Eyelids & 3rd eyelid Flashcards
What is the tarsus of the eye?
fibrocartilaginous layer of the eyelid that contains meibomian glands
(the holding layer for surgical eyelid closures)
What is the holding layer for surgical eyelid closures?
Tarsus of the eyelid ( fibrocartilaginous layer)
What is lagophthalmos?
Incomplete eyelid closure / coverage of the eyeball
What are the 4 layers of the eyelid from outside to inside?
- Skin
- Muscle (orbicularis oculi)
- Tarsus
- Conjunctiva
What muscles and nerves can be affected to cause lagophthalmos?
Muscle: Orbicularis oculi
Nerve: palpebral branch CN VII
Action: closes eyelids
Dysfunction causes lagophthalmos - incomplete closure of the eyelid
What muscles and nerves can be affected to cause ptosis?
- levator palpebrae superioris m., innervated by CN III, opens upper eyelid
- Muller’s muscle, sympathetic innervation, opens upper eyelid
____________ is rolling in of the eyelid margin such that hairs are touching the ocular surface
Entropion
What are the causes of hereditary entropion?
- Abnormal medial canthus (common in brachycephalics)
- Abnormal palpebral fissure (hounds, giant breeds)
- Excessive facial folds (sharpeis)
What are the causes of acquired entropion?
- Enophthalmos (dehydration, emaciation, muscle atrophy)
- Chronic ocular pain causing blepharospasm associated entropion
How can you differentiate anatomic from blepharospasm entropion?
Use a topical anesthetic like proparacaine, if entropion resolves it was due to ocular pain causing blepharospasm
What treatment options are available for temporary correction of entropion?
- Lubrication
- Eyelid tacking (rolls out the eyelid)
- Partial temporary tarsorrhaphy (brings eyelid margins together)
- Hyaluronic acid subdermal filler (for old patients who can’t tolerate anesthesia)
What treatment options are available for permanent correction of entropion?
- Hotz-Celsus (rolls out the eyelid)
- Hotz-Celsus with lateral canthoplasty (rolls eyelid out and shortens palpebral fissure
What are the most common canine eyelid tumors?
- Meibomian gland adenoma (most common)
- Melanocytoma
usually benign tumors unlike cats
What are the most common feline eyelid tumors?
- SCC (most common)
- Fibrosarcoma
- MCT
- Adenocarcinoma
(mostly malignant tumors unlike dogs)
What are the treatment options are available for canine eyelid tumors?
- Debulk and cryotherapy (great for tumors > 1/3 eyelid margin)
- Complete excision
What suture pattern is used to close eyelid margin defects?
Figure 8 suture pattern
What are the causes of hereditary ectropion?
- Abnormal palpebral fissure
(common in hounds and giant breeds)
What treatment options are available for permanent correction of ectropion?
- Lateral canthoplasty (eyelid wedge resection), shortens palpebral fissure
- V to Y plasty (rolls eyelid inward)
What are the common causes of lagophthalmos?
- Breed variation (brachycephalics)
- Exophthalmos
- Buphthalmos
- CN VII or CN V dysfunction
Dysfunction of what cranial nerves can result in lagophthalmos?
CN VII or CN V dysfunction
What is the treatment protocol for patients presenting with lagophthalmos?
- ID underlying cause (breed vs CN dysfunction vs buphthalmos vs exopthalmos)
- Temporary correction vs lubrication and temporary tarsorrhaphy
- Permanent correction via permanent tarsorrhaphy or canthoplasty
How can abnormalities of eyelid innervation be detected?
- Abnormal palpebral reflex (CN V, CN VII)
- Ptosis (drooping of upper eyelid)
- +/- lip drooping
What medication can be applied topically to diagnose Horners syndrome?
Phenylephrine
If affected pupil dilates in 20 mins = post ganglionic
If affected pupil dilates in 30-40 mins = pre ganglionic `
What treatment options are available for permanent correction of eyelid agenesis?
- Cryoepilation
- Collagen injection
- Reconstruction blepharoplasty (skin grafts, lip to lid transposition, oral mucosal graft)
What is trichiasis?
Hairs growing from a normal location that are touching the conjunctiva/corneal surface
Ex: Excessive facial folds causing hair of folds to touch the eye
What options are available for conservative and aggressive treatment of trichiasis?
Conservative - frequent lubrication
Aggressive - Facial fold resection, medial canthoplasty
What is distichia?
Cilia that emerges from the meibomian glands
(meibomian gland is part of the tarsus, which is underneath where normal eyelashes should be)
What options are available for treatment of distichia?
1. Cryotherapy / Cryoepilation
(freeze the abnormal eyelash, apply probe to palpebral conjunctiva)
**Caution: eyelid necrosis and depigmentation
2. Thermal cautery (burns the abnormal eyelash)
** Caution: charred material in eye causing further irritation
only requires tx if causing corneal or conjunctival dz
What is ectopic cilia?
Eyelashes protruding through palpebral conjunctiva (inner mucosa of eyelids, touching the eyeball)
How do patients with ectopic cilia present?
- Severe pain and corneal disease
- CS wax and wane due to hair life cycle
- Ulceration
- Keratitis (inflammation of the cornea)
What options are available for treatment of ectopic cilia?
Surgical excision with cryotherapy
(isolate hair follicle and evert eyelid, excise hair follicle and freeze)
_________ is inflammation of the eyelid
Blepharitis
List inflammatory eyelid disorders
- Chalazion
- Hordeolum (Stye)
- Blepharitis (bacterial, fungal, parasitic, immune mediated)
What is chalazion?
Enlargement of the meibomian gland due to blockage of its duct
How is chalazion treated?
- Warm compress
- Surgical incision and drainage
- Topical Abx with steroids
What is Hordeolum?
Purulent bacterial infection of the meibomian gland
(Staph aureus most common)
What clinical signs can be seen in patients with hordeolum?
- erythema and swelling of the lids
- pruritis
- painful
- chemosis
- conjunctivitis
(Hordeolum - purulent bacT infection of the meibomian gland)
What is the treatment protocol for bacterial blepharitis?
- Systemic Abx for 3-4 weeks
- Topical Abx + steroid ointment
- Warm compress
(Amoxiclav, doxycycline, cephalosporin)
What is a parasitic cause of blepharitis?
Demodex
What are immune mediated causes of blepharitis?
- Pemphigus diseases
- Medial canthal ulcerative blepharitis
What can occur if cherry eye is left untreated?
- Chronic conjunctivitis
- KCS (dry eye)
**3rd eyelid contributes to 35-45% of the the aqueous tear film
When is complete excision of the 3rd eyelid an appropriate treatment option?
Only indicated if neoplasia
never indicated for cherry eye
What treatment options are available for patients with prolapse of the 3rd eyelid?
1. Morgan pocket technique
2. Orbital tacking
A ________ shaped incision should be made in cases of eyelid tumor removal
House
Which of the following is a surgical treatment option for trichiasis?
A. Lateral canthoplasty
B. Medial canthoplasty
C. Cryotherapy
D. Orbital tacking
B. Medial canthoplasty
Which of the following is a surgical treatment option for prolapse of the 3rd eyelid?
A. Lateral canthoplasty
B. Medial canthoplasty
C. Cryotherapy
D. Orbital tacking
D. Orbital tacking
(also Morgan pocket technique)
Which of the following is a surgical treatment option for ectropion?
A. Lateral canthoplasty
B. Medial canthoplasty
C. Cryotherapy
D. Orbital tacking
A. Lateral canthoplasty
(also can do V to Y plasty)
Which eyelid condition can be treated surgically using a V to Y plasty?
Ectropion
Which of the following is a surgical treatment option for entropion?
A. Hotz Celsus
B. Medial canthoplasty
C. Cryotherapy
D. Orbital tacking
A. Hotz Celsus (+ lateral canthoplasty)
(taking out a piece of skin underneath the eye and then suturing it back together)
A lip-to-lid transposition can be a surgical treatment option for which of the following eyelid disorders?
Eyelid agenesis
Which eyelid disorder should be reconsidered at 8-12 months, once a dog grows into their face?
Entropion
