A Look at the Pediatric Myopia Control Pipeline: Light Therapy

Myopia represents a rapidly escalating global health concern, with projections indicating its prevalence could affect nearly 40% of children by 2050.¹ Recent treatments focus beyond mere refractive correction, aiming instead to slow axial elongation. Although not yet FDA-approved in the United States, low-level red-light therapy (ie, repeated low-level red-light [RLRL] therapy), has emerged as a promising modality; still, safety and regulatory concerns warrant attention.²

MECHANISM OF ACTION

RLRL therapy typically involves exposing the retina to nonthermal red wavelengths (~635 to 650 nm) through LED or low-power laser devices. Protocols usually recommend 3-minute sessions, conducted twice daily, 5 to 7 days per week.3 The therapy aims to enhance choroidal blood flow and thickness, potentially alleviating scleral hypoxia associated with myopic axial elongation.1 It also induces cellular photobiomodulation via nitric oxide photodissociation, increasing mitochondrial adenosine triphosphate production and promoting tissue remodeling.⁴

Early clinical trials in China reported axial length reduction or significantly slowed elongation in pre-myopic and myopic children, with axial growth rates of less than 0.1 mm per year, surpassing some results obtained with orthokeratology lenses.^4,5

THERAPEUTIC GOALS

The primary aim of RLRL therapy is to slow axial myopia progression, rather than offer a definitive cure. Stabilization or slight reversal of axial elongation within a 12-month period may substantially decrease the risk of progressing to high myopia and developing associated ocular pathologies such as retinal degeneration and glaucoma.¹ Clinicians typically consider RLRL a standalone therapy or in conjunction with atropine drops, specialized spectacles, or contact lenses.

CLINICAL EFFICACY

Data from controlled studies show significant promise. A randomized double-blind trial showed approximately 0.24 mm less axial elongation over 1 year compared with low-dose (0.01%) atropine.^1,4 Retrospective comparative analyses revealed that RLRL-treated groups experienced less axial elongation (0.17 mm over 2 years) compared with orthokeratology users (0.50 mm), although differences narrowed after 2 years.⁴ A 12-month trial observed significant reductions in myopia among pre-myopic children and delayed progression in early myopic cases.⁶

Despite encouraging outcomes, research is necessary to confirm long-term efficacy, evaluate potential rebound effects, and assess durability.

SAFETY CONCERNS

Critical safety issues related to RLRL therapy have emerged from recent studies, highlighting the need for caution in clinical practice. Laboratory analyses found that several commercially available devices approach or exceed ANSI Z136.1-2014 maximum permissible exposure (MPE) limits for thermal and photochemical retinal injury during standard 3-minute sessions.⁷ Additionally, advanced retinal imaging techniques, such as adaptive optics scanning light ophthalmoscopy and OCT, have revealed concerning retinal structural changes, including decreased cone photoreceptor density and drusen-like lesions, even with devices adhering to safety standards.⁷

While systematic reviews report a relatively low adverse event incidence (0.088 per 100 patient-years) without permanent visual function loss, isolated cases of macular photic injury and ellipsoid zone disruption underscore the potential risks involved.^4,8

Responding to these safety concerns, China’s National Medical Products Administration reclassified RLRL devices as class III medical devices effective July 1, 2024, mandating rigorous safety testing (including primate histopathological evaluations) and restricting use to children 8 years of age and older, prohibiting preventive use in pre-myopic individuals.²

GETTING AHEAD OF THE CURVE

Through meticulous patient selection, rigorous monitoring, potential combination therapy, and continued research, RLRL therapy could become an effective option for pediatric myopia management, provided its therapeutic benefits unequivocally outweigh its retinal risks during a patient’s critical developmental years.

Patient Selection

Limit therapy to children 8 years of age and older in compliance with local regulations. Employ verified, approved devices with proven adherence to MPE standards. Emphasize patient education, explicitly detailing rare but documented retinal risks and uncertain long-term safety data.

Monitoring and Management

Conduct baseline retinal imaging using OCT, multifocal electroretinography, and adaptive optics when feasible. Perform annual follow-up visits, vigilantly screening for structural or functional retinal alterations. Immediately discontinue therapy upon identification of adverse retinal effects.

Combination Therapies

Consider adjunctive use of low-dose atropine or optical defocus strategies to minimize treatment burden and optimize safety. After discontinuing therapy, closely monitor patients for potential axial length rebound, which has been observed in some patients.⁴

Continued Research

Further investigation into RLRL therapy is critically needed, including: longer-term randomized clinical trials (> 2 years) with standardized imaging and functional outcome measures, dose-response studies to refine optimal wavelengths, irradiance levels, and treatment frequency, investigations encompassing diverse age groups, ethnicities, and baseline refractive profiles, and comprehensive evaluations of rebound effects post-therapy and effective tapering strategies.

PROCEED WITH CAUTION

RLRL therapy is a novel and potentially valuable tool for pediatric myopia management, demonstrating encouraging early results. However, substantial safety and regulatory issues necessitate cautious integration into clinical practice.