Eyelids Flashcards
describe the anatomy of the eyelids
- should rest on cornea
- most problems due to abnormal lid position, abnormal globe position/size, or both
- most movement is from the upper eyelids
- open via levator palpebrae superioris (CN 3), Mullers (sympathetic)
- close via orbicularis oculi (CN 7)
- composed of skin, palpebral conjunctiva, muscle, and glandular tissue (meibomian glands)
-ducts of meibomian glands are on lid margin
describe congenital defects in the eyelid
- lids are sealed at birth and open around 10-15 days
- premature opening leads to exposure, keratoconjunctivitis, or severe ulceration
- lids protect, lubricate surface, and provide temporary tarsorrhaphy
describe anklyoblepharon
- delayed or incomplete opening
- associated-ophthalmia-neonatorum-infectious keratoconjunctivitis
- open surgically, drain, give topical antibiotics
- can cause blindness
describe eyelid agenesis/coloboma
- absence of eyelids
- more common in cats and often associated with other abnormalities
- exposure, trichiasis (hairs rubbing cornea) lead tro keratitis, ulceration, and neovascularization
- treatment: surgical repair
-graft from lower lid, sliding grafts, wedge resection, etc.
-nothing does eyelid like eyelid though
describe macropalpebral fissure
- also called euryblepharomacroblepharon, abnormally large palpebral fissue
- common in brachycephalic breeds (we breed for it)
- associated with lagophthalmos (incomplete blink) and tear film abnormalities
- leads to corneal pigmentation, keratitis, ulceration (often severe), sometimes called ocular brachycephalic syndrome
- for mild pigmentation: observation, lubrication, cyclosporine
- with progressive pigmentation (particularly in young dogs) can cause severe ulceration that needs surgical repair: medial and lateral canthal closure
describe entropion
- inward rotation of all or part of lid margin
-hair rubs against conjunctiva and cornea - breed disposition
- can be mild or severe based on degree of lid involvement
-can cause corneal ulcers, pigmentation, self trauma - primary:
-congenitally long or lax lids, heavy brow folds - secondary: due to pain/spastic or cicatricial form
- repair: evaluate lid movement, concurrent ocular problems (ulcers), structural component (anatomic) versus spastic component
-use topical anesthetic like proparicaine to evaluate
describe temporary tacking of entropion
1, in young puppies, to allow corneal defects to heal
- common for shar pei puppies
- use 3-0/4-0 nonabsorbable suture, leave in for 3-4 weeks
describe Hotz-Celsus for permanent entropion correction
- strip of skin/muscle removed adjacent to defect, one layer closure, simple interrupted
- 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 - suture middle first
describe lateral canthoplasty for entropion repair
- wedge resection at lateral canthus +/- hotz-celsus
- good for large breed (hunting) dogs with excessive lid length
- may address short lateral canthal ligament
- MUST get proper re-alignment of lateral canthus
describe ectropion
- outward rolling of lid causes exposure of conjunctival tissue +/- lagophthalmos
- usually lower eyelid
-upper eye lid is cicatricial - can cause low grade conjunctivitis and tear film issues
- desirable in some brreds
- correct is: conjunctivitis ongoing or progressive corneal pathology
- wedge resection to remove extra length is simplest repair, use a 2 layer closure
describe combined entropion/ectropion
- diamond eye
-breeds with macropalpebral fissures, smallish globes, deep orbits (relative enophthalmos), heavy skin folds - entropion temporal and nasal, ectropion centrally
- lateral canthoplasty can correct
- face lift to remove dorsal skin
-stellate rhytidectomy: not commonly performed but can be effective
-also can use brow slings
describe distichia
- additional row of lashes originating from metaplastic meibomian glands
-one to many per opening - usually incidental; variable clinical significance, if worried causing a problem, pluck it out and see if signs resolve
- breed pre-disposition; use facial illumination/magnification to diagnose
- treatment:
-cryotherapy most common
–double freeze thaw meibomian gland base on the conjunctival side
–there will be swelling and depigmentation of lid post op
describe trichiasis
- normally placed cilia directed toward the cornea or conjunctiva
- primary or secondary
-nasal folds in brachycephalics - can cause blepharospasm or corneal ulceration
- 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
describe ectopic/aberrant cilia
- cilia growing straight down through the conjunctiva directly at the eyeball
-must flip eyelid out to see this, usually on upper lid - causes clinical disease! hit the cornea, causes blepharospasm, corneal ulceration, epiphora
- 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 - treatment:
-excision of hair and associated follicles through conjunctiva - shih tzus, lhasas, form nests of hair and must excise all
describe trichomegaly
long, normal eyelashes
describe eyelid trauma
- well vascularized area so large defects heal well
- 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) - lavage and clean wound, use a 2 layer closure (esp in horses, may get away with just 1 in dogs)
describe eyelid neoplasms in dogs
- typically older dogs, mostly benign
- 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 - 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 - 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!
describe eyelid neoplasms in cats
- not as common as in dogs, but similar clinical signs
-more common in older cats - MORE LIKELY TO BE MALIGNANT; LOCALLY INVASIVE
- 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
describe apocrine hydrocystomas in cats
- gray, multiple cysts on eyelid margins
-may also be found on lips - can be surgically excised, cryotherapy, but often recur
describe blepharitis
- typically: hyperemia, marked edema (vascularity of eyelids)
-a derm disease! systemic so use systemic treatment - blepharospasm, exudate, alopecia, ulceration, hyperpigmentation
- chronic lid distortion
describe bacterial blepharitis
- common in puppies with juvenile pyoderma
-use antibiotic therapy - straphylococcus/streptococcus are most common agent sin adult bacterial blepharitis
- may get abscessation of meibomian glands
-potentially allergic reaction to bacterial dermotoxins
describe parasitic blepharitis
- in cats and dogs due to demodex and sarcoptes
- will see hyperemia, alopecia, pruritis, self trauma (particularly sarcoptes)
- dx: skin scrape
- tx: topical, protect cornea
describe immune-mediated blepharitis
- allergic: acute onset edema and hyperemia
- local exposure to contact allergen or generalized response
- insect bites/vaccines: swelling of lid and muzzle
- contact: often drugs
- treatment: immunosuppressives: CSA, azathioprine, cyclosporine
- not as common in cats
describe hordeolum (stye) and chalazion
- chalazion: granuloma formation; retained meibomian secretions leak into surrounding tissue and cause inflammatoery response
- hordeolum/stye:
-usually staphylococcal infection of glandular tissue of lids
-external: inflam of glands of Zeiss, Moll
-internal: infection of meibomian gland - treatment:
-hot packs +/- manual expression
-topical and systemic antibiotics