Correlation between effective optical zone and higher-order aberrations in keratorefractive lenticule extraction and wavefrontguided laser in situ keratomileusis

Sep 30, 2026

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Retrospective observational analysis investigates how higher-order aberration induction (ΔHOAs) relates to the effective optical zone (EOZ) in keratorefractive lenticule extraction (KLEx) and wavefront-guided laser in situ keratomileusis (WG-LASIK), and whether EOZ size alters these relationships. Patients treated for myopia or myopic astigmatism from 2018–2022 were assessed with Scheimpflug imaging one month postoperatively. Among 271 eyes, smaller EOZ areas showed modality-specific EOZ decentration associations with Δcoma and Δvertical coma, while EOZ size contributed to Δspherical aberration.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Introduction

Relevance of optical zone and HOAs to night vision complaints

Study gap and objectives

Methods

Study design and participants

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Correlation between effective optical zone and higher-order aberrations in keratorefractive lenticule extraction and wavefrontguided laser in situ keratomileusis Erh-Tsan Lin1,6, Tsung-Hsien Tsai2,3,6, Wei-Hsiang Lin4, Nan-Ni Chen5, Po-Chun Chang2 & Chi-Chin Sun2,3􀀍 This study aimed to analyze the correlations between the induction (Δ) of higher-order aberrations (HOAs) and the effective optical zone (EOZ) in keratorefractive lenticule extraction (KLEx) and wavefront-guided laser in situ keratomileusis (WG-LASIK), and to examine the effect of EOZ size on these correlations. This retrospective observational study included patients treated with KLEx and WGLASIK for myopia or myopic astigmatism between 2018 and 2022. ΔHOAs and EOZ parameters were analyzed using Scheimpflug imaging at one month after surgery. Correlation analysis and multivariate linear regression between EOZ parameters and ΔHOAs were performed. A total of 271 eyes were included, of which 141 underwent KLEx and 130 underwent WG-LASIK. In eyes with smaller EOZ areas (≤ 24.9 mm²), EOZ decentration in KLEx showed positive correlations with Δcoma and Δvertical coma (correlation coefficient (ρ) = 0.551 and 0.524, respectively) . EOZ decentration on theY-axis in KLEx also correlated positively with Δvertical coma (ρ = 0.540), while in WG-LASIK, EOZ decentrationon theX-axis correlated with Δcoma (ρ = 0.522) under similarly small EOZ areas. EOZ size parameters significantly contributed to Δspherical aberration in both procedures (p < 0.001). Conversely, these correlations were either not observed or significantly smaller in eyes with larger EOZ areas (> 24.9 mm²). In conclusion, maintaining a sufficiently large EOZ postoperatively is crucial. Moreover, precise surgical centration is vital for patients with smaller EOZ sizes, to reduce the induction of HOAs. Keywords KLEx, Wavefront-guided LASIK, Higher-order aberration, Effective optical zone Abbreviations KLEx WG-LASIK POZ CCT TCT KM µ µ(x) & µ(y) RMS HOA SA Keratorefractive lenticule extraction Wavefront-guided laser in situ keratomileusis Planned optical zone Central corneal thickness Thinnest corneal thickness Mean keratometry Chord distance (mm) x & y deviation of CV from PC (mm) Root mean square Higher order aberration Spherical aberration 1Department of Medical Education, Chang Gung Memorial Hospital, Keelung, Taiwan. 2Department of Ophthalmology, Chang Gung Memorial Hospital, Keelung, Keelung, Taiwan. 3School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan. 4Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan. 5Department of Ophthalmology, Chang Gung Memorial Hospital, Chiayi, Chiayi, Taiwan. 6Erh-Tsan Lin andTsung-Hsien Tsai contributed equally to this work. 􀀍 email: [chichinsun@gmail.com](chichinsun@gmail.com) [www. nature.com/scientificreports/](www. nature.com/scientificreports/) Refractive surgery is one of the most commonly performed elective procedures, known for its highly predictable outcomes1. A review of 97 articles published since 2008 on laser in situ keratomileusis (LASIK) reported that over 98.6% of patients achieved final target refraction within ± 1.0 diopter2. Despite the excellent refraction outcome, night vision complaints (NVCs) remained a significant issue post-LASIK. According to Pop et al., 26% of LASIK patients experienced NVCs one month after surgery3. These symptoms were closely linked to the induction (Δ) of higher-order aberrations (HOAs) by the conventional ablation profile of LASIK4–6. To address this, two advanced surgical procedures had gained popularity: wavefront-guided LASIK (WGLASIK) and keratorefractive lenticule extraction (KLEx) . WG-LASIK minimizes HOAs through customized aspheric ablation profiles based on whole-eye aberration data, while KLEx reduces flap-induced HOAs due to its flapless, minimall

FAQs

What was the study’s main goal?

To analyze correlations between induced higher-order aberrations (ΔHOAs) and the effective optical zone (EOZ) in KLEx and WG-LASIK, and to evaluate how EOZ size affects these correlations.

How were ΔHOAs and EOZ parameters measured?

Using Scheimpflug imaging at one month after surgery, with subsequent correlation analysis and multivariate linear regression.

What happened in eyes with smaller versus larger EOZ areas?

Smaller EOZ areas (≤ 24.9 mm²) showed positive correlations between EOZ decentration and specific Δcoma components, and EOZ size significantly contributed to Δspherical aberration; these relationships were absent or weaker in larger EOZ areas (> 24.9 mm²).

What clinical conclusion does the study emphasize?

Maintaining a sufficiently large EOZ postoperatively is crucial, and precise surgical centration is particularly important for patients with smaller EOZ sizes to reduce HOA induction.

Sep 30, 2026

Uploaded by Aria