China: Study on Atropine Concentration for Myopia

Younger patients should be treated with a higher concentration of atropine for slowing myopia development, finds a recent study. According to the study, published in the journal Ophthalmology, low concentration of atropine ophthalmic solution at 0.05%, 0.025%, and 0.01% is associated with poor treatment outcomes in younger age.

Among atropine concentrations studied, younger children required the highest concentration of 0.05% for achieving the same reduction in myopic progression as older children on lower concentrations.

Fen FenLi, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, and colleagues investigated the effect of age of treatment and other factors on the treatment response to atropine in the Low-concentration Atropine for Myopia Progression (LAMP) study.

For the purpose, the researchers performed the secondary analysis from a randomized trial. It included 350 children (aged 4 to 12 years). The randomization was stratified by age and gender, originally assigned to receive 0.05%, 0.025%, 0.01% atropine, or placebo once daily in both eyes who completed 2 years of the LAMP study. In the second year, the placebo group was switched to 0.05% atropine group.

Change in spherical equivalent (SE) and axial length (AL) -- potential predictive factors for treatment response -- were evaluated by generalized estimating equations in each of treatment group separately over two years. The factors evaluated included age at treatment, gender, baseline refraction, parental myopia, time outdoors, diopter hours of near work, and treatment compliance.

The primary outcomes measures included factors associated with SE change and AL change over two years. Secondary outcome measures included associated factors during first year.

Key Findings of the Study

• In 0.05%, 0.025%, and 0.01% atropine group, younger age was the only factor associated with SE progression (coefficient=0.14, 0.15, and 0.20, respectively) and AL elongation (coefficient=-0.10, -0.11, and -0.12, respectively) over two years; the younger age, the poorer response.
• At each year of age from 4 to 12 across the treatment groups, higher-concentration atropine showed a better treatment response, following a concentration-dependent effect.
• In addition, the mean SE progression in 6-years-old children in 0.05% atropine was similar to that of 8-years-old in 0.025% atropine, and 10-years-old in 0.01% atropine.
• All concentrations were well tolerated at all age groups.

"Younger age is associated with poor treatment outcomes to low-concentration atropine at 0.05%, 0.025%, and 0.01%. Among atropine concentrations studied, younger children required the highest 0.05% concentration to achieve similar reduction in myopic progression as older children on lower concentrations," wrote the authors.

"Age effect on treatment responses to 0.05%, 0.025%, and 0.01% atropine: Low-concentration Atropine for Myopia Progression (LAMP) Study," is published in the journal Ophthalmology.

DOI: https://www.sciencedirect.com/science/article/abs/pii/S0161642021000014