Eyelids

Question 1

describe the anatomy of the eyelids

Answer 1

1. should rest on cornea
2. most problems due to abnormal lid position, abnormal globe position/size, or both
3. most movement is from the upper eyelids
4. open via levator palpebrae superioris (CN 3), Mullers (sympathetic)
5. close via orbicularis oculi (CN 7)
6. composed of skin, palpebral conjunctiva, muscle, and glandular tissue (meibomian glands)
   -ducts of meibomian glands are on lid margin

Question 2

describe congenital defects in the eyelid

Answer 2

1. lids are sealed at birth and open around 10-15 days
2. premature opening leads to exposure, keratoconjunctivitis, or severe ulceration
3. lids protect, lubricate surface, and provide temporary tarsorrhaphy

Question 3

describe anklyoblepharon

Answer 3

1. delayed or incomplete opening
2. associated-ophthalmia-neonatorum-infectious keratoconjunctivitis
3. open surgically, drain, give topical antibiotics
4. can cause blindness

Question 4

describe eyelid agenesis/coloboma

Answer 4

1. absence of eyelids
2. more common in cats and often associated with other abnormalities
3. exposure, trichiasis (hairs rubbing cornea) lead tro keratitis, ulceration, and neovascularization
4. treatment: surgical repair
   -graft from lower lid, sliding grafts, wedge resection, etc.
   -nothing does eyelid like eyelid though

Question 5

describe macropalpebral fissure

Answer 5

1. also called euryblepharomacroblepharon, abnormally large palpebral fissue
2. common in brachycephalic breeds (we breed for it)
3. associated with lagophthalmos (incomplete blink) and tear film abnormalities
4. leads to corneal pigmentation, keratitis, ulceration (often severe), sometimes called ocular brachycephalic syndrome
5. for mild pigmentation: observation, lubrication, cyclosporine
6. with progressive pigmentation (particularly in young dogs) can cause severe ulceration that needs surgical repair: medial and lateral canthal closure

Question 6

describe entropion

Answer 6

1. inward rotation of all or part of lid margin
   -hair rubs against conjunctiva and cornea
2. breed disposition
3. can be mild or severe based on degree of lid involvement
   -can cause corneal ulcers, pigmentation, self trauma
4. primary:
   -congenitally long or lax lids, heavy brow folds
5. secondary: due to pain/spastic or cicatricial form
6. repair: evaluate lid movement, concurrent ocular problems (ulcers), structural component (anatomic) versus spastic component
   -use topical anesthetic like proparicaine to evaluate

Question 7

describe temporary tacking of entropion

Answer 7

1, in young puppies, to allow corneal defects to heal

2. common for shar pei puppies
3. use 3-0/4-0 nonabsorbable suture, leave in for 3-4 weeks

Question 8

describe Hotz-Celsus for permanent entropion correction

Answer 8

1. strip of skin/muscle removed adjacent to defect, one layer closure, simple interrupted
2. 1st incision is 1-2mm from lid margin
   -under, not over correct (take less if unsure how much to take)
   -can do with upper or lower lid
   -can do upper and lower at same time
3. suture middle first

Question 9

describe lateral canthoplasty for entropion repair

Answer 9

1. wedge resection at lateral canthus +/- hotz-celsus
2. good for large breed (hunting) dogs with excessive lid length
3. may address short lateral canthal ligament
4. MUST get proper re-alignment of lateral canthus

Question 10

describe ectropion

Answer 10

1. outward rolling of lid causes exposure of conjunctival tissue +/- lagophthalmos
2. usually lower eyelid
   -upper eye lid is cicatricial
3. can cause low grade conjunctivitis and tear film issues
4. desirable in some brreds
5. correct is: conjunctivitis ongoing or progressive corneal pathology
6. wedge resection to remove extra length is simplest repair, use a 2 layer closure

Question 11

describe combined entropion/ectropion

Answer 11

1. diamond eye
   -breeds with macropalpebral fissures, smallish globes, deep orbits (relative enophthalmos), heavy skin folds
2. entropion temporal and nasal, ectropion centrally
3. lateral canthoplasty can correct
4. face lift to remove dorsal skin
   -stellate rhytidectomy: not commonly performed but can be effective
   -also can use brow slings

Question 12

describe distichia

Answer 12

1. additional row of lashes originating from metaplastic meibomian glands
   -one to many per opening
2. usually incidental; variable clinical significance, if worried causing a problem, pluck it out and see if signs resolve
3. breed pre-disposition; use facial illumination/magnification to diagnose
4. treatment:
   -cryotherapy most common
   –double freeze thaw meibomian gland base on the conjunctival side
   –there will be swelling and depigmentation of lid post op

Question 13

describe trichiasis

Answer 13

1. normally placed cilia directed toward the cornea or conjunctiva
2. primary or secondary
   -nasal folds in brachycephalics
3. can cause blepharospasm or corneal ulceration
4. treatment: most of the time we just live with it (dogs don’t have the same corneal sensation as humans)
   -Hotz-celsus
   -removal of nasal folds

Question 14

describe ectopic/aberrant cilia

Answer 14

1. cilia growing straight down through the conjunctiva directly at the eyeball
   -must flip eyelid out to see this, usually on upper lid
2. causes clinical disease! hit the cornea, causes blepharospasm, corneal ulceration, epiphora
3. just plucking is not adequate treatment, will grow back and be short and sharp when start to grow back
   -need to use a biopsy punch to remove entire hair follicle so cannot regrow
4. treatment:
   -excision of hair and associated follicles through conjunctiva
5. shih tzus, lhasas, form nests of hair and must excise all

Question 15

describe trichomegaly

Answer 15

long, normal eyelashes

Question 16

describe eyelid trauma

Answer 16

1. well vascularized area so large defects heal well
2. most important principle: accurate apposition of eyelid margins!!
   -never cut off eyelid!!!!! just aggressive debridement and put it back together (nothing does eyelid like eyelid)
3. lavage and clean wound, use a 2 layer closure (esp in horses, may get away with just 1 in dogs)

Question 17

describe eyelid neoplasms in dogs

Answer 17

1. typically older dogs, mostly benign
2. treatment is removal and histopathology
   -excision: 1/3 to 1/4 of lid margin involvement (depends on breed), full thickness wedge resection (house) or 4 side excision
3. if the mass is more than 1/3 to 1/4 of the lid margin:
   -use an advancement flap, a semicircular flap, or a lid to lid flap
   -usually referral surgeries
4. debulk and cryotherapy
   -advantages: cheaper, use sedation instead of gen anesthesia, can use in larger lesions
   -disadvantages: more likely to need repeating, swelling, depigmentation
   -double freeze thaw: fast freeze and slow thaw is key!

Question 18

describe eyelid neoplasms in cats

Answer 18

1. not as common as in dogs, but similar clinical signs
   -more common in older cats
2. MORE LIKELY TO BE MALIGNANT; LOCALLY INVASIVE
3. squamous cell carcinoma is most common:
   -slightly raised or often depressed, ulcerated area on or adjacent to eyelid margin
   -metastasis late but locally invasive
   -surgical excision (graft), cryotherapy, brachytherapy

Question 19

describe apocrine hydrocystomas in cats

Answer 19

1. gray, multiple cysts on eyelid margins
   -may also be found on lips
2. can be surgically excised, cryotherapy, but often recur

Question 20

describe blepharitis

Answer 20

1. typically: hyperemia, marked edema (vascularity of eyelids)
   -a derm disease! systemic so use systemic treatment
2. blepharospasm, exudate, alopecia, ulceration, hyperpigmentation
3. chronic lid distortion

Question 21

describe bacterial blepharitis

Answer 21

1. common in puppies with juvenile pyoderma
   -use antibiotic therapy
2. straphylococcus/streptococcus are most common agent sin adult bacterial blepharitis
3. may get abscessation of meibomian glands
   -potentially allergic reaction to bacterial dermotoxins

Question 22

describe parasitic blepharitis

Answer 22

1. in cats and dogs due to demodex and sarcoptes
2. will see hyperemia, alopecia, pruritis, self trauma (particularly sarcoptes)
3. dx: skin scrape
4. tx: topical, protect cornea

Question 23

describe immune-mediated blepharitis

Answer 23

1. allergic: acute onset edema and hyperemia
2. local exposure to contact allergen or generalized response
3. insect bites/vaccines: swelling of lid and muzzle
4. contact: often drugs
5. treatment: immunosuppressives: CSA, azathioprine, cyclosporine
6. not as common in cats

Question 24

describe hordeolum (stye) and chalazion

Answer 24

1. chalazion: granuloma formation; retained meibomian secretions leak into surrounding tissue and cause inflammatoery response
2. hordeolum/stye:
   -usually staphylococcal infection of glandular tissue of lids
   -external: inflam of glands of Zeiss, Moll
   -internal: infection of meibomian gland
3. treatment:
   -hot packs +/- manual expression
   -topical and systemic antibiotics