title: Myopia and the long-term incidence of cataract and cataract surgery: the Blue Mountains Eye Study.
abstract: BACKGROUND
  To assess the association between refractive errors and the 10-year incidence of cataract and cataract surgery.
  
  
  METHODS
  Population-based prospective study.
  
  
  METHODS
  Three thousand six hundred fifty-four persons aged 49+ years living in a well-defined geographical region were examined at baseline; 2564 were re-examined after 5 and/or 10 years.
  
  
  METHODS
  Baseline refractive error was measured using autorefraction with subjective refinement. Lens photographs were taken at each visit and assessed using the Wisconsin Cataract Grading System.
  
  
  METHODS
  Long-term incidence of cataract and cataract surgery.
  
  
  RESULTS
  Compared with emmetropia, high myopia was associated with increased incidence of nuclear cataract (adjusted odds ratio 3.01, 95% confidence intervals 1.35-6.71). Low (odds ratio 1.86, confidence interval 1.03-3.35) and high myopia (odds ratio 7.80, confidence interval 3.51-17.35) were significantly associated with higher incidence of posterior subcapsular cataract. Low, moderate and high myopia were associated with increased incidence of cataract surgery (odds ratio 2.54, confidence interval 1.76-3.68; odds ratio 2.61, confidence interval 1.45-4.69; and odds ratio 4.81, confidence interval 2.33-9.93, respectively). Either any (odds ratio 1.35, confidence interval 1.08-1.69) or moderate hyperopia (odds ratio 1.76, confidence interval 1.32-2.34) was associated with increased incidence of nuclear cataract.
  
  
  CONCLUSIONS
  Our longitudinal study confirms the association between myopia and an increased risk of nuclear and posterior subcapsular cataract. It also suggests that hyperopia may increase the risk of nuclear cataract.
authors.affiliation: Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia.
authors.forename: Gowri L
authors.initials: GL
authors.lastname: Kanthan
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
authors.forename: Elena
authors.initials: E
authors.lastname: Rochtchina
authors.forename: Robert G
authors.initials: RG
authors.lastname: Cumming
authors.forename: Jie Jin
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000175:diagnosis / Q000453:epidemiology*; D002387:Cataract Extraction / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000175:diagnosis / Q000453:epidemiology*; D009517:New South Wales / Q000453:epidemiology; D016017:Odds Ratio; D011446:Prospective Studies; D012029:Refraction, Ocular; D011795:Surveys and Questionnaires; D014787:Vision Tests; D014792:Visual Acuity
keywords: Blue Mountains Eye Study; cataract; cataract surgery; refractive error