JAN 28, 2022
This was the first prospective, randomized, multicenter study of repeated low-level red-light therapy for myopia control in children, a treatment currently approved in China for amblyopia.
A total of 264 Chinese children aged 8 to 13 years were randomized into 2 groups: one given single-vision spectacles and red-light therapy and the other given spectacles alone. Red-light therapy involved a device that emits a red light with a wavelength of 650 nm and an illumination level of ~1600 lux; treatment was administered in twice-daily 3-minute sessions (≥4 hours between sessions) for 5 days per week. Treatment compliance was monitored automatically through the device. The primary outcomes were axial length and spherical equivalent at the 12-month follow-up visit.
At 12 months, the mean axial elongation was 0.13 mm in the treatment group compared with 0.38 mm in the control group, a 69.5% reduction in myopia progression. Adjusted mean spherical equivalent progression was −0.20 D in the treatment group and −0.79 D in the control group. In addition, 31.6% of participants in the treatment group showed a ≥0.05-mm axial length shortening at 12 months. The median treatment compliance rate was 75%. There were no severe adverse events seen in either group.
Study limitations included the fact that the timeframe of the study spanned the outbreak of COVID-19. Due to this, about 50% of study participants were lost to follow-up for the 6-month visit; however, many had been recaptured for the 1-year visit. In addition, the control group did not receive a placebo light treatment. It is unknown whether these data are generalizable to other devices, wavelengths of light, exposure times, and power intensities.
Red-light therapy shows promise in decreasing myopia progression and is the first intervention that may also reverse axial lengthening. This treatment is currently available only in China, but good safety data are available due to its long-term use for amblyopia.