ince 1985, it has been my privilege to be the Director of The - ciety of Byron Smith Fellows. During the years in which Byron SSmith was with us, his former fellows would meet at the Ame- can Academy of Ophthalmology's annual meeting. They would present to him, and to one another, interesting cases of their own compli- tions that had occurred or cases that had been sent to them that were complications to be repaired. This forum provided the fellows with an excellent format for evaluating their own problems and also for d- cussing how to treat extremely difficult cases. Shortly after Dr. Brian Brazzo completed his fellowship with me in 1998, he asked if I thought it would be appropriate for him to edit a new book on complications of ophthalmic plastic surgery. Certainly, during his fellowship, it became apparent that Dr. Brazzo was pr- ably the most gifted academician and writer that I had ever had the pleasure of training and meeting. I could think of no one more - propriate to continue the work initiated by Dr. Byron Smith and c- ried on by his students.

The 4th International Visual Field Symposium of the International Perimetric Society, was held on the 13-16 April 1980 in Bristol, England, at the occasion of the 6th Congress of the European Society of Ophthalmology. The main themes of the symposium were comparison of classical perimetry with visual evoked response, comparison of classical perimetry with special psychophysi cal methods, and optic nerve pathology. Understandably many papers dealt with computer assisted perimetry. This rapidly developing subgroup of peri metry may radically change the future of our method of examination. New instruments were introduced, new and exciting software was proposed and the results of comparative investigations reported. There have been many confusing statements in the literature on the relative value of perimetry and the registration of visual evoked responses. Several reports attempted to bring some clarity in this issue. There is reason for further comparative research. A number of papers dealt with special psychophysical methods, i.e. methods not using the simply monocular differential threshold. The old critical fusion frequency received new attention. Fundusperimetry was used for testing spatial summation. Acuity perimetry, binocular perimetry etc. showed that there exist many possibilities for examining visual function. At present it is not clear to us what exactly the place of these methods is in our diagnostic armament. However it is quite clear that some of them are promising and may lead to a further differentiation of perimetric methods."

Forty-eight eyes with massive periretinal proliferation were examined with ultrasonography. In addition to the triangular retinal detachment T-sign was indicative of severe MPP. And irregular thickening and bending of the retina were observed on ultrasonography in eyes with MPP. The detached retina was immobile in all eyes. Preoperative ultrasonographic findings did not prove the value on the assessment of operative prognosis. REFERENCES Bronson, N.R. & Turner, F.T. A simple B-scan uitrasonoscope. Arch. Ophthalmol. 90: 237 (1973). Coleman, D.J., Koning, W.F. & Katz L.: A Hand-Operated ultrasound scan system for ophthalmic evaluation, Am. J. Ophthalmol. 68: 258 (1969). Fuller. D.G., Laqua, H. & Machemer, R. Ultrasonographic diagnosis of massive periretinal proliferation in eyes with opaque media (triangular retinal detachment). Am. J. Ophthalmol. 83: 460 (1977). Laqua, H. & Machemer, R. Glial cell proliferation in retinal detachment (massive periretinal proliferation). Am. 1. Ophthalmol. 80: 1 (1975). Laqua, H. & Machemer R. Oinical-pathological correlation in Massive periretinal proliferation. Am. J. Ophthalmol. 80: 912 (1975). Machemer, R. & Laqua, H. Pigment epithelial proliferation in retinal detachment (massive periretinal proliferation). Am. J. Ophthalmol. 80: 1 (1975). Machemer, R. & Laqua, H. A logical approach to the treatment of massive periretinal proliferation. Ophthalmology 85: 584 (1978). Machemer, R. Van Horn, D. & Aaberg, T.M. Pigment epithelial proliferation in human retinal detachment with massive periretinal proliferation, Machemer, R. Pathogenesis and classification of massive periretinal proliferation. Br. J. Ophthalmol. 62: 737 (1978).

The Conference on Subretinal Space, held between October 14 and 19, 1979, was organized to bring into the forefront some of the developments in basic and c1il')ical sciences in this field. Indeed the interaction between choroid, pigment epithelium and sensory retina in terms of the physical adherence between the tissues, transport of materials and changes produced by the growth of new vessels, fluid penetration, light damage, etc. are some of the outstanding ophthalmic problems of today. We hope that the proceedings of this Conference may be of some help in providing better understanding both of the subretinal space and of its boun daries. HANAN ZAUBERMAN, M.D. CONTENTS Preface, H. Zauberman v Basic problems related to sub retinal space The retinal circulation: past, present and future. The Fifth Abraham Albert Ticho Lecture, Paul Henkind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pathology of the sub-retinal space, Mark O. M. Tso ....... . 11 Proteins of the bovine interphotoreceptor matrix, Alice J. Adler & Katherine M. Severin 25 Pigment epithelium, retina junction and photoreceptor distribution in man and in the horse. Histological, ultrastructural and electrophy siologicai study, J. Franr;ois, V. Victoria-Troncoso, A. De Rouck, L. Wouters & A."

This book is based on the papers presented at the Workshop on "Rehabilitation of the Visually Impaired" held in Flo rence at the Institute for the Research on Electromagnetic Waves of the Italian Research Council on April 4-6, 1984. The Workshop, sponsored by the Committee for Medical and Public Health Research of the Commission of the European Communities, was meant to exchange ideas about the need, importance and feasibility of a European cooperation in the field of visual impairment and to identify promising research areas, where current national activities could take advantage of such a collaboration in order to increase their efficiency. In particular, it dealt with the develop ment and use of technical aids (mainly based on computers and signal processing techniques) and with the elaboration, evaluation and standardization of new methods and tests. The attendance was multidisciplinary, including researchers from the fields of technology, medicine and psychology and representatives from organizations involved in the rehabi litation of the visually impaired. Five technical sessions were organized, dealing with the following topics: automatic production of Braille and systems for paperless Braille, aids for reading and for the interaction with coded informa tion sources, low vision aids, transduction of visual infor mation into a tactile representation, mobility aids. Three different application sectors were mainly considered: education and culture, vocational training, mobility. A final session was devoted to a discussion in working groups. The results are briefly outlined in the following concise report of the Workshop.

Measurement of visual acuity has been the cornerstone of visual testing since Snellen began quantitating visual acuity using letter optotypes in the 1860s. Bjerrum in the 1880s brought sophistication and quantitation to the assessment of the visual field with tangent screen examination using differently sized and colored targets. Further advances in visual testing did not occur until the Goldmann perimeter and the Farnsworth Munsell 100 Hue test were introduced in the 1940s, permitting further refinement in the detection and quantitation of acquired visual loss. An explosion of interest in sensory visual function testing followed the demonstration by Quigley and his colleagues in 1982 that despite the loss of more than 40% of the axons in the optic nerve, Snellen acuity and kinetic perimetry remained normal. Much of this interest has focused on a search for more sensitive and disease-specific sensory visual tests. Previously, novel tests used to probe visual function remained in the province of the visual physiologist and psychophysicist. These tests are now being introduced by the ophthalmologist into clinical practice. Concomitantly, the mass production of microcomputers and other technical advances have made tests such as automated perimetry and visual evoked response testing affordable for most offices. The clinician is presently being inundated with a plethora of visual function tests that may require a knowledge of visual psychophysics and statistics to understand and interpret. The purpose of this book is to acquaint the clinician with these new tests so that they may be used to maximum benefit.

This book comprises the proceedings of the first meeting of the Internatio nal Society for Corneal Research, held in Kyoto on May 12 and 13, 1978, on the occasion of the International Congress of Ophthalmology. The Society was founded by Dr. Stuart I. Brown (USA), who has to be congratulated very sincerely for this idea. The cornea, window of the eye, becomes, indeed, more and more important and its diseases more and more frequent. Consequently, cornea research is of the greatest necessity not only to cure but also to prevent the various disorders of the membrane. The scientific program of the meeting, established by Dr. Brown, was outstanding. The limiting membranes, the epithelium as well as the endo thelium, the stroma, the corneal transplantation, as well as the graft rejec tion, the inflammations as well as the immunological aspects, were discussed by experts in the field. The meeting, which was conducted by Professor Motokazu Itoi, honorary Chairman, and successfully organized by his Japanese colleagues, Professor Nakajima, Professor Mishima and their staff, was as interesting as fruitful and left in our mind the best memory. I am convinced that the ophthalmologists will take a great interest in reading the various papers, which bring the latest advances in corneal patho logy. Prof. Jules Franyois President of the International Council of Ophthalmology."

Proceedings of the Seventh Symposium of the International Research Group on Colour Vision Deficiencies Held at Centre Medical Universitaire, Geneva, Switzerland, 23-25 June, 1983

The 5th International Visual Field Symposium of the International Peri metric Society was held on October 20-23, 1982, in Sacramento, California, before the joint meeting of the International Congress of Ophthalmology and the American Academy of Ophthalmology. A majority of the members of the International Perimetric Society took part in the meeting together with many guests. The topics of the symposium were: glaucoma: correlation between the visual field and the optic disc; the visual field in low-tension glaucoma; neuro-ophthalmology and ergo-perimetry. Apart from this there were many papers on automated perimetry and general topics. The papers concerning the correlation of optic disc and visual field dealt with several aspects: peripapillary atrophy, defects in the retinal nerve fiber layer, fluorescein angiography and the characteristics of the glaucomatous excavation itself. New and interesting findings were presented showing that the careful, detailed observation of the disc and peripapillary area is re warding. The visual fields in low-tension glaucoma were studied extensively by four groups. Various approaches to the problem have led to some differences in results, which were extensively discussed. In the general glaucoma session the visual fatigue phenomenon was dis cussed extensively; apparently conflicting results were demonstrated re garding the stability of contrast threshold measurements during one and the same test session in glaucoma. The relationship between the visual field and the performance at the working place was considered in the session on ergo-perimetry."

The authors of this book are busy practical men with no particular barrow to push. The text of the book includes a comprehensive review of all aspects of intraocular lens surgery including details of the design, optics chem istry and sterilization of intraocular lenses. Its value is enhanced by excellent illustrations and extensive tabulated references to the litera ture. Accounts of patient acceptability are balanced against candid discus sion of complications and their management. The historical introduction recalls that in the early stages of develop ment of the art, over a period of 10 years, two dozen different lens designs were proposed, most claiming elimination of problems which had arisen with their predecessors. Eventually nearly all disappeared from the scene. In an age where every cataract surgeon has to determine a personal position on intraocular lens implantation the author's reflections on these matters are timely. Intraocular lenses are neither a miracle nor a menace, provided that personal decisions and preferences are carefully thought through and put into practice upon the basis of known facts and not upon the basis of fickle fashion and fad. This book provides a background upon which the reader can eva luate in his own mind the validity of information provided by the manufacturers of various lens designs."

Numerous drugs administered either generally or locally have shown a cata- ractogenic action. From a pathogenic point of view a di,stinction must be made between drugs which modify the transparency of the lens due to accumulation (mer- curic,'silver, gold salts, etc.) from those influencing its metabolism. Among the latter, Triparanol, antimitotic drugs, various phenothiazinic derivates, corticosteroids and certain miotics cause the most significatn dam- age. It is necessary to indicate the most frequent reports which evidence a relationship between a prolonged oestroprogestinic therapy and alterations of the lens transparency. The authors also indicate pathogenic mechanisms which probably cause iatrogenic cataracts. REFERENCES Apponi G., Rinaldi E. & De Simone S. Cataratta monolaterale dopo iniezione endo- carotidea di 2-3-5 Trisetilenimmino 1-4 benzochinone (Trenimon Bayer). Ann. Ot- tal. 90, 224, 1964. Baron J.B., Morel P., Rivollan Y. & Soulairac A.: Incidences ophtalmologiques du traitement prolonge par la chloropromazine associee ou non Ii des troubles cutanes. Agressiologie, 9, (2) 293, 1968. Bryk E.: Generalized argyrosis with involvement oflenses. Klin. Oczna 26,217,1956. Conel E.B. & Kelman C.D.: Ophthalmologic findings with oral contraceptives. Obstet. Gynec. 31,456, 1968. Conklin, Upton & Christenberry & MC.Donald: Citato da Duke-Elder. Radiat. Res. 19, 156,1963. Davidson S.I.: Reported adversa effects of oral contraceptives on the eye. Trans. Oph- thai. Soc. U.K. 91,561,1971. De Long S.L.: Incidence and significance of chloropromazine-induced eye changes. Dis. Nerv. Syst. 29 (3), Suppl. 19, 1968.

The Theory of Binocular Vision is a book about neurological control theory. In this sense it was far ahead of its time, for the formal development of control theory was many decades in the future when this book appeared in 1868. Hering's principal concept is that the control of eye movements is greatly simplified if there is only one neurological control system commanding the 'double-eye' as a single organ. This idea leads directly to the first thorough exposition of what is now known as Hering's law, that the corresponding muscles of the two eyes are always equally innervated. As Hering eloquently states it, "one and the same impulse of will directs both eyes simultaneously as one can direct a pair of horses with single reins" (Ch. 2). The 19th Century The book was written during an exciting era for physiological research. Before the mid-19th century the study of physiology had been limited to isolated efforts by great men who worked largely without colleagues or organized laboratories. Now for the first time of inquiry, with many sensory physiology was becoming a living field groups working simultaneously on fundamental problems. Like the classical Greeks before them in philosophy, the physiologists of the 19th century were defining in a burst of creative energy the problems 1 2 Introduction which would shape subsequent inquiry; and like the Greeks, they produced a splendid period of science.

The proceedings of this symposium on Medical Therapy in Glaucoma are divided in four major parts. The pharmacological introduction gives the reader a short description of factors that are involved between administration of the drug and its action at the desired position in the eye. The new and exciting field of drug delivery systems will be dealt with in this part and part II. Originally we had asked Ken Richardson to give part of the lectures on Membrane technology and basic aspects of cholinergic action. Unfortu nately at the last moment he could not come. Our thanks go to Gavin Paterson and Klaus Heilmann who were willing to take over a part of his job. Part II on cholinergic action offers next to the well-known drugs infor mation about Ocusert. Part III covers the new developments in the adrenergic field, including guanethidine and atenolol. The clinical aspects of medical therapy in glaucoma are covered by Part IV. Many subjects could not be handled. We left out the systemic treatment of glaucoma (diamox, mannitol etc.). We left out all special cases and prob lem cases. Some questions could be answered during the round table discus sion, most remained unanswered. It is clear that there is enough subject-mat ter and interest for another symposium on therapy of glaucoma."

This text was designed for the physicians, nurses, technical personnel, and staff members of medical facilities using lasers for surgical, therapeutic, and diagnostic purposes. The objective is to provide an understanding of the potential health and safety hazards associated with the use of medical laser systems and the precautions needed to use them safely. To do this, it is necessary to have an awareness of applicable standargs and regula tions that apply to laser use. This book is not intended as a substitute for the American National Standards Institute (ANSI) Z-136. 3, "Safe Use of Lasers in Health Care Facilities," but to facilitate its implementation as well as the implementation of the many other related regulations and guidelines that are pertinent. These other regulations include the Medical Device Amendments to the Food and Drug Act, the Federal Laser Product Performance Standards issued under the Radiation Control for Health and Safety Act, and applicable regulations of the Occupational Safety and Health Administration (OSHA). The text is organized to provide first an overview of laser hazards, laser surgical applications, and laser biological effects. General safety control measures and safety standards are then presented. Because laser tech nology is rapidly evolving, these general guidelines will allow safe use of new laser systems as they become available. Finally, specific safety guide lines and precautions are provided for specialized laser applications in the different health care specialties."

Curbside Consultation in Cataract Surgery: 49 Clinical Questions has been updated into a Second Edition! The Second Edition contains new questions and is completely updated! Curbside Consultation in Cataract Surgery, Second Edition contains new questions and brief, practical, and evidence-based answers to the most frequently asked questions that are posed during a "curbside consultation" between surgical colleagues. Dr. Terry Kim and associate editors Drs. Derek Delmonte and Preeya Gupta have assembled 49 of the top cataract consultants from the U.S. and abroad to offer expert advice, preferences, and opinions on tough clinical questions commonly associated with cataract surgery in this updated reference. The unique Q&A format provides quick access to current information related to cataract surgery in the simplicity of a conversation between two colleagues. Numerous images, diagrams, and references are included to enhance the text and to illustrate surgical pearls. Some of the questions that are answered inside the Second Edition include: My patient has unreliable topography due to ocular surface pathology. What are my options for treatment and IOL selection? How do I pick the right IOL formula for my patient with a longer/shorter than average eye? My capsulorhexis is heading out peripherally. How should I proceed and what should I do if it tears radially? How/when should I change my phaco/fluidics settings in the following situations: IFIS, shallow chamber, high axial length, post vitrectomy? I have a radial tear in the anterior capsule. How do I proceed with phaco and IOL implantation? When should I use a toric intraocular lens versus astigmatic keratotomy/LRI? How do I incorporate femtosecond (FS) laser into my current cataract surgery techniques? Curbside Consultation in Cataract Surgery: 49 Clinical Questions, Second Edition provides information basic enough for residents while also incorporating expert pearls that even experienced cataract surgeons will appreciate. General ophthalmologists, residents, and cataract specialists alike will benefit from the user-friendly and casual format as well as the expert advice contained within.

Proceedings of the Ninth symposium of the International Research Group on Colour Vision Deficiencies, held at St. John's College, Annapolis, MD, July 1-3, 1987.

The eye has fascinated scientists from the earliest days of biological in vestigation. The diversity of its parts and the precision of their interaction make it a favorite model system for a variety of developmental studies. The eye is a particularly valuable experimental system not only because its tissues provide examples of fundamental processes, but also because it is a prominent and easily accessible structure at very early embryonic ages. In order to provide an open forum for investigators working on all aspects of ocular development, a series of symposia on ocular and visual devel opment was initiated in 1973. A major objective of the symposia has been to foster communication between the basic research worker and the clinical community. It is our feeling that much can be learned on both sides from this interaction. The idea for an informal meeting allowing maximum ex change of ideas originated with Dr. Leon Candeub, who supplied the nec essary driving force that made the series a reality. Each symposium has concentrated on a different aspect of ocular development. Speakers have been selected to approach related topics from different perspectives."

The three most striking characteristics of the cornea are: a) Its structure or rather its perfectly regular architectonic, by virtue of which it is transparent. b) The absence of vessels, the cornea being nourished by the perilimbic vessels, the endothelial surface in communication with the aqueous humour and the epithelial surface in contact with the pre-corneal film. c) The very slow turnover of the cells, that is to say the keratocytes, with the result that the metabolism of the cornea is very weak. It is this third characteristic which justifies our present investigation. The keratocytes, which are apparently inactive, have in fact a latent activity. They can be activated by central corneal incisions and also by tissue cultures. Under either of those conditions, the keratocytes become very active, develop all the cytoplasmic organites and produce mucopoly saccharides as well as the precursors of the collagen (Fig. 1). In order to study the pathological keratocyte, we chose a storage disease, wherein the catabolism of the mucopolysaccharides is blocked, namely the macular dystrophy of the cornea. We undertook the same investigation both for normal and for pathologi cal corneas and studied the keratocyte 'in situ' and in tissue cultures using various microscopical and histochemical techniques. In macular dystrophy, we investigated also the deteriorations secondary to the changes in the keratocytes."

This volume is a collection of essays which attempts to summarize the recent progress in the field of photoreceptor and retinal physiology. Reflecting the way in which research is organized, each author reports on the studies performed with the techniques with which he is most familiar: morpholo gical, chemical or physiological. The first chapters describe the structure of visual cells and the histological architecture of the retina. Next comes a summary of the laws governing photochemical reactions and a report on the biochemistry of photopigments. Four articles cover the optical properties of invertebrate eyes and the electrophysiology and the interactions of their photoreceptors. These are followed by a discussion of the properties of vertebrate eyes, including chapters on optics, on the electrical responses of rods and cones and on the functional organization of the retina. The final chapter provides an extensive review of retinal biochemistry and metabolism. Even though the experimental approach differs, all studies are directed toward the solution of two basic problems: transduction in the photoreceptors and orga nization (often called "information processing") in the retina. The central problem of photoreceptor cells is to determine how light produces a response. We know that illumination evokes electrical changes and we have recently learned a great deal about the features of these changes. The evidence indicates however that elaborate processes must be interposed between the ab sorption of photons by the pigment and the production of electric currents through the membrane. These intermediary cvents remain to be unraveled."

The HF A is a computerized perimeter with a very comprehensive set of test point patterns, strategies and custom tests. The instrument employs several solutions which have proved useful in earlier computerized perimeters and several new concepts. The construction with stimulus generation through a projection system, input through a CRT, programmes stored in PROMs and a double disc drive for storage of test results makes it simple to adapt the instrument to future needs, whether these are new test algorithms or point patterns, different input or display screens or new statistical analysis programmes. All these changes could be made without modification of actual instrument hardware. REFERENCES 1. Dannheim, F. and Drance, S.M. Psycho visual disturbances in glaucoma. A study of temporal and spatial summation. Arch. Ophthalmol. 91: 463 -468 (1974). 2. Fankhauser, F. and Hiiberlin, H. Dynamic range and stray light. An estimate of the falsifying effect of stray light in perimetry. Documenta Ophthalmol. 50: 143-167 (1980). 3. Fankhauser, F., Hiiberlin, H. and Jenni, A. Octopus programs SAPRO and F. Two new principles for the analyses of the visual field. Graefes Arch. Klin. exp Ophthal- mo1216: 155-165 (1981). 4. Gramer, E. and Krieglstein, G.K. Zur Spezifitiit der iiberschwelligen Computer- perimetrie. Klin. Mbl. Augenheilk. 181; 373-375 (1982). 5. Gramer, E., Kontic, D. and Krieglstein, G.K. Die computerperimetrische Dar- stellung glaukomatoser Gesichtsfelddefekte in Abhangigkeit von der Stimulus- grosse. Ophthalmologica 183: 162-167 (1981).

This volume contains chapters derived from a N. A. T. O. Advanced Study Institute held in June 1983. As the director of this A. S. I. it was my hope that some of the e1ectrophysiologists could express the potentialities of their work for perceptual theory, and that some perceptionists could speculate on the underlying "units" of perception in a way that would engage the imagination of physio logists. The reader will have to be the judge of whether this was achieved, or whether such a psychophysiological inter1ingua is still overly idealistic. It is clear that after the revolution prec pitated by Hube1 and Weisel in understanding of visual cortical neurons we still have only a foggy idea of the behavioral output of any particular species of cortical detector. It was therefore particularly unfortunate that two persons who have made great strides in correlating interesting facets of cat cortical physio logy with human psychophysics (Max Cynader and Martin Regan of Dalhousie University) were unable to attend this meeting. Never theless, a number of new and challenging ideas regarding both spatial perception and cortical mechanisms are represented in this volume, and it is hoped that the reader will remember not only the individual demonstrations but the critical questions posed by the apposition of the two different collections of experimental facts. David Ingle April 1984 VII TABLE OF CONTENTS PREFACE V D. N. Lee and D. S. Young Visual Timing of Interceptive Action 1 J. J."

The eye can become involved in immune-mediated diseases that affect it alone or as part of a multi-organ disease process. Much immunological attention has been focused on other organs affected by these processes and the subject of the immunology of eye diseases is a relatively new one. Many of these diseases that involve the eye are not life-threatening but can result in devastat ing loss of sight that if bilateral, will have major effects on the patient's life. Systemic immunological investigations are generally unhelpful in these patients and one of the major problems in this field has been the lack of diseased tissue available for examination to determine the pathological processes involved. Our poor understanding of basic mechanisms of disease in the eye has meant that treatment of many of these conditions is often inadequate. It has become possible to apply in the eye many ofthe techniques used to investigate the role of the immune system in other systems. Animal models of many of the disease processes have also allowed dissection of the immune response both within and outside the eye. It is my belief that a greater understanding of the mechanisms by which the structures in the eye become damaged will allow more specific and effective therapeutic strategies to be devised."

This book has been written for radiologists, ophthalmologists, neurologists, neurosur geons, plastic surgeons, and others interested in the evaluation of disorders with ophthalmologic signs and symptoms. It is designed to provide recent knowledge in this area derived from ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI). In the past decade, the advent of ultrasonography, computed tomography, and more recently magnetic resonance imaging has provided diagnostic images of the eye, orbit, and brain in a fashion that had been a dream of many prior to the develop ment of these techniques. These newer modes of diagnosis have replaced some previous techniques, such as nuclear medicine imaging and, to some degree, vascular studies and orbitography. There are three sections to this book. The first section is a discussion of the imaging techniques. The second is devoted to the role of these imaging methods in the evaluation of ophthalmic disorders. The last section, dealing with radiotherapy for ophthalmologic tumors, is included because the current imaging techniques are needed for treatment planning. We wish to thank the many people who have assisted us in preparing this manuscript. Among these are many librarians, secretaries, trainees, and photographers. Weare especially indebted to artist Peter Clark for his illustrations and to Mr. Martin Leibo vici, Associate Curator of New York University Medical School and Director of Health Sciences Library of Goldwater Memorial Hospital, New York City. Also, we wish to thank our families for their help and patience."

Evoked potentials are potentials that are derived from the peripheral or central nervous system. They are time locked with an external stimulus and can be influenced by subjective intentions. Evoked potentials have become increasingly popular for clinical diagnosis over the last few years. Evoked potentials from the visual system are used by ophthalmologists in order to localize the abnormalities in the visual pathway. The otologists are mainly involved in brainstem auditory evoked potentials, while the pediatricians, neonatologists, neurologists and clinical neurophysiologists make use of multimodal stimulation. The psychiatrists and psychologists, generally, examine the slow potentials such as P300 and CNV. Anesthesiologists use short latency somatosensory and visual evoked potentials in order to monitor the effectiveness of the anesthesia. Pharmaco evoked potentials are very promising measures for the quan tification of the effectiveness of drug action on the cerebral cortex. Urologists are more and more involved in pudendal somatosensory evoked potentials and in the intensive care unit evoked potentials are used in order to monitor the functional state of the central nervous system of the patient. This overwhelming number of examinations and exam ina tors clearly demonstrates the need for guidelines and standardization of the methods used. The evoked potential metholody is restricted by the relative poor signal to noise ratio. In many diseases this signal to noise ratio decrease rapidly during the progression of the illness. Optimal technical equipment and methodology are therefore essential."

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 per manent 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.