Conjunctiva and Lacrimal System Flashcards
what are the 3 conditions that cause red eye
keratoconjunctivitis
uvetitis
glaucoma
what dis?
prominent episcleral vessel - normal conjunctival variation
what is shown here
epiphora
Abnormal overproduction of tears. This is a common response to ocular irritation.
what dis?
mucoid discharge
goblet cells - overproduce mucus when inflamed
when you see this what should you be thinking?
Schirmer Tear Test - KCS
when you see mucopurulent discharge, KCS should be your top differential, do an STT
what structure is only seen normally on the bulbar surface of the 3rd eyelid
lymphoid tissue
A dog comes into your clinic and during your ophthalmic exam you see follicles on the palpebral conjunctiva. You determine they are lymphoid follicles. What is your top differential
primary conjunctivitis
what condition is shown here
conjunctival hyperemia
think of superficial vessels, think of superficial disease
conjunctival hyperemia detected or not detected
not detected
episcleral injection - think deep vessels, think of deep or intraocular disease
clinical signs of allergic conjunctivits
young, atopic dogs
blepharospasm (squinting)
epiphora
mucoid discharge
hyperemia
lymphoid follicles
minimum database needed to confirm primary conjunctivits
STT
fluoroscein stain
tonometry
what can be used to treat allergic conjunctivitis
treat underlying cause (allergy/atopy) if present
topical anti-inflammatories: steroid (neo-poly-dex), NSAIDs (diclofenac 0.1%), T-cell inhibitor (optimmune/cyclosporine 0.2%)
functions of tear film
nourish
cleanse
protect
3 layers of tear film
oil/lipid - outermost
aqueous - middle
mucinous - innermost
2 categories of KCS
quantitative
qualitative
causes of KCS
immune mediated - most common
excision of glands of 3rd eyelid
drugs (sulfonamides, atropine)
trauma
neurogenic
infectious (distemper)
quantitative KCS is due to
aqueous deficiency
one of most common eye diseases seen in practice, STT to Dx
common clinical history and signs of quantitative KCS
presents with musopurulent discharge - perscribed topical antibiotics, discharge returns after antibiotics stopped
STT never performed
one of most commonly missed diagnoses
qualitative KCS is due to
lipid or mucin deficiency
what is the only common cause of bacterial conjunctivitis in dogs
quantitative KCS
clinical signs of KCS
most often bilateral
Keratitis - superficial corneal neovascularization, corneal fibrosis, superficial corneal pigmentation, corneal ulceration, WBC infiltrates
conjuntivitis - mucopurulent discharge
KCS treatment
majority of cases: topical cyclosporin BID controls clinical signs
must be given lifelong
how does cyclosporin work to treat KCS
T cell inhibitor, immunomodulator
supresses further destruction of lacrimal tissue
stimulates tear production
anti-inflammatory effect (reduces vessels, clears fibrosis, clears pigment)
T/F KCS can be cured with cyclosporin therapy
False
cyclosporin controls but does not cure
what are the 4 objectives of KCS treatment
replace the tears
stimulate more tears
anti-inflammatory therapy
temporary antibiotic therapy - clears secondary BacT infection while tear film recovers
clinical presentation of neurogenic KCS
unilateral in older dogs
dry nose
what are the most common causes of feline conjunctivitis
feline herpesvirus keratoconjunctivitis
chlamydial conjunctivitis
mycoplasma conjunctivitis
calicivirus conjunctivitis
what is the most common cause of feline keratits/conjunctivitis
Herpes!!
2 clinical forms of feline herpesvirus keratoconjunctivitis
primary - disease (young cats) of acute lysis followed by latency then..
recrudescence with lysis
T/F Feline herpesvirus keratoconjunctivitis is easy to diagnose based on history and clinical signs
False
diagnosis and treatment difficult - lack evidence based medicine with reguards to effective treament
ulcers associated with feline herpesvirus keratoconjunctivitis will be superficial/deep
superifical
FHV has epithelial tropism
what is the typical presentation of primary FHV-1 infection in naive cats/kittens
URT and simultaneous ocular surface infection
kittens displaying blepharospasm, epiphora and mucoid discharge in addition to URT infection; naturally resolves in 2-4 weeks
latent FHV-1 becomes reactivated due to:
environmental stress- most common
spontaneous
corticosteroids
co-infection
specific clinical signs associated with FHV-1
UTR infection - primary
hyperemia
very specific - conjunctival and possible corneal epithelial ulceration (dendritis ulceration is pathognomonic); symblepharon (permanent adhesions b/w conjunctiva and cornea)
key point - If you observe conjunctivitis and evidence of present or historic keratitis, then consider FHV-1 over other cause of feline conjunctivitis
what dis?
symblepharon - adhesion of conjunctiva to cornea
FHV-1 treatment
antivirals - cidofovir (topical), famcliclovir (oral)
supportive - topical erythromycin (mocrolide broad spectrum antibiotic - effective against mycoplasma and chlamydia)
what is the second most common cause of conjunctivitis in cats
chlamydia
what is a specific sign for chlamydial conjunctivitis
chemosis
_Ch_emosis is for _Ch_lamydia
what is chemosis
conjunctival edema
how is chlamydial conjunctivits diagnosed
PCR, history, compatible clinical signs
cytology - intracytopplasmic inclusion bodies
T/F mycoplasma conjunctivits can cause corneal or conjunctival ulceration
False
what is the best way to diagnose mycoplasma conjunctivis
cytology
can find membrane associated bacteria
clinical signs associated with calicivirus conjunctivits
conjunctival ulceration - will not have corneal ulceration
oral/tungue ulceration - pathognomonic when present
T/F calicivirus conjunctivitis can be treated with antivirals and supportive topical therapy
False
don’t respond to antivirals, treat with supportive topical therapy (erythromycin)
