The Origin, Principles of Intense Pulsed Light and Its Proper Application in Clinical Practice / 대한피부과학회지

Intense pulsed light (IPL) is a high-intensity polychromatic incoherent light of a determined wavelength spectrum, fluence, and pulse duration. Clinicians can combine these variable factors of IPL for the purpose of selective destruction of target chromophores. Due to these properties, IPL has been widely used for numerous indications including hair removal and treatment of vascular or pigmented lesions. For skilled and experienced clinicians, IPL is a great treatment modality; however it can be a source of serious adverse effects when performed by untrained clinicians. Thus, to promote the proper and safe use of IPL, we summarized the origin, history, basic principles, and clinical application of IPL and discussed qualification factors needed for clinicians who use IPL.

The Principles of Intense Pulsed Light and Its Clinical Application / 대한피부과학회지

Intense pulsed light (IPL) is a high-intensity pulsed light source emitting polychromatic, non-coherent, and defocused light with a broad wavelength spectrum. However, IPL can similarly work as a conventional laser with the help of variable cut-off filters. It enables selective destruction of target chromophores based upon the theory of selective photothermolysis. Clinicians can combine variable factors including wavelengths, pulse durations, and fluences in IPL systems, which allow great versatility in treating wide ranges of dermatologic diseases and flexibility in optimizing individual treatment parameters according to different skin types or indications. These properties are of great advantage for skilled and experienced clinicians but can be a source of unwanted serious adverse effects for untrained ones at the same time. Therefore, we summarized the basic principles and clinical application of IPL devices to provide the practical guidance. In addition, critical diagnostics, a great deal of experience, and a thorough knowledge of skin pathology and physiology are required for an effective and safe IPL treatment.

New Melasma Treatment by Collimated Low Fluence Q-switched Nd : YAG Laser / 대한피부과학회지

BACKGROUND: Laser treatment in melasma has previously failed because of the resulting inflammation and consequent pigmentation and excessive thermal damage caused by the use of high fluence. OBJECTIVE: This study is aimed at establishing the concept of the collimated low fluence Q-switched Nd : YAG laser as a treatment for melasma by investigating its therapeutic effects clinically as well as histopathologically. METHODS: 27 patients were treated weekly with Q-switched Nd : YAG laser (1,064 nm wavelength, 7 mm spot size, 1.6~2.5 J/cm2 fluence) for 8 weeks. The results were evaluated based on standardized clinical images that used Robo skin analyzer, spectrophotometer, MASI score and general severity. RESULTS: 17 (58.8%) patients showed "GOOD" (50~75% improvement) and no case of full recurrence was examined and partial recurrence was detected in 12/17 patients. Common adverse effects include pain, erythema, and temporary edema. Rarely partial hypopigmented macules and diffuse hyperpigmentation appeared. Additional studies, such as immunohistochemical examination and electron microscopic examination, are also currently in progress. CONCLUSION: The collimated low fluence Q-switched Nd : YAG Laser is effective in melasma treatment. This treatment method is a new concept that can be described as selective photothermolysis with minimal thermal damage and inflammation reaction to affected tissues by pigmentation. We consider this treatment method should be regarded as Minimized Selective Photothermolysis (MSP) that will provide a new effective treatment for melasma.

Lasers in Dermatology / 대한피부과학회지

The basic concept of the laser was first described by Einstein in 1917. Laser is an acronym for "Light Amplification by Stimulated Emission of Radiation". The applications of laser light to the field of medicine were begun in 1960s. Since that time there has been a great increase in the development of laser technology and in the understanding of laser-target tissue interactions. The theory of selective photothermolysis mans that a chromophore can be selectively damaged with a laser light of an appropriate wavelength and of a suitably short pulse duration that is shorter than the thermal relaxation time of the chromophore. The introduction of pulsed tunable dye lasers has considerably improved the treatment of vascular lesions, particularly light pink nevus flammeus in children. The argon pumped dye laser and copper vapor laser may be better for telangiectatic and the hypertrophic nevus flammeus often seen in adults. Since the Q-switched and pused green light lasers are capable of selective photothermolysis of melanosomes and tattoo dyes, their efficacy has been under investigation for the treatment of pigmented lesions. The automated delivery systems such as Hexascan produce a superior cosmetic result when compared with manual delivery of laser light and the risk of scarring is reduced. Further comparative study is needed to determine which lesions respond best to each laser system, and which treatment techniques are optimal. Treatment combining more than one of these laser systems may prove superior to any of them used alone.