Impacts of Chronic Kidney Disease on Retinal Neurodegeneration: A Cross-Cohort Analysis

center dot PURPOSE: To assess the cross-sectional and longitudinal associations between chronic kidney disease (CKD) and ganglion cell-inner plexiform layer (GCIPL) thickness in a UK Biobank population and a Chinese cohort.center dot DESIGN: Prospective observational cohort study and cross-sectional study.center dot METHOD: This study included 23,014 individuals without neurodegenerative diseases from the UK Biobank, and 3 years of annual follow-up data of 2197 individuals from a Chinese cohort. Three groups were defined by estimated glomerular filtration rate (eGFR) based on serum creatinine classifying CKD severity as no CKD, mild CKD, and moderate to severe CKD (MS-CKD). GCIPL thickness, measured using optical coher-ence tomography, was analyzed through linear regres-sion over time to determine its decline rate in microm-eters per year. Linear regression models were used to assess the correlation between renal function and both the baseline GCIPL thickness and the GCIPL decline rate.center dot RESULTS: The cross-sectional analysis in a largely white population showed that poorer renal function negatively correlated with GCIPL thickness with a mean of 0.15 mu m thinner (95% confidence interval [CI] -0.30 to -0.01; P = .042) in mild CKD and 0.83 mu m thinner (95% CI -1.34 to -0.32; P = .001) in MS-CKD compared with that of control subjects without CKD. Longitudinal anal-ysis in the Chinese cohort showed that the GCIPL de-creased more rapidly in persons with poorer renal func-tion. After correcting for all confounding factors, the rate of GCIPL thinning was 0.30 mu m/year (95% CI -0.41 to -0.19; P < .001) more in the mild CKD group and 0.52 mu m/year (95% CI -0.79 to -0.26; P < .001) more in the MS-CKD group compared with control subjects with-out CKD. This relationship also occurred in individuals with diabetes or hypertension.center dot CONCLUSIONS: Poor renal function was associated with a lower baseline GCIPL thickness in the UK pop-ulation and a faster decline rate in Chinese participants. However, the detailed underlying mechanisms still need further exploration. (Am J Ophthalmol 2024;258: 173-182. (c) 2023 Elsevier Inc. All rights reserved.)