title: Peripheral refraction in different ethnicities.
abstract: OBJECTIVE
  Peripheral refraction is commonly used to infer retinal shape. Because of the different prevalence of myopia in the white compared with East Asian populations, peripheral refraction along the horizontal meridian was compared in white and East Asian young adults with emmetropic, low myopic, and moderately myopic refractive errors.
  
  
  METHODS
  Thirty-five white and 37 East Asian subjects were recruited with central refraction between +1.00 DS and -5.50 DS and ≤ -1.50 DC. Central and peripheral noncycloplegic autorefraction was measured along the horizontal meridian at 5° intervals up to ± 35°, and corneal topography maps were also quantified.
  
  
  RESULTS
  There were no significant differences between whites and East Asians in peripheral refraction profiles in the emmetrope and low myope groups, which had peripheral myopic and emmetropic refraction, respectively. However, in the moderate myope group, there was a statistically significant difference between whites and East Asians in peripheral refraction, which was generally hyperopic. East Asian moderate myopes had more relative peripheral hyperopia than did whites of similar central refractive error. Corneal shape and power were comparable between white and East Asian subjects in the three refractive groups.
  
  
  CONCLUSIONS
  East Asian moderate myopes have a greater degree of relative peripheral hyperopia and hence a more prolate ocular shape than do white subjects of similar central refractive error. Differences in ocular shape may play a role in the greater propensity for East Asians to develop and progress in myopia compared with whites.
authors.affiliation: School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors.forename: Pauline
authors.initials: P
authors.lastname: Kang
authors.forename: Paul
authors.initials: P
authors.lastname: Gifford
authors.forename: Philomena
authors.initials: P
authors.lastname: McNamara
authors.forename: Jenny
authors.initials: J
authors.lastname: Wu
authors.forename: Stephanie
authors.initials: S
authors.lastname: Yeo
authors.forename: Bonney
authors.initials: B
authors.lastname: Vong
authors.forename: Helen
authors.initials: H
authors.lastname: Swarbrick
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000208:ethnology*; D003315:Cornea / Q000473:pathology; D019781:Corneal Topography; D058453:Emmetropia / Q000502:physiology*; D006801:Humans; D009216:Myopia / Q000208:ethnology*; D012029:Refraction, Ocular / Q000502:physiology*; D044465:White People / Q000208:ethnology*; D055815:Young Adult