Light based technologies have immense therapeutic potential and differences in shape, size, power and versatility. From professional sports teams to clinical use, red light and infrared therapy is starting to be used very effectively to treat injured tissue and nerves. Light-based therapy used to treat pain and inflammation can be delivered by both lasers and LEDs, and consumers often want to know the benefits and differences between them.
Laser and LED therapies rely on their capability to deliver a sufficient amount of energy to the target tissue in order to bring about a photochemical process known as photobiomodulation (PBM). PBM is a nonthermal process involving endogenous chromophores eliciting photophysical and photochemical events at various biological scales. Some processes that are impacted include, but are not limited to, pain relief and inflammation, immunomodulation, and promotion of wound healing and tissue and nerve regeneration."1
Both sources of light share similar mechanisms of action and are both generated using diode technology. When studied in therapeutic use, both lasers and LEDs are often built to emit similar wavelengths, and in the A) red light and, B) near-infrared spectrum, and have been shown to have pain and anti-inflammatory properties. However, significant differences between the two do exist, that create merit in use each or both to treat your condition. The differences lie within the power generated, the specificity of wavelength, and the physical characteristics of the beam generated from the diode. As well as other factors such coverage area, application or conformance to treatment site.
Laser light is unique, in that it is monochromatic, coherent, and collimated. These aspects make it well-suited to many medical applications.3 The monochromatic, or single wavelength, beam is ideal for stimulating chromophores in biological tissue that only respond to very specific wavelengths. Coherent photons are organized where non-coherent photons are not. This property is key in minimizing photon scatter as light interacts with tissue and nerves. Further, since injured tissue is normally deep in the tissue, laser's columnated beam helps focus energy in a narrow, direct path which is ideal for treating tissues at depth.
LEDs emit light in a small band of wavelengths (~20 nm wide) but cannot emit a single specified wavelength (~1 nm wide). This bandwidth impacts their ability to target deep into the tissue. Additionally, LEDs do not produce a collimated nor coherent beam, which is less ideal when treating deep into the tissue. Lastly, LED's operate at lower power (wattage) than lasers, which impacts their ability to reach deeper tissue in shorter treatment sessions.
When trying to target deeper tissues, wavelength is a critical variable that can play a significant role in the light's ability to penetrate tissue. But it is not the only determining factor in therapeutic effectiveness. Power is a second variable that also plays a large role in determining both proper use and consistency of outcomes for light-based therapies. Lasers are generally capable of producing much higher powers than LEDs, which significantly impacts their ability to reach deeper tissues.
Because there is a loss of light energy as it passes through skin and tissue, the stronger the power at the surface, then the light energy can drive deep without dissipating.
For wound healing, skin treatment, injury recovery, nerve regeneration, and a topical pain relief effect, LED's are highly effective as the energy is not dissipated. For deeper or more chronic conditions, a stronger amount of energy should be delivered for a more effective therapeutic result.
However, an LED wrap that is made with a high quantity of LED diodes and with a higher ratio of them being in the infrared range rather than in the red-light range, can have a therapeutic result as well. Note infrared LED's are invisible to the naked eye, so these diodes will appear to be off. But under a camera they will illuminate as purple and you can clearly see they are emitting.
So, Lasers and LED's can and often should be used in tandem, as LED's provide the coverage area, quantity of diodes per area of coverage, and joint application placement that Lasers do not.