Treatment Of Epidermal Pigmented Lesions Research Articles

Nonlinear absorption-based analysis of energy deposition in melanosomes for 532-nm short-pulsed laser skin treatment.

The clinical use of 532-nm short-pulsed lasers has provided effective treatment of epidermal pigmented lesions. However, the detection of significant differences in treatment effects between picosecond and nanosecond lasers has still varied among clinical studies. For robust evaluation of the differences based on the treatment mechanism, this study presents a nonlinear absorption-based analysis of energy deposition in melanosomes for 532-nm short-pulsed laser treatment. Nonlinear absorption by melanin is modeled based on sequential two-photon absorption. Absorption cross-sections and nonradiative lifetimes of melanin, which are necessary for the nonlinear absorption-based analysis, are determined from transmittance measurement. Using the model and parameters, energy deposition in melanosomes was calculated with varying fluence and pulse width settings, including actual clinical parameters. The energy deposition in melanosomes increased with shorter laser pulses, and subnanosecond laser pulses were found to be most efficient. The comparison of energy deposition calculated using clinical parameters demonstrated the differences in treatment effects between picosecond and nanosecond lasers reported in clinical studies. The nonlinear absorption-based analysis provides quantitative evidence for the safety and efficacy evaluation of short-pulsed laser treatments, which may lead to the establishment of numerical indices for determining treatment conditions. Future studies considering the effects of the surrounding tissue on energy deposition in melanosomes will be needed.

Long pulsed dye laser with a back-to-back double-pulse technique and compression for the treatment of epidermal pigmented lesions.

In the recent past, long pulsed dye lasers (LPDL) have been investigated for the treatment of epidermal pigmented lesions (EPLs). Using a pigmented lesion compression headpiece, blood is pushed laterally out of the laser field focusing laser energy on melanin. Recent studies have demonstrated excellent responses using a single-pulse at the following settings: 9-12 J/cm2 , 1.5 milliseconds, 7-10 mm spot size with compression. However, the majority of these studies report patients requiring up to four treatments for lesion resolution. Herein, we describe our experiences utilizing a back-to-back double-pulse technique to decrease the total number of treatments needed for EPL clearance. Thirty-six patients (27 females, 9 males; skin types I-IV) with benign facial EPLs were included. Each lesion received two back-to-back pulses (fluence of 9-12 J/cm2 , 1.5 milliseconds duration, and 7 mm spot size). If needed, a second treatment was delivered 4-8 weeks later. Pre- and post-photos after the first treatment were evaluated by two independent board-certified dermatologists. Lesion clearance after the first treatment was graded on a Likert scale as: 1 = poor (<25% clearance); 2 = fair (25-50%); 3 = good (51-75%); and 4 = excellent (>75%). Of the 36 participants, 23 had excellent clearing, 10 with good, 2 with fair and 1 with poor clearance. There was only one case of post-inflammatory hyperpigmentation that subsequently resolved, and no cases or scarring or hypopigmentation. LPDL with compression continues to be a safe and effective modality for treatment of EPLs. Double-pulsing decreases the total number of treatments needed for lesion resolution, while maintaining safety and potentially decreasing cost. Lasers Surg. Med. 51:136-140, 2019. © 2018 Wiley Periodicals, Inc.

Treatment of Epidermal Pigmented Lesions with 578 nm Yellow Laser

Treatment of Epidermal Pigmented Lesions with 578 nm Yellow Laser

Pulsed dye laser treatment of pigmented lesions: a randomized clinical pilot study comparison of 607‐ and 595‐nm wavelength lasers

The 595-nm pulsed dye laser has been used for the treatment of benign epidermal pigmented lesions (EPLs), but there is a risk of inducing undesirable purpura with treatment. To compare a 607-nm laser with a commercially-available 595-nm laser for the treatment of EPLs. Monte-Carlo simulations were performed to characterize laser interaction with skin. Ten patients with EPLs were treated with a 607-nm study prototype laser and the 595-nm pulsed dye laser twice at 2- to 4-week intervals on the left or right side on a randomized basis. Study endpoints included clearance rate of lesions, side effects immediately after treatment and at final follow-up, and patient discomfort/pain. Monte-Carlo simulations show that the 607-nm is absorbed more specifically by melanin than the 595-nm wavelength. Both lasers were effective in treatment of EPLs. The average degree of improvement overall was 41.2% with the 607-nm laser and 40% with the 595-nm laser. Patients reported less discomfort/pain during treatment with the 607-nm laser. Our findings suggest that the 607-nm laser is safe and at least as effective as the 595-nm laser in treatment of EPLs. There was less patient discomfort/pain during treatment using the 607-nm laser.

Cutaneous Compression for the Laser Treatment of Epidermal Pigmented Lesions with the 595-nm Pulsed Dye Laser

BACKGROUND The 595-nm pulsed dye laser has been the standard of care for many vascular lesions and has rarely been used in the treatment of epidermal pigmented lesions. OBJECTIVE The objective was to investigate the effectiveness and safety of a compression technique for the treatment of epidermal pigmented lesion using a modified 595-nm pulsed dye laser with no epidermal cooling. METHODS Twelve subjects (mean age 58 years) underwent treatments using a modified 595-nm dye laser with a compression handpiece and no epidermal cooling. Treatments were performed with radiant exposures of 7 to 12 J/cm2, 7-mm spot size, and 1.5-ms pulse duration. Each subject received one to four treatments, 4 to 6 weeks apart. Follow-up evaluations were held before each treatment and 4 months after last treatment. RESULTS Clearance of 75% to 100% was obtained in 43, 59, 76, and 79% of the lesions treated after one, two, three, and four treatments respectively. The fourth treatment was evaluated 4 months posttreatment. Side effects included immediate erythema and edema and rare cases of transient hyperpigmentation and atrophy. No purpura and long-lasting side effects were observed. CONCLUSION The compression technique with a modified 595-nm pulsed dye laser system is effective and safe for the treatment of epidermal pigmented lesions.

Cutaneous Compression for the Laser Treatment of Epidermal Pigmented Lesions with the 595-nm Pulsed Dye Laser

The 595-nm pulsed dye laser has been the standard of care for many vascular lesions and has rarely been used in the treatment of epidermal pigmented lesions. The objective was to investigate the effectiveness and safety of a compression technique for the treatment of epidermal pigmented lesion using a modified 595-nm pulsed dye laser with no epidermal cooling. Twelve subjects (mean age 58 years) underwent treatments using a modified 595-nm dye laser with a compression handpiece and no epidermal cooling. Treatments were performed with radiant exposures of 7 to 12 J/cm(2), 7-mm spot size, and 1.5-ms pulse duration. Each subject received one to four treatments, 4 to 6 weeks apart. Follow-up evaluations were held before each treatment and 4 months after last treatment. Clearance of 75% to 100% was obtained in 43, 59, 76, and 79% of the lesions treated after one, two, three, and four treatments respectively. The fourth treatment was evaluated 4 months posttreatment. Side effects included immediate erythema and edema and rare cases of transient hyperpigmentation and atrophy. No purpura and long-lasting side effects were observed. The compression technique with a modified 595-nm pulsed dye laser system is effective and safe for the treatment of epidermal pigmented lesions.

The use of the frequency-doubled Q-switched Nd:YAG laser in the treatment of small cutaneous vascular lesions.

The frequency-doubled Q-switched, neodymium:yttrium-aluminum-garnet (FD QSNd:YAG) laser has proven to be safe and effective in treating cutaneous pigmented lesions and tattoos. The observance of purpura following FD QSNd:YAG laser treatment of epidermal pigmented lesions led us to evaluate the use of this laser in the treatment of vascular lesions. The treatment protocol was designed to assess the efficacy of the FD QSNd:YAG laser in the treatment of small cutaneous vascular lesions such as telangiectases and small angiomas. The FD QSNd:YAG laser (532 nm, 3-mm spot size, and 5-10-nanosecond pulse width) at 1-2 J/cm2 and 3-4 J/cm2 was used on two comparable cutaneous vascular lesions on the skin of each subject. Patients were treated once, with follow-up at 1-, 2-, and 6-month intervals, to examine both clinical improvement as well as potential adverse sequelae. Lesions treated with the FD QSNd:YAG laser at both 1-2 J/cm2 and at 3-4 J/cm2 were improved. Statistically greater improvement was achieved when the FD QSNd:YAG laser was used at 3-4 J/cm2. Clinical improvement of small cutaneous vascular lesions is possible with the FD QSNd:YAG laser.

Treatment of Epidermal Pigmented Lesions With the Frequency-Doubled Q-Switched Nd:YAG Laser

The removal of benign, aesthetically important, pigmented lesions can be effectively treated with multiple modalities. Selective removal of the pigment by lasers is becoming increasingly popular. A three-center trial evaluated the effectiveness of the frequency-doubled Q-switched neodymium (Nd):YAG laser (532 nm, 2.0-mm spot size, 10 nanoseconds) in removing benign epidermal pigmented lesions with a single treatment. Forty-nine patients were treated for multiple lentigines (n = 37), for cafe au lait macules (n = 7), and for miscellaneous lesions (n = 5). Treatment areas were divided into four quadrants, irradiated with fluences of 2, 3, 4, or 5 J/cm2 and evaluated at 1- and 3-month intervals following treatment. For lentigines, response was related to dose with a greater than 75% pigment removal achieved in 60% of those lesions treated at higher energy fluences. Responses were more variable with other lesions, with fair-to-good improvement noted in most cases. Mild, transient erythema; hypopigmentation; and hyperpigmentation were noted in several patients, but resolved spontaneously within 3 months. No other textural changes, scarring, or other side effects were noted. The frequency-doubled Q-switched Nd: YAG laser (532 nm) safely and effectively treats benign epidermal pigmented lesions.

Treatment of epidermal pigmented lesions with the frequency-doubled Q-switched Nd:YAG laser. A controlled, single-impact, dose-response, multicenter trial

Treatment of epidermal pigmented lesions with the frequency-doubled Q-switched Nd:YAG laser. A controlled, single-impact, dose-response, multicenter trial

Clinical Use of the Q-Switched Nd:YAG Laser for Treatment of Dermal and Epidermal Pigmented Lesions

The Frequency Doubled Q-Switched Nd:YAG Laser system with a pulse duration of 10 ns and a dual wavelength of 1064 nm and 532 nm has been demonstrated to successfully remove tattoos and epidermal pigmented lesions. Additionally, the author has used this laser system to treat dermal melanocytosis. Dermal melanocytosis, such as nevus of Ota and aberrant or persistant Mongolian spot, is more common in Asian people. Conventional treatments for these lesions, including cryosurgery with dry ice or liquid nitrogen, dermabrasion, excision or skin grafting, have limited success or undesirable side effects such as hyper or hypopigmentation and scarring. The author has used a 1064 nm wavelength Q-switched Nd:YAG laser for two years to treat nevus of Ota and aberrant Mongolian spot on both adults and children. Clearing or significant lightening with no scarring or permanent hypo or hyperpigmentation was seen in all cases. The author suggests that the Q-switched Nd:YAG laser is both safe and effective for treatment of dermal melanocytosis. Regarding treatment of epidermal pigmented lesions it is important to tell if the pigmentation seen after laser irradiation of Asian skin using a wavelength of 532 nm is postinflammatory pigmentation or whether it is due to incomplete clearance or a recurrence of the lesion.