Myopia Control With the Multi-segment Lens

MS lens is a novel lens designed in attempt to slow myopia progression. It is a multifocal spectacle lens which corrects distance refractive error and at the same time produces myopic defocus images on the retina for all distances. The myopic defocus aims at slowing down myopia progression. The purpose of this study is to investigate if the MS lens can slow myopia progression in Hong Kong Chinese schoolchildren. The subjects will be randomly assigned to either treatment group (wear MS lenses) or control group (wear ordinary single vision lenses). Their cycloplegic refraction and axial length will be monitored every six months over 2 years. The changes in refractive errors and axial length in two groups will be compared.

Inclusion criteria

• Age at enrolment: 8-13 year
• Spherical equivalent refractions (SER): -1.00 to -5.00 Dioptres (D)
• Astigmatism and anisometropia of 1.50 D or less
• Spectacle corrected monocular logMAR visual acuity: 0 or better
• Parents' understanding and acceptance of random allocation of grouping

Exclusion criteria

• any ocular and systemic abnormalities might affect visual functions or refractive development
• prior treatment of myopic control, e.g. drugs, orthokeratology, progressive addition lenses, bifocal lenses, drugs (e.g. atropine), etc.