Purpose:
To estimate the prevalence and associated conditions of visual impairment (VI) among people 40 years and older in the US.
Methods:
Visual acuity (VA) data on 6364 participants aged 40 years and older were obtained in the 2005-2008 National Health and Nutrition Examination Survey, a statistically representative sample of the US civilian population. Presenting VI was defined as distance VA (wearing usual correction, if any) in the better-seeing eye worse than 20/40. Uncorrectable VI was defined as VA in the better-seeing eye worse than 20/40 after refraction. Diabetic retinopathy (DR) and age-related macular degeneration (AMD) were assessed by grading fundus images. Glaucoma was defined as visual field loss on 2 complete, reliable frequency doubling tests using a 2-2-1 algorithm and a cup-to-disc ratio ≥ 0.7. Multivariate logistic regression was used to find risk factors for uncorrectable VI.
Results:
The prevalence of presenting VI among US adults aged 40 and older was 5.5% (95%CI=4.8%-6.3%). Of those with presenting VI, 83% would not have VI with refractive correction. Nearly 60% of the 17% with uncorrectable VI had one or more age-related eye condition. 12% had only AMD, 3% had only DR, 3% had only glaucoma, and 30% had 2 or more age-related eye diseases. People 70 years and older (OR=4.74, 95%CI=1.31-17.1), males (OR=2.85, 95%CI=1.31-6.16), with AMD (OR=3.8, 95%CI=1.1-13.3), or hypertension (OR=3.11, 95%CI=1.23-7.83) were at increased risk for uncorrectable VI.
Conclusions:
Nearly 1 in 18 Americans aged 40 and older has VI. Almost 4.9 million people can have their VI corrected with refractive modalities, leaving 1 million Americans with uncorrectable VI due to eye disease. A more comprehensive understanding of the psychosocial, demographic, and medical factors associated with risk of developing VI is necessary to design and integrate effective preventive and therapeutic strategies into patient management guidelines to improve the nation’s vision health.
Keywords: aging • age-related macular degeneration • aging: visual performance