Abnormal retinal vascularization associated with compromised visual function emerges as diabetic retinopathy progresses.[23] Advanced stages of diabetic retinopathy are characterized by vessel loss, as evidenced by preclinical and clinical research.[23, 24] Vessel density, a critical indicator of retinal blood supply, was significantly higher in the retinas of Ubc9 CKO mice after 5 months of diabetes, particularly in the intermediate and deep vascular layers in both central and peripheral regions (Figure 2C,D). This evidence concerns the gene UBE2I and diabetic retinopathy.