Photochemical effect: clinically referred to as photodynamic therapy. Photosensitizer (photophrin II) is administered which is taken up by the tumor tissue and later irradiated by laser light resulting in highly toxic substances with resultant necrosis of the tumor. Photodynamic therapy is used in palliation of oesophagial and bronchial carcinoma and ablation of mucosal cancers of Gastrointestinal tract and urinary bladder.
Photoablative effect: Used in eye surgeries like band keratoplast, and endartectomy of peripheral blood vessels.
Photothermal effect: this property is used for endoscopic control of bleeding e.g. Bleeding peptic ulcers, oesophagial varices