Lasers in medicine and surgery

The laser produces an intense beam of pure monochromatic light. The wavelength of the light determines its effects on body tissues, and this defines the clinical role of each laser. The carbon dioxide laser is absorbed by water and it is used as a high precision, bloodless, 'light scalpel'. The blue/green argon laser beam is absorbed by structures which have its complementary colour red, and it can coagulate vessels through the without damage to clear, normal tissues. The neodymium: YAG laser is deeply absorbed in the tissues, and is used both for vessel coagulation and thermal tissue destruction. The tunable dye laser is used to photoactivate intra-tumour haematoporphyrin derivative in the treatment of many forms of malignant disease by photoradiation therapy. Lasers should only be used when they offer significant advantages over established conventional techniques, and this paper attempts to define the areas in which lasers offer these advantages.