About Photobiomodulation

The official MESH definition from the National Library of Medicine describes PBMt as

“A form of light therapy that utilizes non-ionizing forms of light sources, including lasers, LEDs and broad-band lights in the visible and infrared spectrum.

It is a non-thermal process involving endogenous chromophores eliciting photophysical (i.e. linear and non-linear) and photochemical events at various biological scales.

This process results in beneficial therapeutic outcomes including but not limited to the alleviation of pain or inflammation, immunomodulation and promotion of wound healing and tissue regeneration.”

Photobiomodulation (PBM), previously referred to as low-level laser therapy (LLLT) is the application of light with wavelengths from 450 – 1064nm delivered as LASER (Light Amplification by Stimulated Emission of Radiation) or LEDs (light emitting diodes) to modulate cell physiology to initiate therapeutic benefits. These effects occur by stimulating anti-inflammatory activity, optimising tissue repair, enhancing muscle function and modulating peripheral nerve activity, including nociceptors and central nervous system neurons to enhance brain function.

PBM has also been referred to as “cold” laser to differentiate it from the many current uses of ablative or “hot” lasers which cause thermally mediated tissue destruction in surgery, tissue rejuvenation and hair removal.  In contrast PBM is athermal, more akin to the modulating effect of, for example, ultraviolet (UV) light in the 200-450nm range stimulating production of vitamin D in skin, for treating dermatological conditions, or the treatment with blue light (390 – 470nm) of hyperbilirubinaemia in neonates.

Within a decade of the development of laser in 1960 by Maiman at the Hughes Research Laboratories clinical research had commenced, initially in wound healing.  Clinical research since then has expanded exponentially across a range of conditions from osteoarthritis (OA) to neurodegenerative disease with more than 4,000 published, human, laboratory and animal studies exploring the mechanisms of these effects.

Light of different wavelengths penetrates the skin and is absorbed by photoacceptors or chromophores in various cellular, sub-cellular and molecular structures. This is the primary event in the initiation of PBM effects.

The most well-known of the photoacceptors is Cytochrome C Oxidase, however membranes, ion channels (e.g. TRPV), Opsins (1-5), adenine nucleotides (NADH) and receptor tyrosine kinases are also transduce light energy to photophysical and photochemical effects in a non-visual phototransduction cascade.

Once the light is absorbed secondary and tertiary events occur at a cellular level. These include:

• ATP synthesis
• Release nitric oxide
• Brief bursts of reactive oxygen species (ROS) to achieve redox homeostasis
• Modulation of intracellular calcium
• Induction of NF-κB
• mRNA transcription
• Expression of growth factors e.g. bFGF, VEGF, TGFb
• Protein synthesis

The clinical effects initiated by these changes at a tissue, organ and whole body level include:

• Reduce inflammation
• Stimulate healing
• Relieve pain
• Improve lymphatic flow
• Relieve muscle spasm/trigger point activity
• Improve performance
• Modulate CNS neurotransmitters
• Initiate systemic (abscopal) effects including stem cell mobilisation

Different Regulations for Use Across Australian States

Laser and laser use is regulated in:

• Queensland – Class 4 lasers only (not required to hold a licence and 3B lasers not required to undergo any practical and theoretical training
• Tasmania – Class 3B & 4 + registration of place
• Western Australia – Class 3B & 4 (dentists, medical practitioners, physiotherapists & chiropractors – podiatrists may treat onychomycosis)
• “The Commonwealth” i.e. CSIRO, military

These states do not have controls over who or may not use a laser:

• NSW
• ACT
• SA
• NT

They do not “recognise” lasers and there is no training or experience required.

AMPA runs a Laser Safety Course which has been accredited by the Government of Western Australia Radiological Council, please check our events page to see when courses are being run.