Exam 3 - Keratoconjunctivitis Sicca Flashcards
successful diagnosis & treatment of KCS depend on what 2 things?
- highly magnified view of ocular structures
- appreciation of depth within the eye paying special attention to the quality of the specular reflection
what is the ‘classic’ quantitative KCS?
dog presenting for ‘red eyes with film’
what is the ‘diversion’ KCS?
animal is presented for another issue causing KCS to be overlooked in the other eye!!!
what is the ‘nose’ presentation of KCS?
neurogenic KCS - animal presents for red eye & itching
what is the treatment failure patient of KCS?
refractory & absolute KCS
what is the ‘puzzle’ patient of KCS?
patient that has multifactorial qualitative KCS that presents for squinting & discharge
what ocular lesion is shown in this photo?
pigmentary keratitis
what makes up the 3 layers of the tear film?
- oil/lipid production through meibomian gland
- aqueous middle layer - lacrimal gland (65%) & 3rd eyelid gland (35%)
- mucinous, innermost, conjunctival goblet cells - connects the aqueous layer to the cornea
what is the function of the tear film of the eye?
to nourish, cleanse, & protect the ocular surface
what defines quantitative KCS? how is it diagnosed?
aqueous deficiency!!!!
diagnosed by schirmer tear test < 15 mm/min + clinical signs
T/F: quantitative KCS is the ONLY common cause of bacterial conjunctivitis in dogs
true
what does the schirmer tear test do?
quantifies the aqueous portion of the tear film
what are the guidelines for performing a schirmer tear test?
performed before any other drops or ointments!!!
performed before sedation or anesthesia
performed for 60 SECONDS
what is the normal test result for a schirmer tear test in a dog? what about a cat?
> 15 mm of wetting/min including basal & reflex tearing
unpredictable in cats!!!
what is the most common cause of quantitative KCS?
immune-mediated destruction
what causes neurogenic quantitative KCS?
loss of parasympathetic input to tears
apart from immune-mediated & neurogenic causes of KCS, what are some other causes of this condition?
trauma causing proptosis, congenital alacrima, iatrogenic (removal of the gland of the 3rd eyelid), drugs (sulfonamides & atropine), & infectious (canine distemper virus)
what signalment of animals are commonly affected by KCS?
toy breeds - yorkies, pomeranians
brachycephalic breeds - bulldogs, pugs, shih tzus
cocker spaniels