Long-term longitudinal changes in astigmatism and their effect on refraction development in Chinese clinical school-age children

Abstract

Abstract Objectives To investigate longitudinal changes in astigmatism in Chinese clinical school-age children and to explore the effect of astigmatism on refraction development. Methods The medical records of patients with long-term follow-up data from 2006 to 2018 were retrospectively reviewed. Patients who were 6–10 years old at initial visit and 16 years old at last assessment were selected for analysis. The enrolled patients had a cylinder refraction of 0.75 or greater. Astigmatism was analyzed in clinical notation and vector notation (J0, J45). The related factors of changes in astigmatism and spherical equivalent per year and the interaction between the two were analyzed. Results A total of 3101 patients (median age 9 years at initial visit) were followed up for an average of 7 years (IQR, 6–8 years). Astigmatism increased with age in low astigmats (< 1.50 D, 0.025 D/y) and decreased with age in high astigmats (≥ 3.00 D, -0.048 D/y). The oblique astigmatism (J45, 0.005D/y) increased and with-the-rule (WTR) astigmatism (J0, -0.008D/y) decreased. Higher myopia of the SE at the initial visit was associated with a greater increase in astigmatism magnitude(p < 0.001). A higher magnitude of initial astigmatism was associated with less progression in spherical equivalent(p < 0.001). Conclusion In Chinese clinical school-age children, the longitudinal development of astigmatism from 6–10 to 16 years of age varied with baseline astigmatism. The presence of myopia at baseline was a risk factor for astigmatism progression. However, high astigmatism seems to prevent the progression of myopia.