A study of nearly 3,500 patients shows no link between thiazolidinedione use and diabetic macular edema, but given case reports of such an association, the findings still must be interpreted with caution, researchers say.
The authors of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial Eye Substudy say the findings are reassuring yet inconclusive. “We cannot rule out the possibility of either a modest protective or deleterious association,” wrote Walter T. Ambrosius, Ph.D., of Wake Forest University, Winston-Salem, N.C., and colleagues in the ACCORD Study Group. “A more definitive answer may be provided from the 4-year follow-up data, which will enable us to examine prospectively the relationship between thiazolidinedione exposure and [diabetic macular edema] incidence.”
The Eye Substudy, which involved 3,473 participants from the ACCORD trial, is the largest study to examine the association between diabetic macular edema and thiazolidinedione (TZD) use, the authors noted. Subjects had a mean age of 62 years and were eligible if they had no previous laser photocoagulation or vitrectomy for diabetic retinopathy in either eye.
A total of 695 subjects (20%) had used TZDs, and 217 (6%) had diabetic macular edema. In the adjusted analysis, TZD use was not significantly associated with diabetic macular edema, nor were hemoglobin A1c, duration of diabetes, gender, or ethnicity. Significant association was found between TZDs and both retinopathy and age (Arch. Ophthalmol. 2010;128:312–8).
The study was funded by the National Eye Institute and the National Heart, Lung, and Blood Institute. Dr. Gerstein has received honoraria and grants from GlaxoSmithKline. The University of North Carolina, Chapel Hill, has contracted with various pharmaceutical companies for coauthor Dr. John B. Buse's research or consulting on thiazolidinediones. Dr. Goff has received research funding from Merck and Co.