Eyelids Flashcards
What are the 4 layers of the eyelid?
Skin
Muscle
Tarsus
Conjunctiva
What is the main function of the skin of the eyelid?
Sensory protection
CN V maxillary and ophthalmic branches of ophthalmic
What muscle functions to open the eyelid?
Levator palpebrae superioris (oculomotor nerve)
Mullers muscle (sympathetic innervation)
What muscle functions to close the eyelids?
Orbicularis oculi
Dysfuntion of the levator palpebrae superioris causes drooping of the eyelid, which is called?
Ptosis
Dysfuntion of the orbicularis oculi causes incomplete closure of the eyelids, which I is called?
Lagophthalmos
What is the tarsus of the eyelid?
Fibrous and glandular layer
== holding layer for surgical closure
Supports meibobmian glands
What do you call rolling of the eyelid margin so that the hairs are touching the ocular surface?
Entropion
What are the two types of entropion?
Anatomic — hereditary or acquired
Blepharospasm — stimulated by ocular pain and globe retraction
What are hereditary entropion causes?
Abnormal medial canthus—brachycephalic
Abnormal palpebral fissure — often too large and loose in hounds and giant breeds
Excessive facial folds
What are acquired causes of anatomic entropion?
Enophthalamos
Blepharospasm (ocular pain causes blepharospasm —> entropion—> more irritation and pain)
How can we differentate anatomic and blepharospasm entropion ?
Take away the pain that causes the blepharospasm —- procaracaine
Why do we need to differentate between anatomic and blepharospastic components of entropion?
Failure to assess the spastic component can lead to over correction and ECTroption
You have determined that an entropion in your patient is secondary to dehydration retaliated enophthalamos.
How would you treat this?/
Temporary correction
Viscous lubrication
Eyelids tacking (rolls out the eyelid)
Partial temporary tarsorrhaphy brings eyelid margins together
Your patient has a congenital entropion due to excessive facial folds.. how will you treat this?
temporary suture tacking — until grown into face
If not fixed once growth is complete… permanent correction
— modified hotz-celsus (rolls out the eyelid)
What do you call an eversion or rolling out of the eyelid?
Entropion
Common causes of ectropion?
Iatrogenic — overcorrection of entropion
Hereditary in hounds and giant breeds
Treatment if ectropion ?
Lateral eyelids wedge excision
V to U plasty
What are common causes of lagophthalmos?
Breed variation
Exophthalmos
Buphthamos
CN V or CN VII dysfunction
Temporary treatment of lagophalmos?
Lubrication or temporary tarsorrhaphy
Permanent treatment of lagophthalmos ?
Permanent tarsorrhaphy
Canthoplasty
What is horners syndrome?
Loss of sympathetic innervation —> lack of tone of orbital smooth and skeletal muscle
What clinical signs are associated with horners syndrome?
Enophthalamos
Passive elevation of third eyelid
Ptosis
Miosis
What is the EDx of horners syndrome
Idiopathic (most cases)
Injury/infarction/neoplasia of thoracic spinal cord
Avulsion of brachial plexus
Thoracic inlet or cranial mediastinal lesions
Injury or neoplasia of cervical sympathetic trunk
Otitis media
Nasopharyngeal polyps
Retrobulbar disease
How can you confirm and localize horners syndrome?
Phenylephrine (diluted to 1%)
Normal eye— dilation should occur in 60 to 90minutes
Affected eye
—post ganglionic -> dilation in 20mins
—pre ganglionic -> dilation in 30-40mins
What are three conditions of abnormal hairs that can cause irritation to the cornea or conjunctiva
Trichiasis
Disctichiasis
Ectopic cilia
Hairs growing from normal skin and reach the cornea/conjunctival surface are called?
Trichiasis
Treatment for trichiasis?
Conservative — lubrication
Aggressive — facial fold resection, medial canthoplasty (must preserve nasolacrimal duct)
What do you call cilia that emerge from the meibomian glands?
Distichia
What breeds can have an inherited ditichia?
Cocker spaniel
Poodles
Sheepdogs
Treatment for distichia and ectopic cilia?
Cryotherapy
- two freeze thaw cycles
- then pluck
Multiple treatments required
What do you call hair/cilia protruding through the palpebral conjuntiva?
Ectopic cilia
Cause pain and corneal disease (ulcers)
Canine tumors mostly demonstrate (malignant/benign) characteristics
Benign
Feline eyelids tumors mostly demonstrate (malignant/benign) characteristics
Malignant
What are the most common canine eyelid tumors?
Meibomian gland adenoma
Melanocytoma
Most common tumors of feline eyelid?
Squamous cell carcinoma
Fibrosarcoma
Mast cell tumor
Adenocarcinoma
What are three common factors to consider before removing an eyelid tumor in a canine?
Irritation? - causing KCS?
Size? — cannot remove more than 1/3rd of eyelid margin
Location — involving nasolacrimal ducts or canthus??
What are the treatment options for eyelid tumors?
Debulk and cryotherapy
-higher chance of regrowth
Complete excision
-must reconstruct eyelids margin
What are the four key concepts when closing eyelid margin defects?
Limited debridement
Closure must be perfect
Avoid full thickness suture bites
Tarsus is the holding layer
What suture pattern do you use when bringing the eyelid margin back together?
Figure 8
First bite from skin to defect
Defect to eyelid margin
Eyelid margin to defect
Defect back to skin
What do you call inflammation of the eyelids?
Blepharitis
What do you call an enlargement of the meibomian gland due to blockage of its duct and inspissation of its secretory products?
Chalazion
How do you treat a chalazion?
Warm compresses
Surgical incision and drainage (chalazion curette)
Tropical antibiotic with steroids
What do you call a purulent bacterial infection of the meibomian gland? What if multiple are involved?
Hordeolum
Meibominanitis (multiple)
What are signs of hordeolum, and the most common bacteria involved?
Erythema and swelling of lids Pruritus Pain Chemosis Conjunctivitis
Staph aureus
Therapy for bacterial blepharitis?
Initially Systemic antibiotics -amoxicillin-clavulanic acid -doxycycline -cephalosporin
Tropical antibiotic-steroid ointment
Warm compress
The third eyelid is located?
Ventral and medially
There are two surfaces of the third eyelid, both lined with conjunctiva. What are they?
Palpebral surface
Bulbar surface
What provides the support for the third eyelid?
T shaped cartilage
What lives at the base of the T shaped cartilage of the third eyelid?
Gland of the third eyelid
What is cherry eye?
Prolapse of the third eyelid
What happens if you leave cherry eye untreated?
Contributes 35-45% of the aqueous tear film
Chronic conjunctivitis
KCS
T/F: excision of the glad in an appropriate treatment for cherry eye
False
The ONLY indication for removal is neoplasia
Treatment for cherry eye?
Morgan pocket technique
-incise over bulbar conjunctiva inferior and superior to gland and connect the incision
Orbital tacking
- third eyelid is elevated, cut made through orbital rim and conjuntiva
- suture passed through incision to engage periosteum, then through the palpebral surface to engage gland
- anchors eyelid in more ventral position
Possible complication to morgan pocket technique?
If tears are not allowed to drain at either end of incision, cyst may form
