(18) The treatment of portwine stains with the tunable dye laser at 577 nm

Abstract

The treatment of portwine stains (PWS) by lasers has become established as the treatment of choice in recent years. Most experience has been with the argon laser which emits predominantly at 488 and 514 nm. These wavelengths do not coincide with the absorption maxima of haemoglobin at 415, 542 and 577 nm. Light at 577 nm is particularly well transmitted through the epidermis and selectively absorbed by haemoglobin. We have been treating patients with PWS with a Coherent CR599 argon-pumped continuous wave tunable dye laser emitting at 577 nm. Seventy-one patients with PWS have been treated in Leeds, mean age 36·9 years, range 11–61 years. Ninety-six per cent had PWS on the face or neck. The majority were treated under local anaesthesia; the longest follow-up has been 42 months. The minimal blanching method was used1 with a spot diameter of 1 mm, power range of 0·3 – 0·5 W in most patients, with a pulse duration of 0·5–2 s. Energy fluence was 38–63 J/cm2. Improvement in the treated area from partial to complete paling occurred in 75% with scarring in 5% which was usually atrophic, and minor pigmentary changes in 7%. These results are comparable with the best series reported from argon laser therapy and confirm the theoretical advantage of treatment with laser light at 577 nm.