Optimum laser parameters for port-wine stain treatment

The choice of suitable laser parameters is important for effective treatment of port-wine stains. The considerations in the choice of laser parameters are discussed with the aim of coagulating and sealing the abnormal blood vessels and completely denaturing the associated perivascular tissues, while confining the thermal damage to the vicinity of the abnormal vessels. A mathematical model was used to simulate the volume absorbed photon intensity in skin for argon, dye, Nd:YAG, and CO 2 lasers. The model computes the number of photons absorbed within each region, and an optimum wavelength is chosen by selecting that which has the highest absorption ratio in the blood vessel compared with absorption in the epidermis and dermis. The model further computes the input energy and the corresponding pulse duration required to seal the blood vessels and hence remove the port-wine stain.