Photodynamic therapy (PDT), also known as photosensitivity or photochemistry therapy, its principle is to selectively accumulate the photosensitizer in the target tissue, and then to stimulate the photosensitizer with a specific wavelength of light to produce a photochemical reaction to treat the disease.
Commonly laser treatmontor include semiconductor laser, ammonia-neon (He-Ne) laser, nitrogen molecular laser, hydrogen ion laser, ammonia-cadmium laser, Nd-YAG laser, carbon dioxide laser and so on. These lasers are applied in different clinics in the low, medium, and high energy ranges, respectively.