A new multicentre randomised clinical trial, published by the American Journal of Ophthalmology, found repeated low-level red-light therapy (RLRL) to be safe and effective in high myopes (-6.00D).  

Two hundred and two high myopic children aged 7 to 12 years (cycloplegia spherical equivalent refraction ≤–6.00D, astigmatism less than 2.50D, anisometropia of 1.50D) were randomly assigned to either the intervention group of RLRL plus single-vision spectacles (SVS) or control with SVS alone. The RLRL treatment was administered twice daily for three minutes, with an interval of at least four hours. 

After 12-months’ treatment, axial shortening >0.05mm was observed in 59% in the RLRL group and 0% in the control. Changes of choroidal thickness (ChT) and retinal thickness (RT) were analysed in one centre. In the RLRL group, ChT had increased in all sectors at 12 months, while RT was increased in parafoveal and perifoveal circles. In the control group, all sectors of ChT and only perifoveal RT were significantly diminished at 12 months. A multivariate linear regression model revealed significant correlations between changes in ChT central foveal circle and RT perifoveal circle at one month and AL changes at 12 months. No fundus structure changes, afterimage exceeding six minutes, nor best corrected visual acuity decreases were reported.  

In conclusion, authors said their findings indicated RLRL is an effective and safe method to delay the progression of myopia in children with high myopia, with axial length (AL) shortening sustained over 12 months. Noting that the mechanisms for AL shortening have not yet been confirmed, they suggested this change may be related to choroidal and retinal thickening.