Excimer Laser Light Research Articles

Efficacy and safety of traditional and surgical treatment modalities in segmental vitiligo: A review article.

Segmental vitiligo (SV) is a distinctive variant of vitiligo that is usually resistant to traditional treatments. Therefore, surgical therapies are mainstay of treatment in this type of vitiligo. To date, there is no review article or systematic review that evaluates specifically efficacy of treatment modalities on SV. To evaluate current evidence regarding efficacy and safety of traditional and surgical treatment modalities in SV. We conducted a search in PubMed, Embase, Web of science, and Google Scholar for key words of "vitiligo" AND "segmental" AND "treatment" OR "therapy" OR "surgical treatments" OR "medical treatments" OR "laser" OR "phototherapy". Inclusion criteria were English literature that investigated efficacy of different treatments on three or more cases on SV from January 2000 until July 2021. A total of thirty-four articles were selected for detailed assessment. Different treatment modalities include medical treatment [systemic corticosteroid (SCS), topical CS (TCS), and topical calcineurin inhibitors (TCI)], phototherapy [narrow band-ultraviolet B (NB-UVB), psoralen and UVA (PUVA) and psoralen+solar exposure (PUVASOL)], laser/lights [helium-neon and Excimer laser/light (EL)] and surgical treatments [punch graft (PG), follicular graft, suction blister epidermal grafting (SBEG), spilt-thickness skin graft (STSG), and cultured/non-cultured-melanocytes-keratinocytes transplantation (MKTP)]. There were few randomized controlled trials (RCT) evaluating the efficacy of treatments in SV. Therefore, future high quality studies are required for better assessment of various treatment modalities in SV. Results of current evidence indicate resistance of SV to traditional therapies unless in patients with short duration of vitiligo. Therefore, surgical interventions are the first-line of treatment in refractory cases, long-standing disease, or presence of leukotrichia in depigmented patches.

Excimer laser/light treatment of alopecia areata: A systematic review and meta-analyses.

The excimer laser/light (EL) has been reported to be effective for alopecia areata (AA), but its treatment response has not been systematically reviewed. To determine the treatment response and safety of EL treatment of AA. A comprehensive search of the Medline, EMBASE, Cochrane library, and Web of Science (from inception to December 31, 2018) was conducted to identify prospective clinical studies assessing the treatment response of EL for AA. The primary outcome was cosmetically acceptable hair regrowth (hair regrowth ≥75%); random-effects meta-analyses using generic inverse variance weighting were performed to estimate treatment responses. The study was registered with PROSPERO (CRD42019121092). Of 52 records initially identified, 13 full-text articles were finally assessed in terms of eligibility. A total of 9 prospective clinical studies (129 AA patients) including 5 controlled clinical trials were identified. Cosmetically acceptable hair regrowth was achieved in 50.2% (95% confidence interval 31.5%-68.9%; 8 studies). EL treatment significantly improved hair regrowth compared with untreated controls (relative risk 7.83; 95% confidence interval 2.11-29.11; 5 controlled clinical trials). No serious adverse effect was noted. EL treatment appeared to produce a favorable therapeutic response in AA patients. The use of EL should be encouraged for AA patients with the advantages of the non-invasiveness and no systemic effect.

GW28-e1173 Excimer laser in Acute myocardial infarction: Three Cases Report

Pulsed-wave ultraviolet excimer laser light at 308 nm can vaporize thrombus, suppress platelet aggregation and ablates the underlying plaque. Here we present the first initial experience in china with three cases of acute myocardial infarction treated by excimer laser instrument. Three cases, aged

Laser-assisted immobilization of colloid silver nanoparticles on polyethyleneterephthalate

Immobilization of nanoobjects on the surface of underlying material belongs to current issues of material science. Such altered materials exhibits completely exceptional properties exploitable in a broad spectrum of industrially important applications ranging from catalysts up to health-care industry. Here we present unique approach for immobilization of electrochemically synthesized silver nanoparticles on polyethyleneterephthalate (PET) foil whose essence lies in physical incorporation of particles into thin polymer surface layer induced by polarized excimer laser light. Changes in chemical composition and surface structure of polymer after particle immobilization were recorded by wide range of analytical techniques such as ARXPS, EDX, RBS, AAS, Raman, ICP-MS, DLS, UV–vis, SEM, TEM, and AFM. Thorough analysis of both nanoparticles entering the immobilization step as well as modified PET surface allowed revealing the mechanism of immobilization process itself. Silver nanoparticles were physically embedded into a thin surface layer of polymer reaching several nanometers beneath the surface rather than chemically bonded to PET macromolecules. Laser-implanted nanoparticles open up new possibilities especially in the development of the next generation cell-conform antimicrobial coatings of polymeric materials, namely due to the considerable immobilization strength which is strong enough to prevent particle release into the surrounding environment.

Phototherapy in Atopic Dermatitis.

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. Currently management of AD includes avoidance of triggering factors, skin care aiming to compensate the skin barrier defects, anti-inflammatory therapy (mostly topical corticosteroids and topical calcineurin inhibitors). When these first-line approaches are unsuccessful, systemic treatment or phototherapy ought to be carried out as next line of defence. Current phototherapy modalities for AD include broadband UVB (290-320nm), narrowband UVB (311-313nm), UVA-1 therapy (340-400nm), UVA therapy plus 8-methoxypsoralens (PUVA), 308 nm excimer laser (EL) and Full spectrum light (FSL).

Luminescence properties of pure and Eu-doped SrI2 crystals purified by a “Liquinert” process and grown by vertical Bridgman method

We have prepared high quality crystals of pure SrI2 and Eu-doped SrI2 by our original “Liquinert” process and investigated their luminescence properties. Under the excitation with the 193nm light of an ArF excimer laser, which corresponds to the wavelength above the bandgap of SrI2 bulk crystals, the pure and Eu doped SrI2 crystals exhibit no luminescence band related to defects or impurities around 560nm. This fact indicates that the crystals prepared by the “Liquinert” process contain lower defects and/or impurities. When the Eu-doped SrI2 crystals are excited with the 325nm light of a He–Cd laser, only the luminescence band due to the 5d→4f transition in the Eu2+ ions is observed around 425nm. The 425nm band observed at a forward configuration exhibits the shift to the longer wavelength side and the decrease of the luminescence intensity with increasing Eu concentration. The Eu concentration dependences of the peak wavelength and luminescence intensity are simulated on the basis of a simple self-absorption model.

Successful Treatment of Segmental Vitiligo in Children with the Combination of 1-mm Minigrafts and Phototherapy

Background: Minigrafts using a 1-mm biopsy punch (1-mm minigrafts) are being increasingly used to treat vitiligo. However, there have been few reports of the use of 1-mm minigrafts in pediatric patients. Objective: To examine the effectiveness of combination therapy with 1-mm minigrafts and phototherapy in children with segmental vitiligo. Methods: Minigrafts were placed in 13 patients aged ≤16 years with segmental vitiligo. Following surgery, 11 patients underwent irradiation with excimer laser light and 2 with narrow-band ultraviolet B light. Results: A mean repigmentation of 81.6% was obtained. A particularly high mean repigmentation of 87.9% was seen in patients aged ≤12 years, indicating greater efficacy in these patients than in patients aged ≥13 years (mean, 67.5%). Although a transient cobblestone appearance occurred as an adverse effect, it improved over time. Conclusions: Combined treatment of segmental vitiligo with 1-mm minigrafts and phototherapy can be performed safely and is highly effective in young patients.

The efficacy of 308-nm excimer laser/light (EL) and topical agent combination therapy versus EL monotherapy for vitiligo: A systematic review and meta-analysis of randomized controlled trials (RCTs)

Combination therapies of excimer laser/light (EL) and various topical agents are widely used in the treatment of vitiligo. We sought to compare the efficacy of EL and topical agent combination therapy versus EL monotherapy for vitiligo. Manual searches of reference lists and computerized searches of the MEDLINE, EMBASE, and Cochrane library (from inception through December 15, 2014) were conducted to identify randomized controlled trials that assessed the efficacy of EL alone or in combination with topical agents for vitiligo. The primary outcome was treatment success (≥75% repigmentation), and the secondary outcome was treatment failure (<25% repigmentation); meta-analyses were performed when possible. We analyzed 8 randomized controlled trials comprising a total of 425 patches/patients. The combination of EL and topical calcineurin inhibitors (4 studies: relative risk 1.93, 95% confidence interval 1.28-2.91; number needed to treat 4.5, 95% confidence interval 2.9-10) was superior to EL monotherapy for vitiligo. There was insufficient evidence to support beneficial effects of topical vitamin-D3 analogs (3 studies) and corticosteroids (1 study). These findings are based on small numbers of randomized controlled trials and heterogeneities among included studies are another limitation. Topical calcineurin inhibitors in conjunction with EL are more effective compared with EL monotherapy.

“Artificial” chirality induced in doped polymer by irradiation with circularly polarized excimer laser light

Creation of artificial optical response, which is determined by the materials geometry rather than chemical composition, is one of the main challenges of modern physics. In this paper application of large-area chiral excimer laser patterning for the creation of artificial chirality is described. Polymethylmethacrylate was doped with chromophore (Fast Red ITR) and this film was irradiated with circularly polarized KrF excimer laser beam. Surface morphology of pristine and treated samples was studied by confocal and AFM microscopy, absorption was studied by FTIR and VCD spectroscopies. It was initially proposed, that surface structure induced by rotationally polarized laser beam will have chiral nature and response. Actual experiments indicate that circularly polarized light induces the formation of many microscopic spirals or more complex structures on the polymer surface. Shape and density of the surface structures were determined by experimental conditions and in all cases the initially non-chiral doped PMMA becomes equivalent to the classical, optically active media. In particular, created structures gave rise to a photoinduced circular dichroism response, with the response being determined by experimental conditions. The resulting chiral structures show long-time stability and offer interesting possibility to manipulate the light polarization.

Aluminum doping of 4H-SiC by irradiation of excimer laser in aluminum chloride solution

We have found that aluminum doping into 4H-SiC is performed by irradiating excimer laser light to 4H-SiC immersed in aluminum chloride solution. Aluminum is introduced in SiC at the concentration of over 1 × 1020 cm−3 near the surface while, chlorine hardly diffuses into 4H-SiC. After the laser irradiation in aluminum chloride solution, the resistance of the laser-irradiated region decreases with increasing laser fluence. Hall effect measurement shows that the laser irradiation produces a p-type layer and that its sheet carrier concentration is 2.14 × 1011 cm−2. In addition, we produce a pn junction by doping the surface of n-type 4H-SiC and by aluminum doping. The pn junction shows rectifying characteristics whose on/off ratio is about 7 decades and ideality factor is 1.15. This technique is one of the strong candidate local doping techniques for SiC.

Phosphorus Doping into 4H-SiC by Irradiation of Excimer Laser in Phosphoric Solution

We developed a method to dope phosphorus into 4H-SiC by irradiating excimer laser light to 4H-SiC immersed in phosphoric acid solution. A KrF excimer laser was used. The surface is slightly ablated by the laser irradiation. However, no amorphous layer is generated near the surface. Phosphorous is introduced at a concentration of over 1020 cm-3 near the crystal surface. The laser irradiation in phosphoric acid solution significantly improves the ohmic contact characteristic between metal and 4H-SiC. Hall effect measurement shows that the irradiation produces an n-type layer at the surface whose sheet carrier concentration is 2.25×1012 cm-2. In addition, we produce a pn junction by irradiating p-type 4H-SiC. The pn junction shows a rectifying characteristic whose on/off ratio is over 8 decades and ideality factor is 1.06.

Preparation and characterization of fully separated gold nanowire arrays

We reported on the development of an unconventional approach for the physical synthesis of laterally ordered self-organized arrays of well-separated metallic nanowires supported on nanostructured dielectric templates. The method, combining nanoscale patterning of the polyethylene terephthalate substrate by polarized light of excimer laser with glancing angle deposition of the gold, provides an interesting alternative to lithography-based nanopatterning approaches. Separation of individual nanowires is manifested by anisotropy of their electrical properties. Focused ion beam equipped scanning electron microscopy analysis revealed that the resulting nanowires were organized in parallel arrays of approximately 2500 wires with an average length of about 1000μm and uniform width of about 150nm.

Effect of topical anesthetic agents and ethanol on corneoepithelial wound healing in an ex vivo whole-globe porcine model

To assess the impact of topical anesthetic agents and ethanol on ocular surface wound healing using an ex vivo whole-globe porcine model. Department of Ophthalmology, Inselspital, University of Bern, Bern, Switzerland. Experimental study. Standardized corneoepithelial lesions (5.0 mm diameter, 40 μm depth) were created with excimer laser light in freshly enucleated porcine eyes. The globes (6 per group) were exposed to different concentrations of ethanol (2.0% to 99.0%), cocaine (2.0% to 10.0%), procaine hydrochloride (0.4%), tetracaine (0.5% to 1.0%), or lidocaine (2.0%), 3 drops/hour for 3 hours. Control solutions were physiologic saline, balanced salt solution, and tissue-culture medium. After 20 to 26 hours, wound-healing response was compared by measuring the diameter of each corneoepithelial lesion. The mean diameter of corneoepithelial lesions exposed to physiologic saline decreased from 4.78 mm ± 0.19 (SD) to 4.44 ± 0.17 mm between 20 and 26 hours. After 24 hours, the mean lesion size, compared with physiological saline, was larger after cocaine 5.0% (5.20 ± 0.26 mm) and 10.0% (5.39 ± 0.12 mm), tetracaine 0.5% (5.59 ± 0.35 mm) and 1.0% (5.55 ± 0.27 mm), and procaine hydrochloride 0.4% (5.76 ± 0.12 mm), but not after lidocaine 2.0% (5.01 ± 0.17 mm). Balanced salt solution, tissue-culture medium, ethanol 2.0% to 99.0%, and cocaine 2.0% did not inhibit the wound-healing response. In an ex vivo whole-globe porcine model, lidocaine 2.0% and cocaine 2.0% were the least toxic anesthetic agents. At all concentrations, ethanol had no impact on wound healing. No author has a financial or proprietary interest in any material or method mentioned.

Characterization with the Simulation of Transmission Spectra in Long-Period Fiber Grating Fabricated by the Point Exposure Method

Long-Period Fiber Gratings (LPFGs) which have a periodic structure in the refractive index in the longitudinal direction of the fiber with a period of about 0.5 mm, convert incident light in the fundamental LP01 mode into higher-order LP0m modes through mode coupling. Because the higher-order modes cannot propagate in a single-mode fiber but are lost outside the fiber, an LPFG works as an attenuator. LPFGs with different Bragg wavelengths were fabricated by using the point exposure method in which the period was freely changed. Just after excimer laser light exposure, transmission spectra of LPFGs were measured. Furthermore, compared to the simulation, the higher-order modes of peaks in the transmission spectra of experimentally fabricated LPFGs were identified.

1701 ArFエキシマレーザー光源用フッ化カルシウム単結晶チャンバウィンドウの使用環境下における複屈折解析(OS17. 電子デバイス・電子材料と計算力学(1),オーガナイズドセッション講演)

1701 ArFエキシマレーザー光源用フッ化カルシウム単結晶チャンバウィンドウの使用環境下における複屈折解析(OS17. 電子デバイス・電子材料と計算力学(1),オーガナイズドセッション講演)

Vitiligo therapy

Vitiligo can be treated using various new and experimental therapies, such as narrow-band ultraviolet B microphototherapy (NB-UVB), narrow-band ultraviolet B excimer laser and monochromatic excimer light. The first is recommended for generalized vitiligo, whereas the latter two are indicated in patients affected by segmental and bilateral symmetrical vitiligo with < 20% cutaneous involvement. Medical treatments include topical corticosteroids and other topical treatments, such as antioxidants, tacrolimus and pimecrolimus, prostaglandin E, and vitamin D derivatives. Excellent therapeutic results can be achieved through combination treatments; surgical intervention is reserved for adolescent or adult patients with stable vitiligo.

Effects of Excimer Laser Annealing on InGaZnO4 Thin-Film Transistors Having Different Active-Layer Thicknesses Compared with Those on Polycrystalline Silicon

Excimer laser annealing (ELA), which can raise the temperature of InGaZnO4 (IGZO) films for a desired very short time, is effective for obtaining good transfer characteristics in IGZO thin-film transistors (TFTs) on plastic substrates. In this study, we investigate the dependence of the effects of ELA on IGZO-TFTs in comparison with that of its effects on low-temperature polycrystalline silicon (LTPS) for various film thicknesses. We show that the optimum laser energy density with respect to TFT performance decreases with increasing IGZO thickness. Results for IGZO film properties such as carrier density and Hall mobility show the same tendency. This is contrary to the tendency for the ELA of LTPS, in which the threshold energy density for micro crystallization increases with increasing film thickness. In order to gain an insight into the mechanisms at work here, we have numerically estimated the rise in temperature of the IGZO and Si films on the basis of a heat-flow equation. Unlike the case for LTPS, the calculated maximum temperature in IGZO films increases with increasing film thickness. We show that this discrepancy is influenced significantly by the difference in penetration depth between the IGZO film (roughly 70 nm) and Si film (roughly 6 nm) for excimer laser light. To improve the IGZO-TFT characteristics, it is necessary to take into account IGZO penetration depth when determining a suitable IGZO thickness and laser energy density.

Recent advances in the treatment of childhood vitiligo

Vitiligo can be treated using traditional, new and experimental therapies, and newly available treatments can be divided into medical, physical and surgical types. Medical treatments include topical corticosteroids and other topical treatments, such as antioxidants, tacrolimus and pimecrolimus, prostaglandin E and vitamin D derivates. Physical therapies include narrow-band UVB light (NB-UVB), NB-UVB microphototherapy, NB-UVB excimer laser and monochromatic excimer light. All can be safely used in children. NB-UVB is recommended for generalized vitiligo, while the others are indicated in patients affected by segmental and bilateral symmetrical vitiligo with a cutaneous involvement of less than 20%. They enable drastic reduction of the total dose of radiation, even though they preserve a potential long-term carcinogenic risk that has to be considered in this type of patient. Surgical therapies are reserved for adolescent or adult patients with a stable vitiligo.

Effects of laser repetition rate on corneal tissue ablation for 193‐nm excimer laser light

The goal of the present work is to assess whether bovine corneal ablations generated at laser repetition rates of up to 400 Hz are comparable to ablations performed at rates consistent with current clinical laser systems. A combination of experiments was used to assess a comprehensive range of ablation parameters, including ablation plume dynamics via imaging and transmission, corneal ablation profiles via scanning interferometry, and high-resolution electron microscopy of collagen structure following ablation. Using white-light interferometry analysis, no statistical difference was found between corneal ablation profiles created at 60 and 400 Hz, with an average rate of 0.94 microm/pulse at 60 Hz versus 0.92 microm/pulse at 400 Hz. In addition, based on plume imaging and transmission studies, the bulk ablation plume was found to dissipate on a time-scale less than the pulse-to-pulse separation for a laser repetition rate up to about 400 Hz. A persistent, diffuse gas-phase component of the ablation products was observed and concluded to be comparable at both repetition rates. Finally, SEM and TEM analysis revealed no signs of differential thermal tissue damage, including collagen fibril analysis, for laser repetition rates up to 400 Hz. In summary, investigation of the relative effects of excimer laser repetition rate on the overall corneal ablation metrics revealed no measurable difference under conditions typical of clinical refractive procedures. This study suggests that increases in ArF laser repetition rates for clinical applications (up to approximately 400 Hz) appear feasible.

Excimer laser in acute myocardial infarction: Single centre experience on 66 patients

Background Pulsed-wave ultraviolet excimer laser light at 308 nm can vaporise thrombus, suppress platelet aggregation, and, unlike other thrombectomy devices, ablates the underlying plaque. Aim To evaluate both safety and efficacy of laser ablation in patients presenting with Acute Myocardial Infarction (AMI) complicated by persistent thrombotic occlusion. Methods From May 2003 to October 2006, we enrolled 66 AMI patients (age 59 ± 11 years; 57 men) presenting complete thrombotic occlusion of the infarct related vessel. All patients were treated with laser. Primary acute angiographic end-points was corrected TIMI frame count. Secondary echocardiographic end-point was left ventricular remodeling defined as an increase in end-diastolic volume ≥ 20% 6 months after infarction. Tertiary clinical endpoint was event-free survival at 6 months follow-up. Results There were no intra-procedural death or coronary perforation. One primary angiographic failure was observed during lasing. Major dissection occurred in 1 (1.5%) and distal embolization in 4 patients (6%). Corrected TIMI frame count was 100 at baseline, 29 ± 0.6 after lasing and 22 ± 3 after stenting. At 6-months follow-up, left ventricular remodeling occurred in 8% patients. Event-free survival was 95% at 6-months follow-up. Conclusion Laser angioplasty is feasible, safe and effective for the challenging treatment of patients with AMI and thrombus-laden lesions. The acute effects on coronary epicardial and myocardial reperfusion are excellent.