Preface

Age-related macular degeneration (AMD) remains one of the most enigmatic diagnoses for elderly patients. Over the past two decades, there has been significant progress in the pathophysiology and treatment of AMD. These research strides have resulted in novel therapies that offer not only sight-saving, less destructive forms of treatment for exudative AMD but also treatment to prevent progression of nonexudative AMD. The purpose of this book is to summarize and synthesize in a single resource this information for clinicians and scientists involved in AMD patient care and research. I have asked retinal experts first to summarize established information and then to present the recent developments in their specific areas of AMD research.

It is important to understand how the normal eye ages. In Part I, Chapter 1 focuses on aging-related changes of the retina and retinal pigment epithelium and compares them with the retinal findings of AMD. Chapter 2 presents the light and electron microscopic findings of AMD to facilitate understanding of its ultrastructural pathophysiology. Such an understanding is useful in directing future areas of research toward a cure for AMD. Chapter 3 elucidates immunological aspects of AMD. This avenue of research may offer clues to the pathophysiology of AMD and point to potential new treatments.

Part II focuses on clinical features of nonexudative and exudative AMD, which are discussed with respect to the natural history and prognosis for vision. This information is useful for the clinician who frequently must provide information to the patient regarding prognosis.

Evaluation of the patient and planning treatment for AMD is aided by imaging techniques. Part III discusses imaging techniques, such as OCT, which are helpful not only for evaluating the patient but also for making objective assessments of treatment outcome. Application of OCT to animal and clinical research studies helps to determine efficacy outcomes objectively. Continued application of ICG angiography to the evaluation of AMD patients has led to refinements in the diagnosis of AMD and to ICG-based laser treatments for choroidal neovascularization (CNV) lesions. Chapter 7 summarizes the current state of knowledge about the application of ICG angiography to diagnosis and treatment of AMD.

Parts IV to VI of this book present the current and experimental forms of treatment for nonexudative and exudative forms of AMD. Much progress in the area of AMD research has occurred since the MPS study first began over 20 years ago. Thus, the clinical application of the MPS data is updated in light of the availability of newer, less destructive forms of therapy for CNV. Refinements in the application of laser photocoagulation, such as feeder-vessel treatment and subthreshold laser, have contributed to new applications for thermal laser for AMD.

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from photodynamic therapy, radiation therapy, transpupillary thermotherapy, and antiangiogenesis drugs to submacular surgery and macular translocation. Discussions of the basic mechanism of action, clinical treatment technique, target patient population, expected outcomes, and both positive and negative aspects of the treatment are included.

When possible, comparisons between the results of the different treatments are drawn. Known risk factors for AMD progression are discussed, as well as the recent AgeRelated Eye Disease Study (AREDS) finding of risk reduction through micronutrient supplementation.

Basic science research followed by its application to clinical trials is the mode by which new treatments for AMD are created. Part VII of this book focuses upon active areas of basic science research that may lead to clinical trials in the near future. The future application of genetics research to gene therapy for AMD may be curative and/or preventative for younger patients possessing the gene for AMD. Retinal pigment cell transplantation research may lead to future treatments that reverse damage from AMD. The discussion of these future treatments is intriguing and presents new hope for the future generations afflicted with AMD.

Despite the progress in AMD research and the attendant clinical applications, in reality there still exist patients with visual loss and untreatable disease. For these patients, visual rehabilitation is extremely important. A discussion of the available low-vision devices and the psychosocial aspects of visual loss from AMD is included to help counsel patients with AMD and visual loss. The possibility of using an intraocular retinal prosthesis to restore vision in the future is intriguing and this area of research is presented. The prosthesis may represent the ultimate low-vision device for patients with AMD and vision loss.

Throughout the book, clinical trials data are summarized. Clinical trials remain the gold standard for proving clinical efficacy of a new treatment. Part VIII discusses the design of clinical research trials and quality-of-life assessments. The importance of qual- ity-of-life assessments as part of clinical research outcome measurements is now recognized.

No single volume can present all the existing knowledge about AMD. Thus, only the most clinically useful and exciting research information was included in this book. My goal is for this book to serve as a first-hand resource for researchers and clinicians in the area of AMD. My contributors and I hope we have achieved this and that the information presented herein will inspire inquiry and ignite research that may unearth answers to those enigmatic questions about the etiology of and cure for AMD.

I wish to thank all the outstanding contributors, without whom this book would not be possible. Their eagerness to collaborate and their expertise made my job as editor extremely enjoyable, educational, and satisfying. I am grateful to Onita Morgan-Edwards and Charlotte Kler for their efficient and accurate secretarial assistance, and to the staff at Marcel Dekker, Inc., for their great help in compiling this book.

I dedicate this book to my parents, to my husband, John Miao, and to our daughter, Bernadette, who was with me (in utero) during the preparation and editing of most of this book.

Jennifer I. Lim

Contents

I.Pathophysiology of the Aging Eye

II.Clinical Features of AMD

III.Diagnostic Ancillary Tests

Antonio P. Ciardella, Lawrence A. Yannuzzi, Jason S. Slakter,

David R. Guyer, John A. Sorenson, Richard F. Spaide,

K. Bailey Freund, and Dennis Orlock

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IV. Current and Experimental Medical Treatment for Exudative AMD

9.Laser Photocoagulation for Choroidal Neovascularization in

13.Transpupillary Thermotherapy of Subfoveal Occult Choroidal

V.Surgical Treatment for AMD

15.Submacular Surgery for Patients with Age-Related

Frank J. McCabe and Allen C. Ho