Cognition & Senses 2: Lacrimal/Nasolacrimal Flashcards
what 2 glands PRODUCE TEARS?
TEARS are made up of what 2 components?
- ORBITAL LACRIMAL GLAND
- GLAND of the THIRD EYELID
TEARS are…
1. AQUEOUS
2. LIPID from MEIBOMIAN GLANDS
why is LIPID in tears?
to PREVENT IT FROM EVAPORATING OFF OF THE SURFACE OF THE EYE
what is the FUNCTION of the PRE-CORNEAL TEAR FILM?
this is VITAL for ___ ACTIVITY
to give NUTRITION to the CORNEA (clear portion of eye) because it is AVASCULAR and WOULD NOT HAVE NUTRITION OTHERWISE
this is VITAL for OPTICAL ACTIVITY
what is one potential consequence of LOSING THE AQUEOUS portion of TEARS?
more at risk of INFECTION and can cause BACTERIAL KERATITIS
KERATOCONJUNCTIVITIS SICCA (KCS)
“aka?”
= definition?
commonality in dogs?
important HISTORY finding that can indicate it?
EARLY vs. LATE dz presentation?
aka “DRY EYE DZ”
= AQUEOUS TEAR deficiency causing INFLAMMATION of CONJUNCTIVA & CORNEA
commonality in dogs? = MOST COMMON OCULAR DZ IN DOGS
in HISTORY = can see MUCOPURULENT DISCHARGE from INFLAMMATION due to RECURRENT INFECTION from LOSS OF ANTIMICROBIAL AQUEOUS
EARLY dz = CONJUNCTIVITIS, REDNESS & DISCHARGE
LATE dz = CORNEAL CHANGES & DRYNESS
ID DZ & why
KERATOCONJUNCTIVITIS SICCA
the eye is RED because CONJUNCTIVA COVERS THE WHOLE THING and IS INFLAMED
PRIMARY cause of KCS?
SECONDARY cause of KCS?
PRIMARY = usually BREED-ASSOCIATED; usually TOY BREEDS such as SHIH TZUS
SECONDARY = IMMUNE-MEDIATED, often SPECIFIC to LACRIMAL GLAND
what LARGE BREED DOG can get KCS & why?
GERMAN SHEPHERD DOGS because they are LIKELY TO HAVE IMMUNE DYSFUNCTION
FIVE LESS COMMON causes of KCS?
- NEUROGENIC from LOSS of PARASYMPATHETIC INNERVATION to LACRIMAL GLAND
- GLAND of THIRD EYELID SURGERY (cherry eye)
- CONGENITAL
- DRUG-INDUCED (SULFONAMIDES, TOPICAL ATROPINE)
- INFECTIOUS DZ (CANINE DISTEMPER)
if a dog comes in with CONJUNCTIVITIS & REDUCED TEAR PRODUCTION, what DZ do we suspect?
CANINE DISTEMPER
5 clinical signs of KCS?
2 clinical signs of CHRONIC KCS?
5 clinical signs?
1. OCULAR PAIN
2. DRY & LUSTERLESS CORNEA
3. THICK MUCOID DISCHARGE
4. REDNESS
5. PHOTOPHOBIA
2 clinical signs of CHRONIC KCS?
1. CORNEAL PIGMENTATION
2. REDUCED VISION
2 reasons we see REDNESS in the eye in KCS?
- CONJUNCTIVAL HYPEREMIA
- CORNEAL VASCULARIZATION
DIAGNOSIS of KCS…
via WHAT test/parameter?
what 2 things does it measure?
via SCHIRMER TEAR TEST
if tear production BELOW 15 mmHg, then KCS!
2 things it measures… (AQUEOUS)
1. TEAR PRODUCTION from LACRIMAL GLAND
2. TEAR PRODUCTION from THIRD EYELID GLAND
TRUE/FALSE
IMMUNE-MEDIATED KCS is UNCOMMON IN CATS but COMMON IN DOGS
FALSE
CATS DO NOT GET IMMUNE-MEDIATED KCS
TREATMENT for IMMUNE-MEDIATED KCS…
we should INITIALLY treat the…
3 things we can do for tx? & give examples for second
we should INITIALLY treat the UNDERLYING CAUSE
3 tx?
1. REPLACE tears with ARTIFICIAL TEARS (many brands)
- STIMULATE PRODUCTION of tears via CALCINEURIN INHIBITORS for 3-4 WEEKS
–> CYCLOSPORINE/TACROLIMUS
–> MOST COMMONLY USE OPTIMMUNE (contains cyclosporine) which is VERY EFFECTIVE - address any INFLAMMATION/INFECTION
PILOCARPINE…
WHEN is this given? (3)
how does it work?
given when..
1. DO NOT RESPOND TO OPTIMMUNE
2. DO NOT RESPOND TO HIGH DOSE CYCLOSPORINE
3. DO NOT RESPOND TO TACROLIMUS
how does it work? = DIRECTLY STIMULATE LACRIMAL GLAND to see if we can REPLACE TEARS
PROGNOSIS for KCS…
generally?
if left UNTREATED… (3)
once the patient is STABLE (____ ____), what should we do for tx? what is the frequency?
is GENERALLY GOOD when TREATED WITH CALCINEURIN INHIBITORS
if left UNTREATED…
1. SCARRING
2. PIGMENTATION
3. BLINDNESS
once patient is STABLE (making tears), usually can DISCONTINUE ALL MEDS except LIFELONG CYCLOSPORINE BID
if patients with KCS DO NOT RESPOND TO ANY MEDICAL TREATMENT but owners DO NOT WANT ENUCLEATION, what TREATMENT should be done? (3 words)
= how is it done?
this is a ___ PROCEDURE because…
PAROTID DUCT TRANSPOSITION
= MOVE PAROTID SALIVARY GLAND’S DUCT and TURN IT TOWARDS EYE, then SUTURE IT to the CONJUNCTIVAL FORNIX to allow for SALIVA TO ENTER EYE and LUBRICATE IT
this is a SALVAGE PROCEDURE because IT IS NOT IDEAL, and saliva can either cause TOO MUCH TEARING or PRECIPITATE FORMATION IN EYE
QUALITATIVE tear film disorders…
= definition?
two clinical signs?
what confounding finding might we find on diagnostics? what can this tell us?
= when the LIPID from MEIBOMIAN GLANDS & GOBLET CELLS in the CONJUNCTIVA is ABNORMAL & DYSFUNCTIONAL causing LOSS OF TEAR FILM STABILITY
clinical signs?
1. DESSICATION
2. INFLAMMATION of CONJUNCTIVA & CORNEA
diagnostics show NORMAL SCHIRMER TEAR TEST even though SIGNS RESEMBLE KCS; this can ACTUALLY BE DIAGNOSTIC FOR QUALITATIVE TEAR FILM DISORDER
2 DIAGNOSTICS & what we EXPECT for QUALITATIVE TEAR FILM disorders?
also describe what they are/what they’re looking for
- TEAR FILM BREAK UP TIME = put FLUORESCIN dye on eye and SEE HOW LONG IT TAKES FOR SURFACE TENSION to cause CLUMPS
–> if it TAKES TOO LONG then ABNORMAL LIPID PORTION or GOBLET CELL PRODUCTION - CONJUNCTIVAL BIOPSY to look for ABNORMAL GOBLET CELLS
it IS POSSIBLE to have BOTH QUANTITATIVE & QUALITATIVE tear film disorders in WHAT species?
CATS
difference between MEIBOMIANITIS vs. CHALAZION?
CHALAZION = ONE INFLAMED MEIBOMIAN GLAND
MEIBOMIANITIS = MULTIPLE INFLAMED MEIBOMIAN GLANDS
ID CLINICAL SIGN
MEIBOMIANITIS
what is the TREATMENT for MEIBOMIANITIS? (2)
why might we use CYCLOSPORINE?
- treat UNDERLYING CAUSE, often ATOPY/SKIN DISEASE
- OCULAR LUBRICANTS
CYCLOSPORINE used for ANTI-INFLAMMATION, but NOT CONCERNED WITH MAKING MORE TEARS
what is the MOST COMMON cause of CHRONIC CONJUNCTIVITIS in the CAT? why?
what does this then CAUSE in the eye? (2)
treatment? (2)
FELINE HERPESVIRUS
–> why? because it CAUSES CONJUNCTIVAL GOBLET CELLS DYSFUNCTION
in the eye, causes…
1. QUALITATIVE TEAR FILM DEFICIENCY
2. DRYNESS of CORNEA
treatment?
1. treat UNDERLYING DZ (herpesvirus)
2. TOPICAL EYE LUBRICANT
why can it be HARD to read results of a SCHIRMER TEAR TEST on a CAT?
instead, what CAN we use this test for in cats?
cats are often STRESSED at the vet, so HIGH SYMPATHETIC TONE –> FALSE LOW READING ON STT
INSTEAD, we should look to see IF TEAR PRODUCTION VARIES BETWEEN EYES
what are the 2 things we should DISTINGUISH between in TEAR DRAINAGE ABNORMALITIES?
- EPIPHORA (tear overflow bc tears cannot drain)
- EXCESS LACRIMATION (tearing too much)
EXCESS LACRIMATION…
is usually caused by ___ ____ ____, which includes these possibilities… (4)
unilateral vs. bilateral?
is usually caused by OCULAR SURFACE IRRITATION, which includes these possibilities…
1. TRICHIASIS
2. DISTICHIA
3. ENTROPION
4. CORNEAL ULCER
can be UNILATERAL or BILATERAL
EPIPHORA…
= definition
unilateral vs. bilateral?
suggests ____ ____ ____, which can be caused by WHAT 4 THINGS?
what results do we expect on STT?
= TEAR OVERFLOW
usually UNILATERAL
suggested NASOLACRIMAL DUCT OBSTRUCTION, which can be caused by…
1. CONGENITAL issues
2. FOREIGN BODIES (grass awns)
3. TRAUMA/laceration of duct
4. NEOPLASIA/tumors pressing on duct
on STT, expect NORMAL
JONE’S TEST…
= what does it test for?
steps? (3)
= tests for EPIPHORA caused by NASOLACRIMAL DUCT OBSTRUCTION
steps?
1. put FLUORESCIN in BOTH EYES
2. put SALINE IN BOTH EYES
3. look for DYE COMING OUT THROUGH NOSE
what TEST is this? what is it TESTING FOR?
TEST = JONE’S TEST
tests for NASOLACRIMAL DUCT OBSTRUCTION
if we see DYE IN THE MOUTH on a JONE’S TEST, what does this tell you?
what test can be MORE SPECIFIC? what do we look for?
THIS CAN STILL BE NORMAL as sometimes tear ducts can open into mouth!
the NASOLACRIMAL DUCT FLUSH can be MORE SPECIFIC to see if we INJECT FLUID INTO TEAR DUCT if it will COME OUT THROUGH NOSE
ID DIAGNOSTIC & WHEN we do it
NASOLACRIMAL DUCT FLUSH
we do this when JONE’S TEST shows DYE COMING THROUGH MOUTH or if we suspect NEGATIVE RESULT from NASOLACRIMAL DUCT SPASM; we can CONFIRM if there’s an OBSTRUCTION OR NOT
PHYSIOLOGIC EPIPHORA
= what is it?
what TYPE of dogs are likely to have this?
what 2 diagnostics can we do? which is most definitive/what results do we expect?
= dogs have TRICHIASIS due to a CARUNCLE in CORNER OF EYE allows for WICKING OF TEARS OVER THE LID and BLOCKS NASOLACRIMAL DUCT
likely in WHITE FLUFFY DOGS
2 diagnostics…
1. JONES TEST can or cannot be negative, UNSURE
2. NASOLACRIMAL DUCT FLUSH will show FLUID OUT THROUGH NOSE
what is the NASAL PUNCTA?
TEAR DUCT
what BREED of dog is PRONE TO PUNCTAL (tear duct) ABNORMALITIES?
COCKER SPANIEL
what DISEASE in CATS can cause STENOSIS of the NASOLACRIMAL DUCT SYSTEM?
why?
how do they usually present?
FELINE HERPESVIRUS-1
because CHRONIC INFLAMMATION
presents as an OTHERWISE HEALTHY CAT with CHRONIC UNILATERAL TEARING
DACRYOPS…
= definition?
etiology?
commonality?
= CYST of the LACRIMAL GLAND or ANYWHERE ALONG NASOLACRIMAL DUCT SYSTEM that allows TEARS TO ACCUMULATE
etiology = CONGENITAL
commonality? = UNCOMMON
ID LESION & DEFINE
DACRYOPS (lacrimal gland or somewhere along nasolacrimal duct has a CYST that causes TEARS TO ACCUMULATE)
