Abstract
Purpose:
Provide updated estimates of the annual incidence and prevalence of low vision in the United States by age and updated projections of the growth in low vision.
Methods:
Prevalence and incidence rates of low vision in the United States as a function of age were estimated from the NHANES 2007-2008 vision evaluation data. Low vision was defined using two criteria: best-corrected visual acuity (BCVA) in the better seeing eye <20/40 and <20/60. NHANES measured BCVA in a population-based sample of 6,370 participants ranging in age from 12 to 85+ years, organized into 5-year age bins. The fraction of participants that met each of the two visual acuity criteria were calculated for each age group to obtain estimates of prevalence rate as a function of age. These estimates were fit with an exponential function of age and differentiated to generate estimates for annual incidence rates for each of the two BCVA criteria. The prevalence and annual incidence of low vision in the U.S. was estimated from the rate models applied to the 2010 U.S. census data by age. U.S. Administration on Aging population growth estimates in each age group were used to project the 2010 census data to 2015 and beyond.
Results:
The prevalence of people with low vision in the U.S. in 2010 with BCVA <20/40 = 3,233,757 and <20/60 = 886,524. The total annual incidence <20/40 = 323,699 and <20/60 = 86,436. The projected prevalence estimates for 2015 from the 2010 census data for BCVA <20/40 = 3,867,967 and <20/60 = 1,058,535. The projected 2015 annual incidence for <20/40 = 387,183 and <20/60 = 103,207. The projected prevalence estimates for 2030 for BCVA <20/40 =5,644,379 and <20/60 = 1,539,618. Projected 2030 annual incidence for BCVA <20/40 = 565,002 and <20/60 = 150,113.
Conclusions:
Low Vision prevalence and incidence rate estimates from this study are more accurate than earlier estimates that relied on meta-analyses of older epidemiologic studies, which disagreed on visual acuity criteria and the definitions of age groups. The annual incidence of low vision is 10% of the prevalence for both BCVA criteria. The prevalence rates in the oldest age groups are lower for the present model than for earlier models, which results in a lower estimated prevalence and incidence of low vision for 2015 than was projected by earlier studies.