title: Uncorrected refractive error in older British adults: the EPIC-Norfolk Eye Study.
abstract: OBJECTIVE
  To investigate the prevalence of, and demographic associations with, uncorrected refractive error (URE) in an older British population.
  
  
  METHODS
  Data from 4428 participants, aged 48-89 years, who attended an eye examination in the third health check of the European Prospective Investigation into Cancer-Norfolk study and had also undergone an ophthalmic examination were assessed. URE was defined as ≥1 line improvement of visual acuity with pinhole-correction in the better eye in participants with LogMar presenting visual acuity (PVA) <0.3 (PVA <6/12). Refractive error was measured using an autorefractor without cycloplegia. Myopia was defined as spherical equivalent ≤-0.5 dioptre, and hypermetropia ≥0.5 dioptre.
  
  
  RESULTS
  Adjusted to the 2010 midyear British population, the prevalence of URE in this Norfolk population was 1.9% (95% CI 0.6% to 3.1%). Lower self-rated distance vision was correlated with higher prevalence of URE (p(trend)<0.001). In a multivariate logistic regression model adjusting for age, gender, retirement status, educational level and social class, independent significant associations with URE were increasing age (p(trend)<0.001) and having hypermetropic or myopic refractive error. Wearing distance spectacles was inversely associated with URE (OR 0.34, 95% CI 0.21 to 0.55, p<0.001). There were 3063 people (69.2%) who wore spectacles/contact lenses for distance vision. Spectacle wear differed according to type of refractive error (p<0.001), and use rose with increasing severity of refractive error (p(trend)<0.001).
  
  
  CONCLUSIONS
  Although refractive error is common, the prevalence of URE was found to be low in this population reflecting a low prevalence of PVA<0.3.
authors.affiliation: Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge School of Clinical Medicine, Cambridge, UK.
authors.forename: Justin C
authors.initials: JC
authors.lastname: Sherwin
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Khawaja
authors.forename: David
authors.initials: D
authors.lastname: Broadway
authors.forename: Robert
authors.initials: R
authors.lastname: Luben
authors.forename: Shabina
authors.initials: S
authors.lastname: Hayat
authors.forename: Nichola
authors.initials: N
authors.lastname: Dalzell
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Wareham
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Foster
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005139:Eyeglasses / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012030:Refractive Errors / Q000453:epidemiology* / Q000503:physiopathology; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology; D014786:Vision Disorders / Q000453:epidemiology* / Q000503:physiopathology; D015351:Vision Screening / Q000295:instrumentation; D014792:Visual Acuity / Q000502:physiology