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.

Efficacy and safety of Q-switched lasers for the treatment of naevus of Ota in children: a retrospective analysis.

To identify factors influencing the efficacy of Q-switched laser in the treatment of naevus of Ota in children and to compare the efficacy, safety, and recurrence rate between 1064 nm Q-switched Nd:YAG laser (QSNL) and 755 nm Q-switched alexandrite laser (QSAL). We retrospectively analysed 160 children with naevus of Ota who completed QSAL or QSNL laser treatment at our centre. Age at initial treatment (P = 0.004), colour of lesions (P = 0.025), and number of treatments (P = 0.002) were related to efficacy. Compared with patients aged 0-11 months at initial treatment, patients who started treatment at 1-3 years (OR adj = 0.47), 4-8 years (OR adj = 0.20), and 9-12 years (OR adj = 0.27) had inferior efficacy. The efficacy of brown-violet (OR adj = 2.67) and blue-violet lesions (OR adj = 2.51) was better than that of brown lesions. Moreover, patients who received 3-4 (OR adj = 2.83) or 5-6 (OR adj = 7.35) treatment sessions showed a better response than those who received 1-2 sessions. Additionally, as the age at initial treatment increased, the rate of complications increased from 2.0 to 14.3%, while the recurrence rate decreased from 8.2 to 0%. In addition, the complication rate increased with an increase in the number of treatments. There were no significant differences in clinical efficacy (P = 0.94), risk of complications (P = 0.752), or recurrence (P = 0.834) between QSAL and QSNL for treating naevus of Ota in children. QSAL and QSNL are equally effective for children's naevus of Ota, with low complications and recurrence rates. Younger age at initial treatment and a greater number of treatments are beneficial for efficacy, whereas brown lesions are a negative factor.

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.

Aiming to personalized laser therapy for nevus of Ota: melanin distribution dependent parameter optimization.

Aiming to the personalized laser therapy of nevus of Ota (NO), a local thermal non-equilibrium model was employed to optimize laser wavelength, pulse duration, and energy density under different melanin depth and volume fraction. According to our simulation, the optimal pulse duration is between 15 and 150 ns to limit heat transfer inside the hyperplastic melanin, and 50 ns is recommended to decrease the energy absorption by normal melanin in epidermis. Correlations of the minimum and the maximum energy densities are proposed with respect to melanin depth and volume fraction for the 755-nm and 1064-nm lasers. For the same NO type, the therapy window of the 755-nm laser is larger than that of 1064-nm. For NO with shallow depth or low volume fraction, the 755-nm laser is recommended to make the treatment more stable owing to its lager therapy window. For deeper depth or higher volume fraction, the 1064-nm laser is recommended to avoid thermal damage of epidermis. Through comparison with clinical data, the optimized laser parameters are proved practicable since high cure rate can be achieved when energy density falls into the range of predicted therapy window. With developing of non-invasive measurement technology of melanin content and distribution, personalized treatment of NO maybe possible in the near future.

Nevus of Ota on the auricle successfully treated with Q-switched ruby laser.

Nevus of Ota is a dermal melanocytosis that consists of blue-brown spots, patches and plaques along the distribution of the first and second branches of trigeminal nerve. The efficacy of Q-switched ruby laser treatment against nevus of Ota on dark skin has not been described. The present case, a 2-month-old Indonesian girl, showed rare auricular involvement. Because ear has complicated steric structure, whose skin is sensitive and thin, pain and inflammatory reaction are inevitable. We discussed the difficulty of laser treatments on auricular lesions.

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.

Efficacy evaluation and treatment parameter optimization for laser surgery of Ota's nevus based on an advanced non-equilibrium bio-tissue heat transfer model.

This study was performed to better understand the laser-tissue interaction mechanism and optimize the laser wavelength and pulse duration for the laser treatment of Ota's nevus, thereby providing the precise theoretical guidance for clinician to improve the therapeutic effect. A non-equilibrium bio-tissue heat transfer model coupled with thermo-mechanical effect for the explosive vaporization of melanin granule induced by laser heating was developed to investigate the temperature and thermal damage distribution using alexandrite (755 nm) and Nd:YAG (1064 nm) lasers with the pulse width of 10-120 ns. Cryogen spray cooling (CSC) was introduced to prevent the epidermal thermal damage due to competitive laser absorption between epidermal and dermal melanin. Thermal injury of the epidermis with temperature in the melanin zone reaching 132.3 °C was induced by alexandrite laser. The optimal pulse durations were 50 and 30 ns, and the corresponding incident laser fluence thresholds were 6.45 and 19.5 J·cm-2 for alexandrite and Nd:YAG laser, respectively, with the pre-cooling of R32 spray. Using R32 spray cooling, the 1064-nm laser fluence threshold of melanin can be increased by 56.0%, resulting in an indirect increase (80.4%) of injury thickness. Nd:YAG laser (1064 nm) was highly suitable for the removal of melanin in the deep tissue owing to its deep penetration. Too short pulse duration should be avoided to prevent the epidermal thermal damage. The improvement of therapeutic effect by CSC demonstrates its high clinical application potential.

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.

Treatment of nevus of Ota with 1064 nm picosecond Nd:YAG laser: A retrospective study.

Nevus of Ota has been successfully treated by lasers. Currently, 1064 nm picosecond Nd:YAG lasers have become available for the treatment of pigmented disorders. However, there are few studies concerning the application of 1064 nm picosecond Nd:YAG laser in nevus of Ota. This study aimed to evaluate the efficacy and safety of a 1064 nm picosecond Nd:YAG laser for the treatment of nevus of Ota. We conducted a retrospective analysis of Chinese patients with nevus of Ota who had been treated with a 1064 nm picosecond Nd:YAG laser. Those who had any other laser treatment during the period of picosecond laser treatment were excluded. Via a visual analog scale for percentage of pigmentary clearance in standard photographs, the treatment efficacy was assessed by three blinded physician evaluators. A total of 16 subjects were included in this retrospective study. The average age at the beginning of treatment was 16.87 years old (range of 4 months to 59 years), and all patients were of Fitzpatrick skin type IV. Total treatment ranged from 1 to 5 sessions. A 1064 nm picosecond Nd:YAG laser with a mean fluence of 1.8-4.3 J/cm2 was used at 3-12 month intervals. The mean efficacy score for all 16 patients was 2.56 after one session, and the mean efficacy score of 13 patients who completed two sessions and nine patients who completed three sessions were 3.15 and 3.51, respectively. Postinflammatory hyperpigmentation after treatment was only observed in 1 (1/16, 6.25%) patient. The 1064 nm picosecond Nd:YAG laser is an effective and safe approach for treating nevus of Ota.

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.

Long-Term Follow-Up for Q-Switched Nd:YAG Treatment of Nevus of Ota: Are High Number of Treatments Really Required? A Case Report.

Objective: Q-switched laser is considered a gold standard treatment for Nevus of Ota (NO). We report how few laser sessions in long intervals of time may achieve satisfying outcomes reducing the rate of possible procedure-linked side effects such as burning, cornea injuries, or hyperpigmentation. Background: NO represents a congenital dermal melanocytosis in the trigeminal distribution majorly occurring in Asian individuals. Multiple reports have shown efficacy and safety of Q-switched laser for the treatment of this condition, but they were based on an empiric regimen, often leading to unnecessary overtreatments. At the best of our knowledge, no long-term follow-up observations of single laser sessions have been conducted to assess the proper intervals and number of treatments. Materials and methods: A 36-year-old Asian woman, Fitzpatrick skin type IV with clinical diagnosis of NO, was treated with 1064 nm 6 ns Q-switched laser one session per year for a total of two sessions. Clinical result was valued by two physicians independently using standardized and polarized light. No use of general anesthesia or sedation was needed in our experience. Corneal shields have been used. Results: After only two sessions of the Q-switched laser performed 1 year apart, the result was excellent with a 95% of clinical response. No side effect was observed. Conclusions: In our experience, Q-switched Nd:YAG laser is an effective treatment for NO with no necessity of high number of treatments. A larger population is needed to confirm this preliminary result.

Combination of 1064-nm Q-switched neodymium-doped yttrium-aluminum-garnet laser with Modified Jessner's peel for the treatment of Nevus of Ota: A case series of seven patients.

1064-nm Q-switched Nd: YAG (neodymium-doped yttrium-aluminium-garnet) laser is widely used for the treatment of Nevus of Ota but multiple treatments are necessary for clinical improvement. Superficial chemical peeling using Modified Jessner's solution has been used for the treatment of facial pigmentation but repetitive chemical peeling can cause irritation and post-inflammatory hyperpigmentation. In this series, we evaluated seven patients who were treated with a combination of 1064-nm Q-switched Nd: YAG laser and Modified Jessner's peel for eight sessions with 85.7% patients showing more than 50% reduction in pigmentation. The added therapeutic benefit of the combination helped to achieve a significant reduction in pigmentation faster with a lesser number of sessions and reduced cost.

A Prospective, Split-Face, Randomized Study Comparing Picosecond to Q-Switched Nd: YAG Laser for Treatment of Epidermal and Dermal Pigmented Lesions in Asians.

BACKGROUND: Whether picosecond lasers outperform Q-switched lasers in treating pigmented lesions has not been clearly evaluated. OBJECTIVE: To compare the efficacy and safety of picosecond and Q-switched lasers in treating epidermal and dermal pigmented lesions in Asians. METHODS: Eight subjects with lentigines and 6 subjects with acquired bilateral nevus of Ota-like macules were enrolled. Subjects was randomly treated with a picosecond laser on one side of the face and a Q-switched laser on the other side. Subjective assessments on pigment clearance, and adverse effect were obtained at Weeks 0, 4, 12, and 24 after the final treatment. RESULTS: Clinical improvement differed between the 2 laser systems at Week 4 (p = .034), Week 12 (p = .039), and Week 24 (p = .027), with 85.7% of picosecond and 57.2% of Q-switched laser sites showing >50% improvement at 6 months. There was no significant difference in the incidence of side effect and healing time, but picosecond laser was significantly associated with a lower treatment discomfort (p = .05). CONCLUSION: The picosecond laser seems to be more effective and better tolerated than Q-switched laser for the treatment of pigmented lesions in Asians.

Use of a Picosecond Alexandrite Laser for Treating Acquired Bilateral Nevus of Ota-Like Macules in Chinese Patients.

BACKGROUND AND OBJECTIVES: Acquired bilateral nevus of Ota-like macules (ABNOM) is common among the Chinese population. There have been few studies on the use of a picosecond alexandrite laser for the treatment of ABNOMs. The goal of this study was to evaluate the efficacy and safety of a 755 nm picosecond alexandrite laser for the treatment of ABNOMs. STUDY DESIGN/MATERIALS AND METHODS: A total of 225 subjects diagnosed with ABNOMs were included in this retrospective study. A 755 nm picosecond alexandrite laser system was used to treat all subjects. The safety and effectiveness of the laser were determined using a clinical photo assessment. The correlating factors of the patients, including the age, Fitzpatrick skin type, lesion location, lesion color, treatment procedures, melasma, and outcomes, were analyzed. RESULTS: The patients underwent one to four treatment sessions with clinical clearance (>90%) rates of 8.89%, 30.99%, 56.65%, and 60.00%, respectively. A higher number of sessions was positively associated with a better treatment response. The hyperpigmentation incidence rate was 22.67%, and one case of hypopigmentation was observed. CONCLUSION: Our results suggest that a picosecond alexandrite laser is an effective and safe approach for treating ABNOMs in Chinese patients. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Successful and quick treatment of nevus of Ota with 755nm picosecond laser in Chinese.

Nevus of Ota, also known as nevus fusco-caeruleus ophthalmo-maxillaris, is a benign dermal melanocytosis. In the past, this disease was usually treated by Q-switched laser therapy, but the course of treatment was relatively long. In recent years, it has been reported that 755nm picosecond laser, which was firstly reported to treat tattoos, is also effective in the treatment of nevus of Ota. Here, we report six cases of nevus of Ota which were treated with 755nm picosecond laser in Chinese people. We find amazingly that these lesions almost disappeared after only one or two sessions of treatment.

Treatment of Laser-Responsive Dermal Pigmentary Conditions in Type III-IV Asian Skin With a 755-nm Picosecond Pulse Duration Laser: A Retrospective Review of Its Efficacy and Safety.

BACKGROUND: Picosecond lasers have become very popular in the treatment of hyperpigmentation. OBJECTIVE: Evaluating the efficacy and safety of picosecond 755-nm laser in treatment of nevi of Ota (NO) and Hori's nevi (HN) in Asians with Fitzpatrick skin Types III/IV. METHODS: A retrospective review of patient records at the National Skin Center, Singapore, from 2015 to 2017. Three independent blinded dermatologists assessed pre-and-post treatment photographs using the physician's global assessment (PGA) score (0-clear, 1-almost clear, 2-mild, 3-moderate, and 4-severe). RESULTS: There were 18 cases of NO and 11 cases of HN. Mean treatment sessions were 2.22 (NO; range 1-6) and 3.82 (HN; range 1-6). In the NO group, mean pre-and-post treatment PGA scores were 3.1 and 1.3, respectively (1.8 point change, p-value 0.0002), and average fluence used was 2.02 J/cm (range: 1.02-2.38). In the HN group, mean pre-and-post treatment PGA scores were 2.6 and 1.1, respectively (1.5 point change, p-value 0.004), and average fluence was 2.08 J/cm (range: 1.98-3.40). Eleven patients (37.9%) experienced postlaser erythema, and 1 (3.4%) patient developed transient postlaser hypopigmentation. No permanent hyper/hypopigmentation was seen. CONCLUSION: The picosecond 755-nm laser is effective in the treatment of dermal pigmentary conditions in Asians with Fitzpatrick skin Types III/IV, with minimal risk of postlaser complications, and compared with the center's past experience with the Q-switched nanosecond 1064-nm laser, results in faster and more effective pigment clearance.

Clinical characteristics and treatment of 52 cases of phakomatosis pigmentovascularis.

Phakomatosis pigmentovascularis is a rare syndrome characterized by widespread capillary malformation and pigmented nevus. The objective of this study was to evaluate its characteristics and treatment. Fifty-two patients presenting between 2003 and 2017 were retrospectively reviewed. Type IIa (port-wine stain and dermal melanocytosis with oculocutaneous involvement) was most common. Systemic involvement was observed in 17.3% and it was not significantly correlated to extent of capillary malformation or pigmented nevus. However, systemic involvement was significantly frequent in patients with nevus of Ota and in patients with pigmented nevus located on the head and neck (P = 0.004 and 0.035, respectively). Capillary malformation was almost cleared in 28.6% of patients using pulsed dye laser, whereas pigmented nevus was almost cleared in 23.7% and completely cleared in 42.1% of patients using Q-switched neodymium:yttrium-aluminum-garnet laser. Treatment outcome score showed significant inverse correlation with the extent of port-wine stain or pigmented nevus (P = 0.047, ρ = -0.308 and P = 0.011, ρ = -0.410, respectively). Pigmented nevus demonstrated better treatment response to lasers than did capillary malformation. Smaller lesions tended to show better treatment outcomes for both capillary malformation and pigmented nevus.