Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Ophthalmology PPT 16 Optic Nerve Lecture Notes
Optic Neuritis, Papil edema and Optic Atrophy
Department of Ophthalmology
Acknowledgement
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Yanoff and Duker. Papil edema. 2016 In: Ophthalmology. Mosby Inc.
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Khurana AK. Optic atrophy 2014 In: Comprehensive Ophthalmology. CBS Publishers
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Weerasinghe, D., & Lueck, C.J. (2016). Mimics and chameleons of optic neuritis. Practical
neurology;16(2):96-110.
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CME: Optic Neuritis: Diagnosis, Treatment, and Prognosis.
https://www.medscape.org/viewarticle/571660_2
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Kahloun R et al. Infectious optic neuropathies: a clinical update. Eye and Brain 2015;7:59-81
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Creel D. Visual y Evoked Potentials. 2012 Mar 1. In: Kolb H, Fernandez E, Nelson R, editors. Webvision:
The Organization of the Retina and Visual System [Internet]. Salt Lake City (UT): University of Utah
Health Sciences Center; 1995-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK107218/
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Pastora-Salvador N et al. Foster Kennedy syndrome: papil edema in one eye with optic atrophy in the
other eye. CMAJ 2011;183(18):2135
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Reynolds SA. Pinpointing Papil edema. Optometric Management 2015:82-4
https://www.optometricmanagement.com/issues/2015/september-2015/clinical-posterior
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Schiffmann J et al. Evaluation and treatment of papil edema in pregnancy. Comprehensive ophthalmology
update 2006;7(4):187-202
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Toosy AT. Optic Neuritis. Lancet Neurol. 2014 Jan;13(1):83-99
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Learning Objectives
? At the end of the class, students shall be able to
? Define and classify optic neuritis.
? Understand the aetiology and principles of
management of optic neuritis.
? Understand the stages and importance of
papilloedema.
? Differentiate between various types of optic atrophy.
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Normal optic disc
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Question
? The disc in question is
of a 60 year old myope
who is instil ing timolol
eye drops since the past
5 years.
? Is this a normal optic
disc?
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Optic Neuritis
Definition: Inflammation of the optic nerve,
impairing nerve conduction.
Secondary to demyelination, infection or
autoimmune pathology.
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Classification
A. Papillitis
B. Retrobulbar neuritis
? Acute
? Chronic (toxic
amblyopia)
C. Neuroretinitis
D. Perineuritis
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Aetiology
? Idiopathic
? Demyelinating disorders
? Multiple Sclerosis
? Presenting feature in 25% patients
? 70% cases occur in established disease
? Recurs in same/ opposite eye in 25% patients
? Uhthoff"s phenomenon: impairment of vision more
with increased body temperature
? Pulfrich phenomenon: altered perception of moving
objects
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Aetiology
? Neuromyelitis optica (of Devic): acute, bilateral optic
neuritis in young patient with paraplegia
? Post-viral: mumps, measles, chicken pox, whooping
cough
? Metabolic/Nutritional deficiency:
B1, B6, B12, B2, Folic acid deficiency
Thyroid dysfunction, diabetes
? Hereditary optic neuritis (Leber's disease)
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Aetiology
? Toxic amblyopia:
Chloroquine, Ethambutol
Tobacco, Ethyl alcohol, methyl alcohol
Lead, Arsenic.
? Ischaemic: Giant cel arteritis, Takayasu's disease,
PAN, SLE
? Granulomatous inflammation:
Sarcoidosis, tuberculosis, syphilis
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Symptoms
? Idiopathic/demyelinating : 20-40 years of age
? Viral: children
? Uniocular sudden/rapid diminution of vision
? Visual loss, usually maximum by end of second week,
improves by 1-4 weeks
? Discomfort/pain behind eyeball especially when moved
superiorly
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Signs
? Visual Acuity: Usually 6/60 or less
? Local tenderness
? Pupil ary reaction: Sluggish, ill-sustained or RAPD
? Impaired coloured vision: hue, brightness
? Impaired contrast sensitivity
? Delayed dark adaptation
? Visual Field: central, centrocaecal or paracentral
scotoma, more pronounced for coloured fields
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Ophthalmoscopic findings
? Optic neuritis: MC in children,
engorged, oedematous optic disc
with obliteration of optic cup,
small haemorrhages on disc
? Retrobulbar neuritis: MC in
adults
? Neuroretinitis:
Optic neuritis+ macular star
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Differential diagnosis
? Papilloedema
? Pseudopapillitis
High hypermetropia,
Myelinated nerve fibres,
Optic nerve head drusen
(blurred margin, disc not significantly
elevated, no vascular changes, stationary)
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Investigations
? MRI: demyelinating
lesions, SOL
? VEP: reduced
amplitude and delayed
transmission time
(P100 latency
increased)
Right optic neuritis
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Advanced case of optic neuritis
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Course and prognosis
? Recovery takes 4-6 weeks
? 90% recover normal VA, but colour vision
defects may persist
? No correlation between initial visual loss
and final visual outcome
? 10% secondary or post-neuritic optic
atrophy
? Better outcome in young, unilateral cases
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Treatment
? Of cause e.g. anti-infective therapy
? Intravenous methyl prednisolone 20
mg/kg/day(250 mg QID) for 3 consecutive days
followed by oral prednisolone 1-1.5 mg/kg
? Dexamethasone 200 mg OD pulse for 3-5 days
is a cheaper alternative
? Supportive therapy
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Papil oedema
? Definition: Bilateral, non-inflammatory
passive swelling of optic disc due to raised
Intracranial pressure.
? Does not develop if optic nerve is atrophic
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Foster-Kennedy syndrome : contralateral
papil oedema with ipsilateral pressure atrophy of
optic nerve
Due to - frontal lobe tumour, olfactory meningioma
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D/D: Causes of 'disc oedema'
? Papillitis, neuroretinitis
? Anterior Ischemic Optic Neuropathy
? Optic Nerve glioma, meningioma
? Central Retinal Venous Occlusion
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Aetio-Pathogenesis
? Elevated Intracranial pressure due to any cause
? Prelaminar Optic Nerve is affected by changes in tissue
pressure, IOP and CSF pressure
? Increased CSF pressure increases tissue pressure
hampering axoplasmic flow
? This further increases pressure on pre-laminar capillaries
and small veins causing vasodilatation and tortuosity
? Venous drainage compromise further increases
congestion
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General Symptoms
? Headache, made worse by coughing or
straining
? Vomiting
? Focal neurological deficit with/without
changes in level of consciousness
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Ocular symptoms
? VA may be normal until late stages
? Amaurosis fugax in some
? In 25% patients, visual symptoms occur
only in severe, advanced papilloedema
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Signs
? Pupillary reactions are normal until
secondary atrophy sets in
? Early:
? Blurring of nasal>superior>inferior margins of
disc
? Disc hyperemia and dilated capil aries
? Spontaneous venous pulsation absent
? Splinter haemorrhages at/just off disc margin
? Normal optic cup preserved
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Established papilloedema
? Margins indistinct and cup
obliterated
? Surface elevated upto more
than +3 D with direct
ophthalmoscope
? Flame-shaped haemorrhages,
cotton-wool spots
? Venous engorgement and
peripapillary oedema
? Paton's Lines-radial lines
cascading from optic disc
? Macular star
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With progression
? Chronic papilloedema
? Central cup remains
obliterated
? Haemorrhagic and exudative
components resolve gradually
? 'Champagne cork' appearance
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? Atrophic papilloedema
? Retinal vessels attenuated
with perivascular sheathing
? Dirty white colour due to
reactive gliosis
? Leads to secondary optic
atrophy
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Visual fields
? Early-no changes
? Established stage- enlarged blind spot
? Chronic- peripheral constriction of field
with nerve fibre bundle defects
? Finally- total loss of visual field
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Fundus photo, FFA , OCT
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Papil oedema
Optic neuritis
History
Headache, vomiting
Rapid DV preceded by
fever/respiratory infection
Laterality
usually bilateral
usually unilateral
VA
normal till late stage
severely reduced <6/60
Pain/tenderness of eyeball
absent
may be present
Pupil reaction
normal
RAPD (Marcus-Gunn's pupil)
Disc swelling
>+3 D in established
+2D to +3D
Haemorrhage, exudates
More, in established
relatively less
Visual fields
Enlarged blind spot,
Central or centrocaecal scotoma
later gradual
constriction
Colour vision
No effect
Affected
CT/MRI
SOL
Demyelinating disorder
Recovery of vision
May not be complete Usually complete after adequat
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even after treatment
treatment
Treatment
? Treat Cause
? Acetazolamide 250 mg 4 times a day
? Surgical decompression of optic nerve to
preserve vision
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Optic Atrophy
? Definition: Degeneration of optic nerve
fibres with loss of their myelin sheaths
characterised by pallor of the optic disc
due to loss of vascularity owing to
obliteration of disc capillaries
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Classification-Aetiological
Primary Optic Atrophy
? No local disturbance,
associated with CNS
disease or no discoverable
cause
? Commonest cause ?
Multiple Sclerosis
? Leber's optic atrophy
? Nerve compression:
Tumour, hydrocephalus
? Injury to retrobulbar optic
nerve
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Cavernous type of Primary Optic
Atrophy
? Deep excavated
cup with
undermined
edges
? Glaucomatous
optic atrophy
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Aetiological classification
? Secondary optic atrophy:
preceded by swelling of optic disc-
papilledema, optic neuritis, neuroretinitis
? Consecutive optic atrophy:
follows extensive disease of the retina -
Retinitis pigmentosa
Long-standing retinal detachment
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Anatomical classification
? Ascending: Lesion in retina, terminates at
lateral geniculate body ?
? Eg: RP, CRAO
? Descending: Disease involving optic
nerve fibres anterior to LGB, terminates at
optic disc ?
? Eg: chiasmal compression
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Symptoms
? Gradual/rapid loss of central/peripheral
vision
? Impairment of colour vision
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Signs
? Visual Acuity impaired in proportion to
death of optic nerve fibres
? RAPD in unilateral Optic Atrophy
Ultimately pupil dilated and immobile
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Primary OA ophthalmoscopy
? Pale disc, classically
paper white in colour
? Margins sharply defined
? Minimal atrophic
cupping
? Blood vessels
attenuated with marked
reduction of small blood
vessels on ONH to <6
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Secondary OA ophthalmoscopy
? Pale disc with dirty-grey
colour, blurred margins
? Physiological cup is full,
lamina cribrosa obscured
? Narrowing of blood
vessels with sheathing
? Gliosis over disc surface
extending towards
peripapillary retina
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Primary OA
Secondary OA
Appearance
chalky white
dirty grey
Margins
sharply defined
blurred
Cup
deep
obliterated
Laminar dots
visible
not visible
Glial proliferation
absent
marked
Vessels
no sheathing
sheathing
Previous disc oedema
absent
present
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Consecutive optic atrophy
? Yellowish-waxy pallor of the disc
? Margins less sharply defined
? Marked narrowing, even obliteration of
retinal blood vessels
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Investigations
? Visual field: In partial OA, central vision is
depressed with concentric contraction of
the visual field
? FFA of Optic nerve head
? VEP especially in children
? Neurological evaluation
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Hereditary optic atrophy
? Autosomal recessive/dominant
? LHON: Leber's hereditary OA
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Treatment
? Treat the cause
? Gene therapy is
emerging
? Community based
rehabilitation in
bilateral cases as
prognosis is poor
Low-vision aids
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Question
? The adjoining
photograph belongs
to a 12 year old boy
who has difficulty in
seeing at night.
? Can you identify the
disc abnormality in
the photograph?
? What condition does
he suffer from?
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Thank you
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This post was last modified on 07 April 2022