Specially designed glasses can slow the progression of myopia, even during shutdowns imposed by the COVID-19 pandemic, researchers say.
Myopia progressed 46% slower in children prescribed Incorporated Defocused Crossover Lenses (DIMS) than in children prescribed standard prescription eyeglasses for 12 months when children attended remote school , said Henry Chan, PhD, associate professor of optometry at Hong Kong Polytechnic University in Hong Kong.
“So that means the DIMS lens can be effective in this confined environment,” Chan said. Medscape Medical News. He and his colleagues published the finding in JAMA network open.
The prevalence of myopia has increased worldwide, particularly in East Asia. According to some estimates, half of the people in the world will have myopia by 2050, which will increase their risk of sight-threatening diseases, such as glaucoma and retinal degeneration.
Previous research has shown correlations between nearsightedness and time spent near work and between nearsightedness and time spent indoors. Several studies have documented an accelerated progression of myopia when children spent more time indoors using remote learning devices during lockdowns to prevent transmission of COVID-19.
Two treatments are now used to slow the progression of myopia: atropine-based eye drops and positive-power lenses that project a focal plane in front of the retina, slowing the axial growth of the eye.
Contact lenses using defocus have been used for a long time, but contact lenses can be difficult for young children to manage. Chan’s colleagues at Hong Kong Polytechnic University therefore used the same principle to design the DIMS glasses. “We can’t say it’s the most efficient, but at least it’s the most convenient, because it’s just a show,” Chan said. The DIMS lenses incorporate 3.50 D myopic defocus with multiple peripheral field lenses.
A double-blind, randomized clinical trial showed that the DIMS lens could slow the progression of myopia. The lens is now available in Hong Kong, UK, Singapore, Europe, China, Taiwan, Malaysia, South Korea, Canada, Australia and South Africa, Chan said. However, the US Food and Drug Administration has not approved it.
Separate studies have found atropine to be much less effective than usual during COVID-19 shutdowns. Chan and his colleagues therefore wanted to know if the same was true for DIMS lenses.
Because no one had anticipated the COVID-19 lockdown, researchers could not plan a study dividing subjects into a control arm and a treatment arm. Additionally, finding children to serve as controls has become difficult in Hong Kong as most parents want their children to be treated for myopia.
The researchers therefore compared 115 children who had recently been prescribed DIMS lenses as part of a charity project to 56 children who wore single vision lenses as controls in a previous trial.
The two groups did not match perfectly. Participants in the single vision group had an average age of 10.8 years, while those in the DIMS group had an average age of 10.3 years.
In addition, children in the single vision group had on average milder myopia, an average spherical equivalent refraction (SER) of -2.99 D compared to -4.02 D for the DIMS group.
Because the studies had started at different times, the researchers only looked at the subjects’ ratings from June 2019, treating them as the baseline.
The Hong Kong government suspended in-person school activities from February 2020 to May 2021. Since some participants had more pre-lockdown visits than others, the researchers also compared those who had more than the median time of locking to those who had less.
The progression of myopia in the children in this study accelerated on average about a third faster during confinement than in previous studies of children who were not confined.
And the more time they spent locked up, the faster their myopia progressed. It progressed on average by -0.54 D in SER and 0.29 mm in axial length in children who spent more time locked up against -0.34 D in SER and 0.20 mm in axial length in children who have spent less time locked up (P = 0.001).
But the DIMS lenses seemed to help. After adjusting for covariates, the researchers found that axial length increased by 0.19 mm in children wearing the DIMS lenses, but by 0.30 mm in those wearing the single vision lenses (P = 0.001).
Similarly, the SER changed by -0.31 D in DIMS lens wearers compared to -0.57 D wearing the single vision lenses.
The results came as no surprise to Jeffrey Cooper, OD, professor emeritus at the State University of New York, College of Optometry in New York, who now treats children with myopia in private practice. He has closely followed the research on DIMS lenses and wants to be able to prescribe them to his patients. “It would be important to slow the progression of myopia in the United States to have these tools,” he said. Medscape Medical News.
He was not concerned that the DIMS population in this study was younger, as previous research has shown that DIMS is more effective in older children. “The fact that they slow down the pattern is what’s clinically important,” he said. “Clinicians are choosing risk over benefit. There is very little risk and it can make a big difference in someone’s life.”
Chan and Cooper did not report any relevant financial relationship.
JAMA Netw Open. 2022;5:e2143781. Full Text
Laird Harrison writes about science, health and culture. His work has appeared in magazines, newspapers, on public radio and on websites. He is working on a novel about alternate realities in physics. Harrison teaches writing at Writers Grotto. Visit him at lairdharrison.com or follow him on Twitter: @LairdH.
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