To study the association of diabetic retinopathy with microalbuminuria and glomerular filtration rate

Introduction: Diabetic retinopathy (DR) and diabetic nephropathy (DN) are major microvascular complications of type 2 diabetes mellitus. Both share common pathophysiological mechanisms including chronic hyperglycemia-induced endothelial dysfunction. While microalbuminuria and estimated glomerular filtration rate (eGFR) are recognized markers of renal involvement, their association with the severity of DR remains variable across studies. This study aimed to assess the relationship between DR and renal parameters – specifically microalbuminuria and eGFR – in patients with type 2 diabetes. Materials and Methods: This prospective observational study included 71 type 2 diabetes patients with a disease duration of over 5 years attending the Ophthalmology Department at The Oxford Medical College, Bangalore. Ocular examination included fundus evaluation and DR grading based on the Early Treatment Diabetic Retinopathy Study criteria. Biochemical evaluation included fasting and postprandial glucose, glycated hemoglobin, serum creatinine, and urine protein–creatinine ratio (uPCR). eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration 2021 formula. Albuminuria and chronic kidney disease (CKD) stages were categorized using KDIGO guidelines. Results: The mean age was 52.4 ± 8.9 years, with 83.1% of patients showing some degree of DR. A significant increase in uPCR and decline in eGFR were observed with advancing DR stages ( P < 0.0001). Patients with advanced diabetic eye disease had a mean uPCR of 419.3 ± 28.9 mg/g and eGFR of 32.5 ± 3.7 mL/min/1.73 m 2 . The association between DR severity and CKD stage was also statistically significant ( P = 0.0255). Conclusion: Microalbuminuria showed a stronger association with DR severity than eGFR. Routine renal and retinal screening should be incorporated into diabetes care to detect microvascular complications early.