[Indications for photodynamic therapy in age-related macular degeneration]

Abstract

Exudative age-related macular degeneration (ARMD) is now benefitting from new therapeutic approaches. Three international randomized clinical trials have demonstrated the efficacy of photodynamic therapy (PDT) in stabilizing visual acuity at 2 years. PDT is based on the activation of a photosensitizer with an adapted wavelength. In age-related macular degeneration, the photosensitizer used is verteporfin (Visudyne), which accumulates preferentially in choroidal new vessels. Functional results are obtained on the basis of a strict classification based on fluorescein angiography examining the type of the new vessels responsible for exudative ARMD. Thus, subfoveal lesions, either predominantly classic (>50%) or occult only, are the indication for PDT. Classic CNVs where laser photocoagulation thermal burns extend into the foveola may be an extrapolation of the indication for PDT. In addition, fluorescein angiography is essential for considering retreatment, usually necessary. Demonstrated growth and the persistence of leakage from the CNV is an absolute indication for a new session of PDT. A number of features still require assessment in order to define the responder group more accurately and to refine and possibly simplify the indications for retreatment.