{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T18:30:52Z","timestamp":1790274652619,"version":"4.1.0"},"reference-count":45,"publisher":"BMJ","issue":"12","license":[{"start":{"date-parts":[[2023,12,30]],"date-time":"2023-12-30T00:00:00Z","timestamp":1703894400000},"content-version":"unspecified","delay-in-days":29,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the National Key R&D Program of China","award":["2020YFC2008200"],"award-info":[{"award-number":["2020YFC2008200"]}]},{"name":"the National Key R&D Program of China","award":["2021YFC2702100"],"award-info":[{"award-number":["2021YFC2702100"]}]},{"name":"Capital\u2019s Funds for Health Improvement and Research","award":["2022-1G-4083"],"award-info":[{"award-number":["2022-1G-4083"]}]},{"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":[[2023,11,27]]},"published-print":{"date-parts":[[2023,12]]},"abstract":"<jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>This study aims to investigate the associations of axial length to corneal radius of curvature (AL\/CRC) ratio with refractive error and to determine the effect of AL\/CRC ratio on hyperopia reserve and myopia assessment among Chinese preschoolers.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>This was a retrospective cross-sectional study that evaluated subjects aged 4\u20136 years. AL and CRC were obtained using a non-contact ocular biometer. Correlation analysis was performed to explore the associations of AL\/CRC ratio with spherical equivalent refractive error (SER). The accuracy of AL\/CRC ratio for hyperopia reserve and myopia assessment was analysed using cycloplegic refraction by drawing receiver operating characteristic (ROC) curves.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>The analysis included 1024 participants (537 boys, 52.4%). The mean AL\/CRC ratios in hyperopes, emmetropes and myopes were 2.90\u00b10.06, 2.95\u00b10.05\u2009and 3.08\u00b10.07, respectively. The SER was found to be more strongly correlated with AL\/CRC ratio (\u03c1=\u22120.66, p&lt;0.001) than either AL or CRC alone (\u03c1=\u22120.52, p&lt;0.001; \u03c1=\u22120.03, p=0.33, respectively). AL\/CRC was correlated with SER in hyperopes (\u03c1=\u22120.54, p&lt;0.001), emmetropes (\u03c1=\u22120.33, p&lt;0.001) and myopes (r=\u22120.67, p&lt;0.001). For low hyperopia reserve assessment, the area under the ROC curves of AL\/CRC ratio was 0.861 (95% CI 0.829 to 0.892), the optimal cut-off value of the AL\/CRC ratio was \u22652.955. For myopia assessment, the area under the ROC curves of AL\/CRC ratio was 0.954 (95% CI 0.925 to 0.982), the optimal cut-off value of the AL\/CRC ratio was \u22652.975.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>The SER showed a better correlation with AL\/CRC ratio than either AL or CRC alone, especially in myopes, among children aged 4\u20136 years. These findings indicate that when cycloplegic refraction is unavailable, AL\/CRC ratio could be used as an alternative indicator for identifying low hyperopia reserve and myopia among preschoolers, helping clinicians and parents screen children with low hyperopia reserve before primary school in a timely manner.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjopen-2023-075115","type":"journal-article","created":{"date-parts":[[2023,12,30]],"date-time":"2023-12-30T08:51:22Z","timestamp":1703926282000},"page":"e075115","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":17,"title":["Axial length to corneal radius of curvature ratio and refractive error in Chinese preschoolers aged 4\u20136 years: a retrospective cross-sectional study"],"prefix":"10.1136","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2876-9543","authenticated-orcid":false,"given":"Tao","family":"Tang","sequence":"first","affiliation":[{"name":"Institute of Medical Technology, Peking University Health Science Center, Beijing, China"},{"name":"Department of Ophthalmology & Clinical Centre of Optometry, Peking University People\u2019s Hospital, Beijing, China"},{"name":"College of Optometry, Peking University Health Science Center, Beijing, China"},{"name":"Eye Disease and Optometry Institute, Peking University People\u2019s Hospital, Beijing, China"},{"name":"Beijing Key Laboratory of the Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heng","family":"Zhao","sequence":"additional","affiliation":[{"name":"Institute of Medical Technology, Peking University Health Science Center, Beijing, China"},{"name":"Department of Ophthalmology & Clinical Centre of Optometry, Peking University People\u2019s Hospital, Beijing, China"},{"name":"College of Optometry, Peking University Health Science Center, Beijing, China"},{"name":"Eye Disease and Optometry Institute, Peking University People\u2019s Hospital, Beijing, China"},{"name":"Beijing Key Laboratory of the Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Duanke","family":"Liu","sequence":"additional","affiliation":[{"name":"Institute of Medical Technology, Peking University Health Science Center, Beijing, China"},{"name":"Department of Ophthalmology & Clinical Centre of Optometry, Peking University People\u2019s Hospital, Beijing, China"},{"name":"College of Optometry, Peking University Health Science Center, Beijing, China"},{"name":"Eye Disease and Optometry Institute, Peking University People\u2019s Hospital, Beijing, China"},{"name":"Beijing Key Laboratory of the Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuewei","family":"Li","sequence":"additional","affiliation":[{"name":"Institute of Medical Technology, Peking University Health Science Center, Beijing, China"},{"name":"Department of Ophthalmology & Clinical Centre of Optometry, Peking University People\u2019s Hospital, Beijing, China"},{"name":"College of Optometry, Peking University Health Science Center, Beijing, China"},{"name":"Eye Disease and Optometry Institute, Peking University People\u2019s Hospital, Beijing, China"},{"name":"Beijing Key Laboratory of the Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4171-825X","authenticated-orcid":false,"given":"Kai","family":"Wang","sequence":"additional","affiliation":[{"name":"Institute of Medical Technology, Peking University Health Science Center, Beijing, 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