Hair Removal With Blended 755/1064 nm Laser Energy.

BACKGROUND AND OBJECTIVES: The 1064 nm wavelength is optimized for dark skin, but within the range of available fluences for commercially available 1064 nm devices, may not provide effective treatment for lighter hair. The 755 nm alexandrite wavelength can treat a full range of hair colors but is not ideal for darker skin. The hypothesis is that a new laser system capable of emitting 755/1064 nm wavelengths simultaneously allows for safer, effective, and less painful hair reduction over a range of skin and hair types. STUDY DESIGN/MATERIALS AND METHODS: We completed treatment in 36 patients in this institutional review board approved prospective randomized study. Ages ranged from 20 to 55 and the distribution of skin types was: I (14% of patients), II (50% of patients), III (18% of patients), IV (18% of patients). Areas included the axilla and lower extremity. A prototype laser system emitted 755/1064 nm simultaneously. The spot size was 12 mm and the pulse duration was 3 milliseconds. The percentage of each wavelength in the mixture varied from 0% to 100%. Total radiant exposure ranged from 20 to 50 J/cm2 . Test spots were performed with escalating doses of light for each category (alexandrite alone, Nd YAG alone, and blended). Patients returned within 1 week for evaluation of side effects. The highest fluence without side effects for each category was then applied in two sessions 1 month apart. Final hair counts were performed 2 months after the final treatment. RESULTS: Optimal light doses (in J/cm2 ) for the range of skin types were as follows: for alexandrite alone, YAG alone, and blended. (Skin type I) 40, 70, 40-10; (II) 40, 70, 40-10; (III) 34, 60, 30-20; (IV) 26, 60, 20-30; (V) 18, 50, 14-36. After 2 months, there was greater than 50% hair reduction in 40%, 24%, and 60% of subjects on the lower extremity for the alexandrite, Nd YAG, and blended groups, respectively, and 20%, 25%, and 24% for the axilla. Our data show that for "challenging" cases, that is, darker skin types or tanned skin with lighter hairs, a 70/30 mixture of Nd:YAG and alexandrite wavelengths tended to produce the greatest hair reduction and least epidermal compromise while maintaining a lower pain level than Nd YAG alone. CONCLUSIONS: Modeling and data suggest that 755/1064 nm mixture is useful in lighter hair removal treatment for darker skin types. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Use of a variable long-pulse alexandrite laser in the treatment of facial telangiectasia.

BACKGROUND: The alexandrite laser selectively targets melanin and hemoglobin. We used the alexandrite laser with variable pulse widths to treat facial telangiectasia. METHODS: Nineteen patients were enrolled in this study, which consisted of two parts: a series of test spots over a range of pulse durations (3-80 ms) and treatment over a larger area based on the pulse width-specific outcomes from the test spots. The final follow-up visit was 12 weeks after irradiation. RESULTS: The 40-ms pulse width achieved the optimal balance of pain tolerance, epidermal tolerance, and vessel reduction. Mean fluence was 88 J/cm(2), with a 6-mm spot. Overall, a 48% reduction in vessels was noted after one treatment. Side effects were minimal. CONCLUSIONS: In fair-skinned patients with large telangiectasia, the alexandrite laser is a good option for vessel reduction.

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

BACKGROUND: 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. OBJECTIVE: To compare a 607-nm laser with a commercially-available 595-nm laser for the treatment of EPLs. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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/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. 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.

Use of a novel pulse dye laser for rapid single-pass purpura-free treatment of telangiectases.

BACKGROUND: Purpura-free elimination of telangiectases with a single pass of a pulsed dye laser with a large spot has proved difficult. OBJECTIVE: The purpose of this report was to define parameters that achieve single-pass purpura-free telangiectasia reduction. MATERIALS: Thirty patients between the ages of 23 and 78 years were treated with a pulsed dye laser with a 10-mm spot and fluences ranging from 9 to 10 J/cm2. The macropulse width was 20 ms. Each macropulse was composed of eight pulselets. Treatments were carried out over facial areas with discrete telangiectases. RESULTS: Smaller telangiectases (<600 microm) showed transient bluing followed by stenosis. Larger vessels (600-10,000 microm) showed bluing but inconsistent closure. A second pass typically resulted in closure. CONCLUSION: A modified pulsed dye laser was capable of single-pass purpura-free reduction with a 10-mm spot size.

Use of a long-pulse alexandrite laser in the treatment of superficial pigmented lesions.

BACKGROUND/OBJECTIVE: Although the alexandrite 755-nm-wavelength laser is effective in the treatment of unwanted hair, there are no published studies gauging the efficacy of the variable long-pulse alexandrite laser in the treatment of superficial pigmented lesions. STUDY DESIGN/METHODS: Eighteen patients underwent a single treatment session using a variable pulse-width alexandrite laser. Test sites were performed using a 10-mm spot size and up to four pulse widths (3, 20, 40, 60 ms) with and without epidermal cooling. Full treatments were performed 3 weeks later using optimum test parameters. The patients were evaluated at 3 and 6 weeks. RESULTS: Patients with darker lentigines had greater lesion clearance than those patients with lighter colored lentigines. Shorter pulse widths and treatment without cryogen cooling both, independently, lowered the fluence threshold for lentigo clearance. CONCLUSION: A long-pulse alexandrite laser is effective in clearing solar lentigines in a single pass with minimal adverse effects.

Variable-pulse Nd:YAG laser in the treatment of facial telangiectasias.

BACKGROUND: Variable-pulse 1,064 nm wavelength lasers have been used with good effectiveness on leg telangiectasias and reticular veins and have shown promising results on facial telangiectasias as well. OBJECTIVE: To investigate the effectiveness of a variable-pulse neodymium:yttrium-aluminum-garnet (Nd:YAG) laser using a small spot size in the treatment of facial telangiectasias. METHODS: Eight male patients (mean age 75 years) underwent a single treatment session using a variable-pulse 1.5 mm spot size Nd:YAG laser with epidermal cooling. Telangiectasia diameters were 0.3 to 2.0 mm. Test sites were performed using three pulse widths (3, 20, and 60 ms), with fluences varying depending on vessel size and response. Full treatments were performed using test parameters giving the best response. Thirteen weeks later, the patients returned for final evaluation and satisfaction rating. RESULTS: Fluences ranged from 226 to 425 J/cm2, with smaller vessels requiring larger energies. Pulse duration was equally divided between the 20 and 60 ms settings. The shortest pulse width (3 ms) was inferior in all patients. Longer pulse durations achieved superior vessel elimination with minimal immediate purpura and no postinflammatory hyperpigmentation. The average mean vessel clearance was 26 to 50% in half of the patients and 51 to 75% in the other half as evaluated by three unbiased dermatologists with extensive laser experience. CONCLUSION: A small-spot size Nd:YAG laser using a pulse width of 20 ms or higher appears to be effective in clearing a significant percentage of facial telangectasias with a single pass. The side effects were minimal.

Optimal pulse durations for the treatment of leg telangiectasias with a neodymium YAG laser.

BACKGROUND: Leg veins can be effectively treated with lasers. However, the optimal pulse duration for small leg veins has not been established in human studies with a Nd:YAG laser. OBJECTIVES: The purpose of this study was to investigate a range of pulse durations to determine an optimal pulse duration for clearance of leg veins. STUDY DESIGN/MATERIALS AND METHODS: After mapping and photo documentation of the leg veins to be treated, a variable pulse duration Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser (3-100 milliseconds) was used in a single test site session. Pulse durations of 3, 20, 40, 60, 80, and 100 milliseconds were used. At the 3-week follow-up, the optimal pulse duration was defined as that pulse duration which resulted in the most complete clearance of vessels with the least side effects. Up to 20 vessels were then treated using the established "optimal" pulse duration. Final evaluation was at 16 weeks after the initial visit. Three blinded observers rated the percent of vessels completely cleared based on initial and final photographs. RESULTS: Eighteen patients completed the study. Fluence thresholds for immediate vessel changes varied depending on spot size and vessel diameter, with larger fluences required for smaller spot sizes and smaller vessels. Shorter pulse durations (< or =20 milliseconds) were associated with occasional spot sized purpura and spot sized post-inflammatory hyperpigmentation. Longer pulse durations (40-60 milliseconds) achieved superior vessel elimination with less post-inflammatory hyperpigmentation. With a single laser treatment, 71% of the treated vessels cleared. CONCLUSIONS: Compared to shorter pulses (<20 milliseconds), longer pulses may provide gentler heating of the vessel and a greater ratio of contraction to thrombosis.

Laser treatment of leg veins: Physical mechanisms and theoretical considerations.

BACKGROUND AND OBJECTIVES: A discussion of laser treatment of leg veins is based on a review of the literature, theoretical analysis, and the clinical experiences of the authors. Theoretical computations are discussed within the context of clinical observations. STUDY DESIGN/MATERIALS AND METHODS: A Monte Carlo model is used to examine volumetric heat production, fluence rate, and temperature profiles in blood vessels at 1,064 and 532 nm wavelengths with various beam diameters, vessel diameters, and pulse durations. RESULTS: Clinical observations, Monte Carlo results, and a review of the literature suggest that longer wavelengths and longer pulses durations favor vessel contraction over intraluminal thrombosis. Monte Carlo simulations show that longer wavelengths are more likely to uniformly heat the vessel compared to highly absorbing wavelengths. Methemoglobin production causes deeply penetrating wavelengths to generate more volumetric heat for the same input radiant exposure. CONCLUSIONS: Clinical observations and models support the role of long wavelengths and long pulses in optimal clearance of most leg telangiectasias.

Laser leg vein treatment: a brief overview.

Laser treatment of leg veins has been associated with a number of disadvantages, but the introduction of new devices has increased the role of lasers in the treatment of leg veins. This paper reviews the role of laser devices applied from the surface in the treatment of reticular and spider veins. Success is determined by the proper selection of wavelength, fluence, pulse duration, spot size, and number and frequency of treatments.