{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T13:04:04Z","timestamp":1785416644785,"version":"3.56.0"},"reference-count":27,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T00:00:00Z","timestamp":1784160000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Seoul Metropolitan Government","award":["0720234027"],"award-info":[{"award-number":["0720234027"]}]},{"award":["0720234027"],"award-info":[{"award-number":["0720234027"]}],"id":[{"id":"https:\/\/ror.org\/002wfgr58","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004332","name":"Seoul National University Hospital","doi-asserted-by":"publisher","award":["3020230260"],"award-info":[{"award-number":["3020230260"]}],"id":[{"id":"10.13039\/501100004332","id-type":"DOI","asserted-by":"publisher"}]},{"award":["3020230260"],"award-info":[{"award-number":["3020230260"]}],"id":[{"id":"https:\/\/ror.org\/01z4nnt86","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Digital device use has substantially altered children\u2019s visual environments, yet the specific behaviors associated with axial elongation and early retinal remodeling remain unclear in highly urbanized settings. This study investigated biological and behavioral correlates of axial length (AL) and associated macular microstructural changes in preadolescent children. Participants underwent ophthalmic examinations and completed questionnaires assessing lifestyle and digital device use factors. Multivariable linear mixed-effects models identified factors associated with AL and macular thickness. The participant-level prevalence of myopia, defined as spherical equivalent \u2264 \u22120.50 D, was 53.2% and increased from 37.1% in Grade 1 to a peak of 78.7% in Grade 4. Older age, a greater number of myopic parents, flatter corneal curvature, male sex, continuous smart device use exceeding 1 h per session, and viewing distance &lt; 30 cm were independently associated with longer AL. Each 1 mm increase in AL was associated with significant subfoveal choroidal thinning and generalized extrafoveal macular thinning, whereas the central fovea remained relatively preserved. Pediatric AL was associated with hereditary susceptibility, specific digital viewing behaviors, and early extrafoveal retinal structural variation.<\/jats:p>","DOI":"10.3390\/life16071174","type":"journal-article","created":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T08:08:34Z","timestamp":1784189314000},"page":"1174","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Behavioral and Structural Correlates of Axial Length in School-Aged Children: Baseline Findings from the Seoul Myopia Cohort Study"],"prefix":"10.3390","volume":"16","author":[{"given":"Ju-Yeun","family":"Lee","sequence":"first","affiliation":[{"name":"Department of Ophthalmology, Boston Children\u2019s Hospital, Harvard Medical School, Boston, MA 02115, USA"},{"name":"Department of Preventive Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chang Hwan","family":"Lee","sequence":"additional","affiliation":[{"name":"Kim\u2019s Retina Clinic, Cheonan 31127, Republic of Korea"},{"name":"Department of Ophthalmology, Seoul National University Hospital, 101, Daehak-Ro, Jongno-Gu, Seoul 03080, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9007-7025","authenticated-orcid":false,"given":"Kyungsik","family":"Kim","sequence":"additional","affiliation":[{"name":"Cancer Research Institute, Seoul National University, Seoul 03080, Republic of Korea"},{"name":"Institute of Environmental Medicine, Seoul National University Medical Research Center, Seoul 03080, Republic of Korea"},{"name":"Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3588-4497","authenticated-orcid":false,"given":"Un Chul","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Seoul National University Hospital, 101, Daehak-Ro, Jongno-Gu, Seoul 03080, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kunho","family":"Bae","sequence":"additional","affiliation":[{"name":"Department of Preventive Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea"},{"name":"Department of Ophthalmology, Seoul National University Hospital, 101, Daehak-Ro, Jongno-Gu, Seoul 03080, Republic of Korea"},{"name":"Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA"},{"name":"Biomedical Research Institute, Seoul National University Hospital, 101, Daehak-Ro, Jongno-Gu, Seoul 03080, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1036","DOI":"10.1016\/j.ophtha.2016.01.006","article-title":"Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050","volume":"123","author":"Holden","year":"2016","journal-title":"Ophthalmology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.preteyeres.2017.09.004","article-title":"The epidemics of myopia: Aetiology and prevention","volume":"62","author":"Morgan","year":"2018","journal-title":"Prog. 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