Diabetes is a disorder of glucose metabolism that affects all organs, tissues and blood vessels of the body. Retinopathy caused by diabetes is one of the most common and serious complications for diabetic patients, causing serious harm to the patients themselves, their families and society, and has become a major cause of blindness worldwide. According to China’s diabetes survey, the total number of diabetic patients in China is about 40 million, and diabetic retinopathy accounts for 49-58% of them, so it is estimated that there are about 20 million diabetic retinopathy patients in China. The occurrence and development of diabetic retinopathy is closely related to the type and duration of diabetes, and the incidence of retinopathy gradually increases as the duration of diabetes increases. Patients with hypertension or hyperlipidemia will have a higher incidence of retinopathy. In diabetic patients who are pregnant, diabetic retinopathy may worsen due to pregnancy itself or changes in metabolism. (I) Staging of diabetic retinopathy Clinically, the disease is divided into two main stages of development, namely non-proliferative and proliferative lesions, depending on whether neovascularization is present in the retina. In the nonproliferative stage, the patient’s retina shows microangiomas, hemorrhagic spots, hard exudates, and cotton wool spots. The main hazard of this stage lesion is the leakage of plasma components into the retinal tissue due to the disruption of the blood-retinal barrier, resulting in retinal edema, and when the edema occurs in the macula, it causes central visual impairment. When the lesion progresses to a large area of retinal vascular atresia, the lesion has begun to progress to the proliferative stage. The most important fundus changes of proliferative diabetic retinopathy are neovascularization and corresponding complications, mainly manifested by the growth of proliferating neovascularization along the retinal surface or into the vitreous to form a proliferative membrane. When the neovascularization ruptures, it can lead to retinal and vitreous hemorrhage, and the contraction of the proliferative membrane can also cause retinal detachment by traction, at which time, the patient’s vision is seriously affected. (B) Clinical diagnosis and treatment of diabetic retinopathy The diagnosis and assessment of the extent of the lesion and the functional status of the retina can be clarified by the patient’s medical history and detailed ophthalmic instrumentation, including slit lamp, fundoscopy, fundus fluorescence angiography, optical coherence tomography, ocular ultrasound, visual electrophysiology, and so on. When a non-proliferative lesion is diagnosed, the fundus is examined every 3 to 6 months to control the blood glucose in the normal range. At this time, the lesions are still in the early stages of the disease, and local laser photocoagulation is often used to treat macular edema and exudation. Studies have confirmed that local laser photocoagulation can reduce more vision loss and increase the chance of vision progress. For diabetic retinopathy entering the proliferative phase, whole retinal laser photocoagulation of the fundus should be performed promptly to safely and effectively control the disease and protect the patient’s vision. When the lesion progresses to advanced stage, vitreous hemorrhage and retinal detachment by traction occur, vitrectomy is needed in time to remove the blood accumulated in the vitreous, remove the proliferative membrane, relieve the vitreoretinal traction, close the fissure and reset the retina. In recent years, intraocular injection of corticosteroids and anti neovascular drugs have also achieved good therapeutic effects for inhibiting the neovascularization of diabetic retinopathy and relieving macular edema. (C) Prevention of diabetic retinopathy Although diabetic retinopathy can lead to vision loss or even blindness, it can be prevented and treated. Early active and effective treatment of diabetes can delay the onset and development of retinopathy. At the same time, in order to detect and treat diabetic eye lesions early, it is important to receive regular eye examinations with or without vision changes. If you wait until your vision decreases before seeking medical attention, the degree of retinopathy may already be more severe. Suggestions: Have a dilated eye exam every six months for stable blood sugar control, or once every three months for unstable blood sugar control. For diabetic patients who are pregnant, have a history of internal eye surgery (cataract surgery, glaucoma surgery, vitrectomy, etc.) and have existing fundus lesions, the interval between eye examinations should be shortened or reviewed as prescribed by the doctor.