Usefulness of a narrow-band reflectance spectrophotometer in evaluating effects of depigmenting treatment.
As a depigmenting treatment, combined topical applications of all-trans retinoic acid (atRA) aqueous gel and 5% hydroquinone, 7% lactic acid ointment were used for Oriental patients with hyperpigmented skin lesions such as senile lentigines and nevus spilus. A narrow-band reflectance spectrophotometer and a tristimulus colorimeter were used to evaluate objectively the intensity of pigmentation and erythema at each clinical visit. L*, a*, and b* values measured with a tristimulus colorimeter (Chroma Meter CR-300) enabled the evaluation of erythema but not pigmentation. On the other hand, the melanin and hemoglobin values measured with a narrow-band reflectance spectrophotometer (Mexameter MX-16) expressed both erythema and pigmentation well. It was revealed that, in our bleaching protocol, the narrow-band reflectance spectrophotometer was quite useful for estimating accurately the intensity of pigmentation and erythema and determining the best time point for the cessation of atRA treatment.
Yoshimura
K
K
Department of Plastic and Reconstructive Surgery, University of Tokyo, 7-3-1, Hongo, Bunkyo-Ku, Tokyo 113-8655, Japan.
Harii
K
K
Masuda
Y
Y
Takahashi
M
M
Aoyama
T
T
Iga
T
T
D000287:Administration, Topical; D004359:Drug Therapy, Combination; D006801:Humans; D006873:Hydroquinones / Q000008:administration & dosage / Q000627:therapeutic use*; D017495:Hyperpigmentation / Q000188:drug therapy*; D019344:Lactic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D013053:Spectrophotometry / Q000379:methods; D014212:Tretinoin / Q000008:administration & dosage / Q000627:therapeutic use*
D006873:Hydroquinones; D019344:Lactic Acid; D014212:Tretinoin