A concentration of 0.05% atropine slowed the rate of myopia progression in pre-teen children compared with two other concentrations of the drug, according to findings published in Ophthalmology.
Researchers at the Chinese University of Hong Kong studied the efficacy and safety of 0.05%, 0.025% and 0.01% atropine eye drops over two years to determine the most useful concentration for long-term myopia control.
Using data from Phase 2 of the randomised, double-masked Low-concentration Atropine for Myopia Progression (LAMP) study, the researchers identified 383 children – aged 4 to 12 years diagnosed with myopia of -1.0 D or greater – who were split into groups receiving either atropine 0.05%, 0.025%, 0.01% or placebo once daily in both eyes in both phases of the study.
The researchers measured cycloplegic refraction, axial length, accommodation amplitude, photopic and mesopic pupil diameter and best-corrected visual acuity every four months.
Study lead Associate Professor Jason Yam and colleagues concluded that “all concentrations of atropine were well tolerated without apparent adverse effects on the quality of life”.
However, “the efficacy of 0.05% atropine was double that observed with 0.01% atropine in spherical equivalent progression over two years,” they wrote.
In the second year, the researchers observed a similar efficacy between the 0.05% and 0.025% atropine groups compared with the first year and a mild improvement in the 0.01% atropine group.
Myopia progression of children originally placed in the placebo group in phase 1 of the study was significantly reduced after they were moved into to the 0.05% atropine group.
Axial length elongated 0.15 mm in the second year compared with 0.43 mm in the first year in this group, Yam and colleagues wrote.