Laser tattoo removal strategies: Part II: A review of the methods, techniques, and complications involved in tattoo removal.

The rising global popularity of cosmetic and corrective tattoos has concurrently led to an increased demand for their removal. While in the past, methods like surgical excision, chemical destruction, and dermabrasion were employed, lasers have emerged as a reliable and effective tool for tattoo removal. Increasing technological options and combination treatment strategies have raised the importance of understanding the various approaches to laser tattoo removal along with their respective clinical impact. This CME aims to describe the multifaceted aspects of laser tattoo removal, including the method selection, application principles, and safety considerations. Furthermore, it addresses the factors considered when selecting the most suitable laser to achieve optimal treatment outcomes.

Evaluation of a new Q-switched Nd:YAG laser on premacular hemorrhage.

BACKGROUND: Premacular hemorrhage is among the causes of sudden deterioration of visual acuity. This study aimed to investigate the therapeutic outcomes of a new Q-switched Nd:YAG laser on premacular hemorrhage. METHODS: Retrospective, case series study of 16 eyes from 16 patients diagnosed with premacular hemorrhage, including 3 cases of Valsalva retinopathy, 8 cases of retinal macroaneurysm, 3 cases of diabetic retinopathy, 1 case of trauma-related hemorrhage and 1 case with leukemia. A 1064nm Q-switched Nd:YAG laser was performed to puncture the posterior hyaloid and inner limiting membrane to drain the hemorrhage. RESULTS: The success rate of 16 patients with premacular hemorrhage drainage was 100% in this study. Improved visual acuity was observed in each patient. CONCLUSIONS: In this case series of 16 patients, the new Q-switched Nd:YAG laser was successful in draining premacular hemorrhage with no serious complications.

Q-Switched 1064-nm Nd: YAG laser versus fractional carbon dioxide laser for post acne scarring: A split-face comparative study.

OBJECTIVES: Many treatment modalities are available for post acne scarring. However, the response to the treatment is extremely variable among patients. AIM: The aim of this study was to compare the efficacy and safety of Q-switched Nd: YAG (1064 nm) and fractional CO2 (10,600 nm) lasers in the treatment of atrophic post acne scars. METHODS: This study included 20 patients with atrophic facial post acne scars graded according to Sharquie's score. All subjects received four sessions of laser treatment with a 4-week interval between the sessions. The study was designed as a double-blinded, comparative, split-face study applying Q-switched 1064-nm Nd:YAG laser to the right side of the face and fractional CO2  laser to the left side. RESULTS: Q-switched 1064-nm Nd: YAG laser achieved significantly higher improvement percentage when compared to fractional CO2  lasers (33.33% versus 17.37% Sharquie's score reduction, respectively). There was a significant negative correlation between the percentages of improvement and the patients' age on both sides and a significant positive correlation with the baseline Sharquie scores on both sides. CONCLUSION: Q-Switched 1064-nm Nd: YAG laser could be a promising safe option for the management of atrophic post acne scars.

[Clinical efficacy of 585 nm Q-switched laser treatment on inflammatory lesion and postinflammatory erythema of acne vulgaris].

OBJECTIVE: To evaluate the efficacy and safety of 585 nm Q-switched laser in the treatment of acne inflammatory lesions and postinflammatory erythema. METHODS: A total of 25 patients with moderate facial acne, symmetrical distribution of inflammatory lesions and postinflammatory erythema on both sides of the face, were enrolled. Among the 25 patients, 22 patients completed all the treatment and evaluation, and 3 patients were lost to follow-up. 585 nm Q-switched laser was used on a randomly selected side of the face for three times of treatment at a 2 week interval. The evaluations were made before each treatment, 2 and 4 weeks after the last treatment, therefore the evaluation time points were before the treatment, weeks 2, 4, 6, and 8, respectively, for a total of 5 times. Acne severity was assessed using the investigator' s global assessment (IGA) score, and erythema severity was assessed using the investigator' s subjective erythema score and narrow-spectrum reflectance spectrophotometer at each follow-up. RESULTS: After 3 times of treatment, there was statistically significant difference between the IGA score in week 8 and before treatment on both sides(Z=2.64, P < 0.01; Z=2.67, P < 0.01). There was no significant difference in IGA score between the treatment side and the control side before treatment and in week 8 (P=0.59, P=0.26). There was statistically significant difference between the investiga-tor' s subjective erythema score in week 8 and before treatment on the treatment side(Z=4.24, P < 0.01), while no significant difference was showed on the control side(Z=1.73, P=0.08). In week 8, the investigator's subjective erythema score of the treatment side was lower than that of the control side (Z=3.61, P < 0.01). The erythema index of the treatment side was significantly decreased at 5 time points (P < 0.01), and the index decreased significantly in week 8 compared with the index before treatment (P < 0.01), while the erythema index of the control side was not significantly different at 5 time points. The treatment related adverse events included erythema and edema after treatment and pain during treatment, the severity was mild to moderate, which resolved spontaneously within 1 to 3 days. Nine patients were very satisfied with the treatment, 7 patients were satisfied, and 6 patients considered average. CONCLUSION: 585 nm Q-switched laser has some effect in the treatment of postinflammatory erythema, and it ensures good tolerance and safety. There was no statistically significant difference between the treatment side and the control side on the improvement of acne inflammatory lesions.

Metallated Graphynes as a New Class of Photofunctional 2D Organometallic Nanosheets.

Two-dimensional (2D) nanomaterials are attracting much attention due to their excellent electronic and optical properties. Here, we report the first experimental preparation of two free-standing mercurated graphyne nanosheets via the interface-assisted bottom-up method, which integrates both the advantages of metal center and graphyne. The continuous large-area nanosheets derived from the chemical growth show the layered molecular structural arrangement, controllable thickness and enhanced π-conjugation, which result in their stable and outstanding broadband nonlinear saturable absorption (SA) properties (at both 532 and 1064 nm). The passively Q-switched (PQS) performances of these two nanosheets as the saturable absorbers are comparable to or higher than those of the state-of-the-art 2D nanomaterials (such as graphene, black phosphorus, MoS2 , γ-graphyne, etc.). Our results illustrate that the two metallated graphynes could act not only as a new class of 2D carbon-rich materials, but also as inexpensive and easily available optoelectronic materials for device fabrication.

Successful Treatment of Cosmetic Oral Mucosal Tattoos Using QS 694-nm Ruby Laser and 755-nm Alexandrite Picosecond Laser.

BACKGROUND AND OBJECTIVES: Q-switched (QS) and picosecond lasers can effectively and safely remove unwanted tattoo pigments. Cosmetic mucosal tattoos are rare and there are only a handful of cases of successful laser tattoo removal, all with QS 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser. STUDY DESIGN/MATERIALS AND METHODS: A 19-year-old Fitzpatrick skin-type II female presented for treatment of a 6-month-old, black tattoo on the mucosal surface of her lower lip. She underwent six treatment sessions with a QS 694-nm ruby laser on months 0, 1, 3, 5, 7, and 12. A 30-year-old Fitzpatrick skin-type IV male presented for treatment of a 10-year-old black tattoo on his left buccal mucosa. He underwent one treatment with 755-nm alexandrite picosecond lasers. RESULTS: One month after last treatment, both patients demonstrated marked improvement to the treatment area without scarring or dyspigmentation. CONCLUSIONS: Given the excellent results seen in the patients presented here, the authors recommend that lasers should be the first-line treatment for the removal of unwanted cosmetic mucosal tattoos, which are typically easier to remove than cutaneous tattoos and can be accomplished with various wavelengths in the picosecond and nanosecond domains. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Increased Tattoo Fading in a Single Laser Tattoo Removal Session Enabled by a Rapid Acoustic Pulse Device: A Prospective Clinical Trial.

BACKGROUND AND OBJECTIVES: The ability to provide improved tattoo fading using multiple laser passes in a single office laser tattoo removal session is limited. In part, this is due to the loss of laser effectiveness caused by epidermal and dermal vacuole "whitening" generated during the initial laser pass at the tattoo site. The Rapid Acoustic Pulse (RAP) device generates acoustic shock wave pulses that clear epidermal and dermal vacuoles to enable multiple laser passes in a single office laser tattoo removal session. The objectives of this study were to determine if the RAP device, when used as an accessory to the 1064 nm Nd:YAG Q-switched (QS) laser can enable delivery of multiple laser passes in a single office laser tattoo removal session, and therefore result in increased tattoo fading compared to the clinical standard single-pass QS laser tattoo removal session. STUDY DESIGN/MATERIALS AND METHODS: The RAP device was evaluated in a single-center (SkinCare Physicians), prospective, IRB approved study. A total of 32 black ink tattoos, from 21 participants, were divided into three zones and treated with either multiple QS laser passes, each followed by 1 minute of RAP device application (Laser + RAP) in zone one and single-pass QS laser treatment (Laser-Only) in zone two, separated by an untreated control zone. The treatment sites were assessed for the number of laser passes and adverse events immediately, 6 weeks, and 12 weeks following the treatment session. Photographs of the treatment sites were assessed for percent fading at 12 weeks post-treatment by three blinded reviewers. RESULTS: When the RAP device was applied as an accessory to the QS laser in a multi-pass laser tattoo removal treatment, an average of 4.2 laser passes were delivered in a single session, with no unexpected or serious RAP device-related adverse events. At the 12-week follow-up, tattoos treated with Laser + RAP showed a statistically significant increase in average fading (44.2%) compared with tattoos treated with Laser-Only (24.8%) (P < 0.01). Additionally, a significantly higher overall proportion of tattoos treated with Laser + RAP (37.5%) had a response of >50% fading compared with tattoos treated with QS Laser-Only (9.4%) (P < 0.01) as well as a response of >75% fading from Laser + RAP treatment (21.9%) compared with Laser-Only treatment (3.1%) (P < 0.05). CONCLUSIONS: The RAP device, applied as an accessory to the 1064 nm Nd:YAG QS laser, safely enables multiple QS laser treatments in a single office laser tattoo removal session by clearing the whitening caused by the previous QS laser pass. Enabling multiple QS laser passes results in a statistically significant increase in tattoo fading in a single office laser tattoo removal session compared to the clinical standard single-pass QS laser tattoo removal session. © 2019 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Successful treatment of a patient with multicolored nevus of Ota using a combination of 1064 and 532 nm Q-switched Nd:YAG lasers.

Nevus of Ota (NO) is a hamartoma of dermal melanocytes usually presents as unilateral blue, gray or brown macules or patches. It can impose a high burden of cosmetic and psychological disturbances in affected individuals. Q-Switched lasers appear to be an effective treatment for this kind of dermal melanocytosis. Multicolored Ota nevus is a rare variant of this kind of nevus and its treatment may be more challenging compared with unicolor lesions. Herein we report a 21-year-old woman with a multicolored nevus of Ota (blue and brown), which showed a dramatic response to a combination of 1,064 nm and 532 nm Q-Switched Nd:YAG lasers. We also discuss different aspects of the Q-switched laser application of Ota nevus treatment. We also focus on laser combination therapy to treat the nevus of Ota.

Successful and safe use of Q-switched lasers in the treatment of nevus of Ota in children with phototypes IV-VI.

OBJECTIVE: Nevus of Ota represents congenital dermal melanocytosis in a trigeminal distribution, most commonly occurring in Asian individuals and other individuals with skin of color. Evidence suggests early treatment is beneficial. Multiple reports have shown efficacy and safety of Q-switched laser treatment in adults. There is little data on children and in non-Asian skin types. This series was done to demonstrate safe and effective use of Q-switched laser therapy in children of multiple skin types. STUDY DESIGN: Retrospective case series. METHODS: This was a chart review of patients under 18 years old who presented to our practice from 2002 to 2015 with a clinical diagnosis of nevus of Ota who were treated with Q-switched lasers (694 and 1,064 nm). Patients were treated without the use of general anesthesia or sedation, and corneal shields were used in appropriate cases. Percentage of improvement as well as side effects were rated by five physicians independently. Improvement, when present, was rated in quartiles (1-25%, 26-50%, 51-75%, and 76-100% improvement). RESULTS: Twenty-four children were included. The average age at the start of treatment was 3.9 years old (range of 3 months to 12.4 years), and patients had Fitzpatrick skin types IV through VI. The mean number of treatments was 9.3. Assessment revealed excellent response (76-100% improvement) in 70% of patients and good to excellent response (51-100% improvement) in 86%. Two patients (8%) had post-inflammatory hyperpigmentation, one of whom also had focal hypopigmentation. CONCLUSION: Treatment of nevus of Ota with Q-switched lasers in children with skin of color, without general anesthesia or sedation, is safe and effective. Early intervention should be encouraged for better efficacy and to prevent psychosocial distress in later childhood and adulthood. Lasers Surg. Med. 50:56-60, 2018. © 2017 Wiley Periodicals, Inc.

A prospective, randomized, double-blinded, split-face pilot study comparing Q-switched 1064-nm Nd:YAG versus 532-nm Nd:YAG laser for the treatment of solar lentigines.

Treating photoaging with laser technologies has increased in popularity due to their efficacy, minimal downtime, and side effects. New Q-Switched (QS) Nd:YAG lasers' frequency doubled with 532 nm wavelength can both target epidermal chromophores as well as stimulate collagen production. The objective of this study was to compare single-pulsed 1064-nm Nd:YAG with dual-pulsed 532-nm/1064-nm QS laser for reducing solar lentigines. Ten subjects with solar lentigines were enrolled in this prospective, randomized, double-blind, split-face study. Subjects received six laser treatments (half-face dual, half single) at 2-week intervals. Blinded investigator and subject assessments were conducted 1 month posttreatment to evaluate global skin improvement, safety, and patient satisfaction. Blinded investigator assessments showed statistically significant improvement in the dual-treated side. Patient satisfaction was also statistically significantly increased in the dual-treated side. In conclusion, dual laser treatment can result in superior and safe global improvement of photoaging.

Efficacy and Safety of Q-Switched 1064/532 nm Nd:YAG Lasers on Benign Hypermelanosis in Dark-Skinned Individuals-A Preliminary Study.

Background: Facial hypermelanosis is a major cosmetic issue that causes severe social embarrassment and psychological pain, particularly among Asians and dark-skinned individuals. Aim: This study assesses the safety and effectiveness of Q-switched 1064/532 nm nanosecond/picosecond lasers in removing benign hypermelanosis in dark-skinned individuals, evaluating the possible associated side effects. Material and methods: A total of 30 participants (80% females and 20% males) with Fitzpatrick skin types IV-V-VI who presented superficial benign hypermelanoses on the facial and décolleté area were enrolled. All patients underwent to one to two laser treatment sessions with a 1064/532 nm Q-switched laser system. Three months after the final laser session, results were assessed by comparing before- and after-treatment photos and using a quartile scale for lesion clearance (4-point Investigator Global Assessment scale). Results: All patients observed global improvements in their pigmented lesions: 53% of patients achieved excellent clearance, 30% of patients achieved good to moderate clearance, 10% of patients achieved slight clearance, and 7% of patients did not respond to the therapy. No serious adverse event occurred. Photos showed the clinical improvement achieved at 3 months follow-up. Conclusions: The Q-switched 1064/532 nm laser proved to be a key tool for treating benign hypermelanosis in all skin types, including dark-skinned persons.

30-100 kHz, 2 ns passively Q-switched laser for fast and efficient photoacoustic microscopy.

Actively Q-switched (AQS) fiber laser and solid-state laser (SSL) are widely used for photoacoustic microscopy (PAM). In contrast, passively Q-switched (PQS) SSL not only maintains most of the merits of AQS lasers, but also exhibits unique advantages, including the pulse width (PW), pulse repetition rate (PRR) tunability, wavelength, compactness, and cost. These advantages all benefit the PAM. However, there are few reports demonstrating the performance of PQS-SSL on PA imaging. Here, we demonstrate a compact PQS-SSL for fast and efficient PA imaging. The laser uniquely maintains a constant PW (~2 ns) and pulse energy (~3 µJ) during the PRR variation (30-100 kHz), which is valuable for preserving a stabilized imaging performance at different scanning rates. The PA imaging performance is compared by a resolution target and showcased by whole-body scanning of an embryonic zebrafish in vivo. The performance indicates that PQS-SSL is a promising candidate for PAM.

A Watt-Level Pulsed Er:Lu2O3 Laser Based on a TiB2 Saturable Absorber.

TiB2 nanoparticles with a bandgap of 0 eV were prepared, and the corresponding nonlinear optical response at 2.85 µm was investigated. Employing a TiB2 as a saturable absorber, a 2.85 µm pulsed Er:Lu2O3 crystal laser with an average output power of 1.2 W was achieved under a maximum pump power of 9.51 W. Laser pulses with durations of ~203 ns were delivered at a repetition rate of 154 kHz, which corresponds to a pulse energy of ~7.8 µJ and a peak power of 39.3 W. As far as we know, the result represents the highest average output power from all Q-switched Er:Lu2O3 crystal lasers.

Pulsed Optical Vortex Array Generation in a Self-Q-Switched Tm:YALO3 Laser.

Optical vortex arrays are characterized by specific orbital angular momentums, and they have important applications in optical trapping and manipulation, optical communications, secure communications, and high-security information processing. Despite widespread research on optical vortex arrays, the 2 µm wavelength range remains underexplored. Pulsed lasers at 2 µm are vital in laser medicine, sensing, communications, and nonlinear optic applications. The need for 2 µm-pulsed structured optical vortices, combining the advantages of this wavelength range and optical vortex arrays, is evident. Therefore, using just three elements in the cavity, we demonstrate a compact self-Q-switched Tm:YALO3 vortex laser by utilizing the self-modulation effect of a laser crystal and a defect spot mirror. By tuning the position of the defect spot and the output coupler, the resonator delivers optical vortex arrays with phase singularities ranging from 1 to 4. The narrowest pulse widths of the TEM00 LG0,-1, two-, three-, and four-vortex arrays are 543, 1266, 1281, 2379, and 1615 ns, respectively. All the vortex arrays in our study have relatively high-power outputs, slope efficiencies, and single-pulse energies. This work paves the way for a 2 µm-pulsed structured light source that has potential applications in optical trapping and manipulation, free-space optical communications, and laser medicine.

Nonlinear Absorption Response of Zirconium Carbide Films.

Zirconium carbide (ZrC), a novel representative of the MXene family, has attracted considerable interest because of its outstanding physicochemical properties and potential applications in optoelectronic devices. For improving its performance as an optical modulator for ultrashort lasers, there is a call to continue studying the nonlinear optical behavior of MXene ZrC. Herein, for the first time, MXene ZrC films were fabricated on fused silica by magnetron sputtering deposition technology and used as a saturable absorber (SA) optical modulator in a passive Q-switched Nd:YAG laser. The saturation absorption behaviors of the prepared ZrC films were characterized by the Z-scan method. Their morphology, band structure, damage threshold, carrier recovery time, and saturation absorption properties were analyzed. The experimental results show that the MXene ZrC SA films exhibit excellent nonlinear optical characteristics, with a saturation intensity of 48.4 MW/cm2, a large modulation depth of 6.9%, and an ultrashort recovery time of 2.72 ps. In addition, the damage threshold of MXene ZrC SA films was estimated to be greater than 0.2516 J/cm2. By integrating the ZrC SA film optical modulator into the oscillator of the Nd:YAG laser, we achieved stable operation of the Q-switched laser with a central wavelength at 1.06 µm, with the shortest pulse width of 78 ns. The results of this study demonstrate the potential use of MXene ZrC SA films as optical modulators in ultrashort lasers.

Laser Carbon Peel: New Armamentarium for Inflammatory Acne.

There is an increasing interest in procedures to improve skin quality in acne patients with a short downtime. Off late, carbon peel laser technique which uses topical carbon suspension combined with Q-switched Nd:YAG laser treatment has gained popularity. The main advantages of this procedure are easy to perform and it requires less than 30 minutes.

Q-switched frequency-doubled Nd:YAG (532 nm) laser versus trichloroacetic acid 35% peeling in the treatment of dorsal hand solar lentigo: An assessor-blind split-hand randomized controlled trial.

BACKGROUND: Solar lentigo (SL) is a benign hyperpigmented spot occurring due to ultraviolet exposure, most commonly in the elderly. We aimed to compare the safety and efficacy of trichloroacetic acid (TCA) peeling with Q-switched laser in the treatment of SLs. METHODS: This assessor-blind split-hand randomized controlled trial included 45 patients with symmetric SLs on the back of their hands referred to the dermatology clinics from March 1 to June 24, 2021. TCA 35% was applied to the back of one hand, and the contralateral hand received Q-switched laser. The interventions were repeated for a total of three sessions 4 weeks apart. Eight weeks after the last treatment session, lesion lightening was graded from 1 to 4. Patient satisfaction with treatment was assessed using a visual analogue scale (VAS). Adverse events were also noted. RESULTS: Of the 45 patients included in the current study with a mean age of 52.71 ± 9.73 years, 11 (24.4%) were male. The Fitzpatrick skin type was II in 11 patients (24.4%), III in 23 (51.1%), and IV in 11 (24.4%). Lesion lightening and patient satisfaction were both significantly better with Q-switched laser compared to TCA peeling (standardized mean difference [SMD] = -1.25, 95% confidence interval [CI] -1.69; -0.79, p < 0.001 and SMD = -1.12, 95% CI -1.56; -0.67, p < 0.001, respectively). Overall, post-inflammatory hyperpigmentation (PIH) occurred in one patient in the laser group and for in the TCA group. Also, erythema and pruritus were observed in all patients of both groups after intervention which were treated with topical repair cream. CONCLUSIONS: Q-switched laser was superior to TCA peeling for the treatment of SLs in terms of lesion lightening and patient satisfaction with a large effect.

Laser removal of tattoos in vegan and omnivore patients.

BACKGROUND: Clinical outcomes of tattoo removal vary widely among different patients; it is known that tattoo-related features (such as pigments' type or quality, the use of multicolored inks, tattoo location size, location, layering, and duration) and personal habits (as smoking or skin phototype) could influence the clinical response to treatment, the possible role of nutrition in affecting the laser treatment of tattoos has never been investigated. AIMS: This study aims to compare the clinical response of tattoos removal between omnivore and vegan patients treated with Q-switched laser (QSL). PATIENTS/METHODS: Twenty omnivore and twenty vegan patients treated for professional black tattoo removal with Nd:YAG QSL were enrolled in this study. The number of laser sessions and the median days required for complete healing were recorded; clinical improvement was evaluated 4 weeks after the last laser session. RESULTS: The two groups were not different at the baseline in terms of sex, age, skin phototype, tattoos' age, location, and density. Vegans needed more laser sessions (p < 0.001) to achieve the best outcome, showed worst clinical responses (p = 0.001) and needed more days for complete healing (p = 0.006) compared to omnivores. CONCLUSION: The results of this study point out the influence of vegan diet on QLS removal of tattoos.