Optic neuritis Flashcards
What is optic neuritis?
An inflammatory or demyelinating disorder of the optic nerve causing acute visual loss
What neuro disease is optic neuritis associated with?
multiple sclerosis
Give 3 atypical causes of optic neuritis:
- Antibody-mediated
- Infectious
- Sarcoidosis
Give an example of antibody-mediated optic neuritis?
- Syphilis
- Lyme disease
- Herpes
Give 4 risk factors for optic neuritis?
- MS
- Female sex
- Young age (20-50 years)
- Higher latitude (incidence is higher in areas further from the equator)
Give 5 potential presenting complaints associated with optic neuritis?
- Acute unilateral loss of vision
- Retrobulbar and peri-ocular pain
- photopsias
- visual field loss
- reduced contrast sensitivity and colour vision
What does retrobulbar mean?
behind the eye
What is retrobulbar mean?
behind the eye
What is photopsia?
Visual flares
Does optic neuritis present acutely or chronically?
Acute
How long do periods of optic neuritis typically last?
2 weeks
Give 5 examinations used to investigate optic neuritis:
1) visual acuity testing
2) ishihara test for colour vision
3) pupillary light reflex
4) fundoscopy
5) extraocular muscle movements (follow my finger)
What would a pupillary light reflex show in an eye with optic neuritis?
no reflex in the affected eye
What sign may be seen on fundoscopy of an eye with optic neuritis?
swelling of the optic disc
True or false: optic neuritis is typically a clinical diagnosis
true
What scan can be used to view the optic nerve and thus confirm diagnosis of optic neuritis?
MRI brain and orbits
If an MRI does not show any signs of optic neuritis, what investigation can be used to support a clinical diagnosis?
lumbar puncture and CSF analysis (can be used to show signs of multiple sclerosis)
What is the key treatment used for an acute and profound flair up of optic neuritis?
high dose corticosteroid therapy (IV methylprednisolone followed by oral prednisolone)
True or false: an episode of optic neuritis results in definite conversion to multiple sclerosis
false
True or false: patients with optic neuritis have a >90% chance of recovering vision
True
