Color analysis of nevus of Ota for evaluation of treatment with a Q-switched alexandrite laser

• Published in: Skin research and technology Vol. 3; no. 1; pp. 45 - 48
• Main Authors: Miyamoto, Hiroshi, Takiwaki, Hirotsugu, Yamano, Masahiro, Ahsan, Kamrul, Nakanishi, Hideki
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.1997
• Subjects: colorimetry; image analysis; laser treatment; nevus of Ota; video microscope; colorimetry; nevus of Ota; laser treatment; image analysis; video microscope
• ISSN: 0909-752X; 1600-0846
• DOI: 10.1111/j.1600-0846.1997.tb00159.x

Background/aims: The Q‐switched alexandrite laser shows excellent results in treating nevi of Ota. This study sought to examine the utility of color monitoring of the lesion for quantifying the efficacy of laser treatment. Methods: Lesion images were obtained from 12 patients using a video microscope before and after a series of laser treatments. The RGB color data in a 50 mm2 area of the images were converted into coordinates of three color systems and compared with clinical evaluation. Results: On three coordinates representing the brightness of skin color (the intensity, the L* and the melanin index), there were significant differences between data obtained before and after treatment (P<0.01), in accord with clinical impressions. Darker lesions tended to show more improvement. Coordinates based on chromaticity were less useful for evaluation of treatment. Conclusions: Color analysis of nevi of Ota is useful for quantifying efficacy of laser treatment, especially when assessed in a small area of the lesion.