Randomized controlled study of an intravitreous dexamethasone drug delivery system in patients with persistent macular edema

Objective: To evaluate a dexamethasone intravitreous drug delivery system (DDS) in patients with persistent ( >= 90 days despite treatment) macular edema. Methods: This 6-month study randomized 315 patients with persistent macular edema with best-corrected visual acuity (BCVA)of 20/40 to 20/200 in the study eye to observation or a single treatment with dexamethasone DDS, 350 or 700 mu g. Main Outcome Measures: Proportion of patients achieving a BCVA improvement of 10 or more letters or 15 or more letters, safety measures, change in fluorescein angiographic leakage, and central retinal thickness. Results: At day 90 ( primary end point), an improvement in BCVA of 10 letters or more was achieved by a greater proportion of patients treated with dexamethasone DDS, 700 mu g ( 35%) or 350 mu g ( 24%), than observed patients ( 13%; P < 001 vs 700-mu g group; P=. 04 vs 350-mu g group); an improvement in BCVA of 15 letters or more was achieved in 18% of patients treated with dexamethasone DDS, 700 mu g, vs 6% of observed patients ( P=. 006). Results were similar in patients with diabetic retinopathy, vein occlusion, or uveitis or Irvine-Gass syndrome. During 3 months of observation, 11% of treated patients and 2% of observed patients had intraocular pressure increases of 10 mm Hg or higher. Conclusion: In persistent macular edema, a single dexamethasone DDS treatment produced statistically significant BCVA improvements 90 days after treatment and was well tolerated for 180 days.