Abstract
INTRODUCTION: Kerato-lenticule extraction (KLEx) is a refractive surgery technique that, in contrast with femtosecond laser-assisted in situ keratomileusis (FS-LASIK), does not require the creation of a flap to correct refractive defects. The potential advantages of this technique are related to the absence of a flap and its complications. On the other hand, FS-LASIK is the most widely practised refractive surgery worldwide, as it offers excellent visual outcomes and is currently the gold standard of refractive surgery. The objective of this study is to compare the effectiveness and safety of KLEx versus FS-LASIK as a treatment option in patients with myopia or myopic astigmatism. METHODS AND ANALYSIS: This double-masked, parallel-group, single-centre randomised clinical trial will enrol 80 eyes from adults with myopia or compound myopic astigmatism within the ranges sphere -0.50 to -12.00 D and cylinder -0.50 to -6.00 D, recruited at the Instituto de Oftalmología Conde de Valenciana, Mexico City, Mexico. Participants will be allocated to KLEx or FS-LASIK and assessed at baseline and 1 day, 1 week, 1, 3, 6 and 12 months postoperatively. The primary outcome is uncorrected visual acuity at all postoperative visits. Secondary outcomes include postoperative spherical equivalent, best-corrected visual acuity (BCVA), loss of ≥2 BCVA lines, the proportion of eyes within ±0.50 D of the refractive target, corneal aberrations over a 5 mm pupil, epithelial changes and adverse events. Participants and outcome assessors will be masked to the assigned surgical technique. ETHICS AND DISSEMINATION: Participant confidentiality will be maintained with the publication of results. This study was approved by the research and ethics committee of the Instituto de Oftalmología Fundación de Asistencia Privada Conde Valenciana (CI-017-2024). The study results will be disseminated in scientific articles published in peer-reviewed journals and presented through research posters at national and international conferences. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov registry (NCT06477081).