External beam radiation in patients suffering from exudative age-related macular degeneration - A matched-pairs study and l-year clinical follow-up

Background: The aim of this prospective study was to ascertain whether exte rnal beam irradiation is effective in patients with subretinal neovasculari zation (SRN) due to age-related macular degeneration (AMD). Methods: All pa tients had subfoveal SRN due to AMD as verified by fluoresceinangiography. Two hundred and eighty-seven patient-eyes were treated by external beam irr adiation (total dose of 16 Gy in 2-Gy fractions, 5 times a week) from Janua ry 1996. The analysis was restricted to those 73 patients with a minimum fo llow-up of 11 months. Eighteen patients with subfoveal SRN who refused trea tment served as control group (CG). 18 patients of the treatment group (TG) were matched for visual acuity, refraction and extent of SRN. The statisti cal analysis was performed with the unpaired t-test. Results: The mean age of the CG was 73.9 years (range 66.9-81.3 years) and of the TG 75.6 years ( range: 65.7-80.6 years). The median follow-up was 13.5 months (range 11.9-1 8.4 months) in the CG and 12.9 months (range 11-13.9 months) in the TG. The initial visual acuity (VA) was 20/80 in both groups. After 7 months the fo llow-up revealed median VA of 20/400 in the CG and 20/160 in the TG (P=0.03 35). The final median VB was 20/400 in both groups, with a range from 20/40 to 20/1000 in the CG and from 20/63 to 20/500 in the TG (P=0.2433). The SR N doubled in size during this time in both groups. Conclusion: These result s suggest that external beam irradiation applied in 2-Gy fractions 5 times a week slows down the visual loss in exudative AMD for a short time. Nevert heless, the patients' reading vision could not be saved in the long term.