Special Senses Part 1 Flashcards
what is the difference between the palpebral conjunctiva and the bulbar conjunctiva ?
conjunctiva is the mucus membrane
the palpebral conjunciva is the back of the eyelids and the bulbar conjunctiva covers the globe surface and the limbus
what does uveitis mean?
inflammation of the vascular layer of the eye, the uvea
what is the term for inflammation of the uvea and the three ocular chambers (anterior, posterior, and vitreous)
endopthalmitis
what is a hypopyon?
what is a hyphema?
hypopyon: accumulation of neutrophils and fibrin that settles ventrally in the anterior chamber of the eye
hyphema: accumulation of blood in the anterior chamber
what is this?
hypopyon
what is this an example of?
hyphema
the inner most layer of the cornea is called the
descemet’s membrane
the cornea is mainly in a ________ state
dehydrated
inflammation of the cornea is called
keratitis
what is the name of the strain you use to see corneal ulcers?
fluorescin
what is a common sequelae of chronic corneal irritation?
cutaneous metaplasia of the surface epithelium where the surface thickens, rete pegs are formed, pigmentation occur as well as some fibrosis and vascularization (the cornea is becoming more like skin)
a deep corneal ulcer that reaches down to the level of descemet’s membrane is called
a descemetocele, remember they don’t show up with staining but you can usually see the ulcer grossly
what is this lesion called?
a descemetocele
what is an indolent ulcer? what animal are they most common in?
when an ulcer fails to heal with no specific cause. the newly formed epithelium fails to adhere to the underlying stroma. common in dogs
what is this showing?
an indolent ulcer
what kind of ulcer can be sterile but usually involved bacterial or fungal infection?
melting ulcers
what are two common etiologies that can cause this condition?
melting ulcer
gram negative bacteria
fungus especially in horses (keratomycosis)
what is KCS? who is it common in?
keratoconjunctivitis sicca, dessication (removal of moisture) due to reduced quantity of the tear film
common in dogs
what is a dermoid?
a developmental abnormality where you have ectopic hair follicles and adenexal glands/sebacceous glands
aberrant proliferation of normal tissue in an abnormal location is called
choristoma
aberrant proliferation of normal tissue in a normal location is called
hamartoma
what is the actual name for pink eye in cattle? what is it caused by? Cattle can have this disease concurrently with what other disease? When are outbreaks more common?
infectious bovine keratoconjunctivitis
caused by gram positive bacteria like morazella bovis
concurrent with ibfectious bovine rhinotracheitis caused by bovine herpes virus 1
outbreaks more common in the summer
a producer tells you a bunch of his cows have pink eye and you go out to the farm to examine them. When you arrive (it is summer time, nice and hot), you notice there are many flies buzzing around bothering you and the herd of cattle. What is your immediate reaction?
flies are important vectors of pink eye so you should tell the producer to control the fly populations to reduce infection
infectious bovine keratoconjunctivitis can progress to
phthisis (thai-sis) bulbi (end stage scarring and atrophy of the eye, yikes!)
what disease is this?
infectious bovine keratoconjunctivits (pink eye)
how can you tell the difference between pink eye and hypopyon from a sepsis case?
a hypopyon won’t have any conjunctivitis (inflammation of the mucus membrane of the eye) and there will not be ulcerations
what ocular disease in cats is caused by feline herpes virus 1? is this more common in adults or kittens?
herpesvirus keratitis
more common in kittens
the most common cause of keratitis in cats is
feline herpesvirus 1 (herpes virus keratitis)
feline herpes virus targets what 3 areas?
upper respiratory tract, conjunctiva, and cornea
what are some clinical signs of herpesvirus keratitis in cats?
rhinotracheitis, conjunctivitis +- keratitis in kittens, corneal ulceration with a dendritic pattern
what disease is this in a cat?
herpesvirus keratitis
there is a possible association between herpesvirus keratitis in cats and ________ and _______
feline sequestrum, feline eosinophilic keratitis
what are two common secondary bacterial infections cats can get with herpesvirus keratitis?
chlamydia felis and mycoplasma felis
eosinophilic keratitis happens commonly in ____ and _____, and has the following gross features:
CATS> horses
starts lateral as raised white to pink plaques on the cornea/conjunctivita, cytology reveals eosinophils
corneal sequestrums are most common in _____ and are often associated with:
on hist you will see:
cats
central accumulation of orange to brown pigment in the superficial stroma
histo: area of necrotic stroma (stroma is the thick connetive tissue part of the cornea)
what 3 cat breeds are predisposed to corneal sequestrums?
persian, himalayan, and siamese
which breeds are predisposed to pannus? what is another name for this disease? is it unilateral or bilateral? what is the cause?
german shepherds and sighthounds
chronic superficial keratitis of dogs
usually bilateral
it is an immune mediated disease and is associated with solar radiation exposure
what is this disease in a cat?
eosinophilic keratitis
dogs can get limbal melanocytic neoplasia, majority are ______. How do these tumors appear?
benign melanocytomas
darkly pigmented, expansile
what kind of tumor is this in a dog?
limbal melanocytic neoplasia (probably a benign melanocytoma)
persistent pupillary membranes are most common in _____. what kind of disease is this?
dogs, this is a congential condition
uveal cysts are comon in ____. Do they occur in young or old animals? Are they benign or malignant?
dogs
usually older animals
usually benign and degenerate EXCEPT FOR the golden retriever
lens induced uveitis is officially called _____ and it occurs secondary to _____. What is the very basic pathogenesis?
phacoclastic uveitis
trauma
the lens protein is recognized as foreign which leads to immune mediated inflammation
what is the actual name for moon blindness? how does this disease usually present? This disease has an association with what infectious agent?
equine recurrent uveitis
usually recurrent and progressive episodes of uveitis
associated with leptospira spp
what are two possible sequelae of uveitis?
anterior or posterior synechiae
phthisis bulbi
list an etiology that causes uveitis in each of the following species: bovine, feline, rabbit
bovine: malignant catarrhal fever
feline: feline infectious peritonitis
rabbit: encephalitozoon caniculi
a cat named Cheese Grater is at the clinic today and you see this in his eye. What are you concerned about it being, and what do you tell the owner?
Cheese Grater probably has feline diffuse iris melanoma which is a malignant neoplasia that can metastasize outside the eye. I will tell the owner that the progression of this disease can be slow or fast and so I would recommend taking out the eye
diabetic cataracts are often seen in what species? do these happen quickly?
dogs
usually bilateral and rapidly progessing
what can happen if the lens capsule were to rupture in a dog due to a diabetic cataract?
phacoclastic uveitis
what is the pathogenesis of a diabetic cataract in a dog?
high glucose levels in blood cause high glucose in the aqueos humor and excess glucose is absorbed by the lens and converted to sorbitol, which has a hyperosmotic effect fulling fluid into the lens causing the cataract
what is the normal old age change we see in dogs with cloudy eyes?
nuclear sclerosis
how do you tell the difference between nuclear sclerosis and cataract?
if you shine a light through the eye, with sclerosis you can see through the cloudiness but with a cataract you can’t
this 10 year old dog presents to you and when you shine a light through it, you can see through it. What is this?
nuclear sclerosis
regarding lens luxation, what are the major differences between anterior luxation and posterior luxation?
anterior luxation is painful and increases risk of glaucoma because it blocks the drainage (disrupts the iridocorneal angle)
posterior luxation is less likely to be problematic
what is the second most common primary ocular tumor in cats? what is the cause, and how aggressive is it?
feline posttraumatic ocular sarcoma (originating from lens epithelium)
caused by ocular trauma or severe ocular disease (response can be delayed by years, it doesn’t happen right after the trauma occurs)
it is highly infiltrative and can move up the sclera and optic nerve
what is the most common primary ocular tumor of cats?
diffuse iris melanoma
feline post traumatic ocular sarcomas resemble feline injection site sarcomas in what 4 ways?
both trauma associated, both delayed onset, they are both sarcomas, and they are both invasive/agressive
why is the retina prone to detachment?
it is only held in place at the optic nerve and ciliary body and it is held against the back of the eye by the vitreous fuid. this creates a potential space where fluids can accumulate and cause problems
since much of the retina depends on diffusion from the choirod for nutrients, retinal detachment leads to
ischemic degernation
glacuoma is most common in ____, and is a _______ with a variety of causes leading to___
dogs
clinical syndrome
reduced aqueous outflow and sustained elevated intraocular pressure
primary glaucoma occurs without
significant acquired disease
what is goniodysgenesis? what species is it most common?
maldevelopment of the trabecular meshwork where the aqeous drains, a failure in development. This is a risk factor for primary glaucoma. common in dogs esp purebreds
what is secondary glaucoma and who gets it?
blockage of the iridocorneal angle by exudates and cells, horses get it! can have a variety of causes BUT REMEMBER glaucoma is not common in horses
