Basic Ophthalmology

512 Pages·2009·19.641 MB·English

by  Renu Jogi

Basic
Ophthalmology

Basic
Ophthalmology
FOURTH EDITION
Renu Jogi
MBBS MS
Ex Associate Professor
MGM Medical College, Indore (MP)
Pt. Jawahar Lal Nehru Memorial Medical College
Raipur, Chhattisgarh, India
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Basic Ophthalmology
© 2009, Renu Jogi
All rights reserved. No part of this publication should be reproduced, stored in a retrieval system, or transmitted in any form
or by any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the
author and the publisher.
This book has been published in good faith that the material provided by author is original. Every effort is made to ensure
accuracy of material, but the publisher, printer and author will not be held responsible for any inadvertent error(s). In
case of any dispute, all legal matters are to be settled under Delhi jurisdiction only.
First Edition: 1994
Second Edition:1999
Third Edition: 2003
Fourth Edition: 2009
ISBN 978-81-8448-451-9
Typeset at JPBMP typesetting unit
Printed at Ajanta Offset and Packagins Ltd., New Delhi
Dedicated to
our beloved
Anusha

Preface to the Fourth Edition
The eye is the lamp of the body. If your eyes are good, your whole body will be full of light.
The Bible
The need for a textbook for undergraduate medical students in ophthalmology dealing with the basic
concepts and recent advances has been felt for a long-time. Keeping in mind the changed curriculum
this book is intended primarily as a first step in commencing and continuing the study for the
fundamentals of ophthalmology which like all other branches of medical sciences, has taken giant
strides in the recent past.
While teaching the subject I have been struck by the avalanche of queries from the ever inquisitive
students and my effort therefore has been to let them find the answers to all their interrogatories.
It is said that revision is the best testimony to the success of a book. In the competitive market
of medical text publishing, only successful books survive.
Any textbook, more so, a medical one such as this, needs to be updated and revised from time
to time. Yet the very task of revising Basic Ophthalmology presents a dilemma: how does one
preserve the fundamental simplicity of the work while incorporating crucial but complex material
lucubrated from recent research, investigations and inquiries in this ever expanding field.
In essence, Basic Ophthalmology is both a ‘textbook’ and a ‘notebook’ that might as well have
been written in the student’s own hand. The idea is for the student to relate to the material; and
not merely to memorize it mechanically for reproducing it during an examination. It is something I
wish was available to me when I was an undergraduate student not too long ago.
The past few years have witnessed not only an alarming multiplication of information in the
field of ophthalmology, but more significantly, a definite paradigmatic shift in the focus and
direction of ophthalmic research and study. The dominant causes of visual disabilities are no
longer pathological or even genetic in nature, but instead a direct derivative and manifestation of
contemporary changes in predominantly modern urban lifestyles. The student will thus find a new
section devoted to a discussion on Visual Display Terminal Syndrome (VDTS) that is an outcome
of excessive exposure of the eyes to the computer monitor as well as the use of contact lenses.
Two additional sections deal with the Early Treatment for Diabetic Retinopathy Study (ETDRS)
classification and Scheie’s classification for hypertensive retinopathy that replaces the pre-existent
taxonomy prevalent for little less than seven decades. With posterior chamber intraocular lenses
establishing themselves as the primary modality in the optical rehabilitation of patients undergoing
cataract surgery, the emphasis has shifted from just visual rehabilitation to an early, perfect
optical, occupational and psychological rehabilitation.
When I initiated this project I scarcely realized that it only had toil, sweat and hard work to offer.
Whenever anyone reminded me that I was working hard, my answer always was; I am trying to create
something very enduring.
viii Basic Ophthalmology
To conclude, for me, this has really been a trabalho do coracao a phrase which does not have a
correct synonym in English but when literally translated from Portuguese would mean “a work of the
heart”. In truth, it is a vivid reflection of my long lasting concern and affection for my students.
All books are collaborative efforts and I would like to take this opportunity to thank all the people
who have advised and encouraged me in this project: specially my husband Shri Ajit Jogi, my son
Aishwarya, Amit and Dr Nidhi Pandey.
I offer special thanks to my publisher Shri JP Vij, Chairman and Managing Director of
M/s Jaypee Brothers Medical Publishers (P) Ltd., Mr Tarun Duneja, Director (Publishing) and his
staff namely Mrs Yashu Kapoor, Mr Manoj Pahuja, Mr Arun Sharma, Mr Akhilesh Kumar Dubey
and Mrs Seema Dogra.
By the grace of the Almighty God and with the continuing support of the teachers, I am happy
to present the fourth updated edition of my book.
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An eye can perceive forms,
it adorns the face;
it is a source of direct knowledge;
it is a guide to avoid wrong deeds;
hence the eye is most important
of all the sense organs.
Renu Jogi
Contents
1. Embryology and Anatomy................................................................................................ 1
2. Physiology of Vision.......................................................................................................... 9
3. Neurology of Vision .......................................................................................................... 15
4. Examination of the Eye .................................................................................................... 22
5. Errors of Refraction.......................................................................................................... 47
6. The Conjunctiva................................................................................................................ 71
7. The Cornea .......................................................................................................................107
8. The Sclera .........................................................................................................................153
9. The Uveal Tract ...............................................................................................................161
10. The Lens ...........................................................................................................................205
11. The Vitreous.....................................................................................................................246
12. Glaucoma...........................................................................................................................258
13. The Retina.........................................................................................................................300
14. The Optic Nerve ..............................................................................................................341
15. Injuries to the Eye ...........................................................................................................361
16. The Ocular Motility and Squint (Strabismus)..............................................................375
17. The Lids ............................................................................................................................403
18. The Lacrimal Apparatus .................................................................................................424
19. The Orbit...........................................................................................................................437
20. General Therapeutics......................................................................................................448
21. The Causes and Prevention of Blindness....................................................................458
22. Ophthalmic Instruments.................................................................................................469
Index...................................................................................................................................489