Investigation of the Efficacy and Safety of 650nm Low-Level Red Light for Myopia Control in Children: A Randomized Controlled Trial.

Abstract

To evaluate the 6-month efficacy and safety of 650nm low-level red light (LLRL) for myopia control in children. This was a single-center, single-masked randomized controlled trial. A total of 224 children aged 6-12years with spherical equivalent error (SER) of - 6diopter (D) to - 0.5D were enrolled, and were randomized to LLRL group or control group. Children in the LLRL group underwent treatment twice daily, each lasting for 3min, there was an interval of at least 4h between treatments. Children in both groups were allowed to wear single-vision spectacles; no additional intervention was given to the control. The primary outcomes included change in cycloplegic SER and change in axial length (AL) during 6months. The median 6-month changes in AL of the LLRL and control groups were - 0.06mm (interquartile range, IQR - 0.15, 0) and 0.14mm (IQR 0.07, 0.22), respectively. The difference between groups was significant (Z = 10.021, p < 0.001). The median 6-month changes in SER were 0.125D (IQR 0, 0.375) and - 0.25D (IQR - 0.5, 0) for the LLRL and control groups, respectively. The difference between groups was significant (Z = 8.827, p < 0.001). Compared with the control, the proportion of children with hyperopic shift in the LLRL group was higher (51.65% vs. 3.41%, p < 0.001), and the proportion of children with shortened AL in the LLRL group was higher (63.74% vs. 2.27%, p < 0.001). No adverse event was observed. 650nm LLRL significantly slowed down the myopia progression in children aged 6-12years, and there was no observable side effect in the short term.