General

Question 1

3 structures posterior to the septum

Answer 1

• palpebral lobe of lacrimal gland
• lateral canthal tendon
• trochlea of SO

Question 2

What is the arcus marginalis

Answer 2

Where septum fuses with peri-orbita at the orbital rim

Question 3

What are the two vascular arcades of the upper lid

Answer 3

Marginal arcade: at the eyelid margin
Peripheral arcade: just above the top of tarsus (behind levator, in front of muller –> be careful not to hit it in ptosis repair whn you take a bite through levator!)

Question 4

MRI, T1 is what colour for vitreous and orbital fat?

Answer 4

Vitreous dark on T1, bright on t2

Orbital fat is bright on T1, but turns dark with fat suppression (allows you to see optic nerve better)

Question 5

Silicone oil

Answer 5

Band keratopthy
If emulsified: glaucoma, direct effect on endothelium.
Worse in a phakic patients.

Know that there are 2 types of viscosity to the oil (alters calculation)
If traditional a scan ultrasound moves slower and the eyeball will read longer than it is (you’ll need a higher power lens)
Others thibgs: lens choice (calculations, power spericity,

Question 6

Where is a schwannoma on the eyelid usually?

Answer 6

Solitary nodule near medial canthus

Question 7

List orbital choristomas

Answer 7

Tumors of tissues NOT normally found there

• dermoid
• dermatolipoma
• ectopic lacrimal gland
• complex conjunctival choristoma

Question 8

There is a solitary nodular cyst at the lateral canthus. What is it?

Answer 8

Hydrocystoma

• either on lid margin or lateral canthus
• solitary nodular cyst
• lined by double row of cuboidal epithelium

Question 9

5 causes of correctopia

Answer 9

Trauma
Posterior synechiae (inflammation) 
ICE
Axenfeld reiger
Ectopia lentis et pupilae

Question 10

Differential of congenital hypochromic iris

Answer 10

Wardenburg
Horner’s
Hirschprung
Parry Romberg hemifacial atrophy

Question 11

Congenital unilateral hyperpigmented iris

Answer 11

Ocular or oculodermal melanocytosis

Iris pigment epithelial hamartoma

Question 12

When do you see a Kayser Fleischer ring

Answer 12

Wilson’s disease
Chalcosis (foreign body)
Multiple myeloma
Lung carcinoma

Question 13

What is the max dose of lidocaine you should use

Answer 13

5 mg/kg no epi , max dose 300 mg

7 mg/kg with epi, max 500 mg

Question 14

DDx of intra-ocular calcium

Answer 14

Phthisis
RB, retinocytoma
ONH drusen
Choroidal osteoma
Choroidal hemangioma
Retinal astrocytoma

Question 15

DDx of intra-ocular cartilege

Answer 15

Trisomy 13
Medulloepithelioma
PHPV

Question 16

List orbital hamartomas

Answer 16

Tumors of tissues NORMALLY found in that location

• nevus
• neurofibroma
• neurilemmoma = schwannoma
• glioma
• hemangioma
• lymphangioma
• CHHRPE