MiYOSMART®
Manufacturer: Hoya
Material: Polycarbonate 1.59
Design: Defocus Incorporated Multiple Segments (DIMS) technology. Central 9mm diameter ‘clear’ zone with single vision distance correction, annular ‘treatment’ multiple focal zone (33mm diameter) with honeycomb array of 1.03mm diameter segments, each with relative positive power of +3.50D.
Product information
The MiYOSMART spectacle lens employs Defocus Incorporated Multiple Segments (DIMS) technology, designed by Hong Kong Polytechnic University. It is described as "compris[ing] a central optical zone (9 mm in diameter) for correcting distance refractive errors, and an annular multiple focal zone with multiple segments (33 mm in diameter) having a relative positive power (+3.50 D). The diameter of each segment is 1.03 mm. This design simultaneously introduces myopic defocus and provides clear vision for the wearer at all viewing distances. There are multiple foci from myopic defocus at a plane in front of the retina, which would be received as blur images on the retina."1
Myopia control mechanism
The description of the multiple zones creating retinal defocus aligns with the theory of creating simultaneous myopic retinal defocus during both distance and near viewing.
The newest scientific exploration of simultaneous defocus in animal models has been described by world-leading researcher Earl Smith III and co-workers - read a recent publication here.
Myopia control efficacy
One randomized controlled trial over two years showed efficacy in slowing axial and refractive myopia progression in Hong Kong Chinese children aged 8-13 years. After two years, the children in single vision spectacle control group were switched to the DIMS spectacle lens and showed a slowing of their progression compared to an historical age-matched control group. See the scientific paper summary below.
Prescribing information
The ideal childhood myope candidate in age and refraction for the MiYOSMART spectacle lens is not described by the manufacturers, but the participant characteristics in the clinical trial can be noted.
Peer reviewed science on MiYOSMART efficacy and safety
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Lam et al 2020. Defocus Incorporated Multiple Segments (DIMS) spectacle lenses slow myopia progression: a 2-year randomised clinical trial. [link to open access paper] [link to Myopia Profile paper review]
Hong Kong Chinese children aged 8-13 years with myopia -1.00 to -5.00D and no more than 1.50D astigmatism wore either single vision distance (SV) or the DIMS spectacle lens. Cycloplegic autorefraction and axial length were measured. After two years, average myopia progression was -0.41D vs -0.85D and 0.21mm vs 0.55mm in DIMS and SV respectively, representing a 50-60% control effect.
Distance and near acuity in DIMS was similar to SV at around 6/6 or 20/20. While children with strabismus or binocular vision (BV) anomalies were excluded from the study, DIMS showed no influence on near phoria or lag of accommodation compared to SV.
- Lam et al 2021. Myopia control effect of defocus incorporated multiple segments (DIMS) spectacle lens in Chinese children: results of a 3-year follow-up study. [link to open access paper] [link to Myopia Profile paper review] Hong Kong Chinese children aged 10-15 years who had worn DIMS lenses for two years already (Lam et al 2020) continued for a third year, while the single vision control group were switched to DIMS. Comparison to an age-matched historical control group showed a myopia control effect in the third year. In the third year, the mean annual myopia progression in the DIMS group was -0.18D and 0.11mm. The control-to-DIMS children showed 0.05D and 0.08mm change, which was not significantly different from the DIMS group. In both groups, more than 80% progressed by less than 0.50D over one year and 5% or less progressed by more than 1D. More than 50% had axial elongation less than 0.1mm.
References
- Lam CSY, Tang WC, Tse DY, Lee RPK, Chun RKM, Hasegawa K, Qi H, Hatanaka T, To CH. Defocus Incorporated Multiple Segments (DIMS) spectacle lenses slow myopia progression: a 2-year randomised clinical trial. Br J Ophthalmol. 2020 Mar;104(3):363-368. (link)
