Lasers and Light Emitting Diodes (LEDs) are often used for by medical practices for therapeutic purposes to relieve pain and reduce inflammation for various medical conditions.[i] While lasers and LEDs use similar principles and mechanisms of action, there are differences between these therapies to take into consideration when deciding which technology is best fit for your practice.
Laser therapy and LED therapy are types of photobiomodulation therapy (PBMT). PBMT uses non-ionizing light forms such as lasers and LEDs to trigger a series of photochemical reactions which ease pain and inflammation for a variety of conditions.[ii]
There are three main types of LED lights used in LED therapy, blue LED, red LED and infrared LED. Blue LED is often used to treat acne and reduce inflammation, affecting only the uppermost layer of the skin. Red LED light therapy is typically used to improve signs of aging and scarring, traveling further into tissue than blue LED light.[iii] Infrared LED light travels further than blue and red LED light, treating pain and reducing inflammation but does not travel as far as laser light due to its non-coherent nature.[iv] LED light sources are non-coherent, meaning the light scatters and reflects as it interacts with tissue, becoming weaker as it travels away from the source.[v] Due to the non-coherent nature of LEDs, LED light is limited in how deep it can penetrate tissue, meaning it is often used only for surface level conditions.[vi] LED light therapy devices come in many different forms. LED lights can be put into panels for patients to lay on or stand next to, made into facemask devices, or put into a flexible device to wrap around and treat a specific area.[vii]
Different from LED light, laser light is monochromatic and coherent, reaching tissue up to 4cm into tissue and therefore has the capability to treat both superficial and deep tissue conditions.[viii] Lasers have a narrower spot size than many LED technologies, allowing for a small, targeted area to be treated if necessary.[ix] Laser therapy is often used to reduce pain and inflammation while also stimulating the body’s natural healing processes.[x] Lasers, unlike LEDs are subject to the Federal Laser Product Performance Standard (FLPPS) which classifies lasers.[xi] Most therapeutic lasers fit into Class 3B and Class IV. Class 3B lasers have lower power and results are achieved slowly, therefore patient results are achieved over a prolonged period, and are sometimes not seen until the end of the treatment cycle. Class IV lasers operate at higher power to achieve more efficient results, however there is a risk of thermal damage to tissue if the laser energy is not controlled.[xii]
LEDs vs. Lasers
When it comes to laser therapy and LED therapy, there are differences regarding power, wavelength, patient results, and cost. LEDs operate at a lower power level than lasers, meaning that LEDs cannot reach as deep in the tissue.[xiii] Infrared LEDs and lasers emit wavelengths of approximately 600 nm-1,200 nm both within the therapeutic window. This specific window allows photons to penetrate tissue and trigger the photobiomodulation process, however due to coherence and higher power, laser energy can travel deeper into tissue and are more efficient than LEDs.[xiv]
When it comes to the impact of the therapy, both therapeutic methods require several treatments that are cumulative in nature. Due to the coherence and power of laser therapy results are achieved quicker than LED therapy, therefore requiring fewer sessions.[xv] While laser therapy technology might be a larger investment for providers than infrared LED therapy technology, the results of laser therapy are quick and effective making for a satisfied patient and provider experience.