Experimental data suggest that GLP-1 promote endothelial cell growth and angiogenesis which may have beneficial effects on the cardiovascular system but harmful effects on the retina . This project investigate the possible link between incretin therapy and Severe Diabetic Retinopathy. The prevalence of severe DR in patients exposed to incretin therapy (GLP-1 analogs or DPP4 inhibitors) is compared to that in non-exposed patients to these antidiabetic classes.

This study is dedicated to investigate the impact of routinely prescribed hypoglycaemic treatments on the prevalence of severe retinopathy and to seek possible biomarkers of severe retinopathy. Hypoglycemic treatments taken by the patients are those prescribe by the usuel diabetogist in the context of routine care.

The study includes T2D patients according to ADA criteria treated with any kind of hypoglycemic treatment and attending a diabetes center (three in Marseille: Department of Endocrinology, Hôpital Nord, Assistance Publique des Hôpitaux de Marseille and Service d'Ophtalmologie, Hôpital Saint-Joseph and Service de Diabétologie, Hôpital Saint-Joseph, and two in Paris : Centre Universitaire du Diabète et de ses Complications Hôpital Lariboisière, Université Paris 7, Assistance Publique des Hôpitaux de Paris and Service d'Endocrinologie, Diabétologie et Nutrition, Hôpital Bichat).

It consists of two visits: Visits1 "Inclusion" and Visits 2 "three years after the inclusion". In each visit, the investigators will collect results of eye examination (fundus) and annual diabetes check up including anthropometric data, routine biology, diabetes complication status as well as medications taken by the patients (past and current). A bio-banking (blood, urine and hairs) will be also collected. Primary objective : to compare the prevalence of severe DR in patients exposed to incretin therapy (GLP-1 analogs or DPP4 inhibitors) to that in non-exposed patients at baseline.

Secondary objective: To compare the proportion of patients who worsen DR between V1 (inclusion) and V2 (after 3-yr of treatment) in patients exposed to incretin-based therapy from baseline vs non-exposed patients: patients with no DR or mild to moderate non proliferative DR at V1 who progress to severe DR at V2.

To evaluate whether the concentrations of angiogenic/inflammatory molecules and circulating endothelial and inflammatory cells are associated with severe DR in relation with the use of GLP-1 based therapy at V1 and V2.

Inclusion Criteria:

• T2D patients according to ADA criteria treated with any kind of hypoglycaemic treatment
• Age above 18 years

Exclusion Criteria:

• Type 1 diabetes
• Patients with cataract preventing DR grading
• Patients who had panretinal photocoagulation more than 10 years ago
• Documented pregnancy or lactation