Optic Neuritis Flashcards
What is optic neuritis?
inflammation of optic nerve
What can optic neuritis involve?
retobulbar (retrobulbar neuritis) or the intrabulbar (papillitis) portion of the optic nerve or both
What is the most common form of ON?
idiopathic
What is idiopathic ON?
an inflammatory optic neuropathy in absence of evidence of systemic inflammatory disease
What can ON suggest?
- can occur in isolation
- or be a manifestation (first one) of MS
What are the symptoms and signs of optic neuritis?
- Peri-orbital/retro-ocular pain
- Loss of visual acuity with scotoma
- Colour desaturation/loss of colour vision
- Relative afferent papillary defect (RAPD)
What are possible DDx of optic neuritis?
- Lyme disease
- Syphillus
- HIV infection
- Varicella-zoster SLE
- Giant cell arteritis
Etc
What investigations do you do for ON?
- MRI of optic nerve
- FBC
- ESR
- CRP
- VDLR
- NMO antibody and anti MOG antibody
- Uric acid
- Serum ACE
- ANA
What would MRI of optic nerve show?
- swelling of optic nerve
- enhancement in optic nerve
- white matter lesions in patients with multiple sclerosis (MS) or at risk of MS
What would FBC show?
high WBC in infection
What would ESR show?
high in giant cell arteritis
What would CRP show?
high if infection
What would VDLR show?
positive in syphillus
What could early intervention of optic neuritis be?
e.g. interferon-beta and glatiramer acetate which can reduce risk of conversion to MS
What is the 1st line acute treatment for idiopathic ON?
- plus dose methylprednisolone
- high-dose oral or IV corticosteroid treatment
What should not be used in acute treatment of idiopathic ON?
low to medium dose oral corticosteroids alone should not be used in treatment of idiopathic acute ON
What is the treatment for ongoing ON?
immunosuppressive treatment
What are possible complications of ON?
- Development of MS
- Recurrent ON
- Chronically reduced visual acuity
What is normal epid for optic neuritis?
Female 20-40 yo
How common is optic neuritis?
Most common optic nerve disease to affect young people
What is the patho of optic neuritis?
Inflammatory demyelination of optic nerve
What are causes of optic neuritis?
- Multiple sclerosis: can be presenting manifestation of MS
- Infectious
- Drugs
What infections can cause optic neuritis?
- viral encephalitis
- sinusitis
- meningitis
What drugs can cause optic neuritis?
- quinine
- arsenic
- ethambutol
What are symptoms for optic neuritis?
- Vision loss: scrotomas to complete vision loss
- Hours to days
- Decreased visual acuity
- Pain: worse on movement
- Reduced colour vision
- Usually unilateral can be bilateral
What is key investigation for optic neuritis and why?
- Gadolinium-enhanced MRI of the orbit and brain
1. May show enlarged optic nerve
2. Helps diagnose multiple sclerosis too
