Commonly prescribed thiazolidinedione medications for type 2 diabetes – brand names Avandia and Actos among others – may raise the risk of a serious eye condition called diabetic macular edema (DME), according to a study published online in the Archives of Internal Medicine by Iskandar Idris, MD, FRCP and colleagues ofthe University of Nottingham.

The team's large retrospective cohort study analyzed the primary care electronic medical records of more than 100,000 patients with type 2 diabetes. The researchers found that even after adjustment for various factors known to influence diabetic retinopathy, exposure to a thiazolidinedione is associated with an increased risk of developing DME.

Because the condition may eventually lead to blindness, the fact that this study observed that the risk of DME continued to increase during the 10-year of follow-up is important. Also, the patients at greatest risk of developing DME were those taking thiazolidinediones in combination with insulin.