Through this study, the investigators hope to understand the prevalence and influencing factors of diabetic retinopathy in Tianjin, improve the ability of complication detection and intervention in diabetic patients in primary medical and health institutions, and build a diabetes prevention and treatment network. The investigators should adhere to the policy of prevention first, combined with prevention and control, and explore a diabetes' prevention and control model suitable for our city. Extensive publicity and education should be carried out to improve the awareness of self-management ，improve the screening rate of diabetic retinopathy, and reduce the blindness rate.

West of the city, and hebei, heping and binhai new area to carry out the work, diabetic retinopathy screening on 18000 diabetic patients in fundus examination. Tianjin medical university eye hospital, project team, formed in grassroots medical institutions are responsible for screening fundus examination in patients with diabetes, related inspection including vision, computer optometry, fundus photography and optical coherence tomography angiography (OCTA), etc. Blood samples were collected from patients in Hexi District and Heping District to detect glycosylated hemoglobin. Glycated albumin, urine ACR and CO breath test were performed in Chu Hsien-I Memorial Hospital of Tianjin Medical University. Health records were established for the screening personnel after the examination

Inclusion Criteria:

- 1: Clear awareness, barrier-free communication

2: diabetes

Exclusion Criteria:

• 1: Have left the registered home address

  2: In the last 6 months, you have not lived in your place of residence

  3: Have a serious mental illness

Patients with diabetes receive a unified eye examination in the community to confirm whether they have diabetic retinopathy