cm in diameter. Montgomery glands are accessory glands located around the periphery of the areola. They can secrete milk. The nipple is a muscular projection covered by pigmented skin. It is vascular and surrounded by unstriated muscles which make it erectile. It accommodates about 15-20 lactiferous ducts and their openings. Each milk duct (lactiferous duct) dilates to form lactiferous sinus at about 5-10 mm away from its opening in the nipple. When these sinuses are pulled into the teat during nursing, the infants tongue, facial muscles and mouth squeeze the milk from the sinuses into the infant's oropharynx. The whole breast is embedded in the subcutaneous fat. The fat is, however, absent beneath the nipple and areola. +The mature breast consists of about 20% glandular tissue and 80% fat and the rest connective tissue {Figs. 1.13A and B). The breast is composed of 12-20 lobes. Each lobe has one excretory duct (lactiferous duct) that opens at the nipple. Each lobe has about 10-100 lobules. Cooper's ligaments are the fibrous septa, that extend from the skin to the underlying pectoral fascia. These ligaments provide support to the breast. One lactiferous duct drains a lobe. The lining epithelium of the duct is cubical, becomes stratified squamous near the openings. Each alveolus is lined by columnar epithelium where milk secretion occurs. A network of branching longitudinal striated cells called myoepithelial cells surround the alveoli and the smaller ducts. There is a dense network of capillaries surrounding the alveoli. These are situated between the basement membrane and epithelial lining. + + + + +-",- ------- ----- Pectoralis major muscle + + -= -- ------ Pectoral fascia +-- -------Ligament of Cooper + + + --Lobule Subcutaneous fat + + +-:--- Lactiferous sinus Nipple + + + +Capillaries + +Alveolus +cut open + + + + +Alveolar +cells + +Lactiferous duct '" Alveolus +Skin + + +Figs. 1.13A and B: (A) Structure of the basic unit of the mammary gland; (B) Structure of adult female breast. +11 Chapter 1: Anatomy of Female Reproductive Organs + +Contraction of these cells squeezes the alveoli and ejects the milk into the larger duct. Behind the nipple, the main duct (lactiferous) dilates to form ampulla where the milk is stored. +Breast tissue is sensitive to the cyclic changes of hormones estrogen and progesterone. Women often feel breast tenderness and fullness during the luteal phase of the cycle. During the follicular phase, there is proliferation of the ductal system whereas during the luteal phase there is dilatation of the ductal system and differentiation of the alveolar cells into secretory cells. In postmenopausal women, the breast lobules and ducts atrophy. Accessory breasts or nipples can occur along the breast or milk line which extends from the axilla to the groin. Supernumerary nipples (polythelia) are associated with renal abnormalities (10%). Asymmetry of breasts is a normal variation. Massive hypertrophy of the breasts is a rare problem. +BLOOD SUPPLY: Arterial supply: (1) Lateral thoracic­ branches of the axillary artery, (2) Internal mammary, (3) Intercostal arteries. Veins-The veins follow the courses of the arteries. +LYMPHATICS: (1) Lateral hemisphere-anterior axillary nodes (75%). (2) Upper convexity-infraclavicular group. (3) Medial convexity-internal mammary chain of nodes (cross connection between the two breasts). There is no contralateral drainage of lymph, until and unless + + + + + +External oblique muscle + +Internal oblique muscle + +Transversus abdominis muscle + +Lateral cutaneous nerve +Anterior rectus sheath (cut edges) --- + +Posterior rectus sheath Arcuate line Transversalis facia +lliohypogastric nerve + +llioinguinal nerve +Round ligament entering inguinal canal +Pyramidalis muscle + +Inguinal canal + +Genital branch of genitofemoral nerve + + +Labium majus ------- + + +there is ipsilateral obstruction. ( 4) Inferior convexity­ mediastinal glands. +NERVE SUPPLY: The nerve supply is from fourth, fifth and sixth intercostal nerves. +DEVELOPMENT: The parenchyma of the breasts is developed from the ectoderm. The connective tissue stroma is from the mesoderm. + +ANATOMY OF THE ANTERIOR ABDOMINAL WALL + +Langer lines in the anterior abdominal wall, are arranged transversely. Vertical incisions cause more wider scars due to more lateral tensions during the process of healing. Pfannenstiel incisions (low transverse incisions) follow the Langer's lines, heal much better and have superior cosmetic results. There are total eight layers of the anterior wall from front to backwards. These are: (a) skin; (b) superficial fascia; (c) external oblique aponeurosis; (d) internal oblique aponeurosis; (e) transversus abdominis; (f) fascia transversalis; (g) extraperitoneal fatty tissue and (h) the parietal peritoneum. The subcutaneous layers are: Superficial fatty layer-fascia of Camper and the deep membranous layer-fascia of Scarpa. Scarpa fascia continues inferiorly onto the perineum as Colles fascia (Fig. 1.14). +The transverse muscles in the anterior abdominal wall are-(i) external oblique; (ii) internal oblique and + + + + + + + + + + + +Inferior epigastric artery + +Anterior superior iliac spine + +External oblique aponeurosis + +Inguinal ligament + +Superficial circumflex iliac artery + +Superficial epigastric artery + +Femoral artery and vein + +External pudenda! artery + +Superficial inguinal ring +with emerging round ligament, ilioinguinal and genitofemoral nerves + +Fig. 1.14: Anterior abdominal wall anatomy. +Chapter 1: Anatomy of Female Reproductive Organs ll'\ + +(iii) transversus abdominis. The longitudinal muscles +are-(a) rectus abdominis and (b) pyramidalis in the lower part. The external and internal oblique aponeuroses split and invest the rectus muscles and reunite in the midline to form linea alba. The transversus abdominis muscle forms the posterior wall of the rectus sheath up to midway between umbilicus and symphysis pubis. In the lower part, it forms a free margin with concavity downwards known as arcuate line. Thereafter it forms the anterior wall of the same sheath. +Blood supply: The skin, subcutaneous tissues of the anterior abdominal wall and the mons pubis are supplied by the superficial epigastric, superficial circumflex iliac and superficial external pudenda! artery. These are the branches arising from the femoral artery just below the inguinal ligament within the femoral triangle. These vessels are seen while making the low transverse incision. They run above the fascia Scarpa. These vessels are often ligated or coagulated during surgery. The deep epigastric (inferior epigastric) vessels are the branches of the external iliac vessels and arise just above the +inguinal ligament. It runs upwards and medially in the +extraperitoneal tissue (fascia transversalis) along the medial margin of the deep inguinal ring. Here it is hooked laterally by the round ligament of the uterus. It enters rectus sheath in front of the arcuate line and at the level + + +of umbilicus it anastomoses with the superior epigastric artery which is a branch of internal thoracic artery. Both supply the rectus muscles. +Inferior epigastric artery may be injured during rectus muscle transection. Clinically this vessel may be lacerated during cesarean section or hysterectomy or during rectus muscle transection. Rupture of this vessels may cause rectus sheath hematoma. +Hesselback triangle in this region is bounded laterally by the inferior epigastric vessels, medially by the lateral border of the rectus abdominis muscle and below by the inguinal ligament. Hernias in this triangle are termed direct inguinal hernia. Hernias through the deep inguinal ring are the indirect inguinal hernias. +Nerve supply: The entire abdominal wall is supplied by +the intercostal nerves (T -T11), subcostal nerve (T12) and the iliohypogastric and the ilioinguinal nerves (L1 . The space between the transversus abdominis and internal +7 +) +oblique muscle is used for postcesarean analgesia block as the nerves traverse in the plane. The ilioinguinal and the iliohypogastric nerves can be damaged during a transverse incision or entrapped during suturing the wound. Injury to these nerves causes loss of sensation within the areas supplied. There may be chronic pain also. +Analgesia for labor, vaginal birth and cesarean delivery are +discussed (Ch. 34). + +I + +Fundamentals of Reproduction + + + + + + + + + +❖ Gametogenesis ► Oogenesis +► Spermatogenesis ❖ Ovulation + + +❖ Fertilization ► Morula +► Blastocyst ❖ Implantation + + +► Trophoblast ❖ Decidua +❖ Chorion and Chorionic Villi +❖ Development of Inner Cell Mass + + + + +GAMETOGENESIS + +The process involved in the maturation of the two highly specialized cells, spermatozoon in male and ovum in female before they unite to form zygote, is called gametogenesis (Flowchart 2.1). + +I OOGENESIS + +The process involved in the development of a mature ovum is called oogenesis. The primitive germ cells take their origin from the yolk sac at about the end of 3rd week and their migration to the developing gonadal ridge is completed round about the end of 4th week. + + + +Flowchart 2.1: Scheme showing gametogenesis. + + +I OOGENESIS I Germ cells +!Mitosis +Oogonia +! +Primary oocyte +(46,XX) +! +Arrested first meiotic division +(up to puberty) +! +Maturation of Graafian follicle + +I SPERMATOGENESIS I Germ cells +!Mitosis +Spermatogonia +! +Primary spermatocyte (46,XY) +l +l + + +First meiotic division + +Secondary spermatocytes + + +Completion of first meiotic division +23,X 23, Y + + +Secondary oocyte 23,X + + +First polar body 23,X + + +Second meiotic division +! + + + +Ovulation + +23,X 23,X t t + +23, Y 23,Y t t + + + +Not fertilized Fertilized + +Degeneration Completion of second meiotic division within 24 hours +i +! + +Female pronucleus 23, X Second polar body 23, X + +Spermatids + + + +Morphological change to spermatozoa (spermiogenesis) +l +Chapter 2: Fundamentals of Reproduction ll +f +{ }{ + f! : +0 +-:)I:! + + + +Placental + + +--' -C _ _ Yolk sac + + + + + + + +Ect +Mes +Extraembryonic coelom + + + + -== villi +Embry o Amnion ]) Amnion Amniotic cavity + +· -- , -=== -------_ --s.== ·" Chorion + +!I + + + + + + + + + + + + +Figs. 2.9A to F: Schematic representation of formation of amniotic cavity, secondary yolk sac, extraembryonic coelom and body stalk: (A) Enlargement of extraembryonic coelomic cavity; (B) The amniotic sac enlarges and begins to occupy the extraembryonic coelom; (C) By the end of 12 weeks, the amniotic sac has surrounded the embryo with almost completely obliterating the extraembryonic coelom; formation of body stalk completed; (D) TVS showing well-defined gestational sac (GS) (5 weeks); (E) TVS showing yolk sac within the gestational sac (5.5 weeks); (F) TVS showing gestational sac, yolk sac and fetal pole (8 weeks). + + + +Table 2.1: Important events following fertilization. 'O' hour - Fertilization (day-15 from LMP). +30 hours - 2-cell stage (blastomeres). 40-50 hours - 4-cell stage. +72 hours - 12-cell stage. + +Chapter 2: Fundamentals of Reproduction ll + + +10-1 lth days - Trophoblasts invade endometrial sinusoids establishing uteroplacental circulation. +- Interstitial implantation completed with entire decidual coverage. + + + +96 hours 5th day +4-Sth days + + +- 16-cell stage. Morula enters the uterine cavity. +- Blastocyst. +- Zona pellucida disappears. + + +13th day 16th day +21st day + + +- Primary villi. +- Secondary villi. +- Tertiary villi. + +5-6th days - Blastocyst attachment to endometrial surface. 21st-22nd days- Fetal heart. Fetoplacental circulation. + +6-7th days +10th day + + +- Differentiation of cyto- and syncytiotrophoblastic layers. +- Synthesis of hCG by syncytiotrophoblast. + + +5.0 weeks +5.5 weeks + + +- EEC (gestational sac on USG). +- Yolk sac. + +9-lOth days - Lacunar network forms. 12th week - Obliteration of EEC (Figs. 2.9A to C). + + + +totally obliterated. The extraembryonic mesenchrne covering the amnion now fuses with the lining of the chorion. The single layer of fused amniochorion is now formed (Fig. 2.9C). +During the embryonic stage which extends from the fourth to eighth week, individual differentiation of the germ layers and formation of the folds of the embryo occur. Most of the tissues and organs are developed during this period, the details of which are beyond the description of this book. However, the major structures which are developed from the three germinal layers are mentioned below. The embryo can be differentiated as human at 8th week. +ECTODERMAL LAYER: Central and peripheral nervous system, epidermis of skin with its appendages, pituitary gland, chromaffin organs, salivary glands; mucus lining of the nasal cavity, paranasal sinus, roof of the mouth, etc. +MESODERMAL LAYER: Bones, cartilage, muscles, cardio­ vascular system, kidney, gonads, suprarenals, spleen, + +most of the genital tract; mesothelial lining of pericardia!, pleural and peritoneal cavity, etc. + +ENDODERMAL LAYER: Epithelial lining of the gastrointes­ tinal tract, liver, gallbladder, pancreas; epithelial lining of respiratory tract and most of the mucous membrane of urinary bladder and urethra; bulbourethral and greater vestibular glands, etc. + +Germ cell layers and their de"rivatives. +Ectoderm Mesoderm Endoderm +■ Epidermis ■ Muscles ■ GIT +■ Nervous system ■ Skeletal system ■ Respiratory tract ■ Connective tissues II Endocrine glands +■ Auditory system ■ Urinary system + + +Placenta and Fetal Membranes + + + + + + + + + +❖ Placenta +► Development +► Placenta at Term ► Structures + +❖ Placental Circulation ❖ Placental Aging +❖ Placental Function ❖ Fetal Membranes + + +❖ Amniotic Cavity and Amnion ❖ Amniotic Fluid +❖ Umbilical Cord + + + + +PLACENTA + +Only eutherian mammals possess the placenta. The human placenta is discoid, because of its shape; hemochorial, because of direct contact of the chorion with the maternal blood, labrynthine due to complex arrangement in the intervillous space and deciduate, because some maternal tissue is shed at parturition. The placenta is attached to the uterine wall and establishes connection between the mother and fetus through the umbilical cord. +II DEVELOPMENT + +The placenta is developed from two sources. The principal component is fetal which develops from the chorion frondosum and the maternal component consists of decidua basalis. +When the interstitial implantation is completed on 11th day, the blastocyst is surrounded on all sides by lacunar spaces around cords of syncytial cells, called trabeculae. From the trabeculae develops the stem villi + +on 13th day which connect the chorionic plate with the basal plate. Primary, secondary and tertiary villi are successively developed from the stem villi. Arterio­ capillary-venous system in the mesenchymal core of each villus is completed on 21st day. This ultimately makes connection with the intraembryonic vascular system through the body stalk (Fig. 2.9). +Simultaneously, lacunar spaces become confluent with one another and by 3rd-4th week, form a multilocular receptacle lined by syncytium and filled with maternal blood. This space becomes the future intervillous space. As the growth of the embryo proceeds, decidua capsularis becomes thinner beginning at 6th week. The villi and the lacunar spaces in the decidua capsularis get obliterated, converting the chorion into chorion laeve. This is, however, compensated by (a) exuberant growth and proliferation of the decidua basalis and (b) enormous and exuberant division and subdivision of the chorionic villi in the embryonic pole (chorion frondosum). These two, i.e., chorion frondosum and the decidua basalis form the discrete placenta. It begins at 6th week and is completed by 12th week (Figs. 3.IA to C). + + + +Uterine cavity + + + +Decidua parietalis + +r" + + +Amniotic cavity +Chorion frondosum + + + +r +Embryo + + + + +,, frondosum +s +Dec1dua basah Chorion + +" ! ' + +Fused decidua parietal is and , +capsularis , + + +' '' Placenta + +Yolk sac Amnion + +Chorion laeve +Decidua +Chorionic cavity capsularis +Amniotic cavi Chorion laeve !I +m +rJ +Figs. 3.1A to C: Relation of the amniotic cavity, chorionic cavity and uterine cavity of successive stages: {Al End of the 8th week; {Bl 1 O weeks after the last period; (Cl End of the 12th week. + + +Placenta plays an important role for the maternal physiological changes, transport of gases and nutrients and immunological acceptance of the fetus by the mother. Until the end of the 16th week, the placenta grows both in thickness and circumference due to growth of the chorionic villi with accompanying expansion of the intervillous space. Subsequently, there is little increase in thickness but it increases circumferentially till term. +The human hemochorial placenta derived its name from hemo {blood) that is in contact with the syncytiotrophoblasts of chorionic tissue {Figs. 3.3A and B). +I PLACENTA AT TERM + +GROSS ANATOMY: The placenta, at term, is almost a circular disk with a diameter of 15-20 cm and thickness of about 3 cm at its center. It thins off toward the edge. It feels spongy and weighs about 500 g, the proportion to the weight of the baby being roughly 1:6 at term and occupies about 30% of the uterine wall. It presents two surfaces, fetal and maternal, and a peripheral margin. +Fetal surface: The fetal surface (chorionic plate) covered by the smooth and glistening amnion with the umbilical cord attached at or near its center. Branches of the umbilical vessels are visible beneath the amnion as they radiate from the insertion of the cord {Figs. 3.2A and B). The amnion can be peeled off from the underlying chorion except at the insertion of the cord. At term, about four-fifths of the placenta is of fetal origin. +Maternal surface: The maternal surface (basal plate) is rough and spongy. Maternal blood gives it a dull red color. A thin grayish, somewhat shaggy layer which is the remnant of the decidua basalis ( compact and spongy layer) and has come away with the placenta, may be visible. The maternal surface is mapped out into 15-20 somewhat convex polygonal areas known as lobes or cotyledons which are limited by fissures. Each fissure is occupied by the decidual septum which is derived from the basal plate. + +Chapter 3: Placenta and Fetal Membranes + +Numerous small grayish spots are visible. These are due to deposition of calcium in the degenerated areas and are of no clinical significance. The maternal portion of the placenta amounts to less than one-fifth of the total placenta. Only the decidua basalis and the blood in the intervillous space are of maternal origin. +Margin: Peripheral margin of the placenta is limited by the fused basal and chorionic plates and is conti­ nuous with the chorion laeve and amnion. Essentially, the chorion and the placenta are one structure but the placenta is a specialized part of the chorion. +Attachment: The placenta is usually attached to the upper part of the body of the uterus encroaching to the fundus adjacent to the anterior or posterior wall with equal frequency. The attachment to the uterine wall is effective due to anchoring villi connecting the chorionic plate with the basal plate and also by the fused decidua capsularis and vera with the chorion laeve at the margin. +Separation: Placenta separates after the birth of the baby and the line of separation is through the decidua spongiosum. Figure 3.2C shows appearance of placenta on sonography. + +I STRUCTURES + +The placenta consists of two plates. The chorionic plate lies internally. It is lined by the amniotic membrane. The umbilical cord is attached to this plate. The basal plate lies to the maternal aspect. Between the two plates lies the intervillous space containing the stem villi with their branches, the space being filled with maternal blood {Figs. 3.3A and B). + +AMNIOTIC MEMBRANE: It consists of single layer of cubical epithelium loosely attached to the adjacent chorionic plate. It takes no part in formation of the placenta. +CHORION!( PLATE: From within outward, it consists of: {i) primitive mesenchymal tissue containing branches of umbilical vessels, (ii) a layer of cytotrophoblast and + + + + + + + + + + + + + + + +Figs. 3.2A to C: (A) Fetal surface of the placenta showing attachment of the umbilical cord with ramification of the umbilical vessels; (B) Maternal surface of the placenta showing shaggy look with cotyledons limited by fissures; (C) Ultrasonography showing placenta. +l9 Chapter 3: Placenta and Fetal Membranes +, + +(iii) syncytiotrophoblast. The stem villi arise from the plate. It forms the inner boundary of the choriodecidual space. +BASAL PLATE: It consists of the following structures from outside inwards. (1) Part of the compact and spongy layer of the decidua basalis; (2) Nitabuch's layer of fibrinoid degeneration of the outer syncytio­ tropho blast at the junction of the cytotrophoblastic shell and decidua; (3) Cytotrophoblastic shell; ( 4) Syncytiotrophoblast (Figs. 3.3 and 3.4). +The basal plate is perforated by the spiral branches of the uterine vessels through which the maternal blood flows into the intervillous space. At places, placental or decidual septa project from the basal plate into the intervillous space but fail to reach the chorionic plate. The septum consists of decidual elements covered by trophoblastic cells. The areas between the septa are known as cotyledons (lobes), which are observed from the maternal surface, numbering 15-20. + +INTERVILLOUS SPACE: It is bounded on the inner side by the chorionic plate and the outer side by the basal plate, limited on the periphery by the fusion of the two plates. It is lined internally on all sides by the syncytiotrophoblast and is filled with slow flowing maternal blood. Numerous branching villi which arise + +from the stem villi project into the space and constitute chief content of the intervillous space (Figs. 3.3A and 3.4). + +STEM VILLI: These arise from the chorionic plate and extend to the basal plate. With the progressive development-primary, secondary and tertiaiy villi are formed (Figs. 3.5A to C). Functional unit of the placenta is called a fetal cotyledon or placentome, which is derived from a major primary stem villus. These major stem villi pass down through the intervillous space to anchor onto the basal plate (Fig. 3.4). Functional subunit is called a lobule, which is derived from a tertiary stem villi. About 60 stem villi persist in human placenta. Thus, each cotyledon (total 15-29) contains 3-4 major stem villi. The villi are the functional unit of the placenta. The total villi surface, for exchange, approximately varies between 10 square meters and 14 square meters. The fetal capillary system within the villi is almost 50 km long. Thus while some of the villi are anchoring the placenta to the decidua, the majority are free within the intervillous space and are called nutritive villi. Blood vessels within the branching villi do not anastomose with the neighboring one. +Section through the placenta from inside to onwards are: (a) Amnion, (b) Chorionic (plate), (c) Chorionic villi + + + +Decidua basalis----------------, Tertiary stem villi----------:: +Uterine artery------:, +(spiral branches) + +Decidual plate + +-------- - - ---- lntervillous space +----------- Basal plate +------- Uterine vein + - -Syncytiotrophoblast + --- Placental septum + +Chorionic vessels + + + +,.. -- Spiral artery + + ) ''.'F""\' --- Cytotrophoblast + + +Basal plate +- +- + + + +Pnma Chononic plate mesoder + + + +mbilical vesicle + +Umbilical vein +Amniotic membrane + +Umbilical cord I I \ + + +Chorion laeve \" Uterine muscle +L + + +Decidua parietalis and capsularis fused + + + +Fetal membranes - · I Amnion +Mesodermal layer +. +I +--- Atrophied trophoblast L---..I---'--' Decidua capsularis +1 + --- Decidua parietalis + + + + +} Chorion laeve + +} Fused + +Figs. 3.3A and B: Schematic view of: (A) Structure of placenta at term; (BJ Structure of the membranes in relation to decidua. + + + + + +Outer cytotrophoblast shell +Syncytiotrophoblast + +lntervillous space + +Cytotrophoblast + +Mesoderm core with capillaries +¼ == :_ + +Chorionic plate + +Connecting stalk + +Fig. 3.4: Schematic diagram of stem villi, showing connection of the chorionic plate with the basal plate. + +Syncytiotrophoblast Mesoderm core + + + + + + + + +Figs. 3.SA to C: Schematic diagram to show the development of the villus: (Al Primary; (Bl Secondary; (Cl Tertiary. + +(d) Intervillous space, (e) Deciduas (basal plate) and (f) Myometrium. +STRUCTURE OF A TERMINAL VILLUS: In the early placenta, each terminal villus has got the following structures from outside inward: (1) Outer syncytiotrophoblast; (2) cytotrophoblast; (3) basement membrane; (4) central stroma containing fetal capillaries, primitive mesenchymal cells, connective tissue and a few phagocytic (Hofbauer) cells. +In placenta at term, syncytiotrophoblast becomes relatively thin at places overlying the fetal capillaries and thicker at other areas containing extensive endoplasmic reticulum. The former is probably the site for transfer and the latter, the site for synthesis. The cytotrophoblast is relatively sparse. Basement membrane becomes thicker. Stroma contains dilated vessels along with all the constituents and few Hofbauer cells. Hofbauer cells are round cells that are capable of phagocytosis and can trap maternal antibodies crossing through the placenta (immunosuppressive ). + +PLACENTAL CIRCULATION + +Placental circulation consists of independent circulation of blood in two systems: + +Chapter 3: Placenta and Fetal Membranes + +I. Uteroplacental circulation 2. Fetoplacental circulation +UTEROPLACENTAL CIRCULATION (maternal circulation): It is concerned with the circulation of the maternal blood through the intervillous space. A mature placenta has a volume of about 500 mL of blood; 350 mL being occupied in the villi system and 150 mL lying in the intervillous space. As the intervillous blood flow at term is estimated to be 500-600 mL per minute, the blood in the intervillous space is completely replaced about 3-4 times per minute. The villi depend on the maternal blood for their nutrition, thus it is possible for the chorionic villi to survive for a varying period even after the fetus is dead. The pressure within the intervillous space is about 10-15 mm Hg during uterine relaxation and 30-50 mm Hg during uterine contraction. In contrast, the fetal capillary pressure in the villi is 20'-40 mm Hg. +Arterial circulation: About 120-200 spiral arteries open into the intervillous space by piercing the basal plate randomly at numerous sites. Normally, there is cytotrophoblastic invasion into the spiral arteries initially up to the intradecidual portion within 12 weeks of pregnancy. With this invasion the endothelial lining of the spiral artery is replaced and the musculoelastic media is destroyed and replaced by fibrinoid material. There is a secondary invasion of trophoblast between 12 and 16 weeks extending up to radial arteries within the myometrium. Thus, spiral arteries are converted to large bore uteroplacental arteries. The net effect is funneling of the arteries which lowers the pressure of the blood to 70-80 mm Hg before it reaches the intervillous space. It thus increases the blood flow. +Trophoblast cells that do not take part in villous structure are known as Extravillous Trophoblast (EVT). EVT are of two types: (i) Endovascular that migrates down the lumen of the spiral arteries and replaces the endothelium (Fig. 3.6) and (ii) interstitial that invades as far as the inner third of the myometrium. Further invasion is limited by the NK cells to prevent morbid adhesion of placenta (placenta accreta). Defects in trophoblast invasion and failure to establish maternal circulation correctly leads to complications of pregnancy (PIH, IUGR). +Venous drainage: The venous blood of the intervillous space drains through the uterine veins which pierce the basal plate randomly like the arteries. This concept of uteroplacental circulation is based on the studies of Ramsey and coworkers (1963, 1966). Intervillous hemodynamics is mentioned in Table 3.1. +Circulation in the interuillous space: The arterial blood enters the space under pressure (Fig. 3.7). Lateral dispersion occurs, after it reaches the chorionic plate. Villi help in mixing and slowing of the blood flow. Mild stirring effect by the villi pulsation aided by uterine contraction +Chapter 3: Placenta and Fetal Membranes +- += +F +--+'- -c"C 2._ c, .( \ ;; }; ;-: + +Endovascular trophoblasts invading spiral artery + ii + + +, ;j ( ' + +',-(), Basal +- +t +: +-- artery +1:, !;! + + + + + :: +:: +. t,.j-.., · -ty< +'1•·'­ - l + ? +< + ? f + + + +Radial artery (media) +Nqriil:ll + + +' · - · - +; +I + + +. . + +IPrnseclampsia + + +Myometrium ] +Fig. 3.6: Spiral arterioles at the placental site in normal and pre-eclamptic pregnancies. + + +Table 3.1: Summary of intervillous hemodynamics. +a Volume of blood in mature placenta 500ml +a Volume of blood in intervillous space 150ml +• Blood flow in intervillous space 500-600 ml/min • Pressure in intervillous space: +• During uterine contraction 30-50 mm Hg +o During uterine relaxation 10-15mm Hg • Pressure in the supplying uterine artery 70-80 mmHg • Pressure in the draining uterine vein 8mmHg + +help migration of the blood toward the basal plate and thence to the uterine veins. Sometimes syncytial sprouts are set free in the intravillous circulation and are carried through the maternal circulation to the lungs where they disappear by lysis. About 100,000 syncytial sprouts circulate in maternal blood in 24 hours. + +Short circuit of the arterial blood into the neighboring venous channels is prevented by the increased pressure of the endometrial arteries driving the blood in jets towards the chorionic plate. During uterine contraction, the veins are occluded but the arterial blood is forced into the intervillous space; while uterine relaxation facilitates venous drainage. This is brought about by the fact that the spiral arteries are perpendicular and the veins are parallel to the uterine wall. Thus during contraction, larger volume of blood is available for exchange even though the rate of flow is decreased. The blood in the intervillous space is protected from clotting by some fibrinolytic enzyme activity of the trophoblast. + +FETOPLACENTAL CIRCULATION: The two umbilical arteries carry the impure blood from the fetus. They enter the chorionic plate underneath the amnion, + + + + + + + + + + + + + +pH : 7.3 +P02 : 40 mm Hg PC02: 40-50 mm Hg + + + +Maternal spiral artery p)H : 1.4 +Pq2 : 1:Q© mm fllg, POQ2.: 30-, 5 mm Hg +3 +. + +Fig. 3.7: An intervillous space showing intervillous circulation. +Chapter 3: Placenta and Fetal Membranes II +• + + + + + + +Cytotrophoblast + + + + + + + + + + + + + + +Fig. 3.8: Schematic diagram showing terminal capillary networks in the villi. + + +Table 3.2: Summary of fetal hemodynamics. +• +Fetal blood flow through the 400ml/min placenta +• Pressure in the umbilical artery 60mm Hg • Pressure in the umbilical vein l0mmHg +• Fetal capillary pressure in villi 20-40 mmHg +Umbilical Umbilical +artery vein +• 02 saturation 50-60% 70-80% +• +PO2 20-25 mmHg 30-40mmHg + +each supplying one half of the placenta. The arteries break up into small branches which enter the stems of the chorionic villi. Each in turn divides into primary, secondary and tertiary vessels of the corresponding villi. The blood flows into the corresponding venous channels either through the terminal capillary networks or through the shunts (Fig. 3.8). Maternal and fetal bloodstreams flow side by side, but in opposite direction. This countercurrent flow facilitates material exchange + +between the mother and fetus. The villous capillary pressure varies from 20 to 40 mm Hg. The fetal blood flow through the placenta is about 400 ml/min. This is mainly facilitated by the pumping action of the fetal heart (Table 3.2). +Each villous contains fetal capillaries those are the terminal branches of umbilical arteries. The villous capillary blood is separated from the maternal blood in the intervillous space by a thin blood-blood barrier. +Generally spiral arteries are perpendicular but veins are parallel to the uterine wall (Fig. 3.3). This helps closure of veins during uterine contraception and prevents the exit of maternal blood from the intervillous space. Serial sonography including Doppler velocimetry has shown that during contraction larger volume of blood is available for exchange even though the rate of flow is decreased. +PLACENTAL BARRIER (placental membrane): It is a partition between fetal and maternal circulation. However, this barrier is not a perfect barrier as fetal blood cells are found in maternal circulation so also the maternal blood cells are found in fetal circulation. The above two are separated by tissues called placental membrane or barrier, consisting of the following. In early pregnancy, it consists of (I) syncytiotrophoblast, (2) cytotrophoblast, (3) basement membrane, (4) stromal tissue, and (5) endothelium of the fetal capillary wall with its basement membrane. It is about 0.025 mm thick (Figs. 3.8 and 3.9). +Near term, there is attenuation of the syncytial layer. Sparse cytotrophoblast and distended fetal capillaries almost fill the villus. The specialized zones of the villi where the syncytiotrophoblast is thin and anuclear, is known as vasculosyncytial membrane (Figs. 3.IOA and B). These thin zones (0.002 mm) of terminal villi alpha zones are for gas exchange. The thick 'beta zones' of the terminal villi with the layers remaining thick in patches are for hormone synthesis. An increase in thickness of the villous membrane is seen in cases with IUGR, pregnancy with diabetes and cigarette smokers. + +PLACENTAL AGING +As the placenta has got a limited life span, it is likely to undergo degenerative changes as a mark of senescence. The aging process varies in degree and should be + + + +Basement membrane + + +Placental barrier + + +Endothelium and +basement membrane + +••••• • • • • • • -.,.•.•. · -- Maternal blood +,..,.,,_.,_"''"".."'"'"--'"'•-· - -.--------"'""'"'"-i-"'... --- Syncytiotrophoblast +• +:: +, +4.i,.. +,,\-,;.:-::;:;: ,..,. .,,, ,.,,-.,.,,,MT.,_,.,.. Cytotrophoblast +. +Connective tissue +stroma of villus +• •• •• I••• .. • • • ••-• •• • •: .. • ••-••_. -Fetal blood vessel Fig. 3.9: Schematic diagram showing layers of placental barrier. +• +• +• +• +• +• +• + +• +. +, +- +• +• +• +• +• +• +• +• +• +• +• +• +• +• +• +• +• +JI Chapter 3: Placenta and Fetal Membranes Mesodermal core +■ + +Cytotrophoblast Syncytiotrophoblast -- +-" +Capillaryr= + + + +Sparse +cytotrophoblast + +---- Thick syncytiotrophoblast +(synthesis area) + +Thin syncytiotrophoblast +(transfer area) +Fetal capillary + + + + +Fetal mesenchyme +" rn +Figs. 3.10A and B: Schematic diagram showing transverse section of a villus in: (A) Early month; (B) Near term. + + +differentiated from the morbid process likely to affect the organ in some pathological states. The aging process involves both the fetal and maternal components. +VILLI CHANGES: The following changes are observed as pregnancy advances toward term {Figs. 3.IOA and B). +(1) Decreasing thickness of the syncytium and appear­ ances of syncytial knots (aggregation of the syncytium in small areas on the sides of the villus); (2) Partial disap­ pearance of trophoblast cells; (3) Decrease in the stromal tissue including Hofbauer cells (fetal macrophages); (4) Obliteration of some vessels and marked dilatation of the capillaries; ( 5) Thickening of the basement layer of the fetal endothelium and the cytotrophoblast; (6) Deposition of fibrin on the surface of the villi. +DECIDUAL CHANGES: There is an area of fibrinoid degeneration where trophoblast cells (covered with syncytium) meet the decidua. This zone is known as Nitabuch's layer. This layer limits further invasion of the decidua by the trophoblast. The membrane is absent in placenta accreta. +INTERVILLOUS SPACE: The syncytium covering the villi and extending into the decidua of intervillous space undergoes fibrinoid degeneration and form a mass entangling vadable number of villi. These are called white infarcts which vary-in size from few millimeters to a centimeter or more. Calcification or even cyst formation may occur on it. Such type of degeneration is usually near the placental margin. There may be inconsistent deposition of fibrin called Rohr's stria at + + +the bottom of the intervillous space and surrounding the fastening villi. + +PLACENTAL FUNCTION + +Fetomaternal exchange of gases and nutrients occur by several mechanisms such as: diffusion, facilitated diffusion, active transport bulk flow, pinocytosis and leakage. +The main factors for placental transfer are (Table 3.3): +Transfer of nutrients and the metabolites between the mother and the fetus. Important functions are: +(A) Respiratory (B) Excretory (C) Nutritive +(D) Endocrine function: Placenta is an endocrine gland. It produces both steroid and peptide hormones to maintain pregnancy (p. 62). +(E) Barrier function (F) Immunological function. Mechanisms involved in the transfer of substances +across the placenta are {based on concentration +gradient-02, CO2): +(1) Bulk flow and solvent drag: Bulk flow of water along with dissolved solutes (water, dissolved electrolytes) occur through differences in hydrostatic and osmotic pressure; +(2) Simple diffusion (based on concentration gradient and/ or electrical gradient: 02, CO2); +(3) Facilitated diffusion (transporter mediated) using transporter proteins in syncytiotrophoblast (glucose, amino acids); + + + +Table 3.3: Factors for placental transfer from mother to fetus. +A. Substance properties +■ Molecular weight: Lower the molecular weight, more is the transfer. +• Lipid solubility: Lipophilic substances diffuse readily. +lipid membrane +freely. +I zation: Nonionized form crosses · c. Pl +oni acental properties + +■ pH of blood: Lower pH favors ionization of many drugs. ■ Protein binding +■ Spatial configuration + + +B. Maternal properties +• Drug concentration in the maternal blood. • Uterine blood flow. +♦ Concentration gradient on either side of placental membranes. + +♦ Lipid membrane of placenta enhances transfer. • Total surface area of placental membrane. +♦ Functional integrity and thickness of placental barrier (p. 31 ). + +(4) Active transfer (against concentration gradient, energy ATPase-mediated) (amino acids, large ions); +(5) Endocytosis (pinocytosis): Invagination of the cell +membrane to form an intracellular vesicle (pinocytosis) which contains the extracellular molecules (proteins, immunoglobulins); +(6) Exocytosis: Release of the molecule from within vesicle to the extracellular space. Immunoglobulin G (IgG) is taken up by endocytosis from maternal circulation and is transferred to the fetus via exocytosis; +(7) Leakage (break in the placental membranes maternal or fetal red blood cells). +Respiratory function: Although the fetal respiratory movements are observed as early as 11 weeks, there is no gaseous exchange. Intake of oxygen and output of carbon dioxide take place by simple diffusion across the fetal membrane. Partial pressure gradient is the driving force for exchange between the maternal and fetal circulations. The oxygen supply to the fetus is at the rate of 8 mL/kg/min and this is achieved with cord blood flow of 165-330 mL/min. +Excretory function: Waste products from the fetus such as urea, uric acid, and creatinine are excreted in the maternal blood by simple diffusion. +Nutritivefunction: The fetus obtains its nutrients from the maternal blood and when the diet is inadequate, then only depletion of maternal tissue storage occurs. +■ Glucose which is the principal source of energy is transferred to the fetus by facilitated diffusion. There are transporter proteins ( GLUT-1) for facilitated diffusion. GLUT-I is located in syncytiotrophoblast. Glucose transfer from mother to fetus is not linear. Transfer rates decrease as maternal glucose concen­ tration increases. Fetal glucose level is lower than that of the mother indicating rapid rate of fetal utilization of glucose. +■ Lipids for fetal growth and development are transferred across the fetal membrane or synthesized in the fetus. Triglycerides and fatty acids are directly transported from the mother to the fetus in early pregnancy but probably are synthesized in the fetus later in pregnancy. Essential fatty acids are transferred more than the non­ essential fatty acids. Cholesterol is capable of direct transfer. Thus, fetal fat has got a dual origin. +■ Amino acids are transferred by active transport (energy requiring transport) through enzymatic me hanism (ATPase). Amino acid concentration is higher in the fetal blood than in the maternal blood. Some proteins (IgG), cross by the process of endocytosis. Fetal proteins are synthesized from the transferred amino acids and the level is lower than in mother. +■ Water and electrolytes such as sodium, potassium and chloride cross through the fetal membrane by simple diffusion, whereas calcium, phosphorus and iron + +Chapter 3: Placenta and Fetal Membranes + +cross by active transport ( active transporter proteins) against a concentration gradient, since their levels are higher in fetal than in maternal blood. Water-soluble vitamins are transferred by active transport, but the fat-soluble vitamins are transferred slowly so that the latter remains at a low level in fetal blood. +■ Hormones-insulin, steroids from the adrenals, thyroid, chorionic gonadotropin or placental lactogen cross the placenta at a very slow rate, so that their concentration in fetal plasma are appreciably lower than in maternal plasma. Neither parathormone nor calcitonin crosses the placenta. +ENZYMATIC FUNCTION: Numerous enzymes are elabo­ rated in the placenta, mentioning only few of them are: (1) Diamine oxidase which inactivates the circulatory pressure (or pressor) amines, (2) oxytocinase which +neutralizes the oxytocin, (3) phospholipase A2 which +synthesizes arachidonic acid, etc. Placental endo­ crinology is discussed in Ch. 6. +BARRIER FUNCTION: Fetal membrane has long been considered as a protective barrier to the fetus against noxious agents circulating in the maternal blood. In general, substances of high molecular weight of more than 500 daltons are held up, but there are exceptions. Antibody and antigens in immunological quantities can traverse across the placental barrier in both directions. The transfer of the larger molecule is probably facilitated by pinocytosis. The rate of drug transfer is increased in late pregnancy. +Maternal infections during pregnancy by virus (rubella, chickenpox, measles, mumps, poliomyelitis), bacteria (Treponema pallidum, Tubercle bacillus) or protozoa (Toxoplasma gondii, malaria parasites) may be transmit­ ted to the fetus across the so-called placental barrier and affect the fetus in utero. Similarly, almost any drug used in pregnancy can cross the placental barrier and may have deleterious effect on the fetus. +IMMUNOLOGICAL FUNCTION (for details, p. 154, 588): The fetus and the placenta contain paternally determined antigens, which are foreign to the mother. In spite of this, there is no evidence of graft rejection. Placenta probably offers immunological protection against rejection. The exact mechanism is yet speculative, but the interest is centered on the following: +♦ Placental hormones, proteins (SPl), Early Pregnancy Factor (EpF), PAPP-A, steroids and chorionic gonadotropin have got some immunosuppressive effect. +♦ There is a shift of maternal response from cell-mediated (T helper 1) to humoral (T helper 2) immunity, which may be beneficial to pregnancy. +♦ Decidual Natural Killer (NK) cells and trophoblast (extravillous) HLA Class I molecules interact. The cytokines thus derived, will regulate the invasion of extravillous trophoblast cells into the spiral arteries. The spiral arteries +El Chapter 3: Placenta and Fetal Membranes +] + +are thus converted to low resistance, high conductance uteroplacental arteries (Fig. 3.6). +♦ The decidual NK cells and the extravillous interstitial trophoblast cells interact at the trophoblast myometrial junction. Excessive myometrial invasion of trophoblast cells is thus prevented. + +FETAL MEMBRANES + +It consists of two layers: outer chorion and the inner amnion. +CHORION: It represents the remnant of chorion laeve and ends at the margin of the placenta. It is thicker than amnion, friable and shaggy on both the sides. Internally, it is attached to the amnion by loose areolar tissue and remnant of primitive mesenchyme. Externally, it is covered by vestiges of trophoblastic layer and the decidual cells of the fused decidua capsularis and parietalis which can be distinguished microscopically {Fig. 3.3B). Therefore human placenta is a discoid, deciduate, labyrinthine and hemochorial type. +AMNION: It is the inner layer of the fetal membranes. Its internal surface is smooth and shiny and is in contact with liquor amnii. The lining epithelium is described later in this chapter. The outer surface consists of a layer of connective tissue and is apposed to the similar tissue on the inner aspect of the chorion from which it can be peeled off. The amnion can also be peeled off from the fetal surface of the placenta except at the insertion of the umbilical cord. +Functions: (1) Contribute to the formation of liquor amnii; (2) Intact membranes prevent ascending uterine infection; (3) Facilitate dilatation of the cervix during labor; ( 4) Has got enzymatic activities for steroid hormonal metabolism; (5) Rich source of glycerophospholipids containing arachidonic acid­ precursor of prostaglandin E2 and Fza. + +AMNIOTIC CAVITY AND AMNION +DEVELOPMENT: The formation of the amniotic cavity and the amnion has already been described (p. 24). Fluid accumulates slowly at first, but ultimately the fluid-filled cavity becomes large enough to obliterate the chorionic cavity; the amnion and the chorion come in loose contact by their mesenchymal layers (Table 3.4). + + +Production +11 Transudation of maternal serum across the placental membranes. + + +Initially, the cavity is located on the dorsal surface of the embryonic disk. With the formation of the head, tail and lateral folds, it comes to surround the fetus in a manner as described in Figure 2.9. Its two growing margins finally merge into the body stalk. Thus, the liquor amnii surrounds the fetus everywhere except at its attachment with the body stalk. The amnion is firmly attached to the umbilical cord up to its point of insertion to the placenta, but everywhere it can be separated from the underlying chorion. + +STRUCTURE OF AMNION: Fully formed amnion is 0.02-0.5 mm in thickness and from within outwards the layers are-(1) single layer of cuboidal epithelium, (2) basement membranes, (3) compact layer of reticular structure, (4) fibroblastic layer and (5) spongy layer. The amnion has got neither blood nor nerve supply nor any lymphatic system. + +AMNIOTIC FLUID +ORIGIN OF AMNIOTIC FLUID: The precise origin of the liquor amnii is still not well understood. It is probably of mixed maternal and fetal origin. +CIRCULATION: The water in the amniotic fluid is completely changed and replaced in every 3 hours as shown by the clearance of radioactive sodium injected directly into the amniotic cavity. The presence of lanugo and epithelial scales in the meconium shows that the fluid is swallowed by the fetus and some of it passes from the gut into the fetal plasma {Flowchart 3.1). +VOLUME: Amniotic fluid volume is related to gesta­ tional age. It measures about 50 mL at 12 weeks, 400 mL at 20 weeks and reaches its peak of 1 liter at 36-38 weeks. Thereafter the amount diminishes, till at term it measures about 600-800 mL. As the pregnancy continues post-term, further reduction occurs to the extent of about 200 mL at 43 weeks. +PHYSICAL FEATURES: The fluid is faintly alkaline with low specific gravity of 1.010. It becomes highly hypotonic to maternal serum at term pregnancy. An osmolarity of 250 mOsmol/L is suggestive of fetal maturity. The amniotic fluid's osmolality falls with advancing gestation. Color: In early pregnancy it is colorless, but near term it becomes pale straw colored due to the presence + + +Removai +♦ Fetus swallows about 500-1,000 ml of + + + +11 Transudation from fetal circulation across the umbilical cord or placental membranes. 11 Secretion from amniotic epithelium. +• Transudation of fetal plasma through the highly permeable fetal skin before it is keratinized at 20th week. +• Fetal urine-daily output at term is about 400-1,200 ml. +• Fetal lung that enters the amniotic cavity add to its volume. + + +liquor everyday. +♦ lntramembranous absorption of water and solutes (200-500 ml/day) from the amniotic compartment to fetal circulation through +the fetal surface of the placenta. +Chapter 3: Placenta and Fetal Membranes + +Flowchart 3.1: The source and circulation of amniotic fluid. + +I MATERNAL CIRCULATION I - +C +.Q +il I Placenta I I +"O +I +I +t= :, +/) +- +0 +C C +1l 0 +.Q:; +E e- +Q) 0 +E _2 +c + + 1l + +I + + +Amniotic epithelium (placenta) +l +l + + +Secretion + + +AMNIOTIC FLUID I /) +! +! +l +"O +:, +0 +1l 0 + +·- +E e- +Q) Cl /J :, C C +E +Cl +·- _J C :, +- +.2 +Q) 0 +ro +£ "" +fi E 0 .0 - +ti ;: g> Q) 0 +- +l +X +w +:, ') ;: >, 0 E-2 f) .0 + 1l +:s +l + +FETAL CIRCULATION I +I + + + + + + +I Fetal skin +7 +Fetal urine (600-1200 ml) + + + + + +of exfoliated lanugo and epidermal cells from the fetal skin. It may look turbid due to the presence of vernix caseosa. +Abnormal color: Deviation of the normal color of the liquor has got clinical significance. +♦ Meconium stained (green) is suggestive of fetal distress in presentations other than the breech or transverse. Depending upon the degree and duration of the distress, it may be thin or thick or pea soup ( thick with flakes). +♦ Golden color in Rh incompatibility is due to excessive hemolysis of the fetal RBC and production of excess bilirubin. +♦ Greenish yellow (saffron) in postmaturity. +♦ Dark colored in concealed accidental hemorrhage is due to contamination of blood. +♦ Dark brown (tobacco juice) amniotic fluid is found in IUD. The dark color is due to frequent presence of old HbA. +COMPOSITION: In the first half of pregnancy, the compo­ sition of the fluid is almost identical to a transudate of plasma. But in late pregnancy, the composition is very much altered mainly due to contamination of fetal urinary metabolites. The composition includes-(!) water 98-99% and (2) solid (1-2%). The following are the solid +constituents: + +(a) Organic: +Protein-0.3mg% NPN-30mg% Total lipids-SO mg% +Glucose-20mg% Uric acid-4 mg% Hormones (prolactin, insulin and renin) +Urea-30mg% Creatinine-2 mg% + +(b) Inorganic: The concentration of the sodium, chloride and potassium is almost the same as that found in maternal blood. As pregnancy advances, there may be slight fall in the sodium and chloride concentration probably due to dilution by hypotonic fetal urine, whereas the potassium concentration remains unaltered. +(c) Suspended particles include: Lanugo, exfoliated squamous epithelial cells from the fetal skin, vernix + +caseosa, cast off amniotic cells and cells from the respiratory tract, urinary bladder and vagina of the fetus. + +FUNCTION: Its main function is to protect the fetus. +During pregnancy: (I) It acts as a shock absorber, protecting the fetus from possible extraneous injury; (2) Maintains an even temperature; (3) The fluid distends the amniotic sac and thereby allows for growth and free movement of the fetus and prevents adhesion between the fetal parts and amniotic sac; (4) Its nutritive value is negligible because of small amount of protein and salt content; however, water supply to the fetus is quite adequate. +During labor: (I) The amnion and chorion are combined to form a hydrostatic wedge which helps in dilatation of the cervix; (2) During uterine contraction, it prevents marked interference with the placental circulation so long as the membranes remain intact; (3) It guards against umbilical cord compression; (4) It flushes the birth canal at the end of first stage of labor and by its aseptic and bactericidal action protects the fetus and prevents ascending infection to the uterine cavity. +CLINICAL IMPORTANCE: (I) Study of the amniotic fluid provides useful information about the well-being and also maturity of the fetus; (2) Intra-amniotic instillation of chemicals is used as method of induction of abortion; +(3) Excess or less volume of liquor amnii is assessed by amniotic fluid index (AFI) (Fig. 3.ll) (p. 205, 436). +Maternal abdomen is divided into quadrants taking the umbilicus, symphysis pubis and the fundus as the reference points. With ultrasound, the largest vertical pocket in each quadrant is measured. The sum of the four measurements (cm) is the AFI. It is measured to +diagnose the clinical condition of polyhydramnios or oligohydramnios respectively; (4) Rupture of the membranes with drainage of liquor is a helpful method in induction of labor (p. 490). +Chapter 3: Placenta and Fetal Membranes + + + + + + + + + + + + + + + + +Fig. 3.11: Amniotic fluid volume is measured to determine AF!. + +UMBILICAL CORD + +The umbilical cord or funis forms the connecting link between the fetus and the placenta through which the fetal blood flows to and from the placenta. It extends from the fetal umbilicus to the fetal surface of the placenta. +DEVELOPMENT: The umbilical cord is developed from the connective stalk or body stalk, which is a band of mesoblastic tissue stretching between the embryonic disk and the chorion. Initially, it is attached to the caudal end of the embryonic disk, but as a result of cephalocaudal folding of the embryo and simultaneous enlargement of the amniotic cavity the amnioectodermal junction converges on the ventral aspect of the fetus. As the amniotic cavity enlarges out of proportion to the embryo and becomes distended with fluid, the embryo is carried more and more into the amniotic cavity with simultaneous elongation of the connective stalk, the future umbilical cord. +STRUCTURES: The constituents of the umbilical cord when fully formed are as follows {Figs. 3.12A and B). +1. Covering epithelium: It is lined by a single layer of amniotic epithelium but shows stratification like that of fetal epidermis at term. +2. Wharton's jelly: It consists of elongated cells in a gelatinous fluid formed by mucoid degeneration of + + +the extraembryonic mesodermal cells. It is rich in mucopolysaccharides and has got protective function to the umbilical vessels. +3. Blood vessels: Initially, there are four vessels-two arteries and two veins. The arteries are derived from the internal iliac arteries of the fetus and carry the venous blood from the fetus to the placenta. Of the two umbilical veins, the right one disappears by the 4th month, leaving behind one vein which carries oxygenated blood from the placenta to the fetus. Presence of a single umbilical artery is often associated with fetal congenital abnormalities {p. 208). +4. Remnant of the umbilical vesicle (yolk sac) and its vitelline duct: Remnant of the yolk sac may be found as a small yellow body near the attachment of the cord to the placenta or on rare occasion, the proximal part of the duct persists as Meckel's diverticulum. +5. Allantois: A blind tubular structure may be occasi­ onally present near the fetal end which is continuous inside the fetus with its urachus and bladder. +6. Obliterated extraembryonic coelom: In the early period, intraembryonic coelom is continuous with extraembryonic coelom along with herniation of coils of intestine (midgut). The condition may persist as congenital umbilical hernia or exomphalos. +CHARACTERISTICS: It is about 40 cm in length with a usual variation of 30-100 cm. Its diameter is of average 1.5 cm with variation of 1-2.5 cm. Its thickness is not uniform but presents nodes or swelling at places. These swellings (false knots) may be due to kinking of the umbilical vessels or local collection of Wharton's jelly. True knots (1 %) are rare. Long cord may form loop around the neck (20-30%). It shows a spiral twist from the left to right from as early as 12th week due to spiral turn taken by the vessels-vein around the arteries. The umbilical arteries do not possess an internal elastic lamina but have got well-developed muscular coat. These help in effective closure of the arteries due to reflex spasm soon after the birth of the baby. Both the arteries and the vein do not possess vasa vasorum. + +ATTACHMENT: In the early period, the cord is attached to the ventral surface of the embryo close to the caudal + + + +Umbilical arteries +Intestinal loop +Chorion + + + +Primitive umbilical ring + +Abdominal wall of embryo + +Whartoo's jelly +( , , +Umbilical vein +11 + +Figs. 3.12A and B: Schematic drawing of the primitive umbilical cord of: (Al 10-week embryo; (Bl Cross-section of a term umbilical cord. + + +extremity, but as the coelom closes and the yolk sac atrophies the point of attachment is moved permanently to the center of the abdomen at 4th month. Unlike the fetal attachment, the placental attachment is inconsistent. It usually attaches to the fetal surface of the placenta +somewhere between the center and the edge of the + +Chapter 3: Placenta and Fetal Membranes + +placenta, called eccentric insertion. The attachment may be central, marginal or even on the chorion laeve at a varying distance away from the margin of the placenta, called velamentous insertion. The anomalies and various abnormalities of the umbilical cord are discussed in Ch. 17 +(p. 208). + + + + + +► Human placenta is a discoid (disk-shaped), deciduate (covered externally by decidual cells), labyrinthine (hugely branched villous tree) and hemochorial (maternal and fetal blood are separated by the chorionic tissue) type. +► The placenta at term has a diameter of 15-20 cm with two surfaces. Fetal surface appears smooth and glistening as it is covered with amnion. The maternal surface is rough, shaggy and is marked by cotyledons. +► lntervillous Space (IVS) is bounded internally by the chorionic plate and externally by the basal plate. The space is lined by syncytiotrophoblasts. IVS is filled with maternal blood (Figs. 3.3 and_3.4). +► Decidual septa are the projections from the basal plate within the IVS. The areas between the septa are called cotyledons (Figs. 3.3A and 3.7). +► Placental circulation includes: (a) uteroplacental (maternal blood reaching the IVS through the spiral arterioles) and (bl fetoplacental (following exchange, oxygenated blood is carried away by the umbilical vein). The blood flow in the IVS is 500-600 ml/min (Table 3.1 ). +► Placental barrier consists of the following layers: (a) syncytiotrophoblasts, (b) cytotrophoblasts, (c) basement membrane, (d) stromal tissue and (e) endothelium of fetal capillaries (Figs. 3.9 and 3.10A and BJ. It is about 0.025 mm thick and at term it is thinned out to 0.002 mm. +► Trophoblast proliferation, invasion and placental angiogenesis are dependent on oxygen mediation. +► Trophoblast cells, not covering the villous structure are the Extravillous Trophoblasts (EVT). EVT are of two types: (a) endovascular and (b) interstitial (Fig. 3.6). +► Failure of invasion of extravascular trophoblasts results in pregnancy complications like pre-eclampsia and FGR. +► Important factors for placental transfer are: (a) substrate properties, (b) maternal factors, and (c) placental factors (Table 3.3). +► Any molecule for transfer from maternal to fetal plasma and the vice-versa must cross the placental barrier. Basic exchange processes are: Bulk flow and solvent drag, diffusion, transporter mediated mechanism (GLUT-1 for glucose), endocytosis or exocytosis. +► Placental functions are mainly grouped into: Nutritive, respiratory, excretory, endocrine, protective barrier and immunological. +► Human placenta is an important endocrine organ for optimizing maternal physiology and fetal growth. Important hormones produced are: Estrogen, progesterone, PAPP-A, hCG and hPL. +► Amniotic fluid is in continuous circulation through amniotic epithelium secretion and fetal urine production and fluid absorption by the membranes (amnion and chorion) and by fetal swallowing. It is replaced in every 3 hours. +► Amount of amniotic fluid at term is 600-800 ml and it surrounds the fetus. Functions of amniotic fluid in pregnancy and labor are many. Amniotic fluid index (AFI) is an important parameter for assessment of fetal wellbeing. +► Umbilical cord develops from the body stalk connecting the embryonic disk and the chorion. Umbilical cord measures about 40 cm, contains two arteries and one vein. It is usually inserted to the placenta eccentrically, though other attachments are there. Single umbilical artery is associated with fetal congenital malformations. + + +The Fetus + + + + + + + + +, - CHAPTER OUTLINE +❖ Fetal Physiology ❖ Fetal Circulation + + +► Changes in the Fetal Circulation at Birth + + + + +Four periods are distinguished in the prenatal develo­ pment of the fetus (Table 4.1). +■ Gestational age (menstrual age) is the duration of pregnancy since the first day of Last Menstrual Period (LMP). This period starts 2 weeks before ovulation and fertilization. +■ Ovulation age (postconceptional age) is the period expressed in weeks or days since the day of ovulation (Ch. 2). +■ Embryonic period begins on the 3rd week (following ovulation and fertilization) and extends up to 8 weeks postconception. +■ Fetal period begins after the 8th week following conception and ends with delivery. +The chronology in the fetal period is expressed in terms of gestational (menstrual) age and not in embryonic age. +LENGTH OF THE FETUS: To determine the length of the fetus, the measurement is commonly taken from the vertex to the coccyx (crown-rump length) in earlier weeks. While, from the end of 20th week onwards, the + +measurement is taken from the vertex to the heel (crown­ heel length). +AGE OF THE FETUS: Gestational age is the duration of pregnancy calculated from the first day of Last Menstrual Period (LMP). +■ First trimester Transvaginal Ultrasonography (TVS) is the most accurate method to calculate the gestational age. Conception following Assisted Reproductive Technology (ART) should follow this method. +■ The crown-rump length measured in the first trimester is most accurate for calculation of gestational age (variability± 5 days). +GROWTH OF THE FETUS: Normal fetal growth is charac­ terized by cellular hyperplasia followed by hyperplasia and hypertrophy and lastly by hypertrophy alone. The fetal growth increases linearly until 37th week. It is controlled by genetic factor in the first half and by environmental factors in the second half of pregnancy. Imprinted genes (maternal or paternally acquired alleles) primarily control fetal growth. The important physiological factors are: Race (European babies are heavier than Indians); sex (male + + + +Table 4.1: Principal events of embryonic and fetal development. + +Days 14-21 postconception Days 21-28 postconception +Weeks 4-6 postconception (4-15 mm embryo) +Weeks 6-8 postconception (15-30 mm embryo) +Weeks 8-12 postconception (30-60 mm embryo) +Weeks-20 (gestational age) Weeks-28 (gestational age) Weeks-36 (gestational age) +Weeks-40 (gestational age) + +Notochord develops. Ectoderm thickens to form neural plate and neural folds. +Neural folds fuse to form neural tube, four primitive cardiac chambers, first heart beats on D-21. +Optic vesicles appear, complete neural tube closure (D-30) limb buds appear. Formation of face. Cardiac motion seen on ultrasonography. +All major structures form, complete ventricular septum (D-46), recognizably human. + +Fetus makes spontaneous movements, external genitalia develops. + +Skin is covered with lanugo. Vernix caseosa is present. Testes descend to the internal inguinal ring. Baby is viable. +One testicle usually descends into the scrotum. Lanugo tends to disappear. +Both the testicles descend into the scrotum. Nails project beyond the finger tips. Posterior fontanel is closed. + + +baby weighs >female); parental height and weight (tall and heavier mother have heavier babies); birth order (weight rises from first to second pregnancy) and socioeconomic factors (heavier babies in social class I and II). Fetal growth is predominantly controlled by IGF-1, insulin and other growth factors. Growth hormone is essential for postnatal growth. At term, the average fetal weight in India varies from 2.5 to 3.5 kg. Pathological factors affect it adversely (p. 435). + +FETAL PHYSIOLOGY + +NUTRITION: There are three stages of fetal nutrition follow­ ing fertilization: +(1) Absorption: In the early postfertilization period, nutrition is used from the stored cytoplasm and the yolk. The very little extra nutrition that needed is supplied from the tubal and uterine secretion. +(2) Histotrophic transfer: Following nidation and before the establishment of uteroplacental circulation, nutrition is. derived from eroded decidua by diffusion and later on from the stagnant maternal blood in the trophoblastic lacunae. +(3) Placental circulation: With interstitial implan­ tation by D-11 the blastocyst gets nutrition from the lacunar spaces. Subsequently arteriocapillary venous +system (uteroplacental) circulation is completed by 21st day. +( 4) Hematotrophic: With the establishment of the fetal circulation, nutrition is obtained by active and passive transfer from the 3rd week onwards. +The fetus is a separated physiological entity and it takes what it needs from the mother even at the cost of reducing her resources. Two-thirds of the total calcium, three-fifths of the total proteins and four-fifths of the total iron are drained from the mother during the last 3 months. Thus, in preterm births, the store of the essential nutrients to the fetus is much low. +FETAL BLOOD: Hematopoiesis is demonstrated in the embryonic phase first in the yolk sac by 14th day. By 10th week, the liver becomes the major site. The great enlargement of the early fetal liver is due to its erythropoietic function. Gradually, the red cell production sites extend to the spleen and bone marrow and near term, the bone marrow becomes the major site of red cell production. +Fetal erythropoiesis is controlled by fetal erythropoietin as maternal erythropoietin does not cross the placenta. In the early period, the erythropoiesis is megaloblastic but near term it becomes normoblastic. The fetal blood picture at term shows RBC 5-6 million/mm3; Hb = 16.5-18.5 g%, reticulocytes-5% and erythroblast-10%. During the first half, the hemoglobin is of fetal type (a-2, y-2) but from 24 weeks onwards, adult type of hemoglobin + +Chapter 4: The Fetus + +(a-2, -2) appears and at term about 75-80% of the total hemoglobin is of fetal type (HbF). Between 5 and 8 weeks, the embryo manufactures some additional hemoglobin: Hb Gower 1 (1;- and i;-chains), Hb Gower 2 (a- ands-chains) and Hb Portland (1;- and y-chains). Fetal blood produced in the yolk sac has hemoglobins Gower 1, Gower 2 and Portland. Then HbF is produced from the liver. Subsequently HbA appears when hemopoiesis moves to finally to bone marrow. Between 6 and 12 months after birth, the fetal hemoglobin is completely replaced by adult hemoglobin. The fetal hemoglobin has got a greater affinity to oxygen due to lower binding of 2, 3-diphosphoglycerate compared to adult hemoglobin. It is also resistant to alkali in the formation of alkaline hematin. Fetal metabolism is aerobic with +arterial blood PO2 of 25-35 mm Hg. There is no metabolic acidosis. Total fetoplacental blood volume at term is +estimated to be 125 mL/kg body weight of the fetus. The red cells develop their group antigen quite early and the presence of Rh factor has been demonstrated in the fetal blood from as early as 38 days after conception. The life span of the fetal RBC is about two-thirds of the adult RBC, i.e., about 80 days. The activities of all glycolytic enzymes in fetal erythrocytes except phosphofructokinase and 6-phosphogluconate dehydrogenase are higher than those of adults or term or premature infants. +Cord blood level of iron, ferritin, vitamin B12 and folic acid is consistently higher than maternal blood. + +LEUKOCYTES AND FETAL DEFENCE: Leukocytes appear after 2 months of gestation. The white cell count rises to about 15-20 thousand/mm3 at term. Thymus and spleen soon develop and produce lymphocytes, a major source of antibody formation. The fetus, however, rarely forms antibody because of relatively sterile environment. Maternal Immunoglobulin G (lgG) crosses the placenta from 12th week onwards to give the fetus a passive immunity which increases with the increase in gestation period. At term fetal IgG level is 10% higher than the mother. +IgM is predominantly of fetal origin and its detection by cordocentesis may be helpful in diagnosis of intrauterine infection. IgA is produced only after birth in response to antigens of enteric infection. +URINARY SYSTEM: By the end of the first trimester, the nephrons (metanephric kidney) become active and secrete urine. Urinary Stem: At 14 weeks, loop of Henle is functional. Near term, the urine production rises to 650 mL/day. However, kidneys are not essential for survival of the fetus in utero but are important in regulation of the composition and volume of the liquor amnii. Oligohydramnios may be associated with renal hypoplasia or obstructive uropathy. +SKIN: At 16th week, lanugo (downy thin colorless hairs) appears but near term almost completely disappears. +-JI Chapter 4: The Fetus + +Sebaceous glands appear at 20th week and the sweat glands somewhat later. Vernix caseosa-the secretion of the sebaceous glands mixed with the exfoliated epidermal cells is abundantly present smearing the skin. The horny layer of the epidermis is absent before 20th week which favors transudation from the fetal capillaries into the liquor amnii. +GASTROINTESTINAL TRACT: As early as 10-12 week, the fetus swallows amniotic fluid. Digestive system: A term fetus shallows around 500 mL of amniotic fluid per day. The meconium appears from 20th week and at term, it is distributed uniformly throughout the gut up to the rectum indicating the presence of intestinal peristalsis. In intrau­ terine hypoxia (vagal stimulation), the anal sphincter is relaxed and the meconium may be voided into the liquor amnii. +Composition of the meconium: It is chiefly composed of the waste products of the hepatic secretion. It contains lanugo, hairs and epithelial cells from the fetal skin which are swallowed with the liquor amnii. Mucus, exfoliated intestinal epithelium and intestinal juices are added to the content. The greenish black color is due to the bile pigments, especially biliverdin. Meconium is toxic to the respiratory system. It causes meconium aspiration syndrome. + +RESPIRATORY SYSTEM: In the early months, the lungs are solid. At 28th week, alveoli expand and are lined by cuboidal epithelium. There is intimate contact with the endothelium of the capillaries. At 24th week, lung surfactant related to phospholipids-phosphatidyl­ +choline {lecithin-90%) and phosphatidylglycerol {10%) appear. Surfactant is secreted by type-II +pneumocytes. These substances lower the surface tension of the lung fluid so that the alveoli can be opened up easily when breathing starts following delivery. A lecithin:sphingomyelin {L:S) ratio of 2:1 in the liquor amnii signifies full maturity of the fetal lung. Fetal cortisol is the natural trigger for augmented surfactant synthesis. Fetal growth restriction and prolonged rupture of membranes also accentuates surfactant synthesis. +Antenatal maternal therapy with betamethasone or dexamethasone improves fetal lung maturation (p. 303). +Breathing movements are identified by 11 weeks but are irregular until 20th week. Their frequency varies from 30 to 70 per minute and is dependent on the maternal blood sugar concentration. Hypoxia and maternal cigarette smoking reduces FBM while hyperglycemia increases it. The tracheobronchial tree is filled up with liquor amnii. + +FETAL ENDOCRINOLOGY: Growth hormone, ACTH, pro­ lactin, TSH and gonadotropic hormones are produced by the fetal pituitary as early as the 10th week. Vasopressor and oxytocic activity of the posterior pituitary + +have also been demonstrated as early as 12 weeks. Fetal adrenals show hypertrophy of the reticular zone (fetal zone) which is the site of synthesis of estriol precursor, cortisol and dehydroepiandrosterone. This fetal zone is absent in anencephaly. The adrenal medulla +produces small amount of catecholamines. Fetal thyroid starts synthesizing small amount of thyroxine by 11th week. While the fetal ovaries remain inactive, the fetal testicles mediate the development of the male reprodu­ +ctive structures. Fetal pancreas secretes insulin as early as 12th week and glucagon by 8 weeks. + +FETAL CENTRAL NERVOUS SYSTEM (CNS): Fetal body movements, heart rate accelerations and breathing move­ ments reflect functions of fetal CNS. In the later months of pregnancy, fetal activity periods are noted as: (a) reac­ tive, and {b) quiet (non-reactive) period (p. 97). Fetus remains in the active state in about 70% of the time and the quiet period ranges from 15 to 25 minutes. Hypoxemia decreases fetal breathing activity. + +FETAL CIRCULATION + +The umbilical vein carrying the oxygenated blood (80% saturated) from the placenta, enters the fetus at the umbilicus and runs along the free margin of the falciform ligament of the liver. In the liver, it gives off branches to the left lobe of the liver and receives the deoxygenated blood from the portal vein. The greater portion of the oxygenated blood, mixed with some portal venous blood, short circuits the liver through the ductus venosus to enter the Inferior Vena Cava (IVC) and thence to right +atrium of the heart. The 02 content of this mixed blood +is thus reduced. Although both the ductus venosus and hepatic portal/fetal trunk bloods enter the right atrium through the NC, there is little mixing. The terminal part of the NC receives blood from the right hepatic vein. +In the right atrium, most of the well oxygenated (75%) ductus venosus blood is preferentially directed into the foramen ovale by the valve of the NC and crista dividens and passes into the left atrium. Here it is mixed with small amount of venous blood returning from the lungs through the pulmonary veins. This left atrial blood is passed on through the mitral opening into the left ventricle. +Remaining lesser amount of blood (25%), after reaching the right atrium via the superior and inferior vena cava ( carrying the venous blood from the cephalic and caudal parts of the fetus respectively) passes through the tricuspid opening into the right ventricle {Fig. 4.1). The right ventricle blood is 15-20% less saturated with oxygen, compared to the left ventricle. +During ventricular systole, the left ventricular blood is pumped into the ascending and arch of aorta and distributed by their branches to the heart, head, neck, brain and arms. The right ventricular blood with low +Chapter 4: The Fetus 11 Ductus arteriosus + + + + + + +Pulmonary vein ___.___=-.. +Superior vena cava --+ ii-'---\\. + + + +, I +Pulmonary artery + + +_, _____ Left ventricle +_ + + + ------ -- Aorta + ,-:aa:----- Ductus venosus + + + + + + + + + + + + + + +Fig. 4.1: Fetal circulation. Note: Numbers inside the circle indicate the percentage saturation of Or + + +oxygen content is discharged into the pulmonary trunk. Since the resistance in the pulmonary arteries during fetal life is very high, the main portion (90%) of the blood passes directly through the ductus arteriosus into the descending aorta bypassing the lungs where it mixes with the blood from the proximal aorta. About 70% of the cardiac output (60% from right and 10% from left ventricle) is carried by the ductus arteriosus to the descending aorta. About 40% of the combined output goes to the placenta through the umbilical arteries. The deoxygenated blood leaves the body by way of two umbilical arteries to reach the placenta where it is oxygenated and gets ready for recirculation. The mean cardiac output is comparatively high in fetus and is estimated to be 350mL/kg/min. + +CHANGES IN THE FETAL CIRCULATION AT BIRTH +I + +The hemodynamics of the fetal circulation undergoes profound changes soon after birth (Fig. 4.2) due to­ (1) cessation ofthe placental blood flow and (2) initiation + +of respiration. The following changes occur in the vascular system (Fig. 4.2): +1. Closure of the umbilical arteries: Functional closure is almost instantaneous preventing even slight amount of the fetal blood to drain out. Actual obliteration takes about 2-3 months. The distal parts form the lateral umbilical liga­ ments and the proximal parts remain open as superior vesical arteries. +2. Closure of the umbilical vein: The obliteration occurs a little later than the arteries, allowing few extra volume of blood (80-100 mL) to be received by the fetus from the placenta. The ductus venosus collapses and the venous pressure of the IVC falls and so also the right atrial pressure. After obliteration, the umbilical vein forms the ligamentum teres and the ductus venosus becomes ligamentum venosum (Fig. 4.2). +3. Closure of the ductus arteriosus: Within few hours of respiration, the muscle wall of the ductus arteriosus contracts probably in response to rising oxygen tension of the blood flowing +through the duct. The effects of variation of the 02 tension on ductus arteriosus are thought to be mediated through the action +of prostaglandins. Prostaglandin antagonists given to the mother may lead to the premature closure of the ductus arteriosus. Whereas functional closure of the ductus may occur soon after the establishment of pulmonary circulation, the anatomical +Chapter 4: The Fetus + +Arch of aorta- - - - - - - ------- Ligamentum arteriosum + + + + + + + + + +Right atrium + + \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_20.txt b/notes/DC Dutta Obstetrics 10th Edition_20.txt new file mode 100644 index 0000000000000000000000000000000000000000..f68fbdad1c6c0d42a6bd3c2a4532e44070fad7c2 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_20.txt @@ -0,0 +1,2008 @@ +Epidural analgesia 263,271,378,482, 483f, 486 +complications of 483 contraindications of 483 +Epidural anesthesia 225,256,263, 264,271, 279, 362, 388 +Epidural blood patch 484 Epidural morphine 264 Epigastric artery,inferior 15 Epigastric pain 150,214,250,293 Epigastric vessels, deep 15 Epilepsy 277 +effects of 2 77 Epinephrine 444 + + + +Episiotomy 11,303,358,362,387,527,533, 552,611 +complications of 529 deep mediolateral 536 indications of 527b policy 137 +repair of 529f scissors 616f +suture materials for 361 timing of 527 +types of 529f wound,care of 145 +Epithelialization 400 Epithelium 45 Epoxides 477 +Epulis gravidarum 46 Erb's palsy 359, 421, 458f Erectile tissue 2 Ergometrine 352,470 +place of 4 71t uses of 470 +Ergonovine 470 +Ergot derivatives 470,471 +Ergot preparations diuretics 413 Erythema toxicum 420 Erythrocyte +destruction 213 sedimentation rate 49 +Erythromycin 460 Erythropoiesis 247 Erythropoietic cells 247 Erythropoietin 247 Escherichia coli 407, 573 Escutcheon 2 +Esophageal atresia 202, 463 Esophageal tear 151 Esophagus 92 +Estradiol 55 Estriol 57 +low 57 +Estrogen 46, SO, 58, 57, 92, 108, 113, 143, 488,507 +effect 53 +low levels of 148 production 57 +Ethambutol 281 Etonogestrel 51 O Etoposide 189 Euploid +abortions 153 cells 106 +Eutocia 108 Evisceration 552 +Excessive bilirubin production,causes of 449 Excessive heat loss,consequences of 421 Exchange transfusion 326, 452 +complications of 452 indications of 452b +Exercise 146 contraindications of 93b +Exocytosis 33 Exomphalos 36,463,464 Extension 120 +Extensive tongue bite injury 222f +External cephalic version 199,359,374,540,601 steps of 541 f +Extra-amniotic saline infusion 492, 493f Extracorporeal membrane oxygenation 262 + + + + +Extraembryonic coelom 24 cavity,enlargement of 24f +Extraperitoneal cesarean section 550 Extrapulmonary sequestration 46Sf Extravillous trophoblast 29 +Extreme extension,causes of 367 Extremities 421,601 +Eye 422 ball 604 +Eyelids 369 + +F + +Face 46,76 +presentation 367, 367b,370f Facial anomalies 479 +Facial clefts 202 Facial flushing 288 +Facial nerve injury 420 Facial palsy 458f +Facial rash 287 Facial structure 368 +Factor V Leiden mutation 155, 161,328 Faecalibacterium 53 +Fallopian tube 6, 7f, 17, 19, 46 segment of 516f +Fa I lot's tetra logy 263 False knots 36, 208 Faix cerebri 351 Family planning 496 +guidance 147 purposes 515 services 560 +Fascia 10f +transversalis 14,15 Fat 423 +globules 427 metabolism 51 oxidation of 1 SO storage 50 +Fatigue 61 Fatty acids 33 +Fatty liver,acute 293, 578 Fatty tissue,extraperitoneal 14 Faulty pelvic architecture 353 Febrile illness,acute 288 +Fecal incontinence 540 Feed,duration of 424 Feeding 448 +artificial 423 difficulties 426 formula 427 frequency of 424 types of 423 +Female pelvis 331,339 midsagittal section of 4f variations of 331 +Female sterilization 515,518, 518t methods of 515,517 +Femidom 519 +Femur length 6Sf, 436, 626f Fentanyl 481 +Ferguson reflex 124,491 Ferric carboxy maltose 252 Ferric iron 250 +Ferritin 39 Ferroprotein 247 + +Index ED +Ferrous +fumarate 251 gluconate 251 sucrose 252 sulfate 91,251 +Fersolate 91 Fertility +awareness method 520,520t,522 control 496 +benefits of 496 preservation of 297 prospect of 181 return of 507 +Fertilization 19, 21f,61,200 in vitro 18 +Fetal abdomen circumference 601f enlargement of 385,38Sf +Fetal abnormality 356 congenital 205 +Fetal adrenals 40,384 +Fetal adrenergic activity 342 Fetal affection +classic history of 323 severity of 326 +Fetal alcohol syndrome 479 +Fetal anatomical ultrasound 601t Fetal anatomy 599 +Fetal anemia 105,323, 568 assessment of 323 moderate to severe 324 +Fetal aneuploidy 586 screening 106 +Fetal anomalies 195,202,378,386,599 early detection of 269 +Fetal ascites 38Sf +Fetal axis pressure 113 Fetal behavior states 567 Fetal biophysical profile 97 Fetal blood 31, 33,39 +entering,volume of 320 gas 105 +sugar 202 vessels 188 +Fetal bradycardia 224 causes of 566,566t +Fetal brain 604 +Fetal breathing movements 97 Fetal bulk 193 +Fetal cardiac accelerations 100 Fetal cardiotocography 98 Fetal cells 102 +intact 106,107 +Fetal central nervous system 40 Fetal circulation 40, 41, 41f, 439b +Fetal complications 268,305,306,593b, 606 Fetal condition 570 +Fetal congenital abnormalities 36, 96,356 cardiac disease 260 +malformation 95,206,272,563 Fetal cotyledon 28 +Fetal death 95,100,172,269,305,310 Fetal defence 39 +mechanism 565 +Fetal distress 305,327,338,343,421, 468, 541, 550,570 +evacuation of 128 +Index + +Fetal echocardiography 263, 385 Fetal effect 124,125 +Fetal electrocardiogram 570 Fetal endocrinology 40 +Fetal enlargement,generalized 382 Fetal erythrocytes 39, 188 +Fetal factors 347, 379,435,442 Fetal fibronectin +presence of 304, 488 testing 301 +Fetal gender 57 +Fetal genotype,noninvasive 319 Fetal gestational age 86, 591 Fetal growth 95,171,601 +classification 429,429t dynamics 429 monitoring 437 normal 38 +restriction 234,294,434,438fc, 439,487,593 etiology of 439 +predictive factors for 435 velocity 67 +Fetal hazards 338 prevention of 359 +Fetal head 336,532 descent of 338 parts of 120 +progressive descent of 136 Fetal heart rate 128, 306, 342 +categorization of 567t normal 565 +Fetal heart sound 64, 73f, 193, 232, 311, 569 absence of 183 +Fetal hemodynamics 31t Fetal hemoglobin 39, 255 +Fetal hydantoin syndrome 478 Fetal hydration 206 +Fetal hyperglycemia 269 Fetal hyperthyroidism 273 +Fetal hypothalamic-pituitary-adrenal axis 108 Fetal hypoxia 96,154, 447 +effects of 96 progressive 439b +Fetal infection 1 OS, 202 risk of 287 +Fetal inflammatory response syndrome 301 Feta I loss 287 +causes of 154 +marked increase of 374 Fetal lung +maturation 300 maturity 100,243 +Fetal macrophages 32 Fetal macrosomia 266,268 +risk factors for 382 +Fetal malformation 255, 329 congenital 202, 370 +Fetal maturation 295 Fetal maturity +assessment of 99,307fc tests lOOt +Fetal membranes 22, 23, 26, 34 Fetal monitoring 198, 271,291 +methods of 565 Fetal morbidity 233 Fetal mortality,high 205 Fetal movement +active 63, 64 +count 65, 97, 100, 311 + + + +loss of 97 +maternal perception of 97 Fetal muscle tone 97 +Fetal nutrition, stages of 39 Fetal organ anatomy 64 +Fetal pancreas secretes insulin 40 Fetal parameters 602 +Fetal parts 64, 183,193, 203, 242 palpation of 65, 67, 90 +Fetal period 38 Fetal physiology 39 Fetal pole 372, 599 +Fetal presentation 601 +Fetal prognosis 240, 369, 404 Fetal pulmonary +hypoplasia 305 maturity 101 +tests for 99 +Fetal pulse oximetry 570 Fetal red cells 322 +detection of 607 Fetal respiration 441 Fetal salvage 237 Fetal scalp 532 +blood sampling 569 stimulation 569 +Fetal skin 311 +Fetal skull 76, 76f, 77f, 384f, 532 Fetal sleep 568 +Fetal status 361 Fetal stem cells 596 +Fetal stimulation,induced 569 Fetal structures 599 +Fetal surface 27, 622 features on 622 +Fetal surveillance 197,310,326 Fetal syndrome 213 +Fetal tachycardia,causes of 566, 566t Fetal therapy 59, 60,105,106, 601, 603 +direct 465 Fetal tissues 597 +Fetal transfusion 465 Fetal trisomy 21 103 +Fetal venous Doppler 598 Fetal viability 64 +Fetal weight 602 estimation 67, 434 +Fetal wellbeing 128,218,227,437,541,586,587 antenatal assessment of 95, 324 assessment of 308, 312, 601 +clinical evaluation of 95 Fetomaternal bleed 321 Fetomaternal hemorrhage 105,319 +causes of 322f Fetoplacental blood volume 39 Fetoplacental circulation 30 Fetoplacental contribution 108 Fetoplacental factors 562 Fetotoxic agents 477 +Fetus 38,108,188,192,321,404 acardiacus 192 +attitude of 70 back of 353 +birth injury of 455 Buddha' position of 321 compressus 192f,195 +congenital anomalies of 378 degree of affection of 329 delivery of 11 5 + + + +descent of 124 development of 38 disease of 441 effects on 151,382 female 200 growth of 38 +hemolytic disease of 320 intrauterine death of 195,487 in-utero 69 +length of 38 maturity of 308,481 +papyraceous 192{, 195 parts of 70 presentation of 70,192 +selective termination of 201 size of 67 +viability of 193, 375 Fever 285,288 +high 283 +Fibrin degradation products 607 level of 583 +Fibrinogen 49, 213 concentrate 584 estimation of 312,607 level 141 +Fibrinolysis 583 Fibrinolytic activity 49 Fibrinolytic agents 415 +Fibrinolytic inhibitors 584, 585 Fibroid 66, 154, 184, 296, 299 Fibronectin 301 +Filshie clip 517f Fimbrial expression 177 Finger tips 72 +First trimester abortion 160 medical methods of 167 spontaneous 319 surgical methods of 167 +First trimester screening 103,107, 586 First trimester ultrasonography 599 +indications of 599b Fits 225 +onset of 221 +Fitz-Hugh-Curtis syndrome 282 Flat sacrum predisposes 406 Flexion 119, 349 +point 537 Floppiness 421 +Flow velocity waveform 599 Fluid 272,410,547 +accumulate 45 administration 576 balance 224, 432 electrolyte balance 382 loss 141 +Fluorescence +in situ hybridization 1 OS polarization test 100 +Fluoxetine 425 +Foam stability index 99 FOGSI gestosis score 218t Folate deficiency 253 +Foley's catheter 299, 318, 489, 493{, 495, 552, 610 +Folic acid 39, 91, 242, 247, 254, 327, 587 deficiency 241,246,327,477 +causes of 254 supplementation 384 +Follicle 19 + + + +Follicular fluid, amount of 19 +Follicular maturation 55 + + + + +Gastrectomy 254 +Gastric acid suppression 292 + +Index ll correction of 602t +estimation of 67 + + + +Fontanel 76 posterior 77 +Food +amount of 424 volume 433 +Footling presentation 355 Foramen ovale,closure of 42 Force' theory,couple of 120 Forced expiratory volume 279 Forceps 530 +application of 354,402 axis traction devices 616f extraction 353 +functions of 530b +over ventouse,advantages of 538 rotation 353 +sponge-holding 400,613 traction 535 +trial 536 +Forceps blades 533f application of 531 +Forceps delivery 144,199, 363,398,405 trial of 536b +Forceps operation 535 choice of 531 +complications of 537, 537t types of 532f +Formanine glutamic acid 254 Fossa navicularis 2 +Fracture 358,456,458 Fragilis 158,414 Frank breech 355,362 +extraction 365 Free fatty acids SO +Free oxygen radical excess 268 Fresh frozen plasma 212, 584 Friedman's work 379 +Fronto-occipital circumference 421 Fruitful coitus, date of 67 Frusemide 473 +Fulminant pre-eclampsia, acute 220, 229 Functional iron deficiency 258 Functional residual capacity 52{, 608 Fundal dominance 343 +Fundal grip 71,372 Fundal height 64, 65 Fundal placement 501 +Fundal pressure 132, 134{, 137,383{, 396 Fundus 501 +uteri, level of 64{ + +G + +Galactogogues 144 Galactokinesis 59,143 Galactokinetic hormone 143 Galactopoiesis 59, 143 +Galactose-1-phosphate uridyl transferase 450 +Galactosemia 422,450 Gallbladder 52 Gametes +contact of 19 fusion of 19 +Gametogenesis 16, 16fc +Gammaglobulin 182 + + +Gastric contents,aspiration of 485,549 Gastric decompression 444 +Gastric irritation 250 Gastric motility 150 Gastric suction 160 Gastric washings 280 Gastritis 248, 254 Gastroenteritis 284, 407 Gastroenterocolitis 147 +Gastrointestinal disorders 252 Gastrointestinal system 203 Gastrointestinal tract 40,52,141,509 +injury 549 Gastroschisis 602 Gastrulation 24 Gelatin sponge 392 +Gene disorders, single 102,107 +General anesthesia 366,388,390,402,405, 484,484t, 486, 568 +complications of 485, 486 Genetic 307 +abnormalities 102, 204,593 amniocentesis 105 counseling 102,463,562 damage 462 +diagnosis, preimplantation 163 disorders, diagnosis of 104 expression 319 +factors 153 locus 319 syndromes 206 +Genital anomalies 208 +Genital herpes simplex virus infection 288 Genital organs 43,122f,139 +internal 3 Genital prolapse 298 +management for 299 Genital sepsis 381, 409 +Genital tract 351, 380, 381, 407 infection 163, 300 +injury 386 lower 372 +nerve supply of 479 Genitalia 421 +external 3 internal 3 +Genitourinary fistula 381 Genitourinary tract infection 141 Genotypes 318, 319,323 Gentamicin 160,417,460 +Germ cell layers 25 +maturation 7 tumor 296 +Germ disk +endodermal layer of 24 side of 23 +Gestation +period of 87, 96, 179,488 sac 177f +confirms pregnancy 599 +Gestational age 38,61,63t, 64, 67,87t, 479{, 599,601 +advances 99 +assessment of 420t, 428, 601 +chart 96f + + +small for 429 +Gestational diabetes mellitus 89, 265, 266t, 267,272,327,329,593 +complications of 267t risk factors for 266 screening for 272 +screening strategy for 266 treatment of 266, 272 +Gestational hypertension 209, 218, 220, 229, 593 +management of 217 pathology for 229 +Gestational hyperthyroidism 273 Gestational proteinuria 220 Gestational sac 156,599, 624f +Gestational thrombocytopenia 49, 257, 258 Gestational thyrotoxicosis 59 +Gestational trophoblastic disease 182 +neoplasia 182,189,506 persistent 188 +Giant vulsellum 618 Glabellar reflex 421 Glands +group of 12 suprarenal 359 +Glisson's capsule 212 Globin fraction 255 +Glomerular endotheliosis 212 Glomerular filtration rate 52, 141 Glossitis 254 +Glucocorticoids 143 +antenatal administration of 441 Glucokinase gene 265 +Glucose 33,606f concentration of 608 supply of SO +tolerance test 265, 266, 608 Glucose-6-phosphate dehydrogenase +deficiency 477 screening 451 +Glucuronyl transferase,congenital deficiency of 450 +Glutamic acid 256 +Gluteal arteries,superior 13 Glycemic control, procedure of 271 Glycerine 299 +Glycosuria 265 +Glycosylated hemoglobin A,estimation of 269 +Goiter,congenital 368 Gold standard method 511 Gonorrhea 282, 285 Goodell's sign 45,62 Graafian follicle 8,19,55 +maturation of 55 mature 17f +Gradual retrogression 311 Graft rejection,acute 228 Gram-negative septicemia 578 Gram-positive organisms 159 +Grand multipara 87, 327, 386,468 Grandmother theory 319 Granulocyte transfusion 255 +Granulosa cells 55 +Index + +Grasp reflex 421 Graves' disease 273 Gravid uterus 93 +torsion of 295 Gravida 86 +Green-Armytage hemostatic forceps 617 Growth 429 +hormone 58,143 profile 602 +restricted babies 285 restriction 269,310,479 +Gums 52, 88 +Gut microbiome 53 Gynecological disorders 294 Gynecological problems 147 + + + +Hl-Nl infection 286 Hadlock's formula 67,601 Hairs,colorless 39 +Half-hand method 354,354f Hansen disease 282 +Hart's rule 119 +Hashimoto thyroiditis 274 Haultain's operation 397 Head 125,358,420 +assisted delivery of 130f attitude of 356, 370 brim relation 117 circumference 65f, 435 +measurement of 601 f crowning of 120, 129,129f deflexion of 353 +delivery of 120,1 29,130, 368,545 engaging diameter of 368 internal rotation of 349 progressive descent of 124 rotation of 530 +slow delivery of 130 station of 127 +Headache 214,288,293,507 causes of 293b +postdural 483,484 Health sector actions 559 Heart 89,150,420,574 +block 568 +failure 225,249,431 transplantation 262 Heart disease 259,259t congenital 263,446 +diagnosis of 49, 259b specific 262 +Heart lesion 259 congenital 264 effects of 259 organic 327 +Heart rate 49, 443, 577 maternal 128 +Heartburn 92 +Heat and acetic acid test 606t Heat loss,mechanism of 421 Hegar's dilator 612 +Hegar's dilators 612 Hegar's sign 62 Helicobacter pylori 248, 292 Helli n's rules 191 + + + +HELLP syndrome 209,212,215,229,293, 578,583 +hallmark of 213 +Hematinics,supplementary 236 Hematocrit 150,246 Hematologic malignancy 247 Hematological disorders 246,587 Hematological indices 248 Hematology 591 +Hematoma 358,401 infralevator 400,401f larger 401 retroplacental 116,239 subdural 457 +Hematometra 66, 525 Hematuria 285 Hemodialysis 580 Hemodilution 258 +effects of 247 state of 48 +Hemodynamic resuscitation,goal of 576 Hemoglobin 48, 51, 63, 89, 147, 247, 250, +257,296 Bart 257 +concentration 246,247 electrophoresis 451 +H disease 257 level 254 +normal adult 255 oxidizes 420 solutions,artificial 585 types of 39 +Hemoglobinopathies 246, 255, 597 Hemolysis 283 +Hemolytic anemia 451,453,454 drug-induced 255 +Hemolytic crisis 256 +Hemolytic disease 320,449,452 Hemolytic uremic syndrome 578 Hemorrhage 93,105,153,180,181{, 184, +185,244,245,255,303,358,380,389, 396,456,549,559,587,593 +accidental 203, 205, 239,404 acute 578 +amount of internal 171 causes of 184 +cerebral 215, 222,431 clinical manifestations of 240 concealed accidental 71 control of 575 +decidual 239 epidural 456 excessive 525 internal 401 +intracranial 382, 448, 456 intracystic 297 intrapartum 234 +intra peritoneal 172,178 intraventricular 442,448 massive 234,578 +intra peritoneal 172 mild 242 +minute 358 moderate 242 periventricular 442 +primary postpartum 386 recurrent marginal 206 + + + +secondary 393 postpartum 393,549 +severe 242 subarachnoid 456 subdural 456 +subperitoneal petechial 240 third-stage 386,389fc transplacental 322 traumatic 387 +Hemorrhagic anemia 453 Hemorrhagic disorders 561 Hemorrhagic patches 254 Hemorrhagic shock 244,574,575 +basic management of 575 classification of 575t +Hemorrhoids 92,254 Hemostasis 388 +Hemostatic forceps,long straight 611 Hemostatic pressure,direct 392 Heparin 217,264,415,476,584,585 +contraindications of 476 therapy 261, 262 +contraindications of 416 Hepatic abnormality 213 Hepatic dysfunction 150 Hepatic sinusoids 240 +Hepatitis 275, 310 A 93, 276, 277 B 93,275 +core antigen 276 infection 276t +B virus 89,276,519 management of 277 +C 275,276 D 275,276 E 275,276 +fulminant 276 G 275,276 viral 275 +Hepatocellular adenomas 508 Hepatocellular injury 221 Hepatorenal syndrome 276 Hepcidin 247 +Hernia,diaphragmatic 421,463 Herpes simplex 460 +labialis 287 virus 287 +Hesselback triangle 15 Heterotopic pregnancy 181 Hiatus hernia 92 +Hiatus rectalis 9 Hiatus urogenitalis 9 +High-density lipoprotein 508 Hilus cells 8 +Hind milk 424 calorie-rich 424 +Hingorani sign 297 Hirschsprung disease 464 Hissing murmur,continuous 49 Histocompatibility complex 588 Hofbauer cells 29, 32 Homeobox genes 477 +Homogeneous eosinophilic membrane 446 Hookworms 284 +infestation 248 Horiodecidual space 28 Hormonal contraception 513 Hormonal control 479 + + + +Hormonal ectopy 294 Hormonal influences 59 Hormonal stimulation,high 46 Hormone 33,213,471,511,513 +action of 113 pituitary-like 56 +replacement therapy 503 +Hour-glass contraction 343, 389,394 Human albumin solutions 575 Human blastocyst 22 +Human breast milk 148 Human chorionic +gonadotropin 56, 506 somatomammotropin 56 +Human hemochorial placenta 27 +Human immunodeficiency virus 89, 288, 506 infection, stages of 289 +perinatal transmission of 288 Human infection 287 +Human leukocyte antigens 588 Human milk, composition of 427t Human placenta 26,34,37 +lactogen 56,60 Hyaline membrane atelectasis 447f +disease 445 Hyaluronic acid 113,488 +Hydatidiform mole 63,71,151,182,183f, 184f, 185, 18Sf, 189, 192,401,602,623f +histological section of 184f management of 186fc pathology of 182 +Hydralazine 217,221,227,262,474,475 Hydramnios 194,202, 372,375, 411 +complications of 203 management of 204 +Hydramniotic sac 194 Hydration 303 Hydrocele 463 +Hydrocephalus 75, 383,384f, 402,551 Hydrochloric acid 1 SO +loss of 149 +Hydrocortisone 152,279 +Hydrops fetalis 202,204,320,321,321 f, 602 Hydrostatic balloon catheter,types of 392 Hydrostatic method 397 Hydroxychloroquine 280 +Hygroscopic osmotic dilators 168 Hymen 2 +Hyperalimentation,maternal 437 Hyperaminoacidemia 144 Hyperandrogenemia 161 Hyperbilirubinemia 270,432,450,451 +management of 450 neurotoxicity risk factors 451 f +Hyperchromatic nuclei 172 Hypercoagulable state 54 Hypercontractility 344 Hyperemesis 414 +gravidarum 149, 152 progress chart 152 +Hyperglycemia 265, 268 maternal 268,272 +Hyperhomocysteinemia 241,328 Hyperinsulinemia 51, 161,265,269 Hypermagnesemia,life-threatening 621 Hyperosmolar glucose 181 +Hyperoxygenation,maternal 437 + + + +Hyperplacentosis 231 +Hyperplasia 43, 45,58,111,294,429 Hyperplastic cells 182 Hyperprolactinemia 148, 161 Hyperpyrexia 223,225,310 Hyperresponsiveness 278 +Hypertension 86,93,95,144,145,183, 209, 210,224,228,240,293,300,410,508, 559,587 +chronic 95, 209,226,434f classification of 209t essential 226, 227t +long-term treatment of 475 management of severe 217t severe 229, 303 +treatment of severe 475 +Hypertensive disorders 205, 206,209,226, 310,543,561,587 +Hyperthyroidism 154,273 causes of 273 +clinical diagnosis of 273 Hypertonia 421,468 Hypertonic contractions 342f Hypertrophy 43,45,111,429 +cervix 299f Hyperuricemia 293 Hyperventilation,state of 51 Hypervolemia 47,194 Hypocalcemia 270 Hypochromic anemia +causes of 249 microcytic 249f +Hypogastric artery, dissection of 393f Hypoglycemia 269,283,293,308,431 +causes of neonatal 466 fasting 51 +Hypokalemia 1 SO Hypomagnesemia 270 Hypomenorrhea 154,508 Hyponatremia 1 SO Hypoplastic anemia 453 Hypoproteinemia 88,321 Hypoprothrombinemia 151 Hyporeflexia 151 Hypospadias 463 Hypotension 96,468,489 +postural SO Hypothalamopituitary axis 508 Hypothermia 430,432 +consequences of 421 Hypothyroidism 154, 161,274 +maternal 218 Hypotonia 421,463 +Hypotonic uterine dysfunction 341 Hypovolemia 244 +correction of 447 shock 401,572,574 +Hypoxemia 101 +Hypoxia 97, 269,565,568 chronic 210 persistent 571 +Hysterectomy 186,237,392,394,405,410,627f quick subtotal 405 +Hysterography 315 Hysteroscopy 503 +Hysterotomy 169,315,316,402,468, 526 scar 314,315, 315t,402 +rupture 404 + +Index Ei + + + +Iatrogenic rupture 404 Ibuprofen 144,426 +lcterus gravis neonatorum 320, 321 Idiopathic thrombocytopenic purpura 258 lieus pelvic abscess 408 +Iliac artery +anterior division of internal 392 ligation of internal 393f +Iliac fossa 291 Iliac lymph nodes +external 12 internal 12 +Iliac vein 50 external 7 internal 6 +lliofemoral veins 414 lliohypogastric nerves 15 llioinguinal nerves 15 +lliopectineal line 79f, 335 lliopubic eminence 79f Ilium 85 +Immune cells 588 +factors 1 54,161 globulin,intravenous 452 response 320 +system 48 +thrombocytopenic purpura 258 tolerance 589 +Immunization 89,145,319 lmmunoglobulin +A 142 G +level of 45 +maternal 39 Immunological diseases 63 Immunological disorders 154,155 Immunological factor,maternal 21 Immunological function 32,33 Immunological test 58,62,66 lmmunomodulation 588 lmmunomodulatory role 163 lmmunoprophylaxis 360 lmmunosuppressive agents 212 lmmunosuppressive drugs 280 lmmunosuppressive effect 33 lmmunosuppressive factors 589 lmmunotherapy 164 +Impaired glucose tolerance,diagnosis of 267t +Imperfect retraction 234 lmperforate anus 463 Implantation 21 +In vitro fertilization 63 Incarceration +causes of 298 chance of 298 +Incision, extension of 529, 546 Inclination,angle of 80 lndomethacin 204,279, 475 Induction +methods of 495 place of 261 +Infant feeding 147,422 +DD Index + + +Infection 95,144,154, 155, 161,172, 248, 254,256,267,268,288,297,301,310, 382,389,431,432,540,559,563,568 +active 281 acute 284 anemia of 246 congenital 439 +consequences of 287 control 411 disseminated 282 intercurrent 249,257 local 181,408,409 maternal 276,310 +mode of 158, 408,412, 458 multiple opportunistic 289 primary 288 +sites of 408 severe 578 sites of 459 sources of 408 +spread of 159, 408, 409 viral 105,286 +Infectious diseases 94 Infertility 86,154,525 Inflammatory cytokines 239 Influenza 286,310 +vaccine 93, 428 lnfundibulopelvic ligament 6, 46 lnfundibulum 7, 171 +Infusion,flow of 469 Inguinal hernia 463 +direct 15 indirect 15 +Inhalation methods 481 +Inherited thrombophilias 154,161,164,328,414 Injury 369,389,455, 457, 525, 537 +Inlet contraction 338 Innate immune system 588 Inner cell mass 21, 22 +development of 23 lnspiratory reserve volume 52f Insulin 143,266 +antagonism 268 deficiency 265 inhibits 265 +receptors,sensitivity of 50 requirement 268, 272 resistance 265,413 secretion SO +therapy 270 indication of 270 +lnsulinopenia, absolute 265 Integrated test 103 lntegrins 23 +Intelligence quotient,reduced 423 Intelligent anticipation 388 Intense vasospasm 212 +Intensity 112 +Intensive antibiotic therapy 411 Intensive care +monitoring 225 protocol 432 +unit management, indications of 410 Intensive insulin therapy 577 lnterconceptional period 163 +lntercostal retractions 420 Interferon 423 +lnterglandular stromal cells 140 + + +Interstitial cells 8 +Interstitial extravillous cytotrophoblast 22 Interstitial implantation 22, 23, 26, 171 Interstitial line sign 178 +lntertwin membrane 193f lnterventional radiology,place of 395 lntervillous +circulation 30f, 212 hemodynamics 30t space 27-29,32f, 32, 37 thrombosis 210 +Intestinal obstruction 404, 549 Intestinal worms 284 +Intra-abdominal pressure augments 116f Intra-amniotic pressure,generalized 124f lntracardiac injection 201 +lntracranial calcification 287 lntracranial pressure,raised 420 lntracranial stress 380 lntrahepatic cholestasis 275 Intramuscular implantation 171 Intramuscular therapy 252 lntranatal care 557 +lntranatal detection,early 380 lntranatal prophylaxis 409 +lntraparenchymal hemorrhage,management of 457 +lntrapartum care 136,290 lntrapartum complications 587 +lntrapartum cord prolapse,prognosis for 376 lntrapartum fetal +evaluation 565 monitoring 571 +lntrapartum management 586 lntrapartum monitoring 302 lntrapartum sonography 200 +lntrapartum ultrasonography 335, 336{, 339, 603,603{ +lntrapelvic adhesions 170 lntraperitoneal rupture 171 lntraperitoneal transfusion 326 Intrauterine adhesions 154 +Intrauterine contraceptive device 497,502f, 504 +types of 497 +Intrauterine death 195,234,372,462,487,584 Intrauterine devices 262,498, 499{, SOS +complications of 504 nonhormonal 498 +Intrauterine fetal death 71, 300, 310,593 causes of 310b, 313 +management of 313 +maternal complications of 313 Intrauterine fetal transfusion 324, 326 Intrauterine gestational sac 599 Intrauterine growth restriction 95, 434, +562,587 Intrauterine hypoxia 40 +continuation of 442 risk of 99 +Intrauterine infection 205, 380 Intrauterine inflammation 301 Intrauterine packing, tight 238, 392 Intrauterine pregnancy 171,599 Intrauterine pressure 112 +Intrauterine stem cell transplantation 597 lntravascular extravillous cytotrophoblast 22 +lntravascular transfusion 326 + + +Intravenous fluid 576 therapy 156, 433 +Intravenous heparin 415 +Intravenous immunoglobulin, high-dose 326 Intravenous infusion, controlled 468 lntroitus 66, 298 +Intubation 485 indications of 225 +Invasive hemodynamic monitoring, indications of 591 +Invasive procedures 104,107 Iodine 91 +excess 274 Iris 420 +Iron 91,247 absorbable 91 +balance,negative 247 carboxymaltose 252 cord blood level of 39 deficiency 246,258,327 +deficiency anemia 247-249,249b, 254,258 causes of 258 +dextran 252 +diminished intake of 248 hydroxide sucrose 252 isomaltose 252 +loss 248 metabolism 51 poloymaltose 250 +restricted erythropoiesis 258 salt 251 +sucrose 252, 258 therapy 197, 250, 254 +intravenous 258 supplementary 145,250 +Irradiation 462 Irving method 515 +Irving procedure 516f lsabgol tents 614 lschemic injury 457f +lschial spines 127f, 332, 335, 353 level of 365 +lschiopubic ramus 10 lschiorectal fossa 10 lschium 200 +lsoniazid 281 prophylaxis 281 +Isotonic drinks reduce ketosis 380 lsotretinoin 478 +lsoxsuprine 165 +lsthmic cervical apposition suture 238 lsthmic implantation 171 +lsthmic rupture 171 Isthmus 5,7,45 +J + +J incision 545 Jacquemier's sign 43, 62 +Japanese encephalitis vaccine 428 Jaundice 88, 151, 275, 283, 286,321,420, +431,449 +causes of 275, 275t management of 451 +Jejunum 51 Joint 421 +consultation, frequent 560 +ligament laxity 92 + + +K + + + +late 348,374 +latent phase of 123 + +Index :g} + +Lecithin 100 +Leg + + + +Kala-azar 246 Kanamycin 281 +Kangaroo mother care 422 Kaposi's sarcoma 289 Karyotype 188 +Kelly's long forceps 614 Kernicterus 451, 466 Ketamine 279 +Ketoacidosis 150, 152, 268, 382, 407 correction of 344,345,380 +Ketones 606{ +body excess 268 Ketonuria 150 Ketostix 606 +Kidney 52,150,212,240,256,359,574 injury, causes of acute 578, 578t +Kielland's forceps 530,531,536,536f,616f Klebsiel/a pneumoniae 285 +Kleihauer-Betke +acid elution test,modified 322f,608 test 311,322, 329 +Klumpke's palsy 359,458 Knee presentation 355 +Knee-chest position 377 Kocher's forceps 130,491 f, 611 Korsakoff's psychosis 151 +Kroener method 515 Kyphotic pelvis 333 +L + +Labetalol 217,227,474,475 Labia majora 2, 3 +Labia minora 2,3, 43 +Labor 55, 108, 135, 195, 203, 205,243,256, 257,278,279,294,296,318,337,373, 419,446,449,468,480,468,550,609 +abnormal 108,310,379,379t acceleration of 473 +active management of 132,378,379,492, 493,493t, 495 +active phase of 135 anatomy of 120 arrest of 378, 379 +augmentation of 318,469,473,492 care guide 123,379,495 +clinical course of 372, 373f companion 380 +presence of 136 complications of 587 course of 340,351 crucial stage of 132 date of onset of 108 delay of 369 diagnosis of 136 disorder 379 duration of 303 +early 348,374 +effects on 296, 314,329 elective induction of 487 +first stage of 35,113,121, 122,127, 135, 136,261,351,379 +fourth stage of 135 +induction of 243,271,310,313,360,468, +473,487, 487b, 488,489b, 490t, 491 b, 492fc,495, 550 + + +management of 318,351,587 mechanism of 77, 117,118fc, 333,334f, +349, 349fc,356,357f,368,371,372 medical induction of 489t +mini 155 +obstructed 115,294,328,378,381,382, 385,407,559 +onset of 127, 135 pain 111,262 +false 111 true 110 +partographic analysis of 380f +monitoring of 493 +primary dysfunctional 341,346,380 procedure of induction of 271 progress of 128,352,361,405,469,495 prophylactic induction of 382 +second stage of 115, 123,124,129, 135, 137,261,263,351,379,398,550 +secondary arrest of 383 spontaneous onset of 271 spurious 110 +stages of 111,375,386 stress of 480fc +third stage of 116, 125,132,133fc,135, 137,202,261,386,387,394 +trial of 317,339,367, 371 ward 198 +Labyrinthine 34 Lactation 55,142, 509 +amenorrhea 521 failure 144,412 +physiological basis of 143 physiology of 143 +postpartum suppression of 313 reflex arc 143f +stimulation of 144 suppression 144 +Lactic acidemia 269 +Lactiferous duct 13 Lactobacillus 43,46,53 +acidophilus 43 Lactoferrin 142, 423 +Lactogenesis 59,143 Lactoperoxidase 142,423 Lactose concentration,high 427 Lag period 569 +Lambda sign 600 Lambdoid sutures 76 Lamellar body 99 Lamina propria 5 Laminaria tent 524f,614 Lamotrigine 278 Langer's lines 14 Langhans' layer 22 +Laparoscope,removal of 517 Laparoscopic linear salpingostomy 177f Laparoscopic sterilization 516,517 Laparoscopic surgery,guidelines of 292 Laparoscopic tubal sterilization 517f Laparoscopy 174,180,292 +Laparotomy 160,174,176, 179,180,240, 405,410,515 +Laser photocoagulation 196 +Latent syphilis 282 + +cramps 92,507 edema of 88 +Leiomyomas 296 Lemon sign 601 +Leopold maneuvers 71,72f Leprosy 282 +Leptin 57,150 Leukemias 247 +Leukocytes 39, 49,413,423 Leukocytosis 141,291 Leukomalacia, periventricular 431 Leukopenia 254 +Leukorrhea 508 +Leukotriene receptor antagonist 279 Levator ani 9 +muscles 9f origin of 82 +Levetiracetam 278,425 Levonorgestrel 505, 511 +intrauterine system 498, 499,SOS pill 512f +Levorotation 44 +Liberal mediolateral episiotomy 370 Libido 508 +Ligament hematoma 400 Ligamentum venosum 41 Light solid diet 548 Lignocaine 482 +Limb +hypoplasia of 287 reduction deformity 104 +Linea alba 66 +Linea nigra 46,64, 73f, 90 Linear salpingostomy 177 Lipid 33, 508 +metabolism 51,Slt abnormal 210 +peroxidation 268 peroxides 21O +Liquid antacids 92 +Liquor amnii 34,115,308,566 amount of 70 +embolism 491 production of 202 +Liquor volume 601 +assessment of 356 Listeria monocytogenes 284 Listeriosis 162,284 +prevention of 284 Lithium 274,417,478 +Lithotomy position 398,400 Live births 430 +Live vaccine 93 +Liver 52, 89, 150, 212, 229, 240, 359, 574, 577 biopsy 293 +disease of 506 enlarged 254 +enzymes, elevated 226, 293 function tests 212,275,451,608t +Living ligature 43,139 Lizman obliquity 118 +LNG-IUD 498,499,501,503,513 LNG-IUS insertion +device SOlf method of SOOf +Lobes 27 +.. ··il Index + + +Lobule 28 Lochia 141,148 +alba 141,148 discharge 409 rubra 141 serosa 141,148 +Lovset's maneuver 366, 366f +Low birth weight 425,429, 439,562,593 babies, two-thirds of 430 +Low forceps operation 532 steps of 534f +Low-density lipoprotein 508 Lower limb 604 +Lower segment scar 315,316,402,403 rupture 402,403(, 404 +Lower segment transverse scar 314,546 Lower uterine segment 111, 114, 135,140, +230,231 +Low-molecular-weight heparin 217,476 Lumbar epidural analgesia,continuous 482 Lumbosacral trunk 416 +Lung 89,159,359,409,445,574 capacity,total 52(, 608 cells,types of 300 +disease,chronic 448 injury,causes of acute 591 maturation 446 +maturity, assessment of 447 scans 415 +volumes 52f +Lupus antibodies, maternal 280 Lupus anticoagulant 163 +Luteal phase defect 154, 161 Luteal placental shift 55 Lymphatic system 34 Lymphomas 247,289 Lysine,substitution of 256 Lysozyme 423 + + + +MacKenrodt's ligament 5, 11 Macroglossia 420 Macrophages 148,499 +Macrosomia 308, 329, 382, 383, 429 Macrosomic baby 269f +Madlener technique 515 Magnesium 621 +Magnesium sulfate 219,224, 225,302,439, 475,476,621 +side effects of 621 toxicity of 621 +Magnesium toxicity 224,621 detection of 224b management of 224b, 621 +Ma/absorption syndrome 254 Mala-D SOS +Malaise 288 Mala-N 505 +Malar eminences 368 Malar flexion 364f Malaria 154, 246, 283,31 O +congenital 283 effects of 283 t parasites 33, 409 +Malformations,types of 295 Malignant disease 106 +Mallory-Weiss syndrome 151 + + +Malmstrom device 538f Malnutrition 387 +maternal 463 Ma/position 347 +Ma/presentation 347, 468,543 persistence of 232 +Ma/rotation 350 +Mammary gland,basic unit of 13f Mammary murmur 49 Mammogenesis 59,143 +Manual rotation,half-hand method of 354f Manual vacuum aspiration 526 +cannula 526f syringe 526(, 61Sf +Marfan's syndrome 264 Massage 388 +uterus 390 +Massive hypertrophy 14 +Massive transfusion protocols 585 Mastalgia 507 +Mastitis 407,412,412 acute 412 +risk factors for 412 types of 412 +Maternal autoimmune disease 590 Maternal circulation 29 +Maternal circulatory volume expansion 437 Maternal complications 96, 201, 245, 268, +283,306,593b,606 +Maternal death 292,554,558,564,621 causes of 222, 415, 556(, 559,564 clinical causes of 555 +indirect 260 reduction of 235 +Maternal disease 477 +Maternal distress 205, 268,327 evacuation of 129 +Maternal fetal +cell trafficking 589 medicine 205 +Maternal free fatty acid, elevation of 268 Maternal hypotension,correction of 570 Maternal illness, chronic 162 +Maternal injuries 337, 398, 594 +Maternal morbidity 233,327,537,358,561, 564 +severe acute 561 +Maternal mortality 177,196,215,239,259, 409,558,559 +conferences 560 estimates 558t rate 558 +ratio 555, 558 +Maternal near miss 561, 564 Maternal osmoregulation 61 Maternal serum 56 +alpha fetoprotein level 103,269 chorionic gonadotropin 194 iodine 58 +levels 60 +Maternal supine position 381 Maternal surface 27, 134, 622 Maternal syndrome 213 +Maternal toxoplasmosis, chronic 284 Maternal vitals, period 111 +Maternal weight gain 95,435 +Maternal wellbeing,assessment of 587 +Maternity care,respectful 126 + + +Mathews-Duncan method 117f Matrix metalloproteinases 239 Mature ovum 17 +development of 16 structure of 17 +Maturity, suspected 317 +Maturity-onset diabetes of youth 265 Mauriceau-Smellie-Veit technique,modified +364 McBurney's point 291 +McDonald's operation 165 McDonald's technique 164f McRoberts maneuver 383 +Mean corpuscular hemoglobin 247 concentration 247 +Measles 33, 93, 286 +mumps-rubella vaccine 287 Mechanical dilators 489, 492 Mechanical distress 195 Mechanical valves 264 Mechanical ventilation 279 +indications of 432, 575 Meckel's diverticulum 36 Meconium 566 +aspiration 308 syndrome 40,448 +composition of 40 ileus 463, 464 +Median nerve, compression of 53 Medical disorders 327,416,562 +detection of 562 management of 562 +Medical eligibility criteria 497,512 Medical illness,maternal 154 Medical induction 488 +Medical termination of pregnancy 153,166, 515,517 +complications of 169 Medical therapy 176 +Medical-gynecological disorders 543 Medication,preoperative 485 Mediolateral episiotomy 383,528t +steps of 527(, 528 Medroxyprogesteroneacetate 478, 51 O Medulla 8 +Megaloblastic anemia 253-255, 258,283 Meiotic division,first 19 +Melanocyte stimulating hormone 47 Membrane 108, 113,125,374,390 +artificial rupture of 490, 490f bag of 113 +early rupture of 195 +low rupture of 205, 243,325, 490t, 491 prelabor rupture of 304 +premature rupture of 154, 203, 304, 340, 407,487,601 +preterm rupture of 562 prolonged rupture of 304,407 removal of 547 +rupture of 71, 127, 403 separation of 116 +spontaneous rupture of 205, 304 stabilizer 224 +status 124, 351 sweeping of 489 +Mende/son's syndrome 485,486,574 Meningitis 282, 284 +Meningococcal vaccine 428 + + + +Menopause 8 early 594 +Menorrhagia 508 +Menstrual abnormalities 507 Menstrual age 61,599 +Menstrual bleeding,abnormal 501 Menstrual loss 501 +Menstrual period first 142 +last 61, 71,87 Menstruation 19, 142 Mental health 417 Meperidine 481 Mesoderm 21, 25 +Mesosalpinx,attachment of 7 Metabolic acidemia 96,568 +Metabolic acidosis 96, 144,149,283,321, 381,421,575 +Metabolic disorders 416,450 Metabolic disturbances 144 Metabolic syndrome 215,437 Metallic taste 250 Metanephric kidney 39 Metarteriole shunt 572 Metastatic disease 182 Metastatic infection +signs of 409 symptoms of 409 +Metformin 254 Methemoglobinemia 420 Methergine 132,390,470,473 +place of 471f uses of 470 +Methimazole embryopathy 273 Methotrexate 167,176,181,187,189,478 +therapy,contraindications of 177 Methyldopa 474 +Methylergonovine 470 Metoclopramide 151,152,544 +Metronidazole 160, 292,399,417,425, 478 Metroplasty 163 +Microangiopathic hemolytic anemia 212 Microbicide 520, 522 +Microbiome 53 role of 53 +Microchimerism 589 Microinvasive disease 295 Micromuscles,contraction of 19 +Microvascular circulation,anatomy of 572 Micturition,frequency of 61, 65 +Midforceps 531 operation 535 +Mid-pelvic +contraction 351,353 plane 83 +Midpelvis 83 +Mifepristone 167,168,313,489,621 Milia 420 +Milk +ejection 143 reflex 143 +expression,methods of 426 formula 427 +production 144 +causes of inadequate 413 secretion 143, 425 +transfer 424 Minerals 90,247,423 + + + + +Mini-lap vis-a-vis laparoscopic sterilization 517t +Minilaparotomy 516,517 Minipill 509,512,513 +Miscarriage 153,156, 255,298,327,329 causes of 155,161 +complete 156,157f etiology of 153 incomplete 157,157{ inevitable 1 SSf, 156 late 313 +mechanism of 155 missed 157,158{ +prognosis of recurrent 165 rate 195 +recurrent 160, 162, 165, 589 risk of 286 +silent 156 threatened 155,157{ types of 161t +Misoprostol 132,157,158,167,168,313, 472,473,488,489,620,621 +administration 166f Mitochondria 11 O Mitogenic glycoprotein 210 Mitral stenosis 259, 262 Mitral valve +normal 262 prolapse 263 +Mixed infection 158 M-mode 598 +Molar pregnancy 155, 623{ complications of 184 suspected 599 +Mole +incomplete 187 invasive 182 +partial 187, 188{, 188t Mongolian spots 420 Monilia vaginitis 294 Monilial vulvovaginitis 285 Monoamniocity 196 Monochorionic diamniotic +placentas 191 f twins gestations 196 +Monochorionic twins 196,197 complications of 196,201 discordant growth of 195 f post-laser ablation 196 +Monochorionic-monoamniotic twins, placenta of 197f +Monofilament sutures 399 Monosomy X 105, 153, 1 54 +Monozygotic twins 190-192, 194-195, 202 pregnancy 190t +Mons pubis 2 Mons veneris 2 +Montgomery's glands 13 Montgomery's tubercles 46 Moral principles 592 +Morbid adherent placenta 115,239,388, 389,394,405,549 +types of 237 Morning sickness 61 Moro reflex 421 Morphine 415 +Mortality following tubal sterilization 518 Morula 20 + +Index am· Mosquito bites 283 +Mouth 46,420 +Mucocutaneous candidiasis 461 Mucopolysaccharidoses 597 Mucous coat 6, 12 +Mucous membrane 7, 12,50,171 Mucus rhythm 520 +users of 520 +Mucus sucker 363, 617f Mullerian ducts 4, 6,7,162 Mullerian fusion,defective 162 +Multichorionic multiple pregnancy 201 Multidisciplinary team 394 +Multidose methotrexate 176 Multifetal pregnancy +complications of 194t reduction of 201 +Multigravida 87 +Multiload cu-375 498,501 +Multiload intrauterine contraceptive devices, insertion of SOOf +Multilobed placenta 207 Multipara 87,114,373 Multiple birth 190, 192 Multiple gestation 192 Multiple organ failure 574 +Multiple pregnancy 151, 184,190,201,202, 248,273,359,375,414,562,587,593, 599,600 +incidence of 191 suspected 601 +Multiple toothed vulsellum 611 Multisystem abnormalities 286 Mumps 33,93,287 +Muscle 9,43, 140,457 apposition 546 coat 5,12 +fibers,arrangement of 43 incision 545 +layer 12 longitudinal 15 relaxants 485 superficial 399 tone 52,421,443 transverse 14 +Muscular coat 36 Muscular contraction 580 Muscular spasm 92 +Musculoskeletal system 203 Mutigravidae 543 +Myalgia 285,288 Mycoplasma 300,418 +Myocardial function, inhibition of 474 Myocardial infarction 265,574 Myocarditis,treatment of 577 Myoepithelial cells 13,46 +Myofasciitis 41Of Myomectomy +partial 396 place of 296 +Myometrial mantle 1 78 Myometrial oxytocin receptors 109 Myometrial segments 210 Myometrium 5,171,179,401 +contractile system of 109 layer of 181,181 f +Myosin 109 +light chain kinase 110 +ea Index + +N + +Naegele's formula 67,88 Naegele's pelvis 332,333 Naked eye +appearance 182, 296 features 240 +Nalbuphin 481 Naloxone 481 +Narcotics 97, 477,478,485 antagonists 481 +Narrow pelvic plane 82 Nasal bone,absence of 106 +National Diabetes Data Group 266 National Digital Health Mission 563 National Health Mission SSSt,560 National Health Policy 560 +National Institute of Child and Human Development 566 +National Population Policy SSSt National Sociodemographic Goals SSSt Natural birth 126 +Natural killer cells 33,154, 588 Nausea 61,92,149,194,250,468,507 +vicious cycle of 150 Navicular cells 43 +Neck 12,88,420 masses 202 nape of 363 torsion of 120 +Necrotizing enterocolitis 147,442,461 Necrotizing fasciitis 410,41 Of +Needle puncture 241,242 Negative sliding organ sign 179 Negele's obliquity 118 Neoadjuvant chemotherapy 295 +Neonatal complications 268,269,306,593b Neonatal deaths 563 +Neonatal hyperbilirubinemia 466 causes of severe 449 diagnosis of 450 +Neonatal infection 283, 288 prevention of 459 +Neonatal jaundice 275 causes of 449 +Neonatal lupus syndrome 280 Neonatal resuscitation 444 Neonatal seizures 454t Neonatal sepsis 305, 460t Nephritis 300 +Nephrotic syndrome 88 Nerve 359 +injury 457,537 Nervous system 53,421 +Neural tube defects 102,107,384 Neuraxial analgesia 482, 486 Neuraxial anesthesia 482,482t,483 Neuritis,peripheral 151 +Neurological damage,long-term 359 Neuropathy,post-traumatic 416 Neuroprotection 303 +Neuroprotector 224 +Neutral protamine Hagedorn 271 Neutrophilic leukocytosis 48 +Neutrophils,hypersegmentation of 253,254 Nexplanon 510 +efficacy of 511 + + +Nicardipine 475 Niche scar 181 Nicotine 478 +products 94 Nicotinic acid 91 Nidation 21 +Nifedipine 217, 227,474,475 Nile blue sulfate staining 304 Nipple 13,46 +abnormalities 426 accessory 14 cracked 412 +flat 412,426 inflamed 412 inverted 426 long 426 retracted 412 shields 412 short 426 soreness 145 +supernumerary 14 trauma 425 +Nirodh 519 +Nitabuch's layer 28,32,395 Nitabuch's membrane 23 Nitrazine test 304 +Nitric oxide 50,110,210,476 Nitrofurantoin 285, 425,477,478 Nitroglycerin 474 +sodium nitroprusside 217 Nitrous oxide,premixed 481 No scalpel vasectomy 518 +No touch insertion method 500 Non-ciliated columnar epithelium 5 Noncommunicable disease 562 +Noncontraceptive benefits 503,507,510 Noncontraceptive use 509 +Non-gestational trophoblastic disease 182 Non-hematopoietic stem cells 596 Nonimmune fetal hydrops 465 +causes of 466 +Nonimmune hydrops 310, 465f Noninfective mastitis 412 +Non-lactating breasts 13 Nonmetastatic disease 182 Nonmolar pregnancy 189 +Non-nucleoside reverse transcriptase inhibitors 289 +Nonobstructive rupture 402 spontaneous 403,404 +Nonpharmacologic analgesics 481 +Non physiologic jaundice, absolute features of 450b +Non-pneumatic antishock garment 392 Nonreassuring fetal status 570,570b +management of 570 Nonstress test 97, 308, 359 Noradvenaline 576 Norethindrone 167 Norethisterone enanthate 505 +Normal labor 108,113,117,122,340 management of 126 +mechanism of 117,135 physiology of 111 +Normal puerperium 139 management of 144 +No-scalpel vasectomy 514 +operation,methods of 514f + +Nosocomial infections 459 +No-touch insertion technique 501 Nuchal displacement 366 +Nuchal translucency 1 OSf,106,600,600f Nucleoside reverse transcriptase inhibitors +289 Nulligravida 87 Nullipara 87 Nulliparous cervix 66 +Numerous lymphatic channels 44 Nutrients 423 +transfer of 429 Nutrition 39,432,433,461 Nutritional deficit 426 +• Nutritional supplementation 152 Nutritional support 577 +Nutritional therapy,supplementary 90 Nutritive function 33 +Nutritive villi 28 Nuva ring 522 +Nystatin oral suspension 461 + +0 + +Obesity 329,408,410 childhood 147,423 +Obliterative endarteritis 282 Obsessions 417 +Obsessive-compulsive disorder 417 Obstetric +cholestasis 275 +complications 276,278,284,359,416 conjugate 81 +day-care 594 deaths,direct 558 emergency 406 epidemiology of 558 examination 89 grips 71 +indications 200 instruments 609 +management 221,225,227,263,266, 270,281,382 +morbidity 561,564 operative 523 palpation 307 palsy 416 +practical 609 sepsis 583 +Obstetric forceps 530,552 long-curved 530,61 Sf pair of 361 +varieties of 530 Obstetric hemorrhage 394 +classification of 575t Obstetrical perineum 11 Obstetrical transverse 81 Obstructive renal failure 580 Obstructive rupture 402 +spontaneous 404 Obstructive sleep apnea 46 Occipital bone 76 +Occipital lobe 221 Occipitosacral arrest 350,353 Occiput mental plane 531 +Occiput-spine angle,measurement of 603 Occult prolapse 375 +Olanzapine 417 + + + +Oldham's perforator 551 Oligoamnios 205 +Oligohydramnios 35,39,194,196,205,206, 308,311,355,449,487,587,601 +complications of 206 +Oliguria 214,215,221,431,411,576 Omega-3 fatty acids,long-chain 423 Omeprazole 478 +Omphalitis 460 +Omphalocele 200(, 421,464,602 Omphalopagus fetuses 200f Oncogenicity 462 +Ondansetron 151,152 +Onset of labor, mechanism of 490 Oocyte 19 +fertilizable life span of 19 maturation of 17 primary 17 +second meiotic division of 19 secondary 17 +Oogenesis 16 Oophoropexy 295 Operation +destructive 385,550,552 time of 515, 543 +Operative delivery 203,380,387,527 incidence of 493 +Operative vaginal delivery 147,529, 532t,538 +benefits of 540 classification for 532t contraindications of 539b risk of 540 +Ophthalmia neonatorum 459 Ophthalmoplegia 151 Ophthalmoscopic examination 151,214 Opiate analgesics 279,481,486 +Opioids 94 +Oral azithromycin 282 +Oral contraceptive 280,281,294,SOS(, 505t, 512 +formulations,types of 509 Oral corticosteroids 279 +Oral drugs 218 +Oral feeding 338,548 +Oral glucose tolerance test 51 Oral hydration 452 +Oral hypoglycemic drugs 270 +Oral iron therapy,side effects of 250 Oral mifepristone 167 +Oral nifedipine 264 Oral pill 274,477 +combined 187 Oral therapy 250 +contraindications of 252 Oral thrush 420,461 +Organ 509 damage 244 +Organ dysfunction features of 160b +pathophysiology of 211 Oropharynx 131 +Ortolani and Barlow maneuvers 421 Osiander's sign 62 +Osmotic fragility tests 451 Osteogenesis imperfecta 597 Osteomalacic pelvis 333 +Osteonecrosis 256 + + + + +Ostium secundum type 263 Otitis media 147 +Outlet forceps 531 operation 535 +Ovarian arteries 178 Ovarian cancer 297 Ovarian changes 183 Ovarian cycles 46 Ovarian cyst 203, 292 Ovarian fimbria 7 Ovarian fossa Bf Ovarian function 142 Ovarian masses 297 Ovarian pregnancy 179 +diagnosis of 179 +Ovarian tumor 184,296,297f, 299 malignant 297 +Ovarian veins 8 Ovary 7, 46, 508 +histological structure of Bf Overactive bladder 286 Overflow incontinence 41 1 Ovulation 18,55,21f,142 +causes of 55 inhibition of 505,51O resumption of 176 +Ovum +forceps 613 +transperitoneal migration of 170 Oxybutynin immediate release 286 Oxygen 481 +administration of 575 consumption 422 delivery 429 deprivation 96 inhalation 279 reserve,maternal 51 saturation 185 supply 33,96 therapy 415 +humidified 447 Oxygenation 432,448 +Oxytocics 199, 340,344,467,473,547 agents 525 +selection of 473 use of 404 +Oxytocin 109,143, 143(, 148,158,168,169, 243,346,362,388,390,426,467,471, 473,488,489,489 490 +administration of 468 analogue 475 antagonists 475 augmentation 290, 383 challenge test 469 concentrated 167 contraindications of 468t diagnostic use of 469 dose of 469 +high-dose 469 +infusion 185,225,309,313,344,377,489 observation during 469 +intravenous 546 long-acting 388 parenteral 397 sensitivity test 469 side effects of 468 stoppage of 570 +titration technique 468 + +Index ma p + +Pacemaker 112,340 Packed cell volume 247 +Pain 121,124,125,155,297,501,502,528 acute 292 +causes of 292t cramp-like 501 mechanism of 145 probable causes of 112 relief 128,344, 345,479 +methods of 481 spasmodic 145 suprapubic 315 weak 352 +Pallor 88, 419 +Pal mar erythema 47 Palmar grasp 421 Palmer's sign 62 Palpation 71 Pancreas 59 +Pancreatic function tests 608t Pancreatitis,acute 292 +Pap smear,abnormal 295 Para-aminosalicylic acid 281 Paracervical lymph nodes 6 Paracervical nerve block 482 Paracetamol 256 +Paragard 500 Paralytic ileus 549 +Parametrial phlegmon 409 Parametritis 408, 409 Parametrium 5,1 1 Paraplegia 416 +Pararectal fascia 399 Parasitemia 284 Parasites 283 +Parasitic infestation 283 Parathormone nor calcitonin 33 Parathyroid +gland 59 hormone 59,60 +Paraurethral glands 12 Paraurethral tear 398 Paravaginal hematomas 400 +Paravaginal venous plexus, rupture of 400 Parenchyma 14 +Parenteral therapy 252,258 advantages of 252 indications of 252 +Parietal presentation, posterior 1 18 Parity 86, 481 +Partograph 122,493,494f, 495 advantages of 495 components of 494 plotting of 495 +Parturition,initiation of 109f Parvoviruses 287 +Patella 311 +Patent ductus arteriosus 263,431,463 Pathological coagulation,initiation of 581, +582 +Pawlik's grip 72,72f,85 +Peak intrauterine pressure 469 Peak systolic velocity 324f Pectineal line 79f +Pedal edema 214f +ml Index + +Pedicle,torsion of 297 Peg cells 7 +Pelvic +abscess 159, 408-410 adequacy 351,370,375 application 532 +axis 84, 8Sf +brim 70,81, 114,124,354 cellular tis ue 4, 9, 11 cellulitis 407-409 changes 62 +contraction 365 diaphragm 9 dimensions 82, b3 examination 155, 158 fascia 11, 141 fractures 333 hematocele 171 hematoma 400, 406 inflammation 525 +inflammatory disease 170,501, 519 inlet,shape of 347 +joints 84 lymphadenectomy 295 mass 543 +muscles 10f, 401f nerves 9, 11 pathology 147 peritonitis 408, 409 plexus 12 +portion 12 rest 236 shape 119 +structures 140 +tenderness,presence of 409 thrombophlebitis 414 tumors 71, 75,372,375 ultrasound 409 +ureter 12 +vein thrombosis 409 viscera 11 +wall,fascia on 11 +Pelvic floor 9-11, 115,141, 298, 368,378 exercises 399 +fascia on 11 law of 119 +muscle 146,353 tone of 353 training 286 +slope of 119 +Pelvic grip 72,72{, 73, 348, 372 first 73 +Pelvic organs 4f, 9-11, 140 prolapse 286 +Pelvimetry 334 +Pelvis 79,127, 130, 332, 348 assessment of 127, 334, 339,353 clinical assessment of 334f depth of 80f +false 79 flat 333 +generally contracted 333 inclination of 80f +management of contracted 338 maternal 70, 76 +normal 371 part of 80 +physiological enlargement of 85 + +plain X-ray of 502f quadrants of 70 secondary contracted 381 true 80,110 ultrasonography of 159 +Penalities 595 Penicillin 282 +penicillinase-resistant 413 prophylaxis 256 +Peptic ulcer 292 disease,risk of 52 +Peptides, local 23 +Percutaneous transluminal coronary angioplasty 265 +Percutaneous umbilical blood sampling 1 OS Perforation,sites of 551 +Perihepatitis 282 +Peri-implantation genetic diagnosis 106 Perimortem cesarean delivery 550 +place of 591 +Perimortem cesarean section 544 Perinatal asphyxia 441, 466 +etiology of 442 management of 443 sequelae of 448t +Perinatal death 241, 358, 418 reduction in 235 +Perinatal grieving, management of 418 Perinatal infections 458 +Perinatal injury 594 Perinatal loss 382 +procedure-related 326 Perinatal mood disorder 417 +Perinatal morbidity 245, 305, 308,563 risk of 98 +Perinatal mortality 215,245,270,308,327, 376,561,564 +causes of 239,563 predisposing factors of 562 risk of 98 +Perinatal nomenclature 563f Perineal arteries 400 +Perineal damage, chance of 369 Perinea! infiltration 527f Perineal injury 144,351,398 Perinea! laceration +chance of 529 prevention of 130 +Perinea I muscles,repair of 529f Perineal pouch +deep 10 superficial 2,3f +Perinea! scar 398 Perineal surgery 527 Perineal tear 399f +complete 351, 398 fourth degree 406 third-degree 398b +Perineal trauma 137, 540 Perinea! wound 410 Perineum 3, 10,66,134,398 +Peripartum cardiomyopathy 264 Peripartum hysterectomy 550 Peripheral smear, abnormal 212 Periportal hemorrhagic necrosis 212 Peritoneal coat 403 +Peritoneal incision 545 +Peritonitis 408, 410 + + +Personal hygiene 294 Pethidine 568 +Pfannenstiel incision,modified 545t pH rises 51 +Pharmacological agents 575 Pharyngitis 407 +Phenytoin 476,478 Phlegmasia alba dolens 414 Phosphatase levels 53 Phosphatidylcholine 100 Phosphatidylglycerol 100 Phospholipid +degradation 96 release of 581 +Phototherapy 452 adverse effects of 452 +Phrenic nerve injury 458 Phyalism 46 +Physiological anemia 246,421 concept of 247 +criteria of 247 Physiological edema 50,88,89 +Physiological retraction ring 114 Pill +low dose 521 missed 506 withdrawal of 507 +Pinard's maneuver 365,365f Pinard's stethoscope 618 Pinocytosis 33 +Pinopods 21 +Piper forceps 364,536,536f Piperacillin 160 +Piskacek's sign 62 Pituitary failure 244 Pituitary gland 58, 60, 384 +maternal 58 +Pituitary growth hormone 56 Pituitary-ovarian axis,function of 55 +Placenta 22, 26,27,29,37,40,59,108,132, 202,155,182,205,210,208,231,238, 239, 240, 282, 284,296, 308, 311, 343, 387,389(, 390,394,395,404, 604, 622 +abnormalities of 190,206,216 adherent 395, 627f angiogenesis 210 +anomaly 241 appearance of 240f barrier 31, 37 bilobate 207 +blood flow 41 chorioangioma of 202 chorionicity of 193 circulation 29, 35, 37 circumvallate 206, 207f, 233 delivery of 132 +detachment of 116 endocrinology 33, 55 examination of 191,233,271,388 expulsion of 117,126,134, 134f extrachorialis 206 +factor 307, 375, 435 fenestrata 208 +fetal surface of 27f, 34,622f function 32, 37,57 +glucose transport 265 implantation of 115, 230,233,408 +increta 237f, 395f + + +localization of 232t +low-lying 231,237,245,627 manual removal of 322, 388,389 margin of 208 +marginata 206, 207 maternal +portion of 23 surface of 622f +membranecea 207 microbiomes 53 migration 231 mosaics 104 parasitization 283 perfusion 227 polyp 393 +posteriorly situated 232 premature separation of 239 removal of 126, 547 retention of 386 +sending 313 +separation of 116, 117f, 239,394 sign 61 +situated 194 spuria 206 structure of 28f +succenturiata 206, 207,207f, 622f tissue, hyperplasia of 321 +transfer 32, 37 villi 193f +Placenta accreta 29,32, 237, 238,245, 395, 549,602,627 +partial 395 +risk factors for 237 risk of 245,395 +spectrum 237,314,395, 627f total 395 +Placenta growth factor 210,211 hormone 58 +Placenta membrane 31,190 examination of 133 +Placenta previa 75, 91, 115, 194, 230-234, 234t,235,238,244,245,303,315,355, 359,387,400,593,601,627,627f +accreta 234, 238 risk of 245 +anterior 238 complete 233 degree of 231f +fetal complications of 245 high-risk factors for 231b incidence of 318 management of 236fc,245 marginal 233 +maternal complications of 245 neonatal complications of 234 symptom of 232 +types of 231 +Placental abruption 96,215,241,243,245, 274,291,296,327 +complications of 243 etiology of 240 management of 245 risk factors for 245 +Placental hormones 55,56t, 57f, 60 diagnostic value of 58 +Placental insufficiency 310,442 chronic 434 +risk of 308 + + + +Placental separation, premature 239 Placental site 408 +bleeding 388 contracts 139 +trophoblastic tumor 182,188 Placentation,abnormal 210,589 Placentography 232t,234 Placentome 28 +Planned delivery,timing for 197,202 Plantar deep creases 430 +Plasma 48, 608 cells 148 +concentration 56 creatinine 579 fibrinolytic system 582 glucagon 51 +glucose, fasting 266, 270 insulin level SO +lower levels 56 magnesium level 621 maternal 106 membrane 18f potassium 579 +progesterone decreases 57 protein 48, 54 +A, pregnancy associated 57 vasopressin 58 +volume 48 Plasmapheresis 326 Plasmin, activation of 583 Plasminogen inhibitors 582 +Plasmodium falciparum infection 283 Plastic suction cannula 615 +Platelet 49, 607 concentrates 584 consumption 49 count 141 disorders 257 functions 580 problems 453 reduction of 213 +Platypelloid 80,332 Plethora 420 +Pliable tabular bones 76 Plummer Vinson syndrome 249 Plumpy face 269f +Pneumococcal polysaccharide vaccine 428 Pneumonia 147,286,380,407 +neonatal 562 Pneumoperitoneum 517 Pneumothorax 420,448 Podalic version +external 542 internal 540 +place of 405 steps of 542f +Poikilocytosis 248 Polar body 18 +biopsy 106 Poliomyelitis 33 +Polycyclic hydrocarbons 478 Polycystic ovary syndrome 161, 163 Polycythemia 269f,270,308,451 Polydioxanone 399 +Polyglactin 399 +Polyhydramnios 35, 71, 74, 194, 202, 206, 267,268,487,587,601 +acute 205 causes of 206 + +Index - + +complications of 206 mild 204 +severe 204 treatment of 204 +Polymerase chain reaction 105, 282 Polymicrobial infection 158 +Poly-oli syndrome 196 Polythelia 14 +Polyuria 48 +Pomeroy's method 515,516f Pondera! index 434,436 Pontine myelinolysis 151 Popliteal fossa 362,365 +abduction of 365f Population dynamics 496 Port wine color 240 Portable sensors 566 +Positive pressure ventilation 432 Positive serological reaction 282 Postabortion care 524 +Postcoital contraception 511,522 Posterior arm +delivery of 363f extraction of 383 +Posterior reversible encephalopathy syndrome 212, 212f +Postmaturity management of 309fc syndrome 308,487 +Postnatal physiotherapy 279 Postpartum 142, 261 +blues 53 cardiomyopathy 416 care 290 +depression, risk of 220 +depressive disorders, high-risk factors for 417 +eclampsia 416 exercise 145 +hemolytic uremic syndrome 416,580 management 220,226,228 prophylaxis 410 +renal failure 580 +Rh-immunoglobulin prophylaxis 322 thyroiditis 274 +urinary retention 411 vascular collapse 213 +Postpartum hemorrhage 109, 194, 195, 203, 206,234,244,249,256,296,328,369, 380,381,386,387,416,537,549 +causes of 394 late 393 +classification of 386 Postprandial hyperglycemia 51 Post-term pregnancy 310 +complications of 308 +Post-vasectomy syndrome 514 Potassium 151 +chloride 201 +local injection of 181 +Pouch of Douglas 5,6,120,159, 297f, 409 Pouch,superficial 10 +Prague's maneuver 367 modified 367 +Preconception planning 280 Preconceptional counseling 94, 256, 257, +270,274,278,312,595 and care 94 +Index + +Preconceptional folic acid supplementation 94 Prednisolone 228, 280 +Prednisone 279 +Pre-eclampsia 88,89,91,96, 141,184,194, 203,209,211,226,228,229,249,256, 267,288,327,562,583,589 +atypical 226, 229 classification of 229 etiopathogenesis of 211fc features of 183,242 +management of 217t,219fc, 229 nonsevere 229 +prediction of 215 prevention of 215 recurrent 215 +risk factors for 216b,300,302 screening of 215 +severe 211,218,220,22lb,229,301,370 severity of 213 +Pregestational diabetes mellitus 218,267 Pregnancy 57,58, 60, 94,149, 172,184,209, +226,240,246,249,260,294,295,314, 315, 337,372,373,402, 467,502,559, 562,580,587, 609 +acute fatty liver of 578 advanced 179 adverse effects in 283 +and labor, physiology of 448 basic immunology of 588 cholestasis of 487 complications 86, 300,563,587 continuation of 525 +dating 87t +diagnosis of 61-63, 66, 68 duration of 61, 68 +ectopy 294 +effects of 227,228,256,268,277,279,280, 283,291,295,296,298,314,329 +failure +early 600 rate 497 +false 66 first 327 +half of 384 +trimester termination of 167 folate deficiency 253 +high-risk 585 hypertension 229 immunological test for 66 interstitial 178, 178f +late 52, 66,149,319, 578 loss,mechanism of 154 maintenance of 22 +management of 296,313, 316, 317fc mask 46 +normal 86,183,192,210,413,608 periods of 56 +positive signs of 66 postcesarean 370 postmature 310 problems 419 proteins 56 +rarly 144, 149, 153, 179, 319 rate,overall 511 +risk 511 +sign of 46, 66 stage of 415 tendency of 324 + + + +termination of 166 test 62t,68,178 +positive 63 uses of 63 +vaccines in 93 warning signs of 94 +Preinduction score 488 Prelabor 11O Premature rupture 123 +Prematurity 255,355,367,372,375,430, 562,568 +manifestations of 430 prevention of 432 retinopathy of 431, 448 risk of 295 +Premenstrual hysterocervicography 162 Prenatal care, procedures of routine 89t Prenatal cytogenetic testing 107 Prenatal diagnosis 104,277,312 +screening for 107 Prenatal education 493 Prenatal exercise class 91 Prenatal genetic +counseling 102 screening 102, 327 +Prepregnancy counseling 228, 273,278 Prepregnancy health care and counseling 562 Prepregnant health status 248 +Pressure necrosis 381 Preterm birth 300,314,593 +late 304 +syndrome,spontaneous 165 Preterm breech 364 +delivery of 361 Preterm delivery 200,237 +Preterm labor 108,165,169,194,203,215, 234,268,292,300,304,407,473,525, 562,586 +arrest 302, 304 etiopathogenesis of 301, 301fc +management of 302, 302fc, 303, 432 prevention of 302 +risk of 304 syndrome 301 +Previa 327 +Previous childbirth,signs of 66 Pricking sensation 61 Primaquine 283 +Primigravida 46, 87, 114, 216, 218, 373, 378, 543 +Primipara 87 +Primitive mesenchyme 24 Primitive streak 24 Primordial follicles 8,17 +Priscilla White's classification 267 Prochlorperazine 151,152 Progenitor cells 596 +Progesterone 46, 50, 55,57,58,85,109,113, 143,148,150,154,156,257 +effect 53 levels,low 57 +natural micronized 163 only pill 477 +receptor antagonists 488 supplementation 302 therapy 163 +Progestin 167,280, 506, 507,51O implant 187 + + + +only contraception 148 only pill 146,262,272,509 +use of 170 parenteral 262 pill, low-dose 513 +Progestogen only contraception 509,513 Prolactin 143,148, 150 +inhibition 413 Prolapse,effects on 298 Prolongation disorder 379 +Prolonged labor 195, 206,315, 378, 380, 387 detection of 381 +Prolonged pregnancy 300,587 postmaturity 306 +Promethazine 152 Pronucleus, female 19 Prophylactic acyclovir 288 +Prophylactic antibiotic 261,299,303, 544,547 +Prophylactic anticonvulsant therapy 220 Prophylactic booster 256 +Prophylactic cervical cerclage 303 Prophylactic chemotherapy 187 Prophylactic ergometrine 322 Prophylactic forceps 318, 536 +delivery 553 indications of 536b +Prophylactic magnesium sulfate 220 Prophylactic oxytocin 364 Prophylactic therapy 255,447 +Prophylaxis 285,327,405,409,411-415,460 intrapartum 306 +Propylthiouracil 273 +Prostacyclin,vascular synthesis of 210 Prostaglandin 50,108-110,158,168,169, +210,313,470,472,472t, 473,488,489t low-dose 167 +synthesis of 109 Prostanoic acid 471 Prosthetic valves 264, 264t Prostin 620 +E2 gel 472 +Protease inhibitors 289 Protein 55,90,91,423, 508 +C deficiency 328 C resistance 155 deficiency 246 hormones 55 metabolism SO S deficiency 328 +tests for 210, 606 urine for 242 +Proteinuria 89, 145, 183,209-211, 218,293 presence of 228 +severity of 229 Proteus 285 +Prothrombin gene mutation 328,414 Prothrombin time 581 f +Proton pump inhibitors 254 Protozoa! infestation 283 Protraction disorder 340, 379,381 Pseudocapsule 171 +Pseudocyesis 66 Pseudogestational sac 599 Pseudomonas 158,284 +aeruginosa 573 Psychiatric disorders 417 +primary 417 + + + +Psychiatric illness 94, 417 Psychoprophylaxis 480 Psychosis 53, 416 Psychotherapy 417,418 +interpersonal 418 Ptyalism 92 +Puberty 8 +Pubic arch 83,84f,332,335,363 Pubic crest 79f +Pubic tubercle 79f Pubovaginalis 10 +Pudenda! nerve block 482, 486, 532, analgesia 82, 199 +Pudendum 1 Puerpera 87 +Puerperal emergencies 416, 418 Puerperal infection 407 Puerperal psychiatric illness 417 Puerperal pyrexia 407,409 +causes of 407b, 418 +Puerperal sepsis 244, 394,407, 408b, 416, 537,587 +causes of 418 predisposing factors of 407 +Puerperal sterilization 281 Puerperal venous thrombosis 413 +Puerperium 93, 146{, 148, 195, 234, 249, 262, 272,297,299,313,328,329,411-413, 417,468,515 +abnormalities of 407 effects on 2 96 +Pulling cord 396 +Pulmonary angiography 415 Pulmonary artery catheter values 591 Pulmonary circulation 41 +Pulmonary edema 185,213,214,221,222, 225,263,283,285 +Pulmonary embolism 222,386,396,413, 415,416 +signs of 415 +Pulmonary function tests 279, 608t Pulmonary hemorrhage 448 Pulmonary hypertension 263,421 +primary 264 +Pulmonary infection 407,416 Pulmonary insufficiency 285 +acute 184, 185 Pulmonary maturity 99 Pulmonary surfactant 442 +composition of 441 f estimation of 99 +Pulmonary syndrome 430 Pulmonary valve stenosis 263 Pulmonary vascular reistance 49 Pulsatility index 98 +Pulse 128,141 maternal 128, 306 oximeter 225 +rate 124 +wave ultrasound 598 Pustulosis 460 Pyelonephritis 256,407 +acute 284 Pyopagus 190 Pyrazinamide 281 Pyrexia,control of 288 +Pyridoxine 152,281,413 Pyrimethamine 284 + + + + +Q + +qSOFA score,modified 577t Quadruple test 103 Quadruplets 200 +Quality data collection 556 Quickening, date of 67 Quinine 283 +Quinolones 478 Quintero staging 196b + +R + +Rabies 93 vaccine 428 +Rachitic flat pelvis 332, 333f Radiation 462 +exposure 415 +Radical hysterectomy 295 Radioactive iodine 274 Radiology 604 Raltegravir 289 +Random blind sutures 401 Ranitidine 478 +Rapid eye movements 567 +Rapid influenza diagnostic tests 286 Rapid population growth 496 Rashes, eruption of 287f +Real-time sonography 311 Rectal artery,inferior 400 Rectal examination 401 Rectal injury 406 +Rectal mucosa 398 Rectal muscles 398 Rectocele 298 +Rectovaginal fistula 381,561 Rectum 406,421 +Rectus abdominis 15 +Rectus sheath hematoma 404 Recurrent attacks 415 +Red blood cells 48,247, 585 volume 141 +Red cell +alloimmunization 318, 323, 329 antigens 319 +folate 254 Referral system 559 +Reflects fetal nutrition 98 Reflex +behaviors 421 irritability 443 pain 411 rooting 421 swallowing 421 +Regenerative medicine 596 Regional analgesia 378 Regional anesthesia 482 Relaxin 58,85, 92, 113, 488 Remifentanil 481 +Renal abnormality 213 Renal agenesis 205 Renal anomalies 208 +Renal circulation,characteristics of 578 Renal cortical necrosis,bilateral 212 Renal disease 228 +chronic 227,487 effects of 228 + +Index ml +Renal dysfunction 285 development of 216 +Renal failure 151, 215, 283,286 acute 159,222,578,579{ end-stage 228 hemodialysis for 411 pathology of acute 578 prerenal acute 578 prevention of acute 579 +Renal function 141,227 mildly compromised 227 +Renal hypoplasia 39 Renal medulla 256 Renal plasma flow 52 Renal transplant 228 +Renal transplantation,effects of 228 Renin-angiotensin system 47 Reperitonization 546 +Replacement coagulation factors 585 Reproductive morbidity 561 Reproductive mortality 558 Reproductive organs,anatomy of female Reproductive tissues 596 +Reproductive tract infections 557 Rescue therapy 303 +Resistance index 98 Respiration 577 +initiation of 442 Respiratory acidemia 96 Respiratory alkalosis 278 +state of 51 +Respiratory distress 285,420,445 causes of 446t, 466 +syndrome 99,269,409,442, 446fc Respiratory function 33 +Respiratory morbidity,neonatal 314 Respiratory rate 577,608 Respiratory support 432 +Respiratory system 40, 51, 54, 52t, 461 Respiratory tract,development of 431 Resuscitation 444fc, 466 +drugs used for 445 Reticulocyte 48 +Retinal detachments 215 Reti noids 4 78 +Reti nopathy 286 Retraction 112 +effects of 11 3 ring +dystocia 346 pathological 115,344 +Retrolental fibroplasia 448 Retro-orbital pain 288 Retroplacental clot,massive 583 Rh +alloimmunization 320 +anti-D immunoglobulin 321 antigen complex 319 immune globulin 322 incompatibility 310 +isoimmunization 57,169,487,562,589 sensitization 319 +Rh-D alloimmunization,prevention of 321 Rhesus isoimmunization 204, 359 Rheumatic fever, recurrence of 260 Rheumatic valvular lesion 259 +Rh-negative blood, transfusion of 327 Rhythm method 520, 520t +ml Index + +Rhythmic respiration 419 Rhythmic uterine, absence of 239 Riboflavin 91 +Rifampicin 281,282 Rigid cervix 400 +Rigid inelastic perineum 527 Rilpivirine 289 +Ringer's solution 175, 185, 198, 224,313, 318,343,345 361,388 +drip 242 Ripe cervix 110 +Ritgen's maneuver 130, 130f Robert's pelvis 332, 333 Rohr's stria 32 +Roll over test 216 Ropivacaine 482 Rothera's test 606, 607t Round ligament 140 +pain 92,293 +Rubber catheter,simple 609 Rubella 33, 93,166, 286 +infection 421 +Rubin's diagnostic criteria 180f Rupture 297,403, 404t +complete 403, 404 extraperitoneal 171 incomplete 403, 404 interstitial pregnancy 178f lower segment 344 +sites of 171 +spontaneous 376, 402-404 tubal ectopic pregnancy 181 tuboovarian abscess 410 uterus +etiology of 401, 402fc management of 405fc, 406 +s + +Sacral angle 80 +Sacral promontory 81,403 Sacrococcygeal joint 10, 85, 335 Sacrocotyloid diameter 370 Sacroiliac articulation 79f, 85 Sacroiliac joint 10, 82, 85, 348 Sacrosciatic notch 332, 335 Sacrum 85, 332, 335, 356 +Safe motherhood 554,557, 557t, 564 initiative 554 +Safe vaginal delivery 377 Saheli 509 +Saline induced abortion 583 Salpingectomy 176,1 76f, 177 Salpingitis 170,408 Salpingostomy 177 +Sandoz 470 Scalp +beneath 78 electrodes 566f hair 420 injuries 456 +Scanty liquor 96, 360 Scaphoid abdomen 434f Scar 403 +classical 314, 315 ectopic pregnancy 180 effects on 314 endometriosis 529 + +integrity of 314 surgical 90 tissues 47 +Scar dehiscence 314, 315,403 management of 405fc +Scar rupture 31 lb, 402-404 evacuation of 315 incidence of 314 +risk of 546 Schistocytosis 212 Schroeder's ring 343 Schultze method 117f Scissors, long straight 612 Scoliosis 333 +Scoliotic pelvis 333f Score system 361 +Screening fetal anomalies 601 Scrotum 2, 420 +Sebaceous glands 40 Second trimester 63, 90 +abortions 154 miscarriage 162 +Secretion 46 +Secretory columnar cells 7 Sedatives 159,477,481, 485 Segmental resection 177 Seizure 454 +causes of 466 prophylaxis 475 +Selective growth restriction 197 Sensory stimuli 479 +Sepsis 105, 184, 215, 234, 421,449,451, 525, 562,575 +clinical signs of 141 early-onset 458 prevention of 414 risk of 184 +supportive treatment for 459 syndrome 587,591b +workup 446 +Septic abortion 158,578, 158b Septic foci,surgical removal of 411 +Septic pelvic thrombophlebitis 407,408, 410,414,549 +Septic pneumonia 222 +Septic shock 285, 408,409,574 management of 41O pathogenesis of 573fc +Septic thrombophlebitis 416 Septicemia 285,408,409 +risk of 41 O Septostomy 196 +Serial ultrasonography 324 Serosa 401, 403 +Serum 608 albumin 451 bilirubin 254 +creatinine 227, 578 electrolyte 159, 301 +levels 446 ferritin 51,258 +normal 249 iron 51,247,254 +normal 249 lactate 159 magnesium 224 markers 301 phosphorus 92 + + +potassium 504 progesterone 156,174 prolactin 58 +protein bound iodine 59 transaminases 151 +urea 409 vitamin Bl 2 254 +Sexually transmitted disease 519 infections 499,557 +Shake test 99 +Sheehan's syndrome 58, 241, 244, 381, 387 Shepard's formula 67 +Shirodkar's operation,steps of 164 Shirodkar's technique 164f +Shock 184,185,203,215,241,242,244,249, 328, 381, 386, 389, 396,401,416, 525, 549,572 +classification of 574, 574b clinical 389 +features of 574 degree of 396 develops 397 extracardiac 574 features of 172 index 389 +assessment of 394 late 574 management of 575 neurogenic 574 nonhemorrhagic 574 +pathophysiology of 572,584 proteinuria 240 +syndrome 288 treatment of 401 usual treatment of 397 warm 574 +Short cervix 302 +Short cord 208, 241, 360 +Short curved obstetric forceps 531, 616f Shoulder 356 +assisted delivery of 131f birth of 120, 349 delivery of 121f, 129,130 +posterior 358 impaction 383f tip pain 172 traction 364,364f +Shoulder dystocia 266, 267, 382, 383, 385, 398 +complications of 270 prevention of 383 problem of 271 +Shoulder presentation 373 management of 374, 374fc +Shunts 31 Siamese twins 190 Sick placenta 241 Sickle cell +anemia 597 +beta-thalassemia 256 disease 91, 256 hemoglobinopathies 256 trait 256 +Sickling phenomenon 256 Sideropenic dysphagia 249 Sildenafil 217,264 +Silicon cups 540 + + + +Silverman-Andersen scoring 446 Sims' double-bladed posterior vaginal +speculum 610 +Sims' posterior vaginal speculum 524 Singer's alkali denaturation test 244 Singer's test 607 +Single groin traction 365f Single implant rod 51 lf Single layer stitch 547 +Single puncture technique 516 Singleton 375 +gestations 302 pregnancy, course of 47 +Sitz baths 145 Skeletal system 53 Skene's ducts 2, 12 Skene's glands 1, 2 +Skilled birth attendant 557, 559,560,562 Skin 39,50,203,408,457,591 +changes 53 color 419 infections 460 part of 2 +.rashes 288,420 +Skin-to-skin contact 138 Skull +areas of 76 bone 458 diameters of 77 fracture of 358 +Slapped cheek appearance 287 Sleep 46, 87, 145 +apnea 46 cycle 568 deep 567 +disorders,primary 46 Sloughing fistula 405,406 Snowstorm' appearance 184 Sodium 151,427 +ferric gluconate 252 fractional excretion of 578 nitroprusside 474 retention,causes of 47 +Soft tissue abnormality 379 obstructions 381 +Solid organ transplantation 589 Somatomedin inhibition 268 +Sonography 64, 67,193, 232, 307, 308, 359, 371,384 +Sound +disappearance of 89 muffling of 89 +Sound scar 314 tests of 314 +Spastic lower segment 341,343 Spectral Doppler sonography 414 Speculum examination 304 Spence axillary tail 13 +Sperm +capacitation 18 + + + + +Spermicide 520,522 Spermiogenesis 18 Sphincter ani externus 399 Sphincter injury 398b +Sphincter urethrae membranacea 10 Sphingomyelin 100 +Spina bifida 602f open 202 +Spinal anesthesia 264,271,483,486 side effects of 484f +Spinal epidural analgesia combined 484 continuous 484 +Spine 332,421,458,601,604 maternal 69 +Spiral artery 6f, 29,161,589 Spironolactone 473 +Splanchnic circulation, characteristics of 578 Spleen 89 +Splenectomy 258 +Spontaneous expulsion 373,502 Spoon feeding 427 Squamocolumnar junction 6 Squamous cells 45 +Squamous epithelium 2 +Squamous intraepithelial lesions 295 Stallworthy's sign 232 +Staphylococcal exotoxin 409 Staphylococcus 158, 408 +a/bus 407 +aureus 284,407,409 epidermidis 412 +Static endometrial hypoplasia, producing +505 +Status asthmaticus 279 Status eclampticus 222, 225 Stem cells 596 +properties of 596 sample collection 596 sources of 596 transplantation 255 +Stem villi 28, 29f primary 23, 28 +Sterile warm towel 432 +Sterilization 147,262, 272, 318, 513,518, 609,619 +hysteroscopic methods of 518 male 514 +operation 170 Sternocleidomastoid 457 Sternomastoid hematoma 457 Sternomastoid tumor 420 Steroid 57,143,212 +hormones 55, 56, 60 functions of 57 +therapy 237 +Steroidal contraceptions 146, 278,504 Steroidal contraceptives, types of 505fc Steroidal hormones 57 Steroidogenesis 7 +Stillbirth 86,195, 313,563,587, 593 + +Index Im + +Streptococcal toxic shock syndrome 408 Streptococcus 300 +viridans 412 Stress 340, 425 +incontinence 52,298,411 diagnosis of 411 +maternal 300 oxidative 210 +urinary incontinence 286 Stretched perineum 130 Striae 64 +albicans 47 gravidarum 47, 73f +Stripping membranes 490, 491 Stroke volume 50 +Strama 45 Stromal cells 5 Stromal tissue 31 +Structural chromosomal abnormalities 105 Subcapsular hematoma 212 +Subclinical hyperthyroidism 274 Subclinical hypothyroidism 274 Subcutaneous tissues 15,41 Of, 457 Subgaleal hematoma 456 Submentovertical diameter 370f Subpubic angle 83, 332, 335 Subsequent adhesions 546 Subtotal hysterectomy 176,550 +benefits of 550 Suckling, frequency of 143 Suction cannula 402 Sudden infant death 423 +syndrome 147,431 +Sudden postpartum collapse,causes of 416t Sudden uterine decompression 241 +Sugar,tests for 606 Sulpiride 144 +Superoxide +anion radicals 210 dismutase 268 +Super-subparietal diameter 333 Supine hypotension syndrome 50, 241 Supplement therapy 197 +Supportive therapy 274, 393 Suppression, medical methods of 144 Supralevator hematoma 401, 401 f Suprapubic pressure 125, 383 Suprapubic region 125 +Surface epithelium,loss of 412 Surfactant replacement therapy 447 Surfactant therapy 432,449 +Surgery 514 types of 177 +Surgical illness 291 Surgical induction 490 Surgical management 577 Surgical therapy 464 Surprise dystocia 382 Suture 76 +longitudinal 76 +materials, choice of 629 + + + +egg collision 19 tail 18f +Spermatids, development of 18 Spermatogenesis 18 Spermatozoa,phagocytosis of 499 Spermatozoon 19, 20 +structure of mature 18, 18f + + +causes of 563t, 564 evacuation of 311 varies,recurrence of 311 +Stitch, removal of 165,529 Stomach,overdistension of 425 Stool, examination of 249 +Streptococcal infection,group B 283 + +Symphysiotomy 382,383,552 +Symphysis fundal height 65, 6Sf, 96, 96f, 435, 439 +Symphysis pubis 72, 79f, 80, 81, 83, 84, 90, 95,117,12Sf, 140,140f +back of 363 +posterior surface of 335 +ID Index + +Syncopal attack 501 Syncope 93, 172 Syncytial knots 32 +Syncytiotrophoblast 22,28, 31,55,57 Synovial cavity 84,85 +Synovial hinge joint 85 Synthesis 109 Syntocinon 265,279 Syntometrine 470 Syphilis 162,281,310 +clinical features of congenital 282 Syphilitic diseases 259 +Systemic disorders 561 Systemic fluconazole 461 +Systemic inflammatory response syndrome 573,574 +Systemic lupus erythematosus 162,280,31O Systemic vascular resistance 49 +loss of 573 Systolic murmur 49 + +T + +T sign 600 Tachyarrhythmias 262 +Tachycardia 183, 185,259,415,568 persistent 158 +Tachypnea 158,185,420,448 Tachysystole 344, 468, 472 Tacrolimus 228 +Tamponade 61O Tangential pressure 354 Tay-Sachs disease 105 Tazobactam 160 +Teeth 88 Teicoplanin 160 +Temperature rhythm 520 users of 520 +Tentorial tear,mechanism of 456 Tentorium cerebelli 358,45Sf Teratogen information databases 478 Teratogenesis 268 +Teratogenic disorders 96, 102 Teratogenic drugs 166 Teratogenicity 462 Teratogens 486 +Term pregnancy,classification of 306 Terminal villus, structure of 29 +Termination of pregnancy 152, 169, 229,264, 268,277,384,526 +mid-trimester i 68 Testes 8,420 +Tetanus 89 neonatorum 461 protects 89 toxoid 89,93 +Tetracycline 477 Thalassemia 106,255 +syndromes 257 Theca cells 55 +Theca lutein cyst 184, 187, 188 Therapeutic dose 251 Therapeutic goals 394 Therapeutic termination 286 +place of 260,281 Therapy,response of 251 Thermoregulations 444 Thiamine 91,151 + + +Thiazide 473 +Thick blood film 409 Thiopentone sodium 225 Third trimester 90 +ultrasonography 602 +Third-stage bleeding,management of 388 Thoracic cavity 464f +Thoracic sensory 143 Thoracopagus 190 Throat 408 Thrombin 387 +time 581f +Thrombocytopenia 213,214,254,257,283, 286, 287,293 +Thromboembolic disorders 549 Thrombophilias 154,216,241,310,311,328, +413 +Thrombophlebitis 159, 387,389,409, 413 Thrombophophylaxis 548 Thromboplastin +liberated 583 release of 581 +rich liquor amnii 583 Thromboprophylaxis 280,327,414,545 Thrombosis 117,409 +risk of 513 +Thrombotic microangiopathy 578 Thrombotic thrombocytopenic purpura 258 Thumb 372 +Thyroid 58, 94 abnormalities 154, 155 autoantibodies 161 disorders 328 dysfunction 273,31 O function 142 +test 163,451 gland 58 +hormone testing,indication of 274 storm 274 +Thyroidectomy 274 Thyrotoxicosis 303 +Thyrotropin releasing hormone 441 Thyroxin 150 +binding globulin 59 Tidal volume 608 Tissue +anoxemia 321 extrafetal 596 extraperitoneal 15 hypoperfusion 409 pressure 580 +resistance, peripheral 265 Tocolytics 165,485 +agents 303,473,475t contraindications of 303 drug 302, 540 +Tone up back muscles 146 Tongue 88 +tie 420 +Tonic contraction,generalized 343,343f Tonic uterine contraction 344 +Tonsils 88 Tonus 112 +Total cortisol,level of 60 Total fertility rate 555 Total hysterectomy 403f +Total iron binding capacity 247 Toxic features, presence of 413 + + +Toxic shock syndrome 409 Toxins 435 +Toxoplasma 154, 310 gondii 33,284 +Toxoplasmosis 1 OS, 162,284 Traction 535 +force 530 +rods, identification of 531 Tranexamic acid 393,394 Transabdominal cerclage 303 Transcerebellar diameter 599 Transcervical balloon catheter 492 Transcervical sterilization 522 +Transcutaneous electric nerve stimulation 480 +Transdermal patch 522 Transferrin 247 Transplacental infection 284 Transplacental therapy 465 +Transvaginal pudenda I block anesthesia, methods of 483( +Transvaginal route 483 +Transvaginal sonography 63t, 156, 599, 599t Transvaginal ultrasonography 63 Transvaginal ultrasound 599 +Transverse incisions,low 14 Transverse lie 371,540,541 +positions of 371 f Transversus abdominis 14 +Trauma 241, 242, 291, 387, 402, 563, 587 prevention of 414 +Traumatic bleeding 400 management of 388 +Traumatic fistula 405 +Traumatic postpartum hemorrhage 393 causes of 400 +Traumatic rupture,pathology of 403 Treponema pallidum 33,281,282 Trial labor +advantages of 339 conduction of 338 termination of 339 Triangular ligament 10, 11 +Trichomonas 93 vagina/is 294 +Tricyclic antidepressants 417 Triglycerides 33 +Trigone 12 +Trilaminar embryonic disk,formation of 24 Triphasic pill 512 +Triple test 107 +Triplet pregnancy 197f ultrasonographic diagnosis of 201f +Trisomy 356 Trisomy 21 463,593 +Trophectoderm 21,22 biopsy 106 +Trophoblast 22,29,185 atypia 188 +cells 29, 32, 37 hyperplasia 188 invasion 210 proliferation 37 +Trophoblastic cells 184 Trophoblastic disease 273 Trophoblastic proliferation 184( Trophoblastic tissue,invasion of 180 Trophoblastic tumors 58 + + + +Trophosphere 23 +True postpartum hemorrhage 386 management of 389 +Trunk +birth of 120, 349 +delivery of 129, 130,356,546 Tubal abortion 171 +Tubal ectopic pregnancy diagnosis of 173 management of l 75fc +Tubal mole 171 Tubal mucosa 408 +Tubal pregnancy 170, 178 chance of 170 prognosis of 177 recurrence of 177 termination of 173{ +Tubal rupture 171 +Tubal sterilization 517(, 518 hazards of 517 +Tubal surgery 170 +Tubal twin pregnancy l 78f Tube +delivery of 515 developmental defects of 170 functions of 7 +Tubectomy 169,515,518 steps of 5 l 6f +Tubercle bacillus 33 Tuberculin skin test 280 Tuberculosis 88, 246,280 +active 281 congenital 280,281 +Tubular necrosis,acute 578 Tumor +effects of 297 necrosis factor 21 O removal of 299 +Tunica albuginea 8 +Turner's syndrome 105,420 +Twin 71,190, 191,200,203, 355,372, 375, 411 +anemia-polycythemia sequence 196 conjoined 197, 200,385 +fraternal 190 genesis of 190 gestation 550 +growth,discordant 195 +peak sign 193, 193(, 194,194(, 600 placenta 191f +reversed arterial perfusion 196 vanishing 192, 195 +Twin pregnancy 188, 189(, 194(, 197, 201 complications of 201 +diagnosis of 201 monoamonotic 201 screening in 195 +Twins-twin transfusion syndrome 196,310 Two-arm lever theory 119 +u + +Uchida technique 515 Ulcerative colitis 423 Ulipristal acetate 511 +Ultrasonogram 384{, 503f, 623(, 624(, 626{ Ultrasonographic growth profile 602f + +Index ID +Ultrasonography 63, 64, 66,73, 87t, 101, 201, Urinary complications 411 335,367,385,393,451,502,599,601, Urinary incontinence 141, 147, 540 627{ Urinary infection 92 +mid-trimester 601 Urinary output 214,224 Ultrasound 566 Urinary problems 141 +Doppler parameters 436 Urinary retention 286,540 +examination 94,437 Urinary stem 39 images 598 Urinary system 39, 52 indicated cerclage 303 Urinary tract 141 +safety of 599 abnormality 285 +UUUmmmsfcbDbbliloiniioolllwiiigpsccciunlapaaevrtlllleerecaaa3lroororp6ttsrcfeea,dti2urrrt4iyty0da21u8lwy3m3c,,6a2o42,v7r5344ed176,1f,20o,547r972mf801, ,3,996698,0,3f2463(,43,74,3260,86f0, 8 Uriniaadcnencoifpulael5s4retlcyite65cstisc,kit1rio8ikeso,on9t5tnfe1,e78n15so197t95t4fi,2o1686,n03826o,,162f408,46721,46320,02,4490,72,9481,1, 416 ab 231,234f,311,321,36 389f,602 incontinence of 304, 411 bloadvantages of 596 outputc128,242 409 +examination of 218,606 +normalities of 626f +od 596, 608 +midstream 89 +spe imen of +care 422 +clamping 326 retention of 286, 298, 411, 609 delayed 137 suppression of 411 +sample of 141 +compression 376 +factors 435 +insertion 602 +primitive 36f +prolapse 376 +chance of 491 +Urobilinogen 606f +Uro-dip reagent strips 606f Urogenital diaphragm 10 Urogenital sinus 4 Urogenital triangle 10 +Umbilical grip 71,348 Uropathy,obstructed 205 Umbilical hernia 385,463 anomalies 300 +Uterine 27, 154 +congenital 36 +Umbilical sepsis 460 +arteriovenous fistula 393 Umbilical vein 40,99, 105,134 axis, centralized 3 71 +blood flow 50,54 +body 479 +closure of 41 +Umbilical venous pulsations 436 contractile systems 109 Umbilicus 73,421 curette4614 +Umbilical vessels 27f +cycles 6 +Undescended testicle 463 +Unfractionated heparin 415 descent, slight degree of 147 Unicornuate uterus 162 +devascularization 394 +distension 108 +drainage 144 +Unruptured interstitial pregnancy l 78f +Unruptured tubal ectopic pregnancy 172, dressing forceps 614 management of 176 dysfunction 379 +174{,181, 623{ +enlargement 44 +Upper airway obstruction 46 factor 241, 348,379 +Urachus 36 +UUUUUrrrrreeeeeaedtttteeeepnisrrrrltiipaaecc9llsradtim,snuc1aejna52mumn,ra5yeeg2ln5e5t4o49f0152 ihhiiiffrnnniebryevfeeipierteglraocetrhb2iitsradits4iioolti22in2t6nmy046,,43t2u,sy01,leap286vt4e3,eio49s,rn3e,0o229f19473666,953,8368471, 4, 31718 +154 +Urethra 120,298,398, 406, 411 lacerations 549 +female 12 longitudinal 73 +penile 2 massage 137, 390 +Urethral injury 406 musculature 386 Urethral opening 2 pacemaker 341 Urethritis,acute 285 palpation 404 Uric acid 210 pathologies 395b Uridine diphosphoglucoronate glucoronosyl peritoneum 44 +transferase 449 products 41 O Urinalysis 151 prolapse 299{ Urinary antiseptics 411 retraction 111, 113 Urinary bladder 12, 66 sepsis 411 +*· +Index + +septa,hysteroscopic resection of 163 shape 65 +signs 62 +sinuses,open 392 size 188,601 souffle 64 +sound 612 stretch 108 synechiae 525 +systole,degree of 112 tachysystole 489 tamponade 392 tenderness 241 tetany 343 +tone 311 +tonus assessment 138 unification operation 163 vessels,branches of 403 wall 66 +Uterine action 342 abnormal 340, 345, 346 +types of 340fc Uterine activity 341, 380 +nervous control of 479 Uterine artery 4, 5,Sf, 434,436 +anastomosis 392 +Doppler waveforms of 216( embolization 237, 392 ligation of 392, 393f +Uterine bleeding abnormal 502 dysfunctional 506 +Uterine cavity 5,26f, 73,184,502f device inside 503 +half of 7f Uterine closure 546 +technique 315 +Uterine contraction 29,44,71,109,112,113, 116f, 124f, 301,340,341,343,346,351, 372,381,448,469,480,568( +abnormal 378 cessation of 404 height of 404 +normal 340, 341,341f, 342( pelvic adequacy 378 regular 108 +strong 400 +Uterine incision 485,545, 545( extension of 549 +suture of 548 +Uterine malformation 163,169,360 suspected 601 +Uterine muscle 110,117f,467 fibers,retraction of 112( +Uterine perforation 168,169 diagnosis of 502 management protocol of 525 risk of 187 +Uterine rupture 382,402,468 pathognomonic of 405 +Uterine scar 318 dehiscence 404t evacuation of 315 +Uterine tube 5,6 ampullary part of 19 +Uterine wound 314, 548 healing of 314 +suture of 547 + + + +Utero-ovarian artery 393( Uteroplacental apoplexy 239 Uteroplacental arteries 29 Uteroplacental bed 211, 229 Uteroplacental circulation 29 Uteroplacental insufficiency 205, 587 Uteroplacental vascular bed,thrombosis +of 154 Uterosacral ligaments 11 Uterovaginal canal 400 +exploration of 388, 552 Uterovesical pouch 6 +Uterus 4,6,43,47,64,95,115,11 Sf,116,133, 139,140,144,157,158,171,184,232, 342,347,368,372,381,388,390,396, 408,410,411,509 +anatomy of 372 +bimanual compression of 390f body of 43 +centra I ized 69 +congenital malformations of 154,163, 294,355,359,372 +contraction of 132 cornua of 5 dextrorotation of SO double 162 enlargement of 71 evacuation of 159, 160 feel of 183 +fundus of 89 +generalized tonic contraction of 343( height of 67,71, 73f, 203 +hypertonic state of 342 infections of 158 +internal blood supply of 6f inversion of 396,396f, 416 involution of 139 +irritable 360 +lateral border of 403f ligament of 11 f, 15 longitudinal muscles of 113( lower pole of 70 +lower segment of 11 St,403f outside 503 +overdistension of 387,411 part of Sf +pathologic anatomy of 344, 373f perforation of 183, 184,502 polarity of 113, 340 +pregnant 62 prolapse of 411 replacement of 397 retroverted 297 +routine exploration of 318 rupture of 169,328, 343, 345,360, +371,401,402, 403f, 406,623, 623( +sensitivity of 488 septate 162 +size of 67,139,183, 232 sparing 396 +suction evacuation of 185 sudden decompression of 242 tone of 135 +torsion of 241 uninjured 404 +walls of 117 + + + +V + +Vaccination,active 286 Vaccines 93 +schedule 428b Vacuum 540 +aspiration 167, 526,552 delivery 539 +extraction 353 +extractor,application of 539f Vagal stimulation 40 +Vagina 3,4,9, 43, 46,66,134,140,141, 399,509 +congenital malformations of 294 Vaginal artery 4 +Vaginal birth after cesarean section 316,550 Vaginal bleeding 165,172,173,183,186, +200,241,316,599 amount of 404 causes of 172 excessive 400 history of 90 irregular 147 +slight gush of 125 +Vaginal breech delivery 359-361, 367 complications of 358 management of 361 +Vaginal contraceptive 519(,520 sponge 520 +Vaginal delivery 144,198, 201, 233, 237,243, 302,317,325,342,353,370,375,377, 382,399,543 +assisted 530,530t planned 290 purpose of 487 +Vaginal discharge 93,141,298 abnormal 294 +Vaginal evacuation 187 complications of 185 +Vaginal examination 64,67,74,90,126,127, 128,129,184,232-234, 237, 348, 368, 372,523 +contraindications of 237 indications of 127 +Vaginal flora 407 Vaginal ligation 516 Vaginal microbiome 53 Vaginal mucosa 528 +repair of 529f Vaginal obstruction 543 +Vaginal operations, destructive 405 Vaginal operative delivery 351 Vaginal orifice 2 +external 4 +Vaginal pads,inspection of 304 Vaginal pessary 472,571 Vaginal plastic operation 294 Vaginal ring 522 +combined 504 Vaginal route 258 Vaginal secretion 4 Vaginal signs 62,125 Vaginal swab 382 Vaginal tablet 472 Vaginal tear 383, 399 Vaginal transducers 598 +Vaginal wall 43, 399 + + + +Vaginitis 294 Valproate 478 Valproic acid 278 +Valsalva maneuver 304 Valvotomy,place of 263 Valvular heart disease 262 Vancomycin 160 +Vanishes 195 Varicella 93, 287 +pneumonia 287 zoster virus 287 +Varicose veins 92 +Vasa previa 208,231,244 Vascular ectopy 153 Vascular spider 47 Vasculopathy 268 +Vasculosyncytial membrane 31 Vasectomy 514 +Vasodilator 475 prostaglandin 210 therapy 576 +Vasogenic edema 212f Vasopressors 576 Vasospasm 210,211 +selective 574 Veins,superficial 413 +Velamentous insertion 37 Velamentous placenta 208 Vena cava +filters,indications of inferior 416 filters,inferior 415 +inferior 40 +ligation of inferior 415 Venous blood, amount of 40 Venous Doppler 99, 436 Venous drainage 7, 29 Venous parameter 99 Venous pressure 49, SO Venous stasis 413 +Venous thrombectomy 415 +Venous thromboembolic diseases 413 Venous thromboembolism 474,508, 594 +management for 414 risk factors for 414 +Venous ultrasonography 414 Ventilation 415 +Ventilatory resuscitation 444 Ventouse 318,353,537 +contraindications of 539b cup 539f,617,617f delivery,indications of 537 +over forceps, advantages of 538 Ventricular septal defect 263 Ventriculomegaly 384 +Verapamil 475 Vernix caseosa 40 Version 540 Vertex 76 +abnormal position of 347 delivery,anterior 351 presentation 200 +Vesical artery,superior 6, 41 Vesicles,finding of 184 Vesicocervical ligaments 11 Vesicovaginal fistula 561 Vesicular mole,diagnostic of 183 + + + + +Vestibular bulb 1,2,3f +Vibroacoustic stimulation 97,101,569 Vicious circle 566 +Vigorous uterine contraction 145 Villous cytotrophoblasts 22 +Villous stroma, hydropic degeneration of 184f +Villus 212 changes 32 +development of 29f +hydropic degeneration of 188 transverse section of 32f +Vincristine 189 Virchow's triad 413 Virginal vulva 1 f Virus 288,310 +live-attenuated 287 Visceral injuries 359,405,458 Vital capacity 52f, 608 +Vital signs +assessment of 422 examination of 419 +Vitamin 90,247,423 A90,91,478 +Bl 151,152 +B12 39, 91, 152,247,253 +B12 deficiency 246,247,254 causes of 254 +B6 149,152,281 C 152,217,247 +D 90, 91,423 E 217 +fat-soluble 33 K 584 +aqueous solution of 432 deficiency 151 dependent 277 +water-soluble 33 Vitelline +duct 36 membrane 17 +Volume replacement 394, 584 +Vomiting 61,92, 149, 194, 250,285, 293, 468,507 +causes of 149 +von Willebrand disease 258 Vulva 1,43,134,363,398 +care of 145 inspection of 235 +Vulva I cleaning 127 Vulval edema 214f +Vulval hematoma 400, 529 Vulval inspection 232 +Vulval pads,periodic inspection of 236 Vulval skin,lacerations of 398 +Vulvar hematoma 400 +w + +Wandering method 536 Warfarin 166,415, 476 Warm sterile fluid 397 +Waste space of Morris 83, 84f Water +bag of 111 + +Index I + +balance 213 intoxication 468 +Weak uterine contraction 353 Weaning 428 +Weight chart, normal 427f Weight gain 47, 507 +abnormal 214 Weight loss 141 Welcome sign 1 10 +Well-flexed fetal head 83 +Wernicke's encephalopathy 150, 151 Wharton's jelly 36,208, 308 +White's classification 267t Whole blood transfusion 584 Whole-hand method 353, 354 Witch's milk 420 +Withdrawal bleeding 393, 507 Withdrawal technique 501 Wood's maneuver 383 Wound +complications 549 dehiscence 410,529 dressing 145 infection 407, 409 scrubbing 410 +Wrigley's forceps 535,616f Wrinkled skin 434f + +X + +Xiphopagus 200f +X-linked disorder 255 X-ray pelvimetty 335 hazards of 335 + +y + +Yasmin 505 Yellow fever 93 +vaccine 428 +Yolk sac 24, 24f, 39,624f presence of 599,624 secondary 24 +Young chorionic villi 182 Yuzpe method 512 +z + +Z technique 252 Zavanelli maneuver 383 Zidovudine 290 +intravenous 290 monotherapy 290 +Zika virus 94,288 Zinc 91 +Zona +hatching 20, 21 lysis of 21 pellucida 18 reaction 19 +Zygosity 190 +determination of 191,191t diagnosis of 190 +Zygote 19, 20 +mitotic division of 20f diff --git a/notes/DC Dutta Obstetrics 10th Edition_3.txt b/notes/DC Dutta Obstetrics 10th Edition_3.txt new file mode 100644 index 0000000000000000000000000000000000000000..d3689d3e73ada9569ac919ef198381f24c890d53 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_3.txt @@ -0,0 +1,2027 @@ + +Ligamentum venosum - - -­ +Liver + + +__, _ ______ Heart +Pulmonary trunk --------- - - - Right ventricle +- + + + + +------ Kidney + + + + + + + + + + + +Fig. 4.2: Change in the fetal circulation after birth. + + +obliteration takes about 1-3 months and becomes Iigamentum arteriosum. +4. Closure of theforamen ovale:This is caused by an increased pressure of the left atrium combined with a decreased pressure on the right atrium. Functional closure occurs soon after birth but anatomical closure occurs in about I year time. During the + +first few days, the closure may be reversible. This is evidenced clinically by the cyanotic look of the baby during crying when there is shunting of the blood from right to left. +Within I or 2 hours following birth, the cardiac output is estimated to be about 500 mL/min and the heart rate varies from 120 to 140/minute. + +Physiological Changes +During Pregnancy + + + + + + +CHAPTER OUTLINE +❖ Genital Organs ► Uterus +❖ Breasts +❖ Cutaneous Changes + + +❖ Weight Gain +❖ Body Water Metabolism ❖ Hematological Changes ❖ Cardiovascular System + + +❖ Metabolic Changes ❖ Systemic Changes + + + + +During pregnancy there is progressive anatomical, physi­ ological and biochemical change not only confined to the genital organs but also to all systems of the body. This is principally a phenomenon of maternal adaptation to the increasing demands of the growing fetus. Unless well understood, these physiological adaptations of normal pregnancy can be misinterpreted as pathological. + +GENITAL ORGANS +VULVA: Vulva becomes edematous and more vascular; superficial varicosities may appear especially in multi­ parae. Labia minora are pigmented and hypertrophied. +VAGINA: Vaginal walls become hypertrophied, edematous and more vascular. Increased blood supply of the venous plexus surrounding the walls gives the bluish coloration of the mucosa (Jacquemier's sign). The length of the anterior vaginal wall is increased. +Secretion: The secretion becomes copious, thin and curtly white due to marked exfoliated cells and bacteria. The pH becomes acidic (3.5-6) due to more conversion of glycogen into lactic acid by the Lactobacillus acidophilus consequent on high estrogen level. The acidic pH prevents multiplication of pathogenic organisms. +Cytology: There is preponderance of navicular cells in cluster (small intermediate cells with elongated nuclei) and plenty of Lactobacillus. + +I UTERUS +There is enormous growth of the uterus during pregnancy. The uterus which in nonpregnant state weighs about 60 g, with a cavity of 5-10 mL and measures about 7.5 cm in length, at term, weighs 900-1,000 g and measures 35 cm in length. The capacity is increased by 500-1,000 times. Changes occur in all the parts of the uterus-body, isthmus and cervix. + +BODY OF THE UTERUS: There is increase in growth and enlargement of the body of the uterus. +Enlargement: The enlargement of the uterus is affec­ ted by the following factors. +■ Changes in the muscles: (1) Hypertrophy and hyperplasia: Not only the individual muscle fiber increases in length and breadth but also there is limited addition of new muscle fibers. These occur under the influence of the hormones-estrogen and progesterone-limited to the first half of pregnancy but pronounced up to 12 weeks. (2) Stretching: The muscle fibers further elongate beyond 20 weeks due to distension by the growing fetus. The wall becomes thinner and, at term, measures about 1.5 cm or less. The uterus feels soft and elastic in contrast to firm feel of the nongravid uterus. +■ Arrangement of the muscle fibers: Three distinct layers of muscle fibers are evident: +(1) Outer longitudinal: It follows a hood-like arrang­ ement over the fundus; some fibers are continuous with the round ligaments. (2) Inner circular: It is scanty and sphincter-like arrangement around the tubal orifices and internal os. (3) Intermediate: It is the thickest and strongest layer arranged in criss-cross fashion through which the blood vessels run. Apposition of two double curve muscle fibers give the figure of '8' form. Thus, when the muscles contract, they occlude the blood vessels running through the fibers and hence called the living ligature (Figs. 5.1 and 5.2). +■ There is simultaneous increase in number and size of the supporting fibrous and elastic tissues. +Vascular system: Whereas in the nonpregnant state, the blood supply to the uterus is mainly through the uterine and least through the ovarian but, in the pregnant state, the latter carries as much the blood as the former. There is marked spiraling of the arteries, reaching the maximum at 20 weeks; thereafter, they straighten out. +.J.. Chapter 5: Physiological Changes During Pregnancy +[] + + + + + + + + + + + + + + + +Fig. 5.1: Schematic presentation of the longitudinal, oblique and circular muscle fibers of the pregnant uterus. + + + + + + + + + + +Blood vessel + + + + +Position: Normal anteverted position is exaggerated up to 8 weeks. Thus, the enlarged uterus may lie on the bladder rendering it incapable of filling, clinically evident by frequency of micturition. Afterwards, it becomes erect, the long axis of the uterus conforms more or less to the axis of the inlet. As the term approaches, especially in multiparae with lax abdominal wall, there is a tendency of anteversion. But in primigravidae with good tone of the abdominal muscles, it is held firmly against the maternal spine. +Lateral obliquity: As the uterus enlarges to occupy the abdominal cavity, it usually rotates on its long axis to the right (dextrorotation). This is due to the occupation of the rectosigmoid in the left posterior quadrant of the pelvis. This makes the anterior surface of the uterus to turn to the right and brings the left cornu closer to the abdominal wall. The cervix, as a result, is deviated to the left side (Ievorotation) bringing it closer to the ureter. +Uterine peritoneum: The peritoneum maintains the relation proportionately with the growing uterus. The uterosacral ligaments and the bases of the broad ligament rise up to the level of the pelvic brim. This results in deepening of the pouch of Douglas. Large areas of the lower lateral walls of the uterus remain uncovered by peritoneum. These places are filled up by loose and vascular connective tissues. + + + + + + + +Figs. 5.2A and B: (A) Marked elongation of the muscle fibers during pregnancy; (Bl Blood vessels in between interlacing muscle fibers. + +Doppler velocimetry has shown uterine artery diameter becomes double, and blood flow increases by eight-fold at 20 weeks of pregnancy. This vasodilatation is mainly due to estradiol and progesterone. Veins become dilated and are valveless. Numerous lymphatic channels open up. The vascular changes are most pronounced at the placental site. +The uterine enlargement is not a symmetrical one. The fundus enlarges more than the body. It is evident by the low down attachment of the round ligaments or insertion of the uterine end of the Fallopian tubes at term. +Weight: The increase in weight is due to the increased growth of the uterine muscles, connective tissues and vascular channels. +Relation: Shape-nonpregnant pyriform shape is maintained in early months. It becomes globular at 12 weeks. As the uterus enlarges, the shape once more becomes pyriform or ovoid by 28 weeks and changes to spherical beyond 36th week (Fig. 7.3). + +Contractions (Braxton-Hicks): Uterine contraction in pregnancy has been named after Braxton-Hicks who first described its entity during pregnancy. From the very early weeks of pregnancy, the uterus undergoes spontaneous contraction. This can be felt during bimanual palpation in early weeks or during abdominal palpation when the uterus feels firmer at one moment and softer at another. Although spontaneous, the contractions may be excited by rubbing the uterus. The contractions are irregular, infrequent, spasmodic and painless without any effect on dilatation of the cervix. The patient is not conscious about the contractions. Intrauterine pressure remains below 8 mm Hg. Near term, the contractions become frequent with increase in intensity so as to produce some discomfort to the patient. Ultimately, it merges with the painful uterine contractions of labor. In abdominal pregnancy, Braxton-Hicks contraction is not felt. +During contraction there is complete closure of the uterine veins with partial occlusion of the arteries in relation to intervillous space resulting in stagnation of blood in the space. This diminishes the placental perfusion, causing transient fetal hypoxia, which leads to fetal bradycardia coinciding with the contraction. +Endometrium: The changes of the endometrium of the nonpregnant uterus into decidua of pregnancy have already been described (p. 21). +Chapter 5: Physiological Changes Du' ring Pregnancy .. + + + + + + + + + + +Anatomical --" internal OS (AIO) + + +'l-- - - Histological internal OS (HIO) + + +.J rn +Figs. 5.3A to C: Elongation and formation of the lower uterine segment at: (A) 8 weeks; (Bl 12 weeks; (C) 16 weeks, + + +ISTHMUS +There are important structural and functional changes in the isthmus during pregnancy. +During the first trimester, isthmus hypertrophies and elongates to about 3 times its original length. It becomes softer. With advancing pregnancy beyond 12 weeks, it progressively unfolds from above, downward until it is incorporated into the uterine cavity. The circularly arranged muscle fibers in the region function as a sphincter in early pregnancy and thus help to retain the +fetus within the uterus. Incompetency of the sphincteric action leads to mid-trimester abortion and the encir­ clage operation done to rectify the defect is based on the principle of restoration of the retentive function of the isthmus {Figs. 5.3A to C). +CERVIX +Stroma: There are hypertrophy and hyperplasia of the elastic and connective tissues. Fluids accumulate inside and in between the fibers. Vascularity is increased, especially beneath the squamous epithelium of the portio vaginalis which is responsible for its bluish coloration. + + +There are marked hypertrophy and hyperplasia of the glands which occupy about half the bulk of the cervix. All these lead to marked softening of the cerix (Goodell's sign) which is evident as early as 6 weeks. It begins at the margin of the external os and then spreads upward. It not only provides diagnostic aid in pregnancy but also the changes in the cervix facilitate its dilatation during labor. +Epithelium: There is marked proliferation of the endocervical mucosa with downward extension beyond the squamocolumnar junction {Fig. 5.4). +This gives rise to clinical appearance of ectopy (erosion) cervix. Sometimes, the squamous cells also become hyperactive and the mucosal changes simulate basal cell hyperplasia or Cervical Intraepithelial Neoplasia (CIN). These changes are hormone induced (estrogen) and regress spontaneously after delivery. +Secretion: The secretion is copious and tenacious­ physiological secretion of pregnancy. This is due to the effect of progesterone. This mucus is rich in matrix metalloproteinase levels of Immunoglobulin G (IgG) +and IgA increase in pregnancy. Vaginal microbial + + + + + +\ i Vessels +, + +Mucous plug + +Squamocolumnar junction ----- Extension of columnar epithelium r + +Fig. 5.4: Changes of the cervix during advanced pregnancy. +.. Chapter 5: Physiological Changes During Pregnancy + + +composition with increased Lactobacillus species is associated with decrease in cervical interleukin 8 (IL-8). This anti-inflammatory Lactobacillus maintains the pregnancy against the proinflammatory cytokine. The mucus not only fills up the glands but also forms a thick plug effectively sealing the cervical canal. Microscopic examination shows fragmentation or crystallization (beading) due to progesterone effect. +Anatomical: The length of the cervix remains unaltered but becomes bulky. The cervix is directed posteriorly but after the engagement of the head, directed in line of vagina. There is unfolding of the isthmus; beginning 12 weeks onwards and takes part in the formation of the lower uterine segment. +FALLOPIAN TUBE +As the uterine end rises up and the fimbrial end is held up by the infundibulopelvic ligament, it is placed almost vertical by the side of the uterus. The total length is somewhat increased. The tube becomes congested. Muscles undergo hypertrophy. Epithelium becomes flattened, and patches of decidual reaction are observed. + +OVARY +The growth and function of the corpus luteum reaches its maximum at 8th week when it measures about 2.5 cm and becomes cystic. It looks bright orange, later on becomes yellow and, finally pale. Regression occurs following decline in the secretion of Human Chorionic Gonadotropin (hCG) from the placenta. Hormones­ estrogen and progesterone-secreted by the corpus luteum maintain the environment for the growing ovum before the action is taken over by the placenta. These hormones control the formation and maintenance of decidua of pregnancy. Thus both the ovarian and uterine cycles of the normal menstruation remain suspended. Luteoma of pregnancy results from exaggerated luteinization reaction of the ovary. +Decidual reaction: There may be patchy sheet of decidual cells on the outer surface of the ovary. These are metaplastic changes due to high hormonal stimulation. +Vagina: There is marked vascularity and hyperemia (p. 62). There is increased glycogen in the vaginal epithelial cells due to rise in estradiol levels. This glycogen maintains low vaginal pH. Lactic acid is a byproduct of lactobacilli which is a protective microbiome to maintain the physiology of pregnancy. + +BREASTS + +The changes in the breasts are best evident in a primigravida. In multipara, who has once lactated, the changes are not clearly defined. +SIZE: Increased size of the breasts becomes evident even in early weeks. This is due to marked hypertrophy and proliferation of the ducts ( estrogen) and the alveoli + + +(estrogen and progesterone) which are marked in the peripheral lobules. There is also hypertrophy of the connective tissue stroma. Myoepithelial cells become prominent. Vascularity is increased which results in appearance of bluish veins running under the skin. Quite often, the 'axillary tail' (prolongation of the breast tissue undercover of the pectoralis major) becomes enlarged and painful. There may be evidence of striation due to stretching of the cutis. +NIPPLES AND AREOLA: The nipples become larger, erec­ tile and deeply pigmented. Variable number of sebaceous glands (5-15) which remain invisible in the nonpregnant state in the areola, become hypertrophied and are called Montgomery's tubercles. Those are placed surrounding the nipples. Their secretion keeps the nipple and the areola moist and healthy. An outer zone of less marked and irregular pigmented area appears in second trimester and is called secondary areola. +SECRETION: Secretion (colostrum) can be squeezed out of the breast at about 12th week which at first becomes sticky. Later on, by 16th week, it becomes thick and yellowish. The demonstration of secretion from the breast of a woman who has never lactated is an important sign of pregnancy. In latter months, colostrum may be expressed from the nipples. For normal changes and lactation, page 59. +Mouth: Phyalism (increased salivation) is an uncom­ mon complication in pregnancy. Reduced ingestion of starchy food may decrease the amount of saliva. Rarely gingivitis may develop that presents as highly vascular pedunculated lesion at the gum. It may bleed profusely (epulis gravidarum). Oral hygiene should be maintained since the beginning of pregnancy. + +Sleep: Most women in pregnancy (90%) report alteration in sleep pattern. However, it is important to exclude other primary sleep disorders (sleep apnea) that are not related to pregnancy. Snoring, upper airway obstruction and obstructive sleep apnea (OSA) are the important ones. Women with these types of sleep disorders have the higher risks of IUGR, gestational hypertension via endothelial dysfunction. + +CUTANEOUS CHANGES +PIGMENTATION: The distribution of pigmentary changes is selective. +1. Face (chloasma gravidarum or pregnancy mask): It is an extreme form of pigmentation around the cheek, forehead and around the eyes. It may be patchy or diffuse; disappears spontaneously after delivery. +2. Breast: The changes are already described (vide supra). 3. Abdomen: +• Linea nigra: It is a brownish black pigmented area in the midline stretching from the xiphisternum to the +Chapter 5: Physiological Changes During Pregnancy .. + +symphysis pubis (Fig. 8.6). The pigmentary changes are probably due to melanocyte stimulating hormone from the anterior pituitary. However, estrogen and progesterone may be related to it as similar changes are observed in women taking oral contraceptives. The pigmentation disappears after delivery. +• Striae gravidarum: These are slightly depressed linear marks with varying length and breadth found in pregnancy. They are predominantly found in the abdominal wall below the umbilicus, sometimes over the thighs and breasts. These stretch marks represent the scar tissues in the deeper layer of the cutis. Initially, these are pinkish but after the delivery, the scar tissues contract and obliterate the capillaries and they become glistening white in appearance and are called striae albicans. Apart from the mechanical stretching of the skin, increase in aldosterone production during pregna­ ncy are the responsible factors. Controlled weight gain during pregnancy and massaging the abdom­ inal wall by lubricants like olive oil may be helpful in reducing their formation. Apart from pregnancy, it may form in cases ofgeneralized edema, marked obesity or in Cushing syndrome {Fig. 8.5). +OTHER CUTANEOUS CHANGES: These include vascular spider and palmar erythema which are due to high estro­ gen level. Mild degrees of hirsutism may be observed and in puerperium the excess hair is lost. + +WEIGHT GAIN ON PREGNANCY +WEIGHT GAIN: In normal pregnancy, variable amount of weight gain is observed. In early weeks, the patient may lose weight because of nausea or vomiting. During subsequent months, the weight gain is progressive until the last 1 or 2 weeks, when the weight remains static. The total weight gain during the course of a singleton pregnancy for a healthy woman averages 11-12 kg (24 lb). This has been distributed to 1 kg in first trimester and 5 kg each in second and third trimesters. Nearly 60% of the total gestational weight gain is due to the combined weight of the fetus, placenta and amniotic fluid. The total weight gain at term is distributed approximately as mentioned in Box 5.1. +During pregnancy, there is variable amount of retention of electrolytes-sodium (1,000 mEq), potassium (10 g) and chlorides. The sodium is osmotically active and partially controls the distribution of water in various compartments of the body. Causes of increased sodium retention during pregnancy are: (1) increased estrogen and progesterone, (2) increased aldosterone consequent on the activation of the renin-angiotensin system and possibly (3) due to increased antidiuretic hormone. The amount of water retained during pregnancy at term is estimated to be 6.5 liters. + + + +■ Fetus-3.3 kg ■ Placenta-0.6 kg ■ Liquor-0.8 kg a Uterus-0.9 kg +a Maternal store (fat and ■ Breasts-0.4 +protein)-3.5 kg ■ Extracellular fluid-1.3 ■ Blood volume-1.2 +Total weight gain = 12 kg + + +',Table s.1·: Pregnancy weight gain recommendations. +· Pre-pregnancy BM/ Total weigh gain Underweight <18.5 kg/M2 28-40lb +Normal weight 18.5-24.9 kg/M2 25-3Slb Overweight 25.0-29.9 kg/M2 15-2Slb Obese 2:30 kg/M2 11-20lb + +The increased accumulation of fluid in the tissue spaces mainly below the uterus is due to-{ l) diminished colloid osmotic tension due to hemodilution driving the fluid out of the vessels and (2) increased venous pressure of the inferior extremities. Thus, mild edema of the legs is common, in an otherwise normal pregnancy. +Importance of weight checking: Single weight chec­ king is of little value except to identify the overweight or underweight patient. Periodic and regular weight checking is of importance to detect abnormality. +♦ Rapid gain in weight of more than 0.5 kg (l lb) a week or more than 2 kg ( 4 lb) a month in later months of pregnancy may be the early manifestation of pre­ eclampsia and need for careful supervision. +♦ Stationary or falling weight may suggest intrauter­ ine growth retardation or intrauterine death of fetus. +Obese women are in increased risk of complications in pregnancy, labor and puerperium (p. 329). +Ideally weight gain should depend on pre-pregnancy Body Mass Index (BMI) level {p. 329). Weight gain for a woman with normal BMI (20-26) is 11-16 kg. An obese woman (BMI >30) should not gain more than 7 kg, whereas an underweight woman (BMI <19) may be allowed to gain up to 18 kg (Table 5.1). +Maternal nutrition and weight gain during pregnancy are directly related to the newborn weight. However, it may not be a specific indicator as there are other factors for low birth weight infant. + +BODY WATER METABOLISM + +During pregnancy, the amount of water retained at term is about 6.5 liters. The water content of the fetus, placenta and amniotic fluid is about 3.5 liters. Pregnancy is a state ofhypervolemia. There is active retention of sodium (900 mEq), potassium (300 mEq) and water. The important causes of sodium retention and volume overload are: +la Chapter 5: Physiological Changes During Pregnancy + +(i) Changes in maternal osmoregulation, (ii) increased estrogen and progesterone, (iii) increase in Renin­ Angiotensin-Aldosterone System (RAAS) activity, (iv) increased aldosterone, deoxycorticosterone, (v) control by Arginine Vasopressin (AVP) from posterior pituitary and (vi) atrial natriuretic peptide. Serum sodium level and plasma osmolality decreases. There is resetting of the osmotic thresholds for thirst and AVP (ADH) secretion. Plasma levels of AVP (ADH) remain unchanged, in spite of increased production. This is due to increased metabolic clearance of AVP by the enzyme vasopressinase from the placenta. Increase in water intake due to lowered osmotic threshold for thirst causes polyuria in early pregnancy. The threshold for AVP secretion has been reset after 8 weeks for a new steady state of osmolality. Thereafter polyuria decreases. +Atrial and brain natriuretic peptides, secreted by atrial myocytes and brain ventricles. These act as diuretics, natriuretics and vasorelaxants. Both the peptides are antagonist to RAAS. + +HEMATOLOGICAL CHANGES + +BLOOD VOLUME: During pregnancy, there is increased vascularity of the enlarging uterus with the interposition of uteroplacental circulation. The activities of all the systems are increased. Blood volume is markedly raised dming pregnancy. The rise is progressive and inconsistent. All the constituents of blood are affected with increased blood volume. The blood volume starts to increase from about 6th week, expands rapidly thereafter to maximum 40-50% above the nonpregnant level at 30-34 weeks. The level remains almost static till delivery (Table 5.2). +PLASMA VOLUME: It starts to increase by 6 weeks and it plateaus at 30 weeks of gestation. The rate of increase almost parallels to that of blood volume but the maximum is reached to the extent of 50%. Total plasma volume increases to the extent of 1.25 liters. The increase is greater in multigravida, in multiple pregnancy and with large baby. +RBC AND HEMOGLOBIN: The RBC mass is increased to the extent of 20-30%. The total increase in volume is about 350 mL. This increase is regulated by the increased demand of oxygen transport during pregnancy. RBC mass + +begins to increase at about 10 weeks and continues till term without plateauing. Iron supplementation increases the RBC mass by 30%. Reticulocyte count increases by 2%. Erythropoietin level is raised. +The disproportionate increase in plasma and RBC volume produces a state of hemodilution (fall in hematocrit) during pregnancy. Thus, even though the total hemoglobin mass increases during pregnancy to the extent of 18-20%, there is apparent fall in hemoglobin concentration. At term, the fall is about 2 g% from the nonpregnant value (physiological anemia). There is simultaneous fall in number of red cells by 15-20% and the hematocrit level. The excess of circulating hemoglobin left behind after delivery yields iron for storage. +The advantages of relative hemodilution are: (1) Diminished blood viscosity ensures optimum gaseous exchange between the maternal and fetal circulation. This is facilitated by lowered oxygen afinity of maternal red cells observed in later half of pregnancy. (2) It protects the woman against the adverse effects of supine and erect posture. (3) Protection of the mother against the adverse effects of blood loss during delivery. + +LEUKOCYTES and IMMUNE SYSTEM: Neutrophilic leuko­ cytosis occurs to the extent of 8,000/mm3 and even to 20,000/mm3 in labor. The increase may be due to rise in the levels of estrogen and cortisol. The major change in the immune systen'fs'the modulation away from cell­ mediated cytotoxic immune response toward increased humoral and innate immune responses. +TOTAL PROTEIN: Total plasma protein increases from the normal 180 g (nonpregnant) to 230 g at term. However, due to hemodilution, the plasma protein concentration falls from 7 to 6 g%. This results in diminished viscosity of the blood and reduced colloid osmotic tension. Because of marked fall in albumin level from 4.3 to 3 g%-a fall of about 30% and only slight rise of globulin (mainly a globulin), the normal albumin:globulin ratio of 1.7:1 is diminished to 1:1 (Table 5.3). +BLOOD COAGULATION FACTORS: Pregnancy is a hypercoagulable state. Fibrinogen level is raised by 50% from 200-400 mg/dL in nonpregnant to 300-600 mg/dL in pregnancy. As a result of rise in fibrinogen and globulin level and diminished blood viscosity, + + +..a:W::W>. 1.".:f"- ;\. U. ·l@,' ,;.,f< rlt.- (ll')'.',:-;.1-,,4, u i-'fll¼,.l, ;;• :s i?- sl ,. ·,.!:: i;g :;-:;f1,.' ., i' fJ' " 0 ,, +1 +" +« lt i,1,· + l'tJt +. +W +lifl!? +. - : - +P,ri!S!Pa! . .9. !!, 2-8!!:l}:! ! SXJl Ji@l - +,, + +Parameters + +Blood volume (ml) + +Plasma volume (ml) + +Red cell volume (ml) + +Total Hb (g) + +Hematocrit (whole body) + + +Nonpregnant +4000 2500 1400 +475 + +38% + + +Pregnancy near term +5500 3750 1750 560 +32% + + +Total increment +1500 1250 350 +85 + +Change ++ 30-40% + 40-50% + 20-30% + 18-20% +Diminished + +- + +Table 5.3: Plasma· protein changes· during·pr gn- an y: ,,,,;7, • '·' ,, Nonpreg- Pregnancy +.l +Parameters nant near term Change + +Chapter 5: Physiological Changes During Pregnancy dt ,Ta0ble 5.5: He odyna.mic cha ges'duri g pregnancy. +Pregnancy Parameters Nonpregnant near term Change + +Total protein (g) 180 230 Increased Cardiac output (l/min) 45 6.26 +40% + +Plasma protein 7 6 concentration +(g/100 ml) +Albumin (g/100 ml) 4.3 3 Globulin (g/100 ml) 2.7 3 +Albumin:globulin 1.7:1 1:1 + + +Decreased + + +Decreased (30%) Slightly increased +Decreased + + +Stroke volume (ml) Heart rate (per minute) Blood pressure + +Venous pressure + + +65 75 + 27% +70 +17% +85 +Unaffected or mid-pregnancy drop of diastolic pressure by 5-1 0 mm Hg +10 cm 20-25 cm +100% (femoral) (water) + + + + +,:abi s.4: <:h ng·e ir{bJo : tagJ[ !io; fa'°ct f \ 1ti1i'.ttl +Non- Pregnancy Parameters pregnant near term Change +Platelets (mm3) 1,60,000- Conflicting Static or 15% 2,00,000 observation reduction of +the count +Fibrinogen (mg%) 200-400 300-600 + 50% Fibrinolytic activity - Depressed -Clotting time - Unaffected - +Erythrocyte sedi- 10 mm/h 40 mm/h Marked increase mentation rate (ESR) (4 times) + +Erythrocyte Sedimentation Rate {ESR) gives a much higher value (four-fold increase) during pregnancy (Table 5.4). As such, ESR has got little diagnostic value in pregnancy. Platelets count, however, gives a conflicting picture. Recent studies show a static or a slight fall to the extent of 15% of pre-pregnant level. Gestational thrombocytopenia may be due to hemodilution and increased platelet consumption {p. 257). It does not cause any pregnancy complication. Platelet count returns to normal by 1 to 2 weeks postpartum. Fibrinolytic activity is depressed till 15 minutes after delivery. There is increase in plasma levels and activities of clotting factors like VII, VIII, IX, X and I. The levels of II, V and XII are either unchanged or mildly increased. The level of factors XI and XIII are slightly decreased. The clotting time does not show any significant change. These are all effective to control blood loss and hemostasis after the separation of placenta (Table 5.4). Levels of coagulation factors normalize 2 weeks postpartum. Leukocyte levels return +to normal within 2-3 weeks of delivery. + +CARDIOVASCULAR SYSTEM +ANATOMICAL CHANGES: Due to elevation of the diaphragm consequent to the enlarged uterus, the heart is pushed upward and outward with slight rotation to left (Table 5.5). +Abnormal clinical findings: The displacement may, at times, be responsible for palpitation. The apex beat is shifted to the 4th intercostal space about 2.5 cm outside the midclavicular line. Pulse rate is slightly raised, often + +Colloid oncotic 20 18 - 14% pressure (mm Hg) +Systemic vascular - - - 21% resistance (SVR) +Pulmonary vascular - - - 34% reistance (PVR) + +with extrasystoles. A systolic murmur may be audible in the apical or pulmonary area. This is due to decreased blood viscosity and torsion of the great vessels. A continuous hissing murmur may be audible over the tricuspid area in the left second and third intercostal spa­ ces called the 'mammary murmur'. It is due to increased blood flow through the internal mammary vessels (breast). Doppler echocardiography shows an increase in the left ventricular end diastolic diameters. The left and right atrial diameters also increase. A third heart sound (S3} due to rapid diastolic filling and rarely a fourth heart sound may be auscultated. ECG reveals normal pattern except evidences of left axis deviation. Benign pericardia! effusion may be present. ECG changes are: Q waves in lead II, III and avF and flat on inverted T-waves in lead III and Vl-V3. Changes in the normal cardiac sounds are: (a) Splitting of the first sound, (b) no changes in the second sound, (c) third sound is loud. +The physician should be familiar with these physiological findings and should execute a cautious approach in diagnosis of heart disease during +pregnancy {p. 259). + +CARDIAC OUTPUT: The Cardiac Output (CO) starts to increase from 5th week of pregnancy and reaches its peak 40-50% at about 30-34 weeks (Doppler echocardiography}. Thereafter the CO remains static till term when the observation is made at lateral recumbent position. CO is lowest in the sitting or supine position and highest in the right or left lateral or knee chest position. CO increases further during labor ( +50%} and immediately following delivery ( + 70%) over the prelabor values. MAP also rises. There is squeezing out of blood from the uterus into the maternal circulation {autotransfusion) during labor and in the immediate postpartum. In both vaginal and cesarean deliveries the maximum increase in the CO occurs 10-30 minutes. +- Chapter 5: Physiological Changes During Pregnancy + + +after delivery. CO returns to prelabor values by 1 hour following delivery and to the prepregnant level by another 4 weeks' time. +The increase in CO is caused by: (1) Increased blood +volume. (2) To meet the additional 02 demand due to increased metabolic activity during pregnancy. Oxygen +consumption is increased during pregnancy by 20% and in labor by 50%. CO is the product of Stroke Volume (SV) and HR (CO= SV x HR). The increase in CO is chiefly affected by increase in stroke volume and increase in pulse rate to about 15 per minute. A normal heart got enough reserve power to cope with the increased load but a damaged heart fails to do so. +BLOOD PRESSURE (BP): Systemic Vascular Resistance (SVR) decreases (-21 %) due to smooth muscle relaxing effect of progesterone, nitric oxide, prostaglandins or ANP. In spite of the large increase in cardiac output, the maternal BP (BP = CO x SVR) is decreased due to decrease in SVR. There is overall decrease in diastolic blood pressure (BP) and Mean Arterial Pressure (MAP) by 5-10 mm Hg (in mid-pregnancy). The decrease in maternal BP parallels that of SVR. Thereafter a gradual rise is there until term. +VENOUS PRESSURE: Antecubital venous pressure remains unaffected. Femoral venous pressure is markedly raised especially in the later months. It is due to pressure exerted by the gravid uterus on the common iliac veins, more on the right side due to dextrorotation of the uterus. The femoral venous pressure is raised from 8 to 10 cm of water in non pregnant state to about 25 cm of water during pregnancy in lying down position and to about 80-100 cm of water in standing position. This explains the fact that the physiological edema of pregnancy subsides by rest alone. Distensibility of the veins and stagnation of blood in the venous system explain the development of edema, varicose veins, piles and deep vein thrombosis. +CENTRAL HEMODYNAMICS: In pregnancy, there is no significant change in CVP, MAP and PCWP although there is increase in blood volume, cardiac output and heart rate. The reasons are: there is significant fall in SVR, Pulmonary Vascular Resistance (PVR) and colloidal osmotic pressure. +SUPINE HYPOTENSION SYNDROME (POSTURAL HYPO­ TENSION): During late pregnancy, the gravid uterus produces a compression effect on the inferior vena cava when the patient is in supine position. This, however, results in opening up of the collateral circulation by means of paravertebral and azygos veins. In some cases (10%), when the collateral circulation fails to open up, the venous return of the heart may be seriously curtailed. This results in production of hypotension, tachycardia and syncope. The normal BP is quicldy restored by turning the patient to lateral position. The augmentation of the venous return + + +during uterine contraction prevents the manifestation from developing during labor. + +REGIONAL DISTRIBUTION OF BLOOD FLOW: Uterine blood flow is increased from 50 mL/min in nonpregnant state to about 750 mL near term. Nonpregnant uterus receives 2% of CO and breasts 1%. By term, pregnant uterus receives about 15% of total CO. Increase in blood flow going to the organs is about 50% due to overall increase in CO. The increase is due to the combined effect of uteroplacental and fetoplacental vasodilatation (p. 29). The vasodilatation is due to the smooth muscle relaxing effects of progesterone, estrogen, nitric oxide (endothelium derived factor), prostaglandins and Atrial Natriuretic Peptide (ANP). In a normal pregnancy, vascular system becomes refractory to angiotensin II, endothelin I and other pressure agents (p. 210). Pulmonary blood flow (normal 6,000 mL/min) is increased by 2,500 mL/min. Renal blood flow (normal 800 mL) increases by 400 mL/min at 16th week and remains at this level till term. The blood flow through the skin and mucous membranes reaches a maximum of 500 mL/min by 36th week. Heat sensation, sweating or stuffy nose complained by the pregnant women can be explained by the increased blood flow. + +METABOLIC CHANGES +GENERAL METABOLIC CHANGES: Total metabolism is increased due to the needs of the growing fetus and the uterus. Basal metabolic rate is increased to the extent of30% higher than that of the average for the nonpregnant women. + +PROTEIN METABOLISM: There is a positive nitrogenous balance throughout pregnancy. At term, the fetus and the placenta contain about 500 g of protein and the maternal gain is also about 500 g chiefly distributed in the uterus, breasts and the maternal blood. As the breakdown of amino acid to urea is suppressed, the blood urea level falls to 15-20 mg%. Blood uric acid and creatinine level, however, either remain unchanged or fall slightly. Amino acids are actively transported across the placenta to the fetus. Pregnancy is an anabolic state. + +CARBOHYDRATE METABOLISM: Transfer of increased amount of glucose from mother to the fetus is needed throughout pregnancy. Insulin secretion is increased in response to glucose and amino acids. There is hyperplasia and hypertrophy of beta cells of pancreas. Sensitivity of insulin receptors is decreased ( 44%) especially during later months of pregnancy. Plasma insulin level is increased due to a number of contrainsulin factors. These are: estrogen, progesterone, Human Placental Lactogen (hPL), cortisol, prolactin, Free Fatty Acids (FFA), leptin, and TNFa. There is increased tissue resistance to insulin. This mechanism ensures continuous supply of glucose +to the fetus. +Increased insulin level favors lipogenesis (fat storage). During maternal fasting, there is hypoglycemia, hypoinsulinemia, hyperlipidemia and hyperketonemia. + + +Lipolysis generates FFA for gluconeogenesis and fuel supply. Plasma glucagon level remains unchanged. +Overall effect is maternal fasting hypoglycemia (due to fetal consumption) and postprandial hyperglycemia and hyperinsulinemia (due to anti-insulin factors). Oral glucose tolerance test may show an abnormal pattern. This helps to maintain a continuous supply of glucose and FFA to the fetus. As maternal utilization of glucose is reduced, there are gluconeogenesis and glycogenoly­ sis. Glomerular filtration of glucose is increased to exceed the tubular absorption threshold (normal 180 mg%). So glycosuria is detected in 50% of normal pregnant women. + +FAT METABOLISM: An average of 3-4 kg of fat is stored during pregnancy mostly in the abdominal wall, breasts, hips and thighs. Plasma lipids and lipoproteins increase appreciably during the latter half of pregnancy due to increased estrogen, progesterone, hPL and leptin levels. + +LIPID METABOLISM: HDL level increases by 15%. LDL is utilized for placental steroid synthesis. This hyperlipidemia of normal pregnancy is not atherogenic. The activity of lipoprotein lipase is increased. Changes in the lipid components are tabulated in Table 5.6. Leptin, a peptide hormone, is secreted by adipose tissue and placenta. It regulates the body fat metabolism. + +IRON METABOLISM: Iron is absorbed in ferrous form from duodenum and jejunum and is released into the circulation as transferrin. About 10% of ingested iron is absorbed. Iron freed from transferrin is incorporated into hemoglobin (75%) and myoglobin or stored as ferritin or hemosiderin. Iron is transported actively across the placenta to the fetus. Iron requirement during pregnancy is considerable and is mostly limited to the second half of the pregnancy especially to the last 12 weeks. Total iron requirement during pregnancy is estimated approximately 1,000 mg. This is distributed in fetus and placenta 300 mg and expanded red cell mass 500 mg (total increase in red cell volume-450 mL and 1 mL contains 1.1 mg of iron). There is obligatory loss of about 200 mg through normal routes. The iron in the fetus and placenta is permanently lost and a variable amount of iron in the expanded RBC volume is also lost due to blood loss during delivery (45 mg/100 mL) and the rest is returned to the store. However, there is saving of about 300 mg + +Chapter 5: Physiological Changes During Pregnancy + +of iron due to amenorrhea for 10 months (iron loss in menstrual bleeding per cycle is 30 mg). Iron need during lactation is l mg/day. This iron need is not squarely distributed throughout the pregnancy but mostly limited to the third trimester (daily iron requirement in non-menstruating women is 1 mg. This is to compensate the average daily loss of 1 mg). Thus, in the second half, the daily requirement actually becomes very much increased to the extent of about 6-7 mg. +The amount of the iron absorbed from the diet and that mobilized from the store are inadequate to meet the demand. In spite of the fact that absorption through the gut is enhanced during pregnancy, serum ferritin level actually reflects the body iron stores. In the absence of iron supplementation, there is drop in hemoglobin, serum iron and serum ferritin concentration at term pregnancy {p. 247, Table 20.1). Thus, pregnancy is an inevitable iron deficiency state. However, placenta transfers adequate iron to the fetus, despite severe maternal iron deficiency. Thus, there is no correlation of hemoglobin concentrations between mother and fetus. + +SYSTEMIC CHANGES +RESPIRATORY SYSTEM: With the enlargement of the uterus, especially in the later months, there is elevation of the diaphragm by 4 cm. Total lung capacity is reduced by 5% due to this elevation. However, diaphragmatic excursion is increased by 1-2 cm and breathing becomes diaphragmatic (Fig. 5.5). Total pulmona1y resistance is reduced due to progesterone effect. The subcostal angle increases from 68° to 103°, the transverse diameter of the chest expands by 2 cm and the chest circumference increases by 5-7 cm. The mucosa of the nasopharynx becomes hyperemic and edematous. This may cause nasal stuffiness and rarely epistaxis. A state of hyperventilation occurs during pregnancy leading to increase in tidal volume and therefore respiratory minute volume by 40% (Table 5.7). It is probably due to progesterone acting on the respiratory center and also to increase in sensitivity of the center to CO2• The woman feels shortness of breath. +Acid-base balance: The hyperventilation causes +changes in the acid-base balance. The arterial PaCO2 falls +38 to 32 mm Hg and PaO2 rises 95 to 105 mm Hg. These facilitate transfer of CO2 from fetus to mother and 02 from +mother to fetus (Table 5.8). + + + +Table 5.6: Changes in lipid metabolism. + +Parameters Nonpregnant Total lipid (mg/100 ml) 650 +lDl and cholesterol 180 (mg/100 ml) +HDl (mg/100 ml) 60 +Triglycerides (mg/ 80 100 ml) + + + +Pregnancy +near term Change +1000 + 50% 260 + 40% + +70 + 15% +240 + 100% + +The pH rises in order of 0.02 unit and there is a base excess of 2 mEq/L. Thus, pregnancy is in a state of respiratory alkalosis. Partial renal compensation occurs through increased excretion of bicarbonate. Maternal +02 consumption is increased by 20-40% above the nonpregnant level due to increased demand of the fetus, +placenta and maternal tissues. +Maternal oxygen reserve during pregnancy is reduced due to: (a) Increased oxygen consumption and (b) reduced functional residual capacity. These physiological +r + +ID Chapter 5: Physiological Changes During Pregnancy + +3500 Non- Late +pregnant pregnancy + +3000 + +Q) +c +r +0 +C: +Q) +r +2500 ·:; /) +0 +0 +0 1l I! 0 +c +.8 +e +0. +u +c +e +· +o. +E +1l +c +c +- 2000 ·:; 0 .8 ·o. ·:; + +j +1l +0. /) 0. 1i 1500 ]i /) ]i +j +E +1l +u +1l +u +>, +> +> +1l +I +1 +I + +g1 1000 ii E +Q) +-= +ro +-0 :, +Fo +> ;§ 500 1l .8 C: +>, + Q) +e +- +0. +w +:, +-0 +Q) +/) +Q) +·u; ·>< +0 +ii +C ">, 1l Q) +o " +u +ro +C +0. +_g E +/) +- +'. +> +:; .) ·- :, +-500 tr rl Q) 0 + +-1000 +Fig. 5.5: Lung volumes. in nonpregnant and pregnant women. TLC, Total Lung Capacity (4200 is same for nonpregnant and pregnant conditions); VC, Vital Capacity; IC, lnspiratory Capacity; FRC, Functional Residual Capacity; IRV, lnspiratory Reserve Volume; TV, Tidal Volume; ERV, Expiratory Reserve Volume, RV, Residual Volume. Values ofTLC and VC remains unaltered in both +the conditions. + +changes make a pregnant woman more susceptible to effects of apnea (during intubation). +URINARY SYSTEM: Kidney-There is dilatation of the ureters, renal pelvis and the calyces. The kidneys enlarge in length by 1 cm. Renal plasma flow is increased by 50-75%, maximum by the 16 weeks and is maintained until 34 weeks. Thereafter it falls by 25%. Glomerular Filtration Rate (GFR) is increased by 50% all throughout pregnancy. Increased GFR causes reduction in maternal plasma levels of creatinine, Blood Urea Nitrogen (BUN) and uric acid. Renal tubules fail to reabsorb glucose, uric + +J!ablti .7: C:han'i;;?S)l) rf,SPjt. ,!,OIY systeyi?,; - ... ;:, ';«'.. - ·:.'" ,. t :,r Pregnancy + +r +h +; +; +" +' +; +, +• + +M +: +. + +· + + + + +, +, +• +, +J +; + +s +i +f +" +' +; +i + +" +f +, +1 + +: +' + + +: +. +g +, +, +, + +, +i +t + +, +! +f +J +- +g +- +; +, +; +a +e +; +; +- +i +t +r +: +" +: +¾ +" +' +f +, +· +· + +, + +$ + +1 +t +" +r +" +I +Parameters Nonpregnant near term Change + +acid, amino acids and water-soluble vitamins completely. The kidneys normally receive 20-25% of the total cardiac output. +Ureter: Ureters become atonic due to high proges­ terone level. Dilatation of the ureter above the pelvic brim with stasis is marked on the right side, especially in primigravidae. It is due to dextrorotation of the uterus pressing the right ureter against the pelvic brim and also due to pressure by the right ovarian vein which crosses the right ureter at right angle. The stasis is marked between 20 and 24 weeks. There is marked hypertrophy of the muscle and the sheath of the ureter especially the pelvic part probably due to estrogen. There is elongation, kinking and outward displacement of the ureters. The dilatation effect resolves by 6 weeks postpartum. +Bladder: There is marked congestion with hypertrophy of the muscles and elastic tissues of the wall. In late pregnancy, the bladder mucosa becomes edematous due to venous and lymphatic obstruction, especially in primigravidae following early engagement. Increased frequency of micturition is noticed at 6-8 weeks of pregnancy which subsides after 12 weeks. It may be due to resetting of osmoregulation causing increased water intake and polyuria. In late pregnancy, frequency of micturition once more reappears due to pressure on the bladder as the presenting part descends down the pelvis. Stress incontinence may be observed in late pregnancy due to urethral sphincter weakness. +ALIMENTARY SYSTEM: The gums become congested and spongy and may bleed to touch. Muscle tone and motility of the entire Gastrointestinal Tract (GIT) are diminished due to high progesterone level. Cardiac sphincter is relaxed and regurgitation of acid gastric content into the esophagus may produce chemical esophagitis and heart burn. Dyspepsia is common. There is diminished gastric secretion and delayed emptying time of the stomach. Risk of peptic ulcer disease is reduced. Atonicity of the gut leads to constipation, while diminished peristalsis facilitates more absorption of food materials. +LIVER AND GALLBLADDER: Although there is no histo­ logical change in the liver cells, but the functions are depressed. With the exception of raised alkaline + + + +Respiration rate/min 15 Vital capacity (ml) 3200 + +Tidal volume (ml) 500 Residual volume (ml) 965 +lnspiratory capacity 2500 (IC) + + +15 Unaffected +3300 Almost unaltered +700 +40% 765 - 20% +2650 +10% + + + ia' 1e"s.s: Acid-base changes. +b + +Parameters Nonpregnant +Arterial pO2 95 mm Hg Arterial pCO2 40 mm Hg pH 7.40 + + + +Pregnancy near term +106 mm Hg 30 mm Hg +7.42 + + + + +Change Increased Diminished +Slightly increased + + + +Minute ventilation +Total lung capacity (ml) + + +7.5 L/min +4200 + + +10.5 L/min +40% +4000 -5% + + +Plasma HCO3 -Base deficit (mmol/l) + + +26 mmol/L +1.06 + + +22 mmol/L +3.1 + + +Decreased +Rise + + +phosphatase levels, other liver function tests ( serum levels of bilirubin, AST, ALT, CPK, LDH) are unchanged. There is mild cholestasis (estrogen effect). There is marked atonicity of the gallbladder (progesterone effect). This, together with high blood cholesterol level during pregnancy, favors stone formation. + +NERVOUS SYSTEM: Some sorts of temperamental changes are found during pregnancy and in the puerperium. Nausea, vomiting, mental irritability and sleep disorders are probably due to some psychological background. Postpartum blues, depression or psychosis may develop in a susceptible individual (p. 417). +Compression of the median nerve underneath the flexor retinaculum over the wrist joint leading to pain and paresthesia in the hands and arm (carpal tunnel syndrome) may appear in the later months of pregnancy. Similarly, paresthesia and sensory loss over the anterolateral aspect of the thigh may occur. It is due to compression of the lateral cutaneous nerve of the thigh. + +CALCIUM METABOLISM AND SKELETAL SYSTEM: During pregnancy there is increase in the demand of calcium by the growing fetus to the extent of 28 g, 80% of which is required in the last trimester for fetal bone mineralization. Daily requirement of calcium during pregnancy and lactation averages I-1.5 g. Maternal total calcium levels fall but serum ionized calcium level is unchanged. Fifty percent of serum calcium is ionized which is important for physiological function. Calcium absorption from intestine and kidneys are doubled due to rise in the +level of 1,25-dihydroxyvitamin D3• The increase in 1,25-hydroxyvitamin D is due to increased production by +the maternal kidneys and fetoplacental unit. Pregnancy does not cause hyperparathyroidism. Calcitonin levels increase by 20%. Calcitonin protects the maternal skeleton from osteoporosis. Maternal serum phosphate level is unchanged. +There is increased mobility of the pelvic joints due to softening of the ligaments caused mainly by hormone. This along with increased lumbar lordosis during later months of pregnancy due to enlarged uterus produces backache and waddling gait. + +Chapter 5: Physiological Changes During Pregnancy + +There is marked widening of the symphysis pubis by 30 weeks of pregnancy from 3-4 mm to 7-8 mm. +Microbiome: The microbes and the human hosts have evolved as a physiologic community to establish a symbiotic relationship. Microbiome of healthy nonpregnant women was first described in 2021. Microbiome of specific body sites may change during pregnancy. The body site specific changes in the microbiome during pregnancy may be helpful to maintain a healthy state. This microbiome may prepare the body for parturition or develop neonatal microbiome at the time of parturition. +Vaginal microbiome: Like Lactobacillus, decreases vaginal pH and fosters further growth of Lactobacillus. The presence of lactobacilli is known to increase with the progress of pregnancy. Physiologic changes in the vagina interact with vaginal microbiome to protect against infection and help to the continuation of pregnancy. +Gut microbiome: Changes in the gut microbiota in pregnancy have been observed. It is observed that overall increase in proteobacteria and decrease in Faecalibacterium can change the host and microbiome relationship. Proteobacteria is often associated with inflammatory conditions, whereas Faecalibacterium has anti-inflammatory effects. Studies revealed that inflammatory microbiome caused higher levels of inflam­ mation, adeposity and glucose intolerance compared to the presence of anti-inflammatory microbiomes. Hence pregnancy changes with gut miorobiome may induce pro­ inflammatory and prodiabetogenic states. +Placental microbiomes: Studies revealed that composition of microbiome was different among women with term versus preterm birth. It is observed that bacteria present in the placenta most closely resemble the oral microbiome and those did not resemble the vaginal microbiome. It is suggested that these bacteria are not the ascending infections. These may have reached the placenta via hematogenous spread from the oral cavity. Importance of oral hygiene is thought relevant in terms of preterm birth and periodontal disease. +The role of microbiomes in health, pregnancy and its complications are being unfolded. + +ENDOCRINE SYSTEM: The endocrinology in relation to pregnancy is discussed in Ch. 6. + + + + + +► Physiological changes during pregnancy involve all the body systems including the genital organs. +► As the uterus enlarges during pregnancy, it usually rotates on its long axis to the right. This is known as dextrorotation. +► Braxton Hicks (Hicks, John Braxton) contractions are spontaneous, irregular, infrequent, spasmodic and painless in nature. These contractions have no effect on dilation of the cervix. +► Skin changes during pregnancy are several: Face (chloasma), breasts (pigmented nipples, areola), abdomen (linea nigra, striae gravidarun) and palmar erythema. +Contd... +·El Chapter 5: Physiological Changes During Pregnancy Contd... +► Total body water in pregnancy is increased (6.5 L). Maternal blood volume increases by 1.5 L (30-40%). Plasma volume by 40-50%, red cell volume by 20-30%, hemoglobin by 18-20%. The hematocrit is decreased. There is hemodilution in pregnancy {Table 5.1 ). +► There is also alterations in plasma proteins {Table 5.2), increase in clotting factors like X, IX, VIII, VII, and I (Table 5.3). Rise in fibrinogen is +50%. Pregnancy is a hypercoagulable state. +► There are significant physiological changes in the cardiovascular system in pregnancy that may mimic cardiac disease. There is +increase in cardiac output (+40%), stroke volume (+27%) and heart rate. There is decreased colloidal osmotic pressure (-14%) and systemic vascular resistance (-21%) (Table 5.4). Femoral venous pressure is raised. There is mid-pregnancy drop of diastolic pressure and MAP. +► Respiratory system undergoes significant anatomical and physiological changes. Respiratory rate and vital capacity remains almost unchanged. There is rise in tidal volume (+40%), minute ventilation (+40%) and there is fall in residual volume (-20%) and total lung +capacity (-5%). Pa02 is increased and PaC02 falls due to increased minute ventilation. This helps the transfer of CO2 from the fetus to +the mother. +► Metabolic changes in pregnancy are: Hyperglycemia, hyperinsulinemia (insulin resistance) and hyperlipidemia. Tissue insulin resistance is due to many contra-insulin factors (hPL). There is positive nitrogen balance in pregnancy. +► Iron requirement during pregnancy is about 1000 mg. Iron is absorbed in ferrous form from the duodenum and jejunum. Daily iron requirement in the second half of pregnancy is about 6-7 mg. During pregnancy demand of calcium is increased. Daily requirement of calcium during pregnancy and lactation is about 1-1.5 g. +► Uterine blood flow at term is about 750 ml/mm (10% of maternal cardiac output). +► Pregnancy is a hypercoagulable state. Fibrinogen level is increased by 50%. Activity of the some clotting factors (X, IX, VIII, VII, and I) are increased, level of protein S is decreased. There is six-fold rise in the risk of thromboembolic disease. The physiologic changes of hypercoagulability (due to rise in procoagulants, fall in natural inhibitors of coagulation and decrease in fibrinolytic activity) protect the women against the risk of postpartum hemorrhage. + +Endocrinology in +Relation to Reproduction + + + +CHAPTER +" +❖ Maturation of Graafian Follicles and Ovulation +❖ Maintenance of Corpus Luteum after Fertilization +❖ Placental Endocrinology ► Hormones of Placenta ► Protein Hormones + + + + + + +► Steroidal Hormones +► Diagnostic Value of Placental Hormones +❖ Changes in Endocrine Glands During Pregnancy +► Pituitary Gland ► Thyroid Gland + + + + + + +► Adrenal Cortex +► Parathyroid Gland ► Pancreas +❖ Hormonal Influences Necessary for Maintenance of Lactation + + + + +The endocrine glands play very important role in the physiology of reproduction. Endocrinology in relation to reproduction includes the knowledge of: +■ Hormones essential for the maturation of the Graafian follicles, ovulation and maintenance of corpus luteum after fertilization. +11 Following conception, transfer of function of pituitary­ ovarian axis to placenta, which acts temporarily as a new powerhouse or endocrine organ. +11 Physiological alteration of various endocrine glands namely, the pituitary, thyroid, parathyroid, adrenals and pancreas during pregnancy. +11 Endocrine control of labor (Ch. 13). +11 Hormonal influence during puerperium necessary for maintenance of lactation. + +MATURATION OF GRAAFIAN FOLLICLES AND OVULATION + +Follicular maturation takes place during the first half of the cycle. The hormones essential for follicular maturation are mainly FSH and a small proportion of LH. For continued FSH activity, estrogen is necessary. + +OVULATION: Under the influence of FSH, about 20 Graa­ fian follicles develop synchronously and only one of them will be able to ovulate. The rest become atretic and mix-up with interstitial tissue. Read more Dutta's Textbook of Gynecology, Ch. 8. + +CAUSES OF OVULATION: The possible factors involved in ovulation have been described on page 18. + +CHANGES WITHIN THE FOLLICLE AFTER OVULATION: The avascular Graafian follicle becomes vascularized and the granulosa cells become luteinized. The morphologically altered Graafian follicle is now changed into corpus + + +luteum. The corpus luteum secretes progesterone, l 7a-hydroxyprogesterone (Iuteinized granulosa cells) and estradiol, androstenedione (theca cells). + +MAINTENANCE OF CORPUS LUTEUM AFTER FERTILIZATION +Function of corpus luteum is essential to maintain the early pregnancy. Corpus luteum secretes about 40 mg of progesterone a day. After implantation, Human Chorionic Gonadotropin (hCG) and possibly Human Placental Lactogen (hPL), secreted by the syncytiotrophoblast cells maintain the growth and function of the corpus luteum. + +PLACENTAL ENDOCRINOLOGY +At 6-8 weeks, there is transfer of functions of corpus luteum to the placenta (Iuteal-placental shift)-which acts temporarily as a new endocrine organ or powerhouse of hormone production. +I HORMONES OF PLACENTA (TABLE 6.1) +Placenta produces a variety of hormones of which protein and steroid hormones are significantly important. Syncy­ tiotrophoblasts contain abundant rough endoplasmic reticulum, Golgi bodies and mitochondria. Syncytiotro­ phoblasts are the principal site of protein and steroid hormones in pregnancy. + +I PROTEIN HORMONES +Protein hormones are similar but not necessarily identical with those produced by the pituitary. For example, placental lactogen is chemically similar to both pituitaiy growth hormone and prolactin, but biological activity of placental lactogen is much inferior than prolactin or growth hormone produced by pituitaiy. +Chapter 6: Endocrinology in Relation to Reproduction + +Table 6.1: Hormones of placenta and their cytochemical origin. + +Hypothalamic-like (releasing) hormones ■ Corticotropin-Releasing Hormone (CRH) + +■ Gonadotropin-Releasing Hormone (GnRH) ■ Thyrotropin-Releasing Hormone (TRH) +■ Growth Hormone Releasing Hormone (GHRH) Other pregnancy proteins +♦ PSpG, PAPP-A + +♦ Relaxin + + +Cytochemical origin +Cytotrophoblast and syncytiotrophoblast + ++ + ++ + ++ +Cytochemical origin Syncytiotrophoblast + +Corpus luteum, decidua, placenta + + +Pituitary-like hormones +■ Adrenocorticotropic Hormone (ACTH) + +■ Human Chorionic Gonadotropin (hCG) ■ Human Chorionic Thyrotropin (hCT) +■ Human Placental Lactogen (hPL) Growth factors +♦ lnhibin, activin, Transforming Growth Factor-p (TGF-P) +♦ IGF-1 and 2, Epidermal Growth Factor (EGF) + + +Cytochemical origin Syncytiotrophoblast + ++ + ++ + ++ +Cytochemical origin Syncytiotrophoblast + ++ + + + ++ Prolactin ++ Atrial Natriuretic Peptide (ANP) + +♦ Early Pregnancy Factor (EPF) + + +Decidua +Atrial myocyte + +Activated platelets ovaries + + +Steroid hormones ++ Estrogens (estriol) ♦ Progesterone + + ++ Cortisol + + +Cytochemical origin Fetoplacental unit +Before 6 weeks-corpus luteum thereafter placenta +Decidua, adrenal + + + +HUMAN CHORIONIC GONADOTROPIN (hCG): It is a glyco­ protein. Its molecular weight is 36,000-40,000 daltons. It +consists of a hormone nonspecific a ( 92 amino acids) and +a hormone specific p (145 amino acids) subunit. hCG is chemically and functionally similar to pituitary luteinizing +hormone. The a subunit is biochemically similar to LH, +FSH and TSH whereas the p subunit is relatively unique to hCG. Placental GnRH may have a control on hCG formation. + +Functions +1. It acts as a stimulus for the secretion of progester­ one by the corpus luteum of pregnancy. Rescue and maintenance of corpus luteum till 6 weeks of preg­ nancy is the major biological function of hCG. +2. hCG stimulates Leydig cells of the male fetus to pro­ duce testosterone in conjunction with fetal pituitary gonadotropins. It is thus indirectly involved in the development of male external genitalia. +3. It has got immunosuppressive activity, which may inhibit the maternal processes of immunorejection of the fetus as a homograft. +4. Stimulates both adrenal and placental steroidogen­ esis. +5. Stimulates maternal thyroid because of its thyrotropic activity. +6. Promotes secretion of relaxin from the corpus +luteum. +7. Hyperglycosylated isoforms of the p subunit predomi­ nate (hCG-H) for the first 5-6 weeks of pregnancy. This is similar to the pattern seen in choriocarcinoma. +8. hCG-H isoform is released by the extravillous trophoblasts. + +9. Reduced levels of hCG-H in maternal serum often indicates miscarriage and poor obstetric outcome. There is deficient spiral artery remodelling. +Level of hCG at different periods of pregnancy: hCG is produced by the syncytiotrophoblast of the placenta and secreted into the blood of both mother and fetus. The plasma half-life of hCG is about 36 hours. By radio­ immunoassay, it can be detected in the maternal serum or urine as early as 8-9 days postfertilization. In the early pregnancy, the doubling time of hCG concentrations in plasma is 1.4-2 days. The blood and urine values reach maximum levels ranging from 100 to 200 IU/mL between 60 and 70 days of pregnancy. The concentration falls slowly reaching a low level of 10-20 IU/mL between 100 and 130 days. Thereafter, the levels remain constant throughout pregnancy with a slight secondary peak at 32 weeks. High levels of hCG could be detected in­ (a) multiple pregnancy, (b) hydatidiform mole or choriocarcinoma and (c) relatively high in pregnancy with a trisomy 21 fetus (Down's syndrome). Plasma lower levels are found in ectopic pregnancies and in spontaneous abortion. hCG disappears from the circulation within 2 weeks following delivery (Fig. 6.1). + +HUMAN PLACENTAL LACTOGEN (hPL): This is also known as Human Chorionic Somatomammotropin (hCS). The hormone is exclusively synthesized by the syncytio­ trophoblast of the placenta. The hormone is chemically and immunologically similar to pituitary growth hormone (96%) and prolactin (67%). hPL in maternal serum is first detected during the 3rd week of gestation. The level rises progressively from 5 to 25 µg/mL until about 36 weeks of gestation. The plasma concentration of hPL is proportional to placental mass. +Chapter 6: Endocrinology in Relation to Reproduction JI +75 + +hpl +pg/ml hCG IU/ml +20 +200 +15 100 + + +Prog ng/ml +200 + +175 +150 + +Leptin is secreted by adipose tissue. Normally it suppresses appetite through negative feedback effect on the hypothalamus. Pregnancy appears to be a state of central leptin resistance. Thus it allows increased adipose tissue deposition in pregnancy. + + + + + +10 + + +5 + + +0 + + + +10 + + + + + +0 +0 + + +125 100 + + +50 + +25 +0 +70 140 210 280 294 +Days of pregnancy + +Placental function and fetal gender: Levels of IGF-I is found higher in female fetuses. In preeclampsia, placenta of boys show higher levels of proinflammatory cytokines and apoptosis. +Estriol is first detectable at 9 weeks (0.05 ng/mL) and increases gradually to about 30 ng/mL at term. Fetal death, fetal anomalies (adrenal atrophy, anencephaly, Down's syndrome), hydatidiform moles, placental sulfatase or aromatase deficiency are associated with low estriol. + + + +Fig. 6.1: Mean serum levels of placental hormones during pregnancy as measured by radioimmunoassay. + +Functions: hPL has growth promoting and lactogenic effects. hPL antagonizes insulin action. High level of maternal insulin helps protein synthesis. hPL causes maternal lipolysis and promotes transfer of glucose and amino acids to the fetus. As a potent angiogenic hormone, it helps to develop fetal vasculature. It promotes growth and differentiation of breasts for lactation. +PREGNANCY-SPECIFIC P-1 GLYCOPROTEIN (PS p-1 G): It is produced by the trophoblast cells. It can be detected in the maternal serum 18-20 days after ovulation. PS P-lG is a potent immunosuppressor of lymphocyte proliferation and prevents rejection of the conceptus. +Early Pregnancy Factor (EPF) is a protein, produced by the activated platelets and other maternal tissues. It is detectable in the circulation 6-24 hours after conception. EPF is immunosuppressant and prevents rejection of the conceptus. +Growth factors: Inhibin, activin, Insulin-like Growth Factor (IGF-1 and 2), Transforming Growth Factor-P (TGF-P) and Epidermal Growth Factor (EGF) are produced by the syncytiotrophoblast cells. They have varied functions including immunosuppressive, paracrine and steroidogenic. +Pregnancy Associated Plasma Protein-A (PAPP-A) -is a glycoprotein. It is detected in the maternal serum by 5 weeks. Levels rise till the end of pregnancy. It is secreted by the villus trophoblasts. Progesterone upregulates in its synthesis. PAPP-A regulates the bioavailability of IGF. Thus it helps normal fetal growth. Low maternal serum levels of PAPP-A is associated with increased risk of preeclampsia and IUGR. + +I STEROIDAL HORMONES +ESTROGEN: In late pregnancy, qualitatively, estriol is the most important amongst the three major estrogens. The site of its production is in the syncytiotrophoblast. + + +PROGESTERONE: Before 6 weeks of pregnancy, the corpus luteum secretes 17-hydroxyprogesterone. Following the development of trophoblast, progesterone is synthesized and secreted in increasing amount from the placenta. Precursors from fetal origin are not necessary as in estrogen production. The placenta can utilize cholesterol as a precursor derived from the mother for the production of pregnenolone. Pregnenolone is converted to progesterone in the endoplasmic reticulum by 3-P-Hydroxysteroid Dehy­ drogenase (3P-HSD). The daily production rate of progesterone in late normal pregnancy is about 250 mg. Low progesterone levels are observed in ectopic pregnancy and in abortion. High values are observed in hydatidiform mole, Rh-isoimmunization. After delivery, the plasma progesterone decreases rapidly and is not detectable after 24 hours. +Functions of the Steroid Hormones (Estrogen and Progesterone) +It is indeed dificult to single out the function of one from the other. +♦ Together they play an important role in the mainte­ nance of pregnancy. Estrogen causes hypertrophy and hyperplasia of the uterine myometrium, thereby increasing the accommodation capacity and blood flow of the uterus. Progesterone in conjunction with estro­ gen stimulates growth of the uterus, causes decidual changes of the endometrium required for implantation and it inhibits myometrial contraction. +♦ Development and hypertrophy of the breasts during pregnancy are achieved by a number of hormones. Hypertrophy and proliferation of the ducts are due to estrogen, while those of lobuloalveolar system are due to combined action of estrogen and progesterone (details are given below). +♦ Both the steroids are required for the adaptation of the maternal organs to the constantly increasing demands of the growing fetus. +ll Chapter 6: Endocrinology in Relation to Reproduction +♦ Progesterone maintains uterine quiescence, by stabili­ zing lysosomal membranes and inhibiting prostaglandin synthesis. Progesterone and estrogens are antagonistic in the process of labor (Ch. 12). +♦ Estrogens sensitizes the myometrium to oxytocin and prostaglandins. Estrogens ripen the cervix. +♦ Progesterone along with hCG and decidual cortisol inhibits T-lymphocyte mediated tissue rejection and protects the conceptus (immunomodulatory role). +♦ Together they cause inhibition of cyclic fluctuating activity of gonadotropin-gonadal axis thereby preser­ ving gonadal function. + +DIAGNOSTIC VALUE OF PLACENTAL HORMONES + +(a) Diagnosis of pregnancy: Presence of hCG in the plasma can be detected by radioimmunoassay and in urine either by biological or immunological tests. +Radioimmunoassay can detect minute quantity of plasma hCG P subunit soon after the implantation of blastocyst but biological and immunological tests do not become positive at least 44 days after the last menstrual period. +(b) Follow-up cases who had trophoblastic tumors: +Radioimmunoassay for the detection of hCG p subunit is more sensitive in the follow-up study of hydatidiform mole or choriocarcinoma. +(c) Placental Growth Hormone (PGH): It has high growth promoting and low lactogenic properties. It regulates insulin sensitivity and IGF-I concentrations. IGF-I regulates fetal growth through the control of maternal metabolism, placental growth, blood flow, and placental transporter expression. +PAPP-A: P. 55. +RELAXIN: It is a peptide hormone structurally related to insulin. The main source of production is the corpus luteum of the ovary but part of it may be also produced by the placenta and decidua. It has been claimed that relaxin relaxes myometrium, the symphysis and sacroiliac joints during pregnancy and also helps in cervical ripening by its biochemical effect. + +CHANGES IN ENDOCRINE GLANDS DURING PREGNANCY + +Pituitary, thyroid, adrenal cortex, parathyroid and pancreas show distinct physiological changes during pregnancy leading to increase in output of respective hormones. The basic purpose of these changes is to adjust the internal environment of the mother to meet the additional requirements imposed by metabolic changes during pregnancy as well as to meet the extra demands by the growing fetus. +The specific anatomical and physiological changes in the individual endocrine glands are described further. + + + +I PITUITARY GLAND +MORPHOLOGICAL CHANGES IN NORMAL PREGNANCY: During normal pregnancy, the pituitary increases in weight by 30-50% and is enlarged to about twice its normal size. This is principally due to hyperplasia of acidophilic prolactin secreting cells. Sometimes, the pituitary enlargement may impinge on the optic chiasma causing bitemporal hemianopia. Maternal pituita1y gland is not necessary for the maintenance of pregnancy. The pituitary gland during pregnancy becomes more susceptible to alterations in blood supply. Sudden hypotension following postpartum hemorrhage may cause infarction of the gland (Sheehan syndrome). + +PHYSIOLOGICAL CHANGES: Pituitaiy gonadotropins (FSH, LH) levels are low due to increased level of estrogens and progesterone. Growth hormone level is elevated due to growth hormone variant made by syncytiotrophoblast of the placenta and this explains partly the weight gain observed during normal pregnancy. Serum prolactin level increases by 10 times. Transient decrease in TSH in the first trimester is due to the thyrotropic effects of hCG. TSH and +hCG are structurally very similar and they share a common +a subunit and have a similar p unit. TSH secretion is same as in nonpregnant state. ACTH and Corticotropin­ releasing Hormone ( CRH) levels increase. ACTH does not cross the placenta while TRH does. Plasma vasopressin (ADH) level remains unchanged during pregnancy. Oxytocin levels rise significantly throughout pregnancy and reach maximum in labor. All the pregnancy-induced changes in the pituitary revert to normal within few months after delivery. +Ii THYROID GLAND +MORPHOLOGICAL CHANGES DURING PREGNANCY: Hyperplasia of the thyroid gland occurs during normal pregnancy and causes slight generalized enlargement of the gland. However, pregnant women remain euthyroid. +PHYSIOLOGICAL CHANGES: Renal clearance of iodine is increased due to increased glomerular filtration. Maternal serum iodine levels fall due to increased renal loss and also due to transplacental shift to the fetus. These cause hyperplasia of the gland. Iodine intake during pregnancy should be increased from 100 to 200 µg/day (as recommended by WHO}. There is rise in the basal metabolic rate, which begins at about the third month, reaches a value of +25% during the last trimester. The increase in BMR is probably due to increase in net oxygen consumption of mother and fetus. +Human fetus cannot synthesize thyroid hormones until after 12 weeks. During this period fetal requirement is totally met by maternal transfer. +There is stimulatory effect of hCG ( chorionic thyrotropin) to thyroid gland mainly in the first trimester. + + +Due to this thyrotropic effect of hCG, there may be a transient phase of hyperthyroidism in some women ( transient gestational thyrotoxicosis). +The serum protein-bound iodine is increased in pregnancy, the range being 6.2-11.2 µg% instead of the usual 4-8 µg%. Thyroxin-Binding Globulin (TBG) increases and reaches a plateau by 20 weeks. It remains unchanged at that level until delivery. The increase in TBG is due to estrogen stimulation. Iodine and drugs used to treat hyperthyroidism cross the placenta freely. +Fetal thyroid starts functioning after 12 weeks. Till then the fetus is entirely dependent upon the maternal +supply of T4 through the placenta, for all neurologic development. TRH crosses the placenta but TSH crosses +it very minimally. Maternal total T4 and T 3 are increased by 18 weeks but free T4 and T3 levels are unchanged. Maternal TSH remains normal. Secretion of T4 and T3 is 20:1, but biological activity of T3 is five times more than that of T4• Level of calcitonin-a thyroid hormone secreted by the parafollicular cells, increases by 20%. +Calcitonin protects the maternal skeleton from excess bone loss during pregnancy and lactation. Place of routine screening of all pregnant women for thyroid function is currently recommended by ICOG and ESL However, women with high-risk factors should have their serum TSH level checked in their first antenatal visit. + +I ADRENAL CORTEX +MORPHOLOGICAL CHANGES DURING PREGNANCY: There is slight enlargement of the adrenal cortex, particularly the thickness of the zona fasciculata is increased. + +PHYSIOLOGICAL CHANGES: There is significant increase in the serum levels of CRH, ACTH, aldosterone, deoxycorticosterone (DOC), Corticosteroid-Binding Globulin (CBG), total cortisol and free cortisol. The increase of CBG (double) is due to high estrogen level. The levels of total cortisol (metabolically active) increase nearly three times the nonpregnant valves. The level of Corticotropin-Releasing Hormone (CRH) increases markedly. Dehydroepiandrosterone Sulfate (DHEAS) levels are decreased. Testosterone and androstenedione levels are slightly raised. The physiological correlation of CRH, ACTH and cortisol concentrations are maintained. Absence of features of Cushing's syndrome with such a high level of free cortisol might indicate that tissue target sites are less sensitive to cortisol (tissue resistance). Cortisol does cross the placenta but not ACTH. +The explanations of physiologic hypercortisolism in pregnancy are: Increased plasma cortisol half-life, delayed plasma clearance by the kidneys and resetting of hypothalamic-pituitary-adrenal feedback mechanism. +During pregnancy, CRH is also produced by the placenta and is secreted into the maternal circulation. + +Chapter 6: Endocrinology in Relation to Reproduction II +I PARATHYROID GLAND +MORPHOLOGICAL CHANGES IN NORMAL PREGNANCY: Maternal parathyroid hyperplasia occurs during pre­ gnancy. +PHYSIOLOGICAL CHANGES: The concentration of Para­ thyroid Hormone (PTH) is normal during pregnancy. The main functions of PTH are to regulate the renal +synthesis of 1,25-dihydroxyvitamin D3 and mobilization of calcium from bone. 1,25-dihydroxyvitamin D3 enhances calcium reabsorption from the kidneys +and small intestines. Calcitonin opposes the action of PTH and vitamin D. PTH does not cross the placenta but the calcium ions do cross against a concentration gradient. The marked demand of calcium (25-30 g) by the fetus during the second half of pregnancy is achieved by an increase in maternal 1,25-dihydroxyvitamin D levels. The absorption and turnover of calcium occur well in advance of fetal skeletal mineralization. There is active transfer of maternal calcium to the fetus. Total serum calcium level during pregnancy falls slightly but ionized calcium +levels remain unchanged. Blood levels of [l,25(OH)2D3], +calcitriol increase. + +I PANCREAS + +PHYSIOLOGICAL CHANGES IN PREGNANCY: During pre­ gnancy there is hypertrophy and hyperplasia of the l3 cells of islets of Langerhans in maternal pancreas. In pregnancy, there is hyperinsulinemia particularly during third trimester which coincides with the peak concentration of placental hormones. Several antinsulin factors (hPL) and other factors (CRP, IL-6, TNF-a and leptin) decrease insulin sensitivity and increase insulin resistance. Maternal blood glucose level is increased in the second half of pregnancy. This helps increased transfer of glucose from the mother to the fetus through the placenta. + +HORMONAL INFLUENCES NECESSARY FOR MAINTENANCE OF LACTATION + +Human breast is ectodermal in development. It under­ goes changes in adolescence, in reproductive life and later on involution in menopause. Anatomically, it consists of ducts, alveoli and fibrofatty connective tissue. During puberty there is proliferation of fibrofatty tissue without any change in the alveoli-ductal system. +The endocrine control of lactation can be divided into following stages: +(a) Preparation of breast (mammogenesis), (b) synthesis and secretion of milk by breast alveoli (lactogenesis), ( c) ejection of milk (galactokinesis) and (d) maintenance of lactation (galactopoiesis). +ID Chapter 6: Endocrinology in Relation to Reproduction +The preparation of breast development has been described on page 46. Secretion and ejection of milk and maintenance of lactation are discussed on page 142. + + +I Estrogen +r +J +l + +Adrenal steroids Jr Growth hormone + + +( Duct system )f------ - + + +Withdrawal of estrogen and progesterone + + + +The hormones responsible are schematically represented in Figure 6.2. +Ir +n +l +! + + + + +Progesterone Estrogen + Prolactin +---------r one +o +Lobulo-alve lar system +o + + + +Suckling + + + + +Fully developed _ rnammary glana +l +l + +l'"'"i;"rmone Glucocorticoids +Gr +o +wth h +o +Thyr id +o +Prolactin + +BREAST + + + + + + + + + +Ejection of milk + + +Prolactin + + +Supraoptic nucleus + + + + +Posterior pituitary + + +Fig. 6.2: Endocrine glands in relation to lactation. + + + + +► Hormones of the placenta includes hypothalamic like hormones (CRH, GnRH, TRH), pituitary like hormones (ACTH, hCG, hCT, hPL). Others are: pregnancy proteins, growth factors (TGF- ) and steroid hormones (estrogens, progesterone, cortisol). +► hCG is a glycoprotein. subunit of hCG is specific whereas a subunit is similar to LH, FSH and TSH. +► hCG stimulates corpus luteum, adrenal and thyroid glands and the placenta. Doubling time of hCG is 1.4-2 days. Between 60 and 70 days of pregnancy blood level of hCG reach maximum (100-200 IU/ml), thereafter it falls slowly to 10-20 IU/ ml. +► Human placenta lactogen antagonizes insulin action. It causes maternal lipolysis and promotes transfer of glucose and amino acids to the fetus. +► Maternal serum levels of FSH and LH are decreased significantly due to negative feedback inhibition from elevated levels of estrogen, progesterone and inhibin. +► Steroid hormones (estrogen and progesterone) together play an important role in the maintenance of pregnancy. They help physiological adaptation in all the body system including the changes in the breasts. +► Daily iodine requirement during pregnancy is increased to 200 µg/day (WHO). Gestational transient thyrotoxicosis in first trimester +may be due to the thyrotrophic effect of hCG. During pregnancy maternal total T4 and T3 are increased but free T4 and T3 levels are unchanged. Maternal TSH remains normal. +► Fetal thyroid starts function after 12 weeks. Transient gestational thyrotoxicosis may be due to thyrotrophic effect of placental hCG. +T4 crosses the placenta and the fetus is dependent upon maternal T4 supply for normal neurologic development. T4 and TRH cross the placenta. TSH crosses very minimally. +► Parathyroid Hormones (PTH) do not cross the placenta but the calcium ions do cross against the concentration gradient. +► The levels of total cortisol (metabolically active) rise nearly three times compared to the nonpregnant values. This is mainly due to the marked rise in the levels of CRH, ACTH both from the pituitary and the placenta. +► Pituitary gland enlarges in pregnancy with the proliferation of prolactin producing cells. Sudden hypotension (PPH) may cause infraction (Sheehan syndrome) of the gland. Secretion of prolactin, CRH, and oxytocin rise significantly during pregnancy. +► During pregnancy, there is increased serum levels of: ACTH, aldosterone, deoxycorticosterone, CBG, and cortisol. Pregnancy is a state of physiologic hypercortisolism. + + +Diagnosis of Pregnancy + + + + + + + + +CHAPTER OUTLINE +❖ First Trimester (First 12 Weeks) ❖ Second Trimester (13-28 Weeks) ❖ Last Trimester (29-40 Weeks) +❖ Differential Diagnosis of Pregnancy + + +❖ Chronological Appearance of Specific Symptoms and Signs of Pregnancy +❖ Signs of Previous Childbirth + + +❖ Estimation of Gestational Age and Prediction of Expected Date of Delivery +❖ Estimation of Fetal Weight + + + + +The reproductive period of a woman begins at menarche and ends in menopause. It usually extends from 13 to 45 years. While biological variations may occur in different geographical areas, pregnancy is rare below 12 years and beyond 50 years. Lina Medina in Lima, Peru was the youngest one, delivery by cesarean section when she was only 5 years and 7 months old and the oldest one at 57 years and 4 months old. + +DURATION OF PREGNANCY: The duration of pregnancy has traditionally been calculated by the clinicians in terms of 10 lunar months or 9 calendar months and 7 days or 280 days or 40 weeks, calculated from the first day of the last menstrual period. This is called menstrual or gestational age. +But, fertilization usually occurs 14 days prior to the expected missed period and in a previously normal cycle of 28 days duration; it is about 14 days after the first day of the period. Thus, the true gestation period is to be calculated by subtracting 14 days from 280 days, i.e., 266 days. This is called fertilization or ovulatory age and is widely used by the embryologist. + +FIRST TRIMESTER (FIRST 12 WEEKS) + +SUBJECTIVE SYMPTOMS: The following are the presumptive symptoms of early months of pregnancy: +Amenorrhea during the reproductive period in an otherwise healthy individual having previous normal menstruation, is likely due to pregnancy unless proved otherwise. However, cyclic bleeding may occur up to 12 weeks of pregnancy, until the decidual space is obliterated by the fusion of decidua vera with decidua capsularis. Such bleeding is usually scanty, lasting for a shorter duration than her usual and roughly corresponds with the date of the expected period. This is termed as placental sign. This type of bleeding should not be confused with the +commonly met pathological bleeding, i.e., threatened + + +abortion. Pregnancy, however, may occur in women who are previously amenorrheic-during lactation and puberty. Morning sickness (nausea and vomiting) is incon­ sistently present in about 70% cases, more often in the first pregnancy than in the subsequent one. It usually appears soon following the missed period and rarely lasts beyond 16 weeks. Its intensity varies from nausea to loss of appetite or even vomiting and loss of weight. But it usually does not affect the health status of the mother +(p. 149). +Frequency of micturition is quite troublesome sym­ ptom during 8-12th week of pregnancy. It is due to-(1) resting of the bulky uterus on the fundus of the bladder because of exaggerated anteverted position of the ute­ rus, (2) congestion of the bladder mucosa and (3) change in maternal osmoregulation causing increased thirst and polyuria (p. 48). As the uterus straightens up after 12th week, the symptom disappears. +Breast discomfort in the form of feeling of fullness and 'pricking sensation' is evident as early as 6-8th week specially in primigravidae. +Fatigue is a frequent symptom which may occur early in pregnancy. +OBJECTIVE SIGNS: ♦ Breast changes are valuable only in primigravidae, as in multiparae, the breasts are enlarged and often contain milk for years. The breast changes are evident between 6 and 8 weeks. There is enlargement with vascular engorgement evidenced by the delicate veins visible under the skin (Figs. 7.IA and B). +The nipple and the areola (primary) become more pigmented, especially in dark women. Montgomery's tubercles are prominent. Thick yellowish secretion (colo­ strum) can be expressed as early as 12th week. +♦ Per abdomen: Uterus remains a pelvic organ until 12th week, it may be just felt per abdomen as a suprapubic bulge. +·JI Chapter 7: Diagnosis of Pregnancy + + + + + + + + + + + + + + + + + +Figs. 7.1A and B: Breast changes during pregnancy: (A) Pronounced pigmentation of the primary areola and nipple; (Bl Appearance of secondary areola, development of Montgomery tubercles and increased vascularity. + +♦ Pelvic changes: The pelvic changes are diverse and appear at different periods. Collectively, these may be informative in arriving at a diagnosis of pregnancy. +• Jacquemier's (1836) or Chadwick's (1887) sign: It is the dusky hue of the vestibule and anterior vaginal wall visible at about 8th week of pregnancy. The discoloration is due to local vascular congestion. +• Vaginal signs: (a) Apart from the bluish discoloration of the anterior vaginal wall, (b) The walls become softened, (c) Copious non-irritating mucoid discharge appears at 6th week and (d) There is increased pulsation, felt through the lateral fornices at 8th week called Osiander's sign. +• Cervical signs: (a) Cervix becomes soft as early as 6th week (Goodell's sign), a little earlier in multiparae. The pregnant cervix feels like the lips of the mouth, while in the nonpregnant state, like that of tip of the nose. (b) On speculum examination, the bluish discoloration of the cervix is visible. It is due to increased vascularity. +• Uterine signs: (a) Size, shape and consistency: The uterus is enlarged to the size of hen's egg at 6th week, size of a cricket ball at 8th week and size of a fetal head by 12th week. The pyriform shape of the non-pregnant uterus becomes globular by 12 weeks. There may be asymmetrical + +enlargement of the uterus if there is lateral implantation. This is called Piskacek's sign where one half is more firm than the other half. As pregnancy advances, symmetry is restored. The pregnant uterus feels soft and elastic. +(b) Hegar's sign: It is present in two-thirds of cases. It can be demonstrated between 6 and 10 weeks, a little earlier in multiparae. This sign is based on the fact that: (I) upper part of the body of the uterus is enlarged by the growing fetus, (2) lower part of the body is empty and extremely soft and (3) the cervix is comparatively firm. Because of variation in consistency, on bimanual examination ( two fingers in the anterior fornix and the abdominal fingers behind the uterus), the abdominal and vaginal fingers seem to appose below the body of the uterus. Examination must be gentle to avoid the risk of abortion. +(c) Palmer's sign: Regular and rhythmic uterine contrac­ tion can be elicited during bimanual examination as early as 4-8 weeks. Palmer in 1949, first described it and it is a valuable sign when elicited. +IMMUNOLOGICAL TESTS FOR DIAGNOSIS OF PREGNANCY +Principle: Pregnancy tests depend on detection of the antigen (hCG) present in the maternal urine or serum with antibody either polyclonal or monoclonal available commercially (Table 7.1). +Enzyme-Linked Immunosorbent Assay (ELISA): This is more sensitive and specific. ELISA can detect hCG in serum up to 1-2 mIU/mL and as early as 5 days before the first missed period. +With a sensitive test, the hormone hCG can be detected in maternal serum or urine by 8-9 days after ovulation. hCG is a glycoprotein. The a subunit of the molecule is identical to those of LH, FSH and TSH. The subunit is distinct structurally. Antibodies are developed with this highly specific subunit. This specificity allows its detection. +Numerous commercial immunoassay are available for measuring hCG levels. Depending on assay used, the sensitivity for laboratory detection limit in serum is 1.0 mlU/mL. False-positive hCG test results are rare. Rare causes of false-positive test results are: (a) exogenous hCG injection, (b) Physiological pituitary hCG, (c) hCG producing tumors (ovary, lung) and (d) renal failure (delayed hCG clearance). + + + + + + +Immunological tests (urine} +■ Two-site sandwich immunoassay (membrane ELISA/card tests}. + + +30-50 mlU/mL (urine} 1.0 mlU /ml (serum}. + + +4-5 minutes Color bands in the control as well as in test window. + + +On the first day of the missed period (28th day of cycle). + +■ Various kits in card forms are available.. + Pregnant (card test) - Not pregnant (card test) + + + + +11 Enzyme-linked immunosorbent 1-2 mlU/mL (serum). assay (ELISA). + + +5 days before the first missed period. + + +Table 7.2: Gestational age and embryonic structures identified by' +• I ' > +._ +" • > , ' + +' +' +. +0 +transvaginal sonography (TVS). •• , •• I , ' / +! +_ ' +Menstrual CRL +age(weeks) (mm) Fetal structures +4 - Choriodecidual thickness, chorionic sac 5 - Gestation sac +- Yolk sac +5.5 +6 5 Fetal pole, cardiac activity +7 10 Lower limb buds, midgut herniation (physiological) +8 16 Upper limb buds, stomach 9 24 Spine, choroid plexus + +Selection of time: Diagnosis of pregnancy by detecting hCG in maternal serum or urine can be made by 8-9 days after ovulation (3-4 days before the expected date of menses). The test is not reliable after 12 weeks. +Collection of urine: The patient is advised to collect the first voided urine in the morning in a clean container (not to wash with soap). Kits to perform the test at home are also available. +Other uses of pregnancy tests: Apart from diagnosis of uterine pregnancy, the tests are employed in the: (1) diagnosis of ectopic pregnancy (p. 173), (2) to monitor pregnancy following in vitro fertilization and embryo transfer and (3) to follow up cases of hydatidiform mole and choriocarcinoma. Test accuracy ranges from 98.6 to 99%. Nonpregnant level is below 1 mlU/mL. +Limitations: Test accuracy is affected due to presence of (i) hemoglobin, (ii) albumin, (iii) LH and (iv) immuno­ logical diseases. +False-positive hCG test result may rarely occur when the women have got heterophile antibodies in her serum. +Elevated levels of hCG are found in molar pregnancy and choriocarcinoma. +Cases with positive pregnancy tests without pregnancy are: (a) women having exogenous hCG + +Chapter 7: Diagnosis of Pregnancy + +injection; (b) delayed hCG clearance due to renal failure; (c) presence of pituitary hCG (physiological); (d) neoplasms producing hCG (ovary, lung, bladder or gastrointestinal tract). +ULTRASONOGRAPHY: Intradecidual Gestational Sac (GS) is identified as early as 29-35 days of gestation. +Fetal viability and gestational age is determined by detecting the following structures by transvaginal ultrasonography (Table 7.2). Gestational at 5 and yolk sac by 5.5 menstrual weeks; fetal pole and cardiac activity-6 weeks (Table 7.2); emb,yonic movements by 7 weeks. Fetal gestational age is best determined by measuring the CRL between 7 and 12 weeks (variation ± 5 days) (Figs. 7.2A to C). Doppler effect of ultrasound can pick up the fetal heart rate reliably by 10th week. The instrument is small, handy and cheap (Fig. 42.36). The gestational sac (true) must be differentiated from pseudogestational sac (p. 599). + +SECOND TRIMESTER (13-28 WEEKS) +SYMPTOMS: The subjective symptoms-such as nausea, vomiting and frequency of micturition usually subside, while amenorrhea continues. The new features that appear are: +■ 'Quickening' (feeling of life) denotes the perception of active fetal movements by the women. It is usually felt about the 18th week, about 2 weeks earlier in multiparae. Its appearance is a useful guide to calculate the expected date of delivery with reasonable accuracy (later in the chapter). +■ Progressive enlargement of the lower abdomen by the growing uterus. + +GENERAL EXAMINATION +■ Chloasma: Pigmentation over the forehead and cheek may appear at about 24th week. +■ Breast changes: (a) Breasts are more enlarged with prominent veins under the skin, (b) Secondary areola + + + + + + + + + + + + + + + + +Figs. 7.2A to C: Transvaginal ultrasonography showing: (A) Gestational age at 5th week; (B) Yolk sac by 5.5 menstrual weeks; (CJ Gestational age estimation by measuring CRL. +Chapter 7: Diagnosis of Pregnancy + +specially demarcated in primigravidae, usually appears at about 20th week, (c) Montgomery's tubercles are prominent and extend to the secondary areola, (d) Colostrum becomes thick and yellowish by 16th week and (e) Variable degree of striae may be visible with advancing weeks. +ABDOMINAL EXAMINATION +Inspection: (1) Linear pigmented zone (linea nigra) extending from the symphysis pubis to ensiform cartilage may be visible as early as 20th week, (2) Striae (both pink and white) of varying degree are visible in the lower abdomen, more towards the flanks (Fig. 8.6). +Palpation: Fundal height is increased with progressive enlargement of the uterus. Approximate duration of pregnancy can be ascertained by noting the height of the uterus in relation to different levels in the abdomen. The following formula is an useful guide for the purpose (Fig. 7.3). +The height of the uterus is midway between the symphysis pubis and umbilicus at 16th week; at the level of umbilicus at 24th week and at the junction of the lower third and upper two-thirds of the distance between the umbilicus and ensiform cartilage at 28th week. +■ The uterus feels soft and elastic and becomes ovoid in shape. +■ Braxton-Hicks contractions are felt. +■ Fetal parts are palpated distinctly by 20th week. The findings are of value to diagnose pregnancy and to identify the presentation and position of the fetus in late pregnancy. +■ Active fetal movements can be felt at intervals by placing the handover the uterus as early as 20th week. It gives positive evidence of pregnancy and of a live fetus. +■ External ballottement is usually elicited as early as 20th week when the fetus is relatively smaller than the volume + + + + + + + + + + + + + + + + + + +Fig. 7.3: The level of fundus uteri at different weeks. Note the change of uterine shape. + + +of the amniotic fluid (Fig. 7.4). It is dificult to elicit in obese patients and in cases with scanty liquor amnii. +Auscultation +■ Fetal Heart Sound (FHS) is the most conclusive clinical sign of pregnancy. With a stethoscope, it can be detected between 18 and 20 weeks. The sounds resemble the tick of a watch under a pillow. Its location varies with the position of the fetus. The rate varies from 110 to 160 beats per minute. Two other sounds are confused with fetal heart sounds. Those are: +♦ Uterine soufle is a soft blowing and systolic murmur heard low down by sides of the uterus. The sound is synchronous with the maternal pulse and is due to increase in blood flow through the dilated uterine vessels. +♦ Punic or fetal soufle is due to rush of blood through the umbilical arteries. It is a soft, blowing murmur synchro­ nous with the fetal heart sounds. +VAGINAL EXAMINATION: Not commonly done. +INVESTIGATIONS (Ultrasonography) +Sonography: Routine sonography at 18-22 weeks permits a detailed survey of fetal anatomy, placental localization and the length of the cervical canal. Gestational age is determined by measuring the Biparietal Diameter (BPD), Head Circumference (HC), Abdominal Circumference (AC) and Femur Length (FL). It is most accurate when done between 12 and 20 weeks (variation± 8 days). BPD is measured at the level of the thalami and cavum septum pellucid um. BPD is measured from outer edge of the skull to the inner edge of the opposite side (Fig. 42.49). +Fetal organ anatomy is surveyed to detect any malformation. Fetal viability is determined by real-time ultrasound. +Magnetic Resonance Imaging (MRI): MRI can be used in a selected case for fetal anatomy survey, biometry and evaluation of complex malformations. MRI has no radiation risk (Ch. 42, p. 628). + + + + + + + + + + + + + + + + + + +Fig. 7.4: External ballottement. +Chapter 7: Diagnosis of Pregnancy • + + + + + + + + + + + + + + + +Figs. 7.SA to C: Measurement of: (A) Head Circumference (HC); (B) Abdominal Circumference (AC); (C) Femur Length (FL) (details in Ch. 41, 42). + + +LAST TRIMESTER (29-40 WEEKS) + +SYMPTOMS: OAmenorrhea persists, @Enlargement of the abdomen is progressive which produces some mechanical discomfort to the patient such as palpitation or dyspnea following exertion, @) Lightening-at about 38th week, especially in primigravidae, a sense of relief of the pressure symptoms is obtained due to engagement of the presenting part, O Frequency of micturition rea­ ppears and 0 Fetal movements are more pronounced. + +SIGNS +♦ Cutaneous changes are more prominent with increa­ sed pigmentation and striae. +♦ Uterine shape is changed from cylindrical to spherical beyond 36th week. +♦ Fundal height: The distance between the umbilicus and the ensiform cartilage is divided into three equal parts. The fundal height corresponds to the junction of the upper and middle third at 32 weeks, up to the level of ensiform cartilage at 36th week and it comes down to 32 week level at 40th week because of engagement of the presenting part. To determine whether the height of the uterus corresponds to 32 weeks or 40 weeks, engagement of the head should be tested. If the head is floating, it is of 32 weeks pregnancy and if the head is engaged, it is of 40 weeks pregnancy. +Symphysis Fundal Height (SFH): The upper border of the fundus is located by the ulnar border of the left hand and this point is marked. The distance between the upper border of the symphysis pubis up to the marked point is measured by a tape in centimeter (Fig. 7.6). After 24 weeks, the SFH measured in cm corresponds to the number of weeks in pregnancy. This matches up to 36 weeks. A variation of± 2 cm is accepted as normal. Variation beyond the normal range needs further evaluation. +SFH is a simple and inexpensive screening tool for FGR. + ++ Braxton-Hicks contractions are more evident. ♦ Fetal movements are easily felt. ++ Palpation of the fetal parts and their identification become much easier. Lie, presentation and position of the fetus are determined. ++ FHS is heard distinctly in areas corresponding to the presentation and position of the fetus. FHS may not be audible in cases of maternal obesity, polyhydramnios, occipitoposterior position and in a case with IUFD. ++ Sonography-gestational age estimation by BPD, HC, AC and FL is less accurate (variation ±3 weeks). Fetal growth assessment can be made provided accurate dating scan has been done in first or second trimester. ■ Fetal AC at the level of the umbilical vein is used to +assess gestational age and fetal growth profile (IUGR or macrosomia). Fetal weight estimation can be done using tables (Hadlock- 1984 ). Amniotic fluid volume assessment is done to detect oligohydramnios (AFI <5) or polyhydramnios (AFI >25) (Fig. 7.7). +■ Placental anatomy: Location (fundus or previa), thickness (placentomegaly in diabetes) or other abnormalities are noted. + + + + + + + + + + + + + + + +Fig. 7.6: Symphysis Fundal Height (SFH). +il Chapter 7: Diagnosis of Pregnancy +Internal examination reveals-positive Jacquemier's sign, softening of the cervix, bluish discoloration of the vaginal wall and Osiander's sign and Palmer's sign. Uterine enlargement is observed. Immunological tests for pregnancy is positive. TVS is confirmatory. +Ultrasonography: Gestational ring, yolk sac, fetal pole, cardiac activity (p. 599). +BETWEEN 13 AND 20 WEEK: Symptoms: Except amenor­ rhea, all the previous symptoms disappear. +Signs: Breast changes-pigmentation of primary areola and prominence of Montgomery's tubercles. Abdomen: Uterus­ midway between pubis and umbilicus, Braxton-Hicks contrac­ tions, uterine soufle. Sonography is done for confirmation. + + + +Fig. 7.7: Measurement of AC and Amniotic Fluid (AF) measurement. + +■ Other information: Fetal viability, number, presen­ tation and organ anatomy as done in the first and second trimester are surveyed again. + +DIFFERENTIAL DIAGNOSIS OF PREGNANCY +Differention diagnosis includes: Uterine fibroid, cystic ovarian tumor, hematometra or even full urinary bladder. The confusion is further more by the presence of amenorrhea for some other reasons. Pregnancy may also coexist with the above-mentioned swellings. +Pseudocyesis (Syn: phantom, spurious, false pregnancy): It is a psychological disorder where the woman has the false but firm belief that she is pregnant although no pregnancy exists. The woman often is infertile who has an intense desire to have a baby. The conspicuous feature is cessation of menstruation. Obstetric examination often excludes pregnancy. Examination with ultrasound and/ or immunological tests for pregnancy is done to exclude pregnancy. +Cystic ovarian tumor: The diagnostic points are: (1) The swelling is slow growing, usually takes months to grow, (2) Amenorrhea is usually absent, (3) It feels cystic or tense cystic, (4) Absence ofBraxton-Hicks contraction, (5) Absence of positive signs of pregnancy and (6) Ultrasonography confirms the diagnosis. +Fibroid: (1) The tumor is slow growing, often takes years, (2) Amenorrhea is absent, (3) The feel is firm, more towards hard but may be cystic in cystic degeneration, ( 4) Positive signs of pregnancy are absent and (5) Ultrasonography or immunological test for pregnancy is helpful to confirm the diagnosis. +Full urinary bladder: In chronic retention of urine due to retroverted gravid uterus, the distended bladder may be mistaken as ovarian cyst or acute hydramnios. Catheterization of the bladder solves the problem. + +CHRONOLOGICAL APPEARANCE OF SPECIFIC SYMPTOMS AND SIGNS OF PREGNANCY + +AT 6-12 WEEKS: Symptoms-amenorrhea, morning sickness, frequency of micturition, fatigue, breast discomfort. +Signs: Breast enlargement, engorged veins visible under the skin; nipples and areola more pigmented. + +Ultrasonography: Gestational age is determined with the use of parameters: BPD, HC, AC and FL (p. 599). +Fetal anomaly survey is done between 18 and 22 weeks. LATE PREGNANCY (>20 WEEKS TO 40 WEEKS): +Symptoms: Amenorrhea, quickening (18th week). Signs: Breast: Appearance of secondary areola (20th week). +Abdomen: linea nigra (20 weeks), uterus at the level of umbilicus at 24 weeks, Braxton-Hicks contractions, external ballottement (20th week), fetal parts (20 weeks), fetal movements (20 weeks). Sonography for fetal anatomy survey. + +USE OF USG PARAMETERS FOR FETAL ASSESSMENT Utrasonography After 20 Weeks +■ Fetal growth profile BPD, HC, AC, FL. +■ Estimated fetal weight is determined from the following parameters: FL, AC, BPD and HC. +■ Liquor volume ■ Placentation +■ Fetal anatomical survey (18-22 weeks) + +SIGNS OF PREVIOUS CHILDBIRTH + +The following are the features which are to be considered in arriving at a diagnosis of having a previous birth. +Breasts become more flabby; nipples are prominent whoever breast-fed their infant; primary areolar pigmentation still remains and so also the white striae. +Abdominal wall is more lax and loose. There may be presence of silvery white striae and linea alba. +Uterine wall is less rigid and the contour of the uterus is broad and round, rather than ovoid. +Perineum is lax and evidence of old scarring from previous perineal laceration or episiotomy may be found. +Introitus is gaping and there is presence of carunculae myrtiformis. +Vagina is more roomy. +Cervix: Nulliparous cervix is conical with a round external os. In parous women, it becomes cylindrical and the external os is a transverse patulous slit and may admit the tip of the finger (Figs. 7.8A and B). However, as a result of operative mani­ pulation even a nulliparous cervix may be torn and resembles a multiparous cervix. +Chapter 7: Diagnosis of Pregnancy - + + + + + + + + + + +Figs. 7.SA and B: Appearance of external os: (A) Nulliparous; (B) Parous. + + +ESTIMATION OF GESTATIONAL AGE AND PREDICTION OF EXPECTED DATE OF DELIVERY +Estimation of gestational age and thereby calculating the EDD is invaluable for assessing the fetal growth profile in the diagnosis of intrauterine growth restriction. +Gestational age is 280 days calculated from the first day of the Last normal Menstrual Period (LMP). Accurate LMP is the most reliable parameter for estimation of gestational age. +But in significant number of cases (20-30%), the patients either fail to remember the LMP or report inaccurately. The matter becomes complicated when the conception occurs during lactation amenorrhea or soon following withdrawal of contraceptive pills ( ovulation may be delayed for 4-6 weeks) or in cases with bleeding in early part of pregnancy. The following parameters either singly or in combination are useful in predicting the gestational age with fair degree of accuracy. + +■ To add 36 weeks since a recorded positive urine or serum pregnancy test. +■ Ultrasonographic findings at the earliest are: ( a) Gestation sac-at 5 weeks. (b) Measurement of Crown-Rump Length (CRL) detected at 6 weeks, (c) Yolk sac appears at 5.5 weeks. (d) Embryo (CRL of 3 mm) with cardiac motion is seen when gestation age is 6 weeks. (e) CRL of 16 mm with mean sac diameter of 26 mm, the gestational age is 8 weeks. + +OBJECTIVE SIGNS +■ Height of the uterus above the symphysis pubis in relation to the landmarks on the abdominal wall or SFH. +■ Lightening: Following the appearance of the features suggestive of lightening, the labor is likely to commence within 3 weeks. +■ Size of the fetus, change in the uterine shape, volume of liquor amnii, hardening of the skull and girth of the abdomen are of value in assessing the maturity of the fetus, especially if the examinations are done by the same person at intervals. +■ Vaginal examination: If the cervix becomes shorter and dilated, the labor is fairly not far off. But labor may start even with long and closed cervix. +INVESTIGATIONS: Sonography-the following parameters are of use. +■ First trimester-CRL is most accurate (variation ± 5 days). +■ To add 30 weeks since the documentation of fetal heart tones by Doppler USG. + + + +PATIENT'S STATEMENT +■ Date offruitful coitus: If the patient can remember the date of the single fruitful coitus with certainty, it is quite reliable to predict the expected date of delivery with accuracy of 50% within 7 days on either side. As previously mentioned, 266 days are to be added to the date of the single fruitful coitus to calculate the expected date. + + +■ Second trimester by BPD, HC, AC and FL measurement. Most accurate when done between 12 and 20 weeks (variation ± 8 days). +■ To add 20 weeks since the measurement of fetal parameters for anomaly scan (18-20 weeks). +■ Third trimester-less reliable, variation ± 16 days. + + + +■ Naegele's formula: Provided the periods are regular, it is very useful and commonly practiced means to calculate the expected date. Its prediction range is about 50% with 7 days on either side of EDD. If the interval of cycles is longer, the extra days are to be added and if the interval is shorter, the lesser days are to be subtracted to get the EDD. +■ Date of quickening: A rough idea about the probable date of delive1y can be deduced by adding 22 weeks in primigra­ vidae and 24 weeks in multiparae to the date of quickening. +PREVIOUS RECORDS: The required weeks are to be added to make it 40 weeks. +A. Clinical: +■ Size of the uterus prior to 12 weeks more precisely corresponds with the period of amenorrhea. +■ Palpation of fetal parts at the earliest by 20th week. +■ Auscultation of FHR at the earliest by 18-20 weeks using a stethoscope and that using a hand-held Doppler at 10th week (Figs. 42.36A and B). + + +ESTIMATION OF FETAL WEIGHT + +Approximate prediction of the fetal weight is more important than the mere estimation of the uterine size. This is more important prior to induction of labor or elective cesarean section. This is to minimize the risk of preterm delivery. The following methods are useful when considered together to have an idea about the weight of the fetus: +A. Fetal growth velocity: Conditional centiles depending on individual fetal growth velocity is thought to be more important. +B. Sonography: Fetal weight has been estimated by combin­ ing a number of biometric data, e.g., BPD, HC, AC and FL. Tables (Hadlock, Shepard) are currently in use (computer software). Estimated fetal weight likely to be within 10% of actual weight. +♦ Hadlock's formula: Based on HC, AC and FL log 10 weight = 1.326 - 0.00326 x AC x FL + 0.0107 x HC + 0438 x AC + 0.158 x FL. Regional growth charts are preferred. + + + +B. Investigation records: Investigation records during first half of pregnancy are invaluable. + +♦ Shepard's formula: Log 10 EFW (g) = 1.2508 + (0.166 x BPD) + 0.046 x AC) - (0.002646 x AC x BPD). +Chapter 7: Diagnosis of Pregnancy + + + +► Duration of pregnancy is calculated from the first day oflast normal menstrual period. Total duration of pregnancy is 9 calendar months and 7 days or 40 weeks or 280 days. +► Diagnosis of pregnancy in the first trimester is made from: (a) Subjective symptoms-amenorrhea, morning sickness, breast discomfort, frequency of micturition, (b) Objective signs-changes in the breast, changes in vagina, cervix, uterus, (c) Pregnancy tests-detection of hCG in a sample of urine or serum and (d) Ultrasonography to detect gestational sac and yolk sac, by 5 and 5.5 menstrual weeks respectively. +► Presumptive symptoms and signs: It includes the features mainly appreciated by the women: (1) Amenorrhea, (2) Frequency of micturition, (3) Morning sickness, (4) Fatigue, (5) Breast changes, (6) Skin changes and (7) Quickening. +► Probable signs: (1) Abdominal enlargement, (2) Braxton-Hicks contractions, (3) External ballottement, (4) Outlining the fetus, (5) Changes in the size, shape and consistency of the uterus, (6) Jacquemier's sign, (7) Softening of the cervix, (8) Osiander's sign, (9) Internal ballottement and (1 O} Immunological test. +► Positive or absolute signs: (1} Palpation of fetal parts and perception of active fetal movements by the examiner at about 20th week, (2) Auscultation of fetal heart sounds, (3) Ultrasound evidence of embryo as early as 6th week and later on the fetus and (4) Radiological demonstration of the fetal skeleton at 16th week and onwards. + + +The Fetus-in-Utero + + + + + + +ttCHAflTER OUTLINE"'( ' +l +❖ Causes of Preponderance of ❖ Methods of Obstetrical Examination Longitudinal Lie and Cephalic +Presentation + + + +The fetus lies inside the uterus in a closed sac filled with liquor amnii. It has enough freedom of movement until the later months of pregnancy, when it becomes relatively fixed. Till then, periodic examination is essen­ tial to note its lie, presentation, position and attitude. Incidental idea can be gained about the size of the fetus or amount of liquor amnii. +LIE: The lie refers to the relationship of the long axis of the fetus to the long axis of the centralized uterus or maternal spine, the most common lie being longitudinal + + +(99.5%). The lie may be transverse or oblique; sometimes the lie is unstable until labor sets in, when it becomes either longitudinal or transverse (Table 8.1 and Figs. 8.IA to D). + +Table 8.1: Preponderance of lie, presentation and presenting part. Presenting part +Lie Presentation of cephalic Longitudinal (99.5%) Cephalic (96.5%) Vertex (96%) +Transverse Breech (3%) Brow Oblique ) (0.5%) Shoulder (0.5%) Face Unstable +) (0.5%) +) + + + + + + + + + + + + +rn Longitudinal lie + + + + + + + + + + + +Oblique lie rn Transverse lie +Figs. 8.1A to D: (Al Longitudinal lie; (B) The fetus seems to lie in oblique position in relation to the maternal spine but actually remains in longitudinal lie in relation to uterine axis. Correction of the uterine obliquity rectifies the apparent oblique lie of the fetus into longitudinal lie as in (Al; (C) Oblique lie, and (Dl Transverse lie. +I - Ba Chapter 8: The Fetus-in-Utero +rJ + + + + + + + + + + + + + + + +Vertex +(well-flexed head) + +m +Vertex (deflexed head) + + + +Brow Face + +Figs. 8.2A to D: Varieties of cephalic presentations in different attitude. + + +PRESENATION: The part of the fetus which occupies the lower pole of the uterus (pelvic brim) is called the presentation of the fetus. Accordingly, the presentation may be cephalic (96.5%), podalic (3%) or shoulder and other (0.5%). When more than one part of the fetus present, it is called compound presentation. + +PRESENTING PART: The presenting part is defined as the part of the presentation which overlies the internal os and is felt by the examining finger through the cervical opening. Thus, in cephalic presentation, the presenting part may be vertex (most common), brow or face, dep­ ending upon the degree of flexion of the head (Figs. 8.2A toD). +Similarly, the fetal legs in a breech presentation may be flexed (complete breech), extendect"{frank breech) or a foot may be present (footling). However, the term presentation and presenting part are often used synony­ mously and expressed more commonly in clinical practice according to the latter definition. +ATTITUDE: The relation of the different parts of the fetus to one another is called attitude of the fetus. The universal attitude is that of flexion. During the later months, the head, trunk and limbs of the fetus maintain the attitude of flexion on all joints and form an ovoid mass that cor­ responds approximately to the shape of uterine ovoid. The characteristic flexed attitude may be modified by the amount of liquor amnii. There may be exceptions to this universal attitude and extension of the head may occur ( deflexed vertex, brow or face presentation, according to the degree of extension) or the legs may become extended in breech. The course of labor in such circumstances may be modified accordingly. + +DENOMINATOR: It is an arbitrary bony fixed point on the presenting part which comes in relation with the various quadrants of the maternal pelvis. The following are the denominators of the different presentations-occiput in + +vertex, mentum (chin) in face, frontal eminence in brow, sacrum in breech and acromion in shoulder. + +POSITION: It is the relation of the denominator to the different quadrants of the pelvis. For descriptive purpose, the pelvis is divided into equal segments of 45° to place the denominator in each segment. Thus, theoretically, there are 8 positions with each presenting part (Fig. 8.3). +Anterior, posterior, right or left position is referred in relation to the maternal pelvis, with the mother in erect position. However, some have retained the conventional description of four vertex positions. Vertex occupying the left anterior quadrant of the pelvis is the most com­ mon one and is called Left Occipitoanterior (LOA). This is the first vertex position. Similarly, Right Occipitoanterior + +OP1% + +ROP LOP +' +' +7% ' t ' ' t +3% +' ' ' .', . i >.1 + + + + + + + +, , , -, -10% LOA +l +i' +ROA +13% + + + +OA2% +Fig. 8.3: The position and relative frequency of the vertex at the onset of labor. + . Chapter 8: The Fetus-in-Utero .. +(ROA) is the second vertex; Right Occipitoposterior (ROP) anterior wall, cylindrical or spherical shape, (3) undue third vertex and Left Occipitoposterior (LOP) is the fourth enlargement of the uterus, (4) pigmentary changes in the vertex position. skin, (5) skin condition of abdomen for evidence of any infections (ringworm), and (6) any incisional scar mark on +CAUSES OF PREPONDERANCE OF LONGITUDINAL the abdomen. +LIE AND CEPHALIC PRESENTATION Palpation: Height of the uterus: The uterus is to be centralized, if it is deviated. The ulnar border of the left hand is placed on the upper most level of the fundus and +!] !] + !I +. +!J-. +The fetus in the attitude of flexion assumes a +shape of an ovoid with its long verticopodalic axis +measuring about 25 cm (10") at term (Fig. 8.4). .-, an approximate duration of pregnancy is ascertained in +terms of weeks of gestation +Alternatively, the +The fetus accommodates comfortably along the (Fig. 8.6). +long axis of the ovoid shape of the uterine cavity at term. Hence, Symphysio-fundal height (SFH) can be measured with a +there is preponderance of longitudinal lie. tape (Fig. 7.6). +The cephalic presentation, being the absolute majority There are conditions where the height of the uterus +amongst the longitudinal lie, can be explained by: (1) may not correspond with the period of amenorrhea. The +Gravitation-the head being heavier comes down to the bottom. (2) Adaptation-the smallest circumference of the flexed head is about 27.5 cm (11") and the circumference of the breech with both thighs flexed is about 32.5 cm (13"). Thus the cephalic +conditions where the height of the uterus is more than +the period of amenorrhea are: +(1) +mistaken date of the +last menstrual period, +(2) +twins, +(3) +polyhydramnios, +( +4) +big baby, +(5) +pelvic tumors-ovarian or fibroid, +(6) +(7) +and the podalic poles can be comfortably accommodated in +the narrow lower pole and the wider fundal area of the uterus hydatidiform mole and concealed accidental respectively. hemorrhage. The conditions where the height of the +uterus is less than the period of amenorrhea are: METHODS OF OBSTETRICAL EXAMINATION (I) mistaken date of the last menstrual period, +(2) scanty liquor amnii, (3) Fetal Growth Restriction (FGR), abdominal examination beyond 28 weeks of pregnancy (4) Intrauterine Fetal Death (IUFD) and (5) Rupture of +ABDOMINAL EXAMINATION: +A thorough and systematic +Membranes (ROM). +can reasonably diagnose the lie, presentation, position +and the attitude of the fetus (Figs. 8.5A to D). It is not Obstetric grips (Leopold maneuvers) (Figs. 8.5A +unlikely that the lie and presentation of the fetus might to D): Palpation should be conducted with utmost change, especially in association with excess liquor amnii gentleness. Clumsy and purposeless palpation is not only +and hence periodic checkup is essential. uniformative but may cause undue uterine irritability. +Preliminaries: Verbal consent for examination is During Braxton-Hicks contraction or uterine contrac­ +taken. The patient is asked to evacuate the bladder. She tion in labor, palpation should be suspended. +is then made to lie in dorsal position with the thighs (i) Fundal grip (first Leopold): The palpation is done slightly flexed. Abdomen is fully exposed. The examiner facing the patient's face. The whole of the fundal area stands on the right side of the patient. is palpated using both hands laid flat on it to find out Inspection: To note-(1) whether the uterine ovoid which pole of the fetus is lying in the fundus: (a) broad, +is longitudinal or transverse or oblique, (2) contour soft and irregular mass suggestive of breech or (b) smooth, of the uterus-fundal notching, convex or flattened hard and globular mass suggestive of head. In transverse lie, neither of the fetal poles are palpated in the fundal +area. + + + + + + + + + + + + + +V +Fig. 8.4: Diagrammatic representation of a fetus in flexed attitude. V-P-Verticopodalic diameter A-A-Bisacromial diameter +T -T -Bitrochanteric diameter P-P-Biparietal diameter + +(ii) Lateral or umbilical grip (second Leopold): The palpation is done facing the patient's face. The hands are to be placed flat on either side of the umbilicus to palpate one after the other, the sides and front of the uterus to find out the position of the back, limbs and the anterior shoulder. The back is suggested by smooth curved and resistant feel. The 'limb side' is comparatively empty and there are small knob-like irregular parts. After the identification of the back, it is essential to note its position whether placed anteriorly or towards the flank or placed transversely. Similarly, the disposition of the small parts, whether placed to one side or placed anteriorly occupying both the sides, is to be noted. The position of the anterior shoulder is to be felt. It forms a well-marked prominence in the lower part of the uterus above the head. It may be placed near the midline or well away from the midline. +- · .. Chapter 8: The Fetus-in-Utero + + + + + + + + + + + + + + + + + + + +rJ + + + + + + + + + + + + + + + + + + +m +Figs. 8.SA to D: Obstetric grips (Leopold maneuvers): (A) Fundal grip (first Leopold); (B) Lateral grip (second Leopold); (C) Pawlik's grip (third Leopold); (D) Pelvic grip (fourth Leopold). + + +(iii) Pawlik's grip {third Leopold): The examination is done facing toward the patient's face. The overstretched thumb and four fingers of the right hand are placed over the lower pole of the uterus keeping the ulnar border of the palm on the upper border of the srnphysis pubis. When the fingers and the thumb are approximated, the presenting part is grasped distinctly (if not engaged) and also the mobility from side to side is tested. In transverse lie, Pawlik's grip is empty. +(iv) Pelvic grip {fourth Leopold): The examination is done facing the patient's feet. Four fingers of both the hands are placed on either side of the midline in the lower + +pole of the uterus and parallel to the inguinal ligament. The fingers are pressed downward and backward in a manner of approximation of finger tips to palpate the part occupying the lower pole of the uterus (presentation). If it is head, the characteristics to note are: (1) precise presenting area, (2) attitude and (3) engagement. +To ascertain the presenting part, the greater mass of the head (cephalic prominence) is carefully palpated and its relation to the limbs and back is noted. The attitude of the head is inferred by noting the relative position of the sincipital and occipital poles {Figs. 8.8A and B). The engagement is ascertained noting the presence or +Chapter 8: The Fetus-in-Utero + + \' +;a + + + + + + + + + + + + + + + + + +Fig. 8.6: To note the height of the uterus. Linea nigra and striae gravidarum are also visible. + +absence of the sincipital and occipital poles or whether there is convergence or divergence of the finger tips during palpation (Figs. 8.9A and B). This pelvic grip using both the hands is favored as it is most comfortable for the woman and gives most information. +Auscultation: Auscultation of distinct fetal heart sounds (FHS) not only helps in the diagnosis of a live baby, but its location of maximum intensity can resolve doubt about the presentation of the fetus (Fig. 8. 7 A). +The fetal heart sounds are best audible through the back (left scapular region) in vertex and breech presen­ tation, where the convex portion of the back is in contact with the uterine wall. However, in face presentation, the heart sounds are heard through the fetal chest. +As a rule, the maximum intensity of the FHS is below the umbilicus in cephalic presentation and + +around the umbilicus in breech. In different positions of the vertex, the location of the FHS depends on the position of the back and the degree of descent of the head. In occipitoanterior position, the FHS is located in the middle of the spinoumbilical line of the same side. In occipitolateral position, it is heard more laterally and in occipitoposterior position, well back toward the mother's flank on the same side. In left occipitoposterior position, it is most difficult to locate the FHS (Fig. 8.7B). +INTERNAL EXAMINATION: The diagnosis of the presen­ tation and position of the fetus may not be accurate by internal examination during pregnancy when the cervix remains closed. However, during labor, accurate information may be obtained by palpation of the sagittal suture and fontanelles through the open cervix. Stress for strict aseptic precautions during vaginal examination needs no emphasis. +ULTRASONOGRAPHY: The diagnosis of the lie, presentation and position may be difficult in the presence of marked obesity, irritable uterus, excessive liquor amnii and deeply engaged head, especially in primigravidae. Ultrasonography can locate the head and the body (p. 599). Alternatively, straight X-ray may be needed to arrive at a diagnosis in such cases. +INFERENCES: As the vertex is the most common presen­ tation, the relevant information in relation to the vertex is only mentioned. +Lie: The longitudinal lie is evident from: (1) longitudi­ nal uterine ovoid on inspection and (2) the poles of the fetal ovoid-cephalic and podalic are placed, one at the lower and the other at the upper part of the uterine cavity, as evident from the fundal and first pelvic grips. + + + + + + + + + + + +R0SA LS(A) L OP +ROA LOA +RMA LMA + + + + + + +Figs. 8.7A and B: (A} Auscultation of distinct fetal heart sounds (FHS); (B} Location of the FHS in different presentation of position of the fetus. +Chapter 8: The Fetus-in-Utero + +P1'esentation: The cephalic presentation is evident from the first pelvic grip-smooth, hard and globular mass. +Attitude: From the first pelvic grip, the relative positions of the sincipital and occipital poles are determined. In well-flexed head, the sincipital pole is placed at a higher level but in deflexed state, both the poles remain at a same level (Figs. 8.8A and B). +Presenting pa1't: Vertex is diagnosed from the first pelvic grip. The cephalic prominence, being the sinciput, is placed on the same side toward which limbs lie. +Position: The occipitoanterior position is diagnosed by: (1) Inspection-convexity of the uterine contour. (2) Lateral grip-(a) The back is placed not far from the midline to the same side of the occiput and (b) The anterior shoulder is near the midline. (3) Auscultation­ maximum intensity of the FHS is close to the spinoumbilical line on the same side of the back. +Right or left position is to be determined by: (1) Position of the back, (2) position of the occiput and (3) location of the FHS. + + + + + + + + + +s +I + + + +Figs. 8.8A and B: Relative position of the Sincipital (S) and the Occipital (0) pole as felt in first pelvic grip: (A) Well-flexed; (Bl Deflexed. + + + +ENGAGEMENT: When the greatest horizontal plane, the biparietal, has passed the plane of the pelvic brim, the head is said to be engaged. +Diagnosis: First pelvic grip: (1) Both the poles (sinciput and occiput) are not felt per abdomen. However, the sincipital pole can be felt with dificulty even though the head is engaged. (2) Divergence of the examining fingers of both the hands while trying to push downward on the lower abdomen (Figs. 8.9A and B). +Convergence of the fingers while palpating the lateral aspects of the fetal head indicates that the head is not yet engaged. +Vaginal examination: Lower pole of the unmolded head is usually at or below the level of the ischial spines. The distance between the pelvic inlet and ischial spines is about 5 cm. But the distance between the biparietal plane of the unmolded head to the vertex is about 3 cm (Figs. 8.lOA and B). +Imaging: Lateral view sonography is confirmatory. Significance: Engagement of the head always excludes +disproportion at the brim, as the head is the best pelvimeter. +The traditional concept that in primigravidae, the engagement occurs by 38 weeks is not corroborative in clinical practice. In majority, the engagement occurs between 38 and 42 weeks or even during first stage of labor. In multigravidae, however, the engagement occurs late in first stage of labor after the rupture of the membranes. However, if the head fails to engage in primigravidae even at 38th week, the causes are to be sought for. Common causes are: (1) Deflexed head bringing the larger diameter to engage, (2) Cephalopelvic disproportion or big head or a combination of both, (3) Polyhydramnios, (4) Poor formation or yielding of lower uterine segment-preventing the head to sink into the pelvis, + + + + + + + + + + + + + + + + + +rJ +Figs. 8.9A and B: Abdominal palpation to determine engagement of the head: (A) Divergence of fingers-engaged head; (B) Convergence fingers-not engaged. +Chapter 8: The Fetus-in-Utero .. + + + + + + + + + + + + + + + + + +Figs. 8.10A and B: The relationship of the biparietal diameter to the pelvic brim and that of lower pole of the head to the ischial spines in: (A) Nonengaged head; (B) Engaged head. + + + + + + + + + + + + + + + + + +Head fixed Head fixed engaged too big to engage +Fig. 8.11: Schematic representation showing the difference between an engaged and a fixed head by use of egg cups and eggs. + +(5) Hydrocephalus, (6) Placenta previa, (7) Pelvic tumors-ovarian or fibroid, (8) High pelvic inclination and (9) Functional-when no cause can be detected (20%). +Fixed head: The word 'fixed' should not be used to designate an engaged head. Whereas, an engaged head is fixed but conversely, the fixed head is not necessarily engaged. When an egg is placed on the egg cup, it remains fixed yet the maximum diameter does not pass through the rim (Fig. 8.11). +Similarly, the head may be fixed to the brim but that does not mean that the maximum diameter of the head (biparietal) will pass through the brim. As such, the use of the term 'fixed' should be abandoned. Similarly, the term 'engaging' should be withheld. A clear statement is to be made as to whether the head is engaged or not. + + +Fetal Skull and Maternal Pelvis + + + + + + + + + +❖ Fetal Skull ❖ Pelvis +► False Pelvis ► True Pelvis + + +► Inlet +► Cavity ► Outlet +► Midpelvis + +► Physiological Enlargement of Pelvis during Pregnancy and Labor + + + + +FETAL SKULL +Fetal skull is to some extent compressible and made mainly of thin pliable tabular (flat) bones forming the vault. This is anchored to the rigid and incompressible bones at the base of the skull. +AREAS OF SKULL: The skull is arbitrarily divided into several zones of obstetrical importance (Fig. 9.1). These are: +■ Vertex: It is a quadrangular area bounded anteriorly by the bregma and coronal sutures behind by the lambda and lambdoid sutures and laterally by lines passing +through the parietal eminences. +■ Brow: It is an area bounded on one side by the anterior fontanel and coronal sutures and on the other side by the root of the nose and supraorbital ridges of either side. +■ Face: It is an area bounded on one side by root of the nose and supraorbital ridges and on the other, by the junction of the floor of the mouth with neck. + +Sinciput is the area lying in front of the anterior fontanel and corresponds to the area of brow and the occiput is limited to the occipital bone. +Flat bones of the vault are united together by non­ ossified membranes attached to the margins of the bones. These are called sutures and fontanels. Of the many sutures and fontanels, the following are of obstetric significance. +SUTURES (Figs. 9.1 and 9.2) +■ The sagittal or longitudinal suture lies between two parietal bones. +■ The coronal sutures run between parietal and frontal bones on either side. +■ The frontal suture lies between two frontal bones. +■ The lambdoid sutures separate the occipital bone and the two parietal bones. +Importance: (l) It permits gliding movement of one bone over the other during molding of the head, + +Anterior fontanel---- - - - -, or bregma +•··· +lt + + +Parietal .. , . ,m;oeore + + + +Vault Parietal bone + + +Posterior fontanel + + + + + + + --Occipital protuberance + +Mentum-._______ + +Fig. 9.1: Fetal skull showing different regions and landmarks of obstetrical significance. +Chapter 9: Fetal Skull and Maternal Pelvis + + + + + + +Biparietal diameter + + +Superior subparietal diameter + +Bitemporal diameter + +Lambdoid suture + +Posterior fontanel + +Parietal bone + +Parietal eminence +Sagittal suture + +Anterior fontanel + +----- Frontal bone ,-------- Frontal +suture Sinciput + + +Flexed vertex + + + + + + + + +-.--.- Deflexed -:., .j►/ vertex + + +7"---- Partially deflexed vertex \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_4.txt b/notes/DC Dutta Obstetrics 10th Edition_4.txt new file mode 100644 index 0000000000000000000000000000000000000000..bb14ab4e891e5ec95c178556720e18f15adf6a25 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_4.txt @@ -0,0 +1,2027 @@ + + + +Fig. 9.2: Fetal skull showing important sutures, fontanels and diameters of obstetric significance. + +a phenomenon of significance while the head passes through the pelvis during labor. (2) Digital palpation of sagittal suture during internal examination in labor gives an idea of the manner of engagement of the head (asynclitism or synclitism), degree of internal rotation of the head and degree of molding of the head. + +FONTANELS: Wide gap in the suture line is called fontanel. Of the many fontanels (6 in number), two are of obstetric significance: (1) Anterior fontanel or bregma and (2) Posterior fontanel or lambda. +Anterior fontanel (Fig. 9.2): It is formed by joining of the four sutures in the midplane. The sutures are anteriorly frontal, posteriorly sagittal and on either side, coronal. The shape is like a diamond. Its anteroposterior and transverse diameters measure approximately 3 cm each. The floor is formed by a membrane and it becomes ossified 18 months after birth. It becomes pathological, if it fails to ossify even after 24 months. + +Importance: +♦ Its palpation through internal examination denotes the degree of flexion of the head. +♦ It facilitates molding of the head. +♦ As it remains membranous long after birth, it helps in accommodating the marked brain growth; the brain becom­ ing almost double its size during the first year of life. +♦ Palpation of the floor reflects intracranial status-depressed in dehydration, elevated in raised intracranial tension. +♦ Collection of blood and exchange transfusion, on rare occasion, can be performed through it via the superior longitudinal sinus. +♦ Cerebrospinal fluid can be drawn, although rarely, through the angle of the anterior fontanel from the lateral ventricle. +Posterior fontanel: It is formed by junction of three suture lines-sagittal suture anteriorly and lambdoid suture on either side. It is triangular in shape and + +Fig. 9.3: The important landmarks of fetal skull. + + +measures about 1.2 x 1.2 cm (1/2" x 1/2"). Its floor is membranous but becomes bony at term. Thus, truly its nomenclature as fontanel is misnomer. It denotes the position of the head in relation to maternal pelvis. +Sagittal fontanel: It is inconsistent in its presence. When present, it is situated on the sagittal suture at the junction of anterior two-thirds and posterior one-third. It has got no clinical importance. +DIAMETERS OF SKULL (Fig. 9.3): The engaging diameter of the fetal skull depends on the degree of flexion present. The anteroposterior diameters of the head which may engage are shown in Table 9.1. +The transverse diameters which are concerned in the mechanism oflabor are (Fig. 9.2 and Table 9.1): +■ Biparietal diameter-9.5 cm (3¾"): It extends between two parietal eminences. Whatever may be the position of the head, this diameter nearly always engages. +■ Super-subparietal-8.5 cm (3½"): It extends from a point placed below one parietal eminence to a point placed above the other parietal eminence of the opposite side. +■ Bitemporal diameter-8 cm (3¼ "): It is the distance between the anteroinferior ends of the coronal suture. +■ Bimastoid diameter-7.5 cm (3"): It is the distance between the tips of the mastoid processes. The diameter is incompressible and it is impossible to reduce the length of the bimastoid diameter by obstetrical operation. +. +CIRCUMFERENCES: Circumference of the plane of the diameter of engagement differs according to the attitude of the head (Table 9.2). +MOLDING: It is the alteration of the shape of the forecoming head while passing through the resistant birth passage during labor. There is, however, very little +" ,Jla Chapter 9: Fetal Skull and Maternal Pelvis Table 9.1: Important diameters of the skull. + +Diameters +Suboccipitobregmatic-extends from the nape of the neck to the center of the +bregma. +Suboccipitofrontal-extends from the nape of the neck to the anterior end of the +anterior fontanel or center of the sinciput. +Occipitofrontal-extends from the occipital eminence to the root of the nose +(glabella). +Mentovertical-extends from the midpoint of the chin to the highest point on +the sagittal suture. +Submentovertical-extends from junction of floor of the mouth and neck to the +highest point on the sagittal suture. +Submentobregmatic-extends from junction of floor of the mouth and neck to +the center of the bregma. + + + + + +Measurement in cm (inches) +9.5 cm (3¾") + +10cm (4") + +11.5cm (4½") + +14cm (5½") + +11.5 cm (4½") + +9.5 cm (3¾") + + + + + +Attitude of the head +Complete +flexion +Incomplete +flexion +Marked +deflexion +Partial extension + +Incomplete +extension +Complete +extension + + + + + + +Presentation Vertex + +Vertex + +Vertex + +B'row + +Face + +Face + + + +Table 9.2: Circumferences of the head in different attitudes. +Attitude of Circum-the head Plane of engagement ference +Complete Biparietal-suboccipitobregmatic 27.5cm (11 ") +flexion (almost round shape). +Deflexed Biparietal-occipitofrontal (oval shape). 34cm (13½") +lncom- Biparietal-mentovertical (bigger oval 37.5 cm (15") +plete shape). extension +Complete Biparietal-submentobregmatic 27.5 cm (11 ") +extension (almost round shape). +Note: Conversion of centimeters into inches is approximate. + +alteration in size of the head, as volume of the content inside the skull is incompressible although small amount of cerebrospinal fluid and blood escape out in the process. During normal delivery, an alteration of 4 mm in skull diameter commonly occurs. +Mechanism: There is compression of the engaging diameter of the head with corresponding elongation of the diameter at right angle to it (Fig. 9.4). +Thus, in well-flexed head of the anterior vertex presentation, the engaging suboccipitobregmatic diameter is compressed with elongation of the head in mentovertical diameter which is at right angle to suboccipitobregmatic (Figs. 9.5A to D). + +--- --- - -- + + +I \ I 1 +I +\ ' + +--- + +Fig. 9.4: Diagrammatic representation showing the principle of molding of the head. + +During the process, the parietal bones tend to overlap the adjacent bones, viz. the occipital bone behind, the frontal bones in front and the temporal bones at the sides. In first vertex position, the right parietal bone tends to override the left one and this becomes reverse in second vertex position. Molding disappears within few hours after birth. +Grading: There are three gradings. Grade-I-the bones touching but not overlapping, Grade-2-overlapping but easily separated and Grade-3-fixed overlapping. +Importance: ++ Slight molding is inevitable and beneficial. It enables the head to pass more easily, through the birth canal. +♦ Extreme molding as met in disproportion may produce severe intracranial disturbance in the form of tearing of tentorium cerebelli or subdural hemorrhage. ++ Shape of the molding can be a useful information about the position of the head occupied in the pelvis. +CAPUT SUCCEDANEUM: It is the formation of swelling due to stagnation of fluid in the layers of the scalp beneath the girdle of contact. The girdle of contact is either bony or the dilating cervix or vulval ring. The swelling is diffuse, boggy and is not limited by the suture line (Fig. 9.6). It may be confused with cephalhematoma (p. 455). Caput disappears spontaneously within 24 hours after birth. Caput needs to be differentiated from cephalhematoma (Table 9.3). +Mechanism of formation: While the head descends to press over the dilating cervix or vulval ring, the overlying scalp is free from pressure, but the tissues in contact with the full circumference of the girdle of contact is compressed. This interferes with venous return and lymphatic drainage from the unsupported area of scalp ➔ stagnation of fluid and appearance of a swelling in the scalp (Fig. 9.6). Caput usually occurs after rupture of the membranes. +Importance: ++ It signifies static position of the head for a long period of time. +Chapter 9: Fetal Skull and Maternal Pelvis JI + + + + + + + + + +Figs. 9.SA to D: Types of molding in cephalic presentations (shown by dotted line): (A) Vertex presentation with well-flexed head; (Bl Vertex presentation with deflexed head (sugar loaf head); (C) Face presentation; (D) Brow presentation. + + +Table 9.3: Differentiation of caput succedaneum from cephalhe­ matoma. + +bon·e. With increasing flexion, the caput is placed more posteriorly. + + + +Caput succedaneum +■ Appearance: At birth. +■ Feel: Soft, and compressible ■ Extent: Diffuse, spreads over +the suture lines. +■ Position: Changes and moves to the dependant part +■ With observation: Gradually reduces in size and disappears within few hours. +■ Definition: Localized swelling on the scalp due to effusion of serum. +■ Etiology: Pressure by the dilating cervix (Cervical ring) causing obstruction to the venous and lymphatic return resulting in scalp edema + + +Cephalhematoma +■ Hours after birth. +■ Soft but incompressible. +■ Limited to a bone, does not cross the suture lines. +■ Does not change, fixed to one site. +■ It increases in size with time. Disappears only after weeks or months. +■ It is the hemorrhage under the periosteum of bone(s) of the skull. +■ It is following trauma to the skull due to: (a) prolonged pressure on head during labor, (b) forceps/ventouse delivery. +■ Often associated with the fracture of the skull bone(s). + + +PELVIS +From the obstetrical standpoint, it is useful to consider the bony pelvis as a whole rather than separately. For descriptive purpose, an articulated pelvis is composed of four bones-two innominate bones, sacrum and coccyx. These are united together by four joints-two sacroiliac joints, sacrococcygeal joint and the symphysis pubis. +The pelvis is anatomically divided into a false pelvis and a true pelvis, the boundary line being the brim of the +pelvis. The bony landmarks on the brim of the pelvis from anterior to posterior on each side are-upper border of symphysis pubis, pubic crest, pubic tubercle, pectineal line, iliopubic eminence, iliopectineal line, sacroiliac articulation, anterior border of the ala of sacrum and sacral promontory (Fig. 9.7). +I FALSE PELVIS + + + +♦ Location of the caput gives an idea about the position of the head occupied in the pelvis and the degree of flexion achieved. In left position, the caput is placed on right parietal bone and in right position, on left parietal + +The false pelvis is formed by the iliac portions of the innominate bones and is limited above by the iliac crests. It has got little obstetric significance except that its measurements can to a certain extent, predict the size and + + + + + + + +Caput formed by serum +pFeallvsies +Periosteum + + +False +pelvis + + + + + + + + + +Parietal bones +Fig. 9.6: Formation of caput succedaneum. + + +Fig. 9.7: Bony landmarks on the brim of the pelvis separating the true from the false pelvis: (1) Symphysis pubis, (2) Pubic crest, (3) Pubic tubercle, (4) Pectineal line, (5) lliopubic eminence, (6) lliopectineal line, (7) Sacroiliac articulation, (8) Anterior border of the ala of sacrum and (9) Sacral promontory. +Chapter 9: Fetal Skull and Maternal Pelvis + +configuration of the true pelvis. Its only obstetric function is to support the enlarged uterus during pregnancy. Its boundaries are: posteriorly-lumbar vertebrae, laterally­ iliac fossa and anteriorly-anterior abdominal wall. +I TRUE PELVIS +This part of the pelvis is chiefly of concern to the obstetricians, as it forms the canal through which the fetus has to pass. It is shallow in front, formed by symphysis pubis and measures 4 cm (1 ½") and deep posteriorly, formed by the sacrum and coccyx and measures 11.5 cm (4½"). For descriptive purpose, it is divided into inlet, cavity and outlet. +The pelvic measurements given in the text are average when measured radiologically and vary within a limited degree in different countries. The conversion of centimeters into inches is approximate. +I INLET +As the inlet is the brim of the pelvis, the circumference of the inlet is formed by the bony landmarks mentioned previously. +Shape: It is almost round (gynecoid) with the antero­ posterior diameter being the shortest. Other different shapes of the inlet are anthropoid, android and platy­ pelloid (p. 331). +Plane: It is an imaginary flat surface bounded by the bony points mentioned as those of the brim. It is not strictly a mathematical plane and is, therefore, often referred to as superior strait. +Inclination: In the erect posture, the pelvis is tilted forward. As such, the plane of the inlet makes an angle of about 55° with the horizontal and is called angle of inclination. Another way of measuring the inclination radiographically is to take the angle between the plane of the inlet and the front of the body of the fifth lumbar vertebra. The angle is normally about 135° {Fig. 9.8). +When the angle of inclination is increased due to sacralization of fifth lumbar vertebra, it is called high inclination. High inclination has got obstetric significances: +■ There is delay in engagement because the uterine axis fails to coincide with that of inlet +■ It favors occipitoposterior position +■ There is difficulty in descent of the head due to long birth canal and flat sacrum interfering with internal rotation. +The angle of inclination may be lessened in case of lumbarization of first piece of sacral vertebra and is called low inclination. It has got no obstetric significance. It actually facilitates early engagement. +Sacral angle: It is the angle formed by the true +conjugate with the first two pieces of the sacrum {Fig. 9.8). + + + + + + + + + + + + + + + + + +Fig. 9.8: Diagrammatic representation showing plane of the inlet; inclination of the pelvis, sacral angle and depth of the pelvis. + + + + + + + + + + + + + + + +Fig. 9.9: Sagittal section of the pelvis showing anteroposterior diameters in different planes. +(TC: True Conjugate; DC: Diagonal Conjugate; OC: Obstetric Conjugate) + +Normally, it is greater than 90°. A sacral angle of lesser degree suggests funnelling of the pelvis. +Axis: It is a mid-perpendicular line drawn to the plane of the inlet (Fig. 9.17). Its direction is downward and backward. When extended, the line passes through the umbilicus to coccyx. It is important that the uterine axis should coincide with the axis of the inlet so that the force of the uterine contractions will be spread in the right direction, to force the fetus to pass through the brim. +Diameters: The measurements of the diameters are all approximate and minor variation is the rule rather than the exception. +Anteroposterior (Syn: true conjugate, anatomical conjugate, conjugate vera): It is the distance between the midpoint of the sacral promontory to the inner margin of the upper border of symphysis pubis (Fig. 9.9). It measures 11 cm {4¼"). It is not the shortest diameter of the inlet in the anteroposterior plane. In practice, the true conjugate cannot be estimated directly. However, its +Chapter 9: Fetal Skull and Maternal Pelvis -L · + + + + + + + + + + + + + + + + + +Fig. 9.10: Measurement of diagonal conjugate. + +measurement is inferred by subtracting 1.2 cm(½") from the diagonal conjugate thus allowing for the inclination, thickness and height of the symphysis pubis. +Obstetric conjugate: It is the distance between the midpoint of the sacral promontory to prominent bony projection in the midline on the inner surface of the symphysis pubis (Fig. 9.9). +The point is somewhat below its upper border. It is the shortest anteroposterior diameter in the anteroposterior plane of the inlet. It measures 10 cm (4"). It cannot be clinically estimated but is to be inferred from the diagonal conjugate-1.5-2 cm (¾") to be deducted or by lateral radiopelvimetry. +Diagonal conjugate: It is the distance between the lower border of symphysis pubis to the midpoint on the sacral promontory. It measures 12 cm (4¾") (Fig. 9.9). + +It is measured clinically during pelvic assessment in late pregnancy or in labor. Obstetric conjugate is computed by subtracting 1.5-2 cm from the diagonal conjugate depending upon the height, thickness and inclination of the symphysis pubis. +How to measure? The patient is placed in dorsal position. Two fingers are introduced into the vagina taking aseptic precautions. The fingers are to follow the anterior sacral curvature. In normal pelvis, it is dificult to feel the sacral promontmy or at best can be felt with difficulty. However, in order to reach the promontory, the elbow and the wrist are to be depressed sufficiently while the fingers are mobilized in upward direction. The point at which the bone recedes from the fingers is the sacral promontmy. The fingers are then mobilized under the symphysis pubis and a marking is placed over the gloved index finger by the index finger of the left hand {Fig. 9.10). +The internal fingers are removed and the distance between the marking and the tip of the middle finger gives the measurement of diagonal conjugate. For practical purpose, if the middle finger fails to reach the promontory or touches it with dificulty, it is likely that the conjugate is adequate for an average size head to pass through. +Transverse diameter: It is the distance between the two farthest points on the pelvic brim over the iliopectineal lines. It measures 13 cm (5¼") (Figs. 9.11 and 9.12). +The diameter usually lies slightly closer to sacral promontory and divides the brim into anterior and posterior segment. The head negotiates the brim through a diameter, called available or obstetrical transverse. This is described as a diameter which bisects the anteroposterior diameter in the midpoint. Thus, the obstetrical transverse is either equal or less than the anatomical transverse. + + + + + + + + + + + + + + + + + + + + + + + +Fig. 9.11: Different diameters of the inlet of obstetrical significance. Bispinous diameter is also demonstrated. +ml Chapter 9: Fetal Skull and Maternal Pelvis + + + + + + + +11 12 13 + + + +a, +:, +O" 12 12 +j5 +0 + + +13 12 11 + + + +Fig. 9.12: Composite measurements of the diameters of the inlet, cavity and outlet in centimeters. + +Oblique diameters: There are two oblique diameters­ right and left. Each one extends from one sacroiliac joint to the opposite iliopubic eminence and measures 12 cm {4¾"). Right or left denotes the sacroiliac joint from which it starts (Figs. 9.11 and 9.12). +Sacrocotyloid-9.5 cm (3¾"): It is the distance between the midpoint of the sacral promontory to iliopubic eminence {Fig. 9.11). It represents the space occupied by the biparietal diameter of the head while negotiating the brim in flat pelvis. + +I CAVITY +Cavity is the segment of the pelvis bounded above by the inlet and below by plane of least pelvic dimensions. +Shape: It is almost round. +Plane: The plane extends from the midpoint of posterior surface of symphysis pubis to the junction of second and third sacral vertebrae (Fig. 9.17). It is called plane of greatest pelvic dimensions. It is the most roomy plane of the pelvis and is almost round in shape. +Axis: It is the mid-perpendicular line drawn to the plane of the cavity. Its direction is almost downward {Fig. 9.17). +Diameters: Anteroposterior (12 cm or 4¾"): It measures from the midpoint on the posterior surface of the symphysis pubis to the junction of second and third sacral vertebrae {Fig. 9.9). +Transverse {12 cm or 4¾"): It cannot be precisely measured as the points lie over the soft tissues covering the sacrosciatic notches and obturator foramina. +I OUTLET +Obstetrical outlet: It is the segment of the pelvis bounded above by the plane of least pelvic dimensions and below by the anatomical outlet {Fig. 9.13 and Box 9.1). + + +Fig. 9.13: Obstetrical outlet (shaded area). + + + +■ It is the narrowest plane in the pelvis. +■ This plane corresponds roughly to the origin of levator ani muscles (Fig. 9.16). +■ It is at this plane that the internal rotation of the fetal head occurs during labor. +■ It marks the beginning of the forward curve of the pelvic axis (Fig. 9.17). +■ It is a landmark used for pudenda! nerve block analgesia. ■ This level of ischial spines indicate station 'O'. +■ When the fetal head station is at 'O; head is considered to be engaged. +■ DTA usually occurs at this plane. + +Its anterior wall is deficient at the pubic arch; its lateral walls are formed by ischial bones and the posterior wall includes whole of the coccyx. +Shape: It is anteroposteriorly oval. +Plane: The plane is otherwise known as plane of least pelvic dimensions or narrow pelvic plane. The plane extends from the lower border of the symphysis pubis to the tip of ischial spines and posteriorly to meet the tip of the fifth sacral vertebra. +Diameters: Transverse-Syn: Bispinous (10.5 cm or 4/s''): It is the distance between the tip of two ischial spines. +Anteroposterior (11 cm or 4¼ "): It extends from the inferior border of the symphysis pubis to the tip of the sacrum (Fig. 9.9). +Posterior sagittal (5 cm or 2"): It is the distance between the tip of the sacrum and the midpoint of bispinous diameter. +Axis: It is represented by a line joining the center of the plane with the sacral promontory. Its direction is almost vertical. +Anatomical outlet: It is otherwise known as bony +outlet. It is bounded in front by the lower border of the +Chapter 9: Fetal Skull and Maternal Pelvis El + + + + + + + + + + + + + + + + + + +Sacral +promontory + + +Coccyx + + +Sacrotuberous +ligament + +Figs. 9.14A to C: (A) Boundary of the anatomical outlet with its measurements; (Bl Dummy showing false pelvis, true pelvis and the brim of the pelvis; (C) Dummy showing anatomical outlet of the pelvis. + + +symphysis pubis; laterally by the ischiopubic rami, ischial tuberosity and sacrotuberous ligament and posteriorly by the tip of coccyx (Figs. 9.14A to C). Thus, it consists of two triangular planes with a common base formed by a line joining the ischial tuberosities. The apex of the anterior triangle is formed by the inferior border of the pubic arch and that of the posterior triangle by the tip of the coccyx. +Shape: It is diamond-shaped. +Plane: It is formed by a line joining the lower border of the symphysis pubis to the tip of the coccyx (Fig. 9.17). It forms an angulation of 10° with the horizontal. +Axis: It is a mid-perpendicular line drawn to the plane of the outlet. Its direction is downward and forward (Fig. 9.17). +Diameters: Anteroposterior: It extends from the lower border of the symphysis pubis to the tip of the coccyx. It measures 13 cm or 5¼" with the coccyx pushed back by the head when passing through the introitus in the second stage of labor; with the coccyx in normal position, the measurement will be 2.5 cm less {Fig. 9.9). +Transverse Diameter of the Outlet (TDO)-Syn: Intertuberous ( 11 cm or 4¼ "): It measures between inner borders of ischial tuberosities. +Posterior sagittal diameter (8.5 cm or 3½"): It is the anteroposterior distance between the sacrococcygeal joint and the midpoint of transverse Diameter of Outlet (TDO). It is clinically measured by the distance between the sacrococcygeal joint and anterior margin of the anus. +Subpubic angle: It is formed by the approximation of the two descending pubic rami. In normal female pelvis, it measures 85°. +Pubic arch: Arch formed by the descending rami of both the sides is of obstetric importance. Normally, it + + +measures 6 cm in between the pubic rami at a level of 2 cm below the apex of the subpubic arch. Clinically, it is assessed by placing 3 fingers side by side. +The narrower the pubic arch, the more is the fetal head displaced backward and the less the room available for it. Normally, the subpubic arch is rounded and less space is wasted under the symphysis pubis. When a round disk of 9.3 cm diameter (diameter of well-flexed fetal head) is placed under the arch, the distance between the symphysis pubis and the circumference of the disk is measured. This measurement is the waste space of Morris and should not exceed 1 cm in a normal pelvis. +Available anteroposterior diameter: When the waste space of Morris is more than 1 cm, the anterior point of the anteroposterior diameter of the outlet extends below the symphysis pubis on the pubic rami for a distance equivalent to the waste space of Morris {Figs. 9.15A to C). The distance between the said point and the tip of the sacrum is called available anteroposterior diameter of the outlet. It is through this diameter that the head escapes out of the bony outlet. + +I MIDPELVIS +Midpelvis is the segment of the pelvis bounded above by the plane of the greatest pelvic dimensions and below by a plane known as midpelvic plane. +Midpelvic plane: The midpelvic plane extends from the lower margin of the symphysis pubis through the level +of ischial spines to meet either the junction of S4 and S5 +or tip of the sacrum depending upon the configuration of the sacrum. If the plane meets the tip of the fifth sacrum, it coincides with the plane of least pelvic dimensions. If the +El Chapter 9: Fetal Skull and Maternal Pelvis + + + + + + + +01-' +(A 9.3cm + +m +Figs. 9.15A to C: Diagrammatic representation of: (Al Normal pubic arch; (Bl Waste space of Morris; (Cl Available anteroposterior diameter of the outlet. + + + + + + + + + + + + + + + + + + + +Figs. 9.16A and B: Diagrammatic representation of midpelvis and midpelvic plane: (Al Zone of midpelvis (shaded area) with the midpelvic plane becomes a wedge posteriorly; (Bl Midpelvic plane coincides with the plane of least pelvic dimensions. + + +plane meets the junction of S4 and S5, the plane becomes a wedge posteriorly (Figs. 9.16A and B). +Diameters: Transverse diameter-Syn: bispinous (10.5 cm). It measures between the two ischial spines. +Anteroposterior diameter (11.5 cm): It extends from the lower border of the symphysis pubis to the point on the sacrum at which the mid pelvic plane meets. +Posterior sagittal diameter (4.5 cm): It extends from the midpoint of the bispinous diameter to the point on the sacrum at which the midpelvic plane meets. +PELVIC AXIS: Anatomical (curve of Carns): Anatomical pelvic axis is formed by joining the axes of inlet, cavity and outlet. It is uniformly curved with the convexity fitting with + + +the concavity of the sacrum. The fetus does not, however, transverse the uniform curved path (Figs. 9.17 A and B). +Obstetrical: It is through this axis that the fetus negotiates the pelvis. It is not uniformly curved. Its direction is first downward and backward up to the level of ischial spines and then directed abruptly forward (Figs. 9.17A and B). +PELVIC JOINTS: Symphysis pubis: It is a secondary fibrocartilaginous joint. It has got no capsule and no synovial cavity. The articular surfaces are covered with hyaline cartilage. Due to softening of the ligaments during pregnancy, there is considerable amount of gliding movement. +Chapter 9: Fetal Skull and Maternal Pelvis + + + + + + + + + + + + + + + + +Figs. 9.17A and B: Pelvic axis: (A) Axis of inlet, cavity and outlet are shown by arrows drawn perpendicular to the planes. The shaded area over the axis is the anatomical pelvic axis (curve of Carus); (Bl Obstetric pelvic axis-as shown by the shaded area is directed downward and backward up to ischial spines and then directed forward. ' + + +Sacroiliac articulation: It is a synovial joint and is an articulation between the articular surface of the ilium and sacrum. The articulating surfaces are not alike. It has got a capsule and a synovial cavity. +Engagement to diagnose, it is better to palpate gently with two hands facing down over the abdomen (Fig. 8.6) than to prod around with Pawlik's grip, which in non­ experienced hands is painful. +Sacrococcygeal joint is a synovial hinge joint. It allows both flexion and extension. Extension increases the anteroposterior diameter of the outlet. + +PHYSIOLOGICAL ENLARGEMENT OF PELVIS DURING PREGNANCY AND LABOR +Imaging studies show an increase in width and mobility of the symphysis pubis during pregnancy which returns to normal following delivery. The pubic bones may separate by 5-10 mm. Similar changes also occur in sacroiliac joints. There is gliding movement of the symphysis pubis near term. Relaxation of the pelvic joints is due to progesterone and relaxin. There is increase of the anteroposterior diameter of the inlet during labor by the rotatory movement of the sacroiliac joints. In dorsal lithotomy position, the anteroposterior diameter of the outlet may be increased to 1.5-2 cm. Furthermore, the coccyx is pushed back while the head descends down to the perineum. + + +Antenatal + + +CHAPTER II + +Care, Preconceptional +Counseling and Care + + +' CHAPTER OUTLINE + +❖ Procedure at the First Visit ► History Taking +► Examination + + +❖ Procedure at the Subsequent Visits ❖ Antenatal Advice +❖ Minor Ailments in Pregnancy + +❖ Values of Antenatal Care +❖ Preconceptional Counseling and Care + + + + +Systematic supervision (examination and advice) of a woman during pregnancy is called antenatal (pren­ atal) care. The supervision should be regular and periodic in nature according to the need of the individual. Actually prenatal care is the care in continuum that starts before pregnancy and ends at delivery and the postpartum period. Antenatal care bundles are: +■ Careful history taking and examinations (general and obstetrical) +■ To carry out necessary investigations and ■ Advice given to the pregnant woman. + +AIMS AND OBJECTIVE +The aims are: +1. To screen the 'high-risk' cases. +2. To prevent or to detect and treat at the earliest any complication. +3. To ensure continued risk assessment and to provide ongoing primary preventive health care. +4. To educate the mother about the physiology of preg­ nancy and labor by demonstrations, charts and diagrams (mothercraft classes), so that fear is removed and psychology is improved. +5. To discuss with the couple about the place, time and mode of delivery, provisionally and care of the newborn. +6. To motivate the couple about the need of family planning and also appropriate advice to couple seeking medical termination of pregnancy. +The objective is to ensure a normal pregnancy with delive1y of a healthy baby from a healthy mother. +The criteria of a normal pregnancy are delivery of a single baby in good condition at term (between 38 and 42), with fetal weight of 2.5 kg or more and with no maternal complication. As such, a normal pregnancy is a retrospective term. + + +PROCEDURE AT THE FIRST VISIT +The first visit should not be deferred beyond the second missed period. It may be earlier if the patient desires to terminate the pregnancy. +OBJECTIVES: (1) To assess the health status of the mother and fetus. (2) To assess the fetal gestational age and to obtain baseline investigations. (3) To organize continued obstetric care and risk assessment. +Components of routine prenatal care are recorded in a standardized proforma (antenatal record book). + +I HISTORY TAKING Vital statistics +Name: .................................................................................... . +Date offirst examination: .................................................... . + +Address: .................................................................................. +Age: A woman having her first pregnancy at the age C:35 years (FIGO) is called elderly primigravida. Advanced maternal age is at higher risk for aneuploidy, infertility, still birth. Pregnancy-associated complications such as hypertension and diabetes are more. Extremes of age (teenage and elderly) are obstetric risk factors. +Gravida and parity: Gravida denotes a pregnant state both present and past, irrespective of the period of gestation. Parity denotes a state of previous pregnancy beyond the period of viability. +Gravida and para refer to pregnancies and not to babies. As such, a woman who delivers twins in first pregnancy is still a gravida one and para one. A pregnant woman with a previous history of two abortions and one term delivery can be expressed as fourth gravida but primipara. It is customary in clinical practice to +Chapter 10: Antenatal Care, Preconceptional Counseling and Care JI · x 10.1: rrninc>logy. + +■ A nullipara is one who has never completed a pregnancy to the stage of viability. She may or may not have aborted previously. +■ A primipara is one who has delivered one viable child. Parity is +not increased even if the fetuses are many (twins, triplets). +• A multigravida is one who has previously been pregnant. She may have aborted or have delivered a viable baby. + +■ A parturient is a woman in labor. + + +■ A nulligravida is one who is not now and never has been pregnant. +■ A primigravida is one who is pregnant for the first time. + +• Multipara is one who has completed two or more pregnancies to the stage of viability or more. +■ A puerpera is a woman who has just given birth. + + + +summarize the past obstetric histo1y by two digits (the first one relates with viable births and the second one relates with abortion) connected with a plus sign affixing the +letter 'P'. Thus, P Z+I denotes the patient had two viable +births and one abortion. In some centers, it is expressed by four digits connected by dashes. PA-B-C-D, where A: denotes number of term (37-42 weeks) pregnancies, B: number of preterm (28 to <37 weeks) pregnancies, C: number of miscarriages ( <28 weeks) and D: the number of children alive at present. More simple way is: G, P, A and LI where G for gravida, P for parity, A for abortion and LI for living issue. A pregnant woman with a previous hist01y of four births or more is called grand multipara (Box 10.1). +Duration of marriage: This is relevant to note the fertility or fecundity. A pregnancy long after marriage without taking recourse to any method of contraception is called low fecundity and soon after marriage is called high fecundity. +Religion: .................................. . +Occupation: It is helpful in interpreting symptoms of fatigue due to excess physical work or stress. Such women should be informed to reduce such activities. +Occupation of the husband: This knowledge is of value: (a) To anticipate the complications likely to be associated with low social status such as anemia, pre­ eclampsia, preterm labor. {b) To give reasonable and realistic antenatal advice during family planning guidance. +Period of gestation: The duration of pregnancy is to be expressed in terms of completed weeks. In calculating the gestational age, counting is to be done from the first day of Last Normal Menstrual Period (LNMP). Most reliable clinical parameter of gestational age assessment is an accurate LMP. +,.<1 I'' .i "'1- Pregnancy dating (gestational age) by ;ultrasonography.' Pregnancy (weeks) USG (parameters) Accuracy (days) +,,., +' ,. + ' "' ., , -- ,- ·" - -•"" •,. ,,, +; ,; +"- • • • ' , • • I +'Table +10. + +: +<86/7 CRL ±5 9-13617 CRL ±7 16-21617 BPD, HC, FL, AC ±10 +>28 BPD, HC, FL, AC +21 + +Pregnancy resulting from Assisted Reproductive Technology (ART) should calculate gestation age since the day of embryo transfer (266 days)/or the technology guided gestational age for deriving EDD (266 days to add to the date of embryo transfer to derive the EDD) {Table 10.1). +Complaints: Categorically, the complaints is to be noted according to severity or with timing of onset. If there is no complaint, enquiry is to be made about the sleep, appetite, bowel habit and urination. +History of present illness: Elaboration of the chief complaints as regard their onset, duration, severity, use of medications and progress is to be made. +History of present pregnancy: The important complications in different trimesters of the present pregnancy are to be noted carefully. These are hyperemesis and threatened abortion in first trimester, features of Urinary Tract Infection (UTI) in second trimester and anemia, pre-eclampsia and antepartum hemorrhage in the last trimester. Number of previous antenatal visits (booking status), immunization status, has to be noted. Any medication or radiation exposure in early pregnancy or medical-surgical events during pregnancy should be enquired. +Obstetric history: This is only related with multigravidae. The previous obstetric events are to be recorded chronologically as per the proforma given on the previous page. To be relevant, enquiry is to be made whether she had antenatal and intranatal care before (Table 10.2). The minimum spacing between first birth and next pregnancy should be 2 years. +The obstetric history is to be summed up as: Status of gravida, parity, number of deliveries (term, preterm), miscarriage, pregnancy termination (MTP) and living issue (e.g., Mrs RL, G4, P2, miscarriage 1, living 2 at 36 weeks of present pregnancy). +Menstrual history: Cycle, duration, amount of blood flow and first day of the Last normal Menstrual Period (LMP) is to be noted (spontaneous). From the LMP, the Expected Date of Delivery (EDD) has to be +calculated. +JI Chapter 10: Antenatal Care, Preconceptional Counseling and Care Table 10,2: Obstetric history. +Baby + + + +No, Year and date +1. 2017 January + + +Pregnancy Labor events events +Miscarriage at 8 weeks + + +Methods of delivery +Evacuation done + + + +Puerperium +Uneventful + +• Condition at birth (Apgar score) weight and sex • Breastfeeding +• Immunization + + + +2. 2017 December + + + + +3. 2021 January + + +Well-covered antenatally, uneventful + + +-do- + + +Uneventful + + + + +-do- + + +Spontaneous vaginal + + + +-do- + + +Uneventful + + + + +-do- + + +• Baby-boy +• Weight 2700 g • Cried at birth +• Breastfed (6 months) • Alive and well +• Girl weight 2800 g • Cried at birth +• Breastfed (6 months) • Both the babies fully +immunized +• Alive and well + + + + +History of contraception and birth spacing: using IUCD CuT 380A + + + + +Calculation of the Expected Date of Delivery (EDD): This is done according to Naegele's formula (1812) by adding 9 calendar months and 7 days to the first day of the last normal (28 days cycle) period. Alternatively, one can count back 3 calendar months from the first day of the last period and then add 7 days to get the expected date of delivery; the former method is commonly employed. +Example: The patient had her first day of last menstrual period on 1st January. By adding 9 calendar months it comes to 1st October and then add 7 days, i.e., 8th October, which becomes the expected date of delivery. For IVF pregnancy date of LMP is 14 days prior to date of Embryo Transfers (ET). Therefore, 266 days to be added to the date of ET to derive the EDD. +Past medical history: Relevant history of past med­ ical illnesses (urina1y tract infections, tuberculosis) is to be elicited. +Past surgical history: Previous surgery-general or gynecological, if any, is to be enquired. +Family histmy: Family history of hypertension, diabetes, hemoglobinopathy, consanguinity, or twinning is to be enquired. +Personal history: Contraceptive practice prior to pregnancy, smoking or tobacco habits are to be enquired. Previous history of blood transfusion, chronic medication, any drug allergy are also important. +I EXAMINATION +General Physical Examination +Build: Obese/average/thin. Nutrition: Good/average/ poor. +Height: Short stature is likely to be associated with a small pelvis. While an arbitra1y measurement of 5 feet (152.4 cm) or less is considered as short stature in Western + +countries, it is 4 feet 7 inches (139.7 cm) in India taken as the low average height. +Weight: Weight should be taken in all cases (Table 10.l). Repeated weight checking in subsequent visit should preferably be done in the same weighing machine. The importance of weight checking has already been discussed. +Pallor: The sites to be noted are lower palpebral conjunctiva, dorsum of the tongue and nail beds. +Jaundice: The sites to be noted are bulbar conjunctiva, under surface of the tongue, hard palate and skin. +Tongue, teeth, gums and tonsils: Evidences of malnutrition are evident from glossitis and stomatitis. +Evidence of any source of infection in the mouth is to be eradicated least there be a chance of autogenous infection in puerperium. +Neck: Neck veins, thyroid gland or lymph glands are looked for any abnormality. Slight physiological enlargement of the thyroid gland occurs during pregnancy in 50% of cases. +Edema of legs: Both the legs are to be examined. The sites for evidence of edema are over the medial malleolus and anterior surface of the lower one-third of the tibia. The area is to be pressed with the thumb for at least 5 seconds. Varicosity in the legs, if any, is to be noted. +Causes of edema in pregnancy: (l) Physiological, (2) Pre-eclampsia, (3) Anemia and hypoproteinemia, (4) Cardiac failure and (5) Nephrotic syndrome. +Dependent edema is physiological in pregnancy but generalized edema (anasarca) or facial edema can be a first sign of disease. +Physiological edema: The cause of physiological edema is due to increased venous pressure of the +Chapter 10: Antenatal Care, Preconceptional Counseling and Care - + + +inferior extremities by the gravid uterus pressing on the common iliac veins. The features of the physiological edema are: (1) slight degree (ankle edema), usually confined to one leg, more on the right, (2) unassociated with any other features of pre-eclampsia or proteinuria, (3) disappears on rest alone, (4) other pathologies of cardiac, renal and hematological are absent. +Pulse: Rate, rhythm, volume is recorded. +Blood pressure: Disappearance of sounds (KorotKoff 5) rather than mufling of sounds (KorotKoff 4) is the best representation of diastolic pressure during pregnancy. BP is lowest in the lateral recumbent position, BP of the superior arm in the position is lower (about 10-12 mm) than the inferior arm. In the ambulatory setting, BP is measured in sitting position and Korotkoff-5 sound should be used. +Systemic Examination Heart, lungs, liver and spleen +Breasts: Examination of the breasts helps to check the nipples (cracked or depressed) and skin condition of the areola. The purpose is to correct the abnormality; so that there will be no difficulty in breastfeeding following delivery. +Obstetric Examination (more details, p. 71): Abdominal: Tone of the abdominal muscles, presence of any incisional scar or presence of herniation and skin condition of the abdomen are to be looked for. Fundus of the uterus is just palpable above the symphysis pubis at 12 weeks. +Vaginal examination is not generally done in the antenatal clinic when the patient attends the clinic for the first time before 12 weeks. Ultrasound examination has replaced routine vaginal examination. USG is more informative and without any known adverse effect. +Steps of vaginal examination: Details on p. 126,334. +Routine investigations: +♦ Blood: Hemoglobin, hematocrit, ABO, Rh grouping, hemoglobinopathies, blood glucose and VDRL are done. Serology (antibody) screening is done in selected cases. + + +♦ Urine: Protein, sugar and pus cells. If significant pro­ teinuria is found, 'clean catch' specimen of midstream urine is collected for culture and sensitivity test. To collect the midstream urine, the patient is advised to clean the vulva and to collect the urine in a sterile container during the middle of the act of urination. Presence of nitrites and/ or leukocyte esterase by dipstick indicates urinary tract infection (p. 606). +♦ Cervical cytology study by Pap smear or Liquid-Based Cytology (LBC) is a routine unless done before. +Special investigations: +(a) Serological tests for rubella, hepatitis B virus and HIV: Antibodies to detect rubella immunity and screening for hepatitis B virus and HIV (with consent-VCTC). +(b) Prenatal genetic screen: Ch. 11. +( c) Ultrasound examination: First trimester scan helps to detect: (i) Early pregnancy, (ii) accurate dating, (iii) number of fetuses, (iv) gross fetal anomalies and first trimester combined screening (aneuploidy) is done at 13th weeks, (v) any uterine or adnexal pathology. However, it is not done as a routine. +Booking (18-22 weeks) scan has got advantages in addition to first trimester scan: (i) Detailed fetal anatomy survey and to detect any structural abnormality including cardiac, (ii) placental localization. Ultrasound examination is also very reassuring to the couple. +IMMUNIZATION: Tetanus: Immunization against tetanus protects the mother and the neonates. In unprotected women, 0.5 mL tetanus toxoid is given Intramuscularly (IM) at 6 weeks interval for 2 such, the first one to be given between 16 and 24 weeks. Women who are immunized in the past, a booster dose of 0.5 mL IM is given in the last trimester. +Repetition of the investigations: ■ Hemoglobin esti­ mation is repeated at 28th and 36th week. ■ Urine is tested (dipstick) for protein and sugar at every antenatal visit. ■ USG at 11-13 weeks (1st trimester combined screening), 18-22 weeks (detailed anomaly survey) and 36 weeks growth profile (optional) (Table 10.3). + +J'abte 10.3: Procedures of routine prenatal care. , " + +Initial obstetric visit +Investigations + + + +11-14 week gestation (TVS) +16-20 week gestation +18-22 week gestation +24-28 week gestation +36 week gestation + + +History taking and physical examination. +• Blood for ABO and Rh type, antibody screen, CBC, rubella, Hb electrophoresis (if at risk for hemoglobinopathy), urine culture, VDRL, HBV, HIV, cervical cytology. +■ USG to confirm gestational age, viability, and number of fetuses. ■ Offer genetic testing based on personal or family history. +Aneuploidy screening option: first trimester screen (Ch. 12). +Aneuploidy screening option: quadruple ("quad") screen, NIPT (Ch. 12). +Ultrasound evaluation of fetal anatomy and placental location (routine). CBC, GDM screening. +USG to verify fetal presentation, fetal growth profile. + +(CBC: Complete Blood Count; GDM: Gestational Diabetes Mellitus; HBV: Hepatitis B Virus) +,!I Chapter 1 O: Antenatal Care, Preconceptional Counseling and Care PROCEDURE AT THE SUBSEQUENT VISITS + +Generally, checkup is done at interval of 4 weeks up to 28 weeks; at interval of 2 weeks up to 36 weeks and thereafter weekly till delivery. Ideally, this should be more flexible depending on the need and the convenience of patient. In the developing countries, as per WHO recommendation, the visit may be curtailed to at least 4; first in second trimester around 16 weeks, second between 24 and 28 weeks, the third visit at 32 weeks and the fourth visit at 36 weeks. +Objectives: (A) To assess: (1) Fetal well-being, (2) lie, presentation, position and number of fetuses, (3) anemia, pre-eclampsia, amniotic fluid volume and fetal growth, (4) to organize specialist antenatal clinics for patients with problems like cardiac disease and diabetes. (B) To select, time for ultrasonography, amniocentesis or chorion villus biopsy when indicated. +History: To note: (1) appearance of any new symp­ tom (headache, dysuria}, (2) date of perception of fetal movements (quickening). + +Examination +General: In each visit, the following are checked and recorded: (I) weight, (2) pallor, (3) edema legs, ( 4) blood pressure. +Abdominal examination: Inspection: Abdominal enlargement, pregnancy marks-linea nigra, striae, surgical scars (midline or suprapubic}. Palpation: (a) To note the height of the fundus above the symphysis pubis. (b) In the second trimester, to identify the fetus by external ballottement, fetal movements, palpation of fetal parts and auscultation of fetal heart sounds. (c) In the third trimester, abdominal palpation will help to identify fetal lie, presentation, position, growth · pattern, volume of liquor and also any abnormality. Examination also helps to detect whether the presenting part is engaged or not. Girth of abdomen is measured at the level of umbilicus. The girth increases by about 2.5 cm per week beyond 30 weeks and at term, measures about 95-100 cm. (d) Others-any uterine mass (fibroid} or +tenderness. Fetal activity (movements) is also recorded. +Vaginal examination: Vaginal examination in the later months of pregnancy (beyond 37 weeks) with an idea to assess the pelvis is not recommended as it is not informative. Pelvic assessment is best done with the onset of labor or just before induction of labor. Methods of vaginal examination for assessment of the pelvis and test for cephalopelvic disproportion are described in Ch. 24. Any history of vaginal bleeding +contraindicates vaginal examination. +Ongoing assessment and counseling is important as prenatal care has an educational opportunity. The woman should be informed about the list of warning signs so that she can contact the hospital or avail the nearby healthcare facilities in time (Box 10.2). + +■ Leakage of fluid from II Headache, visual changes. vagina. ■ Decrease or loss in fetal +■ Vaginal bleeding, movements. +■ Abdominal pain: distressing ■ Fever, rigor, excess vomiting, in nature. diarrhea. + +ANTENATAL ADVICE +PRINCIPLES: (1) To counsel the women and the family members about the importance of regular checkup. (2) To maintain or improve the health status of the woman to the optimum till delivery by judicious advice regarding diet, drugs and hygiene. (3) To improve the psychology and to remove the fear of the unknown by counseling the woman. +DIET (Table 10.4): The diet during pregnancy should be adequate to provide: (a) Good maternal health, (b) optimum fetal growth, (c) the strength and vitality required during labor and (d) successful lactation. During pregnancy, there is increased calorie requirement due to increased growth of the maternal tissues, fetus, placenta and increased basal metabolic rate. The increased calorie requirement is to the extent of 300 Kcal over the nonpregnancy state during second half of pregnancy. Generally, the diet in pregnancy should be of woman's choice as regard the quantity and the type. Woman with normal BMI should eat adequately so as to gain the optimum weight (11 kg}. Overweight women with BMI between 26 and 29 should limit weight gain to 7 kg and obese women (BMI >29) should gain less weight. Excessive weight gain increases antepartum and intrapartum complications including fetal macrosomia. +The pregnancy diet ideally should be light, nutritious, easily digestible and rich in protein, minerals and vitamins. In terms of figures, the daily requirement during pregnancy and lactation is given in Table 10.4. It is not an absolute recommendation but simply a guide. The diet should consist in addition to the principal food at least half liter, if not, 1 liter of milk (1 liter of milk contains about 1 g of calcium), plenty of green vegetables and fruits. The amount of salt should be of sufficient amount to make the food tasty. At least, half of the total protein should be first class containing all the amino acids and majority of the fat should be animal type which contains vitamins A and D. +Dietetic advice should be given with due consideration to the socioeconomic condition, food habits and taste of the individual. Woman with normal BMI should eat as to maintain the schedule weight gain in pregnancy. The instruction about diet should be reasonable and realistic to individual women. +Supplementary nutritional therapy: Dietetic iron is not enough to meet the daily requirement, especially in +Chapter 10: Antenatal Care, Preconceptional Counseling and Care -,, Table 10.4: D ily dietary allowarices for a woman of reprod ctive age: pregnan_cy and lactation. + +Dietary components Energy {kcal) Protein {g) +Iron {mg) Calcium {mg) Zinc {mg) Iodine {µg) Vitamin A {µg) Vitamin D {µg) Thiamine {mg) Riboflavin {mg) +Nicotinic acid {mg) Ascorbic acid {mg) +Folic acid {µg) + + +Nonpregnant +2,200 kcal +so g + +18 mg + +500 mg +8 mg + +150 µg + +700 µg + +15 µg +1.1 mg + +1.1 mg + +15 mg + +75 mg +400 µg + + +Pregnancy second half +2,500 kcal +71 g + +40 mg* + +1,000 mg + +15 mg + +220 µg +1000 µg + +15 µg +1.5 mg I + +1.6 mg +18 mg + +120 mg + +600 µg + + +Lactation +2,600 kcal + +71 g + +30 mg* + +1,500 mg +19 mg + +290 µg + +1300 µg + +15 µg + + + +Almost same +as in pregnancy + + +Sources +Protein, fat, carbohydrate +Meat, fish, poultry, dairy product + +Meat, egg, grains [* to be supplemented] + +Dairy products +Meat, egg, seafood + +Iodized salt, seafood + +Vegetables, liver, fruits + +Dairy products +Grains, cereals + +Meat, liver, grains + +Meat, nuts, cereals + +Citrus fruits, tomato +Leafy vegetables, liver + +Vitamin B12 {µg) 2.4 µg 2.6 µg j Animal proteins * to be supplemented + + +the second half of the pregnancy. Thus, supplementary iron therapy is needed for all pregnant mothers from 16 weeks onwards. Above 10 g% of hemoglobin, 1 tablet of ferrous sulfate (Fersolate) containing 60 mg of elemental iron is enough. The dose should be proportionately increased with lower hemoglobin level to 2-3 tablets a day. Three tablets provide 45 mg of absorbable iron. As the essential vitamins are either lacking in the foods or are destroyed during cooking, supplementary vitamins are to be given daily from 20th week onwards (Table 10.4). +ANTENTAL HYGIENE: In otherwise uncomplicated cases, the following advices are to be given: +Rest and sleep: The patient may continue her usual activities throughout pregnancy. However, excessive and strenuous work should be avoided especially in the first trimester and the last 4 weeks. Recreational exercise (prenatal exercise class) is permitted as long as she feels comfortable. +There is individual variation of the amount of sleep required. However, on an average, the patient should be in bed for about 10 hours (8 hours at night and 2 hours at noon), especially in the last 6 weeks. In late pregna­ ncy, lateral posture is more comfortable. +Bowel: Constipation is common. It may cause backache and abdominal discomfort. Regular bowel movement may be facilitated by regulation of diet taking plenty of fluids, vegetables and milk or prescribing stool softeners at bedtime. There may be rectal bleeding, painful fissures or hemorrhoids due to hard stool. +Bathing: The patient should take daily bath but be careful against slipping in the bathroom due to imbalance. + +Clothing, shoes and belt: The patient should wear loose but comfortable garments. High heel shoes should better be avoided in advanced pregnancy when the center of balance alters. Constricting belt should be avoided. +Dental care: Good dental and oral hygiene should be maintained. The dentist should be consulted, if necessary. This will facilitate extraction or filling of the caries tooth, if required, comfortably in the second trimester. +Care of the breasts: Breast engorgement may cause discomfort during late pregnancy. A well-fitting brassiere can give relief. +Coitus: Generally, coitus is not restricted during pregnancy. Release of prostaglandins and oxytocin with coitus may cause uterine contractions. Women with increased risk of miscarriage or preterm labor should avoid coitus if they feel such increased uterine activity. +Travel: Travel by vehicles having jerks is better to be avoided, especially in first trimester and the last 6 weeks. The long journey is preferably to be limited to the second trimester. Rail route is preferable to bus route. Travel in pressurized aircraft is safe up to 36 weeks. Air travel is contraindicated in cases with placenta previa, pre-eclampsia, severe anemia and sickle cell disease. Prolonged sitting in a car or aeroplane should be avoided due to the risk of venous stasis and thrombo­ embolism. Seat belt should be under the abdomen. +Smoking and alcohol: In view of the fact that smok­ ing is injurious to health, it is better to stop smoking not only during pregnancy but even thereafter. Heavy smokers have smaller babies and there is also more chance of abortion. Similarly, alcohol consumption is to +.I Chapter 10: Antenatal Care, Preconceptional Counseling and Care + +be drastically curtailed or avoided, so as to prevent fetal maldevelopment or growth restriction. +Prenatal classes are found to be helpful and valuable. +Drugs: Almost all the drugs given to mother will cross the placenta to reach the fetus. Possibility of pregnancy should be kept in mind while prescribing drugs to any woman of reproductive age. +GENERAL ADVICE: The patient should be persuaded to attend for antenatal checkup positively on the schedule date of visit. She is instructed to report to the physician even at an early date if some untoward symptoms arise such as intense headache, disturbed sleep with restlessness, urinary troubles, epigastric pain, vomiting and scanty urination. +She is advised to report to hospital for considera­ tion of admission in the following circumstances: +■ Painful uterine contractions at interval of about 10 minutes or earlier and continued for at least 1 hour­ suggestive of onset of labor. +■ Sudden gush of watery fluid per vaginam-suggestive of premature rupture of the membranes. +■ Active vaginal bleeding, however slight it may be. + +MINOR AILMENTS IN PREGNANCY +Nausea and vomiting: Nausea and vomiting especially in the morning, soon after getting out of bed, are usually common in primigravidae. They usually appear following the first or second missed period and subside by the end of first trimester (Ch. 15). +Backache: It is a common problem (50%) in pregnancy. Physiological changes that contribute to backache are­ joint ligament laxity (relaxin, estrogen), weight gain, hyperlordosis and anterior tilt of the pelvis. Other factors may be faulty posture and high heel shoes, muscular spasm, urinary infection or constipation. Excessive weight gain should be avoided. Rest with elevation of the legs to flex the hips, back support pillow while sitting may be helpful. Improvement of posture, well-fitted pelvic girdle belt which corrects the lumbar lordosis during walking and rest in hard bed often relieve the symptom. Massaging the back muscles, acetaminophen and rest relieve the pain due to muscle spasm. +Constipation: It is a quite common ailment during pregnancy. Atonicity of the gut due to the effect of progesterone, diminished physical activity and pressure of the gravid uterus on the pelvic colon are the possible explanations. Regular bowel habit may be restored with advice mentioned earlier. +Leg cramps: It may be due to deficiency of diffusible serum calcium or elevation of serum phosphorus. Supplementary calcium therapy in tablet or syrup after the principal meals may be effective. Massaging the + +leg, application of local heat and intake of vitamin B1 (30 mg) daily may be effective. +Acidity and heartburn: Heartburn is common in pregnancy due to relaxation of the esophageal sphincter. It is caused by reflux of gastric content into the esophagus. It is due to compression and upward displacement of the stomach by the uterus. Patient is advised to avoid overeating and not to go to bed immediately after the meal. Liquid antacids (aluminium hydroxide) may be helpful. Hiatus hernia which is common during the pregnancy can also produce heartburn, especially when the patient is in lying down position. Sleeping in semi­ reclining position with high pillows relieves the symptoms of hiatus hernia. +Varicose veins: Varicose veins in the legs and vulva ( varicosities) or rectum (hemorrhoids) may appear for the first time or aggravate during pregnancy, usually in the later months. It is due to obstruction in the venous return by the pregnant uterus. For leg varicosities, elastic crepe bandage during movements and elevation of the limbs during rest can give symptomatic relief. Specific therapy is better to be avoided. Varicosities usually disappear following delivery. +Hemorrhoids: It may cause annoying complications like bleeding or may get prolapsed. Regular use of laxative to keep the bowel soft, local application of hydrocortisone ointment and replacement of the piles if prolapsed are essential. Surgical treatment is better to be withheld as the condition sharply improves following delivery. +Carpal tunnel syndrome (10%): Woman presents with pain and numbness in the thumb, index and the middle finger. There is weakness in the muscles for thumb movements. This is due to compression effect on the median nerve. Physiological changes in pregnancy with retention of excess fluid are the common cause. Treatment is mostly symptomatic. A splint is applied during sleep time to the slightly flexed wrist to give relief. Corticosteroid injection or surgical decompression is rarely needed. It resolves spontaneously following delivery. +Round ligament pain: Stretching of the round ligaments during movements in pregnancy may cause sharp pain in the groins. This pain may be unilateral or bilateral. It is usually felt in second trimester onwards. This is more common in right side as a result of dextrorotation of uterus. Pain may be awakening at night time because of sudden roll over movements during sleep. Pain may be reduced by making movements gradual instead of sudden. Local heat application is helpful. Analgesics are rarely needed. +Ptyalism: Increased secretion of saliva is observed during pregnancy. It may be associated with increased intake of starch. This problem is usually self-limiting and may be overcome by decreasing intake of carbohydrates. It is not associated with any adverse pregnancy outcome. +Chapter 10: Antenatal Care, Preconceptional Counseling and Care Ea + + +n Fetal growth restriction ■ History of preterm labor. +(FGR). ■ Hypertension in pregnancy. +■ Cardiac or pulmonary disease. • Risk factors for preterm ■ Cervical insufficiency. labor (p. 300). +■ Vaginal bleeding (APH). + +Syncope: It is often seen in a woman following prolonged standing or standing upright abruptly. This is due to pooling of blood in the veins of the lower extremities. There is the effect of compression of the pelvic veins by the gravid uterus also. Other causes may be dehydration, hypoglycemia or overexertion. +Syncope usually resolves rapidly on lying in left lateral position. Syncope in supine position is also managed by resting in lateral recumbent position. Recurrent syncope needs cardiological evaluation. +Ankle edema: Excessive fluid retention as evidenced by marked gain in weight or evidences of pre-eclampsia has to be excluded. No treatment is required for physiological edema or orthostatic edema. +Edema subsides on rest with slight elevation of the limbs. Diuretics should not be prescribed. +Vaginal discharge: Assurance to the patient and advice for local cleanliness are all that are required. Presence of any infection (Trichomonas, Candida, Bacterial vaginosis) should be treated with vaginal application of metronidazole or miconazole (p. 294). +EXERCISE IN PREGNANCY +A low impact exercise may be continued throughout the period of a normal pregnancy. Placental size and birth weight are more in women who exercised. +However, physiologic changes of pregnancy may restrict certain types of exercises. +Limits of moderate intensity physical activity in pregnancy (Box 10.3): +♦ Exercise should be regular (30 min/ day) of low impact, and as a part of daily activities. +♦ Exercise should avoid any symptoms of breathlessness, fatigue or dizziness. +♦ Exercise should be done in a cool area without becoming uncomfortable and warm. +♦ Prolonged supine position, any compression to the uterus or risk of injury (fall) should be avoided. +♦ Regular moderate intensity physical activities are: walking, stationary cycling and low impact aerobics. + +VACCINES IN PREGNANCY + +Vaccines recommended are: Tetanus, diphtheria and pertussis in each pregnancy between 27 and 36 weeks (CDC). Pneumococcal vaccine is indicated for pregnant women at a high risk of infections such as women with + +heart disease, HIV infection, diabetes and sickle cell disease. +■ Live vaccine should be given either before or after pregnancy (more than 4 weeks). Vaccines contra­ indicated in pregnancy are: Measles, Mumps, Rubella, Varicella and Yellow fever. +■ Rabies, hepatitis A and B, influenza vaccine, tetanus toxoids are given as in non-pregnant state. +■ Human papillomavirus vaccine is not recommended during pregnancy. + +VALUES OF ANTENATAL CARE +The value of antenatal supervision is so much tested and recognized that it is needless to stress its importance. It should be borne in mind that a successful obstetric outcome depends on continued careful supervision which starts in pregnancy and ends in puerperal period. Inadequacy of one cannot be compensated by the other. The chief values are: +• To screen the high-risk cases. Medical disorders and obstetric complications are sorted out at the earliest (Ch. 20). Risk assessment is a continued process and not once only. +• Detection of high-risk factors deserves no credit unless proper steps are taken to rectify it. Cases need to be admit­ ted, investigated and treated. +• Pregnancy should be regularly supervised. Casual antenatal visit or inadequate care is worse than no care at all. Efficacy of prenatal care depends on the quality of care given to the woman. +• Antenatal care is said to be the strategy; the intranatal care is the tactic in obstetrics. One is indispensible from the other to achieve a good result. Care should be thorough and based on individual woman's need. +• Acceptance of advice: During pregnancy, advice regarding diet, drugs, family planning guidance and immunization schedule are better followed than in the nonpregnant state. +• It is an opportunity to make the patient realize that childbirth is a physiological process and to boost up the psychology so that the patient finds herself confident during the ordeal of labor. +• The net effect is marked reduction in maternal mortality (about one-seventh) and morbidity. Similarly, there is significant reduction in perinatal mortality {about one­ fifth) and morbidity. +DRAWBACKS +• Trifling abnormality may be exaggerated for which unnecessary medication or risky operative interference is prescribed. +• Unless quality of care is maintained in the antenatal clinic, the benefits of antenatal care are not obtained. +• Good antenatal care only cannot reduce maternal and neonatal mortality and morbidity unless the woman gets good care during labor and postnatal period. +LIMITATIONS: Many complications in obstetrics often arise as emergency and without any warning during pregnancy, labor and puerperium. These are hemorrhage (APH, PPH), hypertension (eclampsia), premature rupture of membranes, unexplained intrauterine fetal death, cord +Ea Chapter 10: Antenatal Care, Preconceptional Counseling and Care + +prolapse or shoulder dystocia. These are the important causes of maternal morbidity and mortality in India. Simultaneous availability of Emergency Obstetric Care (EmOC) should be there to combat these complications. Therefore, good antenatal care and eficient EmOC are complementary to each other for successful obstetric outcome. +PRECONCEPTIONAL COUNSELING AND CARE +When a couple is seen and counseled about pregnancy, its course and outcome well before the time of actual con­ ception is called preconceptional counseling. +Aim is to ensure that a woman enters pregnancy with an optimal state of health which would be safe both for herself and the fetus. +Objectives: +a To reduce the risk of adverse health effects for the woman, fetus and neonate, to optimize health and provide education about healthy pregnancy. +a Many chronic medical illnesses such as diabetes, hypertension, psychiatric illness, and thyroid disease have adverse effects on pregnancy outcomes. These should be optimally managed before pregnancy. All the medications that the woman is taking should be reviewed. +a Women of reproductive age should have their immuni­ zation status assessed and covered appropriately. +a Screening for STis, exposure to infectious diseases (zika virus), use of alcohol, nicotine products, opioids, risks of intimate partner violance are to be asked about and improved appropriately. +■ The woman should start prepregnancy folic acid supplementation. She should maintain the dietary +adequacy of calcium, iron and vitamins (A, B 2, D and +1 +other nutrients). + +., +Table)0.5: Recom endations for weight gain during pregnancy by prepregnancy body mass index (BMI).· • . '•, • / +" ? ' , ' +0 + "'')' +'. +' +I +• ' •• +Total Rates of weight gain Pregnancy BM/ (kg/ weight in second and third BM/ m2J gain (lb) trimesters (lb/wk) +Underweight <18.5 28-40 1 (1-1.3) +Normal weight 18.5-24.9 25-35 1 (0.8-1) +Overwight 25.0-29.9 15-25 0.6 (0.5-0.7) +Obese all >30.0 11-20 0.5 (0.4-0.6) classes +From composition and compound of gestational weight gain: physiology and metabolism. + +■ Folic acid supplementation (5 mg a day) starting 4 weeks prior to conception up to 12 weeks of pregnancy, is advised. This can reduce the incidence of neural tube defects. +11 Women are encouraged to start pregnancy with a normalBMI. +11 Risks of inheritable diseases (cystic fibrosis, thalassemia) and importance of prenatal diagnosis for chromosomal and genetic diseases are discussed. +Educational classes include discussion as regard delivery, timing, method and possible interventions (ventouse/forceps or cesarean delivery). Such prenatal classes are found helpful and valuable. +The counseling should be done by primary healthcare providers. The help of an obstetrician, physician and geneticist may be required and should be extended. +LIMITATIONS: Only a small percentage of women take the advantage of preconceptual care. It is important to create more awareness. Though many pregnancies are unplanned. + + + + + +► Pregnancy is a physiologic event. Most pregnancies are normal. +► Risk assessment, early detection of risk factors and management, health education, advocacy, all are the key elements in antenatal care. ► Preconceptional folic acid supplementation (0.4 mg) should be given to all women planning pregnancy from 4 weeks before and to +be continued at least 3 months thereafter. +► Ultrasound examination between 11-13 weeks and 18-22 weeks are done for aneuploidy screening to assess accurate gestational age, to detect fetal abnormality, viability and multiple pregnancy. +► Women should be monitored for optimum weight gain (24 lb or 11 kg) in pregnancy (Table 10.5). +► Women should do their normal activities. Heavy weight lifting or excessive physical activity should be avoided. +► Antenatal care is a continued primary and preventive health care. Subsequent visits are done to assess maternal and fetal well-being. List of warning signs should be explained to her. +► Diet in pregnancy should ideally be light, frequent, easily digestible and rich in protein, minerals and vitamins. +► Risk assessment is to reduce the risks of maternal mortality and morbidity as well as unnecessary pregnancy intervention. It improves the perinatal outcome also. +► Women are informed about the warning signs of pregnancy, when they should report the hospital. ► Woman is also counseled to reduce unintended pregnancy (p. 497). +► Preconceptional checkup helps early detection of risk factors and their prevention. + +Antenatal Assessment of +Fetal Wellbeing + + + + + + + + +❖ Clinical Evaluation of Fetal Wellbeing at Antenatal Clinic +► First Visit +► Subsequent Visits + + +► Special Investigations ► Early Pregnancy +❖ Antepartum Fetal Surveillance (Late Pregnancy) + + +❖ Other Investigations in Late Pregnancy + + + + +Majority (80%) of fetal deaths occur in the antep­ artum period. The important causes of deaths are: (i) Chronic fetal hypoxia-30% (IUGR); (ii) maternal comp­ lications-35%, e.g., diabetes, hypertension, infection; (iii) fetal congenital malformation and chromosomal abnormalities-IS%, and (iv) unexplained cause-20%. +There is progressive decline in maternal deaths all over the world. Currently, more interest is focused to evaluate the fetal health. The primary objective of antenatal fetal assessment is to avoid fetal death. As such simultaneously with good maternal care during pregnancy and labor, the fetal health in utero should be supervised with equal vigilance. +Aims of antenatal fetal monitoring (Boxes 11.1 and 11.2): +• To ensure satisfactory growth and wellbeing of the fetus throughout pregnancy. +• To screen out the high-risk factors that affect the growth of the fetus. + +CLINIC AL EVALUATION OF FETAL WELLBEING AT ANTENATAL CLINIC +I FIRST VISIT +The initial antenatal examination should be carried out in the first trimester. At this examination a record is kept of the size of the uterus following bimanual examination or by ultrasonography. This is of immense help in estimating the correct duration of gestation in the last trimester. + + +■ Tests must provide information superior to that of clinical evaluation. +■ Test results should be helpful in management to improve perinatal outcome. +■ Benefits of tests must outweigh the potential risks and the costs. + + +Fetal wellbeing depends on satisfactory maternal health throughout pregnancy. After a thorough clinical examination of the mother, the investigations are initiated as early as possible (p. 88). +I SUBSEQUENT VISITS +At every antenatal visit, the following clinical parameters are taken into account for assessment of satisfactory progress of gestation. +■ Maternal weight gain: During the second half of pregnancy, the average weight gain is 1 kg a fortnight. Any excess weight gain may be due to excess fluid retention and could be the first sign of pre-eclampsia. If the weight gain is less than normal, stationary or even falling, one should be on the look-out for intrauterine growth restriction. +■ Blood pressure: Initial recording of blood pressure prior to 12 weeks helps to differentiate a pre-existing chronic hypertension from a pregnancy-induced hypertension developing later on. Hypertension, pre­ existing or pregnancy-induced, may impair the fetal growth (p. 224). +■ Assessment of the size of the uterus and height of the fundus: In early weeks, the size of the uterus is of great value in confirming the calculated duration of gestation. The height of the fundus should be documented at each visit. The top of the uterinefundus is measured from the superior border of the symphysis pubis (bladder should be empty) using a tape. After 24 weeks of pregnancy, + + + ++ Bedrest ♦ Fetal surveillance ♦ Drug therapy + Urgent delivery of the fetus-term or preterm. ♦ Neonatal Intensive Care (NIC). +♦ Termination of pregnancy for fetal congenital anomaly. +-·ll Chapter 11: Antenatal Assessment of Fetal Wellbeing + + +40 90th centile 50th centile +I :: +j + ,_ +£' +:= + +>, +10th centile + +1-++-l·-i- • :i . ' l 25 lt-+-1-t-Jl + ,,_,, . .. +- ++-·+-+-++-+-+-+-+-+ ++- +II +-+ 1 +-1%- :: ++ +1 +++-++++-++·H-++·H-++1-l-++I +. !? 2 0 - tttttttttttttttttt I +'=-,- . - .. ++-+++-+++-+++ _+_+_ -+_,++_,! +_ +,_ +I/ +I) 15 ,-+-• ! II tt-+++-++++++++++++++I I-+- Pl-+-1-1-_,--l-t-l-+-t-+- +- +f- +' +, +, +10 1-1--J'H-+++++++++1+++++++++-H--H-++I ++ ++ +·I +,. + +16 20 24 28 32 36 40 44 Weeks +Fig. 11.1: Gestational age chart estimated from symphysis-fundal height. + +the distance measured in cm normally corresponds to the period of gestation in weeks. A variation of 1-2 cm is acceptable. +Provided the patient is sure about her date of last normal menstrual period, a measurement of symphysis-fundal height in later month of pregnancy is a useful screening test for further investigation. The measurement is compared to the expected distance plotted on a chart (Fig. 11.1). If the measure­ ment falls below the 10th centile, fetal growth restriction is suspected and more specific investigation should be done. +■ Clinical assessment of excess liquor should be recorded, as well as any scanty liquor in the last trimester. Evidence of scanty liquor may indicate placental insufficiency and the need for undertaking other placental function tests. +■ Documentation of the girth of the abdomen in the last trimester of pregnancy should form a routine part of abdominal examination. This is measured at the lower border of the umbilicus. Normally, the girth increases steadily up to term. If the girth gradually diminishes beyond term or earlier, it arouses suspicion of placental insufficiency. This is of particular value in suspecting placental insufficiency in the high-risk cases such as pre-eclampsia, chronic hypertension andIUGR. + +I SPECIAL INVESTIGATIONS +About 30% of antepartum fetal deaths are due to asphyxia (IUGR, post-dates), 30% due to maternal complications (pre-eclampsia, placental abruption, + + + + +diabetes mellitus), 15% due to congenital malformations and chromosomal abnormalities and 5% due to infection. About 20% of stillbirths have no obvious cause. About 50% of first trimester spontaneous abortions and about 5% of stillborn infants have chromosomal abnormalities. +Congenital abnormalities may be: (1) Chromosomal: numerical (47,XX) or structural (translocations ), (2) single gene (cystic fibrosis), (3) polygenic and multifactorial (NTDs) and (4) teratogenic disorders (drugs). +Apart from clinical evaluation, biochemical and biophysical methods have also been used for the diagnosis. Some of these methods carry risks to the mother and/or the fetus and are also expensive. Therefore, their application should provide definite benefits that clearly outweigh the potential risks and the costs. + +I EARLY PREGNANCY +♦ Biochemical + Biophysical ♦ Cytogenetic +Antenatal assessment of fetal wellbeing in early pregnancy is primarily designed to detect fetal congenital abnormalities. Therefore, this chapter should be read in conjunction with Ch. 12. The candidates for prenatal screening are mentioned on p. 103. Women who are screen positive should be offered fetal karyotyping for confirmation. + +FETAL RESPONSE TO HYPOXIA + +Effects of fetal hypoxia depends upon the frequency, degree and duration of oxygen deprivation. Reduced oxygen supply (fetal hypoxia), tissues may be forced to switch from aerobic to anaerobic metabolism. There is accumulation of lactic acid in tissues to cause metabolic acidosis. Buffer bases (bicarbonates) are used to stabilize pH. Unless hypoxia is corrected, blood pH may begin to fall to cause metabolic acidemia. Acidemia is assessed with increased hydrogen ion content ( decreased pH) in the blood. Respiratory acidemia often is clinically benign. Cascade of cellular events occur with persistent metabolic acidemia and hypotension. Important organs involved are the brain and the heart. Disruption of normal cellular metabolism (enzyme function, ion shifts, water regulation, free radical production and phospholipid degradation) leads to cellular and tissue dysfunction, injury and even death. It is concluded that unless acidemia is significant, likelihood of neurologic and cardiovascular metabolic morbidities are low. + +ANTEPARTUM FETAL SURVEILLANCE (LATE PREGNANCY) +OBJECTIVES (ACOG)-(1) Assessment of fetal !J !) wellbeing; (2) Prevention of fetal death and (3) Avoidance of unnecessary interventions. +!]R +METHODS: 11 Clinical u Biochemical ■ Biophysical +Chapter 11: Antenatal Assessment of Fetal Wellbeing iiJlr + +CLINICAL: The clinical assessment of fetal growth can be evaluated by the parameters mentioned earlier in the chapter. They may be useful as screening test for further investigation. +BIOCHEMICAL: Biochemical tests are mainly done for assessment of pulmonary maturity. +BIOPHYSICAL: Principle-Biophysical profile is a scre­ ening test for uteroplacental insufficiency. The fetal biophysical activities are initiated, modulated and regulated through fetal nervous system. The fetal CNS is very much sensitive to diminished oxygenation. Hypoxia ➔ metabolic acidosis ➔ CNS depression ➔ changes in fetal biophysical activity. +The following biophysical tests are used: ■ Fetal movement count. +■ Ultrasonography. ■ Cardiotocography. +■ Non-Stress Test (NST). +■ Fetal Biophysical Profile (BPP). +■ Doppler ultrasound to study of fetal vessels. ■ Vibroacoustic stimulation test. +■ Amniotic fluid volume. +■ Contraction Stress Test (CST). +Fetal movement count-any of the two methods can be applied: +1. Cardiff 'count 10' formula: The patient counts fetal movements starting at 9 am. The counting comes to an end as soon as 10 movements are perceived. She is instructed to report the physician if-(i) less than 10 movements occur during 12 hours on 2 successive days or (ii) no movement is perceived even after 12 hours in a single day. +2. Daily Fetal Movement Count (DFMC): Three counts each of 1 hour duration (morning, noon and evening) are recommended. The total counts multiplied by four gives daily (12 hour) fetal movement count. If there is diminution of the number of 'kicks' to less than IO in 12 hours (or less than 3 in each hour), it indicates fetal compromise. +3. Mothers perceive 88% of the fetal movements detected by Doppler imaging. The count should be performed daily starting at 28 weeks of pregnancy. +Loss of fetal movements is commonly followed by disappearance of FHR within next 24 hours. In either of the earlier methods, if the result is ominous, the candidate is subjected to NST. Maternal hypoglycemia is associated with increased fetal movements. Maternal perception of fetal movements may be reduced with fetal sleep (quiet), fetal anomalies (CNS), anterior placenta, hydramnios, obesity, drugs (narcotics), chronic smoking and hypoxia. +Non-Stress Test (NST): In non-stress test, a conti­ nuous electronic monitoring of the fetal heart rate along + + +with recording of fetal movements (cardiotocography) is undertaken. There is an observed association of FHR acceleration with fetal movements, which when present, indicates a healthy fetus. It can reliably be used as a screening test. The accelerations of the FHR associated with fetal movements are presumably reflex mediated. It should be emphasized that the test is valuable to identify the fetal wellness rather than illness. +Interpretation +■ Reactive (reassuring): When two or more accele­ rations of more than 15 beats per minute above the baseline and longer than 15 seconds in duration are present in a 20-minute observation (Ch. 39). +11 Non-reactive (non-reassuring): Absence of any fetal reactivity. +A reactive NST is associated with perinatal death of +about 5 per 1,000. But perinatal death is about 40 per 1,000 when the NST is nonreactive. Testing should be started after 30 weeks and frequency should be twice weekly. The test has a false-negative rate of 0.5% and false-positive rate of SO%. +Vibroacoustic Stimulation (VAS) is used to change the fetal sleep state from quiet (non-REM) to active (REM) sleep. A reactive NST after VAS indicates a reactive fetus. The procedure is harmless. +Fetal Biophysical Profile (BPP)-considers several parameters (Tables 11.1 and 11.2). BPP using real time ultrasonography has a high predictive value. +BPP is composed of 5 components (Table 11.1). Each component is worth 2 points; a score of 10 on 10 is normal; 6 is equivocal; 4 or less is abnormal. BPP score of 10/10 or 8/10 has a low risk of fetal asphyxia (1 per 1000). +Indications for BPP-non-reactive NST, high-risk pregnancy. Test frequency: Weekly after a normal NST, and twice weekly after an abnormal test. +Modified biophysical profile consists of NST and ultrasonographically determined Amniotic Fluid Index (AFI). Modified BPP is considered abnormal + +:·T bft,,.1:.Biophysical profile sc:ori g (M nr\iog modified, 1992).': +Observation for 30 minutes Normal score= 2; Abnormal = O +Parameters Minimal normal criteria Score +Non-Stress Test Reactive pattern. 2 (NST) +Fetal breathing 30 seconds. 2 movements +Gross body 1.0) after 34 weeks, IUGR is suspected (p. 434). Ultrasound examination is the main diagnostic tool to assess fetal growth. +Amniotic Fluid Volume (AFV): It is primarily dependent upon the fetal urine output, pulmonary fluid production and fetal swallowing. Decreasing AFV may be the result of fetal hypoxia and placental insufficiency. A vertical pocket of amniotic fluid 22 cm is considered normal. Amniotic Fluid Index (AFI) is the sum of vertical pockets from four quadrant of uterine cavity. AFI ,;5 is associated with increased risk of perinatal mortality and morbidity. + + + + +(nonreassuring) when the NST is non-reactive and/or the AFI is <5. +An abnormal score of 4 or less is associated with fetal acidemia. Abnormal BPP is associated with high-risks of stillbirth and perinatal mortality. False-negative rate of a normal BPP is 0.1%. +Fetal Cardiotocography (CTG): A normal tracing after 32 weeks, would show baseline heart rate of 110-160 beats per minute (bpm) with an amplitude of baseline variability 5-25 bpm. There should be no deceleration or there may be early deceleration of very short duration. Importantly, there should be two or more accelerations during a 20-minute period (p. 567). +Growth ultrasound: USG for fetal growth profile done at every 2-3 weeks to assess fetal growth. + +Doppler Ultrasound Velocimetry +Doppler study: It is designed for comprehensive multi­ vessel evaluation of fetal status. Doppler studies can be used to assess a compromised fetus (IUGR) and may function as a diagnostic tool. It alerts the clinician either for further evaluation (BPP, continuous CTG) or possible termination of pregnancy. +Doppler flow velocity waveforms are obtained from arterial and venous beds in the fetus (Figs. 11.2A and B). Arterial Doppler (umbilical artery) waveforms are helpful to assess the downstream vascular resistance. The arterial Doppler waveform is used to measure the peak systolic (S), peak diastolic (D) and mean (M) volumes. From these values S/D ratio, pulsatility index (PI) [PI = (S-D)/M] or resistance index (RI) [RI = (S-D)/S] are calculated (Table 11.3). + + + + + + + + + + +mm + + + + + + + +mJ +Figs. 11.2A and B: Umbilical artery flow velocity waveform: (A) Normal; (B) Abnormal-(i) Reduced end-diastolic flow; (ii) Absent end-diastolic flow; (iii) Reversed end-diastolic flow. +Chapter 11: Antenatal Assessment of Fetal Wellbeing II + + + + +Arterial Doppler indices +Systolic/Diastolic (S/D) ratio. Systolic peak velocity +Diastolic peak velocity +Resistance Index (RI). Systolic -end-diastolic peak velocity +Systolic peak velocity +Pulsatility Index (Pl). Systolic -end-diastolic peak velocity +Time arranged maximum velocity + + +In a normal pregnancy the S/D ratio, PI and RI decreases as the gestational age advances. Higher values greater than 2 SDs above the gestational age mean indicate reduced diastolic velocities and increased placental vascular resistance. These features are at increased risk for adverse pregnancy outcome. +Venous Doppler (ductus venosus, umbilical vein) parameters provide information about cardiac forward function ( cardiac compliance, contractility and after­ load). Fetuses with abnormal cardiac function show pulsatile flow in the Umbilical Vein (UV). Normal UV flow is monophasic (Table 11.4). +The fetuses having umbilical artery Doppler flow abnormalities (AEDV or REDV) are at higher risk of intrauterine hypoxia. Risk of stillbirth is high when the Doppler flow in the ductus venosus (venous parameter) is abnormal. +Use of ultrasonography for fetal biometry and Doppler study for umbilical artery flow velocimetry has reduced perinatal mortality and unnecessary early intervention. significantly. +Contraction Stress Test (CST) is based to observe the response of the fetus at risk for uteroplacental insuficiency in relation to uterine contractions (p. 469). + +OTHER INVESTIGATIONS IN LATE PREGNANCY + +Amniocentesis in late pregnancy: +♦ Test for fetal pulmonary maturity. +♦ Assessment of severity of Rh-isoimmunization. + +Pulmonary maturity: Confirmation of lung matur­ ation reduces the incidence of Respiratory Distress Syndrome (RDS) in the newborn. The risk ofRDS is high for infants that are delivered preterm ( <37 weeks). RDS is caused by the deficiency of pulmonary surfactant, which is synthesized by the type II alveolar cells. Surfactant is packaged in lamellar bodies ➔ discharged in the lung alveoli ➔ carried in the pulmonary fluid ➔ carried into the amniotic fluid. +Assessment of fetal pulmonary maturity (Table 11.5): +♦ For evaluation of fetal pulmonary maturity the sample of amniotic fluid should be obtained by amniocentesis. Amniocentesis should be done under ultrasound guidance (p. 605). +♦ Estimation of pulmonary surfactant by lecithin/ sphingomyelin (LIS) ratio. Amniotic fluid L/S ratio at 31-32 weeks is l; at 35 weeks L/S ratio is 2. L/S ratio c:2 indicates pulmonary maturity. +♦ Lamellar body is the storage form of surfactant in the amniotic fluid. They can be counted as the size is same as that of platelets. A lamellar body count >30,000/µL indicates pulmonary maturity. +♦ Shake test or bubble test (Clement's): This is a useful bedside test, rapidly performed with a fair degree of accuracy. The test is based on the ability of pulmonary surfactant to form a foam or bubble, on shaking which remains stable for at least 15 minutes. Increasing dilutions of amniotic fluid are mixed with 96% ethanol, shaken for 15 seconds and inspected after 15 minutes for the presence of a complete ring of bubbles at the meniscus. If it is present, the test is positive and indicates maturity of the fetal lungs. +♦ Foam Stability Index (FSI) is based on surfactant detection by shake test. PSI is calculated by utilizing serial dilutions of amniotic fluid to quantitate the amount of surfactant present. FSI >47 virtually excludes the risk of RDS. +♦ Presence of Phosphatidylglycerol (PG) in amniotic fluid reliably indicates lung maturation. PG is tested by thin layer chromatography similar to L:S measure­ ment. + + + + + +Vessel +Umbilical Artery (UA) + + +Middle Cerebral Artery (MCA) +Ductus Venosus (DV) + +Umbilical Vein (UV) + + +Change +Reduced or absent or reversed +end-diastolic flow (Figs. 11.2A and B). +t Diastolic velocity; +l-S/D or pulsatory index. +t Doppler index*; absent/ +reversed flow (a-wave). +t Doppler index; pulsatile flow. + + +Pathophysiological basis +Failure of villous trophoblast +invasion. + +Dilatation of cerebral vessels. + +t Central Venous Pressure (CVP). + +t CVP or l- cardiac compliance. + + +Clinical significance +t Resistance in fetoplacental circulation➔ +IUGR, pre-eclampsia. + +'Brain sparing' effect in response to +hypoxemia. Fetal acidemia. + +Fetal acidemia + +*Increased Doppler indices means there is increased vascular flow resistance. +·1 Im Chapter 11: Antenatal Assessment of Fetal Wellbeing + + + + + +Fetal surveillance in pregnancy + +SUMMARY: ANTENATAL ASSESSMENT OF FETAL WELLBEING + +Clinical (Ch. 10), prenatal molecular genetic screening (Ch. 12 ) +E + +----1----B-iophysical (USG) + +Biochemical + + + + +- Clinical monitoring+ DFMCR (from 28 weeks),---_, +, + + + Non-reactive-Modified BPP necess •I-----+ + +I +a +r +y +, +a +s +- +R +e +p +e +a +t +t +e +s +t +R +e +a +c +t +i +v +e + + +- Management as on BPP score and Doppler study report + +Normal --- Continue monitoring + +Abnormal -NsT- + + + +Normal - Repeat test at weekly interval + +Abnormal - Detailed BPP and Doppler -flow velocimetry study + + + + +♦ Saturated phosphatidylcholine 2:500 ng/mL indicates pulmonary maturity. +♦ Fluorescence polarization: This test utilizes polarized light to quantitate surfactant in the amniotic fluid. The ratio of surfactant to albumin is measured by an automatic analyzer (TDx -FLM). Presence of 2:55 mg of surfactant per gram of albumin indicates fetal lung maturity. +♦ Amniotic fluid optical density at 650 nm greater than 0.15 indicates lung maturity. +♦ Orange colored cells-desquamated fetal cells obtained from the centrifuged amniotic fluid are stained with 0.1 % Nile blue sulfate. Presence of orange colored cells >50% suggests pulmonary maturity. +♦ Amniotic fluid turbidity: During first and second trimesters, amniotic fluid is yellow and clear. At term it is turbid due to vernix. +Women for whom delivery is mandated by fetal or maternal indications, testing of fetal lung maturity may not be done. +Fluorescence polarization test is in current used widely. It reflects the ratio of surfactant to albumin and is measured by an automatic analyzer such as TDx-FLM. + + ,; ,. ;if.-_ e ,._ .,,.•,.;;;. Jt • ,:--\; , ( ._"! '"'"' "'"; ,;{"' .. ' '' +!: : .f t J!,!"!, turt Y_ t t ,::",t!J +t +cutoff predictive +Test value value Comments +TDx-FLM 96-100% Simple test. +>55 +L/S ratio >2 .0 95-100% Large laboratory variation. +PG "Present" 95-100% Can use vaginal pooled sample. +Lamellar body 30-40 ,000 97-98% Still investigational. counts +Optical density OD0 .15 98% Simple test. +Foam stability >47 95% Affected by +index meconium, blood. +(FLM: Fetal Lung Maturity; L/S: Lecithin/Sphingomyelin; PG: Phosphati-dylglycerol) + +Assessment of severity of Rh-isoimmunization is done by amniocentesis for estimation of bilirubin in the amniotic fluid by spectrophotometric analysis. The optical density difference at 450 nm gives the prediction of the severity of fetal hemolysis. + + + + + +► About 20% of cases with fetal death remain unexplained. Risk increases with increasing gestational age. +► DFMC is a simple, widely used method for monitoring of fetal wellbeing. The principle is-there is decrease in fetal movements when there is fetal hypoxemia. +► Fetal movement count by the mother is an ideal first-line screening test both for high-risk and low-risk patients. A healthy fetus should have minimum 10 movements in 12 -hour period. Count should be done daily beginning at 28 weeks. Mothers perceive 88% of fetal movements detected by sonography. +► Fetal cardiac accelerations are associated with fetal movements in more than 85% of the time. A reactive NST requires at least two accelerations of FHR in 20 minutes of monitoring. +► At term a fetus spends approximately 25% of its time in quiet sleep state (NREM) and 70% in active sleep state (REM). +Contd... +Chapter 11: Antenatal Assessment of Fetal Wellbeing ml Contd ... +► Vibroacoustic Stimulation (VAS) can change fetal state from quiet (non-REM) sleep to active (REM) sleep and it is harmless. A reactive NST after VAS indicates a healthy fetus. +► The observation of FHR accelerations in response to fetal activity or stimulation to the fetus, indicates fetal wellbeing. +► NST should be done twice weekly in complicated pregnancies (diabetes mellitus, IUGR). NST has a low false-negative rate (<1%) but a high false-positive rate (>50%). +> Ultrasound examination is an essential tool for pregnancy dating, detecting structural and/or chromosomal anomalies, growth profile and wellbeing of the fetus. Important parameters for fetal growth assessment are: BPD, HC, AC, FL and amniotic fluid volume. +► FBPP is assessed by using real-time sonography. The fetal biophysical activities that appear first are the last to disappear with fetal hypoxia. BPP correlates well with fetal acid-base status. False-negative rate of normal BPP is less than 0.1 %. +► Fetal BPP includes NST, fetal breathing and gross body movement. Management is based on total score. A score of 6 is suspicious and should be repeated. +> Modified BPP includes NST and AFI. It takes less time. BPP has lower false-positive rate than NST and high positive predictive value. ► Hypoxemia decreases fetal breathing movements. +► Cardiotocography is the cornerstone of antenatal fetal assessment. A normal trace should have a baseline fetal heart rate of 110-160 bpm, variability of 5-25 bpm and at least two accelerations in a 20-minute period. +► In a normal pregnancy, the S/D ratio and the Resistance Index (RI) decrease as pregnancy advances. +► Absent or reversed end-diastolic flow velocity in the umbilical artery is associated with an increase in perinatal mortality and morbidity. ► Abnormal Doppler flow in the ductus venosus is associated with increased perinatal morbidity and mortality. +> Ultrasonography and Doppler flow velocimetry when used in antenatal fetal wellbeing assessment, the risk of perinatal mortality and unnecessary early intervention for delivery, could be reduced significantly. +> Fetal pulmonary maturity can be accurately predicted by amniotic fluid tests (LIS ratio, lamellar body count). + +Prenatal Genetic Counseling, +Screening and Diagnosis + + +C H A P T E R !1 !1 + +❖ Prenatal Genetic Screening ► Prenatal Diagnosis +❖ Invasive Procedures for Prenatal Diagnosis + + +► Chorionic Villus Sampling ► Amniocentesis +► Cordocentesis or Percutaneous Umbilical Blood Sampling + +❖ Noninvasive Method of Prenatal Testing from Maternal Plasma/Blood ► Fetal DNA + + + + +Genetic counseling: Nearly 3% of newborns have major congenital anomaly. Usually genetic factors are responsible. Chromosomal abnormalities are observed in majority of all first trimester miscarriages and about 5% of all stillborns. The different etiologic factors for fetal malformations are: +• Chromosomal abnormalities (numeric or structural). • Single gene disorders (cystic fibrosis)-1 %. +• Polygenic or multifactorial disorders. +• Teratogenic disorders due to exposure of exogenous factors (drugs). +Prenatal genetic counseling, screening and diagnosis are done to evaluate a fetus with risk of chromosomal, genetic abnormality or a structural anomaly (Table 12.1). Couple is communicated with the basic knowledge of genetic abnormalities. Different possible causes are discussed. Written information (leaflets) may be handed over as that allows the couple for discussion among themselves. Couples are encouraged to ask questions. Women's or couples' risk assessment for having a baby with increased risk of genetic disease should be done based on the ethnicity, race, personal (age, drug history) or family history (Table 12.1). In cases where the risk is high, couple needs additional counseling by + +a genetic counselor. Noninvasive prenatal screening for aneuploidy or neural tube defects is offered to all women regardless of age. +The means to diagnose such abnormality is to obtain fetal tissue or cells by: +a. Chorionic Villus Sampling ( CVS). b. Amniocentesis. +c. Cordocentesis. +d. Fetal cells from maternal blood. +e. Free fetal DNA from maternal plasma/blood. f. Ultrasonography (USG). +g. Fetal echocardiography. + +PRENATAL GENETIC SCREENU\I_G . __ +Aims: Detection and identification of couples (individuals) who are at high-risk for having a child with an inherited (chromosomal or genetic) disorder (Table 12.1). +Noninvasive screening for chromosomal anomaly (trisomy 21, 18, 13) should be a routine to all pregnant women, irrespective of their age. Women who are screen positive should be offered fetal karyotyping for confirmation (Box 12.1). + + +Table 12, 1: Ri* factors for prenatal genetic screening.. ' · , • / · ,i.,,r•, - ..,. :, - Maternal risk factors Prenatal risk factors +", > {>' , S +T +> +< +', +·':l,1:: it + ,:1 +. + +11 Maternal age >35 years. +11 Family history of neural tube defects. 11 Previous baby born with neural tube +defect. +11 Previous child with chromosomal anomaly. a One or both parents-carriers of sex-linked +or autosomal traits. +11 One parent is known to carry a balanced translocation. +11 History of recurrent miscarriage. + + +11 Oligohydramnios 11 Polyhydramnios +■ Severe symmetrical fetal growth restriction. +■ Abnormal ultrasound findings (structural anomalies). +■ Uncontrolled diabetes mellitus in the periconceptional period. +■ Contact with infection (teratogenic), e.g., rubella, cytomegalovirus or intake of teratogenic drugs. +■ Presence of soft tissue markers of chromosomal anomaly on ultrasonography. • Abnormal maternal serum screening. +Chapter 12: Prenatal Genetic Counseling, Screening and Diagnosis ID + ;li:;!j;;?flf.::!:,. f.;tl, }l_fl'ii!!,, ,r1- T""-w¾,f'tg·pr.t ,"..•:n.,i...@k. -, 1;"',e ...I. '· 117.l. '}7,""'t"' -,,1-..'Ht'-""•-"' .,.,,-,,.-1";.<" 1"-"W<".> -lf'.•,_•;."F'IJ{ """ ''\ w ,_ $1"'""'q ,,,' )1 "''ti,;. P '1,C,,' ,:t:.i,. Y' +,; +Box 12.1: +"> +: +) +Procedures for early dete tion of fetal: (I) Genetic, (II) ch omosomal and (Ill) structural abnormalities: iti,,:•t/,:,',J:\i ·' +. +Y +r +J +; +_ += +, +, +. +- +. +n +, +v +" +i + +« +, + +. +1 +. + ++ Quadruple test: MSAFP, uE3, hCG, inhibin A. ♦ Integrated test: NT, PAPP-A+ hCG. ++ Cell-free DNA from maternal plasma/blood. + Maternal Serum Alpha Fetoprotein (MSAFP). + Chorionic villus biopsy. ++ Cordocentesis. + + + +BIOCHEMICAL ANALYTES +1. Maternal Serum Alpha Fetoprotein (MSAFP): Alpha Fetoprotein (AFP) is an oncofetal protein (molecular weight 70,000). It is produced by yolk sac and fetal liver. Highest level of AFP in fetal serum and amniotic fluid is reached around 13 weeks and thereafter it decreases. Maternal serum level reaches a peak around 32 weeks. MSAFP level is elevated in a number of conditions: +a. Wrong gestational age. +b. Open Neural Tube Defects (NTDs). +c. Multiple pregnancy, Rh-isoimmunization. d. IUFD. +e. Anterior abdominal wall defects. f. Renal anomalies. +Low levels are found in trisomies (Down's syndrome), gestational trophosblastic disease. +2. lnhibin A is a dimeric glycoprotein. It is produced by the corpus luteum and the placenta. Serum level of inhibin A is raised in women carrying a fetus with Down's syndrome. +3. Others: hCG; uE3; PAPP-A (p. 55). + +Screening Method +First Trimester Screening +Screening parameters are: (A) Biophysical: (i) ultrasound measurement of nuchal translucency (NT), (ii) nasal bone; (B) Biochemical: (i) free -hCG, (ii) pregnancy associated plasma protein-A (PAPP-A). +Time oftest: Between 11 and 14 weeks. +Values: PAPP-A-reduced; -hCG-increased; NT­ measurement increased in trisomy 21. +NT is the fluid-filled space (detected by USG) between the fetal skin and the underlying soft tissue at the region of the fetal neck. NT 2:3 mm is abnormal. Combined tests can detect trisomy 21 in 92% cases with a false-positive rate of 5%. +First trimester screening is either equal or even superior to second trimester screening. +Advantages: Once a woman is screen positive, diagnos­ tic tests should be done early. +A targeted ultrasound examination during the second trimester and fetal echocardiography are to be done when +NT is 2:3 mm. + + ++ Amniocentesis. ++ Fetal cell isolation from maternal blood (from isolated fetal nucleated red blood cells or trophoblast cells). ++ High resolution ultrasonography for (nuchal thickening, nasal bone). ++ Peri-implantation genetic diagnosis. ++ 3D or 4D ultrasound with increased resolution. + Fetoscopy. + + +Comparison of differen method_s of screening for fetal trisomy 21 +Detection False positive Method of screening rate(%) rate(%) +Maternal age 30 5 First trimester combined test 90 5 +Second trimester: +• +Quadruple test (AFP, free -hCG, 70-75 5 uE3, inhibin A) +Cell-free DNA test 99 0.1 +(AFP: Alpha Feto Protein; 13-hCG: j3-Human Chorionic Gonadotrophin; uE3: Unconjugated Estriol. + +Second Trimester Screening +It is done between 15 and 22 weeks. + +MSAFP: This test is done between 15 and 20 weeks. MSAFP value of2.5 Multiples of the Median (MOM) when adjusted with maternal weight and ethnicity is taken as cut-off point. Elevated MSAFP detects 85% of all neural tube defects. Cases with such high values are considered for high resolution ultrasound imaging and/or amniocentesis. Very low MSAFP levels are associated with increased rates of miscarriage, stillbirth and neonatal death. +Quadruple (Quad) screening includes four biochemical analytes: (1) Maternal Serum Alpha Fetoprotein (MSAFP), (2) Unconjugated Estriol (uE3), (3) dimeric inhibin-A and (4) hCG. +Quad screen can detect trisomy 21 in 85% of cases with a false-positive rate of 0.9%. Levels of serum analytes in cases with trisomy 21: hCG-increased; uE3-reduced; inhibin A-elevated; MSAFP-reduced. +Adjustments are to be made for maternal age, weight and ethnic group. +Best screening procedure is combined first and second trimester procedures (AGOG). + +Screening for Trisomies 18 and 13 +Trisomy 18, 13 and 21 are associated with increased maternal age, increased fetal nuchal translucency and decreased maternal serum PAPP-A. However, in Down syndrome serum-free -hCG is increased, whereas in Edwards' and Patau's syndromes -hCG is decreased. +······ Im Chapter 12: Prenatal Genetic Counseling, Screening and Diagnosis Table 12.2: Prenatal diagnosis: Biochemical and biophysical screening tests. + + +Parameters Time (weeks) Observation + +Anomaly to detect +Comment + + +Detection rate + +Combined test (J-hCG +PAPP-A+NT +11-14 + -hCG (t), PAPP-A (J,) +Down's syndrome + +A cut-off value 1 in 300 is screen positive + +85-92% + +MSAFP, uE3, hCG, inhibin A (quad screening) +15-20 +M5AFP (.[,}; uE3 .J,; hCG (t); inhibin (t) +Down's syndrome + +Detection rate is high + + +85-96% + +Soft tissue marker (nuchal translucency; nasal bone) +11-14 +Nuchal thickness (NT) >3 mm, nasal bone absent (Fig. 12.1 ). +Down's syndrome, Turner's syndrome and others. +Detection rate of Down's syndrome is high (92%), when NT and NB are combined. +85-92% + + +Cell-free fetal DNA (cff-DNA) >l0 weeks +Massively Parallel DNA Shotgun Sequencing (MPSS). +Trisomy 21, 18, 13 and single gene disorders. +Highly sensitive and specific. + + +99% + +Note:Women who are screen positive should be offered fetal karyotyping by invasive method. + + +Table 12.3: Pren tal diagnosis: Chorio ic villus sampling, amnio. centesii and cordocentesis. ' ' + + +Time + +Materials for study + +Karyotype result + +Fetal loss Accuracy + +Termination of pregnancy when indicated. +Maternal effects following termination of pregnancy. + + +Chorionic villus sampling +• Transcervical 10-13 weeks. +• Transabdominal 10 weeks to term. +Trophoblast cells. + +• Direct preparation: 24-48 hours. • Culture: 10-14days. +0.2-0.5% +Accurate; may need amniocentesis for confirmation. +1st trimester-safe. + +Very little + + +Amniocentesis +After 15 weeks (early 12-14 weeks). +• Fetal fibroblasts. +• +Fluid for biochemical study. +Culture: 3-4 weeks. + +0.2% +Highly accurate. + +2nd trimester-risky. + +More traumatic; physically and psychologically. + +Cordocentesis 18-20 weeks. + +Fetal white blood cells (others-infection and biochemical study). +Culture: 24-48 hours. + +1-2% +Highly accurate. + +2nd trimester-risky. + +Same as amniocentesis. + + + +I PRENATAL DIAGNOSIS +Screen positive women are offered fetal karyotyping. Fetal tissues are obtained for confirmation of diagnosis. The procedures are: (a) invasive and {b) noninvasive (Tables 12.2 and 12.3). + +INVASIVE PROCEDURES FOR PRENATAL DIAGNOSIS +I CHORION IC VILLUS SAMPLING (CVS) +Chorionic villus sampling is performed for prenatal diagnosis of genetic disorders. It is carried out transcervically between 10 and 13 weeks and transab­ dominally from 10 weeks to term. Diagnosis can be obtained by 24 hours, and as such, if termination is considered, it can be done in the first trimester safely. A few villi are collected from the chorion frondosum under ultrasonic guidance with the help of a long malleable polyethylene catheter with a metal obturator introduced transcervically (TC-CVS) along the extraovular space. The obturator is then withdrawn. About 15-25 mg of villi are aspirated in a 20 mL syringe creating a negative + + +pressure. The tissues are obtained in a tissue culture media within the syringe. Transabdominal (TA-CVS) is done using a spinal needle (18-20 gauge) under ultrasound guidance {Fig. 12.2). It provides earlier diagnosis than amniotic fluid studies. Complications are: fetal loss (1-2%), oromandibular limb deformities or vaginal bleeding. False-positive results (2-3%) are there due to placental mosaics and maternal cell contamination. In such a situation, amniocentesis should be performed to confirm the diagnosis. Limb Reduction Deformity (LRD) is low when CVS is performed after 9 completed weeks of gestation. Placenta biopsy has mostly replaced cordocentesis. This procedure is of low risks, technically easier and cytogenetic results are obtained within 24-48 hours. Pregnancy termination when needed can be done a safely in the early weeks of gestation. +TC-CVS is avoided in cases with, cervical myoma, acutely angulated uterus, uterine malformations or in presence of infections, such as the genital herpes or cervicitis or in presence of vaginal bleeding. Anti-D immunoglobulin 50 Lg IM should be administered following the procedure to a Rh-negative woman. +Chapter 12: Prenatal Genetic Counseling, Screening and Diagnosis &, + + + + + + + + + + + + + + + + + + +Fig. 12.1: Nuchal Translucency and its measurement of a 12 week fetus in sagittal plane. Nasal bone is seen. +Courtesy: Dr K Oswal, Sonologist. + +The information obtained by CVS, amniocentesis or cordocentesis is discussed below. +♦ Cytogenetic diagnosis: Fetal trophoblast cells from CVS or the desquamated fetal cells in the amniotic fluid obtained by amniocentesis or fetal blood cells obtained by cordocentesis are cultured, G-banded and examined to make a diagnosis of chromosomal anomalies, e.g., trisomy 21 (Down's syndrome), monosomy X (Turner's syndrome) and others. +♦ DNA analysis: Single gene disorders (cystic fibrosis, Tay-Sachs disease, B thalassemia), can be diagnosed using specific DNA probes. DNA amplification is done by Polymerase Chain Reaction (PCR) or chromosomal microarrays. The specific chromosomal region containing the mutated gene can be indentified. +♦ Biochemical: Amniotic fluid AFP level is high when the fetus suffers from open neural tube defects. This is also confirmed by ultrasound scanning. The normal AFP con­ centration in liquor amnii at the 16th week is about 20 mg/L. Amniotic fluid level of 17-hydroxyprogesterone is raised in congenital adrenal hyperplasia. +Structural chromosomal abnormalities ( translocations, inversions, mutations) can be detected by Fluorescence In Situ Hybridization (FISH). Chromosome-specific probes can be used to detect the unknown DNA. + +I AMNIOCENTESIS +11 Genetic amniocentesis is an invasive procedure. It is performed after 15 weeks under ultrasonographic guidance (p. 605). The fetal cells obtained in this procedure are subjected for cytogenetic analysis. +11 Early amniocentesis has been carried out at 12-14 weeks of gestation. Amnifiltration has been used to increase the cell yield. Genetic amniocentesis before 13 weeks is not recommended (ACOG). + + +Fig. 12.2: Chorionic villus sampling-transabdominal method. + + + +CORDOCENTESIS OR PERCUTANEOUS UMBILICAL BLOOD SAMPLING (PUBS) + +Cordocentesis (percutaneous umbilical blood sam­ pling): A 22-gauge spinal needle, 13 cm in length, is inserted through the maternal abdominal and uterine wall under real-time, color Doppler ultrasound guidance using a curvilinear probe. The needle tip is progressed carefully and it punctures the umbilical vein approximately 1-2 cm from the placental insertion. Umbilical vein is preferred. The advantages are: (a) vein is larger in size, {b) causes less bradycardia and (c) less hemorrhage. Generally, 0.5-2 mL of fetal blood is collected. It is performed under local anesthetic usually from 18 weeks of gestation. +RISKS: This invasive procedure may lead to abortion, preterm labor, fetal bradycardia and intrauterine fetal death. These may be due to bleeding, cord hematoma formation, sepsis (amnionitis), fetomaternal hemorrhage or preterm rupture of membranes. Overall fetal loss is 1-2%. Anti-D immunoglobulin 100 µg IM should be given to Rh-negative, yet unimmunized woman. +All the information as obtained in amniocentesis or chorion villus sampling, could be gathered. Additional values are mentioned below. +Hematological: For fetal anemia, bleeding disorders (autoimmune thrombocytopenia), Rh disease and hemoglobinopathies. +Fetal infections: Toxoplasmosis, viral infections. Fetal therapy: Blood transfusion, drug therapy. +Fetal blood gas and acid-base status: In fetal growth restriction. +la Chapter 12: Prenatal Genetic Counseling, Screening and Diagnosis + +NONINVASIVE METHOD OF PRENATAL SCREENING FROM MATERNAL PLASMA/BLOOD +I CELL-FREE DNA ANALYSIS + + +11 Nasal bone. +11 Choroid plexus cysts. 11 Pyelectasis. +11 Echogenic intracardiac focus. + + +11 Echogenic bowels. 11 Shortened femur or +humerus. +11 Increased nuchal fold. + + + +Cell-free DNA comes in the maternal circulation through the placenta. Cell-free DNA (cf-DNA) can be detected in maternal plasma and whole blood from the first trimester onward. This is rapidly cleared from the maternal circulation after delivery. Cell-free DNA is a reliable source for prenatal diagnosis. Approximately 5% of cell­ free DNA in the maternal blood is fetal. The amount of cf-DNA in maternal blood increases with gestational age. The test is generally done from 10 weeks of pregnancy. The smaller fetal DNA fragments (50-200 base pairs) are separated from the maternal cell-free DNA for confirmation. The newer technology of Massively Parallel DNA Shotgun Sequencing (MPSS) allows virtually all DNA molecules in the plasma to be analyzed. +Massively Parallel DNA Shotgun Sequencing (MPSS) is used to screen for aneuploidy. Using MPSS, millions of fragments of maternal and fetal DNA are sequenced from a sample of maternal plasma. The detection rate for trisomy 21 m in 100% with a false-positive rate of 0.1 %. However, women need to be counseled that a negative cf-DNA test does not ensure an unaffected pregnancy (ACOG-2013). +Circulating levels of cf-DNA comprise about 3-13% of the total cell-free DNA in maternal plasma. It is cleared from maternal circulation within hours after child birth. cf-DNA is not a diagnostic test and it has high sensitivity and specificity. The possible sources of error for detection of aneuploidy are ( <0.5%). Maternal obesity, multiple pregnancies, placental mosaicism and certain maternal conditions (malignant disease). +Cell-free DNA is the most sensitive and specific screening procedure for these common fetal aneuploidies. It appears that invasive procedures of prenatal diagnosis will be done in fewer cases. Prenatal genetic testing will gradually shift from cytogenetics to molecular genetics. Fewer biochemical tests are now required. +A woman with a positive test result should be referred for genetic counseling and should be offered invasive prenatal diagnosis for confirmation of test results (ACGM-2013). +Screening with intact fetal cells: Currently it is the most promising approach using the fetal trophoblasts in maternal blood. It is expected to replace all other procedures used to isolate fetal DNA. +Fetal aneuploidy screening: Multiple sonographic markers of aneuploidy have been identified. These 'marlcers'when seen, are associated with an increased risk of aneuploidy. The presence of single or multiple markers in adjustment with patient's age, the risks of aneuploidy are judged. Such USG findings are: + + +With high sensitivity and specificity of cf-DNA testing these second trimester markers are not used, when cf-DNA result is negative. +Ultrasonographic examination of the fetus in the early (10-14 weeks) pregnancy can detect fetal anomalies. Crown-Rump Length {CRL) smaller than the gestational age is associated with the risk of chromosomal anomalies (trisomy or triploidy). Increased Nuchal Translucency (NT) at 10-14 weeks is associated with many chromosomal abnormalities (trisomy, monosomy, triploidy-Fig. 41.2). Detection rate is about 70-80% with a false-positive rate of 5-6%. Absence of Nasal Bone {NB) on USG at 10-12 weeks is associated with fetal Down's syndrome. When NB and NT were combined, detection rate of trisomy 21 was 92% with a false-positive rate of 3.5%. +Magnetic Resonance Imaging (MRI): Information superior to ultrasonography could be obtained (p. 603). +Ultrasonographic evaluation of fetal anatomy may detect major structural anomalies including: anence­ phaly, hydrocephaly, facial clefts and diaphragmatic hernias. The basic fetal anatomic survey include visuali­ zation of the 4 chamber view of the heart, spine, stomach and the kidney. Fetal anatomic survey is done at 18-22 weeks. +Peri-implantation Genetic Diagnosis (PGD) is done +by: (a) Polar body biopsy, (b) blastomere biopsy (from 6-8 cell embryo) and (c) trophectoderm biopsy (5-6 days blastocyst). Diagnostic accuracy in PGD is high (98-99%) both for cytogenetic and single gene disorders. FISH technique is used for detection of aneuploidy, translocation and other chromosomal rearrangements. PGD may be preferred to usual prenatal diagnosis (CVS or amniocentesis) where pregnancy termination is not accepted. +Polar body biopsy: It is done by removing the first or second polar body in the preconceptional phase. Paternal genotype is not assessed here. +Blastomere biopsy: One or two cells are aspirated through a hole made in the zona pellucida by mechanical, laser or chemical means. This does not affect the normal embryonic development. +Trophectoderm biopsy (blastocyst stage) gives more material for analysis, lower rates of mosaicism and more to be of euploid cells. +Fetal therapy: Intrauterine fetal transfusion for fetal anemia (alloimmunization, thalassemia) is done. Fetal medical therapy is done for various conditions through maternal medication. Medicines are carried +Chapter 12: Prenatal Genetic Counseling, Screening and Diagnosis ID +! + +transplacentally to the fetus. Maternal oral therapy with propylthiouracil for fetal hyperthyroidism, digoxin or flecainide for fetal tachyarrhythmias and oral dexamethasone for congenital adrenal hyperplasia of a female fetus have been found effective. Fetal stem cell transplantation and fetal gene therapy could be used for many hematological, metabolic, immunological and + +inherited diseases. Intrauterine fetal surgery has been attempted in few selected cases. Common fetoscopic surgeries done are: laser therapy for TTTS, cystoscopic laser for posterior urethral valves, fetal tracheal occlusion for congenital diaphragmatic hernia and release of amniotic bands. Read more Dutta's Clinics in Obstetrics, Ch. 10, 57 and 69, p. 244. + + + + + +► Approximately 3% of live-born infants have a major birth defect. Majority (80%) of fetal deaths occur antenatally. +► Birth defect may be-(a) Chromosomal: numerical or structural, (b) Single gene disorder, (c) Polygenic or multifactorial and (d) Teratogenic disorder (drugs). About half of chromosomal abnormalities are due to autosomal trisomy and remaining half is due to sex chromosomal abnormalities. +► Screening for prenatal diagnosis should be offered to all pregnancies. MSAFP estimation is done between 15 and 18 weeks. Value of 2.5 MOM adjusted with maternal age is taken as cut-off point. Elevated level can detect 85% of all open NTDs. +► Triple test (MSAFP, hCG, uE3) is used for detection of Down's syndrome. It is done between 15 and 18 weeks. +► Neural tube defects (NTDs) can be detected by ultrasonography between 11 and 14 weeks of pregnancy. MSAFP screening is done for detection of open NTDs between 15 and 20 weeks. +► First trimester screening with biochemical analytes (!,) PAPP-A and (t) hCG and USG measurement of NT (t) can improve detection rate (87%) of Down's syndrome. For confirmation, prenatal genetic study (CVS, amniocentesis or cordocentesis) has to be performed. +► Second trimester screening (quad screening) at 15-18 weeks: (,I,) MSAFP, (,I,) uE3, {t) inhibin A and {t) hCG can detect trisomy 21 in 85% of cases with a false-positive rate of 0.9%. When it is combined with first trimester screening, the detection rate is increased to 95%. +► Screen positive women are offered fetal karyotyping for confirmation. Fetal tissues are obtained from CVS, amniocentesis or cordocentesis. All these are invasive procedures. +► Invasive procedures carry risks. CVS (done between 10 and 13 weeks), is comparable to genetic amniocentesis in terms of fetal loss rate and diagnostic accuracy. To avoid the problems of LRD, CVS should be done after 9 completed weeks. The complications of cordocentesis appear to be 1-2%. +► Single gene disorders can be detected by enzymatic analysis and/or by molecular genetics. Direct analysis is done when gene sequence is known otherwise linkage analysis is done. +► PGD can be done by removing a single cell from the embryo. Molecular genetics including FISH can detect genetic or chromosomal disorder accurately and safely. Currently implantation rate is only 20-30% in most IVF centers. After genetic screening, implantation rate increases by 50%. PGD is not associated with any birth defects. +► Prenatal cytogenetic testing has been best done with banded karyotyping. Chromosome microarrays (MAs) allow comprehensive analysis of entire genome and is superior to routine karyotyping. +► Cell-free Fetal DNA (cf-DNA) can be obtained from maternal plasma and whole blood. cf-DNA is a reliable source for prenatal diagnosis. It is a noninvasive procedure. Fetal aneuploidy (trisomy 21, 18, 13) and single gene disorders can be diagnosed. Testing for cff-DNA is highly sensitive and specific. +► Intact fetal cells have also been recovered from maternal circulation. Genetic and chromosomal disorders are detected from a fetal cell using DNA probes and FISH or Comparative Genomic Hybridization (CGH) and chromosomal microarrays. + +Normal Labor lntrapartum Care for a Positive Child Birth Experience (WHO) + + + + + + +' C:HARTER +❖ Labor +► Onset +► Contractile System of the Myometrium +❖ Physiology of Normal Labor ❖ Events in First Stage of Labor +❖ Events in Second Stage of Labor ❖ Events in Third Stage of Labor + + +❖ Mechanism of Normal Labor ❖ Anatomy of Labor +❖ Clinical Course of First Stage of Labor ❖ Clinical Course of Second Stage of +Labor +❖ Clinical Course of Third Stage of Labor ► Place of Delivery +❖ Management of Normal Labor + + +❖ Management of First Stage of Labor ❖ Management of Second Stage of +Labor +► Immediate Care of the Newborn +❖ Management of Third Stage of Labor ► Active Management of Third Stage +of Labor (AMTSL) +► Labor Care Guide (WHO) + + + + +LABOR + +DEFINITION: Series of events that take place in the genital organs in an effort to expel the viable products of conception (fetus, placenta and the membranes) out of the womb through the vagina into the outer world is called 'labor'. It may occur prior to 37 completed weeks, when it is called the preterm labor. Labor is characterized by the presence of regular uterine contractions with effacement and dilatation of the cervix with fetal descent. A parturient is a patient in labor and parturition is the process of giving birth. Delivery is the expulsion or extraction of a viable fetus out of the womb. It is not synonymous with labor; delivery can take place without labor as in elective cesarean section. Delivery may be vaginal, either spontaneous or aided, or it may be abdominal. +NORMAL LABOR (EUTOOA): Labor is called normal if it fulfils the following criteria: +1. Spontaneous in onset and at term 2. With vertex presentation +3. Without undue prolongation +4. Natural termination with minimal aids +5. Without having any complications affecting the health of the mother and/ or the baby. +ABNORMAL LABOR (DYSTOOA): Any deviation from the definition of normal labor is called abnormal labor. Thus, labor in a case with presentation other than vertex or having some complications even with vertex presentation affecting the course of labor or modifying the nature of termination or adversely affecting the maternal and/ or fetal prognosis is called abnormal labor. +DATE OF ONSET OF LABOR: It is ve1y much unpredictable to foretell precisely the exact date of onset of labor. It is + +not only varies from case to case but even in different pregnancies of the same individual. Calculation based on Naegele's formula can only give a rough guide. Based on the formula, labor starts approximately on the expected date in 4%, I week on either side in 50%, 2 weeks earlier and I week later in 80%, at 42 weeks in I 0%, and at 43 weeks plus in 4%. + +CAUSES OF ONSET OF LABOR + +The precise mechanism of initiation of human labor is still obscure. Endocrine, biochemical and mechanical stretch pathways as obtained from animal experiments, however, put forth the following hypotheses. +■ Uterine distension: Stretching effect on the myometrium by the growing fetus and liquor amnii can explain the onset of labor at least in twins or polyhydramnios. Uterine stretch increases gap junction proteins, receptors for oxytocin and specific Contraction Associated Proteins (CAPs ). +■ Fetoplacental contribution: Cascade of events activate fetal hypothalamic-pituitary-adrenal axis prior to onset of labor ➔ increased CRH ➔ increased release of ACTH ➔ fetal adrenals ➔ increased cortisol secretion ➔ accelerated production of estrogen and prostaglandins from the placenta (Fig. 13.1). +■ Estrogen: The probable mechanisms are: +- Increases the release of oxytocin from maternal pituitary. +- Promotes the synthesis of myometrial receptors for oxytocin (by 100-200 folds), prostaglandins and increase in gap junctions in myometrial cells. +- Accelerates lysosomal disintegration in the deci­ dual and amnion cells resulting in increased prostaglandin (PGF2a) synthesis. + + + +Parturition Cascade + r +I +I +PLACENTA + +6' = CRH Placenta +-t Oxytocin +t Prostaglandins +(PGE , PGF ) +2a +2 +t +ACTH +j Estrogen ,,,_, - -1, Progesterone +o +- - - +s + C rti oi --t Interleukins 1, 6, 8 +_ +_ +-+ +----- __ + +DHEA-S Estrogens + + + +liver +Fig. 13.1: Initiation of parturition. + +Chapter 13: Normal Labor Im I M©Y'ER I +Hypothalamus➔ posterior pituitary ➔ oxytocin + + +• t Myometrial +receptors +--POGxystocin Gap junction Decidual +• t +• t +PGF w +• t +Stretch receptor +• Uterine +sensitivitynd contractions I LABOR I +number a +-1, + + + +- Stimulates the synthesis of myometrial contractile protein-actomyosin through cAMP. +Increases the excitability of the myometrial cell membranes. +- +■ Progesterone: Increased fetal production of Dehy­ droepiandrosterone Sulfate (DHEA-S) and cortisol inhibits the conversion of fetal pregnenolone to pro­ gesterone. Progesterone levels therefore fall before labor. It is the alteration in the estrogen-progesterone ratio rather than the fall in the absolute concentration of progesterone, which is linked with prostaglandin synthesis. +■ Prostaglandins: They are the important factors, which initiate and maintain labor. The major sites of synthesis of prostaglandins are-amnion, chorion, decidual cells and myometrium. Synthesis is triggered by-rise in estrogen level, glucocorticoids, mechanical stretching in late pregnancy, increase in cytokines (IL-1, 6, TNF), infection, vaginal examination and separation or rupture of the membranes. Prostaglandins enhance gap junction (intramembranous gap between two cells through which stimulus flows) formation. +Biochemical Mechanisms Involved in the Synthesis of Prostaglandins (Flowchart 13.1) +Phospholipase A in the lysosomes of the fetal membranes near term ➔ esterified arachidonic acid ➔ formation of free arachidonic acid ➔ synthesis of prostaglandins through prostaglandin synthetase. Prostaglandins (E and F ,,) diffuse in the myometrium ➔ act directly at the sarcoplasmic reticulum ➔ inhibit intracellular cAMP generation ➔ increase local free calcium ions ➔ uterine contraction. Once the arachidonic acid cascade is initiated, prostaglandins themselves will activate lysosomal enzyme systems. The prostaglandin synthesis reaches a peak during the birth of placenta probably contributing to its expulsion and to the control of postpartum hemorrhage. +2 +2 +2 + + +■ Oxytocin and myometrial oxytocin receptors: +(i) Large number of oxytocin receptors are present in the fundus compared to the lower segment and the cervix. +(ii) Receptor number increases during pregnancy reaching maximum during labor. +(iii) Receptor sensitivity increases during labor. +(iv) Oxytocin stimulate synthesis and release of PGs +(E2 and F2a) from amnion and decidua. Vaginal examination and amniotomy (stretching of +the lower genital tract), cause rise in maternal plasma oxytocin level (Ferguson reflex). Fetal plasma oxytocin level is found increased during spontaneous labor compared to that of mother. Its role in human labor is not yet established. +■ Neurological factor: Although labor may start in denervated uterus, labor may be also initiated through nerve pathways. Both a and adrenergic receptors are present in the myometrium; estrogen causing the a receptors and progesterone the receptors to function predominantly. The contractile response is initiated through the a receptors of the postganglionic nerve fibers in and around the cervix, and the lower part of the uterus. This is based on observation that onset of labor occurs following stripping or low rupture of the membranes. +I CONTRACTILE SYSTEM OF THE MYOMETRIUM +The basic elements involved in the uterine contractile systems are: (a) Actin, (b) myosin, (c) adenosine triphosphate (ATP), (d) the enzyme myosin light chain kinase (MLCK) and (e) Ca++. +Structural unit of a myometrial cell is myofibril which contains the proteins-actin and myosin. The interaction of myosin and +11 Chapter 13: Normal Labor +Flowchart 13.1: Possible mechanism in initiation of labor. + + + + + +Activation of fetal hypothalamo-pituitary-adrenal axis + + +Cortisol Placenta + + +1 + -----Progesterone!, +/'''"'" ++ + ------------- +Mater nal posterior pituitar ltered balan c +e +y A + +Pla ent a, amni n, toc c o e id +c +o +y +x t cin A s +O : 0- y_r_ - t___:_ _:,_·t'__ :iF_,_.__C_ i_ _t_N i°- +L +_c +h i +- +x +Activation of myometrial contractile system + +(CAPs: Contraction Associated Proteins; NO: Nitric Oxide; PGE2: Prostaglandin E2) + + +actin is essential for muscle contraction. The key process in actin-myosin interaction is myosin light chain phosphorylation. This reaction is controlled by Myosin Light Chain Kinase (MLCK). Oxytocin acts on myometrial receptors and activates phospholipase C, which increases intracellular calcium level. Calcium is essential for the activation of MLCK and binds to the kinase as calmodulin-calcium complex. Intracellular calcium levels are regulated by two general mechanisms: (I) Influx across the cell membrane and (2) release from intracellular storage sites. Calcium is stored within the cells in the sarcoplasmic reticulum and in mitochondria. Progesterone and cAMP promote calcium +storage at these sites. PGF20_, E2 and oxytocin on the other hand stimulate its release. +♦ Intracellular Ca++ ➔ calmodulin Ca++ ➔ MLCK ➔ phosphor­ ylated myosin + actin ➔ myometrial contraction. +♦ Decrease of intracellular Ca++ (or its shift to the storage sites) ➔ dephosphorylation of myosin light chain ➔ inactivation of myosin light chain kinase ➔ myometrial relaxation. + +Uterine muscles have two types of adrenergic receptors-(!) a receptors, which on stimulation, produce a decrease in cyclic AMP (adenosine monophosphate) and result in contraction of the uterus and (2) 13 receptors, which on stimulation, produce rise in cyclic AMP and result in inhibition of uterine contraction. +FALSE PAIN (Synonym: false labor, spurious labor): It is found more in primigravidae than in parous women. It usually appears prior to the onset of true labor pain by 1 or 2 weeks in primigravidae and by a few days in multiparae. Such pains are probably due to stretching of the cervix and lower uterine segment with consequent irritation of the neighboring ganglia. +PRELABOR (Synonym: premonitory stage): The premonitory stage may begin 2-3 weeks before the onset of true labor in primigravidae and a few days before in multiparae. + + +The features are inconsistent and may consist of the following: +■ Lightening: A few weeks prior to the onset of labor especially in primigravidae, the presenting part sinks into the true pelvis. It is due to active pulling up of the lower pole of the uterus around the presenting part. It signifies incorporation of the lower uterine segment into the wall of the uterus. This diminishes the fundal height and hence minimizes the pressure on the diaphragm (Figs. 13.2A and B). The mother experiences a sense of relief from the mechanical cardiorespiratory embarrassment. There may be frequency of micturition or constipation due to mechanical factor-pressure by the engaged presenting part. It is a welcome sign as it rules out cephalopelvic disproportion and other conditions preventing the head from entering the pelvic inlet. \ No newline at end of file diff --git a/notes/DC Dutta Obstetrics 10th Edition_5.txt b/notes/DC Dutta Obstetrics 10th Edition_5.txt new file mode 100644 index 0000000000000000000000000000000000000000..c38ab8440ad1c41b432e0d9467bcfb1c64cfac55 --- /dev/null +++ b/notes/DC Dutta Obstetrics 10th Edition_5.txt @@ -0,0 +1,2027 @@ +■ Cervical changes: A few days prior to the onset of labor, cervix becomes ripe. A ripe cerix is (a) soft, (b) 80% effaced (<1.5 cm in length), (c) admits one finger easily, and (d) cervical canal is dilatable. +■ Appearance of false pain (see next page). +True labor pain is characterized by: +(i) Painful uterine contractions at regular intervals. (ii) Frequency of contractions increase gradually. +(iii) Intensity and duration of contractions increase progressively. +(iv) Associated with 'show'. +(v) Progressive effacement and dilatation of the cervix. +(vi) Descent of the presenting part. +Chapter 13: Normal Labor DI Diaphragm Diaphragm + + + + + + + + + + + + + + +Figs. 13.2A and B: Showing phenomenon of 'lightening': (A) Before; (B) After lightening. + + +( vii) Formation of the 'bag of forewaters'. (viii) Not relieved by enema or sedatives. +False labor pain is characterized by: (i) Dull in nature. +(ii) Confined to lower abdomen and groin. +(iii) May be associated with hardening of the uterus. (iv) They have no other features of true labor pain as +discussed above. +(v) Usually relieved by analgesic. +Labor pain: Throughout pregnancy, painless Braxton­ Hicks contractions with simultaneous hardening of the uterus occur. The contractions are irregular and do not increase in frequency or regularity. These contractions change their character, become more powerful, intermittent and are associated with pain. Pain more often felt in front of the abdomen or radiating toward the thighs. +Show: With the onset of labor, there is profuse cervical mucoid discharge. Simultaneously, there is slight oozing of blood from rupture of capillary vessels of the cervix and from the raw decidual surface caused by separation of the membranes due to stretching of the lower uterine segment. Expulsion of cervical mucus plug mixed with blood is called 'show'. +Dilatation of internal os: With the onset of labor pain, the cervical canal begins to dilate more in the upper part than in the lower, the former being accompanied by corresponding stretching of the lower uterine segment. +Formation of 'bag of waters': Due to stretching of the lower uterine segment, the membranes are detached easily because of its loose attachment to the poorly formed decidua. With the dilatation of the cervical canal, the lower pole of the fetal membranes becomes unsupported and tends to bulge into the cervical canal. As it contains liquor, which has passed below the presenting part, it is called 'bag of waters'. During uterine contraction with consequent rise of intra-amniotic pressure, this bag becomes tense and convex. After the contractions + + +pass off, the bulging may disappear completely. This in association with regular contractions and cervical changes are signs of onset of labor. However, in some cases the membranes are so well applied to the head that the finding may not be detected. +STAGES OF LABOR: Conventionally, events of labor are divided into three stages: +■ First stage: It starts from the onset of true labor pain and ends with full dilatation of the cervix. It is, in other words, the 'cervical stage' of labor. Its average duration is 12 hours (WHO) in primigravidae and 6 hours (WHO-10 hours) in multiparae. +■ Second stage: It starts from the full dilatation of the cervix (not from the rupture of the membranes) and ends with expulsion of the fetus from the birth canal. It has got two phases: (1) The propulsive or passive phase-starts from full dilatation up to the descent of the presenting part to the pelvic floor. (2) The expulsive or active phase is distinguished by maternal bearing down efforts and ends with delivery of the baby. Its average duration is 2 hours (WHO-3 hours) in primigravidae and 30 minutes +(WHO-2 hours) in multiparae . @ +■ Third stage: It begins after expulsion of the fetus and ends with expulsion of the placenta and membranes (afterbirths). Its average duration is about 15 minutes in both primigravidae and multiparae. The duration is, however, reduced to 5 minutes in active management. +■ Fourth stage: It is the stage of observation for at least 1 hour after expulsion of the afterbirths. During this period maternal vitals, uterine retraction and any vaginal bleeding are monitored. Baby is examined. These are done to ensure that both the mother and baby are well. + +PHYSIOLOGY OF NORMAL LABOR +During pregnancy there is marked hypertrophy and hyperplasia of the uterine muscle and the enlargement +Chapter 13: Normal Labor + +of the uterus. At term, the length of the uterus measures about 35 cm including cervix. The fundus is wider both transversely and anteroposteriorly than the lower segment. The uterus assumes pyriform or ovoid shape. The cervical canal is occluded by a thick, tenacious and mucus plug. +UTERINE CONTRACTION IN LABOR: Throughout preg­ nancy there is irregular involuntary spasmodic uterine contractions which are painless (Braxton-Hicks) and have no effect on dilatation of the cervix (p. 43). The character of the contractions changes with the onset oflabor. The pacemaker of the uterine contractions is situated in the region of the tubal ostia from where waves of contractions spread downward. While there are wide variations in frequency, intensity and duration of contractions, they remain usually within normal limits in the following patterns. +■ There is good synchronization of the contraction waves from both halves of the uterus and also between upper and lower uterine segments. +■ There is fundal dominance of contractions that diminish gradually in duration and intensity through midzone down to lower segment. It takes about 10-20 seconds. +■ The waves of contraction follow a regular pattern. +■ The upper segment of the uterus contracts more strongly and for a longer time than the lower part. +■ Intra-amniotic pressure rises beyond 20 mm Hg during uterine contraction. +■ Good relaxation occurs in between contractions to bring down the intra-amniotic pressure to less than 8 mm Hg. Contractions of the fundus last longer than that of the midzone. +During contraction, uterus becomes hard and somewhat pushed anteriorly to make the long axis of the uterus in line with that of pelvic axis. Simultaneously, the patient experiences pain which is situated more on the hypogastric region, often radiating to the thighs. Probable causes of pain are: (a) Myometrial hypoxia during contractions (as in angina), {b) stretching of the peritoneum over the fundus, (c) stretching of the + + + +cervix during dilatation, (d) stretching of the ligaments surrounding the uterus and ( e) compression of the nerve ganglion. Pain of uterine contractions is distributed +along the cutaneous nerve distribution ofT 10 to L1. Pain +of cervical dilatation and stretching is referred to the back through the sacral plexus. +Tonus: It is the intrauterine pressure in between contrac­ tions. During pregnancy, as the uterus is quiescent (inactive), the tonus is of 2-3 mm Hg. During the first stage of labor, it varies from 8 to 10 mm Hg. It is inversely proportional to relaxation. The factors which govern the tonus are: (i) Contractility of uterine muscles, (ii) intra-abdominal pressure, and (iii) overdistension of uterus as in twins and hydramnios. +Intensity: The intensity of uterine contraction describes the degree of uterine systole. The intensity gradually increases with advancement of labor until it becomes maximum in the second stage during delivery of the baby. Intrauterine pressure is raised to 40-50 mm Hg during first stage and about 100-120 mm Hg in second stage oflabor during contractions. In spite of diminished pain in third stage, the intrauterine pressure is probably the same as that in the second stage. The diminished pain is due to lack of stretching effect. +Duration: In the first stage, the contractions last for about 30 seconds initially but gradually increase in duration with the progress oflabor. Thus in the second stage, the contractions last longer than in the first stage. +Frequency: In the early stage of labor, the contractions come at intervals of 10-15 minutes. The intervals gradually shorten with advancement of labor until in the second stage, when it comes every 2-3 minutes. +It is important to note that all the features of uterine contractions mentioned are very effective only when they are in combination. +RETRACTION: It is a phenomenon of the uterus in labor in which the muscle fibers are permanently shortened. Unlike any other muscles of the body, the uterine muscles have this property to become shortened once and for all. Contraction is a temporary reduction in length of the fibers, which attain their full length during relaxation. In contrast, retraction results in permanent shortening and the fibers are shortened once and for all {Fig. 13.3). + + + + + + + + + + + +Contracted + + + + +Relaxed +------ Progressive retraction------➔ Fig. 13.3: Showing phenomenon of contraction and retraction of uterine muscle fibers during labor. + + +The net effects of retraction in normal labor are: +11 Essential property in the formation of lower uterine segment and dilatation and effacement of the cervix. +11 To maintain the descent of the presenting part made by the uterine contractions and to help in ultimate expulsion of the fetus. +11 To reduce the surface area of the uterus favoring sepa­ ration of placenta. +11 Effective hemostasis after the separation of the placenta. + +EVENTS IN FIRST STAGE OF LABOR + +The first stage is chiefly concerned with the preparation of the birth canal so as to facilitate expulsion of the fetus in the second stage. The main events that occur in the first stage are-(a) dilatation and effacement of the cervix and (b) full formation of lower uterine segment. +DILATATION OF THE CERVIX: Prior to the onset of labor, in the prelabor phase (phase-I) there may be a certain amount of dilatation of cervix, especially in multiparae and in some primigravidae. Important structural components of the cervix are-(a) smooth muscle (5-20%), (b) collagen and (c) the ground substance. Predisposing factors which favor smooth dilatation are: a. Softening of the cervix. +b. Fibromusculoglandular hypertrophy. c. Increased vascularity. +d. Accumulation of fluid in between collagen fibers. +e. Breaking down of collagen fibrils by enzymes collage­ nase and elastase. +f. Change in the various glycosaminoglycans (e.g., increase in hyaluronic acid, decrease in dermatan sulfate) in the matrix of the cervix. +These are under the action of hormones-estrogen, progesterone and relaxin. Too much fibrosis as in chronic cervicitis or prolapse or organic lesion in the cervix as + +Chapter 13: Normal Labor + +in carcinoma, results in deficiency of these factors. As a result, cervix may fail to dilate. +Actual Factors Responsible are: +♦ Uterine contraction and retraction: The longitudinal muscle fibers of the upper segment are attached with circular muscle fibers of the lower segment and upper part of the cervix in a bucket-holding fashion (Figs. 13.4A and B). Thus, with each uterine contraction, not only the canal is opened up from above down but also it becomes shortened and retracted. There is some coordination between fundal contraction and cervical dilatation called 'polarity of uterus While the upper segment contracts, retracts and pushes the fetus, the lower segment and the cervix dilate in response to the forces of contraction of upper segment. +♦ Fetal axis pressure: In labor with longitudinal lie and with well-fitted (flexed) fetal head on the cervix, fetal vertebral column is straightened by the contractions of the circular muscle fibers of the body of the uterus. This allows the fundal strong contraction force to be transmitted through the fetal podalic pole and verte­ bral column to the well-fitted fetal head. This causes mechanical stretching of the lower segment and opening up ( dilatation) of the cervical canal. With each uterine contraction, there is elongation of the uterine ovoid and decrease in the transverse diameter. In transverse lie fetal axis pressure is absent. With progressive contraction and retraction, the upper segment becomes shorter and thicker while the lower segment becomes thinner and wider. The cervical canal starts dilating. +♦ Bag of membranes: The membranes (amnion and chorion) are attached loosely to the decidua lining the uterine cavity except over the internal os. In vertex presentation, the girdle of contact of the head (that part of the circumference of the head which first comes in + + + + + + + + + + + + + + + + + + + +Figs. 13.4A and B: Diagrammatic representation showing dilatation of the cervix by the pull of the longitudinal muscles of the uterus: (A) Before labor; (Bl After labor. +I m Chapter 13: Normal Labor +r +contact with the pelvic brim) being spherical, may well fit with the wall of the lower uterine segment. Thus, the amniotic cavity is divided into two compartments (Figs. 13.5A to C). The part above the girdle of contact contains the fetus with bulk of the liquor called hindwaters, and the one below it containing small amount of liquor called forewaters. With the onset of labor, the membranes attached to the lower uterine segment are detached and with the rise of intrauterine pressure during contractions there is herniation of the membranes through the cervical canal. There is ball-valve like action by the well-flexed head. Uterine contractions generate hydrostatic pressure in the forewaters that in turn dilate the cervical canal like a +wedge. When the bag of forewaters is absent (PROM) the pressure of the presenting part pushes the cervix centrifugally. +♦ Vis-a-tergo: The final phase of dilatation and retraction of the cervix is achieved by downward thrust of the presenting part of the fetus and upward pull of the cervix over the lower segment. This phenomenon is lacking in transverse lie where a thin cervical rim fails to disappear. +EFFACEMENT OR TAKING UP OF CERVIX: Effacement is the process by which the muscular fibers of the cervix are pulled upward and merges with the fibers of the lower uterine segment. The cervix becomes thin during first stage of labor or even before that in primigravidae. In primigravidae, effacement precedes dilatation of the cervix, whereas in multiparae, both occur simul­ taneously {Figs. 13.6A and B). Expulsion of mucus plug is caused by effacement. +LOWER UTERINE SEGMENT: Before the onset of labor, there is no complete anatomical or functional division of the uterus. During labor the demarcation of an active upper segment and a relatively passive lower segment + + + + + + + + + + + + +Forewaters + + +Hindwaters + + + + + + + + + + + + +Figs. 13.SA to C: (A) Formation of bag of membranes and forewaters; (B) Well-fitting presenting part dividing the fore­ waters from hindwater; (C) Ill-fitting presenting part allows the hindwaters to force into the bag of membranes during contrac­ tion which may lead to its early rupture. + +is more pronounced. The wall of the upper segment becomes progressively thickened with progressive thinning of the lower segment (Figs. 13.7A to C). This is pronounced in late first stage, especially after rupture of the membranes and attains its maximum in second stage. A distinct ridge is produced at the junction of the two, called physiological retraction ring which should not be + + + + + + + + + + + + + + + + + +Figs. 13.6A and B: Diagrammatic representation of the dilatation and 'taking up' of the cervix in-(A) Primigravida; (B) Multipara: (A)-(a) cervix before labor; (b and c) progressive 'taking up' of the cervix without much dilatation; (d) cervix completely taken up with external os still remaining undilated; (B)-(a) cervix before labor, to note the patulous cervix; (b and c) progressive and simultaneous dilatation and 'taking up' of the cervix; (d) taking up and dilatation of the external os occur simultaneously. +Chapter 13: Normal Labor 11 • + + + + +Active segment + + + +Physiological +internal os retraction ring +Anatomical +Histological ---,-11-,1----­ Internal os +internal os External os + + + +Passive segment + + +Obliterated internal +OS + +Figs. 13.7A to C: Sequence of development of the active and passive segments of the uterus: (Al Uterus at term; (Bl In early labor; (Cl Late second stage. + + + + +Anatomical features +■ LS is developed from the isthmus of the (nonpregnant) uterus, which is bounded above anatomical and below by histological internal os. +■ In labor, LS is bounded above by the physiological retraction ring and below by the fibromuscular junction of cervix and uterus. +■ This segment is formed maximally during labor and the peritoneum is loosely attached anteriorly. +■ It measures 7.5-10 cm when fully formed and becomes cylindrical during the second stage of labor (Figs. 13.7B and C). +■ The wall becomes gradually thin due to: (i) Relaxation of the muscle fibers to allow elongation, (ii) the muscle fibers are drawn up by the muscle fibers of the upper uterine segment by contraction and retraction during labor and (iii) descent of the presenting part causes further stretching and thinning out of wall. +■ This segment has got poor retractile property compared to the upper segment. + + +Clinical significance +■ The phenomenon of receptive relaxation enables expulsion of the fetus by formation of complete birth canal along with the fully dilated cervix (Fig. 13.17). +■ Implantation of placenta in lower segment is known as placenta previa. +■ It is through this segment that cesarean section is performed. +• Poor decidual reaction in this segment facilitates morbid adherent placenta, once the placenta is implanted here. +■ In obstructed labor, the lower segment is very much stretched and thinned out and ultimately gives way (ruptures) especially in multiparae. +■ It is entirely the passive segment of the uterus. Because of poor retractile property, there is chance of postpartum hemorrhage if placenta is implanted over the area. + + + + +confused with the pathological retraction ring-a feature of obstructed labor (p. 344). Lower segment of uterus is characterized by following features (Table 13.1). + +EVENTS IN SECOND STAGE OF LABOR + +The second stage begins with the complete dilatation of the cervix and ends with the expulsion of the fetus. This stage is concerned with the descent and delivery of the fetus through the birth canal. +Second stage has two phases: +1. Propulsive-from full dilatation until head touches the pelvic floor. +2. Expulsive-since the time mother has irresistible desire to 'bear down' and push until the baby is delivered. +With the full dilatation of the cervix, the membranes usually rupture and there is escape of good amount of liquor amnii. The volume of the uterine cavity is thereby reduced. Simultaneously, uterine contraction and retraction become stronger. The uterus becomes + +elongated during contraction, while the anteroposterior and transverse diameters are reduced. The elongation is partly due to the contractions of the circular muscle fibers of the uterus to keep the fetal axis straight. +Delivery of the fetus is accomplished by the downward thrust offered by uterine contractions supplemented by voluntary contraction of abdominal muscles (Fig. 13.8) against the resistance offered by bony and soft tissues of the birth canal. There is always a tendency to push the fetus back into the uterine cavity by the elastic recoil of the tissue of the vagina and the pelvic floor. This is effectively counterbalanced by the power of retraction. Thus, with increasing contraction and retraction, the upper segment becomes more and more thicker with corresponding thinning of lower segment. Endowed with power of retraction, the fetus is gradually expelled from the uterus against the resistance offered by the pelvic floor. After the expulsion of the fetus, the uterine cavity is permanently reduced in size only to accommodate the afterbirths. +11 Chapter 13: Normal Labor +successive retractions, which attains its peak immediately following the birth of the baby. +After the birth of the baby, the uterus measures about 20 cm (8") vertically and 10 cm ( 4") antero­ posteriorly, the shape becomes discoid. The wall of the upper segment is much thickened while thin and flabby lower segment is thrown into folds. The cavity is much reduced to accommodate only the afterbirths. + + + + + + + + + + +Fig. 13.8: Diagram showing the expulsive forces in the second stage. Increased intra-abdominal pressure augments the downward expulsive force of uterine contraction. + +The expulsive force of uterine contractions is added by voluntary contraction of the abdominal muscles called 'bearing down' efforts. For details, p. 124. + +EVENTS IN THIRD STAGE OF LABOR +The third stage of labor comprises the phase of placen­ tal separation; its descent to the lower segment and finally its expulsion with the membranes. +PLACENTAL SEPARATION: At the beginning of labor, the placental attachment roughly corresponds to an area of 20 cm (8") in diameter. There is no appreciable diminution of the surface area of the placental attachment during first stage. During the second stage, there is slight but progressive diminution of the area following + +Mechanism of separation: Marked retraction reduces effectively the surface area at the placental site to about its half. But as the placenta is inelastic, it cannot keep pace with such an extent of diminution resulting in its buckling (Figs. 13.9A and B). A shearing force is instituted between the placenta and the placental site which brings about its ultimate separation. The plane of separation runs through deep spongy layer of decidua basalis so that a variable thickness of decidua covers the maternal surface of the separated placenta. There are two ways of separation of placenta (Figs. 13.IOA and B). + +(1) Central separation (Schultze): Detachment of placenta from its uterine attachment starts at the center resulting in opening up of few uterine sinuses and accumulation of blood behind the placenta (retroplacental hematoma). With increasing contraction, more and more detachment occurs facilitated by weight of the placenta and retroplacental blood until whole of the placenta gets detached. + +(2) Marinal separation (Mathews-Duncan): Separation starts at the margin as it is mostly unsupported. With progressive uterine contraction, more and more areas of the placenta get separated. Marginal separation is found more frequently. + +SEPARATION OF THE MEMBRANES: The membranes, which are attached loosely in the active part, are thrown into multiple folds. Those attached to the lower segment are already separated during its stretching. The separation is facilitated partly by uterine contraction and + + + + + + + + + + + + + + + + + + +Figs. 13.9A and B: Diagram showing area of placental site: (A) Before the delivery of the baby; (Bl After the delivery of the baby. Note: The reduction of the surface area of the placental site resulting in buckling of the placenta. +(PS: Placental Surface) +Chapter 13: Normal Labor fl walls of the uterus following expulsion of the placenta (myotamponade) also contributes to minimize blood loss. + + + + + + + + + + + + + + +Figs. 13.10A and B: Types of separation of the placenta: (A) Schultze method; (B) Mathews-Duncan method. + +mostly by weight of the placenta as it descends down from the active part. The membranes so separated carry with them remnants of decidua vera giving the outer surface of the chorion its characteristic roughness. +EXPULSION OF PLACENTA: After complete separation of the placenta, it is forced down into the flabby lower uterine segment or upper part of the vagina by effective contraction and retraction of the uterus. Thereafter, it is expelled out either by voluntary contraction of abdo­ minal muscles (bearing down efforts) or by manual procedure (p. 132). +Mechanism of control of bleeding: After placental separation, innumerable torn sinuses which have free circulation of blood from uterine and ovarian vessels have to be obliterated. The occlusion is affected by com­ plete retraction whereby the arterioles, as they pass tortuously through the interlacing intermediate layer of the myometrium, are literally clamped (Figs. 13.llA and B). It (living ligature) is the principal mechanism of hemostasis. However, thrombosis occurs to occlude the torn sinuses, a phenomenon, which is facilitated by hypercoagulable state of pregnancy. Apposition of the + +MECHANISM OF NORMAL LABOR +DEFINITION: The series of movements that occur on the head in the process of adaptation during its journey through the pelvis is called mechanism of labor (Flowchart 13.2). It should be borne in mind that while the principal movements are taking place in the head, the rest of the fetal trunk is also involved in it, either participating in or initiating the movement. +MECHANISM: In normal labor, the head enters the brim more commonly through the available transverse diameter (70%) and to a lesser extent through one of the oblique diameters. Accordingly, the position is either occipitolateral or oblique occipitoanterior. Left occipitoanterior is little more common than right occipitoanterior as the left oblique diameter is encroached by the rectum. The engaging anteroposterior diameter of the head is either suboccipitobregmatic 9.5 cm (3¾ ") or in slight deflexion-the suboccipitofrontal 10 cm (4"). The engaging transverse diameter is biparietal 9.5 cm (3.74"). As the occipitolateral position is the most common, the mechanism of labor in such position will be described. The principal movements are: (1) Engagement, (2) descent, (3) flexion, (4) internal rotation, (5) crowning, (6) extension, (7) restitution, (8) external rotation and (9) expulsion of the trunk. Although the various movements are described separately but in reality, the movements at least some, may be going on simultaneously. +Engagement: Head brim relation prior to the engagement as revealed by imaging studies shows that due to lateral inclination of the head, the sagittal suture does not strictly correspond with the available transverse diameter of the inlet. Instead, it is either deflected anteriorly toward the symphysis pubis or posteriorly toward the sacral promont01y (Figs. 13.12A to C). Such deflection of the head in relation to the pelvis is called asynclitism. + + + + + + + + + + + + + + + +Figs. 13.11A and B: Blood vessels: (A) Running through the interlacing muscle fibers; (B) Literally clamped due to effective retraction of the uterine muscles. +'· · EJ Chapter 13: Normal Labor +Flowchart 13.2: Summary of mechanism of labor. + +(Occipitolateral position) + +Diameter of engagement: Available transverse diameter of the inlet Engaging diameter of the head: Suboccipitobregmatic 9.5 cm (3¾) or suboccipitofrontal 10 cm (4") + +Engag!ement Increasing flexion + +D +Internal rotation of occiput anteriorly to two-eighths of circle E Simultaneous rotation of the shoulders to one-eighth of circle + +sC Crowlning +E Delivery of the head by extension + +N Restitution T +External rotation + +Delivery of the shoulders and trunk by lateral flexion + + + + + + + + + +Sagittal suture +Anterior -;:-' parietal + + +Posterior parietal + + + + +Figs. 13.12A to C: Head brim relation prior to engagement: {A) Anterior parietal presentation; {Bl Head in synclitism; {C) Posterior parietal presentation. + + +■ Engagement of head with asynclitism, the two parietal eminences cross the brim one at a time. This helps lesser diameter (super subparietal: 8.5 cm), to cross the pelvic brim instead of larger biparietal diameter (9.5 cm) for engagement in synclitism. +■ Asynclitism is beneficial in the mechanism of engagement of head. +11 Marked and persistent asynclitism is abnormal and indicates cephalopelvic disproportion. + + +When the sagittal suture lies anteriorly, the posterior parietal bone becomes the leading presenting part and is called posterior asynclitism or posterior parietal presentation (Lizman obliquity). This is more frequently found in primigravidae because of good uterine tone and a tight abdominal wall. +In others, the sagittal suture lies more posteriorly with the result that the anterior parietal bone becomes the leading presenting part and is then called anterior + + +parietal presentation or anterior asynclitism (Negele's obliquity). It is more commonly found in multiparae. +Mild degrees of asynclitism are common but severe degrees indicate cephalopelvic disproportion (Box 13.I). +Posterior lateral flexion of the head occurs to glide the anterior parietal bone past the symphysis pubis in posterior parietal presentation. Lateral flexion in the reverse direction occurs to glide the posterior parietal +Chapter 13: Normal Labor la + +bone past the sacral promontory in anterior parietal presentation. After this movement which occurs early in labor, not only the head enters the brim but also synclitism occurs. However, in about 25% of cases, the head enters the brim in synclitism, i.e., the sagittal suture corresponds to the diameter of engagement. +In primigravidae, engagement occurs in a significant number of cases before the onset of labor while in multi­ parae, the same may occur in late first stage with rupture of the membranes. +Descent: Provided there is no undue bony or soft tissue obstruction, descent is a continuous process. It is slow or insignificant in first stage but pronounced in second stage. It is completed with the expulsion of the fetus. In primigravidae, with prior engagement of the head, there is practically no descent in first stage; while in multiparae, descent starts with engagement. Head is expected to reach the pelvic floor by the time the cervix is fully dilated. Factors facilitating descent are-(1) uterine contraction and retraction, (2) bearing down efforts and (3) straightening of the ovoid fetal especially after rupture of the membranes. +Flexion: While some degree of flexion of the head is noticeable at the beginning of labor but complete flexion is rather uncommon. As the head meets the resistance of the birth canal during descent, full flexion is achieved. Thus, if the pelvis is adequate, flexion is achieved either due to the resistance offered by the unfolding cervix, the walls of the pelvis or by the pelvic floor. It has been seen that flexion precedes internal rotation or at least coincides with it. Flexion is essential for descent, since it reduces the shape and size of the plane of the advancing diameter of the head. +Flexion is explained by the two-arm lever theory­ the fulcrum represented by the occipitoallantoid joint + + + + + + + + + + + + + + + + + + +Figs. 13.13A and B: Lever action producing flexion of the head reducing the engaging diameter of the head from occipitofrontal (A) to suboccipitobregmatic (B). + + +of the head, the short arm extends from the condyles to .the occipital protuberance, and the long arm extends from condyles to the chin. When resistance is encountered, by ordinary law of mechanics, the short arm descends and the long arm ascends resulting in flexion of the head {Figs. 13.13A and B). +Internal rotation: It is a movement of great impor­ tance without which there will be no further descent. The mechanism of internal rotation is ve1y complex, although easy to describe. The theories which explain the anterior rotation of the occiput are: +- Slope of pelvic floor: Two halves of levator ani form a gutter and viewed from above, the direction of the fibers is backward and toward the midline. Thus, during each contraction, the head, occiput in particular, in well-flexed position, stretches the levator ani, particularly that half which is in relation to the occiput. After the contraction passes off, elastic recoil of the levator ani occurs bringing the occiput forward toward the midline. The process is repeated until the occiput is placed anteriorly. This is called rotation by law of pelvic floor (Hart's rule). +- Pelvic shape: Forward inclination of the side walls of the cavity, narrow bispinous diameter and long anteropo­ sterior diameter of the outlet result in putting the long axis of the head to accommodate in the maximum available diameter, i.e., anteroposterior diameter of the outlet leaving behind the smallest bispinous diameter. +- Law of unequal flexibility (Sellheim and Moir): The inter­ nal rotation is primarily due to inequalities in the flexibility of the component parts of the fetus. +In occipitolateral position, there will be anterior rotation by two-eighths of a circle of the occiput {Fig. 13.14) whereas in oblique anterior position, rotation will be one-eighth of a circle forward, placing the occiput behind the symphysis pubis. There is always an accom­ panying movement of descent with internal rotation. + + + + + + + + + + + + + + + + + + +Fig. 13.14: Degree of internal rotation, restitution and external rotation of the head in left occipitolateral position. +m Chapter 13: Normal Labor + +Thus, prerequisites of anterior internal rotation of the head are well-flexed head, efficient uterine contraction, favorable shape at the midpelvic plane, and tone of the levator ani muscles. + +The level at which internal rotation occurs is variable. Rotation in the cervix although favorable is a less frequent occurrence. In majority of cases, rotation occurs at the pelvic floor. Rarely, it occurs as late as crowning of the head. +Torsion of the neck: It is an inevitable phenomenon during internal rotation of the head. If the shoulders remain in the anteroposterior diameter, the neck has to sustain a torsion of two-eighths of a circle corresponding with the same degree of anterior rotation of the occiput. But the neck fails to withstand such major degree of torsion and as such there will be some amount of simultaneous rotation of the shoulders in the same direction to the extent of one-eighth of a circle placing the shoulders to lie in the oblique diameter with one-eighth of torsion still left behind. Thus, the shoulders move to occupy the left oblique diameter in left occipitolateral position and right oblique diameter in right occipitolateral position. In oblique occipitoanterior position, there is no movement of the shoulders from the oblique diameter as the neck sustains a torsion of only one-eighth of a circle. +Crowning: After internal rotation of the head, further descent occurs until the subocciput lies underneath the pubic arch. At this stage, the maximum diameter of the head (biparietal diameter) stretches the vulval outlet without any recession of the head even after the contraction is over called 'crowning of the head'. +Extension: Delivery of the head takes place by extension through 'couple of force' theory. The driving force pushes the head in a downward direction while the pelvic floor offers a resistance in the upward and forward direction. The downward and upward forces neutralize and remaining forward thrust helping in extension (Figs. 13.15A to D). The successive parts of the fetal head to be born through the stretched vulval outlet are vertex, brow and face. Immediately following the release of the chin through the anterior margin of the stretched perineum, the head drops down, bringing the chin in close proximity to the maternal anal opening. +Restitution: It is the visible passive movement of the head due to untwisting of the neck sustained during internal rotation. Movement of restitution occurs rotating the head through one-eighth of a circle in the direction opposite to that of internal rotation (Fig. 13.14). The occiput thus points to the maternal thigh of the corresponding side to which it originally lay (Fig. 13.26). + +External rotation: It is the movement of rotation of the head visible externally due to internal rotation of the shoulders. As the anterior shoulder rotates toward the symphysis pubis from the oblique diameter, it carries the head in a movement of external rotation through one-eighth of a circle in the same direction as restitution. The shoulders now lie in the anteroposterior diameter. The occiput points directly toward the maternal thigh corresponding to the side to which it originally directed at the time of engagement (Figs. 13.14 and 13.26). + +Birth of shoulders and trunk (Figs. 13.16A and B, Flowchart 13.2): After the shoulders are positioned in anteroposterior diameter of the outlet, further descent takes place until the anterior shoulder escapes below the symphysis pubis first. By a movement of lateral flexion of the spine, the posterior shoulder sweeps over the perineum. Rest of the trunk is then expelled out by lateral flexion. + +ANATOMY OF LABOR +As labor advances, the body of uterus, cervix and vagina together form a uniformly curved canal called the birth canal. Normally, at the onset of labor when the head is not engaged, the pelvic structures anterior to the vagina are urethra and bladder, and those posterior to the vagina are the pouch of Douglas with coils of intestine, rectum, anal canal, perineum and anococcygeal raphe. +As the head descends down with progressive dila­ tation of the vagina, it displaces the anterior structures upward and forward, and the posterior structures dow­ nward and backward, as if the head is passing through a swing door (Figs. 13.17A to C). The bladder which remains a pelvic organ throughout the first stage bec­ omes an abdominal organ in the second stage of labor. However, there is no stretching of the urethra as was previously thought. Rather, the urethra is pushed anteriorly with the neck of the bladder still lying in the vulnerable position behind the symphysis pubis. The changes in the posterior structures due to downward and backward displacement are marked when the head is sufficiently low down and in the stage of 'crowning'. The perineum which is a triangular area of about 4 cm thickness becomes a thinned out, membranous structure of less than 1 cm thickness. The anus, from being a closed opening, becomes dilated to the extent of 2-3 cm. The anococcygeal raphe is also thinned and stretched. Thus, the posterior wall of the birth canal becomes about 23 cm (9") in length, 11.5 cm ( 4½") for the depth of the sacrum, and 11.5 cm ( 4½ ") for the stretched soft tissue, while its anterior wall remains the same 4 cm (l½") in length. The canal becomes almost a semicircle. +Chapter 13: Normal Labor II + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +m +Figs. 13.15A to D: Lateral view showing mechanism of labor in left occipitolateral position: (A and B) Posterior parietal presentation, posterior lateral flexion of the head and engagement; (C and D) Internal rotation of the head with movement of the shoulders; descent and delivery of the head by extension. + + + + + + + + + + +1] +Figs. 13.16A and B: Delivery of the shoulders by lateral flexion: (A) Anterior shoulder; (B) Posterior shoulder. + + +CLINICAL COURSE OF FIRST STAGE OF LABOR + +The first symptom to appear is intermittent painful uterine contractions followed by expulsion of blood-stained mucus (show) per vaginam. Only few drops of blood mixed with mucus is expelled and any excess should be considered abnormal. + +PAIN: Pains are felt more anteriorly with simultaneous hardening of the uterus. Initially, pains are not strong enough to cause discomfort and come at varying intervals of 15-30 minutes with duration of about 30 seconds. But gradually the interval becomes shortened with increasing intensity and duration so that in late first stage the contraction comes at intervals of 3-5 minutes and lasts +1I Chapter 13: Normal Labor + + + + + + + + + + + + + + +....1.======----- Physiological retraction ring + +_ +, + + +.--..---- - Internal os +. +\ +... + + + + + + + + +Figs. 13.17A to C: (Al The relative position of the bladder, urethra and the genital organs at the beginning of labor; (Bl Formation of birth canal with the cervix fully dilated. Note the forward displacement of the urethra and bladder neck behind the pubis; (Cl Marked stretching with downward and backward displacement of the posterior wall of the canal as the head descends down. + + +for about 45 seconds. The relation of pain with uterine contraction is of great clinical significance. In normal labor, pains are usually felt shortly after the uterine contractions begin and pass off before complete relaxation of the uterus. Clinically pains are said to be good if they come at intervals of 3-5 minutes and at the height of contraction the uterine wall cannot be indented by the fingers. +DILATATION AND EFFACEMENT OF THE CERVIX: Pro­ gressive anatomical changes in the cervix, such as dilatation and effacement, are recorded following each vaginal examination. Cervical dilatation relates with dilatation of the external os and effacement is determined by the length of the cervical canal in the vagina. In primigravidae, the cervix may be completely effaced, feeling like a paper although not dilated enough to admit a fingertip. It may be mistaken for one that is fully dilated. While in multiparae, dilatation and taking up occur simultaneously which are more abrupt following rupture of the membranes. The anterior lip of the cervix is the last to be effaced. The first stage is said to be completed only when the cervix is completely retracted over the presenting part during contractions. + + +Cervical dilatation is expressed either in terms of fingers-I, 2, 3 or fully dilated or better in terms of centimeters (10 cm when fully dilated). It is usually measured with fingers but recorded in centimeters. One finger equals to 1.6 cm on average. Simultaneously, effacement of the cervix is expressed in terms of percentage, i.e., 25%, 50% or 100% (cervix less than 0.25 cm thick). The term 'rim' is used when the depth of the cervical tissue surrounding the os is about 0.5-1 cm. +Partograph (Fig. 35.6): Friedman (1954) first devised it. Partograph is a composite graphical record of cervical dilatation and descent of head against duration of labor in hours. It also gives information about fetal and maternal condition, which are all recorded on a single sheet of paper (for details, p. 494). Cervical dilatation is a sigmoid curve and the first stage of labor has got two phases-(1) latent phase and (2) active phase {Fig. 13.18). +First stage of labor (Friedman 1971) is divided into a relatively flat latent phase and a rapidly progressive active phase (Fig. 13.18). The active phase has three compartments. Presently active phase is refined to start with 5 cm {WHO) or 6 cm {ACOG, SFMM). + +-2 + +Latent phase of labor is defined as the period between the onset of true labor pain and the point when the cervical dilatation becomes 5 cm (WHO)/6 cm (ACOG). Normal duration of latent phase of labor in a primigravida is about 20 hours (average 8.6 hours) and 14 hours (average 5.3 hours) in a multipara (Fig. 13.18). +Prolonged latent phase does not endanger the mother or the fetus. No intervention is needed. +The active phase has got three components: +i. Acceleration phase with cervical dilatation of 3-4 cm. ii. Phase of maximum slope of 4-9 cm dilatation. +iii. Phase of deceleration of 9-10 cm dilatation. +The rate of cervical dilatation is <0.5 cm/h in a primi and 0.5 to 1.3 cm/h in a multi. The rate of descent of the presenting part is 60 seconds and ■ Labor progress-cervical dilatation [Plot X] since 5 cm to 10 cm. +(b) Pelvic grip: Gradual disappearance of poles of the head (sinciput and occiput) which were felt previously, (usually occur in labor). Abdominal palpation for descent of the fetal head in terms of fifths felt above the brim is to be used (Figs. 13.21A and B). +(c) Shifting of the maximal intensity of the fetal heart­ beat downward and medially. +To note the fetal wellbeing: +■ Fetal Heart Rate (FHR) along with its rhythm and intensity should be noted every half hour in the first stage and every 15 minutes in second stage or following rupture of the membranes. To be of value, the observation should be made immediately following uterine contraction. The count should be made for 60 seconds. For routine clinical observation, ordinary stethoscope is quite suitable. Doppler ultrasonic car­ diography (Dopplex), however, is helpful in the case of obesity and polyhydramnios (Fig. 42.36). To avoid confusion of maternal and fetal heart rates, maternal pulse should be counted. Otherwise maternal tachycardia may be wrongly treated as fetal heart rate. Normal fetal heart rate ranges from llO to 160 per minute. +CONTINUOUS ELECTRONIC FETAL MONITORING (Fig. 35.5): The device consists of simultaneous recording of fetal heart action by fetal electrocardiography and uterine contraction by tocography (details on p. 567). It is commonly used for high-risk pregnancies and not as a routine. +Vaginal examination: (a) Dilatation of the cervix in centimeters in relation to hours of labor is recorded. (b) Position of the head and degree of flexion. ( c) Station of the head ( degree of descent) in relation to the ischial spines. (d) Color of the liquor (clear or meconium stained) if the membranes are ruptured. (e) Degree of molding of the head-molding occurs first at the junction of occipitoparietal bones and then between the parietal bones (p. 78). (f) Caput formation-progressive increase is more important than its mere presence. +EVIDENCES OF FETAL DISTRESS (intrapartum fetal monitoring, p. 565). +TO WATCH THE MATERNAL CONDITION: Routine checkup includes: (a) To record 2 hourly pulse, blood pressure and temperature; (b) to observe the tongue periodically for hydration; (c) to note the urine output, urine for acetone, glucose and ( d) IV fluids, drugs. +Chapter 13: Normal Labor Im + +Evidence of maternal distress are: ♦ Anxious look, dry tongue. +♦ Rising pulse rate of 100 per minute or more. ♦ Dehydration, dry tongue. +♦ Hot, dry vagina. +♦ Acetone smell in breath. +♦ Scanty high colored urine with presence of acetone. + +MANAGEMENT OF SECOND STAGE OF LABOR +The transition from the first stage to the second stage is evidenced by the following features: +♦ Increasing intensity of uterine contractions. ♦ Bearing-down efforts. +♦ Urge to push or defecate with descent of the presenting part. +♦ Complete dilatation of the cervix as evidenced on vaginal examination. + +PRINCIPLES: (1) To assist in the natural expulsion of the fetus slowly and steadily, (2) To prevent perinea! injuries. +GENERAL MEASURES: +- The patient should be in bed. +- Constant supervision is mandatory and the FHR is recorded at every 5 minutes. +- To administer inhalation analgesics, if available, in +the form of gas N20 and 02 to relieve pain during con­ tractions. +- Vaginal examination is done at the beginning of the second stage not only to confirm its onset but to detect any accidental cord prolapse. The position and the station of the head are once more to be reviewed and the progressive descent of the head is ensured. +PREPARATION FOR DELIVERY +- Position: Positions of the woman during delivery may be lateral, squatting or partial sitting ( 45°). Dorsal position with 15° left lateral tilt is commonly favored as it avoids aortocaval compression and facilitates pushing effort. Leg holders or stirrups may be used. Upright position (sitting, kneeling, squatting) or dorsal had no advantage over the recumbent one. Upright position increases blood loss (>500 mL) and second degree perinea! lacerations. However, it is associated with less episiotomy, less OVD, less FHR pattern abnormalities, less pain, reduction in duration of 2nd stage of labor. Prolonged sitting position in second stage may cause neuropathy (common perinea! nerve). +- The accoucheur scrubs up and puts on sterile gown, mask and gloves and stands on the right side of the table. +- Toileting the external genitalia and inner side of the thighs is done with cotton swabs soaked in Savlon or Dettol solution. One sterile sheet is placed beneath the buttocks of the patient and one over the abdomen. + + +Sterilized leggings are to be used. Essential aseptic procedures are remembered as three Cs: (a) Clean hands, {b) Clean surface and (c) Clean cutting and ligaturing of the cord. +- To catheterize the bladder, if it is full. + +CONDUCTION OF DELIVERY: The assistance required in spontaneous delivery is divided into three phases: +1. Delivery of the head +2. Delivery of the shoulders 3. Delivery of the trunk +11 Delivery of the head: The principles to be followed are to maintain flexion of the head, to prevent its early extension and to regulate its slow escape out of the vulval outlet. +• The patient is encouraged for the bearing-down efforts during uterine contractions. This facilitates descent of the head. +• When the scalp is visible for about 5 cm in diameter, flexion of the head is maintained during contractions. This is achieved by pushing the occiput downward and backward by using thumb and index fingers of the left hand while pressing the perineum by the right palm with a sterile vulval pad. If the patient passes stool, it should be cleaned and the region is washed with antiseptic lotion. +• The process is repeated during subsequent contractions until the subocciput is placed under the symphysis pubis. Guarding the perineum "hands on" (perinea! massage) is recommended (WHO). At this stage, the maximum diameter of the head (biparietal diameter) stretches the vulval outlet without any recession ofthe head even after the contraction is over, and it is called 'crowning of the head' {Fig. 13.23). The purpose of increasing the flexion of the head is to ensure that the small suboccipitofrontal diameter 10 cm ( 4") distends the vulval outlet instead of larger occipitofrontal diameter 11.5 cm (4½") {Fig. 13.24). + + + + + + + + + + + + + + + +Fig. 13.23: Crowning of the head. +Im Chapter 13: Normal Labor + + + + + + + + + + + + + + + + +Fig. 13.24: Suboccipitofrontal diameter distending the vulva! outlet. + + +• When the perineum is fully stretched and threatens to tear especially in primigravidae, episiotomy is done at this stage after prior infiltration with 10 mL of 1 % lignocaine. Bulging thinned out perineum is a better criterion than the visibility of 4-5 cm of scalp to decide the time of performing episiotomy. Episiotomy is done selectively and not as a routine. +• Slow delivery of the head in between the contrac­ tions is to be regulated. This is done when the suboccipitofrontal diameter emerges out. This is accomplished by pushing the chin with a sterile towel covered fingers of the right hand placed over the anococcygeal region while the left hand exerts pressure on the occiput {Ritgen's maneuver, Fig. 13.25). The forehead, nose, mouth and the chin are thus born successively over the stretched perineum by extension. +■ Care following delivery of the head: +- Immediately following delivery of the head, the mucus and blood in mouth and pharynx are to be wiped with sterile gauze piece on a little finger. Alternatively, mechanical or electrical sucker may be used. This simple procedure prevents the serious consequence of mucus blocking the air passage during vigorous inspiratory efforts. +- The eyelids are then wiped with sterile dry cotton swabs using one for each eye starting from the medial to the lateral canthus to miqimize contamination of the conjunctiva! sac. +- The neck is then palpated to exclude the presence of any loop of cord (20-25%). If it is found and if loose enough, it should be slipped over the head or over the shoulders as the baby is being born. But if it is sufficiently tight enough, it is cut in between two pafrs of Kocher's forceps placed 1 inch apart. + + +Fig. 13.25: Assisted delivery of the head by extension, exerting an upward pressure to the chin by the right hand placed over the anococcygeal raphe (Ritgen's maneuver). + +PREVENTION OF PERINEAL LACERATION: More attention should be paid not to the perineum but to the controlled delive1y of the head. +• Delivery by early extension is to be avoided. Flexion of the subocciput comes under the symphysis pubis so that lesser suboccipitofrontal 10 cm (4") diameter emerges out of the introitus. +• Spontaneous forcible delivery of the head is to be avoided by assuring the patient not to bear down during contractions. +• To deliver the head in between contractions. +• To perform timely episiotomy ( when indicated). +• To take care during delivery of the shoulders as the wider bisacromial diameter (12 cm) emerges out of the introitus. +■ Delivery of the shoulders: Not to be hasty in delivery of the shoulders. Wait for the uterine contractions to come and for the movements of restitution and exte­ rnal rotation of the head to occur {Figs. 13.26A to D). This indirectly signifies that the bisacromial diameter is placed in the anteroposterior diameter of the pelvis. During the next contraction, the anterior shoulder is born spontaneously behind the symphysis. If there is delay, the head is grasped by both hands and is gently drawn posteriorly until the anterior shoulder is released from under the pubis. By drawing the head in upward direction, the posterior shoulder is delivered out of the perineum (Figs. 13.27A and B). Traction on the head should be gentle to avoid excessive stretching of the neck causing injury to the brachia! plexus, hematoma of the neck or fracture of the clavicle. Hooking the fingers in the axilla should not be done to avoid the injury of brachia! plexus. +■ Delivery of the trunk: After the delivery of the shoulders, the forefinger of each hand are inserted under the axillae and the trunk is delivered gently by lateral flexion. +Chapter 13: Normal Labor 11 + + + + + + + + + + +i + + + + + + + + + + + + + + + +m +Figs. 13.26A to D: (Al Head is born by extension; (Bl Head drops down with the face close to the anus; (Cl Restitution; (Dl External rotation. + + + + + + + + + + + + + + +Figs. 13.27A and B: Assisted delivery of the shoulders: (A) Anterior shoulder; (Bl Posterior shoulder. + + +I IMMEDIATE CARE OF THE NEWBORN +11 Soon after the delivery of the baby, it should be placed on a tray covered with clean dry linen with the head slightly downward (15°). It facilitates drainage of the mucus accumulated in the tracheobronchial tree by gravity. The tray is placed between the legs of the mother and should be at a lower level than the uterus to facilitate gravitation of blood from the placenta to the infant. + + +■ Air passage (oropharynx) may be cleared of mucus and liquor. Bulb syringe or suction catheter aspiration may be used. +11 Apgar rating at 1 minute and at 5 minutes is to be recorded. +11 Clamping and ligature of the cord: The cord is clamped by two Kocher's forceps, the near one is placed 6-10 cm away from the umbilicus and is cut in between. Two separate cord ligatures are applied with sterile cotton threads 1 cm apart using reef-knot, +-fJ Chapter 13: Normal Labor +the proximal one being placed 3 cm away from the navel. Squeezing the cord with fingers prior to applying ligatures or plastic cord clamps (Fig. 42.31), prevents accidental inclusion of embryonic remnants. Leaving behind a length of the cord attached to the +navel not only prevents inclusion of the embryonic structure, if present, but also facilitates control of primmy hemorrhage due to a slipped ligature. The cord is divided with scissors about 1 cm beyond the ligatures taking aseptic precautions so as to prevent cord sepsis. Presence of any abnormality in cord vessels (single umbilical artery) is to be noted. The cut end is then covered with sterile gauze piece after making sure that there is no bleeding. The purpose of clamping the cord on the maternal end is to prevent soiling of the bed with blood and to prevent fetal blood loss of the second baby in undiagnosed monozygotic twin. +Delay in clamping for 2-3 minutes or till cessation of the cord pulsation facilitates transfer of 80-100 mL blood from the compressed placenta to a baby when placed below the level of uterus. This is beneficial to a term baby. Benefits of delayed cord clamping: Increases total body iron stores, the blood volume and reduces anemia of the newborn (WHO-2014). Delayed cord clamping in preterm neonate is also helpful. This increases total red cell mass, reduces the need for blood transfusion, low and reduced rates of NH, NEC. But early clamping should be done in cases of Rh-incompatibility ( to prevent antibody transfer from the mother to the baby) or babies born asphyxiated or one of a diabetic mother. +♦ Quick check is made to detect any gross abnormality and the baby is wrapped with a dry warm towel. The identification tape is tied both on the wrist of the baby and the mother. Once the management of third stage is over (usually 10-20 minutes), baby is given to the mother or to the nurse. + +MANAGEMENT OF THIRD STAGE OF LABOR +Third stage is the most crucial stage of labor. Previously uneventful first and second stage can become abnormal within a minute with disastrous consequences. +The principles underlying the management of third stage are to ensure strict vigilance and to follow the management guidelines strictly in practice so as to prevent the complications, the important one being postpartum hemorrhage. +STEPS OF MANAGEMENT: Two methods of management are currently in practice (Flowchart 13.3). +1 Active management (preferred) 2. Expectant management +ACTIVE MANAGEMENT OF THIRD STAGE OF LABOR (AMTSL) +The underlying principle in active management is to excite powerful uterine contractions within 1 minute + + + +of delivery of the baby (WHO) by giving parenteral oxytocic. This facilitates not only early separation of the placenta but also produces effective uterine contractions following its separation. +The advantages are-(a) to minimize blood loss in third stage approximately to one-fifth and (b) to shorten the duration of third stage to half; and ( c) Reduces maternal anemia. (d) Less need for blood transfusion. (e) Less need to manage PPH. The only disadvantage is slight increased incidence of retained placenta (1-2%) and consequent increased incidence of manual removal. Accidental administration following +delivery of the first baby in undiagnosed twins, produces danger to the unborn second baby caused by asphyxia due to tetanic contraction of the uterus. Thus, it is essential to limit its use in twins only following delivery of the +second baby. Use of oxytocin decreases PPH by 60%, reduces need of other therapeutic oxytocics by 50%. AMTSL as such reduces PPH by 60%. +Procedures: Injection oxytocin 10 units IM (preferred) or misoprostol 600 µg or methergine 0.2 mg IM is given to the mother within 1 minute of delivery of the baby (WHO). The placenta is expected to be delivered soon following delivery of the baby. If the placenta is not delivered thereafter, it should be delivered forthwith by controlled cord traction (Brandt-Andrews) technique after clamping the cord while the uterus still remains contracted. If the +administration is mistimed as might happen in a busy labor room, one should not be panicky but conduct the third stage with conventional watchful expectancy. +Active management is certainly of value, for cases likely to develop postpartum hemorrhage. These high risk cases are: anemia, hydramnios, twins, multiparae and previous history of PPH. Tablet misoprostol 600 µg, can be given, orally or rectally in cases with home delivery. It can be given by a community health worker (WHO-2012) also. Methergine should not be used in cardiac cases or severe pre-eclampsia, for the risk of precipitating cardiac overload and failure in the former and aggravation of blood pressure or eclampsia in the latter. +Assisted delivery of the placenta: (a) Controlled cord traction (modified Brandt-Andrews method): The palmar surface of the fingers of the left hand is placed (above the symphysis pubis) approximately at the junction of upper and lower uterine segment (Fig. 13.28). The body of the uterus is pushed upward and backward, towards the umbilicus while by the right hand steady tension (but not too strong traction) is given in downward and backward direction holding the clamp until the placenta comes outside the introitus. It is thus more an uterine elevation which facilitates expulsion of the placenta. The procedure is to be adopted only when the uterus is hard and contracted. +(b) Fundal pressure: The fund us is pushed down­ ward and backward after placing four fingers behind the +Chapter 13: Normal Labor Im Flowchart 13.3: Scheme of management of third stage of labor. +i +l + + + +Expectant 1•nagement Active management +l + + +Delise,y the bab, Injection oxytocin 10 units IM (preferred) or tablet misoprostol 600 Lg orally, or rectally +or injection methergine 0.2 mg IM to the mother ,-----------------, within one minute of birth of the baby. +Advantages of Delayed Cord Clamping: + +Delayed cord clamping +(90-120 seconds) + + + +Clamp, divide and ligate the cord +1 + + +Wait and watch + + +■ Improved transitional circulation. Delayed cord clamping +(90-120 seconds) of birth or +■ Improved red cell volume in the fetus. cessation of cord pulsation +11 +Increased total body iron store. +■ Decreased need for blood transfusion. +■ Beneficial to preterm neonates also. +■ Lower incidence of NEC. Clamp, divide and ligate the cord ■ Lower incidence of IVH. +t + +To deliver the placenta by controlled cord traction (CCT) availing first uterine contraction + + + +11 Guard the fundus. +■ Wait for spontaneous separation of placenta. +11 Catheterize the bladder (if needed). + +Placenta separated + + +Wait for spontaneous expulsion with the aid of gravity or with bearing down effert. + + +Fails + + +Massaging the uterus immediately after delivery of the placenta to incite uterine contractions. + + +■ Careful examination of the placenta for its completeness + + +■ Examination of the genital tract to exclude any injury and to repair if any. +l + +Postpartum vigilance: +■ Palpation of the uterus at every 15 minutes for 2 hours to +ensure uterus is hard. + + +Assisted expulsion 11 Estimate the blood loss. 1 + + + + +Controlled cord traction + + + + +To examine the placenta and membranes + + +fundus and the thumb in front using the uterus as a sort of piston (Fig. 13.29). Pressure must be given only when the uterus becomes hard. If it is not, then make it hard by gentle rubbing. The pressure is to be withdrawn as soon as the placenta passes through the introitus. If the baby is macerated or premature, this method is preferable to cord traction as the tensile strength of the cord is much reduced in both the instances. + +Newborn care: Keep baby dry and skin to skin contact with mother, to cover baby and mother. Initiation of breastfeeding within an hour. + + + + +To inspect vulva, vagina and perineum + + +The cord may be accidentally torn which is not likely to cause any problem. The sterile gloved hand should be introduced, and the placenta is to be grasped and extracted. - The uterus is massaged to stimulate uterine contra­ +ctions and to make it hard. This also facilitates expulsion of retained clots if any. +- Examination of the placenta membranes and cord: The placenta is placed on a tray and is washed +·· •-m Chapter 13: Normal Labor +- Vulva, vagina and perineum are inspected carefully for injuries and to be repaired, if any. The episiotomy wound is now sutured. The vulva and adjoining part are cleaned with cotton swabs soaked in antiseptic solution. A sterile pad is placed over the vulva. + +EXPECTANT MANAGEMENT OF THIRD STAGE (PHYSIOLOGICAL) + +♦ In this management, the placental separation and its descent into the vagina are allowed to occur spontaneously. Minimal assistance may be given for the placental expulsion if it needed. +♦ Constant watch is mandatory and the patient should not be left alone. +♦ If the mother is delivered in the lateral position, she should be changed to dorsal position to note features of placental separation and to assess the amount of blood loss. + + +Fig. 13.28: Expression of the placenta by controlled cord traction. + + + + + + + + + + + + + + + + + +Fig. 13.29: Expression of the placenta by fundal pressure. + +out in running tap water to remove the blood and clots. The maternal surface is first inspected for its completeness and anomalies. The maternal surface is covered with grayish decidua (spongy layer of the decidua basalis). Normally the cotyledons are placed in close approximation and any gap indicates a missing cotyledon. The membranes-chorion and amnion are to be examined carefully for completeness and presence of abnormal vessels indicative of succenturiate lobe. The amnion is shiny but the chorion is shaggy. The cut end of the cord is inspected for number of blood vessels. Normally, there are two umbilical arteries and one umbilical vein. An oval gap in the chorion with torn ends of blood vessels running up to the margin of the gap indicates a missing succenturiate lobe. The absence of a cotyledon or evidence of a missing succenturiate lobe or evidence of significant missing membranes demands exploration of the uterus urgently. + +♦ A hand is placed over the fundus-(a) to recognize the signs of separation of placenta, (b) to note the state of uterine activity-contraction and relaxation and (c) to detect, though rare, cupping of the fundus which is an early evidence of inversion of the uterus. +Desire to fiddle with the fundus or massage the uterus is to be strongly condemned. Placenta is sepa­ rated within minutes following the birth of the baby. A watchful expectancy can be extended up to 15-20 minutes. In some institutions, 'no touch' or 'hands off' policy is employed. The patient is expected to expel the placenta within 20 minutes with the aid of gravity. +♦ Expulsion of the placenta: Only when the features of placental separation and its descent into the lower segment are confirmed, the patient is asked to bear down simultaneously with the hardening of the uterus. The raised intra-abdominal pressure is often adequate to expel the placenta. If the patient fails to expel, one can wait safely up to 10 minutes if there is no bleeding. As soon as the placenta passes through the introitus, it is grasped by the hands and twisted round and round with gentle traction so that the membranes are stripped intact. If the membranes threaten to tear, they are caught hold of by sponge-holding forceps and in similar twisting movements the rest of the membranes are delivered. Gentleness, patience and care are prerequisites for complete delivery of the membranes. If the spontaneous expulsion fails or is not practicable, because of delivery under anesthesia, anyone of the following methods can be used to expedite expulsion. + +Difference between Active and Passive third stage +Active stage Passive stage +Duration of third stage of labor Shortened Not shortened +Incidence of nausea and vomiting 10% 5% +Postpartum hemorrhage incidence 1.5% 3% +Blood transfusion 15% 40% + + +MANAGEMENT OF FOURTH STAGE: Pulse, blood pressure, tone of the uterus (well retracted} and any abnormal vaginal bleeding are to be watched at least for 1 hour after delivery. When fully satisfied that the + +Chapter 13: Normal Labor + +general condition is good, pulse and blood pressure are steady, the uterus is well retracted and there is no abnormal vaginal bleeding, the patient is sent to the ward. + + + +SUMMARY First Stage of Labor +First stage of labor starts from the onset of true labor pain and ends with full dilatation of the cervix. Its average duration is about 12 hours in primigravidae and 6 hours (WHO-10 hours) in multiparae. First stage consists of latent phase (up to 5 cm of cervical dilatation) and active phase (up to 10 cm). The stage is chiefly concerned with dilatation and effacement of the cervix. +This stage is clinically manifested by progressive uterine contraction, dilatation and 'effacement' of the cervix and ultimate rupture of the membranes. Maternal and fetal conditions remain unaffected except during uterine contraction. Management consists of: (1) Noninterference with watchful expectancy. (2) Women is given encouragement, emotional support and adequate pain relief during the entire course of labor. (3) To monitor carefully the progress of labor, maternal condition and fetal behavior so as to detect any deviation from the normal. (4) Partograph is maintained. +Second Stage of Labor +The second stage of labor starts from full dilatation of the cervix and ends with expulsion of the fetus. Its average duration is 2 hours (WHO-3 hours) in primigravidae and 30 minutes (WHO-2 hours) in multiparae. This stage concerns with the descent and delivery of the fetus through the birth canal. This stage is clinically manifested by increased frequency and intensity of uterine contractions with appearance of 'bearing-down' efforts which result in expulsion of the fetus. The mother may show features of exhaustion. The principles in management are: (1) To assist the natural expulsion of the fetus slowly and steadily. (2) To prevent perinea I injuries. During conduction of delivery, head is delivered slowly in between contractions. Flexion is maintained so that smaller diameter of the head stretches the perineum. Thus, timely performed episiotomy (selective), prevents perinea I laceration. Shoulders are delivered slowly with next contraction. Immediate care of the newborn includes clearing of the air passage and eyes, delayed clamping and ligaturing of the umbilical cord and Apgar scoring. +Third Stage of Labor +The third stage begins after the expulsion of the fetus and ends with expulsion of the placenta and membranes. Its average duration is 15 minutes. This stage concerns with placental separation and its expulsion. The separation is achieved by marked reduction in the uterine surface area of the placental site following delivery due to retraction. The placenta being inelastic, shears off its attachment through the deep spongy decidual layer. There are two ways of separation-central (Schultze) and marginal (Mathews-Duncan). The bleeding is controlled by effective myometrial contraction and retraction (living ligature) and by thrombosis. The expulsion may occur through 'bearing-down' efforts or more commonly with assistance. The management is either by employing watchful expectancy or by active management (WHO) in cases where oxytocin 10 units IV (slowly) or IM/methergine 0.2 mg IV is administered within 1 minute following the delivery of the baby. +Tablet misoprostol 600 µg, can be given orally or rectally in cases with home delivery. It can be given by a community health worker. Placenta is delivered by CCT soon following delivery of the baby. Uterine massage may be given to make it hard. The placenta and the membranes should be examined following their expulsion. +Fourth Stage of Labor +It is the stage of observation for at least 1 hour after the delivery of the baby, placenta and the membranes to ensure that both the mother and the baby are well. + +t.fi•MIH +> Labor involves a series of changes in the genital organs associated with regular painful uterine contractions with effacement and dilatation of the cervix. Delivery is not synonymous with labor as it can take place without labor. Normal labor should fulfil some defined criteria. +> Onset of labor is difficult to understand. Role of estrogen, progesterone, prostaglandins, oxytocin, and the fetus have been explained. > Active phase of labor begins when the cervix is 5 cm dilated. Management of latent phase (observation) and active phase of labor are +different. +> Labor events are conventionally divided into two phases (latent phase and active phase) and three stages. +> Main events in the first stage of labor are: (a) dilatation and (b) effacement of the cervix. Second stage events are: (a) descent and (b) delivery of the fetus. Second stage is characterized by two phases: (a) propulsive and (bl expulsive (bear down) to deliver the fetus. Third stage events are separation of placenta and expulsion of placenta. +> Lower uterine segment is formed mainly during the first stage of labor. Clinical importance of lower uterine segment is very much. +> Mechanism of normal labor involves a series of movements on the head in the process of adaptation during its passage through the pelvis. +Contd ... +ID Chapter 13: Normal Labor Contd... +► The principal movements are: Engagement➔ Descent with increasing flexion of the head➔ Internal rotation➔ Crowning➔ Delivery of the head by extension ➔ Restitution ➔ External rotation ➔ Delivery of the shoulders (anterior first followed by the posterior) ➔ Delivery of the trunk by lateral flexion. Descent and increasing flexion of the head are the continued process throughout the course of labor. +► Diagnosis of labor (true labor pains) includes regular painful uterine contractions, progressive cervical dilatation and effacement and presence of show. +► Progressive descent of fetal head is assessed abdominally in terms of 'fifths' (Crichton) (Figs. 13.20 and 13.21) and also on vaginal examination by noting the station. +► Successful labor and delivery are dependent on complex interactions of three variables (three 'Ps'): the Power (uterine contractions), the Passenger (fetus), and the Passage (pelvis). +► Partograph is used to record labor events. Electronic fetal monitoring is used for high-risk cases. +► Presence of a labor companion (family member) is helpful for her emotional support. This reduces the need of analgesia, oxytocin and also the need of instrumental vaginal or cesarean delivery. +► Upright position during labor significantly reduces the duration of first stage and also the risk of cesarean delivery. + + +INTRAPARTUM CARE FOR A POSITIVE CHILD BIRTH EXPERIENCE {WHO) + + + +Care throughout labor and birth + +Respectful maternity care + +Effective communication + +Companionship Continuity of care + + +First stage of labor +Definitions of the latent and active first stages of labor + + + +Duration of the first stage of labor + +Progress of the first stage of labor + +Clinical pelvimetry on admission +Routine assessment of fetal wellbeing on labor admission +Perineal/pubic shaving Enema on admission +Digital vaginal examination +Continuous cardiotocog-raphy during labor + +1. Respectful maternity care-is the care provided to all women that maintains their dignity, privacy and confidentiality. This also ensures freedom from harm and mistreatment and enables informed choice and continuous support during labor and childbirth. This is recommended. +2. Effective communication between maternity care providers and women in labor, using simple and culturally acceptable methods is recommended. +3. A companion of choice for all women throughout labor and childbirth is recommended. +4. Midwife-lead continuity-of-care models, in which a known midwife or small group of midwives supports a woman throughout the antenatal, intrapartum and postnatal continuum, are recommended in settings with well-functioning midwifery programs. This is context specific recommendation. + +5. The use of the following definitions of the latent and active first stages of labor is recommended: +• The latent, first stage is a period of time characterized by painful uterine contractions and variable changes of the cervix, including some degree of effacement and slower progression of dilatation up to 5 cm for first and subsequent labors. +• The active first stage is a period of time characterized by regular painful uterine contractions, a substantial degree of cervical effacement and more rapid cervical dilatation from 5 cm until full dilatation for first and subsequent labors. +6. Women should be informed that a standard duration of the latent first stage can vary widely from one woman to another. However, the duration of active first stage (from 5 cm until full cervical dilatation) usually does not extend beyond 12 hours in first labors, and 1 O hours in subsequent labors. This is recommended. +7. Labor may not naturally accelerate until a cervical dilatation threshold of 5 cm is reached. Therefore, the use of medical interventions to accelerate labor and birth (such as oxytocin augmentation or cesarean section) before this threshold is not recommended, provided that fetal and maternal conditions are reassuring. +8. Routine clinical pelvimetry on admission in labor is not recommended for healthy pregnant women. + +9. Auscultation using a Doppler ultrasound device or Pinard fetal stethoscope is recommended for the assessment of fetal wellbeing on labor admission. + +10. Routine perineal/pubic shaving prior to giving vaginal birth is not recommended. +11. Administration of an enema for reducing the use of labor augmentation is not recommended. +12. Digital vaginal examination at interval of 4 hours is recommended for routine assessment of active first stage of labor in low-risk women. +13. Continuous cardiotocography is not recommended for assessment of fetal wellbeing in healthy pregnant women undergoing spontaneous labor. +Contd... + + +Contd... + +Care option (selected) +Intermittent fetal heart rate auscultation +Epidural analgesia for pain relief +Opioid analgesia for pain relief +Relaxation techniques for pain management + +Manual techniques for pain management +Oral fluid and food +Maternal morbidity and position +Early amniotomy and oxytocin +Antispasmodic agents Second stage of labor +Definition and duration of the second stage of labor + + + +Birth position (for women with or without epidural) +Method of pushing + +Techniques for preventing perinea! trauma +Episiotomy policy Fundal pressure + +Third stage of labor +Prophylactic uterotonics + +Chapter 13: Normal Labor + + +Recommendation status +14. Intermittent auscultation of the fetal heart rate with either a Doppler ultrasound device or Pinard fetal stethoscope is recommended for healthy pregnant women in labor. +15. Epidural analgesia is recommended for healthy pregnant women requesting pain relief during labor. This depends on a woman's preferences. +16. Parenteral opioids, such as fentanyl, diamorphine and pethidine, are recommended options for healthy pregnant women requesting pain relief during labor. This depends on a woman's preferences. +17. Relaxation techniques such as including progressive muscle relaxation, breathings, music, mindfulness and other techniques are recommended for healthy pregnant women requesting pain relief during labor. This depends on a woman's preferences. +18. Manual techniques, such as massage or application of warm packs, are recommended for healthy pregnant women requesting pain relief during labor. This depends on a woman's preferences. +19. For women at low risk, oral fluid and food intake during labor are recommended. +20. Encouraging the adoption of mobility and an upright position during labor in women at low risk is recommended. +21. The use of early amniotomy with early oxytocin augmentation for prevention of delay in labor is not recommended. +22. The use of antispasmodic agents for prevention of delay prevention of delay in labor is not recommended. + + +23. The use of the following definition and duration of the second stage of labor is recommended for practice: • The second stage is the period of time between full cervical dilatation and birth of the baby, during +which the woman has an involuntary urge to bear down, as a result of expulsive uterine contractions. • Women should be informed that the duration of the second stage varies from one woman to another. +In first labors, birth is usually completed within 3 hours whereas in subsequent labors, birth is usually completed within 2 hours. +For women with or without epidural analgesia, encouraging the adoption of a birth position of the individual woman choice, including upright positions, is recommended. +24. +25. Women in the expulsive phase of the second stage of labor should be encouraged and supported to follow their own urge to push. This is recommended. +26. For women in the second stage of labor, techniques to reduce perinea! trauma and facilitate spontaneous birth (including perinea! massage, warm compresses and a "hands on" guarding of the perineum) are recommended, based on a woman's preferences and options available to her. +27. Routine or liberal use of episiotomy is not recommended for women undergoing spontaneous vaginal birth. +28. Application of manual fundal pressure to facilitate childbirth during the second stage of labor is not recommended. + + +29. The use of uterotonics for the prevention of postpartum hemorrhage (PPH) during the third stage of labor is recommended for all births. +30. Oxytocin (10 IU, IM/IV) is the recommended uterotonic drug for the prevention of postpartum hemorrhage (PPH). + + + + + + +Delayed umbilical cord clamping +Controlled cord traction (CCT) +Uterine massage + +31. In settings where oxytocin is unavailable, the use of other injectable uterotonics (if appropriate, ergometrine/methylergometrine, or the fixed drug combination of oxytocin and ergometrine) or oral misoprostol (600 µg) is recommended. +32. Delayed umbilical cord clamping (not earlier than 1 minute after birth) is recommended for improved maternal and infant health and nutrition outcomes. +33. In settings where skilled birth attendants are available, CCT is recommended. + +Sustained uterine massage is not recommended as an intervention to prevent postpartum hemorrhage in women who have received prophylactic oxytocin. +34. +Contd... +ID Chapter 13: Normal Labor + +Contd... +Care option (selected) Care of the newborn +Routine nasal or oral suction +Skin-to-skin contact + +Breastfeeding + + +Recommendation status + +35. Suctioning of the mouth and nose should not be performed in the case of neonates born through clear amniotic fluid who start breathing on their own after birth. It is not recommended. +36. Newborns without complications should be kept in skin-to-skin contact with their mothers during the first hour after birth to prevent hypothermia and promote breastfeeding. This is recommended. +37. All newborns, including low birth-weight babies who are able to breastfed, should be put to the breast as soon as possible after birth when they are both clinically stable, and the mother and baby are ready. This is recommended. + +Care of the women after birth + +Uterine tonus assessment +Routine postpartum maternal assessment + + +Discharge following uncomplicated vaginal birth + +38. Postpartum abdominal uterine tonus assessment for early identification of uterine atony is recommended for all women. +39. All postpartum women should have regular assessment of vaginal bleeding, uterine contraction, fundal height, temperature and heart rate (pulse) routinely during the first 24 hours starting from the first hour after birth. Blood pressure should be measured shortly after birth, if normal, the second blood pressure measurement should be taken within 6 hours. Urine void should be documented within 6 hours. This is recommended. +40. After an uncomplicated vaginal birth in a healthcare facility, healthy mothers and newborns should receive care in the facility for at least 24 hours after birth. This is recommended. + +Source: World Health Organization; 2020 + + +Normal Puerperium + + + +CHAPTER + + + + +❖ Involution of the Uterus +❖ Involution of Other Pelvic Structures ► Lochia + + +❖ General Physiological Changes ❖ Lactation +► Physiology of Lactation + + +❖ Management of Normal Puerperium ❖ Management of Ailments +❖ Postnatal Care + + + + +DEFINITION: Puerperium is the period following child­ birth during which the body tissues, especially the pelvic organs revert back approximately to the pre­ pregnant state both anatomically and physiologically. The retrogressive changes are mostly confined to the reproductive organs with the exception of the mammary glands which in fact show features of activity. Involution is the process whereby the genital organs revert back approximately to the state as they were before pregnancy. The woman is termed as a puerpera. +DURATION: Puerperium begins as soon as the placenta is expelled and lasts for approximately 6 weeks when the uterus regresses almost to the nonpregnant size. The period is arbitrarily divided into: (a) immediate-within 24 hours, (b) early-up to 7 days and (c) remote-up to 6 weeks. Similar changes occur following abortion but takes a shorter period for the involution to complete. +Fourth trimester is the time from delivery until complete physiological involution and psychological adjustment. + +INVOLUTION OF THE UTERUS +ANATOMICAL CONSIDERATION +Uterus: Immediately following delivery, the uterus becomes firm and retract with alternate hardening and softening. The uterus measures about 20 x 12 x 7.5 cm3 (length, breadth and thickness) and weighs about 1,000 g (Fig. 14.1). At the end of 6 weeks, its measurement is almost similar to that of the nonpregnant state and weighs about 60 g. The decrease in size of the uterus and cervix has been shown with serial USG or MRI (Fig. 14.2). The placental site contracts rapidly. Immediately after the delivery, hemostasis is achieved by arterial wall smooth muscle contraction, compression and constriction of vessels by the involuting myometrial fibers (living ligature) and other mechanisms are-formation of thrombus and vessel wall hyalinization. + + + + + + + + + + + + + + + + + +Fig. 14.1: Sagittal section showing uterus 5 days after delivery. + + + + + + + + + + + + + + + + + + + + + +Fig. 14.2: MRl-sagittal view of the uterus and cervix showing large size and thick walls after 6 days of delivery. +Chapter 14: Normal Puerperium + + + + + + + + +First day +.__ +Secon d day--+- - - -=----Third day ,.. +Fifth day Seventh day Tenth day + + + + + + + +Fig. 14.3: Clinical assessment of rate of involution by noting the height of the fundus in relation to symphysis pubis. + +Lower uterine segment: Immediately following delive1y, the lower segment becomes thin and flabby. It takes a few weeks to revert back to the normal shape and size of the isthmus. +Cervix: The cervix contracts slowly; the external os admits two fingers for a few days but by the end of 1st week, narrows down to admit the tip of a finger only. The contour of the cervix takes a longer time to regain ( 6 weeks) and the external os never reverts back to the nulliparous state. + +PHYSIOLOGICAL CONSIDERATION +The physiological process of involution is most marked in the body of the uterus. Changes occur in the following components: (1) muscles, (2) blood vessels, (3) endo­ metrium. +Muscles: There is marked hypertrophy and hyperplasia of muscle fibers during pregnancy and the individual muscle fiber enlarges to the extent of 10 times in length and 5 times in breadth. During puerperium, the number of muscle fibers is not decreased, but there is substantial reduction of the myometrial cell size. Withdrawal of the steroid hormones, estrogen and progesterone, may lead to increase in the activity of the uterine collagenase and the release of proteolytic enzyme. Autolysis of the protoplasm occurs by the proteolytic enzyme with liberation of peptones which enter the bloodstream. These are excreted through the kidneys as urea and creatinine. The connective tissues also undergo the same type of degeneration. The conditions which favor involution are-(a) eficacy of the enzymatic action and (b) relative anoxia induced by effective contraction and retraction of the uterus. +Blood vessels: The changes of the blood vessels are pronounced at the placental site. The arteries are + + + +constricted by contraction of its wall and thickening of the intima followed by thrombosis. During the 1st week, arteries undergo thrombosis, hyalinization and fibrinoid endarteritis. Veins are obliterated by thrombosis, hyalinization and endophlebitis. New blood vessels grow inside the thrombi. +Endometrium: Following delivery, the major part of the decidua is cast off. The endometrium left behind varies in thickness from 2 to 5 mm. The superficial part containing the degenerated decidua, blood cells and bits of fetal membranes becomes necrotic and is cast off in the lochia. There is infiltration of polymorphs, lymphocytes over the decidua and the placental site. These act as an antibacterial barrier. Regeneration starts by 7th day. It occurs from the epithelium of the uterine gland mouths and interglandular stromal cells. Regeneration of the epithelium is completed by 10th day and the entire endometrium is restored by the day 16, except at the placental site where it takes about 6 weeks. +CLINICAL ASSESSMENT OF INVOLUTION +The rate of involution of the uterus can be assessed clinically by noting the height of the fundus of the +uterus in relation to the symphysis pubis (Fig. 14.3). The measurement should be taken carefully at a fixed time everyday, preferably by the same observer. Bladder must be emptied beforehand and preferably the bowel too, as the full bladder and the loaded bowel may raise the level of the fund us of the uterus. The uterus is to be centralized and with a measuring tape, the fundal height is measured above the symphysis pubis. Following delivery, the fundus lies about 13.5 cm (5 1/2") above the symphysis pubis. During the first 24 hours, the level remains constant; thereafter, there is a steady decrease in height by 1.25 cm (0.5") in 24 hours, so that by the end of 2nd week the uterus becomes a pelvic organ. The rate of involution thereafter slows down until by 6 weeks, the uterus becomes almost normal in size. +The involution may be affected adversely and is called subinvolution. Sometimes, the involution may be continued in women who are lactating so that the uterus may be smaller in size-superinvolution. The uterus, however, returns to normal size if the lactation is withheld. + +-. · INVOLUTION OF OTHER PELVIC STRUCTURES +Vagina: The distensible vagina, noticed soon after birth takes a long time (6-10 weeks) to involute. It regains its tone but never to the virginal state. Rugae partially reappear at 3rd week but never to the same degree as in prepregnant state. Introitus remains permanently larger than the virginal state. Hymen is lacerated and is represented by nodular tags-the carunculae myrtiformes. +Broad ligaments and round ligaments require consi­ derable time to recover from the stretching and laxation. +Chapter 14: Normal Puerperium II + +Pelvic floor and pelvic fascia take a long time to involute from the stretching effect during parturition. +I LOCHIA + +It is the vaginal discharge for the first fortnight during puerperium. The discharge originates from the uterine body, cervix and vagina. +Odor and reaction: It has got a peculiar offensive fishy smell. Its reaction is alkaline, tending to become acid toward the end. +Color: Depending upon the variation of the color of the discharge, it is named as: (1) lochia rubra (red) 1-4 days, (2) lochia serosa (5-9 days)-the color is yellowish or pink or pale brownish, (3) lochia alba (pale white) 10-15 days. +Composition: Lochia rubra consists of blood, shreds of fetal membranes and decidua, vernix caseosa, lanugo and meconium. +Lochia serosa consists of less RBC but more leukocytes, wound exudate, mucus from the cervix and microorganisms (anaerobic streptococci and staphylococci). The presence of bacteria is not pathognomonic unless associated with clinical signs of sepsis. +Lochia alba contains plenty of decidual cells, leukocytes, mucus, cholesterin crystals, fatty and granular epithelial cells and microorganisms. +Amount: The average amount of discharge for the first 5-6 days is estimated to be 250 mL. +Normal duration: The normal duration may extend up to 3 weeks. +Clinical importance: The character of the lochial discharge gives useful information about the abnormal puerperal state. The vulva! pads are to be inspected daily to get information of: " Odor: If malodorous-indicates infection. Retained +plug or cotton piece inside the vagina should be kept in mind. +" Amount: Scanty or absent-signifies infection or loch­ iometra. If excessive-indicates infection. +11 Color: Persistence of red color beyond the normal limit signifies subinvolution or retained bits of conceptus. +" Duration: Duration of the lochia alba beyond 3 weeks suggests local genital lesion. + +GENERAL PHYSIOLOGICAL CHANGES +PULSE: For few hours after normal delivery, the pulse rate is likely to be raised, which settles down to normal during the second day. +TEMPERATURE: The temperature should not be above 37.2°C (99°F) within the first 24 hours. There may be slight reactionary rise following delivery by 0.5°F but comes down to normal within 12 hours. On the 3rd day, there may be slight rise of temperature due to breast engorgement which should not last for more than 24 hours. However, genitourinary tract infection should be excluded if there is rise of temperature (p. 407). + +URINARY TRACT: The bladder mucosa becomes edematous and hyperemic and often shows evidences of submucous extravasation of blood. The bladder capacity is increased. The bladder may be overdistended without any desire to pass urine. The common urinary problems are: overdistention, incomplete emptying and presence of residual urine. Urinary stasis is seen in more than 50% of women. The risk of urinary tract infection is, therefore, high. Dilated ureters and renal pelvis return to normal size within 8 weeks. There is pronounced diuresis on the 2nd or 3rd day of the puerperium. Only 'clean catch' sample of urine should be collected and sent for examination and contamination with lochia should be avoided. Urinary incontinence is a significant problem in the postpartum period (see below). +GASTROINTESTINAL TRACT: Increased thirst in early puerperium is due to loss of fluid during labor, in lochia, diuresis and perspiration. Constipation is a common problem. +WEIGHT LOSS: In addition to the weight loss (5-6 kg) as a consequence of the expulsion of the fetus, placentae, liquor and blood loss, a further loss of about 2 kg (4.4 lb) occurs during puerperium chiefly caused by diuresis. This weight loss may continue up to 6 months of delivery. +URINARY TRACT AND RENAL FUNCTION: In relation to changes in pregnancy persistence of urinary stasis in the ureters and bladder is observed even up to 12 weeks postpartum. Glomerular filtration returns to normal by 8 weeks postpartum. An overall increase in diuresis of the expanded water volume occurs in postpartum. Increased GFR in pregnant state returns normal by 8 weeks. Due to this significant physiologic adaptations of pregnancy drug dose need to be readjusted at 4-6 weeks postpartum. +FLUID LOSS: There is a net fluid loss of at least 2 liters during the 1st week and an additional 1.5 liters during the next 5 weeks. The amount of loss depends on the amount retained during pregnancy, dehydration during labor and blood loss during delivery. The loss of salt and water are larger in women with pre-eclampsia and eclampsia. +BLOOD VALUES: Immediately following delivery, there is slight decrease of blood volume due to blood loss and dehydration. Blood volume returns to nonpregnant level by the 2nd week. Cardiac output rises soon after delivery to about 80% above the prelabor value but slowly returns to normal within 1 week. +RBC volume and hematocrit values returns to normal by 8 weeks postpartum after the hydremia disappears. Leukocytosis to the extent of 25,000/mm3 occurs following delivery probably in response to stress of labor. Platelet count decreases soon after the separation of the placenta but secondary elevation occurs, with increase in platelet adhesiveness between 4 and 10 days. Fibrinogen level remains high up to +Chapter 14: Normal Puerperium +:,Table +"'','4,1 · +Per +ofo t· +anff +b e; s +of + ---- +. i & + +Flowchart 14.1: Scheme of mechanism of amenorrhea and anovulation in lactating mothers. + + +Breastfeeding + + + +Increased serum prolactin levels (>50 ng/ml) + + +Suckling** +■ Frequency (>8/24 hours) lntenslty +■ +■ Duration + + + + +Inhibits ovarian response to FSH + +Less follicular growth +l + +Hypoestrogenic state +l +/ No menstruation I + + +Suppresses the release of LH -J, GnRH secretion +l + + +No LH surge + + + +Anovulation + + +** Increased frequency, intensity and duration of suckling is associated with high prolactin level, prolonged ovarian suppression and lactational amenorrhea. + + + +the 2nd week of puerperium. A hypercoagulable state persists for 48 hours postpartum and fibrinolytic activity is enhanced in first 4 days. The secondary increase in fibrinogen, factor VIII and platelets in the 1st week increases the risk for thrombosis. The increase in fibrinolytic activity after delivery acts as a protective mechanism. + +OVARIAN FUNCTION (MENSTRUATION AND OVULA­ TION): The onset of the first menstrual period following delivery is very variable and depends on lactation. If woman does not breastfeed her baby, menstruation returns by 12th week following delivery in 80% of cases. The meantime for onset of first menstruation is 7-9 weeks (Flowchart 14.1). +In nonlactating mothers, ovulation may occur as early as 4 weeks and in lactating mothers about 10 weeks after delivery. Duration of anovulation depends upon the frequency (>8/24 hours), intensity and duration of breastfeeding. The physiological basis of anovulation and amenorrhea is due to elevated levels of serum prolactin associated with suckling. In lactating mothers the mechanism of amenorrhea and anovulation are depicted in Flowchart 14.1. Women who are exclusively breastfeeding, the contraceptive protection is about 98% up to 6 months of postpartum. Thus, lactation provides a natural method of contraception. After 6 months, the woman needs contraception even if she is breastfeeding. However, ovulation may precede the first menstrual period in about one-third and it is possible for the patient to become pregnant before she menstruates following her confinement. Nonlactating mother should use contraceptive measures in 3rd postpartum week and the +lactating mother in 3rd postpartum month. + + --• ·~" ""'"'- "'-- - "... enta' {e om'positlori' c, s't. ui "' · ,., ... . .;. t •milk:-, Protein Fat Carbohydrate Water +Colostrum 8.6 2.3 3.2 86 Breast milk 1.2 4.2 7.5 87 + +THYROID FUNCTION: Thyroid volume regresses gradually to prepregnant state by 12 weeks of time. Thyroid functions return to normal by 4 weeks postpartum. Women on thyroid medications should get their thyroid function checked to readjust the drugs. + +LACTATION + +For the first 2 days following delivery, no further anatomic changes in the breasts occur. The secretion from the breasts called colostrum, which starts during pregnancy becomes more abundant during the period. + +COMPOSITION OF THE COLOSTRUM: It is deep yellow serous fluid, alkaline in reaction. It has got a higher specific gravity; a high protein, vitamin A, sodium and chloride content but has got lower carbohydrate, fat and potassium than the breast milk (Table 14.1). Colostrum and milk contain immunologic components such as immunoglobulin A (IgA), complements, antibodies, macrophages, lymphocytes, antibacterial products, lactoferrin and other enzymes (lactoperoxidase). +Microscopically: It contains fat globules, colostrum corpuscles and acinar epithelial cells. The colostrum corpuscles are large polynuclear leukocytes, oval or round in shape containing numerous fat globules. +Advantages: (1) The antibodies (IgA, IgG, IgM) and humoral factors (lactoferrin) provides immunological defense to the newborn. (2) It has laxative action on the +Chapter 14: Normal Puerperium ., + + +baby because of large fat globules. (3) It reduces allergic disease. +I PHYSIOLOGY OF LACTATION +Although lactation starts following delivery, the preparation for effective lactation starts during pregnancy. The physiological basis of lactation is divided into four phases: +1. Preparation of breasts (mammogenesis). +2. Synthesis and secretion from the breast alveoli (lactogenesis). +3. Ejection of milk (galactokinesis). +4. Maintenance of lactation (galactopoiesis). +The endocrine control in relation to different phases of lactation has been depicted in Figure 6.2. +• Mammogenesis: Pregnancy is associated with remark­ able growth of both ductal and lobuloalveolar systems. An intact nerve supply is not essential for the growth of mammary glands during pregnancy. +♦ Lactogenesis: The alveolar cells are the principal sites for production of milk. Though some secretory activity is evident (colostrum) during pregnancy and accelerated following delivery, milk secretion actually starts on 3rd or 4th postpartum day. Around this time, the breasts become engorged, tense, tender and feel warm. In spite of a high prolactin level during pregnancy, milk secretion is kept in abeyance. Probably, steroids-estrogen and progesterone circulating during pregnancy make the breast tissues unresponsive to prolactin. When the estrogen and progesterone are withdrawn following delivery, prolactin begins its milk secretory activity in previously fully developed mammary glands. Prolactin, insulin, growth hormone and glucocorticoids are the impo­ rtant hormones in this stage. The secretory activity is also enhanced directly or indirectly by growth hormone, thyroxine and insulin. For milk secretion to occur, nursing effort is not essential. +♦ Galactokinesis: Oxytocin is the major galactoki­ netic hormone. Discharge of milk from the mam­ mary glands depends not only on the suction exerted by the baby during suckling but also on the contrac­ tile mechanism which expresses the milk from the alveoli into the ducts. +♦ Prolactin and oxytocin: Both affects the function of breast target cells. Prolactin stimulates alveolar epithelium to secrete milk and oxytocin stimulates the myoepithelial cells that surrounds the alveolar epithelium to contract and to eject the milk from the acini to the duct. +DURING SUCKLING, A CONDITIONED REFLEX IS SETUP (Fig. 14.4): The ascending tackle impulses from the nipple and areola pass via thoracic sensory ( 4, 5 and 6) afferent neural arc to the paraventricular and supraoptic nuclei of the hypothalamus to synthesize + + +and transport oxytocin to the posterior pituitary (Fig. 14.4). Oxytocin ( efferent arc via blood) is liberated from the posterior pituitary, produces contraction of the myoepithelial cells of the alveoli and the ducts containing the milk. This is the 'milk ejection' or 'milk let down' reflex whereby the milk is forced down into the ampulla of the lactiferous ducts, where from it can be expressed by the mother or sucked out by the baby. Presence of the infant or infant's cry can induce let down without suckling. A sensation of rise of pressure in the breasts by milk experienced by the mother at the beginning of sucking is called 'draught'. This can also be produced by injection of oxytocin. +The milk ejection reflex is inhibited by factors such as pain, anxiety, breast engorgement or adverse psychic condition (depression). The ejection reflex may be deficient for several days following initiation of milk secretion and results in breast engorgement. +• Galactopoiesis: Prolactin appears to be the single most important galactopoietic hormone. For maintenance of effective and continuous lactation, frequency of suckling (>8/24 hours) is essential. Distension of the alveoli by retained milk is due to failure of suckling. This causes decrease in milk secretion by the alveolar epithelium. Ductal and alveolar distension due to failure of milk transfer (suckling) is a cause of lactation failure. + +Cerebral cortex I + + + +Hypothalamus + +Ol +C I UI +C 0 +.Q Prolactin to alveolar cells +0 +E +_J, Mammar C glan +C + + +L uckling +milk + + + + + +Puerperal uterus +f +GI hormones involution +f GI motility + +Fig. 14.4: Lactation reflex arc and the role of prolactin and oxytocin. +m Chapter 14: Normal Puerperium +Milk pressure reduces the rate of production and hence periodic breastfeeding is necessmy. +MILK PRODUCTION: A healthy mother will produce about 500-800 mL of milk a day to feed her infant. This requires about 750 Kcal/day for the mother, which must be made up from diet or from her body store. For this purpose a store of about 5 kg of fat during pregnancy is essential to make up any nutritional deficit during lactation. +STIMULATION OF LACTATION: Mother is motivated as regard the benefits of breastfeeding since the early pregnancy. No prelacteal feeds (honey, water) are given to the infant. Following delivery important steps are: (i) to put the baby to the breast