title: Prevalence of visual impairment, blindness, and cataract surgery in the Hong Kong elderly.
abstract: BACKGROUND
  The prevalence of vision impairment, unilateral/bilateral blindness, and cataract surgery were estimated in a population based survey among the elderly in a suburban area of Hong Kong.
  
  
  METHODS
  15 public, private, and home ownership scheme housing estates in the Shatin area of Hong Kong were subjected to cluster sampling to randomly select a cross section of people 60 years of age or older. Visual acuity measurements and ocular examinations were conducted at a community site within each estate. The principal cause of reduced vision was identified for eyes with presenting visual acuity worse than 6/18.
  
  
  RESULTS
  A total of 3441 subjects from an enumerated population of 4487 (76.7%) completed an eye examination. The prevalence of presenting visual acuity less than 6/18 in at least one eye was 41.3%; and 73.1% in those 80 years of age or older. Unilateral blindness (acuity <6/60) was found in 7.9% of subjects and bilateral blindness in 1.8%. Refractive error and cataract were, respectively, the main causes of vision impairment and blindness. Visual impairment with either eye <6/18 increased with advancing age and was more prevalent in males, the less educated, and those living in public housing estates. The prevalence of cataract surgery was 9.1% and was associated with advancing age and less education.
  
  
  CONCLUSIONS
  Blindness and visual disability were common in this socioeconomically advanced population, with most of it easily remedied. Because of a rapidly ageing population, healthcare planners in Hong Kong must prepare for an increasing burden of visual disability and blindness.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong.
authors.forename: John J
authors.initials: JJ
authors.lastname: Michon
authors.forename: Joseph
authors.initials: J
authors.lastname: Lau
authors.forename: Wing Shing
authors.initials: WS
authors.lastname: Chan
authors.forename: Leon B
authors.initials: LB
authors.lastname: Ellwein
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000453:epidemiology / Q000209:etiology; D002387:Cataract Extraction / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D004522:Educational Status; D006306:Health Surveys; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D015995:Prevalence; D017678:Sex Distribution; D014786:Vision Disorders / Q000453:epidemiology* / Q000209:etiology