title: Prevalence of nonrefractive visual impairment in US adults and associated risk factors, 1999-2002 and 2005-2008.
abstract: BACKGROUND
  Over the past decade, chronic illnesses with ophthalmic sequelae such as diabetes and diabetic retinopathy have increased.
  
  
  OBJECTIVE
  To estimate prevalence of nonrefractive visual impairment and to describe its relationship with demographic and systemic risk factors including diagnosed diabetes.
  
  
  METHODS
  The National Health and Nutrition Examination Survey (NHANES) examined a representative sample of the US noninstitutionalized population. In 1999-2002 and 2005-2008, 9471 and 10,480 participants aged 20 years or older received questionnaires, laboratory tests, and physical examinations. Visual acuity of less than 20/40 aided by autorefractor was classified as nonrefractive visual impairment.
  
  
  METHODS
  Nonrefractive visual impairment.
  
  
  RESULTS
  Weighted prevalence of nonrefractive visual impairment increased 21% among US adults aged 20 years and older from 1.4% in 1999-2002 to 1.7% in 2005-2008 (P = .03); and increased 40% among non-Hispanic whites aged 20-39 years from 0.5% to 0.7% (P = .008). In multivariable analyses, statistically significant risk factors for nonrefractive visual impairment in 1999-2002 included age (per year odds ratio [OR], 1.07; 95% CI, 1.05-1.09), poverty (OR, 2.18; 95% CI, 1.31-3.64), lack of insurance (OR, 1.85; 95% CI, 1.16-2.95), and diabetes with 10 or more years since diagnosis (OR, 1.93; 95% CI, 1.15-3.25). In 2005-2008, risk factors included age (OR, 1.05; 95% CI, 1.04-1.07), poverty (OR, 2.23; 95% CI, 1.55-3.22), education less than high school (OR, 2.11; 95% CI, 1.54-2.90), and diabetes with 10 or more years since diagnosis (OR, 2.67; 95% CI, 1.64-4.37). Prevalence of diabetes with 10 or more years since diagnosis increased 22% overall from 2.8% to 3.6% (P = .02); and 133% among non-Hispanic whites aged 20-39 years from 0.3% to 0.7% (P < .001).
  
  
  CONCLUSIONS
  Prevalence of nonrefractive visual impairment was significantly higher in 2005-2008 than in 1999-2002 and may be attributable, in part, to higher prevalence of diabetes, an associated risk factor that increased in prevalence during this time period.
authors.affiliation: Wilmer Eye Institute, Dana Center for Preventive Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Ko
authors.forename: Susan
authors.initials: S
authors.lastname: Vitale
authors.forename: Chiu-Fang
authors.initials: CF
authors.lastname: Chou
authors.forename: Mary Frances
authors.initials: MF
authors.lastname: Cotch
authors.forename: Jinan
authors.initials: J
authors.lastname: Saaddine
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D048909:Diabetes Complications / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000453:epidemiology*; D003930:Diabetic Retinopathy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014786:Vision Disorders / Q000453:epidemiology*; D055815:Young Adult