title: Ethnicity-specific prevalences of refractive errors vary in Asian children in neighbouring Malaysia and Singapore.
abstract: OBJECTIVE
  To compare the prevalences of refractive errors in Malay, Chinese and Indian children in Malaysia and Singapore.
  
  
  METHODS
  Children aged 7-9 years from three schools in the Singapore Cohort study of the Risk factors for Myopia (n = 1962) and similarly aged children from a random cluster sample in the metropolitan Kuala Lumpur area in the Malaysia Refractive Error Study in Children (n = 1752) were compared. Cycloplegic autorefraction was conducted in both countries.
  
  
  RESULTS
  The prevalence of myopia (spherical equivalent of at least -0.5 diopters (D) in either eye) was higher in Singapore Malays (22.1%) than in Malays in Malaysia (9.2%; 95% confidence interval (CI) 11.2 to 14.7; p<0.001). Similarly, Singapore Chinese (40.1%) had higher prevalences than Malaysian Chinese (30.9%; 95% CI 1.5 to 16.9). Singapore Indians had a higher prevalence (34.1%) than Malaysian Indians (12.5%; 95% CI 17.4 to 25.9). The multivariate odds ratio of astigmatism (cylinder at least 0.75 D in either eye) in Singapore Malays compared with Malaysian Malays was 3.47 (95% CI 2.79 to 4.32). Ethnicity-specific hyperopia rates did not differ in Singapore and Malaysia.
  
  
  CONCLUSIONS
  The ethnicity-specific prevalences of myopia in Singapore Malays, Chinese and Indians are higher than those in Malaysian Malays, Chinese and Indians. As Malays, Chinese and Indians in Malaysia have genetic make-up similar to that of Malays, Chinese and Indians in Singapore, environmental factors may contribute to the higher myopia rates.
authors.affiliation: Department of Community, Occupational and Family Medicine, National University of Singapore, Singapore, Singapore. cofsawsm@nus.edu.sg
authors.forename: S-M
authors.initials: SM
authors.lastname: Saw
authors.forename: P-P
authors.initials: PP
authors.lastname: Goh
authors.forename: A
authors.initials: A
authors.lastname: Cheng
authors.forename: A
authors.initials: A
authors.lastname: Shankar
authors.forename: D T H
authors.initials: DT
authors.lastname: Tan
authors.forename: L B
authors.initials: LB
authors.lastname: Ellwein
mesh_terms: D044466:Asian People / Q000706:statistics & numerical data; D001251:Astigmatism / Q000208:ethnology; D002648:Child; D004522:Educational Status; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000208:ethnology; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D009216:Myopia / Q000208:ethnology; D015995:Prevalence; D012030:Refractive Errors / Q000208:ethnology*; D012846:Singapore / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data