[Photodynamic therapy. Minimally invasive treatment of choroidal neovascularization]

The exudative stage of age-related macular degeneration (AMD) with choroidal neovascularization (CNV) commonly leads to rapidly progressive visual loss. Conventional laser coagulation with its unspecific destruction of the CNV, including adjacent retinal structures, often causes an additional reduction in visual acuity, particularly in cases with central localization of the pathological process. Photodynamic therapy (PDT) induces selective occlusion of CNV via light-induced pharmacological thrombosis without any damage to the retina in the macular area. Pilot studies have demonstrated complete occlusion of CNV with subsequent restoration of retinal function. Even repeated application was not associated with any alteration of the photoreceptor layer. The treatment strategy in PDT consists of repetitive thrombosis of CNV with progressive occlusion of the exudative lesion adjusted to the angiographic appearance. A randomized multicenter trial is currently underway and is evaluating the long-term visual results documented in 609 patients with subfoveal CNV who underwent control and eventual PDT at 3-month intervals. If PDT proves to be beneficial, an easy and non-invasive treatment modality could be offered to numerous patients who demonstrated occult classic CNV and are otherwise facing an extremely poor prognosis.