Herpes Simplex Virus is the fifth monograph to be published in the Bloomsbury Series of Clinical Science. It provides an authoritative review of the key issues related to this common clinical problem. The characteristics of the virus, its epidemiology and the diag nosis and management of the various forms of infection are all considered. Adrian Mindel is an international authority on this subject; he joined the Academic Department of Genito-urinary Medicine at the Middlesex Hospital in 1980 and has been actively involved in HSV research since that time. His major research interests include the epidemiology and treatment of genital herpes, the epidemi ology of neo-natal herpes and the many and varied features of HSV infections in immuno-compromised patients. The continuing aim of the Bloomsbury Series is to identify the growing areas of clinical research and relate these to current and future medical practice. In Herpes Simplex Virus such aspirations have been successfully achieved. London, May 1989 Jack Tinker Preface There has been considerable interest in herpes simplex viruses (HSV) over recent years. Amongst the many reasons for this are the introduction of safe and efficacious therapy, the recognition that HSV may cause life-threatening infections in neonates and immunocompromised patients, the observation that genital herpes is one of the commonest viral sexually transmitted diseases and the possible association of HSV with cervical cancer."

Management of retinal venous occlusions (RVO) has changed dramatically in recent years. With an increase in medical information, technological advances, and clinical trials, ophthalmologists need a concise, updated reference. Management of Retinal Vein Occlusion: Current Concepts fills this current need in the market. In Management of Retinal Vein Occlusion, Dr. Seenu Hariprasad is joined by multiple section editors to provide this easy-to-read and nicely formatted resource, which is divided into organized sections: Background: The epidemiology, risk factors, and classification of RVO History: Seven large clinical trials involving RVO and the pros and cons of earlier treatment modalities Anti-VEGF Therapies: The rationale and outcomes of large clinical trials Corticosteroid Therapies: The rational and outcomes of various steroid treatment modalities Imaging: Case presentations and emerging technology that highlights the relationship between peripheral ischemia and macular edema Difficult cases: Combination therapies, management of recalcitrant cases, and surgical approaches for cases that do not respond to standard management Future of RVO: A summary overview of the subject and future directions With an unparalleled list of contributors that are leaders in the retina field, Management of Retinal Vein Occlusion goes beyond the conclusions of clinical trials and delves deeper into practical recommendations for patient management in daily practice. With abundant illustrations, fundus photographs, concise tables, and summary boxes that enhance the written text, Management of Retinal Vein Occlusion: Current Concepts is a valuable resource.

In Dedication to Hermann Burian (1906-1974) T. LAWWILL (Louisville) This 14th Symposium of the International Society for Clinical Electro- retinography is dedicated to the memory of a great ophthalmologist, great physiologist, former officer of this Society, and my professor, Hermann Martin Burian. Dr. Burian was a visual physiologist and an ophthalmologist. His physiol- ogy heritage was the finest. His father, Richard, was an eminent European physiologist who at the time of Dr. Burian's birth was director of the Stazione Zoologica in Naples. The family later moved to Leipzig and Belgrade, where Dr. Burian's father held professorships. Hermann Burian's ophthalmological academic heritage was also outstand- ing. After graduating from medical school in 1930 in Belgrade, he became a student of Tschermak and along the way worked with such famous men as Siegrist, Goldmann and Weigert. In 1936, Dr. Burian came to the USA to join the Dartmouth Eye Insti- tute. Here he worked in ocular motility under Professor Bielschowsky and in physiological optics under Professor Ames. He was chief ophthalmologist of the Darmouth Eye Institute from 194245. He was in the private practice of ophthalmology in Boston for six years before moving to Iowa City, Iowa where, for twenty years, he practiced and taught ophthalmology and carried out research on many problems in ophthalmology and visual physiology. Dr. Burian's two main interests were strabismus and electrophysiology, but this did not keep him from publishing outstanding work on glaucoma, congenital anomalies, and color vision.

This volume contains the proceedings of a work shop entitled "Physiological and Pathological Aspects of Eye Movements" held at the Pont d'Oye Castle, Habay-Ia-Neuve, Belgium, March 27-30 1982. The meeting was sponsored by the European Communi ties. It brought together specialists of oculomotricity mainly from Europe but also from North-America. With such actions, the Communities want to encourage inter national and multidisciplinary contacts between re searchers of a particular field. Oculomotor neuroscien tists, for quite a long time, have developed such con tacts. This cooperation - this is not so common in biological research - embodies various approaches, from basic mechanisms to behavioral studies, but also this applied science that medicine is or should be. Many basic discoveries about eye movement mechanisms, made with the help of human of animal subjects, have found rapid medical applications in neurology, neuro ophthalmology or otolaryngology. This is illustrated in this book by the fact that results obtained on rats or cats are interspersed with reports of clinical in vestigations. The workshop was mainly focused onto three themes: (a) eye and head movements in man, (b) visuo-vestibular interaction and (c) eye-head coordination. In each theme, one or more "review" papers were included. In addition, most of the oral presentations or posters on display mainly contained unpublished material."

Considering the high incidence of myopia - and its inherent morbidit- it may wonder that the item is dealt with only sporadically in recent literature, and almost never at international conferences. However, there was a First International Conference on Myopia in New York 1964, and the Second was held in Yokohama 1978, affiliated to the XXIII World Congress of Ophthalmology. Here it was attempted to set out lines for future myopia research, and, as a practical implicaton, the arrange ment of the Third International Conference on Myopia was entrusted to Danish ophthalmolOgists. This conference took place in Copenhagen, August 24-27, 1980. To make the scope the widest possible, the conference was, as was the pre decessing in Japan, open not only to ophthalmologists, but 'to all being active in the various aspects of myopia research'. The conference report gives a picture of the Copenhagen meeting. Furthermore, a platform or current status of myopia research has hereby been established. The editors have made it their main task to arrange the papers, and to bring them in a form suited for print, while criticism by editorial referees has been considered inappropriate. The papers give an impression of the ambiguity still prevailing in the field, and although 't, rends' are obvious, a fmal consensus of Conference was not arrived at. To document this state of affairs, however, is considered a useful task."

We have registered the ERG in 26 chronic uraemics treated with periodic haemodialysis, nearly always finding a subnormal b-wave. In 11 chronic uraemics treated only with dietetic-conservative therapy, the electroretino- gram resulted only slightly reduced and with a voltage clearly superior to that of the previous group. REFERENCES Agzamova, H.S. Tonographic values in patients with chronic renal insufficiency. Of tal. Zh. 20: 32-34 (1975). Berlyne, G.M. Microcrystalline conjunctival calcification in renal failure. Lancet II: 366-370 (1968). Biagini, M. & E.M. Gloria. Comportamento della pressione intraoculare durante emo- dialisi in pazienti affetti da uremia cronica.Ann. Ottal. 93: 705-713 (1967). Boudet, Ch., B. Arnaud & D. Pincemin. Cataracte au cours d'h'emodialyses (dans les insuffisances renales chroniques). Bull. Soc. Ophtal. France 73: 199-205 (1973). Burn, R.A. Intraocular pressure during haemodialysis. Br. I. Ophthal. 57: 511-513 (1973). Cavallacci, G., G. Tota & A. Wirht. Studio sperimentale sull'effetto della difenilidan- toina sull'Elettroretinogramma. Ann. Ottal. 100: 560-568 (1974). Demco, T.A., A.Q. McCormick & J.S.F. Richards. Conjunctival and corneal changes in chronic renal failure. Can. I. Ophthal. 9: 208-213 (1974). Deodati, F., P. Bec, M. Camezind & J .B. Labro. Les manifestations oculaires au cours de l'hemodialyse periodique. Bull. Soc. Ophtal. France 71: 87-92 (1971). Ehlers, N., F. Kruse Hansen, H.E. Hansen & O.A. Jensen. Corneoconjunctival changes in uremia. Acta Ophthal. Kbh. 50: 83-94 (1972).

The forth meeting of the Organizing Committee of the Glaucoma Society of the International Congress of Ophthalmology was held on March 10-13,1990 in Bali, Indonesia. Traditionally this meeting is attended by committee mem- bers and invited experts and precedes the International Congress of Ophthal- mology under the auspices of the International Council of Ophthalmology. The scientific format was structured by Stephen M. Drance, OC, MD,lVan- couver (President of the Society from 1982-1990) and John Hetherington, JR, MD,ISan Francisco (General Secretary of the Society from 1982-1990). The local organization was in the very competent assistance of Josef Kadi, an ophthalmologist from Surabaya, Indonesia. Glaucoma Update IV comprises forty presentations from this meeting high- lighting the latest progress in global glaucomatology. Basic research related to the pathomechanisms of the disease, new diagnostic approaches and treat- ment modalities contribute to the best possible care of our patients. The ob- jectives of the Society are to share the frontiers of knowledge presented in these proceeding with everyone dealing with glaucoma patients all over the world. The Society is indebted to Chibret International/Rahway, Allergan Pharma- ceuticals/Irvine, and Otsuka Pharmaceuticals/Tokushima for support of the meeting and to Chibret Pharmaceuticals GmbH Munich for supporting the printing expenses of this volume.

Aspects of Lyme Borreliosis is a comprehensive scientific presentation of virtually all aspects of lyme borreliosis. It starts with a concise history of lyme borreliosis and its causative agent, Borrelia burgdorferi. The morphological and biological characteristics of B. burgdorferi are presented, followed by outlines on the ecology and histopathology of LB.The various aspects of the clinical manifestations of LB are systematically dealt with, starting with a clinical overview. A special chapter covers the microbiological diagnosis. After a presentation on the susceptibility of B. burgdorferi in vitro and in animals against a great variety of antibiotics, a thorough discussion on the treatment of LB including criticalremarks follows. The book closes with a chapter on the epidemiology of LB.

The XVlIIth ISCEV symposium was organized by the Netherlands Ophthal- mic Research Institute and took place May 18-22, 1980, at the Wilhelmina Gasthuis in Amsterdam. The invited speakers and the theme "Electrophysio- logy and pathology of the visual pathways" were selected by a programme committee consisting of G.H.M. van lith, D. van Norren, L.H. van der Tweel and H. Spekreijse. The success of a symposium depends not only on the topics selected but also on the clarity and qUality of the presentations. In this respect it is a pleasure to acknowledge the four invited speakers for their clear and comprehensive presentations of recent research results. My co-editor, P. Apkarian, and I wish to thank all participants for timely submission of the manuscripts and for prompt response to inquiries regarding editorial matters. Mr. Peters of Junk Publishers should be acknowleged for observing publication deadlines, thus ensuring that the proceedings will reach all participants prior to the next ISCEV meeting.

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."

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."

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."

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).

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.

Cataract Surgery With Phaco and Femtophaco Techniques offers a unique insight into the evolution of phacoemulsification machines and the development of new ways to supply energy, as well as new devices that improve fluidics therefore increasing the safety of the phaco and femtophaco surgical procedures. Dr. Lucio Buratto, Dr. Stephen Brint, and Dr. Rosalia Sorce provide a step-by-step approach to everything the surgeon must learn about the physical principles that regulate the fluidics and energy to understand the machine's working during the surgical procedure. Cataract Surgery With Phaco and Femtophaco Techniques covers a wide variety of topics, including anterior chamber phacoemulsification, endocapsular techniques, irrigation and aspiration, fluidics and pumps, and principles of femtosecond cataract surgery. Supplemented by more than 300 color illustrations, diagrams, a glossary, and references, all surgeons from beginner to expert will want this unique resource by their side.

Cataract Surgery: Introduction and Preparation offers the latest information and examines the most popular instruments used, the preoperative examination, and the operating technique for cataract surgery. The authors provide a step-by-step approach to facilitate assessing the patient, performing the technique, and managing cataract surgery in the most optimal way possible. Cataract Surgery will lead beginning surgeons down the exciting path of cataract surgery as they increase their knowledge of phacoemulsification and the femtolaser by learning all the details associated with the procedures. It covers a wide variety of topics, including presurgery examination, incisions, capsulorhexis, hydrodissection, prevention of endophthalmitis, and ophthalmic viscosurgical devices for modern cataract surgery. Supplemented by more than 200 colour illustrations, diagrams, a glossary, and references, all surgeons from beginner to expert will want this unique resource by their side.

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.

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."

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."

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 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."