Dye Laser Research Articles

Treatment of erythematous acne scars using 595-nm pulsed dye laser combined with 1565-nm ResurFX nonablative fractional laser.

Acne vulgaris is a common inflammatory disease associated with various sequelae after skin lesion remission. Acne erythema has been considered simple erythema or a vascular lesion; however, because the understanding of this disease has improved, acne erythema is currently considered an early scar with erythematous components. This study evaluated the efficacy of using both a 595-nm pulsed dye laser (PDL) and 1565-nm nonablative fractional laser (NAFL) for the treatment of erythematous scars caused by acne. Ninety patients with acne scars were equally randomized to two groups. Group A (n = 45) received treatment with the NAFL. Group B (n = 45) received treatment with the PDL and NAFL. Each patient underwent one treatment session and 4 weeks of follow-up. Qualitative (χ2 = 12.415; p < 0.05) and quantitative (t = 2.675; p < 0.05) scores of Groups A and B were determined using a global scarring grading system and exhibited statistically significant differences. The quantitative score of Group A was higher than that of Group B (6.67 ± 3.46 vs. 4.98 ± 2.44). The erythema areas of the groups differed significantly after treatment, with Group B exhibiting more notable score improvements (5.00 [3.10, 7.10] vs. 2.80 [1.65, 4.60]; Z = 3.072; p < 0.05). The erythema regression rate of Group B (88.9%) was significantly higher than that of Group A (66.7%) (χ2 = 20.295; p < 0.001). Adverse events, including redness and swelling (86.6%), scabbing (78.8%), and purpura (36.6%), occurred within 7 days for 86.6% of patients. The combined use of the PDL and NAFL is safe and effective for erythematous acne scars.

Laser and Lights in Psoriasis.

Psoriasis is a chronic inflammatory skin condition affecting millions of individuals worldwide. Over the years, various treatment modalities have been explored to alleviate the symptoms and improve the quality of life for patients with psoriasis. Among these treatment options, lasers and lights have emerged as promising non-invasive approaches with significant efficacy. This review aims to provide an overview of the current understanding and clinical applications of lasers and lights in the management of psoriasis. We have discussed the mechanisms of action behind different laser and light therapies and their impact on psoriatic plaques. Additionally, we discuss the various types of lasers and lights utilized, including excimer lasers, pulsed dye lasers, and narrowband ultraviolet B (NB-UVB) phototherapy, highlighting their unique properties and clinical outcomes. Moreover, we have addressed important considerations related to patient selection, treatment protocols, and potential side effects associated with lasers and lights. We emphasize the need for proper evaluation, monitoring, and customization of treatment plans to ensure optimal outcomes and minimize adverse events.

Manipulating random lasing correlations in doped liquid crystals.

Random lasers are highly configurable light sources that are promising for imaging and photonic integration. In this study, random lasing action was generated by optically pumping N-(4-methoxybenzylidene)-4-butylaniline (MBBA) liquid crystals infiltrated with gold nanoparticles and a laser dye (pyrromethene 597 (PM597)). By varying the pump energy near a lasing threshold, we show that it is possible to control intensity correlations between random lasing modes. The correlations in the system were phenomenologically characterized using the Levy statistics of the emission spectrum survival function. We also find that correlations and persistence of lasing action are correlated. These results demonstrate the possibility to dynamically control a key physical feature of random lasers, which may find applications in biomedical settings and network communications.

Expanding the bandwidth of fluorescence-detected two-dimensional electronic spectroscopy using a broadband continuum probe pulse pair.

We demonstrate fluorescence-detected two-dimensional electronic spectroscopy (F-2DES) with a broadband, continuum probe pulse pair in the pump-probe geometry. The approach combines a pump pulse pair generated by an acousto-optic pulse-shaper with precise control of the relative pump pulse phase and time delay with a broadband, continuum probe pulse pair created using the Translating Wedge-based Identical pulses eNcoding System (TWINS). The continuum probe expands the spectral range of the detection axis and lengthens the waiting times that can be accessed in comparison to implementations of F-2DES using a single pulse-shaper. We employ phase-cycling of the pump pulse pair and take advantage of the separation of signals in the frequency domain to isolate rephasing and non-rephasing signals and optimize the signal-to-noise ratio. As proof of principle, we demonstrate broadband F-2DES on a laser dye and bacteriochlorophyll a.

Bidirectional Neuronal Actuation by Uncaging with Violet and Green Light

AbstractWe have developed a photochemical protecting group that enables wavelength selective uncaging using green versus violet light. Change of the exocyclic oxygen of the laser dye coumarin‐102 to sulfur, gave thio‐coumarin‐102, a new chromophore with an absorption ratio at 503/402 nm of 37. Photolysis of thio‐coumarin‐102 caged γ‐aminobutyric acid was found to be highly wavelength selective on neurons, with normalized electrical responses &gt;100‐fold higher in the green versus violet channel. When partnered with coumarin‐102 caged glutamate, we could use whole cell violet and green irradiation to fire and block neuronal action potentials with complete orthogonality. Localized irradiation of different dendritic segments, each connected to a neuronal cell body, in concert with 3‐dimenional Ca2+ imaging, revealed that such inputs could function independently. Chemical signaling in living cells always involves a complex balance of multiple pathways, use of (thio)‐coumarin‐102 caged compounds will enable arbitrarily timed flashes of green and violet light to interrogate two independent pathways simultaneously.

Bidirectional Neuronal Actuation by Uncaging with Violet and Green Light.

We have developed a photochemical protecting group that enables wavelength selective uncaging using green versus violet light. Change of the exocyclic oxygen of the laser dye coumarin-102 to sulfur, gave thio-coumarin-102, a new chromophore with an absorption ratio at 503/402 nm of 37. Photolysis of thio-coumarin-102 caged γ-aminobutyric acid was found to be highly wavelength selective on neurons, with normalized electrical responses >100-fold higher in the green versus violet channel. When partnered with coumarin-102 caged glutamate, we could use whole cell violet and green irradiation to fire and block neuronal action potentials with complete orthogonality. Localized irradiation of different dendritic segments, each connected to a neuronal cell body, in concert with 3-dimenional Ca2+ imaging, revealed that such inputs could function independently. Chemical signaling in living cells always involves a complex balance of multiple pathways, use of (thio)-coumarin-102 caged compounds will enable arbitrarily timed flashes of green and violet light to interrogate two independent pathways simultaneously.

Temperature effect on spectral characters and dipole moment in short-lived excited singlet S1 state of 3HBI-7D-2HChromen-2-one laser dye in non-associative and highly viscous glycerol solvent

Steady state method is employed to study the effect of temperature on the absorption and emission characteristics of 3-(1H-benzo[d]imidazol-2-yl)-7-(diethylamino)-2H-chromen-2-one(3HBI-7D-2HChromen-2-one) laser dye in glycerol solvent. Temperature induces thermal effect on maxima absorption, emission wavelength, fluorescence intensity etc. Radiative and non-radiative transition probabilities mechanism, fluorescence lifetime, frequency assisted parameters decay rate constants, and activation energy is estimated. Advance thermochromic shift method is adopted to determine the ground and excited state dipole moments.

Microviscosity-Assisted Disaggregation of a Model Ophthalmic Drug and FRET-Controlled Singlet Oxygen Generation in Lyotropic Liquid Crystals.

Different phases of lyotropic liquid crystals (LLCs), made up of mesogen-like sodium dodecyl sulfate (SDS), mainly bestow different bulk viscosities. Along with this, the role of microviscosities of the individual LLC phases is of immense interest because a minute change in it due to guest incorporation can cause significant alteration in their property as a potential energy transfer scaffold. Recently, LLCs have been identified as plausible drug delivery agents for ocular treatments. In this direction, the present work illustrates photophysical modulations of an important laser dye as well as an ophthalmic medicine, coumarin 6 (C6), inside different LLC phases in an aqueous medium. C6 molecules spontaneously accumulate in water, leading to aggregation-caused quenching (ACQ) of fluorescence. However, the different phases of the LLCs prepared from SDS and water helped in disintegrating the C6 colonies to various extents depending upon the microviscosity. The heterogeneity in the LLC phases, in turn, could modulate the Förster resonance energy transfer (FRET) between C6 and the LLC incorporated with N-doped carbon nanoparticles (N-CNPs). The N-CNPs act as potential photosensitizers and generate singlet oxygen (1O2), a reactive oxygen species (ROS), to different extents. Microviscosities of the prepared LLCs were calculated by using fluorescence correlation spectroscopy (FCS). The different phases of the LLCs, viz., lamellar and hexagonal, with different microviscosities controlled the extent of C6 disaggregation and hence the FRET and the ROS generation. The results are encouraging since ROS generation has a significant role in the vision mechanism and PDT-based applications. LLC-based drug administration with potential FRET to control ROS generation may become handy in ophthalmology. The LLC phases used in this experiment not only served the purpose of drug delivery but also the photophysical events therein are compatible with the ocular environment.

Basal cell carcinoma - the most common form of skin cancer. Methods of treatment

Introduction: Basal cell carcinoma is the most common form of skin cancer. The lifetime risk is estimated as 33% to 39% in white men and 23% to 28% in white women. Because of that it is a very crucial disease for public health. In this article will be described main pathways of treatment which are especially recommended and are the most wide used for different types of basal cell carcinoma. Main division of interventions type used in treatment of basal cell carcinoma are surgical (physical) and non-surgical (medical). Surgical (physical) includes surgical standard excision, Mohs micrographic surgery, curettage and cautery, cryosurgery and laser therapy (ablative lasers, pulsed dye lasers). Non-surgical (medical) includes radiotherapy, topical imiquimod, topical 5- fluorouracil, photodynamic therapy, intralesional interferon. Aim of study: Literature review of the most recommended treatment of basal cell carcinoma. State of knowledge: In this publication will be desribed a current state of knowledge about basic and the most crucial basal cell carcinoma treatment. Conclusion: Because of incidence rate of basal cell carcinoma which is very high- there are many reports about treatment of this disease. Treatment of this disease, especially among low risk patients, is very effective.

Efficient Fluorescence Utilization and Photon Density of States‐Driven Design of Liquid Crystal Lasers

AbstractLiquid‐crystal random lasers (LCRLs) represent a burgeoning field in soft‐matter photonics, holding promise for ushering in an era of ultrathin, versatile laser sources. Such lasers encompass a multitude of remarkable features, including wide‐band tunability, large coherence area and, in some cases, multidirectional emission. In this paper, an LCRL is developed by doping a laser dye, pyrromethene 597 (PM597), into cholesteric LC, but achieving a wide‐range wavelength‐controllable (560–720 nm) bandgap lasing through voltage control. Bandgap lasing intriguingly occurs in media with extremely low dye gain, which is mainly contributed by the extremely high photon density of states (DOS) at the edge of the LC bandgap. In addition, the utilization rate of the fluorescence spectrum (550–750 nm) of laser dye PM597 is as high as 80%. The multivariate linear regression model is used to characterize the inherent relationship between the lasing intensity emitted by LC and the photon DOS, fluorescence quantum yield, and internal scattering under specific pumping energy. This model shows the potential to predict the critical conditions of laser emission accurately and provides the capability to design and fabricate large‐scale multifunctional responsive photonic crystals using a simple fabrication procedure.

Scientific validation of clinical visual scales and Antera 3D™ consistency with derived measurements in the assessment of infantile haemangioma after laser therapy

Laser therapy is a treatment for infantile haemangiomas. The efficacy of laser therapy for red lesions is determined by visual evaluation; however, this assessment is inaccurate and lacks objectivity. To scientifically validate the consistency between pre- and post-treatment visual assessment grades for infantile haemangioma treated with pulsed dye laser (PDL) and the values calculated from images obtained with Antera 3D™. This study involved 81 cases of infantile haemangiomas treated with PDL alone from 2012 to 2015 and with Antera 3D™ images of the lesions. Using images obtained before treatment and 4-6 weeks after the last treatment, the lesions were rated using a visual four-step scale. Ratings were categorised as Poor/Fair/Good/Excellent by the degree of improvement in the red colour tone. The red colour ratio was calculated using the haemoglobin distribution in the lesion and surrounding skin, and the improvement difference and improvement rate were then obtained. The correlation between the improvement difference and improvement rate, and visual evaluation was statistically analysed. No serious adverse effects were observed, with an average of 4.3 treatments per patient; 60.1% of the patients achieved Good/Excellent results. There were statistically significant differences in the post-treatment red colour ratio and improvement ratio in each category after visual evaluation classification. The improvement rate and the four visual grades were statistically correlated. This study confirmed the scientific validity of visual evaluation and the evaluation criteria calculated from Antera 3D™. This method could objectively determine treatment effectiveness.

Non-invasive efficacy assessment of pulsed dye laser and photodynamic therapy for port-wine stain.

Port wine stain (PWS) is a congenital vascular malformation that commonly occurs on the face and neck. Currently, the main treatments for port wine stain are pulsed dye laser (PDL) and photodynamic therapy (PDT). However, the efficacy evaluation of PWS mostly relies on the subjective judgement of clinicians, and it is difficult to accurately respond to many small changes after treatment. Therefore, some non-invasive and efficient efficacy assessment methods are also needed. With the continuous development of technology, there are currently many visualisation instruments to evaluate PWS, including dermoscopy, VISIA-CR™ system, reflectance confocal microscopy (RCM), high-frequency ultrasound (HFUS), optical coherence tomography (OCT), Photoacoustic imaging (PAI), laser speckle imaging (LSI) and laser Doppler imaging (LDI). Among them, there are simple and low-cost technologies such as dermoscopy and the VISIA-CR™ system, but they may not be able to observe the deeper structures of PWS. At this time, combining techniques such as HFUS and OCT to increase penetration depth is crucial to evaluate PWS. In the future, the combination of these different technologies could help overcome the limitations of a single technology. This article provides a systematic overview of non-invasive methods for evaluating treatment efficacy in port wine stains and summarises their advantages and disadvantages.

On the Luminescence Properties of Carbon Dots Synthesized on the Basis of Nile Red Laser Dye

On the Luminescence Properties of Carbon Dots Synthesized on the Basis of Nile Red Laser Dye

Two-dimensional coherent electronic spectrometer with switchable multi-color configurations.

Broadband implementation of two-dimensional electronic spectroscopy (2DES) is a desirable goal for numerous research groups, yet achieving it presents considerable challenges. An effective strategy to mitigate these challenges is the utilization of two-color approaches, effectively broadening the spectral bandwidth accessible with 2DES. Here, we present a simple approach to include multi-color configurations based on adjustable mirror mounts. This enables seamless toggling between single-color, two-color, and transient 2DES within the same spectroscopic apparatus, which is benchmarked on two common laser dyes, Rhodamine 6G and Nile blue. Upon mixing the dyes, single-color 2DES shows overlapping signals, whereas a high selectivity toward Nile blue responses is maintained in two-color and transient 2DES, owing to the fully resonant excitation that is spectrally shifted relative to the detection window. This method is readily implemented in other setups with similar experimental layouts and can be used as a simple solution to overcome existing bandwidth limitations. With the inclusion of transient 2DES, additional insights into excited-state processes can be gained due to its increased sensitivity toward excited-state coherences.

Clinical efficacy of ablative laser combined with pulsed dye laser in the treatment of pathological scars: A systematic review and meta‐analysis

AbstractObjectiveA systematic review and meta‐analysis were conducted to evaluate the efficacy and safety of ablative laser combined with pulsed dye laser to treat pathological scars.MethodsA systematic literature review was conducted to identify all blind, randomized, controlled trials of ablative laser and pulsed dye laser for treating pathological scars. The databases PubMed, Embase, and Cochrane were used. All research on ablative laser combined with PDL in treating pathological scars with ablative laser or no treatment as controls were included in the meta‐analysis. The retrieved studies' reference lists were thoroughly examined.ResultsPOSAS and VSS were used as evaluation criteria in seven studies involving 189 patients. Effect of combined laser group therapy (−1.259 95% confidence interval, −1.515 to −1.003; p &lt; 0.0001). The difference between the combined treatment and control groups was (−1.375; 95% CI, −1.727 to −1.023; p &lt; 0.0001) and (−1.150; 95% CI, −1.523 to −0.777; p &lt; 0.0001).ConclusionsAblative laser combined with PDL is more effective and safer than ablative laser or PDL alone in the treatment of pathological scars.

Practical management of hypertrophic scarring: the mayo clinic experience.

Hypertrophic scarring is a potential consequence of wound healing that causes functional and aesthetic disability. Common treatments include intralesional pharmacotherapy (e.g., triamcinolone), surgical excision, and energy-based laser devices. While numerous treatment methods have been described for hypertrophic scarring, an optimal treatment strategy has yet to be established given variability in clinical presentation. This study aims to identify patient- and provider-preferred treatment patterns. This is a single-center, retrospective study of adult patients that developed post-surgical hypertrophic scarring between 2007 and 2017. Specifically, trends in procedural management for hypertrophic scarring among this cohort were examined. A total of 442 procedures (intralesional steroid injection, surgical excision, laser-based treatment) were identified in 218 patients with a clinical diagnosis of hypertrophic scarring. Approximately 73% were female; 87% were Caucasian. The median age at first procedure was 45.6years (SD = 17.4). The most frequent anatomical locations for procedures were the trunk (n = 242; 54.8%), followed by head/neck (n = 86; 19.5%), upper extremities (n = 67; 15.2%), and lower extremities (n = 45; 10.2%). Procedural therapies included intralesional steroid injection (n = 221; 50%), surgical excision (n = 112; 25.3%) and laser (fractional non-ablative laser vs. pulsed dye laser; n = 109; 24.5%). Treatment modality varied by stage of treatment, scar anatomical location, and scar size. This single-center series of patients with hypertrophic scarring highlights a patient-centered management approach and offers clinical guidelines for provider-patient shared decision making.

A comparative study of spectral and luminescent properties of Eu3+-doped cation-deficient perovskite phosphors

Eu3+ is not only a major red-emitting activator, but also an excellent spectral probe ion. This work reports the Eu3+-sites and luminescence in the cation-deficient perovskite tungstates, A-site deficient SrLa2(Mg2W2)O12 [Sr1/2□1/2La(MgW)O6] and B-site deficient Sr2La2(MgW2)O12 [SrLa(Mg1/2□1/2W)O6]. The 7F0→5D0 excitation spectra of Eu3+ activators in two lattices were measured via pulsed dye laser. In SrLa2(Mg2W2)O12:Eu3+, there is only one 7F0→5D0 transition, which could be related to the Eu3+ center on La3+ sites; while, two 7F0→5D0 transitions in Sr2La2(MgW2)O12 indicate Eu3+ ions occupy Sr2+ in addition to La3+, resulting in the luminescent centers related to heterovalent substitution defects. The different Eu3+ sites make two phosphors exhibit different red luminescence properties. SrLa2(Mg2W2)O12:Eu3+ shows higher luminescent efficiency and thermal quenching due to its regular distribution of the activators resulting in lower dispersion losses of the energy transfer. The experimental results show that rare earth ions occupy different crystallographic positions in A-site and B-site deficient perovskite oxides, and this microstructure can be important for the corresponding luminescent properties.

Temperature Effect on Fluorescence Intensity and Dipole Moment Using Thermochromic Shift Method of 7DA3MHBI-2HChromen-2-one Laser Dye in Highly Viscous Glycerol Solvent.

The steady-state method is used to study the effect of temperature on the fluorescence characteristics of 7-(diethylamino)-3-(1-methyl-1H-benzo[d]imidazol-2-yl)-2H-chromen-2-one (7DA3MHBI-2HChromen-2-one) laser dye in glycerol solvent for the temperature range 293-343K. Absorption and emission characteristics are affected by varying temperatures due to induced thermal effects. Transition probabilities mechanism of non-radiative and radiative are studied and frequency dependent parameters are estimated. Dipole moments in the ground and excited state are estimated using the thermochromic shift method over general solvatochromic methods.

A 595 nm pulsed dye laser as an adjuvant intervention for post-comedone extraction erythema and comedone reduction: A randomized, split-face controlled trial.

Comedone extraction provides greater satisfaction for acne treatment than conventional treatment alone; however, post-comedone extraction erythema (PCEE) remains a concern for patients. To evaluate the efficacy of pulsed-dye laser (PDL) in PCEE and comedone reduction. Mild-to-moderate acne patients were randomly allocated in split-face fashion. Three comedones were extracted on each facial side. On the PDL-treated side, 595-nm PDL was delivered to the entire side with an additional shot on three comedone-extracted sites. Erythema index (EI) and total acne lesion counts (TALC) were evaluated at baseline, week 2 and 4. The comprehensive acne severity scale (CASS) was assessed by three blinded independent pediatric dermatologists. Participant satisfaction surveys were completed at the end of the study. Thirty-five participants (age 12.9-24.2 years) showed no differences in the EI and TALC at baseline on both sides. At weeks 2 and 4, the EI on the PDL-treated side was significantly lower (p < 0.001) with a greater EI reduction (p < 0.001) when compared to the control side regardless of gender and menstruation. There was significantly lower TALC on the PDL-treated side at week 2 (p < 0.001) and week 4 (p = 0.02). No complications were noted with high participant satisfaction reported (median 8; IQR 7-9). PDL remained significantly associated with EI improvements after controlling for gender, menstruation cycle, and examination stress. PDL can be an adjunctive intervention for the treatment of PCEE and comedone reduction due to its effectiveness and high participant satisfaction.

Effect of Laser and Energy-based Device Therapies to Minimize Surgical Scar Formation: A Systematic Review and Network Meta-analysis.

Utilization of lasers and energy-based devices for surgical scar minimization has been substantially evaluated in placebo-controlled trials. The aim of this study was to compare reported measures of efficacy of lasers and energy-based devices in clinical trials in preventing surgical scar formation in a systematic review and network meta-analyses. Five electronic databases, PubMed, Scopus, Embase, ClinicalTrials.gov, and the Cochrane Library, were searched to retrieve relevant articles. The search was limited to randomized controlled trials that reported on clinical outcomes of surgical scars with treatment initiation no later than 6 months after surgery and a follow-up period of at least 3 months. A total of 18 randomized controlled trials involving 482 participants and 671 postsurgical wounds were included in the network meta-analyses. The results showed that the most efficacious treatments were achieved using low-level laser therapy) (weighted mean difference -3.78; 95% confidence interval (95% CI) -6.32, -1.24) and pulsed dye laser (weighted mean difference -2.46; 95% CI -4.53, -0.38). Nevertheless, low-level laser therapy and pulsed dye laser demonstrated comparable outcomes in surgical scar minimization (weighted mean difference -1.32, 95% CI -3.53, 0.89). The findings of this network meta-analyses suggest that low-level laser therapy and pulsed dye laser are both effective treatments for minimization of scar formation following primary closure of surgical wounds with comparable treatment outcomes.