Page 51 - An Introduction to Laser Tattoo Removal

Chapter 2 – Fundamentals of Laser Tattoo Removal v1.0
Various clinical studies have shown that certain wavelengths appeared to induce ‘better’ reactions in certain colours, but, of course, those were the colours they tested. If they had tested another set of colours, they would likely have observed different results!
We believe it was Abraham Lincoln who said that we should not believe everything we read on the Internet.... (on a conspiracy website, of course!!!)
Figure 25: The South Korean study found that each ink colour was affected in different ways by the incident wavelengths and pulsewidths.
A South Korean1 comparative study looked at the efficacy of a picosecond Nd:YAG laser, a picosecond alexandrite laser and a Q-switched Nd:YAG laser on various ink colours. A summary of their findings is shown above.
They found that the picosecond Nd:YAG laser worked best on black, red, orange and yellow pigments, while the picosecond alex worked best on green and blue. However, surprisingly, the Q-switched 532nm energy appeared to be ‘second best’ on all colours, except black!
As mentioned above, most tattoo colours are composed of various colours mixed together. It is rare to find a ‘pure’ colour in a tattoo!
1: Choi M.S., et.al. “Effects of picosecond laser on the multi-colored tattoo removal using Hartley guinea pig: A preliminary study.”
There are a number of things which must be considered when choosing the most appropriate wavelength:
Wavelength (nm)
Absorption by melanin
Absorption by blood
Dermal scattering
532
Very strong – leads to overheating of the basal layer and blistering. Can produce hyperpigmentation
Very strong – leads to rupture of capillaries and deeper vessels
Very strong – poor penetration into the reticular dermis
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Chapter 2 LEVEL A Laser Tattoo Removal
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