Optic neuritis

Abstract

Demyelinating optic neuritis is the most common cause of unilateral painful visual loss in the United States. Although patients presenting with demyelinating optic neuritis have favorable long-term visual prognosis, optic neuritis is the initial clinical manifestation of multiple sclerosis in 20% of patients. The Optic Neuritis Treatment Trial (ONTT) has helped stratify the risk of developing multiple sclerosis after the first episode of optic neuritis based on abnormal findings on brain MRI. The ONTT also demonstrated that while initial treatment of optic neuritis with intravenous corticosteroids followed by an oral taper accelerates visual recovery, its use does not improve long-term visual outcomes. Long-term treatment with immunomodulating agents such as interferons has been shown to improve clinical outcomes and neuroimaging abnormalities in multiple sclerosis; furthermore interferon use has been associated with decreased risk of subsequent multiple sclerosis in patients with an acute neurologic syndrome. However, several questions regarding the presentation, management, and implications of acute demyelinating optic neuritis remain unanswered.

Keywords: Demyelinating Diseases; Optic Nerve Diseases; Optic Neuritis.

Figure 1

Coronal T1 contrast-enhanced fat suppressed magnetic resonance imaging showing enhancement of the left optic nerve (arrow) which is typical of optic neuritis.

Figure 2

Axial magnetic resonance imaging fluid-attenuated inversion recovery (FLAIR) sequence demonstrates periventricular lesions typical of demyelination from multiple sclerosis.

Figure 3

Life-table analysis of multiple sclerosis (MS) according to the number of lesions on baseline brain magnetic resonance imaging (MRI). Life-table intervals are defined by annual examinations during the first 5 years of the study and periods after the 5- and through the 10-year examinations and after the 10- and through the 15-year examinations. The table under the horizontal axis represents the number of patients during follow-up who had not developed MS at the end of the previous interval. Patients with 1 or 2 lesions on MRI were combined into a single group because the rates of MS were similar. From “Multiple sclerosis risk after optic neuritis: final optic neuritis treatment trial follow-up. Arch Neurol 2008;65:727-732.”

Figure 4

A 45 year-old man with prior optic neuritis in the right eye. The right optic disc (A) is pale compared to the normal left optic disc (B).

Figure 5

Optical coherence tomography shows thinning of the retinal nerve fiber layer of the right eye in the same patient as in Fig. 4.