title: [Prevalence of blindness among adults aged 50 years or above in Shunyi county of Beijing].
abstract: OBJECTIVE
  To estimate the prevalence of blindness among older adults aged >or= 50 years in Shunyi county of Beijing, China.
  
  
  METHODS
  Cluster sampling was used in randomly selecting individuals aged >or= 50 years in 28 villages in Shunyi county in fall, 1996. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out.
  
  
  RESULTS
  5,555 individuals were enumerated. The response rate was 91.5%. In this population, the prevalence of blindness was 1.7% defined as pinhole visual acuity < 0.05 in both eyes; or 2.8% were blind, defined as presenting visual acuity < 6/60 in both eyes. Blindness was associated with older age and female gender. The principal cause of blindness in eyes was cataract.
  
  
  CONCLUSIONS
  The prevalence of blindness was decreased 35.8% after ten year active eye-care program in the survey area. However, cataract blindness continues as a significant problem among elderly, especially females, in this population sample of rural area.
authors.affiliation: Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730.
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.forename: L
authors.initials: L
authors.lastname: Jia
authors.forename: R
authors.initials: R
authors.lastname: Sui
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Xiang
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: G
authors.initials: G
authors.lastname: Sun
authors.forename: X
authors.initials: X
authors.lastname: Song
authors.forename: J
authors.initials: J
authors.lastname: Mao
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000453:epidemiology* / Q000209:etiology; D002386:Cataract / Q000150:complications / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015995:Prevalence; D012424:Rural Population; D012737:Sex Factors