Abstract
To describe corneal epithelial remodeling patterns after femtosecond LASIK (FS-LASIK) and keratorefractive lenticule extraction (KLEx; SMILE in this study), and to evaluate within-cohort associations between epithelial thickness changes and anterior corneal higher-order aberrations (HOAs). This study included 245 patients (138 eyes in the SMILE cohort and 107 eyes in the FS-LASIK cohort; right eyes only). Corneal epithelial thickness in the central, paracentral, and mid-peripheral zones was measured preoperatively, 1 month, and 3 months postoperatively using optical coherence tomography (OCT). Corneal HOAs were assessed using the Pentacam system with a 6 mm pupil diameter. Repeated-measures analysis of variance and Spearman correlation analyses were used to characterize postoperative changes and examine within-cohort associations between epithelial remodeling and HOAs. In both cohorts, postoperative epithelial thickening was observed in the central and paracentral zones; in the SMILE cohort, thickening was also observed in the mid-peripheral zone. The spatial distribution of epithelial thickening differed between cohorts, and the magnitude of thickening varied by zone across time points. Both cohorts demonstrated postoperative changes in HOAs. In the SMILE cohort, changes in spherical aberrations (Z40, Z60) and coma-related terms (Z3−1, Z3−3) were observed over follow-up. In the FS-LASIK cohort, HOA changes showed greater regional variability across time points. Within-cohort correlation analyses indicated that epithelial thickening in the SMILE cohort was positively associated with spherical aberrations and negatively associated with coma-related terms, whereas correlations in the FS-LASIK cohort were generally weaker and region-dependent. Across two clinical cohorts undergoing SMILE or FS-LASIK, postoperative epithelial thickening and changes in anterior corneal HOAs were observed, with measurable within-cohort associations between epithelial remodeling and HOA metrics. Because preoperative refractive status (spherical equivalent) differed markedly between cohorts, these findings should be interpreted as descriptive patterns and within-cohort associations rather than evidence of isolated procedure effects or between-procedure superiority.
Data availability
The datasets generated and/or analysed during the current study are not publicly available due to restrictions imposed by institutional ethics approval and patient confidentiality agreements, but are available from the corresponding author on reasonable request.
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Xinwei Yang: Contributed to study design, data acquisition, statistical analysis, figure/table preparation, and drafted the initial manuscript. Jialin Niu: Participated in data analysis and interpretation, prepared figures, and assisted in manuscript revision. Hongyue Wu: Participated in patient recruitment and assisted in data interpretation. Siying Song: Performed literature review, managed clinical follow-up schedules, and assisted in data collection and formatting. Yuehua Zhou: Supervised the entire project, contributed to study conception, critical revision of the manuscript for important intellectual content, and is the corresponding author responsible for final approval of the version to be published. All authors have read and approved the final manuscript.
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Yang, X., Niu, J., Wu, H. et al. Within-cohort associations between corneal epithelial remodeling and anterior corneal higher-order aberrations after FS-LASIK and KLEx (SMILE): a two-cohort descriptive study. Sci Rep (2026). https://doi.org/10.1038/s41598-026-40156-8
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DOI: https://doi.org/10.1038/s41598-026-40156-8
