Axial length growth and the risk of developing myopia in European children

PurposeTo generate percentile curves of axial length (AL) for European children, which can be used to estimate the risk of myopia in adulthood. MethodsA total of 12386 participants from the population-based studies Generation R (Dutch children measured at both 6 and 9years of age; N=6934), the Avon Longitudinal Study of Parents and Children (ALSPAC) (British children 15years of age; N=2495) and the Rotterdam Study III (RS-III) (Dutch adults 57years of age; N=2957) contributed to this study. Axial length (AL) and corneal curvature data were available for all participants; objective cycloplegic refractive error was available only for the Dutch participants. We calculated a percentile score for each Dutch child at 6 and 9years of age. ResultsMean (SD) AL was 22.36 (0.75) mm at 6years, 23.10 (0.84) mm at 9years, 23.41 (0.86) mm at 15years and 23.67 (1.26) at adulthood. Axial length (AL) differences after the age of 15 occurred only in the upper 50%, with the highest difference within the 95th percentile and above. A total of 354 children showed accelerated axial growth and increased by more than 10 percentiles from age 6 to 9years; 162 of these children (45.8%) were myopic at 9years of age, compared to 4.8% (85/1781) for the children whose AL did not increase by more than 10 percentiles. ConclusionThis study provides normative values for AL that can be used to monitor eye growth in European children. These results can help clinicians detect excessive eye growth at an early age, thereby facilitating decision-making with respect to interventions for preventing and/or controlling myopia.