Long-term Changes in Refractive Error after Spectacle Use

Abstract

Purpose: To evaluate the long-term changes in spherical equivalent (SE) refractive error and astigmatism in patients after spectacle use. Methods: A total of 103 patients with refractive error without strabismus and amblyopia who received at least 3 years of follow-up after using spectacles were included in this study. Patients were divided into groups according to the age at which spectacles were used (<4 years, >= 4 to <7 years, >= 7 years), the initial degree of SE refractive error (<-0.50 diopter [D], -0.50 to +0.75 D, >+0.75 D), and the initial degree of astigmatism (<1.00 D, 1.00 to 3.00 D, >= 3.00 D). Changes in the SE refractive error and astigmatism were compared between these groups using mixed linear models. Results: Patients were followed up for a mean of 9.1 +/- 1.6 years. An overall negative shift in SE refractive error and an increasing tendency in astigmatism during follow-up were noted regardless of the age at which spectacles were used (p < 0.001). The myopic group showed the largest negative shift in SE and the largest increase in astigmatism (p < 0.001, p = 0.02 respectively). The low and moderate astigmatism groups were more likely to have significant increases in astigmatism (p < 0.001). Conclusions: Patients with refractive error showed a negative shift in SE and an increasing tendency in astigmatism regardless of the age at which spectacles were used. Changes in SE and astigmatism may be influenced by the initial degree of SE, and the initial degree of astigmatism may influence changes in astigmatism.