Rationale, Design, Methodology and Baseline Data of Fushun Diabetic Retinopathy Cohort Study (FS-DIRECT)

Purpose: To describe the rationale, design, methodology and baseline characteristics of Fushun Diabetic Retinopathy Cohort Study (FS-DIRECT), a community-based prospective cohort study in patients with type 2 diabetes mellitus (T2DM) living in northeast China.Methods: Patients with T2DM, aged 30 years and above from communities of Fushun city, Liaoning province, China, were recruited. The presence and severity of the diabetic retinopathy (DR) were determined by a modified Early Treatment Diabetic Retinopathy Study (ETDRS) retinopathy scale of 6 fields fundus photographs. Detailed ocular examinations and questionnaires were collated, in addition to blood and urine sample collection.Results: Of the 2224 subjects eligible for the FS-DIRECT, 2033 (91.4%) participated in the study. The majority of participants were female (58.9%), the average age was 62.1 ± 9.1 years. The overall prevalence rates of DR, non-proliferative DR, proliferative DR, diabetic macular edema, and vision-threatening retinopathy were 44.3%, 40.0%, 4.3%, 15.2%, and 12.3%, respectively. Compared to the patients without DR, patients with DR had lower income, an earlier onset of diabetes, a longer duration of diabetes, higher proportion of insulin use, higher fasting plasma glucose, HbA1c, systolic blood pressure, total cholesterol and high density lipoprotein, as well as a higher level of urine protein (all P < .05).Conclusion: The baseline data of FS-DIRECT showed a high prevalence of DR in a community of northeast China. Further investigation will provide key information about the risk factors, impact, and trends of DR in this region.