Longitudinal analysis of 5-year refractive changes in a large Japanese population

Abstract

Refractive changes are reportedly affected by age, sex, and current refractive error. To clarify the pattern of refractive changes in a Japanese population, we conducted a 5-year follow-up longitudinal analysis of spherical equivalent (SE) refractive changes with stratification by sex, age, and SE in 593,273 eyes from Japanese individuals ages 3-91 years. The 5-year SE change with myopic shift dramatically increased over time after age 4 years, and the largest change was observed in both males and females who were age 8 years at baseline [males: - 2.654 ± 0.048 diopters (D); females: - 3.110 ± 0.038 D]. During school age, the 5-year myopic change was greater in females than in males, and emmetropic and low-to-moderate myopic eyes underwent larger myopic changes than hyperopic and high-to-severe myopic eyes. After the peak at age 8 years, the 5-year myopic change gradually declined with age and fell below - 0.25 D at age 27 in males and age 26 years in females. The 5-year SE changes transitioned from a myopic to a hyperopic shift at age 51 in both sexes, and hyperopization advanced more quickly in hyperopic eyes. Our findings highlight the importance of myopia prevention in school-aged children.

Figure 1

5-year mean change in spherical equivalent (SE) refractive error for each age at baseline. The x-axis represents ages at baseline, in years. The y-axis represents the magnitude of 5-year mean SE refractive changes at each baseline age in males (black circles) and females (white circles).

Figure 2

5-year mean change in spherical equivalent (SE) refractive error stratified by age group and SE level in males (A) and females (B). The 5-year mean SE change value and standard error (in parentheses) in each category classified by age group and SE level are shown within the respective square. The categories stratified by both age group and SE level are surrounded by a thick black line. Larger 5-year myopic and hyperopic changes are indicated by brighter red and blue, respectively. ^†5-year mean SE change (standard error) adjusted by analysis of covariance (ANCOVA) with baseline age as an independent variable. ^#5-year mean SE change (standard error) adjusted by ANCOVA with baseline SE as an independent variable. ^*5-year mean SE changes significant at P < 0.05 after Bonferroni correction based on the number of categories stratified by age and SE groups.