Diabetic eye disease on the rise

With the aging of the population, the number of Americans with major eye diseases is increasing, and vision loss is becoming a major public health problem. By the year 2020, the number of people who are blind or have low vision is projected to increase substantially. These findings appear in the April issue of Archives of Ophthalmology.

Blindness or low vision affects 3.3 million Americans age 40 and over, or one in 28, according to study authors. This figure is projected to reach 5.5 million by the year 2020. The study reports that low vision and blindness increase significantly with age, particularly in people over age 65. People 80 years of age and older currently make up eight percent of the population, but account for 69 percent of blindness. The study provides the most robust and up-to-date estimates available of the burden of visual impairment. It was sponsored by the National Eye Institute (NEI), part of the Federal government's National Institutes of Health (NIH).

"Blindness and low vision can lead to loss of independence and reduced quality of life," said Elias A. Zerhouni, M.D., Director of the NIH. "As our population lives longer, eye disease will be an ever greater concern. These data underscore NIH's commitment to the support of vision research that will prevent, delay, and possibly cure eye diseases."

The study identifies age-related macular degeneration (AMD), glaucoma, cataract, and diabetic retinopathy as the most common eye diseases in Americans age 40 and over. The leading cause of blindness among white Americans is AMD, accounting for 54 percent of all blindness. Among African Americans, the leading causes of blindness are cataract and glaucoma. Among Hispanics, glaucoma is the most common cause of blindness. The study authors emphasize the importance of annual comprehensive eye examinations in preventing and/or delaying eye disease for those at higher risk for blindness, such as those over age 65, people with diabetes, or African Americans over age 40.

Study authors provide estimates of the number of Americans with each disease. The authors say that due largely to the aging of the population, the prevalence of low vision and blindness will increase markedly by 2020.

There were other significant findings from the study:

• AMD is strongly associated with increasing age, particularly after age 60. AMD rises dramatically in whites over age 80; more than one in 10 white Americans over age 80 has vision loss from AMD.
• Glaucoma is almost three times as common in African Americans as in whites.
• The prevalence of glaucoma rises rapidly in Hispanics over age 65.
• Cataract is the leading cause of low vision among all Americans, responsible for about 50 percent of all cases.
• One in every 12 people with diabetes age 40 and older has vision-threatening diabetic retinopathy.

"These data will help identify areas where we should direct our research efforts," said NEI Director Paul A. Sieving, M.D., Ph.D. "Also, health professionals and state and local agencies can use study data to prioritize public health programs emphasizing the importance of early detection and timely treatment. Developing blindness prevention strategies could help address the potentially devastating impact of the increased prevalence of eye diseases in the next few decades."

Frederick Ferris III, M.D., director of clinical research at the NEI, said that the estimates of low vision and blindness "are the first to take full advantage of information derived from several excellent eye disease studies reported since 1990. These data, collected from different populations, allow us to identify the most common eye diseases and give us good estimates of their relative magnitudes."

The study was conducted by the Eye Disease Prevalence Research Group, a consortium of principal investigators who have conducted population-based eye disease studies. The Eye Disease Prevalence Research Group produced prevalence estimates of blindness and low vision in people age 40 and over by analyzing standardized data from several high quality studies.The derived prevalence rates were then modeled to the U.S. population using 2000 census data, and projected to 2020 based on 2020 US census estimates.

A list of the eye disease studies of various populations analyzed by the Eye Disease Prevalence Research Group, and their respective authors, and data tables are attached.