title: Prevalence and causes of visual impairment among the elderly in Nantong, China.
abstract: OBJECTIVE
  To investigate the prevalence and causes of visual impairment among adults aged 60 and above in Nantong city, China.
  
  
  METHODS
  A stratified random sampling was used to select the people from eight communities in Xinchengqiao administrative sub-district of Nantong. The eye examinations were conducted at the community activity centres. The definitions of visual impairment were based on the pinhole visual acuity (low vision: visual acuity <6/18 to 3/60 in the better eye; blindness: visual acuity <3/60 in the better eye). Prevalence of visual impairment based on presenting visual acuity was also calculated. Both univariate and multiple analysis were used to do the statistics.
  
  
  RESULTS
  A total of 3040 (90.69%) out of 3352 enumerated subjects participated in the survey. The prevalence of blindness and low vision based on the pinhole visual acuity was 1.35% (presenting, 1.32%) and 1.84% (presenting, 6.05%) respectively. The prevalence of blindness and low vision grew up exponentially with age (R2=0.9993, F=1385.84, P=0.0007; R2=0.9949, F=195.65, P=0.0051) and down with increasing education level (score test for trend of odds: chi2=30.35, P=0.0000; chi2=22.31, P=0.0000), and was higher among women than men (LR chi2=9.62, P=0.0019; LR chi(2)=5.14, P=0.0234).
  
  
  CONCLUSIONS
  Blindness and low vision were prevalent in the urban area of China, especially in the elderly women, with cataract the most common cause in the Chinese elderly. Therefore, our study highlights an urgent necessity for launching some programs for blindness and low vision prevention, especially on the early treatment of cataract.
authors.affiliation: Department of Ophthalmology, Affiliated Hospital, Nantong University, Nantong, Jiangsu Province, China.
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Guan
authors.forename: P
authors.initials: P
authors.lastname: Xun
authors.forename: J
authors.initials: J
authors.lastname: Zhou
authors.forename: H
authors.initials: H
authors.lastname: Gu
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D002386:Cataract / Q000150:complications / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D003318:Corneal Opacity / Q000150:complications / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012164:Retinal Diseases / Q000150:complications / Q000453:epidemiology; D017678:Sex Distribution; D015354:Vision, Low / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D014792:Visual Acuity