The estimated prevalence of diabetic retinopathy is about 29% in U.S. adults aged 40 years and older who have diabetes, according to a report in the Aug. 11 issue of JAMA.
The estimated prevalence of vision-threatening retinopathy in the same population is about 4%.
These figures were derived from the most recent (2005-2008) National Health and Nutrition Examination Survey (NHANES) data. “Despite the documented increase in the prevalence of diabetes in the U.S. population, national population-based data on the prevalence and severity of diabetic retinopathy remain scarce, with previous nationwide prevalence estimates dating back to 1988-1994,” said Dr. Xinzhi Zhang of the Centers for Disease Control and Prevention, Atlanta, and his associates.
The investigators based their analysis on a nationally representative sample of 1,006 patients with diabetes who were aged 40 or older when they underwent ophthalmic digital fundus photography as part of the NHANES study.
“Extrapolating to the overall U.S. population in the same period, the prevalences nationwide would be 3.8% and 0.6%,” the investigators wrote (JAMA 2010;304:649-56).
About 1.5% of the study subjects had proliferative diabetic retinopathy and 2.7% had clinically significant macular edema. This translates to rates of 0.2% and 0.4%, respectively, in the general U.S. population.
In the study subjects, there was no significant difference in the rates of retinopathy between patients aged 40-64 years and those aged 65 years and older.
Men were found to have a higher rate of retinopathy (31.6%) than women (25.7%).
Compared with white study subjects, members of minority groups were more likely to have diabetic retinopathy. The rate was 26.4% in whites, compared with 38.8% in black subjects, and 34% in Mexican-American subjects.
As expected, subjects who used insulin and those with higher hemoglobin A1c levels, longer duration of diabetes, and higher blood pressure all were more likely to have retinopathy than were those who did not have these risk factors.
This updated information shows that there is a high prevalence of diabetic retinopathy and a high prevalence of vision-threatening diabetic retinopathy in the United States, particularly in men and racial/ethnic minorities, the authors concluded.
The study was supported by the National Center for Health Statistics and the National Eye Institute, in addition to the CDC. The authors reported no financial conflicts of interest.