Tattoos have become extremely common in our society. People from the teenage years to senior citizens now get tattoos. Tattoo studios have proliferated across the country, offering an ever-expanding range of artistic expression on one's own body. The public has also become more familiar with the possibility of removing an unwanted tattoo, especially with laser tattoo removal. This has fueled parallel growth in the tattoo removal industry.
Tattoo removal has been around almost as long as tattooing. Old methods of removal included surgical excision, sometimes with skin grafting. This is a tried and true method and requires only one treatment. However, the side effect is an unsightly scar, and possibly another scar where a skin graft was obtained. Other older methods of removal included abrasives, such as salt crystal scrubbing just after a tattoo is removed. Dermabrasion is similar, and uses a power sanding device to abrade the skin down to below the tattoo. This can also be effective but may leave a scar, depending on the depth of dermabrasion required. Acids, such as glycolic acid or TCA, have also been used and worked by a similar mechanism, through a chemical burn. One method of tattoo removal favored by tattoo artists involves over-tattooing with an acid or saline. This is variable effective and can lead to severe scarring in some cases.
Laser tattoo removal was first broadly performed with the CO2 laser. This laser works by burning off a wonderful layer of skin with each pass. A cloth is used to wipe off the layer, with extra focus on picking out the tattoo pigment fragments. This method fell out of favor due to the superb scarring that is inherent to how this method and other caustic techniques work. However, a single CO2 laser session may completely remove a tattoo.
Q-switched lasers are currently the state of the art for laser tattoo removal. Q-switching means that a very short, high-energy burst of laser light is directed at the tattoo. It works on the principle of selective photothermolysis. The ink preferentially absorbs the laser light and has to expand, as would any substance does when heated. However, the q-switched burst of light is so rapid that it fractures the tattoo ink instead, much as very cold ice cubes crack when put in a glass of warm water. As the tattoo ink is broken down into finer particles that are small enough for the body's immune cells to absorb, the tattoo is typically lightened with each treatment. This process has to be repeated multiple times in order to completely remove a tattoo. Some colors, such as yellow, that do not absorb the laser light well may not be able to be removed. Also, if the ink is too deep in the skin, the light may not penetrate far enough to affect it. Finally, this process depends on a functioning immune system and good lymphatic flow, so an impairment of these would probably impair effectiveness.
The Q-switched lasers that have been on the market include the ruby, alexandrite and Nd: YAG. The ruby was the first laser available and has affinity for blue ink but has the disadvantage of a high-degree of melanin absorption. This can lead to burns in darkly-pigmented individuals at higher energies. The alexandrite functions at a slightly longer wavelength and has a greater affinity for green pigment. The Nd: YAG has affinity for black pigment at 1064 nm and the least melanin absorption. It can also be used with frequency doubling to 532 nm in order to treat red pigment. For multicolor tattoos, a combination of different lasers may be necessary for the greatest range of effectiveness
As with any laser, even q-switched lasers can have side effects. The most common are hypopigmentation and hyperpigmentation. These improve with time and usually resolve. It is possible to completely remove a tattoo using these lasers without causing any scarring, however one must not be tempted to turn up the laser's energy excessively. For patrons that have the patience to return for multiple visits, q-switched laser treatment offers the best chance for scar-free complete tattoo removal.
Research in tattoo removal is focusing on alternative inks. Some inks have been micro-encapsulated so that single laser treatment would completely remove them. Other inks are made to fade over different lengths of time. The latter does not give you the option of keeping the tattoo if you decide that you really like it. Research on new lasers is also ongoing.