Discontinuation Approach and Follow-Up of Low-Concentration Atropine for Myopia Progression: Eight-Year Results of the LAMP Randomized Clinical Trial

Abstract

Importance Some but not all clinical trials have found 0.05% atropine effective for myopia control; however, discontinuation management remains unclear. Objective To evaluate a taper vs stop treatment discontinuation approach. Design, Setting, and Participants This randomized clinical trial involved children aged 4 to 12 years originally from the Low-Concentration Atropine for Myopia Progression (LAMP) study who were followed up for 8 years. All children who completed year 5 follow-up and were receiving atropine treatment were randomized into taper and stop groups at a 1:1 ratio. Interventions During the prediscontinuation period (year 6), participants in the taper group received 0.05% atropine for 6 months and then 0.025% atropine for another 6 months, while the stop group received 0.05% atropine eye drops for a full year. During the discontinuation period (years 7 and 8), all participants stopped the treatment and were monitored for 2 years. Main Outcomes and Measures Myopia progression in the taper and stop groups over 3 years; proportion of good response to treatment discontinuation, defined as spherical equivalent (SEP) progression −0.5 diopter (D) or more in both eyes during the discontinuation period; and associated factors with myopia progression over 3 years. Results Among 246 children who completed the year 5 follow-up, 180 children (73.2%) went on to complete 8 years of follow-up. The mean (SD) age was 13.47 (1.63) years; there were 139 male children (56.5%) and 107 female (43.5%). Over 3 years, SEP and axial length (AL) elongation were faster in the stop group than in the taper group: –0.78 D vs –0.54 D, respectively (difference, −0.24 D; 95% CI, −0.46 to −0.03 D; P =.02) and 0.44 mm vs 0.33 mm, respectively (difference, 0.11; 95% CI, 0.03 to 0.19 D; P =.01). The proportion of good response to treatment discontinuation in the taper group was greater than in the stop group (65.1% vs 42.6%, respectively; P =.003). Younger age and more myopic spherical equivalent/longer AL at prediscontinuation were associated with faster SEP and AL elongation over 3 years. Notably, the younger the age and the more myopic the spherical equivalent, the greater the estimated mean differences of SEP/AL elongation between the taper and stop groups. Conclusions and Relevance This study found that over 3 years, the participants in the taper group had less myopia progression than the stop group, particularly in children who were younger and had more myopia. However, to our knowledge, the clinical relevance of this approximately 0.25-D difference between treatment groups is not well understood from the current medical literature.