Abstract Purpose Although axial length (AL) growth reference curves exist for several populations, there are no AL growth reference curves or established methods for AL-for-age z -score calculation for Japanese children and adolescents. This study aimed to develop AL growth reference curves and lambda-mu-sigma (LMS) parameters for Japanese children and adolescents aged 4–20 years, enabling a standardised evaluation of ocular development in both clinical and research settings. Methods A cross-sectional analysis was conducted of the AL data from 14,482 children (7457 boys and 7025 girls) enroled in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Optical biometry was performed using 10 consecutive measurements per eye and the mean values used to reduce measurement variability. Participants with a history of ophthalmic diseases that could affect AL were excluded. The LMS method with a Box-Cox-Cole-Green distribution was used to construct smoothed references and estimate the LMS parameters using the gamlss package in R. Results Age- and sex-specific LMS values for the AL z -score calculation were provided at 0.1-year intervals to allow detailed age-specific assessment. Percentile and standard deviation curves were generated for each sex across the ages of 4–20 years. AL growth patterns in Japanese children were broadly comparable to those reported in other East Asian populations. Conclusion The AL growth reference curves and LMS parameters established in this study offer a clinically relevant framework for evaluating ocular growth and monitoring myopia-related axial elongation in the Japanese paediatric population. These references contribute to early identification and intervention efforts in childhood myopia management and international comparisons.
Kobayashi et al. (Sat,) studied this question.