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

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.