Impact of repeated low-level red-light therapy on axial length, refraction, and macular retinal blood flow density in adolescents with mild to moderate myopia.

BACKGROUND

In order to evaluate the effectiveness of repeated low-level red-light (RLRL) therapy on stabilizing axial elongation and refractive changes in adolescents with mild to moderate myopia. In addition, we also examined whether RLRL therapy affects retinal blood flow density in the macular region, a factor previously unstudied in this context.

METHODS

Conducted at a single clinical site, this retrospective, single-arm study followed participants over six months, with assessments at baseline, 1 month, 3 months, and 6 months. The primary outcomes included axial length and spherical equivalent refraction (SER) changes. Secondary assessments included retinal blood flow density (superficial and deep macular layers), white-to-white corneal diameter, central corneal thickness, intraocular pressure (IOP), corneal curvature, light sensitivity, and peripheral retinal thickness.

RESULTS

There were 32 enrolled participants (mean age = 11.5 ± 1.72) in the current study. The spherical equivalent (SER) remained relatively stable over the first three months, but it significantly improved at six months, changing from -2.39 ± 2.21 D at baseline to -2.01 ± 2.12 D (P < 0.05). However, the axial length also showed minimal variation across follow-up visits, indicating stable eye growth with no substantial elongation throughout the study period. Furthermore, RLRL therapy resulted in stable measurements across primary and secondary outcomes (all P > 0.05), with no significant changes over the six months. There were no obvious side effects following the treatment.

CONCLUSIONS

Low-energy red light therapy shows promise as a non-invasive approach for stabilizing myopia in adolescents, with no observed compromise to retinal blood flow density. Further longitudinal research is needed to validate these findings and support clinical recommendations for myopia management.