Harb A, Daher A, Tlaiss Y, Warrak J, Abou Chaar J, Jabbour N, Haddam M, Warrak E. Comparing single and multiple laser-assisted in situ keratomileusis enhancements: Factors influencing recurrence safety and efficacy. World J Ophthalmol 2026; 10(1): 118802 [DOI: 10.5318/wjo.118802]
Corresponding Author of This Article
Yehya Tlaiss, Department of Ophthalmology, University of Balamand, Hazmieh, Beirut 1100, Beyrouth, Lebanon. yehyatlaiss@hotmail.com
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Ophthalmology
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research-article
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Harb A, Daher A, Tlaiss Y, Warrak J, Abou Chaar J, Jabbour N, Haddam M, Warrak E. Comparing single and multiple laser-assisted in situ keratomileusis enhancements: Factors influencing recurrence safety and efficacy. World J Ophthalmol 2026; 10(1): 118802 [DOI: 10.5318/wjo.118802]
World J Ophthalmol. Sep 12, 2026; 10(1): 118802 Published online Sep 12, 2026. doi: 10.5318/wjo.118802
Comparing single and multiple laser-assisted in situ keratomileusis enhancements: Factors influencing recurrence safety and efficacy
Adham Harb, Anthony Daher, Yehya Tlaiss, John Warrak, Jennifer Abou Chaar, Nour Jabbour, Majd Haddam, Elias Warrak
Adham Harb, Anthony Daher, Yehya Tlaiss, John Warrak, Jennifer Abou Chaar, Nour Jabbour, Majd Haddam, Elias Warrak, Department of Ophthalmology, University of Balamand, Beirut 1100, Beyrouth, Lebanon
Co-first authors: Adham Harb and Anthony Daher.
Author contributions: Harb A designed research and performed research; Daher A contributed new analytic tools and analyzed data; Tlaiss Y designed research and supervised the study; Warrak J performed research; Abou Chaar J performed research; Jabbour N performed research and wrote the paper; Haddam M analyzed data; Warrak E supervised the study. Harb A and Daher A contributed equally to this work as co-first authors.
Institutional review board statement: This is to certify that the IRB/REC of University of Balamand is in compliance with the Ethical Principles in the Declaration of Helsinki (1964, amended 2013), the Belmont Report (1979), the Standards and Operational Guidelines for Ethics Committees (EC) that Review Biomedical Research (WHO, Geneva 2000), the International Conference on Harmonization (ICH) Guidelines (Section E6), the International Ethical Guidelines for Health-related Research Involving Humans (CJ OMS, Geneva 2016), and applicable local laws and regulations.
Informed consent statement: Informed consent was waived due to the retrospective nature of the study.
Conflict-of-interest statement: The authors declare no conflicts of interest related to this study.
Data sharing statement: The data supporting the findings of this study are available from the corresponding author upon reasonable request, subject to institutional and ethical restrictions.
Corresponding author: Yehya Tlaiss, Department of Ophthalmology, University of Balamand, Hazmieh, Beirut 1100, Beyrouth, Lebanon. yehyatlaiss@hotmail.com
Received: January 12, 2026 Revised: February 15, 2026 Accepted: March 19, 2026 Published online: September 12, 2026 Processing time: 242 Days and 3.4 Hours
Abstract
BACKGROUND
Refractive regression after laser-assisted in situ keratomileusis (LASIK) can necessitate enhancement procedures. While single enhancements are common, a subset of patients require multiple enhancements, and predictors of repeated retreatment and related safety outcomes remain incompletely defined.
AIM
To compare single vs multiple LASIK enhancements, identify factors associated with repeated enhancements, and summarize safety outcomes over a two-year follow-up.
METHODS
We performed a retrospective study of 80 eyes (42 patients) that underwent LASIK enhancement by a single surgeon. Eyes were grouped as single-enhancement (one enhancement) vs multiple-enhancement (≥ 2 enhancements). Collected variables included age, refractive error (spherical equivalent and cylinder), corneal thickness, and interval between primary LASIK and first enhancement. Outcomes included enhancement frequency patterns, time to first enhancement, refractive stability over two years, and documented intraoperative/postoperative complications. Time-to-recurrence was assessed using Kaplan-Meier analysis, and multivariable logistic regression was used to evaluate predictors of multiple enhancements.
RESULTS
Of 80 eyes, 57 (70.7%) underwent a single enhancement and 23 (29.3%) underwent multiple enhancements. Mean age was 39.9 ± 14.0 years in the single-enhancement group and 43.9 ± 14.8 years in the multiple-enhancement group (P = 0.453). The interval from primary LASIK to first enhancement was longer in the single-enhancement group than in the multiple-enhancement group (62.1 ± 40.1 months vs 39.7 ± 37.3 months, P = 0.020). Mild refractive errors were associated with higher enhancement frequency than severe errors. Greater cylindrical error was associated with higher enhancement frequency (severe astigmatism averaging 2.0 enhancements/eye vs 1.34 in mild astigmatism). Thicker corneas were associated with more enhancements (mean enhancements/eye: 1.0 for 450-500 μm, 1.3 for 500-550 μm, and 1.56 for 550-600 μm), but corneal thickness did not correlate with the magnitude of regression at two years (Pearson r = -0.006, P = 0.96), suggesting feasibility/eligibility effects rather than increased biological regression risk. Intraoperative complications occurred in 2/80 eyes (2.5%), and postoperative complications occurred in 6/80 eyes (7.5%), most commonly epithelial ingrowth (3/80, 3.8%) and epithelial cyst (2/80, 2.5%). No cases of postoperative ectasia were observed.
CONCLUSION
A shorter interval from primary LASIK to first enhancement is associated with the likelihood of requiring multiple enhancements. Mild refractive errors, higher cylindrical error, and greater corneal thickness (reflecting enhancement feasibility) are linked to repeated enhancements. Complications were uncommon and no postoperative ectasia was observed, supporting careful patient selection and counseling; larger multicenter prospective studies are warranted to refine prediction of retreatment risk.
Core Tip: This study highlights the factors influencing the need for multiple laser-assisted in situ keratomileusis (LASIK) enhancements, including refractive error severity, corneal thickness, and time to recurrence. Patients with mild refractive errors, higher cylindrical errors, and thicker corneas are more likely to require additional procedures. Early recurrence of refractive error serves as a predictor for subsequent enhancements, emphasizing the importance of careful patient selection and counseling for long-term LASIK success.
