Sun protection and myopia management - Q&A with Dr May Zhang and Jeff Brown

Dr. May Zhang is the Global Head of Professional Affairs at HOYA Vision Care and has rich experience in clinical practice and the eye health industry. Mr. Jeff Brown is the Vice President of Research and Development, Advanced Technology Center at HOYA Vision Care, where the MiYOSMART Sun spectacle lenses were developed.

We talk to both about the importance of outdoor time and sun protection when it comes to managing children with myopia progression and how we can incorporate this into our clinical practice.

May: In recent years, the importance of outdoor time for childhood myopia has been recognized by more and more Eye Care Professionals worldwide. A research paper investigating the international prescribing trends of pediatric ophthalmologists reported that 86% recommended increased time spent outdoors to their patients.¹ Our market research among optometrists and ophthalmologists has a similar finding, with 91% giving such recommendations. A large body of evidence shows that increased time outdoors could lower the risk of myopia onset.^2,3 Several studies suggest that outdoor time also protects against myopia progression and could probably boost the treatment effect of myopia management intervention.^4,5 The increasing attention on time outdoors is also evidenced by many studies on the mechanism of outdoor time and its related application in school.^6-7 In the myopia management community, the idea of suggesting children spend at least 2 hours a day outdoors has been widely adopted.

 One of the proposed reasons for the protective role of outdoor time is higher light intensity. The International Myopia Institute (IMI) paper defines being outdoors as exposure to light intensities over 1,000 Lux.⁸ Studies show that outdoor activities with strong sunlight exposure may not be necessary: spending enough time under trees or in the hallways at school is still beneficial.^9,10

May: These days there are many barriers to getting children outdoors. Educational pressure from school and more screen time with the wide use of digital devices and social media are two common barriers to getting children to go outside. The COVID-19 lockdown further worsened the situation when children spent more time confined indoors on screens and less time on physical activity.¹¹ A study in the UK found that even after easing lockdown restrictions, children still reported decreased amounts of physical activity and sedentary behaviours.¹²

People in some countries, such as Australia, are concerned about melanoma from excessive sun exposure. There have been dedicated awareness campaigns about sun exposure. However, sun exposure can occur safely with the help of sun protection.

It is also important to note that not all parents or schoolteachers are aware of the protective role of outdoor time against myopia. More public education is needed. Eye Care Professionals need to educate parents and children continuously.

May: Children are more susceptible to damage from UV light than adults because their pupil size is larger, and their crystalline lens is more transparent.^13,14 Of course, we don't typically consider cataracts, age-related macular degeneration, and pterygium in very young children. But UV radiation causes damage over time, and excessive exposure without sun protection in childhood increases the risk of these conditions later.¹⁵

The other perspective that is often overlooked is visual comfort under sunlight among children. When we encourage children to spend more time outdoors, a lens that brings more comfort will make them enjoy outdoor time more. Myopic children undergoing atropine treatment are a special group that particularly needs sun protection: some have to deal with glare and photophobia due to mydriasis.¹⁶

Jeff: The MiYOSMART Sun spectacle lens solutions using the D.I.M.S. Technology have been developed to meet this exact need. After all, we encourage children with myopia to spend time outdoors to slow myopia progression, but sun protection options are limited. Clip-on sunglass lenses, single-vision prescription sunglasses, contact lenses, and plano sunglasses are currently the only available options. Although they are good options, they still have limitations and don't fully combine high-efficacy myopia management and sun protection.

MiYOSMART Sun spectacle lens solutions now come in two options: MiYOSMART Chameleon, which are photochromic lenses with category 2 tinting, and MiYOSMART Sunbird, which are polarized lenses with category 3 tinting. They both offer 100% UV-A and UV-B protection.

MiYOSMART Chameleon spectacle lens provides swift darkening, transitioning from clear to 90% dark state in less than 30 seconds*. The spectacle lens fades back to clear very quickly, reaching 60% transmission after 60 seconds*. These features enable MiYOSMART Chameleon spectacle lenses as an all-in-one solution for any time and any place. At the same time, MiYOSMART Sunbird is the ideal addition to MiYOSMART clear spectacle lenses for continuous myopia management indoors and outdoors.

Jeff: For the MiYOSMART Chameleon spectacle lenses, a patented technology - Molded Laminate Photochromic Film Technology, is adopted to preserve the optical performance of the D.I.M.S. Technology used for slowing down myopia progression. During the production, we incorporate a laminate containing either a photochromic or polarizing function into the front of the polycarbonate lens.  Our process allows us to replicate the same D.I.M.S. Technology features as on a clear MiYOSMART spectacle lens.  We replicate the micro-segment geometry and spatial pattern. Therefore, the structure of multiple micro-segments remains the same. Hence, D.I.M.S. Technology is not impacted at all. The prescription is then cut to the back surface of the lens. The MiYOSMART Chameleon and Sunbird spectacle lenses adopt the same basic production process, with no impact on the D.I.M.S. Technology.

MiYOSMART Chameleon spectacle lens provides 97% light transmission in the clear state as compared to the MiYOSMART clear spectacle lens*, and the amount of light reaching the eye through the MiYOSMART Sunbird spectacle lens and the dark state of the MiYOSMART Chameleon spectacle lens is still higher than the protective level (over 1,000 Lux or 3,000 Lux) against myopia,^9,10 especially on sunny days (20,000-100,000 Lux).¹⁷

As children under MiYOSMART treatment don't have to switch to single-vision sunglasses when they go outside, wearing MiYOSMART Sun spectacle lenses could potentially increase the wearing time or treatment time of D.I.M.S. Technology. We also hope that the better visual comfort the MiYOSMART Sun spectacle lenses bring could enable children to spend more time outdoors, which may bring additive effects, as a recent study found that more outdoor time was associated with a better treatment outcome of myopia management solution.⁵

Based on technical specifications and literature,^9,10,17 the myopia management effects of MiYOSMART Sun spectacle lens solutions are comparable to MiYOSMART clear spectacle lens when the lens is prescribed with proper instruction†. Of course, patients should always consult their Eye Care Professional for treatment decisions and instructions for use.

May: Sun protection is much needed but often overlooked, even for an emmetropic child. It is equally important for children with or without myopia management. Of course, it is a greater need among some young patients, such as light-sensitive children and those under atropine treatment. It is also worth noting that continuous treatment indoors and outdoors could maximize the myopia control effect.

Because MiYOSMART Chameleon spectacle lens with photochromic feature offers an all-in-one solution, it could be the first choice in many cases, while MiYOSMART Sunbird is ideal as the 2^nd pair to MiYOSMART clear spectacle lenses. But obviously, some considerations need to be made for each child undergoing myopia management, as every child's situation is different. For example, what location and climate do you live in? In Australia, there's a lot of sun exposure, so it's important to consider sun protection. A child's lifestyle is another factor to consider: do they spend much time in the sun, such as in outdoor sports? Lastly, if your patient is wearing MiYOSMART and you're combining this with atropine, light sensitivity, and glare are possible side effects that you must manage.

In the end, it's all about giving your patients options and making sure you're doing the best you can for your patient: and that also means making sure they're doing what they can as well, which is spending time outdoors and doing so safely.

• Clinical Article: Understanding The HOYA MiYOSMART Spectacle Lens Performance

• Science Summary: Three Year Follow Up Clinical Study Results Of The Defocus Incorporated Multiple Segments (DIMS) Spectacle Lens

PRODUCT DISCLAIMERS:

• 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.
• † Assuming Photochromic as single or second pair of MiYOSMART spectacles lenses and Polarized as a second pair used in addition to clear MiYOSMART clear lenses.  Patients should always consult their Eye Care Professional for treatment decisions and instructions for use.