Impact of repeated low-level red-light exposure on choroidal thickness and blood flow in pediatric patients: A SS-OCTA study

• Repeated low-level red-light (RLRL) therapy significantly increases subfoveal choroidal thickness (SChT) in myopic children. • A reduction in axial length was observed after three months of RLRL therapy, suggesting potential efficacy in controlling myopia progression. • RLRL therapy notably enhanced choroidal vessel volume (CVV) and blood flow across all choroidal regions, with a more prolonged response in the peripheral choroid. • Choroidal vascularity index (CVI) showed a significant decrease, particularly in the foveal region, following three months of therapy. • The findings suggest that RLRL therapy might mitigate myopia progression by increasing choroidal blood flow and thickness. To evaluate the impact of repeated low-level red-light (RLRL) therapy on choroidal thickness and blood flow in pediatric myopia. A three-month trial (April 1, 2023 – September 30, 2023) was conducted involving 44 children (ages 6–16) with myopia. Participants underwent RLRL therapy at home twice daily for five days per week, with each session lasting three minutes. Assessments at baseline, one month, and three months included cycloplegic refraction, best-corrected visual acuity (BCVA), intraocular pressure (IOP), ocular biometrics, swept-source optical coherence tomography angiography (SS-OCTA), slit-lamp, and fundus examinations. The study included 44 children (average age: 9.79 years; 56.82 % male). RLRL therapy significantly increased subfoveal choroidal thickness (Baseline: 272.82 ± 64.01 μm; 1-month: 297.77 ± 72.94 μm; 3-month: 298.77 ± 77.17 μm, p = 0.001), reduced axial length (Baseline: 24.97 ± 1.47 mm; 3-month: 24.88 ± 1.38 mm, p = 0.002), and showed a marginal regression in spherical equivalent ( p = 0.055). Significant elevations in choroidal vessel volume and thickness were noted, with positive correlations intensifying with distance from the fovea. RLRL therapy shows promise in managing pediatric myopia by increasing choroidal vessel volume and thickness, potentially mitigating myopia progression.