Photodynamic therapy in choroidal new vessels

Photodynamic therapy (PDT) is a new approach for subfoveal choroidal new vessels (CNV) in age-related macular degeneration (ARM) and myopia, currently being evaluated in clinical trials. PDT is a two-step procedure: the intravenous perfusion of a photosensitizer is followed by light irradiation at the adapted wavelength. Verteporfin, the photosensitizer under investigation, has a maximum absorption at 692nm. Phase I and II studies determined the settings necessary to obtain optimal effects in humans with Verteporfin in the phase III study. It has been shown that this treatment is efficient and preserves initial visual acuity in 67% of Verteporfin-treated ARM eyes vs 39% of placebo-treated ARM eyes at 1 year. Fluorescein angiographic follow-up found a photo-occlusion of the CNV 14 days after treatment application followed by a partial reperfusion or reproliferation of the CNV at 3 months, resulting in the need for repeated treatments. Two-year results of the Phase III randomized clinical trial are awaited.