Abstract
Purpose :
This study aims to examine if there is an increasing trend of the prevalence of moderate (decimal visual acuity <1.0) or poor (decimal visual acuity <0.3) uncorrected visual acuity in middle school students (14 years old) using nation-wide vision examination between 2012 and 2016.
Methods :
This is a cross-sectional time-series data (panel data) analysis at municipal level between 2012 and 2016. We obtained results of nation-wide vision examination by 47 prefectures from a database provided by the Japanese statistics bureau. We used multiple variate regression models with a fixed effects model, random effects model, spatial autoregressive model accounting for the municipal level variation and location.
Results :
In 2012, mean prevalence of moderate/poor uncorrected visual acuity by prefecture for 13-year-old boys and girls were 38.4%/14.9% and 47.8%/20.6%, respectively. In 2016, mean prevalence of moderate uncorrected visual acuity by prefecture for 14-year-old boys and girls were 39.2%/15.5% and 49.7%/21.2%, respectively. With visual inspections, there exists a variation in the trend over time. Using a spatial autoregressive model for random effects accounting for variations by location, there was a significant increasing trend in the prevalence of moderate uncorrected visual acuity for both boys and girls (+0.35%, 95% confidence interval [CI] 0.11, 0.57; p=0.003 and +0.55%, 95%CI 0.28, 0.81; p<0.001). Similarly, there was a significant increasing trend in the prevalence of poor uncorrected visual acuity for both boys and girls (+0.22%, 95%CI 0.03, 0.41; p=0.025 and +0.27%, 95%CI 0.02, 0.52; p=0.036).
Conclusions :
After accounting for geographical location and heterogeneity between municipal level, there was a clear increasing trend in the prevalence of both moderate and poor uncorrected visual acuity in middle school students in Japan. Given that uncorrected visual acuity in school-age students is known to be caused mainly by myopia in Japan, this is indicating an increasing trend of myopia in young generation in Japan.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.