title: Ocular component data in schoolchildren as a function of age and gender.
abstract: OBJECTIVE
  To describe the refractive error and ocular components of a large group of school-aged children as a function of age and gender.
  
  
  METHODS
  In this report, we describe the refractive error and ocular components of 2583 school-aged children (49.3% girls, overall mean [+/-SD] age 10.0 +/- 2.3). Measurement methods included cycloplegic autorefraction, autokeratometry, videophakometry, and A-scan ultrasonography. For statistical comparisons across gender and age, a critical point of alpha = 0.005 was used to assess significance because of the large sample size and the large number of comparisons made.
  
  
  RESULTS
  Of these 2583 children, 10.1% were myopic (-0.75 D or more myopia in both meridians), and 8.6% were hyperopic (+1.25 D or more hyperopia in both meridians). As would be expected, there was a significant effect of age on refractive error (spherical equivalent, p < 0.0001), toward less hyperopia/more myopia. There was no significant difference in the average refractive error between girls and boys (p = 0.0192). Girls had steeper corneas than boys (0.74 D steeper in the vertical meridian and 0.63 D steeper in the horizontal meridian, p < 0.0001). There were no significant differences in corneal power with age (p = 0.16). Both older age and male gender were significantly associated with deeper anterior chambers (p < 0.0001 for both). The crystalline lens showed significant thinning with age (p < 0.0001), however, there was no significant difference in the lens thickness between girls and boys (p = 0.66). Both Gullstrand lens power and calculated lens power showed significant effects of age and gender (p < 0.0001 for both). Girls, on average, had Gullstrand lens powers that were 0.28 D steeper and calculated lens powers that were 0.80 D more powerful than boys. Axial length also showed significant effects of age and gender (p < 0.0001 for both). Girls' eyes were, on average, 0.32 mm shorter than those of boys.
  
  
  CONCLUSIONS
  These cross-sectional data show a general pattern of ocular growth, no change in corneal power, and crystalline lens thinning and flattening between the ages of 6 and 14 years. Girls tended to have steeper corneas, stronger crystalline lenses, and shorter eyes compared with boys.
authors.affiliation: The Ohio State University College of Optometry, Columbus, 43210-1240, USA. zadnik.4@osu.edu
authors.forename: Karla
authors.initials: K
authors.lastname: Zadnik
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Manny
authors.forename: Julie A
authors.initials: JA
authors.lastname: Yu
authors.forename: G Lynn
authors.initials: GL
authors.lastname: Mitchell
authors.forename: Susan A
authors.initials: SA
authors.lastname: Cotter
authors.forename: Julio C
authors.initials: JC
authors.lastname: Quiralte
authors.forename: Melvin
authors.initials: M
authors.lastname: Shipp
authors.forename: Nina E
authors.initials: NE
authors.lastname: Friedman
authors.forename: Robert  N
authors.initials: R
authors.lastname: Kleinstein
authors.forename: Terry W
authors.initials: TW
authors.lastname: Walker
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Jones
authors.forename: Melvin L
authors.initials: ML
authors.lastname: Moeschberger
authors.forename: Donald O
authors.initials: DO
authors.lastname: Mutti
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000886:Anthropometry / Q000379:methods; D002648:Child; D019781:Corneal Topography; D005123:Eye / Q000254:growth & development*; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000175:diagnosis / Q000503:physiopathology; D012737:Sex Factors; D015351:Vision Screening / Q000379:methods; D014792:Visual Acuity / Q000502:physiology