A randomized trial comparing intravitreal triamcinolone and focal/grid photocoagulation for diabetic macular edema baseline features

Purpose: To compare baseline demographic, systemic, and ocular characteristics within age and racial subgroups among participants in this Diabetic Retinopathy Clinical Research Network clinical trial and to compare this cohort with other cohorts enrolled in phase 3 clinical trials for diabetic retinopathy. Methods: Thirty-six month, randomized, controlled, multicenter clinical trial of 693 participants with diabetic macular edema enrolled at 88 clinical sites in the United States. Participants were categorized into self-reported race/ethnicity subgroups and into one of three age groups: 18 to <60, 60 to <70, and 70 and older. Results: Mean age of participants was 63 years, 72% were white, and median visual acuity letter score was 62 (-20/63). No substantial difference was identified between racial subgroups for any baseline variable. Older participants were more likely to have Type 2 diabetes mellitus and longer duration disease. The most frequent levels of diabetic retinopathy among 840 study eyes were moderate (level 43) to moderately severe (level 47) nonproliferative disease. Conclusion: While the racial composition of this cohort does not differ from other cohorts in large phase 3 trials that have evaluated participants with diabetic retinopathy, the inclusion of many subjects over age 70 and a better level of glycemic control are distinguishing features. RETINA 28:919-930, 2008.