Repeated low-level red light (RLRL) treatment during a 12 month trial effectively delayed myopia progression in children, with a stronger impact on myopic than pre-myopic children, scientists in China reported.
Between March 2022 and May 2023, researchers from the Tianjin Medical University Eye Hospital conducted a study to compare the effects on RLRL treatment on axial length growth and refractive error changes.
A total of 104 participants completed the trial, split into myopia (M-RL), myopia-control (M-C), pre-myopia (PM-RL) and pre-myopia control subgroups (PM-C), each receiving three minute RLRL treatments twice a day, seven days per week.
Follow up treatments were scheduled at one month, three month, six month and 12 months with repeated measures analysis of variance used to compare spherical equivalent refractive errors (SE) and axial length (AL).
Results showed that SE and AL changes were −0.078±0.375 D and 0.033±0.123 mm for the M-RL group and −0.861±0.556 D and 0.415±0.171 mm for the M-C group.
In the pre-myopia group, progression of SE and AL was −0.181±0.417 D and 0.145±0.175 mm for PM-RL and −0.521±0.436 D and 0.292±0.128 mm for PM-C.
The researchers concluded that RLRL ‘effectively delayed myopia progression’ but exhibited a ‘stronger impact’ on myopic children rather than pre-myopic children, with ‘further research needed to identify specific reasons’.
The study, Effectiveness of repeated low-level red light in myopia prevention and myopia control, was published in the British Journal of Ophthalmology online on April 17.