Lecture 2 Flashcards
what do you see
epiphora: tear staining on the face originating from the medial canthus
tears flow onto the face, stains the hair, and can cause moist dermatitis
what causes epiphora?
increased production from irritation
decreased outflow from an obstruction of nasolacrimal system
what is imperforate puncta? how do you treat?
the lower tear duct opening has not developed, can cause epiphora due to decreased tear drainage
open the imperforate puncta and give topical steroids to prevent closure
what is dacryocystitis? how do you treat?
inflammation of the nasolacrimal duct and it blocks the nasolacrimal system.
can be caused by an obstruction like a grass awn, neoplasm, dental disease, facial bone fractures, etc.
tx: flush the NL system, give topical steroids/antibiotics, but can reoccur. do not use long term oral antibiotics
canine conjunctivitis is often caused by….
you’ll see…
allergies–>associated with atopic dermatitis
will see chemosis (edema of conjunctiva) and hyperemia
how should you treat allergic canine conjunctivitis?
treat underlying atopy
topical steroids and anti histamine (Pataday 0.2% 1-2x daily, these are antihistamine drops)
list some causes of feline conjunctivitis
herpesvirus: will also have URT dz
chlamydophila felis: mostly chemosis
mycoplasma: uncommon
a cute wittle kimten comes to you with conjunctivitis. will you treat this cat?
assuming it’s herpes, no, it is self limiting
if the cat doesn’t improve and I think it might be chlamydia, I would give oral doxycyline for 4 weeks 2x day
what is this? it is pathognomonic for…
a dendritic ulcer: you can see the branching fluorescin stain in the superficial cornea and some corneal vessels laterally
pathognomonic for feline herpesvirus keratitis, often with concurrent conjunctivitis
how can you treat feline herpesvirus keratitis?
can give antivirals
systemic: famciclovir
topical: cidofovir, trifluridine, idoxuridine
oral lysine (no real evidence it works tho)
could do topical broad spec antibitiocs
warn owners that recurrance is common
what is neonatal ophthalmia?
primary FHV infection with secondary bacterial infection before the eyelids open, may be discharge
give topical antibiotics and open the eyelids to give this
what do you see? what is the cause?
corneal sequestrum: lateral central black superficial lesion with vessels encircling
this is a necrotic cornea, this is unqiue to the cat, most often in brachy cat breeds. can be a primary dystrophy or after a corneal ulceration/irritation
what do you see?
a corneal sequestrum caused by lower entropion, can see vessels encircling the lesion
what things determine the treatment plan for a corneal sequestrum in a cat?
level of discomfort and the depth
if comfortable and it’s superficial, let it slough naturally! steroids and antibiotics have no effect on these ones! this process can take months to years
if its painful and/or deep, do a superficial keratectomy (remove it), +/- a conjunctival graft, corneoconjunctival transposition, corneal transplant
this is a cat. what do you see, what is #1 ddx and how will you confirm?
eosinophilic keratitis: pink with white deposits on the surface, superficial blood vessels on lateral cornea
this is a proliferative disease of the superficial cornea. there is NO association with eosinophilic granuloma complex
do cytology of corneal scrapings revealing lymphocytes, eosinohpils, mast cells, neutrophils
how do you treat eosinophilic keratitis?
0.1% dexamethasone or 0.1% prednisolone QID initially
cyclosporin or tacrolimus and taper slowly
recurrance is common
true or false: cats with eosinophilic keratitis respond very fast to treatment
true! within 2 weeks they can be normal!
this is a 12yo shiz tzu. what do you see? ddx?
corneal degeneration: dense white corneal opacity rim around a clear zone, some white areas. the clear zones are areas in which calcium has flaked off and this dog had previous ulcers.
usually will have a gritty look to them, calcium and/or lipid deposits, flakes can cause an ulcer too
what is this and how do you treat it
corneal degeneration: can see the grittty mineral appearance, there is also a desmetocele
treatment:
1) remove the mineral either by doing a keratectomy + corneoconjunctival transportation (best option) or a corneal burr
2) EDTA to get rid of mineral (doesn’t work great), requires the epithelium to be absent and often used with the burr
3) lubricants
DO NOT USE topical steroids
this dog had corneal degernation. what treatment was done?
corneaoconjunctival transportation, essentially moving the limbus down. super effective for non healing mineralization or descmetoceles
what is this? treatment?
corneal dystrophy: fat deposit, does not cause vision issues, not painful, often in young dogs, we don’t really know why they happen, usually bilateral
can leave alone or give cyclosporin to get rid of them but it takes 6-12 months
DO NOT USE TOPICAL STEROIDS
what do you see here? cause?
endothelial dystrophy: can see OU temporal blue/white cloudiness. essentially the endothelial cells start to die off earlier than they should, and the cells can no longer pump fluid out of the cornea to keep it dehydrated so you get corneal edema. endothelial cells cannot be replaced.
true or false: endothelial dystrophy begins medial and moves lateral
false! starts lateral and moves medial
what are 2 common sequelae to endothelial dystrophy?
bullae (fluid filled sacs) due to fluid accumulation
superficial ulceration due to fluid sac rupture
how do you treat endothelial dystrophy?
thermokeratoplasty: cauterize the superficial cornea to limit edema (burn the cornea), used when ulcers are present, and this heals ulcers in 90% of cases within 2-4 weeks
keratectomy + conjunctival graft: this slows down/stops progression and can improve corneal edema, the graft is placed on lateral 3rd of the cornea
can do corneal transplant but riskier and harder to find donator corneas
hypertonic saline to suck fluid out of cornea: brian doesn’t do this
what do you see here?
corneal edema with a superficial ulcer
what do you see here?
this is thermokeratoplasty to treat ulcers/endothelial dystrophy: cauterize the cornea to get blood vessels to come in and heal the ulcer. ulcers usually do not recurr if you do this.
what is the difference between endothelial dystrophy and endothelial degeneration
endothelial dystrophy: the cells start to die off earlier than they should
endothelial degeneration: something is damaging the endothelial cells, such as
- anterior uveitis, glaucoma, trauma, endothelitis (rare)
treat the underlying disease and cause of damage, although damage may be permanant
this cat was normal yesterday. what is this?
bullous keratopathy: extreme corneal cloudiness and bullae over the medial cornea
this can occur in hours! can be focal or diffuse, not very common, can cause perforation but rare
what is this? what is the cause? treatment?
bollous keratopathy: causing protrusion of the cornea
cause is unknown, thought to be an endothelial cell malfunction. a lot of these cats have chronic uveitis and are on topical steroids.
tx: stop topical steroids, place a 3rd eyelid flap, leave flap for 2 weeks and givetopical antibiotic while flap is there,and the prognosis is very good
cats on what drug have an increased risk of bullous keratopathy?
cyclosporin
we dont know why
what is this ocular condition called?
macropalpebral fissure syndrome: OU laterally displaced globes, lateral strabismus, extensive showing of sclera, large eyelid opening resulting in inability to close eyelids properly (lagophthalmia)
this is a pug, how did this lesion happen?
this is macropalpebral fissure syndrome and corneal irritation leading to hyperkeratosis/corneal pigment (the eye trying to protect itself)
this is a pug. what do you see here?
macropalpebral fissure syndrome! medial entropion causing irritation of the cornea
what is going on in this pug?
chronic macropalpebral fissure syndrome leading to severe hyperpigmentation of the cornea and consequent blindness (eye trying to protect the cornea)
name 3 causes of macropalpebral fissure syndrome leading to corneal irritation
lagophthalmia
entropion
nasal folds (brian says this is fake news)
you have a french bulldog with macropalpebral fissure syndrome. what treatment options do you have?
medial canthoplasty: narrow the eyelid opening, helps eliminate entropion
increase tears: cyclosporin, keep cornea moist
true or false: once corneal pigmentation is present, there is no way to get rid of it
true
a german shepherd presents with this. ddx?
pannus/immune keratitis: can see ventral superficial corneal pigmentation and some blood vessels
the variant of pannus causing inflammation of the 3rd eyelid (same cause as pannus), is called
Plasmoma: hyperemia, cobblestone appearance and depigmentation of 3rd eyelid
what is this?
plasmoma
true or false: pannus is painful
false
is pannus more severe in younger or older animals?
younger
risk factors for pannus
breed: GSD or greyhounds
environment: high elevations and UV radiation
how do you treat pannus/immune keratitis?
controllable but not curable
topical dexamethasone, cyclosporin, tacrolimus all QID and then decrease
can use subconjunctival triamcinolone which is a long lasting steroid injection
give them the cute doggy goggles like Trigger to help avoid UV
what are the 3 steps to manageing a corneal ulcer?
1) determine the cause
2) medical treatment
3) protect and support the cornea
list 5 things that can cause corneal ulcers
trauma, alkali shampoo or acids, trichiasis, distichiasis, ectopic cilia, infections (usually bacterial), entropion, foreign bodies, KCS, endothelial dystrophy/degeneration, anterior stromal calific degeneration
how to diagnose corneal ulcers
fluorescin stain
list the different kinds of corneal ulcers
superficial
refractory
stromal
descmetocele
melting
perforation
superficial corneal ulcers are confined to _____ and are classified as either ____ or _____
loss of the epithelium
simple, refractory
clinical signs of a superficial corneal ulcer
squinting, epiphora, discharge, enopthalmos, hyperemic conjunctiva and 3rd eyelid elevation
Fido has a superficial corneal ulcer, how are you gonna treat him? prognosis?
topical broad spec antibiotics to prevent infections
should heal in 4-7 days and if it doesn’t, go looking for an underlying cause
wot dis
a refractory ulcer–>a superficial ulcer that has not healed. the epithelium is peeling off and nit adhering to underlying anterior stroma
you need to go looking for a cause
wot dis?
a refractory ulcer–>the stain is going underneath the epithelium and this is not normal! the epithelium is loose and not adhereing to the anterior stroma
true or false: in most cases causes of a refractory ulcer are not identified
true
how do you diagnose a refractory ulcer?
if its an ulcer in a middle to old aged patient that doesnt heal in 7-14 days, it should be suspected to be refractory/indulent
if it has epithelium that isn’t adhering to the underlying stroma=refractory
if the stain migrates underneath the epithelium and creates a halo around the ulcer
what breed loves to get refractory ulcers
boxers
a boxer named Mr. Bingley comes to you with a refractory ulcer. what initial treatment options are there?
1) debridement with a DRY cotton swab and topical anesthetic to remove all the non adherent epithelium
2) treatment
a: grid keratotomy: superficial incisions in the anterior cornea over the ulcer with a 22G needle
OR
b: diamond burr debridement to remove superficial stroma
80% success rate the first time, 99% after the second time
how will you treat a refractory ulcer than is non responsive to grid/burr treatment?
superficial keratectomy: remove the abnormal anterior stroma and requires GA
a stromal ulcer/descmetocele is one that…
invades into the stroma of the cornea and sometimes all the way to descemet’s membrane
usually stroma is lost due to bacterial infection
what is different about diagnosis of a stromal ulcer compared to a superficial one?
if it’s a descmetocele, it won’t take up stain, only the stroma will uptake the stain
how to treat a stromal ulcer?
initially, just like a superficial one: broad spec antibiotics for 7 days ish
for deeper ones you may need to do more
wot dis?
3 different stromal ulcers that are healing
can see blood vessels coming in: indicative of healing
what is this
a healing ulcer (can tell bc all the blood vessels)
what dis? how treat?
a descmetocele–>this wont pick up stain, this is an ocular emergency
tx: requires corneal reinforcement, either conjunctival graft or corneoconjunctival transportation
what dis
a conjunctival graft to help heal an ulcer
what dis? what causes this?
a melting ulcer (keratomalacia) with some hypopeon and uveitis
from excessive levels of proteolytic enzymes. these come from bacteria, fungi, and yeast
DO NOT USE STEROIDS! they increase the effects of proteases
a dog named Lizard comes to you with a goopy eye and the owner says shes been bothered by it for a while now. you take a look and suspect a melting ulcer. what diagnostics will you recommend?
cytology: put in topical anesthetic and use the blunt end of a scalpel. this will help you determine the cause (cocci, rods, yeast, etc)
you do a fluorscin stain on a dog and you see this. what treatment will you recommend?
melting ulcer
requires aggressive medical therapy
- broad spec antibiotics (NOT tobrex, need moxifloxacin, oflaxacin, ciprofloxacin)
- anti-collagenase therapy like serum or doxycycline (anti-protease) until the melting has stopped
can also do surgery: conjunctival graft, esp if the ulcer looks like it could rupture or is not getting better with medical management
what is this and what is the treatment? prognosid?
corneal perforation: can see central area od red tissue which is a fibrin plug
tx: this is an emergency, needs surgery, either a conjunctival graft or corneoconjunctival transposition + collagen
prognosis depends on the size, smaller = better prognosis for the eye
this is an english bulldog. what dis? what has caused this? How will you treat this dog?
a dermoid
it is a congenital problem
tx: keratectomy, excellent prognosis
what dis? prognosis?
a dermoid: hairs coming from conjunctiva
prognosis is excellent and you just take this off
describe what’s going on here in this cat
this is persistent pupillary membrane. it should normally regress by 6 months of age. they are not painful and dont need treatment. if it’s still there after 6 months it’s not going away but it’s not worrysome
not only can persistent piupillary membranes be iris to iris, they can also be
iris to lens and iris to cornea
if a persistent pupillary membrane is from iris to cornea you get _____ and if its from iris to lens you get _____
leukoma (opacity)
cataract
4 yo DSH with red eyes for 3 days and had aqueous flare. this cat also had low IOP OU. what is this?
anterior uveitis
what is aqueous flare?
when there’s more protein in the aqueous humor which increases tubidity and decreases visual acuity and it’s usually indicative theres some uveitis going on
why do /patients with anterior uveities have a low IOP
reduced prodctuon of aqueous humor by the ciliary body when it’s inflammaed
why do patients with anterior uveitis have miosis?
prostaglandins are released due to inflammation and the pupillary sphincter muscle has PG receptors on it causing miosis
why do patients with uveitis get corneal edema?
the corneal endothelium normally removes fluid from the corneal stroma, however these endothelial cells require aqeous humor to function and become malnourished with less aqeous humor around.
also happens due to inflammatory mediators
what is this?
keratic precipitates: inflammatory cells tat indicate the patient has or had anterior uveitis
what is this?
can see black areas on the aterior lens capsule and places where the iris is stuck to the anterior lens capsule and this is called=posterior synechiae
_____ is the most common cause of significant cataracts in horses and cats
anterior uveitis
wot dis
a melting ulcer with a hypopyon too
what causes anterior uveitis in cats most commonly? (in order)
immune mediated/idipathic 90% of cats
neoplasia either intraocular (rare) or systmeic (lymphoma)
lens induced uveitis (more common in dogs)
infections (FIV, FeLV, FIP, toxoplasma, etc)
what causes anterior uveitis in dogs?
algal
bacteria
fungal
rickettskial
viral
protozoan
immune mediated
parasitic
neoplastic
systemic blasto causing uveitis is rare in cats but how do you treat it?
oral itraconazole and then some topical prednisolone eye drops to reduce inflammation
you send a cat with anterior uveitis home with pred drops and some meloxicam for pain. 2 weeks later the cat is “feeling” much better and has gained weight, but her OS IOP is now 62 and the eye is big! and she seems blind :( what options are there for this cat?
removal of the eye :(
what is iris bombé?
when there’s anterior uveitis that results in fibrin formation which allows the iris to stick to the lens (posterioer synechiae) which prevents aqueous humor flowing through the pupil. the iris then gets pushed forwards and sticks to the cornea and completely blocks off the iridocorneal angle. this spikes the IOP causing glaucoma and the prognosis is very poor
