Two or more dexamethasone intravitreal implants in treatment-naïve patients with macular edema due to retinal vein occlusion: subgroup analysis of a retrospective chart review study

BACKGROUND: Dexamethasone intravitreal implant (DEX implant) is a biodegradable, sustained-release implant that releases dexamethasone for up to 6 months. We evaluated the efficacy and safety of DEX implant in the treatment of macular edema secondary to retinal vein occlusion (RVO) in treatment-naïve patients. METHODS: A multicenter, retrospective, open-label chart review study investigated the efficacy and safety of DEX implant treatment in 289 patients with macular edema secondary to branch or central RVO (BRVO, CRVO) who received ≥2 treatments with DEX implant in the study eye. Concomitant adjunctive RVO treatments were permitted. Data collected from the time of the first implant (baseline) to 3–6 months after the last implant included best-corrected visual acuity (BCVA) and central retinal thickness measured with optical coherence tomography. In this subgroup analysis, we evaluated outcomes in patients who had received no previous treatment for RVO complications. RESULTS: Thirty-nine patients were treatment-naïve at the time of their first DEX implant (18 BRVO, 21 CRVO). Before the initial DEX implant, the mean duration of macular edema in treatment-naïve patients was 4.9 months, mean central retinal thickness was 550 μm, and mean Early Treatment Diabetic Retinopathy Study BCVA was 8.5 lines (20/125 Snellen). Treatment-naïve patients received a mean of 2.9 implants, either as monotherapy (n = 12) or with adjunctive RVO treatments (n = 27). The mean interval between implants was 177 days. After the first through sixth implants, mean changes from baseline BCVA ranged from +3.0 − +8.0 lines, and mean decreases from baseline central retinal thickness ranged from 241–459 μm. BCVA improved in both BRVO and CRVO and in both phakic and pseudophakic eyes. Overall, 83.8 % of treatment-naïve patients gained ≥2 lines in BCVA, 70.3 % gained ≥3 lines in BCVA, and 56.4 % achieved central retinal thickness ≤250 μm. The most common adverse event was increased intraocular pressure. Fifteen treatment-naïve patients had intraocular pressure ≥25 mm Hg; none required laser or incisional glaucoma surgery. CONCLUSION: Treatment with 2 or more DEX implants had a favorable safety profile and improved visual acuity and anatomic outcomes when used, either alone or with adjunctive RVO therapy, as initial treatment for RVO-associated macular edema. TRIAL REGISTRATION: ClinicalTrials.gov NCT01411696, registered on August 5, 2011.