{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T03:26:04Z","timestamp":1789097164425,"version":"build-2803163510"},"reference-count":34,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2022,6,19]],"date-time":"2022-06-19T00:00:00Z","timestamp":1655596800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Innovation and Technology Commission","award":["ITB-FBL-4010-18-P InnoHK CEVR project 5.1"],"award-info":[{"award-number":["ITB-FBL-4010-18-P InnoHK CEVR project 5.1"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Children"],"abstract":"<jats:p>During the COVID-19 pandemic, the Hong Kong Government enforced a \u201cschool from home\u201d policy between February and September 2020. This cross-sectional epidemiological study was conducted to investigate the prevalence of astigmatism and visual habits after the home confinement period. Vision screenings were conducted at three local government-funded primary schools in Hong Kong from October 2020 to December 2020. A total of 418 ethnically Chinese primary school children completed the eye examination and returned questionnaires concerning demographic information and visual habits. It was found that 46.5% (95% CI, 41.7\u201361.4%) of the children aged 8 to 11 years had astigmatism \u2265 0.75 D, which was predominately With-The-Rule astigmatism. The prevalence of astigmatism reported in these children is generally higher than that of studies conducted before COVID. Compared to their non-astigmatic peers, astigmatic children had a longer axial length (p &lt; 0.001) and engaged in fewer outdoor activities (p = 0.04). Multiple linear regression analyses also revealed significant relationships between axial length and both cylindrical error and J0 astigmatism. Due to the high astigmatism prevalence, there is a pressing need for further studies on the long-term impact of the pandemic on children\u2019s vision.<\/jats:p>","DOI":"10.3390\/children9060919","type":"journal-article","created":{"date-parts":[[2022,6,19]],"date-time":"2022-06-19T10:14:52Z","timestamp":1655633692000},"page":"919","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["High Prevalence of Astigmatism in Children after School Suspension during the COVID-19 Pandemic Is Associated with Axial Elongation"],"prefix":"10.3390","volume":"9","author":[{"given":"Suei-Cheng","family":"Wong","sequence":"first","affiliation":[{"name":"Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chea-Su","family":"Kee","sequence":"additional","affiliation":[{"name":"Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong"},{"name":"School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong"},{"name":"Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Kowloon, Hong Kong"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tsz-Wing","family":"Leung","sequence":"additional","affiliation":[{"name":"Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong"},{"name":"School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong"},{"name":"Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Kowloon, Hong Kong"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.joco.2017.08.009","article-title":"Global and Regional Estimates of Prevalence of Refractive Errors: Systematic Review and Meta-Analysis","volume":"30","author":"Hashemi","year":"2017","journal-title":"J. Curr. Ophthalmol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"984","DOI":"10.1097\/OPX.0b013e31825da156","article-title":"Characteristics of Astigmatism as a Function of Age in a Hong Kong Clinical Population","volume":"89","author":"Leung","year":"2012","journal-title":"Optom. Vis. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1097\/OPX.0000000000000242","article-title":"Vision in Preschoolers (VIP) Study Group (2014) Risk Factors for Astigmatism in the Vision in Preschoolers (VIP) Study","volume":"91","author":"Huang","year":"2014","journal-title":"Optom. Vis. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1141","DOI":"10.1001\/archopht.121.8.1141","article-title":"Refractive Error and Ethnicity in Children","volume":"121","author":"Kleinstein","year":"2003","journal-title":"Arch. Ophthalmol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1974","DOI":"10.1016\/j.ophtha.2011.06.031","article-title":"Risk Factors for Astigmatism in Preschool Children: The Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies","volume":"118","author":"Varma","year":"2011","journal-title":"Ophthalmology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1016\/S0002-9394(99)00452-3","article-title":"Refractive Error Study in Children: Results from Shunyi District, China","volume":"129","author":"Zhao","year":"2000","journal-title":"Am. J. Ophthalmol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"793","DOI":"10.1167\/iovs.03-1051","article-title":"Refractive Error and Visual Impairment in Urban Children in Southern China","volume":"45","author":"He","year":"2004","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Wu, J.F., Bi, H.S., Wang, S.M., Hu, Y.Y., Wu, H., Sun, W., Lu, T.L., Wang, X.R., and Jonas, J.B. (2013). Refractive Error, Visual Acuity and Causes of Vision Loss in Children in Shandong, China. The Shandong Children Eye Study. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0082763"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"348","DOI":"10.3109\/09286586.2013.842596","article-title":"Design, Methodology and Baseline Data of a School-Based Cohort Study in Central China: The Anyang Childhood Eye Study","volume":"20","author":"Li","year":"2013","journal-title":"Ophthalmic Epidemiol."},{"key":"ref_10","first-page":"2103","article-title":"Epidemiological Study on Visual Acuity and Refractive Status of Primary Students and Junior High School Students in Shenzhen","volume":"16","author":"Han","year":"2016","journal-title":"Int. J. Ophthalmol. Clin. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"606","DOI":"10.1097\/00006324-200209000-00012","article-title":"Prevalence Rates and Epidemiological Risk Factors for Astigmatism in Singapore School Children","volume":"79","author":"Tong","year":"2002","journal-title":"Optom. Vis. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"568","DOI":"10.1111\/opo.12397","article-title":"Childhood Exposure to Constricted Living Space: A Possible Environmental Threat for Myopia Development","volume":"37","author":"Choi","year":"2017","journal-title":"Ophthalmic Physiol. Opt."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"08006","DOI":"10.7189\/jogh.11.08006","article-title":"Prevalence and Time Trends of Refractive Error in Chinese Children: A Systematic Review and Meta-Analysis","volume":"11","author":"Tang","year":"2021","journal-title":"J. Glob. Health"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Zhang, X., Cheung, S.S.L., Chan, H.-N., Zhang, Y., Wang, Y.M., Yip, B.H., Kam, K.W., Yu, M., Cheng, C.-Y., and Young, A.L. (2021). Myopia Incidence and Lifestyle Changes among School Children during the COVID-19 Pandemic: A Population-Based Prospective Study. Br. J. Ophthalmol., bjophthalmol-2021-319307.","DOI":"10.1136\/bjophthalmol-2021-319307"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1001\/jamaophthalmol.2020.6239","article-title":"Progression of Myopia in School-Aged Children after COVID-19 Home Confinement","volume":"139","author":"Wang","year":"2021","journal-title":"JAMA Ophthalmol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"859285","DOI":"10.3389\/fpubh.2022.859285","article-title":"Trends in Myopia Development among Primary and Secondary School Students during the COVID-19 Pandemic: A Large-Scale Cross-Sectional Study","volume":"10","author":"Mu","year":"2022","journal-title":"Front. Public Health"},{"key":"ref_17","first-page":"19","article-title":"Significant Increase in Astigmatism in Children after Study at Home during the COVID-19 Lockdown","volume":"11","author":"Liang","year":"2022","journal-title":"Clin. Exp. Optom."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1097\/APO.0000000000000486","article-title":"Risk Factors for Myopia in 2 Hong Kong School Systems: A Pilot Study","volume":"11","author":"Liang","year":"2022","journal-title":"Asia-Pac. J. Ophthalmol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1097\/00006324-199706000-00019","article-title":"Power Vectors: An Application of Fourier Analysis to the Description and Statistical Analysis of Refractive Error","volume":"74","author":"Thibos","year":"1997","journal-title":"Optom. Vis. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1007\/s10384-018-0580-y","article-title":"Astigmatism in Chinese Primary School Children: Prevalence, Change, and Effect on Myopic Shift","volume":"62","author":"Chan","year":"2018","journal-title":"Jpn. J. Ophthalmol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"342","DOI":"10.7150\/ijms.7.342","article-title":"Refractive Status and Prevalence of Refractive Errors in Suburban School-Age Children","volume":"7","author":"Pi","year":"2010","journal-title":"Int. J. Med. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1071","DOI":"10.1167\/iovs.03-1151","article-title":"Prevalence, Incidence, and Progression of Myopia of School Children in Hong Kong","volume":"45","author":"Fan","year":"2004","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1097\/00006324-200402000-00007","article-title":"The Prevalence of Astigmatism in Taiwan Schoolchildren","volume":"81","author":"Shih","year":"2004","journal-title":"Optom. Vis. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1097\/00006324-200401000-00010","article-title":"Accuracy of Noncycloplegic Autorefraction in School-Age Children in China","volume":"81","author":"Zhao","year":"2004","journal-title":"Optom. Vis. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2813","DOI":"10.1007\/s00417-021-05305-x","article-title":"Progression of Myopia in a Natural Cohort of Chinese Children during COVID-19 Pandemic","volume":"259","author":"Ma","year":"2021","journal-title":"Graefes Arch. Clin. Exp. Ophthalmol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"723","DOI":"10.1167\/iovs.09-4356","article-title":"Parameters Associated with the Different Astigmatism Axis Orientations","volume":"51","author":"Mandel","year":"2010","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.1016\/S0042-6989(99)00237-0","article-title":"Astigmatism and the Development of Myopia in Children","volume":"40","author":"Gwiazda","year":"2000","journal-title":"Vis. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1097\/00006324-200401000-00012","article-title":"The Association between Spherical and Cylindrical Component Powers","volume":"81","author":"Guggenheim","year":"2004","journal-title":"Optom. Vis. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.exer.2013.02.007","article-title":"An Updated View on the Role of Dopamine in Myopia","volume":"114","author":"Feldkaemper","year":"2013","journal-title":"Exp. Eye Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"491","DOI":"10.1007\/s10654-016-0128-8","article-title":"Low Serum Vitamin D Is Associated with Axial Length and Risk of Myopia in Young Children","volume":"31","author":"Tideman","year":"2016","journal-title":"Eur. J. Epidemiol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2856","DOI":"10.1167\/iovs.11-9091","article-title":"Time Outdoors and Physical Activity as Predictors of Incident Myopia in Childhood: A Prospective Cohort Study","volume":"53","author":"Guggenheim","year":"2012","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1279","DOI":"10.1016\/j.ophtha.2007.12.019","article-title":"Outdoor Activity Reduces the Prevalence of Myopia in Children","volume":"115","author":"Rose","year":"2008","journal-title":"Ophthalmology"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1097\/00006324-200401000-00006","article-title":"Astigmatic Axis Is Related to the Level of Spherical Ametropia","volume":"81","author":"Farbrother","year":"2004","journal-title":"Optom. Vis. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1251","DOI":"10.1016\/j.jfma.2020.04.009","article-title":"Comparison of Open-Field Autorefraction, Closed-Field Autorefraction, and Retinoscopy for Refractive Measurements of Children and Adolescents in Taiwan","volume":"119","author":"Kuo","year":"2020","journal-title":"J. Formos. Med. Assoc."}],"container-title":["Children"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9067\/9\/6\/919\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:35:11Z","timestamp":1760139311000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9067\/9\/6\/919"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,6,19]]},"references-count":34,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2022,6]]}},"alternative-id":["children9060919"],"URL":"https:\/\/doi.org\/10.3390\/children9060919","relation":{},"ISSN":["2227-9067"],"issn-type":[{"value":"2227-9067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,6,19]]}}}