Abstract: Endothelial-to-mesenchymal transition (EndoMT) is a complex biological process in which endothelial cells lose their specific markers and acquire mesenchymal phenotype and function. EndoMT is involved in both the extraocular and intraocular complications of diabetes, such as diabetic cardiomyopathy, diabetic nephropathy and neovascular glaucoma due to diabetic retinopathy (DR). EndoMT also plays significant roles in the pathogenesis of DR. Under the stimulation of high glucose and hypoxia, EndoMT occurs in retinal microvascular endothelial cells, and promotes the formation of retinal neovascularization and fibrovascular membrane through key factors like SNAI and TWIST as well as signal pathways such as TGF-β, Notch and Wnt. Exploring the roles and mechanisms of EndoMT in the pathogenesis of DR will provide new ideas and theoretical basis for the prevention and treatment of DR. (Int Rev Ophthalmol, 2021, 45: 110-117)

Key words: endothelial to mesenchymal transition, diabetic mellitus, diabetic retinopathy