—The Q-switched ruby laser has been demonstrated to provide selective photothermolysis of pigmented tissue at a wavelength of 694 nm and a pulse width of 40 ns with dermal penetration. It was used to treat 15 patients with nevus of Ota involving the face with an age range of 6 to 52 years. Other methods of treatment for the nevus of Ota have either left scarring or were ineffective. The clinical efficacy of this laser treatment was evaluated in a comparative photographic analysis.
—Complete clearing was noted in four of the 15 patients and a minimum of 50% lightening of the original color in the remaining 11. Ten of the 15 patients were Asian, two were white, two were Hispanic, and one was Indian. The energy fluence used varied between 6 and 10 J/cm2, and the number of treatments ranged from 1 to 7. Significant lightening or clearing was found at the higher energy ranges of 9 to 10 J/cm2 with significantly less lightening noted at the lower energy range of 6 to 8.5 J/cm2. No scarring was noted in any of the 15 patients, and some isolated hypopigmentation was noted in one of the subjects. Transient postinflammatory hyperpigmentation of 2 months' duration was noted in only one patient.
—Q-switched ruby selective photothermolysis appears to be an effective and safe method of lightening or removing nevus of Ota.
Geronemus RG. Q-Switched Ruby Laser Therapy of Nevus of Ota. Arch Dermatol. 1992;128(12):1618-1622. doi:10.1001/archderm.1992.04530010056008