Although Mastropasqua et al. found that retinal vessel plexi density did not change significantly after DEX implant and there was no correlation between vessel density and functional parameters such as visual acuity and retinal sensitivity [36], it has been demonstrated that intravitreal steroid, in eyes with macular edema due to retinal vein occlusion or diabetic retinopathy, causes a reduction of vessel diameter probably due to the blockage of VEGF [37, 38]. This evidence concerns the gene VEGFA and retinal vein occlusion.