LASER SURGERY OF NEVUS OF OTA AND NEVUS OF ITO

Abstract

Introduction. Clinical variants of congenital melanocytosis in the dermis- nevus of Ota and nevus of Ito (NOI) - may cause marked cosmetic effects; they fail to regress and are reported to be associated with the risk of malignancy. Purpose. To develop criteria and the algorithm for selecting the optimal laser system and radiation specifications to remove NOI considering specific properties of the optical pattern of skin lesions having different locations and melanin concentration. Methods. A scientific and analytical review of publications indexed in PubMed, ScienceDirect, Embase, Web of Science, Russian Medicine, RSCI. Calculation of laser radiation absorption coefficients for various pathomorphological variants of dermal melanocyte locations, given the peculiarities of laser light interaction with targeted photothermophores in NOI focus. Results. The authors present data on epidemiology, history and clinical features of congenital derma melanocytosis of nevus of Ota and nevus of Ito (NOI) - localized, predominantly in periocular and periclavicular regions. Molecular mechanisms of NOI progression in children and adolescents are discussed. There are also data [WU1] on the efficacy and risks of side effects when treating NOI lesions with ruby (wavelength 694 nm), alexandrite ( wavelength 755 nm) and neodymium ( wavelength 1064 nm) laser light. Effectiveness and features of side effects of different wavelengths of laser light are compared. In the article, one can find criteria for selecting an optimal option for NOI laser treatment: maximal efficiency assessed by the visual analogue scale (VAS), number of laser sessions and severity of early and late side effects. For the first time, the authors present data on calculations of quantitative characteristics of optic skin biophotonic pattern if a melanocyte is localized in the papillary and reticular dermis in periocular zone. Conclusion. The obtained calculations on optic characteristics of skin biophotonics suggest [WU2] that two-wave laser irradiation with wavelengths 511 nm and 578 nm will be highly effective with a minimum risk of side effects when removing atypical melanocytes in case of congenital melanocytosis in the papillary and reticular dermis in periocular zone. Algorithms for different pathomorphological variants of melanocyte locatied in the dermis in NOI focus have been proposed to obtain an optimal modality for laser treatment using two-wavelength laser light with 511 nm and 578 nm which is generated by Russian-made copper vapor laser system "Yakhroma-Med" manufactured by Lebedev Physical Institute subordinate to the Russian Academy of Sciences (RAS).