Impact of menopause on subfoveal choroidal thickness: population-based evidence from the 2017 to 2021 KNHANES

OBJECTIVE: To evaluate the association between menopausal status, oral contraceptive use, and choroidal thickness in a nationally representative Korean population. METHODS: This study included 12,326 women (6,721 menstruating and 5,605 menopausal) from the 2017 to 2021 Korea National Health and Nutrition Examination Survey. Survey-weighted linear regression was used to examine associations of subfoveal choroidal thickness and central macular thickness with menopausal status, adjusting for demographic, ocular, and systemic covariates. A subanalysis was performed among 5,886 menstruating women with available information on oral contraceptive use (742 users and 5,144 nonusers). RESULTS: In the multivariate model, menopausal status was not significantly associated with either subfoveal choroidal thickness (β=-0.51 µm; 95% confidence interval (CI), -7.31 to 6.29; P=0.883) or central macular thickness (β=1.01 µm; 95% CI, -1.20 to 3.22; P=0.370). However, a significant interaction between menopausal status and blood pressure was observed in subgroup analyses (P for interaction=0.007). Likewise, oral contraceptive use was not associated with either subfoveal choroidal thickness (β=5.45 µm; 95% CI, -4.58 to 15.48; P=0.287) or central macular thickness (β=-1.67 µm; 95% CI, -4.81 to 1.47; P=0.297). CONCLUSIONS: Menopausal status and oral contraceptive use were not associated with subfoveal choroidal thickness and central macular thickness in this large-scale, nationally representative cohort. These findings provide reliable population-level evidence that menopause has little effect on choroidal thickness, helping resolve prior inconsistent results. However, the observed interaction with blood pressure indicates that this association may vary across cardiovascular risk subgroups and warrants further investigation.