Long term impact of a myopia control lens on myopia progression and ocular health of young myopic eyes

Abstract

Myopia, characterized by the inability to focus light from distant targets due to the elongation of the posterior eyeball, results in blurred vision. The global prevalence of myopia has surged, particularly in East and Southeast Asia, where rates approach 100% in young urban populations. Structural changes in the posterior eye associated with elongation can lead to sight-threatening pathologies such as myopic maculopathy, a special concern for high myopias (SE<-6.00D). Research has focused on understanding myopia onset and progression and developing interventions to slow its progression. Studies in non-human primates have shown that hyperopic defocus accelerates eye growth, while myopic defocus can retard this growth. Dual focus optics, which introduce myopic defocus, have been effective in animal models and inspired the development of MiSight, a dual focus contact lens designed to slow myopia progression. Assessing efficacy of myopia control treatments is complex due to varied visual environments and the need for long-term monitoring to provide evidence of sustained effectiveness. Concerns about the long-term sustainability of initial myopia control effects and the safety of daily full-time contact lens wear in young children necessitated comprehensive clinical trials to assess both efficacy and safety. The MiSight study, a multi-year, multi-center clinical trial was designed to meet this need. This thesis is based upon seven publications that examine the ability of a dual focus contact lenses to safely slow myopia progression. Chapters explore the challenges of assessing treatment efficacy while quantifying risks of long-term contact lens wear in children. Different approaches for assessing efficacy are explored, along with efforts to quantify the treatment "dose" delivered to the retina. This work has shown that a contact lens intervention based on the principle of delivering myopic defocus to the retina can sustain slowed eye growth for multiple years in safe and effective manner.