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Abstract

span lang="EN-US">Clinical trials have reported the efficacy and safety of PS lasers in the treatment of multicolored and recalcitrant tattoos.</span
THEMED ISSUE LASERS IN DERMATOLOGY: CURRENT STATUS
Copyright © 2017 Saki N. This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non Commercial 4.0
International License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any me-
dium, provided the original work is properly cited. 1
EDITORIAL
Picosecond laser applications in aesthetic dermatology
Nasrin Saki
Molecular Dermatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
he time needed for a tissue to cool halfway down
to its initial temperature is the thermal relaxation
time (TRT) of that tissue. In order to reach the
goal of selective photothermolysis, tissue ablation by
laser beam should be fast with pulse duration shorter
than or nearly equal to the TRT of the skin targets. The
introduction of concept-selective photothermolysis by
pulsed lasers was a breakthrough in laser surgery by
minimizing the risks of dyspigmentation and scarring
associated with old continuous wave lasers[1].
Q-switched (QS) lasers are defined by extremely short,
nanosecond pulses that induce photomechanical and
photoacoustic tissue interactions. This short pulse dura-
tion limits the damage to the lysosome [2]. QS Lasers with
pulse duration of 5 to 100 ns have been the main lasers
for tattoo removal since the 1980s. Since most tattoo
particles’ size are approximately 100 nm, corresponding
to a thermal relaxation time of less than 10 ns, picose-
cond (PS) lasers could be more effective than QS lasers,
theoretically. Clinical trials have reported the efficacy
and safety of PS lasers in the treatment of multicolored
and recalcitrant tattoos [3].
Reiter et al. in 2016 designed a great systematic
review regarding the use of PS lasers for tattoo removal.
They concluded that using a PS laser causes a drastic
photoacoustic effect that may be beneficial for the
removal of a wider variety of tattoo colors, in theory. The
ability of PS lasers to remove multicolored tattoos was
shown for green, yellow, red, and purple tattoos.
However, the findings was not directly compared with
the results of the traditional QS lasers[3].
As a new technology, PS lasers are receiving more
attention in aesthetic dermatology, and their application
for other cosmetic problems, beyond tattoos, are being
investigated by many dermatologists.
Brauer et al. in 2015 demonstrated favorable results in
acne scar treatment with the 755-picosecond laser plus
diffractive lens array. Improvements in texture and
pigmentation of the surrounding skin were also noted,
suggesting there may be favorable results for indications
other than scarring[4].
In another study by Petersen et al. in 2016, wound
healing after incision with a novel picosecond infrared
laser (PIRL) was compared with different surgical
techniques in a rat skin model. They concluded that PIRL
results in minimal scarring and improves aesthetic
outcomes. The resection of skin neoplasms, hypertrophic
scars and keloids, particularly, could be interesting fields
for PIRL application[5].
Ohshiro et al. in 2016 designed a retrospective study
investigating the results of PS laser for the treatment of
dermal melanocytosis in Asians. They concluded that PS
lasers, both the 1064-nm Nd:YAG and the 755-nm
alexandrite, are beneficial for the removal of dermal
melanocytosis with minimal side effects[6].
The effectiveness of the PS 755-nm alexandrite laser
in the treatment of benign pigmentary lesions, especially
Nevus of Ota, was also shown by Chan et al. It was
demonstrated that PS laser is associated with a lower risk
of post-inflammatory hyperpigmentation in Asians[7].
In 2017, Weiss et al. designed an interesting prospec-
tive, blinded study investigating the effectiveness of a
novel diffractive lens array using a PS 755-nm alexan-
drite laser in the treatment of facial wrinkles. They have
found it safe and highly effective for the improvement of
rhytides and other signs of skin aging[8].
In summary, PS lasers have been introduced as a
novel modality mostly as a treatment for challenging
pigmented lesions or tattoos. Nevertheless, their spec-
trum of beneficial effects in cosmetic dermatology seems
to go further day by day.
However, there are still some controversies regarding
their cost and efficacy, and further well-designed studies
are needed to evaluate the efficacy of this novel
technology.
T
Picosecond laser applications in aesthetic dermatology
2
doi:10.18282/jsd.v2.i2.142
Conflict of interest
The author declares no potential conflict of interest with
respect to the research, authorship, and/or publication of
this article.
References
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laser for treatment of wrinkles. Lasers Surg Med 2017;
49(1): 4044. doi: 10.1002/lsm.22577.
Keywords: Picosecond laser; dermatology, aesthetic
Citation: Saki N. Picosecond laser applications in aesthetic dermatology. J Surg Dermatol 2017; 2(T1):
http://dx.doi.org/10.18282/jsd.v2.it1.142.
Received: 2nd March 2017; Published Online: 15th March 2017
Correspondence to: Nasrin Saki, Molecular Dermatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran,
nasrinsa85@yahoo.com.
... In dermatology, picosecond lasers treat lesions with 1/3 to 1/2 of the energy used in nanosecond lasers. Compared to nanosecond lasers, picosecond lasers have more photoacoustic effects and fewer photothermal effects [2,3]. Therefore, the risk of collateral damage to surrounding tissue is less. ...
... In dermatology, picosecond lasers treat lesions with 1/3 to 1/2 of the energy used in nanosecond lasers. Picosecond lasers have more photoacoustic effects and less photothermal effects, compared to nanosecond lasers [2,3]. Therefore, the risk of collateral damages to surrounding tissue is less. ...
... The dermatology applications for picosecond laser have made huge improvement after Cynosure's PicoSure published in December, 2012 [1]. The wavelength of those picosecond lasers has 1064 nm, 532 nm, and 755 nm, and recently published 730 nm using Ti:Sapphire rod [2][3][4][5]. Most of the picosecond lasers have the typical laser pulse width. ...
Article
Full-text available
Introduction: Picosecond lasers have been reported to be effective for removal of tattoo pigment. This prospective study evaluated the efficacy and safety of the treatment of peri-oral and -ocular wrinkles using a novel diffractive lens array coupled with a picosecond 755 nm alexandrite laser. Methods: Forty female subjects presenting with wrinkles from photodamage were enrolled in an IRB approved study. Subjects received four picosecond diffractive lens array treatments to the full face at 1 month intervals. Six subjects were biopsied (two subjects at 1 month, two subjects at 3 months, and two subjects at 6 months). Digital photographic images were taken at 1, 3, and 6 months post-final treatment visits. Images were graded by blinded physicians for fine lines/wrinkles, erythema, dyschromia, and global improvement. Data on discomfort level, satisfaction, and side effects were recorded. Results: Overall blinded physician rated global improvement ranged from improved to much improved at 1-, 3-, and 6-month time points. At baseline the average Fitzpatrick wrinkle score was 5.48. At the 6-month follow-up the average score was 3.47. The overall average change in score from pre-treatment to post-treatment was 1.97. Subject self-assessment at 6 months indicated that 90% of subjects were extremely or satisfied with their results. Unanticipated adverse events were absent with anticipated post-treatment erythema lasting for just several hours. Conclusions: A novel diffractive lens array used with a picosecond 755 nm alexandrite laser for treatment of wrinkles is highly effective and safe for wrinkles and other signs of photoaging. Lasers Surg. Med. © 2016 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.
Article
Full-text available
Given that the pigment particles in tattoos have a relaxation time of <10 ns, picosecond lasers would be expected to be more effective than nanosecond lasers in tattoo removal. To systematically review the evidence regarding the effectiveness and safety of picosecond lasers for tattoo removal, Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and reference lists were searched for relevant trials. The primary outcome was >70 % clearance of tattoo pigment. Secondary outcomes were 90–100 % clearance of tattoo pigment, number of laser sessions required, and adverse effects. Eight trials were included, six with human participants (160 participants) and 2 with animal models. Seven of the eight trials explored the usage of either 755, 758, 795, 1064, or 1064/532-nm picosecond lasers for black and blue ink tattoos. In the human trials, 69–100 % of tattoos showed over 70 % clearance of pigment after 1–10 laser treatments. Reported side effects included pain, hyperpigmentation and hypopigmentation, blister formation and transient erythema, edema, and pinpoint bleeding. Included articles varied in type of laser investigated, mostly non-comparative studies and with a medium to high risk of bias. There is sparse evidence that picosecond lasers are more effective than their nanosecond counterparts for mainly black and blue ink tattoo removal, with minor side effects.
Article
Background and aims: Recently novel picosecond duration lasers (ps-lasers) have been developed for the treatment of multicolored and recalcitrant tattoos, and safety and efficacy have been reported. We therefore hypothesized that the ps-laser could be an alternative treatment for dermal pigmented lesions and performed a retrospective review to evaluate the efficacy and safety of the ps-laser could be an alternative treatment for dermal pigmented lesions and performed a retrospective review to evaluate the efficacy and safety of the ps-laser. Subjects and methods: A retrospective photographic review of 10 patients with dermal pigmented lesions was performed (ages from 4 months to 52 yr), 6 nevus of Ota, 3 ectopic Mongolian spots and 1 Mongolian spots. The patients were treated in the Ohshiro Clinic with picosecond 755 nm alexandrite laser (ps-Alex laser) and picosecond 1064 nm Nd:YAG laser (ps-Nd:YAG laser) from April 2014 to December 2015 (ps-Alex laser, 7 patients; ps-Nd:YAG laser, 3 patients, 1 to 3 treatment sessions). Improvement was evaluated as percentage of pigmentation clearance comparing the baseline findings with those at 3 months after the final treatment using a five category grading scale: Poor, 0-24%; Fair, 25-49%; Good, 50-74%; Excellent, 75-94%; and Complete, 95-100% improvement. Adverse events were also assessed.Results: All ten patients obtained clinical improvement ranging from fair to excellent. Treatment with the ps-Alex laser caused transient hyperpigmentation followed by improvement to complete resolution at 3 months follow-up. The ps-Nd:YAG laser caused severe transient erythema and swelling but no post-inflammatory hyperpigmentation.Conclusions: Our results suggest that the 755 nm and 1064 nm ps-lasers are efficacious for the treatment of dermal pigment lesions, with minimum adverse events.
Article
Background and objective: As a result of wound healing the original tissue is replaced by dysfunctional scar tissue. Reduced tissue damage during surgical procedures beneficially affects the size of the resulting scar and overall healing time. Thus the choice of a particular surgical instrument can have a significant influence on the postoperative wound healing. To overcome these problems of wound healing we applied a novel picosecond infrared laser (PIRL) system to surgical incisions. Previous studies indicated that negligible thermal, acoustic, or ionization stress effects to the surrounding tissue results in a superior wound healing. Study design/materials and methods: Using the PIRL system as a surgical scalpel, we performed a prospective wound healing study on rat skin and assessed its final impact on scar formation compared to the electrosurgical device and cold steel. As for the incisions, 6 full-thickness, 1-cm long-linear skin wounds were created on the dorsum of four rats using the PIRL, an electrosurgical device, and a conventional surgical scalpel, respectively. Rats were euthanized after 21 days of wound healing. The thickness of the subepithelial fibrosis, the depth and the transverse section of the total scar area of each wound were analyzed histologically. Results: After 21 days of wound healing the incisions made by PIRL showed minor scar tissue formation as compared to the electrosurgical device and the scalpel. Highly significant differences (P < 0.001) were noted by comparing the electrosurgical device with PIRL and scalpel. The transverse section of the scar area also showed significant differences (P = 0.043) when comparing PIRL (mean: 141.46 mm2; 95% CI: 105.8-189.0 mm2) with scalpel incisions (mean: 206.82 mm2; 95% CI: 154.8-276.32 mm2). The subepithelial width of the scars that resulted from using the scalpel were 1.3 times larger than those obtained by using the PIRL (95% CI: 1.0-1.6) though the difference was not significant (P < 0.083). Conclusions: The hypothesis that PIRL results in minimal scar formation with improved cosmetic outcomes was positively verified. In particular the resection of skin tumors or pathological scars, such as hypertrophic scars or keloids, are promising future fields of PIRL application.
Article
Background and objectives: Photo-aging in Chinese often presents with benign pigmentary lesions. Q-switched lasers for pigmentary lesions in Asians had reported a risk of post-inflammatory hyperpigmentation (PIH) up to 25%. Longer pulse widths in the millisecond domains were advocated with reduced risk of PIH. Recently, picosecond lasers of various wavelengths were introduced with proven efficacy in tattoo removal. The objective of this study is to assess the efficacy and safety of a novel picosecond 755-nm alexandrite laser for the treatment of benign pigmented lesions in Asians retrospectively. Methods: A list of all patients who received picosecond 755-nm alexandrite laser treatment at a private dermatology center in Hong Kong was included. Those who had any other laser or topical treatment during the period of picosecond laser treatment were excluded. The age, skin phototype, type of pigmentary lesion, number of treatments performed was recorded. The baseline and most recent standardized photographs were assessed by trained physicians for comparison. A score of 0-4, representing poor 0-24%, fair 25-49%, good 50-74%, excellent 75-95%, and complete 95%+ improvement was given. Adverse events associated with the laser treatment were also recorded. All patients were followed up until 6 months after the last laser session. Results: A total of 13 subjects were included in the present study. The number of treatment sessions received ranged from one to seven. The benign pigmentary lesions consist of Nevus of Ota, café-au-lait patches, lentigines, Becker's nevus, Hori's macules, and nevus spilus. Among patients with Nevus of Ota, one patient achieved complete clearance after four treatments and two other patients had excellent clearance after three and four sessions, respectively. Patients with café-au-lait had fair to good clearance after one to seven treatment sessions. One patient who has Hori's macules was resistant to laser treatments and a fair response was achieved after eight treatments. In the present series, two patients (4.8%) developed transient hypopigmentation, which had improved upon subsequent follow-up in both cases and none had post-inflammatory hyperpigmentation. Conclusions: The novel picosecond 755-nm alexandrine laser is effective for the treatment of benign pigmentary lesions in Chinese, especially for the clearance of Nevus of Ota. Picosecond laser appears to be associated with a much lower risk of PIH for treatment of pigmentary lesions in Asians.
Article
Fractional laser technology is routinely used in the treatment of acne scarring, with thermal injury resulting in collagen synthesis and remodeling. Use of a picosecond pulse duration with a diffractive lens array may be a new technologic advancement in the treatment of acne scarring. To investigate the safety and efficacy of a 755-nm alexandrite picosecond pulse duration laser with diffractive lens array for the treatment of facial acne scarring. This single-center, prospective study performed in a private practice with a dedicated research department included patients with clinically diagnosed scarring secondary to inflammatory or cystic acne. Patients received 6 treatments with a 755-nm picosecond laser with a spot size of 6 mm, fluence of 0.71 J/cm2, repetition rate of 5 Hz, and pulse width of 750 picoseconds in combination with a diffractive lens array, allowing for greater surface area and pattern density per pulse. The pain and satisfaction scores for overall appearance and texture were recorded. Masked assessment of clinical photographs and analysis of 3-dimensional volumetric data were performed. Biopsy specimens were obtained for independent histologic evaluation by 2 investigators at baseline and at 3 months after last treatment. Fifteen women and 5 men (mean age, 44 years; age range, 27-61 years) with Fitzpatrick skin types I through V and facial acne scarring were enrolled. The mean pain score was 2.83 of 10. Patients were satisfied to extremely satisfied with improvement in appearance and texture at their final treatment and follow-up visits. The masked assessment scores of 17 patients were 1.5 of 3 and 1.4 of 3 at 1 and 3 months, respectively (a score of 0 indicates 0%-25% improvement and a score of 3 indicates >75% improvement). A 3-dimensional analysis revealed a mean 24.3% improvement in scar volume, maintained at 1 (24.0%) and 3 (27.2%) months after treatment. Histologic analysis revealed elongation and increased density of elastic fibers, with an increase in dermal collagen and mucin. Treatment of facial acne scars with a diffractive lens array and 755-nm picosecond laser produced improvement in appearance and texture at 3 months after the last treatment, with objective findings similar to those published for a series of fractional ablative laser treatments. Histologic findings suggest that improvement in scarring from this treatment goes beyond remodeling of collagen.
Laser therapy. 3 rd ed
  • C B Zachary
  • R Rofagha
Zachary CB, Rofagha R. Laser therapy. 3 rd ed. In Bolognia JL, Jorizzo JL, Schaffer JV (editors). Dermatology. Spain: Mosby Elsevier; 2012. p. 2267-2268.
Keywords: Picosecond laser; dermatology, aesthetic Citation: Saki N. Picosecond laser applications in aesthetic dermatology
49(1): 40-44. doi: 10.1002/lsm.22577. Keywords: Picosecond laser; dermatology, aesthetic Citation: Saki N. Picosecond laser applications in aesthetic dermatology. J Surg Dermatol 2017; 2(T1): http://dx.doi.org/10.18282/jsd.v2.it1.142. Received: 2 nd March 2017; Published Online: 15 th March 2017
  • J L Bolognia
  • J L Jorizzo
  • J V Schaffer
rd ed. In: Bolognia JL, Jorizzo JL, Schaffer JV, (editors). Dermatology. Spain: Mosby Elsevier; 2012. p. 2251-2253.