A COMMON ASSUMPTION is that progress in laser dermatology depends mainly on new technology. However, there is little evidence to support this hypothesis. History of the world's oldest laser suggests that progress is more often limited by understanding how to use existing technology than by the technology itself. At times, adoption of new laser technology may actually have inhibited or delayed this understanding.Arch Dermatol. 2003;139:70-74
In the first study of laser effects on skin in 1963, Leon Goldman et al1 clearly describe selective injury to pigmented skin structures, including hair follicles. More than 3 decades later, a nearly identical ruby laser became the first device available for permanent removal of pig mented hair. Herein we trace the use of ruby lasers in dermatology across 4 decades and 3 continents, finding them at times in fashion and at times abandoned, emphasizing not the technology but rather the ideas that affected the progress of dermatologic laser use. The story consists largely of understanding how and why to optimize laser pulse duration, a challenge that continues to this day. How can a short ruby laser pulse permanently remove the nevus of Ota from a man's face but not his beard, while a long ruby laser pulse does exactly the opposite? Moreover, why did it take so long to figure this out?
Anderson RR. Dermatologic History of the Ruby LaserThe Long Story of Short Pulses. Arch Dermatol. 2003;139(1):70-74. doi:10.1001/archderm.139.1.70