VEGFA and diabetic retinopathy: Activation of β-ARs is considered to upregulate the hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF), which plays a key role in the formation of pathogenic blood vessels in various retinal diseases, such as retinopathy of prematurity and diabetic retinopathy [183,184,185].