Test 2: lecture 25 lacrimal Flashcards
(28 cards)
lacrimal glands found — in the eye
above- orbital lacrimal gland
gland of third eyelid
tear film is made by
lacrimal glands
meibomian glands
conjunctival goblet cells
dry eye
KCS
function of tears
nourish, lubricate and clean cornea
optical clearity
antibacterial
tears are a trilaminar fluid made of
meibomian gland: lipid outerlayer
lacrimal: watery layer
conjunctival goblet cells: mucus
aqueous layer is made by — glands
orbital lacrimal gland and
gland of third eyelid
— layer of the tear film feeds the avascular cornea and lubricates and cleanses the eyeball
aqueous
made by the orbital lacrimal gland and gland of third eyelid
meobomian glands makes — that will —
chosterol waxy lipid
prevent evapotation of aqueous layer (lacrimal gland)
lipid layer and mucin layer help stabilize tear film
conjunctival goblet cells will make — that promote — and trap—
mucin
smooth ocular surface
bacteria and foreign material
lipid layer and mucin layer help stabilize tear film
drainage of tears
puncta x2
canaliculi x2
converge at lacrimal sac
nasolacrimal duct
nasal puncta
dry eye is called
KCS
keratoconjunctivitis sicca
KCS is caused by low—
aqueous layer (lacrimal gland not working)
cause desiccation, inflammation of conjunctiva and cornea, pain, ulcers, discharge, melanin pigmentation and vascularization
what causes dry eye
immune mediated damage of lacrimal glands
breed associated: little white dogs
besides for immune mediated, what else can cause dry eye
radiation
infectious disease- feline herpes and distemper
removal or 3rd eye lid, which has one of the lacrimal glands
loss of PARA innervation to the gland: neurogenic KCS
how to measure tear production
schirmer tear test
measures aqueous tear production
cats can have low results
treatment of dry eye
eyedrops
treat underlaying condition
cyclosporine/optimmune or tacrolimus
pilocarpine for neurogenic KCS- stimulates PARA to eyelid
prognosis of KCS
good if you treat- may need to give artifical tears for life
but if you leave untreated, can cause scarring, pigmentation and blindness
parotid duct transposition
move parotid so “spitting into eye”
surgical treatment for KCS
meibomian gland disease- issue with lipid layer of tear
-tears evaporate
-will look like KCS, but SST normal cause aqueous production is normal
will form yellow lipid clumps/accumulations
abnormalities of the goblet cells will cause
loss of mucin layer- tears can’t adhere to eyes (loss of tear film stability)
clinical signs and treatment similar to KCS
can be caused by feline herpes or chronic conjunctivitis
— can cause mucin abnormalities
feline herpes
chronic conjunctivitis
attacks goblet cells in the eyelid- leading to mucin abnormalities and loss of tear film stability
how to measure tear film stability
tear film break up time (TBUT)
place stain, and time for dry spots
normal less then 20 secs
— is tear overflow
epiphora
how to check for drainage of the tears
jones test
add stain and see if it comes out of the nose
