Long‐term Effect of Dual‐focus Contact Lenses on Myopia Progression in Children: A 6‐year Multicenter Clinical Trial

SIGNIFICANCE Treatment of myopic children with a dual‐focus soft contact lens (DFCL; MiSight 1 day) produced sustained slowing of myopia progression over a 6‐year period. Significant slowing was also observed in children switched from a single vision control to treatment lenses (3 years in each lens). PURPOSE This study aimed to evaluate the effectiveness of DFCLs in sustaining slowed progression of juvenile‐onset myopia over a 6‐year treatment period and assess myopia progression in children who were switched to a DFCL at the end of year 3. METHODS Part 1 was a 3‐year clinical trial comparing DFCLs with a control contact lens (Proclear 1 day) at four investigational sites. In part 2, subjects completing part 1 were invited to continue for 3 additional years during which all children were treated with MiSight 1 day DFCLs (52 and 56 from the initially treated T6 and control T3 groups, respectively). Eighty‐five subjects (45 T3 and 40 T6) completed part 2. Cyclopleged spherical equivalent refractive errors (SEREs) and axial lengths (ALs) were monitored, and a linear mixed model was used to compare their adjusted change annually. RESULTS Average ages at part 2 baseline were 13.2 ± 1.3 and 13.0 ± 1.5 years for the T6 and T3 groups, respectively. Slowed myopia progression in the T6 group observed during part 1 was sustained throughout part 2 (mean ± standard error of the mean: change from baseline SERE in diopters, −0.52 ± 0.076 vs. −0.51 ± 0.076; change in AL in millimeters, 0.28 ± 0.033 vs. 0.23 ± 0.033; both P >. 05). Comparing progression rates in part 2 for the T6 and T3 groups, respectively, indicates that prior treatment does not influence efficacy (SERE, −0.51 ± 0.076 vs. −0.34 ± 0.077; AL, 0.23 ± 0.03 vs. 0.18 ± 0.03; both P >. 05). Within‐eye comparisons of AL growth revealed a 71% slowing for the T3 group (3 years older than part 1) and further revealed a small subset of eyes (10%) that did not respond to treatment. CONCLUSIONS Dual‐focus soft contact lenses continue to slow the progression of myopia in children over a 6‐year period revealing an accumulation of treatment effect. Eye growth of the initial control cohort with DFCL was slowed by 71% over the subsequent 3‐year treatment period.