Amaurosis Fugax

Eugene F. Bernstein Editor

Amaurosis Fugax

With 87 Figures, 3 in Full Color

Springer-Verlag New York Berlin Heidelberg

London Paris Tokyo

Eugene F. Bernstein, M.D., Ph.D. Division of Vascular and Thoracic Surgery Scripps Clinic and Research Foundation 10666 North Torrey Pines Road; Adjunct Professor of Surgery University of California, San Diego La Jolla, California 92037, USA

Library of Congress Cataloging-in-Publication Data Amaurosis fugax.

Includes bibliographies and index. I. Amaurosis fugax. I. Bernstein, Eugene F ..

1930- . [DNLM: I. Blindness. WW 276 A489] RE92.5.A43 1987 617.7'12 87-23517

ISBN-13: 978-1-4612-8345-4 e-ISBN-13: 978-1-4612-3776-1 DOl: 10.1007/978-1-4612-3776-1

© 1988 by Springer-Verlag New York Inc.

Softcover reprint of the hardcover 1st edition 1988

All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer-Verlag, 175 Fifth Avenue, New York. NY 10010, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval. electronic adaptation. computer software. or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use of general descriptive names, trade names, trademarks. etc. in this pUblication, even if the former are not especially identified. is not to be taken as a sign that such names, as understood by the Trade Marks and Merchandise Marks Act. may accordingly be used freely by anyone. While the advice and information in this book are believed to be true and accurate at the date of going to press, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty. express or implied, with respect to the material contained herein.

Typeset by David E. Seham Associates, Metuchen, New Jersey.

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Preface

Amaurosis fugax, or "fleeting blindness," has been known as a clinical entity for hundreds of years (1). Since 1859, we also have understood that the phenomenon frequently is related to atheroembolic disease and that it is considered a classic manifestation of ocular transient ischemic attacks and a potential precursor to stroke. However, many questions about this syndrome have remained unanswered until quite recently, when a great deal of new information and thought has been directed to the subject.

Transient monocular blindness (TMB) is only one manifestation of a complicated syndrome of ocular, systemic, and cerebral diseases that may include some degree of monocular blindness. The duration of blindness varies from very brief (seconds) to complete and permanent. The per­manent type is referred to as ocular infarction or ocular stroke. Retinal infarction is the most severe degree of monocular blindness and usually is due to embolic occlusion of the central retinal artery or one of its branches. Varying types of arterial emboli have been described, including thrombus, cholesterol, platelets, and fibrin.

More information is now available concerning both ocular stroke from arterial disease and ischemic optic neuropathy as a result of reduced orbital blood flow to the optic nerves. Each of these entities is now known to be quite distinct, with a different underlying pathology and implications for diagnosis and treatment. Recent investigations that span the specialties of ophthalmology, neuro-ophthalmology, neurology, neurosurgery, and vascular surgery have resulted in a further appreciation of the complexities of this syndrome and have opened the doors to new questions.

The purpose of this volume is to collect and organize in a single source not only the contributions to knowledge that recently have been made by the dIverse medical specialties involved in the syndrome ofTMB but also to place in perspective that knowledge which is uncertain and those ques­tions that remain to be answered. To this end, this work represents an effort at dealing with a number of vexing questions. Why is the blindness episode transient? Why do some patients describe it as the descent of a curtain and others as a blur or a mist or a film? Why is the location of

vi Preface

the blind area variable, sometimes originating from the top or the side or the center of the eye? Is the curtain related to the size, location, or com­position of emboli? Is the duration of the symptoms important as long as they are completely reversed? Should the word "fleeting" be limited to a particularly short period of blindness?

Other questions deal with specific pathophysiologic aspects of the syn­drQme. Many patients report repeated episodes in the same eye or the same part of the eye. If the cause is embolic, why do these emboli take the same vascular pathway each time? How much information should we try to obtain about the composition of the emboli in a given patient? Should such information determine the type and degree of suggested treatment? What is the frequency of emboli from the heart, great vessels, carotid bifurcation, or intracranial internal carotid and more distal ophthalmic arterial branches? How can we distinguish between embolic and spastic conditions? Does spasm exist in either the ophthalmic or the retinal ar­teries? What should be done to distinguish intraocular from extraocular causes for this syndrome?

In addition to these questions about the pathophysiology and mechanism of disease, new information has become available from noninvasive di­agnostic laboratory techniques, precise angiographic studies, computerized tomography, magnetic resonance imaging, and positron emission tomog­raphy. What is the role of these techniques in the workup of the average patient with TMB? Is there a need for the development of ophthalmic blood flow tests or the use of ophthalmodynamometry? What form of angiographic studies is most appropriate for the workup of these patients? Does it require formal contrast studies or can digital subtraction angiog­raphy, either intravenous or intra-arterial, be used? Will the new tran­scranial Doppler equipment that can be focused accurately on many in­tracranial vessels be useful in the study of patients with TMB? Does it provide the potential for studying spasm in the ophthalmic artery or for monitoring embolic phenomena? These questions are dealt with in the succeeding chapters of this volume.

Finally, it is most important to try to place in perspective known in­formation about the natural history of this complex condition in comparison with available information about the results of both medical and surgical treatments for the disease. Although data on each of these areas are less complete than we would wish, it is clear that more knowledge than ever before has become available within the last few years on both the untreated and treated patient with various aspects of the amaurosis fugax syndrome. Unfortunately, much of the data from treated patients do not include syn­chronous controls. Nevertheless, our data base does permit some con­clusions to be drawn. Therefore, it seems quite reasonable to collect in a single volume the recent contributions of various investigators who have looked at this syndrome from their own special point of view and to try

Preface VII

to synthesize a common approach to the study, diagnosis, and treatment of patients with this disease.

The final chapter in this book is the collaborative work of this entire group of experts, who have attempted to create a Consensus Statement on amaurosis fugax at this time. This "position paper" includes some compromises from the individual points of view of some of the contrib­utors, but it appears to be a reasonable, practical guideline for both cli­nicians and investigators. It is also an effort to put into perspective those areas in which our current information base is deficient and in which new studies are necessary to help us understand and treat patients with TMB and complete the unraveling of this complex clinical syndrome.

Reference

1. Von Graefe A: Ueber Embolie der Arteria Centralis Retinae als Ursacht plotzlicher Erblindung. Albrecht von Graefes Arch Klin Exp Ophthalmol 1859; 5:136-157.

Preface

Contributors

Background

Contents

Arterial Anatomy of the Eye Sohan Singh Hayreh

2 Clinical Presentation and Differential Diagnosis of Amaurosis Fugax Jean-Claude Gautier

3 Neurologic Mechanisms of Visual Loss Louis R. Caplan

Pathophysiology

4 Angiography of Retinal and Choroid Vascular Disease Joseph B. Michelson and Mitchell H. Friedlaender

5 Visual Aspects of Extracranial Carotid Artery Disease Shirley H. Wray

6 Occlusion of the Central Retinal Artery Shirley H. Wray

7 Retinal Cholesterol Emboli and Retinal Stroke Peter J. Savino

8 Acute Ischemia of the Optic Nerve Sohan Singh Hayreh

v

Xlii

24

43

51

72

81

90

93

x Contents

9 Risk of Cerebrovascular Disease in Patients with Anterior Ischemic Optic Neuropathy 114 Peter J. Savino

10 Chronic Ocular Ischemia and Carotid Vascular Disease 118 John E. Carter

11 The Controversy of Venous Stasis Retinopathy Sohan Singh Hayreh

12 Role of Vascular Spasm and Ocular Migraine Donald J. Dalessio

13 Nonembolic Sources of Amaurosis Fugax Marjorie E. Seybold

Natural History

14 Natural History of Amaurosis Fugax Ralph W. Ross Russell

Workup

135

159

168

174

15 Noninvasive Vascular Examination in Amaurosis Fugax 183 Shirley M. Otis

16 Data from CT Scans: The Significance of Silent Cerebral Infarction and Atrophy 200 Andrew N. Nicolaides, K. Papadakis, M. Grigg, A. AI-Kutoubi, M.A. Williams, and D.F.S. Deacon

17 Angiography in Amaurosis Fugax 227 Michael J.G. Harrison

Therapy

18 Aspirin Trials in the United States 236 William S. Fields and Noreen A. Lemak

19 Antithrombotic Therapy in Patients with Transient Ischemic Attacks or Amaurosis Fugax 251 Laurence A. Harker

Contents xi

20 The Safety of Carotid Endarterectomy for Amaurosis Fugax 264 Nicolee C. Fode and Thoralf M. Sundt, Jr.

21 Long-Term Results of Surgical Therapy for Amaurosis Fugax 273 Daniel P. Connelly, Steven Okuhn, and William K. Ehrenfeld

Summary

22 Amaurosis Fugax: A Consensus Statement The Amaurosis Fugax Study Group

Index

286

303

Contributors

A. Al-Kutoubi. M.D .. F.R.C./ .. D.M.R.D .. Irvine Laboratory for Car­diovascular Investigation and Research, St. Mary's Hospital Medical School, London, UK

Henry J. M. Barnett. M.D .. Scientific Director, The John P. Roberts Re­search Institute, London, Ontario, Canada

Eugene F. Bernstein. M.D .. Ph.D .. Division of Vascular and Thoracic Surgery, Scripps Clinic and Research Foundation; and Adjunct Professor of Surgery, University of California, San Diego, School of Medicine, La Jolla, California, USA

Allan D. Callow. M.D .. Ph.D .. Professor, Department of Surgery, Tufts University / New England Medical Center, Boston, Massachusetts, USA

Louis R. Caplan. M.D., Professor and Chairman, Department of Neu­rology, Tufts University, Boston, Massachusetts, USA

John E. Carter, M.D., Assistant Professor, Division of Neurology and Ophthalmology, The University of Texas, San Antonio, San Antonio, Texas, USA

Daniel P. Connelly, M.D .. Department of Surgery, University of Cali­fornia. San Francisco. California. USA

Donald J. Dalessio. M.D .. Chairman, Department of Medicine. Scripps Clinic and Research Foundation, La Jolla, California, USA

D. F. S. Deacon, M.D., Irvine Laboratory for Cardiovascular Investigation and Research, St. Mary's Hospital and Medical School, London, UK

Ralph B. Dilley, M.D., Head, Division of Vascular and Thoracic Surgery, Scripps Clinic and Research Foundation, La Jolla, California, USA

xiv Contributors

J. Donald Easton, M.D ... Professor and Chairman, Department of Neu­rology, Brown University, Providence, Rhode Island, USA

William K. Ehrenfeld, M.D., Professor, Department of Surgery, University of California, San Francisco, San Francisco, California, USA

William S. Fields, M.D., Professor and Chairman, Department of Neuro­Oncology, The University of Texas System Cancer Center, Houston, Texas, USA

Nicolee C. Fode, R.N., M.S., Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, USA

Mitchell H. Friedlaender, M.D., Division of Ophthalmology, Scripps Clin­ic and Research Foundation, La Jolla, California, USA

Professeur Jean-Claude Gautier, Professor of Neurology, Chief, Service d' U rgenc' es Cere brovasculaires, Hopital de la Sal petri ere , Paris, France

M. Grigg, F.R.A.C.S., Irvine Laboratory for Cardiovascular Investigation and Research, S1. Mary's Hospital Medical School, London, UK

Laurence A. Harker, M.D., Director, Roon Research Center for Arter­iosclerosis and Thrombosis, Department of Basic and Clinical Research, Scripps Clinic and Research Foundation, La Jolla, California, USA

Michael J.G. Harrison, D.M., F.R.C.P., Francis and Renee Hock Director of Research, The Reta Lila Weston Institute of Neurological Studies, University of London, London, UK

Sohan S. Hayreh, M.D., Ph.D .. Professor of Ophthalmology, The Uni­versity of Iowa Hospitals and Clinics, Iowa City, Iowa, USA

William F. Hoyt, M.D., Professor of Neuro-Ophthalmology, Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, USA

Noreen A. Lemak, M.D., Department of Neuro-Oncology, The University of Texas System Cancer Center, Houston, Texas, USA

Joseph B. Michelson, M.D., Head, Division of Ophthalmology, Scripps Clinic and Research Foundation, La Jolla, California, USA

Jay P. Mohr, M.D., Sciarra Professor of Clinical Neurology, College of Physicians and Surgeons of Columbia University, New York, New York, USA

Contributors xv

Andrew N. Nicolaides, M.S., F.R.C.S., Honorary Consultant Cardio­vascular Surgeon, Professor of Vascular Surgery, St. Mary's Hospital Medical School, London, UK

K. Papadakis, M.D .. Irvine Laboratory for Cardiovascular Investigation and Research, St. Mary's Hospital Medical School, London, UK

Steven Okuhn, M.D., Department of Surgery, University of California, San Francisco, San Francisco, California, USA

Shirley M. Otis, M.D., Head, Division of Neurology, Scripps Clinic and Research Foundation, La Jolla, California, USA

Ralph W. Ross Russell, M.D., F.R.C.P., Professor of Neurology, Con­sultant Physician, St. Thomas Hospital Medical School, London, UK

Peter J. Savino, M.D., Director, Neuro-Ophthalmology Department, Wills Eye Institute, Philadelphia, Pennsylvania, USA

Marjorie E. Seybold, M.D., Divisions of Ophthalmology and Neurology, Scripps Clinic and Research Foundation, La Jolla, California, USA

Thora(f M. Sundt, Jr., M.D., Professor and Chairman, Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA

James F. Toole, M.D., Teagle Professor of Neurology, Wake Forest Uni­versity, Winston-Salem, North Carolina, USA

M. A. Williams, F.R.C.S., Irvine Laboratory for Cardiovascular Inves­tigation and Research, St. Mary's Hospital Medical School, London, UK

Shirley H. Wray, M.D., Ph.D., Associate Professor, Department of Neu­rology, Harvard Medical School, and Director, N eurovisual Unit, Mas­sachusetts General Hospital, Boston, Massachusetts, USA

FIGURE 6-1. Opacifica­tion of the retina and macula cherry red spot following occlusion of the central retinal artery.

FIGURE 8-2. Blood supply of the optic nerve head and retrolaminar optic nerve. For details, see p. 95.

C

s

PCA p

Normal

Color Plate

FIGURE 8-3. Blood supply of the optic nerve head and intraorbital optic nerve (right) and blood vessels on the surface of the optic disk and adjacent retina (left). For details, see p. 97.