Ch 2 Eye and Orbit

Question 1

Which bone forms the medial wall of the orbit?

Answer 1

Frontal bone

Question 2

What echogenicity is the optic nerve?

Answer 2

Hypoechoic, outlined by adjacent hyperechoic fat.

Question 3

What is the arrow pointing to? The asterisk is the lens.

Answer 3

Hyaloid vessel in a fetal eye

Question 4

Answer 4

(feline) bullous keratopathy; the anterior stroma has many fluid-filled areas, and the entire corneal thickness is severely increased.

Question 5

Answer 5

inclusion cyst

Question 6

Answer 6

sequestrum

Question 7

Answer 7

limbal neoplasia (melanocytoma) in 2 dogs

Question 8

What is the most common intraocular tumor in dogs?

Answer 8

Benign or malignant melanoma, associated with anterior uvea

Question 9

arrows are indicating which 2 changes in this eye?

Answer 9

posterior synechia, secondary iris bombe

this dog has chronic uveitis, secondary glaucoma (from the synechia maybe).

Question 10

11y Shih Tzu. what kind of lenticular change is this?

Answer 10

nuclear sclerosis

Question 11

In what stage of cataract formation is this eye?

Answer 11

hypermature/morgagnian; the lens has reduced volume (resorption/liquefaction).

NB asteroid hyalosis in the VB

Question 12

Paraxial (dorsal-ventral) view, 3y Labrador

Answer 12

capsular rupture

Question 13

these are examples of:

Answer 13

lens subluxation (A) and luxation (B and C)

Question 14

arrow indicates?

Answer 14

posterior lenticonus

other: intralenticular haemorrhage and cataract

Question 15

What may occur concurrently with posterior lenticonus?

Answer 15

PHPV persistent hyperplastic primary vitreous i.e. hyaline artery

Question 16

what kind of cataracts?

Answer 16

anterior and posterior cortical cataracts

Question 17

what is the arrowhead pointing to?

Answer 17

capsular ectasia

Question 18

Answer 18

Persistent hyperplastic primary vitreous.

Question 19

Difference between asteroid hyalosis and synchisis scintillans?

Answer 19

Substance: AH (Ca-lipid), SS (cholesterol crystals)
Location: AH (suspended), SS (mobile)
Presentation: AH (common geriatric, brachy/Italian greyh), SS (end-stage disease)

Question 20

Answer 20

asteroid hyalosis

Question 21

yellow arrow and arrowheads ?

Answer 21

arrow - retinal detachment
arrowheads - vitreal detachment

Question 22

They may appear similar, but what might help differentiate retinal from vitreal detachment?

Answer 22

Retinal tissue is more echogenic than the vitreal ‘membrane’. It is also vascularised and attaches at the ONH (unlike the vitreous).

Question 23

What percentage of ret det is missed on US (confirmed on histo)? (Gallhoefer et al. 2013).

Answer 23

30-40%

Question 24

What type of intra-ocular foreign body is this?

Answer 24

Porcupine quill, they have a characteristic double-lined appearance

Question 25

Answer 25

Thickened optic nerve; optic neuritis

Question 26

A-B: 2yy crossbreed C-E: 9mo Labrador

Answer 26

EOM, Thickened (hypoechoic) extraocular muscles, secondary exophthalmos

Question 27

Retrobulbar cellulitis results in increased/decreased echogenicity of the retrobulbar space.

Answer 27

increased

Question 28

types of optic nerve tumors:

Answer 28

meningioma neurofibroma astrocytoma lymphoma

Question 29

List the EOMs:

Answer 29

Rectus: D, V, M, L Oblique: D, V Retractor bulbi

Question 30

Extraocular muscle innervation in dogs/cats

Answer 30

Question 31

EOM predisposition signalment

Answer 31

young Golden retrievers