The MOSAIC2 trial, a continuation of the MOSAIC clinical study, investigated the safety and efficacy of varying atropine eye drop concentrations for controlling myopia progression in children. This 3-year randomized clinical trial was conducted at the Centre for Eye Research Ireland and assessed 0.01% and 0.05% atropine concentrations.
The study involved 199 predominantly White, European children (mean age 13.9 years) who were divided into 2 groups:
- Group 1: Nightly placebo for 2 years, then 0.05% atropine in year 3.
- Group 2: Nightly 0.01% atropine for 2 years, followed by 1 of 3 regimens in year three:
- Nightly placebo
- Tapering placebo
- Tapering 0.01% atropine
Group 1 experienced 0.13 diopters (D) less spherical equivalent progression and 0.06 mm less axial elongation compared with participants using placebo or tapering regimens. Participants using tapering 0.01% atropine had more axial elongation (0.04 mm) compared to those on 0.05% atropine. No significant rebound progression was observed in participants transitioning from 0.01% atropine to placebo or tapering regimens.
The 0.05% atropine group reported higher rates of blurred near vision (15%) and photophobia (8%) compared to negligible adverse events in other groups. However, despite these effects, no participants discontinued treatment due to side effects.
Completion rates were comparable across groups: 81% of participants adhered to their assigned regimens.
“Atropine, a nonselective muscarinic antagonist,” wrote James Loughman, PhD, of the Centre for Eye Research Ireland, Environmental and Sustainability Health Institute, Technological University Dublin, and colleagues in their recently published JAMA Ophthalmology article, “has been shown in some but not all clinical trials to slow the progression of myopia in a dose-dependent manner. However, high-concentration atropine poses challenges including blurred near-vision, pupil dilation, and increased photosensitivity.” Previous studies, including MOSIAC and CHAMP, showed mixed efficacy in children of European descent, while children of Asian descent have experienced more consistent and efficacious results.
According to the MOASIAC2 investigators, the absolute treatment effects seen in the MOASIAC and LAMP studies indicate that “low-concentration atropine eye drops may have a proportional treatment effect that is relative to the expected untreated myopia progression. Clinically, this implies that patients who are likely to have the most myopia progression will get the greatest absolute treatment benefits from atropine treatment, although it is possible that this greater effect is seen when starting from a higher level of myopia at baseline. This may be one explanation for the modest 0.01% atropine efficacies found in clinical trials in slower-progressing European populations.”
Further studies are needed to explore long-term outcomes and refine treatment protocols for different demographic groups, the authors noted.
A full list of author disclosures can be found in the published research.
