Photodynamic therapy (PDT) is a new potential treatment of the subfoveal choroidal neovascularization (CNV) that may accompany age-related macular degeneration (AMD). PDT involves the use of a photosensitizing agent which, when activated by light, may selectively kill proliferating cells in a non-invasive, non-thermal manner. PDT may thus offer repetitive, short-term cessation of vascular leakage of CNV without the severe collateral thermal injury to nonvascular tissues that is seen with laser photocoagulation. Photodynamic agents used currently in clinical trials (Purlytin, Optrin) have had modest efficacy in arresting progression of classic subfoveal CNV; however, these results have been accompanied by side effects, such as skin photosensitivity (Purlytin), paresthesias, eye discomfort, and transient serous retinal detachment (Optrin). The current application proposes to test several new photodynamic agents for their effectiveness in photodynamic cell toxicity in an RIF cell line and in preventing experimental CNV in a mouse model of laser-induced CNV. The most promising agent among these compounds will be selected for further tests of efficacy in possible use in PDT
