๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Lesions
Lesions
INTRODUCTION
Laser therapy for vascular lesions targets oxyhemoglobin as the chromophore, with absorption peaks at 418, 542, and 577 nm. One of the main goals in laser therapy is to focus the laser on its desired target with minimal effect on normal skin, including melanocytes and hair follicles.1 Blood vessel depth, thickness, and skin type are factors that are often considered for each patient.
Types of lasers available for the treatment of vascular lesions
Several types of lasers are available for the treatment of vascular lesions, including the pulsed-dye laser (PDL); potassium titanyl phosphate (KTP) laser; neodymium:yttrium aluminum garnet (Nd:YAG) laser; CO2 laser; argon laser; copper vapor laser; and intense pulsed light (IPL).
CO2 and argon lasers are mainly of historical interest, as the scarring and skin texture changes seen with these treatments mean that they are not generally used to treat vascular lesions. PDL has been used to treat vascular lesions such as port-wine stains (PWS), superficial hemangiomas, poikiloderma of Civatte, facial telangiectasias, and rosacea.2 PDL treatments utilize a wavelength of 585 or 595 nm to allow for deeper tissue penetration compared to the first-generation 577-nm wavelength emission. KTP laser therapy, also known as a frequency-doubled Nd:YAG laser, is a 532-nm laser that is created by passing a 1,064-nm Nd:YAG laser through a KTP crystal. By doing so, the frequency is doubled and the wavelength cut in half. KTP lasers can be used to treat telangiectasias without eliciting purpura. Nd:YAG lasers have a lower affinity for hemoglobin, though due to their deeper penetration and lower affinity for melanin, this laser is a popular choice for treating darker skin types. IPL emits filtered polychromatic
light with wavelength between 500 and 1,200 nm. IPL can be used for relatively nonspecific treatment of rosacea, PWS, hemangiomas, and poikiloderma of Civatte. In addition, IPL has been used in skin types IโIII for photorejuvenation for chronic photodamage and hair removal.