Eyelid and Third Eyelid Flashcards
Define blepharospasm.
Spasm of the orbicularis oculi muscle resulting in eyelid closure
Squinting
Define cilia.
Eyelashes
Define distichia.
Eyelashes which emerge from the Meibomian glands
Define ectopic cilia.
Eyelashes protruding through the palpebral conjunctiva
Define ectropion.
The outward rolling of the eyelids
Define eyelid margin.
Identified by the grey line of Meibomian gland orifices
Important landmark to identify when closing the eyelid surgically
Define entropion.
Rolling of the eyelid margin such that hairs are touching the ocular surface
Define lagophthalmos.
Incomplete eyelid closure/coverage of the eyeball
Define ptosis.
Drooping of the eyelids caused by sympathetic denervation to the eyelid
Define tarsorrhaphy.
A surgical procedure in which the eyelids are sutured together
Define tarsus.
The fibrocartilaginous layer of the eyelid that contains the Meibomian glands
Define trichiasis.
Hairs growing from normal skin reach the corneal and/or conjunctival surface
What are the 4 layers to the eyelid?
Skin
Muscle
Tarsus and Meibomian glands
Conjunctiva
What does the orbicularis oculi do?
Closes the eyelids like a zipper
CN 7
Dysfunction will cause lagophthalmos
What does the levator palpebrae superioris do?
Opens the upper eyelid
CN 3
Dysfunction will cause ptosis
What does Muller’s muscle do?
Opens the upper eyelid
Think Horner’s syndrome
General visceral efferent
Dysfunction will cause ptosis
What are the 4 common causes of lagophthalmos?
Breed variation
Exophthalmos
Buphthalmos
CN 5 or 7 dysfunction
What will secondary eye exposure due to lagophthalmos cause?
Exposure keratoconjunctivitis
Band keratopathy
What is a good question to ask clients to determine lagophthalmos?
Does your dog sleep with its eyes open?
What are the common clinical signs for Horner’s syndrome?
Miosis
Ptosis
Protrusion of the third eyelid
Enophthalmos
What is the most common cause for Horner’s syndrome?
Idiopathic
What does using dilute phenylephrine for diagnosis of Horner’s syndrome tell you?
Utilizes concept of denervation hypersensitivity
Post ganglionic Horner’s syndrome should partially or completely resolve in <15 mins
What breeds are most commonly affected with trichiasis?
Brachycephalic breeds
Where does the hair with trichiasis usually come from?
The nose
What breed is common for disticia?
Cockers
What is a common treatment for distichia?
Cryotherapy
Multiple treatments are occasionally required
What is a complication to cryotherapy?
Eyelid depigmentation
Eyelid necrosis
Where are ectopic cilia generally located?
12 o clock position
What is the biologic behavior for eyelid tumors in cats and dogs?
Cats - most often malignant
Dogs - most often benign
What are the three common factors to consider when surgically removing canine eyelid tumors?
Is there irritation to ocular surface? - remove or debulk if yes
Size? - Cannot take more than 1/3 without causing functional disturbance
Location - involving nasolacrimal ducts or canthus
What are the 4 key concepts for closure of eyelid margin defects?
Limited debridement
Closure must be perfect - figure 8 suture pattern at margin
Avoid full thickness suture bites
The tarsus is the holding layer
What can happen if you left a prolapsed gland of the third eyelid untreated?
Chronic conjunctivitis
KCS
When should be the only reason for removal of the gland of the third eyelid?
Neoplasia
