Optic Nerve Flashcards
Pressure in subarachnoid space affects?
Affects pressure in optic nerve head.
3 common symptoms of patients with optic nerve disease?
- Complain of poor vision
- Transient loss of vision
- Rarely pain unless inflammatory condition
Signs of optic nerve dysfunction?
- Reduced VA- distance & near
- Colour vision- night Vision affected
- Pupils: RAPD
What 3 changes can be seen at the optic disc?
- Disc swelling
- Optico- ciliary shunts (abnormal blood vessels)
- Optic atrophy - end stage
Optico- ciliary shunts associated with which conditions?
central retinal vein occlusion, optic nerve sheath meningioma, chronic glaucoma and chronic papilledema and are a nonspecific sign of chronic retinal venous congestion.
Optico- ciliary shunts- how do they look on the disc?
appearing as tortuous vascular loops that start and end on the disc
Optico- ciliary shunts needs to be differentiated from neovasc, why?
They must be differentiated from neovascularization of the disc because neovascularization requires prompt treatment with laser photocoagulation or anti-VEGF intravitreal injections, while shunt vessels do not and can protect against retinal ischemia.
Optico- ciliary shunts needs to be differentiated from neovasc: physical difference?
Optociliary shunt vessels can be differentiated from neovascularization of the disc by their large caliber and lack of leakage on fluorescein angiogram.
What causes papilloedema?
Raised Intracranial pressure
Papilloedema - how does it look and what happens if long standing?
Bilateral optic disc swelling.
If long-standing = optic atrophy
Features of early papilledema
- VA normal
- Mild disc hyperemia
- Nasally indistinct margin
- Mild venous engorgement
- Normal optic cup
- Spontaneous venous pulsation absent
Features of acute papilledema (disc, VA, margins)?
VA- normal
Severe disc elevation hyperemia
Very indistinct margin
Obstruction of small vessels on the disc
Features of late papilledema?
- Marked venous engorgement
- Reduced or absent cup
- Haemorrhages and cotton wool spot
- Macular star
Discs and VA in chronic papilloedema?
VA- Variable (Visual obstruction, macular star)
Marked disc elevation (vintage cork look), disc margin indistinct, variable venous engorgement, absent optic cup.
Bilateral disc swelling vs unilateral- what could the condition be?
Bilateral- papilledema
Unilateral- CRVO
Do VF need to be done before referring papilloedema?
If yes, what is seen?
Yes
Enlarged blind spot
VA and disc in secondary optic atrophy?
- VA severely decreased
- Mild disc elevation
- Indistinct disc margin
- Disc pallor with few crossing vessels
- Absent cup
Causes of secondary optic atrophy?
Papilloedema, treated papilloedema, congenital optic atrophy, trauma
What are pseudopapilloedema?
Other causes of swollen disc rather than raised ICP
Acquired = papillitis, ischemic papillopathy, juxapapillary choroiditis, optic disc infiltration
Most common tumour assosiated with optio-ciliary shunts?
Nerve sheath meningioma
Optio-ciliary shunts- EMERGENCY OR URGENT?
Refer, but non- emergency
Optic atrophy causes?
Post Optic neuritis
Long standing papilledema
Compressive optic atrophy - due to tumours
Herediatery optic atrophies (Leber’s hereditary optic neuropathy)
Optic atrophy- how does the disc look?
Pale
Example of with systemic condition congenital optic nerve anomalies?
Morning glory coloboma