The intravitreal injection of drugs that inhibit vascular endothelial growth factor (anti-VEGF) is the first therapeutic option in the treatment of choroidal neovascularization that appears in age-related macular degeneration (AMD), as well as in the treatment of diabetic macular edema and macular edema secondary to retinal vein occlusion. The gene discussed is VEGFA; the disease is retinal vein occlusion.