What is the importance of the spastic component of entropion?
eyelid rolls in - irritates cornea - rolls in more - vicious cycle
Entropion in cats is often cicatricial. What does this mean and why?
cicatricial means there is scarring/fibrosis; it is often secondary to chronic spastic entropion, conjunctivitis, trauma, or irritation
What is difference in entropion etiology in young v. older cats?
- young: 2ndary to conjunctivitis (or corneal ulceration)
- older: lid laxity, enophthalmos
What is important thing to remember before you try to sx correct entropion?
remove spastic component (proparicaine) or you will overcorrect (then many tx options exist)
most common eyelid tumors: dog? cat? large animals?
- dog: benign adenoma
- cat: invasive carcinoma (SCC)
- large animals:carcinomas common (SCC and sarcoid in horse)
when performing sx to remove eyelid tumors, what must you always remember to do after removing tumor?
submit for histopath
What are clinical implications of 3rd eyelid prolapse? How is it treated?
- can cause KCS, chronic irritation, cosmetic concern
- sx replace, morgan pocket technique
- **never cut it out** (unless neoplastic)
what are some causes of protruding (not prolapsed) 3rd eyelid?
- decr. orbital contents (dehydration, pthisis bulbi)
- incr. orbital contents (hematoma, neoplasia)
- breed related enopthlasmos
- horner's (symp. denervation)
- ocular pain - retractor bulbi m. contraction
How is everted 3rd eyelid treated?
- the bent cartilage is removed surgically
- **don't remove the gland**
what is most common tumor of 3rd eyelid in domestic animals?
from superficial to deep, what are the layers of fluid of nasolacrimal system?
lipid - aqueous - mucous
what produces the aqueous layer? what drains it?
- orbital lacrimal gland, 3rd eyelid gland, accessory glands
- drained by puncta - canaliculi - down nasolacrimal duct out nose at nasal punctum
which layer is nasolacrimal system is decreased with KCS? which layer is in excess? What are results of Schirmer Tear Test in KCS patient?
- decreased aqueous
- increased mucous
- 5-10mm/60s (<5 severe)
is KCS more common in dogs or cat? what is #1 cause?
- dogs more common
- #1 immune mediated
how do you treat KCS?
- tear stimulation and immunomodulation with topical tacrolimus/cyclosporine + frequent tear substitutes
- + mucinolytics (acetylcysteine) + NSAIDS
what are important point to teach clients about managing pt with KCS?
- saline flush first before apply meds to eye; tilt head up
- wait 5 minutes between drops; warm ointment if cold
What is Jones test in relation to evaluation of epiphora?
fluorescein stain in eye - see if stain drains out to nasal punctum to make sure epiphora is not due to blocked nasolacrimal ducts
what are some signs of conjunctival disease?
- chemosis (swollen conjunctiva)
- epiphora/mucopurulent exudate
- tissue proliferation (lymphoid follicle, mass)
- emphysema (horse via sinus trauma; tracheostomy)
- hemorrhage (from vasculitis, strangulation, sepsis, coagulation problem)
what is infectious causes of chemosis in cats? how do you treat it?
- chlamydophila felis (also mycoplasma)
- oral doxy/azithromycin; topical tetracycline
hyperemia is either conjunctival or scleral. which is deep v. superficial? tortuous v. strait vessels? which branches more? Which will blanch w/epinephrine?
- conj: superficial, tortuous, branching, blanches
- scleral: deep, strait, less branching, slowly blances
what species are more likely to have conjunctivitis of infectious etiology vs. noninfectious?
- infectious: cat, ruminant
- non: dog, horse
what are some noninfectious causes of conjunctivitis in the dog? (can get 2ndary bact. infections)
KCS, pannus, foreign body, entropion
what are treatment goals of conjunctivitis?
diagnose - cleanse - moisture - control infection - reduce inflammation
what topical eye medication should be avoided in cats with conjunctivitis? what are the side effects and why other reason are these meds not indicated?
- neomycin, TAB, poly-bac --> not effective for common causes of feline conjunctivitis (Chamydofelis, viruses)
- (signs of rxn: chemosis, anaphylaxis, epiphora)
what are common clinical signs in cats with herpes? how to treat?
- sneezing and nasal discharge; dendritic corneal lesions (hyperemia and keratitis)
- oral lysine, famciclovir (caution antivirals can be toxic)
What ocular signs does calicivirus have in cat? what systemic signs?
- usually no keratitis, minimal conjunctivitis, some discharge
- oral ulcers, ptyalism, nasal discharge, sneezing
what are 3 major signs associated with KCS in dogs? what diagnostic test do you do?
- keratitis, conjunctivitis, mucopurulent discharge
- Schirmer tear test
what neoplasia of cats often presents with ocular signs?
from inside to out, what are the 4 layers of cornea? which layer is hydrophilic?
- endothelium - descement's membrane - stroma - epithelium
- stoma = hydrophilic
what are causes of ciliary flush (hedges)?
deep keratitis, scleritis, glaucoma, uveitis
what does a "blue" cornea indicate? what could be the cause if "blue" is diffuse also painful, abnormal IOP, and flare present with negative fluorescein stain?
- uveitis, glaucoma, lens luxation
what is cause of diffuse corneal edema ("blue eye") that is non-painful and stains negative, no flare, and normal IOP?
what is "whispy/gray and white" cornea? is it painful? stain positive or negative? how to treat?
- scar tissue
- non painful
- usu. does not need treatment
what is sparkly white cornea?
- lipid/mineral deposits (cholesterol/Ca)
- lipids can be degeneration/dystrophy/infiltrates
what is black/brown cornea? how did it get there?
- -carried by vessels (irritation/poor protection/immune)
- -impregnated (ruptured/iris shows),
- -sequestrated (cat/brachycephalics)
what is greasy/tan cornea? which layer is affected?
- keratic precipitates on ENDOTHELIUM
What is yellow/green cornea? what almost always coexists?
- cellular infiltrates (stromal inflammatory cells)
what are some feline diseases that cause keratitis and conjunctivitis?
- corneal sequestrum
- eosinophilic keratitis
- herpes virus
- nodular granulomatous episclerokeratoconjunctivits (NGE)
what is chronic superficial keratitis? treatment?
- pannus (immune mediated)
- topical steroid/cyclosporines (can not cure, just control)
what is a choristoma? treatment?
- dermoid (normal tissue in abnormal location)
what are some true ophtho emergencies?
- glaucoma +/- lens luxation
- eyelid laceration
What is number 1 cause of keratitis in cat v. dog?
- cat: infectious (herpes)
- dog: noninfectious (KCS)
how do neuro defects result in keratitis?
problems w/CrN 5/7 --> inadequate sensory/blink protection
describe the fluorescein stain and what layers are effected with superficial corneal ulcer.
- distinct borders
- epithelial layer lost so stain sticks to stroma
what is SCCED and what layers are effected? how do you distinguish fluorescein stain of SCCED from superficial ulcer?
- spontaneous chronic corneal epithelial defect
- epithelial loss only (stroma intact)
- indistinct stain borders/halo v. sharp borders w/superficial
what is tx plan for both superficial ulcers and SCCED? What additionally do you need to do to tx SCCED?
- prevent 2ndary bacterial infection (TAB)
- tx reflex uveitis (atropine/NSAIDS)
- e-collar + reck in 7d
- SCCED also debride + grid/burr keratotomy to promote healing in dogs only
Deep ulcers include melting ulcer, desmetocele and deep stromal ulcer. Describe the layers effected and staining pattern for each.
- melting: variable stroma loss = stains throughout
- desmetocele: complete stroma loss = stain walls only (flood is negative)
- deep stromal: epith + stoma loss = stains wall + floor
what changes to the cornea are indicative of perforation? what is seidel test for perforation?
- pigment and hemorrhage in corneal stroma
- fluorescein stain then look for pale rivulets of stain = aqueous egress through perforation
what can you give to prevent or treat melting ulcers medically? what are indications an ulcer required surgery (grafts, transposition or tissue glue/cyanocrylate)?
- serum or potassium EDTA
- -ulcer greater than 1/2 stroma depth, rapidly progressing/melting, no neovascular response, actively leaking/perforated
should you use ointments or solutions in an eye with/about to perforate?
what does atropine do when applied topically to the eye?
- cycloplegia (stops ciliary m. spasm assoc. w/uveitis)
- stabilizes blood-eye barrier to decr. vascular permeability
what is a corneal facet?
healed ulcer so intact epithelium but stain pools there --> thin but healthy
what are 3 reasons ulcers fail to heal within 7-10days?
- original cause still present
- became infected
- its an indolent ulcer
- **if it's not healing w/in a wk, change diagnosis NOT the antibiotic**