Photodynamic therapy (PDT) is a treatment that uses a light-sensitive drug, which is activated by a specific wavelength of light, to treat certain eye conditions. PDT is most commonly used for age-related macular degeneration (AMD), particularly for patients with wet AMD, where abnormal blood vessels leak fluid into the macula and damage vision.

During the procedure, the drug is injected into the bloodstream and absorbed by abnormal blood vessels in the eye. A laser is then used to activate the drug, which selectively destroys the abnormal blood vessels while leaving the surrounding tissue unharmed.

PDT can help stabilize vision and prevent further damage in patients with wet AMD, providing an alternative to more invasive treatments.