title: [Prevalence of low vision and blindness in defined populations in rural and urban areas in Beijing].
abstract: OBJECTIVE
  To investigate the prevalence and causes of low vision and blindness in Beijing residents aged 40 and over.
  
  
  METHODS
  4,451 residents aged 40 and over in 3 rural communities and 5 urban communities in Beijing underwent eye examination, including examination of distant and near visual acuity (VA), best corrected distant and near VA, pinhole VA, and visual field, slit lamp biomicroscopy, and dilated ocular examination in the form of in-home survey by defined population-based sampling. The medical history was surveyed too. The data were analyzed based on the criteria of the World Health Organization.
  
  
  RESULTS
  The general prevalence rates of low vision and blindness were 0.99% (95% CI: 0.70-1.28) and 0.39% (95% CI: 0.21-0.57) respectively. The prevalence rate of low vision in females was 1.45%, 2.23 times that of males (0.65%) (OR: 1.97, 95% CI: 1.00-3.95). The prevalence rate of low vision of rural residents was 1.76%, 2.89 times that of urban residents (0.61%) (OR: 2.93, 95% CI: 1.43-6.11). The prevalence rate of blindness in females was 0.64% and 0.37% in males. The prevalence rate of blindness of rural residents was 1.06%, 2.04 times that of the urban residents (0.52%) (OR: 3.77, 95% CI: 1.41-10.62). The 3 major causes of blindness were cataract (37.50%), glaucoma (29.20%), and high myopic macular degeneration (8.30%). The prevalence of blindness increased with age.
  
  
  CONCLUSIONS
  The prevalence rates of low vision and blindness are higher in the rural areas. Cataract, glaucoma, and high myopic macular degeneration are the major causes of blindness. The prevalence of low vision and blindness are influenced by age, sex; area, health care level, educational level, and environmental factors.
authors.affiliation: Beijing Institute of Ophthalmology, Tongren Hospital, Capital Medical University, Beijing 100730, China.
authors.forename: Jian-hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.forename: Ai-lian
authors.initials: AL
authors.lastname: Hu
authors.forename: Bao-chen
authors.initials: BC
authors.lastname: Sun
authors.forename: Jian-jun
authors.initials: JJ
authors.lastname: Li
authors.forename: Ke
authors.initials: K
authors.lastname: Ma
authors.forename: Cui-ran
authors.initials: CR
authors.lastname: Xia
authors.forename: Tong-tong
authors.initials: TT
authors.lastname: Cui
authors.forename: Yuan-yuan
authors.initials: YY
authors.lastname: Zheng
authors.forename: Yi-bin
authors.initials: YB
authors.lastname: Li
authors.forename: Rong-xiu
authors.initials: RX
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Xiu-ying
authors.initials: XY
authors.lastname: Sun
authors.forename: Yang
authors.initials: Y
authors.lastname: Zou
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Bin-rong
authors.initials: BR
authors.lastname: Ma
mesh_terms: D000328:Adult; D000368:Aged; D001766:Blindness / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012737:Sex Factors; D014786:Vision Disorders / Q000453:epidemiology* / Q000209:etiology