Abbreviations: BRVO = Branch retinal vein occlusion, RVO = Retinal vein occlusion, CFT = Central foveal thickness, MFT = Maximum foveal thickness, VEGF = Vascular endothelial growth factor, MO = Macular oedema, CDVA = Corrected distance visual acuity, PRN = Pro-re-Nata, SD-OCT = Special-domain optical coherence tomography, FT = Foveal thickness, LogMAR = Logarithm of the Minimum Angle of Resolution, WHO = World Health Organization, RPE = Retinal pigment epithelium. This evidence concerns the gene VEGFA and macular retinal edema.