More than 7 Million People in US Living with Visual Acuity Loss, Blindness

Rates of visual acuity (VA) loss and blindness in the US are substantially higher than previously published reports suggest according to findings published in JAMA Ophthalmology.

Researchers conducted a meta-analysis to estimate VA loss and blindness by age, sex, race, ethnicity, and region. The data they analyzed originated from the American Community Survey, National Health and Nutrition Examination Survey, National Survey of Children’s Health, and population-based studies from 2000 to 2013. Main outcome measures were the prevalence of VA loss (logMAR ≥0.3) and blindness (logMAR ≥1) in the better-seeing eye.

The analysis was conducted from March 2018 to March 2020. It found an estimated prevalence of 7.08 million people (95%CI, 6.32-7.89) living with VA loss. Of this number, 1.08 million (95%CI, 0.82-1.3) are living with blindness. A total of 1.62 million people with VA loss (95%CI, 1.32-1.92) and 141,000 with blindness (95%CI, 95,000-187,000) are younger than 40 years.

The researchers explain that the study’s estimates of VA loss are 68.7% higher than the previous VPUS study’s numbers, which may be due to the present study’s inclusion of NHANES (National Health and Nutrition Examination Survey) data, as well as its method of imputation to address missing NHANES data. However, they note that its estimation of prevalence of blindness is lower than that of previous studies. 

Both the present study and previous analyses of NHANES data estimate a higher prevalence of VA loss in Hispanic and Black patients compared with White patients, the study explains, as well as in women compared with men, although these findings were not statistically significant in the present study. 

The study notes that there were several limitations, including NHANES’s missing data (up to 12%) and its possible effect on findings, as well as the age of some included data sets. Additionally, the researchers say that confounding is possible due to the self-reported nature of some data, and finally, the researchers made certain assumptions in their analysis in order to account for all members of group quarters.

“We have assumed that the decomposition of visual acuity loss in distinct subcategories of visual impairment and blindness follow the same percentage breakdown in group quarters as in households,” the researchers explain. 

Reference

Flaxman A, Wittenborn J, Robalik T, et al; for the Vision and Eye Health Surveillance System study group. Prevalence of visual acuity loss or blindness in the US: a Bayesian meta-analysis. JAMA Ophthalmol. Published online May 13, 2021. doi:10.1001/jamaophthalmol.2021.0527