Data from: Axial length elongation and myopia incidence increase in primary school-age children: 3-year follow-up study

Objective: To investigate the axial length (AL) elongation in primary
school-age children during 3-year follow-up period, and evaluate the
associations of AL elongation with spherical equivalent (SE), AL at
baseline, body height and weight. Design: A 3-year observational cohort
study from 2014 to 2017. Setting: Jinshan Hospital of Fudan University in
Shanghai. Methods: A total of 452 children successfully completed their
measurements in the 3-year follow-up period. Among those children, the
mean age was 6.9 ± 0.7 years, ranging from 6 years to 8 years, and 217
(42.7%) were boys. AL was measured with an ocular biometry system.
Refractive error was measured using an auto-refractor without cycloplegia.
Results: The mean changes of ALs were 0.27 ± 0.28 mm, 0.52 ± 0.40 mm, and
0.89 ± 0.51mm over 1 year, over 2 years and over 3 years, respectively.
The mean changes of Spherical equivalents (SEs) were -0.27 ± 0.80 D, -0.56
± 1.00 D, and -0.95 ± 1.41 D over 1 year, over 2 years and over 3 years,
respectively. Multivariate linear regression analysis revealed that mean
change of AL was associated with mean change of SE at all points (all P
< 0.001). In addition, linear regression analysis revealed that AL
elongation in the 3-year follow-up period was associated with AL at
baseline (R2 = 0.009, P = 0.045). Conclusions: AL elongation is relatively
high in the primary school-age children in Jinshan District, Shanghai.
Effect strategies are needed to control AL elongation.