Contrast-Reducing Spectacles Could Slow Myopia

DENVER ― Spectacles that reduce retinal contrast could slow the progression of myopia, the results of the CYPRESS clinical trial suggest.

The eyes of children wearing the Diffusion Optics Technology (DOT) spectacles for 2 years did not change as much in axial length or spherical equivalent refraction as did the eyes of children wearing standard spectacles, said Joe Rappon, OD, former chief medical officer of SightGlass Vision, in Palo Alto, California.

Spectacles will become the standard of care for preventing myopia progression in children, he told Medscape Medical News. “It just makes sense,” he said. “They have to wear spectacles anyway. The safety profile is great. And parents and children are accepting of the technology.”

Rappon presented the results of the CYPRESS trial here at the Association for Research in Vision and Ophthalmology (ARVO) 2022 Annual Meeting.

The prevalence of myopia has been increasing around the world. By some estimates, half the people in the world will have myopia by 2050, increasing their risk of sight-threatening diseases, such as glaucoma and retinal degeneration. The trend appears to result from children spending more time indoors doing near work.

Current treatments to slow the progression of myopia include atropine eyedrops, orthokeratology, and positive-powered lenses that cast a focal plane in front of the retina.

Defocus-incorporated multiple segments (DIMS) spectacles are on the market in many countries in Europe and Asia, though they have not been approved by the US Food and Drug Administration (FDA). They combine a central optical zone for correcting distance refractive errors with an annular multiple focal zone, creating peripheral defocus.

Rappon and his colleagues approached the problem from a different angle. Studies in severe inherited myopia implicated the MYP1 chromosomal region. A mutation in this region causes some photoreceptors to be insensitive, creating a high contrast between them and their neighbors. From this finding, the researchers hypothesized that abnormally high retinal contrast signaling from near work leads to high myopia.

They designed the DOT lenses to reduce contrast with thousands of microscopic light-scattering centers throughout the entire lens, except for a small, clear aperture in the center. The central aperture is intended only for use in looking at small objects.

They recruited a 256 children aged 6–10 years with spherical equivalent refractive error from -0.75 D to -4.50 D. The mean age of the children was 8.1 years. They were from 14 sites in the United States and Canada and were racially and ethnically diverse.

The demographics are important because previous DIMS studies have been conducted primarily in Asian populations and have shown that efficacy is greater for children who are slightly older.

“The age of the children is known to affect myopia progression,” Rappon said. “The racial characteristics of the children are known to affect myopia progression, and now in the age of COVID, COVID lockdowns may affect myopia progression in certain patients as well .”

In CYPRESS, the children were divided into three groups. Two groups wore different versions of the DOT spectacles, with the second version scattering light more than the first version. The third group wore spectacles not designed to scatter light.

The researchers asked the children to wear their spectacles constantly except in situations in which spectacles would pose difficulties, such as while engaging in contact sports and swimming. About a third of the children removed the spectacles for near vision activities, and the researchers excluded these children from their primary analysis.

After 24 months, the mean change from baseline in axial length was 0.33 for the first version of the spectacles, 0.34 for the second version, and 0.53 for the control spectacles. The mean change from baseline in spherical equivalent refraction (was -0.36 for the first version of the spectacles, -0.48 for the second version, and -0.88 for the control spectacles. The differences between the first version and the control spectacles were statistically significant (P < .0001).

The children’s visual acuity remained clinically stable throughout the 24 months, and there were few adverse events in any of the groups.

“It’s very exciting,” said the ARVO session moderator, Timothy Gawne, PhD, an associate professor of optometry and vision sciences at the University of Alabama in Birmingham.

But the mechanism by which the spectacles might work came as a surprise to him. “Virtually all of the data from animal models suggests that you need high contrast to not get myopia and that reducing contrast, if anything, would promote myopia,” he told Medscape Medical News.

Rappon responded that the contrast used in the DOT spectacles is far less than the amount that promotes myopia in animal studies.

It’s difficult to say how the DOT spectacles compare to other methods of slowing myopia progression, Rappon said. The study populations have been different, and there have been no head-to-head trials. No one has yet investigated whether DOT spectacles could be combined with atropine drops for increased efficacy.

The DOT spectacles are cleared for use in Canada, the United Kingdom, Europe, and Israel. SightGlass is “in discussion” with the FDA, Rappon said.

Rappon has patents in the DOT spectacles and a financial interest in SightGlass. Gawne has patents for other myopia products.

Association for Research in Vision and Ophthalmology (ARVO) 2022 Annual Meeting: Presented May 1, 2022.

Laird Harrison writes about science, health, and culture. His work has appeared in magazines, newspapers, on public radio, and on websites. He is at work on a novel about alternate realities in physics. Harrison teaches writing at the Writers Grotto. Visit him at lairdharrison.com or follow him on Twitter: @LairdH.

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