title: Axial Length and Associated Factors in Children: The Shandong Children Eye Study.
abstract: To investigate ocular axial length (AL) in Chinese children.
  
  
  
  The Shandong Children Eye Study included 6,364 children aged 4-18 years.
  
  
  
  Longer AL (mean 23.45 ± 1.20 mm, range 18.80-28.59 mm) was associated (multivariate analysis; correlation coefficient r2: 0.61) with older age (p < 0.001, standardized correlation coefficient β = 0.35, unstandardized regression coefficient B = 0.13, 95% confidence interval [CI] 0.12, 0.15), male gender (p < 0.001, β = -0.24, B = -0.10, 95% CI -0.29, -0.19), urban region (p < 0.001, β = 0.10, B = 0.25, 95% CI 0.20, 0.31), body height (p < 0.001, β = 0.22, B = 0.02, 95% CI 0.01, 0.02), maternal education (p < 0.001, β = 0.07, B = 0.07, 95% CI 0.05, 0.10), paternal myopia (p < 0.001, β = 0.09, B = 0.26, 95% CI 0.20, 0.33), maternal myopia (p < 0.001, β = 0.08, B = 0.23, 95% CI 0.17, 0.30), more time spent indoors reading/writing (p < 0.001, β = 0.05, B = 0.03, 95% CI 0.02, 0.04), less time spent outdoors (p = 0.005, β = -0.03, B = -0.01, 95% CI -0.02, -0.003), longer corneal curvature radius (p < 0.001, β = 0.36, B = 1.63, 95% CI 1.53, 1.74) and higher intraocular pressure (p = 0.008, β = 0.03, B = 0.01, 95% CI 0.004, 0.02). High axial myopia (AL ≥26.0 mm) present in 202 children (3.4 ± 0.2%, 95% CI 2.92, 3.84) was associated with less time spent outdoors (p = 0.002, odds ratio 0.92, 95% CI 0.87, 0.97) in multivariate analysis.
  
  
  
  In children in the less developed Eastern Chinese province of Shandong, the prevalence of high axial myopia was >10% among 16-year-olds. A modifiable factor associated with higher prevalence of high axial myopia was less time spent outdoors.
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China.
authors.forename: Tai Liang
authors.initials: TL
authors.lastname: Lu
authors.forename: Jian Feng
authors.initials: JF
authors.lastname: Wu
authors.forename: Xiang
authors.initials: X
authors.lastname: Ye
authors.forename: Yuan Yuan
authors.initials: YY
authors.lastname: Hu
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Da Dong
authors.initials: DD
authors.lastname: Guo
authors.forename: Xing Rong
authors.initials: XR
authors.lastname: Wang
authors.forename: Hong Sheng
authors.initials: HS
authors.lastname: Bi
authors.forename: Jost B
authors.initials: JB
authors.lastname: Jonas
mesh_terms: D000293:Adolescent; D000367:Age Factors; D058452:Axial Length, Eye; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D009216:Myopia / Q000453:epidemiology* / Q000473:pathology; D011159:Population Surveillance; D012424:Rural Population / Q000706:statistics & numerical data*; D012737:Sex Factors; D014505:Urban Population / Q000706:statistics & numerical data*