Branch retinal vein occlusion (BRVO) is a relatively prevalent cause of reduced vision primarily due to macular edema. Vascular endothelial growth factor (VEGF) is the major stimulator of excessive vascular leakage and also contributes to retinal hemorrhages and progressive retinal nonperfusion (RNP). Progressive RNP results in worsening of retinal ischemia further increasing levels of VEGF, resulting in a positive feedback loop for disease worsening over time. Aggressive early treatment with a specific antagonist of VEGF causes rapid improvement in edema and visual acuity, speeds resolution of hemorrhages, and stabilizes or improves RNP. Therefore, first-line treatment of acute BRVOs is monthly injections of an anti-VEGF agent for at least 6 months. After that, a period of monthly follow up with anti-VEGF treatment, only if there is recurrent edema, can be used to gauge persistent disease activity and the need for grid laser photocoagulation to diffuse leakage in the macula outside the foveal avascular zone. Following grid laser, another period of monthly follow up with anti-VEGF treatment only if there is recurrent edema provides a measure of persistent disease activity, and if frequent injections are still needed to control edema, the benefits and risks for switching to dexamethasone implants should be discussed with the patient.
Changes in metamorphopsia after the treat-and-extend regimen of anti-VEGF therapy for macular edema associated with branch retinal vein occlusion