Younger age tied to poor response to low-concentration atropine

Younger age appears to contribute significantly to poor treatment response to low-concentration atropine at 0.05%, 0.025%, and 0.01%, a study has found.

“Among concentrations studied, younger children required the highest 0.05% concentration to achieve similar reduction in myopic progression as older children receiving lower concentrations,” the investigators said.

This secondary analysis examined the effect of age at treatment and other factors on treatment response to atropine in the Low-Concentration Atropine for Myopia Progression (LAMP) Study. In total, 350 children aged 4–12 years who were originally assigned to receive 0.05%, 0.025%, or 0.01% atropine or placebo once daily, and who completed 2 years of the LAMP Study, were included. The placebo group shifted to the 0.05% atropine group in the second year.

Generalized equations were used to evaluate potential predictive factors for change in spherical equivalent (SE) and axial length (AL) in each treatment group over 2 years. Analysed factors were gender, age at treatment, baseline refraction, parental myopia, time outdoors, dioptre (D) hours of near work, and treatment compliance. The investigators also generated estimated mean values and 95 percent confidence intervals (CIs) of change in SE and AL over 2 years.

In all low-concentration atropine groups, only younger age correlated with SE progression (coefficient of 0.14, 0.15, and 0.20, respectively) and AL elongation (coefficient of –0.10, –0.11, and –0.12, respectively) over 2 years: the younger the age, the poorer the response.

Higher-concentration atropine exhibited better treatment response at each year of age from 4 to 12 years across treatment groups following a concentration-dependent effect (p_trend<0.05 for each age group). Moreover, the mean SE progression in 6-year-old children on 0.05% atropine (–0.90 D, 95 percent CI, –0.99 to –0.82) was comparable to that of 8-year-old children receiving 0.025% atropine (–0.89 D, 95 percent CI, –0.94 to –0.82) and 10-year-old children given 0.01% atropine (–0.92 D, 95 percent CI, 0.99 to –0.85).

“All concentrations were well tolerated in all age groups,” the investigators said.