ABSTRACT
Photodynamic therapy (PDT) is a clinically approved modality that utilizes a photosensitizing compound in conjunction with light and molecular oxygen to produce a localized cytotoxic e¨ect. §e photosensitizer is nontoxic in the absence of light. PDT has gained greatest acceptance in the ©elds of oncology (especially oncological dermatology) and ophthalmology, although other non-oncological and antimicrobial applications have recently begun to be exploited. Speci©c illumination of the photosensitizer results in the local formation of reactive oxygen species, primarily singlet oxygen, causing a variety of direct and indirect cytotoxic e¨ects on the cellular targets, discussed in more detail in Section 64.2.
