Selective photodynamic treatment
First Claim
1. A method to selectively phototreat an abnormal intraocular blood vessel having an altered membrane without adversely affecting normal intraocular blood vessels comprisingadministering a photosensitizing agent susceptible to phototreatment into said normal and abnormal vessels,allowing a sufficient time for said agent to be released from said abnormal vessel through said altered membrane and into a site adjacent said abnormal vessel and maintaining said agent in said normal vessels,thereafter transiently constricting said normal vessels at a phototreatment site for displacing said agent from said normal vessels at said site and preserving said normal vessels during phototreatment,phototreating said site for a defined time during constriction of said normal vessels to selectively treat said abnormal vessel having said agent in said adjacent tissue, andthereafter restoring said normal vessels to an unconstricted state.
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Accused Products
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.
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Citations
18 Claims
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1. A method to selectively phototreat an abnormal intraocular blood vessel having an altered membrane without adversely affecting normal intraocular blood vessels comprising
administering a photosensitizing agent susceptible to phototreatment into said normal and abnormal vessels, allowing a sufficient time for said agent to be released from said abnormal vessel through said altered membrane and into a site adjacent said abnormal vessel and maintaining said agent in said normal vessels, thereafter transiently constricting said normal vessels at a phototreatment site for displacing said agent from said normal vessels at said site and preserving said normal vessels during phototreatment, phototreating said site for a defined time during constriction of said normal vessels to selectively treat said abnormal vessel having said agent in said adjacent tissue, and thereafter restoring said normal vessels to an unconstricted state.
Specification