Optic Neuritis Flashcards
Prognosis of optic neuritis
90% of patients experience good visual recovery (though not necessarily complete recovery)
When optic neuritis presents in a child, it is most likely due to. . .
. . . an infectious or post-infectious etiology, as opposed to a primary autoimmune etiology
Of note, these are also more likely to be bilateral
When optic neuritis presents in a patient over the age of 45, it is most likely due to. . .
. . . ischemic optic neuropathy
This may be due to diabetes mellitus, giant cell arteritis, or other vascular disease
Optic neuritis in a patient age 20-40
Highly likely to be due to an autoimmune myelopathy, especially multiple sclerosis
Infectious neuroretinitis etiologies
- Numerous viruses
- Toxoplasmosis
- Bartonella
- Syphilis
- Lyme
- Secondary to a primary meningitis
Inflammatory optic neuritis with associated rheumatic disease (etiologies)
- Sarcoidosis
- SLE
- Sjogren’s
- IBD
- Paraneoplastic disease
- Parainfectious disease
Leber hereditary optic neuropathy
- 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
Scotoma
Isolated area of diminished vision within the visual field
The two most common symptoms of optic neuritis are vision loss and ___
The two most common symptoms of optic neuritis are vision loss and pain
It is generally a painful form of vision loss
Most common defect in optic neuritis
Central scotoma
Dyschromotopsia
Color vision defect
Two categories of dilated fundoscopic exam findings in optic neuritis
- Papillitis
- Retrobulbar neuritis
Papillitis
- 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
“Macular star”
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
Retrobulbar neuritis
- 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
Typical course of optic neuritis
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
As a form of myelitis, optic neuritis is exacerbated by . . .
. . . heat!
The Uhthoff phenomenon.
Classically seen when exercising or showering, but also on a hot day
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:
- CBC
- Syphilis serology
- Lyme serology
- ESR and CRP
- Serum chemistries
- Lumbar puncture and CSF studies
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. . .
. . . start a disease modifying therapy for MS empirically
This has been show to delay the onset of second attacks
“Delay of the P100 waveform on visual evoked potentials”
Suggests demyelinating optic neuritis
This basically means that the optic nerve is conducting slower than usual
Optical coherence tomography
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
Treatment for optic neuritis
-
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
