low-level laser / photobiomodulation
/ foh-toh-by-oh-mod-yoo-LAY-shun /
We are used to thinking of lasers as cutting tools, but a very low-power laser or LED light does not cut or even noticeably heat tissue. Photobiomodulation — also called low-level laser therapy or 'cold laser' — shines weak red or near-infrared light onto the skin with the aim of nudging cells to work a little differently, easing pain and perhaps helping healing.
The light is far too weak to burn; instead, the proposed mechanism is that certain wavelengths are absorbed by structures inside cells, especially the mitochondria (the cell's energy plants), where the light may slightly boost energy production and influence inflammation and blood flow. A device with a small probe or a light pad is held over the painful or injured area for a few minutes. Because it neither heats strongly nor delivers a sensation, the person usually feels nothing during treatment. It has been tried for tendon pain, arthritis, neck and back pain, mouth ulcers from cancer treatment, and slow-healing wounds.
Photobiomodulation is one of the more biologically intriguing modalities, and for a few specific uses the evidence is moderately encouraging, but overall it remains uncertain: results vary widely between studies, and the right wavelength, dose, and timing are not well settled. It is reasonable to view it as low-risk and occasionally helpful rather than reliably effective. Eye protection is needed because even low-level laser light can harm the retina, and it is generally avoided directly over tumours, the thyroid, and a pregnant abdomen.
A clinic offers cold laser over a patient's chronically sore elbow tendon; he feels nothing during the few-minute session, and it is added as a low-risk extra alongside the loading exercises that do the real work.
Biologically intriguing, low-risk, but only sometimes helpful.
Despite the high-tech name, results are inconsistent and the best dose is unsettled; treat it as low-risk and occasionally helpful, not reliably effective — and always protect the eyes.