Association of the Duration of Lutein and Vitamin A Supplementation with Central Macular Thickness and Subfoveal Choroidal Thickness in Healthy Eyes

Purpose: This study aimed to evaluate the associations of the duration of lutein and vitamin A supplementation with central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) using nationally representative data from Korea.Methods: We analyzed participants from the 2018-2021 Korea National Health and Nutrition Examination Survey (KNHANES) who reported using lutein and vitamin A supplements.Individuals with diabetic retinopathy, age-related macular degeneration, epiretinal membrane, macular hole, or retinal vein occlusion were excluded.Participants were categorized by supplement duration (≤1 month, 1-3 months, 4-6 months, 7-11 months, ≥1 year).The primary outcomes were CMT and SFCT.Survey-weighted univariable and multivariable linear regression models were used to identify factors associated with CMT and SFCT.Results: The final cohort included 1,169 participants.The mean age was 47.4 ± 0.6 years, and 45.4% were male.In univariable and multivariable regression analyses, supplement duration was not independently associated with CMT or SFCT after adjusting for age, sex, axial length, and systemic covariates.Compared with participants taking supplements for ≤1 month, the estimated β coefficients for CMT in the right and left eyes in the multivariable model were -3.10 and -0.84 (p = 0.390 and 0.802) for 1-3 months, -0.47 and -2.10 (p = 0.910 and 0.649) for 4-6 months, -11.34 and -5.28 (p = 0.140 and 0.400) for 7-11 months, and -1.98 and 1.65 (p = 0.619 and 0.668) for ≥1 year.The corresponding multivariable β values for SFCT were 1.72 and -4.73 (p = 0.903 and 0.768), -0.02 and -15.61 (p = 0.999 and 0.298), -4.18 and 20.98 (p = 0.834 and 0.312), and -4.26 and -8.39 (p = 0.727 and 0.573).Conclusions: In this population-based analysis of KNHANES participants, the duration of lutein and vitamin A supplementation was not associated with CMT or SFCT.