{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T14:40:59Z","timestamp":1788273659401,"version":"build-2803163510"},"reference-count":43,"publisher":"BMJ","issue":"12","license":[{"start":{"date-parts":[[2024,12,18]],"date-time":"2024-12-18T00:00:00Z","timestamp":1734480000000},"content-version":"unspecified","delay-in-days":17,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Capital's Funds for Health Improvement and Research","award":["No. 2022-1G-4083"],"award-info":[{"award-number":["No. 2022-1G-4083"]}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["No.2021YFC2702100"],"award-info":[{"award-number":["No.2021YFC2702100"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82171092"],"award-info":[{"award-number":["82171092"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82371087"],"award-info":[{"award-number":["82371087"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2024,11,8]]},"published-print":{"date-parts":[[2024,12]]},"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To examine the ocular biometric parameters and predict the annual growth rate of the physiological axial length (AL) in Chinese preschool children aged 4\u20136 years old.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This retrospective cross-sectional study included 1090 kindergarten students (1090 right eyes) between the ages of 4 and 6 years from Pinggu and Chaoyang District, Beijing. Dioptre values were ascertained following cycloplegic autorefraction. Predicted AL was obtained through the application of the Gaussian process regression model as an optimisation technique. Subsequently, the annual growth rate of physiological AL for non-myopic preschool children (n=1061) was computed via the backward difference method.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>In total, 85.4% of preschool children (931 individuals) had hyperopic refractive status in the 4\u20136 years age group, while only 2.7% (29 individuals) showed myopia. Boys had longer AL, larger AL-to-corneal radius ratio, deeper anterior chamber depth and lower lens power. The average physiological axial growth for boys and girls ranged from 0.050 mm\/year to 0.165\u2009mm\/year and 0.063 mm\/year to 0.168\u2009mm\/year, respectively. As age increased, the physiological AL growth in non-myopic cases decreased. Additionally, as hyperopic spherical equivalent refraction error lessened, the physiological AL growth component slowed down.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In preschool children, refractive development predominantly exhibits mild hyperopia. The concept of physiological AL provides valuable insights into the complexities of ocular development.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2024-084891","type":"journal-article","created":{"date-parts":[[2024,12,24]],"date-time":"2024-12-24T02:57:57Z","timestamp":1735009077000},"page":"e084891","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":4,"title":["Ocular biometric parameters in Chinese preschool children and physiological axial length growth prediction using machine learning algorithms: a retrospective cross-sectional study"],"prefix":"10.1136","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3153-0923","authenticated-orcid":false,"given":"Duanke","family":"Liu","sequence":"first","affiliation":[{"name":"Department of Ophthalmology & Clinical Centre of Optometry, Peking University People's Hospital, Beijing, China"},{"name":"Institute of Medical Technology, Peking University 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