In his Whitney G. Sampson Lecture during “Current Approaches to Myopia Control” (Sym33) on Sunday, Kazuo Tsubota, MD, PhD, MBA, presented an update on one of the newest myopia research interventions in development: violet light.
We know that time spent outdoors is beneficial in preventing myopia, said Dr. Tsubota. He began connecting the dots between myopia and violet light through his refractive surgery experience, where he observed retrospectively that adults implanted with a phakic IOL that transmits violet light (Artiflex) had significantly lower myopia progression than those implanted with IOLs that blocked violet light.
The connection between violet light and myopia. Violet light is 360 to 400 nm in wavelength. It is abundant outdoors in sunlight but virtually absent indoors due to the blocking effect of most UV-protective windows. This shortwave light activates one of the five nonvisual photoreceptors, OPN5, which is associated with maintaining the thickness of the choroid, said Dr. Tsubota. The choroid has the important job of supplying nutrients and oxygen to the eye. Recent research has suggested that thinning of the choroid and resulting eye elongation may be a precursor to myopia, he said.
Standard eyeglasses block violet light. Because they are made with UV protection, conventional eyeglasses block violet light. Dr. Tsubota and colleagues tested glasses that transmit violet light against standard eyeglasses in a two-year double-blind randomized clinical trial of children aged 6 to 12 years old and followed the subjects for two years. The mean change in axial length in the eyes of children who wore violet light glasses was significantly smaller than in the eyes of children who wore placebo glasses, he said. This demonstrated the potential of glasses that transmit violet light in suppressing myopia progression.1
Glasses that mimic the benefits of sunlight? Of course, children will only benefit from glasses that transmit violet light if they spend enough time outdoors, which many don’t. That’s why Dr. Tsubota and his team invented violet light–emitting glasses. Dr. Tsubota is now running a two-year study with 160 elementary school-aged children to test the efficacy and safety of these innovative spectacles. The last patient was just enrolled in October 2023.
Possible benefits beyond ocular health. Dr. Tsubota is also testing the potential of violet light to increase blood flow not only to the choroid but also to the brain. He hypothesized that violet light may have beneficial applications for conditions including depression, Alzheimer disease, and Parkinson disease.
“Kids need outdoor time, and adults need it, too—not only to stimulate your eyes but also to stimulate your brain,” he concluded. —Reena Mukamal
1 Mori K et al. J Clin Med. 2021:10(22):5462.
Financial disclosures: Kazuo Tsubota, MD: Tsubota Laboratory, Inc.: EE.
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