Ординатура / Офтальмология / Английские материалы / Shields Textbook of Glaucoma, 6th edition_Allingham, Damji, Freedman_2010

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AUTHORS

Authors: Allingham, R. Rand

Title: Shields Textbook of Glaucoma, 6th Edition Copyright ©2011 Lippincott Williams & Wilkins > Front of Book > Authors

SENIOR AUTHOR

R. Rand Allingham MD

Richard and Kit Barkhouser Professor of Ophthalmology Duke University School of Medicine

Chief Glaucoma Service Duke Eye Center

Durham, North Carolina, USA ASSOCIATE AUTHORS Karim F. Dam JI, MD, MBA

Professor of Ophthalmology

University of Alberta—Faculty of Medicine & Dentist ry

Director, Ophthalmology Fellowship Programs

Royal Alexandra Hospital

Edmonton, Alberta, Canada

Sharon F. Freedman MD

Professor of Ophthalmology and Pediatrics

Duke University School of Medicine

Chief Pediatric Ophthalmology and Strabismus Service

Duke Eye Center

Durham, North Carolina, USA

Sayoko E. Moroi MD, PHD

Associate Professor of Ophthalmology and Visual Sciences

University of Michigan Medical School

Director, Glaucoma Fellowship Program

The University of Michigan W. K. Kellogg Eye Center

Ann Arbor, Michigan, USA

Douglas J. Rhee MD

Assistant Professor of Ophthalmology

Harvard Medical School

Associate Chief, Practice Development

Massachusetts Eye and Ear Infirmary

Boston, Massachusetts, USA

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FOREWORD

Authors: Allingham, R. Rand

Title: Shields Textbook of Glaucoma, 6th Edition Copyright ©2011 Lippincott Williams & Wilkins > Front of Book > Foreword

Foreword

Most of us, as we approach the “golden years” of life, can look back with joy and pride on how we watched our children grow from infancy through adolescence to adulthood, with accomplishments well beyond the ability of their parents. My feelings are much the same with this book. During its infancy in the early 1980s, it was small and naïve, and it grew slowly over the next 20 years, due in large measure to kind encouragement from generous readers. But the day came, as we crossed into the new century, when I could no longer fully provide for the book—the remarkable advances in glaucoma on so many fronts were exceeding my ability to keep up— and I was fortunate to have an extended family step in and author the fifth, and now this sixth, edition.

When I first approached each of them with the request to assume authorship of the book, to the person they did not hesitate to agree (at least they showed no outward hesitation), for which I will always be profoundly grateful. And it truly has been a family affair. My Duke partner and longtime friend, Dr. R. Rand Allingham, graciously agreed to serve as managing author, despite his heavy load as Chief of the Duke Glaucoma Service, and skillfully guided the preparation of the latest two editions. Three of the authors, in whom I take great pride, are former Duke glaucoma fellows who have gone on to become leaders in our profession at major universities: Drs. Karim F. Damji, University of Alberta; Sharon F. Freedman, Duke University; and Sayoko E. Moroi, University of Michigan. The final author of the fifth edition was my Yale partner, Dr. George Shafranov, who has since gone into private practice and has been replaced in the sixth edition by Dr. Douglas J. Rhee, also a rising star at the Massachusetts Eye and Ear Infirmary in the fine tradition of Drs. Paul A. Chandler and W. Morton Grant.

Each of these talented friends has added immensely to the editions in their areas of expertise, and I am grateful to them not only for taking the time from their busy practices to perpetuate this textbook but also for truly raising it to a new level. Sales of the fifth edition have approached 9000, which is quite remarkable (I felt good if we broke 2000 with the earlier editions). This success is undoubtedly due to the contributions of the team of authors. They not only updated all the chapters with the latest advances but also added new chapters on molecular genetics and clinical epidemiology and expanded information on evolving technologies, including ultrasound and image analysis. They updated information on the clinical forms of glaucoma, most notably

exfoliation syndrome, and greatly enhanced the chapters on filtering surgery, glaucoma drainage-device surgery, and glaucoma surgery for children.

While the fifth edition was a vast improvement over the previous ones, the sixth edition offers even more. Two special features are the addition of color illustrations throughout the book and the accompanying Internet version (the latter is an example of how times are changing, since the Internet was not even heard of when the book began).

A goal of this book from the beginning has been to base the content on a moderately extensive bibliography of both the classic and recent literature and to provide balanced viewpoints where controversy exists. The authors have adhered admirably to this goal, and I hope it will continue to be the foundation of any future editions.

Another strength of the book is its limited number of authors. Multiple-author textbooks, which are in the majority today, have the advantage of providing viewpoints by many individuals in their area of expertise, but a book that is written, rather than edited, by a small number of authors provides the advantages of more cohesiveness and consistent style throughout the book. This means more work for each author, several of whom were responsible for a dozen chapters or more, but I hope that this feature can also be perpetuated in future editions.

And so my hat is off to Rand, Karim, Sharon, Sy, and Doug for this latest accomplishment. I also want to again thank Mr. Jonathan Pine and all those at Lippincott Williams & Wilkins for their continued support over these past 30 years. Now I will sit back, like the proud parent, and watch with profound gratitude and admiration as these good friends continue to advance our understanding of glaucoma for the ultimate goal of preserving the precious gift of sight in our patients.

M. Bruce Shields

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PREFACE

Authors: Allingham, R. Rand

Title: Shields Textbook of Glaucoma, 6th Edition Copyright ©2011 Lippincott Williams & Wilkins > Front of Book > Preface

Preface

Nearly 30 years have passed since A Study Guide for Glaucoma was published by M. Bruce Shields in 1982. The first edition of the series that we now know as Shields Textbook of Glaucoma, has been embraced by generations of practitioners at all levels of training. No small measure of this book's popularity is the fact that it has become the leading subspecialty textbook on the subject of glaucoma. This should come as no surprise since the core qualities of simple organization and ease to read were adroitly established by Bruce Shields himself.

Over the past few decades, we have witnessed a logarithmic expansion of information in all areas of science and medicine. This certainly has been the case for the subspecialty of glaucoma, where our complete armamentarium consisted of three drugs after which surgery was the next step. Ironically, the mainstay of our treatment 30 years ago—pilocarpine, epinephrine, an d systemic carbonic anhydrase inhibitors—is seldom, if ever, used today. Now, joining timolol, prostaglandin analogs, a2-agonists, and topical carbonic anhydrase inhibitors is a multitude of laser surgical treatments, with many more therapeutic interventions in development. Similarly, technology for diagnosing and following glaucoma has undergone major changes. Optical coherence tomography is an increasingly used technology that will likely replace fundus photography as a mainstay to diagnose and monitor glaucoma. Keeping up with the broad advance in technology and treatment strategy is challenging but is essential if we are to utilize this knowledge effectively for patient care.

It has been a great joy seeing how Shields Textbook of Glaucoma is also evolving. It is immediately apparent that the sixth edition, like the field of glaucoma itself, continues to evolve. With the incorporation of full color, there is a sharper sense of what one sees clinically. Additionally, Shields has taken its place on the Internet, making it accessible almost anywhere or anytime. With increasing types of data, the ability to analyze and utilize multiple types of information will only increase. The need to have rapid and accurate information immediately at hand is becoming essential to the practice of medicine as the demands for higher efficiency and efficacy continue.

As you open the sixth edition of Shields Textbook of Glaucoma, we hope you, the reader, will appreciate the efforts of a dedicated team that values the tradition that was started so long ago.

R. Rand Allingham

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ACKNOWLEDGMENTS

Authors: Allingham, R. Rand

Title: Shields Textbook of Glaucoma, 6th Edition Copyright ©2011 Lippincott Williams & Wilkins > Front of Book > ACKNOWLEDGMENTS ACKNOWLEDGMENTS

It has been a great pleasure and an honor to serve as the senior author of the sixth edition of Shields Textbook of Glaucoma. What would seem a daunting task has been an exciting and enjoyable journey. This landmark work, initiated almost 3 decades ago by Bruce Shields, has become the leading textbook on glaucoma worldwide. What Bruce did himself now takes a dedicated and talented team. I have had the honor of sharing this journey with four seasoned and gifted authors, Karim, Doug, Sy, and Sharon. Remarkably, this group has managed to keep the passion and spirit of this great work. This is no small undertaking when one considers the tidal wave of new information and technology that has occurred over the intervening years.

To assist us in this process has been the addition of a talented new member on our team, Cris Coren, our manager, copyeditor, and amazing “fix it” person! Cris was selected and elected to this position by unanimous decree of the authors and editor. She has seamlessly edited text, managed references and figures, improved flow, and organized the authorship and editing process. Being a stickler for detail, Cris refined the language and structure of Shields, not unlike a conductor for a symphony. In brief, Cris has made this edition of Shields better while making the journey a true pleasure.

Of course, none of this would be possible without the many dedicated and talented persons at Lippincott Williams & Wilkins who have shepherded this process from the beginning. Not only is this the first complete four-color edition, it is also the first to have an online version. This enhances the value to our readership and allows us to pursue new content in an increasingly wireless society. In particular, I would like to thank Eric Johnson at Red Act Group for his steady encouragement and wise counsel; Emilie Moyer, who has worked her magic on the appearance and “feel” of this edition; Jonathan Pine, a seasoned veteran at LWW whose oversight and guiding hand have been crucial to our success over the years; and Purnima Narayanan and the talented compositor and copyeditor teams at MPS Limited, a Macmillan Company, for their exceptional attention to detail and professionalism. Thanks as well to Julie Cancio Harper, our “permissions guru,” for help with copyright clearance; and Beth Jenkinson and Ryan McCammon, for valuable editorial assistance.

Of course, all success derives from family and friends. Bruce Shields remains the person I come to for advice, counsel, and a heart-to-heart. Thank you, dear friend, for these many years together and those to come! My undying gratitude goes to Robin Goodwin, who has, most would say miraculously, kept order in my professional life at Duke for over 17 years. Erin, my daughter and soon-to-be English professor, who has been my “in-house” resource for all things literate! Michael, my son and evolving ophthalmologist and scientist, I can only imagine how the world of Ophthalmology will change in your lifetime. Of course, Anna, my wife, whose patience, understanding, and support have been central to this and so many other undertakings.

Finally, I wish to thank all of you who read and benefit from the knowledge contained in these pages. Your kind and constructive comments are critically important to us as we strive to provide lucid and useful information that will help those who suffer from glaucoma.

Rand Allingham

I am grateful to Bruce and Rand for having provided the opportunity to participate in this undertaking, which I regard as a privilege and an honor. I consider them exemplars par excellence. I have also enjoyed collaborating with my coauthors and have learned many new things from them. Over the years, residents and fellows, particularly from the Universities of Ottawa and Alberta, have offered many helpful suggestions. I am thankful for their feedback and hope that users of this book continue to provide input. My wife, Salima, daughters, Safeera, Nabeeha, and my parents, Fateh and Gulshan Damji, have provided incredible inspiration. I am particularly indebted to Salima, whose extraordinary strength, encouragement, and understanding have made it a joy to dedicate time and effort to this endeavor.

Karim Damji

I express my gratitude to my husband, Neil, and to our wonderful children, Rebecca and Benjamin, for unwavering encouragement and support. I am grateful to Rand and Bruce for the privilege of participating in this wonderful creation; to my coauthors for continuing to teach me so much about glaucoma; to Cris Coren for making the process seamless and simple; and to Bruce Shields, my mentor, inspiration, and friend.

Sharon Freedman

To my husband, Mike Fetters, and my four sons, Kori, Tomo, Kazu, and Taka, for understanding and supporting my contributions to this book. I am grateful to Gale Oren and her staff for medical information and literature, Richard Hackel and the photography staff for their support of this project, my coauthor colleagues and Cris Coren for their patience and support of this project, and my mentor and friend Bruce Shields.

Sayoko (“SY”) Moroi

I would like to thank my lovely wife, Tina, for your continual support, patience, and encouragement. To our daughters, Ashley and Alyssa, whose smiles and laughter bless our lives. To my father and mother, Dennis and Serena Rhee, for your support and guidance. To Susan Rhee, for your understanding, and to all my families— Rhee, Chang, Kim, and Chomakos. Finally, to my friends and coauthors, for the honor of working with you, and to Bruce Shields, our inspiration.

Douglas Rhee

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INTRODUCTION: AN OVERVIEW OF GLAUCOMA

Authors: Allingham, R. Rand

Title: Shields Textbook of Glaucoma, 6th Edition Copyright ©2011 Lippincott Williams & Wilkins

> Front of Book > Introduction: An Overview of Glaucoma Introduction: An Overview of Glaucoma

HISTORICAL BACKGROUND

Although our modern understanding of glaucoma dates back only to the mid-19th century, this group of disorders was apparently recognized by the Greeks as early as 400 BC. In Hippocratic writings, it appears as “glaucosis,” in reference to the bluish-green hue of the affected eye (1). This term, however, was also applied to a larger group of blinding conditions that included cataracts. Although an association with elevated intraocular pressure (IOP) is found in 10th-century Arabian writings, it was not until the 19th century that glaucoma was clearly recognized as a distinct group of ocular disorders.

SIGNIFICANCE OF GLAUCOMA

Glaucoma is a leading cause of irreversible blindness throughout the world. World Health Organization statistics, published in 1995, indicate that glaucoma accounts for blindness in 5.1 million persons, or 13.5% of global blindness (behind only cataracts and trachoma at 15.8 million persons, or 41.8% of global blindness, and 5.9 million, or 15.5%, respectively) (2). Worldwide, it has become the second most common cause of bilateral blindness. Open-angle glaucoma and angle-closure glaucoma were estimated to affect approximately 66.8 million persons by the year 2000, with 6.7 million experiencing bilateral blindness (3).

In the United States, glaucoma is the second leading cause of blindness and the most frequent cause of blindness among African Americans. The U.S. Department of Commerce's Bureau of the Census 1990 population data (provided by the National Society to Prevent Blindness in 1993) estimated the total number of glaucoma cases among persons 40 years of age or older to be 0.5 million (5.6%) among African Americans and 1.5 million (1.7%) among whites and others (including Hispanics, Asians, and Native Americans). Glaucoma is also the second most common reason for ambulatory visits to ophthalmologists in the United States by Medicare beneficiaries and is the leading cause of such visits among African Americans. An analysis of a random 5% subsample of 1991 Medicare beneficiaries (National Claims History File—Part B) revealed approximately 223 office visits for glaucoma per 1000 patients among African Americans and 154 such visits for whites (compared with 136 and 194 office visits, respectively, for cataracts) (4). Although glaucoma more commonly affects older adults, it occurs in all segments of society, with significant health and economic consequences (5), making it a major public health problem.

A DEFINITION OF GLAUCOMA A Group of Diseases

The most fundamental fact concerning glaucoma is that it is not a single disease process. Rather, it is a large group of disorders characterized by widely diverse clinical and histopathologic manifestations. This point is not commonly appreciated by the general public, or even by a portion of the medical community, which frequently leads to confusion. For example, a patient may have difficulty understanding why she has no symptoms with her glaucoma, when a friend experienced sudden pain and redness with a disease of the same name. Another individual may avoid the use of cold medications because the package inserts cautions against its use in patients with glaucoma, but this caution is only warranted for certain types of glaucoma.

Terminology

1 - Cellular and Molecular Biology of Aqueous Humor Dynamics Page 2 of 225

in aqueous humor dynamics. A: Limbus. B: Main route of aqueous humor outflow (“ conventional” or trabecular outflow). C: Ciliary body (site of aqueous humor production and other outflow route of

“ unconventional” or uveoscleral outflow). D: Iris and lens. OVERVIEW OF THE ANATOMY

Aqueous humor has multiple physiologic functions throughout the various ocular structures. The two main structures related to aqueous humor dynamics are the ciliary body, the site of aqueous humor production, and the limbal region, which includes the trabecular meshwork, the principal site of aqueous humor outflow. Figure 1.1 shows the close relationship between these two structures and the surrounding anatomy.

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The limbus is the transition zone between the cornea and the sclera. On the inner surface of the limbus is an indentation; the scleral sulcus, which has a sharp posterior margin; the scleral spur; and a sloping anterior wall that extends to the peripheral cornea.

A sieve-like structure, the trabecular meshwork, bridges the scleral sulcus and converts it into a tube, called the Schlemm canal. Where the meshwork inserts into the peripheral cornea, a ridge is created, known as the Schwalbe line. The Schlemm canal is connected by intrascleral channels to the episcleral veins. The trabecular meshwork, Schlemm canal, and the intrascleral channels make up the main route of aqueous humor outflow

The ciliary body attaches to the scleral spur and creates a potential space, the supraciliary space, between itself and the sclera. On cross section, the ciliary body has the shape of a right triangle, and the ciliary processes (the actual site of aqueous humor production) occupy the innermost and anterior-most portion of this structure in the region called the pars plicata (or corona ciliaris). The pars plicata region is also composed of smooth muscle, which serves the important functions of accommodation and uveoscleral outflow. The ciliary processes consist of 70 to 80 radial ridges (major ciliary processes), between which are interdigitated an equal number of smaller ridges (minor or intermediate ciliary processes) (1) Figure 1.2. The posterior portion of the ciliary body, called the pars plana (or orbicularis ciliaris), has a flatter inner surface and joins the choroid at the ora serrata.

The anterior-posterior length of the ciliary body in the adult eye ranges from 4.6 to 5.2 mm nasally to 5.6 to 6.3 mm temporally, according to various reports, with the pars plana accounting for approximately 75% of the total length. The most rapid phase of growth of the proportions of the pars plana occurs between 26 and 35 weeks' gestation (2). At birth, these measurements are 2.6 to 3.5 mm nasally and 2.8 to 4.3 mm temporally, and they reach three fourths of the adult dimen-sions by 24 months, with a constant ratio between pars plicata and pars plana (3).

Figure 1.2 Gross anatomic view of the inside view of the anterior segment showing the radial ridges of the ciliary processes at the pars plicata portion of the ciliary body.

The iris inserts into the anterior side of the ciliary body, leaving a variable width of the latter structure visible between the root of the iris and the scleral spur, referred to as the ciliary body band. The lens is suspended from the ciliary body by zonules and separates the vitreous posteriorly from the aqueous humor anteriorly. The iris separates the aqueous humor compartment into a posterior and an anterior chamber, and the angle formed by the iris and the cornea is called the anterior chamber angle. Further details regarding the gonioscopic appearance of the anterior chamber angle are considered in Chapter 3. With this basic outline of the anatomic structures that regulate aqueous humor dynamics, it is important to review the development of these structures and other structures of the eye. Current clinical training teaches clinicians to subclassify various ocular disease phenotypes among patients who have “outside” ocular abnormalities (or ocular phenotypes) that often have a strong genetic component, which is discussed in Chapter 8. (Another useful resource for information on human diseases with a genetic component is “Online Mendelian Inheritance in Man,” or OMIM. It can be accessed at www.ncbi.nlm.nih.gov.) As more disease genes are identified, the clinical phenotypic presentations, which are an “outside in” approach to understand di sease, will merge with an “inside out” approach, whereby identified gene mutations and risk alleles are related to the ocular and systemic phenotypes. Our knowledge of the human genome, which has approximately 30,000 genes (4), and proteinomics (5), which is the study of proteins, will provide a blueprint for understanding individual variations in eye anatomy and ocular disease presentations (6).

EMBRYOLOGY OF THE EYE

The eye shows incredible diversity among the various phyla from simple eye spots, through compound eyes, to complex structures with a single lens and photoreceptor arrays (7). The developmental biology of the vertebrate eye from surface ectoderm, neural crest, and mesodermal mesenchyme has been extensively investigated (8). An overall schematic of eye development is summarized in Figure 1.3. The tissue origin of the various ocular structures is summarized in Table 1.1.

Ocular development from these three tissue sources involves complex, specific cell growth, and differentiation processes, which are not fully understood. These complex processes involve carefully timed expression of various growth factors and their receptors, other signaling molecules and their pathways, transcription factors, and structural components (9). In general, the genes that regulate development can be categorized into different functional classes as follows: (a) structural genes, such as cytoskeletal components, which may be considered as “housekeeping” genes that carry out ubiquitous biochemical and structural functions; (b) regulatory genes, such as transcription factors (i.e., molecular switches that control mRNA production by other genes) and cell signaling molecules, which mainly determine specialized expression of

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genes; and (c) cell-specific genes encoding for specialized proteins of a particular cell type within an organ, such as the unique proteins expressed in the photoreceptors. Abnormalities in expression of the individual genes or interaction among multiple genes caused by gene mutations or altered expression can lead to congenital defects and human disease (Table 1.2).

Figure 1.3 Schematic of early eye development from the optic vesicle stage (A), lens placode stage (B), and optic cup stage (C). During the optic cup stage (C), the neurogenesis of the retina proceeds in a highly regulated process with ganglion cells differentiating first, followed by the amacrine cells, bipolar cells, horizontal cell photoreceptors, and Müller ( glial) cells. (Modified from Traboulsi El, ed. Genetic Diseases of the Eye; 1998:12, 15. By permission of Oxford University Press.)