Ten-Year Cumulative Incidence of Diabetic Retinopathy. The Beijing Eye Study 2001/2011

Objective: To assess the cumulative 10-year incidence of diabetic retinopathy (DR) and its associated factors in a population living in Greater Beijing. Methods: The population-based longitudinal Beijing Eye Study, which included 4439 subjects (age in 2001: 40+years) in 2001, was repeated in 2011 with 2695 subjects participating (66.4% of the survivors). The study participants underwent a detailed ophthalmic examination. Fundus photographs were examined for the new development of DR. Results: After excluding individuals with DR at baseline (n = 87) or no sufficient fundus photographs in 2011 (n = 6), the study included 2602 subjects with a mean age of 64.6 +/- 9.7 years (median: 64.0 years; range: 50 to 93 years). In the 10-year period, 109 subjects (39 men) developed new DR with an incidence of 4.2% (95% confidence interval (CI): 3.45,5.03). In multiple logistic regression analysis, incident DR was significantly associated with higher HbA1c value (P < 0.001; Odds Ratio (OR): 1.73; 95% Confidence Interval (CI): 1.35,2.21), longer duration of diabetes mellitus (P < 0.001; OR: 1.16; 95% CI: 1.10,1.22), higher serum concentration of creatinine (P = 0.02; OR: 1.01; 95% CI: 1.002,1.022), lower educational level (P = 0.049; OR: 0.74; 95% CI: 0.55,0.99), higher estimated cerebrospinal fluid pressure (P = 0.038; OR: 1.10; 95% CI: 1.01,1.22), and shorter axial length (P < 0.001; OR: 0.48; 95% CI: 0.33,0.71). Conclusions: The cumulative 10-year incidence (mean: 4.2%) of DR in a North Chinese population was significantly associated with a higher HbA1c value, longer known duration of diabetes mellitus, higher estimated CSFP and shorter axial length (P, 0.001). Shorter axial length (or hyperopia) and, potentially, higher CSFP may be additional risk factors to be taken into account when counseling and treating patients with diabetes mellitus.