Myopia Control Using Optimized Optical Defocus RCTs

The purpose of the current study is to evaluate whether the DISC3.5 Plus contact lens will slow myopia progression and axial length growth in myopic children as compared with single vision soft contact lenses.

The Defocus Incorporated Soft 3.5 Plus Contact Lens (DISC3.5 Plus) is a soft contact lens that comprises of simultaneous distance optical prescription and myopic defocus areas.

The efficacy of the DISC3.5 Plus lens in slowing myopia progression (change in refractive error) will be compared to a spherical (front and back surface) single vision soft contact lenses in this one-year prospective, randomised and double-masked clinical trial. The hypothesis of this study is that the DISC3.5 Plus will slow myopia progression more than spherical single vision soft contact lenses.

Inclusion criteria

• Age at enrolment: 8-13 year; Hong Kong Chinese
• Spherical equivalent refractions (SER): -1.00 to -5.00D
• Astigmatism: -1.00D or less
• Anisometropia: 1.25D or less
• Spectacle corrected monocular visual acuity (VA): 0.0 logMAR or better
• Contact lens corrected monocular VA: 0.1 logMAR or better
• Normal binocular function
• Willingness to wear contact lenses regularly
• Parents' understanding and acceptance of random allocation of grouping and masking

Exclusion criteria

• Prior myopia control treatment, e.g. orthokeratology, defocus soft contact lenses, progressive addition lenses, bifocal lenses, drugs (e.g. atropine), etc.
• Strabismus or decompensated phoria (checked by cover test at far and near in screening)
• Known contraindications for contact lens wear
• Have any ocular and systemic diseases and abnormalities that might affect visual function or refractive development