New long-term and observational study data on Hoya MiYOSMART

The Defocus Incorporated Multiple Segments (DIMS) spectacles lens, commercialised by Hoya Corporation as MiYOSMART, introduced a completely novel spectacle lens designed specifically for the control of myopia. The recent publication of MiYOSMART’s 6-year data marks the longest running clinical trial involving this new generation of myopia controlling spectacle lenses. This article will explain the insights gained from the 6-year data, as well as the data obtained on European children out of the United Kingdom.

The 6-year clinical trial was a continuation of the eminent 2-year randomized control trial. 90 children ended up completing the six-year trial, from the initial 183 children that were involved in the published two-year data. Due to the COVID-19 pandemic, the trial site was closed at the 3.5-year mark of the trial. The children were told to continue wearing the treatment and to return when the clinic was reopened again. 

90 children completed 6-year follow-up visit and divided into 4 groups:

• Group 1 (n=36) wore the DIMS spectacle lenses from 0 to 6 years
• Group 2 (n=14) wore DIMS spectacles from 0 to 3.5 years and changed to single vision (SV) spectacles afterwards
• Group 3 (n=22) wore SV spectacles in the first 2 years and switched to DIMS spectacles afterwards
• Group 4 (n=18) wore SV spectacles in the first 2 years, switched to wear DIMS spectacles for 1.5 years and then switched to SV spectacles again

The 6-year follow-up revealed important findings from each of the groups:

• Group 1 exhibited a consistent rate of myopia progression over the course of 6 years of DIMS spectacle wear: in the first 3 years myopia progression was − 0.52 ± 0.66D (annual rate: − 0.17D/year), and the later 3 years it was − 0.40 ± 0.71D (− 0.13D/year). They exhibited an average cumulative myopia progression of slightly under -1.00D, specifically -0.92D or -0.15D per year, along with an average axial elongation of 0.60mm, equivalent to 0.10mm per year, over a span of 6 years. This showed that the myopia management effect of the DIMS spectacle lenses was sustained over the 6 years. In comparison, the children in the control group showed the same progression in the first two years as the children who wore DIMS spectacle lenses for six years.
• Group 3 wore DIMS spectacle lenses for 4 years (started after the 2-year RCT) and started the treatment at an older age while those in Group 1 wore the DIMS spectacle lenses for 6 years; the myopia management effect of the DIMS spectacle lenses was sustained over the 4 years.      Group 3 exhibited slower myopia progression and axial growth than Group 1 – this indicates that older children may benefit from greater treatment effect with DIMS wear. However, starting myopia treatment early is still recommended.³
• The DIMS spectacle lens groups (Groups 1 and 3) overall had markedly less progression and axial elongation than the single vision groups (Groups 2 and 4).
• No adverse events were reported over the 6-year period from all groups.

The rebound effect occurs when the initial therapeutic benefits of a treatment are followed by a worsening of myopia once the treatment is discontinued or reduced. It is defined as an accelerated eye growth upon cessation of a treatment when compared to an age-normative, untreated cohort.⁴ Groups 2 and 4 exhibited progression when switched back to single vision spectacles from DIMS spectacle lenses, however this does not signal a rebound effect: wearing DIMS spectacle lenses showed a flatter slope for progression rates, but SV wear after DIMS spectacle lens wear did not show faster progression when compared to progression rate prior to DIMS spectacle lens wear, and was also at age-normal rates.

Data from studies by Wong et al and Chamberlain et al were used to form the black line representing axial length progression of normative, non-treated myopic children.^5,6 The blue line represents the change in axial length of children in Group 2 and becomes a dotted line after 42 months representing the switch to SV lenses.¹

The myopia management benefit from DIMS lenses appears to be highest within the initial 12 months, and gradually decreases thereafter. The switchover to SV lenses from DIMS shows a continued progression; notably, the dotted line does not exceed the age-normative non-treated group at any point. This indicates that the DIMS therapeutic effect remains intact even after cessation of DIMS lens wear due to the absence of a rebound effect.

While Group 2 children wore DIMS lenses continuously before switching to SV, Group 4 had a different experience as they wore SV for 2 years before switching to DIMS lenses for 1.5 years and then being switched back to SV lenses as represented in the graphs below.

The short period of DIMS wear indicated with the solid blue line reveals a substantially decreased myopia progression rate in both SER and axial length as compared to prior and post-DIMS lens wear. The rate of progression post-DIMS wear continued at a similar rate to single vision wear prior to DIMS lens wear, indicating that there was no worsening of progression upon cessation of DIMS lens wear and hence no rebound effect.

The 6-year data for the DIMS spectacle lens is invaluable as it provides a robust evidence base for its use in myopia management.^1-2,7 Short-term studies may only offer limited insights into the immediate impact of myopia management interventions. However, long-term studies provide a more comprehensive evaluation of an intervention's safety and effectiveness over an extended period. They also help in determining the predictability and stability of the effects over time.⁶ That the myopia management effect is sustained over 6 years is valuable clinically as it allows confidence in prescribing for long-term safety and effectiveness. The absence of a rebound effect is also a valuable observation as it ensures assurance in treatment planning and management after cessation of treatment.

Though the 6-year RCT data is important, it does have limitations: the study site was conducted in Hong Kong and therefore only involved ethnically Chinese children.      In order to compare the effectiveness of the DIMS spectacle lens on other populations, an observational study is currently being conducted over a 2-year period in the UK to investigate MiYOSMART’s tolerability, efficacy, and impact of age. The 1-year results have recently been presented at the Association for Research in Vision and Ophthalmology (ARVO) 2023 meeting⁷ and the latest (unpublished) data at the European Academy of Optometry and Optics 2023.⁸ The study involved 128 children aged between 5-15 years old, of predominantly Caucasian ethnicity: 63% White, 19% Indian Asian, 6% Chinese, and 12% classified as Other. Children with spherical equivalent refraction (SER) from -0.50D to -8.50D, anisometropia ≤1.50D and astigmatism ≤2.50DC were included in the study. They found that:

• Average 12-month change of the whole cohort aged 5-15 years old in refraction and axial length (AL) were -0.36±0.42D and 0.18±0.20mm respectively.⁵
• Children younger than 10 years showed significantly more myopic progression (-0.56D vs -0.22D) and AL increase over 12-months (0.32mm vs 0.08mm) than those age 10-15 years.⁷
• DIMS spectacle lenses had excellent tolerability and acceptance rates by European children based on questionnaires. Within one week, most children were symptom-free. Children younger than 10 years old typically had better tolerance rates.⁸
• Visual performance was excellent in DIMS spectacle lenses: distance and near visual acuity, stereoacuity, accommodative lag and near heterophoria did not appear to have any clinically significant differences from SV spectacle lens performance.⁸

The study involved children of Caucasian and other ethnicities. In the graph below, the red line represents change in SER in the UK population of only children aged 8-13 years old, to age-match the population in the original Lam et al study which is represented by the solid blue line. From the graph, it can be seen that changes in SER in  the UK population is close to that of the Asian population meaning that MiYOSMART efficacy can be expected to be comparable between the ethnicities involved in both studies, even though the study in the UK was partially affected by COVID. European children experienced an average -0.26±0.37D change in SER while Asian children experienced -0.17±0.05D. Similarly, European children exhibited an axial length change of 0.14±0.16mm in a 12-month period while Asian children exhibited 0.11±0.02mm.

Importantly, this study shows that MiYOSMART is effective in children of Caucasian and potentially other ethnicities, which supports its use in the wider population. This data appears to be in support of the recent comment on how myopia management     efficacy appears to be consistent in absolute terms when compared across ethnicities.⁹ Similar to the original RCT, this observational study also noted that MiYOSMART spectacle lens appears to be more effective in older children Along with research indicating increased efficacy of MiYOSMART as a combination treatment with atropine,10,11 the 2-year data would add to the body of evidence indicating the versatility of MiYOSMART as a myopia management solution.

Long-term MiYOSMART spectacle lens data provides a robust evidence base for its use in myopia management, showing that DIMS spectacle lenses are not only efficacious, but safe for myopia control and do not result in a rebound effect on discontinuation of wear. Based on the UK data, it also has application in Caucasian children and potentially other ethnicities.

PRODUCT DISCLAIMER - MiYOSMART has not been approved for myopia management in all countries, including the U.S., and is not currently available for sale in all countries, including the U.S.