(18) The treatment of portwine stains with the tunable dye laser at 577 nm

The treatment of portwine stains (PWS) by lasers has become established as the treatment of choice in recent years. Most experience has been with the argon laser which emits predominantly at 488 and 514 nm. These wavelengths do not coincide with the absorption maxima of haemoglobin at 415, 542 and 577 nm. Light at 577 nm is particularly well transmitted through the epidermis and selectively absorbed by haemoglobin. We have been treating patients with PWS with a Coherent CR599 argon-pumped continuous wave tunable dye laser emitting at 577 nm.
Seventy-one patients with PWS have been treated in Leeds, mean age 36·9 years, range 11–61 years. Ninety-six per cent had PWS on the face or neck. The majority were treated under local anaesthesia; the longest follow-up has been 42 months.
The minimal blanching method was used¹ with a spot diameter of 1 mm, power range of 0·3 – 0·5 W in most patients, with a pulse duration of 0·5–2 s. Energy fluence was 38–63 J/cm².
Improvement in the treated area from partial to complete paling occurred in 75% with scarring in 5% which was usually atrophic, and minor pigmentary changes in 7%.
These results are comparable with the best series reported from argon laser therapy and confirm the theoretical advantage of treatment with laser light at 577 nm.     

Treatment of vascular lesions in pigmented skin with the pulsed dye laser

BACKGROUND: Vascular lesions occurring in African-American patients are often not treated because of the risk of local side effects. OBJECTIVE: The study was to determine the efficacy of the flashlamp-pumped dye (FLPD) laser in the treatment of vascular malformations in African-American patients. METHODS: All lesions in three patients were treated with the FLPD laser using a 585 nm wavelength, 5 mm spot size, 450 pulse width, and fluences ranging from 6.5 to 8.5j per cm2. CONCLUSION: The FLPD was effective in treating vascular malformations. Transient changes in colour and skin texture occurred at the treated sites.     

Pulsed dye laser treatment of vascular lesions in childhood

Almost all congenital vascular abnormalities affect the skin and are evident from birth or become so during the first few weeks of life. The two most common types of vascular birthmarks, hemangiomas and vascular malformations, may appear to be very similar but their course and treatment are different. Hemangiomas appear in the first few weeks of life and usually regress spontaneously over time. Vascular malformations are always present from birth even though they might not be apparent, never disappear and often grow during the person's lifetime and may vary extremely from high blood flow lesions, sometimes located in critical sites that may be life-threatening to asymptomatic spots of mere aesthetic concern. Laser therapy nowadays has become indispensable in the management of pediatric vascular lesions. With a proper balance of wavelength, energy density and pulse duration, the laser energy of thermo coagulation could be molded to effectively manage different lesions. Both dermatology and plastic surgery have been transformed by understanding vascular lesions biology and modern laser technology. As a result, we can now provide an optimal selective treatment with minimal collateral damage. Although alternatives such as the potassium titanyl phosphate (KTP), red/infrared (IR), or intense pulsed light lasers are available, pulsed dye lasers continue to be the standard of care for the majority of pediatric vascular lesions.     

Ultrastructure: effects of melanin pigment on target specificity using a pulsed dye laser (577 nm)

It has been shown recently that brief pulses of 577 nm radiation from the tunable dye laser are absorbed selectively by oxyhemoglobin. This absorption is associated with highly specific damage to superficial vascular plexus blood vessels in those with lightly pigmented (type I-II) skin. To determine whether pigmentary differences in the overlying epidermis influence this target specificity, we exposed both type I (fair) and type V (dark) normal human skin to varying radiant exposure doses over 1.5-microsecond pulse durations from the tunable dye laser at a wavelength of 577 nm. Using ultrastructural techniques, we found in type I skin that even clinical subthreshold laser exposures caused reproducible alterations of erythrocytes and adjacent dermal vascular endothelium without comparable damage to the overlying epidermis. In contrast, degenerated epidermal basal cells represented the predominant form of cellular damage after laser exposure of type V skin at comparable doses. We conclude that epidermal melanin and vascular hemoglobin are competing sites for 577 nm laser absorption and damage, and that the target specificity of the 577 nm tunable dye laser is therefore influenced by variations in epidermal pigmentation. This finding is relevant to the clinical application of the tunable dye laser in the ablative treatment of vascular lesions. We also found on ultrastructure that the presence of electron-lucent circular structures of approximately 800 A in diameter were observed only at and above clinical threshold doses in those with type I skin and at the highest dose of 2.75 J/cm2 in type V skin. It has been proposed that these structures might be heat-fixed molds of water vapor. Both this and ultrastructural changes of epidermal basal cells demonstrate mechanisms responsible for alteration of tissue after exposure to 577 nm, which are discussed.     

Copper vapour laser (578 nm) and flashlamp-pumped pulsed tunable dye laser (585 nm) treatment of port wine stains: results of a comparative study using test sites

The copper vapour laser (CVL), emitting at 578 nm, has recently become available for treating vascular skin lesions. Its place in the management of port wine stains (PWS) requires clarification. We have compared a CVL with a pulsed tunable dye laser (PTDL; 585 nm) in 43 patients with macular, blanchable PWS. Test areas were performed with the CVL, using a Hexascan and an energy fluence just sufficient to produce immediate tissue change (mean fluence 18.2J/cm² and mean pulse width 50 ms). Test areas were performed with the PTDL using a 5-mm spot at 6.5 J/cm². Assessments were made after 4 months, subjectively using a clinical fading score and objectively using an index of light absorbence derived from reflectance spectrophotometry. The fading produced by the PTDL was significantly better than the CVL, as determined by clinical assessment (mean fading scores 2.41 and 1.67, respectively, P<0.0005) and reflectance spectrophotometry (mean absorbence index 149 and 157 respectively, P<0.0005). These results indicate that the PTDL is the preferred treatment for most macular, blanchable PWS. However, in a proportion of lesions responses were equivalent with both lasers, and in a small proportion, the CVL produced a better response.     

Pulsed dye laser (577 nm) treatment of portwine stains: ultrastructural evidence of neovascularization and mast cell degranulation in healed lesions

Portwine stains were examined before, immediately after, and 1 yr after successful clearance by a pulsed dye laser (577 nm) using ultrastructural techniques. Dilated vascular channels and mast cell hypoplasia characterized lesional skin before treatment. Immediately after treatment, widespread selective vessel necrosis, similar to changes previously described, was observed. One year after laser irradiation, the abnormally ectatic portwine stain vessels had been replaced by small venules and arterioles, similar in number and diameter to blood vessels in normal skin; the only difference noted was that these new vessels were surrounded by easily identifiable mast cells. Many of these mast cells exhibited evidence of activation and degranulation. We conclude that mast cells may play an important role in the neovascularization of portwine stains treated by 577-nm dye laser irradiation.     

Patient-reported morbidity following flashlamp-pumped pulsed tunable dye laser treatment of port wine stains

Sixty-two patients with port wine stains completed a questionnaire related to their flashlamp-pumped pulsed tunable dye laser treatment. The treatment wtis well tolerated by the majority. Forty-eight per cent of patients experienced some weeping or crusting after treatment. The major cause of morbidity was protracted bruising following treatment, and this caused a significant restriction of activities in 45% of patients.     

Treatment of angioma serpiginosum using a pulsed tunable dye laser

Angioma serpiginosum (AS) is a rare vascular naevoid disorder due to ectatic dilation of capillaries in the papillary dermis. The condition is found almost exclusively in females who have grouped erythematous punctate lesions usually on the lower limbs or buttocks, which may be unsightly. We report five patients with AS treated using a Candela SPLTl pulsed tunable dye laser. All patients had a good to excellent response. The lesion resolved in tine patient, virtually resolved in two and is considerably improved in a further patient in whom treatment is continuing. In one patient, the angiomatous lesion improved but the patient developed hyperpigmentation at the treatment site and the treatment has been temporarily suspended. The results suggest that treatment using the pulsed dye laser is very effective for AS and, in most patients, produces an excellent cosmetic result.     

Objective assessment of port-wine stains following treatment with the 585 nm pulsed dye laser

Previous studies assessing the treatment of port-wine stains (PWS) with the 585 nm pulsed dye laser have relied on either subjective clinical assessment or in vivo measurement of skin colour alone. The aim of the present retrospective study was to develop an objective method of assessing available pre- and post-treatment photograph pairs. Port-wine stains depicted in photographs of 23 patients following six or more treatment sessions were assessed for changes in colour (DeltaH*) and PWS size by computer image analysis and were compared with a subjective assessment of PWS reduction by a "blinded" physician examining the same images. The post-treatment mean reduction in the PWS assessed by the physician was 39.7%. A global assessment score incorporating values of DeltaH* and PWS size by computer analysis showed a mean reduction of 12%, with a more significant correlation with the physician assessment (Spearman's rank correlation coefficient 0.627; P=0.001) than changes in size or colour alone.     

The treatment of port-wine stains with the pulsed dye laser at 600 nm

The standard wavelength in the treatment of port-wine stains (PWS) with the pulsed dye laser is 585 nm. In many cases, the response to therapy is not adequate despite many treatments, depending partly on vessels out of reach of the laser. Longer wavelengths penetrate deeper into the dermis, but are absorbed less by oxyhaemoglobin, and require higher fluences. In this study, 22 patients with PWS were treated with the flashlamp-pumped pulsed dye laser using two different wavelengths, 585 and 600 nm. Four adjacent sites with PWS were treated on one occasion with 585 nm, 600 nm and equal fluence, and with 1.5 and 2 times the 585 nm fluence. The test areas were examined blindly, by four evaluators, an average of 12.5 weeks later. There was significantly less lightening with 600 nm than with 585 nm (P0.001) when equal fluences were used. When 1.5 and 2 times the 585 nm fluence were applied, with 600nm the lightening was equal to that after 585 nm. However, in individual cases (11 of 22) 600 nm showed a superior lightening of at least 20% compared to 585 nm. There was slight hyperpigmentation and hypopigmentation, but no atrophy or scarring. In conclusion, 585 nm remains the wavelength of choice in treatment of PWS with the pulsed dye laser. However, in cases that do not respond satisfactorily with 585 nm, it may be worth trying 600 nm with a fluence that is at least 1.5–2 times the 585 nm fluence.     

Efficacy of 577 nm pro-yellow laser in the treatment of melasma: a prospective split-face study

ABSTRACT

We aimed to study the effectiveness of 577 nm pro-yellow laser in the treatment of melasma. A total of 82 patients with melasma were included in this comparative study. A detailed medical history, examination, and calculation of Melasma Area and Severity Index were done for all patients. All participants were treated with topical sunscreen and hydroquinone 4% cream on both sides of the face. In addition, the left side of the face was subjected to a single pass of 577-nm pro-yellow laser at a monthly interval for three sessions. Follow up was done by comparing the Melasma area and severity index at 0, 3 and 6 months. At baseline, there is no significant difference in the Melasma area and severity index score between both sides of the face. At 3 months, MASI score was statistically significantly decreased on both sides of the face compared to pretreatment (P < .05). At 6 months, the mean MASI score at the laser-treated side was statistically significantly decreased compared to the non-laser-treated side (P < .05). we concluded that the addition of 577 nm pro-yellow laser in the treatment of melasma leads to maintain the improvement and reduction of the recurrence rate.     

High-fluence fractional treatment of photodamaged facial skin using a 2940 nm erbium:yttrium-aluminum-garnet laser

Abstract

Introduction: Fractional resurfacing with an Erbium:yttrium-aluminum-garnet (Er:YAG) 2940 nm laser is an increasingly popular option for the treatment of the signs of facial photoaging, which include wrinkles as well as pigmentation issues and unwanted textural changes. Fractional treatment has produced favorable clinical responses, but with less complications and shorter recovery times than traditional laser resurfacing. This study was conducted to evaluate a fractionated Er:YAG treatment regimen of 1–2 higher fluence sessions with a multiple-pass technique. Materials and methods: Eight subjects with moderate to severely photodamaged facial skin received one to two full-face laser treatments. Multiple-pass (MP) treatment results were evaluated in terms of procedure time, discomfort, social downtime and effectiveness. A photographic evaluation, subject improvement assessments and a subject satisfaction assessment were performed. Results: An investigator's photographic review showed a 26–75% improvement in the signs of overall photoaging. Subjects treated with the MP technique exhibited a relatively short 3–4 day downtime and ratings of mostly moderate discomfort with the use of topical anesthetic cream only. Subjects treated with higher fluences demonstrated the highest average improvement in specific features of photoaging. Two laser treatments resulted in substantially higher improvement scores than those received just one laser treatment.     

Efficacy of a 2–mm spot size lens for the treatment of superficial vascular lesions with a flashlamp-pumped dye laser

Background The flashlamp-pumped dye laser, using either a 3 or 5 mm spot size, is an excellent instrument for the treatment of port-wine stains and other superficial cutaneous vascular lesions. Problems exist with patient acceptance due to prominent and prolonged blue-black discoloration and the pain associated with the treatment. Objective To assess the effectiveness of a flashlamp-pumped dye laser equipped with a 2 mm spot size lens in the treatment of superficial vascular lesions. Methods Twenty-one patients with telangiectasias, cherry angiomas, and angiokeratomas were treated at a variety of fluences. Results Three of 21 patients had complete clearing of their superficial vascular lesions. An improvement of greater than 75% was noted by 11 patients, and six patients noted a 50%–75% improvement. One patient had less than 50% improvement. Less post-treatment discoloration and less pain were noted with the 2 mm spot size lens. Conclusions The 2 mm spot size lens, used with the flashlamp-pumped dye laser is an effective instrument for the treatment of superficial cutaneous vascular lesions.     

New approaches to the laser treatment of vascular lesions

The pulsed dye laser (PDL) was developed based on the concept of selective photothermolysis. Using a wavelength of light well absorbed by the target and a pulse duration short enough to spatially confine thermal injury, specific vascular injury could be produced. While the PDL revolutionized the treatment of port wine stains (PWS) and a variety of other vascular lesions, the mathematical model predicted that the ideal thermal relaxation time for the vessels in PWS is actually 1-10 msec, not 450 microseconds. These original theoretical calculations have been proved correct recently in a study using both an animal vessel model and in human PWS. Longer wavelengths of light within the visible spectrum penetrate deeper into the skin and are more suitable for deeper vessels; while longer pulse duration is required for larger calibre vessels. A variety of lasers have been developed recently for the treatment of vascular lesions that incorporate these concepts into their design, including PDL at 1.5 msec, a filtered flash-lamp pulsed light source with pulse durations of 1-20 msec, several 532 nm pulsed lasers with pulse durations of 1 to as high as 100 msec, long pulsed alexandrite lasers at 755 nm with pulse durations up to 20 msec, pulsed diode lasers in the 800-900 nm range, and long pulsed 1064 Nd:YAG sources. Preliminary results are encouraging.