Myopia, or near-sightedness, is on the rise: Nearly half of the world’s population will be nearsighted by 2050, according to the World Health Organization. The condition is increasingly common among children in particular, which ophthalmologists attribute to a combination of less time spent outdoors and more time spent with iPads and iPhones.
Glasses or contact lenses, as well as procedures such as Lasik surgery, help correct the blurred vision associated with myopia, which is caused by the eye growing too long. But they do not treat the condition itself, which is associated with a number of pathologies later in life, including retinal detachment and glaucoma. And so recent studies on low-level red light (LLRL) therapy — a treatment done through devices that deliver red light directly into the eye which has been used in China in the past few years — have generated a lot of excitement.
According to data from one of the red-light device makers, at least 100,000 children are already using this treatment in China and other Asian countries, and it’s also been approved in some European countries and Australia.
As interest grows in the United States and LLRL devices become available on the online marketplace, some experts are raising concerns. A recent paper in the journal Ophthalmic & Physiological Optics warns that the benefits of the treatment may come at the risk of causing other kinds of long-term damage, and urges clinicians and parents not to try the therapy — which has not been approved by the Food and Drug Administration — until better safety data becomes available.
How does red light therapy work?
LLRL therapy is delivered in twice-daily sessions of three minutes each until the end of teenage growing years. It’s not the only innovation in the treatment of myopia. In recent years, there have been several developments including novel spectacles and contact lenses that stop the eyeball from growing too long, and a pharmacological option, atropine eye drops. All delay the progression of the condition. But such therapies slow down progression of myopia by 30% to 60% — LLRL was slowing it down by up to 80%.
“When we started seeing these papers using red light therapy, the effectiveness was better than anything else we could have imagined,” said Lisa Ostrin, an associate professor at the University of Houston College of Optometry who co-authored the new study on LLRL therapy. Some children [were] even regressing in their myopia, which to this date has been unheard of.”
It was this excitement that prompted Ostrin to look into LLRL — only to find that the studies published on the treatment thus far didn’t provide sufficient information on its safety profile. “It’s not looking closely at the retinal tissue and the blood supply behind it,” she said. The devices are also so new that long-term studies of the therapy have not yet been possible.
STAT reached out to two of the device makers (Beijing Mingren Shikang Science and Eyerising International) and two authors of Chinese studies on the treatment, none of whom returned a request for comment.
Ostrin is familiar with red light treatment. “I was involved in some of the animal studies that showed that red light could be effective in slowing experimental myopia,” she said. But the conditions of light exposure were very different: rather than being hit by focused red light for short periods of time, the animals were raised in an environment where there was a diffused LED red light for 12 hours a day.
Getting results in children with only three minutes of exposure a day would require a much stronger laser. Part of the challenge in evaluating the safety of the laser devices has been that the devices were not at all available in the U.S. until very recently, nor easy to get from China.
“We’ve reached out to the companies several times to work with them, or at least, you know, be able to evaluate the device, and they turned us down this year,” said Ostrin. “I think no one realized how strong the lasers were until they brought the instrument to […] a vision science expo,” in May 2023, she added.
“I think no one realized how strong the lasers were”
In the study she co-authored, Ostrin was able to analyze two LLRL devices — the Sky-n1201a and the Future Vision. Both are Class 1 laser devices, with the same safety classification of a laser pointer. This, claims Eyerising, one of the device makers, indicates that “no potential light hazard exists.” But Ostrin thinks this is a misunderstanding.
“If you accidentally glance at it and then look away, it’s safe. But it’s not meant to be stared at with your central vision for minutes on end,” she said. “And that’s where we’re going to start to see damage, when they’re doing this repeatedly every day, twice a day.”
Ostrin doesn’t question that the improvements studies have shown so far as a result of LLRL therapy are real and significant. But she worries about the potential harms the therapy could inadvertently cause, too.
“We see from the clinical trials that it absolutely is slowing myopia. The eye stops growing. But, there’s no explanation right now for the mechanism of how that’s happening,” she said. For instance, she said, it could prevent the retina from growing how it normally would, damaging it even as it treats the myopia. Or, the light may be powerful enough to have effects on the blood flow to the back of the eye, or the sclera (the white part of the eye).
The appeal of the treatment is clear. It’s quick, non-invasive, relatively inexpensive (the devices are available online between $50 and $700) and easy enough that families could use them at home. “It would be great if something like this worked,” said Ostrin.
Other experts agree that there’s more work to be done in evaluating the treatment’s safety. “While LLRL therapy has shown promise as a potential treatment option, it is vital to ensure its safety before it can be widely adopted as a treatment for myopia,” Dwight Akerman, the chief medical editor of the Review of Myopia Management, wrote in a review of Ostrin’s article to be published on February 15.
Aaron Salzano, an assistant professor at Pacific University College of Optometry, who was not involved in the study, wrote in an email that Ostrin’s study “confirms many of the concerns shared by other clinicians and researchers monitoring the growing popularity of this treatment.” But that doesn’t mean the treatment should now be dismissed entirely: “My hope is that we will eventually be able to develop devices which utilize red light in a safe yet still effective manner.”