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Published on: September 16, 2025
Comparative analysis of epithelial remodeling after photorefractive keratectomy and keratorefractive lenticule
Ahmed Elmassry1, Amr Habib1, Ihab M Osman1
1Department of Ophthalmology, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
Purpose:
This study aims to characterize and compare the patterns of epithelial remodeling following photorefractive keratectomy (PRK) and femtosecond small incision lenticule extraction (Femto-SMILE) using high-resolution anterior segment optical coherence tomography (OCT) imaging.
Methods:
In this prospective comparative study, 48 eyes of 24 myopic patients underwent PRK (Group A) or Femto-SMILE (Group B). Preoperative assessments included a full ophthalmologic examination, corneal topography, and epithelial mapping using the MS-39 anterior segment OCT. Postoperative evaluations were conducted at 1 week, 1 month, and 6 months, with epithelial thickness changes analyzed and compared.
Results:
The mean preoperative minimum epithelial thickness was 42.33 µm in Group A and 44.25 µm in Group B, while the mean maximum epithelial thickness was 54.46 µm and 54.25 µm, respectively. At 6 months, the thinnest epithelial point increased in all patients. There were no statistically significant differences in epithelial thickness in the paracentral quadrants between the two groups. However, the central 3-mm zone exhibited early postoperative epithelial thickening after PRK, which later normalized over time.
Conclusions:
PRK and Femto-SMILE exhibited different patterns of epithelial remodeling, with more pronounced early changes observed after PRK. By 6 months, both procedures showed stable epithelial profiles. These findings highlight the value of epithelial mapping in postoperative evaluation and suggest the need for further studies to validate these trends.

