Impact of the Laser on Nevi And Melanomas

The incident energy of the powerful beam of the ruby laser has been shown to be absorbed more effectively by colored tissues. 1-3 Nevi and melanomas in an accessible organ, such as the skin, provide adequate masses of such tissues. Superficial changes in pigmented nevi and in melanoma were produced in experiments with low energy lasers (0.5-1.0 joules of exit energy from the laser head) . 1-3 Continued work with high energy lasers (25 to 125 joules of exit energy) has produced more extensive change. Outputs of laser energy were measured by a TRG calorimeter in conjunction with a Keithley microvolt-ammeter. The cellular nevi exposed to the laser included two junctional, seven mixed, and three dermocellular types. The nevi were excised, moistened with saline, and placed on glass slides. In three of the dermocellular nevi, 1% aqueous solution of Evans blue dye was injected into portions of the tissue to determine