VEGFA and macular retinal edema: Although the pathogenesis of macular edema secondary to RVO is, as yet, unclear, the production of anti-inflammatory cytokines (prostaglandins and interleukin-6) and angiogenic factors as vascular endothelial growth (VEGF) and the upregulation of tight junctional proteins resulting from the hydrostatic effects of venous hypertension appear to be the keys [2, 3].