Abstract
Purpose :
The projected prevalence of visual impairment (VI) in the USA has been estimated but has not accounted for the increasing prevalence of myopia, particularly in older individuals. We estimate the USA prevalence of VI in 2050 accounting for the changing distribution of both age and myopia.
Methods :
1. Age projections of the USA population in 2050 were taken from the USA census website.
2. Overall prevalence of myopia (–0.50 D or worse) of 49.8% was used, based on Vitale et al. (2008) and Holden et al. (2016).
3. The distribution of myopia, by severity, was calculated using the model of Brennan et al. (2020)
4. VI as a function of age and refractive error was modelled by multiple linear regression from a large data set of an advanced European population (Tideman et al. 2016). This data set is agnostic with respect to the disease condition associated with VI.
5. Finally, by convolving the distributions of myopia and age with the cumulative risk of VI, the number of individuals in the USA with VI in 2050 was calculated.
Results :
Of the estimated 2050 USA population of 399.8 million, 199.1 million will be myopic and 29.5 million will have high myopia (< -5D). The cumulative odds of visual impairment (20/40 or worse) is 10(0.057Age – 0.122Rx – 4.03)and the projected total number with VI is 19.1 million. Of these, 12.6 million will be myopes compared with 6.5 million non-myopes. Given approximately equal numbers of myopes and non-myopes, an estimated 6 million cases of VI will therefore be directly attributed to increased risk of eye disease associated with myopia (= 12.6 – 6.5). Among individuals 65 years and younger, myopes will comprise 75% of individuals with VI, while representing only half of the population. At 82 years, myopes will still account for two-thirds of VI.
Conclusions :
Assuming that the data from Tideman et al. are applicable to the USA, we predict that some 30% of VI in the US population in 2050 will be attributable to myopia. Failure to account for the increasing prevalence of myopia among the aging population leads to a substantial underestimate of the prevalence of VI. Approaches that treat disease-states associated with myopia are needed to reduce the threat of VI in the USA.
This is a 2021 ARVO Annual Meeting abstract.