Comparison of ocular residual astigmatism between children with clinically significant and non-significant astigmatism

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Methods: This is a cross-sectional study. Participants were divided into the clinically significant astigmatism group (refractive astigmatism [RA] ≥ 1.00 D) and non-significant astigmatism group (RA < 1.00 D) based on RA on spectacle plane. Anterior corneal astigmatism (ACA) were obtained from IOL-Master 500. RA is the cylinder power after cycloplegia. ORA was calculated by the vector difference between RA and ACA. Multivariate linear regression was used to adjust for potential confounders, ensuring robust comparisons. The physical methods were used to evaluate the vector relationship between ORA and with-the-rule ACA. Results: A total of 306 participants (306 right eyes) were included, among whom 155 (50.7%) were male. Results from multiple linear regression analysis indicated that the ACA was a significant positive predictor of ORA (B = 0.386, 95% confidence interval [CI]: 0.327 to 0.445, t = 12.826, P <0.001). In contrast, group emerged as a significant negative predictor of ORA (B = -0.553, 95% CI: -0.651 to -0.456, t = -11.212, P < 0.001). The ORA exerted a negative effect on with-the-rule ACA in 86.7% of eyes in the clinically significant astigmatism group, as compared to a much higher proportion of 99.0% in the non-significant astigmatism group( χ² = 19.765, P < 0.001). Conclusions: Children with clinically significant astigmatism exhibited smaller ORA and lower compensatory efficacy of ORA against with-the-rule ACA compared with peers without significant astigmatism. clinically significant astigmatism ocular residual astigmatism children vector difference Introduction As one of the most common refractive errors, astigmatism is characterized by uneven refractive power across different meridians of the eye[ 1 ], resulting in blurred vision at both near and far distances[ 2 , 3 ]. Beyond this blurring effect, it induces retinal image degradation and compromises overall visual quality[ 4 ]. Notably, when clinically significant (≥ 1.0 D), it impairs contrast sensitivity and visual acuity, disrupts visual maturation, and elicits a range of visual manifestations[ 5 ]. Particularly in pediatric populations, uncorrected astigmatism elevates the risk of amblyopia, strabismus, and long-term visual acuity deficits. Compounding these concerns, astigmatism exhibits a high prevalence, with recent epidemiological studies indicating that the prevalence of astigmatism (≥ 1.00 D) among children ranges from approximately 31.1% to 34.7%[ 2 , 6 ]. Refractive astigmatism (RA) is the total astigmatism measured clinically. The anterior corneal astigmatism (ACA) refers to astigmatism originating from the anterior corneal surface, while ocular residual astigmatism (ORA) encompasses astigmatism from posterior corneal surfaces, the lens, and other intraocular structures[ 7 – 9 ]. RA is the vector sum of ACA and ORA. Depending on the magnitude of the angle between ORA and ACA vectors, ORA can either amplify (positive vector relationship) or counteract (negative vector relationship) the effect of ACA on total RA [ 10 ]. Our previous research had shed light on potential variations in ORA across different refractive phenotypes. In a cohort of children with astigmatism, we observed that ORA values were generally smaller, suggesting a limited contribution of ORA to total RA [ 10 ]. Conversely, ORA was greater in a study of myopic children, in which only 19.9% (48 eyes) had an RA ≥ 1.00 D, implying that the ORA effect may be more significant in these cases [ 11 ]. These contrasting findings raise the hypothesis that ORA differences may be driven by the proportion of astigmatism within the total refractive error. However, prior studies have limitations: they rarely stratified analyses by astigmatism severity, and the mechanisms underlying ORA variations between children with significant vs. non-significant astigmatism remain unclear. Specifically, whether ORA’s offsetting effect on with-the-rule ACA differs by astigmatism severity has not been systematically investigated, leaving a gap in our understanding of astigmatism pathogenesis. To address these gaps, the present study aimed to: (1) compare the difference of ORA between children with clinically significant astigmatism (RA ≥ 1.00 D) and non-significant astigmatism (RA < 1.00 D); (2) identify key factors influencing ORA; and (3) investigate differences in ORA’s offsetting rate against with-the-rule ACA between the two groups. We analyzed data from children who underwent cycloplegic refraction in an ophthalmic clinic, excluding those with organic ocular diseases. Multivariate linear regression was used to adjust for potential confounders (age, sex, ACA, spherical equivalent refraction [SER], mean corneal curvature [MCC]), ensuring robust comparisons of ORA and its relationships with other refractive parameters. This study seeks to clarify the role of ORA in pediatric astigmatism and inform clinical strategies for refractive correction. Materials and Methods The study was approved by the Hospital review board (2024-XM-025) and was conducted in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Verbal informed consent was obtained from at least one parent of all participating children after explanation of the nature of the study. Participants Selection This was a cross-sectional study. Participants underwent cycloplegia optometry at the ophthalmology clinic from February to June 2025. Patients were included in the study if they were 3–12 years old and had regular astigmatism between − 4.00 D and − 0.25 D. The exclusion criteria included any organic diseases of the eyes, such as cataract, glaucoma, keratoconus, irregular astigmatism, nystagmus, and children with strabismus. Finally, a total of 306 children met the inclusion criteria: 151 females and 155 males. The mean age was 6.4 ± 2.2 years. They were divided into the clinically significant astigmatism group (RA ≥ 1.00 D, n = 99) and non-significant astigmatism group (RA < 1.00 D, n = 207) based on RA (spectacle plane). Only right eye data were included for analysis. Examination protocol and collect parameters Following administration of a single drop of topical anesthetic (Alcaine; Alcon), cycloplegia was induced using two drops of 1% cyclopentolate (Alcon) and one drop of Mydrin P (Santen, Japan), administered at 5–8 minute intervals. After each instillation, lacrimal sac compression was maintained for 3 minutes. A minimum 30-minute waiting period was observed after the three applications until the pupillary light reflex was absent or only a faint reflex persisted. If the pupillary light reflex remained detectable or pupil diameter was < 6.0 mm, an additional drop of cyclopentolate was administered [ 10 ]. Cycloplegic autorefraction was conducted using a desktop autorefractor (ARK-1, NIDEK, Japan). Measured two times, took the mean value of the results with confidence ≥ 8. RA is the cylindrical part of refractive status. ACA is the difference in power between the steep and flat meridians, measured by the IOL-Master 500(Carl Zeiss, Meditec AG Jena, Germany). Data analysis and calculations ORA was computed via the vector difference between RA and ACA. Preceding this calculation, RA underwent transformation to the corneal plane, with both RA and ACA subsequently converted to positive-cylinder notation. The SER was computed as the sum of the spherical power and half of the cylindrical power[ 12 ]. The MCC was calculated as the average of keratometry 1 (K1) and keratometry 2 (K2) from IOL-Master 500. On the double-angle vector diagram, when the angular difference between the vector of the ORA and that of the ACA exceeds 90°, the ORA exerts a negative impact on the ACA; conversely, it demonstrates a positive effect [ 10 ]. Statistical methods SPSS statistics software package version 25.0 for Windows (IBM, Armonk, NY, USA) was used for the statistical analysis and calculations. Normality of all data samples was checked by means of the Kolmogorov–Smirnov test. The magnitude of ACA, SER, ORA and MCC were normal or approximate normal distribution. They were expressed as mean ± standard deviation (SD). A t test was used for between-group comparison for continuous variables. For between-group comparison for categorical variables, a chi-square test was used. P values less than 0.05 were considered statistically significant. Given the imbalance in baseline characteristics between the two groups and the failure to meet the assumptions for analysis of covariance (ANCOVA), multiple linear regression was employed to compare differences between the two groups. Results Characteristics of the study population A total of 306 participants (306 right eyes) were included, among whom 155 (50.7%) were male. The mean age of the participants was 6.4 ± 2.2 years (range: 3–12 years). The mean MCC was 43.58 ± 1.36 D (range: 40.24–47.82 D), while mean cylinder power measured − 0.87 ± 0.74 D (range: -4.00 to -0.25 D). The mean SER was 0.00 ± 1.95 D, with a range of -9.75 D to 8.25 D. Regarding ACA and ORA, their mean magnitudes were 1.51 ± 0.79 D (range: 0.11–4.82 D) and 0.79 ± 0.40 D (range: 0.07–2.44 D), respectively. Comparisons of baseline characteristics between the two groups were presented in Table 1 . Table 1 Comparison of data between the two groups. Groups Sex(female/male) Age(years) SER(D) ACA(D) MCC(D) ORA(D) RA < 1.00 D 108/99 6.5 &<plusmn; 2.1 -0.98 ± 1.87 1.16 ± 0.52 43.38 ± 1.30 0.83 ± 0.41 RA ≥ 1.00 D 43/56 6.1 ± 2.4 0.22 ± 2.09 2.23 ± 0.78 43.98 ± 1.41 0.69 ± 0.36 t /χ² 2.05 1.38 −1.35 −12.33 −3.63 3.00 P 0.15 0.17 0.18 < 0.001 < 0.001 0.003 RA = refractive astigmatism; ACA = anterior corneal astigmatism; SER = spherical equivalent refraction; ORA = ocular residual astigmatism; MCC = mean corneal curvature ORA comparison results between the two groups Given the imbalance in baseline characteristics between the two groups and the failure to meet the assumptions for analysis of covariance (ANCOVA), multiple linear regression was employed for the analysis. To eliminate the influence of confounding factors, a multiple linear regression analysis was performed with ORA as the dependent variable, incorporating six variables (age, sex, group, SER, MCC, and ACA) as independent variables. The results were shown in Table 2 . Table 2 Prediction model parameters for ORA Model B SE for B 95.0% CI for B t P R 2 Lower Upper Durbin-Watson 1 Constant 0.153 0.636 -1.099 1.405 0.240 0.810 1.733 0.398 Age 0.000 0.010 -0.020 0.019 -0.026 0.979 Sex 0-.050 0.037 -0.122 0.023 -1.347 0.179 SER -0.005 0.011 -0.027 0.017 -0.461 0.645 MCC 0.007 0.014 -0.021 0.035 0.499 0.618 ACA 0.386 0.030 0.327 0.445 12.826 < 0.001 Group -0.553 0.049 -0.651 -0.456 -11.212 < 0.001 CI = confidence interval; SE = standard error; MCC = mean corneal curvature SER = spherical equivalent refraction; ACA = anterior corneal astigmatism Comparison of the vector relationships between ORA and ACA in the two groups In the present study, 98 eyes (99.0%) in the significant astigmatism group had with-the-rule ACA, while 192 eyes (92.8%) in the non-significant astigmatism group were diagnosed with with-the-rule ACA. A statistically significant difference was observed in the incidence of with-the-rule ACA between the two groups ( χ² = 5.256, P = 0.022). To eliminate the impact of differences in the rate of with-the-rule ACA on the study results, the analysis was restricted to the vector relationship between ORA and with-the-rule ACA. The ORA exerted a negative effect on with-the-rule ACA in 86.7% of eyes in the significant astigmatism group, as compared to a much higher proportion of 99.0% in the non-significant astigmatism group( P < 0.001). Results were provided in Table 3 . Table 3 Comparison of vector relationship between ORA and with-the-rule ACA between two groups Groups Positive effects Negative effects Total χ² P RA < 1.00 D 2(1.0%) 190(99.0%) 192(100.0%) 19.765 < 0.001 RA ≥ 1.00 D 13(13.3%) 85(86.7%) 98(100.0%) Note: No cells (0.0%) had an expected count less than 5. The minimum expected count was 5.07. Discussion In the current study, following adjustment for potential confounding variables, children with clinically significant astigmatism demonstrated a significantly smaller ORA compared to their counterparts with non-significant astigmatism, with a mean difference of -0.553 D (95% CI: -0.651 to -0.456 D). Multiple linear regression analysis further identified ACA and group stratification (clinically significant astigmatism vs. non-significant astigmatism) as statistically significant predictors of ORA (both P 0.05).Notably, among children with clinically significant astigmatism, the offset rate of ORA relative to with-the-rule ACA was substantially lower than that observed in children with non-significant astigmatism. Consistent with previous research, the findings of this study confirm the positive association between ACA and ORA, while further validating ACA as a key determinant of ORA. For example, Wallerstein et al. [ 13 ] documented a significant positive correlation between ACA and ORA, with a correlation coefficient (r) of 0.44. Additionally, another study focusing on eyes with low to moderate myopia also identified a positive correlation between ORA and ACA ( r = 0.50, P < 0.001) [ 10 ]. Building upon these prior observations, our multivariate linear regression analysis—after adjusting for potential confounding variables including age, sex, SER, and MCC—revealed that ACA remained a statistically significant predictor of ORA ( P < 0.001). This finding represents a meaningful advancement in clinical understanding, as it eliminates the confounding influences of systemic and ocular biometric factors, thereby strengthening the evidence that ACA is not merely associated with ORA but exerts a causal role in regulating ORA magnitude. Mechanistically, this relationship may be explained by the fact that ACA directly modulates the optical pathway of incident light entering the eye. Laboratory investigations employing both human and animal models indicated that the visual system was capable of detecting and compensating for perceived astigmatic blur, particularly when astigmatism exhibited orientations along the WTR and ATR axes[ 14 – 16 ]. As the primary refractive element of the visual system, the ACA introduces a "baseline" optical deviation; in response, the eye’s internal structures (e.g., crystalline lens, vitreous humor) partially offset this deviation through adjustments in ORA. A critical new finding of the present study was that children with clinically significant astigmatism (RA ≥ 1.00 D) exhibited smaller ORA and lower compensatory efficacy of ORA against with-the-rule ACA compared with peers without significant astigmatism. Such attenuated ORA compensation suggested a fundamental alteration in the internal optical mechanisms, potentially due to disruptions in the dynamic equilibrium between corneal and internal components in children with significant astigmatism. This specific impairment in visual compensation was the result of the combined contributions of its congenital origin and acquired characteristics over the course of visual development. Notably, recent epidemiological evidence had revealed a marked surge in both the prevalence and severity of RA and ACA following the COVID-19 pandemic [ 2 ]—a trend presumably driven by profound shifts in environmental and lifestyle factors. These factors included prolonged near-work duration, extended digital device exposure, and reduced outdoor activity duration [ 17 – 19 ], all of which heightened ocular surface stress and may disrupt visual compensatory pathways. Moreover, sleep insufficiency was correlated with elevated astigmatism prevalence and greater cylinder power, whereas total sleep duration was negatively associated with cylinder power. This connection was thought to be primarily driven by impairments in internal compensatory mechanisms[ 20 ]. In terms of genetic and familial correlates, both paternal and maternal astigmatism had been identified as risk factors for RA, though neither was linked to ACA. Furthermore, longer outdoor activity duration was shown to elevate the likelihood of oblique internal compensation; notably, such oblique internal compensation may confer a reduced risk of oblique RA [ 21 ]. This new findings, combined with previous epidemiological and mechanistic evidence, hold important clinical implications for the management of pediatric astigmatism and amblyopia. First, these findings enhance the understanding of the fundamental mechanisms underlying astigmatism. Attenuation of internal compensatory mechanisms may exacerbate astigmatism progression, impair visual quality, and elevate the risk of amblyopia; this observation aligns with epidemiological evidence. Specifically, in the aftermath of the COVID-19 pandemic, environmental factors (e.g., increased near-work duration and reduced outdoor activity) have driven an increase in the prevalence and severity of astigmatism by augmenting corneal astigmatism and disrupting compensatory balance [ 2 , 22 ]. Second, these combined insights—including the link between congenital or acquired factors and visual compensatory impairment, the surge in RA/ACA prevalence post-COVID-19 driven by lifestyle shifts (e.g., prolonged near-work, reduced outdoor activity), and the association of sleep insufficiency with increased astigmatism risk—support targeted interventions. Clinicians may integrate these insights into family guidance by optimizing daily outdoor time, limiting digital device use, ensuring adequate sleep, and monitoring refractive status in children with a parental history of astigmatism. Finally, the potential protective role of oblique internal compensation against oblique RA, alongside ORA assessment, provides a basis for refining therapeutic strategies, such as prioritizing compensatory function monitoring in children with significant astigmatism to prevent amblyopia progression. Collectively, these findings bridge basic mechanistic understanding with clinical practice, facilitating more precise risk stratification, early intervention, and improved long-term visual outcomes in pediatric patients. The present study has several limitations that should be acknowledged. First, as a cross-sectional study, it cannot determine whether ORA reduction precedes or results from the development of clinically significant astigmatism. Longitudinal studies tracking changes in ACA, ORA, and RA over time are needed to clarify the temporal dynamics of these relationships. Second, the study’s single-center design may limit the generalizability of results, as regional differences in pediatric astigmatism prevalence and ocular biometric characteristics (e.g., corneal curvature, lens thickness) could influence outcomes. Future multicenter studies with larger, more diverse cohorts would strengthen the external validity of our findings. Finally, the study focused exclusively on with-the-rule ACA, and the offset rate of ORA against other astigmatism subtypes (e.g., against-the-rule or oblique astigmatism) remains unaddressed, limiting insights into subtype-specific compensatory mechanisms. Our future research will be extended to the subtypes of against-the-rule and oblique astigmatism to explore the subtype-specific compensation mechanism, so as to more comprehensively reveal the occurrence and development law of astigmatism in children. In summary, this cross-sectional study demonstrates three key findings in pediatric astigmatism: (1) children with clinically significant astigmatism (RA ≥ 1.00 D) have significantly smaller ORA than those with non-significant astigmatism (RA < 1.00 D); (2) these children also exhibit a lower offset rate of ORA against with-the-rule ACA; and (3) ACA and group classification (significant vs. non-significant astigmatism) are independent predictors of ORA, whereas age, sex, SER, and MCC have no significant effects. These findings deepen understanding of astigmatism mechanisms, emphasizing that impaired internal compensation exacerbates astigmatism progression and amblyopia risk. These findings support targeted interventions: optimizing outdoor time, limiting digital device use, ensuring adequate sleep, and monitoring refractive status in children with parental astigmatism history. Additionally, they aid refining therapeutic strategies (e.g., prioritizing compensatory function monitoring) to enable precise risk stratification, early intervention, and improved long-term visual outcomes in pediatric patients. Declarations Acknowledgments Not applicable Conflict of Interest The authors declare no conflict of interest. Consent for publication Not Applicable Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Authors' contributions JL the main author, DM Yan and J Zhu the corresponding authors designed the study, collected, analyzed,interpreted data, wrote the manuscript, approved the final version of the manuscript, and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. DX An collected, analyzed, and interpreted the manuscript data. JL wrote the main manuscript text. All authors read and approved the final manuscript. Ethics approval and consent to participate Institutional Review Board (IRB)/Ethics Committee approval was obtained by the Human Medical Ethics Committee of Lianyungang Maternal and Child Health Hospital. The authors confirm that the research followed the tenets of the Declaration of Helsinki and that informed consent was obtained from each subject after explanation of the nature and possible consequences of the study. Availability of data and materials The datasets generated and/or analysed during the current study are available from the corresponding author on reasonable request. References Yin XL, Ji ZY, Li XX, Liang XM, Ji SX. Surgical approaches to correct corneal astigmatism at time of cataract surgery: a mini-review. Int J Ophthalmol. 2024;17(7):1370–4. 10.18240/ijo.2024.07.23 . Kam KW, Shing E, Zhang Y, et al. Prevalence and Severity of Astigmatism in Children After COVID-19. JAMA Ophthalmol. 2025;143(5):383–91. 10.1001/jamaophthalmol.2025.0205 . Sigireddi RR, Weikert MP. How much astigmatism to treat in cataract surgery. Curr Opin Ophthalmol. 2020;31(1):10–4. 10.1097/ICU.0000000000000627 . Namba H, Sugano A, Murakami T, et al. Age-Related Changes in Astigmatism and Potential Causes. Cornea. 2020;39(1):S34–8. 10.1097/ICO.0000000000002507 . Kee CS. Astigmatism and its role in emmetropization. Exp Eye Res. 2013;114:89–95. 10.1016/j.exer.2013.04.020 . Garcia-Lozada D, Rey-Rodríguez DV, Angulo-Sánchez SV, Sánchez-Espinosa JM. Prevalence of refractive errors in school-aged and preadolescent children in Colombia. Int J Ophthalmol. 2024;17(12):2288–94. 10.18240/ijo.2024.12.18 . Alpins NA. New method of targeting vectors to treat astigmatism. J Cataract Refract Surg. 1997;23(1):65–75. 10.1016/s0886-3350(97)80153-8 . Piñero DP, Alió JL, Barraquer RI, Uceda-Montanes A, Murta J. Clinical characterization of corneal ectasia after myopic laser in situ keratomileusis based on anterior corneal aberrations and internal astigmatism. J Cataract Refract Surg. 2011;37(7):1291–9. 10.1016/j.jcrs.2010.12.063 . Teus MA, Arruabarrena C, Hernández-Verdejo JL, Cañones R, Mikropoulos DG. Ocular residual astigmatism's effect on high myopic astigmatism LASIK surgery. Eye (Lond). 2014;28(8):1014–9. 10.1038/eye.2014.133 . Epub 2014 Jun 27. Lin J. The contribution of ocular residual astigmatism to anterior corneal astigmatism in refractive astigmatism eyes. Sci Rep. 2021;11(1):1018. 10.1038/s41598-020-80106-6 . Lin J, An D, Lu Y, Yan D. Correlation between ocular residual astigmatism and anterior corneal astigmatism in children with low and moderate myopia. BMC Ophthalmol. 2022;22(1):374. 10.1186/s12886-022-02560-2 . Xu S, Ruan Z, Wang Y et al. Establishment of Myopia Occurrence Prediction Model in Children without Myopia Using Cycloplegic Refraction and Prior Axial Length Change. Ophthalmology . 2025:S0161-6420(25)00359-8. 10.1016/j.ophtha.2025.06.010 Wallerstein A, Gauvin M, Qi SR, Cohen M. Effect of the Vectorial Difference Between Manifest Refractive Astigmatism and Anterior Corneal Astigmatism on Topography-Guided LASIK Outcomes. J Refract Surg. 2020;36(7):449–58. 10.3928/1081597X-20200609-01 . Chan KH, Shik HT, Kwok KW, Kee CS, Leung TW. Bi-directional Refractive Compensation for With-the-Rule and Against-the-Rule Astigmatism in Young Adults. Invest Ophthalmol Vis Sci. 2022;63:15. 10.1167/iovs.63.10.15 . Hoseini-Yazdi H, Vincent SJ, Read SA, Collins MJ. Astigmatic defocus leads to short-term changes in human choroidal thickness. Invest Ophth Vis Sci. 2020;61:48. 10.1167/iovs.61.8.48 . Schmid KL, Wildsoet CF. Natural and imposed astigmatism and their relation to emmetropization in the chick. Exp Eye Res. 1997;64:837–47. 10.1006/exer.1997.0282 . Madigan S, Eirich R, Pador P, McArthur BA, Neville RD. Assessment of Changes in Child and Adolescent Screen Time During the COVID-19 Pandemic: A Systematic Review and Meta-analysis. JAMA Pediatr. 2022;176(12):1188–98. 10.1001/jamapediatrics.2022.4116 . Li M, Xu L, Tan CS, et al. Systematic Review and Meta-Analysis on the Impact of COVID-19 Pandemic-Related Lifestyle on Myopia. Asia Pac J Ophthalmol (Phila). 2022;11(5):470–80. 10.1097/APO.0000000000000559 . Cortés-Albornoz MC, Ramírez-Guerrero S, Rojas-Carabali W, de-la-Torre A, Talero-Gutiérrez C. Effects of remote learning during the COVID-19 lockdown on children's visual health: a systematic review. BMJ Open. 2022;12(8):e062388. 10.1136/bmjopen-2022-062388 . Zhao X, Peng Y, Yu T, et al. Association between insufficient sleep and astigmatism in preschool children. Eur J Pediatr. 2025;184(2):177. 10.1007/s00431-025-06004-z . Published 2025 Feb 5. Wang Z, Tong H, Hao Q, et al. Risk factors for astigmatic components and internal compensation: the Nanjing Eye Study. Eye (Lond). 2021;35(2):499–507. 10.1038/s41433-020-0881-5 . Liang Y, Kang BS, Kee CS, Leung TW. Compensatory Interactions between Corneal and Internal Astigmatism despite Lifestyle Changes. Children (Basel) . 2024;11(2):154. Published 2024 Jan 25. 10.3390/children11020154 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 28 Nov, 2025 Read the published version in BMC Ophthalmology → Version 1 posted Editorial decision: Revision requested 05 Nov, 2025 Reviews received at journal 27 Oct, 2025 Reviews received at journal 25 Oct, 2025 Reviewers agreed at journal 24 Oct, 2025 Reviewers agreed at journal 23 Oct, 2025 Reviewers agreed at journal 23 Oct, 2025 Reviewers invited by journal 23 Oct, 2025 Editor invited by journal 29 Sep, 2025 Editor assigned by journal 26 Sep, 2025 Submission checks completed at journal 26 Sep, 2025 First submitted to journal 25 Sep, 2025 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. 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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-7713323","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":538674137,"identity":"91192407-8012-4960-b99a-38b1db9cf956","order_by":0,"name":"Jian Lin","email":"","orcid":"","institution":"Lianyungang Maternal and Child Health Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Lin","suffix":""},{"id":538674138,"identity":"1bb502a0-5667-4202-ad97-a7613a09ea6c","order_by":1,"name":"Dexiang An","email":"","orcid":"","institution":"Lianyungang Maternal and Child Health 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13:45:23","extension":"html","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":86447,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7713323/v1/35e36262fd0e57154d0db682.html"},{"id":97178776,"identity":"0016d9da-cc27-46dd-a888-2582fe75fbc5","added_by":"auto","created_at":"2025-12-01 16:13:33","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":670006,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7713323/v1/75180df9-a1eb-4c54-a273-5222a8d81be8.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison of ocular residual astigmatism between children with clinically significant and non-significant astigmatism","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAs one of the most common refractive errors, astigmatism is characterized by uneven refractive power across different meridians of the eye[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], resulting in blurred vision at both near and far distances[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Beyond this blurring effect, it induces retinal image degradation and compromises overall visual quality[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Notably, when clinically significant (\u0026ge;\u0026thinsp;1.0 D), it impairs contrast sensitivity and visual acuity, disrupts visual maturation, and elicits a range of visual manifestations[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Particularly in pediatric populations, uncorrected astigmatism elevates the risk of amblyopia, strabismus, and long-term visual acuity deficits. Compounding these concerns, astigmatism exhibits a high prevalence, with recent epidemiological studies indicating that the prevalence of astigmatism (\u0026ge;\u0026thinsp;1.00 D) among children ranges from approximately 31.1% to 34.7%[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eRefractive astigmatism (RA) is the total astigmatism measured clinically. The anterior corneal astigmatism (ACA) refers to astigmatism originating from the anterior corneal surface, while ocular residual astigmatism (ORA) encompasses astigmatism from posterior corneal surfaces, the lens, and other intraocular structures[\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. RA is the vector sum of ACA and ORA. Depending on the magnitude of the angle between ORA and ACA vectors, ORA can either amplify (positive vector relationship) or counteract (negative vector relationship) the effect of ACA on total RA [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eOur previous research had shed light on potential variations in ORA across different refractive phenotypes. In a cohort of children with astigmatism, we observed that ORA values were generally smaller, suggesting a limited contribution of ORA to total RA [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Conversely, ORA was greater in a study of myopic children, in which only 19.9% (48 eyes) had an RA\u0026thinsp;\u0026ge;\u0026thinsp;1.00 D, implying that the ORA effect may be more significant in these cases [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. These contrasting findings raise the hypothesis that ORA differences may be driven by the proportion of astigmatism within the total refractive error. However, prior studies have limitations: they rarely stratified analyses by astigmatism severity, and the mechanisms underlying ORA variations between children with significant vs. non-significant astigmatism remain unclear. Specifically, whether ORA\u0026rsquo;s offsetting effect on with-the-rule ACA differs by astigmatism severity has not been systematically investigated, leaving a gap in our understanding of astigmatism pathogenesis.\u003c/p\u003e\u003cp\u003eTo address these gaps, the present study aimed to: (1) compare the difference of ORA between children with clinically significant astigmatism (RA\u0026thinsp;\u0026ge;\u0026thinsp;1.00 D) and non-significant astigmatism (RA\u0026thinsp;\u0026lt;\u0026thinsp;1.00 D); (2) identify key factors influencing ORA; and (3) investigate differences in ORA\u0026rsquo;s offsetting rate against with-the-rule ACA between the two groups. We analyzed data from children who underwent cycloplegic refraction in an ophthalmic clinic, excluding those with organic ocular diseases. Multivariate linear regression was used to adjust for potential confounders (age, sex, ACA, spherical equivalent refraction [SER], mean corneal curvature [MCC]), ensuring robust comparisons of ORA and its relationships with other refractive parameters. This study seeks to clarify the role of ORA in pediatric astigmatism and inform clinical strategies for refractive correction.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e The study was approved by the Hospital review board (2024-XM-025) and was conducted in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Verbal informed consent was obtained from at least one parent of all participating children after explanation of the nature of the study.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eParticipants Selection\u003c/h2\u003e\u003cp\u003eThis was a cross-sectional study. Participants underwent cycloplegia optometry at the ophthalmology clinic from February to June 2025. Patients were included in the study if they were 3\u0026ndash;12 years old and had regular astigmatism between \u0026minus;\u0026thinsp;4.00 D and \u0026minus;\u0026thinsp;0.25 D. The exclusion criteria included any organic diseases of the eyes, such as cataract, glaucoma, keratoconus, irregular astigmatism, nystagmus, and children with strabismus. Finally, a total of 306 children met the inclusion criteria: 151 females and 155 males. The mean age was 6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2 years. They were divided into the clinically significant astigmatism group (RA\u0026thinsp;\u0026ge;\u0026thinsp;1.00 D, n\u0026thinsp;=\u0026thinsp;99) and non-significant astigmatism group (RA\u0026thinsp;\u0026lt;\u0026thinsp;1.00 D, n\u0026thinsp;=\u0026thinsp;207) based on RA (spectacle plane). Only right eye data were included for analysis.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003e\u003c/h3\u003e\n\u003cdiv class=\"Heading\"\u003e\u003cb\u003eExamination protocol and collect parameters\u003c/b\u003e\u003c/div\u003e\u003cp\u003eFollowing administration of a single drop of topical anesthetic (Alcaine; Alcon), cycloplegia was induced using two drops of 1% cyclopentolate (Alcon) and one drop of Mydrin P (Santen, Japan), administered at 5\u0026ndash;8 minute intervals. After each instillation, lacrimal sac compression was maintained for 3 minutes. A minimum 30-minute waiting period was observed after the three applications until the pupillary light reflex was absent or only a faint reflex persisted. If the pupillary light reflex remained detectable or pupil diameter was \u0026lt;\u0026thinsp;6.0 mm, an additional drop of cyclopentolate was administered [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Cycloplegic autorefraction was conducted using a desktop autorefractor (ARK-1, NIDEK, Japan). Measured two times, took the mean value of the results with confidence\u0026thinsp;\u0026ge;\u0026thinsp;8. RA is the cylindrical part of refractive status. ACA is the difference in power between the steep and flat meridians, measured by the IOL-Master 500(Carl Zeiss, Meditec AG Jena, Germany).\u003c/p\u003e\n\u003ch3\u003eData analysis and calculations\u003c/h3\u003e\n\u003cp\u003eORA was computed via the vector difference between RA and ACA. Preceding this calculation, RA underwent transformation to the corneal plane, with both RA and ACA subsequently converted to positive-cylinder notation.\u003c/p\u003e\u003cp\u003eThe SER was computed as the sum of the spherical power and half of the cylindrical power[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The MCC was calculated as the average of keratometry 1 (K1) and keratometry 2 (K2) from IOL-Master 500.\u003c/p\u003e\u003cp\u003eOn the double-angle vector diagram, when the angular difference between the vector of the ORA and that of the ACA exceeds 90\u0026deg;, the ORA exerts a negative impact on the ACA; conversely, it demonstrates a positive effect [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\n\u003ch3\u003eStatistical methods\u003c/h3\u003e\n\u003cp\u003eSPSS statistics software package version 25.0 for Windows (IBM, Armonk, NY, USA) was used for the statistical analysis and calculations. Normality of all data samples was checked by means of the Kolmogorov\u0026ndash;Smirnov test. The magnitude of ACA, SER, ORA and MCC were normal or approximate normal distribution. They were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD). A \u003cem\u003et\u003c/em\u003e test was used for between-group comparison for continuous variables. For between-group comparison for categorical variables, a chi-square test was used. P values less than 0.05 were considered statistically significant. Given the imbalance in baseline characteristics between the two groups and the failure to meet the assumptions for analysis of covariance (ANCOVA), multiple linear regression was employed to compare differences between the two groups.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eCharacteristics of the study population\u003c/h2\u003e\u003cp\u003eA total of 306 participants (306 right eyes) were included, among whom 155 (50.7%) were male. The mean age of the participants was 6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2 years (range: 3\u0026ndash;12 years). The mean MCC was 43.58\u0026thinsp;\u0026plusmn;\u0026thinsp;1.36 D (range: 40.24\u0026ndash;47.82 D), while mean cylinder power measured \u0026minus;\u0026thinsp;0.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.74 D (range: -4.00 to -0.25 D). The mean SER was 0.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.95 D, with a range of -9.75 D to 8.25 D. Regarding ACA and ORA, their mean magnitudes were 1.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79 D (range: 0.11\u0026ndash;4.82 D) and 0.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.40 D (range: 0.07\u0026ndash;2.44 D), respectively. Comparisons of baseline characteristics between the two groups were presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of data between the two groups.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroups\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSex(female/male)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAge(years)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSER(D)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eACA(D)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eMCC(D)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eORA(D)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRA\u0026thinsp;\u0026lt;\u0026thinsp;1.00 D\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e108/99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.5\u0026thinsp;\u0026\u003cplusmn;\u0026thinsp;2.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;1.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e43.38\u0026thinsp;\u0026plusmn;\u0026thinsp;1.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRA\u0026thinsp;\u0026ge;\u0026thinsp;1.00 D\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e43/56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.22\u0026thinsp;\u0026plusmn;\u0026thinsp;2.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e43.98\u0026thinsp;\u0026plusmn;\u0026thinsp;1.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003et\u003c/em\u003e/χ\u0026sup2;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026minus;1.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026minus;12.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026minus;3.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e3.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eRA\u0026thinsp;=\u0026thinsp;refractive astigmatism; ACA\u0026thinsp;=\u0026thinsp;anterior corneal astigmatism;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eSER\u0026thinsp;=\u0026thinsp;spherical equivalent refraction; ORA\u0026thinsp;=\u0026thinsp;ocular residual astigmatism;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eMCC\u0026thinsp;=\u0026thinsp;mean corneal curvature\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eORA comparison results between the two groups\u003c/h3\u003e\n\u003cp\u003eGiven the imbalance in baseline characteristics between the two groups and the failure to meet the assumptions for analysis of covariance (ANCOVA), multiple linear regression was employed for the analysis.\u003c/p\u003e\u003cp\u003eTo eliminate the influence of confounding factors, a multiple linear regression analysis was performed with ORA as the dependent variable, incorporating six variables (age, sex, group, SER, MCC, and ACA) as independent variables. The results were shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePrediction model parameters for ORA\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"10\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e\u003cp\u003eModel\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eSE for B\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003e95.0% CI for B\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cem\u003et\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eLower\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eUpper\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eDurbin-Watson\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eConstant\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.153\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.636\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-1.099\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1.405\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.240\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.810\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e1.733\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e0.398\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.000\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.010\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.020\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.019\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e-0.026\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.979\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0-.050\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.037\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.122\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e-1.347\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.179\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSER\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e-0.005\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.011\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.027\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.017\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e-0.461\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.645\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMCC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.007\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.014\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.021\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.035\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.499\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.618\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eACA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.386\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.030\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.327\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.445\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e12.826\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGroup\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e-0.553\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.049\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.651\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e-0.456\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e-11.212\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"10\"\u003eCI\u0026thinsp;=\u0026thinsp;confidence interval; SE\u0026thinsp;=\u0026thinsp;standard error; MCC\u0026thinsp;=\u0026thinsp;mean corneal curvature\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"10\"\u003eSER\u0026thinsp;=\u0026thinsp;spherical equivalent refraction; ACA\u0026thinsp;=\u0026thinsp;anterior corneal astigmatism\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\n\u003ch3\u003eComparison of the vector relationships between ORA and ACA in the two groups\u003c/h3\u003e\n\u003cp\u003eIn the present study, 98 eyes (99.0%) in the significant astigmatism group had with-the-rule ACA, while 192 eyes (92.8%) in the non-significant astigmatism group were diagnosed with with-the-rule ACA. A statistically significant difference was observed in the incidence of with-the-rule ACA between the two groups (\u003cem\u003eχ\u0026sup2;\u003c/em\u003e = 5.256, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.022). To eliminate the impact of differences in the rate of with-the-rule ACA on the study results, the analysis was restricted to the vector relationship between ORA and with-the-rule ACA. The ORA exerted a negative effect on with-the-rule ACA in 86.7% of eyes in the significant astigmatism group, as compared to a much higher proportion of 99.0% in the non-significant astigmatism group(\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Results were provided in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of vector relationship between ORA and with-the-rule ACA between two groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroups\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePositive effects\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNegative effects\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTotal\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eχ\u0026sup2;\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRA\u0026thinsp;\u0026lt;\u0026thinsp;1.00 D\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2(1.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e190(99.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e192(100.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e19.765\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRA\u0026thinsp;\u0026ge;\u0026thinsp;1.00 D\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e13(13.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e85(86.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e98(100.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: No cells (0.0%) had an expected count less than 5. The minimum expected count was 5.07.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn the current study, following adjustment for potential confounding variables, children with clinically significant astigmatism demonstrated a significantly smaller ORA compared to their counterparts with non-significant astigmatism, with a mean difference of -0.553 D (95% CI: -0.651 to -0.456 D). Multiple linear regression analysis further identified ACA and group stratification (clinically significant astigmatism vs. non-significant astigmatism) as statistically significant predictors of ORA (both P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). In contrast, demographic factors (age, sex) and ocular biometric parameters (SER, MCC) exerted no significant influence on ORA outcomes (all P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).Notably, among children with clinically significant astigmatism, the offset rate of ORA relative to with-the-rule ACA was substantially lower than that observed in children with non-significant astigmatism.\u003c/p\u003e\u003cp\u003eConsistent with previous research, the findings of this study confirm the positive association between ACA and ORA, while further validating ACA as a key determinant of ORA. For example, Wallerstein et al. [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] documented a significant positive correlation between ACA and ORA, with a correlation coefficient (r) of 0.44. Additionally, another study focusing on eyes with low to moderate myopia also identified a positive correlation between ORA and ACA (\u003cem\u003er\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.50, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Building upon these prior observations, our multivariate linear regression analysis\u0026mdash;after adjusting for potential confounding variables including age, sex, SER, and MCC\u0026mdash;revealed that ACA remained a statistically significant predictor of ORA (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). This finding represents a meaningful advancement in clinical understanding, as it eliminates the confounding influences of systemic and ocular biometric factors, thereby strengthening the evidence that ACA is not merely associated with ORA but exerts a causal role in regulating ORA magnitude. Mechanistically, this relationship may be explained by the fact that ACA directly modulates the optical pathway of incident light entering the eye. Laboratory investigations employing both human and animal models indicated that the visual system was capable of detecting and compensating for perceived astigmatic blur, particularly when astigmatism exhibited orientations along the WTR and ATR axes[\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. As the primary refractive element of the visual system, the ACA introduces a \"baseline\" optical deviation; in response, the eye\u0026rsquo;s internal structures (e.g., crystalline lens, vitreous humor) partially offset this deviation through adjustments in ORA.\u003c/p\u003e\u003cp\u003eA critical new finding of the present study was that children with clinically significant astigmatism (RA\u0026thinsp;\u0026ge;\u0026thinsp;1.00 D) exhibited smaller ORA and lower compensatory efficacy of ORA against with-the-rule ACA compared with peers without significant astigmatism. Such attenuated ORA compensation suggested a fundamental alteration in the internal optical mechanisms, potentially due to disruptions in the dynamic equilibrium between corneal and internal components in children with significant astigmatism. This specific impairment in visual compensation was the result of the combined contributions of its congenital origin and acquired characteristics over the course of visual development. Notably, recent epidemiological evidence had revealed a marked surge in both the prevalence and severity of RA and ACA following the COVID-19 pandemic [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u0026mdash;a trend presumably driven by profound shifts in environmental and lifestyle factors. These factors included prolonged near-work duration, extended digital device exposure, and reduced outdoor activity duration [\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], all of which heightened ocular surface stress and may disrupt visual compensatory pathways. Moreover, sleep insufficiency was correlated with elevated astigmatism prevalence and greater cylinder power, whereas total sleep duration was negatively associated with cylinder power. This connection was thought to be primarily driven by impairments in internal compensatory mechanisms[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In terms of genetic and familial correlates, both paternal and maternal astigmatism had been identified as risk factors for RA, though neither was linked to ACA. Furthermore, longer outdoor activity duration was shown to elevate the likelihood of oblique internal compensation; notably, such oblique internal compensation may confer a reduced risk of oblique RA [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThis new findings, combined with previous epidemiological and mechanistic evidence, hold important clinical implications for the management of pediatric astigmatism and amblyopia. First, these findings enhance the understanding of the fundamental mechanisms underlying astigmatism. Attenuation of internal compensatory mechanisms may exacerbate astigmatism progression, impair visual quality, and elevate the risk of amblyopia; this observation aligns with epidemiological evidence. Specifically, in the aftermath of the COVID-19 pandemic, environmental factors (e.g., increased near-work duration and reduced outdoor activity) have driven an increase in the prevalence and severity of astigmatism by augmenting corneal astigmatism and disrupting compensatory balance [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Second, these combined insights\u0026mdash;including the link between congenital or acquired factors and visual compensatory impairment, the surge in RA/ACA prevalence post-COVID-19 driven by lifestyle shifts (e.g., prolonged near-work, reduced outdoor activity), and the association of sleep insufficiency with increased astigmatism risk\u0026mdash;support targeted interventions. Clinicians may integrate these insights into family guidance by optimizing daily outdoor time, limiting digital device use, ensuring adequate sleep, and monitoring refractive status in children with a parental history of astigmatism. Finally, the potential protective role of oblique internal compensation against oblique RA, alongside ORA assessment, provides a basis for refining therapeutic strategies, such as prioritizing compensatory function monitoring in children with significant astigmatism to prevent amblyopia progression. Collectively, these findings bridge basic mechanistic understanding with clinical practice, facilitating more precise risk stratification, early intervention, and improved long-term visual outcomes in pediatric patients.\u003c/p\u003e\u003cp\u003eThe present study has several limitations that should be acknowledged. First, as a cross-sectional study, it cannot determine whether ORA reduction precedes or results from the development of clinically significant astigmatism. Longitudinal studies tracking changes in ACA, ORA, and RA over time are needed to clarify the temporal dynamics of these relationships. Second, the study\u0026rsquo;s single-center design may limit the generalizability of results, as regional differences in pediatric astigmatism prevalence and ocular biometric characteristics (e.g., corneal curvature, lens thickness) could influence outcomes. Future multicenter studies with larger, more diverse cohorts would strengthen the external validity of our findings. Finally, the study focused exclusively on with-the-rule ACA, and the offset rate of ORA against other astigmatism subtypes (e.g., against-the-rule or oblique astigmatism) remains unaddressed, limiting insights into subtype-specific compensatory mechanisms. Our future research will be extended to the subtypes of against-the-rule and oblique astigmatism to explore the subtype-specific compensation mechanism, so as to more comprehensively reveal the occurrence and development law of astigmatism in children.\u003c/p\u003e\u003cp\u003eIn summary, this cross-sectional study demonstrates three key findings in pediatric astigmatism: (1) children with clinically significant astigmatism (RA\u0026thinsp;\u0026ge;\u0026thinsp;1.00 D) have significantly smaller ORA than those with non-significant astigmatism (RA\u0026thinsp;\u0026lt;\u0026thinsp;1.00 D); (2) these children also exhibit a lower offset rate of ORA against with-the-rule ACA; and (3) ACA and group classification (significant vs. non-significant astigmatism) are independent predictors of ORA, whereas age, sex, SER, and MCC have no significant effects. These findings deepen understanding of astigmatism mechanisms, emphasizing that impaired internal compensation exacerbates astigmatism progression and amblyopia risk. These findings support targeted interventions: optimizing outdoor time, limiting digital device use, ensuring adequate sleep, and monitoring refractive status in children with parental astigmatism history. Additionally, they aid refining therapeutic strategies (e.g., prioritizing compensatory function monitoring) to enable precise risk stratification, early intervention, and improved long-term visual outcomes in pediatric patients.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflict of interest.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJL\u0026nbsp;the main author,\u0026nbsp;DM Yan and J Zhu\u0026nbsp;the corresponding authors designed the study, collected, analyzed,interpreted data, wrote the manuscript, approved the final version of the manuscript, and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.\u0026nbsp;DX An\u0026nbsp;collected, analyzed, and interpreted the manuscript data.\u0026nbsp;JL\u0026nbsp;wrote the main manuscript text. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInstitutional Review Board (IRB)/Ethics Committee approval was obtained by the Human Medical Ethics Committee of Lianyungang Maternal and Child Health Hospital. The authors confirm that the research followed the tenets of the Declaration of Helsinki and that informed consent was obtained from each subject after explanation of the nature and possible consequences of the study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eYin XL, Ji ZY, Li XX, Liang XM, Ji SX. Surgical approaches to correct corneal astigmatism at time of cataract surgery: a mini-review. Int J Ophthalmol. 2024;17(7):1370\u0026ndash;4. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.18240/ijo.2024.07.23\u003c/span\u003e\u003cspan address=\"10.18240/ijo.2024.07.23\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKam KW, Shing E, Zhang Y, et al. Prevalence and Severity of Astigmatism in Children After COVID-19. JAMA Ophthalmol. 2025;143(5):383\u0026ndash;91. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/jamaophthalmol.2025.0205\u003c/span\u003e\u003cspan address=\"10.1001/jamaophthalmol.2025.0205\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSigireddi RR, Weikert MP. How much astigmatism to treat in cataract surgery. Curr Opin Ophthalmol. 2020;31(1):10\u0026ndash;4. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/ICU.0000000000000627\u003c/span\u003e\u003cspan address=\"10.1097/ICU.0000000000000627\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNamba H, Sugano A, Murakami T, et al. Age-Related Changes in Astigmatism and Potential Causes. Cornea. 2020;39(1):S34\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/ICO.0000000000002507\u003c/span\u003e\u003cspan address=\"10.1097/ICO.0000000000002507\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKee CS. Astigmatism and its role in emmetropization. Exp Eye Res. 2013;114:89\u0026ndash;95. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.exer.2013.04.020\u003c/span\u003e\u003cspan address=\"10.1016/j.exer.2013.04.020\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGarcia-Lozada D, Rey-Rodr\u0026iacute;guez DV, Angulo-S\u0026aacute;nchez SV, S\u0026aacute;nchez-Espinosa JM. Prevalence of refractive errors in school-aged and preadolescent children in Colombia. Int J Ophthalmol. 2024;17(12):2288\u0026ndash;94. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.18240/ijo.2024.12.18\u003c/span\u003e\u003cspan address=\"10.18240/ijo.2024.12.18\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlpins NA. New method of targeting vectors to treat astigmatism. J Cataract Refract Surg. 1997;23(1):65\u0026ndash;75. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0886-3350(97)80153-8\u003c/span\u003e\u003cspan address=\"10.1016/s0886-3350(97)80153-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePi\u0026ntilde;ero DP, Ali\u0026oacute; JL, Barraquer RI, Uceda-Montanes A, Murta J. Clinical characterization of corneal ectasia after myopic laser in situ keratomileusis based on anterior corneal aberrations and internal astigmatism. J Cataract Refract Surg. 2011;37(7):1291\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jcrs.2010.12.063\u003c/span\u003e\u003cspan address=\"10.1016/j.jcrs.2010.12.063\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTeus MA, Arruabarrena C, Hern\u0026aacute;ndez-Verdejo JL, Ca\u0026ntilde;ones R, Mikropoulos DG. Ocular residual astigmatism's effect on high myopic astigmatism LASIK surgery. Eye (Lond). 2014;28(8):1014\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/eye.2014.133\u003c/span\u003e\u003cspan address=\"10.1038/eye.2014.133\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2014 Jun 27.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLin J. The contribution of ocular residual astigmatism to anterior corneal astigmatism in refractive astigmatism eyes. Sci Rep. 2021;11(1):1018. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41598-020-80106-6\u003c/span\u003e\u003cspan address=\"10.1038/s41598-020-80106-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLin J, An D, Lu Y, Yan D. Correlation between ocular residual astigmatism and anterior corneal astigmatism in children with low and moderate myopia. BMC Ophthalmol. 2022;22(1):374. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s12886-022-02560-2\u003c/span\u003e\u003cspan address=\"10.1186/s12886-022-02560-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXu S, Ruan Z, Wang Y et al. Establishment of Myopia Occurrence Prediction Model in Children without Myopia Using Cycloplegic Refraction and Prior Axial Length Change. \u003cem\u003eOphthalmology\u003c/em\u003e. 2025:S0161-6420(25)00359-8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.ophtha.2025.06.010\u003c/span\u003e\u003cspan address=\"10.1016/j.ophtha.2025.06.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWallerstein A, Gauvin M, Qi SR, Cohen M. Effect of the Vectorial Difference Between Manifest Refractive Astigmatism and Anterior Corneal Astigmatism on Topography-Guided LASIK Outcomes. J Refract Surg. 2020;36(7):449\u0026ndash;58. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3928/1081597X-20200609-01\u003c/span\u003e\u003cspan address=\"10.3928/1081597X-20200609-01\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChan KH, Shik HT, Kwok KW, Kee CS, Leung TW. Bi-directional Refractive Compensation for With-the-Rule and Against-the-Rule Astigmatism in Young Adults. Invest Ophthalmol Vis Sci. 2022;63:15. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1167/iovs.63.10.15\u003c/span\u003e\u003cspan address=\"10.1167/iovs.63.10.15\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHoseini-Yazdi H, Vincent SJ, Read SA, Collins MJ. Astigmatic defocus leads to short-term changes in human choroidal thickness. Invest Ophth Vis Sci. 2020;61:48. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1167/iovs.61.8.48\u003c/span\u003e\u003cspan address=\"10.1167/iovs.61.8.48\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchmid KL, Wildsoet CF. Natural and imposed astigmatism and their relation to emmetropization in the chick. Exp Eye Res. 1997;64:837\u0026ndash;47. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1006/exer.1997.0282\u003c/span\u003e\u003cspan address=\"10.1006/exer.1997.0282\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMadigan S, Eirich R, Pador P, McArthur BA, Neville RD. Assessment of Changes in Child and Adolescent Screen Time During the COVID-19 Pandemic: A Systematic Review and Meta-analysis. JAMA Pediatr. 2022;176(12):1188\u0026ndash;98. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/jamapediatrics.2022.4116\u003c/span\u003e\u003cspan address=\"10.1001/jamapediatrics.2022.4116\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi M, Xu L, Tan CS, et al. Systematic Review and Meta-Analysis on the Impact of COVID-19 Pandemic-Related Lifestyle on Myopia. Asia Pac J Ophthalmol (Phila). 2022;11(5):470\u0026ndash;80. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/APO.0000000000000559\u003c/span\u003e\u003cspan address=\"10.1097/APO.0000000000000559\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCort\u0026eacute;s-Albornoz MC, Ram\u0026iacute;rez-Guerrero S, Rojas-Carabali W, de-la-Torre A, Talero-Guti\u0026eacute;rrez C. Effects of remote learning during the COVID-19 lockdown on children's visual health: a systematic review. BMJ Open. 2022;12(8):e062388. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/bmjopen-2022-062388\u003c/span\u003e\u003cspan address=\"10.1136/bmjopen-2022-062388\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhao X, Peng Y, Yu T, et al. Association between insufficient sleep and astigmatism in preschool children. Eur J Pediatr. 2025;184(2):177. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00431-025-06004-z\u003c/span\u003e\u003cspan address=\"10.1007/s00431-025-06004-z\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Published 2025 Feb 5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang Z, Tong H, Hao Q, et al. Risk factors for astigmatic components and internal compensation: the Nanjing Eye Study. Eye (Lond). 2021;35(2):499\u0026ndash;507. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41433-020-0881-5\u003c/span\u003e\u003cspan address=\"10.1038/s41433-020-0881-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiang Y, Kang BS, Kee CS, Leung TW. Compensatory Interactions between Corneal and Internal Astigmatism despite Lifestyle Changes. \u003cem\u003eChildren (Basel)\u003c/em\u003e. 2024;11(2):154. Published 2024 Jan 25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/children11020154\u003c/span\u003e\u003cspan address=\"10.3390/children11020154\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"boph","sideBox":"Learn more about [BMC Ophthalmology](http://bmcophthalmol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/boph","title":"BMC Ophthalmology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"clinically significant astigmatism, ocular residual astigmatism, children, vector, difference","lastPublishedDoi":"10.21203/rs.3.rs-7713323/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7713323/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose: \u003c/strong\u003eTo compare the difference of ocular residual astigmatism (ORA) in children with clinically significant astigmatism and non-significant astigmatism.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eThis is a cross-sectional study. Participants were divided into the clinically significant astigmatism group (refractive astigmatism [RA] ≥ 1.00 D) and non-significant astigmatism group (RA \u0026lt; 1.00 D) based on RA on spectacle plane. Anterior corneal astigmatism (ACA) were obtained from IOL-Master 500. RA is the cylinder power after cycloplegia. ORA was calculated by the vector difference between RA and ACA. Multivariate linear regression was used to adjust for potential confounders, ensuring robust comparisons. The physical methods were used to evaluate the vector relationship between ORA and with-the-rule ACA.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eA total of 306 participants (306 right eyes) were included, among whom 155 (50.7%) were male. Results from multiple linear regression analysis indicated that the ACA was a significant positive predictor of ORA (B = 0.386, 95% confidence interval [CI]: 0.327 to 0.445, \u003cem\u003et \u003c/em\u003e= 12.826, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.001). In contrast, group emerged as a significant negative predictor of ORA (B = -0.553, 95% CI: -0.651 to -0.456, \u003cem\u003et \u003c/em\u003e= -11.212, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001). The ORA exerted a negative effect on with-the-rule ACA in 86.7% of eyes in the clinically significant astigmatism group, as compared to a much higher proportion of 99.0% in the non-significant astigmatism group( \u003cem\u003eχ² \u003c/em\u003e= 19.765, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eChildren with clinically significant astigmatism exhibited smaller ORA and lower compensatory efficacy of ORA against with-the-rule ACA compared with peers without significant astigmatism.\u003c/p\u003e","manuscriptTitle":"Comparison of ocular residual astigmatism between children with clinically significant and non-significant astigmatism","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-04 13:45:19","doi":"10.21203/rs.3.rs-7713323/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-11-05T05:50:23+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-27T08:10:43+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-25T16:30:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"294130389262692728906400386341395106041","date":"2025-10-24T20:56:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"322790147501019059777864036636443538107","date":"2025-10-23T21:49:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"286297017198782818369879733526637092451","date":"2025-10-23T11:50:16+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-23T11:41:06+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-29T09:35:09+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-26T08:53:16+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-26T08:52:18+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Ophthalmology","date":"2025-09-25T12:56:25+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"boph","sideBox":"Learn more about [BMC Ophthalmology](http://bmcophthalmol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/boph","title":"BMC Ophthalmology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"55fa102f-2097-4d5a-9b26-99740cf84b68","owner":[],"postedDate":"November 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-01T16:07:39+00:00","versionOfRecord":{"articleIdentity":"rs-7713323","link":"https://doi.org/10.1186/s12886-025-04533-7","journal":{"identity":"bmc-ophthalmology","isVorOnly":false,"title":"BMC Ophthalmology"},"publishedOn":"2025-11-28 15:58:16","publishedOnDateReadable":"November 28th, 2025"},"versionCreatedAt":"2025-11-04 13:45:19","video":"","vorDoi":"10.1186/s12886-025-04533-7","vorDoiUrl":"https://doi.org/10.1186/s12886-025-04533-7","workflowStages":[]},"version":"v1","identity":"rs-7713323","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7713323","identity":"rs-7713323","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}