title: Prevalence and causes of visual impairment in a rural North-east China adult population: a population-based survey in Bin County, Harbin.
abstract: OBJECTIVE
  To investigate the prevalence and causes of visual impairment in a rural population in north-east China.
  
  
  METHODS
  A population-based study was conducted within Bin County, Harbin of north-east China. Low vision and blindness were defined using the World Health Organization categories of visual impairment. The prevalence of visual impairment was estimated, and causes were identified based on best-corrected visual acuity (BCVA) as well as presenting visual acuity (VA).
  
  
  RESULTS
  Out of 5764 people, 4956 (86.01%) aged older than 40 participated in the study. The prevalence of visual impairment, low vision and blindness based on presenting VA was 9.6% (BCVA, 6.6%), 7.7% (BCVA, 4.9%) and 1.9% (BCVA, 1.7%), respectively. Taking the presenting VA, cataract (44%) was the most common cause for visual impairment followed by uncorrected refractive error (24%), treatable causes of visual impairment accounted for 68% of the total cases. Cataract (59%) and glaucoma (15%) were leading causes for blindness based on presenting VA. According to BCVA, cataract was the leading cause of visual impairment and blindness (58% and 60%, respectively), followed by glaucoma (17% and 15%, respectively). The prevalence of visual impairment was higher among women than men (p<0.0001) and increasing with age (p<0.0001) and decreasing with increasing education level (p=0.0075).
  
  
  CONCLUSIONS
  Visual impairment was a serious public health problem in this rural population, with most of it easily remedied. Results highlighted the need for visual impairment prevention programs to an increasing number of elderly people, with a special emphasis on female and those with little or no education.
authors.affiliation: Department of Ophthalmology, The 2nd Affiliated Hospital, Harbin Medical University, Harbin, Heilongjiang, China.
authors.forename: Wulian
authors.initials: W
authors.lastname: Song
authors.forename: Xian
authors.initials: X
authors.lastname: Sun
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Shao
authors.forename: Xinrong
authors.initials: X
authors.lastname: Zhou
authors.forename: Yang
authors.initials: Y
authors.lastname: Kang
authors.forename: Hong
authors.initials: H
authors.lastname: Sui
authors.forename: Huiping
authors.initials: H
authors.lastname: Yuan
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000453:epidemiology* / Q000209:etiology; D002386:Cataract / Q000150:complications / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D005901:Glaucoma / Q000150:complications / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012030:Refractive Errors / Q000150:complications / Q000453:epidemiology; D012424:Rural Population / Q000706:statistics & numerical data*; D017678:Sex Distribution; D015354:Vision, Low / Q000453:epidemiology* / Q000209:etiology; D014792:Visual Acuity / Q000502:physiology; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*