Data collection on retinopathy as a public health tool: The Hubble telescope equivalent of looking back in time

OBJECTIVE:To test whether the rate of diabetic retinopathy development in a population calculated from the prevalence of retinopathy and duration of diabetes can be used to assess their prior glycemic control. RESEARCH DESIGN AND METHODS:9281 patients with type 2 diabetes (T2DM) were grouped by duration of diabetes and plotted against the % of retinopathy in each band. The slope was used to calculate retinopathy development/year (RD/y). We correlated the RD/y with updated HbA1c within groups of different ethnicity, age of diabetes onset, year of the eye examination, socio-economic status and fluency in English. RESULTS:Differences in ethnicity, age of diabetes onset and year of the eye examination affect RD/y to a degree predictable from their respective updated HbA1c. No such relationship with updated HbA1c was evident when a factor has no apparent effect on RD/y. CONCLUSIONS:This relationship between prevalence of retinopathy and duration of diabetes can be used to assess future retinopathy burden. Perhaps more intriguing, the camera can be reversed to allow an estimate of prior glycemic control of a population from its retinopathy prevalence. Health care organizations can use this method to project future needs and to assess adequacy of prior glycemic control.