Ординатура / Офтальмология / Английские материалы / Dry Eye and Ocular Surface Disorders_Pflugfelder, Beuerman, Elliot Stern_2004

Foreword

It is a pleasure to provide a foreword for this exciting new book about dry eye disease. It was written by a team of international experts, many of whom have been personally responsible for advancing our understanding of ocular surface biology and improving our insight into ocular surface disease. Clinicians will find themselves dipping into this book time and time again, to refresh their knowledge of etiology, diagnosis, and the more complex aspects of therapy. They will find that every area is discussed in full, richly referenced, and replete with historical perspective.

Several events have led to a better understanding of dry eye disease. Perhaps one of the simplest, and yet not least important, was the evolution of general consensus as to the major categories of dry eye, recognizing the potential contributions of both aqueous tear deficiency and excessive evaporation to the disorder. It is also now accepted that while tear hyperosmolarity is an obligatory component of dry eye, inflammation is also an essential feature, representing both a part of the mechanism and a potential therapeutic target. Recognition of the role of inflammation in dry eye disease has focused attention on the immunobiology of the ocular surface, and there is a fine summary of that subject in this book. Also, given the clinical overlap between dry eye and some allergic disease, it is appropriate that there is also a chapter on ocular allergy. The role of autoimmunity in exocrine gland destruction has been of longstanding interest to researchers and is of particular relevance to the mechanism of lacrimal and salivary gland destruction in Sjögren’s syndrome; it may also be of relevance to age-related dry eye. Such studies have been helpful in generating hypotheses as to the evolution of dry eye disease and have indicated potential targets for therapeutic intervention using anti-inflammatory agents, immunosuppressants, and inhibitors of specific proinflammatory cytokines.

Another landmark was the discovery of factors that maintain the ocular surface, starting with the recognition of the role played by stem cells and continuing with the definition of growth factors, hormones, and micronutrients that preserve the steady state or regulate the response to injury. With this recognition has come the concept of an ocular surface, comprising two interdependent tissues, occupying a common environment, bathed by the same tears, sharing a common innervation, and exposed to a similar array of excitatory and inhibitory signals. This perception has given rise to the view that the ocular surface and its appendages,

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Preface

Dry eye is one of the most common ophthalmic medical problems. Complaints of dry eye are among the most common reasons patients seek help from eye doctors. Many patients with this condition have had to live with constant and occasionally debilitating pain. Research suggests that the impact on quality of life from this disease is approximately equal to that of angina.

Dry eye was traditionally considered to be an age-related dysfunction of the lacrimal gland. Based on this concept, therapy of dry eye was primarily directed toward lubricating and hydrating the ocular surface. This type of ocular surface palliation provided, at best, transient symptomatic relief due to the fact that this therapy does not address the underlying cause of the disease. Research over the last fifteen years has led to the acknowledgment that dry eye is a complex inflammatory syndrome of the tear-secreting apparatus that results in compositional changes of the tear film.

In 1993 a workshop convened at the National Eye Institute by Dr. Michael Lemp began the process of standardizing the nomenclature and diagnostic criteria involved in this problem. This was an important initial step in formalizing the subclassification of dry eye into aqueous deficient and evaporative loss.

We now understand that the tear film is secreted reflexively from the lacrimal functional unit, which is composed of the ocular surface tissues, the lacrimal glands, and their interconnecting sensory and autonomic innervation. This reflex secretion is initiated by subconscious stimulation of the highly innervated ocular surface epithelia. Almost all clinical “dry eye” conditions are due to dysfunction of this integrated functional unit. This may result in a decrease in the quantity of tears, but more importantly it leads to changes in tear composition that result in loss of tear film integrity and promote inflammation.

In this book, rather than following the traditional view of “dryness” as the putative cause of ocular surface disease, we have defined dry eye as an inflammatory disease of the lacrimal functional unit resulting in tear film compositional changes. We refer to this syndrome as LKC (lacrimal keratoconjunctivitis). This approach allows us to recognize the array of clinical conditions resulting in or from a dysfunctional tear film.

As evidence mounted in support of these concepts, we determined that there was a need to coalesce this body of research into a single usable reference.

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Contents

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Contributors

Leonard P. K. Ang Singapore Eye Research Institute, and National University of Singapore, Singapore

Roger W. Beuerman Louisiana State University Eye Center, New Orleans, Louisiana, U.S.A., and Singapore Eye Research Institute, Singapore

Virginia L. Calder University College London, London, England

Margarita Calonge University of Valladolid, Valladolid, Spain

Reza Dana The Schepens Eye Research Institute, and Harvard University, Boston, Massachusetts, U.S.A.

Cintia S. De Paiva Baylor College of Medicine, Houston, Texas,

U.S.A.

Robert I. Fox Rheumatology Clinic, La Jolla, California, U.S.A.

Abha Gulati The Schepens Eye Research Institute, and Harvard University, Boston, Massachusetts, U.S.A.

Pedram Hamrah The Schepens Eye Research Institute, and Harvard University, Boston, Massachusetts, U.S.A.

Thanh Hoang-Xuan Fondation Ophtalmologique Adolphe de Rothschild, Paris, France

Andrew J. W. Huang University of Minnesota, Minneapolis,

Minnesota, U.S.A.

Syed O. Huq The Schepens Eye Research Institute, and Harvard University, Boston, Massachusetts, U.S.A.

Robert M. Lavker Northwestern University, Chicago, Illinois, U.S.A.

S. Lightman Moorfields Eye Hospital, London, England

William D. Mathers Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, U.S.A.

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