Objective: Explore the biomarkers related to proliferative diabetic retinopathy by analyzing the protein expression profile changes of plasma exosomes in patients with difference phases of diabetic retinopathy, and investigate potential molecular mechanisms and therapeutic targets. Methods: Enrich exosomes from plasma by column extraction method. NTA, WB and TEM were used to characterize the obtained exosomes, and exosome proteinomics was performed by chromatography⁃mass spectrometry. Corhorts: The study was divided into four groups: a healthy control group, a diabetic without diabetic retinopathy group, a non-proliferative diabetic retinopathy group, and a proliferative diabetic retinopathy group, with 6 cases in each group.

Inclusion Criteria:

• Healthy volunteers without diabetes/ Senile cataract patients without diabetes；
• Patients with diabetes who are diagnosed without DR, NPDR, and PDR by mydriatic fundus photography (or FFA)；

Exclusion Criteria:

• Patients with systemic diseases such as cancer, immune diseases, infectious diseases, and blood diseases；
• Patients with cerebral infarction, myocardial infarction and other cardiovascular and cerebrovascular diseases

Plasma exosomal proteomics studies in patients with diabetic retinopathy should include healthy volunteers without diabetes mellitus and elderly cataract patients without diabetes mellitus; patients with systemic diseases such as cancer, immune disorders, infectious diseases, and hematological disorders, as well as patients suffering from cerebral infarcts, cardiac infarcts, and other cardiovascular diseases, are not eligible for enrollment.