Long-pulsed Alexandrite Laser Research Articles

Revealing the mechanism of 755-nm long-pulsed alexandrite laser in inhibiting infantile hemangioma endothelial cells through transcriptome sequencing

Laser therapy has shown promising outcomes in treating infantile hemangiomas. However, the molecular mechanisms underlying laser treatment for IH remain incompletely elucidated. This study aimed to unravel the molecular mechanisms of laser therapy in IH treatment. We evaluated the inhibitory effects of laser treatment on the proliferation and promotion of apoptosis in human hemangioma endothelial cells (HemECs) through cell counting kit-8 (CCK-8) assay, Hoechst 33342 staining, and flow cytometric analysis. Transcriptome sequencing analysis of HemECs following laser treatment revealed a significant decrease in the expression level of the GSTM5 gene. The qRT-PCR and western blot analysis also showed that GSTM5 expression in HemECs was downregulated compared to human umbilical vein endothelial cells (HUVECs), and concomitantly, the p62-Nrf2 pathway was suppressed. Using siRNA to downregulate GSTM5 expression, we observed that inhibiting GSTM5 expression could restrain cell proliferation, elevate intracellular ROS levels, and induce apoptosis in HemECs. Furthermore, upon inhibition of the p62-Nrf2 pathway using p62-specific siRNA, a significant decrease in GSTM5 expression and an elevation in intracellular ROS levels were noted in laser-treated HemECs. These findings suggested that laser treatment may operate by inhibiting the p62-Nrf2 pathway, thereby downregulating GSTM5 expression, elevating ROS levels, and consequently inducing apoptosis in HemECs.

The effects of long-pulsed alexandrite laser therapy on facial redness and skin microbiota compositions in rosacea: Aprospective, multicentre, single-arm clinical trial.

Rosacea is a chronic skin disorder characterised by abnormal neurovasculature and inflammation in the central region of the face. The efficacy of pulsed-dye laser and intense pulsed light treatments for rosacea have been demonstrated in several clinical trials. However, there is currently no research on the efficacy of long-pulsed alexandrite laser (LPAL) therapy alone for rosacea-related facial redness and its effect on skin microbiota. To evaluate the efficacy of LPAL therapy on facial redness in rosacea and assess changes in skin microbiota composition. Subjects with rosacea (n = 21, mean age: 39.2 ± 11.3 years) were recruited from two medical institutions and received monthly LPAL treatments (Clarity II™, Lutronic Corp.) for 3 months. At each visit, clinical photographs were taken, and erythema was measured using a spectrometer. At the initial and final visits, the Dermatology Life Quality Index (DLQI) and Skin Sensitivity Questionnaire (SSQ) were evaluated. Skin swabs were obtained at the initial and final visit, and facial microbiome composition was analysed using 16S rRNA amplicon sequencing. After three LPAL treatment sessions, the average facial erythema index, measured using Mexameter® decreased significantly from 360.0 ± 96.7 at baseline to 312.0 ± 94.5 at the final visit (p < .05). The DLQI and SSQ showed significant improvement of symptoms. Skin microbiome diversity and relative abundance were altered significantly, particularly in the genera Clostridium, Lawsonella, Bacteroides, and Lactobacillus. LPAL therapy alone showed favourable efficacy for the treatment of facial redness in rosacea, with some impacts on the skin microbiota composition.

Inhibition of infantile hemangioma growth and promotion of apoptosis via VEGF/PI3K/Akt axis by 755-nm long-pulse alexandrite laser

BackgroundInfantile hemangioma (IH) is a common vascular tumor in female infants, which can lead to aesthetic issues and facial scarring. This study aimed to investigate the inhibitory effects and underlying mechanisms of 755 nm long-pulsed alexandrite laser on IH. MethodsHemangioma endothelial cells (HemECs) were exposed to 755 nm long-pulsed alexandrite laser to evaluate its impact on cell proliferation and apoptosis. A patient-derived xenograft model was established to assess the inhibitory effects of laser treatment on IH in vivo. ResultsIn vitro, 755 nm long-pulsed alexandrite laser effectively suppressed the proliferation of HemECs and induced cell apoptosis. Laser treatment significantly inhibited the volume and weight of tumors, accompanied by significant downregulation of vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) expression levels in both hemangioma cells and tumors. Additionally, laser treatment resulted in the conversion of VEGFA165a to VEGFA165b. TUNEL staining demonstrated increased apoptosis in tumor cells after laser treatment, along with upregulation of cleaved caspase-3 and Bax, and downregulation of Bcl-2. ConclusionIn addition to the principle of selective photothermal decomposition, modulation of the VEGF/PI3K/Akt axis may serve as a potential mechanism for IH treatment using a long pulse-width 755 nm laser. This sheds valuable light on the molecular mechanisms underlying IH pathogenesis and potential therapeutic targets while providing a theoretical basis for the safe and efficient management of proliferative IH using laser therapy.

Applications of Long-Pulse Alexandrite Laser in Cosmetic Dermatology: A Review.

The long-pulse alexandrite laser uses Cr3+:BeAl2O4 crystals as the activation medium and has a 755nm wavelength and millisecond pulse duration. The long-pulse alexandrite laser has been utilized for hair removal, vascular lesions, pigmented lesions, and other conditions because melanin and hemoglobin in the skin, subcutaneous tissues, and skin appendages can specifically absorb this type of laser. To serve as a guide and source of inspiration for the clinical use of this type of laser, we review the present research status and advancement of the long-pulse alexandrite laser in the treatment of the aforementioned categories of disorders.

Treatment Outcomes for Hemangiomas Using Pulsed Dye Laser (595 nm) and Long-Pulse Alexandrite Laser (755 nm)

Aim. This study aimed to evaluate the therapeutic effiacy of two laser modalities, namely a 595-nm pulsed dye laser and a 755-nm long-pulse alexandrite laser, in the treatment of hemangiomas in patients with concurrent anemia.Methods. A total of 194 patients diagnosed with infantile hemangiomas, characterized by a thickness ranging from over 2 mm to under 8 mm, were included in this study. The patients were randomly assigned to two groups: the control group received treatment with the 595-nm pulsed dye laser, while the experimental group underwent sequential therapy, beginning with the 755-nm long-pulse alexandrite laser followed by the 595-nm pulsed dye laser.Results. In the control group, the overall treatment effiacy was 36.1 %. In contrast, the experimental group exhibited a signifiantly higher effiacy of 76.3 %. Statistical analysis of the abundance data was conducted using the Chi-square (X2) test, with results deemed statistically signifiant at a signifiance level of P &lt; .05.Conclusion. Sequential therapy, which integrates both the 755-nm pulsed dye laser and the 595-nm pulsed dye laser, demonstrates remarkable effectiveness in treating hemangiomas, particularly in cases complicated by anemia.

Efficacy and safety of long-pulsed alexandrite laser for the treatment of solar lentigines

Efficacy and safety of long-pulsed alexandrite laser for the treatment of solar lentigines

Thermal eye injuries from dermatologic laser treatments—an experimental study

In recent years, severe ocular complications after dermatological laser therapies have been reported. One hypothesis is thermal damage due to heating of the metal eye shields. The aim of the present study is to evaluate the safety of ocular metal eye shields during laser therapy of the periocular region. For the experimental study, porcine eyelids were exposed to continuously increasing laser energy and multiple pulses using a number of dermatologic laser systems. Temperature differences of the convex and concave surface of metal eye shields were constantly measured using a thermocouple. Maximum increase of the convex surface of shields was + 8.9 °C (± 0.1 °C) provided by the long-pulsed alexandrite laser (20–25-J/cm2 energy, 15-mm spot size, 20-ms pulse duration, 1 Hz). Present data indicate that metal eye shields provide sufficient thermal protection when clinically used laser parameters are applied. Other safety precautions continue to be essential to protect both the patient and the laser operator. These include the use of nonreflective metal eye shields, precise knowledge of laser physics, and a clear understanding of how they interact with ocular and periocular anatomy.

1553 The effects of long-pulsed alexandrite laser therapy on facial redness and skin microbiota compositions in rosacea: A prospective, multicentre, single-arm clinical trial

1553 The effects of long-pulsed alexandrite laser therapy on facial redness and skin microbiota compositions in rosacea: A prospective, multicentre, single-arm clinical trial

The Application of Color Doppler Ultrasound in the Evaluation of the Efficacy of 595-nm Pulsed Dye Laser Combined with 755-nm Long-Pulse Alexandrite Laser in the Treatment of Hybrid Infantile Hemangiomas.

We used color Doppler ultrasound to conduct an objective evaluation of the 595-nm Pulsed Dye Laser (PDL) combined with 755-nm long-pulse alexandrite sequential laser treatment for hybrid IH. A total of 116 cases of hybrid IH were selected for this study. The interval between laser treatments was around 4 weeks, and 6 laser treatments or complete removal of the tumor was the end point. All children underwent color Doppler ultrasonography at the 0th, 1st, 6th months of treatment. Children were grouped by gender, age (<6 months, ≥6 months), thickness (<8 mm, ≥8 mm), and location (face and neck, trunk, and extremities). Calculate the volume of IHs according to color Doppler ultrasound. The volume ratio before and after treatment was defined as the A-value. Treatment outcomes were defined as effective when the A-value <75%. In total, 74 cases (63.79%) had effective outcomes. Overall, the samples showed a statistically significant difference in the reduction of IH volume after 6 months of laser treatment (P < 0.001). The treatment of <6 months group had better efficacy than the ≥6 months group (P < 0.001), the treatment of thickness <8 mm group had better efficacy than the thickness ≥8 mm group (P < 0.001) and there was no significant difference in efficacy between the three different location groups (P > 0.05). Greater reduction in blood flow in the group with the effective outcome than in the group with the ineffective outcome (P < 0.001). Color Doppler ultrasound can be applied to the diagnosis of hybrid IH and to the evaluation of treatment time and outcomes, and it can help clinicians recognize hybrid IH with greater accuracy. The earlier intervention for hybrid IH we perform, the better outcomes will be.

124 Effects of Long-pulsed Alexandrite Laser treatment on Microbiome in Rosacea Patients

Rosacea is a common cutaneous condition characterized by erythema and vasodilation on the face. Facial flushing and telangiectasia are common symptoms of rosacea, which respond well to treatments with lasers with wavelengths that are selectively absorbed by oxyhemoglobin, such as the pulsed-dye laser (PDL), intense pulsed light (IPL), long-pulsed Nd:YAG and Alexandrite. Additionally, there have been increased data on microbiome diversity imbalance in rosacea patients. The current study was designed to investigate the efficacy and mechanism of long-pulsed Alexandrite laser (LPAL) in rosacea patients by analyzing the facial microbiome in patients receiving laser treatment.

A randomized split-face comparative study of long-pulsed alexandrite plus low-fluence Nd:YAG laser versus pulsed-dye laser in the treatment of rosacea.

To compare the effectiveness of long-pulsed alexandrite laser (LPAL) with that of pulsed-dye laser (PDL) for rosacea. This was a single-blind randomized controlled trial on 27 patients who were clinically diagnosed with rosacea. Randomly assigned split face in each patient received four times monthly treatment of LPAL plus low-fluence Nd:YAG with the contralateral side serving as the control treated with PDL. At every visit, the erythema index (EI) was measured with skin analysis systems, and two independent dermatologists evaluated digital photographs for five-point global aesthetic improvement scale (GAIS). The EI significantly decreased on both treated sides (LPAL 366.5 ± 101.0 vs. 295.8 ± 90.2, p < 0.001, PDL 369.0 ± 124.3 vs. 302.7 ± 92.1, p < 0.001) 1 month after fourthtreatment (visit 5). Also 3 months after the fourth treatment (visit 6), the reduction in the EI was well maintained on both sides (LPAL 360.3 ± 96.8 vs. 282.0 ± 89.2, p < 0.001, PDL 364.3 ± 121.6 vs. 281.6 ± 97.8, p < 0.001). When comparing the improvement in the EI between the two groups, the percentage reduction in the EI on the LPAL-treated side was not inferior to the PDL-treated side (visit 5: LPAL 18.7 ± 15.7% vs. PDL 16.4 ± 12.9%, p = 0.501 and visit 6: LPAL 21.7 ± 13.9% vs. PDL 21.9 ± 15.2%, p = 0.943). The GAIS and patient satisfaction were comparable between the LPAL and PDL sides and did not show any significant difference. No serious adverse events occurred on either of the treated sides. This study showed that the decrease inEI in the treatment of rosacea was comparable between PDL and LPAL. Therefore, LPAL could be a promising alternative treatment option with good merits for rosacea, considering no consumables are required for device maintenance.

Efficacy Evaluation of 755-nm Long-Pulse Alexandrite Laser Combined with 0.5% Timolol Maleate Eye Drops in the Treatment of Thicker Infantile Hemangioma.

PurposeAssessment of the clinical effectiveness and safety of 755-nm long-pulse alexandrite laser combined with 0.5% timolol maleate eye drops in treating thicker infantile hemangioma (IH).Materials and MethodsRetrospective analysis of IH treated with 755-nm long-pulse alexandrite laser and topical timolol in the Second Affiliated Hospital of Wenzhou Medical University from October 2019 to October 2020. Seventy-eight cases were included, with a five-week laser treatment interval. Treatment status was documented during the 35 weeks before each treatment, the effect was assessed at the visual analog scale (VAS), and side effects were recorded. During the 6-month follow-up period, the recurrence and residual skin lesions were monitored. The relationship between IH thickness, treatment duration and VAS was analyzed.ResultsAmong the 78 children with hemangioma, 4 children were treated with a combination of propranolol, fractional laser and cinnamyl alcohol injection due to poor curative effect. Finally, the lesions were effectively alleviated. At the 5th, 15th, 25th, and 35th weeks of treatment, the average VAS of 74 children were 3.56 ± 1.20, 4.61 ± 1.43, 5.63 ± 1.60, and 6.63 ± 1.72, respectively. We analyzed VAS in different thickness groups with Repeated Measures Analysis of Variance(RMANOVA). The results show that the VAS of the thickness 2–3 mm and 3–5mm groups were higher than the 5–7mm and 7–8mm groups (F group = 440.54, P <0.05, F time = 448.31, P <0.05). During the 6-month follow-up period, none of the 74 children relapsed and the residual skin lesions gradually vanished.ConclusionCombined treatment of IHs with a 755-nm long-pulse alexandrite laser and 0.5% timolol maleate eye drops which has apparent clinical efficacy and safety reduce residual skin lesions and decrease the IH recurrence rate.

Efficacy and tolerability of long-pulse Alexandrite laser hair removal for hidradenitis suppurativa.

Efficacy and tolerability of long-pulse Alexandrite laser hair removal for hidradenitis suppurativa.

Sequelae After Involution of Superficial Infantile Hemangioma: Early Intervention with 595-nm Pulsed Laser Combined with 755-nm Long-Pulsed Alexandrite Laser versus Wait-and-See.

Background and ObjectiveInfantile haemangioma (IH) is the most common benign tumor in children. At present, pulsed dye laser (PDL) has made great progress in the treatment of superficial IH, showing good safety and effectiveness. But some doctors think that superficial IH should choose to wait-and-see. However, studies have reported that most of the IH after resolution still has residual disease, and thickness seems to be an important factor. Therefore, the purpose of this study is to investigate the relationship between Sequelae and thickness after superficial IH involution. In addition, compare the Sequelae difference between 595-nm pulsed laser combined with 755-nm long-pulse alexandrite laser treatment and wait-and-see.Materials and MethodsThis retrospective observational study included patients with superficial IH evaluated in the past 6 years and divided them into a laser group and an observation group.ResultsThe incidence of sequelae in the laser group was 44.6%, and the incidence of sequelae in the observation group was 69.5%. The incidence of Sequelae of superficial IH in the laser group was significantly lower than that in the observation group (χ2-test, χ2=10.790, P <0.001). In the observation group, the average A scores of the three thickness subgroups (<2mm, 2–5mm, and >5mm) were 4.38, 3.39, and 1.80, and there were significant differences in the A scores between the three groups (Kruskal–Wallis, p<0.05). There is a significant difference in the A score between the laser group and the observation group in the superficial IH with a thickness of 2–5 mm and>5mm (Wilcoxon rank sum test, P<0.05).ConclusionThis retrospective study showed that the degree of Sequelae of superficial IH after involution is related to its thickness. In addition, the early intervention of 595-nm pulsed laser combined with 755-nm long-pulse alexandrite laser can reduce the incidence and extent of sequelae.

A Treatment of Medium-to-Giant Congenital Melanocytic Nevi with Combined Er:YAG Laser and Long-Pulsed Alexandrite Laser

A Treatment of Medium-to-Giant Congenital Melanocytic Nevi with Combined Er:YAG Laser and Long-Pulsed Alexandrite Laser

Alexandrite Laser for the Treatment of Resistant and Hypertrophic Port Wine Stains: A Clinical, Histological and Histochemical Study

BackgroundPort wine stains (PWSs) are commonly treated by the pulsed dye laser. However, treatment of hypertrophic or resistant PWSs is a major therapeutic challenge. The long-pulsed Alexandrite laser could be a safe and effective treatment for resistant PWSs, due to an increase depth of penetration of 50–75% over PDL. ObjectiveThe aim of this study was to assess the efficacy and safety of a long-pulsed Alexandrite laser in patients with hypertrophic, dark and/or resistant PWSs. Pink pale resistant PWS were excluded from the study. MethodsTwenty-one patients (age 20–75 years), phototypes I–IV on the Fitzpatrick scale, with PDL dark resistant PWSs were treated with long-pulsed Alexandrite laser. We excluded high phototypes and PDL pink resistant PWSs. All patients were treated with 3 laser sessions at settings of 3-ms pulse duration, 10-mm spot, 35–55J/cm2, with cooling (Dynamic Cooling Device 50ms with delay 30ms). Laser sessions were repeated approximately every 2 months. Three dermatologists evaluated treatment effectiveness by means of photographs of the patients before and after laser treatment (scale from 0 to 4). Adverse events were registered. Patient satisfaction was also assessed (scale from 0 to 10). ResultsMean global improvement was rated as 2.28. Long-lasting side effects included minimal scarring after blistering in 1 patient. Mean patient satisfaction was 8.5. ConclusionsOur study concludes that long-pulsed Alexandrite laser was effective for treatment of resistant PWSs, although the therapeutical window is narrow with this treatment.

A Retrospective Analysis of the Treatment of Melasma Using a Fractional Long-Pulsed Alexandrite Laser in Korean Patients.

Long-pulsed, 755-nm, alexandrite lasers have been shown to be effective and safe in the treatment of pigmentary lesions. Clinical outcomes and side effects in the treatment of melasma using a fractional, long-pulsed, alexandrite laser were assessed. Forty-eight patients with melasma received 2 to 4 treatment sessions of fractional, long-pulsed, alexandrite laser at 2 to 3 weeks intervals. The parameter of treatment was 60 to 80 J/cm without dynamic cooling device using 15-mm spot size of fractional hand piece, with a 0.5- to 1-millisecond pulse width. The mean modified melasma area and severity index score decreased significantly 2 months after the final treatment compared with baseline (16.5 ± 8.2 vs 11.5 ± 7.0; p = .002). The patients with epidermal type melasma were more effective compared to dermal type (p < .001). Long-pulsed alexandrite lasers using a fractional hand piece are moderately effective in the treatment of melasma with low risk of adverse effects, and it is suggested that fractional, long-pulsed, alexandrite laser with combination of other modalities can be an additional therapeutic option in patients with melasma.

Alexandrite Laser for the Treatment of Resistant and Hypertrophic Port Wine Stains: A Clinical, Histological and Histochemical Study

BackgroundPort wine stains (PWSs) are commonly treated by the pulsed dye laser. However, treatment of hypertrophic or resistant PWSs is a major therapeutic challenge. The long-pulsed Alexandrite laser could be a safe and effective treatment for resistant PWSs, due to an increase depth of penetration of 50–75% over PDL. ObjectiveThe aim of this study was to assess the efficacy and safety of a long-pulsed Alexandrite laser in patients with hypertrophic, dark and/or resistant PWSs. Pink pale resistant PWS were excluded from the study. MethodsTwenty-one patients (age 20–75 years), phototypes I–IV on the Fitzpatrick scale, with PDL dark resistant PWSs were treated with long-pulsed Alexandrite laser. We excluded high phototypes and PDL pink resistant PWSs. All patients were treated with 3 laser sessions at settings of 3-ms pulse duration, 10-mm spot, 35–55J/cm2, with cooling (Dynamic Cooling Device 50ms with delay 30ms). Laser sessions were repeated approximately every 2 months. Three dermatologists evaluated treatment effectiveness by means of photographs of the patients before and after laser treatment (scale from 0 to 4). Adverse events were registered. Patient satisfaction was also assessed (scale from 0 to 10). ResultsMean global improvement was rated as 2.28. Long-lasting side effects included minimal scarring after blistering in 1 patient. Mean patient satisfaction was 8.5. ConclusionsOur study concludes that long-pulsed Alexandrite laser was effective for treatment of resistant PWSs, although the therapeutical window is narrow with this treatment.

Control of hair growth using long-pulsed alexandrite laser is an efficient and cost effective therapy for patients suffering from recurrent pilonidal disease.

Pilonidal sinus (PNS) and its surgical management have a profound impact on hospital resources in terms of finances and productive man-hours. Surgical treatment has been the mainstay of treatment of both acute and chronic pilonidal sinus but recurrence is common. The control of hair growth in the sinus region plays an important role in preventing recurrence. Here, we discuss our experience of treating 19 patients suffering from recurrent pilonidal sinus with laser depilation and its long-term cost effectiveness. This is a retrospective study on patients who had recurrence of pilonidal sinus following multiple surgical treatments. They were treated using long-pulsed alexandrite laser for depilation in the sinus area, an outpatient procedure. Their clinical characteristics and outcomes were then evaluated. There was a significant reduction in hair density after laser treatment (p < 0.001). The disease-free period after laser treatment was significantly longer than that one after surgical treatment (p < 0.001). The average cost of repeated surgical treatment per disease-free month was significantly higher than that of laser treatment(p < 0.001). Evidence suggests the role of natal cleft hair growth in the evolution of the pilonidal disease; therefore, control of hair growth should be considered as an adjunct to the initial treatment via surgery. Compared to surgical treatment of recurrences, laser depilation is an efficient and cost-effective method of preventing recurrence and reducing morbidity and loss of man-hours. We suggest that laser depilation of the pilonidal sinus should be funded by clinical commissioning groups.

Treatment of Acquired and Small Congenital Melanocytic Nevi With Combined Er

There is no gold standard for the treatment of benign melanocytic nevi for cosmetic purposes. To investigate the efficacy and safety of combined treatment with the short-pulsed erbium:yttrium-aluminum-garnet (Er:YAG) and long-pulsed alexandrite laser for acquired melanocytic nevi (AMN) and small congenital melanocytic nevi (CMN). Fifty-eight AMN and 7 small CMN in 24 Korean patients were treated with Er:YAG laser followed by long-pulsed alexandrite laser at 1-month intervals. At 8 weeks after the final treatment, all treated nevi showed complete removal of pigmentation, and the mean overall improvement score assessed by physicians, with a quartile grading scale, was 3.6 ± 0.7. The mean number of treatment sessions required to treat CMN (1.5 ± 0.3) was significantly greater than that for junctional (1.1 ± 0.2) or compound (1.2 ± 0.5) AMN. Postinflammatory hyperpigmentation (4.6%), erythema (9.2%), hypertrophic scars (1.5%), and mild atrophic scars (10.8%) were observed, but all resolved within 6 months, except for hypertrophic scars and 1 atrophic scar. Recurrence of pigmentation was observed in 1 CMN (1.5%) during 6 months of follow-up. Combined treatment with Er:YAG laser and long-pulsed alexandrite laser is effective for the removal of small benign melanocytic nevi with minimal adverse effects and low recurrence rates.