Wound healing: Laser, light technologies show promise for advancing care of chronic lesions

Key Points

LLLT history

Lasers and light devices are fairly new to medicine. They were introduced as part of the research NASA conducted in the 1980s on healing in space. The more recent focus on lasers and light devices centers around low-level laser therapy (LLLT), also referred to as "cold laser therapy."

Most research on the use of lasers and light devices for wound-healing therapies involves the use of LLLT. These lasers use single-wavelength emissions to affect cellular activity. In the past, light-emitting diodes (LEDs) were included in the category of LLLT. However, because LEDs are not single-wavelength devices (rather, they are a panel of diodes emitting a small range of wavelengths), most current research makes a distinction between these two entities.

The most common lasers used in LLLT are diode and helium neon lasers with wavelengths ranging from visible (red/632.8 nm) to near infrared (830 nm). The fluencies used in LLLT are lower than the common fluencies we use for our dermatologic procedures, producing painless treatment sessions with little to no visible tissue wounding.

The theoretical basis for LLLT therapy is related to the concept of photobiomodulation as opposed to selective photothermolysis. The effects of photobiomodulation are due to photochemical influences on cell activity, as opposed to thermal damage. In other words, in LLLT, heat is not a factor.

The existence of photobiomodulation has been demonstrated by many researchers from many different parts of the world. The in vivo clinical effects of LLLT have been less reproducible, despite the clear data that proves the existence of photobiomodulation.