Overview of age-related ocular conditions.

The United States is an aging society. The number of Americans 65 years or older is expected to more than double over the next 40 years, from 40.2 million in 2010 to 88.5 million in 2050, with aging baby boomers accounting for most of the increase. As the society ages, the prevalence of age-related diseases, including diseases of the eye, will continue to increase. By 2020, age-related macular degeneration, one of the leading causes of vision loss, is expected to affect 2.95 million individuals in the United States. Likewise, the prevalence of open-angle glaucoma, estimated at 2.2 million in 2000, is projected to increase by 50%, to 3.36 million by 2020. As the eye ages, it undergoes a number of physiologic changes that may increase susceptibility to disease. Environmental and genetic factors are also major contributors to the development of age-related ocular diseases. This article reviews the physiology of the aging eye and the epidemiology and pathophysiology of 4 major age-related ocular diseases: age-related macular degeneration, glaucoma, diabetic retinopathy, and dry eye.