Atropine is a mainstay treatment for myopia control, and its various concentrations are continually under investigation to find their effectiveness and potential influence on different parts of the eye. A new study in Ophthalmology reports low concentrations of atropine at 0.05%, 0.025% and 0.01% appear to have no clinical effect on corneal and lens powers, and the anti-myopic effects mainly reduce axial length elongation.

The investigation included 383 children between the ages of four and 12 who were randomly assigned to receive either 0.05%, 0.025% or 0.01% atropine or placebo once daily in both eyes. All participants completed the first year of the Low-concentration Atropine for Myopia Progression (LAMP) study.

Over one year, changes in axial length were 0.20±0.25mm, 0.29±0.20mm, 0.36±0.29mm, and 0.41±0.22mm in 0.05%, 0.025%, 0.01% atropine and placebo, respectively, with a concentration-dependent response.

Corneal power remained stable, and its changes were similar across all atropine concentrations, ranging between -0.02±0.14D and 0.01±0.14D.

Lens power decreased over time in each concentration, but its changes were also similar across all concentrations, with -0.31±0.43D, -0.38±0.47D, -0.40±0.43D, and -0.41±0.43D in 0.05%, 0.025%, 0.01% atropine and placebo respectively.

The study also noted a similar deepening of anterior chamber depth over time for each concentration. The contributions to spherical equivalent progression included changes to K, axial length and lens power after adjusting for age and gender, with similar results in each concentration.

The anti-myopic effects of low-dose atropine act mainly on reducing axial length elongation, and therefore could reduce risk of subsequent myopia complications, the researchers noted.

Li FF, Kam KW, Zhang Y, et al. Effects on ocular biometrics by 0.05%, 0.025%, and 0.01% atropine: low-concentration atropine for myopia progression (LAMP) study. Ophthalmology. June 7, 2020. [Epub ahead of print].