Q-switched Neodymium Research Articles

Tarnish tattoos - localised cutaneous argyria from sterling silver in fresh piercings: a case series.

Tarnish tattoo is a form of localised cutaneous argyria resulting from the deposition of silver into the skin following exposure to silver jewellery in fresh piercings. This report presents the clinical presentation, diagnosis, and management of 4 female patients with tarnish tattoos on the nose and ear from wearing silver jewellery. All four patients wore silver studs or rings immediately following the piercing. Two of the four patients underwent treatment with nanosecond Q-switched 1064nm Neodymium: Yttrium Garnet laser (QS Nd: YAG) and Q-switched Alexandrite 755nm lasers with minimal improvement. Tarnish tattoos are an under-recognized side-effect of wearing silver jewellery in fresh piercings. The grey-blue discolouration from tarnish tattoos can be challenging to treat with nanosecond QS lasers.

The combination of Q-switched neodymium:yttrium–aluminum–garnet (Nd:YAG) laser with photoacoustic pulse technology in combination with polynucleotides (PN) salmon DNA for skin rejuvenation: A case series

Background: Skin aging leads to dyspigmentation, wrinkles, and lentigines. Photorejuvenation, especially Q-switched Nd:YAG laser therapy, is commonly used to address these concerns. We present a case series evaluating the effectiveness of combining Q-switched Nd:YAG laser with Polynucleotides (PN) Salmon DNA for facial photorejuvenation. Case series: Five healthy adults underwent four sessions of full-face laser toning with a QS 1064 nm Nd:YAG laser followed by Polynucleotide (PN) Salmon DNA 2% injections every two weeks. We recorded subjective assessments and pain levels during treatment and captured photographic images for analysis. The treatment significantly improved skin brightness and pigmentation, with some subjects achieving mild or no pigmentation. Skin elasticity improvements varied among subjects. Some experienced significant enhancement, while others showed minor changes or none at all. Skin redness responses varied. Objective measurements revealed pore size, skin elasticity, moisture, skin tone, wrinkles, and skin age improvements. Conclusion: Combining Q-switched Nd:YAG laser with PN Salmon DNA shows promise for enhancing skin health and appearance.

The Role of Air in Laser-Induced Thermal Emission of Surface Layers of Porous Carbon Materials

The influence of the surrounding air on the amplitude and shape of thermal radiation pulses (at a wavelength of 430 nm) during the heating of the surface layer of a porous carbon material (to temperatures of the order of 2000–3000 K) by the radiation of a Q-switched neodymium laser is studied. When the pressure of the surrounding air is reduced to forevacuum conditions, the experiments showed a one-and-a-half-fold increase in the amplitude of pulsed signals of thermal radiation and an increase in the decay time of the glow by about a third. Numerical calculations of the dynamics of the temperature field in the surface layer of the material during the irradiation by nanosecond laser pulses are carried out. An improved model is used in the calculations, which accounts for (i) the porosity of the material and (ii) the temperature dependence of the coefficients of thermal conductivity and the heat capacities of carbon and air. To calculate the thermal conductivity of the porous material, a model of a cubic array of intersecting square rods is used. The satisfactory consistency of calculation results with experimental data is obtained. The above-mentioned improvements of the calculation model made it possible to reconcile the estimates of the thermal characteristics of surface layers of carbon, obtained from the emission decay data, with the reference data published in the literature.

Comparison of a single treatment with a Q-switched ruby laser and a Q-switched Nd:YAG neodymium laser for blue and black tattoo removal

BACKGROUND: Black and blue tattoo pigment are the most commonly used colors and can be injected at different depths. The effectiveness of tattoo removal is related to the selected wavelength, type of laser, energy parameters, number of procedures performed. Q-switched (QS) ruby and neodymium (Nd:YAG) lasers are most effective in removing blue and black tattoos due to their high peak power and ability to break the pigment into small particles that are absorbed by the macrophage system. In the literature available to us, it was not possible to find data on comparative efficacy and adverse events in their application.
 AIM: comparison of single treatment of blue and black tattoos with QS ruby laser (wavelength 694 nm) and neodymium Nd:YAG laser (wavelength 1064 nm).
 MATERIALS AND METHODS: 35 patients with blue and black tattoos were included in our study. The tattoos were divided into two parts or two adjacent tattoos were used on the same part of the body with the same density and color of the tattoo pigment; one side was treated with a ruby laser and the other with a neodymium laser. The comparison took into account the instantaneous reaction, the result of processing and side effects. Statistical significance was set at a power level 0.05.
 RESULTS: Edema and erythema were more common immediately after ruby laser treatment (power 0.05). The neodymium QS laser lightened tattoos better than the ruby QS laser after a single treatment (0.05 power). There was no difference in side effects between the two types of lasers.
 CONCLUSIONS: Neodymium Nd:YAG QS laser shows more efficiency and fewer procedures when removing blue and black tattoos. The instantaneous reaction after treatment with this type of laser is less pronounced than after the ruby laser.

28185 Treatment of hyperpigmented labial lentigines using Q-switched Nd:YAG laser in a preadolescent patient with Peutz-Jeughers syndrome

Peutz-Jeghers syndrome (PJS) is a rare genodermatosis characterized by labial lentigines that can be stigmatizing and lead to significant and potentially lifelong consequences on patients’ quality of life. Over time, these lentigines darken and increase in number. We report a case of a 6-year-old female with PJS—the youngest pediatric patient in the literature to our knowledge—successfully treated with four Q-switched neodymium:yttrium aluminum garnet (QS Nd:YAG) 532nm with only use of topical anesthesia, LMX 4%, without any complications. With each treatment, lightening and decreased number of labial lentigines was noted with over 80% clearance after four treatment sessions. QS Nd:YAG laser treatment is safe and effective for treating preadolescent pediatric patients with labial lentigines with PJS in a clinic setting without sedation. In our patient, there has not been recurrence of lesions over a 1-year follow-up period thus far. Use of laser treatment early in a patient’s course may lead to fewer laser treatments, potential decreased recurrence of lentigines, and positive lifelong impacts on quality of life.

Influence of laser wavelength on the optical and structural properties of MoS2 nanoparticles prepared via laser irradiation in ethylene glycol

MoS2 nanoparticles (NPs) were prepared by nanosecond (ns) laser ablation in ethylene glycol using a Q-switched neodymium:ytterbium aluminum garnet laser at 1064 and 532 nm laser wavelengths. The influence of laser wavelengths in ns laser production of MoS2 NPs is not yet fully understood. The shape, structure, crystalline phase, stability, and optical and photoluminescence (PL) properties of NPs were studied using TEM, dynamic light scattering, scanning electron microscopy with energy-dispersive x-ray, x-ray diffraction (XRD), ultraviolet–visible (UV–Vis), PL, Fourier transform infrared, and Raman spectroscopy. The UV–Vis absorption spectroscopy showed that the optimum laser wavelength for preparing MoS2 NPs is 1064 nm. Also, the absorption peak intensity of MoS2 NPs prepared at 1064 nm was 3.95 times higher than that at a 532 nm wavelength. In the case of ablation with 1064 nm, the most of NPs had spherical shapes and well dispersed compared with 532 nm. While the samples had the same crystalline structure for both wavelengths, as the laser wavelength increased, the mean particle size decreased from 22 to 13 nm. This is because of a photofragmentation phenomenon.

Identification of the fate and regenerative mechanism of zebrafish melanocyte progenitor cells and melanocytes after laser-induced pigment ablation.

Lasers are known to be the most effective treatment modality for pigmentary skin diseases. However, melanocytes and melanin pigment often recur or leave post-inflammatory hyperpigmentation after the laser procedure. Studies have reported on the role of progenitor cells in pigment cell regeneration, which can be constantly replenished through mitosis. However, the response of unpigmented melanocyte progenitor cells to laser treatment is poorly understood. In this study, we used adult zebrafish skin as the melanocyte regenerative system and examined the response of melanocyte progenitor cells to laser photothermolysis. The two groups of adult zebrafish were irradiated with 1064 nm wavelength laser system of Q-switched neodymium:yttrium-aluminum-garnet (Nd:YAG) laser with 0.3 or 0.7 J·cm-2 . We compared the regeneration of pigment at different energy levels by measuring new melanocyte counts and pigment area. We traced and quantitatively compared the melanocyte lineage cells by immunohistochemical staining using specific markers such as sox10, mitfa, and dct during the regeneration process. Three repetitive laser ablations were also held to test the postinflammatory hyperpigmentation. After the laser ablation of melanocytes, most of the new melanocytes appeared between Days 5 and 10. In high-energy irradiation of 0.7 J·cm-2 , the unpigmented mitfa-expressing cells showed significant decrease (p < 0.05) and showed delay in the differentiation process of melanocyte lineage cells. After repeated laser irradiation, hyperpigmentation did not appear and the final recovery ratio of the pigmented area was 87.5% and 75.3% at the 0.3 and 0.7 J·cm-2 energy levels, respectively. We suggest that laser treatment overcoming the recurrence should be planned based on the adequate energy level targeting the melanocyte progenitor cells. High-energy irradiation may induce apoptosis of progenitor cells and delay their process of differentiation. Short-term repetitive sessions of laser therapy can reduce the pigmentation in the long-term observation.

Efficacy and safety of Q-switched Nd:YAG laser in the treatment of facial pigmentary lesions: A retrospective observational study

Background: The Q-switched neodymium: yttrium aluminum garnet laser (QS-Nd:YAG) is effective in the treatment of tattoos and different pigmentary conditions; however, little has been published regarding the removal of facial cutaneous pigmented lesions. The aim of this study was to determine the effectiveness and safety of QS-Nd:YAG laser in the treatment of facial pigmentary lesions in Indian patients. Methods: Data of 100 patients with pigmented facial lesions treated with QS-Nd:YAG laser were analyzed. Clinical improvement of skin lesions was assessed by the physician’s global assessment of two blinded observers. This was done based on photographs taken at the baseline and after the last treatment session. Side effects were recorded if present, and patient satisfaction was evaluated after each treatment session. Results: The majority of the patients had post-inflammatory hyperpigmentation (n=41), followed by melasma (n=19), photomelanosis (n=15), nevus of Ota (n=5), periorbital melanosis (n=5), nevus spilus (n=3), Riehl melanosis (n=3), Cafe-au-lait macules (n=2), freckles (n=2), lichen planus pigmentosus (n=2), compound nevus (n=1), Hori’s nevus (n=1), and pigmentary demarcation lines (n=1). 10% of patients showed more than 50% improvement in pigmentation from the baseline level; no response was seen in 22% of patients, while 7% experienced worsened pigmentation. Conclusion: The degree of improvement and efficacy in clearing pigmentation is partial, variable, and inconsistent. Worsening of pigmentation may be seen and needs to be discussed with the patient prior to treatment

A comparative study of efficacy of 1064-nm Q-switched Neodymium: YAG laser at sub photothermolytic fluence alone and in combination therapy with epicutaneous 20% azelaic acid and in sequential therapy with microdermabrasion in melasma in South India

Introduction: Melasma is a symmetric hyperpigmentary disorder defined by irregular light to brown macules over the face. Treating melasma is demanding and there is curiosity in anticipation of recent various therapeutic options like sub photothermolytic fluence – 1064-nm Q switched Nd:YAG laser (SPF-1064-nm-QSNdYL) with combinational and sequential therapies. Aim: To study and compare the therapeutic effect of SPF-1064-nm-QSNdYL alone and in combinational therapy with epicutaneous 20% Azelaic Acid and in sequential therapy with microdermabrasion in melasma in three study groups of 20 cases each. Materials and Methods: Sixty female cases identified as melasma were randomly segregated into three factions [group L(laser only) = 20 cases of melasma treated with SPF-1064-nm-QSNdYL at weekly intervals, group C (combinational) = 20 cases of melasma treated with twice daily epicutaneous application of 20% azelaic acid and SPF-1064-nm-QSNdYL at weekly intervals and group S (sequential) = 20 cases of melasma treated with Sequential therapy with microdermabrasion followed by SPF-1064-nm-QSNdYL once weekly as given in group L]. The study duration was of 12 weeks for each. The outcome to therapy was analyzed using melasma area and severity index scoring. Results: Convincing therapeutic response was noted in all the three factions. It was statistically highly significant in Group C as compared to Group L (P 0.05). Conclusions: This study highlights the superior therapeutic effect of combinational therapy using SPF-1064-nm- QSNdYL with azelaic acid in epidermal, dermal and mixed types of melasma with minimal adverse effects followed by sequential therapy of microdermabrasion with SPF-1064-nm- QSNdYL and SPF-1064-nm- QSNdYL alone therapy. Keywords: Azelaic acid, SPF-1064-nm-QSNdYL, Microdermabrasion, Melasma.

A promising approach in laser vitrectomy executed by plasma-mediated removal of vitreous body via a diode-pumped Q-switched Nd:YAG laser

To examine the applicability of plasma-mediated vitreous body removal, a diode-pumped Q-switched Neodymium:YAG laser was used for a possible application in eye surgery/vitrectomy. On a total of 1500 porcine vitreous bodies, removal rates were evaluated by comparing different LaserVit-tip designs (Mark I/II Gauge 19 and Mark III Gauge 22). The Nd:YAG laser, operating at a wavelength of 1064 nm and a pulse duration of 4 ns, was utilized for vitreous body removal with respective settings of 2, 3 and 4 mJ and pulse repetition rates (cut rates) from 5 to 25 Hz (300–1500 /min) in 5 Hz-steps as well as for 100 Hz (6000 cuts/min). The exposure times were selected at 10, 20, 40 and 60 s, respectively. Comparative measurements were carried out with mechanical cutters (Gauge 20 and Gauge 23), applying a fixed cut rate of 800 /min (13.33 Hz) at identical exposure times. The LaserVit-tips showed successful vitreous body removal for all laser settings and exposure times (Mark I: 6.2 g/min, Mark II: 8.2 g/min at 1500 cuts/min and 3 mJ, Mark II: 10.1 g/min, Mark III: 3.6 g/min at 6000 cuts/min at 3 mJ). Similar tip-dimensions (Gauge 22laser and Gauge 23cutter) showed comparable removal rates of 3.6 g/minlaser and 1.3 g/mincutter with settings of 6000 cuts/min at 3 mJ (laser) and 800 cuts/min for the mechanical cutter. A diode-pumped Q-switched Nd:YAG laser can successfully and gently remove vitreous body. The efficiency of the laser was comparable to that of mechanical cutters in terms of quantity of material removed per time unit.

A study on efficacy of high fluence Q-switched neodymium doped yttrium aluminium garnet laser in macular amyloidosis

&lt;p class="abstract"&gt;&lt;strong&gt;Background: &lt;/strong&gt;Macular amyloidosis (MA) typically presents as small, dusky-brown or greyish pigmented macules, treatment of which remains challenging with topical and systemic therapies, however Q-switched neodymium-doped yttrium aluminium garnet (Nd:YAG) laser has proven to be an effective treatment modality to reduce hyperpigmentation. The aim of the study is to study the efficacy of Nd:YAG laser in the management of MA.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods: &lt;/strong&gt;30 female patients were treated with Q-switched Nd:YAG laser at 1064 nm with a spot size of 3 mm at a fluence of 6-7 J/cm&lt;sup&gt;2&lt;/sup&gt;, frequency of 2 Hz, for 350-500 pulses. Total number of pulses decreased with each treatment session as the intensity of the hyperpigmentation decreased. The procedure was repeated at one-month intervals for a total of 6 treatment sessions.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results: &lt;/strong&gt;After completion of treatment sessions with Nd-YAG laser 36.66% patients showed &amp;gt;50% improvement in the pigmentation. 66.6% patients were satisfied with the laser treatment. 33.3% patients showed &amp;lt;25% improvement and unsatisfied with the treatment.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;MA remains an enigma and a source of concern for the suffering patients and physicians. Q-switched Nd-YAG laser 1064 nm has shown positive response in the reduction of pigmentation in MA.&lt;/p&gt;

Dermoscopy as a useful tool for evaluating melasma and assessing the response to 1064-nm Q-switched Nd:YAG laser.

Melasma is a hard-to-manage disorder with considerable relapsing behavior. Dermoscopy emerged to help in comprehensive evaluation of pigmentary disorders and melasma. The aim of the study was to evaluate the potential role of dermoscopy in assessing melasma and monitoring the efficacy of 1064-nm low-fluence Q-switched neodymium:yttrium-aluminum-garnet (QS Nd:YAG) laser. A total of 31 patients with facial melasma were included. A total of five laser sessions were performed with 2-week intervals. Patients were evaluated at baseline and 2 weeks after the last session (at the 10th week) by using digital photography, modified melasma area and severity index (mMASI), and colorimetry, as well as dermoscopic score for pigment and vascular elements. Adverse effects were reported. Postlaser sessions, mMASI scores as well as the colorimetric melanin and erythema indices had showed significant improvement. The "dermoscopic score of pigmentary and vascular elements" displayed significant change and confirmed the improvement. Side effects were tolerable. mMASI, colorimetry, and dermoscopy had ascertained the efficacy of low-fluence 1064-nm QS Nd:YAG laser in melasma; however, dermoscopy is superior to other assessments as it can help in the diagnosis of melasma besides the follow-up assessment and can precisely detect the detailed changes in response to treatment.

A Split-Face, Single-Blinded, Randomized Controlled Comparison of 532 nm Picosecond Neodymium-Doped Yttrium Aluminum Garnet Laser versus 532 nm Q-Switched Neodymium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Solar Lentigines.

BackgroundSolar lentigines are the most common form of benign epidermal pigmentation and one of the major cosmetic concerns in Korea. A 532 nm Q-switched neodymium: yttrium-aluminum-garnet (QSND) laser is typically used for the treatment, but the occurrence of post-inflammatory hyperpigmentation (PIH) is not rare. Recently, the use of picosecond (PS) lasers has emerged in pursuit of better outcomes.ObjectiveTo objectively compare the efficacy and safety of 532 nm PS and QSND lasers for the treatment of solar lentigines.MethodsTwenty patients with solar lentigines were enrolled in a prospective, randomized split-face, single-blind study. One side of each face was treated using a 532 nm PS laser, and the other side using a 532 nm QSND laser. After one treatment, all patients were followed up for evaluation after 2, 4, 8, and 12 weeks. The clinical clearance was assessed by three blinded dermatologists using a 5-point quartile improvement scale (QIS). Subjective satisfaction, development of PIH, pain scale during treatment, and adverse problems were also recorded.ResultsClinical clearance measured by QIS showed that the PS laser was more effective than the QSND laser. Subjective satisfaction and pain scale did not significantly differ between the two groups. The incidence of PIH was 5% in sides treated with the PS laser, and 30% with the QSND laser.ConclusionBoth 532 nm PS laser and QSND laser were effective for the treatment of solar lentigines, but the PS laser was more effective with less PIH development.

Decay Kinetics of Thermal Radiation Emitted by Surface Layers of Carbon Materials under Pulsed Laser Excitation

The decay of thermal radiation emitted by surface layers of carbon materials excited by pulses of a Q-switched neodymium laser is investigated experimentally and theoretically. It is discovered that the decay curves can be approximated with satisfactory accuracy by a sum of two exponential components with decay times of about 10 and 100 ns. Changes in the decay curves under sample irradiation by a sequence of laser pulses can be interpreted as being the result of redistribution of intensities of these two components. Based on the results of computer simulation, the conclusion is drawn that the glow-decay time is determined by the ratio of the penetration depth of the laser radiation and the thermal-diffusion length, which creates an opportunity to determine the coefficient of temperature conductivity in a thin surface layer of the studied material at high temperatures (thousands of Kelvins).

Clinical characteristics and treatment of 52 cases of phakomatosis pigmentovascularis.

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

Кинетика затухания теплового излучения поверхностных слоев углеродных материалов при импульсном лазерном возбуждении

For surface layers of carbon materials, under excitation by a Q-switched neodymium laser, the decay of laser-induced thermal emission is investigated both experimentally and theoretically. It is revealed that the decay curves can be fit with satisfactory accuracy by a sum of two exponential components with the decay times of the order of 10 and 100 ns. Under irradiation by a sequence of laser pulses, the observed transformations of the emission decay curves can be presented as redistribution of intensity of the above-mentioned two components. As a result of computer simulations, it is concluded that the emission decay time is determined by the ratio of the penetration depth of laser radiation and the thermal diffusion length. This fact opens a possibility for estimation of thermal diffusivity of an investigated material in a thin surface layer at high temperatures (thousands of Kelvins).

Beneficial Effect of Low Fluence 1,064 nm Q-Switched Neodymium:Yttrium-Aluminum-Garnet Laser in the Treatment of Senile Lentigo.

BackgroundLow fluence 1,064 nm Q-switched (QS) Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser treatment, also known as laser toning, is widely used for pigmentary disorders. There has been no reliable evaluation of the effect of low fluence 1,064 nm QS Nd:YAG laser for senile lentigo.ObjectiveTo investigate the beneficial effect of low fluence 1,064 nm QS Nd:YAG laser in the treatment of senile lentigo on the face.MethodsA retrospective review was conducted on patients treated only with repetitive low fluence 1,064 nm QS Nd:YAG laser. Among them, 12 patients with multiple senile lentigines before treatment were included. All side effects were recorded to assess the safety of the modality.ResultsMean age was 56.1±7.8 years old and male-to-female ratio was 1:11. Mean treatment fluence was 1.62±0.16 J/cm2 and mean total treatment session was 8.8±2.6. Mean interval period between each session was 28.0±11.4 days and mean treatment session to reach marked and near total improvement was 8.7±2.8. At the final visit, seven of 12 (58.3%) patients reached marked and near total improvement, and three of 12 (25.0%) reached moderate improvement. No side effects occurred.ConclusionRepetitive low fluence 1,064 nm QS Nd:YAG laser treatment may be an effective and safe optional modality for senile lentigo.

Induction of melasma by 1064-nm Q-switched neodymium:yttrium-aluminum-garnet laser therapy for acquired bilateral nevus of Ota-like macules (Hori nevus): A study on related factors in the Chinese population.

Laser treatment has emerged as a common treatment modality for acquired bilateral nevus of Ota-like macules (ABNOM). To identify the ratio of melasma induction and exacerbation before and after laser therapy for ABNOM and to observe the risk factors related to the induction and exacerbation of melasma by laser therapy, we analyzed related factors of 1268 adult Chinese patients who underwent 1064-nm Q-switched neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (QNYL) treatment using case series and case-control studies. Overall, 24.0% of the ABNOM patients had mixed melasma. Among the ABNOM patients without melasma, after laser therapy the development of melasma was more frequently noted in patients older than 35 years (P < 0.0001), as well in patients whose ABNOM was less than 10 cm(2) (P = 0.027), ABNOM were light (similar to yellow-brown) in color (P = 0.021) and skin types were closer to type IV (P < 0.0001). New melasma lesions also appeared most frequently in the zygomatic region (P < 0.0001). Among the ABNOM patients with melasma, 89.5% experienced worsening of their melasma, irrespective of their related factors above. We concluded that the risk of inducing melasma is great after 1064-nm QNYL treatment in ABNOM patients, and particularly in the patients with both ABNOM and melasma. ABNOM patients should be treated as early as possible and before the age of 35 years.

The Effect of 3 Sessions of Q Switched Neodymium: Yttrium?Aluminum?Garnet Laser in the Treatment of Freckles

Background: Freckles are common superficial pigmented lesions which can become cosmetic problems. Advances in laser technology have resulted in the ability to treat pigmented lesions with greater safety and efficacy. Objective: The study aimed to evaluate the effectiveness of 1,064 nm Q-switched neodymium: yttrium–aluminum– garnet (Nd- YAG) laser in the treatment of freckles. Methods: Fifty patients with freckles referring to the laser centers of Al-Azhar University hospital (Asyut) were enrolled in this open-label, monocentric study. All participants received 3 sessions of 1,064-nm Q switched Nd:YAG laser at 4-weeks intervals. The pigmentation area and severity index (PSI score) was calculated based on 3 parameters: Area, darkness, and density of the pigmented lesions. Results: Fifty patients (4 males and 46 females) completed the study protocol. The age of the patients ranged from 6-43 years, the duration of freckles showed a wide range, (1 month-20 years) with a mean duration of 5.13 ± 4.72 years. There was a statistical significant improvement in mean PSI after treatment of freckles with 1064 Q-Switched Nd-YAG. Excellent improvement (≥75%) were occurred in 17 cases (34%), very good improvement (50-74%) in 14cases (28%), good improvement (≥25-49%) in 16 cases (32%) and poor improvement (<25% lightening) in 3 cases (6%). The correlation between improvement and clinical parameters showed positive significant correlation with duration of disease and number of sessions. The reported side effects among this study were post-inflammatory hyperpigmentation in 2 cases (4%), hypopigmentation in 3 cases (6%) and erythema in 6 cases (12%). Conclusions: 1064 Q-switched Nd- YAG laser is effective modality in the treatment of freckles especially in patients with long duration.

Efficacy of the Q-switched Neodymium: Yttrium Aluminum Garnet Laser in the Treatment of Blue-black Amateur and Professional Tattoos.

Background:Q-switched neodymium: yttrium aluminum garnet (Nd: YAG) laser at a wavelength of 1064 nm primarily targets dermal melanin and black tattoo ink. Recent studies have shown that this laser is effective in treating black tattoos. There are few studies conducted in India for the same.Aim:The aim was to assess the effectiveness of Q-switched Nd: YAG laser (QSNYL) in the treatment of blue-black tattoos following 3 treatment sessions.Materials and Methods:This study, a prospective interventional study included a total of 12 blue-black tattoos. Following informed consent for the procedure, as well as for photographs, a questionnaire was administered, and improvement perceived by the patient was recorded. In addition, global assessment score (GAS) by a blinded physician was also recorded. Photographs were taken at baseline and at every follow-up. Each patient underwent three treatment sessions with 1064 nm QSNYL at 4–6 weekly intervals. Fluences ranged from 1.8 to 9 J/cm2. The follow-up was done monthly for 4 months from the first treatment session. The response was assessed by patient assessment (PA) and GAS by comparing photographs.Results:After three treatment sessions, although no patient achieved clearance, most patients showed good response with few adverse effects. An average of 64.1% (GAS) and 54.2% (PA) improvement was observed in 12 tattoos. Tattoos more than 10-year-old showed quicker clearing than those less than 10-year-old. Amateur tattoos also showed a better response in comparison to professional tattoos.Conclusion:Totally, 1064 nm QSNYL is safe and effective for lightening blue-black tattoos in pigmented Indian skin. All patients achieved near complete clearance following the continuation of treatment (an average of six sessions) although this was spaced at longer intervals.