title: Corneal diameter and associated parameters in Chinese children: the Shandong Children Eye Study.
abstract: BACKGROUND
  To assess the corneal diameter and its associations in children.
  
  
  METHODS
  Cross-sectional school-based study.
  
  
  METHODS
  Six thousand twenty-six children aged 4-18 years were included in the Shandong Children Eye Study.
  
  
  METHODS
  Horizontal corneal diameter was measured by laser interferometry-based ocular biometry.
  
  
  METHODS
  Horizontal corneal diameter.
  
  
  RESULTS
  Corneal diameter measurements were available for 5970 (99.1%) children. In multivariate analysis, larger horizontal corneal diameter (mean: 12.02 ± 0.38 mm; range: 10.1-15.0 mm) was associated with longer corneal curvature radius longer axial length, male gender, younger maternal age, rural region of habitation and lower intraocular pressure measurements. Higher prevalence of abnormally large corneas (macrocorneas; horizontal diameter ≥ 12.76 mm; mean value +2  ×  standard deviations; mean: 2.6%; 95% CI: 2.2, 3.0) was associated with longer corneal curvature radius, longer axial length, younger maternal age and male gender. Higher prevalence of abnormally small corneas (horizontal diameter ≤ 11.24mm; mean value -2 × standard deviations; mean: 2.4%; 95% CI: 2.0, 2.8) was correlated with shorter corneal curvature radius, shorter axial length and urban region of habitation. Neither abnormally large nor small corneas were correlated with time spent indoors/outdoors.
  
  
  CONCLUSIONS
  In 4 to 18-year-old children, larger corneal diameter was associated most strongly with flatter corneal curvature, followed by longer axial length and male gender. Corneal diameter was independent of age beyond an age of 4 years. Abnormally large and abnormally small corneas may be defined as being ≥12.76 and ≤11.24 mm in diameter, respectively. Corneal diameter was not correlated with time spent indoors/outdoors.
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Wen Jun
authors.initials: WJ
authors.lastname: Jiang
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.affiliation: Medical School of Ophthalmology and Optometry, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Jian Feng
authors.initials: JF
authors.lastname: Wu
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Yuan Yuan
authors.initials: YY
authors.lastname: Hu
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Tai Liang
authors.initials: TL
authors.lastname: Lu
authors.affiliation: The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Da Dong
authors.initials: DD
authors.lastname: Guo
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Xing Rong
authors.initials: XR
authors.lastname: Wang
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China.
authors.forename: Hong Sheng
authors.initials: HS
authors.lastname: Bi
authors.affiliation: Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University Heidelberg, Mannheim, Germany.
authors.forename: Jost B
authors.initials: JB
authors.lastname: Jonas
mesh_terms: D000293:Adolescent; D058452:Axial Length, Eye; D001699:Biometry; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003315:Cornea / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007368:Interferometry; D007429:Intraocular Pressure; D008297:Male; D009216:Myopia / Q000453:epidemiology*; D015995:Prevalence; D012029:Refraction, Ocular / Q000502:physiology*; D012424:Rural Population; D012574:Schools; D014505:Urban Population
keywords: Shandong Children Eye Study; corneal diameter; corneal size; macrocornea; microcornea