Evaluating efficacy of low-dose atropine for myopia management

CHAMP Trial Findings
The CHAMP study, a phase 3 clinical trial (a study conducted to determine if a product can be launched) across 27 clinical sites in North America and five countries in Europe, included 576 participants aged three to 17 years, with initial myopia ranging from -0.50 D to -6.00 D. It compared the efficacy of low-dose atropine (0.01% and 0.02%) against a placebo control group over 36 months. The study found that both concentrations significantly slowed myopia progression; interestingly, the 0.01% concentration demonstrated superior efficacy in reducing axial elongation and refractive error changes. However, it is important to contextualise these results: while statistically significant, the reductions in myopia progression were modest and lower than in a number of optical (e.g. orthokeratology or multifocal contact lens) and atropine studies.  The study also revealed that the preservative-free, low-dose atropine formulation used in the study had a favorable safety profile with participants showing good tolerance to both concentrations (0.01% and 0.02%), with minimal ocular side effects.

PEDIG Trial Findings
The PEDIG study, conducted from June 2018 to September 2022 across the United States, involved 187 children aged three to 12 years with initial myopia between -1.00DS and -6.00DS. It examined the impact of nightly 0.01% atropine eye drops versus a placebo over 24 months, followed by a six-month observation period. The study concluded that 0.01% atropine did not significantly slow myopia progression or axial elongation compared to the placebo, suggesting that this concentration may not be effective to manage myopia in some populations.  This finding contrasts with several studies conducted in East Asia, where low-dose atropine has shown significant efficacy. Potential reasons for these differing outcomes include racial and ethnic differences in response to atropine, iris pigmentation affecting drug efficacy, variations in study design, and differences in baseline myopia progression rates among populations. These factors are crucial for clinicians to consider when interpreting the effectiveness of low-dose atropine across diverse patient groups.

ATLAS Trial Findings
The ATLAS project collated long-term data from mainly Chinese subjects aged six to 12 years who took part in the ATOM1 and ATOM2 trials about 20 and 10 years earlier, respectively. About one quarter of the original trial participants were assessed for this new work; they had initially been treated with either a placebo or atropine between 0.01%, and 1.0% for two to four years. Results indicated no clear long-term benefits in refractive or axial length change across different atropine concentrations compared to controls, although these findings should be interpreted with caution due to selection bias, as a significant number of original participants were not included in the long-term follow-up because of logistical challenges and participant availability. Overall, rates of most adverse events did not differ between the various randomised groups which provides some assurance about the use of atropine for myopia management. One exception here was for myopic macular degeneration which increased significantly with increasing atropine concentration. However, the changes noted were largely retinal tessellation, which may not progress to vision loss.