Correlation of eGFR‐defined Chronic Kidney Disease Stages with Retinopathy Grades Among Hypertensive, Diabetic and CombinedPathology Patients

Background: Microvascular injury underlies both chronic kidney disease (CKD) and retinopathy, yet the relationship between declining renal function and retinal changes across hypertensive, diabetic, and mixed-pathology populations in Bihar remains under-explored. Aim: To evaluate the association between CKD severity defined by estimated glomerular filtration rate (eGFR) and the presence and grade of retinopathy in hypertensive, diabetic, and mixed-pathology adult patients. Methods: In this cross-sectional study, 110 adults (mean age 56.8 ± 9.7 years; 58 males) presenting to our institute were enrolled: 35 with hypertension only, 35 with diabetes mellitus only, and 40 with both conditions. Serum creatinine was measured and eGFR calculated using the CKD-EPI equation, categorizing participants into CKD stages 1–5. Dilated fundus examination was performed on all subjects, and retinopathy graded according to standard criteria. Associations between CKD stage and retinopathy grade were assessed by chi-square test for trend and Spearman’s correlation; multivariable logistic regression evaluated the odds of any retinopathy per advancing CKD stage. Results: Overall, retinopathy prevalence increased progressively from 10% in CKD stage 1 to 82% in stages 45. By group, prevalence was 48% in hypertensive, 72% in diabetic, and 77% in mixed-pathology patients. There was a significant positive trend between CKD stage and retinopathy grade (chi-square for trend = 24.1; p < 0.001) and a strong correlation (Spearman’s rho = 0.69; p < 0.001). In adjusted analysis, each one-stage decline in eGFR was associated with a 1.92-fold increase in odds of retinopathy (95% CI: 1.50–2.47; p < 0.001). Conclusion: Declining renal function is significantly associated with higher prevalence and greater severity of retinopathy across hypertensive, diabetic, and mixed-pathology patients. Early retinal screening should be integrated into CKD management protocols to facilitate timely detection of microvascular complications.