Comparison of the treatment of epidermal pigmented lesions with the Q-switched Nd:YAG laser (1064 nm and 532 nm) and the Q-switched ruby laser (694 nm)

Abstract

COMPARISON of the treatment of epidermal pigmented lesions withthe 0-switched ND:YAG laser (1064nm and 532 run) and the 0-switched ruby laser (694run)Suzanne Linsmeier Kilmer, R. Rox Anderson (Harvard MedicalSchool, Weilman Laboratories of Photomedicine, MassachusettsGeneral Hospital, 50 Blossom St., Boston, MA 02114)The ability of the Q-switched Nd:YAG laser (532 rim and 1064run, 10-20 ns, 10Hz) and the Q-switched Ruby laser (694 nm, 40 ns)to remove pigmented epidermal lesions was assessed in 15patients. Several lesions in the same general area wereirradiated with varying fluences and wavelengths and the resultsof a single treatment session were compared. For the treatmentof solar lentigenes, response was related to wavelength withgreatest improvement (>95% pigment removal) noted with thefrequency-doubled QS Nd:YAG laser (532 run) at 4 or 5 J/cm2. TheQSRL (694 run) had a mean response rate of 75% pigment removal at8 J/cm2. The QS Nd:YAG (1064) had minimal effect at 8 J/cm2, butdid exhibit 25-50% lightening at 12 J/cm2 and 50-75% lighteningat 15 J/cm2. For the treatment of cafe-au-lait macules, a singletreatment with either the 532 run or 694 run wavelength removedonly 50% of the pigment in all 4 cases. Mild, transienterythema, hypopigmentation, and less commonly, hyperpigmentationwere noted with the QS Nd:YAG at 532 nm and the QSRL. No otherside effects including leukotrichia, textural changes or scarringwere noted.