Chan T, et al. - The purpose of this study was to offer updated estimates of the incidence and prevalence of low vision and blindness in the United States. According to findings, a substantial portion of the older US population is affected by low vision and blindness. This information offer assistance to policy planners in allocating and developing resources for this life-changing loss of function.

Methods

• Researchers estimated the prevalence and incidence of visual impairments using visual acuity measurements as a function of age from the 2007-2008 National Health and Nutrition Examination Survey, with representation of racial and ethnic groups.
• They estimated prevalence rates for different age groups by obtaining data from 6016 survey participants, ranging in age from younger than 18 years to older than 45 years.
• Furthermore, incidence and prevalence rates of low vision (best-corrected visual acuity [BCVA] in the better-seeing eye of <20/40 and <20/60) and blindness (BCVA of ≤20/200) in older adults were estimated from exponential models, fit to prevalence rates as a function of age (specified in 5-year age bins).
• They estimated the prevalence and annual incidence of low vision and blindness in the United States, using the 2010 US census data by age, from the rate models applied to the census projections for 2017, 2030, and 2050.
• They collected data from November 1, 2007, to October 31, 2008 and performed data analysis from March 31, 2016, to March 19, 2017.
• Main outcomes and measures included prevalence and incidence rates of low vision and blindness in the United States.

Results

• This study included a total of 6016 people; 1714 (28.4%) were younger than 18 years of age, 2358 (39.1%) were 18 to 44 years of age, and 1944 (32.3%) were 45 years of age or older.
• Overall study population was comprised of 2888 males (48%) and 3128 females (52%).
• Findings demonstrated that the prevalence of low vision and blindness for older adults (≥45 years) in the United States in 2017 is estimated to be 3,894,406 persons (95% CI, 3,034,442-4,862,549 persons) with a BCVA less than 20/40, 1,483,703 persons (95% CI, 968,656-2,370,513 persons) with a BCVA less than 20/60, and 1,082,790 persons (95% CI, 637,771-1,741,864 persons) with a BCVA of 20/200 or less.
• Data showed that in the United States, the estimated 2017 annual incidence (projected from 2010 census data) of low vision and blindness among older adults (≥45 years) is 481,970 persons (95% CI, 375,541-601,787 persons) with a BCVA less than 20/40, 183,618 persons (95% CI, 119,878-293,367 persons) with a BCVA less than 20/60, and 134,002 persons (95% CI, 83,383-215,567 persons) with a BCVA of 20/200 or less.
• Researchers found that the total annual incidence for each BCVA criterion is 12.4% of the total prevalence.