Cells within retinal blood vessels are endowed with a previously unappreciated ability to acquire resistance against the damaging effects of hyperglycemia in patients with diabetes mellitus, researchers report in The American Journal of Pathology. About one third of patients with diabetes mellitus (DM) develop diabetic retinopathy (DR), a leading cause of blindness in working-age individuals. DR typically develops after many years of DM, and some patients do not develop DR for more than 50 years. New research suggests that an endogenous system that protects human retinal endothelial cells from harmful effects of the hyperglycemia (an excess of blood sugar) may be responsible for the delayed onset of DR. Furthermore, degradation of this protective system over time may set the stage for development of DR. The new study appeared September 2, 2022 in The American Journal of Pathology, published by Elsevier. The article is titled “Hyperglycemia Promotes Mitophagy and Thereby Mitigates Hyperglycemia-Induced Damage.”