Effect of Ablation-Zone Diameter on Whole-Corneal Higher-Order Aberrations After LASEK: A Retrospective Study

Effect of Ablation-Zone Diameter on Whole-Corneal Higher-Order Aberrations After LASEK: A Retrospective Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effect of Ablation-Zone Diameter on Whole-Corneal Higher-Order Aberrations After LASEK: A Retrospective Study Huihang Wang, Lu Xu, Shumin Tang, Yijun Lin, Shaobin Zheng, Yihua Zhu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8341631/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Purpose: To evaluate whether modest differences in programmed ablation-zone diameter (AZD) during LASEK affect postoperative whole-corneal higher-order aberrations (HOAs), with emphasis on spherical aberration (SA) and coma (CA). Methods: This retrospective single-center observational study included 120 right eyes that underwent LASEK between January 2020 and June 2025. 120 eyes were grouped by programmed AZD: 5.75 mm (n=41), 6.00 mm (n=40), and 6.25 mm (n=39). Corneal HOAs (total HOA RMS, SA, CA, trefoil aberration) were measured by Pentacam at baseline, 1 and 3 months. Analyses included absolute changes, HOA normalized per treated diopter, and matched-pair sensitivity comparisons. Statistical tests included t tests, ANOVA and χ²; significance set at P<0.05. Results: All groups showed significant postoperative increases in total HOA, SA and CA at 3 months (P<0.001). In unadjusted analyses, larger programmed AZDs exhibited smaller absolute increases in total HOA, SA and trefoil (P0.05 for most comparisons). Matched-pair analyses confirmed AZD enlargement consistently reduced SA but tended to increase CA (matched comparisons P<0.05), yielding no uniform net reduction in total HOA. Conclusions: Larger programmed AZDs in LASEK are associated with smaller absolute induction of SA, CA and total HOAs at 3 months, but this apparent benefit is largely mediated by baseline refractive magnitude and is disappeard after diopter normalization. Matched-pair analyses showed AZD enlargement reduced SA but increased CA without net HOA benefit; therefore precise centration is essential. LASEK ablation-zone diameter higher-order aberrations spherical aberration coma Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction Induction of corneal and ocular higher-order aberrations (HOAs) by corneal refractive surgery is a principal determinant of postoperative visual-quality disturbances, notably glare, halos, and reduced contrast sensitivity under mesopic or scotopic conditions, even when high-contrast acuity is satisfactory 1 – 3 . Multiple cohort studies and systematic reviews have demonstrated that different corneal refractive techniques (FS-LASIK, SMILE, LASEK, et al) produce distinct patterns and magnitudes of HOA induction; spherical aberration (SA) and coma (CA) are consistently reported as dominant aberration components with substantial impact on subjective night-vision complaints 2 , 4 – 6 . Surgical factors that correlate with the magnitude of induced HOAs include refractive correction magnitude, treatment centration, and the programmed ablation zone diameter (AZD) 5 , 6 . The diameter of the ablation zone is a modifiable treatment parameter that has been investigated across various procedures. Several comparative and cohort studies indicate that increasing the optical/ablation zone diameter can attenuate the postoperative increase in SA and total HOAs and may improve subjective visual quality when the pupil dilates; moreover, the relationship between the programmed optical zone and the postoperative effective optical zone (EOZ), and the degree of decentration, are important determinants of the final HOA profile 1 , 2 , 3 , 7 , 11 . Nevertheless, heterogeneity in patient cohorts, surgical modalities, analysis apertures, and follow-up intervals across studies limits direct generalization of results 2 , 3 , 7 . Despite theoretical and empirical rationale for a beneficial effect of larger ablation zones on certain HOA components (notably SA), evidence specifically addressing small, programmatic differences in ablation zone diameter within the surface ablation technique LASEK remains incomplete. Prior reports seldom provide within-technique, well-matched comparisons at consistent postoperative time points, and are frequently confounded by differing preoperative refractive error and ablation depths. Therefore, a focused evaluation of the independent effect of ablation-zone diameter on postoperative corneal total HOA, SA, CA and trefoil aberration (TA) in a LASEK population is warranted to inform evidence-based treatment planning 2 , 8 – 10 . Accordingly, we performed a retrospective analysis of 120 patients, selecting the right eye from each individual, and grouped them by programmed AZD (5.75 mm, 6.00 mm, and 6.25 mm). We compared baseline and postoperative (1 and 3 months) corneal HOA measures (total HOA, SA, CA, TA) and used the 3 months postoperative data as the primary endpoint for intergroup comparisons. The objective was to determine whether modest adjust in AZD within the LASEK technique produce measurable and clinically relevant change in HOA, thereby guiding optimization of treatment zone selection. 2. Patients and Methods 2.1 Study design and patients This retrospective single-center study included 120 patients who underwent LASEK between January 2020 and June 2025. From each patient, the right eye only was selected for analysis. Eyes were grouped by the programmed ablation-zone diameter used in surgery: 5.75 mm (n = 41), 6.00 mm (n = 40), and 6.25 mm (n = 39). Consecutive cases meeting inclusion/exclusion criteria and with complete corneal aberration data at baseline, 1 month and 3 months were enrolled. This study followed the tenets of the Declaration of Helsinki and was approved by the Ethics Committee of the First Affiliated Hospital of Fujian Medical University. Inclusion criteria: age ≥ 18 years, stable refraction for ≥ 2 years, corrected distance visual acuity of 20/20 or better, and discontinuation for 2 weeks and 3 months of soft contact and orthokeratology lens use, respectively. Exclusion criteria: prior ocular surgery, clinically manifest corneal ectasia or other corneal disease, ocular surface disease preventing reliable measurements, glaucoma or uveitis, systemic conditions affecting wound healing. 2.2 Preoperative assessment All subjects underwent a standardized preoperative protocol including manifest and cycloplegic refraction, uncorrected and corrected distance visual acuity (UDVA, CDVA), noncontact intraocular pressure (NCT), slit-lamp biomicroscopy, dilated fundus exam, scanning laser ophthalmoscope (SLO, Heidelberg Engineering, Heidelberg, Germany), optical biometry (Lenstar LS900, Haag Steit AG, Koeniz, Switzerland) and Pentacam tomography system (Oculus Optikgeräte GmbH, Wetzlar, Germany). 2.3 Surgical technique All the surgical procedures were performed by a single surgeon (Dr. Zheng) with extensive experience using a Mel 80 excimer laser (Carl Zeiss Meditec, Jena, Germany) system. After topical anesthesia, a corneal epithelial trephine with an inner diameter of 8.0 mm was used and 20% ethanol was applied for 20s to the corneal surface to loosen the epithelium, and the epithelium was then mechanically removed by scraping. The stromal ablation was performed using an excimer laser with a repetition rate of 250 Hz and a fluence of 150 mJ/cm², applying the programmed ablation zone diameter of 5.75, 6.00, or 6.25 mm. A bandage contact lens was placed at the end of the procedure and removed at postoperative day 5 during the scheduled visit. Postoperative medications included topical antibiotic and a tapered topical steroid regimen together with artificial tears eye drops. 2.4 Corneal wavefront and tomographic measurements Corneal aberrations were measured using a Pentacam tomography system following the manufacturer’s quality criteria; only scans meeting device quality metrics were included. A 3, 4, 5, 6-mm analysis diameter centered on the corneal vertex was used to extract Zernike coefficients. Extracted metrics (RMS, µm) comprised total whole corneal HOA RMS, SA (Z4, 0), CA (Z3, ±1), and TA (Z3, ±3). For each eye we recorded baseline and postoperative (1- and 3-month) values and used for subsequent calculations. 2.5 Statistical analysis All data were analyzed using GraphPad prism 8 statistical software (version 8.2.1, GraphPad Software, San Diego, CA, USA). Continuous variables are expressed as mean ± SD; categorical variables as counts (%). Normality was tested with the Kolmogorov-Smirnov test. For two-group comparisons, an independent-samples t test was used for normally distributed variables, while the Mann–Whitney U test was applied to non-normal data. For comparisons among three or more groups, a one-way analysis of variance (ANOVA) was performed with Bonferroni post hoc correction. Sex distribution was compared using the chi-square (χ²) test. Within-group (pre- vs. postoperative) comparisons were conducted using the paired-samples t test for normal data or the Wilcoxon signed-rank test otherwise. Statistical tests were two-tailed and P < 0.05 was considered significant. 3. Results 3.1 Baseline Characteristics A total of 120 right eyes from 120 patients were analyzed and divided according to the programmed ablation-zone diameter: 5.75 mm (n = 41), 6.00 mm (n = 40), and 6.25 mm (n = 39). Baseline demographics and refractive data are summarized in Table 1. Sex distribution (χ² = 3.534, P = 0.1709) and age (P = 0.0782) were comparable among groups. Preoperative refractive error differed significantly, with higher myopia in smaller ablation zones (P < 0.001). Central corneal thickness increased with larger ablation zones (P < 0.001), which likely reflects a clinical tendency for eyes with thinner corneas and higher refractive errors to be treated with smaller ablation zones to minimize stromal tissue removal. Other baseline parameters, including keratometry and angle kappa, were not significantly different (Table 1). 3.2 Temporal Changes in Corneal Aberrations The evolution of whole corneal HOAs within the central 6 mm analysis zone is shown in Figure 1. In all groups, total HOA RMS, SA, and CA increased markedly at 1 month (P < 0.001) and slightly decreased by 3 months, yet remained elevated relative to baseline. TA showed minimal change. Because HOA values stabilized between 1 and 3 months, the 3 months visit was used for primary intergroup comparisons. 3.3 Postoperative Aberrations at 3 Months As shown in Table 2, there were no significant intergroup differences in preoperative HOA parameters, including total HOA, SA, CA, and TA. At 3 months postoperatively, however, all three groups exhibited significant increases in total HOA, SA, and CA compared with baseline values (P < 0.001). When comparing between groups, the 6.25mm ablation-zone group demonstrated the smallest postoperative increases in total HOA, SA, and CA, whereas the 5.75mm group showed the largest changes, with differences among groups reaching statistical significance (P < 0.001). TA did not differ significantly either pre- or postoperatively among 3 groups. 3.4 Normalized HOA Changes by Refractive Diopter To adjust for baseline spherical equivalent (SEQ) differences, HOA changes were normalized per treated diopter. Across the 3, 4, 5, and 6 mm analysis zones (Supplemental Table 1), no significant intergroup differences were observed in ΔSA/D, ΔCA/D, ΔTA/D, or ΔHOA/D (P > 0.05), except for a mild variation in ΔSA/D at the 4-mm zone (P = 0.018). These findings indicate that the smaller absolute aberrations in larger-zone groups were largely attributable to differences in baseline refractive diopter rather than intrinsic optical effects of the ablation diameter. 3.5 HOA–Diopter Relationship Regression plots in Figure 2 illustrate the relationship between normalized aberrations and refractive diopter across the three ablation-zone groups. Overall, ΔSA/D decreased with higher absolute value of myopic correction, whereas ΔCA/D increased with higher absolute value of myopic correction, indicating that normalization by diopter only partially compensates for the influence of treatment magnitude on postoperative aberrations. Therefore, smaller ablation zones (relatively high diopter) tended to underestimate SA and overestimate CA after normalization, as reflected by the divergent slopes and vertical separation of the regression lines in Figure 2. These results suggest that normalization by refractive diopter alone cannot completely offset the intrinsic bias caused by differences in refractive correction among ablation-zone diameters. 3.6 Matched-Pair Sensitivity Analyses To minimize confounding, matched subsets of eyes with similar baseline SEQ were compared between adjacent groups. In the 5.75 mm vs 6.00 mm comparison (Figure 3), the larger zone produced significantly lower SA at 5 and 6 mm diameters (P < 0.05) but slightly higher CA. Total HOA decreased centrally yet increased peripherally. In the 6.00 mm vs 6.25 mm matched pairs (Figure 4), SA again decreased and CA increased significantly at the 6 mm zone (P < 0.05). Overall, enlargement of the ablation zone consistently reduced SA but tended to increase CA, without a uniform reduction in total HOAs. 4. Discussion This study evaluated the relationship between programmed AZD and postoperative whole corneal HOAs after LASEK. Our principal findings were: (1) absolute postoperative increases in total HOA, SA and CA were evident in all groups; (2) larger programmed AZDs—which in our cohort were associated with smaller preoperative refractive corrections—exhibited significantly smaller absolute postoperative increases in total HOA, SA and TA; and (3) normalization by diopter and matched-pair analyses attenuated these apparent zone-dependent benefits, revealing a more complex interplay between diopter, AZD and the pattern of HOA induction. These results have implications for AZD selection in surface ablation, especially when balancing night-vision quality and corneal tissue preservation. The reduction of SA with larger AZD likely reflects preservation of a greater proportion of the mesopic pupil within the optically corrected area and a smoother, more gradual periphery transition, reducing peripheral asphericity change and associated positive SA induction 2 , 3 , 8 , 10 . This conceptual framework aligns with recent analyses of the EOZ, which emphasize that programmed AZD is not always equivalent to the EOZ actually achieved on the cornea; EOZ size, shape and centration strongly influence functional optical quality after keratorefractive procedures 2 , 3 . However, EOZ is itself influenced by multiple factors including ablation depth, epithelial remodeling and biomechanical responses; therefore, a simple increase in programmed AZD does not guarantee a proportionate increase in EOZ or a commensurate reduction in corneal HOAs. Our normalization analyses showed that many apparent group differences become non-significant, indicating that preoperative refractive diopter is a dominant determinant of induced HOAs. This observation echoes prior reports showing a strong positive association between diopter correction and postoperative HOAs magnitude 10 . Importantly, our regression and graphical analyses demonstrate that normalization does not fully remove bias: higher diopter tended to produce underestimation of SA and overestimation of CA after normalization. In other words, normalization analyses assumes a simple linear, proportional relationship between diopter and HOAs induction that does not hold uniformly across AZDs, analysis apertures, or for different aberration components; geometric factors of the ablation profile and non-linear tissue response result in residual, zone-dependent effects that normalization analyses cannot correct. This limitation has been noted in recent reviews advocating caution in overreliance on normalization without supplementary matched or model-based adjustments 10 , 12 . While larger AZDs reduced SA, the tendency for CA to increase highlights the importance of centration accuracy and ocular alignment. CA is exquisitely sensitive to decentration and asymmetric ablation patterns; larger programmed AZD may amplify the visual impact of even small decentrations because a greater peripheral area contributes to off-axis light 8 , 13 . Consequently, simply selecting a larger AZD without ensuring optimal centration and tracking may shift the aberration spectrum toward coma-dominant patterns, which can degrade subjective optical quality in ways not captured by SA metrics alone. This observation underlines an operational principle: AZD optimization must be coupled with strict centration protocols preoperative and adjustment of the ablation center based on measured angle Kappa to minimize coma induction. Selecting a larger AZD benefits mesopic optical quality but increases stromal tissue removal. In practice, surgeons commonly preferentially select smaller AZDs for eyes with higher myopia or thinner corneas to preserve residual stromal thickness — a pattern reflected in our baseline data and consistent with clinical practice 1 – 3 . However, unless optimal centration is achieved, simply enlarging the AZD does not necessarily reduce vision disturbances; instead, it may shift the symptom profile from predominantly SA–related phenomena toward CA-dominated complaints, which are less mitigated by a larger AZD. Thus, AZD decision-making inherently involves a trade-off between optimizing postoperative optics and maintaining corneal safety margins. Integrating individualized ablation centration strategies and EOZ prediction models into preoperative planning may enable more informed AZD choices that balance these competing priorities 7 , 13 . Strengths of our work include a single-technique focus (LASEK), use of a consistent analysis aperture for HOAs extraction, and multiple complementary analytic strategies (absolute, normalized and matched-pair comparisons). Limitations include retrospective design, limited sample size for matched comparisons and absence of patient-reported night-vision outcomes in all cases. Future work should prospectively evaluate EOZ, quantify decentration with high precision, and combine objective HOA metrics with validated quality-of-vision instruments. Advanced ray-tracing and physical modeling could further disentangle how ablation geometry, epithelial remodeling and biomechanical effects jointly shape HOA induction across AZDs 13 , 14 . In conclusion, in LASEK, increasing the programmed AZD reduces induced SA and total HOA on absolute analysis, but normalization by diopter and matched analyses reveal that this benefit is substantially mediated by preoperative refractive diopter. Moreover, larger AZDs may increase CA if ablation centration is suboptimal. Therefore, AZD selection should be individualized, balancing corneal safety, intended correction diopter and the surgeon’s ability to ensure precise centration. Declarations Funding: This work was supported by the Fujian Province Science and Technology Innovation Joint Fund Project (Grant Number 2024Y9132), the Fujian Provincial Natural Science Foundation (Grant Number 2025J01719) and the National Natural Science Foundation of China (Grant Number 82271079). Acknowledgements: Not applicable. Competing interests: The authors declare that they have no competing interests. Authors' contributions: H.W. conceived and designed the study. H.W. and L.X. conduct experiment, collected the data and drafted the main manuscript text. S.T. and Y.L. performed the analysis, revised the manuscript and prepared all figures. S.Z. performed the surgical procedures. H.W. and Y.Z. obtained funding and had overall responsibility for the study. Ethics approval and consent to participate: The study protocol was approved by the Branch for Medical Research and Clinical Technology Application, Ethics Committee of the First Affiliated Hospital of Fujian Medical University (IRB No.[2015] 084-2). All procedures involving human participants were conducted in accordance with applicable local regulations, institutional requirements, and the tenets of the Declaration of Helsinki. Consent for publication: Not applicable. Availability of data and materials: The datasets used and analysed during the current study are available from the corresponding author on reasonable request. Authors' information: Not applicable. References Al-Mohaimeed MM. Effect of the Optical Zone Ablation Diameter on Higher Order Aberrations After Transepithelial Photorefractive Keratectomy: A Cohort Study. Cureus. 2021 Sep 1;13(9):e17630. Moshirfar M, Herron MS, Cha DS, Santos J, Payne CJ, Hoopes PC. Comparing Effective Optical Zones After Myopic Ablation Between LASIK, PRK, and SMILE With Correlation to Higher Order Aberrations. J Refract Surg. 2023 Nov;39(11):741-750. Huang Y, Han T, Wang Y, Peng X, Ten W, Zhou X, Xu Y. Comparison of long-term changes in the effective optical zone following SMILE and FS-LASIK for moderate and high myopia. BMC Ophthalmol. 2024 Sep 3;24(1):388. Zhou C, Li Y, Wang Y, Fan Q, Dai L. Comparison of visual quality after SMILE correction of low-to-moderate myopia in different optical zones. Int Ophthalmol. 2023 Oct;43(10):3623-3632. Kang EM, Ryu IH, Lee IS, Kim JK, Kim SW, Ji YW. Comparison of Corneal Higher-Order Aberrations Following Topography-Guided LASIK and SMILE for Myopic Correction: A Propensity Score Matching Analysis. J Clin Med. 2022 Oct 19;11(20):6171. Feng Z, Wang Q, Du C, Yang F, Li X. High-order aberration changes after femtosecond LASIK surgery in patients with high myopia. Ann Palliat Med. 2021 Jul;10(7):7689-7696. Çakır GY, Çakır İ, Yıldız BK, Yıldırım Y. Effective optical zone: Differences between small-incision lenticule extraction and femtosecond LASIK for myopia. Indian J Ophthalmol. 2024 Sep 1;72(9):1315-1320. Thananjeyan AL, Bala C. Higher-Order Aberrations Following Ray Trace LASIK and the Impact of Eye Movement on Coma. Clin Ophthalmol. 2024 Nov 22;18:3389-3398. Chen L, Khamar P, Wang Y, Fu H, Shetty R. Evaluation of Higher-Order Aberrations After the Smooth Incision Lenticular Keratomileusis (SILKTM) Procedure Using the ELITATM Femtosecond Platform for Correction of Myopic and Astigmatic Refractive Errors. Clin Ophthalmol. 2024 Jul 24;18:2155-2166. Du Y, Di Y, Yang S, Mo F, Cui G, Chen D, Li Y. Differences in ocular high order aberrations before and after small incision lenticule extraction for correction of myopia: a systematic review and meta-analysis. Front Med (Lausanne). 2024 Mar 27;11:1274101. Huang Y, Zhan B, Han T, Zhou X. Effective optical zone following small incision lenticule extraction: a review. Graefes Arch Clin Exp Ophthalmol. 2024 Jun;262(6):1657-1665. Choi SH, Won YK, Na SJ, Nam D, Lim DH. Limitations of and Solutions to Using 6 mm Corneal Spherical Aberration and Q Value after Laser Refractive Surgery. Bioengineering (Basel). 2024 Feb 16;11(2):190. Reinstein DZ, Archer TJ, Vida RS, Carp GI, Reinstein JFR, McAlinden C. Objective and Subjective Quality of Vision After SMILE for High Myopia and Astigmatism. J Refract Surg. 2022 Jul;38(7):404-413. Liu P, Yu D, Zhang B, Zhou S, Zhu H, Qin W, Ye X, Li X, Zhang Y, Bai Y, Wang Y, Shao Z. Influence of optical zone on myopic correction in small incision lenticule extraction: a short-term study. BMC Ophthalmol. 2022 Oct 21;22(1):409. Tables Table 1: Characteristics of the study groups. Subjects 5.75mm Group 6mm Group 6.25mm Group p -Value No. of cases 41 40 39 - Sex, male, % 41.46 40 58.97 0.1709 Age, years 25.80 ± 7.01 25.00 ± 5.47 22.95 ± 4.40 0.0782 Sphere, diopter -6.35 ± 1.86 -4.51 ± 1.32 -3.26 ± 1.54 ＜0.0001 * Cylinder, diopter -1.44 ± 1.16 -1.11 ± 1.07 -0.67 ± 0.67 0.0032 SEQ, diopter -7.10 ± 1.87 -5.07 ± 1.30 -3.59 ± 1.48 ＜0.0001 * UDVA pre, logMAR 1.42 ± 0.31 1.27 ± 0.28 0.99 ± 0.37 ＜0.0001 * CDVA, logMAR -0.02 ± 0.03 -0.03 ± 0.04 -0.04 ± 0.04 0.1055 UDVA post, logMAR -0.01 ± 0.06 -0.03 ± 0.04 -0.04 ± 0.05 0.0744 NCT, mmHg 16.39 ± 2.96 16.25 ± 2.16 16.97 ± 1.68 0.3475 CCT, μm 519.1 ± 29.86 538.2 ± 31.59 552.3 ± 31.63 ＜0.0001 * K-mean, diopter 43.69 ± 1.14 43.49 ± 1.50 43.13 ± 1.26 0.1584 Angle Kappa, mm 0.21 ± 0.12 0.18 ± 0.10 0.16 ± 0.10 0.1378 SEQ: spherical equivalent; UDVA: uncorrected distance visual acuity; CDVA: corrected distance visual acuity; IOP: noncontact intraocular pressure; CCT: central corneal thickness; * P < 0.05. Table 2: Three-month whole corneal aberrations by different ablation zone. Subjects 5.75mm Group 6mm Group 6.25mm Group p -Value SA, μm preoperative 0.220 ± 0.072 0.212 ± 0.095 0.230 ± 0.057 0.5809 postoperation 0.997 ± 0.245 0.735 ± 0.236 0.632 ± 0.189 ＜0.0001 * p -Value ＜0.0001 * ＜0.0001 * ＜0.0001 * CA, μm preoperative 0.244 ± 0.142 0.272 ± 0.236 0.220 ± 0.093 0.1681 postoperation 1.096 ± 0.646 0.767 ± 0.442 0.527 ± 0.317 ＜0.0001 * p -Value ＜0.0001 * ＜0.0001 * ＜0.0001 * TA, μm preoperative 0.137 ± 0.077 0.143 ± 0.083 0.131 ± 0.066 0.8159 postoperation 0.203 ± 0.157 0.203 ± 0.187 0.188 ± 0.140 0.8970 p -Value 0.0171 * 0.0605 0.0234 * HOAs, μm preoperative 0.415 ± 0.107 0.425 ± 0.114 0.392 ± 0.070 0.3798 postoperation 1.575 ± 0.588 1.171 ± 0.376 0.931 ± 0.249 ＜0.0001 * p -Value ＜0.0001 * ＜0.0001 * ＜0.0001 * SA: spherical equivalent; CA: coma; TA: trefoil aberration; HOAs: higher-order aberrations; * P < 0.05. Additional Declarations No competing interests reported. Supplementary Files SupplementalTable1.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8341631","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":560130323,"identity":"4454925a-3858-49f9-a934-74babb8c7765","order_by":0,"name":"Huihang Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyklEQVRIiWNgGAWjYBACfvmHDQYJFf/s+NkbiNQi2ZB8oODBmQPJkj0HiNRicCAt4ePDlgOMG24kEG3LGcMNiQ13mCVnPt54g6HGJpqgFn7GHmODxB3P+Pil04otGI6l5TYQtKWZx8wg8Qwzs+TsHDMJxobDhLUYHOMx/5HYxsy44eYZYrWcYUswSGw7DPQ+D5FaJGcwHzBIOJMGDGSgXxKI8Qs/0GTDHxU2wKg8vPHGhxobwlpQHCmRQIpyiBZSdYyCUTAKRsHIAAABMkWo6eIZowAAAABJRU5ErkJggg==","orcid":"","institution":"The First Afffliated Hospital, Fujian Medical University","correspondingAuthor":true,"prefix":"","firstName":"Huihang","middleName":"","lastName":"Wang","suffix":""},{"id":560130324,"identity":"986976c9-6f69-40d5-ab40-543be36da09b","order_by":1,"name":"Lu Xu","email":"","orcid":"","institution":"The First Afffliated Hospital, Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Lu","middleName":"","lastName":"Xu","suffix":""},{"id":560130325,"identity":"fc7536af-808b-41bd-af13-42242aa4b956","order_by":2,"name":"Shumin Tang","email":"","orcid":"","institution":"The First Afffliated Hospital, Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shumin","middleName":"","lastName":"Tang","suffix":""},{"id":560130326,"identity":"5f0a5938-ea56-4e7a-8589-47c5d46802d8","order_by":3,"name":"Yijun Lin","email":"","orcid":"","institution":"The First Afffliated Hospital, Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yijun","middleName":"","lastName":"Lin","suffix":""},{"id":560130327,"identity":"0db12098-8280-41c1-af1e-d45558eb18df","order_by":4,"name":"Shaobin Zheng","email":"","orcid":"","institution":"The First Afffliated Hospital, Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shaobin","middleName":"","lastName":"Zheng","suffix":""},{"id":560130328,"identity":"022ce072-b6af-4ffa-9d8b-204b47b80a2d","order_by":5,"name":"Yihua Zhu","email":"","orcid":"","institution":"The First Afffliated Hospital, Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yihua","middleName":"","lastName":"Zhu","suffix":""}],"badges":[],"createdAt":"2025-12-12 04:23:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8341631/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8341631/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98870066,"identity":"77f8c09c-5923-410e-ad69-6b46c923bb00","added_by":"auto","created_at":"2025-12-23 11:40:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":471232,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal changes in HOAs within a 6.0 mm analysis zone for eyes treated with programmed ablation-zone diameters of 5.75 mm, 6.00 mm and 6.25 mm. Mean ± SD are shown for total HOAs, SA, CA and TA at baseline, 1 month and 3 months. All groups demonstrated significant increases from baseline to 1 month (P \u0026lt; 0.05) and remained elevated at 3 months; values decreased modestly between 1 and 3 months.\u003c/p\u003e","description":"","filename":"figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-8341631/v1/33adb6e02f95d1593bede593.png"},{"id":98870070,"identity":"f2cdc297-c4a0-4ec6-b7ae-14f3ce0b510c","added_by":"auto","created_at":"2025-12-23 11:40:17","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":923883,"visible":true,"origin":"","legend":"\u003cp\u003eRegression plots showing the relationship between refractive correction with △SA/D, △CA/D, △TA/D and △HOAs/D among eyes treated with different programmed AZDs. With increasing myopic correction, △SA/D tended to rise while △CA/D declined, demonstrating divergent slopes among AZD groups. These trends indicate that diopter normalization only partially compensates for the influence of treatment magnitude and may introduce bias when comparing postoperative aberrations across different AZDs.\u003c/p\u003e","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-8341631/v1/da296be9cc0b9f0708a66e1b.png"},{"id":98870064,"identity":"e45d019e-9910-453a-962a-e52f710c8c9f","added_by":"auto","created_at":"2025-12-23 11:40:13","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":553769,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of postoperative changes in corneal aberrations between matched eyes treated with 5.75 mm and 6.00 mm programmed AZDs of similar preoperative refractive error. Mean ± SD values of changes in total HOAs, SA, CA, and TA are shown across 3, 4, 5, and 6 mm analysis zones at 3 months postoperatively. Enlargement of the AZD from 5.75 to 6.00 mm reduced SA, significantly at 5 and 6 mm zones (P \u0026lt; 0.05), but increased CA, while total HOAs exhibited a mixed trend depending on analysis diameter.\u003c/p\u003e","description":"","filename":"figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-8341631/v1/bece2dc89a790a9094f10e9f.png"},{"id":98870069,"identity":"bdcddc02-a77c-4d6a-bbab-d27b63d46f96","added_by":"auto","created_at":"2025-12-23 11:40:15","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":538173,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of postoperative changes in corneal aberrations between matched eyes treated with 6.00 mm and 6.25 mm programmed AZDs of similar preoperative refractive error. Mean ± SD values of changes in total HOAs, SA, CA, and TA are shown across 3, 4, 5, and 6 mm analysis zones at 3 months postoperatively. Enlargement of the AZD from 6.00 to 6.25 mm further reduced SA, but significantly increased CA at the 6 mm zone (P \u0026lt; 0.05), while total HOAs showed an overall increasing trend with larger analysis diameters.\u003c/p\u003e","description":"","filename":"figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-8341631/v1/afa8f560d8425e8f47e8479a.png"},{"id":98870086,"identity":"16406053-d9f2-4027-8ae0-61f4b1853533","added_by":"auto","created_at":"2025-12-23 11:40:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3513176,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8341631/v1/cf577085-2a88-4fe2-9693-e0ceb7659da0.pdf"},{"id":98869990,"identity":"7841e9ba-6b53-4881-9f37-534cd485845f","added_by":"auto","created_at":"2025-12-23 11:40:02","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":18278,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementalTable1.docx","url":"https://assets-eu.researchsquare.com/files/rs-8341631/v1/6f79f4c8a401bd2828aadff8.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effect of Ablation-Zone Diameter on Whole-Corneal Higher-Order Aberrations After LASEK: A Retrospective Study","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eInduction of corneal and ocular higher-order aberrations (HOAs) by corneal refractive surgery is a principal determinant of postoperative visual-quality disturbances, notably glare, halos, and reduced contrast sensitivity under mesopic or scotopic conditions, even when high-contrast acuity is satisfactory\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. Multiple cohort studies and systematic reviews have demonstrated that different corneal refractive techniques (FS-LASIK, SMILE, LASEK, et al) produce distinct patterns and magnitudes of HOA induction; spherical aberration (SA) and coma (CA) are consistently reported as dominant aberration components with substantial impact on subjective night-vision complaints\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. Surgical factors that correlate with the magnitude of induced HOAs include refractive correction magnitude, treatment centration, and the programmed ablation zone diameter (AZD)\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe diameter of the ablation zone is a modifiable treatment parameter that has been investigated across various procedures. Several comparative and cohort studies indicate that increasing the optical/ablation zone diameter can attenuate the postoperative increase in SA and total HOAs and may improve subjective visual quality when the pupil dilates; moreover, the relationship between the programmed optical zone and the postoperative effective optical zone (EOZ), and the degree of decentration, are important determinants of the final HOA profile\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Nevertheless, heterogeneity in patient cohorts, surgical modalities, analysis apertures, and follow-up intervals across studies limits direct generalization of results\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eDespite theoretical and empirical rationale for a beneficial effect of larger ablation zones on certain HOA components (notably SA), evidence specifically addressing small, programmatic differences in ablation zone diameter within the surface ablation technique LASEK remains incomplete. Prior reports seldom provide within-technique, well-matched comparisons at consistent postoperative time points, and are frequently confounded by differing preoperative refractive error and ablation depths. Therefore, a focused evaluation of the independent effect of ablation-zone diameter on postoperative corneal total HOA, SA, CA and trefoil aberration (TA) in a LASEK population is warranted to inform evidence-based treatment planning\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003e Accordingly, we performed a retrospective analysis of 120 patients, selecting the right eye from each individual, and grouped them by programmed AZD (5.75 mm, 6.00 mm, and 6.25 mm). We compared baseline and postoperative (1 and 3 months) corneal HOA measures (total HOA, SA, CA, TA) and used the 3 months postoperative data as the primary endpoint for intergroup comparisons. The objective was to determine whether modest adjust in AZD within the LASEK technique produce measurable and clinically relevant change in HOA, thereby guiding optimization of treatment zone selection.\u003c/p\u003e"},{"header":"2. Patients and Methods","content":"\u003cp\u003e\u003cstrong\u003e2.1 Study design and patients\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis retrospective single-center study included 120 patients who underwent LASEK between January 2020 and June 2025. From each patient, the right eye only was selected for analysis. Eyes were grouped by the programmed ablation-zone diameter used in surgery: 5.75 mm (n = 41), 6.00 mm (n = 40), and 6.25 mm (n = 39). Consecutive cases meeting inclusion/exclusion criteria and with complete corneal aberration data at baseline, 1 month and 3 months were enrolled. This study followed the tenets of the Declaration of Helsinki and was approved by the Ethics Committee of the First Affiliated Hospital of Fujian Medical University. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eInclusion criteria: age \u0026ge; 18 years, stable refraction for \u0026ge; 2 years, corrected distance visual acuity of 20/20 or better, and discontinuation for 2 weeks and 3 months of soft contact and orthokeratology lens use, respectively. Exclusion criteria: prior ocular surgery, clinically manifest corneal ectasia or other corneal disease, ocular surface disease preventing reliable measurements, glaucoma or uveitis, systemic conditions affecting wound healing.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Preoperative assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll subjects underwent a standardized preoperative protocol including manifest and cycloplegic refraction, uncorrected and corrected distance visual acuity (UDVA, CDVA), noncontact intraocular pressure (NCT), slit-lamp biomicroscopy, dilated fundus exam, scanning laser ophthalmoscope (SLO, Heidelberg Engineering, Heidelberg, Germany), optical biometry (Lenstar LS900, Haag Steit AG, Koeniz, Switzerland) and Pentacam tomography system (Oculus Optikger\u0026auml;te GmbH, Wetzlar, Germany).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Surgical technique\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the surgical procedures were performed by a single surgeon (Dr. Zheng) with extensive experience using a Mel 80 excimer laser (Carl Zeiss Meditec, Jena, Germany) system. After topical anesthesia, a corneal epithelial trephine with an inner diameter of 8.0 mm was used and 20% ethanol was applied for 20s to the corneal surface to loosen the epithelium, and the epithelium was then mechanically removed by scraping. The stromal ablation was performed using an excimer laser with a repetition rate of 250 Hz and a fluence of 150 mJ/cm\u0026sup2;, applying the programmed ablation zone diameter of 5.75, 6.00, or 6.25 mm. A bandage contact lens was placed at the end of the procedure and removed at postoperative day 5 during the scheduled visit. Postoperative medications included topical antibiotic and a tapered topical steroid regimen together with artificial tears eye drops.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Corneal wavefront and tomographic measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorneal aberrations were measured using a Pentacam tomography system following the manufacturer\u0026rsquo;s quality criteria; only scans meeting device quality metrics were included. A 3, 4, 5, 6-mm analysis diameter centered on the corneal vertex was used to extract Zernike coefficients. Extracted metrics (RMS, \u0026micro;m) comprised total whole corneal HOA RMS, SA (Z4, 0), CA (Z3, \u0026plusmn;1), and TA (Z3, \u0026plusmn;3). For each eye we recorded baseline and postoperative (1- and 3-month) values and used for subsequent calculations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.5 Statistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data were analyzed using GraphPad prism 8 statistical software (version 8.2.1, GraphPad Software, San Diego, CA, USA). Continuous variables are expressed as mean \u0026plusmn; SD; categorical variables as counts (%). Normality was tested with the Kolmogorov-Smirnov test. For two-group comparisons, an independent-samples t test was used for normally distributed variables, while the Mann\u0026ndash;Whitney U test was applied to non-normal data. For comparisons among three or more groups, a one-way analysis of variance (ANOVA) was performed with Bonferroni post hoc correction. Sex distribution was compared using the chi-square (\u0026chi;\u0026sup2;) test. Within-group (pre- vs. postoperative) comparisons were conducted using the paired-samples t test for normal data or the Wilcoxon signed-rank test otherwise. Statistical tests were two-tailed and P \u0026lt; 0.05 was considered significant.\u0026nbsp;\u003c/p\u003e"},{"header":"3. Results","content":"\u003cp\u003e\u003cstrong\u003e3.1 Baseline Characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 120 right eyes from 120 patients were analyzed and divided according to the programmed ablation-zone diameter: 5.75 mm (n = 41), 6.00 mm (n = 40), and 6.25 mm (n = 39). Baseline demographics and refractive data are summarized in Table 1. Sex distribution (\u0026chi;\u0026sup2; = 3.534, P = 0.1709) and age (P = 0.0782) were comparable among groups. Preoperative refractive error differed significantly, with higher myopia in smaller ablation zones (P \u0026lt; 0.001). Central corneal thickness increased with larger ablation zones (P \u0026lt; 0.001), which likely reflects a clinical tendency for eyes with thinner corneas and higher refractive errors to be treated with smaller ablation zones to minimize stromal tissue removal. Other baseline parameters, including keratometry and angle kappa, were not significantly different (Table 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Temporal Changes in Corneal Aberrations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe evolution of whole corneal HOAs within the central 6 mm analysis zone is shown in Figure 1. In all groups, total HOA RMS, SA, and CA increased markedly at 1 month (P \u0026lt; 0.001) and slightly decreased by 3 months, yet remained elevated relative to baseline. TA showed minimal change. Because HOA values stabilized between 1 and 3 months, the 3 months visit was used for primary intergroup comparisons.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Postoperative Aberrations at 3 Months\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Table 2, there were no significant intergroup differences in preoperative HOA parameters, including total HOA, SA, CA, and TA. At 3 months postoperatively, however, all three groups exhibited significant increases in total HOA, SA, and CA compared with baseline values (P \u0026lt; 0.001). When comparing between groups, the 6.25mm ablation-zone group demonstrated the smallest postoperative increases in total HOA, SA, and CA, whereas the 5.75mm group showed the largest changes, with differences among groups reaching statistical significance (P \u0026lt; 0.001). TA did not differ significantly either pre- or postoperatively among 3 groups.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Normalized HOA Changes by Refractive Diopter\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo adjust for baseline spherical equivalent (SEQ) differences, HOA changes were normalized per treated diopter. Across the 3, 4, 5, and 6 mm analysis zones (Supplemental Table 1), no significant intergroup differences were observed in \u0026Delta;SA/D, \u0026Delta;CA/D, \u0026Delta;TA/D, or \u0026Delta;HOA/D (P \u0026gt; 0.05), except for a mild variation in \u0026Delta;SA/D at the 4-mm zone (P = 0.018). These findings indicate that the smaller absolute aberrations in larger-zone groups were largely attributable to differences in baseline refractive diopter rather than intrinsic optical effects of the ablation diameter.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.5 HOA\u0026ndash;Diopter Relationship\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRegression plots in Figure 2 illustrate the relationship between normalized aberrations and refractive diopter across the three ablation-zone groups. Overall, \u0026Delta;SA/D decreased with higher absolute value of myopic correction, whereas \u0026Delta;CA/D increased with higher absolute value of \u0026nbsp;myopic correction, indicating that normalization by diopter only partially compensates for the influence of treatment magnitude on postoperative aberrations. Therefore, smaller ablation zones (relatively high diopter) tended to underestimate SA and overestimate CA after normalization, as reflected by the divergent slopes and vertical separation of the regression lines in Figure 2. These results suggest that normalization by refractive diopter alone cannot completely offset the intrinsic bias caused by differences in refractive correction among ablation-zone diameters.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.6 Matched-Pair Sensitivity Analyses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo minimize confounding, matched subsets of eyes with similar baseline SEQ were compared between adjacent groups. In the 5.75 mm vs 6.00 mm comparison (Figure 3), the larger zone produced significantly lower SA at 5 and 6 mm diameters (P \u0026lt; 0.05) but slightly higher CA. Total HOA decreased centrally yet increased peripherally. In the 6.00 mm vs 6.25 mm matched pairs (Figure 4), SA again decreased and CA increased significantly at the 6 mm zone (P \u0026lt; 0.05). Overall, enlargement of the ablation zone consistently reduced SA but tended to increase CA, without a uniform reduction in total HOAs.\u003c/p\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eThis study evaluated the relationship between programmed AZD and postoperative whole corneal HOAs after LASEK. Our principal findings were: (1) absolute postoperative increases in total HOA, SA and CA were evident in all groups; (2) larger programmed AZDs\u0026mdash;which in our cohort were associated with smaller preoperative refractive corrections\u0026mdash;exhibited significantly smaller absolute postoperative increases in total HOA, SA and TA; and (3) normalization by diopter and matched-pair analyses attenuated these apparent zone-dependent benefits, revealing a more complex interplay between diopter, AZD and the pattern of HOA induction. These results have implications for AZD selection in surface ablation, especially when balancing night-vision quality and corneal tissue preservation.\u003c/p\u003e \u003cp\u003eThe reduction of SA with larger AZD likely reflects preservation of a greater proportion of the mesopic pupil within the optically corrected area and a smoother, more gradual periphery transition, reducing peripheral asphericity change and associated positive SA induction\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. This conceptual framework aligns with recent analyses of the EOZ, which emphasize that programmed AZD is not always equivalent to the EOZ actually achieved on the cornea; EOZ size, shape and centration strongly influence functional optical quality after keratorefractive procedures\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. However, EOZ is itself influenced by multiple factors including ablation depth, epithelial remodeling and biomechanical responses; therefore, a simple increase in programmed AZD does not guarantee a proportionate increase in EOZ or a commensurate reduction in corneal HOAs.\u003c/p\u003e \u003cp\u003eOur normalization analyses showed that many apparent group differences become non-significant, indicating that preoperative refractive diopter is a dominant determinant of induced HOAs. This observation echoes prior reports showing a strong positive association between diopter correction and postoperative HOAs magnitude\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. Importantly, our regression and graphical analyses demonstrate that normalization does not fully remove bias: higher diopter tended to produce underestimation of SA and overestimation of CA after normalization. In other words, normalization analyses assumes a simple linear, proportional relationship between diopter and HOAs induction that does not hold uniformly across AZDs, analysis apertures, or for different aberration components; geometric factors of the ablation profile and non-linear tissue response result in residual, zone-dependent effects that normalization analyses cannot correct. This limitation has been noted in recent reviews advocating caution in overreliance on normalization without supplementary matched or model-based adjustments\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eWhile larger AZDs reduced SA, the tendency for CA to increase highlights the importance of centration accuracy and ocular alignment. CA is exquisitely sensitive to decentration and asymmetric ablation patterns; larger programmed AZD may amplify the visual impact of even small decentrations because a greater peripheral area contributes to off-axis light\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Consequently, simply selecting a larger AZD without ensuring optimal centration and tracking may shift the aberration spectrum toward coma-dominant patterns, which can degrade subjective optical quality in ways not captured by SA metrics alone. This observation underlines an operational principle: AZD optimization must be coupled with strict centration protocols preoperative and adjustment of the ablation center based on measured angle Kappa to minimize coma induction.\u003c/p\u003e \u003cp\u003eSelecting a larger AZD benefits mesopic optical quality but increases stromal tissue removal. In practice, surgeons commonly preferentially select smaller AZDs for eyes with higher myopia or thinner corneas to preserve residual stromal thickness \u0026mdash; a pattern reflected in our baseline data and consistent with clinical practice\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. However, unless optimal centration is achieved, simply enlarging the AZD does not necessarily reduce vision disturbances; instead, it may shift the symptom profile from predominantly SA\u0026ndash;related phenomena toward CA-dominated complaints, which are less mitigated by a larger AZD. Thus, AZD decision-making inherently involves a trade-off between optimizing postoperative optics and maintaining corneal safety margins. Integrating individualized ablation centration strategies and EOZ prediction models into preoperative planning may enable more informed AZD choices that balance these competing priorities\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eStrengths of our work include a single-technique focus (LASEK), use of a consistent analysis aperture for HOAs extraction, and multiple complementary analytic strategies (absolute, normalized and matched-pair comparisons). Limitations include retrospective design, limited sample size for matched comparisons and absence of patient-reported night-vision outcomes in all cases. Future work should prospectively evaluate EOZ, quantify decentration with high precision, and combine objective HOA metrics with validated quality-of-vision instruments. Advanced ray-tracing and physical modeling could further disentangle how ablation geometry, epithelial remodeling and biomechanical effects jointly shape HOA induction across AZDs\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn conclusion, in LASEK, increasing the programmed AZD reduces induced SA and total HOA on absolute analysis, but normalization by diopter and matched analyses reveal that this benefit is substantially mediated by preoperative refractive diopter. Moreover, larger AZDs may increase CA if ablation centration is suboptimal. Therefore, AZD selection should be individualized, balancing corneal safety, intended correction diopter and the surgeon\u0026rsquo;s ability to ensure precise centration.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eThis work was supported by the Fujian Province Science and Technology Innovation Joint Fund Project (Grant Number 2024Y9132), the Fujian Provincial Natural Science Foundation (Grant Number 2025J01719) and the National Natural Science Foundation of China (Grant Number 82271079).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/strong\u003eH.W. conceived and designed the study. H.W. and L.X. conduct experiment, collected the data and drafted the main manuscript text. S.T. and Y.L. performed the analysis, revised the manuscript and prepared all figures. S.Z. performed the surgical procedures. H.W. and Y.Z. obtained funding and had overall responsibility for the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/strong\u003eThe study protocol was approved by the Branch for Medical Research and Clinical Technology Application, Ethics Committee of the First Affiliated Hospital of Fujian Medical University (IRB No.[2015] 084-2). All procedures involving human participants were conducted in accordance with applicable local regulations, institutional requirements, and the tenets of the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003eThe datasets used and analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; information:\u003c/strong\u003e Not applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAl-Mohaimeed MM. Effect of the Optical Zone Ablation Diameter on Higher Order Aberrations After Transepithelial Photorefractive Keratectomy: A Cohort Study. Cureus. 2021 Sep 1;13(9):e17630.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eMoshirfar M, Herron MS, Cha DS, Santos J, Payne CJ, Hoopes PC. Comparing Effective Optical Zones After Myopic Ablation Between LASIK, PRK, and SMILE With Correlation to Higher Order Aberrations. J Refract Surg. 2023 Nov;39(11):741-750.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHuang Y, Han T, Wang Y, Peng X, Ten W, Zhou X, Xu Y. Comparison of long-term changes in the effective optical zone following SMILE and FS-LASIK for moderate and high myopia. BMC Ophthalmol. 2024 Sep 3;24(1):388.\u003c/li\u003e\n \u003cli\u003eZhou C, Li Y, Wang Y, Fan Q, Dai L. Comparison of visual quality after SMILE correction of low-to-moderate myopia in different optical zones. Int Ophthalmol. 2023 Oct;43(10):3623-3632.\u003c/li\u003e\n \u003cli\u003eKang EM, Ryu IH, Lee IS, Kim JK, Kim SW, Ji YW. Comparison of Corneal Higher-Order Aberrations Following Topography-Guided LASIK and SMILE for Myopic Correction: A Propensity Score Matching Analysis. J Clin Med. 2022 Oct 19;11(20):6171.\u003c/li\u003e\n \u003cli\u003eFeng Z, Wang Q, Du C, Yang F, Li X. High-order aberration changes after femtosecond LASIK surgery in patients with high myopia. Ann Palliat Med. 2021 Jul;10(7):7689-7696.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e\u0026Ccedil;akır GY, \u0026Ccedil;akır\u0026nbsp;İ, Yıldız BK, Yıldırım Y. Effective optical zone: Differences between small-incision lenticule extraction and femtosecond LASIK for myopia. Indian J Ophthalmol. 2024 Sep 1;72(9):1315-1320.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eThananjeyan AL, Bala C. Higher-Order Aberrations Following Ray Trace LASIK and the Impact of Eye Movement on Coma. Clin Ophthalmol. 2024 Nov 22;18:3389-3398.\u003c/li\u003e\n \u003cli\u003eChen L, Khamar P, Wang Y, Fu H, Shetty R. Evaluation of Higher-Order Aberrations After the Smooth Incision Lenticular Keratomileusis (SILKTM) Procedure Using the ELITATM Femtosecond Platform for Correction of Myopic and Astigmatic Refractive Errors. Clin Ophthalmol. 2024 Jul 24;18:2155-2166.\u003c/li\u003e\n \u003cli\u003eDu Y, Di Y, Yang S, Mo F, Cui G, Chen D, Li Y. Differences in ocular high order aberrations before and after small incision lenticule extraction for correction of myopia: a systematic review and meta-analysis. Front Med (Lausanne). 2024 Mar 27;11:1274101.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHuang Y, Zhan B, Han T, Zhou X. Effective optical zone following small incision lenticule extraction: a review. Graefes Arch Clin Exp Ophthalmol. 2024 Jun;262(6):1657-1665. \u0026nbsp;\u003c/li\u003e\n \u003cli\u003eChoi SH, Won YK, Na SJ, Nam D, Lim DH. Limitations of and Solutions to Using 6 mm Corneal Spherical Aberration and Q Value after Laser Refractive Surgery. Bioengineering (Basel). 2024 Feb 16;11(2):190.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eReinstein DZ, Archer TJ, Vida RS, Carp GI, Reinstein JFR, McAlinden C. Objective and Subjective Quality of Vision After SMILE for High Myopia and Astigmatism. J Refract Surg. 2022 Jul;38(7):404-413.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eLiu P, Yu D, Zhang B, Zhou S, Zhu H, Qin W, Ye X, Li X, Zhang Y, Bai Y, Wang Y, Shao Z. Influence of optical zone on myopic correction in small incision lenticule extraction: a short-term study. BMC Ophthalmol. 2022 Oct 21;22(1):409.\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 100%;\" colspan=\"5\"\u003e\u003cbr\u003eTable 1: Characteristics of the study groups.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSubjects\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e5.75mm\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e6mm\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e6.25mm\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u003cstrong\u003ep\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e-Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eNo. of cases\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eSex, male, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e41.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e58.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.1709\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eAge, years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e25.80 \u0026plusmn; 7.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e25.00 \u0026plusmn; 5.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e22.95 \u0026plusmn; 4.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.0782\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eSphere, diopter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-6.35 \u0026plusmn; 1.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-4.51 \u0026plusmn; 1.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-3.26 \u0026plusmn; 1.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eCylinder, diopter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-1.44 \u0026plusmn; 1.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-1.11 \u0026plusmn; 1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-0.67 \u0026plusmn; 0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.0032\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eSEQ, diopter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-7.10 \u0026plusmn; 1.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-5.07 \u0026plusmn; 1.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-3.59 \u0026plusmn; 1.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eUDVA pre, logMAR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e1.42 \u0026plusmn; 0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e1.27 \u0026plusmn; 0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e0.99 \u0026plusmn; 0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eCDVA, logMAR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-0.02 \u0026plusmn; 0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-0.03 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-0.04 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.1055\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eUDVA post, logMAR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-0.01 \u0026plusmn; 0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-0.03 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e-0.04 \u0026plusmn; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.0744\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eNCT, mmHg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e16.39 \u0026plusmn; 2.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e16.25 \u0026plusmn; 2.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e16.97 \u0026plusmn; 1.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.3475\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eCCT, \u0026mu;m\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e519.1 \u0026plusmn; 29.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e538.2 \u0026plusmn; 31.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e552.3 \u0026plusmn; 31.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eK-mean, diopter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e43.69 \u0026plusmn; 1.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e43.49 \u0026plusmn; 1.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e43.13 \u0026plusmn; 1.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.1584\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 140px;\"\u003e\n \u003cp\u003eAngle Kappa, mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e0.21 \u0026plusmn; 0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e0.18 \u0026plusmn; 0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 117px;\"\u003e\n \u003cp\u003e0.16 \u0026plusmn; 0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 73px;\"\u003e\n \u003cp\u003e0.1378\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eSEQ:\u0026nbsp;spherical equivalent;\u0026nbsp;UDVA: uncorrected distance visual acuity;\u0026nbsp;CDVA:\u0026nbsp;corrected distance visual acuity;\u0026nbsp;IOP:\u0026nbsp;noncontact intraocular pressure;\u0026nbsp;CCT: central corneal thickness; \u003csup\u003e*\u003c/sup\u003eP \u0026lt; 0.05.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Table 2: Three-month whole corneal aberrations by different ablation zone.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSubjects\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e5.75mm\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e6mm\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e6.25mm\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eGroup\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u003cstrong\u003ep\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e-Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eSA, \u0026mu;m\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.220 \u0026plusmn; 0.072\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.212 \u0026plusmn; 0.095\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.230 \u0026plusmn; 0.057\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.5809\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.997 \u0026plusmn; 0.245\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.735 \u0026plusmn; 0.236\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.632 \u0026plusmn; 0.189\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eCA, \u0026mu;m\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.244 \u0026plusmn; 0.142\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.272 \u0026plusmn; 0.236\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.220 \u0026plusmn; 0.093\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.1681\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e1.096 \u0026plusmn; 0.646\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.767 \u0026plusmn; 0.442\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.527 \u0026plusmn; 0.317\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eTA, \u0026mu;m\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.137 \u0026plusmn; 0.077\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.143 \u0026plusmn; 0.083\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.131 \u0026plusmn; 0.066\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.8159\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.203 \u0026plusmn; 0.157\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.203 \u0026plusmn; 0.187\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.188 \u0026plusmn; 0.140\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.8970\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.0171\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.0605\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.0234\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003eHOAs, \u0026mu;m\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epreoperative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.415 \u0026plusmn; 0.107\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.425 \u0026plusmn; 0.114\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.392 \u0026plusmn; 0.070\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.3798\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003epostoperation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e1.575 \u0026plusmn; 0.588\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e1.171 \u0026plusmn; 0.376\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e0.931 \u0026plusmn; 0.249\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e＜0.0001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 114px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eSA: spherical equivalent; CA: coma; TA: trefoil aberration; HOAs: higher-order aberrations; \u003csup\u003e*\u003c/sup\u003eP \u0026lt; 0.05.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"LASEK, ablation-zone diameter, higher-order aberrations, spherical aberration, coma","lastPublishedDoi":"10.21203/rs.3.rs-8341631/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8341631/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose:\u003c/strong\u003e To evaluate whether modest differences in programmed ablation-zone diameter (AZD) during LASEK affect postoperative whole-corneal higher-order aberrations (HOAs), with emphasis on spherical aberration (SA) and coma (CA).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e This retrospective single-center observational study included 120 right eyes that underwent LASEK between January 2020 and June 2025. 120 eyes were grouped by programmed AZD: 5.75 mm (n=41), 6.00 mm (n=40), and 6.25 mm (n=39). Corneal HOAs (total HOA RMS, SA, CA, trefoil aberration) were measured by Pentacam at baseline, 1 and 3 months. Analyses included absolute changes, HOA normalized per treated diopter, and matched-pair sensitivity comparisons. Statistical tests included t tests, ANOVA and χ²; significance set at P\u0026lt;0.05.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eAll groups showed significant postoperative increases in total HOA, SA and CA at 3 months (P\u0026lt;0.001). In unadjusted analyses, larger programmed AZDs exhibited smaller absolute increases in total HOA, SA and trefoil (P\u0026lt;0.001). After normalization by diopter these zone-dependent differences were largely attenuated (P\u0026gt;0.05 for most comparisons). Matched-pair analyses confirmed AZD enlargement consistently reduced SA but tended to increase CA (matched comparisons P\u0026lt;0.05), yielding no uniform net reduction in total HOA.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions: \u003c/strong\u003eLarger programmed AZDs in LASEK are associated with smaller absolute induction of SA, CA and total HOAs at 3 months, but this apparent benefit is largely mediated by baseline refractive magnitude and is disappeard after diopter normalization. Matched-pair analyses showed AZD enlargement reduced SA but increased CA without net HOA benefit; therefore precise centration is essential.\u003c/p\u003e","manuscriptTitle":"Effect of Ablation-Zone Diameter on Whole-Corneal Higher-Order Aberrations After LASEK: A Retrospective Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-23 11:38:45","doi":"10.21203/rs.3.rs-8341631/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"84acb4a7-7f29-4431-99fe-790bd515ae31","owner":[],"postedDate":"December 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-24T04:38:03+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-23 11:38:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8341631","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8341631","identity":"rs-8341631","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}