Global Axial Length Centile Charts

Importance: Myopia is increasingly common worldwide and poses major public health challenges because axial elongation drives sight-threatening complications. Because axial length (AL) is the primary target for myopia management, population-specific AL reference charts are needed. Objective: To generate region- and sex-specific reference centile charts for AL in children and adolescents. Design, Setting, and Participants: This was a pooled cohort analysis using individual-participant data from population- and school-based studies conducted in East Asia, Europe, and Australia contributing to the CREAM-Kids Consortium. A total of 147 404 children and adolescents contributing 559 799 AL measurements were included. Most participants were from East Asia (84%; ages 6-18 years), followed by Europe (12%; ages 6-21 years) and Australia (4%; ages 6-21 years). After assessment of comparability, European and Australian datasets were combined. Data were included from 1999 to 2024, with the analysis taking place from December 2024 to May 2026. Exposures: AL, age, sex, and geographic region. Main Outcomes and Measures: Region- and sex-specific AL centiles across age and agreement between modeled centiles and empirical values. Results: AL distributions among the 147 404 included individuals varied by sex and region. In female individuals, the 50th centile AL at age 7 years was 22.35 mm in Europe and Australia and 22.67 mm in East Asia; by age 18 years, the 50th centile ALs were 23.31 mm and 24.36 mm, respectively. Regional differences were larger at higher centiles: for female individuals at age 7 years, East Asia vs Europe and Australia differences were 0.33 mm at the 3rd centile and 0.50 mm at the 97th centile; at age 18 years, differences were 0.73 mm and 1.27 mm, respectively. Modeled centile curves closely matched empirical values (intraclass correlations >0.99) with minimal bias across sex and region subgroups (-0.08 mm to 0.04 mm). Conclusions and Relevance: While not based solely on population-based cohorts, the region- and sex-specific AL centile charts developed in this pooled cohort study provide reference values for childhood and adolescence that may be used to support clinical and research applications, including identifying atypical axial elongation and informing targeted strategies for myopia prevention and management.