Abstract
Purpose :
A 6-year clinical trial randomized subjects to MiSight 1 day (Omafilcon A, dual focus design, CooperVision, Inc.; M1d) or Proclear 1 day (Omafilcon A, single vision, CooperVision, Inc.;P1D) contact lenses for the first three years during which M1d significantly slowed axial elongation Chamberlain et al. (2019). This analysis reports annual axial elongation and overall treatment effects over 6 years using a virtual control group.
Methods :
Part 1: 144 myopic children (8-12 years of age) were randomized to wear either M1d or P1d. Part 2: After 3 years, the P1d wearers (n=56) were switched to M1d lenses (M1d-3) while the original treatment group (M1d-6; n=52) continued with M1d. All subjects were followed, unmasked, for an additional 3 years. In the absence of a concurrent control group, a virtual control group was created, based on the axial elongation model of Brennan et al. (AAO 2018). Estimated annual elongation (EAE) was calculated using the age and ethnicity of the P1d control cohort and used to quantify the myopia treatment effect of MiSight over the full 6 years.
Results :
EAE for the virtual control group agrees well with the experimental control group during years 1-3. The EAE was 0.619 mm and 0.624 mm respectively, validating the virtual control group and its use for estimating EAE for an untreated control group for the final 3 years. The EAE for the virtual control group growth in years 4 to 6 was 0.395 mm. The year 4-6 total elongation in the M1d-3 and M1d-6 groups were 0.190 mm and 0.184 mm indicating 0.205 mm and 0.211 mm treatment effects. The treatment effect for the M1d-6 group when compared to the virtual control group over the full 6 years revealed a 0.529 mm reduction in axial eye growth (six year cumulative growth of 1.014 (control) – 0.485 mm (treatment).
Conclusions :
Using a virtual control group, M1d substantially retards myopia by slowing axial elongation throughout six years of wear. This approach also shows effectiveness in newly treated older subjects in years 4-6.
This is a 2021 ARVO Annual Meeting abstract.