Combining myopia treatment with UV protection

At the completion of this article, the reader should be able to improve their myopia management approach, including…

• Recognise the association between outdoor high lux light exposure in childhood and reduced myopia progression. 
• Review some of the evidence linking outdoor activity and UV exposure to both myopia management and UV-related eye conditions. 
• Examine the inverse relationship between myopia and the prevalence of UVR-related eye conditions such as pterygium. 
• Understand how 0.01% atropine can be integrated into holistic myopia treatment protocols alongside outdoor activity recommendations.  

Dr Shanel Sharma
BSc (Med), MBBS, FRANZCO, GAICD,
MBA (Exec) Excellence
Eye & Laser Surgeons, Bondi Junction & Miranda
Paediatric, strabismus and cataract surgery – www.eyeandlaser.com.au 

Dr Daya Sharma
BSc (Med) Hons I, MBBS, MSc (Research),
FRANZCO, GAICD, MBA (Exec)
Eye & Laser Surgeons, Bondi Junction & Miranda
Corneal, cataract and refractive Surgeon – www.eyeandlaser.com.au

Dr Loreto (Loren) Rose
BSc (Hons) MBBS (Hons) FRANZCO PhD
paediatric and general ophthalmic Surgeon
Clinical Senior Lecturer, Macquarie Medical School
Adjunct Associate Professor, University of Canberra
Founding member of Myopia Australia – www.myopiaaustralia.com.au

As eyecare professionals increasingly recommend outdoor activities to curb the myopia epidemic, another concern arises: ultraviolet radiation-related eye disease. But how does one balance their approach, while integrating 0.01% atropine as an early intervention and ensuring proper guidance to prevent UV-induced eye conditions. 

Myopia is a worldwide epidemic, a fact that has justifiably garnered increasing attention and research around the world. The prevalence of myopia is expected to reach 52% by 2050.¹ Complications secondary to myopia can lead to loss of vision and are expected to become the leading cause of permanent blindness in adults. These include retinal detachments, neovascular membranes secondary to myopic macular degeneration, glaucoma and presenile cataracts.² The risk of these complications are significantly higher in patients with axial myopia; and it’s predicted that one billion people will have myopia with axial lengths greater than 26 mm by 2050.¹  

Systematic reviews and meta-analyses have established that increased time spent outdoors in high lux light in childhood is associated with lower incidence of myopia development and progression. It is now widely advised that children spend 14-17 hours outdoors per week to limit their progression to myopia.³  

The silent ocular epidemic

However, myopia is not the only epidemic eyecare professionals have to contend with. Ultraviolet radiation (UVR)-associated eye disease has proven to be the silent ocular epidemic. It’s well understood that sunburns to the skin cause damage in childhood and can lead to the development of skin cancers in adulthood. It’s now becoming apparent in the literature that this is likely to be the same for the eyes. For example, in 2007, a study of Sydney school children showed that UV damage to the eyes was present in 29% of 9-11 year olds and 81% of 12-15 year olds.¹⁷ (Interestingly, the children who were screened under the age of nine did not have any signs of UV damage on the anterior ocular surface. However, it is speculated that the technology is not sophisticated enough to detect low grade damage at this age).¹⁷  

UVR-related eye diseases include periocular skin cancers, pterygium, pinguecula, ocular surface tumours, cataracts and age-related macular degeneration (AMD), which typically presents in adulthood.⁴ These conditions have significant impact on patients’ long term visual health. The Beamer Dam, Rotterdam, and Blue Mountains Eye Studies and the Melbourne Vision Impairment Project have all shown that areas with higher incidences of skin cancers and UV-related diseases have lower levels of myopia.⁵ 

When treating children with myopia, it is important to simultaneously consider the impact of UVR. With this in mind, we reviewed the evidence for outdoor light exposure with high lux light to reduce myopia progression and simultaneously assess the evidence regarding UV-related eye diseases and the need to advocate for UVR protection for children to simultaneously reduce UV related eye diseases later in life.⁶ 

We feel that it is imperative that all eye health care professionals understand that both myopia and UV-related eye diseases can result in impaired vision later in life.  We don’t want to inadvertently give advice that results in increasing the patient’s risk of developing different, yet potentially blinding, ocular complications.  

Evidence for the protective effect of high lux light   

High-intensity outdoor light has been demonstrated to protect against and slow the progression of myopia in epidemiological studies and animal studies. The seminal chick studies⁷ exposed deprivation-induced myopic chicks to UV-free light of varying intensities measured in lux. They demonstrated that high lux UV-free light retarded myopia progression in these chicks. Additionally, fewer chicks developed myopia when exposed to high lux UV-free light. Furthermore, other animal studies including on rhesus monkeys⁸ and tree shrews⁹ showed that high intensity UV-free lighting systems inhibited scleral growth rates.    

Epidemiological studies showed a similar relationship between the amount of time spent outdoors by children and the rates of developing myopia. Rose et al compared the rates of myopia in children of Chinese ethnicity living in Sydney to those living in Singapore. In Sydney, 3.3% of children developed myopia, (who spent 13.5 outdoor hours per week) compared to 29.1% of the Chinese ethnicity children living in Singapore (who spent 3.05 outdoor hours per week).⁵   

Further supporting the importance of the brightness of outdoor light is evident by the seasonal differences noted in the higher rate of myopia progression in winter months compared to summer months. This has been demonstrated in several studies in a number of different ethnic groups including Chinese, Czech and Norwegian Children.^11-13  

Intervention in the form of increased outdoor time has been shown to reduce the incidence of myopia. In Chinese children in China, the incidence of myopia was reduced by increasing outdoor time by 40 minutes a day. Furthermore, less than 40 minutes of outdoor activity daily was associated with rapid axial length progression. Meta-analysis of the dose-response relationship between outdoor light exposure and myopia by Ho et al, found that more than 120 minutes of daily outdoor exposure decreased myopia incidence by 50%, decreased axial elongation by 24.9% and reduced spherical equivalent refraction by 32.9% in Asian children aged four to 14 years.¹⁴ 

Similarly, the National program of Tian-Tian in Taiwan, where schools were encouraged to incorporate 120 minutes of outdoor daily activity into the school day was instituted in 2010. As a result, a reduction in the number of children progressing to myopia was seen.¹⁵   

The problem  

So, the benefit of exposing children to the high lux outdoor light in reducing the incidence and rate of progression of myopia developing is clear. However, it isn’t possible to spend time outdoors exposed to the benefits of high lux light without being simultaneously exposed to UV radiation – the invisible portion of light spectrum which has been known to be damaging to the eyes and skin.  

We know that UV radiation causes sunburns and damage to the skin during childhood. We also know that the long-term complications of this cumulative UV skin damage result in wrinkles, actinic keratosis and both melanoma and non-melanoma skin cancers. Five to 10% of all skin cancers occur in the periocular skin, which includes basal and squamous cell carcinomas and melanomas.¹⁶   

Ooi et al showed that 33% of children aged 12-15 years of age had a pinguecula on clinical examination.¹⁷ Pingueculae are known to progress to pterygium with cumulative UVR exposure. The prevalence of pterygium has been shown to increase linearly with age.⁸  Mackey et al ¹⁸ showed that patients with pterygium had a 24% increased risk of melanoma, as the presence of pterygium, an indication of the cumulative UVR the persons skin was likely to have been exposed to. It’s clear that UV exposure in childhood causes damages both eyes and skin.   

UV and macular degeneration 

It has long been recognised that UVR plays a significant role in the pathogenesis of pinguecula, pterygia, ocular surface neoplasia, periorbital skin cancers and cataract. However, the question of UVR in the pathogenesis of macular degeneration is less clear.  

Proving or disproving the link between childhood UV exposure and the late adulthood development of macular degeneration is difficult. There is a long lag time between the development of macular degeneration and childhood the childhood outdoor behaviour that may have precipitated it.  

Inverse relationship between pterygium and myopia 

To explore the link in adult macular degeneration and childhood outdoor behaviour in our
recently-published paper,⁴  we used the axial length and degree of myopia as an indication of low childhood UVR exposure, and pterygium and pinguecula as a marker for significant childhood UV exposure, particularly as there is a dose-response curve for outdoor exposure and pterygium growth.  

This assumption was validated when it was found that the presence of pterygium was associated with reduced axial length measurements. Only 1.8% of patients with axial lengths of greater than 26 mm have pterygia–compared to 51.4%  of pterygia patients with axial lengths less than 23 mm in the same population group.⁴ 

Global corroborative statistics 

This inverse relationship was also seen in Shanghai where 22.9% myopia rates are associated with a high prevalence of pinguecula at 75.6%. Similarly, the 70.6% rate of myopia in South Korea was inversely correlated with the 3.8% rate of pterygia. This has also been seen in the Blue Mountains Eye Study, where the 69.5% rate of pinguecula correlated with the 15% rate of myopia.^17-20 

As a final point, a systematic review and meta-analysis of 14 studies comprising over 5,800 eligible patients found that hyperopia was a risk factor for developing early macular degeneration and myopia conferred a degree of protection which increased for every additional dioptre of myopia, or millimetre increase in axial length the person had.¹¹

Summary 

Having collected and analysed this information, we can see that advocating for outdoor time as part of our myopia management protocols is important. However, the data shows it must be done with due care and appropriate guidance to minimise the risks of both myopia complications and UV-related eye diseases. 

To best advise our patients, eyecare professionals need to have a clear understanding not only about treating and preventing myopia, but also understanding how UVR reaches the eye. They need an understanding of the damage UVR causes to the eye and the environmental factors associated with an increased risk of developing UVR related eye diseases.  

Having gained these insights, we can advance our approach, refine our strategies, and help define holistic myopia treatment. In a future issue of Insight magazine, the authors will explore the evidence for combining frame and lens designs in sunglasses to maximise eye and periorbital protection.  

Disclosure: As a result of their research in this area and a desire to protect their children and the community, Daya Sharma, Shanel Sharma, and Alina Zeldovich founded Beamers, which produces and sells protective sunglasses.

More reading

Paediatric optometry beyond myopia

Glaucoma: Integrating OSD management with peri-operative optometric care

Accommodation disorders: Recognising, assessing and managing

References 

1. Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology 2016; 123:1036‑42. 
2. Haarman AE, Enthoven CA, Tideman JW, et al. The complications of myopia: A review and meta-analysis. Invest Ophthalmol Vis Sci 2020; 61:49.  
3. Xiong S, Sankaridurg P, Naduvilath T, et al. Time spent in outdoor activities in relation to myopia prevention and control: A meta-analysis and systematic review. Acta Ophthalmol 2017; 95:551-66.  
4. Sharma, Shanel; Rose, Loreto; Schulz, Angela; Sharma, Daya P; et al. Myopia intervention and ultraviolet radiation related eye diseases: A narrative literature review. Taiwan Journal of Ophthalmology 2024. 14 (2): 151-158.  
5. Kempen JH, Mitchell P, Lee KE, Tielsch JM, Broman AT, Taylor HR, et al. The prevalence of refractive errors among adults in the United States, Western Europe, and Australia. Arch Ophthalmol 2004;122:495‑505. 
6. Karouta C, Ashby RS. Correlation between light levels and the development of deprivation myopia. IVOS 2014;56(1) 299 – 309.  
7. Ashby Rs, Schaeffel F. The effect of bright light on lens compensation in chicks. Invest Ophthalmol VisSci 2010; 51; 5247 – 53.  
8. Smith EL 3rd, Hung LF, Huang J. Protective effects of high ambient lighting on the development of form-deprivation myopia in rhesus monkeys. Invest Ophthalmol Vis Sci 2012; 53: 421-8.  
9. Norton TT, Siegwart JT Jr. Light levels, refractive development, and myopia – A speculative review. Exp Eye Res 2013; 114: 48‑57.
10. 10.Rose KA, Morgan IG, Smith W et al. Myopia, lifestyle and schooling in students of Chinese ethnicity in Singapore and Sydney. Arch Ophthalmol 2008; 126: 527030.  
11. Donovan L, Sankaridurg P, Ho A, Chen X, Lin Z, Thomas V, et al. Myopia progression in Chinese children is slower in summer than in winter. Optom Vis Sci 2012;89:1196‑202. \
12. Fulk GW, Cyert LA, Parker DA. Seasonal variation in myopia progression and ocular elongation. Optom Vis Sci 2002;79:46‑51. 
13. Rusnak S, Salcman V, Hecova L, Kasl Z. Myopia progression risk: Seasonal and lifestyle variations in axial length growth in Czech children. J Ophthalmol 2018;2018:5076454. 
14. Ho CL, Wu WF, Liou YM. Dose‑response relationship of outdoor exposure and myopia indicators: A systematic review and meta‑analysis of various research methods. Int J Environ Res Public Health 2019; 16: 2595. 
15. Wu PC, Chen CT, Chang LC, et al. Increased Time Outdoors Is Followed by Reversal of the Long-Term Trend to Reduced Visual Acuity in Taiwan Primary School Students. Ophthalmology. 2020;127(11):1462-1469. 
16. Moran JM, Phelps PO. Periocular skin cancer: Diagnosis and management. Dis Mon 2020; 66: 101046. 
17. Ooi JL, Sharma NS, Papalkar D et al. Ultraviolet fluorescence photography: Patterns in established pterygia. Am J Ophthalmol 2007;143: 97-101.  
18. Crewe JM, Threlfall T, Clark A, Sanfilippo PG, Mackey DA. Pterygia are indicators of an increased risk of developing cutaneous melanomas. Br J Ophthalmol 2018; 102: 496‑501.
19. McKnight CM, Sherwin JC, Yazar S, Forward H, Tan AX, Hewitt AW, et al. Myopia in young adults is inversely related to an objective marker of ocular sun exposure: The Western Australian Raine cohort study. Am J Ophthalmol 2014; 158: 1079‑85.
20. Hashemi H, Khabazkhoob M, Yekta A et al. The prevalence and determinants of pterygium in rural areas. Journal of Current Ophthalmology. 2017; 29: 194 -8.  
21. Bao J, Huang Y, Li X, et al. Spectacle Lenses With Aspherical Lenslets for Myopia Control vs Single-Vision Spectacle Lenses: A Randomized Clinical Trial. JAMA Ophthalmol 2022;140(5):472-78. doi: 10.1001/jamaophthalmol.2022.0401 [published Online First: 2022/04/01]
22. Lam CS, Tang WC, Lee PH, et al. Myopia control effect of defocus incorporated multiple segments (DIMS) spectacle lens in Chinese children: results of a 3-year follow-up study. Br J Ophthalmol 2021 doi: 10.1136/bjophthalmol-2020-317664 [published Online First: 2021/03/19]
23. Lee SSY, Mackey DA, Lingham G, et al. Western Australia Atropine for the Treatment of Myopia (WA-ATOM) study: Rationale, methodology and participant baseline characteristics. Clin Exp Ophthalmol 2020;48(5):569-79. doi: 10.1111/ceo.13736 [published Online First: 2020/02/27]
24. Lee SS, Nilagiri VK, Lingham G, et al. Myopia progression following 0.01% atropine cessation in Australian children: Findings from the Western Australia – Atropine for the Treatment of Myopia (WA-ATOM) study. Clin Exp Ophthalmol 2024 doi: 10.1111/ceo.14368 [published Online First: 20240223]
25. Rose LVT. The quest for safe and effective myopia control in children. Clin Exp Ophthalmol 2024;52(5):503-04. doi: 10.1111/ceo.14391
26. Yam JC, Li FF, Zhang X, et al. Two-Year Clinical Trial of the Low-Concentration Atropine for Myopia Progression (LAMP) Study: Phase 2 Report. Ophthalmology 2019 doi: 10.1016/j.ophtha.2019.12.011 [published Online First: 2020/02/06]
27. Li FF, Zhang Y, Zhang X, et al. Age Effect on Treatment Responses to 0.05%, 0.025%, and 0.01% Atropine: Low-Concentration Atropine for Myopia Progression Study. Ophthalmology 2021 doi: 10.1016/j.ophtha.2020.12.036 [published Online First: 2021/01/11]
28. Zhang LM, Lu Y, Gong L. Pterygium is related to short axial length. Cornea 2020;39:140‑5.