Traumatic optic neuropathy

Background

  • Acute injury to the optic nerve from direct or indirect trauma resulting in vision loss
  • Caused by indirect injury to the optic nerve (intracanalicular portion) from transmitted shock from an orbital impact
  • Can also be caused by directly by penetrating injury or from bony fragments in the optic canal or orbit, or orbital hemorrhage and optic nerve sheath hematoma

Pathophysiology

  • Indirect: Hypothesized to result from shearing injury to the intracanalicular portion of optic nerve, which can cause axonal injury or disturb the blood supply of the optic nerve
  • Direct: Presumed to be the result of tissue disruption secondary to foreign body or bony fragments impacting the optic nerve

Clinical Features

History

  • Acute unilateral vision loss, decreased color sensation, and/or visual field deficit after blunt or penetrating trauma
  • Complaints may be delayed due to the impact of and treatment for other concomitant head injuries

Physical Exam

  • External eye exam may show signs of orbital trauma or fracture (soft tissue edema, hematoma, step-off on palpation of orbital rim)
  • Decreased visual acuity and an afferent pupillary defect (in unilateral cases)
  • On funduscopy, the initial optic nerve head assessment will be normal; optic atrophy may be seen 3-6 weeks after trauma

Differential Diagnosis

  • Posterior ischemic optic neuropathy
  • Optic neuritis
  • Optic nerve avulsion
  • Non-organic vision loss
  • Pre-/intra-/subretinal hemorrhage
  • Choroidal rupture
  • Commotio retinae
  • Traumatic iritis

Acute Vision Loss (Noninflamed)

Emergent Diagnosis

Orbital trauma

Acute

Subacute/Delayed

Evaluation

Workup

  • Non-contrast CT of head and face (including orbits)

Diagnosis

  • Primarily a clinical diagnosis

Management

  • Ophthalmology consult
    • Generally, no acute interventions are known to change prognosis

Contraindicated

  • Corticosteroids not helpful[1]
  • Surgical intervention has not shown to be beneficial, although some support the use of surgery in certain scenarios (e.g. bony fragment abutting optic nerve or optic nerve sheath hematoma)

Disposition

  • Outpatient ophthalmology follow up

Prognosis

  • Visual improvement in only about 50% of patients

See Also

External Links

References

  1. Levin, L.A., et al., The treatment of traumatic optic neuropathy: the International Optic Nerve Trauma Study. Ophthalmology, 1999. 106(7): p. 1268-77.