Researchers caution clinicians against using two devices for red-light myopia treatment (2024)

Key takeaways:

• For both devices, 3 minutes of continuous viewing approached or surpassed the maximum permissible exposure of low-level red light.
• Researchers expressed safety concerns about LLRL device use in children.

Researchers cautioned clinicians to strongly reconsider using low-level red-light therapy in children with myopia, citing safety concerns revealed by a study published in Ophthalmic and Physiological Optics.

“To date, there are no published studies that have used sensitive enough functional testing and high-resolution imaging to assess the retina,” study author Lisa A. Ostrin, OD, PhD, FAAO, FARVO, associate professor at University of Houston College of Optometry, told Healio. “Additionally, there are no long-term studies; therefore, potential long-term side effects remain unknown.”

Ostrin and colleague, Alexander W. Schill, PhD, examined two Class 1 low-level red-light (LLRL) devices, Sky-n1201a and Future Vision.

According to the study, the Sky-n1201a device delivered laser light with a 654 nm wavelength at 0.2 mW power, 1.17 mW/cm² corneal irradiance and 7.2 W/cm² retinal irradiance. The maximum permissible exposure (MPE) for photochemical damage is 0.55 seconds to 7 seconds for 2 mm to 7 mm pupils and 0.41 seconds to 10 seconds for thermal damage for 4.25 mm to 7 mm pupils.

The Future Vision device delivered a laser light with a 652 nm wavelength, at 0.06 mW power, 0.624 mW/cm² corneal irradiance and 0.08 W/cm² retinal irradiance. The MPE for photochemical damage is 50 seconds to 625 seconds for 2 mm to 7 mm pupils, but this device does not put the retina at risk for thermal damage, the researchers noted.

Three minutes of continuous viewing with either device “approached or surpassed the MPE, putting the retina at risk of photochemical and thermal damage,” they wrote.

“We caution both clinicians and parents in using the devices we tested, particularly the Sky-1201n, for red-light therapy,” Ostrin told Healio. “There are many different devices on the market, and they have not all gone through thorough testing and safety cannot be assumed. From an evidence-based standpoint, the exact specifications required for effective red-light therapy in myopia management are unknown.”

Since the publication of the study, Eyerising International, the manufacturer of the Eyerising Myopia Management Device, submitted a letter to the editor at Ophthalmic and Physiological Optics written by John Battersby, public relations contact for Eyerising, to address alleged inaccuracies and misrepresentations in the study. He wrote that “only two devices were tested in their laboratory, and neither of them was an Eyerising device.”

Paul Cooke, Eyerising CEO, told Healio that the company has “every confidence in the safety of [its] device.”

“We were not surprised by the response to our study,” Ostrin told Healio. “We recognize that our findings have broad implications in clinical practice. Since the publication of our paper, several colleagues and researchers have reached out and confirmed our initial findings and conclusions. There is widespread concern that, at least from some manufacturers, these devices might not be safe for children to be viewing.

“We hope that our study increases the quality and depth of research related to low-level red-light devices,” she added.