Effectiveness of the Defocus Incorporated Spectacle Lenses on Fast Progressing Myope

Effectiveness of the Defocus Incorporated Spectacle Lenses on Fast Progressing Myope: A Randomised Control Trial

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 (DG2) 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 (DG2) group (treatment). After 12 months of lens wear, the SV lens prescribed to the control group will be replaced with the DG2 lens and be monitored for another 12 months. In parallel, the DG2 treatment groups will continue their corresponding intervention for 12 months. Their cycloplegic refraction and axial length will be monitored every 6 months over 2 years. The changes in refractive errors and axial length in two groups will be compared.

Participants will be randomly allocated to either control (wearing single vision lenses) group or treatment (DG2 lens) group for first 12 months. After 12 months, the SV lens prescribed to the control group will be replaced with the DG2 lens and be monitored for another 12 months. In parallel, the DG2 treatment groups will continue their corresponding intervention for 12 months.

Both participants and their guardians will be masked from the grouping. The outcomes assessors will be also masked from the grouping.

Subjects in single vision lens group will receive a pair of single vision lenses for the first year of study. They will then receive a pair of DG2 lenses for the second year of the study.

DG2 is a variant of Defocus Incorporated Spectacle lens that corrects the distance refraction and provides myopic defocus simultaneously

Cycloplegic SER (in diopter) will be measured using an open field autorefractor. Change in SER with cycloplegia from the baseline over a first 12-month period and a 12-month period of follow-up will be measured

Axial length (mm) will be measured after cycloplegia using a non-contact optical biometer. Change in axial length from the baseline over a first 12-month period and a 12-month period of follow-up will be measured

Inclusion Criteria: SER: -1.00D or below 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 Best-corrected monocular visual acuity (VA) in both eyes: 0.00 logMAR (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