While long-term (five years or longer) clinical trial data on anti-VEGF drugs for DR are not available, the observations that a VEGF neutralizing antibody and shRNA cause retinal degeneration in experimental diabetes and retinopathy of prematurity [24,25] suggest a possibility of having adverse effects in some long-term anti-VEGF drug-treated patients. This evidence concerns the gene VEGFA and retinal degeneration.