In Vivo Investigation of the Safety and Efficacy of Pulsed Dye Laser with Two Spot Sizes in Port-Wine Stain Treatment: A Prospective Side-by-Side Comparison

Objective: Pulsed dye laser (PDL) with 7 and 10 mm spot sizes is widely used on a regular basis for the treatment of port-wine stain (PWS). Background data: No studies have reported on the differences in efficacy outcomes resulting from the use of different laser spot sizes in the treatment of PWS by PDL. Thus, an in vivo investigation into the differences in safety and efficacy of treatment between two spot sizes (7 vs. 10 mm) of PWS by PDL was conducted. Materials and methods: A total of 35 PWS patients underwent three treatment sessions by using a 595 nm wavelength PDL (Vbeam (R), Candela Corp) with two laser settings: (1) 7 mm spot size, radiant exposure of 12 J/cm(2) and (2) 10mm spot size, radiant exposure of 10 J/cm(2). Cryogen spray cooling and 1.5 msec pulse duration were applied. Therapeutic outcomes were evaluated by visual and chromametric evaluation 3 months after the final treatment. Results: Average blanching rates were 34.03% and 36.51% at sites treated by PDL with 7 and 10 mm laser spot sizes, respectively (p < 0.05). Conclusions: On the basis of the laser setting, the therapeutic outcomes of PDL with 7 and 10mm spot sizes were similar. PDL with a 10 mm laser spot size is more efficacious with lower radiant exposure than PDL with a 7mm spot size; it can also reduce the treatment time.