Verteporfin

Verteporfin is a photosensitizing medication used in photodynamic therapy (PDT) to treat certain choroidal neovascular conditions of the eye. It is a benzoporphyrin derivative formulated for intravenous administration and is marketed under the brand Visudyne.

In PDT with verteporfin, the drug is given as a short intravenous infusion. About 15 minutes after the start of the infusion, a non-thermal red laser light with a wavelength of approximately 689 nanometers is directed at the abnormal retinal vessels. The light activates the verteporfin, which generates reactive oxygen species that damage the endothelial cells of the neovascular tissue, causing selective occlusion of the abnormal vessels and a reduction in leakage.

Indications for verteporfin PDT include the treatment of neovascular (wet) age-related macular degeneration, as well as choroidal neovascularization due to other conditions such as pathologic myopia and ocular histoplasmosis syndrome. The goal is to stabilize or improve vision by reducing leakage from abnormal vessels, often in combination with other therapies or in cases where anti-VEGF treatment is unsuitable or insufficient.

Pharmacokinetics and safety considerations: verteporfin binds to circulating lipoproteins and accumulates in neovascular tissue, with clearance occurring over days to weeks. A notable safety consideration is photosensitivity; patients must avoid bright light for several days after treatment (commonly about five days). Common adverse effects include infusion-related reactions, headaches, transient visual disturbances, and ocular irritation.

Verteporfin PDT has played an important role in the management of certain retinal neovascular conditions, though its use has evolved with the broader adoption of anti-VEGF therapies.