title: [Systematic review of population-based studies of the prevalence of cataracts].
abstract: OBJECTIVE
  The prevalence of cataracts has increased due to the progressive ageing of the population and the fact that cataracts affect a wide and increasing proportion of the population. The goal of the present study was to describe the prevalence of cataracts through a systematic and exhaustive review of population-based studies.
  
  
  METHODS
  A systematic review of population-based studies of the prevalence and incidence of cataracts was performed. Inclusion criteria were: a healthy non- institutionalised population, older than 40 years of age, of white race, with a sample size of greater than 1,000 and published between 1980 and 2002.
  
  
  RESULTS
  Ten studies met the inclusion criteria (3 European, 5 from the United States and 2 from Australia), and were performed between 1984 and 2001. The cataract prevalence, according to lens opacity criteria, ranged between 15% and 19%. When the cataract was defined as a lens opacity combined with a decreased visual acuity, the prevalence ranged from 15% to 30%. The overall prevalence increased with age, reaching 40% and more than 60% in populations older than 70 and 75 years respectively. The prevalence among women was higher than that among men, with a more marked increase being evident at older ages than for men.
  
  
  CONCLUSIONS
  There were variations among the criteria used to measure the prevalence of cataract, which made it difficult to compare all the studies. Overall the prevalence was higher in the older population, especially among women. The increasing prevalence associated with age predicts an increasing burden of cataract to health services, this being particularly related to the ageing of the population.
authors.affiliation: Hospital del Mar-Esperança, Institut Municipal d'Assistencia Sanitaria (IMAS), Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Acosta
authors.forename: L
authors.initials: L
authors.lastname: Hoffmeister
authors.forename: R
authors.initials: R
authors.lastname: Román
authors.forename: M
authors.initials: M
authors.lastname: Comas
authors.forename: M
authors.initials: M
authors.lastname: Castilla
authors.forename: X
authors.initials: X
authors.lastname: Castells
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000453:epidemiology*; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D017678:Sex Distribution