Association between non-invasive liver fibrosis indices and neuroretinal thickness from a nationwide cross-sectional study in South Korea
Joon Yul Choi, Chan Ho Lee, Tae Keun YooObjective
To evaluate associations of non-invasive liver fibrosis indices with optical coherence tomography (OCT)-derived retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness in Korean adults.
Methods
This cross-sectional study used Korea National Health and Nutrition Examination Survey data from 2019–2021. The analytic cohort included 5,830 adults contributing 10,814 eyes after excluding chronic liver disease, ocular disease, and missing or invalid laboratory or ocular data. Primary exposures were fibrosis-4 index (FIB-4) and aspartate aminotransferase-to-platelet ratio index (APRI), standardized to z scores. Outcomes were corrected average RNFL thickness and average GCIPL thickness. Generalized estimating equation models accounted for inter-eye correlation and adjusted for demographic, ocular, cardiometabolic, and lifestyle covariates.
Results
Corrected average RNFL and GCIPL thickness decreased across FIB-4 categories. In fully adjusted models, higher FIB-4 was associated with thinner corrected average RNFL thickness (β=−0.438 µm; 95% CI, −0.679 to −0.197; P<0.001), as was higher APRI (β=−0.270 µm; 95% CI, −0.461 to −0.078; P=0.006). GCIPL associations were weaker but nominally significant. After false discovery rate correction, only FIB-4 and APRI remained significantly associated with corrected average RNFL thickness. RNFL associations persisted after non-linear age adjustment and in survey-weighted participant-level analyses.
Conclusions
Higher non-invasive liver fibrosis indices were associated with slightly thinner OCT-derived neuroretinal measurements, most robustly corrected average RNFL thickness. The small effect sizes support population-level epidemiologic interpretation rather than individual-level clinical use.