Fig. 5.

Pathology and molecular mechanisms of DR. Multiple mechanisms are involved in the pathogenesis of DR. Hyperglycemia can promote oxidative stress through the polyol pathway, accumulation of advanced glycosylation end-products (AGEs), the protein kinase C (PKC) pathway, and the hexosamine pathway, and exacerbate inflammation and abnormal angiogenesis by stimulating the secretion of inflammatory factors and vascular endothelial growth factor, inducing retinal dysfunction until vision loss