Many current myopia control interventions work well – but when young progressing myopes venture outside on the advice of their eyecare professional, their eyes are often unprotected from the sun. This was the impetus for HOYA to broaden its MiYOSMART range to incorporate two new sun lens options.
For Australian eyecare professionals wanting to control myopia with proven interventions, it’s been an exciting time as many new products come to market, particularly in the spectacle lens category. Myopes now have access to a suite of solutions that will correct their refraction and slow progression, but what options are there when heading outdoors into harmful UV rays and intense sunlight?
In the flurry of headlines about myopia innovations, it’s important not to lose sight of one of the most important positive factors – outdoor daylight. In fact, in a 2022 position paper, RANZCO recommends children spend at least two to three sun-protected hours outdoors daily.1 The college also called for a more nuanced approach towards sunlight exposure that optimises UV exposure, but not to the level that results in vitamin D deficiency, and, importantly, maintains exposure to sufficient high-intensity sunlight to minimise myopia progression.
But a problem remains: of the myopia interventions available, few can offer continuous myopia management indoors and outdoors. This means children may not be receiving effective myopia management with single-vision sunglasses, could be avoiding heading outdoors due to the sunlight intensity and/or photophobia, or may be out in the sun without adequate protection.
Ophthalmic lens manufacturer HOYA Vision Care has acknowledged this gap in myopia care – and in July 2023 will launch the MiYOSMART sun range, comprising:
• MiYOSMART Chameleon – photochromic spectacle lenses, offering an all-in-one solution to myopia management and protected outdoor activity. It rapidly adapts to the level of sunlight and fades back to clear indoors in seconds.
• MiYOSMART Sunbird – polarised spectacle lenses that work as an addition to MiYOSMART clear spectacle lenses, for extra protection from intense sunlight and glare. It also offers vibrant colours and rich contrast in bright light.
While protecting from sunlight, the lenses incorporate HOYA’s DIMS technology found in the company’s original non-invasive MiYOSMART clear spectacle lenses, launched in Australia in October 2020. The technology has been shown to slow myopia progression by 60% in children aged 8 to 132 after two years, with more recent six-year data showing the treatment effect has been sustained over time.3
Mr Ulli Hentschel, national training and development manager for HOYA Lens Australia, says increased time outdoors is one of the major factors for tackling myopia onset and potentially progression – and he expects the new MiYOSMART sun range to have high uptake in sun-drenched Australia.
“If we have children already wearing MiYOSMART clear lenses and we’re trying to encourage them to spend more time outdoors, then we’re potentially exposing them to increased sunlight exposure and additional UV. By creating MiYOSMART Chameleon and MiYOSMART Sunbird, we’re offering something that addresses two major issues – allowing children to spend more time safely outdoors, along with the treatment effect of a proven optical intervention,” he says.
“HOYA has also done a lot of work in the past year around combining atropine with MiYOSMART for those progressing beyond the treatment target, and the new sun range could be beneficial to patients who may have issues with photophobia due to atropine dilating the pupil.”
Increasing the overall wearing time
To support the introduction of the MiYOSMART sun range, HOYA held an advisory meeting where four independent experts, suggested by the International Myopia Institute (IMI), provided a consensus on daylight and myopia management.
They found the role of outdoor time in children with myopia is still unclear but it was scientifically accepted that spending more than 80 minutes a day outdoors in daylight has a preventive effect on the onset of myopia and possibly reducing progression.4 The experts mentioned that each 45 minutes additionally spent outdoors can prevent 20% of the onset of myopia.
“The longer the optical treatment options are worn, the greater the expected effectiveness of the treatment will be,” they added.
Emphasising the importance of sun protection from UV rays, the experts said this was important to avoid the risk of early cataracts, damage to the conjunctiva and potentially the retina.5
When it comes to understanding the role of light transmission on myopia management lenses, the consensus group stated UV rays should be cut below 380nm – a standard in sun protection.6 However, from animal studies in a white paper from the IMI, it is unclear which visible wavelengths play a role in regulating eye growth.7 It may be the full visible light spectrum, light intensity and child behaviour influence on the axial eye length rather than a particular wavelength itself.8
The experts mentioned that even with sunglasses, children will still be exposed to more intense light outdoors than indoors and still have the positive effect of daylight for myopia management.9 Hence, HOYA says myopic children should be encouraged to partake in any activities outdoors, from vigorous play to quiet reading.
On the question of whether combining sun protection with an optical treatment like MiYOSMART would have a greater overall effect, the independent experts said the evidence wasn’t available yet.
“It requires further investigations to find out if the treatment effect is influenced by the combination of myopia management spectacles alongside sun protection filters compared to the current studies on clear spectacle lenses,” they reported.
“A potentially beneficial effect of using myopia management spectacles lenses in combination with protection from intense sunlight may occur if this leads children to spend more time outdoors or increases the overall wearing time of the optical myopia management treatment. Photochromic lenses would make it easier for the child to have one pair of spectacles for both indoors and outdoors.”
They conclude: “The possible slowing of myopia progression by increasing the wearing time of defocus optics could be positively influenced by prolonged exposure to daylight when symptoms from intense sunlight would be less disturbing due to inbuilt sun protection.”
The opportunity for optical practices
Hentschel says it made sense for HOYA to develop two MiYOSMART sun lens designs to cater for the differing needs of progressing myopic children.
MiYOSMART Chameleon, considered an all-in-one solution, could be suitable for children who find it inconvenient to change their glasses when they step outside. The lens rapidly adapts to the levels of sunlight, providing children with as much protection as they require at any time.
When developing MiYOSMART Chameleon, Hentschel says the company had to take a different approach to that used on its Sensity light-adaptive photochromic range.
“We had to come up with a different way of manufacturing MiYOSMART Chameleon, adopting a technology where the photochromic layer is not applied on the front surface so that the DIMS treatment zone is not affected,” he says. “These lenses adopt a Patented Molded Laminate Photochromic Film Technology to preserve optical performance of DIMS Technology.”
With MiYOSMART Sunbird polarised spectacle lenses, Hentschel says these are an ideal addition to MiYOSMART clear spectacle lenses, for continuous myopia management indoors and out. Patients who adopt this approach will likely require two pairs.
“For a patient that’s particularly glare sensitive, and this goes back to those on combination treatment involving doses of atropine, having a polarised sunglass in MiYOSMART Sunbird that cuts out more of the light compared to the photochromic lens may be more beneficial. And if there’s a need for darker sunglasses, then that’s potentially the better option,” he explains.
“But I see the potential of MiYOSMART Chameleon photochromic becoming a more standard option because they’re really clear indoors and then the child doesn’t have to have a separate pair for outdoor use. I see it more as a go-to product that addresses the majority of needs most of the time.”
Acknowledging that additional pairs lead to increased costs for parents, Hentschel says HOYA is running a special promotion that will help bridge the gap.
In addition, for MiYOSMART Chameleon, all children who received these lenses will get a 30-day “satisfaction or free exchange” warranty, meaning they have the option to switch back to MiYOSMART clear spectacle lenses free-of-charge within 30 days of receiving MiYOSMART Chameleon.
Alongside the launch of the MiYOSMART sun range, HOYA will launch a campaign called: ‘Protect how they see the world’, to raise awareness of the importance of outdoor time and sun protection in children.
More reading
When to combine HOYA MiYOSMART lens with atropine
A myopia first: Hoya lens shows long-term efficacy
Hoya and Haag-Streit’s new alliance brings one-two approach to myopia
References
1. RANZCO Position Statement: Progressive Myopia in Childhood – 2022
2. Lam CSY, Tang WC, Tse DY, et al. Defocus Incorporated Multiple Segments (DIMS) spectacle lenses slow myopia progression: a 2-year randomised clinical trial. Br J Ophthalmol. 2020;104(3):363-368.
3. Lam CSY, Tang WC, Zhang A, Tse D, To CH. Myopia control in children wearing DIMS spectacle lens: 6 years results. ARVO 2022 Annual Meeting, May 1-4, Denver, US.
4. Jonas JB, Ang M, Cho P, et al. IMI prevention of myopia and its progression. Invest Ophthalmol Vis Sci. 2021;62(5):6. https://doi. org/10.1167/iovs.62.5.6Morgan IG, Wu P-C, Ostrin LA, et al. IMI Risk factors for myopia. Invest Ophthalmol Vis Sci. 2021;62(5):3. https://doi.org/10.1167/iovs.62.5.3
5. Backes C, et al., Sun exposure to the eyes: predicted UV protection effectiveness of various sunglasses. J Expo Sci Environ Epidemiol. 2019 Oct;29(6):753-764. doi: 10.1038/s41370-018-0087-0. Epub 2018 Oct 31. PMID: 30382242; PMCID: PMC6803516.
6. ISO 8980-3:2013(en)Ophthalmic optics
7. Troilo D, et al.; IMI – Report on Experimental Models of Emmetropization and Myopia. Invest. Ophthalmol. Vis. Sci. 2019;60(3):M31-M88. doi:10.1167/iovs.18-25967.
8. Zhang, P., Zhu, H. Light Signaling and Myopia Development: A Review. Ophthalmol Ther 11, 939-957 (2022). https://doi. org/10.1007/s40123-022-00490-2
9. Lanca C, Teo A, Vivagandan A, Htoon HM, Najjar RP, Spiegel DP, et al. The Effects of Different Outdoor Environments, Sunglasses and Hats on Light Levels: Implications for Myopia Prevention. Transl Vis Sci Technol. 2019;8(4):7.
