Histological and quantitative morphometric evaluation of striae distensae treated by long-pulsed 1064-nm Nd:YAG laser

Background: Striae distensae are frequent undesirable skin lesions that result in considerable esthetic concern. Treatment has always been challenging. Several modalities are available; however, none of them is consistently effective. Laser has become a popular therapeutic alternative. Objective: The aim of this study was to evaluate the possible therapeutic effect of a long-pulsed 1064 nm Nd:YAG laser in striae distensae using histological and quantitative morphometric studies. Patients and methods: Forty female patients with striae (group I: striae rubra and group II: striae alba) were included. All patients received four laser sessions at 4-week intervals. Three skin biopsies were obtained from every patient: one from normal control skin, the second from the selected striae before treatment, and the third from the same striae 1 month after treatment. Paraffin-embedded skin sections were subjected to histological and quantitative morphometric studies for assessment of collagen and elastic fibers. Results: In both groups, some clinical improvement was achieved, which was statistically nonsignificant. However, histological examination showed increased collagen and decreased elastic fibers with reorganization after treatment. The image analyzer showed a significant quantitative increase in the mean area percent of collagen fibers and decrease in the mean area percent of elastic fibers. Side effects were nonsignificant, mostly pain during the session and pigmentary alterations. Conclusion: Although the clinical improvement in the treated striae was nonsignificant, the histological improvement was significant, with few side effects. The use of different laser parameters with a long follow-up period may improve the clinical response.