97th DOG Annual Meeting 1999

P553

CONFORMAL RADIOTHERAPY OF AGE RELATED OCCULT SUBFOVEAL NEOVASCULARIZATION - PRELIMINARY RESULTS

N. Becker*, G. Kovács, R. Schneider, P. Niehoff, R. Rochels*, B. Wiechens*

This study was performed to investigate the outcome of radiotherapy of occult subfoveal neovascularization (CNV) in age realated macular degeneration (AMD). Outcome was evaluated in this internim analysis after a follow-up of 10 months.

Patients and Methods: Twenty-four eyes of 22 Patients with angiographically confirmed subfoveal occult CNV were enrolled in this study. The mean observation time was 4.4 months. The visual acuity prior to therapy was between 0.05 and 0.5. Conformal photon radiotherapy was applied by a 6 MV linear accelerator after individual treatment planning using CT-based virtual simulation and non-coplanar three-field technique by thermoplast mask fixation of the head and light-fixation of the eye. Total dose applied was 18 Gy in daily 2 Gy fractions, five times a week. The follow-up examinations were at 3 weeks, 3 and 6 months. On follow-up examinations the following parameters were tested: visual acuity test, Regan test, swinging flashlight test, Amsler test and fluorescein angiography (FAG) after 3 weeks and 6 months respectively.

Results: Three weeks after therapy 87.5% of the treated eyes had the same or two lines better visual acuity compared to baseline. In 12.5% of the eyes we observed a decrease of visual acuity by two lines. Three months follow-up was reached in 19 cases: 63.2% of the patients had a better or unchanged visual acuity than before treatment compared to baseline. In 36.8% of the eyes there was a decrease of visual acuity. Up to now in only 10 eyes follow-up investigations after 6 months could be performed. Sixty percent of these 10 eyes had no change or were better and a decrease was observed in 40% of the cases, respectively. No radiation related side effects were observed in all cases.

Conclusion: The preliminary results of this study show that conformal radiation can lead to a stabilization of visual acuity. Given the fact that no alternative therapy in these patients is established and that side effects are rare, radiotherapy in occult age related CNV should be considered.

Department of Ophthalmology* and Clinic for Radiation Therapy (Radiooncology), Christian-Albrechts-University of Kiel, Hegewischstr. 2, D-24105 Kiel


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