Laser-induced transepidermal elimination of content by fractional photothermolysis
View Patent ↗Subjects treated with nonablative fractional photothermolysis (FP) have an intact stratum corneum, but can have microscopic lesions and vacuole formation within the epidermis. The vacuoles thus formed can trap dermal material and extrude it through the epidermis. Thus, FP can be used for the treatment of recalcitrant melasma, solar elastosis, and tattoos.
1. A method for eliminating dermal content through the skin, the method comprising:
exposing a region of the skin to laser radiation to create a plurality of treatment zones, wherein the treatment leaves stratum corneum within each treatment zone substantially intact and creates a vacuole below the stratum corneum within each treatment zone; and
encompassing the dermal content in the vacuole of each treatment zone,
wherein the dermal content is exfoliated through the skin, the laser radiation has a wavelength between 1200 nm to 2000 nm, the laser radiation has a pulse energy of 1 mJ to 50 mJ per treatment zone, the laser radiation has a spot size of 10 μm to 400 μm, each vacuole has a depth of 50 μm to 1000 μm, and the treatment zones have a fill factor of between 1% and 90% of a total treatment surface area.
2. The method of claim 1 , wherein the laser radiation has a wavelength between 1500 nm to 1600 nm.
3. The method of claim 1 , wherein the laser radiation has a pulse energy of 5 mJ to 40 mJ per treatment zone.
4. The method of claim 3 , wherein the laser radiation has a pulse energy of 6 mJ per treatment zone.
5. The method of claim 3 , wherein the laser radiation has a pulse energy of 20 mJ per treatment zone.
6. The method of claim 1 , wherein the laser radiation has a spot size of 40 μm to 200 μm.
7. The method of claim 1 , wherein the laser radiation has a spot size of 20 μm to 120 μm.
8. The method of claim 1 , wherein the laser radiation has a spot size of 60 μm.
9. The method of claim 1 , wherein the laser radiation has a spot size of 140 μm.
10. The method of claim 1 , wherein the treatment zone width is 10 μm to 500 μm.
11. The method of claim 10 , wherein the treatment zone width is 30 μm to 500 μm.
12. The method of claim 1 , wherein each vacuole is present in the dermal layer of the treated region of the skin.
13. The method of claim 1 , wherein each vacuole is present below the dermal layer of the treated region of the skin.
14. The method of claim 1 , wherein each vacuole has a depth of 100 μm to 500 μm.
15. The method of claim 1 , wherein each vacuole has a volume of 0.01 nl to 60 nl.
16. The method of claim 1 , wherein each vacuole has a volume of 0.05 nl to 4 nl.
17. The method of claim 1 , wherein the dermal content comprises material from a region of tissue with a condition selected from the group consisting of recalcitrant melasma, Hori's macule, tattoo, post-inflammatory hyperpigmentation, solar elastosis, mucinosis, amyloidosis, and scar tissue.
18. The method of claim 17 , wherein the dermal content comprises melanin.
19. The method of claim 17 , wherein the dermal content comprises tattoo particles.
20. The method of claim 17 , wherein the dermal content comprises scar tissue.
21. The method of claim 1 , wherein the electromagnetic radiation treatment is a skin resurfacing treatment.
22. The method of claim 1 , wherein the electromagnetic radiation treatment is a fractional photothermolysis treatment.
23. A method of eliminating tattoos, the method comprising:
exposing a region of the skin to laser radiation to create a plurality of treatment zones, wherein the treatment leaves stratum corneum within each treatment zone substantially intact and creates a vacuole below the stratum corneum within each treatment zone; and
encompassing ink of the tattoos in each vacuole
wherein the ink is exfoliated through the skin, the laser radiation has a wavelength between 1200 nm to 2000 nm, the laser radiation has a pulse energy of 1 mJ to 50 mJ per treatment zone, the laser radiation has a spot size of 10 μm to 400 μm, each vacuole has a depth of 50 μm to 1000 μm, and the treatment zones have a fill factor of between 1% and 90% of a total treatment surface area.
24. The method of claim 23 , wherein the laser radiation has a wavelength between 1500 nm to 1600 nm.
25. The method of claim 23 , wherein the laser radiation has a pulse energy of 5 mJ to 40 mJ per treatment zone.
26. The method of claim 25 , wherein the laser radiation has a pulse energy of 6 mJ per treatment zone.
27. The method of claim 26 , wherein the laser radiation has a pulse energy of 20 mJ per treatment zone.
28. The method of claim 23 , wherein the laser radiation has a spot size of 40 μm to 200 μm.
29. The method of claim 23 , wherein the laser radiation has a spot size of 20 μm to 120 μm.
30. The method of claim 23 , wherein the laser radiation has a spot size of 60 μm.
31. The method of claim 23 , wherein the laser radiation has a spot size of 140 μm.
32. The method of claim 23 , wherein the treatment zone width is 10 μm to 500 μm.
33. The method of claim 32 , wherein the treatment zone width is 30 μm to 500 μm.
34. The method of claim 23 , wherein each vacuole is present in the dermal layer of the treated region of the skin.
35. The method of claim 23 , wherein each vacuole is present below the dermal layer of the treated region of the skin.
36. The method of claim 23 , wherein each vacuole has a depth of 100 μm to 500 μm.
37. The method of claim 23 , wherein each vacuole has a volume of 0.01 nl to 60 nl.
38. The method of claim 23 , wherein each vacuole has a volume of 0.05 nl to 4 nl.
39. The method of claim 23 , wherein the electromagnetic radiation treatment is a fractional photothermolysis treatment.