Abstract
Purpose :
There are limited longitudinal data on refractive progression between teenage and senior adult years. A recent analysis suggests that the ratio of the prevalence of high myopia to that of myopia increases over this time.1
Methods :
The literature was reviewed to identify papers where both myopia and high myopia prevalence were reported. Adult studies largely comprised population-based cohorts whereas studies of children and teenagers were principally from school-based populations. To reduce confounding caused by lenticular changes, subjects over 70 years of age were excluded. Prevalence rates were adjusted to bring the thresholds for myopia and high myopia to -0.50 D and -5.00 D according to previously developed equations.1
Results :
Figure 1 plots the prevalence of high myopia versus that of myopia by age group for 292 cohorts from 76 studies (a total of 1,034,220 individuals). The ratio of the prevalence of high myopia to that of myopia increases with myopia prevalence, as has been previously reported. But, it also increased across the lifespan. Figure 2 presents modelled data for the prevalence of high myopia against that for myopia at different ages. This model predicts, for example, that high myopia prevalence will increase by about two-thirds between ages 20 and 70 years for a constant myopia prevalence of 80%. Race and gender had minimal influence on the ratio of high myopia to myopia.
Conclusions :
While there are numerous possible explanations for this observation, the most likely is continued myopic progression during adulthood among moderate myopes such that they become high myopes later in life. The apparent substantial progression in this group across age has not been previously quantified and may mean that the already substantial projections of future morbidity from myopia underestimate the true likely toll.
1. Brennan et al. Optom Vis Sci 2020; 97:E-abstract 2053.
This is a 2021 ARVO Annual Meeting abstract.