Orbital Fracture Resulting in Contralateral Optic Canal Fracture with Traumatic Optic Neuropathy: A Case Report

Abstract

Introduction: Traumatic optic neuropathy (TON) can cause acute vision loss after head trauma, either due to indirect shearing forces or direct trauma, i.e., by a bony fragment of an optic canal fracture (OCF). We present a case of TON due to an isolated OCF with contralateral orbital fracture and injury.

Case presentation: A 19-year old male presented with immediate total loss of vision to no light perception in the right eye after being struck on the left cheek by a lawn sign. Computed tomography and magnetic resonance imaging revealed left orbital floor fracture and right optic nerve enhancement. The patient was treated with high-dose intravenous corticosteroids and plasma exchange for a presumed inflammatory or TON. Repeat orbital imaging revealed a right OCF with bony impingement of the optic nerve. The patient underwent endoscopic optic nerve decompression; a 4 × 5 mm bone fragment abutting the optic nerve was removed. 1 month later, vision improved to hand motion.

Conclusion: Imaging may fail to detect OCF, and visual prognosis depends on time to surgery and fracture pattern. Therefore, operative management and preoperative intravenous corticosteroids, though controversial, may be considered even in the absence of radiographic findings of bony impingement causing direct TON. Isolated OCF without continuous fractures originating at the injury site is also a rare fracture pattern and potential cause of direct TON.

Keywords: Neuroimaging; Optic canal fracture; Orbital floor fracture; Trauma; Traumatic optic neuropathy.

Fig. 1.

a Magnetic resonance imaging (MRI) of the orbits with gadolinium contrast and fat suppression (arrow): coronal (left) and axial (right) views displaying abnormal enhancement of the intracranial and canalicular segments of the right optic nerve consistent without corresponding T2 hyperintensity. b Computed tomography (CT) of the orbits with contrast: coronal (left) and axial (right) views displaying a fracture involving the right inferomedial optic canal and roof of the right sphenoid sinus with a bony fragment projecting superiorly.

Fig. 2.

Endoscopic images displaying the initial injury (top left) with depressed bone fragment (top right), elevation of the bone fragment (bottom left), the decompressed optic nerve after fragment removal (bottom center), and the 4 × 5 mm bone fragment (bottom right).