A Clinical Conundrum: Intensifying Glycemic Control in the Presence of Advanced Diabetic Retinopathy.

Abstract

Diabetic retinopathy (DR) is a potentially devastating complication of diabetes because of the risk of developing blindness. While therapies to prevent blindness are improving, in much of the world visual impairment continues to occur and impact on the lives of people with diabetes and the societies they live in (1,2). Glycemic control has been shown to provide protection from progression of DR (3–5), but there appear to be limits to that protection. Lowering A1C with a goal of achieving A1C <7% was no better than using a goal slightly above that (6.8% vs. 7.3%) when baseline A1C was ∼7.5% at the outset; this small decrement and small continued difference did not further protect the retina (6). Furthermore, if duration of diabetes is sufficiently long, even relatively tight control is eventually associated with development of DR (3–5), suggesting that there are other factors that mediate DR besides glycemia (7,8). Another factor that might limit the effect of improving glycemia to prevent progression is the presence of advanced DR at the time of initiating a glycemic control trial (9). The Veterans Affairs Diabetes Trial (VADT) did not show evidence of protection against DR progression, explained by the severity level of DR at the start of the trial (9), which was greater than in other comparable large trials (3–5). This month's issue of Diabetes Care contains another publication from the VADT with the major outcome focused on eye procedures that were performed subsequent to entry into …