Biological effect of laser-assisted scar healing (LASH) on standardized human three-dimensional wound healing skin models using fractional non-ablative 1540 nm Er:Glass or 1550 nm diode lasers.

PURPOSE: In postoperative wound healing after surgical operations or ablative laser treatments, recent studies suggest the timely use of non-ablative fractional laser treatments with the aim to improve wound healing and prevent pathological scar formation. However, the underlying molecular mechanisms are poorly understood. The aim of this study was to investigate the effects of laser-assisted scar healing (LASH) at the molecular level and to combine it with already established wound healing-promoting local treatments. METHODS: We irradiated full-thickness 3D skin models with a fractional ablative Er:YAG laser to set standardized lesions to the epidermal and upper dermal layer. Subsequently, LASH was induced by irradiating the models with either a fractional non-ablative 1540 nm Er:Glass or 1550 nm diode laser. In addition, we tested the combination of non-ablative fractional laser treatment and topical aftercare with a dexpanthenol-containing ointment (DCO). RESULTS: Histological analysis revealed that models irradiated with the 1540 nm Er:Glass or 1550 nm diode laser exhibited accelerated but not complete wound closure after 16 h. In contrast, additional topical posttreatment with DCO resulted in complete wound closure. At gene expression level, both non-ablative laser systems showed similar effects on epidermal differentiation and mild anti-inflammatory properties. The additional posttreatment with DCO enhanced the wound-healing effects of LASH, especially the upregulation of epidermal differentiation markers and anti-inflammatory cytokines at the gene expression level. CONCLUSION: This in vitro study deciphers the biological effects of LASH with a fractional non-ablative 1540 nm Er:Glass or a 1550 nm diode laser in 3D skin models. These data help to better understand the biological properties of the LASH technique and is important to optimize its application.

A prospective, randomized, double-blind comparison of an ablative fractional 2940-nm erbium-doped yttrium aluminum garnet laser with a nonablative fractional 1550-nm erbium-doped glass laser for the treatment of photoaged Asian skin.

BACKGROUND: As compared with ablative fractional CO2 laser, ablative fractional erbium-doped yttrium aluminum garnet (Er:YAG) laser is considered to be a more suitable treatment option for photoaged skin in Asians due to the lower incidence of postinflammatory hyperpigmentation. OBJECTIVE: To compare the efficacy and safety of ablative fractional Er:YAG laser (ablative fractional resurfacing [AFR]) and nonablative fractional 1550-nm Er:glass laser (non-AFR [NAFR]) in the treatment of photoaging. METHODS: This was a prospective, randomized, double-blinded comparative study. In three sessions, at four-week intervals, 19 patients received Er:YAG AFR, and 15 patients received Er:glass NAFR. Pigmentation, uneven tone/erythema, wrinkles and overall features of photoaging were scored. Patient satisfaction, adverse effects and pain scores were recorded. Melanin and erythema indexes were measured. RESULTS: Reductions in pigmentation and uneven tone/erythema scores were significantly greater after Er:YAG AFR, while wrinkle score reduction was significantly greater after Er:glass NAFR. Physician and patient assessments for the overall features showed greater improvement in the Er:glass NAFR. Treatment-related pain or adverse events were less in the Er:YAG AFR. CONCLUSION: Both Er:YAG AFR and Er:glass NAFR are effective and safe and could be used in a complementary manner for treating photoaged Asian skin.

Láser fraccional en estrías de distensión / Fractional laser in distension stretch marks

Introducción: Las estrías de distensión son frecuentes y representan un problema estético importante. Se han intentado múltiples terapias, no habiendo ninguna realmente efectiva. Objetivo: Evaluar respuesta al tratamiento con láser fraccional en estrías de distensión. Método: Estudio retrospectivo en trece pacientes con estrías. Fueron tratados con cuatro sesiones de láser fraccional Er: Glass Mosaic Lutronic ®. Se consignó edad, sexo, tipo de estría (roja o blanca), causa (posembarazo, adolescencia y otras) y fototipo. Fueron evaluados con control fotográfico y una escala de satisfacción subjetiva. Para el análisis estadístico se utilizó el test exacto de Fisher. Resultados: Se incluyeron trece pacientes. Nueve pacientes (69,2 por ciento ) consideraron una franca mejoría después del tratamiento, tres(23,1 por ciento) una mejoría parcial y un caso (7,7 por ciento), ausencia de cambios. No hubo diferencias significativas entre estrías blancas y rojas. Discusión: La terapia láser fraccional fue efectiva tanto para el tratamiento de estrías rojas como blancas.

Introduction: Stretch marks are common and represent a major cosmetic problem. Many therapies have been tried not being any truly effective. Objective: To evaluate response to treatment with fractional laser in distension stretch marks. Methods: A retrospective study in patients with stretch marks, who were treated with 4 sessions of fractional laser Er: Glass Mosaic Lutronic ®. We recorded age, sex, type of stretch mark (red or white), cause (post pregnancy, adolescence, etc.) and phototype. Patients were evaluated with photographic control and a subjective satisfaction scale. For statistical analysis we used the Fisher test. Results: We included 13 patients. 9 patients (69.2 percent had a marked improvement after treatment, three (23.1 percent) partial improvement and one case (7.7 percent), no change. There were no significant differences between white and red striae. Discussion: The fractional laser therapy was effective for the treatment of both red and white stretch marks.

Treatment of Striae Distensae with Nonablative Fractional Laser versus Ablative CO(2) Fractional Laser: A Randomized Controlled Trial.

BACKGROUND: Striae distensae are atrophic dermal scars with overlying epidermal atrophy causing significant cosmetic concern. Although a variety of laser and light sources have been used for the treatment of striae distensae, to date no definite 'gold standard' treatment modality has been determined. OBJECTIVE: To assess and compare the efficacy and safety of nonablative fractional photothermolysis and ablative CO(2) fractional laser resurfacing in the treatment of striae distensae. METHODS: Twenty-four ethnic South Korean patients with varying degrees of atrophic striae alba in the abdomen were enrolled in a randomized blind split study. The patients were treated with 1,550 nm fractional Er:Glass laser and ablative fractional CO(2) laser resurfacing. Each half of the abdominal lesion was randomly selected and treated three times at intervals of 4-weeks using the same parameters. Digital photography was conducted and skin elasticity and the width of the widest striae in each subject were measured at the baseline and 4 weeks after the final treatment. Clinical improvement was assessed by comparing pre- and post-treatment clinical photographs by two blinded physicians and participant satisfaction rates were evaluated. Skin biopsies were taken from three participants. All adverse effects were reported during the study. RESULTS: Although they do not statistically differ, both treatments with nonablative fractional laser and ablative CO(2) fractional laser showed a significant clinical and histopathologic improvement of striae distensae over pretreatment sites. CONCLUSION: These results support the use of nonablative fractional laser and ablative CO(2) fractional laser as effective and safe treatment modalities for striae distensae of Asian skin. However, neither treatment showed any greater clinical improvement than the other treatment.

Treatment of Striae Distensae with Nonablative Fractional Laser versus Ablative CO2 Fractional Laser: A Randomized Controlled Trial

BACKGROUND: Striae distensae are atrophic dermal scars with overlying epidermal atrophy causing significant cosmetic concern. Although a variety of laser and light sources have been used for the treatment of striae distensae, to date no definite 'gold standard' treatment modality has been determined. OBJECTIVE: To assess and compare the efficacy and safety of nonablative fractional photothermolysis and ablative CO2 fractional laser resurfacing in the treatment of striae distensae. METHODS: Twenty-four ethnic South Korean patients with varying degrees of atrophic striae alba in the abdomen were enrolled in a randomized blind split study. The patients were treated with 1,550 nm fractional Er:Glass laser and ablative fractional CO2 laser resurfacing. Each half of the abdominal lesion was randomly selected and treated three times at intervals of 4-weeks using the same parameters. Digital photography was conducted and skin elasticity and the width of the widest striae in each subject were measured at the baseline and 4 weeks after the final treatment. Clinical improvement was assessed by comparing pre- and post-treatment clinical photographs by two blinded physicians and participant satisfaction rates were evaluated. Skin biopsies were taken from three participants. All adverse effects were reported during the study. RESULTS: Although they do not statistically differ, both treatments with nonablative fractional laser and ablative CO2 fractional laser showed a significant clinical and histopathologic improvement of striae distensae over pretreatment sites. CONCLUSION: These results support the use of nonablative fractional laser and ablative CO2 fractional laser as effective and safe treatment modalities for striae distensae of Asian skin. However, neither treatment showed any greater clinical improvement than the other treatment.