Myopia Control Efficacy of Second-generation DIMS Spectacle Lenses on Fast Progressing Myopes

The purpose of this study is to examine the efficacy and performance of the variant of Defocus Incorporated Spectacle lenses on controlling myopia progression in fast progressing myopic children.

The variant of Defocus Incorporated Spectacle lenses (D2) is a multifocal spectacle lens that produces myopic defocus images and corrects distance refractive errors at the same time. Participants will be randomly allocated to either single vision lens group (control) or the variant of Defocus Incorporated Spectacle lens (D2) group (treatment). After 12 months of lens wear, the SV lens prescribed to the control group will be replaced with the D2 lens and be monitored for another 36 months. In parallel, the D2 treatment groups will continue their corresponding intervention for another 36 months. Their cycloplegic refraction and axial length will be monitored every 6 months over 4 years. The changes in refractive errors and axial length in two groups will be compared.

Inclusion Criteria: * SER: -0.75D or below in both eyes * Documented history of fast progressing myopia, either in SER or AL * SER progression: 0.50D/year or more * AL elongation: 0.27mm/year or more * For children aged 4-6 years without past prescription forms, * 4-5 years old: myopia of -0.75D or below in both eyes * 6 years old: myopia of -1.25D or below in at least one eye, with the other eye -0.75D or below * Best-corrected visual acuity (VA) in both eyes: * 4 - 6 years old: 0.20 logMAR (or its equivalent) or better * 7-12 years old: 0.00 logMAR (or its equivalent) or better * Acceptance of random group allocation and the masked study design * Anisometropia of 1.50 D or less * Astigmatism of 2.00 D or less Exclusion Criteria: * Strabismus and binocular vision abnormalities * Ocular and systemic abnormalities * Prior experience of myopia control