Traumatic Optic Neuropathy

Abstract

A host of different types of direct and indirect, primary and secondary injuries can affect different portions of the optic nerve(s). Thus, in the setting of penetrating as well as nonpenetrating head or facial trauma, a high index of suspicion should be maintained for the possibility of the presence of traumatic optic neuropathy (TON). TON is a clinical diagnosis, with imaging frequently adding clarification to the full nature/extent of the lesion(s) in question. Each pattern of injury carries its own unique prognosis and theoretical best treatment; however, the optimum management of patients with TON remains unclear. Indeed, further research is desperately needed to better understand TON. Observation, steroids, surgical measures, or a combination of these are current cornerstones of management, but statistically significant evidence supporting any particular approach for TON is absent in the literature. Nevertheless, it is likely that novel management strategies will emerge as more is understood about the converging pathways of various secondary and tertiary mechanisms of cell injury and death at play in TON. In the meantime, given our current deficiencies in knowledge regarding how to best manage TON, "primum non nocere" (first do no harm) is of utmost importance.

Keywords: optic canal decompression; optic neuropathy; steroids; trauma; traumatic optic neuropathy.

Fig. 1

Anterior indirect traumatic optic neuropathy in a young boy who was hit in the right eye while playing soccer.

Fig. 2

Fatal indirect anterior traumatic optic neuropathy. Note subdural hematoma at the junction of the optic nerve and globe.

Fig. 3

Direction of concussive forces from blunt trauma to the forehead. Note that the lines of force can traverse either the ipsilateral or the contralateral optic canal.

Fig. 4

Horizontal section through the canalicular portion of the left optic nerve. Note the tight attachment of the dura to the nerve within the canal.

Fig. 5

CT scans from two patients with indirect retrobulbar traumatic optic neuropathy. Left: patient has a fracture of the left anterior clinoid process ( long arrow ) as well as the right skull base. Note that there is a soft-tissue shadow in the right sphenoid sinus, probably representing blood. Right: there is a fracture of the right anterior clinoid process extending to the optic canal.