Randomized Controlled Trial of an Intravitreous Dexamethasone Drug Delivery System in Patients With Diabetic Macular Edema

OBJECTIVE: To evaluate the safety and efficacy of a dexamethasone intravitreous drug delivery system (DDS) in eyes with diabetic macular edema (DME). METHODS: Patients with persistent macular edema (> or = 90 days' duration) were randomized to treatment with 700 microg or 350 microg of dexamethasone DDS or observation. One eye from each patient was designated as the study eye. The analysis is of the eyes in this study with DME (n = 171). MAIN OUTCOME MEASURES: The primary outcome measure was the proportion of eyes that achieved an improvement in best-corrected visual acuity (BCVA) of 10 letters or more from baseline at day 90. Other outcome measures included fluorescein leakage, central retinal thickness, and safety parameters. RESULTS: At day 90, a BCVA improvement of 10 letters or more was seen in more eyes in the 700-microg group (33.3%) and 350-microg group (21.1%) than the observation group (12.3%; P = .007 vs 700-microg group). At day 180, a BCVA improvement of 10 letters or more was seen in 30% of eyes in the 700-microg group, 19% in the 350-microg group, and 23% in the observation group (P > or = .4 for treated vs observed eyes). There were also significantly greater improvements in central retinal thickness and fluorescein leakage in treated eyes than observed eyes (P = .03; day 90). Dexamethasone DDS was well tolerated. CONCLUSIONS: In eyes with persistent DME, treatment with 700 microg of intravitreal dexamethasone DDS is well tolerated and produces significant improvements in BCVA, central retinal thickness, and fluorescein leakage compared with observation (statistically significant at day 90). APPLICATION TO CLINICAL PRACTICE: Dexamethasone DDS, 700 microg, may have potential as a treatment for persistent DME. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00035906.