98th Annual Meeting DOG 2000

V 468

Photodynamic therapy (PDT): ICG-angiographic evaluation in the TAP-Investigation

S. Michels, I. Barbazetto, H. Laqua, U. Schmidt-Erfurth

Purpose: ICG-angiography (ICGA) was used to document the effect of repeated PDT(verteporfin) on size and leakage of choroidal neovascularisation in age related macular degeneration (AMD) and the treatment-related side-effects on the choroid.

Methods: 61 Patients were followed over 24 months in a double masked clinical trial for PDT in AMD (TAP Investigation). ICGA was performed every 3 months with a confocal laser scanning system . 42 patients received repeated verteporfin- (Visudyne, Ciba Vision) and 19 patients placebo-treatments. At each control visit patients were retreated if leakage was present in the fluorescein angiography (FA).

Results: In the PDT-group we found a continous reduction of CNV size and leakage area over 24 months. The initial CNV-size of 3,9mm² was reduced by 23% to 2,98mm² and the original leakage area of 5.0mm² by 30,3% to 3,5mm². In the placebo group CNV size and leakage area grew steadily to 341% and 271% of its original size.

A significant side-effect of PDT on the choroid was documented by an increased hypofluorescent area in ICGA. The maximum size of the hypofluorescent area was reached after 12 months. At month 24 choroidal fluorescence showed recovery in respect to area and intensity of fluorescence. But hypofluorescence surrounding the CNV lesion was already present in 58 out of 61 eyes pre treatment. A continous progression of hypofluorescence in the placebo group was found reaching 200% of the initial size at 24 months.

Conclusion: ICGA confirms that repeated PDT treatments, in contrast to placebo controls, lead to a significant reduction in CNV size and leakage area over as long as two years. CNV lesions are surrounded by choriocapillary hypofluorescence in ICGA. PDT causes further hypoperfusion of the choroid but shows in the longterm significant fluorescence recovery whereas in the placebo group a progessive increase of hypofluorescence was found.

Augenklinik, Universität zu Lübeck, Ratzeburger Allee 160, D-23538 Lübeck