Evaluation of a New Super-Long-Pulsed 810 nm Diode Laser for the Removal of Unwanted Hair: The Concept of Thermal Damage Time

BACKGROUND: Laser hair removal is based on the dual concepts of selective photothermolysis and thermal relaxation time. In most laser hair removal systems, light with emitted pulse durations of 2-50 msec targets hair follicles. A novel concept of laser hair removal uses the thermal damage time rather than the thermal relaxation time of the hair follicle. The follicle's thermal damage time is the amount of time required for diffusion of delivered laser energy from the treated hair to follicular-associated hair stem cells. This can range from 170 to 1000 msec. OBJECTIVE: To investigate the theory of thermal damage time, we performed a pilot study to evaluate the clinical efficacy and side effect profile of a modified 810 nm diode laser device operating in a super-long-pulse mode (200-1000 msec). METHODS: Ten female subjects with Fitzpatrick skin types I-VI received either one or two laser treatments at eight test sites. Super-long pulse durations of 200-1000 msec were evaluated with delivered fluences ranging from 23 to 115 J/cm2. Subjects were followed for 6 months after the first treatment. Subjects were evaluated for hair removal efficiency, optimal pulse duration and delivered fluence, and associated complication rate. RESULTS: The clinical results show that safe hair removal in all skin types can be accomplished with an 810 nm diode laser delivering super-long pulse durations. Pain and complications were greatest at the highest pulse duration (1000 msec) and the highest fluence (115 J/cm2). Optimal hair reduction at 6 months (31%) was achieved at a thermal diffusion time of 400 msec (46 J/cm2). CONCLUSION: The super-long pulsed 810 nm diode laser can safely remove unwanted hair in a full variety of skin types. Pain and increased risk of complications may preclude the use of the laser at very high fluences and pulse duration in the range of 1000 msec.     

Analysis of epidermal protection using cold air versus chilled sapphire window with water or gel during 810 nm diode laser application

BACKGROUND AND OBJECTIVES: Many cutaneous laser devices incorporate a temperature-based epidermal protection system to minimize surface damage while continuing to affect targeted tissue. The use of cold air is a new technique to aid in epidermal protection during the application of cutaneous lasers. This study investigates the efficacy of cold air versus chilled sapphire in regards to epidermal preservation when used with an 810 nm diode laser. STUDY DESIGN/MATERIAL AND METHODS: White-haired pink piglets and dark-haired pigmented piglets were treated using the 810 nm diode laser in conjunction with either (1) no cryogen protection; (2) cold air alone; (3) chilled sapphire window alone; (4) cold air with water/gel; or (5) chilled sapphire window with water/gel. Laser fluence was varied by adjusting laser duration time while maintaining the intensity at 60 W. Biopsies were obtained from the sacrificed animals, stained with Masson's trichrome, and analyzed for extent of epidermal damage. RESULTS: Among white-haired pink pigs, the cold air afforded the same degree of epidermal preservation as the chilled sapphire window. Epidermal protection was further enhanced with the addition of either gel or water. Among dark-haired pigmented pigs, the chilled sapphire window alone likewise provided significant epidermal protection, although the cold air alone did not. However, with the addition of water/gel, epidermal preservation was demonstrated in both. CONCLUSIONS: Cold air is an effective means in promoting epidermal preservation, though slightly inferior to the chilled sapphire window on darkly pigmented subjects. Combining either method with water or gel further enhances surface protection, enabling safe use of higher fluences.     

A side-by-side comparative study of 1064 nm Nd:YAG, 810 nm diode and 755 nm alexandrite lasers for treatment of 0.3-3 mm leg veins.

BACKGROUND: Laser and intense pulsed light device treatments of leg veins have generally yielded disappointing results. Use of longer wavelengths, longer pulse widths, and better cooling devices have recently sparked renewed interests in these methods. OBJECTIVE: To prospectively compare, side by side, a 3-msec cryogen spray-equipped 755 nm alexandrite, a sapphire window cooled super-long-pulse 810 nm diode, and a variable pulse width, cryogen spray-equipped 1064 nm Nd:YAG laser for the treatment of 0.3-3mm leg veins. METHODS: Thirty female volunteers, skin types I-V, age 32-67 years with comparable sets of leg veins were treated with the Nd:YAG laser and either the diode laser, alexandrite laser, or both. In most patients two to three sets of comparable sites were treated. Treatment parameters varied with each laser and according to the size of veins being treated. Patients were examined 1 week after each treatment and at 1, 2, and 3 months after the last treatment. Pre- and posttreatment 35mm photographs were taken. Improvement was judged by two experienced physicians both visually on patients and by comparison of pre- and posttreatment photographs. Results were graded as percent resolution, in five groups, 0%, 0-25%, 25-50%, 50-75%, and 75-100%. RESULTS: In the 22 patients completing the study, 36 leg vein sites were treated with the Nd:YAG laser, 18 leg vein sites were treated with the diode laser, and 12 leg vein sites were treated with the alexandrite laser. Greater than 75% improvement was observed at 88% of the Nd:YAG laser-treated sites, 29% of the diode laser-treated sites, and 33% of the alexandrite laser-treated sites. Greater than 50% improvement was observed at 94% of the Nd:YAG laser-treated sites, 33% of the diode laser-treated sites, and 58% of the alexandrite laser-treated sites. Less than 25% improvement was observed at 6% of the Nd:YAG laser-treated sites, 39% of the diode laser-treated sites, and 33% of the alexandrite laser-treated sites. Pain during treatment was variably perceived by patients, but occasionally sufficient for patients to decline further treatment. Posttreatment purpura and telangiectatic matting were a significant drawback for the alexandrite laser. Transient hemosiderin pigmentation, as seen with sclerotherapy, was common with larger vessels. CONCLUSION: The cryogen spray-equipped 1064 nm Nd:YAG laser was remarkably effective and safe for the treatment of 0.3-3 mm leg veins. The use of topical anesthesia may be needed for some patients. The super-long-pulse 810 nm diode laser gave unpredictable results. Additional refinements of fluence and pulse width could improve its performance. The 3-msec, 755 nm alexandrite laser at fluences of 60-70 J/cm2 and an 8 mm spot can be effective, but inflammatory response, purpura, and matting limit its usefulness. Longer pulse widths might decrease these problems. For leg vein treatment, the 1064 nm wavelength is very safe for type V skin, the 810 nm wavelength at super-long pulse widths of 400-1000 msec is very safe for type IV and marginal for type V skin, and the 755 nm wavelength is limited to nontanned type I-III skin.     

Pulsed dye laser treatment of benign cutaneous pigmented lesions.

Superficial benign cutaneous pigmented lesions that commonly present to the dermatologists and plastic surgeons have been treated by many conventional modalities such as dermabrasion, depigmenting creams as well as several types of lasers. Many of these treatment modalities lack specificity of injury, which has meant that normally pigmented and even non-pigment containing structures such as collagen as well as the hyperpigmented lesion itself have all been indiscriminately destroyed. This has resulted variously in hypopigmentation, hyperpigmentation, in addition to scar formation in some cases. A coaxial 504 nm laser with a pulse duration of 300 nsec was used to treat fifty two patients with superficial benign cutaneous pigmented lesions. Although the number of treatments required to clear the lesion varied according to the type of lesions being treated, on average, between 2 and 4 treatments were required to completely eradicate the superficial benign cutaneous pigmented lesions using 504 nm pulsed dye laser. The skin at the site successfully cleared of the pigmented lesion remained normal in skin color, texture, markings, and mobility.     

Diode Laser Hair Removal in Patients Undergoing Isotretinoin Therapy

BACKGROUND: It is generally believed that any intervention in skin while on isotretinoin or within 6 months after the treatment can lead to prolonged healing and scarring. OBJECTIVE: The objective was to evaluate the side effects of laser hair removal in patients undergoing isotretinoin treatment. METHODS: Seven female patients undergoing isotretinoin therapy for acne were treated with a diode laser with a wavelength of 810 nm, a contact-cooling device, and a variable pulse width of 50 to 1000 ms. All volunteers received first treatment in the axillary or bikini area at 21 J/cm(2) (80 W) and the second treatment was done in the same area at 24 J/cm(2) (90 W). Six volunteers received additional treatments of chin area with a fluence of 21 or 24 J/cm(2). All volunteers were evaluated and photographed 1 week and 1 month after each treatment and degree of erythema, pigmentary change, vesiculation, swelling, and scarring was documented. RESULTS: There was no erythema, pigmentary change, swelling, or scarring at any follow up visits. One volunteer presented with a bulla 1 week after second treatment, which was resolved at 1-month follow-up. All volunteers were satisfied with the degree of hair removal with two treatments. CONCLUSION: This limited study suggests that diode laser hair removal is safe in patients undergoing isotretinoin therapy.     

Optical properties of human trabecular meshwork in the visible and near-infrared region.

BACKGROUND AND OBJECTIVES: Despite disparate treatment parameters, similar success in laser trabeculoplasty (LT) is attained using the argon (514.5 nm) and diode (810 nm) laser. However, the mechanism of this success remains unresolved. To further understand LT, this study characterizes the optical properties of trabecular meshwork (TM). STUDY DESIGN/MATERIALS AND METHODS: Reflectance was measured from 10 TM samples over wavelengths of 400-820 nm, using an integrating sphere/spectrophotometer. Corrections were made for reflections at boundaries of refractive index mismatch. Kubelka-Munk coefficients were calculated and converted to linear transport coefficients. RESULTS: Scattering greatly dominated absorption. The scattering and absorption coefficients were, respectively, 141.20 +/- 15.80 cm(-1) and 4.89 +/- 1.95 cm(-1) at 514.5 nm, and 94.44 +/- 15.03 cm(-1) and 0.0874 +/- 0.111 cm(-1) at 810 nm (estimated anisotropy of 0.90). The corresponding penetration depths (1/e) were 69 microm (514.5 nm) and 106 microm (810 nm). CONCLUSION: The absorption coefficient of 514 nm energy is two orders of magnitude greater than 810 nm energy, while scattering coefficients are much closer. The fluence used at 514.5 nm is higher at the surface than that at 810 nm, but falls below it deep within the TM due to the differential absorption. Therefore, similar initial therapeutic effects are obtained with 810 nm using less total absorbed energy. Thermal damage resultant from excess energy deposited at 514.5 nm may be related to the lack of success in repeat argon LT, pointing out the need for studies of repeat diode LT.     

Laser Hair Removal with Alexandrite versus Diode Laser Using Four Treatment Sessions: 1-Year Results

BACKGROUND: Laser hair removal is the treatment of choice for hypertrichosis. The two most commonly used hair removal lasers are compared. OBJECTIVE: To present the results of a comparative study examining the role of wavelength, fluence, spot size, pulse width, and cooling systems on long-term results after a series of four laser hair removal treatments using the 755 nm alexandrite and 800-810 nm diode lasers. METHODS: The axillae of 15 untanned, type I-V patients were treated side by side four times at 4- to 6-week intervals with a 755 nm, 3-msec pulse width, cryogen spray-equipped alexandrite laser and an 800 nm, variable pulse width, cooled sapphire window-equipped diode laser. Each patient was pretested and treated with the maximum fluence tolerated at the largest spot size available for each laser (12 mm round/113 mm2 for the alexandrite and 9 mm for the diode). RESULTS: Evaluations were done at 3, 6, 9, and 12 months after the last treatment. Twelve-month results with the alexandrite and diode lasers achieved 85% versus 84% hair reduction. The fact that tan avoidance was strictly followed permitted the use of relatively high fluences (25-30+ J/cm(2)) even in type IV patients. For most patients, four treatment sessions using high fluences (30-40 J/cm(2)) with relatively large spot sizes (12 mm round for the 755 nm alexandrite and 9 mm for the 800 nm diode) resulted in 12-month hair reductions in the 90% range. CONCLUSION: Both the alexandrite and diode lasers in this 12-month study produced excellent long-term hair reductions.     

Diode laser hair removal of the black patient

BACKGROUND AND OBJECTIVE: The 810-nm wavelength diode laser can safely and successfully treat all skin types, including dark pigmented skin. STUDY DESIGN/METHODS: Eight Fitzpatrick level V-VI skin type patients, four of which presented with the diagnosis of pseudofolliculitis barbae, were treated with the diode laser for hair removal using low-energy settings and long pulse duration. RESULTS: All eight patients had excellent results with unwanted hair greatly reduced, and pseudofolliculitis barbae resolved. CONCLUSIONS: Diode lasers can be used on dark pigmented skin with positive outcomes. Complications such as hypopigmentation, or hyperpigmentation occurred, but all were transient and resolved within a few months.     

Optimized Photodynamic Therapy with Systemic Photosensitizer Following Debulking Technique for Nonmelanoma Skin Cancers

BACKGROUND: The thickness and depth of invasion of skin tumors may be limiting factors for topical photosensitizer-based photodynamic therapy (PDT). The use of PDT with systemic photosensitizer needs to be further explored as a modality of treatment for nonmelanoma skin cancer (NMSC). OBJECTIVE: The objective was to present six patients with multiple, nodular, and/or pigmented NMSC treated successfully with purified hematoporphyrin derivative (PHD) and PDT using prior debulking. METHODS: After 24 hours of systemic PHD (1.5 mg/kg), 12 lesions of NMSC were selected for PHD-PDT alone and 6 nodular/elevated lesions for PHD-PDT following a debulking procedure. The tumor area was illuminated in one single-dose session of 300 J/cm(2), at an intensity range of 130 to 150 mW/cm(2), with a 630-nm-wavelength diode laser. RESULTS: The prior curettage provided significant reduction in volume and/or pigmentation of lesions. After the session of PHD-PDT with prior curettage and additional topical 20% ALA-PDT in two lesions or PHD-PDT alone, 83% (5/6) of lesions and 58% (7/12) of lesions, respectively, maintained a complete clinical response, 22.2+/-8.9 months of follow-up. CONCLUSIONS: The combination of prior debulking with systemic agents-PDT appears to be a good option for multiple, pigmented, and/or nodular lesions of NMSC and can allow the improvement of clinical results.     

A newly modified 595-nm pulsed dye laser with compression handpiece for the treatment of photodamaged skin

BACKGROUND AND OBJECTIVES: The pulsed dye laser set the standard of care for the treatment of vascular lesions, and recent modifications have enabled improved efficacy with fewer side effects. An investigational high energy, variable pulse duration pulsed dye laser has been modified to treat both vascular and pigmented lesions associated with photoaging. Each laser pulse is comprised of a sequence of eight uniform micropulses, which evenly distribute the pulse energy, effectively increasing the purpura threshold at any given fluence. Pigmented lesions are treated with a compression handpiece (CHP) that removes competing vascular target from the field, and helps to prevent purpura. This pilot study was undertaken to determine the optimum laser settings, and to investigate the ability of this device to improve vascular and pigmented lesions associated with photoaging. STUDY DESIGN/MATERIALS AND METHODS: Twenty-four patients with photoaged skin and phototype I-III were enrolled in the study. Thirteen received treatment for vascular and pigmented lesions, and 11 subjects were treated for pigmented lesions alone. Subjects received one to three treatments at 3-4 weeks intervals, and underwent 3- and 12-week follow-up evaluation. The degree of improvement was assessed by subject evaluation as well as comparison of standardized digital photographs by three independent dermatologists. Background erythema was treated with a 12-mm spot size, at a fluence of 7 J/cm(2), and a pulse width of 10 ms. The cryogen cooling was set at 30 mseconds with a 30 ms delay. Individual telangiectasias were treated with a 5- or 7-mm spot size at fluences of 9-14 J/cm(2) and pulse widths of 6-20 mseconds. Pigmented lesions were treated using a 5- or 7-mm spot size, with energy of 9-15 J/cm(2) and a pulse width of 1.5-10 ms without cooling. The CHP had a 7-mm spot size, and fluences of 9-16 J/cm(2), and pulse widths of 1.5 or 3 ms were used in the treatment of pigmented lesions. RESULTS: The treatment was well tolerated without the use of topical anesthetic. All subjects noted improvement in the both vascular and pigmented lesions, and were satisfied with their outcomes. Objectively, there was moderate improvement in background erythema, telangiectasia, and pigmented lesions. Three subjects who were treated with sun tans developed transient hypopigmentation and two subjects developed a transient textural change following pulse stacking for the treatment of pigmented lesions with the conventional handpiece. Purpura was noted in all patients treated for pigment with the conventional handpiece at pulsewidths less than 6 mseconds, as compared to only one that was treated with the CHP. Three patients treated in rapid succession for vascular, and then pigmented lesions with the CHP exhibited purpura, which was prevented in future treatments with 1-2 minutes of topical ice cooling between passes. CONCLUSIONS: This novel 595-nm pulsed dye laser, with a modified pulse sequence and CHP, now has the versatility to safely treat both pigment and vascular changes associated with photoaging.     

Therapeutic ratio quantifies laser antisepsis: ablation of Porphyromonas gingivalis with dental lasers

BACKGROUND AND OBJECTIVES: It is established that both pulsed Nd:YAG (1,064 nm) and continuous diode (810 nm) dental lasers kill pathogenic bacteria (laser antisepsis), but a quantitative method for determining clinical dosimetry does not exist. The purpose of this study was to develop a method to quantify the efficacy of ablation of Porphyromonas gingivalis (Pg) in vitro for two different lasers. STUDY DESIGN/MATERIALS AND METHODS: The ablation thresholds for the two lasers were compared in the following manner. The energy density was measured as a function of distance from the output of the fiber-optic delivery system. Pg cultures were grown on blood agar plates under standard anaerobic conditions. Blood agar provides an approximation of gingival tissue for the wavelengths tested in having hemoglobin as a primary absorber. Single pulses of laser energy were delivered to Pg colonies and the energy density was increased until the appearance of a small plume was observed coincident with a laser pulse. The energy density at this point defines the ablation threshold. Ablation thresholds to a single pulse were determined for both Pg and for blood agar alone. RESULTS: The large difference in ablation thresholds between the pigmented pathogen and the host matrix for pulsed-Nd:YAG represented a significant therapeutic ratio and Pg was ablated without visible effect on the blood agar. Near threshold the 810-nm diode laser destroyed both the pathogen and the gel. CONCLUSIONS: Clinically, the pulsed Nd:YAG may selectively destroy pigmented pathogens leaving the surrounding tissue intact. The 810-nm diode laser may not demonstrate this selectivity due to its greater absorption by hemoglobin and/or longer pulse duration.     

Port wine stain coagulation experiments with a 540-nm continuous wave dye-laser

Treatment of port wine stains with a continuous wave dye laser at 540 nm was performed in three patients. Coagulation of the capillary blood plexus without damaging the epidermis and superficial dermis was shown to be possible for laser energy densities between 5 J/cm2 and 6.5 J/cm2. Vascular destruction was realised up to about 0.3 mm dermal depth. After 5 months the skin was perfectly normal. A comparison with argon laser treatment was made.     

Treatment of superficial cutaneous pigmented lesions by melanin-specific selective photothermolysis using the Q-switched ruby laser.

The Q-switched ruby laser at 694 nm, a wavelength well absorbed by melanin relative to other optically absorbing structures in skin, causes highly selective destruction of pigment-laden cells. In addition, the 20-nsec pulse duration produced by this laser approximates the thermal relaxation time for melanosomes, thereby confining the energy to the target. This new laser system produces clinically significant fading of superficial cutaneous pigmented lesions in patients, without complications such as hypertrophic scarring or changes in the normal skin pigmentation, often seen with conventional laser systems or other therapeutic methods. In ongoing clinical trials at our facility, excellent results have been obtained for lentigines, café-au-lait macules, nevus spilus, Becker's nevi, and ephelides (freckles), without skin scarring or textural or permanent pigment changes. The purpose of this report is to (1) describe the theoretical considerations that can be understood and used by a nonlaser-oriented practitioner involved in achieving selective removal of superficial cutaneous pigmented lesions, and (2) describe the practical application of the device to the clinical management of patients.     

A high-throughput comparative characterization of laser-induced soft tissue damage using 3D digital microscopy

3D digital microscopy was used to develop a rapid alternative approach to quantify the effects of specific laser parameters on soft tissue ablation and charring in vitro without the use of conventional tissue processing techniques. Two diode lasers operating at 810 and 980 nm wavelengths were used to ablate three tissue types (bovine liver, turkey breast, and bovine muscle) at varying laser power (0.3, 1.0, and 2.0 W) and velocities (1–50 mm/s). Spectrophotometric analyses were performed on each tissue to determine tissue-specific absorption coefficients and were considered in creating wavelength-dependent energy attenuation models to evaluate minimum heat of tissue ablations. 3D surface contour profiles characterizing tissue damage revealed that ablation depth and tissue charring increased with laser power and decreased with lateral velocity independent of wavelength and tissue type. While bovine liver ablation and charring were statistically higher at 810 than 980 nm (p?<?0.05), turkey breast and bovine muscle ablated and charred more at 980 than 810 nm (p?<?0.05). Spectrophotometric analysis revealed that bovine liver tissue had a greater tissue-specific absorption coefficient at 810 than 980 nm, while turkey breast and bovine muscle had a larger absorption coefficient at 980 nm (p?<?0.05). This rapid 3D microscopic analysis of robot-driven laser ablation yielded highly reproducible data that supported well-defined trends related to laser–tissue interactions and enabled high throughput characterization of many laser–tissue permutations. Since 3D microscopy quantifies entire lesions without altering the tissue specimens, conventional and immunehistologic techniques can be used, if desired, to further interrogate specific sections of the digitized lesions.     

Mathematical modeling of 980-nm and 1320-nm endovenous laser treatment

BACKGROUND AND OBJECTIVES: Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein (GSV) and small saphenous vein (SSV). Numerous studies have since demonstrated that this technique is both safe and efficacious. ELT was presented initially using diode lasers of 810 nm, 940 nm, and 980 nm. Recently, a 1,320-nm Nd:YAG laser was introduced for ELT. This study aims to provide mathematical modeling of ELT in order to compare 980 nm and 1,320 nm laser-induced damage of saphenous veins. STUDY DESIGN/MATERIALS AND METHODS: The model is based on calculations describing light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation, and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma, Inc., Arlington, MA). Calculations were performed so as to determine the damage induced in the intima tunica, the externa tunica and inside the peri-venous tissue for 3 mm and 5 mm vessels (considered after tumescent anesthesia) and different linear endovenous energy densities (LEED) usually reported in the literature. RESULTS: Calculations were performed for two different vein diameters: 3 mm and 5 mm and with LEED typically reported in the literature. For 980 nm, LEED: 50 to 160 J/cm (CW mode, 2 mm/second pullback speed, power: 10 W to 32 W) and for 1,320 nm, LEED: 50 to 80 J/cm (pulsed mode, pulse duration 1.2 milliseconds, peak power: 135 W, repetition rate 30 Hz to 50 Hz). DISCUSSION AND CONCLUSION: Numerical simulations are in agreement with LEED reported in clinical studies. Mathematical modeling shows clearly that 1,320 nm, with a better absorption by the vessel wall, requires less energy to achieve wall damage. In the 810-1,320-nm range, blood plays only a minor role. Consequently, the classification of these lasers into hemoglobin-specific laser wavelengths (810, 940, 980 nm) and water-specific laser wavelengths (1,320 nm) is inappropriate. In terms of closure rate, 980 nm and 1,320 nm can lead to similar results and, as reported by the literature, to similar side effects. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT.     

Modified Superlong Pulse 810 nm Diode Laser in the Treatment of Pseudofolliculitis Barbae in Skin Types V and VI

BACKGROUND: Laser hair removal is a well-established therapy for pseudofolliculitis barbae, but there have been few studies on the use of a very-long-pulse 810 nm diode laser for this condition. OBJECTIVE: To determine the efficacy and tolerability of a modified 810 nm superlong-pulse diode laser (Palomar Medical, Burlington, MA, USA) in the treatment of pseudofolliculitis barbae (PFB) in subjects with type V and VI skin. METHODS: Thirteen patients were treated three times at 2-week intervals on one side of their neck with varying fluences. They were evaluated for (1) reduction of shaving bumps and (2) pain tolerance on the treated versus the untreated side. RESULTS: There was a statistically significant improvement in shaving bumps. The treatment side showed a baseline PFB lesion count of 22.5 (+/- 20 SD), which decreased to a mean of 5 (+/- 5 SD) (p<.05). The control baseline mean count was 27.6 (+/- 22 SD) and at the end of the study was 15 (+/- 12 SD) (p = .13). Pain was rated at 2.5 of 10 for subjects treated both with and without anesthetic. The margin of safety was greater in type V compared with type VI skin. CONCLUSION: A modified 810 nm superlong-pulse diode laser is both effective and well tolerated in the reduction of shaving bumps, especially in patients with type V skin.     

Hair Reduction Using a Scanning 800 nm Diode Laser

BACKGROUND: Numerous lasers are currently available for hair removal, yet there are still few studies that have examined the role of fluence, light dose, hair color, and treatment number in laser hair reduction. OBJECTIVE: To demonstrate the efficacy and safety of a scanning 800 nm diode laser for hair reduction. METHODS: An 800 nm scanning diode laser was used to deliver 24, 38, or 48 J/cm2 to a 3 cm x 3 cm area of skin located on the back, groin/bikini area, or thigh in 36 adult patients with varying shades of brown or black hair. Patients received one to four treatments during the course of the study. Hair loss was evaluated at both 30 and 90 days after final treatment. Biopsies were obtained from 20 consenting patients. RESULTS: Significant fluence-dependent hair reduction was demonstrated between treatment and control groups. At 48 J/cm2, the highest dose, a mean hair reduction of 43% was achieved 30 days after the final treatment, and 34% was achieved 90 days after the final treatment. Darker hairs were more effectively treated than lighter hairs. CONCLUSIONS: Hair reduction can be safely and effectively achieved using a scanning 800 nm diode laser.     

Treatment of Facial Venous Malformations with Combined Radiofrequency Current and 900 nm Diode Laser

BACKGROUND: Laser treatment of venous malformations is a major challenge because of the large variations in skin pigmentation, anatomic location, and vessel size and depth. OBJECTIVE: To determine the safety and effectiveness of electro-optical synergy, a new technology that combines the 900 nm diode laser with radiofrequency current for the treatment of facial venous malformation. METHODS: Fourteen patients with Fitzpatrick skin types II to IV were treated for facial venous malformations with simultaneous radiofrequency energy (60-80 J/cm3) and optical diode laser energy (fluence 80-100 J/cm2) in one to three sessions. All lesions measured less than 100 cm2. Lesion clearance was evaluated by three specialists on the basis of digital photographs taken before the first treatment and 1 and 2 months after the last treatment. RESULTS: Thirteen patients showed a complete response and one patient a partial response. The results were rated excellent in the 13 patients and good in one patient. Transient swelling, erythema, and pain were present in all patients, with permanent scarring in only one patient. CONCLUSION: The combination of laser light and radiofrequency energy is effective and safe for the treatment of facial venous malformations. It provides additional heating of the vessels without increasing laser intensity. The side effects are minimal.     

The Use of a New Diode Laser for Hair Removal

BACKGROUND: Diode and long-pulse 1064 Nd:YAG lasers, because of their long wavelengths and extended pulse durations, have gained popularity over the last several years for photoepilation in individuals with dark skin phenotypes. OBJECTIVE: To analyze the clinical efficacy and histologic features of a new 810-nm diode laser in the treatment of unwanted hair in individuals with Fitzpatrick skin types II-IV. METHODS: Twenty-four female subjects (mean age, 33; range, 17-53) were treated three times at monthly intervals with the MeDioStara diode laser (Zeiss-Meditech, Jenna, Germany): wavelength 810 nm, spot size 12 mm, pulse duration 50 msec; fluence 25-35 J. Patients had skin types II-IV and light to dark brown hair. Hair counts were carried out using handheld magnifiers at baseline and at months 1, 2, 3, and 6. Six individuals had biopsies taken after treatment and at 3 and 6 months. RESULTS: A mean hair removal efficiency of 74% and 79% was noted at 3 and 6 months, respectively, and was best in those individuals with skin type III. Hair counts after treatment and at last follow-up were significantly lower when compared with the baseline counts (P<0.0001). Histologic analysis revealed a range from early catagen induction to complete follicular destruction. CONCLUSIONS: This study supports the clinical photoepilatory efficiency of a new 810-nm diode laser in producing 70% clinical hair removal efficiency at 6 months. Histopathologic evaluation suggests that this decrease in hair counts is probably secondary to heat trauma to the follicular epithelium, resulting in complete follicular destruction and stopping of anagen phase.     

Laser treatments on skin enhancing and controlling transdermal delivery of 5-fluorouracil

BACKGROUND AND OBJECTIVE: Laser ablation of stratum corneum (SC) enhances transdermal delivery of hydrophilic drugs. The influence of the infrared (IR) (lambda = 1,064 nm), visible (lambda = 532 nm), and ultraviolet (UV) (lambda = 355 nm) radiations of a Nd:YAG laser on transdermal delivery of 5-Fluorouracil (5-Fu) across skin was studied in vitro. MATERIALS AND METHODS: Pinna skin of the inner side of rabbit ear, was used for the skin permeation. The light source for laser treatment was a Q-switched Nd:YAG laser (Lotis TII SL-2132). Ablation thresholds were estimated by using a photoacoustic technique. In addition, permeation study, and morphological and structural skin examination by histology and differential scanning calorimetry (DSC) were carried out. RESULTS: A significant increase in the permeation of 5-Fu across skin pre-treatment with the three different wavelengths studied was obtained. Since irradiation at 1,064 nm allows deep penetration of the radiation, collagen fibers were affected [7.7 J/cm(2) (15 Hz)]. Visible radiation of Nd:YAG laser showed the wider range of fluences (3-8.4 J/cm(2) at 15 Hz) to enhance skin delivery of 5-Fu, without risk of skin lesion. UV radiation required minor energy contribution to produce the same effects within a narrower range of fluences [0.3 J/cm(2) (5 Hz)-1.5 J/cm(2) (15 Hz)] so the process is less controlled and this radiation shows greater impact on the lipidic structure than visible and IR radiations. CONCLUSIONS: Use of the visible radiation of a Nd:YAG laser is a good method for improving the efficacy of topical chemotherapy of 5-Fu.