IGF1 and Hyperglycemia: Hyperglycemia promotes the secretion of growth factors, such as vascular endothelial growth factor (VEGF) (Rezzola et al., 2021), fibroblast growth factor (FGF) (Li et al., 2019), insulin-like growth factor-1 (IGF-1) (Actis Dato et al., 2021), and transforming growth factor-β (TGF-β) (Schmalen et al., 2021), which are involved in the regulation of neovascularization and cause retinal fibrosis in DR.