Evaluation of an ablative and non-ablative laser procedure in the treatment of striae distensae

Background: Striae distensae or stretch marks are atrophic linear dermal scars with epidermal atrophy. There are many therapeutic options for management, but no consistently effective modality is available yet. Objective: We compared the efficacy of 1064 nm long pulse (LP) Nd: YAG laser and 2940 nm variable square pulse (VSP) erbium: YAG laser in the treatment of striae distensae. Methods: Twenty female volunteers (Fitzpatrick skin types II-V) aged between 20 and 40 years with striae (3 patients with the rubra type and 17 with the alba type) were enrolled in the study. The duration of striae ranged from 4 months to 12 years. Lesions were located on the abdomen in all patients except one patient who had striae on the arms and two patients with striae in the lumbar region. Treatments were randomly allocated to both sides of the body in each patient, one side being treated with VSP erbium: YAG laser and the opposite side with LP Nd: YAG laser. All subjects were treated monthly for a total of three treatments. Two 3-mm punch biopsies were obtained from six subjects, both of the same striae, one before the first treatment and one 4 weeks after the last session. Results: Response was evaluated clinically by photographic comparison and was found to be poor in 17 subjects, both on the LP Nd: YAG laser treated side and VSP erbium YAG laser treated side. All these patients had mature lesions (striae distensae alba). Three subjects had a moderate response on both sides; these patients' striae were immature (striae distensae rubra). Histologically, elastic fibers were slightly increased in post-treatment samples compared with pretreatment skin biopsies. Conclusion: We observed no satisfactory clinical improvement in striae distensae alba lesions although histopathological changes were seen. We suggest that variable square pulse Er: YAG and long pulse Nd: YAG lasers are not useful in the treatment of striae distensae alba.