Test 2: lecture 31 uvea Flashcards
uvea
vascular, pigmented (melanin) coat
iris, ciliary body – anterior uvea
choroid – posterior uvea
major iridal circle
collarette (darker area around pupil)
horse eye
corpora nigra
sphrincter of the iris is controlled by — nerve and has a — arrangement
PARA, CN3
circular
will constrict pupil
the dilator iris muscle is controlled by —, is arranged —
SYM, CN5
radial
will dialte pupil
what does ciliary body do?
makes aqueous humor
provides nutrition to lens and inside of the cornea
tapetum lucidim
choroid
accomodation
ciliary muscle contract and release tension on the lens, making lens fatter
— supplies 80% of oxygen to cat retina
choriocapillaris
when does tapetum lucidem mature
16 weeks
dycoria
misshaped pupil- usually caused by iris atrophy
iris atrophy- common in > 7-8 year old dogs
dyscoria- misshaped pupil
sluggish contraction
persistent pupillary membrane
common, vascular strands remain after birth, extend from the iris collarette
persistent pupillary membranes extend from the —
iris collarette (darker area around the pupil)
nevus
freckle of color in the iris (melanosis)
normal in dogs, probably cancer in a cat
melanocytic neoplasm
melanocytoma- raised and dark
common in dogs, slow growing, locally expansive, rarely metastasize
treatment: enucleation
cat eye
feline diffuse iris melanoma
can transform from melanosis into cancer
locally destructive and frequently metastasize but slow
treatment enucleate
lymphoma
presumed solitary ocular lymphoma
could be metastatic from elsewhere, but it would be very advanced to get to eye
ciliary body epithelial tumor
* adenoma > adenocarcinoma
uveal cyst
benign but can look like melaloma if pigmented
cleared walled cysts may lead to glaucoma
anterior uveitis- inflammation, cloudy, red, painful
— prevents protein movement between plasma and the eye
blood-ocular barrier
blood-aqueous barrier (BAB)
blood retinal barrer (BRB)
what happens to blood ocular barrier during inflammation
tight junctions between iris endothelial cells and non-pigemented ciliart body epithelium break down
allows protein to come into eye called aqueous flare
aqueous flare
break down of the blood aqueous barrier that allows protein into the anterior chamber of the eye
hypopyon
white cells/pus in the anterior chamber
what can cause cloudy eye?
aqueous flare- protein into anterior chamber
corneal edema
hypopyon – white cells in the anterior chamber
keratic precipitates – macrophages
anterior uvetitis is painful and can causes
blepharospasm (squinting)
tearing, enophthalmos (sucken eye)
iridocyclospasm
hyphema
RBC in the anterior chamber
uvetitis will do what to IOP
decreases
inflammation will decrease production of aqeuous humor
what can cause uveitis
primary
* blunt trauma, corneal ulcer, cataract
systemic
* infectious disease, hypertension, neoplasia
immune mediated
* often not identified
Golden Retriever Pigmentary
Uveitis (GRPU)
immune mediated uvetitis
diagnosis of exclusion
may be associated with thin wall cysts and can lead to glaucoma
progressive → usually results in removal of the eye
how to treat uveitis
treat underlying cause if we know it
treat for inflammation and pain: prednisone, doxy, atropine
long term uveitis can lead to
cataract
glaucoma- by iris sticking to cornea and blocking exit of aqueous humor out of the eye
phthhsis bulbi- eye shrinks from scarring
4 year-old DLH Cat
* six-month history of colour change to right eye
* describe the abnormalities in the right eye?
* what are the likely causes of the iris abnormality?
uveitis
caused by
* primary: blunt trauma, ulcer, cataract
* systemic: infection (FeLV, FIP, FIV, crypto), HTN, cancer
* immune mediated
