Five-year Results of a Randomized Trial with Open-label Extension of Triamcinolone Acetonide for Refractory Diabetic Macular Edema

Objective To report 5-year outcomes from a clinical trial of intravitreal triamcinolone acetonide (IVTA) in eyes with diabetic macular edema (DME) and impaired vision despite previous laser treatment. Design Prospective, double-masked, randomized clinical trial. After completing the 2-year visit, all eyes, including those initially randomized to receive placebo, received IVTA according to prospectively defined guidelines. Participants and Controls A total of 69 eyes (41 patients) were entered into the study, with 34 eyes initially receiving active treatment and 35 eyes receiving placebo. Five-year data were available for 44 of 67 eyes (66%). For the 23 eyes with missing 5-year data, of which 13 received placebo and 10 received IVTA, the last observation was carried forward. Intervention Intravitreal injection of 0.1 ml of 40 mg/ml triamcinolone acetonide with adjunctive laser therapy where appropriate. Main Outcome Measures Improvement of best-corrected logarithm of the minimum angle of resolution visual acuity by ≥5 letters after 5 years compared with baseline and 2 years, and incidence of adverse events. Secondary outcome was the change in central macular thickness. Results Improvement of ≥5 letters after 5 years was found in 14 of 33 eyes (42%) initially treated with IVTA compared with 11 of 34 eyes (32%) initially treated with placebo (zGEE = 0.81, P = 0.4). Foveal thickness decreased by 30 μm (95% confidence interval, −47 to 107 μm) less in the initial-IVTA group than in the initial-placebo group at 5 years (zGEE = 0.76, P = 0.45); 5 of 11 eyes (45%) from the initial-IVTA group that were phakic at commencement of the third year required cataract surgery. A similar number of eyes from each group required ongoing treatment from the third year onward with both laser and IVTA, indicating that IVTA treatment for 2 years does not lead to reduction in the risk of recurrent edema. Conclusions The majority of eyes that initially improved with IVTA maintained their gain after 5 years. No new safety concerns were identified. IVTA treatment may be considered in carefully selected cases of impaired vision caused by advanced DME that are unresponsive to other interventions. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.