Purpose:
To assess the change in prevalence of non-refractive error related visual impairment, its demographics, and associated risk factors.
Methods:
National Health and Nutrition Examination Survey (NHANES) data from 1999-2000 and 2005-2008 were analyzed and compared using SAS 9.2 statistical analysis data. Diabetes was defined as fasting glucose >=140, and poverty as income-to-poverty ratio <1.
Results:
Non-refractive error related visual impairment (NRERVI; corrected visual acuity <20/40) has risen significantly from 1999-2000 to 2005-2008 among 20-39 year olds, from 0.6% to 1.4% (p-value 0.0030); and 40-59 year olds, from 0.4% to 1.0% (p-value 0.0158); but not among those <20 or >=60 years old. The rise has been significant among non-hispanic Whites (p-value 0.02) and Mexican-Americans (p-value 0.03), but not among blacks or other groups. In univariate analysis of 2005-2008 data controlled for age, risk factors associated with NRERVI include age >=60 (versus age 20-39) (OR 5.40, 95%CI 3.81 - 7.64), nonwhite ethnicity (OR 1.81, 95%CI 1.36 - 2.41), poverty (OR 2.26, 95%CI 1.73 - 2.95), education less than high school diploma or equivalent (OR 2.68, 95%CI 2.19 - 3.28), and diabetes mellitus (OR 2.20, 95%CI 1.23 - 3.94); among diabetics, duration >= 10 years (OR 4.49, 95%CI 2.78 - 7.25) and insulin dependence (OR 3.74, 95%CI 2.51 - 5.58) were significantly associated with NRERVI; risk factors without significant association include sex, access to health care, insurance status, body mass index >=30, blood pressure >= 140/90, total cholesterol >=240, HDL <50 for women or <40 for men, LDL >=160, triglycerids >=200, and tobacco use.
Conclusions:
The age-adjusted prevalence of non-refractive error related visual impairment appears to have increased among working-age Americans. Markers for lower socioeconomic status constitute significant risk factors for NRERVI; among diabetics, longer duration of diabetes and insulin dependence is associated with higher risk. Strategies for reducing risk of NRERVI present a new challenge for vision health.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: risk factor assessment • diabetes