Intravitreal Ranibizumab for Macular Edema Secondary to Central Retinal Vein Occlusion

Purpose: To evaluate the safety and efficacy of intravitreal ranibizumab for macular edema secondary to central retinal vein occlusion. Methods: Patients with macular edema secondary to perfused central retinal vein occlusion were enrolled in this ongoing, prospective, open-label study. Treatment was initiated with monthly intravitreal ranibizumab for 3 months. In the first year, additional injections were administered for edema in quarterly intervals as needed (PRN) for Cohort 1 (n = 10) and monthly PRN for Cohort 2 (n = 10). In the second year of treatments, all patients received monthly PRN treatment. Early Treatment Diabetic Retinopathy Study best-corrected visual acuity, central retinal thickness, fundus photographs, and fluorescein angiograms were evaluated, and the incidence and severity of adverse events were documented. Results: Mean change in best-corrected visual acuity and central retinal thickness improved during the induction phase in both groups. During the remainder of the first year for Cohort 1, initial gains were lost during quarterly treatment but returned with monthly PRN treatment in the second year. For Cohort 2, improvement in best-corrected visual acuity and central retinal thickness from the induction phase was maintained through Month 24. Nineteen of 20 patients experienced a reduction in intraretinal hemorrhage, optic nerve swelling, and/or venous diameter after treatment. One myocardial infarction, one cerebrovascular accident, and no serious ocular adverse events were reported. Iris neovascularization was developed in none of the eyes. Conclusion: Ranibizumab was well tolerated and associated with a greater reduction in macular edema and improvement in visual acuity in the monthly PRN regimen compared with quarterly treatment. Vision lost during the quarterly PRN injection intervals in the first year of Cohort 1 could be regained by switching to monthly PRN dosing.