Choosing the Right Wavelengths for Laser Tattoo Removal


Once upon a time, tattoos were primarily applied in black ink. Today, buying a laser for tattoo removal that only treats black ink would be like buying a black-and-white TV. Today’s challenge is color, and lots of it.

 

There are numerous technical considerations when selecting a tattoo removal laser that meets the challenges of today and tomorrow, including:

  • Wavelength(s) of the device
  • Power
  • Pulse Duration
  • Beam Profile
  • Spot Size

This article will explain why the right wavelengths are imperative for successful treatments.


Tattoos can be classified as cosmetic, decorative, for medical purposes, or traumatic in nature, and their placement may have been done by a professional artist, by an amateur, or through an accident.  When assessing removal of intentional tattoos, the depth of the needle used, composition of the ink, and colors of the inks are all key factors to consider.

Depth: In the most controlled conditions, a professional tattoo artist inserts an ink-coated needle which penetrates the skin about 100 times per second, and deposits ink particles anywhere from 1.5 mm to 2.0 mm below the surface of the skin. The body reacts to this insult through tissue swelling (edema) and an immune system response. Resultant scar tissue and fibroblast response forces these particles deeper into the dermis. The relative strength of the tattoo recipient’s immune system plays an important role in this process. It would be easy to imagine that a tattoo applied by an amateur, or through an accident, would have greater variation in particle depth. A laser tattoo removal professional must be able to remove all tattoos, regardless of depth.

Composition: Manufacturers of tattoo ink are not compelled to reveal the precise ingredients or chemical composition of their ink products despite their potential systemic absorption.

The FDA states, “While state and local authorities oversee the practice of tattooing, ink and ink colorings (pigments) used in tattoos are subject to FDA regulation as cosmetics and color additives. However, because of other public health priorities and a previous lack of evidence of safety concerns, FDA has not traditionally regulated tattoo inks or the pigments used in them.” – http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm048919.htm

A successful laser practice must be able to remove tattoo inks regardless of their composition.

Color: The following ink sample from Silverback Ink® is a great example of the complexity faced by many laser tattoo removal professionals:

SBM-S00

In its darkest hue, and placed at a tissue depth of 1.5-2.0 mm (or deeper), this ink appears to be black at first glance. However, once treatment begins, it quickly becomes apparent that this ink is green. To a laser tattoo removal professional, this is a world of difference. Their laser must be equipped to remove the broadest possible color spectrum, whether the tattoo color is self-evident upon initial patient examination or only once treatment has begun.

So now that we know a little about the depth, composition and color challenges of tattoos, let’s discuss how we remove them through lasers. Laser tattoo removal is done through a photoacoustic or photomechanical effect. This process is how light of a defined laser wavelength selectively destroys a target, and only the desired target. Like a magic bullet, laser light of a specific wavelength will destroy a specific target while ignoring and completely bypassing another target and leaving surrounding tissue unharmed.

To understand this more completely, one must understand that lasers have four unique characteristics of their light, regardless of their color. Lasers emit energy:

  • of the same wavelength and energy
  • that is extremely intense
  • in phase in both space and time
  • traveling in the same direction

This is true whether the energy is visible or not.  In fact, just a very narrow band of energy is in the Visible Light spectrum. Within this spectrum, the color of light (energy) is determined by its wavelength.

A relatively shorter wavelength will appear violet or blue, and will have more energy, than a longer relative wavelength such as orange or red.

Lasers operate in the ultraviolet, visible and infrared spectrum.

 

visible_spectrum noaa

However, for the purposes of laser tattoo removal, we are only concerned with lasers that interact with, and are absorbed by, the targeted tattoo ink.

A great deal of research has been conducted with the goal of optimizing technology for the purpose of laser tattoo removal. A delicate balance must be achieved in three competing areas:

  1. Safety:  Abrasives and irritants such as salts and sandpapers were once used to remove a tattoo, just as burning of the skin through fire, heated objects and electrocautery and surgical excision. Whether the tattoo was successfully removed or not was left to the eye of the beholder. However, the safety of the treatment in most cases was unacceptable, often leading to scarring, infection, and hyper- & hypopigmentation. Today, laser tattoo removal using Q-switched and picosecond lasers is the safest method of removal.
  1. Efficacy:  Tattoos vary significantly, not only in design, but in size, depth, composition and color. The tattoo patient also introduces variables such as tattoo placement and their own immune response. The ability to remove tattoos consistently and completely is a complex undertaking. Generally speaking, a laser tattoo removal professional requires a flexible device capable of delivering precise energy with the broadest of variables possible. Q-switched and picosecond lasers are the current gold standard (efficacy) for laser tattoo removal.
  1. Cost:  In a perfect world, cost of a laser tattoo removal device would be no object. However, in the business world, cost is an important component of the value equation for optimized technology.  Optimized technology is that which takes into account your budget, along with the patient population in your area and offers successful removal of the most tattoo ink colors.

One needs to be smart, utilizing the right technology to balance safety, efficacy and cost. This is precisely why wavelengths matter!

Modern tattoo removal requires the use of Q-switched and picosecond lasers.  The 3 most common are:

  1. Nd:YAG
  2. Ruby
  3. Alexandrite lasers

These lasers emit a specific and unique wavelength:

  1. Nd:YAG: emits energy at 1064 nanometers (nm) and can be frequency-doubled to 532 nm
  2. Ruby: emits energy at 694 nm
  3. Alexandrite: emits energy at 755nm

Let’s look at each wavelength.

Nd:YAG (1064nm)

Effective with:

  • Black ink
  • Dark blue ink
  • Brown ink

Nd:YAG (532nm)

Effective with:

  • Red ink
  • Orange ink
  • Purple ink
  • Tan ink

Ruby (694nm)

Effective with:

  • Blue ink
  • Sky blue ink
  • Black ink
  • Green ink
  • Violet ink

Alexandrite (755nm)

Effective with:

  • Black ink
  • Blue ink

In summary, it is clear that the correct wavelength is a critical component to consider when selecting a tattoo removal laser. It should also be clear that selection of a laser with the right combination of wavelengths is key to ultimate success in your tattoo removal business.  To perform treatments well, the optimal device would be equipped with:

  1. An Nd:YAG laser operating at 1064nm
  2. An Nd:YAG laser operating at 532nm
  3. A Ruby laser operating at 694nm

Quanta Aesthetic Lasers has been a leader in tattoo removal technology for many years, and has multiple devices that include all of the wavelengths necessary for treatment success.

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