Light Emitting Diode (LED): LED is a semiconductor device that emits incoherent low intensity light.
LED Clusters: Deliver energy superficially over broader regions.
Laser Light: Delivers photonic energy deeply and specifically
The main difference is coherency. Laser light is coherent (“coherent waveform”), which means all the light waves move in phase together in both time and space. A laser has a very tight beam that is strong and concentrated.
An LED (“incoherent waveform” ) releases light in many directions; with the result that the light is weak and diffuse
LED Devices Are Not Lasers
There are many different configurations of phototherapy instruments in the market, some offering laser output only, some offering only LEDs, and – excluding LEDs that are provided for indication only – other devices combining both lasers and LEDs as active therapeutic components. The two latter types are sometimes deceptively called “laser” with no reference made to other emitter types; this is inaccurate, at best. Often the buyer is unaware of the distinction, thinking they have bought a true laser device.
LED Promoting Laser Clinical Studies
Of the hundreds of referenced and reported clinical and scientific studies and papers available, they are almost exclusively done with laser light sources as the medically beneficial light source.
In fact, even on the web sites of the leading LED light devices, the sources and references they list are not for LED therapy, but rather for laser light therapy.
Manufacturers of such devices as Bioflex, Anodyne and the Dynatron Solaris units, which are LED therapy devices, primarily use laser light studies as their medical efficacy support.
A number of studies have been completed that compared the effectiveness of laser light to LED light and the majority have found laser light to be far more effective, particularly in treating tissue of any significant depth.
While LED light therapy does have some beneficial effect, it is limited to superficial tissue treatment only.
Significant Difference in Biostimulation Effects
The authors of the leading and most widely used laser therapy textbooks are unanimous in their opinion that there are significant differences between laser light and LED light and that their respective biostimulative effects are far from being equal.
The preponderance of opinion is that laser light can achieve much greater and deeper stimulative and therapeutically beneficial effect. The following is taken from one of the most respected laser therapy textbooks in use today, “Laser Therapy”, by Turner and Hode.
“Many producers of therapeutic instruments have claimed that treatment with LED’s is as effective as laser treatment. However, in light of the clear lack of peer-reviewed studies supporting these claims, LED producers make references to laser research in their marketing materials. A significant effect was observed with lasers, which was not achieved with the other, less narrow-band light sources (LED).
Conclusion: Either all the investigators who conducted the research cheated, or the effects are specific to laser light. In the literature there is a good support for the hypothesis that at least some of the biostimulative effects in-vivo are laser specific. In fact, we have not yet found one single study indicating that non-coherent light (LED) is as efficient as coherent light. This does not mean non-coherent light (LED) is not useful, only that it (LED) is less efficient and probably only efficient on superficial structures.”
Review by Researchers
These international laser experts and researchers agree that in comparison, laser light therapy is far superior to LED therapy, as indicated by the studies of these researchers’ published work.
Bihari – LED’s, when compared to lasers, demonstrate a much lower efficacy.
Kubota – found there was no difference between control and LED 840 nm groups.
Berki – found the positive effects from laser therapy were not seen when irradiating the cell cultures with normal monochromatic (LED) light of the same wavelength and doses.
Muldiyarov – Analyzed cases where the rats were treated with ordinary red light and found there was no essential differences from the control group.
Haina – compared to the 22% increase in positive laser effects, the increase in the incoherent (LED) group was less than 10%.
Laakso – ACTH and B-endorphin levels were significantly elevated in the LLLT groups but not in the LED group.
Pöntinen – 670nm laser induced a temporary vasodilation and increased blood flow; however, LED at 635nm with doses between 0.68 and 1.36 J/cm2 decreased blood flow at least for 30 minutes after irradiation.
Lederer – found that incoherent light of the same wavelength and power density showed no influence.
Rosner – found that non coherent infrared light was ineffective or had adverse effect.
Nicola – Non-coherent light of the same wavelength and dose was less favorable.
Onac – The therapeutic window appears to be narrower for monochromatic noncoherent light.
Zhou – laser showed the best effect while the non-coherent LED light showed the poorest. Coherency does not influence the transmission; rather, because of interference in the scattered light field, coherency influences the microscopic light distribution into tissue. While it is easier to achieve higher power density with lasers than with LED’s, this is not the general reason for the better results with lasers; the coherency of the laser light source is the most important factor behind the superior results of laser light.
Insurance Determination: LED Not Effective
“Monochromatic infrared energy therapy or monochromatic, near-infrared photo energy (MIRE™) (e.g., Anodyne® Therapy or Anodyne® Therapy System) remain unproven for all conditions, due to the lack of well-designed, controlled, randomized, double-blind trials. In addition, there is lack of evidence of long-term health outcomes supporting the efficacy of this treatment.”
Laser Therapy surpasses LED Therapy for clinical effectiveness and results.