Prevalence and risk factors associated with retinopathy in diabetic patients at Parirenyatwa Hospital outpatients’ clinic in Harare, Zimbabwe

Diabetic retinopathy is the fifth leading cause of blindness worldwide accounting for nearly 5% of all blindness. However, most of the prevalence and incidence data is from developed countries, with very limited information from sub-Saharan Africa. The study sought to determine the prevalence of, and factors associated with, retinopathy in diabetic patients. Diabetes mellitus patients attending the outpatients’ clinic at Parirenyatwa Group of Hospitals between October 2013 and July 2014 were recruited into this analytical cross-sectional study. Demographic information was collected. A nurse carried out anthropometric measurements. An ophthalmologist using slit lamp indirect ophthalmoscopy with a 20-diopter and a 90-diopter lens diagnosed retinopathy. Blood samples were collected and analysed for triglycerides, total cholesterol, HDL cholesterol, glycosylated hemoglobin and serum creatinine. A total of 340 patients were enrolled into the study, of whom 73.2% were female. Mean (SD) age was 57.5 (14.9) years and there was no difference in age between females [57.6 (14.1) years] and males [57.2 (16.8) years]. The overall prevalence of diabetic retinopathy was 28.4%. Using multivariate logistic regression analysis retinopathy was associated with longer duration of diabetes mellitus (OR 1.06, 95% CI 1.03-1.09, p value ？ 0.001) and lower serum creatinine (OR 0.99, 95% CI 0.97-1.00, p value 0.025). The prevalence of diabetic retinopathy was 28.4%. Longer duration of diabetes mellitus and lower serum creatinine, which is a marker of renal damage, were independent risk factors of diabetic retinopathy.