A Study of the Therapeutic Effect of Nevus of Ota by the Q - switched Nd : YAG Laser

Kim, Joong Gie; Kim, Kyun Tae; Nam, In Whan; Ahn, Sung Ku

Abstract

BACKGROUND: The nevus of Ota is a benign dermal melanocytic lesion that was previously proved difficult to treat. Recently, the Q-switched ruby laser and Q-switched Nd: YAG laser have been reported to by, successful in the treatment of benign pigmented lesions and tattos.
OBJECTIVE
Our study evaluates the treatment of 60 patients with nevus of Ota with Q-switched Nd: YAG lase (l064nm). METHOD: Sixty patients with nevus of Ota were treated by the Q-switched Nd: YAG laser with pulse width 10nsec, and energy fluences ranging from 5.8 to 12J/cm and the laser repetition rate was 5 or 10Hz. The response to treatment was assessed by four independent investigators with photographs.
RESULTS
1. Total therapeutic effects of Q-switched Nd: YAG laser showed excellent result in 23.3%, good in 45%, fair in 18,3%, and poor in 13.3%. 2. Therapeutic effects by distribution proposed by Tanino showed excellent or good results in 84.6% at type Ia, 78.6% at, type Ib, 66.7% at type II, 60% at type III and 45.5% at type N. 3. Therapeutic effects by the number of treatments showed excellent or good results in 22.2% of patients after one treatment, 72.7% after two treatments, 93.3% after three treatments and 100% after four treatment. 4. Therapeutic effects by energy showed excellent or good results in 9.2% at energy range of 10 to 12J/arl and 66.6%, at energy range of 5.8-9.5J/cm. 5. Complications included transient hyperpigmentation (6.7% ), secondary bacterial infection (1.7 %), hypopigmentation (1.7%) and atrophic scar (1.7%). However these subsided spontaneously in a year. 6. The recurrence rate was 2.4%.
CONCLUSION
The Q-switched Nd: YAG laser is a very effective mode of treatment for nevus of Ota which has provent unresponsive to other therapeutic modalities.