The Epidemiology of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness. Because AMD adversely affects activities of daily living, rendering it more difficult to read, write, and drive, many affected individuals lose their independence in their retirement years. Age-related macular degeneration is estimated to affect more than 8 million individuals in the United States; the advanced form of the disease affects more than 1.75 million individuals. The population over age 85 years is expected to increase by 107% by the year 2020, so the prevalence of this disease will continue to rise dramatically. The only proven treatment available for the dry or nonexudative forms of this disease, which make up about 85% of the cases, is an antioxidant/mineral supplement that can slow the progression of the disease by 25% over 5 years. For the remaining 15% of cases, laser treatment and photodynamic therapy are the only therapies that have been demonstrated by randomized clinical trials to be beneficial for certain subgroups of these patients. Preventive measures are needed to reduce the burden of this disease. Smoking is the most consistently identified modifiable risk factor. Obesity, sunlight exposure, and factors including antioxidants and dietary fat intake may also affect AMD incidence and progression.Nonmodifiable risk factors include increasing age, gender, and family history of the disease. Although much progress has been made over the past decade, finding the causes and mechanisms of this condition remains a challenge.