A war of words between a well-respected researcher and an established device manufacturer over the safety of repeated low-level red light (RLRL) devices for childhood myopia has escalated, putting the myopia control technology front and center.
Australia-based firm Eyerising International, producer of a leading red light therapy device, issued a press release on Feb 3 taking exception with a study published in Ophthalmic & Physiological Optics (OPO) on safety issues over RLRL therapy.
The article in question was penned by Dr. Lisa A. Ostrin and Dr. Alexander W. Schill from the University of Houston College of Optometry. In the piece, “Red light instruments for myopia exceed safety limits,” lead author Dr. Ostrin calls on optometrists to reconsider the use of red light therapy devices for the treatment of myopia.1
The central claim of the article is that as-directed usage may cause thermal and photochemical damage to the retina, and that the devices tested do not adhere to the safety standard they claim to.
Eyerising’s recent press release challenges the OPO article’s findings on a number of points and promises a detailed written rebuttal in a forthcoming issue of OPO. So what’s behind the controversy?
Squabble over standards
At the heart of the matter is a discrepancy between the American National Standards Institute (ANSI) regulations used for safety guidance.
Drs. Ostrin and Schill performed their tests and reported results according to one standard, the ANSI Z136.1-2014 standard, and found that the two lasers they tested—the Sky-n1201a (Beijing Ming Ren Shi Kang Science & Technology Co., Ltd; Beijing, China) and Future Vision (manufacturer unknown)—exceeded safety limits.
Z136.1-2014 classifies lasers according to their potential for biological harm, with so-called Class 1 devices being exempt due to their lack of perceived hazard. Both lasers in the Ostrin and Schill study were listed under this classification, and according to the authors, did not adhere to the maximum permitted exposure (MPE) set forth in Z136.1-2014.1
According to Eyerising’s press release, however, their Myopia Management Device has been tested to a different standard—ANSI Z80.36-2021. This protocol deals specifically with the potential light hazard of optometric and ophthalmic equipment that involves directing laser light into the eye.
Upon examination and testing in an FDA ASCA-accredited testing lab, the company claims that the device was awarded a Group 1 instrument classification according to the ANSI Z80.36-2021 benchmark, indicating no potential light hazard exists. This is opposed to a Group 2 instrument classification, which indicates a device with potential hazard to the eye.
Ultimately, Eyerising contends that Drs. Ostrin and Schill’s report is off-base because it evaluates RLRL devices according to a standard inappropriate for purpose-made eye care devices. Their report also used an older version of ANSI Z136.1-2014, which has been superseded by Z136.1-2022.
It’s unclear exactly how the more recent version differs in terms of MPE levels, but a blog post by ANSI concerning the change does elucidate that a vertical standard like Z80.36-2021 take precedence over more general ones like Z80.36.
“The previous edition of this standard, ANSI Z136.1-2014, revised the 2007 edition of the same American National Standard. Overall, it marked several major updates with a focus on increased usability,” the post concludes.
“Some of these changes included new terms, a significant increase in allowed exposure levels for wavelengths between 1.2 µm and 1.4 µm, and the official positioning of ANSI Z136 as a horizontal standard, whereby vertical standards for laser safety take precedence over this one within their scope.”2
Differences in Devices
The controversy extends beyond this titanic tangle of groups and classes and ANSI regulations. Another key point of dispute in the OPO study regards the tested devices themselves.
Drs. Ostrin and Schill conducted their tests using the two afforementioned laser products, the Sky-n1201a and Future Vision.1
Enter the regulatory mishmash mentioned above. While the evidence in the OPO study unequivocally suggests that these devices are not as safe as their Class 1 designation indicates, Eyerising counters that its Myopia Management Device device is Group 1 certified according to ANSI Z80.36—putting it in an entirely different class of safety considerations from the tested devices.
The firm addressed these differences in their press release. “Unlike the two copycat devices tested by the authors of the OPO article, the Eyerising Myopia Management Device also meets the quality, safety, and efficacy standards required by medical regulators in over 30 countries across Europe and APAC, with several more pending.”
Case Studies: Harbingers or Outliers?
The final fault line in the dispute lies along a series of case studies presented in the OPO report. Eyerising’s press release takes particular umbrage with what the firm feels is the mischaracterization of a report on adverse events following use of their device.
This includes the most contentious case in the OPO report, involving a girl who sustained damage to the retina while using an RLRL device. The firm argues in its press release that this was due to repeated use of the device against manufacturer instructions despite the onset of progressive discomfort.
Eyerising’s indignation notwithstanding, Dr. Ostrin expresses evidence-based concerns regarding the potential for harm to children’s eyesight that cannot be dismissed out of hand.
“Thermal ocular injury from a laser can occur with exposures at any wavelength when the temperature change of the retina is greater than 10°C, resulting in the denaturation of proteins,” Dr. Ostrin noted in a news release.
The adverse event reports cited in the OPO article, meanwhile, suggest these fears may have some foundation in reality—whether adverse events are due to the individual device involved, not following the manufacturer’s instructions, or due to RLRL therapy itself.
It is, however, also equally hard to ignore the volume of data Eyerising has marshaled in defense of its flagship product. The firm cites 10 clinical trials and 4 real-world studies spanning over 9 years and 160,000 patients, leaving a heap of data on both sides of the debate with seemingly no end in sight.
Where does this leave RLRL?
The way through this RLRL morass thus looks trickier than ever. It is clear, however, that any kind of fair and impartial analysis of this debate must take into account the Wild West-style regulatory landscape for medical devices like those for RLRL.
Standards are far less rigorous and defined than the safety protocols that govern the testing of biologics. Such a regulatory miasma is a fertile breeding ground for crossed wires on safety guidelines and confusion over standards.
In the end, the efficacy data of RLRL for myopia remains promising and Eyerising appears to be doing its level best to advance this new therapy in as safe and conscientious a manner as possible.
On the one hand, Dr. Ostrin’s work is a clarion call to action for better regulation of RLRL devices—and is the result of rigorous, peer-reviewed science.
On the other hand, blaming a company like Eyerising—which has invested heavily into peer-reviewed research investigating safety and efficacy—for a permissive and confusing regulatory climate and the potentially unsafe products it breeds could consign a potentially game-changing technology to eye care history’s landfill.
Moving forward, Dr. Ostrin’s comments on her work may shed light on a way forward that will do the most good for patients while minimizing harm.
“The safety profiles of red-light laser devices for myopia have not been fully investigated,” she commented. And ultimately, both the safety of our eyes and their ability to deliver clear vision is well worth a full investigation.
References:
- Ostrin LA, Schill AW. Red light instruments for myopia exceed safety limits. Ophthalmic Physiol Opt. 2024 Mar;44(2):241-248.
- American National Standards Institute. ANSI Z136.1-2022: Safe Use of Lasers. Available at: https://blog.ansi.org/ansi-z136-1-2022-safe-use-of-lasers/ Accessed on 15 February 2024.