Use of photodynamic therapy for treatment of ocular malignancies

Photodynamic therapy is a treatment modality using activation of a photosensitizer with light of an appropriate wavelength. Ocular tumors are good candidates for such clinical application because of excellent visualization of tumors regardless of their locations. Early clinical studies with hematoporphyrin derivatives, with their skin photosensitivity and lack of tissue penetration, have been less than convincing that PDT could replace existing conventional ocular tumor treatments. With a surge of second generation photosensitizers with much improved photophysical properties, however, experimental studies in animal models of iris and choroidal melanoma have been performed with encouraging results. PDT for retinoblastoma, however, needs further investigation, requiring a good animal model. With further refinements in PDT, such as improving tissue localization of the photosensitizers and the light delivery system, PDT may provide an additional treatment option for ocular malignancies.