African Americans have the highest rates of vision loss related to diabetes compared to other Americans with the disease, and researchers suspect access to eye exams may play a role in the disparity.
Diabetic macular edema (DME), one of the leading causes of blindness in diabetic patients in the United States, occurs when fluid and protein accumulates on the macula of the eye, which is part of the retina, causing it to thicken and swell. Central vision is affected and, if left untreated, can lead to slight blurring or even blindness.
“We were surprised that our research showed that African Americans have the highest rates of DME, when Hispanics tend to have the highest prevalence of diabetes,” says Rohit Varma, professor and chair of ophthalmology at University of Southern California and director of the USC Eye Institute.
“There is not enough vision screening for DME among diabetics, yet there are much better therapies available that are covered by insurance. We hope that our research will help those in the position to influence policy to get a better handle on costs and where the need for treatment is the greatest.”
For the study, published online in the Journal of the American Medical Association (JAMA) Ophthalmology, researchers used the National Health and Nutrition Examination Study (NHANES) database, a national dataset measuring the health and nutritional status of American adults and children.
The assessment has been surveying about 5,000 Americans every year since the early 1960s and is used by researchers nationwide to determine the prevalence of major diseases and risk factors for disease.
As part of NHANES, subjects undergo a physical exam that includes photos of their retinas, which Varma’s team reviewed to determine the prevalence of DME.
Diabetic eye disease is one of the leading causes of vision loss in people ages 20-70 years. Approximately 347 million people throughout the world have diabetes mellitus, and the Centers for Disease Control estimates that 25.8 million Americans had diabetes in 2010.
Clinicians should assess diabetes patients, especially those who are African American or Hispanic, more closely for vision loss, Varma says. Also, patients should do everything they can to control their glucose and monitor their own vision.
Varma says he will next examine barriers African Americans face concerning access to eye care.
Researchers from Johns Hopkins University School of Medicine, Outcomes Insights, Ohio State University Division of Public Health, and Genentech contributed to the study. Varma is a consultant for Genentech, which funded the research.