Anthropometric Measurements of Eyelid Margin Width and the Distance between Eyelashes and the Gray Line in Han Chinese Children

Anthropometric Measurements of Eyelid Margin Width and the Distance between Eyelashes and the Gray Line in Han Chinese Children | 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 Anthropometric Measurements of Eyelid Margin Width and the Distance between Eyelashes and the Gray Line in Han Chinese Children A li Sun, Zi Han Liu, Lei Li, Zhi Jia Hou, Yue Wang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9460158/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Background To measure the eyelid margin width and the distance between the eyelash gray lines in Han Chinese children, providing data for pediatric ocular anthropometry. Methods This prospective, single-center, observational study included 33 Han Chinese children (66 eyes) aged 3–13 years (mean age: 6.01 ± 2.31 years) with strabismus. Children with eyelid diseases were excluded. Under general anesthesia, prior to strabismus surgery, a senior oculoplastic surgeon measured the upper and lower eyelid margin widths and the distances between the eyelash gray lines using a transparent soft ruler with a precision of 0.1 mm.Each parameter was measured three times and averaged. Results Upper eyelid margin widths increased from the medial to the central and lateral regions (1.07 ± 0.11 mm, 1.40 ± 0.16 mm, and 1.47 ± 0.17 mm), while lower eyelid margins showed a similar pattern (0.82 ± 0.15 mm, 0.88 ± 0.13 mm, and 0.98 ± 0.08 mm). Eyelash gray line distances were relatively consistent across regions in both upper (0.55–0.68 mm) and lower eyelids (0.50–0.59 mm). When grouped by age, children over 8 years old had significantly wider eyelid margins at the lateral upper eyelid, central lower eyelid, and lateral lower eyelid compared to those under 8 years old, while no significant differences were found in eyelash gray line distances. Conclusion : The width of the upper and lower eyelid margins in Chinese children is not uniform, being narrower medially and wider laterally. Eyelid margin width increases with age but shows no significant correlation with gender. Eyelid margin width Eyelash gray line distance Children Anthropometry Figures Figure 1 Figure 2 Background Previous literature on the measurement of aesthetic parameters of the eyes in children and adolescents has not reported on the measurement of eyelid margin width and the distance between the eyelash gray lines in children. It may be attributed to two main reasons: first, young children may be unable to cooperate with the measurement process due to their age; second, there is a lack of a portable, practical, precise, and easy-to-use measurement tool. The eyelid margin is the junction between the skin and mucosa of the eyelid, and the eyelid margin width is defined as the distance from the anterior border which is the first row of eyelashes to the posterior border which is the mucocutaneous junction (MCJ). Measuring the eyelid margin width not only provides anthropometric data for the eye but also aids in the diagnosis of ocular diseases and the design of eyelid surgical procedures. Given the absence of reported measurements of eyelid margin width in Chinese children, the objective of this study is to measure the eyelid margin width and the distance between the eyelash gray lines in Han Chinese children, thereby contributing anthropometric data specific to this population. Subjects and Methods Study Subjects A total of 33 children (66 eyes) diagnosed with strabismus and requiring general anesthesia surgery at Beijing Tongren Eye Hospital from September 2022 to January 2024 were included in this study. Among them, 21 were male and 12 were female, with a mean age of 6.01 ± 2.31 years (range: 3–13 years). All participants were of Han ethnicity. This study was a prospective single-center observational study and was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (TRECKY2020-063). The research was conducted in strict accordance with the principles of the Declaration of Helsinki, and all subjects provided written informed consent. Inclusion criteria: Children with strabismus requiring general anesthesia surgery. Exclusion criteria: Cases with significant keratitis, conjunctivitis, blepharitis, irregular eyelid margins, eyelash loss or madarosis, or eyelid lesions such as chalazion or hordeolum. Methods Definition of Eyelid Margin Width: The eyelid margin width is defined as the relatively constant distance from the first row of eyelashes at the anterior border of the eyelid to the mucocutaneous junction at the posterior border, commonly used as the theoretical basis for measuring eyelid margin width. Definition of Eyelash Gray Line Distance: The eyelash gray line distance refers to the distance from the first row of eyelashes at the anterior eyelid border to the gray line (Fig.1). Measurement Procedure: Under general anesthesia, prior to the commencement of surgery, a senior oculoplastic surgeon measured the upper and lower eyelid margins using surgical microscopic magnification. All measurements were performed by the same physician using a transparent soft ruler which the accuracy of ruler was 0.1 mm (Fig.2). Measurement Sites: The eyelid margin width and Eyelash gray line distance were measured at three locations every upper eyelid and lower eyelid, totaling six sites of the eyelid. Medial Eyelid Margin: Corresponding to the midpoint between the medial corneal limbus and the upper or lower lacrimal punctum. Central Eyelid Margin: Corresponding to the pupil center. Lateral Eyelid Margin: Corresponding to the midpoint between the lateral corneal limbus and the lateral canthus (Fig.1) .Measurement Protocol: Each site was measured three times, and the average value was statistically analyzed. Statistical Analysis Statistical analysis was performed using SAS 9.4 software. Data from the right eyes were analyzed in this study, as no statistically significant differences were observed between left and right eyes. Both eyelid margin width and eyelash gray line distance measurements followed a normal distribution and were expressed as mean ± standard deviation. Intergroup comparisons: One-way ANOVA was used for comparisons among multiple groups. If statistically significant differences were found, post hoc pairwise comparisons were conducted. Two-group comparisons: Independent samples t-tests were applied. A significance level of P< 0.05 was considered statistically significant. Results A total of 33 Chinese children were measured, all were of Han ethnicity, including 21 males and 12 females, with an average age of 6.67 ± 2.56 years. The widths of the medial, central and lateral eyelid margins of the upper eyelid are respectively: 1.07 ± 0.11mm, 1.40 ± 0.16mm, and 1.47 ± 0.17mm. The widths of the medial, central and lateral eyelid margins of the lower eyelid are respectively: 0.82 ± 0.15mm, 0.88 ± 0.13mm and 0.98 ± 0.08mm. The width of the eyelid margin is narrowest at the medial and central portions of the lower eyelid, followed by the medial portion of the upper eyelid and the lateral portion of the lower eyelid. The widest measurements are observed at the central and lateral portions of the upper eyelid (Table 1 ). The spacing between eyelash and gray on the medial, central, and lateral regions of the upper eyelid were 0.55 ± 0.09 mm, 0.64 ± 0.16 mm, and 0.68 ± 0.17 mm, respectively. On the lower eyelid, corresponding measurements for medial, central, and lateral regions were 0.50 ± 0.08 mm, 0.54 ± 0.08 mm, and 0.59 ± 0.11 mm, respectively. The narrowest eyelash line spacing is observed on the inner side of the lower eyelid, whereas the widest spacing is found on the outer side of the upper eyelid (Table 2 ). When analyzed by gender, no statistically significant differences were observed in the width of the eyelid margin or the distance between eyelash lines of the upper and lower eyelids (Tables 3 and 4 ). When categorized by age, children over 8 years old exhibited greater eyelid margin width on the outer side of the upper eyelid and the central region of the lower eyelid compared to those under 8 years old. Additionally, the outer side of the lower eyelid in children over 8 years old was significantly wider than that in their younger counterparts. However, no significant difference was found in the distance between the first row of eyelash and gray lines between the two age groups (Tables 5 and 6 ). Table 1 Measurement and comparison of eyelid margin Width in Normal Group Children Group Number of cases Mean ± standard deviation The medial portion of the upper eyelid 33 1.07 ± 0.11 The central portion of the upper eyelid 33 1.40 ± 0.16 The lateral portion of the upper eyelid 33 1.47 ± 0.17 The medial portion of the lower eyelid 33 0.82 ± 0.15 The central portion of the lower eyelid 33 0.88 ± 0.13 The lateral portion of the lower eyelid 33 0.98 ± 0.08 F value . 131.13 P value . < 0.001 Note: There was a statistically significant difference in the overall comparison of the six groups (F = 131.13, P < 0.001). Further pairwise comparisons showed that there was no statistically significant difference in the central upper eyelid and the lateral upper eyelid, the medial upper eyelid and the lateral lower eyelid, and the medial lower eyelid and the central lower eyelid. The differences in the other two groups were statistically significant. Table 2 The distance between the first row of eyelashes of the upper (the lower)eyelid and the grey line Group Number of cases Mean ± standard deviation The medial portion of the upper eyelid 33 0.55 ± 0.09 The central portion of the upper eyelid 33 0.64 ± 0.16 The lateral portion of the upper eyelid 33 0.68 ± 0.17 The medial portion of the lower eyelid 33 0.50 ± 0.08 The central portion of the lower eyelid 33 0.54 ± 0.08 The lateral portion of the lower eyelid 33 0.59 ± 0.11 F value . 10.33 P value . < 0.001 Note: There was a statistically significant difference among the six groups as a whole (F = 10.33, P < 0.001). Further pairwise comparisons showed that there was no statistically significant difference between the upper eyelid medial and upper eyelid lateral, upper eyelid medial and lower eyelid lateral and lower eyelid central, and lower eyelid medial and lower eyelid central. However, there were statistically significant differences in the remaining pairs. Table 3 Comparison of the widths of the upper and lower eyelid margins after grouping by gender Gender Number of cases The medial portion of the upper eyelid The central portion of the upper eyelid The lateral portion of the upper eyelid The medial portion of the lower eyelid The central portion of the lower eyelid The lateral portion of the lower eyelid male 21 1.09 ± 0.10 1.38 ± 0.15 1.50 ± 0.20 0.83 ± 0.14 0.89 ± 0.12 0.96 ± 0.08 female 12 1.06 ± 0.12 1.40 ± 0.17 1.45 ± 0.15 0.82 ± 0.15 0.87 ± 0.14 1.00 ± 0.09 Total 33 1.07 ± 0.11 1.40 ± 0.16 1.47 ± 0.17 0.82 ± 0.15 0.88 ± 0.13 0.98 ± 0.08 t value 0.5259 0.1383 0.6153 0.0711 0.2761 1.4743 P value 0.4738 0.7125 0.4387 0.7914 0.603 0.2338 Note: When grouped by gender, there was no statistically significant difference in the width of the eyelid margin at each position between the two groups. Table 4 A comparison of the distance between the first row of eyelashes of the upper and lower eyelids and the grey line by gender Gender Number of cases The medial portion of the upper eyelid The central portion of the upper eyelid The lateral portion of the upper eyelid The medial portion of the lower eyelid The central portion of the lower eyelid The lateral portion of the lower eyelid male 21 0.51 ± 0.03 0.58 ± 0.08 0.61 ± 0.09 0.49 ± 0.07 0.53 ± 0.07 0.55 ± 0.05 female 12 0.58 ± 0.10 0.68 ± 0.18 0.72 ± 0.19 0.51 ± 0.08 0.54 ± 0.09 0.62 ± 0.13 Total 33 0.55 ± 0.09 0.64 ± 0.16 0.68 ± 0.17 0.50 ± 0.08 0.54 ± 0.08 0.59 ± 0.11 t value 5.2592 2.7044 3.7258 0.4031 0.0248 3.1144 P value 0.0288 0.1102 0.0628 0.5301 0.8758 0.0875 Note: When grouped by gender, there was no statistically significant difference in the distance between the eyelashes and the grey line at each position between the two groups. Table 5 Comparison of the widths of the upper and lower eyelid margins grouped by age Age Number of cases The medial portion of the upper eyelid The central portion of the upper eyelid The lateral portion of the upper eyelid The medial portion of the lower eyelid The central portion of the lower eyelid The lateral portion of the lower eyelid < 8 21 1.05 ± 0.11 1.37 ± 0.16 1.42 ± 0.15 0.79 ± 0.14 0.84 ± 0.14 0.96 ± 0.09 ≥ 8 12 1.12 ± 0.10 1.44 ± 0.16 1.56 ± 0.17 0.88 ± 0.13 0.94 ± 0.09 1.03 ± 0.06 Total 33 1.07 ± 0.11 1.40 ± 0.16 1.47 ± 0.17 0.82 ± 0.15 0.88 ± 0.13 0.98 ± 0.08 t value 3.0582 1.553 6.1933 3.3203 5.5362 5.6208 P value 0.0902 0.222 0.0184 0.0781 0.0252 0.0241 Note: The age groups were divided into two groups: under 8 years old and ≥ 8 years old and above. There were statistically significant differences in the width of the eyelid margin on the lateral side of the upper eyelid, the center of the lower eyelid and the lateral side of the lower eyelid (t = 6.19,5.54,5.62;P < 0.05), while there were no statistically significant differences in the width of the eyelid margin in the other parts between the two groups. Table 6 Compare the distances between the first row of eyelashes and gray lines by age groups Age Number of cases The medial portion of the upper eyelid The central portion of the upper eyelid The lateral portion of the upper eyelid The medial portion of the lower eyelid The central portion of the lower eyelid The lateral portion of the lower eyelid < 8 21 0.56 ± 0.09 0.65 ± 0.16 0.69 ± 0.17 0.50 ± 0.06 0.51 ± 0.07 0.60 ± 0.12 ≥ 8 12 0.53 ± 0.08 0.63 ± 0.17 0.67 ± 0.18 0.51 ± 0.10 0.58 ± 0.10 0.59 ± 0.11 Total 33 0.55 ± 0.09 0.64 ± 0.16 0.68 ± 0.17 0.50 ± 0.08 0.54 ± 0.08 0.59 ± 0.11 t value 0.8182 0.059 0.142 0.0869 4.6364 0.0076 P value 0.3727 0.8097 0.7088 0.7701 0.0392 0.9312 Note: They were divided into two groups according to those under 8 years old and those 8 years old and above. There was no statistically significant difference in the distance between the first row of eyelashes and the gray line at each position of the eyelid between the two age groups. Discussion The measurement of eyelid margin width has significant clinical value, as increased width is a common feature of blepharitis and advanced meibomian gland dysfunction (MGD) ( 1 ). The prevalence of MGD rises with age, and mild meibomian gland atrophy is also highly prevalent in asymptomatic pediatric patients( 2 ). Therefore, early identification of MGD is becoming increasingly important, and timely intervention may help prevent disease progression. Our study demonstrates that the upper eyelid margin width gradually increases with age. This widening may be attributed to age-related thickening of the eyelid skin, orbicularis oculi muscle, and meibomian glands. However, measuring eyelid margin width in children is challenging due to their narrower, more curved eyelid margins which closely follow the eyeball and their poor cooperation. Previous studies have employed various measurement techniques, including transparent rulers, calipers, Scheimpflug imaging, Oculus Keratography, and anterior segment optical coherence tomography (AS-OCT). However, these methods face clinical limitations due to cumbersome equipment (e.g., heavy calipers), operational complexity (e.g., time-consuming imaging techniques), or insufficient accuracy. Additionally, since the eyelid margin has a curved rather than linear structure, conventional straight-line measurements may underestimate the true width of eyelid margin. Hykin et al. used calipers to report adult upper and lower eyelid margin widths of 1.95 ± 0.07 mm and 1.87 ± 0.06 mm, respectively, with no gender differences( 3 ). Pult et al., using Scheimpflug imaging, measured the adult central lower eyelid thickness as 1.7 mm( 4 ). Da-Hu Wang's AS-OCT measurements showed a narrower Chinese adult lower central eyelid width (0.86 ± 0.23 mm)( 5 ), while Jie Yao's Oculus Keratography reported 0.956 ± 0.17 mm at the same position as adults( 6 ). Our study measured six eyelid margin sites in Chinese children, revealing an average central upper eyelid width of 1.40 ± 0.16 mm and lower eyelid width of 0.88 ± 0.13 mm. Both eyelids exhibited a progressive widening from medial to lateral regions, confirming non-uniform width distribution (narrower medially, broader laterally). We also quantified the first row eyelash-to-gray line distance at all six anatomical locations. This study is the first to conduct microscopic measurements of eyelid margin width and eyelash-to-gray line distance in Han Chinese children under an operating microscope. The results demonstrated that eyelid margin width increases with age, independent of gender. This finding provides important reference data for the diagnosis and treatment of pediatric eyelid disorders. Additionally, this study introduces for the first time the concept of measuring the first row eyelash-to-gray line distance in Chinese children, offering valuable reference data for diagnosing ocular diseases and planning surgical interventions—such as resection and reconstruction of anterior lamellar eyelid lesions and gray line incision for pediatric lower eyelid entropion with trichiasis. The transparent flexible ruler used in this study is simple, precise, and easy to operate, making it particularly suitable for pediatric measurements. Since children are often uncooperative during awake examinations, measurements were performed under general anesthesia prior to surgery using an operating microscope, ensuring data accuracy. Furthermore, the transparent flexible ruler offers high precision (0.1 mm resolution) and flexibility, making it ideal for measuring the curved eyelid margin and meeting the demands of delicate ocular measurements. The limitation of this study lies in its small sample size and the fact that it only targets Han Chinese children. Future research can expand the sample size and include children of different ethnic groups and age groups to obtain more comprehensive anthropometric data on children's eyes. Conclusion This study measured the width of the eyelid margin and the distance between the eyelash lines of Han Chinese children. It was found that the width of the eyelid margin widened with age, regardless of gender, and both the upper and lower eyelid margin widths showed a state of "narrow inside and wide outside". This study provides and enriches the data for ocular anthropometry in children, which has certain guiding significance for clinical diagnosis and treatment. Declarations Ethics approval and consent to participate This study adhered to the Declaration of Helsinki and was approved by Ethical Review Committee of Beijing Tongren Hospital, Capital Medical University, China. Informed consent to participate was obtained from the parents or legal guardians of any participant under the age of 16. Consent for publication Not applicable. Consent for publication All authors of this study consent to the publication and have no objections to the order of authorship. Competing interests Not applicable Funding Not applicable Author Contribution A.S. was responsible for data collection and manuscript preparation; Z.L. was responsible for data collection; L.L. was responsible for statistical analysis of the data; Z.H. was responsible for data acquisition; and Y.W. was responsible for data measurement, as well as manuscript review and revision. All authors read and approved the final manuscript. Acknowledgements Not applicable Data Availability Data measurement, collection, and analysis are accurate and reliable. References Foulks GN, Bron AJ. Meibomian gland dysfunction: a clinical scheme for description, diagnosis, classification, and grading. Ocul Surf. 2003;1(3):107–26. Gupta PK, Stevens MN, Kashyap N, Priestley Y. Prevalence of Meibomian Gland Atrophy in a Pediatric Population. Cornea. 2018;37(4):426–30. Hykin PG, Bron AJ. Age-related morphological changes in lid margin and meibomian gland anatomy. Cornea. 1992;11(4):334–42. Pult H, Korb DR, Murphy PJ, Riede-Pult BH, Blackie C. A new model of central lid margin apposition and tear film mixing in spontaneous blinking. Cont Lens Anterior Eye. 2015;38(3):173–80. Wang DH, Yao J, Liu XQ. Comparison of two measurements for the lower lid margin thickness: vernier micrometer and anterior segment optical coherence tomography. Int Ophthalmol. 2020;40(12):3223–32. Yao J, Liu XQ, Zhu Y, Wang DH. Measurement of the Lower Lid Margin Thickness by Oculus Keratograph. Eye Contact Lens. 2021;47(6):341–6. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 07 May, 2026 Editor assigned by journal 07 May, 2026 Editor invited by journal 28 Apr, 2026 Submission checks completed at journal 26 Apr, 2026 First submitted to journal 26 Apr, 2026 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-9460158","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":635996810,"identity":"8ad45693-1015-44c3-ba0e-ced884a4de77","order_by":0,"name":"A li Sun","email":"","orcid":"","institution":"Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"A","middleName":"li","lastName":"Sun","suffix":""},{"id":635996811,"identity":"38bb0936-3194-48f4-b705-2ae2d5acd26f","order_by":1,"name":"Zi Han Liu","email":"","orcid":"","institution":"Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zi","middleName":"Han","lastName":"Liu","suffix":""},{"id":635996812,"identity":"3609c73f-65d6-41df-ac24-efd08ce00338","order_by":2,"name":"Lei Li","email":"","orcid":"","institution":"Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"Lei","middleName":"","lastName":"Li","suffix":""},{"id":635996813,"identity":"4c4a81bf-03f1-482f-85e8-f72397a77bf2","order_by":3,"name":"Zhi Jia Hou","email":"","orcid":"","institution":"Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zhi","middleName":"Jia","lastName":"Hou","suffix":""},{"id":635996814,"identity":"4a6e9db5-57ee-449b-be82-a22d2a58c567","order_by":4,"name":"Yue Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6ElEQVRIiWNgGAWjYDACZiAEAX72/o8PPjBIkKBFsueAseEMorQwQLUY3HAwk+YhRr05O/NjY56aO3YzZzAkSNv8scjjb2B++OgGHi2WzWzGyTzHniX3SzccMM5tkyiWOMBmbJyDR4vBYR7mwzlsh5Ml5xxsSM5tkEhsOMDDJk1Yy7/DyQY3khkOW/yRSJxPjJbk3LbDdgY30hibGdgkEjcQ1gJ0+d++wwmSPWeYGXvbJBI3Hibkl/OHH0vO+HbYnp+9h/3Hjz91ifOONz98jE8LDCQ2wJnMRCgHAXsi1Y2CUTAKRsFIBAB2Q01hk8t2wgAAAABJRU5ErkJggg==","orcid":"","institution":"Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University","correspondingAuthor":true,"prefix":"","firstName":"Yue","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2026-04-19 07:39:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9460158/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9460158/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109332623,"identity":"b1bc2b85-6376-47ad-a302-abc239ce583e","added_by":"auto","created_at":"2026-05-15 16:21:08","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":11612371,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement sites of eyelid margin width and eyelash gray line distance. The blue arrows indicate the width of the eyelid margins at various positions of the upper and lower eyelids. The red arrows indicate the distances from the first row of eyelashes to the gray line at each point of the eyelid margin of the upper and lower eyelids.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-9460158/v1/6dd4fa9a825172b79fdc495b.png"},{"id":109332624,"identity":"552c3186-664e-40e4-b1bc-aba8dc912fa4","added_by":"auto","created_at":"2026-05-15 16:21:08","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":5375921,"visible":true,"origin":"","legend":"\u003cp\u003eMeasuring instrument used for eyelid margin assessment. It is a 1cm transparent flexible ruler with laser-printed scales. Each millimeter is further divided into 10 equal parts. The accuracy of this flexible ruler is 0.1 millimeters.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-9460158/v1/c67f5511acd35a8cd63eee7a.png"},{"id":109405473,"identity":"37ca0e58-3b23-429a-994e-b0448c00b051","added_by":"auto","created_at":"2026-05-17 13:18:22","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":16647422,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9460158/v1/110d5baf-3d33-4efe-a5d0-2c6689207d70.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Anthropometric Measurements of Eyelid Margin Width and the Distance between Eyelashes and the Gray Line in Han Chinese Children","fulltext":[{"header":"Background","content":"\u003cp\u003ePrevious literature on the measurement of aesthetic parameters of the eyes in children and adolescents has not reported on the measurement of eyelid margin width and the distance between the eyelash gray lines in children. It may be attributed to two main reasons: first, young children may be unable to cooperate with the measurement process due to their age; second, there is a lack of a portable, practical, precise, and easy-to-use measurement tool. The eyelid margin is the junction between the skin and mucosa of the eyelid, and the eyelid margin width is defined as the distance from the anterior border which is the first row of eyelashes to the posterior border which is the mucocutaneous junction (MCJ). Measuring the eyelid margin width not only provides anthropometric data for the eye but also aids in the diagnosis of ocular diseases and the design of eyelid surgical procedures. Given the absence of reported measurements of eyelid margin width in Chinese children, the objective of this study is to measure the eyelid margin width and the distance between the eyelash gray lines in Han Chinese children, thereby contributing anthropometric data specific to this population.\u003c/p\u003e\n\u003cp\u003eSubjects and Methods\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy Subjects\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 33 children (66 eyes) diagnosed with strabismus and requiring general anesthesia surgery at Beijing Tongren Eye Hospital from September 2022 to January 2024 were included in this study. Among them, 21 were male and 12 were female, with a mean age of 6.01 ± 2.31 years (range: 3–13 years). All participants were of Han ethnicity. This study was a prospective single-center observational study and was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (TRECKY2020-063). The research was conducted in strict accordance with the principles of the Declaration of Helsinki, and all subjects provided written informed consent. Inclusion criteria: Children with strabismus requiring general anesthesia surgery. \u0026nbsp;Exclusion criteria: Cases with significant keratitis, conjunctivitis, blepharitis, irregular eyelid margins, eyelash loss or madarosis, or eyelid lesions such as chalazion or hordeolum.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eDefinition of Eyelid Margin Width: The eyelid margin width is defined as the relatively constant distance from the first row of eyelashes at the anterior border of the eyelid to the mucocutaneous junction at the posterior border, commonly used as the theoretical basis for measuring eyelid margin width. Definition of Eyelash Gray Line Distance: The eyelash gray line distance refers to the distance from the first row of eyelashes at the anterior eyelid border to the gray line (Fig.1). Measurement Procedure: Under general anesthesia, prior to the commencement of surgery, a senior oculoplastic surgeon measured the upper and lower eyelid margins using surgical microscopic magnification. All measurements were performed by the same physician using a transparent soft ruler which the accuracy of ruler was 0.1 mm (Fig.2). Measurement Sites: The eyelid margin width and Eyelash gray line distance were measured at three locations every upper eyelid and lower eyelid, totaling six sites of the eyelid. Medial Eyelid Margin: Corresponding to the midpoint between the medial corneal limbus and the upper or lower lacrimal punctum. Central Eyelid Margin: Corresponding to the pupil center. Lateral Eyelid Margin: Corresponding to the midpoint between the lateral corneal limbus and the lateral canthus (Fig.1) .Measurement Protocol: Each site was measured three times, and the average value was statistically analyzed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analysis was performed using SAS 9.4 software. Data from the right eyes were analyzed in this study, as no statistically significant differences were observed between left and right eyes. Both eyelid margin width and eyelash gray line distance measurements followed a normal distribution and were expressed as mean \u0026plusmn; standard deviation. Intergroup comparisons: One-way ANOVA was used for comparisons among multiple groups. If statistically significant differences were found, post hoc pairwise comparisons were conducted. Two-group comparisons: Independent samples t-tests were applied. A significance level of P\u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 33 Chinese children were measured, all were of Han ethnicity, including 21 males and 12 females, with an average age of 6.67\u0026thinsp;\u0026plusmn;\u0026thinsp;2.56 years. The widths of the medial, central and lateral eyelid margins of the upper eyelid are respectively: 1.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11mm, 1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16mm, and 1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17mm. The widths of the medial, central and lateral eyelid margins of the lower eyelid are respectively: 0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15mm, 0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13mm and 0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08mm. The width of the eyelid margin is narrowest at the medial and central portions of the lower eyelid, followed by the medial portion of the upper eyelid and the lateral portion of the lower eyelid. The widest measurements are observed at the central and lateral portions of the upper eyelid (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The spacing between eyelash and gray on the medial, central, and lateral regions of the upper eyelid were 0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 mm, 0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 mm, and 0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 mm, respectively. On the lower eyelid, corresponding measurements for medial, central, and lateral regions were 0.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 mm, 0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 mm, and 0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11 mm, respectively. The narrowest eyelash line spacing is observed on the inner side of the lower eyelid, whereas the widest spacing is found on the outer side of the upper eyelid (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). When analyzed by gender, no statistically significant differences were observed in the width of the eyelid margin or the distance between eyelash lines of the upper and lower eyelids (Tables\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). When categorized by age, children over 8 years old exhibited greater eyelid margin width on the outer side of the upper eyelid and the central region of the lower eyelid compared to those under 8 years old. Additionally, the outer side of the lower eyelid in children over 8 years old was significantly wider than that in their younger counterparts. However, no significant difference was found in the distance between the first row of eyelash and gray lines between the two age groups (Tables\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e and \u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\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\u003eMeasurement and comparison of eyelid margin Width in Normal Group Children\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe medial portion of the upper eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe central portion of the upper eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe lateral portion of the upper eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe medial portion of the lower eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe central portion of the lower eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe lateral portion of the lower eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e131.13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eNote: There was a statistically significant difference in the overall comparison of the six groups (F\u0026thinsp;=\u0026thinsp;131.13, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Further pairwise comparisons showed that there was no statistically significant difference in the central upper eyelid and the lateral upper eyelid, the medial upper eyelid and the lateral lower eyelid, and the medial lower eyelid and the central lower eyelid. The differences in the other two groups were statistically significant.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\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\u003eThe distance between the first row of eyelashes of the upper (the lower)eyelid and the grey line\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe medial portion of the upper eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe central portion of the upper eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe lateral portion of the upper eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe medial portion of the lower eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe central portion of the lower eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe lateral portion of the lower eyelid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eNote: There was a statistically significant difference among the six groups as a whole (F\u0026thinsp;=\u0026thinsp;10.33, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Further pairwise comparisons showed that there was no statistically significant difference between the upper eyelid medial and upper eyelid lateral, upper eyelid medial and lower eyelid lateral and lower eyelid central, and lower eyelid medial and lower eyelid central. However, there were statistically significant differences in the remaining pairs.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\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 the widths of the upper and lower eyelid margins after grouping by gender\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\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=\"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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eThe medial portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eThe central portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eThe lateral portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eThe medial portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eThe central portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eThe lateral portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.89\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003efemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003et value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.5259\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.1383\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.6153\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0711\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.2761\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.4743\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.4738\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.7125\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.4387\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.7914\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.603\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.2338\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eNote: When grouped by gender, there was no statistically significant difference in the width of the eyelid margin at each position between the two groups.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eA comparison of the distance between the first row of eyelashes of the upper and lower eyelids and the grey line by gender\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\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=\"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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eThe medial portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eThe central portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eThe lateral portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eThe medial portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eThe central portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eThe lateral portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.49\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003efemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.62\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003et value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.2592\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.7044\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.7258\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.4031\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0248\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e3.1144\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0288\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.1102\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0628\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.5301\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.8758\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0875\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eNote: When grouped by gender, there was no statistically significant difference in the distance between the eyelashes and the grey line at each position between the two groups.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of the widths of the upper and lower eyelid margins grouped by age\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\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=\"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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eThe medial portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eThe central portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eThe lateral portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eThe medial portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eThe central portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eThe lateral portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.94\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003et value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.0582\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.553\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.1933\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.3203\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.5362\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e5.6208\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0902\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.222\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.0184\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0781\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0252\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0241\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eNote: The age groups were divided into two groups: under 8 years old and \u0026ge;\u0026thinsp;8 years old and above. There were statistically significant differences in the width of the eyelid margin on the lateral side of the upper eyelid, the center of the lower eyelid and the lateral side of the lower eyelid (t\u0026thinsp;=\u0026thinsp;6.19,5.54,5.62;P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), while there were no statistically significant differences in the width of the eyelid margin in the other parts between the two groups.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCompare the distances between the first row of eyelashes and gray lines by age groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\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=\"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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eThe medial portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eThe central portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eThe lateral portion of the upper eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eThe medial portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eThe central portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eThe lateral portion of the lower eyelid\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003et value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.8182\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.059\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.142\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0869\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4.6364\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.0076\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.3727\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.8097\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.7088\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.7701\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0392\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.9312\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eNote: They were divided into two groups according to those under 8 years old and those 8 years old and above. There was no statistically significant difference in the distance between the first row of eyelashes and the gray line at each position of the eyelid between the two age groups.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe measurement of eyelid margin width has significant clinical value, as increased width is a common feature of blepharitis and advanced meibomian gland dysfunction (MGD) (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). The prevalence of MGD rises with age, and mild meibomian gland atrophy is also highly prevalent in asymptomatic pediatric patients(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Therefore, early identification of MGD is becoming increasingly important, and timely intervention may help prevent disease progression. Our study demonstrates that the upper eyelid margin width gradually increases with age. This widening may be attributed to age-related thickening of the eyelid skin, orbicularis oculi muscle, and meibomian glands. However, measuring eyelid margin width in children is challenging due to their narrower, more curved eyelid margins which closely follow the eyeball and their poor cooperation. Previous studies have employed various measurement techniques, including transparent rulers, calipers, Scheimpflug imaging, Oculus Keratography, and anterior segment optical coherence tomography (AS-OCT). However, these methods face clinical limitations due to cumbersome equipment (e.g., heavy calipers), operational complexity (e.g., time-consuming imaging techniques), or insufficient accuracy. Additionally, since the eyelid margin has a curved rather than linear structure, conventional straight-line measurements may underestimate the true width of eyelid margin. Hykin et al. used calipers to report adult upper and lower eyelid margin widths of 1.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 mm and 1.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 mm, respectively, with no gender differences(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Pult et al., using Scheimpflug imaging, measured the adult central lower eyelid thickness as 1.7 mm(\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Da-Hu Wang's AS-OCT measurements showed a narrower Chinese adult lower central eyelid width (0.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 mm)(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e), while Jie Yao's Oculus Keratography reported 0.956\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 mm at the same position as adults(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Our study measured six eyelid margin sites in Chinese children, revealing an average central upper eyelid width of 1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 mm and lower eyelid width of 0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 mm. Both eyelids exhibited a progressive widening from medial to lateral regions, confirming non-uniform width distribution (narrower medially, broader laterally). We also quantified the first row eyelash-to-gray line distance at all six anatomical locations.\u003c/p\u003e \u003cp\u003eThis study is the first to conduct microscopic measurements of eyelid margin width and eyelash-to-gray line distance in Han Chinese children under an operating microscope. The results demonstrated that eyelid margin width increases with age, independent of gender. This finding provides important reference data for the diagnosis and treatment of pediatric eyelid disorders. Additionally, this study introduces for the first time the concept of measuring the first row eyelash-to-gray line distance in Chinese children, offering valuable reference data for diagnosing ocular diseases and planning surgical interventions\u0026mdash;such as resection and reconstruction of anterior lamellar eyelid lesions and gray line incision for pediatric lower eyelid entropion with trichiasis. The transparent flexible ruler used in this study is simple, precise, and easy to operate, making it particularly suitable for pediatric measurements. Since children are often uncooperative during awake examinations, measurements were performed under general anesthesia prior to surgery using an operating microscope, ensuring data accuracy. Furthermore, the transparent flexible ruler offers high precision (0.1 mm resolution) and flexibility, making it ideal for measuring the curved eyelid margin and meeting the demands of delicate ocular measurements. The limitation of this study lies in its small sample size and the fact that it only targets Han Chinese children. Future research can expand the sample size and include children of different ethnic groups and age groups to obtain more comprehensive anthropometric data on children's eyes.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study measured the width of the eyelid margin and the distance between the eyelash lines of Han Chinese children. It was found that the width of the eyelid margin widened with age, regardless of gender, and both the upper and lower eyelid margin widths showed a state of \"narrow inside and wide outside\". This study provides and enriches the data for ocular anthropometry in children, which has certain guiding significance for clinical diagnosis and treatment.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e \u003cp\u003e This study adhered to the Declaration of Helsinki and was approved by Ethical Review Committee of Beijing Tongren Hospital, Capital Medical University, China. Informed consent to participate was obtained from the parents or legal guardians of any participant under the age of 16.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003eNot applicable.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003e All authors of this study consent to the publication and have no objections to the order of authorship.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eNot applicable\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eNot applicable\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eA.S. was responsible for data collection and manuscript preparation; Z.L. was responsible for data collection; L.L. was responsible for statistical analysis of the data; Z.H. was responsible for data acquisition; and Y.W. was responsible for data measurement, as well as manuscript review and revision. All authors read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eNot applicable\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData measurement, collection, and analysis are accurate and reliable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFoulks GN, Bron AJ. Meibomian gland dysfunction: a clinical scheme for description, diagnosis, classification, and grading. Ocul Surf. 2003;1(3):107\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGupta PK, Stevens MN, Kashyap N, Priestley Y. Prevalence of Meibomian Gland Atrophy in a Pediatric Population. Cornea. 2018;37(4):426\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHykin PG, Bron AJ. Age-related morphological changes in lid margin and meibomian gland anatomy. Cornea. 1992;11(4):334\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePult H, Korb DR, Murphy PJ, Riede-Pult BH, Blackie C. A new model of central lid margin apposition and tear film mixing in spontaneous blinking. Cont Lens Anterior Eye. 2015;38(3):173\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang DH, Yao J, Liu XQ. Comparison of two measurements for the lower lid margin thickness: vernier micrometer and anterior segment optical coherence tomography. Int Ophthalmol. 2020;40(12):3223\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYao J, Liu XQ, Zhu Y, Wang DH. Measurement of the Lower Lid Margin Thickness by Oculus Keratograph. Eye Contact Lens. 2021;47(6):341\u0026ndash;6.\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":false,"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":"Eyelid margin width, Eyelash gray line distance, Children, Anthropometry","lastPublishedDoi":"10.21203/rs.3.rs-9460158/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9460158/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cb\u003eBackground\u003c/b\u003e\u003c/p\u003e \u003cp\u003eTo measure the eyelid margin width and the distance between the eyelash gray lines in Han Chinese children, providing data for pediatric ocular anthropometry.\u003c/p\u003e\u003cp\u003e\u003cb\u003eMethods\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThis prospective, single-center, observational study included 33 Han Chinese children (66 eyes) aged 3\u0026ndash;13 years (mean age: 6.01\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31 years) with strabismus. Children with eyelid diseases were excluded. Under general anesthesia, prior to strabismus surgery, a senior oculoplastic surgeon measured the upper and lower eyelid margin widths and the distances between the eyelash gray lines using a transparent soft ruler with a precision of 0.1 mm.Each parameter was measured three times and averaged.\u003c/p\u003e\u003cp\u003e\u003cb\u003eResults\u003c/b\u003e\u003c/p\u003e \u003cp\u003eUpper eyelid margin widths increased from the medial to the central and lateral regions (1.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11 mm, 1.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 mm, and 1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 mm), while lower eyelid margins showed a similar pattern (0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 mm, 0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 mm, and 0.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 mm). Eyelash gray line distances were relatively consistent across regions in both upper (0.55\u0026ndash;0.68 mm) and lower eyelids (0.50\u0026ndash;0.59 mm). When grouped by age, children over 8 years old had significantly wider eyelid margins at the lateral upper eyelid, central lower eyelid, and lateral lower eyelid compared to those under 8 years old, while no significant differences were found in eyelash gray line distances.\u003cb\u003eConclusion\u003c/b\u003e: The width of the upper and lower eyelid margins in Chinese children is not uniform, being narrower medially and wider laterally. Eyelid margin width increases with age but shows no significant correlation with gender.\u003c/p\u003e","manuscriptTitle":"Anthropometric Measurements of Eyelid Margin Width and the Distance between Eyelashes and the Gray Line in Han Chinese Children","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-15 16:21:00","doi":"10.21203/rs.3.rs-9460158/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2026-05-07T04:10:19+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-07T04:09:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-28T12:56:33+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-26T10:29:48+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Ophthalmology","date":"2026-04-26T10:25:02+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":"6c7a8472-2459-4603-b2cd-471d0c9d182a","owner":[],"postedDate":"May 15th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewersInvited","content":"2","date":"2026-05-07T04:10:19+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-07T04:09:53+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-15T16:21:00+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-15 16:21:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9460158","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9460158","identity":"rs-9460158","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}