Walsh & Hoyt: Traumatic Optic Neuropathies: Imaging

The superior imaging afforded by computed tomography and magnetic resonance imaging has made plain films and hypoclinoidal tomograms obsolete. Manfredi and coworkers reviewed the medical records of 379 patients with facial fractures. Twenty-one patients lost all vision in one eye (6%) and 3 of these 21 lost vision in both eyes; 12 of the 21 patients with visual loss had CT scans of the head as part of the initial assessment and of these 12, visual loss was attributed to traumatic globe injuries in 7 cases. CT scans in the remaining 5 patients demonstrated a fracture through the optic canal. The fracture may injure the optic nerve directly or it may serve as a marker of the severity of force transferred into the optic nerve. Seiff et al. reported CT results of nine patients with traumatic optic neuropathy. Six of the nine patients demonstrated fractures of the optic canal. Fractures were present in adjacent structures but not extending into the optic canal in two additional patients. In a follow-up study, canal fractures were found in 16 of 36 patients and fractures of the bones adjacent to the optic canal, but not involving the optic canal, in an additional 10 of 36 patients. However, 63% of the patients with canal fractures presented with no light perception compared with a 40% incidence of no light perception when there was no fracture or the fracture did not extend to the optic canal.