Research into multiple aspects of myopia control warranted.
Researchers have looked to the potential of atropine to control myopia for a long time, but the results of various studies have caused prescribing confusion among clinicians.
The confusion lies in the results of a recent study that suggested that atropine does not slow the progression of myopia in low to moderate myopes when compared to use of a placebo.1 One unique thing about this study was its location—it was one of the first large randomized clinical trial in the US. Most previous trials have been conducted in East Asia where myopia prevalence is very high.
The trial population included children who were from 5 to 12 years of age with myopia that ranged from -1.00 to -6.00 diopters spherical equivalent, 1.5 diopters of astigmatism or less, and less than 1 diopter of anisometropia. Only 13% of the study consisted of East Asian children, while the remaining were mostly White and Black children. The children either received atropine 0.01%, a low dose, or a placebo drop. The participants or their parents and guardians were instructed to instill 1 drop every night for 24 months then to continue for 6 months with no eye drops. Participants were examined at 6-month intervals for 30 months.
The study found that atropine 0.01% did not slow myopia progression or axial elongation in the cohort. The group does not support the use of atropine 0.01% given their confidence in their findings.
These findings contradict many studies previously supporting the use of atropine 0.01% for myopia management such as the CHAMP study that investigated the use atropine 0.01% in North America and Europe.2 The demographics distribution, refractive error inclusion criteria, and outcome measures were similar.
The study by Repka et al.1 is likely to create confusion on whether to continue current atropine 0.01% therapy or to look to different therapies altogether in their current patients given the contradicting results.
I believe that due to the variability in that results, it is hard to really decide whether to stop the use of atropine 0.01% completely. I have personally seen the efficacy of atropine 0.01% therapy alone on myopia progression with minimal side effects. I think further research into the true mechanism of how atropine works and the underlying pathophysiology of myopia is needed to make conclusions.”
I also think that conducting studies that focused on atropine concentrations in a single race population will help clinicians to decide which specific concentrations to use with different cases. It is well known that Asians have the highest prevalence of myopia compared to Caucasians which is the lowest.3Studies like this could tell us whether to use higher or lower dose atropine in Asian populations compared to a Caucasian population.”
Questions such as these may direct further research on how to better understand and guide treatment decisions.
I look forward to further research that will better explain the mechanisms of myopia and its treatment options. Once some of these things are identified, tailored treatments can be easily done. I think to continue low dose atropine as long as it is beneficial. Low-dose atropine may become a supplementary treatment aside from others that are known to be effective if they begin to lose some efficacy.
My concerns for the future revolve around the following issues:
Do we prescribe atropine percentages based on the rate of progression, race, and/or age, considering that Asian patients have known higher rates of progression compared to Caucasians patients? Identifying dose effectiveness within each individual big race groups may be helpful in determining overall efficacy rather than grouping all races together.
Clinical evidence already exists that low-dose atropine is effective in slowing progression in moderate myopia. How does this affect future prescribing patterns?
New findings may not stop doctors from prescribing low-dose atropine completely but the low dose may not be the first concentration they choose for patients who are high myopes with high disease progression.
Finally, use of low-dose atropine may not be as moot as we think, and research may be warranted to study synergistic effects when combined with other therapies (ortho-K lenses, multi-focal soft contact lenses, and multifocal spectacles).