title: Prevalence of and associated factors for corneal blindness in a rural adult population (the southern Harbin eye study).
abstract: OBJECTIVE
  To examine the distribution and causes of corneal blindness in a rural Chinese population.
  
  
  METHODS
  Cluster sampling of populations age > 50 was used. The protocol consisted of a detailed interview, visual acuity (VA) testing, and clinical examinations. An eye was considered to have cornea blindness if the visual acuity was < 20/400 due to a corneal disease.
  
  
  RESULTS
  A total of 5057 eligible subjects agreed to participate, giving an attendance rate of 91.0%. Corneal blindness in at least one eye was present in 48 participants, prevalence of 0.949% (95% CI: 0.682-1.216%) in at least one eye, which included 0.16% prevalence of corneal blindness in both eyes. The most frequent causes of corneal blindness in at least one eye included keratitis during childhood (39.6%), keratitis during adulthood (27.1%), and trauma (20.8%). We found that aging and male gender were associated with prevalence of corneal blindness. Multivariate analysis shows a higher OR of corneal blindness in subjects age 70 and older (1.746) and male gender (1.177).
  
  
  CONCLUSIONS
  Corneal blindness is a public health problem in southern Harbin, the majority of which is either preventable or treatable. Eye care planning must focus on corneal blindness as well as cataract.
authors.affiliation: Department of Ophthalmology, First Affiliated Hospital, Harbin Medical University, Harbin, China.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Cui
authors.forename: Liqiong
authors.initials: L
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Bai
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000208:ethnology*; D001766:Blindness / Q000208:ethnology*; D002681:China / Q000453:epidemiology; D003318:Corneal Opacity / Q000208:ethnology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D017678:Sex Distribution; D014792:Visual Acuity