RESUMO
Background: The picosecond laser was primarily designed to enhance tattoo removal. Because it has a new innovative mechanism for energy delivery, it has been modified to be used in other conditions such as skin resurfacing, which was usually treated with fractional CO2 laser. Comparing both technologies in managing postburn scars has not been widely addressed. Methods: The current prospective comparative randomized intrapatient study was done on 15 patients who presented with unsightly postburn scarring. As a split study, one-half of the affected areas were treated using the picosecond Nd: YAG laser. The other areas were treated with a fractional CO2 laser. After three treatment sessions, the results were analyzed both objectively and subjectively. Results: The assessment by the image analysis system (Antera camera) showed improvement in all the parameters in both groups. The melanin relative variation decreased from 11.65â ±â 2.86, 15.85â ±â 5.63 to 10.60â ±â 1.96, 12.56â ±â 3.98, respectively in picosecond laser sites and fractional CO2 sites. The percentage change in overall opinion decreased in in favor of the fractional CO2 laser sites, which is a statistically significant improvement. Instead, color scores revealed a greater reduction in the picosecond sites in comparison with the fractional CO2 sites, as it decreased from 7.67â ±â 1.76, 7.73â ±â 1.83 to 2.87â ±â 1.06, 6â ±â 1.2, respectively. Conclusions: When compared with fractional CO2 lasers, picosecond Nd:YAG shows comparable improvements in scars' erythema, texture, and height, with some superiority in the management of hyperpigmented scars.
RESUMO
Introduction: Recently, the monochromatic excimer light (MEL) of 308 nm wavelength has shown some advantages in comparison to narrow band ultraviolet B (NB-UVB) for the treatment of vitiligo. To histopathologically compare the early effects of NB-UVB and 308-nm MEL phototherapy on vitiliginous patches using H&E and HMB-45. Methods: Thirty subjects with non-segmental vitiligo lesions were treated twice a week for 6 weeks with 308-nm MEL, while NB-UVB was used to treat lesions contra laterally. Skin biopsies were taken from lesional areas before and after 6 weeks of treatment by either modality. It was prepared for light microscopy and immunohistochemical study (HMB-45). This study was performed as a clinical trial (Trial registration: http://www.pactr.org; Identifier: PACTR201705002279419) Results: All lesions before treatment had labeling index (number of pigmented cells/non-pigmented cells) of 0.0 (0%). After treatment the LI for MEL was 4.2 ± 2.6, while for NB-UVB LI it was 0.3 ± 0.7. MEL showed higher statistical significance regarding increase of basal pigmented cells, and significant decrease in vacuolated keratinocytes and basal membrane thickness than NB-UVB. Conclusion: Although NB-UVB is considered as treatment of choice for vitiligo, MEL is acknowledged as an effective treatment modality for vitiliginous lesions that induces more repigmentation than NB-UVB, and more rapidly, as confirmed by our study.