Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CVSOH BVSc4 > Ophth - Orbit and eyelids > Flashcards

Ophth - Orbit and eyelids Flashcards

1
Q

What species have open orbits?

A

Dogs and cats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What species have closed orbits?

A

Horses and cattle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does having a closed orbit mean?

A

Space between the zygomatic bone and frontal bone is linked with orbital ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the extra-ocular muscles of the eyes?

A

4 cardinal rectus muscles
2 oblique muscles
Retractor bulbi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where do all of the extra-ocular muscles attach?

A

All attached at equator - widest part of eyeball

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where do all the extra-ocular muscles meet at the back of the eye?

A

Annulus of Zinn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What cranial nerve innervates the majority of the extra-ocular muscles?

A

CNIII - oculomotor nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the thee muscles that are innervated by nerves other than CNIII?

A

Lateral rectus
Dorsal oblique
Retractor bulbi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What nerve innervates the dorsal oblique muscle?

A

CNIV - trochlear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What nerve innervates the lateral rectus muscle?

A

CNVI - abducens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some examination techniques for examining the eye?

A

Check the visual axis
Check the position of the eye in the orbit
Size of globe
Retropulsion - can eye move back in the orbit
Inspect oral cavity
Inspect the nasal/sinus cavities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the name for abnormal protrusion of the eye from the orbit?

A

Exophthalmos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the name for abnormal recession of the eye in the orbit?

A

Enophthalmos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is lagophthalmos?

A

Incomplete eyelid closure and globe coverage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the name for deviation of the eyes from the axis so they arent aligned towards the same object?

A

Strabismus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What can cause exophthalmos?

A

Space occupying lesions
Neoplastic
Inflammatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some common causes of space occupying lesions?

A

Foreign body
Infection from oral cavity
Infection from sino-nasal
Trauma
Haematogenous infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are some primary neoplasms in the orbit?

A

Mesenchymal tumours
Epithelial tumours
Orbital meningioma - nerve sheath tumours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are some secondary neoplasms in the orbit?

A

Lymphoma
Metastasis
From adjacent tissues eg. SCC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is orbital myositis?

A

Immune mediated disease affecting eye causing bilateral exophthalmos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is it called when the eye pops out of the socket?

A

Globe proptosis (globe popped-out-is heheh)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What should you do if globe proptosis occurs?

A

Emergency
Must keep eye moist
Check systemic injuries
Supportive care

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do you treat proptosis?

A

Lift lids over globe to replace under GA
Flush conjunctival sac
Roll out lids and place temporary tarsorraphy

24
Q

When should you perform enucleation in proptosis cases?

A

When globe is ruptures
3 or more extraocular muscles torn
Complete hyphaema - eye full of blood

25
Q

What can cause enophthalmos?

A

Muscular atrophy
Dehydration
Reduced orbital fat
Ocular pain - retractor bulbi pulls back
Breed related - dolichocephalic dogs
Horners syndrome

26
Q

What are the signs of horner’s syndrome?

A

Miosos
Third eyelid protrusion
Enophthalmos
Ptosis

27
Q

What is miosis?

A

Small pupil

28
Q

What is ptosis?

A

Drooping of the upper eyelid

29
Q

When should you perform enucleation?

A

Irreversible loss of vision
Ongoing pain and discomfort
Chronic glaucoma

30
Q

What are the two approaches of performing enucleation?

A

Transconjunctival - simpler
Transpalpebral

31
Q

When should you perform a transpalpebral enucleation?

A

When there is infection or neoplastic cells on the surface

32
Q

How do you perform a transpalpebral enucleation?

A

Suture lids
Dissect around
Dont pull - can affect other eye across chiasm
Remove eye
Homeostasis

33
Q

What is different about a transconjunctival enucleation?

A

Lateral canthotomy - widen the palpebral fissure
Section extraocular muscles individually

34
Q

What are the main muscles of the eyelid?

A

Levator palpebrae superioris
Orbicularis oculi
Medial palpebral ligament

35
Q

What is the structural plate of the eyelid called?

A

Tarsus

36
Q

What are the glands called that produce the lipid portion of tears?

A

Meibomian glands

37
Q

What are the functions of the eyelid?

A

Mechanical protection
Produce/spread tear film
Part of lacrimal functional unit

38
Q

What is the name for introversion of the eyelid?

A

Entropion

39
Q

What is the name for excessive eyelid length?

A

Macroblepharon

40
Q

What is the name for combined entropion and ectropion?

A

Diamond eye

41
Q

What is the name for hairs of normal skin irritating the eye?

A

Trichiasis

42
Q

What is the name for when cilia emerge from the meibomian gland and irritate the eye?

A

Distichiasis

43
Q

What is the name for when the cilia arise from the meibomian gland but protrude through the conjunctiva (inside of the eyelid)?

A

Ectopic cilia

44
Q

What is the difference between distichiasis and ectopic cilia?

A

They both grow out of the meibomian gland but
Distichiasis is through the meibomian gland orifice on the eyelid margin
Whereas ectopic cilia emerge through the palpebral conjunctiva

45
Q

What is the term for when they cant blink properly?

A

Lagophthalmos

46
Q

What are the 4 parts that make up brachycephalic ocular syndrome?

A

Macroblepharon
Lagophthalmos
Medial entropion
Reduced corneal sensitivity

47
Q

How do you treat macroblepharon?

A

Frequent lubrication
Surgical correction to reduce palpebral fissure

48
Q

What is the normal eyelid length? What is an oversized lid?

A

33-35mm - normal
40-50mm - oversized

49
Q

How do you treat diamond eye?

A

Blepharoplasty - reconstructive surgery to shorten eyelid and stabilise lateral canthus

50
Q

What indicates that an animal has entropion?

A

The eyelid margin is not visible

51
Q

How do you treat entropion?

A

Hotz- celsus technique
Tacking sutures - in very young, can grow and correct
Refer in complex cases

52
Q

What is the hotz-celsus technique?

A

Insize along parallel to lid as long as the lid inversion
Remove a semicircle of skin
Undertreatment is better than taking too much

53
Q

What does ectropion cause?

A

Frequent conjunctivitis - cant spread tear film

54
Q

How do you treat ectropion?

A

Eyelid shortening - wedge resection

55
Q

How do you treat distichiasis/ectopic cilia?

A

Check eyelids thoroughly
Can pluck but will grow back
Permanent surgical removal en bloc - cryosurgery and electrolysis

56
Q

What are the most common eyelid tumours?

A

Meibomian gland epithelioma
Adenoma
Adenocarcinoma
Melanoma
Squamous papilloma

57
Q

When should you surgically remove eyelid tumours? How is it done?

A

When the mass is <1/3 of the eyelid length
Chalazion clamp stabilises the lid
Wedge resection
Close with figure-8 suture

CVSOH BVSc4 (86 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions