Neuro - Orbit

Question 1

Difference between Coats (Exudative Retinitis) and Retinoblastoma?

Answer 1

Retinoblastoma

Primary malignancy of globe

• Normal sized globe*
• Calcification in the globe*

Coats Disease (Exudative retinitis)

Retinal telangiectasia resulting in leaky blood and subretinal exudate. Hyperdense on CT. High T1/T2

Usually diagnosed before age 20

• Small globe*
• No calcification*

Question 2

What is most common intraocular lesion in an adult?

Answer 2

Melanoma

• Enhancing soft tissue mass usually affecting uvea/ciliary body*
• Liver mets is common*
• Will appear as ‘collar button’ shape*

Question 3

Optic Nerve Glioma

What are associations?

Answer 3

90% occur under age of 20

Expansion/enlargement of the optic nerve

Think of NF1 if they are bilateral

Question 4

Optic Nerve Meningioma

What are classical features?

Answer 4

• Tram track calcifications*
• ‘Doughnut’ appearance due to circumferential enhancement around optic nerve*

Assc with NF2

Question 5

What is most common extra ocular malignancy in a child?

Answer 5

Rhabdomyosarcoma

(dermoid is most common benign mass)

• Favours superior medial orbit*
• Picture shows soft tissue rhabdo of the inferior rectus muscle*

Question 6

What are features of metastatic neuroblastoma?

Answer 6

Can involve orbits, skull base and dura

• Usually bilateral*
• PROPTOSIS*
• Periorbital mass*

Typically involves greater wing of sphenoid

• Spiculated periostitis of orbits and skull*
• ‘RACOON EYES’*

Question 7

Typically what type of mets do Scirrhous cancer of the breast cause?

Answer 7

Retrobulbar mass + ENophthalmos = metastatic scirrhous breast cancer

Question 8

Whats most common cause of spontaneous orbital haemorrhage?

Answer 8

Orbital varix

These distend with valsalva manoever (in comparison to lymphangiom which doesnt - these present with fluid fluid levels)

Varix can thrombose and present with pain

Can present with intermittent diplopia or proptosis during straining

Question 9

Carotid cavernous fistula

What is presentation?

Answer 9

2 types

1. Direct communication between ICA and cavernous sinus

2. Indirect communication between ICA/ECA and cavernous sinus via branches (usually meningeal branches of ECA)

Presentation

Pulsatile exophthalmos/proptosis

Distention of superior ophthalmic vein

Retro-orbital fat stranding and enlargement of muscles

Prominent cavernous sinus

Direct

• Most common causes include:*
• -rupture of carotid aneurysm*
• -trauma*

Indirect

• Seen in post menopausal women*
• Cavernous sinus thrombosis can be risk factor*
• Pregnancy also*

Question 10

What is coloboma?

Answer 10

A focal discontinuity in the structure of the eye

Due to failure of closure of the choroidal fissure

• Usually posterior
• can be bilateral, if so think of CHARGE syndrome

C: coloboma

H: heart defects

A: atresia choanae

R: retarded growth and development

G: genital hypoplasia

E: ear abnormalities and/or deafness