03 - diseases of the orbit

Question 1

(anatomy of the orbit)

1. herbivores have closed or open orbit? dogs and cats?

what is the difference

Answer 1

1. closed, open

closed = bone 360 degrees around orbit

open = supraorbital ligament at lateral aspect

Question 2

(extraocular muscles)

1. name the 7 eye muscles and what they do
2. all CN III expect what ones?

Answer 2

dorsal/medial/ventral/lateral rectus muscles (move)

dorsal and ventral oblique muscles (spin)

retractor bulbi (retract)

2. lateral retractor and retractor bulbi (IV)
3. dorsal oblique (VI)

Question 3

exophthalmos = ?

Answer 3

bulging of eye

Question 4

cellulitis = ?

Answer 4

bacterial infection of the skin

Question 5

(abscesses and cellulitis)

1. see what?
2. painful when open mouth?
3. causes?
4. tx?

Answer 5

1. exopthalmos
2. yes (diff w/ neoplasia)
3. trauma, FB, fungal/parasite infection, tooth-rot abscess, sinus infection, inflammation of zygomatic salivary gland
4. drain abscess + systemic abx

Question 6

(orbital neoplasia)

1. see what?
2. pain on opening mouth?
3. benign or malignant?
4. tx?
5. prog?

Answer 6

1. exophtalmos
2. not usually
3. 90% malignant
4. excision (often enucleation - often needs complete orbitectomy)
5. poor!

Question 7

(orbital trauma: traumatic proptosis)

1. what is this?
2. tx?
3. what % of vision after proptosis?

Answer 7

1. eyelids trapped behind equator of globe
2. non-replaceable -> enucleate

replaceable -> tarsorraphy (eyelids partially sewn together to narrow opening)

3. 20 to 30%