1,550 nm Erbium-Doped and 1,927 nm Thulium Nonablative Fractional Laser System: Best Practices and Treatment Setting Recommendations.

BACKGROUND: The Fraxel Dual laser system (Solta Medical, Inc., Bothell, WA) contains a 1,550 and 1,927 nm wavelength single handpiece with different indications for each wavelength. OBJECTIVE: To discuss treatment setting recommendations and best practices for select on-label and investigational applications of the 1,550 and 1,927 nm dual laser system. MATERIALS AND METHODS: Eight board-certified dermatologists with 10 or more years of experience with the 1,550 and 1,927 nm laser system completed an online survey about their clinical experience with the system and then participated in a roundtable to share clinical perspectives and best practices for using the laser system. RESULTS: For all Fitzpatrick skin types, treatment recommendations were described for selected approved indications for the 1,550 and 1,927 nm laser system, including both lasers in combination. Treatment recommendations were also reached for investigational applications with the 1,550 nm laser and 1,927 nm laser. Best practices for using the lasers during the treatment session to achieve optimal outcomes and decrease the post-treatment recovery time were compiled. CONCLUSION: The 1,550 and 1,927 nm dual laser system is effective for a wide range of aesthetic and therapeutic applications, on and off the face and across all Fitzpatrick skin types.

Study of a 532/1064 Fractional Picosecond Laser for Facial Rejuvenation.

BACKGROUND AND OBJECTIVES: Picosecond (ps) fractional lasers create small wounds, presumably by laser-induced optical breakdown. We studied a ps fractional laser in the treatment of wrinkles and mottled pigment. MATERIALS AND METHODS: This was a single center, prospective, open-label clinical trial. Patients with at least 2 facial areas, with visible wrinkles and dyschromia, were enrolled in the study and received 3 treatments at monthly intervals and appeared at 3 follow-up visits at 1, 3, and 6 months after treatment. The laser is an 800 ps fractional system with nominal 10 mm macrospot diameter. Both 532 nm and 1,064 nm wavelengths were applied in each subject. Wrinkle and pigmentation clearance were assessed by 2 blinded investigators using a 5-point clearance scale. Skin improvement was assessed by investigators using the 5-point Global Aesthetic Improvement (GAI) Scale based on before/after photographs for the following categories: (1) fine lines/wrinkles and (2) pigmentation. RESULTS: A total of 18 healthy subjects at a single site were enrolled. At least moderate pigmentation and fine line/wrinkles improvement were observed in 93% and 79% of patients at 1 month after the last treatment according to GAI, respectively. Pigment clearance approached a mean of approximately 40%. CONCLUSION: A ps 1,064/532 fractional laser achieves reduction in fine lines and pigment.

Airborne particulate concentration during non-thermal nano-pulse stimulation wart clearance is negligible compared to thermal modalities.

OBJECTIVES: As clinicians continue to implement safety protocols amid the global pandemic, considerations to mitigate potential viral transmission of airborne particulates (plume) generated from certain dermatologic procedures are of growing interest. This study intended to measure the change in airborne particulate matter using a non-thermal energy modality called nano-pulse stimulation (NPS) and compare levels of concentration to common thermal modalities (CO2 laser and electrocautery). NPS is a new non-thermal modality that applies nanosecond pulses of electrical energy to induce regulated cell death in cellular structures while sparing the surrounding acellular structure of the dermis. MATERIALS AND METHODS: The study used a Condensation Particle Counter during four types of dermatologic procedures: (1) using non-thermal NPS for the clearance of cutaneous, nongenital warts; (2) an electrocautery treatment of warts; (3) a CO2 laser for facial resurfacing; and (4) an electrocautery procedure for a facelift. Four subjects and a total of 11 warts were treated with NPS while a particle counter was used to detect the average particles per cubic centimeter once per second. The same particle counter was used, for comparison, during a wart removal procedure using electrocautery for comparison, and for control, during a skin resurfacing procedure with a CO2 laser and a facelift in which electrocautery was used. RESULTS: Only one of the 11 NPS wart procedures generated any detectable change in the particulate concentration and that change was negligible in comparison to the increase in particulate concentration measured during the CO2 laser resurfacing and the electrocautery use during a facelift procedure. CONCLUSIONS: Procedures using non-thermal NPS technology do not generate significant plume when applied to eliminate warts, suggesting it is unlikely that this new energy modality would release viral DNA into the air.

"Photon recycling" can enhance cutaneous response to lasers: A pilot human study.

BACKGROUND: Depending on wavelength and pigmentation, human skin can reflect up to 70% of incident laser light. AIMS: We tested the hypothesis that returning ("recycling") this diffusely reflected light to the site of laser exposure would increase cutaneous response. MATERIALS AND METHODS: Thirteen adult volunteers with Fitzpatrick skin types I-IV participated in this IRB-approved study. Matched contralateral test sites on the volar forearms were exposed to a pulsed dye laser operated at 585 nm, 450 microseconds pulse duration in a uniform 5 mm circular exposure spot without skin cooling. On one arm, the laser handpiece was fitted with an aluminized hemispherical mirror with a reflectance of 67%. The minimum fluence causing skin purpura, and the purpura lesion diameter were measured. RESULTS: The mean purpura threshold fluence with the reflector was 3.1 J/cm2 (0.5 SD), and 3.7 J/cm2 without the reflector (0.36 SD) (p < 0.001). The mean laser-induced purpura lesion diameter was approximately 5.3 mm with the reflector and 5.0 mm without the reflector. CONCLUSION: Consistent with a theoretical model and in vitro measurements, this human study confirms that "recycling" reflected laser light can increase skin response. Potentially, the therapeutic response can also be improved with "photon recycling."

Hair Removal With Blended 755/1064 nm Laser Energy.

BACKGROUND AND OBJECTIVES: The 1064 nm wavelength is optimized for dark skin, but within the range of available fluences for commercially available 1064 nm devices, may not provide effective treatment for lighter hair. The 755 nm alexandrite wavelength can treat a full range of hair colors but is not ideal for darker skin. The hypothesis is that a new laser system capable of emitting 755/1064 nm wavelengths simultaneously allows for safer, effective, and less painful hair reduction over a range of skin and hair types. STUDY DESIGN/MATERIALS AND METHODS: We completed treatment in 36 patients in this institutional review board approved prospective randomized study. Ages ranged from 20 to 55 and the distribution of skin types was: I (14% of patients), II (50% of patients), III (18% of patients), IV (18% of patients). Areas included the axilla and lower extremity. A prototype laser system emitted 755/1064 nm simultaneously. The spot size was 12 mm and the pulse duration was 3 milliseconds. The percentage of each wavelength in the mixture varied from 0% to 100%. Total radiant exposure ranged from 20 to 50 J/cm2 . Test spots were performed with escalating doses of light for each category (alexandrite alone, Nd YAG alone, and blended). Patients returned within 1 week for evaluation of side effects. The highest fluence without side effects for each category was then applied in two sessions 1 month apart. Final hair counts were performed 2 months after the final treatment. RESULTS: Optimal light doses (in J/cm2 ) for the range of skin types were as follows: for alexandrite alone, YAG alone, and blended. (Skin type I) 40, 70, 40-10; (II) 40, 70, 40-10; (III) 34, 60, 30-20; (IV) 26, 60, 20-30; (V) 18, 50, 14-36. After 2 months, there was greater than 50% hair reduction in 40%, 24%, and 60% of subjects on the lower extremity for the alexandrite, Nd YAG, and blended groups, respectively, and 20%, 25%, and 24% for the axilla. Our data show that for "challenging" cases, that is, darker skin types or tanned skin with lighter hairs, a 70/30 mixture of Nd:YAG and alexandrite wavelengths tended to produce the greatest hair reduction and least epidermal compromise while maintaining a lower pain level than Nd YAG alone. CONCLUSIONS: Modeling and data suggest that 755/1064 nm mixture is useful in lighter hair removal treatment for darker skin types. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Epidermal Fluence Threshold Determination by Real-Time Melanin Measurements.

BACKGROUND AND OBJECTIVE: Epidermal preservation is essential during laser treatment for vascular, hair, and benign pigment dyschromias. Epidermal tolerance is determined by epidermal melanin content, fluence, pulse width, wavelength, skin cooling, and spot size. The authors' objective was to determine the maximum epidermal tolerance for the long-pulse alexandrite 755 nm and the long-pulse neodymium-doped yttrium aluminum garnet (Nd:YAG) 1064-nm lasers for varying epidermal melanin content. MATERIALS AND METHODS: Skin melanin measurements were performed at the test sites with a melanin reader, and 0.5 to 1 second of refrigerated air precooled the skin. Then, alexandrite and Nd:YAG laser test spots of 5 to 18 mm were delivered in a series of ascending fluences using 5-, 20-, and 50-ms pulse widths. Skin response at 24 to 48 and 96 hours was scored from 0 to 15 varying from "no reaction" to "severe scabbing." RESULTS: Alexandrite laser, mean threshold fluences increased by a factor of 1.2 increasing from 5 to 20 ms, and by a factor of 1.4 increasing from 5 to 50 ms, among subjects with a melanin index (MI) from 9 to 25 (Fitzpatrick skin phototype I-III). The Nd:YAG fluence to reach epidermal tolerance was 6X the fluence with the alexandrite laser for the same MI in subjects with MI 26 to 35. CONCLUSION: Epidermal melanin measurements are quantitative and objective, therefore, improving treatment setting determination by decreasing the risk of overtreatment or undertreatment.

Long-term clinical evaluation of hair clearance in darkly pigmented individuals using a novel diode1060 nm wavelength with multiple treatment handpieces: A prospective analysis with modeling and histological findings.

OBJECTIVE: The purpose of this study was to determine the efficacy and safety of a 1060 nm diode laser system with multiple handpieces for permanent hair reduction. STUDY DESIGN: An open-label, prospective, multi-center study of adult subjects (≥18 years old) of any skin type, having dark brown or black hairs at the areas to be treated and seeking to permanently remove hair underwent six treatment sessions, at 4 to 6 weeks intervals with either a 1060 nm chilled sapphire tip or seven treatment sessions, at 6 weeks interval with a large spot vacuum based handpiece. METHODS: Subjects received treatments on various body areas using chilled sapphire tip or large spot size vacuum-assisted handpiece. Hair counts as well as assessments of hair coarseness and color were performed using photographs taken at baseline, prior to pre-selected treatments and at the follow up visits. At every visit, immediate skin responses and adverse events were evaluated by the investigator and treatment associated pain level experienced was quantified by the subjects. Subjects were asked to assess their improvement and satisfaction at pre-selected treatment sessions and at all the follow up visits. A sub group of subjects that were treated with the large spot size vacuum-assisted handpiece contributed two punch biopsy specimens for histological analysis. RESULTS: A total of 16 subjects age 33 ± 10.9 years were treated with the chilled sapphire tip, and 26 subjects age 36.3 ± 7.67 years were treated with the large spot size vacuum-assisted handpiece. Treatment with chilled sapphire tip yielded a mean of 68%, 82%, and 76% skin type-independent hair reduction in axillae, shin, and arm, respectively, at 6 month follow up visit as compared to baseline. The majority of subjects (≥80%) rated their hair reduction to be either good or very good and were satisfied to highly satisfied with the outcome. Treatment with the large spot size vacuum-assisted handpiece, was most effective in axillae and calves, with a 77.9% and 78.5% hair count reduction, respectively, at the 6 month follow up visit. Subjects reported high satisfaction and improvement throughout the treatments and follow-up periods. Treatments with both handpieces were not associated with intolerable pain levels and common post procedural responses included mild to moderate erythema and/or edema. CONCLUSION: The 1060 nm diode laser system is safe and effective for hair removal and long-term hair reduction in all skin types including darkly pigmented individuals. Lasers Surg. Med. 50:893-901, 2018. © 2018 Wiley Periodicals, Inc.

Airborne particulate concentration during laser hair removal: A comparison between cold sapphire with aqueous gel and cryogen skin cooling.

BACKGROUND: High concentrations of sub-micron nanoparticles have been shown to be released during laser hair removal (LHR) procedures. These emissions pose a potential biohazard to healthcare workers that have prolonged exposure to LHR plume. OBJECTIVE: We sought to demonstrate that cold sapphire skin cooling done in contact mode might suppress plume dispersion during LHR. METHODS: A total of 11 patients were recruited for laser hair removal. They were treated on the legs and axilla with a 755 or 1064 nm millisecond-domain laser equipped with either (i) cryogen spray (CSC); (ii) refrigerated air (RA); or (iii) contact cooling with sapphire (CC). Concentration of ultrafine nanoparticles <1 µm were measured just before and during LHR with the three respective cooling methods. RESULTS: For contact cooling (CC), counts remained at baseline levels, below 3,500 parts per cubic centimeter (ppc) for all treatments. In contrast, the CSC system produced large levels of plume, peaking at times to over 400,000 ppc. The CA cooled system produced intermediate levels of plume, about 35,000 ppc (or about 10× baseline). CONCLUSIONS: Cold Sapphire Skin cooling with gel suppresses plume during laser hair removal, potentially eliminating the need for smoke evacuators, custom ventilation systems, and respirators during LHR. Lasers Surg. Med. 50:280-283, 2018. © 2017 Wiley Periodicals, Inc.

Cutaneous siderosis secondary to intramuscular iron dextran treated with 755 nm Q-switched alexandrite laser: A case report.

BACKGROUND: Cutaneous siderosis is accumulation of iron in the dermis and the subcutaneous tissue secondary to extravasation of an intramuscular or intravascular iron injection. It presents as varying shades of brown macules with no distinct contours. The hyperpigmentation is permanent without treatment. OBJECTIVE: Q-switched lasers have been used effectively to treat lentigines and tattoos however, there is little data on the treatment of cutaneous siderosis with lasers. Our objective was to effectively treat cutaneous siderosis with a Q-switched alexandrite laser. RESULTS: A 50-year-old female had received nine injections of intramuscular iron dextran, one injection every 2 weeks alternating right buttock and left buttock over the course of 5 months. A couple of weeks after her 9th injection which was on the left, she noted brown hyperpigmentation in the injection area with the left worse than the right. She waited 3 months for the hyperpigmentation to self-resolve before presenting in our clinic. We utilized the Q-switched alexandrite laser to treat the patient with a test spot. One week later, there was nice partial clearance from the test spot so we commenced full treatment of the hyperpigmentation. There was significant improvement after the first treatment and she has been treated 4 times with continued improvement over the past 2 months. CONCLUSION: The Q-switched alexandrite laser is a useful tool in the treatment of cutaneous siderosis secondary to iron injection.

Treatment of acral persistent papular mucinosis using an Erbium-YAG laser.

BACKGROUND AND OBJECTIVES: Acral persistent papular mucinosis (APPM) is a rare condition with persistent flesh colored papules on the hands and extensor wrists. The authors aim to present a novel treatment option for this condition. PATIENTS AND METHODS: A female with APPM was treated using a 2940 nm Erbium-YAG laser with a 1 mm spotsize defocused to 2-3 mm with settings of 200-300 mJ until the lesion was flush with the surrounding skin. RESULTS: Healing of the wounds with resolution of the individually treated papules. CONCLUSIONS: Erbium-YAG lasers should be considered a treatment option for APPM.

New frontiers in laser surgery.

The simultaneous advances in engineering, medicine, and molecular biology have accelerated the pace of introductions of new light-based technologies in dermatology. In this review, the authors examine recent advances in laser surgery as well as peer into the future of energy-based cutaneous medicine. The future landscape of dermatology will almost undoubtedly include (1) noninvasive imaging technologies and (2) improved "destructive" modalities based on real-time feedback from the skin surface.

Evaluation of the vacuum-assisted handpiece compared with the sapphire-cooled handpiece of the 800-nm diode laser system for the use of hair removal and reduction.

BACKGROUND: A handpiece with a 35 × 22-mm treatment window that uses vacuum technology has been designed for the diode laser system. Vacuum suction stretches the skin and brings the hair follicle closer to the surface with the intent to damage the hair follicle at a lower surface fluence. The objective of this study was to compare the degree of follicular thermal damage between the sapphire-cooled smaller handpiece at a higher fluence versus the larger vacuum-assisted handpiece at a lower fluence. METHODS: Five male patients with Fitzpatrick skin types I-IV were enrolled in the study. Three test spots on the right back were treated with the vacuum-assisted laser handpiece at a setting of 10-12 J/cm², and 61-ms pulse duration. Three test spots on the left back were treated with the sapphire-cooled handpiece with a setting of 30-34 J/cm² and a pulse duration of 14-16 ms. A punch biopsy was obtained from one treated area for each handpiece type. The biopsies were sectioned horizontally and examined for the degree of thermal damage to the hair follicle at the level of the isthmus and the bulb. Immediate treatment response, pain score, and total treatment time were recorded. RESULTS: Biopsies from the skin treated with the sapphire-cooled handpiece and the vacuum-assisted handpiece showed the mean hair follicle diameter was 258.3 µm (SE [standard error] 41.7) and 225.1 µm (SE 17.1), respectively. The mean thermal damage diameter to hair diameter ratio was 0.91 (SE 0.10) and 0.72 (SE 0.12), respectively. The mean immediate treatment response, the mean pain severity, and the mean total treatment time were all lower for the vacuum-assisted handpiece. CONCLUSION: Treatment with the vacuum-assisted handpiece is faster and has a tendency to be more comfortable. Thermal damage to the hair follicle was greater with the sapphire-cooled handpiece.

Use of a novel erbium laser in a Yucatan minipig: a study of residual thermal damage, ablation, and wound healing as a function of pulse duration.

BACKGROUND AND OBJECTIVE: Theoretical models show that varying pulse duration influences residual thermal damage in erbium YAG skin resurfacing. Accordingly, our objective was to compare residual thermal damage, ablation, tissue shrinkage, and wound healing between a variable pulsewidth erbium YAG laser and a popular CO2 resurfacing laser. STUDY DESIGN/MATERIALS AND METHODS: The erbium laser delivered a typical ablative pulse (250 microseconds), followed by a heating pulse of variable duration. Pulse durations for specific coagulation depths were selected based on existing heat transfer models. The bilateral flanks of one Yucatan pig were irradiated. Eight sites were treated per group. Biopsies were performed just after treatment and 1, 3, 7, 21, and 60 days postoperatively. RESULTS: Just after irradiation, gross examination of "cold" (without a coagulation pulse) erbium sites showed a reddish papillary dermis consistent with conventional erbium laser ablation. Two and three pass CO2 sites showed uniform surface yellowing. The longer pulsewidth ("hot") erbium groups showed only slight surface yellowing. Biopsies showed immediate thermal damage that increased with erbium pulse duration; however, actual residual thermal damage (RTD) was sometimes less than that predicted by the laser control panel. All wounds healed uneventfully by 14 days. CONCLUSIONS: An erbium laser with a variable macropulse pulsewidth was capable of achieving RTD of up to 80 mum. Even greater RTD depths may be obtainable with future manipulations of fluence and pulse duration.