title: Effects of refraction and axial length on childhood optic disk parameters measured by optical coherence tomography.
abstract: OBJECTIVE
  To assess the effects of refraction and axial length on optical coherence tomography (OCT) measures of childhood optic disk parameters.
  
  
  METHODS
  Population-based cross-sectional study.
  
  
  METHODS
  Of 4,118 children examined in the Sydney Myopia Study (Sydney Childhood Eye Study) from 34 randomly selected primary schools and 21 secondary schools from 2003 through 2005, 3,529 (85.7%) were included in the analysis (1,395 6-year-old children [year 1 students] and 2,134 12-year-old children [year 7 students]). Comprehensive standardized eye examinations included best-corrected visual acuity, cycloplegic autorefraction, biometry measurements, and fast optic disk scans using OCT.
  
  
  RESULTS
  After adjusting for magnification, the mean optic disk area was positively associated with axial length (P(trend) < .0001, both age groups) but was not associated consistently with spherical equivalent refraction (SER).
  
  
  CONCLUSIONS
  Optic disk parameters in childhood are influenced by axial length, but not by refractive error itself.
authors.affiliation: Centre for Vision Research, Department of Ophthalmology, University of Sydney, Westmead Millennium Institute, Westmead Hospital, New South Wales, Australia.
authors.forename: Chameen
authors.initials: C
authors.lastname: Samarawickrama
authors.forename: Xiu Ying
authors.initials: XY
authors.lastname: Wang
authors.forename: Son C
authors.initials: SC
authors.lastname: Huynh
authors.forename: George
authors.initials: G
authors.lastname: Burlutsky
authors.forename: Fiona
authors.initials: F
authors.lastname: Stapleton
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D001699:Biometry; D001837:Body Weights and Measures; D002648:Child; D003430:Cross-Sectional Studies; D005123:Eye / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000473:pathology; D008297:Male; D009216:Myopia / Q000473:pathology; D009898:Optic Disk / Q000033:anatomy & histology*; D012029:Refraction, Ocular / Q000502:physiology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity