Efficacy of Q-Switched Ruby Laser in the Treatment of Nevus of Ota

Abstract

The Q-switched ruby laser has been demonstrated to provide selective photothermolysis of pigmented tissue at a wavelength of 694nm and a pulse width of 30ns with dermal penetration. It was used to treat 114 patients with nevus of Ota with an age range of 8 to 63 years. Other methods of treatment for the nevus of Ota have either left scarring or were ineffective. In most cases, the entire area was treated at an energy fluence of 6 J/cm2 in each treatment session. Treatment intervals ranged from 3 to 4 months. The clinical efficacy of this laser treatment was evaluated in a comparative photographic analysis. Five treatment response levels were established according the percentage of pigment lightening of the original color excellent if there was more than 70% lightening; good from 40 to 69%; fair from 10 to 39%; unchanged if there was not a lightening of at least 9%; worsened if there was 10% darkening. Of the 23 patients who received only one treatment, good responses were achieved in 3 (13%), fair in the 13 (57%), and unchanged in 7 (30%). Of the 25 patients who received two treatments, excellent responses were achieved in 2 (8%), good in 16 (64%), and fair in 7 (28%). Of the 31 patients who received 3 treatments, excellent responses were achieved in 4 (13%), good in 26 (84%), and fair in 1 (3%). Of the 17 patients who received 4 treatments, excellent responses were achieved in 15 (88%) and good in 2 (12%). Excellent responses were achieved in all 18 (100%) patients who received more than 5 treatments. No hypertrophic or atrophic scarring was noted in any of the patients. However, transient postinflammatory hyperpigmentation of 2 months' duration was noted in a few patients. Q-switched ruby selective photothermolysis appears to be an effective and safe method of lightening or removing nevus of Ota.