Radiation-associated choroidal neovasculopathy

Purpose: To characterize a newly discovered choroidal vascular abnormality in patients who have received radiation therapy for subfoveal choroidal neo vascularization (CNV) secondary to age-related macular degeneration. Design: Two-center cross-sectional study. Participants: In the United States, there were 95 patients who were treated with 10 or 12 Gy of external beam photons. In Belgium, 98 patients were tr eated with 20 Gy. These patients were examined retrospectively for the pres ence of a specific CNV abnormality. Results: During the follow-up period, an unusual vascular growth pattern wa s identified in 12 patients (12.6%) of those treated in the United States a nd in 7 (7.1%) of those treated in Belgium. These patients developed round or oval vascular blebs along the outer border of their neovascular lesions. These blebs profusely leaked fluorescein dye and could be imaged best by i ndocyanine green angiography. Patients with these blabs appeared to have a marked propensity for loss of visual acuity. Conclusion: An unusual pattern of new vessel growth occurred in 19 of the 1 93 patients with CNV treated with radiation. This new entity, termed radiat ion-associated choroidal neovasculopathy, is a recognizable disorder that a ppears to have a particularly poor prognosis.