Orbit and Adnexa

Question 1

Which bones form the orbital roof?

Answer 1

Frontal bone

lesser wing of sphenoid

Question 2

What sign indicated a defect in the orbital roof?

Answer 2

pulsatile proptosis

Question 3

Which bones form the lateral wall of the orbit?

Answer 3

greater wing of sphenoid

zygomatic bone

Question 4

Which bones form the floor of the orbit?

Answer 4

zygomatic bone
palatine bone
maxilla

Question 5

Which bone in the orbital floor is mostly likely to fracture?

Answer 5

maxilla

Question 6

What sign indicates maxillary fracture?

Answer 6

unable to elevate eye due to inferior rectus entrapment

Question 7

Which bones make up the medial wall of the orbit?

Answer 7

maxilla
lacrimal bone
ethmoid bone

Question 8

which structures enter/leave the orbit via the optic canal?

Answer 8

optic nerve

ophthalmic artery

Question 9

Which structures enter/leave the orbit via the SOF?

Answer 9

superior and inferior divisions of ophthalmic vein
CN III, IV and VI
larimal, frontal and nasociliary branches of CN V1

Question 10

Which structures enter/leave the orbit via the IOF?

Answer 10

inferior ophthalmic vein
infraorbital artery, vein and nerve
zygomatic nerve (branch of CN V2)

Question 11

Which muscles attach to the common tendinous ring (annulus of Zinn)?

Answer 11

4 recti

Question 12

Hx of eyelid trauma. Eyelid swelling and erythema, associated low grade fever.

Answer 12

pre-septal cellulitis

treat oral Abx

Question 13

What is the most common cause of unilateral and bilateral axial proptosis in adults?

Answer 13

thyroid eye disease

Question 14

What leads to ophtalmoplegia and eyelid retraction in thyroid eye disease?

Answer 14

sympathetic overstimulation of Muller’s muscle

fibroblastic deposition of glycosaminoglycans in the EOM resulting in oedema and fibrosis.

Question 15

Describe the following signs seen in thyroid eye disease:
Dalrymple sign
Kocher sign
Von Graefe’s sign

Answer 15

Lid retraction
Staring appearance
Lid lag on downward gaze

Question 16

What muscle is most commonly affected in thyroid eye disease related restrictive myopathy?

Answer 16

inferior rectus

REMEMBER I’M SLO

Question 17

What MRI changes might be seen in thyroid eye disease?

Answer 17

coke bottle appearance- thickening of EOM muscle bellies ( commonly IR and MR) with tendon sparing

Question 18

Elderly hypertensive female. Pulsatile proptosis, diplopia, whooshing sound, decreased VA. dilated conjunctival vessels, raised IOP and ophthalmoplegia.

Answer 18

direct carotid-cavernous fistula

Question 19

What is the most common benign orbital tumour in adults?

Answer 19

cavernous haemangioma

Question 20

Pregnant lady. Unilateral axial proptosis, globe indentation, induced hyperopia, decreased visual acuity. MRI shows well circumscribed lesion within the muscle cone

Answer 20

cavernous haemangioma

Question 21

what are the three layers of the tear film and where are they secreted from?

Answer 21

lipid layer- meibomian gland
aqueous layer- lacrimal gland
mucous layer- conjunctival goblet cells

Question 22

Which valve in the lacrimal system prevents reflux of tears?

Answer 22

Rosenmuller valve

Question 23

Which valve in the lacrimal system prevents air entering the nasolacrimal system during increased intranasal pressure?

Answer 23

Valve of Hasner

Question 24

What are three causes of acquired lacrimal obstruction?

Answer 24

punctal stenosis
Nasolacrimal obstruction
conjunctivochalasis (ageing)

Question 25

Unilateral epiphora, red eye and discharge on pressure over the canaliculus?

Answer 25

canaliculitis

Question 26

What is the most common causative organism in canaliculitis?

Answer 26

Actinomyces israelii (gram positive)

Question 27

erythematous tender swelling over the lacrimal sac. associated epiphora

Answer 27

acute dacryocystitis

Question 28

epiphora and recurrent unilateral conjunctivitis.

Answer 28

chronic dacryocystitis

Question 29

What is the most common lacrimal gland tumour?

Answer 29

pleomorphic adenoma

Question 30

Which lacrimal tumour has a swiss cheese growth pattern?

Answer 30

adenoid cystic carcinoma

Question 31

what sort of gland is the meibomian gland?

Answer 31

holocrine

Question 32

which nerves give sensory supply to the upper eyelid?

Answer 32

lacrimal and frontal (CNV1)

Question 33

which nerve gives sensory supply to the medial canthal area?

Answer 33

infratrochlear nerve (CNV1)

Question 34

Which nerve gives sensory supply to the inferior eyelid?

Answer 34

infraorbital nerve

Question 35

What are the attachments of LPS?

Answer 35

lesser wing of sphenoid to tarsal plate

Question 36

What is the function of LPS?

Answer 36

Eyelid retraction

Question 37

What are the attachments of Mullers muscle?

Answer 37

aponeurosis of LPS to tarsal plate

Question 38

What is the nervous supply to Mullers muscle?

Answer 38

sympathetic

Question 39

What is the function of Mullers muscle?

Answer 39

Assists with eyelid retraction

Question 40

Histologically, what is a chalazion?

Answer 40

sterile lipogranuloma

Question 41

Patient with rosacea. Presents with painless, slow growing, round nodule within the superior tarsal plate that has appeared over a few weeks.

Answer 41

chalazion

Question 42

Which eyelid is more commonly affected by BCC?

Answer 42

lower

Question 43

Which surgical technique can be used to remove BCC or SCC?

Answer 43

Mohs micrographic surgical excision

Question 44

What is trichiasis?

Answer 44

misdirected growth of lash follicles

Question 45

What are the most common causes of trichiasis?

Answer 45

herpes zoster ophthalmicus and blepharitis

Question 46

What is distichiasis?

Answer 46

formation of a posterior row of lashes

Question 47

What organism most commonly causes a hordoleum (stye)?

Answer 47

staph

Question 48

What is the pathogenesis of aquired distichiasis?

Answer 48

meibomian gland metaplasia to pilosebaceous units

Question 49

Dysfunction of which gland causes posterior blepharitis?

Answer 49

Meibomian gland

Question 50

What skin conditions can cause anterior blepharitis?

Answer 50

``` atopic dermatitis (staphylococcal) Seborrhoeic dermatitis ```

Question 51

What skin condition is a risk factor for posterior blepharitis?

Answer 51

acne rosacea and demodex mites

Question 52

Patient with atopic dermatitis. Bilateral lid hyperaemia and swelling. Hard scales and crusting of the base of the lashes.

Answer 52

staphylococcal anterior blepharitis

Question 53

Patient with seborrhoeic dermatitis. Lid hyperaemia and oily lid margins. Waxy scales.

Answer 53

Seborrhoeic anterior blepharitis

Question 54

Patient with acne rosacea. Foamy and unstable tear film. Posterior lid margin hyperaemia and telangectasia.

Answer 54

Posterior blepharitis

Question 55

What is the treatment for blepharitis?

Answer 55

lid hygiene and warm compresses tetracyclines tea tree oil for demodex mites

Question 56

What causes congenital ptosis?

Answer 56

failure of development of LPS

Question 57

what causes age related ptosis

Answer 57

dysfunction of levator aponeurosis

Question 58

Whats the most common cause of lid retraction?

Answer 58

Graves