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

Abstract

Abstract Objectives: To investigate longitudinal changes in astigmatism in 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 sphericalequivalent 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). The mean cylinder refraction at initial examination was 2.11±1.18Dand decreased to 2.08±1.18Dat 16 years old, which was statistically(p=0.034) but not clinically significant. The Oblique astigmatism(J45, 0.005D/y) increased and with-the-rule astigmatism(J0, -0.008D/y) decreased. A lower magnitude of astigmatism and more myopia of the SE at the initial visit were 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 southern Chinese children, the mean cylinder power decreased slightly from 6-10 to 16 years of age, accompanied by a progression of the oblique axis and a reduction of with-the-rule axis. The presence of myopia at baseline was a risk factor for astigmatism progression. However, high astigmatism seems to prevent reductions in the spherical equivalent.