Varying ratios of wavelengths in dual wavelength LED photomodulation alters gene expression profiles in human skin fibroblasts.

BACKGROUND AND OBJECTIVE: LED photomodulation has been shown to profoundly influence cellular behavior. A variety of parameters with LED photomodulation can alter cellular response in vitro. The effects of one visible and one infrared wavelength were evaluated to determine the optimal ratio to produce a net increase in dermal collagen by altering the ratio of total energy output of each wavelength. The ratio between the two wavelengths (590 and 870 nm) was shifted in 25% increments. STUDY DESIGN/MATERIALS AND METHODS: Human skin fibroblasts in culture were exposed to a 590/870 nm LED array with total combined energy density fixed at 4.0 mW/cm.. The ratio of 590/870 nm tested parameters were: 100/0%, 75/25%, 50/50%, 25/75%, and 0/100%. These ratios were delivered using pulsed duty cycle of exposure (250 milliseconds "on" time/100 milliseconds "off" time/100 pulses) for a total energy fluence of 0.1 J/cm.. Gene expression was examined using commercially available extra cellular matrix and adhesion molecule RT PCR Arrays (SA Biosciences, Frederick, MD) at 24 hours post-exposure. RESULTS: Different expression profiles were noticed for each of the ratios studied. Overall, there was an average (in an 80 gene array) of 6% expression difference in up or downregulation between the arrays. The greatest increase in collagen I and decrease in collagenase (MMP-1) was observed with 75/25% ratio of 590/870 nm. The addition of increasing proportions of IR wavelengths causes alteration in gene expression profile. The ratios of the wavelengths caused variation in magnitude of expression. CONCLUSIONS: Cell metabolism and gene expression can be altered by simultaneous exposure to multiple wavelengths of low energy light. Varying the ratios of specific wavelength intensity in both visible and near infrared light therapy can strongly influence resulting fibroblast gene expression patterns.

Topical anesthetics update: EMLA and beyond.

BACKGROUND: Topical anesthetics remain a powerful, new advance for pain relief prior to cutaneous procedures. They are frequently used by dermatologists to decrease the pain associated with laser pulses, surgical procedures, or soft tissue augmentation. EMLA is the most commonly used agent, however, several new topical anesthetic agents have been released recently that claim increased efficacy and a faster onset of action. OBJECTIVE: We review and compare the efficacy of several commonly used topical anesthetics and provide a look into the future. CONCLUSION: EMLA remains the most widely used topical anesthetic given its proven efficacy and safety by several clinical trials. There has been a recent release of several new topical anesthetic agents with some demonstrating efficacy after a 30-minute application time. A reservoir of anesthetic is located and stored in the upper skin layers during application, providing additional anesthetic benefit 30 minutes after removal. As the options for the practitioner continue to grow, the demand for faster onset, comparative efficacy, and safety trials will continue to be of paramount importance.

The role of dermatologists in the evolution of laser surgery.

The role dermatologists have played throughout the history of laser development is an extremely vital one. The initial interests of Dr. Leon Goldman stimulated many other individual dermatologists to further his work and develop surgical techniques using newer laser systems to provide more effective treatment for patients with a variety of skin diseases. The long list of current cutaneous laser applications developed by dermatologists makes it virtually certain that members of our specialty will continue to play a significant future role in the refinement of laser instrumentation and operative techniques that are inevitable to occur.

Prospective study of hair reduction by diode laser (800 nm) with long-term follow-up.

BACKGROUND: Multiple laser systems are available for the purpose of hair removal. OBJECTIVE: The purpose of this study was to determine the safety and long-term efficacy of the 800 nm, pulsed diode laser at reducing hair count. METHODS: Fifty volunteers, primarily Fitzpatrick skin types II and III, with dark brown or black hair, were treated with a diode laser (800 nm, 10-40 J/cm2, 5-30 msec, 9 mm 9 mm, 5 degrees C chilled handpiece). Each subject had eight treatment sites at varying fluences and pulse durations, as well as a varying number of treatments and pulses. Hair counts were obtained at each site at baseline, 1, 3, 6, 9, and an average of 20 months after treatment. RESULTS: After one treatment, hair regrowths ranged from 22 to 31% at the 1-month follow-up visit, then remained stable between 65 and 75% from the 3-month to the averaged 20-month follow-up. After two treatments there were relatively longer growth delays, with hair regrowths plateauing beginning at 6 months after treatment and ranging from 47 to 66% for the remainder of the follow-up evaluations. Side effects were limited to pigmentary changes, transient in subjects with skin types II and III. CONCLUSIONS: This 800 nm diode laser with a chilled sapphire tip and variable pulse duration is safe and effective for long-term hair reduction in individuals with skin types II and III.

Effects of topical vitamin K and retinol on laser-induced purpura on nonlesional skin.

BACKGROUND: Pulsed dye laser treatments usually result in purpura. Any topical application that eliminates or shortens the duration of purpura would be extremely useful. OBJECTIVE: The purpose of this prospective study was to determine the safety and efficacy of topical vitamin K cream in shortening the duration of laser-induced purpura. METHODS: Twenty adult subjects were enrolled. Each subject had five 1.5 cm sites treated with a pulsed dye laser at 585 nm, 450 nsec, 7 mm spot size at each subject's respective threshold fluence. Each subject had a control site where no topical application was used and four other sites where a different formulation was applied to each for 2 weeks before and for 2 weeks after laser irradiation. Five vitamin K formulations with or without retinol were studied: 3% vitamin K in acrylates copolymer cream, 5% vitamin K in acrylates copolymer cream, 1% vitamin K and 0.3% retinol in acrylates copolymer cream, 1% vitamin K and 0.15% retinol in acrylates copolymer cream, 1% free vitamin K cream. Purpuric discoloration at each site was rated on days 0, 1, 3, 7, 10, and 14 after laser treatment on a quartile scale. Each site was assigned 100% discoloration on day 0 after laser irradiation. RESULTS: Laser-induced purpuric discoloration resolved faster with 1% vitamin K and 0.3% retinol in acrylates copolymer cream than with no topical application. The difference is statistically significant from day 3 onward. CONCLUSION: A combination of 1% vitamin K and 0.3% retinol in acrylates copolymer cream hastened the resolution of laser-induced purpura.

Cryogen spray cooling in combination with nonablative laser treatment of facial rhytides.

BACKGROUND: Cryogen spray cooling can be used to provide epidermal protection while still achieving spatially selective photocoagulation in the upper dermis. The objective of this study is to determine the efficacy and safety of cryogen spray cooling in combination with a nonablative Nd:YAG (lambda = 1320 nm) laser treatment of facial rhytides in human volunteers. OBSERVATIONS: Thirty-five adults with bilateral periorbital rhytides were treated with cryogen spray cooling in combination with 3 nonablative laser treatments performed sequentially at intervals of 2 weeks. Small but statistically significant improvements were noted in the mild, moderate, and severe rhytid groups 12 weeks after the final laser treatment. A final assessment performed 24 weeks after the last treatment showed statistically significant improvement only in the severe rhytid group. The procedure was found to be safe; 4 sites (5.6%) developed transient hyperpigmentation. Two sites (2.8%) subsequently developed barely perceptible pinpoint pitted scars. CONCLUSIONS: Cryogen spray cooling is a safe and effective method for protecting the epidermis during nonablative laser treatment of facial rhytides thereby avoiding much of the morbidity associated with other resurfacing procedures. Minor improvements in rhytides can be achieved with the current technology. Optimization of treatment parameters may further improve these results.

Stress and family satisfaction in parents of children with facial port-wine stains.

A cross-sectional survey was employed to assess parenting stress, family satisfaction, and parental concerns and to determine predictors of stress in parents of children with port-wine stains (PWSs). The participants were 46 parents of 24 children receiving treatment with pulsed dye laser photocoagulation for facial PWS at an outpatient dermatology clinic based at a university medical center. Outcome measures used were self-report instruments assessing psychosocial adjustment (Parenting Stress Index, Family Satisfaction Scale, and Parental Concerns Questionnaire). As a group, parents scored in the average range on the stress and family satisfaction measures when compared with a normative sample; five parents (11%) scored in the clinical range for stress. Forty-nine percent of the variance in parenting stress was accounted for by four variables: the child's age (beta = 0.34; p = 0.031), the parents' degree of family satisfaction (beta = -0.27; p = 0.077), the level of parental concern regarding the child's facial PWS (beta = 0.45; p = 0.005), and the parents' satisfaction with staff communication (beta = -0. 51; p = 0.002). The data suggest that while, as a group, parents of children with a facial PWS report to be in the average range for psychological stress, some do not fare as well as others. Factors associated with lower stress include younger children, more family cohesion and adaptation, fewer parental concerns, and greater satisfaction with parent-staff communication. The potential for the development of medical complications and psychological problems over time suggests the need for treatment of the PWS at an early age. Health care providers should be prepared to screen for clinical levels of distress and to refer parents for psychological intervention when needed.

Scar resurfacing with high-energy, short-pulsed and flashscanning carbon dioxide lasers.

BACKGROUND: Scars have a significant effect on a person's physical and social being. Many treatment modalities for scar improvement such as surgical scar revision, electrosurgical planing, chemical peeling, filler substance implantation, and dermabrasion have been developed. Recently, the resurfacing carbon dioxide (CO2) laser systems have proven to be a useful and safe treatment in the treatment of facial rhytides and acne scarring. OBJECTIVE: The purpose of this study was to evaluate the resurfacing CO2 lasers in the treatment of various surgical, traumatic, acne, and varicella scars. METHODS: Thirty subjects, aging between 14 and 84 years, with surgical, traumatic, acne, or varicella scars were evaluated. Two types of resurfacing laser systems were utilized in this study, a high-energy, short-pulsed CO2 laser and a continuous wave CO2 laser with an optico-mechanical computer flash-scanner. Post-surgical scars were treated with laser resurfacing between 4 and 6 weeks after scar formation. Traumatic, acne, and varicella scars were treated after scar maturation (range, 1-10 years). Scar improvement was evaluated by photographic analysis of before and after images by four independent health care workers using a quartile scale of improvement (< 25%, 25-49%, 50-74%, > 75%) as well as optical profilometry using silicone surface impressions in 12 scars. RESULTS: Twenty of 24 surgical scars had greater than 75% improvement, and 24 of 24 had greater than 50% improvement by photographic analysis. All six traumatic, acne and varicella scars had greater than 50% improvement. Optical profilometry and surface topography maps reveal a significant flattening of related and depressed scars. CONCLUSION: The high-energy, short-pulsed CO2 laser and the continuous wave CO2 laser with flash-scanning attachment are safe and effective as a treatment modality for scar revision. In general, elevated scars improve more dramatically than depressed scars.

Effect of dynamic cooling on 585-nm pulsed dye laser treatment of port-wine stain birthmarks.

BACKGROUND AND OBJECTIVE: The objective of this study was to determine the effectiveness of a dynamic cooling device (DCD), spraying the skin with a brief spurt of cryogen prior to the laser pulse, in reducing transient pain associated with 585-nm pulsed dye laser (PDL) treatment of port-wine stains (PWS), and reducing epidermal damage (hypo/hyperpigmentation) caused by this laser during PWS treatment. MATERIALS AND METHODS: Matched treatment sites were compared with and without the use of the cryogen spray in 47 patients at two investigational sites. Pain ratings, clearance of the PWS, and pigmentation changes were assessed. The results were analyzed by skin type and patient age. RESULTS: A statistically significant reduction in pain ratings was found in all patient groups using the DCD without changing the efficacy of PWS clearance. Pain reduction was most remarkable in patients with darker skin types. Dynamic cooling prevented the occurrence of epidermal damage or pigmentation change in most cases. CONCLUSIONS: This study suggests that dynamic cooling can dramatically diminish pain during PWS treatment with the 585-nm PDL without reducing treatment efficacy. The absence of epidermal damage in most patients suggests that precooling with the DCD may allow the use of higher laser fluences to expedite clearance without inducing epidermal change. Dynamic cooling has potential use with other lasers and different lesions where discomfort and epidermal effects limit therapy.

Histology of laser resurfacing.

The development of high-peak power or scanned CO2 lasers that precisely remove layers of photodamaged skin has provided a novel method of skin rejuvenation. Clinical data suggest that laser resurfacing provides comparable or better results than conventional methods of chemical peeling and mechanical dermabrasion, with a lower risk-to-benefit ratio. Histologic studies of the effects of these lasers on tissue have been helpful in establishing guidelines for appropriate clinical use of these lasers and insights into the mechanisms whereby facial skin rejuvenation is achieved.