Design and Baseline Data of the Diabetes Registration Study: Guangzhou Diabetic Eye Study

The incidence and risk factors for diabetic retinopathy (DR) in southern China remain unclear. This project aims to explore the onset and progression of DR and their determinants through a prospective cohort in South China.The Guangzhou Diabetic Eye Study (GDES) recruited patients with type 2 diabetic registered in the community health centers in Guangzhou, China. Comprehensive examinations were performed including visual acuity, refraction, ocular biometry, fundus imaging, blood and urine tests.A total of 2305 eligible patients were included in the final analysis. In total, 14.58% of the participants had any DR and 4.25% had vision-threatening DR (VTDR), among which 76 (3.30%), 197 (8.55%), 45 (1.95%) and 17 (0.74%) were classified as mild NPDR, moderate NPDR, severe NPDR and PDR, respectively. There were 93 (4.03%) patients with diabetic macular edema (DME). The presence of any DR was independently associated with a longer duration of DM, higher degree of HbA1c, insulin treatment, higher average arterial pressure, higher concentration of serum creatinine, presence of urinary microalbumin, older age, and lower body mass index (BMI) (all p < 0.001). For VTDR, seven factors were significant: older age, a longer duration of DM, higher concentration of HbA1c, use of insulin, lower BMI, higher concentration of serum creatinine, and high albuminuria (all p < 0.05). These factors were also independently associated with DME (all p < 0.001).The GDES is the first large-scale prospective cohort study of the diabetic population in southern China, which will help to identify novel imaging and genetic biomarkers for DR in this population.