The breakdown of the BRB, which is a pathological sign of several major vision-threatening vascular diseases, like diabetic retinopathy, age-related macular degeneration and retinopathy of prematurity [38], might modify the RGC microenvironment, and may contribute to a contralateral transfer of overproduced BDNF. The gene discussed is BDNF; the disease is age-related macular degeneration.