Usefulness of picosecond pulse alexandrite laser treatment for nevus of Ota

Evaluation of the Efficacy of the 755 nm Picosecond Laser in Eliminating Pigmented Skin Lesions after a Single Treatment Based on Photographic Analysis with Polarised Light

INTRODUCTION

Pigmentary changes can be bothersome and affect one's well-being. Laser therapy has been shown to effectively treat such skin discolouration. We aimed to assess the utility of a 755 nm alexandrite laser in pigmented lesions removal.

MATERIALS AND METHODS

A total of 109 patients aged 44.17 ± 8.2 years were enrolled and underwent laser treatment of facial skin hyperpigmentation. The efficacy was analysed on the basis of photographic diagnosis using the VISIA Complexion Analysis System. The following measures were assessed: (1) score; (2) feature count; (3) comparison figure.

RESULTS

A single laser treatment significantly improved the size and area of the lesion and decreased the number of lesion features. Parallelly, the overall skin condition significantly improved (p < 0.05). We found a statistical tendency of a higher feature count baseline, thus its change in men (p = 0.05 and 0.07, respectively), but failed to find any statistically significant associations (p > 0.05) between tested measures and skin phototypes and hyperpigmentation types. Age was also not correlated with the laser efficacy (p > 0.05).

CONCLUSIONS

The use of the 755 nm laser is effective in reducing pigmented lesions.

Update on lasers in pediatric dermatology: how primary care providers can help patients and families navigate appropriate treatment options and timelines

PURPOSE OF REVIEW

The use of lasers in pediatric dermatology is well established, but recent literature has expanded the evidence for specific timelines of treatment. Additionally, new devices and combinations with medical therapy have improved outcomes and treatment options for various conditions.

RECENT FINDINGS

Pulsed dye laser remains the first-line laser for vascular lesions. Recent guidelines support early initiation of laser treatment in port-wine birthmarks to optimize outcomes. For hemangiomas, laser treatment can offer a meaningful addition to oral propranolol therapy. Lasers with shorter wavelengths offer improved outcomes with decreased downtime for pigmented lesions. General anesthesia in the pediatric population continues to be a controversial topic, and the decision to perform laser under general versus topical anesthesia requires discussion with family of risks and benefits.

SUMMARY

Primary care providers can benefit their patients by prompt referral to dermatology for discussion of laser treatment. Port-wine birthmarks require referral in the first weeks of life so that laser treatment can be initiated if appropriate. Although many dermatologic conditions cannot be completely cleared or cured with laser, treatment can offer meaningful outcomes and benefit for patients and families.

Nevus of Ota: Combination Treatment with Q-Switched Neodymium-Doped Yttrium Aluminum Garnet Laser and Fractional CO2 Laser

Background

Nevus of Ota is a facial dermal melanocytic hamartoma occurring more commonly in Asians. The mainstay of treatment is 1064-nm Q-Switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, which has shown variable results in pigmented skin.

Objective

The aim of this study was to determine whether Q-Switched Nd:YAG laser treatment combined with fractional CO2 laser is more efficacious than Q-Switched Nd:YAG laser alone.

Materials and Methods

This was a prospective study with 81 patients. The patients were randomly divided into two groups. Group 1 received 1064-nm Q-Switched Nd:YAG laser alone and group 2 in addition received a fractional CO2 laser as well. Both groups received six sittings at monthly intervals. The treatment response was documented with physician global assessment (PGA) and patient's treatment satisfaction on Wong-Baker Facial Pain Scale (WBFPS). Dermoscopic evaluation was done to see subsurface pigment clearance.

Results

In the combination group, 25% of patients had more than 50% improvement as compared with 5.71% in group 1. To achieve a mean PGA score of 1.4, it took six sessions for group 1 versus only four for group 2. Dermoscopic evaluation showed faster pigment clearance in the combination group.

Conclusion

Combining two lasers shows statistically significant faster and greater degree of improvement as compared with Q-Switched Nd:YAG laser monotherapy in nevus of Ota.

Efficacy and Safety of Extracellular Matrix on Wound Healing After Picosecond Laser Therapy

BACKGROUND

Extracellular matrix (ECM), a material with tissue repair function, is applied to treat various wounds. However, the role of ECM in facilitating wound healing after facial laser treatment remains elusive.

OBJECTIVE

To assess the efficacy and safety of ECM in promoting wound healing after picosecond laser therapy (PLT).

MATERIALS AND METHODS

Eighteen female subjects with benign pigmentation disorders were randomly assigned to the ECM (n = 9) and control groups (n = 9). After PLT, the ECM and control groups were treated with ECM and facial moisturizer in the first 7 days, respectively. The severity of erythema and edema was assessed using photographs. The duration of erythema, edema, scab shedding, postinflammatory hyperpigmentation incidence (PIH), and adverse events was documented in detail.

RESULTS

Compared with the control group, the ECM group had a shorter duration of erythema, edema, and scab shedding after PLT (p < .01). A significantly decreased severity of erythema (p < .05) and edema (p < .01) was found in the ECM group versus the control group, respectively. The PIH incidence in the ECM group was lower than in controls, albeit without statistical significance. No serious adverse events were observed during the follow-up.

CONCLUSION

Extracellular matrix is an effective and safe dressing for promoting wound healing after PLT.

Prospective comparison study of a 550 picosecond 755 nm laser vs a 50 ns 755 nm laser in the treatment of nevus of Ota

Since the introduction of selective photothermolysis, Q-switched nanosecond lasers have been used for the treatment of dermal pigmented lesions. Over the past several years, picosecond lasers have been introduced to the cosmetic community. We recently performed a study comparing a 550 picosecond 755 nm laser versus a 50 ns 755 nm laser, with the purpose of evaluating the clinical efficacy and complications of each laser when treating nevus of Ota. Ten Asian patients with nevus of Ota were enrolled in the study. Each lesion was split into 2 parts, and patients were treated with a 755 nm picosecond laser (PSL) and a 755 nm nanosecond laser (NSL). The clinical endpoint for fluence choice was immediate whitening (PSL: 2.33 ~ 3.36 J/cm2, NSL: 5.5 ~ 7 J/cm2) of the treated area. The pulse duration was fixed at 550 picoseconds (PSL) and 50 ns (NSL). The spot size of each laser was 2.5-3 mm. Laser treatments were performed until excellent clinical improvement was observed. Patients were examined 1 week after the first treatment, at each follow-up visit, and 6 months after the last laser treatment. The average number of treatment sessions to achieve excellent clinical improvement was 4.2 treatments using PSL and 5.4 treatments using NSL. One case of hyperpigmentation and one case of hypopigmentation were observed in the NSL treatment group. There were no complications in the PSL treatment group. The 755 nm 550 picosecond laser is significantly more effective than the 755 nm 50 ns laser in the treatment of nevus of Ota. The PSL treatment group also had minimum side effects.

Laser treatment of benign melanocytic lesion: a review

Treatment of pigmented lesions is one of the major challenges of laser and cosmetic practitioners. The most common pigmented lesions that are treated by lasers are melanocytic nevi, ephelides, solar lentigines, and café au lait macules. Melanin absorbs different wavelengths (500-1100 nm); thereby, treatment of various pigmented lesions requires the application of lasers with different wavelengths. Choosing the most appropriate type of laser depends on various factors such as the chromophore and the location of a specific lesion in the skin. In this paper, we aim to review the most efficient laser treatment protocols for each pigmented skin lesion and compare their efficacy in each part based on the previous studies.

Efficacy and safety of picosecond 755-nm alexandrite laser for treatment of nevus of Ota in Taiwanese children: A retrospective study

OBJECTIVES

To evaluate the efficacy and safety of picosecond 755-nm alexandrite laser in the treatment of nevus of Ota in children.

MATERIALS AND METHODS

A retrospective study was conducted by reviewing medical charts and photographs of 86 Taiwanese children with various types of nevus of Ota between January 2017 and September 2020. Picosecond 755-nm alexandrite laser therapy was used to treat pigmentary lesions. Percent clearance of lesions during treatment and the treatment time required to achieve 95%-100% clearance were determined.

RESULTS

According to Tanino's classification or Peking University Medical College Hospital (PUMCH) classification of nevus of Ota, most patients belonged to Tanino's Type II (32%) and Type III (38%) or PUMCH Type IIb (33%) and Type IIIb (26%), which indicated that the nevus was mainly distributed in the forehead, upper and lower eyelid, zygomatic, cheek, and temple regions. After treatment with picosecond 755-nm alexandrite laser, 96.5% of the patients achieved 95%-100% clearance with an average of 4.3 treatment sessions. The earlier onset of lesions (before 5 months of age) and the darker Fitzpatrick skin types (type IV vs. type III) significantly increased the number of treatments required to achieve clear response, while sex, age at first treatment, Tanino's classification of nevus, and color of nevus had no significant effect. Posttreatment hypopigmentation or hyperpigmentation was transient and resolved within 6 months. No serious response of the skin was evident.

CONCLUSION

Picosecond 755-nm alexandrite laser treatment of nevus of Ota in children was safe and effective. The treatment was well-tolerated, and only a few transient, minor side effects occurred.

Effective Picosecond Nd:YAG laser on seborrheic dermatitis and its mechanism

BACKGROUND

The Picosecond Nd:YAG laser has advantages in skin rejuvenation, which has little damage to surrounding tissues due to the ultra-short pulse width. We perform clinical application of Picosecond Nd:YAG laser's tender skin mode, which could improve the seborrheic dermatitis.

MATERIALS AND METHODS

Sixty-three subjects with facial seborrheic dermatitis are randomized to be control and observation groups. Records regarding skin subjective improvement, skin barrier function-related data, skin microbial status, and dermoscopy detection of the two patient groups before and after treatments are investigated.

RESULTS

Improvements of erythema and scales in observation group are significant compared with controls (p < 0.05). In terms of skin barrier function, there are significant changes regarding transepidermal water loss and epidermal seborrhea content in observation group after the laser treatments. Skin microbial state, pityrosporum furfur, and Demodex significantly decrement in observation group. Microscopical findings of infiltration mode advise that scales and capillary congestion and dilatation are significantly improved in observation group. Compared with controls, epidermal gloss increases, pore fineness improves, and capillary density decreases in the observation group.

CONCLUSIONS

Picosecond Nd:YAG laser could efficiently decrease erythema area and seborrheic dermatitis scales and reduce pruritus incidence. The sebaceous gland secretion of seborrhea and multiplying of epidermal parasitic microbiological are inhibited after laser treatment. Less epidermal seborrhea content and inflammation are induced by parasitic microbiology, which is helpful for skin barrier function and microvascular remodeling.

Novel Application of the 730 and 785 nm Picosecond Titanium Sapphire Lasers for the Treatment of Nevus of Ota

BACKGROUND AND OBJECTIVES

Nevus of Ota is a benign dermal melanocytosis that may pose significant psychosocial distress to patients. Q-switched nanosecond lasers have traditionally been considered the first-line treatment but pain, bleeding, and postinflammatory pigmentary alteration are common adverse effects. Picosecond devices have been increasingly used to treat nevus of Ota with promising results. We present two cases demonstrating novel applications of the 730 and 785 nm picosecond titanium sapphire lasers for the treatment of nevus of Ota in two patients with types III and IV skin.

STUDY DESIGN/MATERIALS AND METHODS

A 730 and 785 nm picosecond titanium sapphire laser with pulse durations of 250 and 300 picoseconds, respectively, were used to treat two cases of nevus of Ota. Four to seven treatment sessions were conducted at monthly intervals, and follow-up evaluation was performed 1-3 months following the final treatment session.

RESULTS

Both cases demonstrated greater than 75% clearance following treatment. There were no adverse events or pigmentary alteration noted as a result of picosecond titanium sapphire laser treatment.

CONCLUSIONS

The 730 and 785 nm picosecond titanium sapphire lasers are safe and effective for the treatment of nevus of Ota. Lasers Surg. Med. 00:00-00, 2021. © 2021 Wiley Periodicals LLC.

Incident Fluence Analysis for 755-nm Picosecond Laser Treatment of Pigmented Skin Lesions Based on Threshold Fluences for Melanosome Disruption

Background and Objectives

In this study, the threshold fluences for disrupting the melanosomes for pigmented skin lesion treatment were determined using a 755‐nm picosecond laser for clinical use. Based on the melanosome disruption thresholds, incident fluences corresponding to the target lesion depths were evaluated in silico for different laser spot sizes.

Study Design/Materials and Methods

Melanosome samples were isolated from porcine eyes as alternative samples for human cutaneous melanosomes. The isolated melanosomes were exposed to 755‐nm picosecond laser pulses to measure the mean particle sizes by dynamic light scattering and confirm their disruption by scanning electron microscopy. The threshold fluences were statistically determined from the relationships between the irradiated fluences and the mean particle sizes. Incident fluences of picosecond laser pulses for the disruption of melanosomes located at different depths in skin tissue were calculated through a light transport simulation using the obtained thresholds.

Results

The threshold fluences of 550‐ and 750‐picosecond laser pulses were determined to be 2.19 and 2.49 J/cm², respectively. The numerical simulation indicated that appropriate incident fluences of picosecond laser pulses differ depending on the depth distribution of the melanosomes in the skin tissue, and large spot sizes are desirable for disrupting the melanosomes more deeply located within the skin tissue.

Conclusion

The threshold fluences of picosecond laser pulses for melanosome disruption were determined. The incident fluence analysis based on the thresholds for melanosome disruption provides valuable information for the selection of irradiation endpoints for picosecond laser treatment of pigmented skin lesions. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC

Treatment of pigmentary disorders using picosecond laser in Asian patients: A meta-analysis and systematic review

There were many studies evaluating the effect of picosecond (PS) lasers, but no meta-analysis examined the effects of PS laser in the treatment of pigmentary disorders in Asians. The aim of this article was to review the before-after effect of PS laser in Asians for the treatment of pigmentary disorders. PubMed, Embase, and Cochrane library were searched for articles published up to May 2020. The evaluations were summarized into a 4-point scale that ranged from <25% (poor), 25%-50% (fair), 50%-75% (good), and 75%-100% (excellent). Effect sizes (ESs) were calculated according to laser wavelengths and lesion types. There were two randomized controlled trials, three single-arm trials, and three case series, with 200 patients. At 3 months after treatment, of all included patients, 3% (95%CI: 1%-6%) were evaluated as poor or worse, 9% (95%CI: 2%-21%) as fair, 29% (95%CI: 12%-50%) as good, and 56% (95%CI: 28%-83%) as excellent. The 532 and 1064, and 755 nm PS lasers had similar ESs across all four response groups. This meta-analysis suggested that 56% of Asian patients who underwent PS laser for the treatment of pigmentary disorders were evaluated as "excellent" about the pigment clearance by a dermatologist at least 3 months after treatment.

Safety and Efficacy of a Novel 730 nm Picosecond Titanium Sapphire Laser for the Treatment of Benign Pigmented Lesions

BACKGROUND AND OBJECTIVES

Picosecond lasers in dermatology were originally focused on optimizing the removal of unwanted tattoos. Subsequent advances in this technology have expanded its clinical indications to include treatment of benign pigmented lesions, photodamage, melasma, and scar revision. In this retrospective review, we evaluate a novel 730 nm picosecond titanium sapphire laser in treating benign pigmented lesions.

STUDY DESIGN/MATERIALS AND METHODS

This is a retrospective review of all patients who presented to our institution between December 2019 and March 2020 for treatment of their benign pigmented lesions with a 730 nm picosecond titanium sapphire laser. All Fitzpatrick skin types (I-VI) were included. Absolute and relative evaluations were conducted by two blinded board-certified dermatologists using high-resolution photographic images.

RESULTS

Twenty-two of 64 patients satisfied inclusion and exclusion criteria. Patients received 1.1 ± 0.3 treatment sessions. The absolute average pigmentation score prior to treatment was 2.04 ± 0.7 versus 1.39 ± 0.6 after treatment (P < 0.05). Improvement in pigmentation was observed in 86% of the patients, while 3% had no improvement and 11% had worsening of pigmentation. No other adverse events were observed. Downtime consisted of 1-2 days of mild edema and erythema followed by 3-5 days of mild pigment darkening and superficial crust.

CONCLUSION

The novel 730 nm picosecond titanium sapphire laser is a safe and effective treatment for benign pigmented lesions. Future prospective randomized control studies would be beneficial to further clarify its role in the treatment of benign pigmentation. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Comparing the efficacy and safety of Q-switched and picosecond lasers in the treatment of nevus of Ota: a systematic review and meta-analysis

Nevus of Ota is cosmetically burdensome and often prompts patients to seek treatment. Lasers are commonly used in removing these lesions; however, no systemic analysis has been conducted to support a gold standard laser. To conduct a meta-analysis of the efficacy and safety of Q-switched Nd:YAG lasers (QSNL), Q-switched ruby lasers (QSRL), Q-switched alexandrite lasers (QSAL), and picosecond alexandrite lasers (PSAL) in removing nevus of Ota. Inclusion criteria were nevus of Ota patients treated with QSNL, QSRL, QSAL, or PSAL and documentation of percent clearance and the rate of at least one adverse event. Articles in English, Chinese, or Japanese were included. The prespecified outcome measures were efficacy (percent clearance) and safety (rates of hyperpigmentation, hypopigmentation, scarring, and recurrence). The review included 57 studies and 13,417 patients. The pooled success rate was 64% for QSNL (95% CI 52-76%), 54% for QSRL (95% CI 39-69%), 58% for QSAL (95% CI 44-72%), and 100% for PSAL (95% CI 98-102%). The pooled adverse event rate was 5% for QSNL (95% CI 4-6%), 14% for QSRL (95% CI 9-19%), 9% for QSAL (95% CI 6-12%), and 44% (95% CI 31-57%) for PSAL. QSNL has the most evidence for effectively and safely treating nevus of Ota. PSAL potentially has a superior efficacy; however, further studies are needed to elucidate its side effect profile when treating nevus of Ota.

A Systematic Review of Picosecond Laser in Dermatology: Evidence and Recommendations

BACKGROUND AND OBJECTIVES

The use of picosecond laser in dermatology was originally focused on optimizing the removal of unwanted tattoos. Subsequent advances in this technology have broadened its clinical indications to include treatment of benign pigmented lesions, photodamage, melasma, and scar revision. In this systematic review, evidence-based recommendations are developed for the use of picosecond laser in dermatology.

STUDY DESIGN/MATERIALS AND METHODS

A comprehensive search of the English language literature was performed up to and including November 2019. Relevant citations were individually evaluated, synthesized, and categorized based on the Level of Evidence. With the addition of the authors' combined clinical experience, clinical recommendations were developed.

RESULTS

After application of inclusion and exclusion criteria, a total of 77 unique studies were evaluated. Treatment of benign pigmented lesions was associated with level I-IV evidence; rejuvenation was associated with level II evidence; melasma was associated with level II evidence; scar revision was associated with level II-III evidence; tattoo removal was associated with level I evidence.

CONCLUSION

Picosecond laser is a safe and effective treatment modality for an increasing range of dermatologic indications. Further development of this technology is warranted. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.