Author:
Christopher J.Dudley
Description
- Optic nerve dysfunction due to an inflammatory process, commonly associated with myelin destruction, leading to acute vision loss
- Highly associated with multiple sclerosis (MS); presenting feature in 15-20% of MS patients
- Grouped by site of inflammation:
- Papillitis: Inflammation of the optic disk
- Retrobulbar neuritis: Inflammation of the optic nerve proximal to the globe
- 5 yr risk for clinically definite MS following optic neuritis:
- Normal MRI - 16%
- >3 lesions on MRI - 51%
- Recurrence is seen in 35% of patients
Etiology
- Idiopathic:
- Most common
- Single isolated events
- MS:
- 20-50% of patients with optic neuritis
- Likely genetic component
- High prevalence of A23, B7, and DR2 HLA alleles in patients with optic neuritis
- Viral infections:
- Chicken pox
- Measles
- Mononucleosis
- HSV and HZV
- Encephalitis
- Postviral optic neuritis:
- Usually occurs 4-6 wk after a nonspecific viral illness
- Granulomatous inflammation:
- TB
- Syphilis
- Sarcoidosis
- Cryptococcal infection
- SLE
- HIV:
- Cytomegalovirus
- Toxoplasmosis
- Histoplasmosis
- Cryptococcus
- Lyme disease
- Contiguous inflammation of meninges, orbit, sinuses, and intraocular inflammation
- Drug induced:
Signs and Symptoms
- Vision loss and eye pain most common symptoms
- Visual loss occurring over days (rarely over hours), peaks in 1-2 wk:
- Adults usually unilateral (90%)
- Bilateral visual loss more common in children
- Retrobulbar pain: Increased with movement of the affected eye
- Light, color vision, and depth perception loss more pronounced than visual acuity loss
- Afferent pupillary defect almost always occurs in unilateral cases if other eye is healthy
- Visual field defects:
- Usually characterized by central scotoma
- Deficits resolve by 1 yr in 56% of patients, and 73% resolve by 10 yr
- Funduscopic exam usually reveals either swollen (papillitis) or normal disk
- Uhthoff sign:
- Visual deficit occurring with exercise or increased body temperature
- Unusual sign seen occasionally
History
- Sex (2/3 of cases occur in women)
- Age (typically 20-50 yr)
- Pain on eye movement
- Speed of onset of symptoms
- Associated symptoms
- Previous episodes
- Family history of optic neuritis and /or MS
Physical Exam
- Check BP
- Complete ophthalmologic and neurologic exam, especially assessment of:
- Pupillary function
- Afferent pupillary defect (if other eye unaffected)
- Visual field defect
- Color vision (Ishihara color plates)
- “Red desaturation” subject may perceive that a red object appears “washed out” when viewed with the affected eye, compared to their unaffected eye's perception
- Slit lamp exam (uveitis or anterior chamber cells are uncommon and suggest alternate diagnosis)
- Dilated retinal exam (swollen optic disk)
Diagnostic Tests & Interpretation
Lab
- CBC
- ESR
- Rapid plasma regain (RPR), fluorescent treponemal antibody-absorption (FTA-ABS)
- Lyme titer
- Antinuclear antibody
- Angiotensin converting enzyme levels
- Purified protein derivative
- HIV
Imaging
- CXR for TB, sarcoid
- CT scan or MRI of brain and orbits:
- Inflammation of the retrobulbar optic nerve during the acute phase may appear as enlargement, thus falsely raising the issue of an optic nerve mass
- Optic nerve inflammation is seen in 95% of gadolinium-enhanced MRIs
- Visual field testing (preferably automated testing, such as Octopus or Humphrey)
Differential Diagnosis
- Acute papilledema
- Ischemic optic neuropathy
- Severe systemic hypertension
- Intracranial tumor compressing the afferent visual pathway
- Orbital mass compressing the optic nerve
- Toxic or metabolic neuropathy:
- Leber hereditary optic atrophy (most common inherited mitochondrial disorder)
Pediatric Considerations |
| In children, infectious and postinfectious causes should be considered |
Geriatric Considerations |
| In patients >50 yr, ischemic optic neuropathies (e.g., diabetes and giant cell arteritis) are more common, and appropriate workup should be obtained |
ED Treatment/Procedures
- Early ophthalmologic and neurologic consultations
- IV steroid pulse followed by oral steroids:
- Recommended for those with ≥2 demyelinating lesions on MRI without a prior history of MS or optic neuritis, or severe vision loss
- Decreases recurrence and progression to MS over 2 yr and shortens duration of visual impairment, but does not affect visual outcome at 1 yr nor rate of progression at 5 yr
- Treatment should be individualized for those with 1 lesion on MRI
- Alert: Oral prednisone used alone increases recurrence and should be avoided
Medication
Methylprednisolone: 250 mg IV q6h for 3 d, followed by oral prednisone (1 mg/kg/d) for 11 d with subsequent 4-d taper
Disposition
Admission Criteria
- Bilateral vision loss
- If other sources of acute vision loss cannot be ruled out
- IV steroid pulse treatment needed
Discharge Criteria
- Unilateral visual impairment
- Good home support systems
- Neurology and ophthalmology follow-up arranged
Issues for Referral
Referral for interferon β-1a treatment as outpatient for high-risk patients (those with ≥2 demyelinating lesions on MRI):
Follow-up Recommendations
Needs Ophthalmology referral
- GalRL, VedulaSS, BeckR. Corticosteroids for treating optic neuritis . Cochrane Database Syst Rev. 2015;14:CD001430.
- KaleN. Optic neuritis as an early sign of multiple sclerosis . Eye Brain. 2016;26:195-202.
- ToosyAT, MasonDF, MillerDH. Optic neuritis . Lancet Neurol. 2014;13:83-99.
- WeerasingheD, LueckC. Mimics and chameleons of optic neuritis . Pract Neurol. 2016;16:96-110.
See Also (Topic, Algorithm, Electronic Media Element)
Visual Loss
The authors gratefully acknowledge Douglas Lowery-North's for his contribution to the previous edition of this chapter.