Comparison of clinical efficacy and complications between Q-switched alexandrite laser and Q-switched Nd:YAG laser on nevus of Ota: a systematic review and meta-analysis

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.

Dual-wavelength long-pulsed 755-nm alexandrite/1,064-nm Nd:YAG laser versus Nd:YAG alone for treatment of palmoplantar verruca

We compared the effectiveness and safety of the long-pulsed neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser alone and combined with a 755-nm alexandrite laser for treating palmoplantar warts. We divided patients into two groups to receive up to four monthly treatments with Nd:YAG alone (single-wavelength) or combined with the alexandrite laser (dual-wavelength). We assessed treatment responses (according to clearance rate), vascular/hyperkeratosis grades, and patient satisfaction and pain ratings. The differences in treatment response (p = .348), patient satisfaction (p = .560), and pain ratings (p = .728) between the groups were not significant. The single- and dual-wavelength treatment options were equally effective in treating recalcitrant palmoplantar warts.

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.

Bubble Dynamics during Laser Irradiated Thermo-Mechanical Response of Pigmented Skin Phantom

During the laser treatment of pigmented dermatosis such as Nevus of Ota, vapor bubbles will be generated by the laser with short pulse width and high energy density. Laser irradiation is efficacious for the clinical treatment of Ota’s Nevus caused by hyperplasia of melanosomes in dermis. Since the mechanism of the laser–melanosome interaction is not yet clear, the clearance rate is generally low and bleeding of irradiated skin frequently occurs. This work conducted a flow visualization experiment to investigate the laser–melanosome interaction mechanism by using high-speed imaging. Pigmented phantom was prepared to simulate the diseased dermis tissue, where agar acted as substrate and synthetic melanin particles was infused as hyperplastic melanosomes. Putting the phantom into water, its thermo-mechanical responses to single-pulse 1064-nm Nd:YAG laser irradiation with energy density of 4–7 J/cm2 and pulse duration of 6 ns were recorded. The results indicated that laser-induced bubble formation caused by the gasification of tissue moisture is the key mechanism of laser–melanosome interaction, and an optimal energy density of 6 J/cm2 is recommended.

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.

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.

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.

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.

Case report: nevus of Ota and nevus of Ito associated with meningeal melanocytosis

BACKGROUND

Nevus of Ota and nevus of Ito are hyperpigmentary dermal melanocytoses which develop as a consequence of disturbances or failures during migration of melanocytes from the neural crest towards the epidermis; they have a relatively unknown aetiopathogenesis and may be congenital or acquired.

CASE REPORT

This case involves a male patient with a simultaneous diagnosis of nevus of Ota and nevus of Ito at birth. He attended the Neurosurgery department at Carlos Andrade Marín hospital (Quito) with sudden severe headache associated with left brachio-crural hemiparesis.

PROGRESS

Investigations revealed two extra-axial space-occupying lesions, one parasagittal at the right frontal and parietal lobes and the other located at the right temporal lobe pole. A surgical resection was planned for the parasagittal lesion and the histopathological diagnosis was meningeal melanocytosis. The temporal pole lesion was referred for treatment with Gamma Knife®.

CONCLUSION

Primary melanocytic neoplasms are extremely rare. There is evidence of their association with dermal melanocytosis and, in particular, with nevus of Ota. This highly unusual case describes the coexistence of two very rare dermal melanocytoses (nevus of Ota and nevus of Ito) and a primary melanocytic neoplasms in the same patient.

Usefulness of picosecond pulse alexandrite laser treatment for nevus of Ota

Background and aims

Recently, novel picosecond pulse duration lasers (ps-lasers) have been developed for the treatment of multicolored and recalcitrant tattoos, and safety and efficacy have been reported. We therefore hypothesized that ps-lasers could be an alternative treatment for dermal pigmented lesions. We performed a retrospective review to evaluate the efficacy and safety of the ps-laser for nevus of Ota.

Subjects and methods

A retrospective photographic review of 15 patients with nevus of Ota was performed (ages from 10 months to 65 yr). The patients were treated in the Ohshiro Clinic with a picosecond-domain 755 nm alexandrite laser (ps-Alex laser) from June 2015 to August 2017. Improvement was evaluated as the percentage of pigmentation clearance comparing the baseline findings with those at 3 months after the final treatment using a four category grading scale: Poor, 0-24%; Fair, 25-49%; Good, 50-74%; and Excellent 75-100% improvement. Adverse events were also assessed.

Results

All patients obtained clinical improvement ranging from fair to excellent. All 5 patients whose primary treatment was the ps-Alex laser obtained excellent in 2-3 treatment sessions (average 2.5 sessions), and the average total treatment span was 10.0 months. Treatment with the ps-Alex laser caused transient hyperpigmentation followed by improvement to complete resolution at 3 months of follow-up.

Conclusions

Our results suggest that 755 nm ps laser treatment is efficacious for the treatment of nevus of Ota with minimum adverse events.

A retrospective analysis of the clinical efficacies and recurrence of Q-switched Nd:YAG laser treatment of nevus of Ota in 224 Chinese patients

BACKGROUND

Nevus of Ota can be treated successfully using the Q-switched (QS) laser; but few studies are long-term retrospective of the efficacy and influencing factor, studies on the recurrence is even less.

PURPOSE

Retrospective analysis of the clinical characteristics and recurrence of QS Nd:YAG laser treatment of nevus of Ota in 224 Chinese patients at Laser Cosmetology Center of Department of Dermatology, the Second Hospital, Xi'an Jiaotong University.

METHODS

The data of 224 patients with nevus of Ota were analyzed retrospectively, which included the correlation among lesion color, treatment sessions, gender, age, lesion types and effect, and all patients were followed up for 2-10 years.

RESULTS

Higher number of treatment sessions that were conducted using the QS Nd:YAG laser system was positively associated with better responses to treatment. 99.11% of patients acquired more than 75% improvement with an average of 3.7 sessions. Only eight patients (3.57%) who had been completely cleared developed recurrence at the same site as before.

CONCLUSION

The treatment of nevus of Ota with QS Nd:YAG laser is safe and effective with rare recurrence.