Commenced in January 2007
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Clinical Factors of Quality Switched Ruby Laser Therapy for Lentigo Depigmentation

Authors: SunWoo Lee, TaeBum Lee, YoonHwa Park, YooJeong Kim


Solar lentigines appear predominantly on chronically sun-exposed areas of skin, such as the face and the back of the hands. Among the several ways to lentigines treatment, quality-switched lasers are well-known effective treatment for removing solar lentigines. The present pilot study was therefore designed to assess the efficacy of quality-switched ruby laser treatment of such lentigines compare between pretreatment and posttreatment of skin brightness. Twenty-two adults with chronic sun-damaged skin (mean age 52.8 years, range 37–74 years) were treated at the Korean site. A 694 nm Q-switched ruby laser was used, with the energy density set from 1.4 to 12.5 J/cm2, to treat solar lentigines. Average brightness of skin color before ruby laser treatment was 137.3 and its skin color was brightened after ruby laser treatment by 150.5. Also, standard deviation of skin color was decreased from 17.8 to 16.4. Regarding the multivariate model, age and energy were identified as significant factors for skin color brightness change in lentigo depigmentation by ruby laser treatment. Their respective odds ratios were 1.082 (95% CI, 1.007–1.163), and 1.431 (95% CI, 1.051–1.946). Lentigo depigmentation treatment using ruby lasers resulted in a high performance in skin color brightness. Among the relative factors involve with ruby laser treatment, age and energy were the most effective factors which skin color change to brighter than pretreatment.

Keywords: skin color, depigmentation, quality switched ruby laser, lentigo

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[1] Jun HJ, Cho SH, Lee JD, Kim HS. A split-face, evaluator-blind randomized study on the early effects of Q-switched Nd:YAG laser plus Er:YAG micropeel (combined therapy) versus Q-switched Nd:YAG alone in light solar lentigines in Asians. Lasers Med Sci. 2014 May;29(3):1153-8
[2] Raziee M, Balighi K, Shabanzadeh-Dehkordi H, Robati RM. Efficacy and safety of cryotherapy vs. trichloroacetic acid in the treatment of solar lentigo. 2008 Mar;22(3):316-9.
[3] Negishi K, Akita H, Tanaka S, Yokoyama Y, Wakamatsu S, Matsunaga K. Comparative study of treatment efficacy and the incidence of post-inflammatory hyperpigmentation with different degrees of irradiation using two different quality-switched lasers for removing solar lentigines on Asian skin. J Eur Acad Dermatol Venereol. 2013 Mar;27(3):307-12.
[4] Wang CC, Chen CK. Effect of spot size and fluence on Q-switched alexandrite laser treatment for pigmentation in Asians: a randomized, double-blinded, split-face comparative trial. J Dermatolog Treat. 2012 Oct;23(5):333-8.
[5] Sadighha A, Saatee S, Muhaghegh-Zahed G. Efficacy and adverse effects of Q-switched ruby laser on solar lentigines: a prospective study of 91 patients with Fitzpatrick skin type II, III, and IV. Dermatol Surg. 2008 Nov;34(11):1465-8.
[6] Ho SG, Yeung CK, Chan NP, Shek SY, Chan HH. A comparison of Q-switched and long-pulsed alexandrite laser for the treatment of freckles and lentigines in oriental patients. Lasers Surg Med. 2011 Feb;43(2):108-13.
[7] Yamashita T, Negishi K, Hariya T, Yanai M, Iikura T, Wakamatsu S. In vivo microscopic approaches for facial melanocytic lesions after quality-switched ruby laser therapy: time-sequential imaging of melanin and melanocytes of solar lentigo in Asian skin. Dermatol Surg. 2010 Jul;36(7):1138-47.
[8] Njoo MD, Westerhof W. Effective removal of certain skin pigment spots (lentigines) using the Q-switched ruby laser. Ned Tijdschr Geneeskd. 1997 Feb 15;141(7):327-30.
[9] Trafeli JP, Kwan JM, Meehan KJ, Domankevitz Y, Gilbert S, Malomo K, Ross EV. Use of a long-pulse alexandrite laser in the treatment of superficial pigmented lesions. Dermatol Surg. 2007 Dec;33(12):1477-82.
[10] Kono T, Manstein D, Chan HH, Nozaki M, Anderson RR. Q-switched ruby versus long-pulsed dye laser delivered with compression for treatment of facial lentigines in Asians. Lasers Surg Med. 2006 Feb;38(2):94-7.
[11] Kopera D, Hohenleutner U, Stolz W, Landthaler M. Ex vivo quality-switched ruby laser irradiation of cutaneous melanocytic lesions: persistence of S-100-, HMB-45- and Masson-positive cells. Dermatology. 1997;194(4):344-50.
[12] Kopera D, Hohenleutner U, Landthaler M. Quality-switched ruby laser treatment of solar lentigines and Becker's nevus: a histopathological and immunohistochemical study. Dermatology. 1997;194(4):338-43.