title: Symmetry of optical coherence tomography retinal measurements in young children.
abstract: OBJECTIVE
  To examine symmetry of macular, peripapillary nerve fiber layer (NFL), and optic disk measurements in healthy children.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  We examined a population-based sample of six-year-old children (n = 1,765) in the Sydney Childhood Eye Study. Optical coherence tomography (OCT) scan data for right and left eyes were compared.
  
  
  RESULTS
  High interocular correlations (>0.8) were found for foveal minimum thickness and cup-to-disk ratios. Average NFL thickness was moderately correlated (0.7). Other macular, NFL, and optic disk parameters showed negligible or small mean interocular differences. In 95% of children, interocular difference in macular thickness was <22 microm for foveal minimum and <40 microm for other areas, and 16 to 17 microm for average NFL thickness. Cup-to-disk ratio was highly symmetric, varying by <0.25 in 95% of children.
  
  
  CONCLUSIONS
  Interocular asymmetry of retinal/optic disk parameters should be interpreted in the context of other clinical measures because of the potential for large degrees of asymmetry among individuals.
authors.affiliation: Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia.
authors.forename: Son C
authors.initials: SC
authors.lastname: Huynh
authors.forename: Xiu Ying
authors.initials: XY
authors.lastname: Wang
authors.forename: George
authors.initials: G
authors.lastname: Burlutsky
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D000886:Anthropometry; D001699:Biometry; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009412:Nerve Fibers; D009898:Optic Disk / Q000033:anatomy & histology*; D009900:Optic Nerve / Q000033:anatomy & histology*; D012160:Retina / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence