abstract |
A method and apparatus for selectively targeting photodynamic therapy (PDT) to abnormal tissues. The abnormal tissues may be neovascular intraocular tissue or neoplastic cells. In the eye, a photosensitizing agent is to the vessels then the vessels are collapsed by application of pressure before PDT. Abnormal vessels allow agent to leak into the surrounding tissues, while agent in normal vessels is contained. Upon pressure-induced collapse of intraocular vessels, agent is removed from the vessels and is targeted by subsequent PDT only in surrounding tissues which are susceptible to PDT. Vessel occlusion may be enhanced by administering agents to promote and/or prevent dissolution of clots. The interaction of light with the photosensitizing agent which leaked from neovascular tissue results in cellular or tissue destruction in areas where the agent is located. Thus, normal vessels have no photosensitizing agent and are undamaged by light radiation, while abnormal areas are treated. An apparatus to regulate intraocular pressure is also disclosed. |