title: Refractive errors in an older population: the Blue Mountains Eye Study.
abstract: OBJECTIVE
  To determine prevalence and associations with refractive errors in a defined older population.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  A total of 3654 residents, aged 49-97, of the Blue Mountains, west of Sydney, Australia.
  
  
  METHODS
  Comprehensive questionnaire and detailed eye examination, including refraction.
  
  
  METHODS
  Refractive error of phakic eyes, age, gender, and education.
  
  
  RESULTS
  Prevalence rates were determined for myopia (15%), hyperopia (57%), and emmetropia (28%). Hyperopia prevalence was age-related, increasing from 36% in persons aged <60 years to 71 % of persons aged > or = 80 (P < 0.0001), whereas myopia prevalence decreased with age, from 21 % in persons aged <60 years to 10% of persons aged > or = 80 years (P < 0.0001). Younger myopic subjects in this population reported first wearing distance correction at a significantly younger age than older subjects, P < 0.0001. After adjustment for age, women were slightly more hyperopic (mean +0.75 diopters [D]) than men (mean +0.59 D, P = 0.0012. The gender-adjusted mean spherical error increased with age from +0.03 D in persons aged <60 years to +1.2 D in persons aged > or = 80 years (P < 0.0001). The gender-adjusted mean cylinder power also increased with age, from -0.6 D in persons aged <60 years to -1.2 D in persons aged > or = 80 years (P < 0.0001). The mean axis of astigmatism was "against the rule" in all age groups. Anisometropia increased with age, from a mean of 0.4 D in persons aged <60 to 0.9 D in persons aged > or = 80 years (P < 0.0001). Higher education was associated with myopia in men (P = 0.009) but not in women (P = 0.21) after adjustment for age.
  
  
  CONCLUSIONS
  This report has documented the detailed refractive status of an older population, confirming previously described trends but also finding an apparent higher prevalence of myopia among younger members of this community.
authors.affiliation: Department of Ophthalmology, The University of Sydney, New South Wales, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Attebo
authors.forename: R Q
authors.initials: RQ
authors.lastname: Ivers
authors.forename: P
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004522:Educational Status; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D011795:Surveys and Questionnaires; D014787:Vision Tests; D014792:Visual Acuity