What are the disadvantages of the pulsed dye laser?

The pulsed dye lasers are not very useful in treating thicker vascular lesions, because the short pulse duration is not usually sufficient to damage the target vessels without increasing the power to a level that could lead to generalized damage and scarring. There may be significant posttreatment purpura that takes 7 to 10 days to resolve. This purpura results from the explosive opticoacoustic pulse generated by the pulsed dye lasers. This is a cosmetic problem that limits the use of the laser in some patients. The newer pulsed dye lasers are able to treat lesions without purpura by using longer pulse durations in the range of 10 msec (Table 54-5).