Week 2 Eyelids Study Questions

Question 1

what is the function of the tarsal plate

Answer 1

provides surface for muscle attachment, gives eyelid margin rigidity

Question 2

what type of glands are meibomian glands? where are they located? what is their function?

Answer 2

sebaceous glands, located along eyelid margin at mucocutaneous junction, they secrete lipid layer of precorneal tear film

Question 3

what muscle functions to close the eyelids? whats its innervation?

Answer 3

orbicularis oculi, innervated by palpebral branch of CN VII

Question 4

what muscle functions to close the eyelids? what is its innervation?

Answer 4

levator palpebral superioris, innervated by palpebral branch of CN III

Question 5

what structures anchor the eyelids to the orbital rim?

Answer 5

retractor anguli muscle

Question 6

what muscle provides “tone” to the upper eyelid? whats its innervation?

Answer 6

muller’s muscle, innervated by sympathetic nerve. deviated in horner’s syndrome = droopy eyelid

Question 7

what is the term for a normal misdirected hair?

Answer 7

trichiasis

Question 8

what is the term for an abnormal hair exiting a Meibomian gland opening?

Answer 8

Distichiasis

Question 9

what is the term for an abnormal hair exiting the conjunctiva?

Answer 9

ectopic cilia

Question 10

what is a congenital defect in the upper eyelid of a cat?

Answer 10

coloboma

Question 11

what causes ophthalmia neonatorum

Answer 11

in utero FHV-1 or bacteria in dogs

Question 12

what are the clinical signs, breed dispositions, and treatment of entropion

Answer 12

blepharospasm, periocular wetting, staining, corneal vascularization, corneal fibrosis, corneal ulcer, corneal pigment

sharpei, lab, bulldog, golden, mastiff, any breed with excessive loose skin
brachycepalic dogs and cats - medial canthal entropion

topical lubricants or surgery - permanent lateral canthoplasty & modified holtz-celsus

Question 13

what are the clinical signs, breed dispositions, and treatment of ectropion

Answer 13

hyperemia, chemosis, mucoid discharge

spaniels, hounds, great dane, st bernard, bloodhound

tear supplement, surgical fix- full thickness wedge resection, of lower eyelid or permanent, lateral canthoplasty

Question 14

what 2 conditions of the eyelid are associated with entropion in dogs

Answer 14

macroblepharon and lateral canthal laxity

Question 15

what are two procedures used to correct entropion? which one is performed first?

Answer 15

permanent lateral canthoplasty (1st) & modified holtz-celcius

Question 16

what are the three most common eyelid tumors in the dog

Answer 16

meibomian gland adenoma, papilloma, melanoma

Question 17

what are the three most common eyelid tumors in the cat

Answer 17

Squamous cell carcinoma, basal cell carcinoma, mast cell

Question 18

what are the three most common eyelid tumors in the horse

Answer 18

Squamous cell carinoma, sarcoid, melanoma

Question 19

what is the most common eyelid tumor in the cow

Answer 19

Squamous cell carinoma

Question 20

are eyelid tumors in dogs more commonly benign or malignant?

Answer 20

benign

Question 21

how much of the eyelid margin can be excised while allowing primary closure

Answer 21

25-33%

Question 22

what types of adjunctive therapy are recommended for squamous cell carcinoma

Answer 22

cryosurgery, radiation, intralesional chemo

Question 23

in the horse, what are the best treatment options for squamous cell carcinoma of the eyelid or medial canthus?

Answer 23

surgical excision + adjunctive therapy

cyrosurgery, hyperthermia, radiation, chemo, photohynamic

Question 24

what is chalazion and how is it treated?

Answer 24

meibomian granuloma, warm compresses, topical +/- systemic abx

Question 25

what is blepharitis? what are the common causes in dogs and cats?

Answer 25

inflammation of the eyelids

allergic, pyogranulomatous, parasites (mites), equine habronemiasis, immune-mediated

Question 26

what parasitic infection in horses is a differential diagnosis for squamous cell carcinoma

Answer 26

habronemiasis

Question 27

what principles should you keep in mind when you repair eyelid lacerations in small animals and horses

Answer 27

debride conservatively, only trim necrotic tissue, do complete exam, primary intention using 2 layer closure (subconjunctival and skin)