Intravitreal Pharmacotherapy for the Treatment of Macular Edema Secondary to Branch Retinal Vein Occlusion: A Narrative Review

Branch retinal vein occlusion (BRVO) is the next most common retinal vascular disorder following diabetic retinopathy, and macular edema is the most frequent cause of visual impairment in patients with BRVO. For many years, grid laser photocoagulation was the standard of care for the treatment of BRVO-associated macular edema. Grid laser photocoagulation was used for patients with macular edema secondary to BRVO longer than 3 months and visual acuity less than 20/40. Currently increasing data supports the effect of anti-vascular endothelial growth factors in the treatment of BRVO-associated macular edema. Recent studies have shown that intravitreal bevacizumab injection is a safe and effective modality for the treatment of BRVO-associated macular edema; however, the recurrence of macular edema is common following an intravitreal bevacizumab injection. Other anti-vascular endothelial growth factor (VEGF) agents such as ranibizumab, pegaptanib, and aflibercept are effective options. Combining anti-VEGFS with grid laser may be effective in refractory cases and also may prolong the interval between intravitreal injections. Switching to a different anti-VEGF or dexamethasone implant may be effective in the treatment of refractory cases; however, the efficacy of an intravitreal dexamethasone implant may diminish after a few months, and elevated intraocular pressure and cataract formation may occur.