Fig. 1
From: Oxidative stress and epigenetics in ocular vascular aging: an updated review
Schematic illustration of retinal vascular aging in response to oxidative stress in diabetic retinopathy (DR). Oxidative stress is manifested as increased levels of ROS, NADPH oxidase and superoxide, in contrast with decreased expression of SOD, catalase and antioxidants. Oxidative stress induces endothelial degeneration, pericyte loss and basement membrane thickening, which aggravates vasoregression in the process of DR. Concurrently, retinal ischemia occurred due to the compromised endothelium-dependent dilation and decreased blood flow in retinal microvessels. Vasoregression and ischemia coordinate with each other and eventually result in BRB breakdown and neovascularization during DR progression. ROS: reactive oxygen species, SOD: superoxide dismutase