Journal Highlights
Ophthalmology, January 2019
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Low-concentration atropine is a new treatment for myopia progression, but its efficacy and optimal concentration are uncertain. In a large double-masked trial, Yam et al. compared efficacy and safety between eyedrops containing low amounts of atropine (0.05%, 0.025%, or 0.01%) and placebo eyedrops. They noted a concentration-dependent effect for the reduction of myopia progression. All doses were well tolerated and had no adverse effect on vision-related quality of life. The highest concentration (0.05%) proved the most effective for controlling spherical equivalent (SE) progression and axial length (AL) elongation in their one-year study.
This randomized placebo-controlled study included 438 children between the ages of 4 and 12 who had myopia of at least –1.0 D and astigmatism of –2.5 D or less. Patients were assigned randomly (1:1:1:1) to receive atropine eyedrops (0.05%, 0.025%, or 0.01%) or control drops, which contained sodium chloride. Drops were applied nightly for a full year. Accommodation amplitude, AL, best-corrected visual acuity, cycloplegic refraction, and pupil diameter were measured at five points (baseline, week 2, and months 4, 8, and 12). A visual function questionnaire was administered at the one-year visit. Main outcomes were changes in SE and AL. A generalized estimating equation was used to compare findings.
At one year, mean SE had changed by –0.27 D, –0.46 D, –0.59 D, and –0.81 D in the 0.05%, 0.025%, and 0.01% atropine groups and the placebo group, respectively. The corresponding mean increases in AL were 0.20 mm, 0.29 mm, 0.36 mm, and 0.41 mm. Accommodation amplitude was reduced by 1.98 D, 1.61 D, 0.26 D, and 0.32 D, respectively. The increases in pupil size under photopic and mesopic conditions (respectively) were 1.03 and 0.58 mm in the 0.05% atropine group, 0.76 and 0.43 mm in the 0.025% atropine group, 0.49 and 0.23 mm in the 0.01% atropine group, and 0.13 and 0.02 in the placebo group. (All p values < .001.) Visual acuity and vision-related quality of life were not impaired in any group.
More phases of the study are planned to assess the durability and longevity of these effects. After the second phase, the authors will report two-year efficacy and safety findings for the three concentrations of atropine. Subsequently, the researchers will assess the viability of discontinuing treatment once the myopia progression has been controlled, and atropine will be resumed in appropriate cases. (Also see related commentary by Padmaja Sankaridurg, PhD, in the same issue.)
The original article can be found here.