Long-term astigmatism progression and its interaction with spherical equivalent in Chinese school-age children: A hospital-based cohort study

In this large longitudinal cohort of Chinese school-age children, astigmatism progression exhibited a baseline-dependent pattern. Myopia was associated with a modest acceleration of astigmatism progression, whereas higher astigmatism conferred a slight protective effect against myopic shift. This study demonstrates these refractive interactions, though their clinical applicability is limited by small effect sizes.