Effect of Low-Concentration Atropine Eyedrops vs Placebo on Myopia Incidence in Children

Importance Early onset of myopia is associated with high myopia later in life, and myopia is irreversible once developed. Objective To evaluate the efficacy of low-concentration atropine eyedrops at 0.05% and 0.01% concentration for delaying the onset of myopia. Design, Setting, and Participants This randomized, placebo-controlled, double-masked trial conducted at the Chinese University of Hong Kong Eye Centre enrolled 474 nonmyopic children aged 4 through 9 years with cycloplegic spherical equivalent between +1.00 D to 0.00 D and astigmatism less than −1.00 D. The first recruited participant started treatment on July 11, 2017, and the last participant was enrolled on June 4, 2020; the date of the final follow-up session was June 4, 2022. Interventions Participants were assigned at random to the 0.05% atropine (n = 160), 0.01% atropine (n = 159), and placebo (n = 155) groups and had eyedrops applied once nightly in both eyes over 2 years. Main Outcomes and Measures The primary outcomes were the 2-year cumulative incidence rate of myopia (cycloplegic spherical equivalent of at least −0.50 D in either eye) and the percentage of participants with fast myopic shift (spherical equivalent myopic shift of at least 1.00 D). Results Of the 474 randomized patients (mean age, 6.8 years; 50% female), 353 (74.5%) completed the trial. The 2-year cumulative incidence of myopia in the 0.05% atropine, 0.01% atropine, and placebo groups were 28.4% (33/116), 45.9% (56/122), and 53.0% (61/115), respectively, and the percentages of participants with fast myopic shift at 2 years were 25.0%, 45.1%, and 53.9%. Compared with the placebo group, the 0.05% atropine group had significantly lower 2-year cumulative myopia incidence (difference, 24.6% [95% CI, 12.0%-36.4%]) and percentage of patients with fast myopic shift (difference, 28.9% [95% CI, 16.5%-40.5%]). Compared with the 0.01% atropine group, the 0.05% atropine group had significantly lower 2-year cumulative myopia incidence (difference, 17.5% [95% CI, 5.2%-29.2%]) and percentage of patients with fast myopic shift (difference, 20.1% [95% CI, 8.0%-31.6%]). The 0.01% atropine and placebo groups were not significantly different in 2-year cumulative myopia incidence or percentage of patients with fast myopic shift. Photophobia was the most common adverse event and was reported by 12.9% of participants in the 0.05% atropine group, 18.9% in the 0.01% atropine group, and 12.2% in the placebo group in the second year. Conclusions and Relevance Among children aged 4 to 9 years without myopia, nightly use of 0.05% atropine eyedrops compared with placebo resulted in a significantly lower incidence of myopia and lower percentage of participants with fast myopic shift at 2 years. There was no significant difference between 0.01% atropine and placebo. Further research is needed to replicate the findings, to understand whether this represents a delay or prevention of myopia, and to assess longer-term safety. Trial Registration Chinese Clinical Trial Registry: ChiCTR-IPR-15006883