This randomized clinical trial evaluates the efficacy and safety of daily 650-nm low-level red light for myopia treatment among children aged 6 to 12 years in China.
Key Points
Question
What is the effect of daily 650-nm low-level red light (LLRL) on spherical equivalent error (SER) and on axial length (AL)?
Findings
In this randomized clinical trial of 336 children at a single center where the device is patented, the mean change in SER was almost 1 diopter more myopic, with about one-third of a millimeter greater axial length in the control compared with the LLRL group, without adverse effects noted in the retina.
Meaning
These findings suggest that daily use of 650-nm LLRL for 1 year can slow the progression of SER and AL without safety concerns identified; confirmation of these findings at independent sites seems warranted.
Abstract
Importance
Treatments are needed to slow progression of or reduce incidence of myopia.
Objective
To evaluate the efficacy and safety of daily 650-nm low-level red light (LLRL) for myopia treatment.
Design, Setting, and Participants
Single-masked, randomized clinical trial at 1 site in China. Baseline measurements were completed from August to September 2021. Participants were children aged 6 to 12 years with spherical equivalent error (SER) of −6 diopters (D) to 3 D. Data were analyzed from March to July 2023.
Interventions
Irradiation daily with 650-nm LLRL for 3 minutes twice daily 4 or more hours apart or no intervention.
Main Outcomes and Measures
Primary outcomes were changes in cycloplegia SER and axial length (AL) at 6- and 12-month follow-up visits. Safety was assessed on masked fundus photograph evaluations.
Results
A total of 336 children were randomly allocated into the LLRL group or control group in a 1:1 ratio. The control group contained 86 female patients (51.2%), and the treatment group contained 90 female patients (53.6%). The mean (SD) age, SER, and AL were 9.0 (1.9) years, −1.3 (1.5) D, and 23.8 (1.0) mm for all patients. A total of 161 (95.8%) in the LLRL group and 159 (94.6%) in the control group returned for the 6-month follow-up. A total of 157 (93.5%) in the LLRL group and 152 (90.5%) in the control group returned for the 12-month follow-up. Mean (SD) changes in SER were 0.15 (0.16) D and −0.26 (0.21) D for the LLRL group and the control group, respectively (difference, −0.41 D; 95% CI, −0.48 to −0.34 D; P < .001), at 6 months and 0.24 (0.27) D and −0.65 (0.33) D for the LLRL group and the control group, respectively (difference, −0.89 D; 95% CI, −0.95 to −0.83 D; P < .001), at 12 months. Mean (SD) changes in AL were −0.06 (0.08) mm and 0.13 (0.12) mm for the LLRL group and control group, respectively (difference, 0.19 mm; 95% CI, 0.16 to 0.22 mm; P < .001), at 6 months and −0.11 (0.10) mm and 0.26 (0.16) mm for the LLRL group and control group, respectively (difference, 0.37 mm; 95% CI, 0.34 to 0.40 mm; P < .001). Masked fundus photograph review did not identify retinal changes in either group.
Conclusions and relevance
These findings suggest daily use of 650-nm LLRL for 1 year can slow progression of SER and AL without safety concerns identified. Confirmation of these findings at independent sites seems warranted, as well as determining whether these effects can be sustained with or without continued treatment and whether LLRL has any effect on pathological myopia.
