A split-face, single-blinded, randomized controlled comparison of alexandrite 755-nm picosecond laser versus alexandrite 755-nm nanosecond laser in the treatment of acquired bilateral nevus of Ota–like macules

Efficacy and Safety of 730-nm Picosecond Laser for the Treatment of Acquired Bilateral Nevus of Ota-like Macules

BACKGROUND

The effectiveness and safety of 730-nm picosecond laser for treating acquired bilateral nevus of Ota-like macules remain uncertain.

OBJECTIVE

This study aims to evaluate the potential benefits and risks of using the 730-nm picosecond laser for ABNOM removal.

METHODS

This is a retrospective review of patients who were presented to the clinic between January 2020 and January 2024 for the treatment of ABNOM with 730-nm picosecond laser alone. The efficacy of the laser was assessed based on the Quartile Improvement Scale, using high-resolution photographs evaluated by blinded dermatologists.

RESULTS

A total of 72 Chinese participants with Fitzpatrick skin types III to IV were included in the study. The overall effective rate of the treatment was 75%, achieved after an average of 2.42 ± 0.75 sessions. A subgroup analysis of 41 patients who completed 3 treatment sessions showed statistically significant differences in outcomes across the sessions. The mean improvement scores for sessions 1, 2, and 3 were 1.63 ± 1.04, 2.66 ± 1.22, and 3.29 ± 1.17, respectively ( p < .01). No cases of hypopigmentation were observed. The incidence of postinflammatory hyperpigmentation was 5.56%.

CONCLUSION

The 730-nm picosecond laser is a safe and effective treatment for ABNOM in Chinese patients.

A Retrospective Study of Picosecond Alexandrite Laser Treatment for Acquired Bilateral Nevus of Ota-Like Macules in Children

BACKGROUND

Picosecond lasers have been increasingly applied to the treatment of acquired bilateral nevus of Ota-like macules (ABNOMs), and proved safe and effective for adult patients. But there has been limited data concerned with their use in children.

OBJECTIVE

To analyze the efficacy, safety, and correlative influencing factors of a 755 nm picosecond alexandrite laser in treating ABNOMs in children.

METHODS

We retrospectively analyzed children with ABNOMs from January 2017 to July 2023 who received the treatment using a 755 nm picosecond alexandrite laser. Treatment parameters used were as follows: 750 ps pulse duration, 2.34-4.07 J/cm² fluence, and 2.5-3.3 mm spot size. The mean treatment interval was 7 months. The efficacy was evaluated based on a five-point scale according to the percentage of pigmentation clearance.

RESULTS

A total of 49 pediatric patients were included in this retrospective study. The average age at the beginning of treatment was 16.87 months old (range of 4 months to 59 months). These patients received an average of two treatments, achieving an average of 76% pigment clearance, which corresponded to excellent improvement (75%-94%). After the first treatment, six cases reached clinical clearance, and an average of pigment clearance was 61%. The initial efficacy was positively correlated with Fitzpatrick type (p < 0.05). Patients with Fitzpatrick III skin type responded better than patients with Fitzpatrick IV skin type. Besides, the initial efficacy was negatively correlated with the first treatment age and disease duration (p < 0.05). Eight cases developed postinflammatory hyperpigmentation, accounting for 16.3% of the cases.

CONCLUSION

The 755 nm picosecond alexandrite laser is safe and effective in treating ABNOMs in children. Being younger at the initial treatment, having Fitzpatrick III skin type, and experiencing a shorter disease duration are beneficial for initial efficacy.

Comparison of the Efficacy of 1064- and 730-nm Picosecond Lasers for Acquired Dermal Melanocytosis

BACKGROUND

Acquired dermal melanocytosis (ADM) is a pigmentary lesion caused by melanocytes in the dermis. These conditions are refractory, and a consensus on treatment remains elusive.

AIMS

To compare the efficacy of 730- and 1064-nm picosecond lasers in the treatment of ADM and to supplement the comparison with a literature review.

PATIENTS

We retrospectively examined patients who underwent picosecond laser therapy between April 2021 and February 2024. Treatments were performed three times with spot irradiation using a 730-nm laser (3-mm spot, 1.7-1.8 J/cm2; or 2-mm spot, 2.5-3.25 J/cm2) and a 1064-nm laser (3-mm spot, 3.1-4.0 J/cm2). Two months after each procedure, patient satisfaction was evaluated using questionnaires, macroscopic findings were assessed using photographs, and melanin accumulation was analyzed using skin analysis software. Evaluations were conducted on a 4-point scale (excellent, good, fair, and poor), with good or higher considered effective.

RESULTS

Seventy-eight and 83 patients were assigned to the 730- and 1064-nm groups, respectively. After three sessions, the 730-nm group exhibited superior outcomes in terms of subjective symptoms (patient satisfaction), objective findings, and software analysis improvements. The incidence of hyperpigmentation was 15.4% in the 1064-nm group and 14.5% in the 730-nm group, with no significant differences observed in the rates of other complications.

CONCLUSIONS

The use of a 730-nm picosecond laser, which possesses high melanin selectivity, relatively deep penetration, and a short pulse width, suggests a potentially more effective treatment for ADM, compared to the effects of the conventional 1064-nm wavelength, without increasing complications.

Characteristics of Skin Lesions Determine the Therapeutic Response of Facial Café Au Lait Macules Laser Therapy

BACKGROUND

The efficacy of laser treatment for facial café au lait macules (CALMs) is random.

AIM

To compare the response of different characteristics of CALMs skin lesions to laser treatment.

PATIENTS/METHODS

In this single-center retrospective case series, patients with café au lait macules who received laser treatment between 2015 and 2022 at our clinic were reviewed. A total of 319 consecutive patients were eligible and were treated with either a 755-nm-alexandrite picosecond laser or a quality-switched 755-nm-alexandrite laser. Observers were blinded to the final patient groups. Efficacy was graded according to four levels of treatment response: poor (Grade 1, 0%-25% improvement), fair (Grade 2, 26%-50% improvement), good (Grade 3, 51%-75% improvement), and excellent (Grade 4, 76%-100% improvement). Treatment effects evaluated as Grades 2-4 were considered effective.

RESULTS

Of the 319 patients, excellent and good responses were observed in 80 (25.08%) and 66 (20.69%) cases, respectively. Fifty-two patients (16.30%) displayed an outcome of Grade 2 (26%-50% improvement), whereas 121 (37.93%) cases showed an outcome of Grade 1 (0%-25% improvement). The overall treatment effective rate (Grades 2-4) was 62.07%. Binary logistic regression analysis showed a significant association of therapeutic efficacy with lesion distribution (segmental vs. non-segmental CALMs) and lesion border (irregular vs. regular) (p < 0.05 for both).

CONCLUSIONS

Segmental and irregular border CALMs tended to respond well to laser therapy. Clinicians can leverage these characteristics to predict efficacy and manage patient expectations more effectively.

Treatment of café-au-lait macules with picosecond and nanosecond 1064-nm nd: YAG laser: a retrospective study

To investigate the efficacy and safety of picosecond (PS) and nanosecond (NS) 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG) laser in treating Café-au-lait macules (CALMs). We retrospectively analyzed the medical records of patients with CALMs, who were treated with PS or NS 1064-nm lasers from January 2020 to January 2022. The efficacy was determined based on the before and after pictures by two independent investigators. The incidence of adverse events and recurrence were explored after treatments. A total of 116 patients (83 in the PS group and 33 in the NS group) were recruited. For subjects in the PS group, after 1-9 sessions, the lesion clearance was poor in 15 patients (18.1%), fair in 29 (34.9%), good in 14 (16.9%), and excellent in 25 (30.1%). In the NS group, after 1-7 sessions, the lesion clearance was poor, fair, good, and excellent in 7 (21.2%), 8 (24.2%), 13 (39.4%), and 5 (15.2%) patients, respectively. There was no statistically significant difference in efficacy between the two lasers (p > 0.05). The incidence of complications (hyperpigmentation, hypopigmentation) in the PS group (16.9%) was numerically lower than in the NS group (24.2%) (p = 0.136). Among patients who responded well to the treatment, 10.3% of patients in the PS group experienced relapse, compared with 22.2% in the NS group (p = 0.926). The PS 1064-nm laser provided comparable efficacy and potentially fewer complications compared with the NS laser in treating CALMs.

Efficacy and safety of a novel 785 nm picosecond neodymium-doped yttrium aluminum garnet laser for the treatment of facial benign pigmented lesions in Asian skin: a pilot study

BACKGROUND AND OBJECTIVES

Benign pigmented lesions and a general uneven tone in people with skin of color are growing issues that have been presented to dermatologists. To the best of our knowledge, this is the first controlled study to examine the efficacy and safety of using the newly introduced 785 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) picosecond laser to treat facial benign pigmented lesions in Asian patients with diffractive lens array.

MATERIALS AND METHODS

A 785 nm Nd:YAG picosecond laser was used to treat 15 healthy female volunteers older than 18 years who had Fitzpatrick skin types II-IV and facial benign pigmented lesions. Each volunteer received five weekly treatments in dual modes. The clinical improvement was assessed by independent investigators and by objectively measuring the melanin index.

RESULTS

After the treatment, the melanin and erythema indices decreased, and the pigmented lesions showed clinical improvements. No serious adverse effects were observed during the study period.

CONCLUSIONS

A 785 nm Nd:YAG picosecond laser may be safe and effective in treating facial benign pigmented lesions in Asian skin.

Comparison of the efficacy and safety of a 730-nm picosecond titanium sapphire laser and a 1064-nm picosecond neodymium yttrium aluminum garnet laser for the treatment of acquired bilateral nevus of Ota-like macules: A split-face, evaluator-blinded, randomized, and controlled pilot trial

BACKGROUND

The picosecond neodymium yttrium aluminum garnet laser (PNYL) has been successfully used in treating acquired bilateral nevus of Ota-like macules (ABNOM). The 730-nm picosecond titanium sapphire laser (PTSL) is an emerging tool for pigmentary disorders. However, no studies have compared two different wavelengths of picosecond laser for the treatment of ABNOM.

AIMS

To compare the efficacy and safety of the 730-nm PTSL with the 1064-nm PNYL in the treatment of ABNOM.

METHODS

Fifteen participants with ABNOM were randomized to undergo a single session of either the 730-nm PTSL on one side of the face and 1064-nm PNYL on the other side. Efficacy and safety assessments were performed by blinded visual evaluations at baseline, 12 weeks, and 24 weeks posttreatment. Participants' satisfaction and adverse effects were recorded.

RESULTS

Compared to baseline, The 730-nm PTSL-treated side showed better improvement than that of the 1064-nm PNYL-treated side at 24 weeks posttreatment (1.67 ± 1.047 vs. 0.87 ± 0.640, p = 0.027). There were no significant differences in pain sensation and participants' satisfaction between the two laser treatments.

CONCLUSIONS

The 730-nm PTSL is more effective than the 1064-nm PNYL in the treatment of ABNOM.

Advancements in Laser Therapies for Dermal Hyperpigmentation in Skin of Color: A Comprehensive Literature Review and Experience of Sequential Laser Treatments in a Cohort of 122 Indian Patients

The heightened awareness of ethnic dermatology aligns with the growing prevalence of skin of color communities globally, where hyperpigmentation disorders pose a common dermatological challenge. Effectively addressing dermal pigmentation is challenging due to its resistance to conventional therapies and its association with impaired quality of life. This underscores the need for effective treatments and a thorough grasp of laser advancements. A relevant literature search spanning the last 7 years across the PubMed database reveals core studies, challenges, and the evolution of laser technologies tailored for various forms of congenital and acquired dermal hyperpigmentation in skin of color. This comprehensive review explores the mechanisms, applications, and recommendations for pigmentary laser technologies, highlighting the key role of Q-switched lasers in their established millisecond/ nanosecond forms and emerging picosecond lasers, fractional non-ablative and ablative lasers, Intense Pulsed Light, etc. The summary of evidence includes studies on dermal melanocytosis (nevus of Ota and Hori's nevus), tattoos, acquired dermal macular hyperpigmentation, etc., and also entities with mixed epidermal-dermal components, such as melasma and post-inflammatory hyperpigmentation. The review offers valuable insights for clinicians to make informed decisions based on diagnosis, skin type, and the latest technologies to optimize results and minimize complications, especially in darker Fitzpatrick skin types. In their five-year study with 122 Indian patients, the authors applied specific laser combinations for diverse dermal melanoses, including tattoos, dermal/mixed melasma, acquired dermal macular hyperpigmentation, and dermal nevi. Substantial pigmentation reduction, subjectively assessed by both physicians and patients, was observed across all groups. A one-way ANOVA indicated a significant difference in mean improvement scores across various pigmentary conditions (F = 3.39, p = 0.02), with melasma patients exhibiting a significantly higher improvement score than tattoos (p = 0.03). The results affirmed the safety and efficacy of sequential laser therapy for dermal pigmentation in skin of color, advocating for flexibility in approach while maintaining the rationale behind the laser sequences. Despite advancements, challenges persist, and gaps in the current literature are identified. In conclusion, this summary highlights the ongoing pursuit of optimal protocols in dermatological laser treatments for dermal melanoses, offering valuable insights for future research and clinical practice.

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.

A retrospective study of 1064-nm Q-switched Nd:YAG laser therapy for acquired bilateral nevus of Ota-like macules

BACKGROUND

The therapeutic efficacy of laser treatments for acquired bilateral nevus of Ota-like macules (ABNOM) varies among studies, and few studies have evaluated the factors affecting therapeutic effects.

AIMS

To evaluate the efficacy and safety of 1064-nm Q-switched Nd:YAG laser (QSNYL) therapy for ABNOM and to identify the factors influencing the outcome.

METHODS

A total of 110 patients with ABNOM were retrospectively evaluated and received two-to-nine treatment sessions. The effects of different factors on the therapeutic effect were analyzed on the basis of the number of treatments, age at first treatment, skin type, lesion color, affected area, number of lesion sites, and presence of concomitant melasma.

RESULTS

The curative effect was positively correlated with the treatment time and negatively correlated with the increasing age at first treatment (p < 0.05). The curative effect was better in patients with skin type III than those with type IV ( p < 0.05) and in patients with a lesion area of less than 10 cm2 than those with a larger affected area (p < 0.05). Additionally, the treatment effect was poorer in patients with concomitant melasma (p < 0.05). The treatment effect was not significantly correlated with the lesion color or number of affected sites (p > 0.05). Eleven patients (10%) developed postinflammatory hyperpigmentation (PIH).

CONCLUSIONS

Early and repeated QSNYL therapy achieved satisfactory results for ABNOM. The risk of PIH after laser treatment is highest among patients with older age, darker lesion color, and darker skin color. For patients with ABNOM with concurrent melasma, low-energy laser therapy is recommended to reduce the risk of melasma aggravation.

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

Since the advent of the theory of selective photothermolysis, the importance of targeting the chromophore and minimizing the surrounding damage has been extensively discussed. Picosecond-domain laser (ps-laser) treatment with a wide range of wavelengths is an emerging option for various pigmented lesions; however, no definitive treatment choice has been confirmed. The authors aimed to investigate the efficacy and safety of a ps-laser with a 785-nm wavelength for the treatment of facial pigmented lesions in Asians. Three Korean patients with facial pigmented lesions were recruited for the study. A 785-nm ps-laser with a fractionated and an unfractionated handpiece was utilized to administer the treatment. The clinical outcome was evaluated by a clinician by comparing pre- and post-treatment photographs. All patients exhibited a significant improvement in pigmented lesions including freckles, lentigines, and melasma, after three to four sessions of treatment. No adverse events, including post-inflammatory hyperpigmentation or hypopigmentation were observed. In conclusion, this novel 785-nm Ti:sapphire ps-laser may be an effective and safe modality for treating pigmented lesions in skin of color.

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 755 nm Q-switched Alexandrite Laser for Hori's nevus: a retrospective analysis of 482 Chinese women

To evaluate the efficacy and safety of 755 nm Q-Switched alexandrite laser for Hori's nevus in a large cohort of Chinese women. We retrospectively analyzed the efficacy and safety of 755 nm Q-Switched alexandrite laser for Hori's nevus. Reduction in pigment was evaluated using a 4-score method. A total of 482 patients, aged 16 to 52 years, were included in this analysis. Patients were treated with 755 nm Q-Switched alexandrite laser at fluence levels of 5-8 J/cm2 for 2-4 treatment sessions. Following the treatments, 53% of patients showed over 75% reductions in pigment while 50-75% reductions in pigment were observed in 28% of patients. The rest displayed less than 50% improvements. Efficacy was positively correlated with the number of treatment sessions (p < 0.0001). Adverse reactions were temporary, mild erythema, and edema. A small portion of patients (15%) had hyperpigmentation, which disappeared within 2-6 months. 755 nm Q-Switched alexandrite laser is safe and has moderate benefits for Hori's nevus. Because its efficacy is positively correlated with the number of treatment sessions, increase in treatment sessions possibly could achieve a better outcome.

Early Treatment Initiation Improves Outcomes in Nevus of Ota: A 10-Year Retrospective Study

BACKGROUND

Nevus of Ota is a psychologically burdensome facial pigmentation birthmark common in Asian populations. Laser therapy is currently the first-line treatment, but no guidelines on when to initiate treatment have yet been established.

OBJECTIVES

Our objective was to determine the correlation between treatment efficacy and safety, risk of recurrence, and age of treatment initiation in patients receiving laser therapy for nevus of Ota.

METHODS

We conducted a 10-year (2008-2018) retrospective cohort study of all patients who completed a minimum of five laser treatments at Siriraj Skin Laser Center, Mahidol University, Bangkok, Thailand.

RESULTS

A total of 84 patients (aged 4 months-50 years) with nevus of Ota lesions were enrolled in the study. All patients were treated with a 1064-nm Q-switched Nd:YAG or a 755-nm or 1064-nm picosecond-domain laser (or a combination thereof). Our analysis identified that initiation of laser therapy before the age of 5 years was a significant factor in reducing the number of sessions necessary to achieve aesthetic improvement (P < 0.01; 95% confidence interval [CI] 1.06-3.21). In total, 18 patients (21.4%) initiating treatment before the age of 5 years required an average of 2, 4, and 7 treatment sessions to achieve > 25, 50, and 75% of pigment lightening, respectively, whereas 66 patients (78.6%) initiating treatment after the age of 5 years required an average of 3, 7, and 11 sessions to achieve comparable clearance. The risk of postinflammatory hyperpigmentation was significantly lower in patients starting treatment before the age of 5 years (P < 0.01; 95% CI - 43.76 to - 11.94). Recurrences were not observed in patients achieving > 95% clearance.

CONCLUSIONS

In our patient cohort, initiation of laser treatment for nevus of Ota before the age of 5 years significantly improved therapeutic outcomes and reduced the risk of adverse events and recurrence.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov PRS number: NCT04481178.

Efficacy of a laser with a pulse duration of 300 ps in skin rejuvenation and treatment of pigmentation disorders in Asians: a series of four cases

The photothermal effect of lasers is minimized and the photoacoustic effect is maximized as the pulse duration is shortened. Therefore, picosecond lasers with a short pulse and high peak power can be used to effectively treat various pigment disorders by reducing tissue damage. The first picosecond lasers were used for tattoo removal; they are also widely used for pigment treatment because of their reduced side effects compared with nanosecond lasers. Recently, picosecond lasers have been shown to be effective in the treatment of various skin conditions such as acne scars and large pores. There are many studies on picosecond lasers; however, there are no studies on a laser with a pulse duration of 300 ps. This report describes the use of a 300 ps Nd:YAG laser for treating pigment disorders and for skin rejuvenation in four Asians, with no side effects. Determining the clinical significance of the 300 ps pulse duration through comparative studies with various picosecond lasers is needed.

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.

Skin diseases in Asian individuals that you do not want to miss: A selection of unique or relatively more common conditions in Asian populations

The Asian population currently constitutes a simple majority of the global population, comprising nearly 60%. The percentage of the US population that identifies as Asian is expected to grow to 41 million by the year 2050, making up an eventual 9% of the US population. As the world and US populations of Asian individuals increase, the demand for dermatologic care from this population will increase, requiring dermatologists to become more familiar with the diagnosis and treatment of Asian-specific skin characteristics and diseases. In this contribution, we review skin conditions specific to or relatively more common in Asian patients to help recognition and management of diseases in an increasing Asian patient population. We discuss prurigo pigmentosa, primary cutaneous plasmacytosis, lipodystrophia centrifugalis abdominalis infantilis, Epstein-Barr viru-positive T- and natural killer-cell lymphoproliferative disorders, acquired bilateral nevus of Ota-like macules, and Behҫet disease.

Q-Switched 1064/532 nm Laser with Picosecond Pulse to Treat Benign Hyperpigmentations: A Single-Center Retrospective Study

(1) Benign melanoses are a frequent issue in aesthetic dermatology. Solar lentigo, ephelides, café au lait spots, and other melanoses represent a cosmetic issue for a growing number of subjects. The Q-switched 1064/532-nanometer (nm) laser may be considered the gold standard for management of these aesthetic issues. A new generation of Q-switched lasers, capable of concentrating the energy pulse in the spectrum of hundreds of picoseconds, is emerging, promising better results than previous ones. In this paper, we report the use of a Q-switched laser with a picosecond pulse to manage hypermelanoses. (2) Methods: 36 patients seeking melanosis removal were retrospectively enrolled at Magna Graecia University of Catanzaro. Treatment parameters, although variable, were the following: 1064 nm with a pulse duration of 450 picoseconds (ps) for dermic lesions and 532 nm with 370 ps for epidermal lesions. Up to four treatments, with a minimum interval between laser treatments of 30 days, were performed. After the last session, patients’ satisfaction was assessed at a three-month follow up with a Visual Analogue Scale (VAS). Two blinded dermatologists measured the aesthetic outcome using a five-point scale comparing pictures before laser sessions and during follow-up. (3) Results: 36 patients were enrolled; 23 were females (63.9%) and 13 males (36.1%). The mean reported age was 49.2 ± 18.9 years. All participants were assessed with a complete/almost complete melanosis removal at the dermatological evaluation, with a mean VAS score of 9.39 ± 0.90. (4) Conclusions: The Q-switched 1064/532 nm laser may be considered the main weapon in treating benign hypermelanosis. The picosecond pulse seems to guarantee better results than other devices. However, a clinical trial comparing Q-switched nanosecond pulse with picosecond pulse is necessary to confirm this study’s findings.

Beneficial Effects of Treatment With Low-Fluence 755-nm Q-Switched Alexandrite Laser for Nevus of Ota

BACKGROUND AND OBJECTIVE

Nevus of Ota is a benign dermal and mucosal melanocytic nevus that can be cured by Q-switched lasers. However, the incidence rate of post-treatment hyperpigmentation in Asian patients remains high. Low-fluence Q-switched Nd:YAG laser (QSNY) has been proved effective in the early treatment of nevus of Ota. Q-switched alexandrite laser (QSAL) was found to achieve a higher success rate and lower complication rate than QSNY. This study aims to evaluate the efficacy and safety of low-fluence 755 nm QSAL in the treatment of nevus of Ota.

MATERIALS AND METHODS

A total of 81 patients with nevus of Ota were retrospectively evaluated. Among them, 39 went through the high-fluence QSAL (3 mm spot, 5.0-8.0 J/cm² ) and 42 were treated by low-fluence QSAL (5 mm spot, 2.2-2.8 J/cm² ). Treatments were given every 6 months three times. Standard photos of the lesions were taken to evaluate the efficacy. All adverse events were noted.

RESULTS

The low-fluence QSAL group achieved a significantly higher mean efficacy score than the high-fluence QSAL group after the first treatment (3.62 ± 0.85 vs. 2.9 ± 0.79, P < 0.001) and at the final follow-up visit (4.52 ± 0.63 vs. 4.03 ± 0.96, P < 0.05). Post-inflammation hyperpigmentation rate was significantly lower in the low-fluence QSAL group than in the high-fluence QSAL group (4.8% vs. 25.6%, P < 0.001). No patient reported hyperkeratosis, scarring, bleeding, skin textural change, or recurrence at the final visit in either group.

CONCLUSION

The low-fluence QSAL is more effective and safer than the traditional high-fluence QSAL because of its better clinical outcome and lower complication rate in the treatment of nevus of Ota. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

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.

Three-Year Results of Facial Photoaging in Asian Patients After Alexandrite 755 nm Picosecond Laser With Diffractive Lens Array: A Split-Face, Single-Blinded, Randomized Controlled Comparison

BACKGROUND AND OBJECTIVE

The long-term efficacy of a picosecond alexandrite laser (PSAL) with a diffractive lens array (DLA) for the treatment of photoaging is absent. To observe the long-term efficacy of PSAL for the treatment of photoaging.

STUDY DESIGN/MATERIALS AND METHODS

Each patient (n = 10) received 10 treatments at 2-week intervals. One side of the face was randomly selected for treatment. At 1, 3, 6, and 36 months after the final treatment, two blinded physicians evaluated photographs with four clinical indicators of photoaging (dyschromia, skin texture, skin laxity, and rhytids). A quartile scale was used.

RESULTS

At baseline, there were no significant differences in dyschromia, skin texture, facial laxity, or rhytids between the treated and control sides (P > 0.05). Picosecond laser-treated side showed 0.85 and 1.05 (both P < 0.05) better for dyschromia at 3- and 6-month follow-up, and 0.6 (P < 0.05) better for skin texture at 6-month follow-up. At 36-month follow-up, the degree of photoaging is intensified on the control side while the rejuvenation efficacy maintained on the treated side, with 1.4, 0.75, and 0.8 (all P < 0.05) better for dyschromia, skin texture, and rhytids relative to the control side measures.

CONCLUSION

Our results demonstrate the long-term efficacy and safety of PSAL with DLA for the treatment of facial photoaging.

LIMITATION

Small sample size and the lack of objective evaluation. Lasers Surg. Med. © 2021 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.

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.

Comparative Effectiveness of 755-nm Picosecond Laser, 755- and 532-nm Nanosecond Lasers for Treatment of Café-au-Lait Macules (CALMs): A Randomized, Split-Lesion Clinical Trial

BACKGROUND AND OBJECTIVES

Many types of lasers have been used to treat café-au-lait macules (CALMs) since the introduction of the selective photothermolysis theory. However, the efficacy and safety of picosecond lasers, compared with those of nanosecond lasers, have not been researched. To compare the efficacy and safety of 755 nm picosecond laser (PS-755 nm), Q-switched (QS) Alexandrite 755 nm nanosecond laser (QS-755 nm), and QS Nd:YAG 532 nm nanosecond laser (QS-532 nm) for treating CALMs.

STUDY DESIGN/MATERIALS AND METHODS

Forty-one patients received several treatments at 3-month intervals. Lesions were divided into two or three approximately equal parts, which were randomly treated with PS-755 nm, QS-755 nm, and QS-532 nm. The safety and efficacy of three lasers were determined based on blinded visual assessments and self-reports of patients three months after the comparative trial.

RESULTS

Visual assessment 3 months after the comparative trial revealed that there was no statistically significant difference among the sites treated by QS-755 nm (2.84 ± 1.11), QS-532 nm (2.63 ± 1.06), and PS-755 nm (2.74 ± 1.05) lasers. Five (26.32%) of 19 patients showed lesion recurrence. Adverse effects included acneiform miliaris, hypopigmentation, and hyperpigmentation, which were resolved within 12 months. Five (26.32%) of 19 patients who showed lesion recurrence 1-5 months after laser treatment had lightened or cleared at least 50% of the lesion. 46.67% of patients were satisfied or very satisfied with the outcome of the overall treatment.

CONCLUSIONS

PS-755 nm, QS-755 nm, and QS-532 nm laser treatments were equally effective in treating and improving CALMs. PS-755 nm caused fewer adverse effects. Individuals can react differently to different types of lasers. Patch tests should be conducted before the treatment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

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.

Clinical improvement of photoaging-associated facial hyperpigmentation in Korean skin with a picosecond 1064-nm neodymium-doped yttrium aluminum garnet laser

Traditional attempts at alleviating photoaging-associated facial pigmentation conditions such as melasma, mottled hyperpigmentation, and post-inflammatory hyperpigmentation have yielded disfiguring cosmetic results. Laser toning using a low-fluence Q-switched 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser has been more commonly applied to date. However, the treatment efficacy and safety of this approach have not been widely reported. This study therefore evaluated the efficacy and safety of picosecond 1064-nm Nd:YAG laser application for photoaging-associated facial pigmentation treatment in Korean subjects. Forty-seven Korean subjects with photoaging-associated facial pigmentation underwent picosecond 1064-nm laser application. The clinical improvement of 17 patients was assessed by objective measurements such as melanin and erythema indices. All subjects received six biweekly treatments with the laser in a three-pass fashion delivering approximately 2000 to 2500 shots using a zoom handpiece with a spot size of 7 mm, fluence ranging from 0.4 to 0.7 J/cm², and a repetition rate of 10 Hz. Clinicians evaluated the improvement of pigmentation using the pigmentation area and severity index (PSI), and subjects reported their satisfaction level on a four-point scale. Statistical analyses were performed using the SPSS version 19.0 for Windows software program (IBM Corp., Armonk, NY, USA). Forty-seven subjects (45 females and two males) completed this study with a 12-week follow-up period. The average decrease in PSI value at 12 weeks after treatment was 6.85 ± 6.35 points (p < 0.001). The average decreases in the values of the erythema and melanin indices were 19.41 ± 64.64 points (p = 0.234) and 28.88 ± 32.89 points (p = 0.002). An analysis of 32 subjects' reports (68.1%) suggested good or excellent improvement. No serious adverse effects were observed during treatment or the follow-up period. Picosecond 1064-nm Nd:YAG laser application appears to be safe and effective in improving various photoaging-associated facial pigmentation conditions in Korean skin.

Retrospective photographic review of nontattoo indications treated by picosecond laser

BACKGROUND

Picosecond (PS) lasers were approved by the US FDA in 2012 after being shown to remove tattoos with more success and fewer treatments compared with traditional methods. PS lasers were shown to be versatile, indicated for the treatment of lentigines, café-au-lait macules (CALMs), and acne scars and skin rejuvenation.

OBJECTIVE

We report our experience treating our patients for different indications using a PS laser.

METHODS

We performed a retrospective chart and photographic review of all patients seen between 2016 and 2018 that were treated in our centers with a PS laser for nontattoo indications. Clinical outcomes were evaluated using side-by-side comparisons of the clinical photographs by two blinded, independent physicians using a visual analog scale consisting of six levels of treatment response.

RESULTS

A total of 233 patients were studied. Most sought treatment for solar lentigo (27%) and skin rejuvenation (14%). Epidermal nevi exhibited the greatest improvement with treatment, while acne scarring demonstrated the least. Only 24% of patients experienced noteworthy, transient adverse effects.

CONCLUSION

Picosecond lasers were efficacious and safe for a variety of indications. They were effective in treating epidermal nevi and pigmented lesions, such as Lentigines and CALMs.

Picosecond Laser-Induced Photothermal Skin Damage Evaluation by Computational Clinical Trial

Background and Objectives

Computational clinical trial (CCT) in the field of laser medicine promotes clinical application of novel laser devices, because this trial carried out based on numerical modeling of laser-tissue interactions and simulation of a series of treatment process. To confirm the feasibility of the computational clinical trial of skin treatment with a novel picosecond laser, this paper presents an evaluation method of the safety.

Study Design/Materials and Methods

In this method, the light propagation and thermal diffusion process after ultrashort light pulse irradiation to a numerical skin model is calculated and the safety based on the photothermal damage is evaluated by computational modeling and simulation. As an example, the safety of a novel picosecond laser device was examined by comparing with several laser devices approved for clinical use.

Results

The ratio of the maximum thermal damage induced by picosecond laser irradiation was 1.2 × 10^-2 % at the epidermis, while that caused by approved laser irradiation was 99 % at the capillary vessels. The numerical simulation demonstrated that less thermal damage was observed compared with the approved devices. The results show the safety simulated by photothermal damage calculation was consistent with the reported clinical trials.

Conclusions

This computational clinical trial shows the feasibility of applying computational clinical trials for the safety evaluation of novel medical laser devices. In contrast to preclinical and clinical tests, the proposed computational method offers regulatory science for appropriately and quickly predicting and evaluating the safety of a novel laser device.

Therapeutic options for management of Hori's nevus: A systematic review

Hori's nevus is a pigmentation disorder reported mainly in middle-aged Asian women. There is no systematic review addressing its pharmacotherapy. The population for our systematic review was patients with a clinical/histological diagnosis of Hori's nevus (both sex, any age group). We screened five literature databases using relevant keywords. All RCTs, observational studies and case series mentioning at least one intervention and outcome of that intervention were included. Nineteen studies were included in the final systematic review from total 680 identified nonduplicate records. Different forms of laser (alexandrite laser [QSAL and PSAL], Nd:YAG laser [QSNYL high fluence, low fluence, 532 followed by 1064 nm], Er: YAG and Nd:YAG combination, ruby laser [QSRL], CO₂ laser followed by QSRL) and dermabrasion were found to be useful in treatment of Hori' nevus. Among alexandrite lasers, PSAL is more efficacious and safe than QSAL. In case of high fluence QSNYL, hyperpigmentation rate is quite high while low fluence QSNYL requires more number of treatment sessions. The combined 1064 nm + 532 nm protocol is better in terms of efficacy and safety. Er:YAG + Nd:YAG combination have similar efficacy and added advantage of synergistic action and no adverse event.

A randomized, single-blind, study evaluating a 755-nm picosecond pulsed Alexandrite laser vs. a non-ablative 1927-nm fractionated thulium laser for the treatment of facial photopigmentation and aging

Background: Laser toning is one of the most popular strategies to treat facial photopigmentation and aging. Several laser modalities, including fractional non-ablative, Q-switched (QS) lasers and new generation picosecond lasers have been used for this indication. However, there is paucity of head to head comparisons of older generation of lasers with new ones. Objective: To compare a 755 nm picosecond pulsed alexandrite laser with a non-ablative 1927 nm fractionated thulium laser for the treatment of facial photopigmentation and aging through a randomized, single-blind study. Materials and methods: 20 subjects (skin types I-IV) were randomized to receive either four 755-nm picosecond alexandrite laser treatments, spaced 3 weeks apart, or two dual wavelength thulium fiber fractionated 1550/1927 nm laser treatments, spaced 6 weeks apart. Follow-up assessment visits occurred 4 and 12 weeks after the last study treatment. Results: At the 4- and 12-week follow-up, both groups showed significant improvement of photoaging, pigmentation, skin quality according to the investigator and subjects assessments. When comparing the two groups, subjects in 755 nm group had statistically significant greater improvement in investigator assessments of photoaging/skin quality and subject satisfaction than those in the 1927 nm group. Conclusion: Both the non-ablative 1927 and 755 nm picosecond laser can improve facial photopigmentation, but the latter can yield superior results with less pain and side effects according to patient and investigator assessments.