Neuro-ophthalmology: Raised Optic Disc Flashcards
What are the symptoms of orbital compressive lesions?
- Monocular
- Slow growing
- Slow, compressive, visual loss
- VF loss – may be central or diffuse – depends on exact location of lesion
What are the associated signs/symptoms of orbital compressive lesions?
- Eyelid oedema
- Proptosis – eye pushed forward from usual position
- Extraocular muscle involvement – may get painful, restricted eye movements, diplopia
- Pupils:
o RAPD on affected side - Disc Appearance:
o If anterior lesion disc oedema – will be raised
o If intraorbital/ intracanalicular, get disc pallor 4-6 weeks after it damaged the nerves
o If vasculature (BVs) not compromised, get optic nerve dysfunction & atrophy w/o preceding disc oedema – may just get disfunction w/o raised disc
o May have simple oedema or visible signs of infiltration (cells)
o Optocilliary shunt vessels
Which hospital investigations are needed in suspect orbital compressive lesions?
MRI & CT scan
What is the management of orbital compressive lesion?
- Unexplained sudden loss of vision = SAME DAY referral
- Unexplained gradual loss of vision = URGENT referral
- Optic disc pallor (suspected compressive lesion) = URGENT referral
What are the main types of orbital compressive lesions?
- Optic nerve sheath meningioma
- Optic nerve glioma
- Melanocytoma
Describe optic nerve sheath meningioma (orbital compressive lesion)?
- Benign tumour
- Proliferation of meningoepithelial cells lining the sheath of the optic nerve
- One third of optic nerve tumours
- Mean age of presentation: 40-50yrs
- Female > Male (as are meningiomas elsewhere)
- Symptoms/Signs:
o Painless, slowly progressive monocular visual loss (95% of cases)
o Proptosis (60-90% of cases)
o Disc Appearance:
Optic oedema then atrophy
Optocilliary shunt vessels - Treatment:
o Observe if stable & no visual loss
o Radiotherapy:
Stability or improvement in up to 94%
Complications: - Radiation retinopathy
- Pituitary dysfunction
o Surgery:
Biopsy or excision - Risk of optic nerve trauma & visual loss
- Considered if intracranial extension
Describe optic nerve glioma (orbital compressive lesion)?
- Optic glioma are usually pilocyctic tumours
- Most common primary tumour of optic nerve
- Most are slow growing & benign
- Some are malignant & more rapidly progressing, causing blindness & death
- 70% detected during 1st decade of life, 90% by 2nd
- Association w/ Neurofibromatosis 1 (NF1):
o 10-30% of NF1 have optic gliomas
o 10-70% w/ optic glioma have NF1 - Presenting Symptoms:
o Proptosis – 94%
o Visual loss – 87%
o Optic disc pallor – 59%
o Disc oedema – 35%
o Strabismus – 27% - Signs:
o RAPD
o Visual Field Defect
o Optocilliary shunt vessels - Hospital Management:
o Observation if good vision & stable imaging appearance
o Chemotherapy when visual loss severe
o Radiotherapy has a risk of complications including pituitary dysfunction
Describe melanocytoma (orbital compressive lesion)?
- Really a pigmented tumour of uveal tract
o The other two were not pigmented - Predilection of lamina cribrosa of ONH
- Typically benign composed of melanocytes & melanin & don’t grow
- Rarely become malignant
- Presentation:
o Optic nerve dysfunction if large but usually coincidental finding - Signs:
o Black lesion w/ feathery edges
o Typically small & don’t grow – monitor with photographs - Complications:
o Central retinal vein occlusion – theses are taking up space & can comoress on vein causing it to occlude
o Malignant transformation - Hospital tx:
o Observation every 6-12 months
Describe infiltrative lesions causeing raised optic disc?
Infiltration/invasion of optic nerve by neoplastic (cells that replicate – either benign or malignant) or inflammatory cells
Ocular involvement may be presenting feature of systemic disease
What are the symptoms and signs of raised optic disc due to infiltrative lesions?
Symptoms:
* Progressive (progressively getting worse), severe visual loss over days to weeks
* Associated w/ headache due to pressure from infiltrative lesions
Signs:
* Retrobulbar infiltration – disc appears normal – disc can become pale after 4-6 weeks
* Disc involvement – swollen appearance
What are the causes of infiltrative lesions that could lead to raised optic disc?
- Leukaemia
- Lymphoma
- Granulomatous infiltration:
o Sarcoidosis, TB, syphilis - Metastases:
o Rare but most commonly from breast or lung cancer
o V useful to gather this info in H&S
What are the hospital investigations of raised optic disc due to infiltrative lesions?
- Send to ophthalmology
- MRI of brain & orbits
- CSF analysis – looking at papilloedema type causes
- Screening tests for inflammatory/ infective/ neoplastic disorders
- Early identification allows life-saving tx
- Palliative care may improve vision if poor prognosis
What is the management of raised optic disc due to infiltrative lesions?
- Unexplained sudden loss of vision = SAME DAY referral
- Unexplained gradual loss of vision = URGENT referral
- Optic disc pallor (suspected compressive lesion) = URGENT referral
Describe Leber Hereditary Optic Neuropathy?
- Hereditary (inherited) condition characterised by bilateral optic atrophy
- Affects maternal mitochondrial DNA
- Males, 10-30 years
May cause a raised optic disc
What are the symptoms and signs of Leber Hereditary Optic Neuropathy?
- Ask about family hx
- Acute, severe, painless visual loss (<6/60)
- Central/ centrocecal visual loss
- RAPD when monocular involvement but both eyes become involved relatively quickly
o Will not get an RAPD when bilateral - Disc Appearance:
o Normal in up to 40%
o Hyperaemia & elevation of disc
o Thickening or peripapillary retina
o Peripapillary telangiectasia – dilation of smaller BVs & can look like spiders legs
o Tortuosity of medium sized retinal vessels
o Eventual optic atrophy in affected area - Hospital Management:
o MRI scan to exclude a treatable cause
o Once diagnosed no tx (because it is hereditary) & visual loss usually permanent
Describe toxic optic neuropathies (nutritional optic neuropathy)?
- Typical hx is of alcohol &/or tobacco excess w/ neglect of diet (B vitamins & thiamine)
o Toxic effect of the alcohol/tobacco excess with reduction in the nutritional component of diet - Can get neuropathy in well-nourished individuals w/ pernicious anaemia (cannot metabolise iron properly) or vitamin B12 deficiency
- Other causes:
o Methanol intoxication – component of industrial solvents, antifreeze, fuel
o Amiodarone – tx of cardiac arrhythmias
o Tamoxifen – prevention & tx of breast cancer
o Ethalbutamol tx for tuberculosis
o Isoniazid – tx for tuberculosis
o Isotretinoin – tx for acne
Hard to stop these treatments due to the conditions they are for
What are the symptoms of toxic optic neuropathies (nutritional optic neuropathy)?
- Chronic (gradual & progressive) or acute – depending upon cause
- Bilateral & symmetrical
- Painless visual loss
- Dimness of vision – like they’ve walked into a cloud
What are the signs of toxic optic neuropathies (nutritional optic neuropathy)?
- Affects central vision w/ central/caecocentral scotoma
- Minimal findings on initial presentation:
o Optic disc can be normal/mild pallor/ hyperaemia
In a small group of pxs w/ hyperaemic discs, could get small splinter haemorrhages on disc edge
o Mild depression on Amsler fixation target
o Reduced colour vision - Months-years after presentation:
o Papillomacular bundle dropout
o Temporal disc (side of disc that leads onto macula) pallor followed by optic atrophy
What is the hospital management of toxic optic neuropathies (nutritional optic neuropathy)?
- Investigations of exclusion:
o Fluorescein angiography
o Blood testing
o Electrophysiology
o MRI imaging - Tx:
o Reversal of inciting cause
Can often be difficult: - If someone has addiction to alcohol or tobacco then that is hard to stop
- If someone is on medication for a condition – hard to stop this too – can sometimes substitute with other meds (if available)
o Can get reversal of ocular signs if optic atrophy has not supervened
Optic atrophy is a sign of permanent damage – if hasn’t happen yet then there is the potential for reversal
Describe traumatic optic neuropathy - including direct and indirect?
- Optic nerve damage from trauma to head/orbit/globe
o Px should tell you in H&S - Direct traumatic optic neuropathy:
o Avulsion of nerve from laceration by bone fragments/ FBs
Nerve has dislocated or gone out of its position
o Direct compression from haemorrhage - Indirect traumatic optic neuropathy:
o Nothing has directly happened to the nerve
o Shear forces on nerve
o Shear forces on vascular supply – blockage of BVs which can cause a raised optic disc
Describe the signs of traumatic optic neuropathy?
- Highly variable depending on type of trauma
- Visual loss:
o Immediate
o Severe – no perception of light - RAPD – if monocular
- Optic Disc:
o Depends on physical location where it has happened
o If posterior pathology may appear normal
o Eventual atrophy - Neuroimaging:
o Assesses extent of injury & co-morbidity – as often cannot see it from the front
What is the hospital management of traumatic optic neuropathy?
- Neuroimaging to assesses extent of injury and co-morbidity
o Often do not present to community ophthalmology as normally have other broken bones - Therapy controversial
- Prognosis poor if the injury is severe
- Intravenous steroids
o Anti-inflammatory and neuroprotective (protect the nerves) - Increased risk of mortality when combined with other head injuries
- Consider when isolated injury with no other evidence of head injury
