Traumatic dysfunction of the optic chiasm.
BACKGROUND: Trauma of the optic chiasm has been reported but its incidence is low. PATIENTS AND METHODS: Retrospective review of patients diagnosed with traumatic optic neuropathy between 1992 and 2002. RESULTS: Among 91 patients with a diagnosis of traumatic optic neuropathy, 10 showed evidence of optic chiasm involvement. All were males, the average age was 32 years (range 22-43). Injuries resulted from a rapid deceleration in 8 cases (car or motorcycle accident or fall from a minimum height of 5 meters). Coma was present in 6 cases and neurologic disorders in 8 cases. Optic neuropathy was present in 8/10 cases. Visual improvement was noted in two patients who suffered from milder head trauma. CONCLUSIONS: Optic chiasm dysfunction following head trauma is not that rare, as 11 % of our traumatic optic neuropathy group presented such a dysfunction. In some cases the visual field defect was obvious, but in some others it was more subtle. Visual prognosis was generally poor, probably related to the the severity of the impact.