The evolution of quality-switched lasers.

Quality-switched (QS) lasers and their applications have evolved greatly since the ruby laser's effect on tattoo ink was first reported in the 1960s. The 1983 description of selective photothermolysis explained the efficacy of QS lasers for the treatment of cutaneous pigmented lesions and tattoos and cemented their status as the gold standard for these targets. Within the past decade, the uses for QS lasers have expanded dramatically, including nonablative rejuvenation and the treatment of onychomycosis. Additional applications and refined techniques and technologies promise to maintain the stature of QS lasers as an integral part of the laser surgeon's arsenal.