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Shingles (Nerve Pain and Blistering, Crusty Eyelids)

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Shingles (Nerve Pain and Blistering, Crusty Eyelids) LARGE PRINT edition THE EYE BOOK A JOHNS HOPKINS PRESS HEALTH BOOK The Eye Book A Complete Guide to Eye Disorders and Health Gary H. Cassel, M.D. Michael D. Billig, O.D. Harry G. Randall, M.D. The Johns Hopkins University Press Baltimore & London Note to the Reader: This book is not meant to substitute for professional eye care, and decisions about treatment should not be based solely on its contents. In- stead, treatment must be developed in a dialogue between the individual and his or her eye care professional. Our book has been written to help with that di- alogue. © 1998 The Johns Hopkins University Press All rights reserved. First edition 1998 Large Print Edition 2000 Printed in the United States of America on acid-free paper 987654321 The Johns Hopkins University Press 2715 North Charles Street Baltimore, Maryland 21218-4363 www.press.jhu.edu -- Cassel, Gary H., 1953– The eye book : a complete guide to eye disorders and health / Gary H. Cassel, Michael D. Billig, Harry G. Randall.—Large print ed. p. cm. — (A Johns Hopkins Press health book) Includes bibliographical references and index. ISBN 0-8018-6520-4 (pbk. : alk. paper) 1. Eye—Diseases—Popular works. 2. Eye—Popular works. 3. Large type books. I. Billig, Michael D., 1956– II. Randall, Harry G., 1934– III. Title. IV. Series. RE51.C34 2001 617.7—dc21 00-055275 A catalog record for this book is available from the British Library. Illustrations by Jacqueline Schaffer A webpage for this book and an e-mail link to the authors are located within the Johns Hopkins University Press website at www. press.jhu.edu. This book is dedicated to all our patients, who over the years have helped us realize that caring is one of the most important aspects of eye care. Contents List of Figures ix Foreword,by Morton F. Goldberg, M.D., F.A.C.S. xii Preface xiv PART I Introduction 1. A Guide to the Adult Eye 3 2. How Our Vision Changes over Time 21 PART II Getting to 20/20 3. The Eye Exam 51 4. All about Eyeglasses 79 5. Contact Lenses: Everything You Need to Know 117 6. Refractive Surgery: Don’t Discard Those Spectacles Just Yet 174 PART III The Big Problems for Aging Eyes 7. Cataracts 191 8. Glaucoma, the “Silent Thief ” 244 9. Age-Related Macular Degeneration 291 viii / CONTENTS PART IV Other Eye Problems: Diagnosis and Treatment 10. The Eyelids 313 11. The Cornea 329 12. The Conjunctiva 342 13. The Complicated World of Tears 353 14. The Uvea: Iris, Ciliary Body, and Choroid 372 15. The Retina and Vitreous 378 16. The Optic Nerve 396 PART V Other Things You Need to Know 17. Eye Trauma and Emergencies 407 18. General Health Problems That Can Affect the Eyes 419 19. Coping with Low Vision 476 20. Common Medications That Affect the Eyes 492 APPENDIX A Guide to Eye Medications and Their Side Effects 505 Signs and Symptoms Index 538 General Index 546 Figures 1.1. Anatomy of the Eye 6 1.2. The Cornea, Iris, Pupil, and Lens 12 1.3. The Lens 12 1.4. Retina, Choroid, and Sclera, and Neural Connections in the Retina 14 1.5. The Retina 16 1.6. Eye Muscles 16 1.7. How We See 18 1.8. Crossover System between the Eyes and the Brain 19 2.1. Normal Eye, Nearsighted Eye, and Farsighted Eye 24 2.2. Astigmatism 28 2.3. Presbyopia 30 2.4. Binocular Fusion System 38 3.1. Slit Lamp Biomicroscope 62 3.2. Slit Lamp Biomicroscope with Applanation Tonometer 62 x/FIGURES 3.3. Visual Fields 67 3.4. Amsler Grid 68 4.1. Bifocals, Trifocals, and Progressive Addition Lenses 84 4.2. Eyeglass Adjustments 90 6.1. Radial Keratotomy 180 6.2. Nearsighted Eye before and after Radial Keratotomy 180 7.1. The Parts of the Lens 194 7.2. Types of Cataracts 194 7.3. Intracapsular Extraction 224 7.4. Extracapsular Extraction 224 7.5. Phacoemulsification 228 7.6. Incisions for Extracapsular Extraction and Phacoemulsification 228 8.1. Fluid and Gel Cavities in the Eye 248 8.2. The Path of Fluid Movement in the Eye 248 8.3. Closed-Angle Glaucoma 252 8.4. Open-Angle Glaucoma 252 8.5. Cupping of Optic Nerve Disc 260 8.6. Visual Field Loss from Glaucoma 264 8.7. Peripheral Iridectomy 282 8.8. Trabeculectomy 284 9.1. Macular Region 293 9.2. Dry Age-Related Macular Degeneration 296 9.3. Drusen of the Retina 296 9.4. Wet Age-Related Macular Degeneration and Distortion of Vision Caused by Disciform Scar 298 10.1. Chalazion 326 FIGURES /xi 12.1. Pinguecula 349 13.1. Tear Layers 354 13.2. Tear Gland and Ducts 354 15.1. Arteries and Veins in the Retina 385 15.2. Central Retinal Vein Blockage 388 18.1. Nonproliferative Diabetic Retinopathy 424 18.2. Intraretinal Microvascular Abnormalities (IRMA) 424 18.3. Macular Edema 425 18.4. Proliferative Diabetic Retinopathy 427 Foreword As the consumerism movement has flourished in the United States, so too has the need increased for more personal participation in health care decisions. Individ- ual responsibility for understanding one’s own health is an obvious component of this process. Numerous self- help periodicals and books have appeared to meet the growing demands of the public for health information of all kinds. Drs. Cassel and Randall, experienced community ophthalmologists and part-time faculty members of the Wilmer Eye Institute at Johns Hopkins, along with their respected colleague, Dr. Billig, now publish The Eye Book: A Complete Guide to Eye Disorders and Health within this educational framework. It is an exceptionally useful book for the public because it dispels myths and offers prac- tical guidelines in a very readable style. It covers the routine (for example, eyeglasses) and the serious (for ex- ample, macular degeneration). The authors are appro- FOREWORD / xiii priately cautious about recommending new, but un- proven, treatments. We are entering a golden age of knowledge about heretofore perplexing and sometimes blinding diseases, and futuristic techniques, ranging from optoelectronics to genetic engineering, promise bright prospects for our aging population. Medical and scientific institutions such as the Wilmer Institute at Johns Hopkins are ac- tively continuing the search for better treatment tech- niques; simultaneously, they continue their dedication to the clinical care of routine and complex eye disease as well as to the education of doctors and researchers—and the general public. For the good health of your own eyes and vision, I encourage you to read and consult this helpful book for information, and to seek the assistance of highly experienced eye care specialists for diagnosis and treatment. Morton F. Goldberg, .., .... Director, Wilmer Eye Institute The Johns Hopkins Medical Institutions Baltimore, Maryland Preface The eye, responsible for one of our most vital senses, is one of the most important organs in the body. When all is well, most of us take our eyes for granted. But as you no doubt know from experience, when your vision is blurred, or your eyes are itchy and watery, or it feels like there’s something “sticking” in there, it’s hard to con- centrate on anything but your eyes. When something’s not right with your eyes, then nothing’s right with the world. As eye care specialists, we devote our working hours to helping people with eye problems of all kinds. And we have written this book to help the many people who have such problems, or who are worried about their eyes or the eyes of someone they care about. It’s remarkable and humbling to consider how far the field of ophthalmology—the medical specialty covering the anatomy, functions, pathology, and treatment of the eye—has progressed over the last three decades, a period when we have seen our patients helped by innovations PREFACE /xv in every aspect of eye care that were unheard of only a short time ago. New antibiotics and medications, safer cataract surgery with shorter recovery time, better glau- coma treatments, refined surgical techniques for mend- ing retinal detachments and clearing vitreous hemor- rhages, and retinovitreous treatments—not to mention a revolution in lens-making materials and technology— have helped thousands of people to see better longer. In this book we describe all of these recent innova- tions and offer information and advice about what you and your eye doctor can do together to safeguard your vision, and your general health. We describe the eye’s anatomy and what changes occur naturally over time, as well as what changes are not natural and may be dan- gerous—and tell you what to do about them. We de- mystify the eye examination, describe how eyeglasses and contact lenses work (and how to tell what will work best for you), and take up the controversial vision-corrective surgery called refractive surgery. Cataracts, glaucoma, and age-related macular degen- eration are the three major diseases of the eye that rob older people of good vision. Knowing the signs and symptoms of these diseases and how to get proper check- ups and screening are crucial first steps; once the diag- nosis is made, treatment options must be weighed and decisions made. The three chapters in the second part of the book discuss each of these problems in detail. In part 4 of the book we continue the discussion of eye problems, beginning from the front of the eye, at the lids and lashes, and ending up at the back, with the optic xvi / PREFACE nerve. Explanations of problems ranging from the an- noying (“floaters and flashes,” for example, or a twitch- ing eyelid) to the more serious (uveitis, or arthritis of the eye) may be found here.
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