Therapy of macular edema with an intravitreal dexamethasone implant

Purpose: Macular edema is the main cause for visual decline after branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO) or at diabetic retinopathy (DRP). Current therapeutic options are not yet satisfying. Intravitreal steroids (e.g. Triamcinolone acetate) are promising, but they have to be repeated often. Methods and patients: Posurdex (Allergan, Inc.) is a small biodegradable polymer-implant (0.45 x 6.5 mm), also called "dexamethasone posterior segment drug delivery sys-tem" (DEX PS DDS) and injected at pars plana with an injector intravitreally where it should be active 6 to 12 months. A phase 2 randomized multicenterstudy for treatment of macular edema due to different causes including 306 eyes in 3 groups (350 jig dexamethason, n = 100, 750 mu g dexamethason, n = 101, control group, n = 105) has been finished after 6 months. Results: The first clinical trial showed dose dependent improvement of visual acuity and reduction of retinal thickness in OCT after 3 months of treatment. A significant potency could be observed at macular edema due to BRVO, CRVO, DRP, uveitis and after cataract surgery. Complications included rise of intraocular pressure and vitreal hemorrhage group. During observation period no other complications could be observed. Conclusion: A prolonged controlled release of intravitreal steroids represents a promising therapeutic option for the treatment of macular edema. The first results of a phase 2 study represent a safe and effective treatment. Further evaluation is necessary to evaluate clinical feasibility and long term results.