Abstract: Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus, which is a serious threat to patients' visual function, and its occurrence is closely related to the imbalance of glucose and lipid metabolism, hypertension and insulin resistance. Fibroblast growth factor 21 (FGF21), as a key metabolic regulator, not only enhances insulin resistance and improves glucose-lipid metabolism, but also directly regulates the function of retinal vascular endothelial cells through specific activation of the FGF receptor/β-Klotho complex. Notably, despite significantly elevated plasma levels of FGF21 in patients with clinical DR, its pathophysiologic significance remains controversial and may involve compensatory protective mechanisms or FGF21-resistant states.The role and possible mechanisms of FGF21 in the progression of DR may be mainly through the activation of signaling pathways such as AKT/ERK and Nrf2, which inhibit oxidative stress, attenuate the inflammatory response, block pathologic angiogenesis, vascular leakage, and improve neural retinal function.

Key words: Fibroblast growth factor 21, Diabetic retinopathy, Molecular mechanism