A RANDOMIZED CONTROLLED CLINICAL-TRIAL ON THE EFFICACY OF RADIATION-THERAPY IN THE CONTROL OF SUBFOVEAL CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION - RADIATION VERSUS OBSERVATION

Background: The results of several pilot studies concerning radiation therapy for age-related subfoveal choroidal neovascularization (CNV) h ave been published recently. Although positive treatment results have been described, it is not known whether this therapy alters the natura l course of eyes with neovascular age-related macular degeneration (AM D). A randomized controlled clinical trial was conducted in which radi ation therapy was compared with observation in patients with subfoveal neovascular AMD. Methods: Seventy-four patients with a recent drop in central vision due to subfoveal age-related CNV were randomized to ei ther radiation treatment or observation. Patients with either classic, occult or mixed type CNV were included. Eyes in the treatment group r eceived a radiation dose of 24 Gy in four fractions of 6 Gy. Evaluatio n of data concerning visual acuity (VA) and fluorescein angiography oc curred at 3, 6 and 12 months after inclusion. Results: At 12 months of follow-up 52.2% of the observation group versus 32.0% of the irradiat ion group had lost 3 or more lines of VA (P=0.03, log rank test). More severe visual decline, 6 lines or more, was observed in 40.9% of the observation versus 8.8% in the irradiation group (P=0.002 using log ra nk test). At 12 months 39.6% of the observation group and 20.0% of the treatment group had VA of less than 0.1 (P=0.08, log rank test). The size of the CNV membrane doubled in 25.2% of eyes in the observation g roup versus 20.0% in the treatment group at 12 months (P=0.5, log rank test). No side effects were observed. Conclusion: Preservation of VA was significantly better in the treatment group compared with the cont rol group at 12 months. Nevertheless we noted a drop in central vision of 3 or more lines in a substantial proportion of the treatment group . Radiation therapy does not prevent visual loss in all patients with age-related subfoveal CNV, and whether the treatment benefit at 12 mon ths will persist has to be awaited.