Axial Length Change a Decisive Factor in Anticipating Myopia Development in Non-Myopes

Baseline SER and prior AL change showed strong predictive value. When developing the model, minimal improvement was found using prior two-year changes; hence, the final model incorporated prior one-year AL change, baseline SER, sex and parental myopia status. Photo: Zeiss. Click image to enlarge. Identifying cases of “pre-myopia” requires precise prediction of eventual myopia onset. Existing research has established multiple predictors, such as spherical equivalent refraction (SER), axial length (AL), age, sex, corneal curvature and the ratio of corneal curvature to axial length. Recently, researchers in China developed and validated a prediction model for myopia. They combined cycloplegic refraction with prior AL changes and created a possible set of criteria for identifying pre-myopia.Their findings suggested a potential new approach to myopia management. Since they determined that prior AL change has predictive value while prior SER change does not, and considering that cycloplegia cannot be conveniently performed in all regions, the researchers suggested that all students take annual AL measurements (without cycloplegia) starting from the first year, combined with cycloplegic refraction in the second year. Individuals at high risk of myopia should continue SER in the third year, while those at low risk can continue with only AL measurement. This approach could ensure prediction accuracy while reducing reliance on resource-intensive cycloplegia.Based on a five-year prospective cohort of 4,437 children ages six to nine from 12 schools, this study developed and validated an algorithm integrating cycloplegic refraction with prior AL change, the subject’s sex and parental myopia status. Myopia onset was defined as SER of -0.50D or less, and emmetropia was defined as SER greater than -0.50D and less than +2.00D. SER was calculated as the sphere power plus half of the cylindrical.External validation demonstrated robust discriminative performance—the researchers write in their paper on the work—excellent calibration consistency and clinical value. SER thresholds in various conditions (prior AL change, sex and myopic parents) were subsequently established, offering an evidence-based framework for pre-myopia identification. If the SER exceeded the established thresholds, the individual would be classified as “high-risk” according to the corresponding standard.“This study first confirmed the high predictive value of prior AL changes,” the researchers wrote in their paper, which was published last week in Ophthalmology. “When comparing baseline characteristics with prior changes, baseline SER showed stronger predictive power than prior SER change, whereas prior AL change outperformed baseline AL. Baseline cycloplegic SER remained the strongest predictor of future myopia onset.”The study concluded that these proposed prediction models and SER thresholds may serve as useful clinical tools to identify pre-myopia and to facilitate early intervention for controlling myopia. Larger-scale studies across diverse populations are warranted to validate these findings.The researchers further developed an online myopia risk calculator to facilitate use in settings such as schools and other institutions.Click here for the journal source. Xu S, Ruan Z, Wang Y, et al. Establishment of myopia occurrence prediction model in non-myopic children using cycloplegic refraction and prior axial length change. Ophthalmology. June 12, 2025. [Epub ahead of print].