Hypertensive retinopathy and associated factors among nondiabetic chronic kidney disease patients seen at a tertiary hospital in Tanzania: a cross-sectional study

Background: Hypertensive retinopathy is a known marker of cardiovascular disease, and among unselected patients with chronic kidney disease (CKD) more severe retinopathy has been associated with lower estimated glomerular filtration rate (eGFR). This association has, however, not been widely studied among nondiabetic hypertensive patients with CKD, especially in sub-Saharan Africa. We aimed to determine the prevalence and severity of hypertensive retinopathy and its relationship with eGFR among nondiabetic CKD patients seen at Muhimbili National Hospital in Dar es Salaam, Tanzania. Methods: A hospital-based cross-sectional study was conducted among nondiabetic CKD adult (>= 18 years) patients with hypertension. A structured questionnaire was used to record patients' demographic characteristics and their cardiovascular risk profile. eGFR was calculated using the Modification of Diet in the Renal Disease (MDRD) equation and only patients with CKD stage 3 or more were enrolled in the study. Grading of retinopathy was done using the Keith-Wagener classification. Results: In total, 224 patients fulfilled the inclusion criteria and were enrolled. Their mean age was 45.8 +/- 14.1 years, and 59.4% were men. The proportions of patients with stage 3, 4, and 5 CKD were 21.4%, 19.6%, and 58.9%, respectively. Hypertensive retinopathy was present in 157 (70.1%) patients and the proportions with grade I, grade II, grade III, and grade IV retinopathy were 17.9%, 18.8%, 19.6%, and 13.8%, respectively. The severity of retinopathy increased with decreasing levels of eGFR, and in multivariate logistic regression analysis, factors found to be independently associated with >= grade II hypertensive retinopathy were more severe CKD, higher hypertension grades, and alcohol use, all p<0.05. Conclusion: The prevalence of hypertensive retinopathy is high among nondiabetic CKD patients seen at a tertiary hospital in Tanzania and is independently associated with CKD severity. Retinopathy grade can be used as a marker of CKD severity among these patients.