title: Impact of ethnicity on the correlation of retinal parameters with axial length.
abstract: OBJECTIVE
  To examine whether the relationship of axial length (AL) to retinal nerve fiber layer (RNFL) and macular parameters measured by optical coherence tomography (OCT) differs according to ethnicity.
  
  
  METHODS
  As part of the Sydney Myopia Study, 2353 children from grade 7 (age range, 11.1-14.4 years) completed detailed ocular examinations in the 2004-2005 school year. AL was measured with noncontact interferometry and Stratus OCT was performed (Carl Zeiss Meditec, Jena, Germany).
  
  
  RESULTS
  East Asian children displayed larger AL correlations with average RNFL, inferior RNFL, nasal RNFL, outer macula, and macular volume (r = -0.25, -0.36, -0.31, -0.35, and -0.31 respectively; P < 0.001) than did Caucasian children (r = -0.14, -0.20, -0.12, -0.17, and -0.13 respectively; P < 0.001). Positive correlations between the temporal RNFL and AL were found only among East Asian and South Asian children (r = 0.28, P < 0.001; and r = 0.27, P = 0.03, respectively). In Caucasian children, the foveal minimum and central macula correlated significantly with AL (r = 0.11 and r = 0.13, respectively, P ≤ 0.001).
  
  
  CONCLUSIONS
  Retinal parameters measured by OCT correlated with AL, and the extent of this correlation varied by ethnicity. It may therefore be that ethnicity should be considered when interpreting OCT scans on individuals with AL outside the usual range.
authors.affiliation: Centre for Vision Research, Department of Ophthalmology, and Westmead Millennium Institute, University of Sydney, Sydney, Australia.
authors.forename: Yasser M
authors.initials: YM
authors.lastname: Tariq
authors.forename: Chameen
authors.initials: C
authors.lastname: Samarawickrama
authors.forename: Amy
authors.initials: A
authors.lastname: Pai
authors.forename: George
authors.initials: G
authors.lastname: Burlutsky
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D000293:Adolescent; D000886:Anthropometry; D002648:Child; D005006:Ethnicity; D005123:Eye / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007368:Interferometry; D008297:Male; D009412:Nerve Fibers; D009898:Optic Disk / Q000033:anatomy & histology*; D012165:Retinal Ganglion Cells / Q000166:cytology*; D011795:Surveys and Questionnaires; D041623:Tomography, Optical Coherence; D014792:Visual Acuity