A preclinical study testing “Focused multiple laser beams,” a new concept of irradiation with the 1064-nm Nd:YAG laser for skin rejuvenation

Introduction: In order to avoid epidermal heat damage, we developed a novel irradiation method termed “Focused multiple laser beams (FMLB),” which allows long-pulse neodymium:yttrium aluminum garnet (Nd:YAG) laser beams to be irradiated from several directions in a concentric fashion followed by focusing into the dermis without epidermal damage. This study aimed to assess whether FMLB achieves the desired dermal improvement without epidermal damage. Materials and methods: The dorsal skin of New Zealand White rabbits was irradiated with FMLB. Macroscopic and histological analyses were performed after 1 hour and 1, 2, 3 and 4 weeks. Real-time PCR analysis of type I and III collagen expression was performed at two and four weeks. Results: Control groups exhibited skin ulcers which were healed with scar formation whereas FMLB groups remained intact macroscopically. Histologically, FMLB group showed increase in dermal thickness at four weeks while the epidermis remained intact. Real-time PCR demonstrated that both type I and III collagen increased at two weeks but decreased at four weeks. Conclusions: FMLB can deliver the target laser energy to the dermis without significantly affecting the epidermis.     

Successful treatment of Becker’s Nevus with long-pulsed 1064-nm Nd:YAG and 755-nm alexandrite laser and review of the literature

Background: Becker’s Nevus is an aesthetically troublesome condition secondary to hyperpigmentation and hypertrichosis. Although several lasers have been employed with varying degrees of success, the exact devices and treatment parameters have yet to be elucidated. Objective: To assess the combination Nd:YAG and alexandrite laser as a safe and efficacious treatment for Becker’s Nevus. Methods: In a 20-year-old Fitzpatrick Skin Type IV male, a Becker’s Nevus was treated with six sessions of long-pulsed 1064 nm Nd:YAG laser at six-week intervals followed by five sessions of long-pulsed 755 nm alexandrite laser at three-month intervals. Results: This patient experienced a significant reduction in both hyperpigmentation and hypertrichosis after these treatment sessions. No serious adverse events were reported. Conclusion: This case supports the use of combination long-pulsed 1064 nm laser and 755 nm laser as a safe and efficacious treatment for Becker’s Nevus.     

Comparison of treatment with an Alexandrite picosecond laser and Nd:YAG nanosecond laser for removing blue–black Chinese eyeliner tattoos

Objective: To retrospectively evaluate the efficacy of an Alexandrite picosecond laser versus Nd:YAG nanosecond laser for removing blue–black eyeliner tattoos which have existed more than 10 years.

Methods: A total of 40 patients were treated with an Alexandrite picosecond laser in our department from August 2015 to July 2017, with a fluence of 1.96–6.37J/cm², spot size of 2.0–3.6 mm, and pulse width of 750 ps. Another 32 patients were treated with an Nd:YAG nanosecond laser, with a fluence of 2.80–7.00 J/cm², spot size of 3 mm, and pulse width of 5–20 ns. All analysed patients completed at least one treatment and follow-up.

Results: The median number of treatment for all the patients was 1 (range, 1–4). After a single session, no difference was found between the two lasers for the eyeliner removal (p > 0.05). For the people who achieved an excellent response of tattoo clearance, there was still no difference between the two groups (p > 0.05). Transient side effects were observed in two groups, but neither group had significant adverse reactions.

Conclusions: To treat blue–black Chinese eyeliner tattoos over 10 years, Alexandrite picosecond laser does not provide better clearance than the Nd:YAG nanosecond laser.     

Nd:YAG laser combined with IPL treatment improves clinical results in non‐ablative photorejuvenation

BACKGROUND: Intense pulsed light (IPL) sources have been reported in non‐ablative photorejuvenation, but the excellent histological findings do not always coincide with the clinical results and patient satisfaction index (SI).

METHODS: Ten female patients (two forehead, four periocular and four perioral), ages ranging from 28 to 46 years, skin types II–IV, wrinkle types I–III, participated in the study. The IPL system was applied with the yellow (570?nm) cut‐off filter, 30?J/cm², single pulse, followed by the Nd:YAG at 120?J/cm², double pulse (7?ms per shot with 20?ms between pulses) on the wrinkled areas only. Three sessions were given at monthly intervals, and an assessment was made 1 and 6 months after the third session. Biopsies were taken from four consenting patients as a cross‐section before the first treatment and then 1 and 6 months after the third session. For clinical control and contrast of tissue results, a group of 10 patients (two forehead, four periocular and four perioral; ages ranging from 27 to 47 years, skin types II–IV, wrinkle types I–III) was treated only with IPL, using the same parameters and sessions. Histologies were taken from four consenting patients.

RESULTS: The histology showed thickening of the epidermis with good dermal collagen organization in both groups. However, the combined treatment showed more dramatic changes in histological tissue condition, and ectatic blood vessels were seen in the deeper dermis. The patient SI values, related to the results, were lower when IPL was used alone. All patients completed the study. In the combined treatment group, overall SIs of 8 (80%) and 8 (80%) were obtained at the control points of 1 and 6 months, respectively, after session 3, compared with SIs of 6 (60%) and 4 (40%) scored by patients in the IPL group at the same points. Discomfort and side effects were minimal in both groups.

CONCLUSIONS: The addition of the Nd:YAG laser to the IPL regimen in non‐ablative skin rejuvenation gave very good histological results, which were echoed by stronger patient satisfaction than in the control group treated only with IPL. Visible improvement in the skin condition of both groups was achieved, but was better in the combined treatment group.     

Treatment of Melasma with low fluence,large spot size, 1064-nm Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser for the treatment of melasma in Fitzpatrick skin types II–IV

Abstract

Melasma is a common condition affecting over six million American women. Treatment of dermal or combined melasma is difficult and does not respond well to conventional topical therapies. Various light sources have been used recently in the treatment of melasma including fractionated ablative and non-ablative lasers as well as intense pulse light. We report the use of low fluence, large spot size Q-switched, Nd:Yag laser for the treatment of melasma in skin types II–IV.     

Fractional 532-nm Q-switched Nd:YAG laser: One of the safest novel treatment modality to treat café-au-lait macules

Café-au-lait macules (CALMs) are benign epidermal basilar hyperpigmentations that can be found in an isolated form or in association with neurocutaneous syndromes. Frequency-doubled Q-switched neodymium-doped yttrium aluminum garnet laser (532-nm QSNYL) does not penetrate deeply into the skin and is therefore suitable for epidermal pigmented lesion. Fractional photothermolysis (FP) targets only very small areas of the skin, without injuring adjacent areas of healthy, normal skin. Herein, we report a case of CALMs successfully treated with fractional 532-nm QSNYL. By applying FP to 532-nm QSNYL, we could treat CALMs safely with less downtime as compared to conventional laser treatments and expect more energy delivery for each microscopic hole, thereby allowing higher response rate.     

Treatment of atrophic facial acne scars with fractional Er:YAG laser in skin phototype III–IV: A pilot study

Background: Fractional ablative lasers have recently been used for the treatment of skin scars. The objective of this study was to assess the efficacy and safety of the fractional erbium-doped yttrium aluminum garnet (Er:YAG) laser (2940 nm) in the treatment of skin scars. Materials and methods: A total of 9 patients (8 female, 1 male) with Fitzpatrick skin types III and IV suffering from atrophic facial acne scars were treated with a fractional Er:YAG laser for 2–5 (mean 3.3) sessions 4–6 weeks apart. One independent investigator assessed the efficacy, using standardized photographs, before and 1 month after the last treatment. The patients’ satisfaction rate was also evaluated. Results: The treatment was well tolerated by all patients without any anesthesia. The downtime was 2–3 days. All patients showed improvement in scars: excellent in 1, good in 1, and fair in 7 patients. Six patients were highly satisfied and 3 were satisfied with treatment. No adverse effect was noted. Conclusion: A fractional Er:YAG laser can deliver an effective and minimally invasive treatment for acne scars.     

Are lasers superior to lights in the photoepilation of Fitzpatrick V and VI skin types? – A comparison between Nd:YAG laser and intense pulsed light

Background and objectives: There are no large volume comparative studies available to compare the efficacy of lasers over lights for hair removal in Fitzpatrick V and VI skin types. This study is designed to compare the efficacy of Nd:YAG laser versus IPL in the darker skin types. Study design/materials and methods: Thirty-nine patients included in Group-1 were treated with Nd:YAG and 31 in Group-2 with IPL. Both groups received 5 sessions of treatment. The hair counts were assessed using digital photography and manual counting method before and after treatment and the results were analysed. Patient satisfaction scores and pain scores were recorded in each session and compared. Results: Mean hair reduction in the IPL group was 25.70 and Nd:YAG group was 24.12 (95% CI). In the Nd:YAG group, 59% of subjects had burning sensation while the figure was 32.3% in IPL group. Burning was less in IPL group (p < 0.023). There were no statistically significant differences noticed regarding hyperpigmentation in both the groups (p < 0.115). Conclusion: Both Nd:YAG and IPL are equally effective for epilation of the darker skin types. Nd:YAG is associated with mild burning sensation in a significant number of patients. Patient satisfaction scores were comparable in both the groups.     

Clinical evaluation and in-vivo analysis of the performance of a fractional infrared 1550 nm laser system for skin rejuvenation

Background: This study was done to demonstrate the safety and efficacy of a novel fractional 1550 nm laser device with a rolling mechanism (FRAX1550 Ellipse Medical, Horsholm, Denmark).

Objectives: To evaluated the effectiveness of the 1550 nm device for improvement in wrinkles, pigmentation, and texture on a six point (?1 to 4) global improvement scale.

Methods: Five female subjects between the ages of 44 and 71 years, with visible wrinkles and/or dyspigmentation were enrolled in the study. Two full face treatments were performed four weeks apart Follow-up visits at 1 and 3 months posttreatment were scheduled for photographic assessments. Assessment of improvement were performed by the investigators and two blinded evaluators through use of a six-point scale.

Results: All subjects demonstrated improvement in all monitored parameters. The mean improvement scores were: wrinkles 1.6, skin texture 1.8, and pigmentation 1.7. All score improvements were statistically significant. Biopsy was performed on one patient immediately post-treatment and showed 800 μ penetration depth at a treatment level of 88 mJ and 400 μ at 44 mJ.

Conclusions: The new rolling fractional 1550 nm laser device from this study offers improvement of aging facial skin with short downtime and minimal side effects.     

Facial skin rejuvenation: Ablative laser resurfacing,chemical peels,or photodynamic therapy? Facts and controversies

Patients and cosmetic surgeons continue to develop innovative devices and techniques in search of the elusive fountain of youth. Our efforts in the past decade can be distilled to three primary approaches: refinement of existing technologies (ablative lasers); refinement of tried-and-true techniques (chemical peeling); and innovative use of new technologies (photorejuvenation). In this contribution, the authors discuss how these three approaches are used to achieve facial skin rejuvenation. Specifically, the authors compare and contrast the clinical benefits and disadvantages of the ablative fractionated and unfractionated carbon dioxide resurfacing lasers, medium-depth and deep chemical peeling, and the combination of photodynamic therapy with intense-pulsed light.     

Treatment of recalcitrant plantar warts with long-pulsed Nd:YAG laser versus cantharidin–podophylline resin–salicylic acid

Background: Treatment for recalcitrant plantar warts remains a continuing challenge as the options for treatment have differing levels of success. long-pulsed Nd:YAG laser is considered a good treatment modality in resistant plantar warts. On the other hand, high cure rates have been reported with a topical proprietary formulation consisting of 1% cantharidin, 5% podophyllotoxin, 30% salicylic acid. Aim: To compare the efficacy of 1% cantharidin, 20% podophylline resin and 30% salicylic acid (CPS) versus long-pulsed Nd:YAG laser in the treatment of recalcitrant plantar warts. Methods: This study included 30 patients with single or multiple recalcitrant plantar warts; patients were assigned to two groups: the first group included 15 patients with 71 recalcitrant plantar warts who were treated by long-pulsed Nd:YAG laser (group I) and the second group included 15 patients with 78 recalcitrant plantar warts who received CPS (group II). The diagnosis of plantar warts was made by clinical examination. Results: Fourteen patients (93%) were completely cleared of their warts with topical CPS, while 11 patients (73%) showed complete clearance with long-pulsed Nd:YAG laser with statistically significant difference between the two groups. Conclusion: Topical CPS is safe and efficacious and represents a promising therapeutic modality than long-pulsed Nd:YAG laser in the treatment of recalcitrant plantar warts.     

Treatment of traumatic tattoo with the Q‐switched Nd:YAG laser

Traumatic tattoos are undesirable tattoos caused by different foreign bodies such as fireworks' particles, sand, metals, glass, gunpowder, asphalt, dust, or petroleum products embedded forcefully in the dermis. We report the case of a 54‐year‐old man who presented with sand and asphalt tattooing on his face following a bomb explosion 15 years ago. Q‐switched Nd:YAG laser at a wavelength of 1064?nm with a spot size of 4?mm and a fluence of 7.96?J/cm² were applied to treat the patient. The patient tolerated the treatment very well. Most of the blue dots became whitened immediately after the procedure and remained almost clear after a 6‐month follow‐up.     

Hair removal on dark‐skinned patients with pneumatic skin flattening (PSF) and a high‐energy Nd:YAG laser

Background: Permanent laser hair removal is normally performed with high‐energy densities and associated with acute pain. Pneumatic skin flattening (PSF) is a new technology, which helps to control the pain during laser aesthetic treatments. Based on the gate theory of pain transmission, it activates tactile and pressure skin receptors just before the laser shot to naturally block the transmission of pain to the brain while the laser is activated. Objective: To test the safety, pain reduction, as well as the efficacy of PSF in hair removal on patients with dark skin (mainly skin types IV, V and VI) with a high‐energy Nd:YAG laser and without skin chilling. Methods: Patients were treated for hair removal with a 1064‐nm laser (GentleYAG, Candela) at energy densities of 40–44 J/cm². Each patient was treated on both axillae: PSF on one side and without PSF (but with a chiller) on control sites. Pain was evaluated on a 1–10 scale. Hair re‐growth was counted after 12 weeks. A second treatment was delivered at that time for additional evaluation of pain and further efficacy evaluation. Post‐treatment erythema and adverse effects were also noted. Results: Pain reduction was demonstrated in all 28 patients: the average was 2.6 with PSF and 4.5 without PSF. Hair removal efficacy with and without PSF was identical: 78–79% hair reduction after 12 weeks (standard deviation 14% and 10% respectively, t‐test: 0.78). There were no cases of adverse effects and post‐treatment erythema was consistently lower with PSF. All patients preferred PSF over non‐PSF treatment. Conclusion: The PSF technology considerably reduces pain in hair removal with high‐energy Nd:YAG lasers on dark skins without side effects, while preserving efficacy. Analgesic creams and skin chilling are not required.     

Treatment of dermatosis papulosa nigra with a 1064 nm Nd:YAG laser: Report of two cases

Dermatosis papulosa nigra (DPN) is a chronic skin condition characterized by verrucous hyperpigmented papules on the face, neck and upper trunk in African American patients. The lesions are more common in females and in older patients. Although the lesions are benign, treatment is often sought for cosmetic reasons. We report two cases of patients with facial DPN who achieved an excellent cosmetic result following a single treatment with a long‐pulsed 1064?nm Nd:YAG laser. We suggest this modality for consideration in treating patients with DPN.     

Effects of neodymium–yttrium–aluminum garnet (Nd:YAG) pulsed high-intensity laser therapy on full thickness wound healing in an experimental animal model

Objective: Wound healing can be aided by the use of low- and medium-intensity lasers. The use of pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) high-intensity laser therapy (HILT) with a 1064-nm wavelength laser provides deeper and more efficient penetration into tissue as it is being less absorbed by chromophores in tissue, e.g., hemoglobin, melanin, and water, thereby enhancing the wound-healing process. In this study, we examined the effect of HILT on wound healing with a Q-switched pulsed Nd:YAG laser in an animal model. Design: Sixty SKH1 hairless male mice (seven weeks old) were randomly divided into four groups according to the amount of laser fluence: control, group 1 (0.8 J/cm²), group 2 (1.6 J/cm²), and group 3 (2.0 J/cm²). Laser treatment was provided to groups 1, 2, and 3 with a 1064-nm Q-switched Nd:YAG laser. Histological analysis was performed with hematoxylin and eosin staining, Masson's Trichrome staining, and Ki-67 staining. Results: Statistically significant increases in the accumulation of collagen fibers, thickness of granulation tissue, and numbers of fibroblasts were observed in group 2 (treated with 1.6 J/cm²) as compared with the control (no laser treatment), group 1 (treated with 0.8 J/cm²), and group 3 (treated with 2.0 J/cm²). Conclusion: Nd:YAG HILT stimulated fibroblast proliferation and increased extracellular matrix production. We expect that this therapy could accelerate the wound-healing process.     

High‐frequency ultrasound evaluation of cellulite treated with the 1064 nm Nd:YAG laser

Objectives: To investigate non‐invasive laser treatment for cellulite using the 1064?nm Nd:YAG laser and to correlate clinical results with high‐frequency skin ultrasound images. Methods: Twelve individuals of normal weight were treated on either the left or right posterior side of the thigh with the following parameters: fluence 30?J/cm, 18?mm spot size and dynamic cooling device pulse duration of 30?ms. Three treatments were performed at intervals of 3–4 weeks, and followed‐up 1 and 3 months after the last session. Photographs and ultrasound imaging were assessed before each session. Results: The 1064?nm Nd:YAG laser resulted in a tightening of the skin and an improvement in cellulite. No side effects were reported. High‐resolution ultrasound imaging showed a significant improvement in dermis density and a reduction of dermis thickness. The method is described in detail in Appendix 1. Conclusion: Infra‐red lasers may constitute a safe and effective treatment for cellulite and high‐frequency ultrasound imaging provides a quantitative and objective measurement of the treatment efficacy.