title: Frequency of under-corrected refractive errors in elderly Chinese in Beijing.
abstract: OBJECTIVE
  The aim of the study was to evaluate the prevalence of under-corrected refractive error among elderly Chinese in the Beijing area.
  
  
  METHODS
  The population-based, cross-sectional, cohort study comprised 4,439 subjects out of 5,324 subjects asked to participate (response rate 83.4%) with an age of 40+ years. It was divided into a rural part [1,973 (44.4%) subjects] and an urban part [2,466 (55.6%) subjects]. Habitual and best-corrected visual acuity was measured. Under-corrected refractive error was defined as an improvement in visual acuity of the better eye of at least two lines with best possible refractive correction.
  
  
  RESULTS
  The rate of under-corrected refractive error was 19.4% (95% confidence interval, 18.2, 20.6). In a multiple regression analysis, prevalence and size of under-corrected refractive error in the better eye was significantly associated with lower level of education (P<0.001), female gender (P<0.001), and age (P=0.001).
  
  
  CONCLUSIONS
  Under-correction of refractive error is relatively common among elderly Chinese in the Beijing area when compared with data from other populations.
authors.affiliation: Department of Ophthalmology and Eye Hospital, Tongren Hospital, Beijing, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.forename: Tongtong
authors.initials: T
authors.lastname: Cui
authors.forename: Zhongbiao
authors.initials: Z
authors.lastname: Tong
authors.forename: Guizhi
authors.initials: G
authors.lastname: Fan
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Baochen
authors.initials: B
authors.lastname: Sun
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zheng
authors.forename: Jost B
authors.initials: JB
authors.lastname: Jonas
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000208:ethnology; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012030:Refractive Errors / Q000208:ethnology*; D012424:Rural Population / Q000706:statistics & numerical data; D014505:Urban Population / Q000706:statistics & numerical data; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data