Lack of association between thiazolidinediones and macular edema in type 2 diabetes: the ACCORD eye substudy.

OBJECTIVE: To assess the cross-sectional association of thiazolidinediones with diabetic macular edema (DME).

METHODS: The cross-sectional association of DME and visual acuity with thiazolidinediones was examined by means of baseline fundus photographs and visual acuity measurements from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. Visual acuity was assessed in 9690 participants in the ACCORD trial, and 3473 of these participants had fundus photographs that were centrally read in a standardized fashion by masked graders to assess DME and retinopathy from October 23, 2003, to March 10, 2006.

RESULTS: Among the subsample, 695 (20.0%) people had used thiazolidinediones, whereas 217 (6.2%) people had DME. Thiazolidinedione use was not associated with DME in unadjusted (odds ratio [OR], 1.01; 95% confidence interval [CI], 0.71-1.44; P = .95) and adjusted (OR, 0.97; 95% CI, 0.67-1.40; P = .86) analyses. Significant associations with DME were found for retinopathy severity (P < .001) and age (OR, 0.97; 95% CI, 0.952-0.997; P = .03) but not for hemoglobin A(1c) (P = .06), duration of diabetes (P = .65), sex (P = .72), and ethnicity (P = .20). Thiazolidinedione use was associated with slightly greater visual acuity (0.79 letter; 95% CI, 0.20-1.38; P = .009) of uncertain clinical significance.

CONCLUSIONS: In a cross-sectional analysis of data from the largest study to date, no association was observed between thiazolidinedione exposure and DME in patients with type 2 diabetes; however, we cannot exclude a modest protective or harmful association. Trial Registration clinicaltrials.gov Identifier: NCT00542178.