Reducing myopia progression with red light therapy: Treatment mechanisms and safety levels.

Myopia (shortsightedness) represents a mismatch between the eyes length and its dioptric system (refracting power), which results in distant fixated objects being imaged in front of the retina. The underlying problem is typically excessive eye elongation, multiplying the risk of sight-threatening eye diseases.

Faced with rapidly increasing myopia prevalence figures worldwide, and associated huge economic burdens, public health systems need more and improved myopia control in children.

A recently described, controversial method for reducing myopia progression in children is low-level red-light therapy (LRL), with clinical trials reporting significant effects with daily, short periods of direct retinal red laser light stimulation.

However, a recent report of retinal damage and reduced vision, along with inadequate safety monitoring calls its safety into question.

MyReL addresses open questions regarding the underlying mechanism, ocular effects, risks and long-term safety of LRL using an established animal (guinea pig) model of myopia and complimentary studies in humans.

The interdisciplinary project will allow detailed evaluation of LRL-induced structural and functional changes in myopic guinea pig eyes.

Results from the latter will be used to inform a complimentary human study focused on 3 areas, in which choroidal thickness will serve as a biomarker for therapeutic effects: (1) the intensity-dependent dose-response effects of LRL (limited to established safe intensities), (2) short-term effects of ambient red-light exposure, (3) effects of manipulating the spectrum of digital device screens.

Plausible outcomes of these novel studies include a prototype for hazard-free LRL, as well as recommendations on optimal spectral settings for digital devices, both aimed at controlling myopia progression in children.

In these ways, MyReL will help to prevent severe eye diseases, with a significant positive impact on health and economic sectors, given EUs aging population.