[Choroidal changes after photodynamic therapy (PDT). A two-year follow-up study of 38 patients].

BACKGROUND

Photodynamic therapy is a new option for treatment of choroidal neovascularisation in patients with age-related macular degeneration. But choroidal changes and associated angiographic characteristics have not been further evaluated.

PATIENTS

Indocyanine green angiography was used to follow 38 patients with subfoveal choroidal neovascularisation in age-related macular degeneration over up to two years. All patients were treated with the photosensitizer Benzoporphyrin Derivative-MA receiving either a single or triple treatment.

RESULTS

Indocyanine green angiography shows two effects of photodynamic therapy. On the one hand a selective and lasting closure of choroidal neovascularisation was documented. Choroidal neovascularisation-size and leakage was significantly reduced in the entire treatment group to 20.7% and 28.3% one week after treatment, followed by a slow increase to 33.3% and 41.2% at up to two years longterm follow up. On the other hand photodynamic therapy causes typically a peri-lesional hypofluorescence in Indocyanine green angiography. This hypofluorescence is most likely due to choroidal hypoperfusion and vascular endothelial changes. A continuous increase in fluorescence was shown, reaching again 90% of the pretreatment intensity at 3 months, documenting a good recovery of the choroidal network.

CONCLUSION

The results show that photodynamic therapy is an alternative treatment in age-related macular degeneration with choroidal, subfoveal neovascularisation. Indocyaningreen angiography reflects well choroidal changes associated with this therapy and may be helpful to choose treatment intervals.