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.

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.

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.

Optimal pulse durations for the treatment of leg telangiectasias with an alexandrite laser.

Background And Objectives: Determine optimal settings using a long pulse 755 nm alexandrite laser in the treatment of superficial leg veins. STUDY DESIGN\

Materials And Methods: Fifteen patients with Fitzpatrick skin types I-III with telangiectasia ranging from 0.2 to 1.

Precise, controlled laser delivery with evanescent optical waves.

Precise laser surgery is possible with laser pulses at wavelengths that are strongly absorbed at the surface of tissue. However, pulses at these wavelengths (far UV, far infrared) are not compatible with fiber-optic transmission, making endoscopic surgical procedures inside the body difficult. We use evanescent optical waves to demonstrate an alternative for confining energy near the tissue surface.

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.

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.

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.

Selective delivery of laser energy to biological tissue based on refractive-index differences.

We report a novel method for selective laser energy delivery into biological tissues based on refractive-index differences. As a specific example, Ho:YAG laser energy is delivered into fat preferentially over other soft tissue, despite the fact that water has a higher absorption coefficient at this wavelength than fat.

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.

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.

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.

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.

Effects of a rapidly scanned carbon dioxide laser on porcine dermis.

This study systematically examined the effect of varying continuous-wave carbon dioxide laser scanning parameters on the resultant tissue effects. The effects of varying scanning speed, laser power, and laser beam diameter were assessed. Residual thermal damage at the center of the crater was approximately 120 microm independent of dwell time and laser irradiance.

Effects of heterogeneous absorption of laser radiation in biotissue ablation: characterization of ablation of fat with a pulsed CO2 laser.

Background And Objective: Physicians encounter several clinical situations in which fat must be removed. In this study, the characterization of fat ablation produced by a pulsed CO2 laser is reported.

Study Design/materials And Methods: An RF excited 800 microns pulsed CO2 laser operating at 10.

Effects of CO2 laser pulse duration in ablation and residual thermal damage: implications for skin resurfacing.

Background And Objectives: Resurfacing with the CO2 laser is rapidly gaining acceptance for skin rejuvenation. Advances in CO2 laser and scanning technology allow for precise tissue removal with minimal thermal damage. High energy CO2 laser pulses have been widely used effectively to smooth the surface of facial skin; however, pulse duration effects on ablation and thermal damage have not been systematically studied over the milli-second region (0.

Characterization of tissue ablation with a continuous wave holmium laser.

Background And Objective: The pulsed holmium laser is a promising tool for tissue ablation but possesses some limitations. For example, it is capable of producing significant mechanical damage in certain tissues in the form of fissures and fractures. Because longer pulse durations should reduce mechanical damage, this study examined the tissue effects produced by a prototype continuous wave holmium laser.

Effects of irradiance and spot size on pulsed olmium laser ablation of tissue.

Threshold radiant exposures for pulsed holmium laser ablation of tissue were measured with a high-speed framing camera. The effects of laser irradiance and beam size on ablation threshold were investigated. Threshold radiant exposure decreased with increasing laser irradiance over the range of 10(5)-10(7) W/cm(2).

Percutaneous obliteration of the cystic duct with a holmium:yttrium-aluminum-garnet laser: results of in vitro and animal experiments.

Objective: The purpose of this study was to investigate the feasibility of using a holmium:yttrium-aluminum-garnet laser to permanently occlude the cystic duct in order to isolate the gallbladder from the biliary-enteric circulation and prevent gallstone formation.

Materials And Methods: To determine the optimal laser parameters (power and pulsing rate) for cystic duct thermocoagulation, 20 freshly excised porcine gallbladders with intact cystic ducts underwent low-energy (0.075-0.

Co:MgF2 laser ablation of tissue: effect of wavelength on ablation threshold and thermal damage.

The wavelength dependence of the ablation threshold of a variety of tissues has been studied by using a tunable pulsed Co:MgF2 laser to determine how closely it tracks the optical absorption length of water. The Co:MgF2 laser was tuned between 1.81 and 2.

Pulsed carbon dioxide laser ablation of burned skin: in vitro and in vivo analysis.

Pulsed lasers produce efficient and precise tissue ablation with limited residual thermal damage. In this study, the efficiency of pulsed CO2 laser ablation of burned and normal swine skin was studied in vitro with a mass loss technique. The heats of ablation for normal and burned skin were 2,706 and 2,416 J/cm3 of tissue ablated, respectively.

Ablation of rabbit liver, stomach, and colon with a pulsed holmium laser.

A pulsed holmium laser (wavelength 2.1 microns, pulse duration 250 microseconds) was used to ablate rabbit liver, stomach, and colon in vivo. Microscopic examination of the tissues revealed zones of thermal damage extending 0.

Reflectance during pulsed holmium laser irradiation of tissue.

Although generally ignored in considerations of laser ablation of tissue, reflectance of laser light from tissue during laser-induced ablation is a potentially important factor in determining ablation efficiency because it determines the amount of laser light coupled into the target. To determine the significance of reflectance changes induced by laser irradiation, we examined the reflectance of liver samples during pulsed holmium laser ablation by placing the target at one focus of an ellipsoidal reflector and a detector at the other focus. The temporal behavior, total reflectance, and effect of multiple pulses were examined.