A 26-year-old amateur boxer noticed a visual field defect without an apparent temporal correlation with a fight. Computerized perimetry showed right inferior homonymous quadrantopsia and congruous horizontal sectoranopia. Magnetic resonance imaging revealed a CSF-filled cavity in the left lateral geniculate body, which was surrounded by a rim of signal change without hemosiderin deposits. A signal change along the course of the left optic radiation consistent with wallerian degeneration was also present. Ischemia in the territories of the perforating branches of the anterior and lateral choroidal arteries due to vascular injury might be responsible for the lateral geniculate body lesion in this patient.