How does photodynamic therapy for neovascular AMD operate?

Photodynamic therapy (PDT) for neovascular age-related macular degeneration (AMD) operates through a specific mechanism involving the administration of a photosensitizing drug, which is typically injected intravenously. Once the drug is in the bloodstream, it accumulates in the abnormal blood vessels associated with neovascularization. After sufficient accumulation, a specific wavelength of light is applied to the affected area of the retina.

The light interacts with the photosensitizing agent, causing it to produce a form of reactive oxygen that damages the endothelial cells lining the neovascular tissue. This effectively occludes the abnormal blood vessels, leading to reduced leakage and subsequent stabilization or improvement in visual acuity. The combination of the intravenously administered drug and the targeted light application is crucial in this therapy, making it a unique and effective treatment for neovascular AMD.