Shell Test 2 Flashcards
What cells secrete the inner mucin layer of tear film?
Goblet cells
What bacteria are part of the normal flora of the conjunctiva?
G+ cocci
What are some signs of conjunctivitis?
Hyperemia
Chemosis
Serous to mucopurulent discharge
Prominent lymphoid follicles
Blepharospasm (pain)
Pruritis
T/F: Mast cell tumors of the conjunctiva are often benign in dogs
True
Is primary conjunctivitis more common in dogs or cats?
Primary = cats
Secondary = dogs
Primary conjunctivitis is usually associated with what infectious agents?
Feline herpesvirus
Chlamydophila
Calici virus
Mycoplasma
What breeds are associated with ligneous or membranous conjunctivitis?
Dobe
Goldens
What breed is associated with plasmoma?
GSD
What breeds are associated with nodular grandulomatous episcleritis?
Collies
Shelties
What is the most common cause of conjunctivitis in cats/kittens?
Herpes
What clinical signs are associated with neonatal herpes?
Ankyloblepharon
Symblepharon
What clinical signs are associated with 8-12 week old kittend with herpes?
Upper respiratory signs
Ocular signs
In mature cats with herpes, where is the virus harbored?
Cranial nerve 5
How would you dx chlamydophila?
Conjunctival swab and PCR
If you see chemosis, whats the infectious agent?
Clamydophila
Tx for chlamydophila?
Topical tetracyclines, chloramphenicol
Systemic doxy if severe
What side effect is associated with tetracyclines in humans?
Bone marrow suppression
Chronic infectious conjunctivitis can lead to other ocular diseases in cats. What are they?
KCS
Epiphora
EØ keratoconjunctivitis
Sequestrum
What is the function of the inner mucin layer of the tear film?
Anchor aqueous tears to corneal epithelium
What is the function of the middle aqueous layer of the tear film?
Supply nutrients to cornea
What percent of the middle aqueous layer of the tear film is made from the lacrimal gland and the nictitans gland?
Lacrimal = 60-70%
Nictitans = 30-40%
What is the function of the outer lipid layer of the tear film?
Stabilize tear film
Slows evaporation
What are the two common tear film abnormalities?
Impaired production
Impaired drainage
What happens as a result of impaired production of the tear film?
KCS
What happens as a result of impaired drainage of the tear film?
Epiphora
What breeds are associated with congenital KCS?
Yorkies
Chihuahuas
What percent of acquired KCS is immune mediates?
80%
Lymphoplasmacytic inflammation of lacrimal and nictitans glands is associated with what condition?
Acquired KCS
What infectious agents can cause nonimmune mediated KCS?
Distemper
Herpes
What drugs can cause acquired KCS?
Sulfa drugs
Etogesic (NSAID)
The loss of what cranial nerves can cause KCS?
5 and 7
What is the normal STT value for dogs?
≥15mm/min
STT value for early KCS
11-14
STT value for moderate KCS?
6-10
STT value for severe KCS?
<5
What is the normal STT value for cats?
10mm/min
T/F: There is no cure for KCS
True
What drugs are used to stimulate tear production?
Topical Cyclosporine A
Topical Tacrolimus
What is it called when normal hairs rub on the cornea?
Trichiasis
What is symblepharism?
Conjunctiva stuck to cornea
If you have a case with KCS that is also neurologic, what drug would you use?
Pilocarpine
What congenital disorders can cause epiphora?
Atresia
Imperforate punctum (usually lower)
Tx for epiphora?
Cannulate punctum and flush
What eye abnormality is associated with immune mediated thrombocytopenia?
Hyphema
What eye abnormality is associated with diabetes mellitus?
Cataracts
What eye abnormality is associated with hypertension?
Retinal detachment
What piece of equipment is used for direct funduscopy exam?
Opthalmoscope
What pieve of equipment is used for indirect funduscopy?
Condensing lens
Cobalt light source
What is the doctor word for bright light?
Photopic
What is the doctor word for dim light?
Scotopic
What cranial nerves are tested with the menace response?
2 and 7
What cranial nerves are tested with the dazzle reflex?
2 and 7
What cranial nerves are tested with PLR?
2 and 3
Also tests retina, iris sphincter, and mid-brain
What cranial nerves are tested with the palpebral blink reflex?
5 and 7
What cranial nerves are tested with the vestibulo-ocular reflex?
3, 4, 6, and 8
What is the order of diagnostic testing for eye disorders?
STT
Fluorescein stain
Tonometry
What is the normal IOP in dogs and cats?
10-25
Which type of tonometers require a topical anesthetic?
Indentation (Schiotz)
Applantation (Tonopen, Accupen)
Which type of tonometer does not require a topical anesthetic?
Rebound (Tono Vet)
What would cause a low IOP?
Uveitis
Decreased aqueous production d/t inflammation
What would cause a high IOP?
Restraint
Glaucoma
Jug occlusion
Pushing on globe
Why do you want to take the IOP before causing mydriasis?
Dont want to dilate the pupil if there is glaucoma
When is tropicamide contraindicated?
Glaucoma
Some lens luxations
How long does tropicamide last?
6-8 hours
What are contraindications of steroids?
Corneal ulcer
Abscess
Is buphthalmia associated with acute or chronic glaucoma?
Chronic
What causes Haab’s striae? (stretch marks)
Break in Descemet’s membrane
How does PLR differ from acute to chronic glaucoma?
Acute = poor to abscent
Chronic = abscent
What breed is predisposed to open angle glaucoma?
Beagles
What is the most common cause of glaucoma in cats?
Uveitis
What diseases in cats can cause uveitis?
FIP
Toxo
What drugs can be used to decrease aqueous production?
IV mannitol
Carbonic anhydrase inhibitor (amides)
What drugs can be used ti increase outflow?
Travoprost - causes miosis
Timolol, betaxolol - decrease aqueous production and increase outflow
Pilocarpine, demecarium bromide - induce miosis
What drugs do you use on the nonaffected eye in acute glaucoma cases?
Timolol
Dorzolamide
Demercarium bromide
What drug is used for pharmacologic ablation of the ciliary body?
Gentamicin - vitreal injection
What is the path of tear drainage?
Lacrimal puncta -> canaliculi -> sac -> NL duct -> nasal punctum
What layer of the cornea is important in normal corneal epithleial cell turnover and wound healing?
Tear film
How many days does it take for complete cell turnover of the epithelial layer?
7
Is the epithelial layer of the cornea hydrophillic or hydrophobic?
Hydrophobic
Is the stroma layer of the cornea hydrophilic or hydrophobic?
Hydrophilic
How long does it take for complete cell turnover of the stroma?
2 years
What cells are responsible for the removal of water from the cornea? What happens if these cells dont remove enough water?
Endothelial cells
The cornea becomes cloudy
T/F: Descemet’s membrane stains with fluorescein
False
What is a descemetocele?
Corneal ulcer that extends to Descemet’s membrane
What layer of the cornea has limited to no mitotic activity?
Endothelium
What cranial nerve supplies the cornea?
Trigeminal
What is aqueous flare?
Particles in anterior chamber
What bacteria can cause melting ulcers?
Pseudomonas
Staph
Strep
E. coli
When would you do surgery for a corneal ulcer?
If its deep or may perforate
What type of ulcers have a crater-like lesion?
Descemetocele
Melting ulcer
T/F: The iris can prolapse because of a corneal laceration
True
T/F: Bullous keratopathy does not always ulcerate
True
What is the growth rate of corneal blood vessels?
1mm/day
How do steroids prevent ulcers from healing?
Potentiate infection
Slow epithelialization
Slow vascularization
Classify the ulcer: Uncomplicated ulcer that involves variable degrees of loss of the corneal epithelium and basement membrane. Does not extend into stroma
Acute Superficial
Tx for acute superficial corneal ulceration?
BNP (not in cats)
Antivirals (cats w/ herpes)
Atropine to prevent synechia
Pain meds
How long does it take for most acute superficial corneal ulcers to heal?
2-6 days
What happens to the layers of the cornea with nonhealing superficial ulcers?
The epithelium does not stick to the stroma
Tx for nonhealing superficial ulcers?
Tx as for normal superficial ulcer
Debride ulcer
Grid or punctate keratotomy if no response to debridement
Superficial keratectomy if all else fails
Why is sufercicial keratectomy not recommended in cats?
May predispose to formation of a corneal sequestrum
What breeds more commonly get deep ulcers?
Brachycephalics
How do melting ulcers form?
Exogenous proteases released by bacteria (usually G-) cause collagenolysis of stroma
When treating a deep ulcer, if the cornea is perforated or looks close to perforation, should you use ointments or drops?
Drops
Avoid ointments (petroleum product)
How often should abx drops be applied to deep ulcers?
1-2 hours for 24 hours
T/F: Topical NSAIDs are best for deep ulcers
False
Systemic are best
Avoid topical
What breeds are predisposed to superficial punctate keratitis?
Dachshunds
Shelties
Pannus breeds
What is the only type of ulcer that it is acceptable to use steroids?
Superficial punctate keratitis
What is the most likely cause of superficial punctate keratitis?
Mucin deficiency
Tx for bullous keratopathy?
Topical 5% sodium chloride ointment
Thermokeratoplasty (surgery)
What breeds get pannus?
GSD
Greyhounds
What will exacerbate pannus?
UV light
High altitudes
Progressive, bilateral, inflammatory nonulcerative potentially blinding condition = ?
Pannus
Tx for pannus?
Dexamethasone
Cyclosporine
Tacrolimus
T/F: Pannus is curable
False
It is controllable but not curable
Do dogs or cats have a well-myelinated optic nerve?
Dogs
What causes hyperreflectivity of the retina?
Thinning of retinal layers
Inflammation, degeneration, toxins, ischemia
What causes hyporeflectivity of the retina?
Fluid or cell infiltrate between retina and tapetum
Hypertension, inflammation, infection, neoplasia, polycythemia
Night blindness is an early sign of what?
Progressive retinal atrophy
What are the exam findings of retinal or optic nerve disorders?
Absent menace
Usually dilated pupils with poor or absent PLRs if lesion is located in fundus or optic nerve or optic chiasm
What does an ERG test and what can it distinguish?
Tests retinal function
Can distinguish retinal blindness from optic nerve or intracranial blindness
What is a good diagnostic test for SARDS?
ERG
What is the condition with a hole in the retina?
Coloboma
Coloboma predisposes animals to what other eye conditions?
Retinal detachment
Hemorrhage
What retinal abnormality can be seen in an animal with congenital retinal dysplasia?
Retinal folds - look like dark gray lines
Signalment for SARDs?
Dogs
5-10 years old
Often obese
Exam findings of SARDs?
Acute onset blindness
Mydriasis
Slow or no PLRs
Positive but slow dazzle
What do you do when you see retinal hemorrhage?
Take blood pressure
Tx for retinal detachment?
Laser retinal reattachment
Tx underlying dz
Enucleation if chronic (hyphema, glaucoma) and painful
What are the causes of retinal degeneration in cats and dogs?
Cats = Baytril >5mg/kg/day, taurine deficiency (oval hyperreflectivity lateral to optic disc)
Dogs = Ivermectin (improve 2-10 days)
Ethylene glycol = retinal detachment
What breed gets uveodermatologic syndrome?
Akitas
What is the difference between congenital optic nerve hypoplasia and micropapilla?
Hypoplasia = blind
Micropapilla = visual
What are the 3 acquired lens conditions?
Nuclear sclerosis
Cataracts
Luxations
T/F: Nuclear sclerosis is not a disease?
True
T/F: Nuclear sclerosis affects vision
False
T/F: You can see the fundus with nuclear sclerosis
True
At about what age do dogs develop nuclear sclerosis? Cats?
7 years
Later than dogs
What is the difference between nuclear sclerosis and advanced nuclear sclerosis?
With advanced:
Fundus view is obscured
Vision is impaired
Found in dogs >14 years old (older in cats)
What is the most common cause of cataracts?
Developmental
What metabolic diseases are associated with cataracts?
DM
Cushing’s
What % of dogs with diabeetush develop cataracts within one year of diagnosis?
75-80%
Special type of cataract that can cause uveitis and possibly glaucoma?
Intumescent cataract
Why dont cats get cataracts associated with DM?
Dont use the sorbitol pathway
T/F: PLR presence does not necessarily mean absence of retinal disease
True
In regards to lens diseases, which ones do you refer and which do you not?
Refer - Lens luxations/subluxations, cataracts with uveitis
Keep - Cataracts w/o uveitis
What breeds are associated with liquefaction of the vitreous?
Italian greyhounds
Whippets
What causes asteroid hyalosis?
Calcium and phospholipids condense within vitreal gel
What structure of the eye makes the aqueous humor?
Ciliary body
What is a coloboma?
Holes or defects in uveal tissue (iris or choroid)
What condition can be confused with nuclear sclerosis?
Iris atrophy
Which type of iris atrophy has scalloped margins?
Senile iris atrophy
Which type of iris atrophy has holes in the iris?
Stromal iris atrophy (essential iris atrophy)
In what breed do you need to refer uveal cysts and why?
Goldens
Associated with uveitis
How would you differentiate neoplasia from uveal cysts?
Use a slit lamp
You can see thougha cyst but not a tumor
What is the most common intraocular tumor?
Uveal melanoma
Why should you enucleate blind traumatized cat eyes?
Prevent the development of ocular sarcoma
What is the most common metastatic tumor in the eye?
Lymphoma
What is the hallmark of uveitis?
Aqueous flare
What are the specific clinical signs associated with uveitis?
Aqueous flare
Miosis
Hypopyon or hyphema
What do doses >5mg/kg/d of baytril in cats cause?
Dilated pupils
Blindness
Retinal degeneration