Optic Neuritis

Question 1

Prognosis of optic neuritis

Answer 1

90% of patients experience good visual recovery (though not necessarily complete recovery)

Question 2

When optic neuritis presents in a child, it is most likely due to. . .

Answer 2

. . . an infectious or post-infectious etiology, as opposed to a primary autoimmune etiology

Of note, these are also more likely to be bilateral

Question 3

When optic neuritis presents in a patient over the age of 45, it is most likely due to. . .

Answer 3

. . . ischemic optic neuropathy

This may be due to diabetes mellitus, giant cell arteritis, or other vascular disease

Question 4

Optic neuritis in a patient age 20-40

Answer 4

Highly likely to be due to an autoimmune myelopathy, especially multiple sclerosis

Question 5

Infectious neuroretinitis etiologies

Answer 5

• Numerous viruses
• Toxoplasmosis
• Bartonella
• Syphilis
• Lyme
• Secondary to a primary meningitis

Question 6

Inflammatory optic neuritis with associated rheumatic disease (etiologies)

Answer 6

• Sarcoidosis
• SLE
• Sjogren’s
• IBD
• Paraneoplastic disease
• Parainfectious disease

Question 7

Leber hereditary optic neuropathy

Answer 7

• An inherited form of optic neuropathy passed from mother to child by mitochondrial DNA (mitochondrial inheritance).
• Onsets in teenage or young adult years, most commonly in males
• Typically presents as subacute visual changes in one or both eyes
• Funduscopic exam typically shows circumpapillary telangectasia
• Pathology: Acute cell death of optic nerve neurons due to error in mitochondrial metabolism

Question 8

Scotoma

Answer 8

Isolated area of diminished vision within the visual field

Question 9

The two most common symptoms of optic neuritis are vision loss and ___

Answer 9

The two most common symptoms of optic neuritis are vision loss and pain

It is generally a painful form of vision loss

Question 10

Most common defect in optic neuritis

Answer 10

Central scotoma

Question 11

Dyschromotopsia

Answer 11

Color vision defect

Question 12

Two categories of dilated fundoscopic exam findings in optic neuritis

Answer 12

• Papillitis
• Retrobulbar neuritis

Question 13

Papillitis

Answer 13

• Swelling of the optic disc with blurring of optic disc margins, seen in anterior optic neuritis
• If a “macular star” of macular exudates is present in addition to papillitis, neuroretinitis is the likely diagnosis, suggesting an infectious etiology

Question 14

“Macular star”

Answer 14

Associated with papillitis in cases of neuroretinitis

Suggests an infectious etiology, such as viral, toxoplasma, bartonella, Lyme, and syphilis

Looks more like a firework to me

Question 15

Retrobulbar neuritis

Answer 15

• Optic disc appears normal, as the inflammation is located in the more posterior optic nerve (after it has exited the eye)
• Defined by optic neuritis in the presence of a normal fundoscopic exam

Question 16

Typical course of optic neuritis

Answer 16

Recovery should begin within weeks.

Continued progression after 2 weeks OR lack of improvement after 8 weeks suggests a diagnosis other than simple optic neuritis

Question 17

As a form of myelitis, optic neuritis is exacerbated by . . .

Answer 17

. . . heat!

The Uhthoff phenomenon.

Classically seen when exercising or showering, but also on a hot day

Question 18

While not required for typical optic neuritis, some tests that might be order to evaluate for atypical optic neuritis or optic neuritis with additional systemic symptoms include:

Answer 18

• CBC
• Syphilis serology
• Lyme serology
• ESR and CRP
• Serum chemistries
• Lumbar puncture and CSF studies

Question 19

If a patient has an initial attack of optic neuritis and MRI shows baseline abnormalities or LP shows oligoclonal bands concerning for (but not diagnostic of) MS, then it is common practice to. . .

Answer 19

. . . start a disease modifying therapy for MS empirically

This has been show to delay the onset of second attacks

Question 20

“Delay of the P100 waveform on visual evoked potentials”

Answer 20

Suggests demyelinating optic neuritis

This basically means that the optic nerve is conducting slower than usual

Question 21

Optical coherence tomography

Answer 21

Noninvasive study performed in neuro-ophtho clinic to assess degree of disc edema and atrophy of retinal nerve fibers

Can be done in a serial fashion to provide a helpful picture of disease progression

Question 22

Treatment for optic neuritis

Answer 22

• Treat with a 3 day course of IV (NOT oral) methylprednosine (or up to 5 days if necessary)
  
  • This hastens recovery by several weeks, but does not modify long-term visual outcomes
  • Also delays the onset of MS by ~2 years in those who will eventually develop MS
• If steroids do not work, plasmaphoresis has been shown to be helpful
• Optic neuritis does NOT respond to IVIG