Rare complication sparks safety concerns

Two months after ceasing RLRL, the patient reported gradual improvement in vision and her corrected visual acuity (both eyes) had recovered to the same level as prior to treatment (0.8). OCT imaging showed the integrity and continuity of the ellipsoid zone in the macular fovea of both eyes had been restored. When seen again after four months, her cornea appeared clear and her retinal structure was intact.

Considering the case

Discussing what caused the adverse effects, authors of the JAMA Ophthalmology article² hypothesised they may have been associated with a potential light power instability of the device, potential improper long exposure, or a possible sensitivity to light toxicity in the patient, although they said no certain evidence was found to support either scenario.

Eyerising International’s CEO Paul Cooke said the reports identified important clinical information for clinicians to be aware of to help identify individuals at risk of rare side effects and to understand the prognosis of these effects. Eyerising’s view, however, is that the patient’s sensitivity to light toxicity is a more likely explanation rather than device malfunction or improperly long exposure, he said, with the former being unlikely because it would have produced far more cases and the latter highly improbable due to the setup of the machine.

Importantly, consulting with the patient’s doctors at Hunan Children’s Hospital, their data showed she initially responded ‘very well’ to RLRL therapy, with a regression of myopia from -6.50D to -4.25D after one month of treatment, said Cooke. “This two-diopter myopic regression, which is highly unusual, suggests that the child may be a super-responder to the light therapy.”

While Cooke conceded the case reports play an important role in the development of RLRL technology, he stressed it is crucial to recognise that these side effects are “extremely rare, foreseeable, characterised by prolonged after-image post treatment and substantial myopia reversion, detectable through reduced best-corrected visual acuity and OCT changes, and ultimately recoverable upon discontinuation of the treatment”.

Eyerising’s Myopia Management Device consists of semiconductor laser diodes, which deliver low-level red light with a wavelength of 650±10nm at an illuminance level of approximately 1,600 lux through the pupil to the fundus. The device is equipped with special safety features to prevent inappropriate and prolonged use. It is CE certified, registered with Medsafe in New Zealand and listed by the Australian Therapeutic Goods Administration. The reported case was a patient using a device from Eyerising Suzhou Xuanjia Optoelectronics Technology, Eyerising International’s original equipment manufacturer in China, which shares the same technology platform.

References

1. Tian Y, Xiao Z. Recovery of retinal structural damage after repeated low-intensity red light therapy for high myopia: a case report. Chin J Exp Ophthalmol, 2023, 41(9): 853-855.
2. Liu H, Yang Y, Guo J, Peng J, Zhao P. Retinal Damage After Repeated Low-level Red-Light Laser Exposure. JAMA Ophthalmol. 2023;141(7):693–695.