title: Visual consequences of refractive errors in the general population.
abstract: OBJECTIVE
  To study the frequency and causes of visual impairment in relation to refractive error.
  
  
  METHODS
  Population-based cohort study.
  
  
  METHODS
  A total of 6597 participants from Rotterdam Study I (baseline and 4 follow-up examinations) and 2579 participants from Rotterdam Study II (baseline and 2 follow-up examinations), all 55 years or older, were included.
  
  
  METHODS
  Participants underwent an extensive ophthalmic examination, including best-corrected visual acuity and objective refraction, fundus photography, visual field perimetry, and optical coherence tomography imaging of macula and optic disc. We calculated cumulative risks and odds ratios of visual impairment for various refractive error categories and determined causes by using all screening information as well as medical records.
  
  
  METHODS
  Unilateral and bilateral low vision (World Health Organization [WHO] criteria, VA < 0.3 and VA ≥ 0.05; United States (US) criteria, VA < 0.5 and VA ≥ 0.1) and blindness (WHO criteria, VA < 0.05; US criteria, VA < 0.1).
  
  
  RESULTS
  Cumulative risks of visual impairment ranged from virtually 0 in all refractive error categories at 55 years of age to 9.5% (standard error, 0.01) for emmetropia and 15.3% (standard error, 0.06) for high hyperopia to 33.7% (standard error, 0.08) for high myopia at 85 years of age. The major causes of visual impairment in highly hyperopic persons were age-related macular degeneration (AMD), cataract, and combined causes (each 25%); in highly myopic persons, the major cause was myopic macular degeneration (38.9%). The major causes of visual impairment for the other refractive error categories were AMD and cataract. Compared with those with emmetropia, those with high myopia had a significantly increased lifetime risk of visual impairment; those with -6 diopters (D) or less and -10 D or more had an odds ratio (OR) risk of 3.4 (95% confidence interval [CI], 1.4-8.2) of visual impairment; those with less than -10 D had an OR of 22.0 (95% CI, 9.2-52.6).
  
  
  CONCLUSIONS
  Of all refractive errors, high myopia has the most severe visual consequences. Irreversible macular pathologic features are the most common cause of visual impairment in this group.
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Virginie J M
authors.initials: VJ
authors.lastname: Verhoeven
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: King T
authors.initials: KT
authors.lastname: Wong
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Gabriëlle H S
authors.initials: GH
authors.lastname: Buitendijk
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; The Netherlands Consortium for Healthy Ageing, Netherlands Genomics Initiative, The Hague, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Johannes R
authors.initials: JR
authors.lastname: Vingerling
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands. Electronic address: c.c.w.klaver@erasmusmc.nl.
authors.forename: Caroline C W
authors.initials: CC
authors.lastname: Klaver
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000209:etiology*; D002386:Cataract / Q000150:complications; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000150:complications*; D008268:Macular Degeneration / Q000150:complications; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000150:complications*; D016017:Odds Ratio; D012029:Refraction, Ocular / Q000502:physiology; D012307:Risk Factors; D041623:Tomography, Optical Coherence; D015354:Vision, Low / Q000209:etiology*; D014792:Visual Acuity / Q000502:physiology; D019987:Persons with Visual Disabilities