Women are nearly five times more likely to be affected than men, and it is rare among Caucasian people. Nevus of Ota may not be congenital, and may appear during puberty. Some researchers believe that it could be caused by a genetic mutation. Others argue that hormonal factors or radiation may cause it, though more research is needed to confirm these things. The hyperpigmentation may darken and extend with age, such as during puberty and after menopause. Sunlight can also darken the lesions.
The characteristic gray-blue hyperpigmentation occurs due to entrapped melanocytes. The melanocytes are entrapped leading to gray-blue hyperpigmentation of the conjunctiva and sclera along with ipsilateral facial skin. There is a similar skin condition called nevus of Ito. It has many of the same features to nevus of Ota but appears on the shoulder and side of the neck.
Laser treatments are the most effective corrective approach to nevus of Ota, although they must be repeated more than once, with multiple approaches and applications. The laser treatments work to destroy the melanocytes that cause the bluish hyperpigmentation, with the goal of returning the skin to its natural pigment.
Picosecond NDYAG laser ( picocare 250 laser) is the most advanced laser treatment for Naevus of OTA