{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,24]],"date-time":"2026-01-24T14:22:50Z","timestamp":1769264570783,"version":"3.49.0"},"reference-count":35,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2023,1,25]],"date-time":"2023-01-25T00:00:00Z","timestamp":1674604800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Background<\/jats:title>\n<jats:p>To explore an influence of the COVID-19-related lockdown on ocular axial elongation in school children in Russia.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>The participants of the school-based Ufa Children Myopia Study in Ufa\/Russia underwent, at baseline in 2019\/2020 before the COVID-19 outbreak and after a COVID-19-related lockdown, a detailed interview and ophthalmological examination including laser interferometric biometry for axial length measurement.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>The study included 461 children (age:10.7\u00b12.1 years;range:6.8\u201316.9 years). The mean follow-up was 1.41\u00b10.33 years. Mean axial length at baseline was 23.96\u00b10.95mm and 23.94\u00b10.95mm in the right and left eyes, respectively. During the study period, annual axial elongation (right\/left eyes) was 0.19\u00b10.17mm\/0.19\u00b10.22mm. Before the COVID-19 lockdown, the age-dependent coefficient for axial length (ADCAL) for the right\/left eyes was 0.21mm (95%CI:0.17,0.25)\/0.20mm (95%CI:0.16,0.24). In children younger than 9.6 years (n = 157), annual axial elongation (right eyes) during the study period was larger than the ADCAL before the COVID-19 outbreak (0.29 mm (95%:0.00,0.66) versus 0.21 mm (95%CI:0.02,0.41)). In the groups aged 9.6 to 11.4 years (n = 148) and aged &gt;11.4 years (n = 156), annual axial elongation during the study period was comparable to the ADCAL before the COVID-19 outbreak (0.18mm (95%CI:-0.07,0.46) versus 0.22mm (95%CI:-0.05,0.48), and (0.09mm (95%CI:-0.15,0.34) versus 0.14mm (95%CI:0.00,0.28), respectively). In children aged \u22649 years at study end, axial length at study end was 0.20 mm larger than axial length at baseline in the participants aged \u22649 years at baseline. Larger axial elongation during the study period was associated (multivariable analysis) with younger age (beta:-0.62;<jats:italic>P<\/jats:italic>&lt;0.001), female sex (beta:0.21;<jats:italic>P<\/jats:italic>&lt;0.001), longer study period (beta:0.22;<jats:italic>P<\/jats:italic>&lt;0.001), and longer axial length at baseline (beta:0.28;<jats:italic>P<\/jats:italic>&lt;0.001), and marginally, with less time spent outdoors (beta:-0.07;<jats:italic>P<\/jats:italic> = 0.06).<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusions<\/jats:title>\n<jats:p>The COVID-19-related lockdown in the Russian city of Ufa was associated with a relatively minor increase in axial elongation, detected only in children aged &lt;9.6 years.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0279020","type":"journal-article","created":{"date-parts":[[2023,1,25]],"date-time":"2023-01-25T18:34:25Z","timestamp":1674671665000},"page":"e0279020","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":9,"title":["Myopic axial elongation in school children and the COVID-19 lockdown in Russia: The Ural Children Myopia Study"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9476-8883","authenticated-orcid":true,"given":"Mukharram M.","family":"Bikbov","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gyulli M.","family":"Kazakbaeva","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Albina 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