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 (>= 90 days' duration) were randomized to treatment with 700 mu g or 350 mu g 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-mu g group (33.3%) and 350-mu g group (21.1%) than the observation group (12.3%; P=.007 vs 700-mu g group). At day 180, a BCVA improvement of 10 letters or more was seen in 30% of eyes in the 700-mu g group, 19% in the 350-mu g group, and 23% in the observation group (P >= .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 mu g 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 mu g, may have potential as a treatment for persistent DME. Trial Registration: clinicaltrials.gov Identifier: NCT00035906