Red Light Therapy Improves Choroidal Perfusion in Children With Myopia

Red light therapy improves choroidal perfusion and increases choroidal thickness in children with myopia, according to a study published in Ophthalmic and Physiological Optics. While the mechanism is unknown, the therapy has shown potential as a treatment for myopia progression.

Researchers enrolled 67 children with myopia (mean age, 9.6 years; boys, 45) in the investigation, which included individuals treated with low-level red light therapy (n=47) and control group participants (n=20). Individuals who underwent red light therapy received treatment 2 times daily at 3 minute intervals separated by 4 hours or more.

The team collected optical coherence tomography (OCT) and OCT-angiography (OCT-A) data at baseline and at 1, 2 and 4 weeks. Measurements included axial length, retinal thickness, sub foveal choroidal thickness (SFCT), total choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI), percentage retinal vascular density (VD%), and choriocapillaris flow voids (FV%). 

SFCT increased significantly among individuals treated with low-level red light therapy (average, 14.5 μm; 95% CI, 9.6–19.5 μm) compared with control group participants, who experienced choroidal thinning (average, −1.7 μm; 95% CI, −9.1-5.7 μm; P < .0001) after 4 weeks of treatment. 

There were no significant changes in retinal thickness or VD% in either group at the study conclusion, according to the report. Furthermore, no abnormal retinal morphology related to photodamage was observed in participants treated with low-level red light therapy. Horizontal OCT-A scans revealed an increase in TCA, LA and CVI with time (all P < .05), while SA and FV% remained unchanged (both P >.05).

“In this study, we observed a significant increase in choroidal thickness, LA, TCA and CVI in children who received repeated [low-level red light therapy],” according to the researchers. “This suggests that repeated exposure to low-level red-light may increase choroidal thickness and blood perfusion, with cumulative effects over time.”

A small sample size, short study duration, and an inability to randomly assign participants to the treatment and control groups are acknowledged limitations to the research.