Prevalence and Associated Factors of Diabetic Retinopathy in a Russian Population. The Ural Eye and Medical Study

AIM: To assess prevalence and associated factors of diabetic retinopathy (DR) in a Russian population. METHODS: Out of 7328 eligible individuals, the population-based cross-sectional Ural Eye and Medical Study included 5899 (80.5%) individuals aged 40+ years, who underwent a detailed medical and ophthalmological examination. Using ocular fundus photographs and optical coherence tomographic images, we assessed prevalence and degree of DR in 5105 participants. RESULTS: DR was present in 99/5105 individuals (1.9%; 95% confidence interval [CI]: 1.6, 2.3). Its prevalence increased from 6/657 (1.0%; 95% CI: 0.2, 1.6) in the age group of 45–50 years to 24/680 (3.5%; 95% CI: 2.1, 4.9) in the age group of 65–70 years, and decreased to 3/153 (2.0%; 95% CI: 0.00, 4.2) in the age group of 80+ years. DR prevalence within the 577 (11.4%; 95% CI: 10.5, 12.2) individuals with diabetes was 99/577 (17.2%; 95% CI: 14.1, 20.2). DR was the cause for moderate-to-severe vision impairment (best corrected visual acuity <6/18 but ≥3/60) in four individuals (4/5105; 0.07%). In multivariable analysis, higher DR prevalence was associated with higher serum glucose concentration (odds ratio [OR]: 1.30; 95% CI: 1.20, 141), longer diabetes duration (OR: 1.06; 95% CI: 1.02, 1.09), type of diabetes therapy (nil/diet/oral/insulin) (OR:4.19;95% CI:3.08, 5.70), lower educational level (OR:0.81;95% CI:0.67, 0.98), lower manual dynamometric force (OR: 0.96; 95% CI: 0.94, 0.99), shorter ocular axial length (OR: 0.73; 95% CI: 0.56, 0.96), and higher diastolic blood pressure (OR: 1.04; 95% CI: 1.01, 1.06), or alternatively, higher estimated cerebrospinal fluid pressure (OR: 1.09; 95% CI: 1.01, 1.18). CONCLUSION: In this urban and rural Russian population aged 40+ years, DR prevalence was relatively low (1.9%; 95% CI: 1.6, 2.3), showed an inverted U-shaped association with age, and in a cross-sectional study design it was associated with shorter axial length and higher estimated cerebrospinal fluid pressure.