verteporfin
verteporfin
An equimolar mixture of the 9-methyl ester and 13-methyl ester of <em>trans</em>-(±)-18-ethenyl-4,4a-dihydro-3,4-bis(methoxycarbonyl)-4a,8,14,19-tetramethyl-23<em>H</em>,25<em>H</em>-benzo[<em>b</em>]porphine-9,13-dipropanoic acid. It is used as a photosensitizer in photodynamic therapy to eliminate the abnormal blood vessels in the eye associated with neovascular (wet) age-related macular degeneration. Verteporfin accumulates in these abnormal blood vessels and, when activated by red (693 nm) laser light in the presence of oxygen, produces highly reactive short-lived singlet oxygen and other reactive oxygen radicals, resulting in local damage to the endothelium and blockage of the vessels.