The Diagnosis and Treatment of Optic Neuritis

Abstract

Background: Typical optic neuritis is often the presenting manifestation of multiple sclerosis (MS). Its incidence in central Europe is 5 cases per 100 000 persons per year.

Methods: This review is based on articles retrieved by a selective search of the PubMed database, on the pertinent guidelines, and on the authors' clinical experience.

Results: The diagnosis of optic neuritis is based on a constellation of symptoms and signs. The onset is usually with pain on eye movement in one eye and subacute visual loss. In unilateral optic neuritis, the direct pupillary light reflex is weaker in the affected eye. One-third of patients with optic neuritis have a mildly edematous optic disc. The visual disturbance resolves in 95% of cases. A less favorable course may be evidence of neuromyelitis optica, and macular involvement may be evidence of neuroretinitis. High-dosed intravenous methylprednisolone therapy speeds recovery but does not improve the final outcome. The risk that a patient with optic neuritis will later develop multiple sclerosis can be assessed with an MRI scan of the brain.

Conclusion: Optic neuritis is easy to distinguish from otherv diseases affecting the optic nerve. Atypical forms of this disease and other optic nerve diseases require special treatment. For patients judged to be at high risk of developing multiple sclerosis, immune prophylaxis with beta- interferon or glatiramer acetate is recommended.

Trial registration: ClinicalTrials.gov NCT01864148 NCT01962571.

Figure 1

An illustration of the visual disturbance in a patient with optic neuritis, visual acuity 0.1. The photograph of a puffin was manipulated with Photoshop until the patient said that the altered image at left, seen with the normal eye, looked roughly the same as the original image at right, seen with the affected eye

Figure 2

Swinging flashlight test in a patient with left optic neuritis (schematic figure). The pupils react more rapidly, and to a greater extent, with illumination of the healthy right eye, compared to the affected left eye

Figure 3

a) Left optic neuritis in a 23-year-old woman with mild papilledema. b) MRI of the same patient, revealing contrast enhancement of the inflamed optic nerve, as well as two periventricular foci of demyelination on the T2-FLAIR sequence