Prevalence of Nonrefractive Visual Impairment in US Adults and Associated Risk Factors, 1999-2002 and 2005-2008

Fang Ko, MD; Susan Vitale, PhD, MHS; Chiu-Fang Chou, DrPH; Mary Frances Cotch, PhD; Jinan Saaddine, MD; David S. Friedman, MD, MPH, PhD

ABSTRACT

Context Over the past decade, chronic illnesses with ophthalmic sequelae such as diabetes and diabetic retinopathy have increased.

Objectives To estimate prevalence of nonrefractive visual impairment and to describe its relationship with demographic and systemic risk factors including diagnosed diabetes.

Design, Setting, and Participants 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.

Main Outcome Measure 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).

Conclusion 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.