Dexamethasone Intravitreal Implant for Early Treatment and Retreatment of Macular Edema Related to Branch Retinal Vein Occlusion: The Multicenter COBALT Study

Purpose: To evaluate the effect of dexamethasone intravitreal implant for macular edema (ME) following branch retinal vein occlusion (BRVO) in Korean patients. Methods: We performed a prospective, open-label, multicenter study of 71 patients with ME for < 3 months. Retreatment was allowed ≥4 months from the last injection. Results: At 6 and 12 months, mean ± SD best-corrected visual acuity (BCVA) improvement was 18.6 ± 12.9 and 15.3 ± 15.0 letters, respectively. Approximately 70% of maximum treatment response was observed after 1 week. Over the 12-month period, 32 and 49% of patients received 1 and 3 injections, respectively, with a mean ± SD interval of 20.0 ± 5.0 weeks. Patients who required 3 injections had higher central retinal thickness (CRT) and larger macular nonperfusion at baseline compared to those requiring only 1 injection. Adverse events included increased intraocular pressure (35%) and newly diagnosed cataract (16%). Conclusions: Intravitreal dexamethasone treatment with an interval of ≥4 months provides rapid and significantly better improvement in BCVA and CRT in patients with BRVO-associated ME.