October 31, 2018
Many people refer to all light therapy for the skin as LASER treatment. In reality though, all light treatments for the skin are not true LASERs. In this segment, I’m going to get a little technical, but I hope it leaves you with a better understanding of the differences between IPL, LED, and LASER skin treatments. For a summary, see the last two paragraphs.
There are many forms of light therapy. They all work by targeting light sensitive pigments in the skin called chromophores. A chromophore is simply a molecule or group of molecules that absorb light of specific wavelengths. Examples of these light-absorbing molecules are blood, (think pink or vascular spots on the skin), melanin (think dark spots on the skin), or hair follicles (think hair removal).
Let’s start with a definition, and move on to some cool history that involves Einstein and Martians. What is a LASER? LASER is an acronym for “light amplification by stimulated emission of radiation.” It’s a mouthful, but basically it is a device that magnifies (amplifies) light, generally of a single wavelength in a narrow, or concentrated beam. The author HG Wells first described the concept in his 1898 science fiction literary classic, War of the Worlds. In this book, he described a “fiery ray” that was used by the invading Martians as a weapon. The energy “ray” he described is uncannily like the modern LASER. The picture I attached is in the public domain and is from his book. We’ve hit Martians, now on to Einstein.
In 1917, Albert Einstein developed the concept of photons and stimulated emission of light, but it wasn’t until 1960 that Thomas Maiman developed the first ruby LASER, and later that same year Dr. Ali Javan produced the first continuous helium-neon LASER. It was only two years after this, in 1962, that Dr. Leon Goldman, commonly known as the “Father of Laser Medicine & Surgery,” first described the clinical use of LASERs in medical practice.
Let’s back up a moment to Einstein’s theory, and the concept of LASERs. Cool physics here: An atom moves from one energy state to another when it absorbes or releases energy. If a specific atom or molecule is stimulated by energy, it can emit light energy (radiation) by changing state. This light energy can be amplified by bouncing the light beam back and forth in a chamber with reflecting mirrors and finally to an output beam, hence, “light amplification by stimulated emission of radiation.” This LASER light can then be directed in short bursts at an area of skin and its energy will be absorbed by components of the skin depending on that component’s color. This energizes the particles in the skin that are of the color (chromophore) that is sensitive the light energy specific to that wavelength or group of wavelengths.
In general, LASERS penetrate the tissue deeper than IPL or LED light, but the treatment pattern is, for most treatments (except for treatments like tattoo removal), a pattern of LASER dots. To review, medical dermatology lasers usually do not treat the whole area of skin in the treatment field, but rather a matrix of dots within the treatment area. Because LASERS target a specific wavelength and are high energy, they are ideal for tattoo removal (the dyes used in tattoos are often absorbed and broken up [ablated] by a specific narrow band of wavelengths). Medically, LASER resurfacing is often called “traumatic ablative” in contrast to IPL rejuvenation, which is often referred to as “non-ablative” therapy.
An IPL is an intense, brief pulse of light that can be filtered to a specific group of wavelengths to impart light-energy to the color-specific component (chromophore) of the skin that that group of wavelengths target. It has been shown that the action spectra for tissue regeneration and repair consist of more than one wavelength; therefore, polychromatic spectrum IPL that covers a broader spectral region of light has advantages for skin rejuvenation and skin repair over either LASER or LED. The other advantage of IPL over LASER or LED is that IPL treats a complete area of skin rather than a usual LASER treatment area that consists of a matrix of dots.
An LED or “light emitting diode” releases light energy that is created by a semiconductor as an electric current passes through it. Light created by an LED is usually monochromatic (one wavelength) like a laser. LED also employs a matrix of LED dots, and is low-level energy that doesn’t penetrate as deeply as either IPL or LASER. Altering cellular function using low-level, non-thermal LED light is called photobiomodulation (PBM), or low-level light therapy (LLLT). PBM bypasses the initial destructive (ablative) step of LASERS and non-ablative higher energy of IPL by directly stimulating regenerative processes in the skin. It is undergoing study as a regenerative modality over wide areas of the skin without inciting as much inflammation. The disadvantage is that it is only one wavelength and that the inflammation caused by IPL or LASER actually incites more rapid repair or regeneration. An example of use of LED is for hair growth stimulation.
So why isn’t there some kind of a scientific study to tell us what the best form of light energy to use for medical applications? There are several reasons. First, each individual has a specific skin type with a specific makeup of melanin, hair color and reactivity to light. Think of it this way: Some people get burned with minutes of exposure to sun, while others virtually never burn. Also, because of progression of instruments approved for medical use it is difficult to study them head to head (a comparison of IPL and LASER devices available in 2014 for example is difficult because devices available in 2018 are quite different than those in use today). For its wide variety of uses and non dot-matrix treatment area, IPL has clear advantages and is most versatile. For hair removal it can be less painful for certain skin types, is less expensive, although it may take a few more treatments (more gentle).
Summary: IPL, LASER and LED are all forms of light energy that can be used in treatment of the skin. They all target pigments in skin to absorb light energy for their result. LASER resurfacing is often medically referred to as traumatic ablative, IPL rejuvenation is often called non-ablative, and LED is referred to as photobiomodulation (PBM).
At our clinic we use the Venus Versa™ machine, an IPL device with additional radiofrequency heads. We were among the first clinic in the San Diego area to have this advanced FDA-approved device, and we have all ten treatment heads including IPL photo facial heads, in various wavelengths, IPL hair removal heads in various wavelengths and differing sizes, the IPL dual-band acne treatment head, and the radiofrequency heads that do skin and tissue resurfacing that is safe for all skin types, and also does deeper tissue tightening that LASERs and LEDs simply cannot do. #BeAllureous, #LASER, #LED, #IPL, #VenusVersa
Thorac Cardiovasc Surg. 1988 Jun;36 Suppl 2:114-7 and Photomed Laser Surg. 2014 Feb 1; 32(2): 93–100.