Retinal findings in diabetic chronic kidney disease patients and non - diabetic chronic kidney disease patients: a comparative study.

Abstract

Introduction: Chronic kidney disease (CKD) is a progressive multisystemic disorder with significant microvascular complications. The retina, due to its embryological and physiological similarity to renal vasculature, reflects systemic vascular changes, particularly in diabetic chronic kidney disease (D-CKD). This study aimed to compare retinal structural and vascular alterations in patients with D-CKD and non-diabetic CKD (ND-CKD), utilizing spectral-domain optical coherence tomography (SD-OCT) and fundus examination todetermine the extent of microangiopathy across groups and its correlation with renal parameters. Methods: A cross-sectional comparative study was conducted on 76 CKD patients (38 D-CKD and 38 ND-CKD) at a tertiary care hospital in Karnataka, India. All subjects underwent detailed ophthalmological evaluation including best-corrected visual acuity, intraocular pressure measurement, slit-lamp biomicroscopy, fundus photography, and SD-OCT imaging. Retinal thickness parameters were analyzed across five quadrants. Renal function was assessed using serum creatinine and estimated glomerular filtration rate (eGFR) via the Cockcroft-Gault formula. Fundus findings were classified according to standard retinopathy grading systems. Statistical comparisons were made using t-tests, chi-square, and correlation analyses. Results: D-CKD patients demonstrated significantly greater retinal thinning across all macular quadrants (p<0.001), with mean subfoveal thickness of 220.11 ± 39.67 μm (RE) versus 265.50 ± 28.34 μm in ND-CKD. Proliferative and non-proliferative diabetic retinopathy were exclusive to the D-CKD group, while hypertensive retinopathy was more common in ND-CKD. A strong inverse correlation was observed between eGFR and retinal thinning (r = -0.65, p<0.01). Patients on dialysis exhibited more severe OCT and fundus abnormalities. Among ND-CKD etiologies, hypertensive nephropathy was most associated with retinal microvascular signs. Conclusion: Retinal changes in CKD reflect systemic microvascular pathology, with diabetic CKD demonstrating more advanced alterations due to synergistic effects of hyperglycemia and uremia. SD-OCT provides a sensitive modality for detecting early neuroretinal damage. Routine retinal imaging may aid in risk stratification, progression monitoring, and interdisciplinary care planning in CKD patients. This study underscores the value of ophthalmic surveillance in nephrology protocols.