Diabetic retinopathy (DR) refers to retinopathy and dysfunction caused by high blood glucose in diabetic patients causing microvascular lesions in various tissues and organs throughout the body, necrosis of peripapillary cells, thinning of endothelial cells, impaired internal barrier function, and leakage of intravascular fluid into the tissues, ultimately resulting in retinopathy and dysfunction. DR is one of the most common and serious microvascular complications of diabetes, an important cause of blindness in diabetic patients, and has become one of the four major blinding eye diseases. According to relevant data, nearly 1/5 of type 2 diabetic patients worldwide already have varying degrees of retinopathy when they are diagnosed with diabetes; with the prolongation of the disease, about 5-10% of patients go blind within 5 years. The blindness rate of diabetes is 25 times higher than the non-diabetic blindness rate in China. Therefore, general practitioners must pay attention to this disease and master the characteristics and prevention points of DR. Typical case] The patient was 50 years old with a history of diabetes mellitus for 5 years and unstable glycemic control. He came to our hospital because of occasional blurred vision while driving recently. The endocrinologist suggested her to undergo a fundus free pupil examination to determine the presence of fundus lesions. The fundus radiography showed that the patient’s retina was hemorrhagic and exudative, and DR had developed, and he underwent fundus fluorescence angiography, optical coherence tomography, and visual electrophysiology to confirm that his DR had progressed to a severe non-proliferative stage and required retinal photocoagulation. After blood glucose control and fundus laser treatment, the patient’s visual acuity stabilized. Risk factors, incidence and pathogenesis】 The occurrence and development of DR are closely related to the duration and type of diabetes, glycemic control, the combination of hypertension or hyperlipidemia, the possibility of eye surgery, pregnancy status, and the presence of diabetic nephropathy. The longer the duration of diabetes and the worse the glycemic control, the higher the prevalence of DR and the more serious the disease; pregnancy and diabetic nephropathy can also accelerate the progress and deterioration of DR. Statistics show that the incidence of DR in patients with type 1 diabetes is 27% if the disease duration is 5-10 years; if the disease duration is more than 10 years, the incidence of DR is 71%; the incidence of DR in patients with disease duration of 20-30 years is as high as 95%. In type 2 diabetic patients, the incidence of DR is 23% if the disease is more than 10 years old and 60% if the disease is more than 15 years old, of which 10% are severe proliferative retinopathy. At present, the pathogenesis of DR is not yet clear, but it is considered to be related to the disturbance of glucose metabolism mechanism, which is the result of a combination of factors (such as the activation of protein kinase C, abnormalities of polyol metabolic pathway, the role of angiotensin-converting enzyme system, etc.).