Study of Natural Course Progression of Diabetic Retinopathy
The goal of this observational study is to observe the formation and development of the non-perfusion area of diabetic retinopathy in the posterior area of the retina in type 2 diabetes patients aged 18-75 years old, who can cooperate with all examinations and sign informed consent, clinical myopathy examination and Optos 7 field of vision with mild than severe NPDR, and no other exclusion indicators.The main questions it aims to answer are whether posterior retinal non-perfusion area occurs earlier than peripheral non-perfusion area and whether the rate of non-perfusion area expansion is a risk factor for the progression of diabetic retinopathy.

Participants will have protocol-specific follow-up examinations at 1, 2, 3, 4, and 5 years (± 3 months). Additional visits are made as required by the study and the patient's condition.

The contents of follow-up examinations are:

History of other diseases, medications being used, eye diseases, surgeries, treatments, height, weight, and blood pressure.

Best corrected vision, logarithmic visual acuity chart. Tupai OCTA, 24×20mm range, 6×6mm range scan. Optos fundus imaging, color and no red light images. Fundus fluorescence angiography (only preliminary examination for the first time found mild to moderate NPDR patients, who have been angiographed in the past, only at the 5th year, or as required by the condition).

Glycosylated hemoglobin. Creatinine, urea, glomerular filtration rate. Total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol.

Urinary microalbumin/urinary creatinine ACR. Microvisual field.
- EligibilityCriteria: Inclusion criteria:  Patients with type 2 diabetes aged 18-75 years Can cooperate with the inspection and sign the informed consent There are no other eye diseases that cause retinal neovascularization There is no known substantial media haze that would hinder fundus image acquisition No history of fundus laser treatment or no possibility of laser treatment expected within six months No previous history of intravitreal drug injection, and no intravitreal drug injection is expected in the next 6 months Macular edema without diabetes (Zeiss OCT women < 290µm, male < 305µm; OCT female in Heidelberg is < 305µm, and for males < 320µm) In the field of visual field of clinical mydriasis and Optos photo 7 field of view, DR Lesions were less severe than NPDR No history of eye surgery  Exclusion criteria:  Patients with kidney failure. History of systemic anti-VEGF therapy within the last month. Follow-up is expected to be difficult or patients from other provinces have traction retinal detachment; The patient has a history of allergy - HealthyVolunteers: No - Gender: All - MinimumAge: 18 Years - MaximumAge: 75 Years - StdAgeList: Adult, Older Adult - StudyPopulation: Type 2 diabetes patients aged 18-75 years old, who can cooperate with all examinations and sign informed consent, clinical myopathy examination and Optos 7 field of vision with mild than severe NPDR, and no other exclusion indicators. - SamplingMethod: Non-Probability Sample