Purpose. To investigate myopia progression in Correction of Myopia Evaluation Trial (COMET) participants who switched to soft contact lenses (CLs) vs. remained in spectacles after the clinical trial ended.
Methods. Four hundred sixty-nine ethnically diverse, 6- to 11-year-old myopic children were randomly assigned to wear single vision lenses (SVLs) or progressive addition spectacle lenses (PALs) for 5 years as part of COMET. Afterwards they could choose another lens type, including CLs. Data in this article are from 286 participants who wore their original spectacle lenses for 6 years (n = 199) or wore CLs most or all the time between the 5- and 6-year visits (n = 87). Refractive error and axial length (AL) were measured after cycloplegia with 1% Tropicamide. The primary outcome was myopia progression between the 5- and 6-year visits. Two-year myopia progression was evaluated in a subset of 183 participants who wore the same lens type for an additional year. Myopia progression and AL were compared between the two lens groups using multiple linear regression.
Results. Participants in the two groups were similar with respect to age, ethnicity, myopia at 5-years, accommodation and phoria, but more girls switched to CLs than remained in spectacles (p < 0.0001). Mean (±SD) myopia progression was higher (p = 0.003) after 1 year in the CL group [-0.28 ± 0.33 diopter (D)] than the spectacle group (-0.14 ± 0.36 D), and remained higher after 2 years in the 2-year subset (-0.52 ± 0.46 D vs. -0.25 ± 0.39 D, p < 0.0001). Results were similar after adjustment for related factors. No significant differences in AL were found between groups after adjustment. Corneal curvature remained unchanged in both groups.
Conclusions. COMET children switching from glasses to CLs experienced a small, statistically significant but clinically inconsequential increase in myopia progression.