Low concentration atropine exerts an antimyopic effect mainly by reducing axial length elongation

Investigators evaluated changes in ocular biometrics among children receiving 0.05%, 0.025% and 0.01% atropine in the Low-Concentration Atropine for Myopia Progression (LAMP) study.

Study design

The LAMP study was a double-masked, randomized, placebo-controlled trial that enrolled 383 children aged 4 to 12 years. They were assigned randomly to receive 0.05%, 0.025%, 0.01% atropine or placebo once daily in both eyes over 1 year. Cycloplegic spherical equivalent (SE), axial length (AL), corneal curvature (K), and anterior chamber depth (ACD) were measured by IOLMaster. Corneal astigmatism and lens power were calculated.

Outcomes

At 1 year, investigators observed that AL had a concentration-dependent response to atropine. Change in AL was 0.20 (±0.25), 0.29 (±0.20), 0.36 (±0.29) and 0.41 mm (±0.22) for the 0.05%, 0.25%, 0.01% and placebo groups, respectively. The contributions to SE progression from the ocular biometric changes after adjusting for age and gender were similar across all groups. For all concentrations the myopia progression was accounted for mainly by AL elongation (more than 70%).

Limitations

This study reported the changes only through 1 year of treatment. Longer-term biometric changes, including those occurring after cessation of treatment, will need to be further evaluated in subsequent phases of the LAMP study.

Clinical significance

Low concentrations of atropine exert a concentration-dependent antimyopic effect mainly by reducing axial length elongation and therefore could reduce the risk of subsequent myopia complications. This is potentially very relevant information for both pediatric ophthalmologists and retina specialists.