Rebound Effect in the Misight Assessment Study Spain (Mass)

Abstract

Purpose: To investigate whether cessation of MiSight contact lens (CLs) wear for myopia control produces rebound effect. Material and Methods: This study recruited participants who had just completed the MASS Study, a two-year randomized clinical trial designed to assess the efficacy of MiSight® CLs versus distance single vision (SV) spectacles in myopic children. To assess the rebound effect, axial length progression was taken into account in those children that continued one more year of follow-up. At this visit, children were divided into three groups: MiSight-C group, in which children from the original study group continued MiSight CLs wear for the duration of the study; MiSight-D group, in which children from the original study group discontinued MiSight CLs wear in the last year; and SV-C group, in which children from the original control group continued wearing single-vision spectacles for the duration of the study. The last group was considered as the control group. Results: Of the 74 children who completed the MASS study, 55 children completed the 1-year follow-up and were included in the analysis. Thirteen children were included in the MiSight-C group, 18 in the MiSight-D group, and 24 in the Single Vision-C group. Axial length and myopia progression in the last year were 0.15± 0.11 mm, 0.22± 0.11 mm, 0.21± 0.10 mm and −0.37±0.44D, −0.46±0.39D and −0.55±0.45D for the three groups, respectively. No significant differences in axial elongation and myopia progression were found among the three groups of participants. Conclusions: Over a one-year period, neither myopia progression nor eye growth was faster for the subjects who discontinued MiSight contact lens wear compared to those who continued to wear MiSight contact lenses or those who continued to wear single-vision spectacles, indicating no rebound effect with MiSight contact lenses for 2 years.