In studying the early warning of diabetic retinopathy, we found that clinical indicators that form key markers have been shown in many literatures to be closely related to the occurrence of the disease, such as glycosylated hemoglobin, serum uric acid, alanine aminotransferase, etc. They induce the occurrence of diseases from the aspects of individual lipid metabolism, cell redox, bone metabolism and bone resorption, as well as cell coagulation function. Here, GPT is linked to diabetic retinopathy.