Axial Length Elongation in Japanese Youth With Myopia.

Abstract

Objectives: To investigate the correlation between the annual axial length (AL) elongation and associated factors in Japanese youth with myopia.

Methods: This retrospective study enrolled patients aged 7 to 21 years with myopia. Axial length was measured using ocular biometry. Refractive errors and curvature radius (CR) were measured using an open-field Binocular Auto Ref/Keratometer without cycloplegia. Subjects were divided into five groups using 3-year age intervals, and the relationship between annual AL elongation and age, spherical equivalent (SE), corneal CR, and sex was evaluated.

Results: Four hundred and eighty-two patients (184 male and 298 female subjects) with a mean age of 15.55±4.09 years were included. The annual AL elongation was largest in the youngest group (0.47±0.19) and decreased with age to 0.03±0.04 in the oldest group. The annual change in AL was associated with age and SE (P<0.01) but not with sex or CR (P>0.05). Axial length elongation stratified by age was significantly correlated with SE in the 15 to 18-year-old (R2=0.20, P<0.01) and 19 to 21-year-old (R2=0.37, P=0.01) groups, whereas there was no significant correlation in the 7 to 9-year-old group (R2=0.04, P=0.14), the 10 to 12-year-old group (R2=0.05, P=0.07), and the 13 to 15-year-old group (R2=0.01, P=0.14).

Conclusions: In Japanese youth with myopia, AL elongation was largest in the youngest group, decreased with age, especially in the group older than 15 years.