Optic neuritis

Background

1. Inflammatory, demyelinating condition of the optic nerve highly associated with MS
   1. 50% will go on to develop MS
2. Presenting feature of MS in 15-20% of pts

Causes

1. Idiopathic
2. MS
3. Postchildhood vaccination
4. Viral infection
   1. Measles, mumps, varicella, zoster, EBV
5. Inflammation of structures contiguous with the optic nerve
   1. Meninges, orbit, sinuses
6. Other infections
   1. Syphilis, TB, Crypto

Clinical Features

1. Acute, usually monocular, vision loss occurring over days (occasionally over hours)
   1. May range from mildly reduced to no light perception whatsoever
2. Retro-orbital headache
3. Pain (esp w/ eye movement)
4. Loss of color vision out of proportion to loss of visual acuity

Diagnosis

1. Red desaturation test
   1. Have pt look with one eye at a dark red object
   2. Test the other eye to see if the object looks the same color
      1. Affected eye often will see the red object as pink or lighter red
2. Afferent Pupilary Defect (APD)
3. Optic disc swelling and edema (papillitis)
   1. Elevated optic nerve disk on US = papilledema
4. MRI of brain and orbits with gadolinium, plus fat suppression
5. CBC
6. CMP
7. ESR, CRP
8. RPR, FTABS
9. CXR

DDx

1. Ischemic optic neuropathy
2. Papilledema
3. Hypertensive retinopathy
4. Orbital tumor compressing optic nerve
5. Intracranial tumor compressing visual pathway

Treatment

1. Consult neuro and ophthalmology
2. MRI to r/o or in MS
3. Inpatient admission for IV methylprednisolone, 1 g qd x3 days

See Also

Multiple Sclerosis (MS)

Source

Tintinalli