Modifiable risk factors of diabetic retinopathy

This study published in the March issue of Diabetes Care examined the global prevalence of and major risk factors for diabetic retinopathy (DR) among people with diabetes. The authors analyzed pooled data from 35 population-based studies worldwide from which they calculated an overall prevalence among diabetic people of 34.6 percent for any DR, 6.96 percent for proliferative diabetic retinopathy (PDR), 6.81 percent for diabetic macular edema (DME) and 10.2 percent for vision-threatening diabetic retinopathy (VTDR). Longer diabetes duration and worse glycemic and blood pressure control were strongly associated with DR.

Based on these data, they conclude that worldwide there are approximately 93 million people with DR, 17 million with PDR, 21 million with DME and 28 million with VTDR. They say these data highlight the substantial global public health burden of DR, the need for effective screening and the importance of modifiable risk factors.

These data were based on a systemic literature review the authors conducted to identify all population-based studies published between 1980 and 2008 in general populations or individuals with diabetes who had ascertained DR from retinal photographs. The included studies provided data on 22,896 individuals with diabetes and for DR end points, including any DR, PDR, DME and VTDR, and major systemic risk factors.

Prevalence estimates of any DR and VTDR were similar in men and women, highest in African-Americans and lowest in Asians. Prevalence rates were substantially higher in those with type 1 diabetes and increased with duration of diabetes and values for HbA1c, blood pressure and cholesterol.