Treatment of facial and non‐facial lentigines with a 730 nm picosecond titanium: Sapphire laser is safe and effective

Abstract

Objective: A 730 nm picosecond-domain laser was developed to improve the clearance of pigmented lesion and reduce adverse events. This study assessed the safety and efficacy of this system for the clearance of lentigines and explores how the short picosecond pulses interact with tissue via histology. Study Design and Methods: Twenty subjects with Fitzpatrick skin types II-IV were enrolled in this prospective, IRB-approved study. Four treatments were administered using a 730 nm picosecond-domain laser. Pre-and posttreatment photos were assessed by blinded reviewers at 4-and 12-week follow-up visits, using a 5-point clearance scale. Subject satisfaction was measured using a 5-point scale. Investigator Global Improvement Score (IGIS) was performed at the 4-and 12-week follow-up visits, using an 11-point clearance scale. Subject pain level was measured using an 11-point scale (no pain [0], extreme pain [10]). Histology of 730 and 532 nm picosecond pulses was compared with 755 and 532 nm nanosecond pulses. Results: Sixteen subjects with a total of 118 discontinuous treatment areas, each comprised of 1-20 lesions, completed all study visits. Thirty body regions were studied, including arms (6), hands (16), scalp (1), forehead (2), face (3), and back (2). Spot sizes ranging from 2 to 5 mm diameters were used with fluences ranging from 0.8 to 4.0 J/ cm 2 . Mean pain score was 3.6 of 10 for all four treatments. Ninety-nine percent of randomly paired 4-week posttreatment images and 100% of 12-week posttreatment images were correctly identified from their respective baseline images by three blinded reviewers. Mean IGIS demonstrated scores of 6.7 and 7.0 at 4-and 12-week follow-up visits, respectively. At the 4-and 12-week follow-up visits, 76% and 73% of subjects, respectively, were satisfied to highly satisfied. The mean clearance score for all 118 treatment areas was 3 of 4 in follow-up visits. At 12-week follow-up, 36% of 118 treatment areas had a clearance score of 4, and 38% had a clearance score of 3. Post treatment, there was typical erythema, edema, dryness, crusting, and itching but negligible purpura, no pinpoint bleeding, blistering or scarring, and no significant hyperpigmentation or hypopigmentation. Histology showed diffuse, focal epidermal vacuolization ~5-10 µm in diameter and mild extravasation of erythrocytes with 730 nm picosecond pulses, while diffuse epidermal vacuolization was observed with coalescence of vacuoles (~20-100 µm), junctional clefting and mild extravasation of erythrocytes with 755 nm nanosecond pulses. Picosecond pulses of the wavelength of 532 nm produced diffuse, focal epidermal vacuolization and larger dermal vacuoles to depths of 500 µm, while 532 nm nanosecond pulses produced diffuse epidermal vacuolization with coalescence of vacuoles and marked dermal hemorrhage. Conclusion:This study demonstrated the potential of a new 730 nm picoseconddomain laser for the clearance of lentigines. The results showed good clearance with no adverse events and good subject satisfaction in patients wi...

Efficacy and Safety of Low Fluence Nd:YAG Laser Treatment in Melasma: A Meta-Analysis and Systematic Review

“…4 Compared with nanosecond pulses, picosecond pulses produce relatively more photomechanical effects over photothermal effects and achieve better confinement of thermal energy. 5 Rather than destruction of the entire cell as seen in high-fluence laser treatments, laser toning delivers enough energy to destroy the melanin granules within cells without damaging the entirety of the cell. 4 This leads to an overall reduction of melanin without triggering inflammation that could lead to a melasma exacerbation or hypopigmentation.…”

Treatment of facial pigmented disorders with a 785‐nm picosecond Ti:sapphire laser in Asians: A report of three cases

“…In fact, cases of patients with epidermal and dermal pigmented lesions successfully treated using 730-and 755-nm wavelength ps-laser devices have been reported. [4][5][6][7][8] With regard to the wavelength, a 785-nm wavelength exhibits a similar melanin absorption curve similar to that of 730-and 755-nm wavelengths. The effectiveness of treatment with a 785-nm ps-laser in removing multicolor tattoos and freckles has been reported.…”

“…Wavelengths of 730 and 755 nm exhibit higher selectivity for melanin pigments than wavelengths of 532 and 1064 nm. In fact, cases of patients with epidermal and dermal pigmented lesions successfully treated using 730‐ and 755‐nm wavelength ps‐laser devices have been reported 4–8 . With regard to the wavelength, a 785‐nm wavelength exhibits a similar melanin absorption curve similar to that of 730‐ and 755‐nm wavelengths.…”

The use of radio‐wave surgery: An underestimated method for small hyperpigmented flat or macular lesions on face

“…All of these leaded to faster wound healing and absence of scar formation. Also, treatment of suchlike lesions with various laser-and light-based systems displayed less satisfactory results, [14][15][16] even with multiple sessions, [17][18][19] and different device combinations. 20 In a study performed on swine tissues, radio-wave surgery revealed less inflammatory response and smaller lateral thermal damage compared with CO 2 laser.…”