National Health and Nutrition Examination Survey (Nhanes)

The leading causes of visual impairment in the United States are primarily age-related eye diseases including cataracts, diabetic retinopathy, glaucoma, and age-related macular degeneration. More than 3.4 million Americans aged 40 years and older are either blind or are visually impaired. Although it is believed that half of all blindness can be prevented, the number of people with blindness continues to increase in the United States. Unfortunately, scant data exist for national estimates and trends, and current estimates are based on data that are 25 years old and not nationally representative. Glaucoma is the leading cause of irreversible blindness and is a prevalent disease associated with aging. Although glaucoma can usually be controlled by early detection and treatment, half of the people with glaucoma are not diagnosed, and glaucoma is still the number one blinding disease among African Americans. Diabetic retinopathy is the leading cause of new cases of blindness among adults aged 20-74 years. It can affect almost anyone with diabetes and contributes to both individual and societal burden. With the growing epidemic of diabetes and demographic changes in the American society, vision loss and eye diseases due to diabetes will be a growing major public health problem. Efficacious and cost-effective strategies to detect and timely treat diabetic retinopathy are available, but among people with diabetes, ocular eye examination is received by only about two-thirds of the persons for whom the exam is recommended and varies significantly across health care settings. Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in the U.S. among people aged 65 years or older. The frequency of AMD is expected to increase as the population lives longer. Population-based estimates of the prevalence and severity of AMD will help in allocating resources as treatment modalities become available.