title: Family history, near work, outdoor activity, and myopia in Singapore Chinese preschool children.
abstract: OBJECTIVE
  To investigate the risk factors for myopia, including near work and outdoor activity, in Singapore Chinese preschool children.
  
  
  METHODS
  A cross-sectional study, with disproportionate random sampling by 6-month age groups, of 3009 Singapore Chinese children aged 6-72 months was performed. Information on family history, near work and outdoor activity was obtained. Spherical equivalent refraction (SER) was assessed.
  
  
  RESULTS
  Children with two myopic parents were more likely to be myopic (adjusted OR=1.91; 95% CI 1.38 to 2.63) and to have a more myopic SER (regression coefficient=-0.35; 95% CI -0.47 to -0.22) than children without myopic parents. For each 1 cm taller height, the SER was more myopic by 0.01 dioptres. Neither near work nor outdoor activity was associated with preschool myopia.
  
  
  CONCLUSIONS
  A family history of myopia was the strongest factor associated with preschool myopia. In contrast, neither near work nor outdoor activity was found to be associated with early myopia. These data suggest that genetic factors may play a more substantial role in the development of early-onset myopia than key environmental factors.
authors.affiliation: Department of Epidemiology and Public Health, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive (MD3), Singapore 117597.
authors.forename: Wilson
authors.initials: W
authors.lastname: Low
authors.forename: Mohamed
authors.initials: M
authors.lastname: Dirani
authors.forename: Gus
authors.initials: G
authors.lastname: Gazzard
authors.forename: Yiong-Huak
authors.initials: YH
authors.lastname: Chan
authors.forename: Hui-Jun
authors.initials: HJ
authors.lastname: Zhou
authors.forename: Prabakaran
authors.initials: P
authors.lastname: Selvaraj
authors.forename: Kah-Guan
authors.initials: KG
authors.lastname: Au Eong
authors.forename: Terri L
authors.initials: TL
authors.lastname: Young
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
authors.forename: Tien-Yin
authors.initials: TY
authors.lastname: Wong
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
mesh_terms: D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D007899:Leisure Activities; D008297:Male; D009216:Myopia / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D011932:Reading; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology
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