Effect of topical atropine on astigmatism

Abstract

Aim: The aim of this study was to determine if topical atropine, used to retard axial length elongation and myopia progression, had any effect on ocular astigmatism.

Methods: Data collected from subjects enrolled in the Atropine in the Treatment of Myopia (ATOM) study were analysed. In this study, 400 myopic children (aged 6-12 years) were randomly assigned to administer atropine 1% or a placebo daily to a randomly selected eye for 2 years. Cycloplegic autorefraction and keratomy readings were measured using a Canon RK5 autorefractor. The refractive error was then split into its power vector components: J0 and J45.

Results: Astigmatism increased by 0.12-0.16 D per year in both treated and placebo groups. There was no difference between groups (p = 0.182). The increase was mirrored by an increase in corneal astigmatism of 0.10-0.13 D per year, suggesting that most of the change was corneal in nature. There was an increase in J0 vector (with-the-rule astigmatism) with no change in the J45 (oblique) vector over time. The change in the J0 vector was significantly larger in the atropine-treated versus atropine-untreated eyes during the 2-year treatment period (p = 0.011), but this difference disappeared after atropine was stopped.

Conclusion: The use of atropine on a daily basis over 2 years did not have any clinically significant effect on astigmatism.