Semi-permanent tattoos are often used to alleviate tedious daily make-up but they also, like other tattoos can become cosmetically unacceptable.
- Available classical treatments include, surgery, dermabrasion but both induce scarring which is not acceptable for patients who are looking for a cosmetic procedure to correct another one.
- Q-Switched lasers have been tried and include: ruby, alexandrite and Nd:YAG
The authors sought to study the best timing and results of using QS Nd-YAG lasers:
- In this study 36 tattoos were done on rat skin with black color (semi-permanent make-up ink (MEI-CHA) and a tattooing machine).
- Then a laser treatment with the 1064nm laser (Medlite) was done with a 2mm size and an fluence (energy) of 6 J/m2:
- on the same day of the tattooing
- after 3 days
- after 5days
- after 1, 2 and 3 weeks
- Pigmentation was measured by colorimetry (chromometer: Mexameter) and biopsies were done on one side compared with a symmetrical contralateral untreated tattoo lesion
- results were evaluated with a mexameter (3 times) with calculation of the relative melanin index (RMI)
- same day:64 for the non laser treatment side vs 16 for the laser treated side
- 3d: 58 vs 14
- 1w: 56 vs 17
- 2w: 52 vs 18
- 3w: 49 vs 17
- it shows that it is effective on the same day of treatment as the location of the pigment is fully epidermal
- after 1w the pigment moves to superficial and mid dermis and the treatment remains effective
- However, after 3w most pigment has moved to the mid-to-deep dermis
- RMI :
- Treatment is most effective, on the day of tattooing to remove pigment but the treatment is safer to do when the crusts have peeled off and wound repair complete.
- Thereafter treatment is less reliable as pigmentatopm progressively migrates to the dermis.