レーザー治療の原理と応用  [in Japanese] Principle of Laser Treatment and its Application  [in Japanese]

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Abstract

近年種々の医学生物学の分野でレーザーの応用が盛んになっているが, その多くの場合, レーザー装置の選択はたまたま手元に存在したからであり, またレーザー治療の方法も単なる経験に基づいたものであった. しかし, selective photothermolysis (SP) という概念が発表され, 特に色素病変の治療に適するレーザーの照射条件が明らかにされた. この条件とは 1. 目的とする色素に特異的に吸収される波長, 2. 目的とする網胞の熱緩和時間よりも短い照射時間, 3. 目的とする細胞を破壊するのに充分な照射エネルギーの3つの条件を満たすレーザー光である. そしてSPの理論は動物実験で確かめられ, SPの条件を満たすレーザーは今まで有効な治療法がなかったいくつかの色素性あるいは血管性皮膚病変の治療に有用であることが示された. さらにSPの理論はレーザーによる脱毛にも応用可能である. その他炭酸ガスレーザーやエキシマレーザーを用いた光切除は皮膚の微小手術, 特に皮膚の皺取り術に使用されている.

Many biomedical applications of lasers have been developed. In many cases, however, selection of a particular laser has been based largely on availability, and treatment protocols have often been developed by an empirical approach. Selective photothermolysis (SP) has been proposed as a construct which may be useful in designing laser systems for biomedical applications, especially for the treatment of pigmentary dermatoses. The necessary conditions are (1) tissue structures which preferentially absorb a wavelength of light more than the surrounding tissue, (2) a pulse of light sufficiently short and energetic to produce localized high temperatures in the absorbing structures, and (3) a predominantly thermal mode of initiation of tissue damage. The concept of selective photothermolysis was confirmed by our experimental observations. The lasers, with a pulse of light sufficiently short and energetic to produce localized high temperatures in the targets, were demonstrated to be useful for treatment of some pigmented and vascular lesions which showed no significant response to previous therapies. Furthermore, SP of hair follicles can also be applied for removal of excess hair growth in unwanted areas. Photoablation by using CO<SUB>2</SUB> or excimer lasers is used for microsurgery of the skin, especially skin resurfacing.

Journal

  • THE JOURNAL OF JAPAN SOCIETY FOR LASER SURGERY AND MEDICINE

    THE JOURNAL OF JAPAN SOCIETY FOR LASER SURGERY AND MEDICINE 19(4), 249-258, 1998

    Japan Society for Laser Surgery and Medicine

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