Prantik Aditya, Bachelor’s of Clinical Optometry

Optometrist, Eye7 Chaudhary Eye Centre, Delhi, India.

Myopia or nearsightedness is a common cause of disability throughout the world. ⁽¹⁾ Due to the current COVID-19 pandemic, most of the people are doing their office work through online basic. Even the schools and colleges are also going on through online mode which means spending more time on the laptop and mobiles. There is lots of evidence which tells us that sustained near work and closer working distance is one of the risk factor in myopic progression. ⁽²⁾ According to another study if the current scenario continues, then 50% of the world’s population is predicted to be myopic by 2050 and nearly 1 billion people will probably become high myopes. ⁽³⁾

Earlier several clinical methods has used in children to control myopic progression such as atropine, ⁽⁴⁾ bifocal or multifocal soft contact lenses, ⁽⁵⁾ orthokeratology, ⁽⁶⁾ progressive addition spectacles (PALs), ⁽⁷⁾ and bifocal and prismatic bifocal spectacles. ⁽⁸⁾ Each method showed efficacy in slowing myopic progression ⁽⁹⁾ but none has been completely successful.

In July 2020, HOYA Vision Care Canada launched MiYOSMART lenses with Defocus Incorporated Multiple Segments Technology (D.I.M.S) in Canada. The D.I.M.S technology is a single vision corrective lens with a convex surface, having a treatment zone of hundreds of small hexagonal segments around 33 mm in diameter, each providing myopic defocus and a central zone of 9.4 mm in diameter where there is no defocus segment. The myopic defocus area in the peripheral portion of the DIMS lens is a new honeycomb multizone design that includes a +3.50 D myopic defocus zone and a clear zone with central power. It is based on the principle that, when the image plane is shifted in front of the retina by a positive lens (i.e., myopic defocus), ocular growth is inhibited, and relative hyperopia develops. ⁽¹⁰⁾ MiYOSMART lens produces two focuses on the retina, one infront of the retina through the defocus segment and the other is on the retina through the central area without segment. This lens structure simultaneously slows the growth of the eyeball and provides clearer vision.

MiYOSMART uses polycarbonate 1.59 which is a highly impact resistant material and had passed the high velocity impact drop ball test. It is also available with UV protection and is very light and thin which is very safe for use by children. The lens is available with a maximum spherical power of -6.00 D , cylindrical power of -4.00 D and a combined power of -6.50D with maximum cylinder of -4.00 D.

In a trial conducted in Hong Kong, it showed that defocus lenses had significantly less myopic progression by 59% and axial elongation by 60% compared to those wearing single vision lenses and did not show any adverse effect over the eye. ⁽¹¹⁾

Lifestyle modification for halting myopic progression:

1. Spend more time with outdoors activities, minimum 2 hours a day.
2. Take regular breaks from long intensive screen time or near-work for minimum 10 minutes.
3. Use proper lighting, posture, keeping the recommended working distance is very important to keep your eyes healthy while doing the near work.
4. Routine eye check-ups to prevent myopic related complication such as myopic degeneration.

Disclosure:

The blog is written solely for education purpose and it does not have any financial support and conflict of interest from the Hoya Company.

References:

1. Fredrick, D. R. (2002). Myopia. Bmj, 324(7347), 1195-1199.
2. Huang, H. M., Chang, D. S. T., & Wu, P. C. (2015). The association between near work activities and myopia in children—a systematic review and meta-analysis. PloS one, 10(10), e0140419.
3. Holden, B. A., Fricke, T. R., Wilson, D. A., Jong, M., Naidoo, K. S., Sankaridurg, P., … & Resnikoff, S. (2016). Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology, 123(5), 1036-1042.
4. Chua, W. H., Balakrishnan, V., Chan, Y. H., Tong, L., Ling, Y., Quah, B. L., & Tan, D. (2006). Atropine for the treatment of childhood myopia. Ophthalmology, 113(12), 2285-2291.
5. Aller, T. A., Liu, M., & Wildsoet, C. F. (2016). Myopia control with bifocal contact lenses: a randomized clinical trial. Optometry and Vision Science, 93(4), 344-352.
6. Cho, P., & Tan, Q. (2019). Myopia and orthokeratology for myopia control. Clinical and Experimental Optometry, 102(4), 364-377.
7. Yang, Z., Lan, W., Ge, J., Liu, W., Chen, X., Chen, L., & Yu, M. (2009). The effectiveness of progressive addition lenses on the progression of myopia in Chinese children. Ophthalmic and Physiological Optics, 29(1), 41-48.
8. Cheng, D., Woo, G. C., Drobe, B., & Schmid, K. L. (2014). Effect of bifocal and prismatic bifocal spectacles on myopia progression in children: three-year results of a randomized clinical trial. JAMA ophthalmology, 132(3), 258-264.
9. Wildsoet, C. F., Chia, A., Cho, P., Guggenheim, J. A., Polling, J. R., Read, S., … & Wolffsohn, J. S. (2019). IMI–interventions for controlling myopia onset and progression report. Investigative ophthalmology & visual science, 60(3), M106-M131.
10. Metlapally, S., & McBrien, N. A. (2008). The effect of positive lens defocus on ocular growth and emmetropization in the tree shrew. Journal of vision, 8(3), 1-1.
11. Lam, C. S. Y., Tang, W. C., Tse, D. Y. Y., Tang, Y. Y., & To, C. H. (2014). Defocus Incorporated Soft Contact (DISC) lens slows myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial. British Journal of Ophthalmology, 98(1), 40-45.