Photochemotherapeutical obstruction of newly-formed blood vessels

Abstract

A photosensitive tetrapyrrole derivative having formula (I)where n stands for 1 or 2 or a pharmaceutically acceptable salt thereof is useful as an effective ingredient in an obstruent composition for photochemotherapeutically obstructing neovascular vessels. The photosensitive tetrapyrroles of the formula (I) may be administered in a photochemotherapeutic method for obstructing neovascular vessels, particularly choroidal and retinal neovascularizations.

We claim:  
     
       1. A method for photochemotherapeutically obstructing neovascular vessels as foraged  formed in a patient having the neovascular vessels, which comprises administering orally or parenterally to the patient an amount of a compound having the formula (I):                    
       where n stands for an integer of 1 or 2, or a pharmaceutically acceptable salt thereof, allowing said compound administered to accumulate in the neovascular vessels to be obstructed after the administration of said compound to the patient, irradiating a part or all or some parts of the neovascular vessels to be obstructed, with a laser beam until the compound accumulated in the neovascular vessels has been elicited photochemically, terminating the irradiation of the laser beam, and then allowing the laser beam-irradiated part or parts of the neovascular vessels to be obstructed. 
     
     
       2. A method according to claim  1 , which is applied to the photochemotherapeutical obstruction of the choroidal or retinal neovascularization. 
     
     
       3. A method according to claim  1 , in which mono- L - aspartyl chlorin e 6  or its tetra - sodium salt is administered.