IGF1 and hypertensive disorder: The complex pathogenesis of hyperglycemia and hypertension in retinal damage remains unclear, but significant evidence has indicated that chronic hyperglycemia and hypertension lead to oxidative injury, microthrombi formation, cell adhesion molecule activation, leukostasis and cytokine activation including vascular endothelial growth factor, insulin-like growth factor-1, angiopoetin-1 and -2, stromal-derived factor-1, fibroblast growth factor-2 and tumor necrosis factor.