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Acute Optic Neuritis
Synonyms: retrobulbar neuritis, papillitis
Optic neuritis (ON) is inflammation of the optic nerve. Classically there is a triad of clinical features - reduced
vision (of varying severity), eye pain (particularly on movement) and impaired colour vision.
The term 'optic neuritis' means inflammatory optic neuropathy from any cause, but is sometimes used to refer to
acute demyelinating optic neuritis. In this article, 'optic neuritis' (ON) refers to optic neuritis of any type, and 'acute
demyelinating optic neuritis' (ADON) will be used for that specific form. Other terms used in the literature are
papillitis (if the optic nerve head is affected) and retrobulbar neuritis (if the nerve is affected more posteriorly).
ADON is a common cause of ON in parts of the world where multiple sclerosis (MS) is common. However, there
are many other possible causes which must not be overlooked, as they may require different and urgent
management.
Neuromyelitis optica (NMO), also known as Devic's disease or Devic's syndrome, is a rare condition in which
there are recurrent and simultaneous optic neuritis and myelitis of the spinal cord. Lesions are different from
those observed in MS, and the condition requires a different course of treatment. [1, 2]
The first part of this article discusses ON of any type: its causes, assessment and diagnosis. The second part
gives more detail about ADON in adults, with a note on Devic's disease.
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Aetiology
Causes of optic neuritis (ON) [3, 4]
Type
Conditions/notes
Acute
demyelinating
ON
The most common cause of ON in regions where MS is relatively common (Caucasian populations and high
latitudes).
Ischaemic
optic
neuropathies
Giant cell arteritis (cranial arteritis), anterior and posterior optic neuropathy, diabetic papillopathy.
Corticosteroidresponsive
ON
Autoimmune diseases, including sarcoidosis, systemic lupus erythematosus, [5] Behçet's disease,
neuromyelitis optica (Devic's syndrome - affects optic nerves and the spinal cord), [6, 7] autoimmune ON, chronic
relapsing inflammatory ON.
Other
inflammatory
causes
Post-infection, post-vaccination, neuroretinitis, acute disseminated encephalomyelitis.
Infections
Tuberculosis, syphilis, [8] mycoplasma and other respiratory tract infections, Lyme disease, [9] toxocariasis, [10]
helminthiasis, cryptococcosis, viral ON (a rare complication of chickenpox), [11] Q fever, [12] periorbital infections
(orbital cellulitis, severe suppurative sinusitis). Other viral infections which have been known to cause ON
include measles, mumps, rubella, herpes zoster, infectious mononucleosis.
Nutritional
Vitamin B12 deficiency.
Drugs and
toxins
Amiodarone, ethambutol, isoniazid, [13] methanol intoxication, tobacco-methanol amblyopia.
Inherited
Leber's hereditary ON.
Optic neuritis
in children
Viral infection is a common cause.
Differential diagnosis
Posterior scleritis.
Maculopathy.
Retinopathy.
Big blind spot syndrome.
Presentation, assessment and diagnosis
Usual presentation
This is usually a triad of:
Visual impairment (of varying severity, usually developing over a period of hours or days, and may
typically be exaggerated by a hot bath or shower).
Pain around the eye (retrobulbar or ocular, typically worse on eye movement).
Dyschromatopsia (impairment of colour vision).
Other symptoms present in ADON are: [4]
Light flashes (phosphenes or photopsias).
Uhthoff's phenomenon - increased symptoms with raised body temperature (hot environment or
exercise).
Pulfrich's phenomenon - altered perception of the direction of movement; objects moving straight
appear to have a curved trajectory, presumably due to asymmetrical conduction in optic nerves.
Fatigue - fading of vision.
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Typical signs
These include:
Decreased pupillary light reaction in the affected eye: A relative afferent pupillary defect (RAPD), or
Marcus Gunn pupil, commonly is found; in bilateral cases, the RAPD may not be apparent.
Varying degrees of vision reduction: From a mildly decreased visual acuity to complete vision loss.
Abnormal contrast sensitivity and color vision: this is seen in almost all patients with adult ON with
decreased visual acuity.
Altitudinal field defects.
Arcuate defects.
Nasal steps.
Scotoma.
Papillitis is seen in one third of patients with ON.
Assessment
Full ophthalmological and neurological examination.
In practice, it is important to assess whether the clinical picture is typical of ADON, or whether there
are atypical features suggesting another cause (see table).
Typical vs atypical features of optic neuritis (ON) [3, 4]
Typical features of acute demyelinating optic neuritis (ADON)
'Warning' or atypical features suggesting another
cause
Adult patient age <45.
Patient aged <12 or >50, black or Asian race.
Symptoms:
Symptoms:
Unilateral reduction in vision.
Time course:
Acute or subacute onset of visual loss, which
progresses for ≤2 weeks.
Spontaneously improves within 3 weeks in
nearly all patients.
Bilateral reduction in vision.
Time course:
Vision loss continuing to progress
>2 weeks after onset.
No recovery by 5 weeks after
onset.
Pain - periocular, onset preceding or with visual loss,
worse on eye movement, does not disturb sleep.
Patients with multiple sclerosis (MS) may have recurrent
attacks of ON, which means that a history of previous
episodes of decreased vision in the same or fellow eye
may be elicited.
Pain - absent, or severe enough to disturb
sleep/restrict eye movements, or pain
persisting >2 weeks after onset, or pain
following onset of vision loss.
History suggesting another cause - eg,
autoimmune or inflammatory conditions,
infection, malignancy, immunosuppression,
systemic symptoms.
Deterioration after withdrawal of
corticosteroids (if given).
Signs:
Signs:
Visual loss varies from mild to no perception of light.
Ipsilateral relative afferent pupillary defect (RAPD).
Loss of contrast and colour vision out of proportion to
loss of acuity.
Normal or swollen optic disc; disc pallor occurs later (4-6
weeks after onset).
Visual field defect - any type.
Normal macula and peripheral retina.
Investigations [4]
Severe visual loss - no perception of light.
Lack of RAPD.
Temporal field defect in contralateral eye.
Unusual ocular findings - eg, marked ocular
inflammation, markedly swollen optic disc,
marked disc haemorrhages, macular star.
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Investigations
[4]
The diagnosis of ADON is a clinical one. If the clinical picture is typical for ADON, initial assessment involves:
Full ophthalmological examination.
Testing of visual acuity, contrast and colour vision, visual field testing.
Further investigations
MRI of the brain may be used to give information about the likelihood of developing MS.
Some studies suggest that testing of contrast vision, using specific charts, may yield similar
information to MRI in this scenario. [3]
If there are atypical features, investigations depend on the clinical picture, and may include:
Blood tests - eg, FBC, ESR, TFTs, autoantibodies and syphilis serology.
Serological testing for neuromyelitis optica immunoglobulin G (NMO-IgG). [6]
CXR - for suspected sarcoidosis, tuberculosis or malignancy.
CT or MRI of the brain and orbits.
Lumbar puncture - for suspected central nervous system infection or inflammatory ON
(CSF is examined for immunoglobulins, oligoclonal bands and infection). CSF analysis is
usually noncontributory to diagnosis. However, the presence of myelin basic protein,
oligoclonal bands, and an elevated IgG index and synthesis rate in the CSF supports the
diagnosis of MS. Even in the absence of other signs of MS during the initial presentation,
patients with positive findings of demyelination in the CSF are more likely to develop MS in
the long term. NMO-IgG is a specific autoantibody marker for NMO.
Acute demyelinating optic neuritis in adults [3]
Epidemiology
ADON demographics closely follow those of MS, which has a higher frequency in Caucasian
populations and at higher latitudes. Children who migrate before puberty take on the MS incidence of
the area to which they migrate.
Annual incidence of ADON is approximately 5/100,000; prevalence is 115 per 100,000.
Pathophysiology
The pathology of ADON involves demyelination and axonal loss, probably due to an inflammatory process and a
delayed hypersensitivity reaction. Recovery is due to remyelination and compensatory neuronal recruitment.
Presentation, diagnosis and investigations
These are explained above (see clinical features, and 'Presentation, assessment and diagnosis' and
'Investigations' sections).
Management
Refer to an ophthalmologist and/or neurologist. Usually, an ophthalmologist is involved in the initial
assessment, diagnosis and treatment. Further management regarding the risk of MS (below) usually
requires neurological expertise.
Consider corticosteroids during the acute phase:
Treatment with methylprednisolone speeds up visual recovery in the acute phase, but has
no effect on final visual acuity. Side-effects of corticosteroids can be serious. Therefore,
they are usually reserved for patients who need to hasten visual recovery, such as those
with poor vision in the fellow eye or bilateral visual loss, or for occupational reasons.
Recommended treatment is methylprednisolone 1 g daily for three days.
Oral prednisolone is not recommended because of (uncertain) evidence that it may
increase the recurrence rate.
There is no treatment that can reverse poor visual outcome in the long term.
Information for patients is important (see 'Prognosis', below).
Consider brain MRI, to give information about the risk of developing MS.
Consider referring to a neurologist for assessment of the patient's risk of developing MS, and the value
of disease-modifying drugs in this context (see 'Role of disease-modifying drugs', below).
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For Pulfrich's phenomenon (disturbed perception of movement), symptoms may be helped by using
spectacles with a tinted lens over the unaffected eye, to balance the delay in conduction from the other
side.
For Uhthoff's phenomenon symptoms (worsening vision with raised body temperature), avoid hot
environments and take cool drinks; reassure patients that this symptom is reversible and does not
further damage vision.
Intravenous immunoglobulin has generally been found to be of no benefit. One trial (small and nonrandomised, using a different regimen) reported improved vision with immunoglobulin treatment. [14]
Prognosis
Visual prognosis
The prognosis for vision in ADON is usually good. [15]
The Optic Neuritis Treatment Trial (ONTT), was a large study of ADON with 15-year follow-up, and
found that:
93% of patients showed improvement within five weeks of onset of ADON; vision continued
to improve for up to one year. One year after onset, 93% had visual acuity better than 6/12
in the affected eye. At 15-year follow-up, 92% had acuity better than 6/12 in the affected eye,
and only 1% had vision worse than 6/60 in both eyes.
The severity of initial visual loss seems to be related to the final visual outcome; however,
even with initial visual acuity of ≤6/60, 85% recover vision to 6/12 or better.
Although visual outcome is good in objective tests, many patients experience subjective reductions in
vision, colour vision, contrast sensitivity or depth/movement perception after recovery from ADON.
Risk of recurrence
ADON can recur in either eye.
The risk of recurrence was 35% over 10 years in the ONTT.
Risk of developing MS
ADON is associated with MS.
In the ONTT, for adults with a single episode of unilateral ADON, the risk of MS was 38% at 10 years
after onset, and 50% at 15 years. [16] Another study found the MS risk was 54% after 30 years. The
risk of developing MS is lower for children and for men.
MRI of the brain gives information about the risk of developing MS. The presence of white matter
abnormalities increases the MS risk and their absence reduces it. In the ONTT, the risk of developing
MS at 15-year follow-up was 25% for patients with no lesions on MRI, and 75% for those with white
matter lesion(s).
Role of disease-modifying drugs
Interferon beta increases the time interval to relapse in MS. Trials suggest that, in a scenario such as a
patient with ADON and white matter lesions on brain MRI, where the risk of developing MS is relatively
high, interferon beta may similarly delay the onset of MS symptoms.
However, bear in mind that:
Many patients with a first episode of ADON and an abnormal MRI scan will not develop MS.
Treatment is only partly effective - eg, six years of interferon beta treatment prevents one
relapse.
The visual prognosis is good even if MS develops.
Discussion with patients
The association between ADON and MS causes anxiety for patients and can impact on insurance
policies.
It is important to emphasise that many ADON patients will not develop MS; even if they do, the
prognosis regarding both vision and other disability can be good.
Information about the prognosis can help patients to decide whether to undergo an MRI scan and
whether to use beta interferon.
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Devic's disease [2]
This is an idiopathic inflammatory demyelinating and necrotising disease mainly involving the optic
nerves and spinal cord. In Asian countries relapsing NMO is known as opticospinal MS.
NMO has a typically relapsing course. Distinctive pathological features of NMO distinguish NMO from
other demyelinating diseases such as MS. An IgG antibody named NMO-IgG has high sensitivity and
specificity.
There is often a long spinal cord lesion that extends through three or more vertebral segments in
length. Brain MRI lesions atypical for MS are found in the majority of cases.
Treatment in the acute phase includes intravenous steroids and plasma exchange therapy.
Immunosuppressive agents are recommended for prophylaxis of relapses.
Further reading & references
Hickman SJ et al; Optic Neuritis: An Update Typical and Atypical Optic Neuritis, Neuro-Ophthalmology 2008; 32: 237–248.
Wilejto M, Shroff M, Buncic JR, et al; The clinical features, MRI findings, and outcome of optic neuritis in children.
Neurology. 2006 Jul 25;67(2):258-62.
1. Minagar A, Alexander JS, Fowler MR, et al ; Devic disease: clinical course, pathophysiology, and management.
Pathophysiology. 2002 Oct;9(1):33.
2. Lana-Peixoto MA; Devic's neuromyelitis optica: a critical review. Arq Neuropsiquiatr. 2008 Mar;66(1):120-38.
3. Shams PN, Plant GT; Optic neuritis: a review. Int MS J. 2009 Sep;16(3):82-9.
4. Hickman SJ, Dalton CM, Miller DH, et al; Management of acute optic neuritis. Lancet. 2002 Dec 14;360(9349):1953-62.
5. Lin YC, Wang AG, Yen MY; Systemic lupus erythematosus-associated optic neuritis: clinical experience and Acta
Ophthalmol. 2009 Mar;87(2):204-10. Epub 2008 May 27.
6. Matiello M, Jacob A, Wingerchuk DM, et al; Neuromyelitis optica. Curr Opin Neurol. 2007 Jun;20(3):255-60.
7. Nandhagopal R, Al-Asmi A, Gujjar AR ; Neuromyelitis optica: an overview. Postgrad Med J. 2010 Mar;86(1013):153-9.
8. Smith GT, Goldmeier D, Migdal C; Neurosyphilis with optic neuritis: an update. Postgrad Med J. 2006 Jan;82(963):36-9.
9. Blanc F, Ballonzoli L, Marcel C, et al; Lyme optic neuritis. J Neurol Sci. 2010 Aug 15;295(1-2):117-9. Epub 2010 Jun 8.
10. Finsterer J, Auer H; Neurotoxocarosis. Rev Inst Med Trop Sao Paulo. 2007 Sep-Oct;49(5):279-87.
11. Tappeiner C, Aebi C, Garweg JG; Retinitis and optic neuritis in a child with chickenpox: case report and review, Pediatr
Infect Dis J. 2010 Jul 8.
12. Ong C, Ahmad O, Senanayake S, et al; Optic neuritis associated with Q fever: case report and literature review. Int J Infect
Dis. 2010 Jun 2.
13. Kokkada SB, Barthakur R, Natarajan M, et al; Ocular side effects of antitubercular drugs - a focus on prevention, early
Kathmandu Univ Med J (KUMJ). 2005 Oct-Dec;3(4):438-41.
14. Tselis A, Perumal J, Caon C, et al; Treatment of corticosteroid refractory optic neuritis in multiple sclerosis Eur J Neurol.
2008 Nov;15(11):1163-7. Epub 2008 Aug 21.
15. No authors listed; Visual function 15 years after optic neuritis: a final follow-up report from the Ophthalmology. 2008
Jun;115(6):1079-1082.e5. Epub 2007 Nov 5.
16. No authors listed; Multiple sclerosis risk after optic neuritis: final optic neuritis treatment Arch Neurol. 2008 Jun;65(6):72732.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical
conditions. EMIS has used all reasonable care in compiling the information but makes no warranty as to its
accuracy. Consult a doctor or other healthcare professional for diagnosis and treatment of medical conditions.
For details see our conditions.
Original Author:
Dr Olivia Scott
Current Version:
Dr Mary Lowth
Peer Reviewer:
Dr Colin Tidy
Document ID:
1765 (v22)
Last Checked:
22/08/2014
Next Review:
21/08/2019
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