2. Introduction & Definition
• An inflammation of the optic nerve is known as optic neuritis.
• The optic nerve may be affected by inflammation in any part of its course.
• Based on the ophthalmoscopic appearance it can be divided into 3 types:
1. Papillitis
2. Neuroretinitis
3. Retrobulbar neuritis
3. 1. Papillitis
• Papillitis is most common type in
children
• It is characterized by:
1. Hyperemia and edema of the optic
disc
2. Associated with peripapillary flame
shaped hemorrhages
3. Cells may be seen in posterior
vitreous
4. 2. Neuroretinitis
• Least common type
• It is characterized by:
1. Papillitis plus
2. Inflammation of the retinal
nerve fiber layer and
3. Macular star
5. 3. Retrobulbar neuritis
• Most common type in adults
• Frequently associated with Multiple
sclerosis
• Characteristics:
1. Optic nerve head not involved
2. Optic disc appears normal (atleast
initially)
6. Papilledema Papillitis Pseudo-papillitis
Laterality Bilateral Unilateral Unilateral or bilateral
Visual acuity Blurred vision Sudden profound loss of
vision
Blurred vision
Pain on ocular
movements
Nil Present Nil
Pupillary light reflex Not affected Depressed & RAPD
present
Not affected
Media Clear Vitreous cells Clear
Peripapillary edema,
venous engorgement,
Retinal hemorrhages &
exudates
Marked Less marked Absent
Field defect Enlarged blind spot Central scotoma to
complete blindness
Nil
FFA Leakage of dye present Minimal leakage Nil
7. Epidemiology
• Annual incidence of optic neuritis – 3 to 5 per 1,00,000/year
• Prevalance – 115 per 1,00,000
• Affected age group – 20 to 50 years
• Women are affected more commonly than men (ONTT – 77% patients are
women)
• Whites are affected more commonly than blacks (ONTT – 85% patients are
whites).
9. Demyelinating disorders
• This is by far the most common cause. It can be:
1. Isolated
2. Associated with Multiple sclerosis
3. Neuromyelitis optica (Devic)
13. Pathogenesis of Optic neuritis
• It is presumed to be demyelination in varying degrees.
• Demyelination could be:
1. Axial
2. Peripheral
• Inflammatory response marked by:
1. Perivascular cuffing
2. T lymphocytes & plasma cells
14. Association between optic neuritis & Multiple sclerosis
• Optic neuritis is the presenting feature of Multiple sclerosis in up to 30%.
• Optic neuritis occurs at some point in 50% of patients with established
Multiple Sclerosis.
• The overall 15-year risk of developing Multiple Sclerosis following an
acute episode of optic neuritis is about 50%.
15. Association between optic neuritis & Multiple sclerosis
• Following an acute episode of optic neuritis, the presence of MRI lesion is
a very strong predictive factor of Multiple sclerosis (MS).
– With no lesions on MRI the risk of MS is 25%
– patients with one or more lesions on MRI – risk is over 70%
16. Clinical features
• Optic neuritis due to various causes will have similar visual symptoms but
will differ in their clinical course.
• Other associated symptoms and signs will be in accordance with the
underlying disease.
• ‘Typical’ optic neuritis implies - Demyelinative syndrome associated with
Multiple sclerosis clinical features of which are described here:
17. Symptoms
1. Loss of vision
• Predominant symptom
• Vision loss can be subtle or profound, unilateral or bilateral
• Typically deteriorates over hours to days and reaches a trough in 1 week
• Vision gradually improves spontaneously.
18. 2. Deep orbital, retroocular or brow pain
• Aggravated by eye movement
• Increased by pressure upon globe
3. Neuralgia or headache
4. Tenderness of eyeball on digital pressure
• Tenderness corresponds roughly with the site of attachment of
Superior rectus tendon (initially only, later disappears)
19. 5. Loss of colour vision
6. Reduced perception of light intensity
7. Pulfrich phenomenon:
• Altered perception of moving objects, seen in unilateral conduction delay.
• Occurs due to a relative difference in signal timings between the two eyes.
20. 8. Systemic features (Multiple sclerosis):
• Spinal cord - weakness, stiffness, sphincter disturbance, sensory loss.
• Brainstem, e.g. diplopia, nystagmus, dysarthria, dysphagia.
• Cerebral, e.g. hemiparesis, hemianopia, dysphasia.
• Psychological, e.g. intellectual decline, depression, euphoria.
21. Signs
1. Decreased visual acuity
• 6/18 to 6/60
• Rarely may be worse
2. Relative afferent pupillary defect (or) Marcus Gunn pupil
• Indicating a defect in afferent limb of pupillary light reflex
• It is of greater diagnostic significance
• Tested by swinging flash light test
23. 6. Visual fields defects
A. Central scotoma
B. Centrocaecal scotoma
C. Nerve fiber bundle
D. Altitudinal
24. 7. Ophthalmoscopic findings:
• No ophthalmoscopically visible changes – in Retrobulbar neuritis
• Optic disc hyperaemia
• Swelling of disc with blurred margins in Papillitis
• Peripapillary flame shaped hemorrhages
• Papillitis features + Macular fan or star – Neuroretinitis
26. (Signs associated with Multiple sclerosis)
8. Uhthoff sign – Worsening of symptoms with exercise or an increase in
body temperature.
9. Lhermitte sign – electrical sensation on neck flexion
27. Differential diagnosis
1. Ischemic optic neuropathy (ION)
• Anterior ION resembles – Papillitis
• Posterior ION resembles – Neuroretinitis
2. Papilloedema
3. Grade IV hypertensive retinopathy
4. Leber hereditary optic neuropathy
5. Toxic and metabolic optic neuropathy
6. Compressive space occupying lesion – in orbit (or) intracranially at chiasmal region
28. Clinical workup & investigations
1. Careful history-taking
• age of the patient
• the rapidity of onset
• occurrence of any previous episodes and
• the presence of pain on eye movements
2. Complete ophthalmic examination
• Visual acuity
• Pupillary reactions
• Colour vision
• Fundus examination
29. Clinical workup & investigations
3. Visual fields
4. VEP – prolonged latency is seen
5. MRI with Gadolinium enhancement
• Recommended for first episode and every atypical case
• Rules out a space-occupying lesion
• Helps in predicting the likelihood of multiple sclerosis
30. Clinical workup & investigations
6. Additional tests should be performed for ‘atypical’ optic neuritis:
• CRP and ESR
• Rapid plasma regain
• Fluorescent treponemal antibody absorption (FTA-ABS) test
• Antinuclear antibody (ANA) test
31. Clinical course of Optic neuritis
• In the majority of cases, especially those with demyelinating disease:
– vision starts to improve in the 2nd or 3rd week.
– by the 4th to 5th week visual acuity returns to normal or near normal
(6/18 to 6/12).
– Subsequently, vision slowly and steadily improves over several months
and is ultimately usually restored to 6/6.
32. Clinical course of Optic neuritis
– Colour vision, contrast sensitivity and visual fields take longer to
recover (6–12 months or so) or may not recover completely.
– Small percentage of cases, vision does not improve to functional levels.
– Rarely, does not improve at all, suggesting an atypical neuritis.
33. Treatment
• Goals of Optic neuritis therapy:
1. One goal of acute therapy is to improve visual outcome.
2. Another goal of optic neuritis treatment is to delay development of
clinically definite demyelinating disease.
• General guidelines for treatment are based on a major multi centre trial
(the Optic Neuritis Treatment Trial - ONTT)
34. • Two major findings of the ONTT with regard to these treatment goals:
1. Intravenous methylprednisolone treatment hastens recovery of visual
function but does not affect long-term visual outcome.
2. Patients treated with oral prednisone alone (without IV methylprednisolone)
demonstrated an increased risk of recurrent optic neuritis.
35. Indications of steroid regimen:
1. Patient with profound visual loss,
2. No previous history of optic neuritis or multiple sclerosis and
3. If MRI shows at least one area of demyelination.
36. Steroid regimen:
– Intravenous Methylprednisolone 1 g daily (given slowly over 30-60 min)
for 3 days f/b
– Oral Prednisolone (1 mg/kg daily) for 11 days, subsequently
tapered rapidly over 3 days.
• Observation is the rule if a patient has already been diagnosed to have
multiple sclerosis or has suffered from prior episodes of optic neuritis.
37. Immunomodulatory treatment (IMT):
• Reduces the risk of progression to clinical MS in some patients.
• But risk versus benefit ratio has not yet been fully defined.
• The presence of two or more white matter lesions on MRI should prompt
consideration of one of these treatments.
38. Immunomodulatory treatment options available
1. Interferon β – 1a :
• Controlled High-Risk Avonex MS Prevention Study (CHAMPS) demonstrated
that treatment with interferon β-1a (Avonex) following acute
monosymptomatic demyelinating optic neuritis significantly reduces the 3-year
cumulative probability of Multiple sclerosis.
2. Glatiramer acetate
3. Teriflunomide
4. Betaseron
