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."

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 Seventh International Visual Field Symposium organized by the Interna tional Perimetric Society was held in Amsterdam, The Netherlands, September 6-10,1986. In many respects it was an exciting and fruitful meeting. The number of participants was greater than ever. The number of papers was too great to accommodate all of them. The quality of the papers reflects the continuously rising interest in perimetry in general and in automated perimetry in particular. Last but not least the social programme was organized in the, by now, almost classical friendly, enjoyable and humouristic style of the International Perimetric Society. This created an atmosphere of openness and free exchange of informa tion whICh was clearly also felt in the scientific sessions. The scientific part was divided in seven sessions with 44 spoken papers and a separate postersession during which the 46 posters were discussed. The major themes of the meeting were 'The influence of media-disturbances on the visual field' and 'Advances in perimetry in glaucoma with special emphasis on pro gression'. The session on 'media' provided interesting information on how the visual field was effected by preretinal filters. The authors either studied the influence of lens or corneal opacities or simulated opacities by special filters placed in front of the eye. In two papers the effect of cataract was qualified by photography or stray light measurements."

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."

With Surface Ablation: Techniques for Optimum Results, refractive surgeons will learn efficient pre- and post-op routines that optimize chair time and lead to improved safety and excellent results for patients. Inside Surface Ablation: Techniques for Optimum Results by Dr. Ellen Anderson Penno is joined by 9 contributors who offer a practical approach with clinically useful tips including patient counseling and post-operative care that will improve patient satisfaction. This up-to-date book is an excellent resource for patient assessment of candidacy for refractive surgery or in post- operative co-management. In addition to chapters with information on patient selection, surgical techniques, post-op care, and prevention and management of complications, Surface Ablation: Techniques for Optimum Results includes several articles, contributed by leaders in the refractive surgery field, covering a variety of topics including surface ablation in keratoconus patients, corneal cross-linking, and ectasia. Surface Ablation: Techniques for Optimum Results is a clinically- oriented resource for residents and new refractive surgeons as well as the many seasoned refractive surgeons, general ophthalmologists following the increasing trend of transitioning away from LASIK towards surface ablation for many of their patients.

Cataract Surgery in Complicated Cases offers the latest techniques in treating complicated cases as faced by today's surgeons performing cataract surgery. Dr. Lucio Buratto; Dr. Stephen Brint; and Dr. Luigi Caretti provide step-by-step approach to facilitate how to assess the patient, perform the technique, and manager the most challenging cataract surgery complicated cases facing both beginning and experienced surgeons. Cataract Surgery in Complicated Cases covers a wide variety of topics including cataract in high myopia, floppy iris syndrome, traumatic cataract, phacoemulsification with a small pupil, and IOL explanation and replacement. Supplemented by more than 250 colour illustrations, diagrams, a glossary, and references, all surgeons, from beginner to expert will want this unique resource by their side.

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.

The purpose of this book is to provide an update both on the present management of proliferative vitreoretinopathy (PVR) and on clinical and experimental research being done to control this disease. The book is divided into three parts. The first part deals with the current management of PVR. The Retina Society Classification of PVR is based in part on a gradation of severity from minimal to massive; therefore, this book attempts to correlate the management of PVR with its severity. The treatment of PVR of varying degrees of severity, from mild to the most severe form, is described by those authors with extensive experience with this spectrum of cases. Much progress has been made in the management of severe PVR as a result of vitreous injections, vitrectomy, periretinal membrane surgery, and retinal surgery. Authors in this book show that in mild and moderately severe PVR excellent results can be obtained with techniques that are less invasive and possibly less likely to stimulate further abnormal cellular proliferation. The new modalities for treatment of PVR are discussed by authors having extensive experience with them. The current status of pharmacological treatment and new concepts of the pathobiology of PVR are discussed. The second part of the book deals with questions frequently encountered in the management of PVR. These questions are answered by a panel of experts including Gary W. Abrams, Steven T. Charles, William H. Havener, Robert Machemer, Charles L. Schepens, and Walter H. Stern.

Corneal Topography is designed to provide complete, practical coverage of a new field for both the general ophthalmologist and the subspecialist in the area of corneal disease. The volume explores the history of corneal topography and comprehensively demonstrates the usefulness of all forms of current instrumentation in clinical and ivestigative work striving toward improved surgical intervention in the cornea

Proceedings of the International Symposium at the Katholieke Universiteit Leuven, Belgium, May 17-19, 1984

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 It is our feeling that much can be learned on both sides from community. 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 on a different aspect of ocular development. Speakers have concentrated been selected to approach related topics from different perspectives."

The European Glaucoma Society was founded in the spring of 1978 at the initiative of Drs Fran ois, Leydhecker and Greve. Representatives of most European countries met in Ghent and agreed to create a society that would promote the contacts and exchange of knowledge between European glauco matologists. The European Glaucoma Society serves to stimulate glaucoma research and diffuse specific knowledge to general ophthalmologists. The European Glaucoma Society would like to cooperate closely with similar glaucoma organizations in other continents. The first symposium of the EGS was held in April 1980 in Brighton, England. No proceedings were published. The second symposium took place in May 1984 in Hyvinkiiii, Finland. A great number of participants enjoyed a well organized scientific programme of attractive quality. The local organization was in the able hands of Raitta and her colleagues, Raivio and Lehto. The scientific programme was coordinated in Amsterdam where a great amount of work was done by Stella Ompi, secretary to the general secretary. The contents of the meeting have been summarized in this book. This second symposium of the EGS, which took place in an atmosphere of great enthusiasm and friendship, has shown great promise for the future of the European glaucoma."