title: Ocular dominance, laterality, and refraction in Singaporean children.
abstract: OBJECTIVE
  To explore the effect of dominance and laterality on refractive error and axial length.
  
  
  METHODS
  Ocular dominance was assessed with the hole-in-the-card test in 543 children during their 2006 follow-up visits for the Singapore Cohort study Of the Risk factors for Myopia (SCORM). Data were compared to cycloplegic refractions and axial lengths measured by ultrasound.
  
  
  RESULTS
  The spherical equivalent refraction was essentially the same between the right and left eyes, although there was a small but statistically significant longer axial length in the right eyes. Right and left ocular dominance was noted in 58% and 30% of the subjects, respectively, with 12% having no eye preference. There was no significant difference in spherical equivalent refraction (2.56 +/- 2.46 D [mean +/- SD] vs. -2.45 +/- 2.52 D, P = 0.22) or axial length (24.36 +/- 1.19 mm vs. 24.32 +/- 1.18 mm, P = 0.05) between dominant and nondominant eyes. In subjects with anisometropia >or=0.5 D, dominant eyes were more myopic in 52%. Dominant eyes, however, had less astigmatic power (-0.88 +/- 0.80 D versus -1.00 +/- 0.92 D; P < 0.001).
  
  
  CONCLUSIONS
  Ocular laterality and dominance have no significant effect on spherical equivalent. All axial length and astigmatic differences were small and clinically insignificant. The study findings suggest that in Singaporean children, bias is not present in those investigations that restrict analyses to right or left eyes. Although there is no apparent association between refraction and ocular dominance in young Singaporean children, more research is needed to resolve the disparate results in existing reports.
authors.affiliation: Singapore Eye Research Institute, Singapore. wla_chia@yahoo.com
authors.forename: Audrey
authors.initials: A
authors.lastname: Chia
authors.forename: Arlie
authors.initials: A
authors.lastname: Jaurigue
authors.forename: Gus
authors.initials: G
authors.lastname: Gazzard
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Wang
authors.forename: Donald
authors.initials: D
authors.lastname: Tan
authors.forename: Richard A
authors.initials: RA
authors.lastname: Stone
authors.forename: Seang Mei
authors.initials: SM
authors.lastname: Saw
mesh_terms: D000293:Adolescent; D015858:Anisometropia / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D044466:Asian People; D001251:Astigmatism / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D002648:Child; D015331:Cohort Studies; D023882:Dominance, Ocular; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology