Card Set Information
Animal Diseases Three
What area the three main categories of ophthalmic problems?
structures of the globe
retinal and neural pathway
What are the accessory structures?
What is conjunctivitis?
inflammation of the conjunctiva
Is conjunctivitis a primary disease?
Is the conjunctiva highly vascular?
What is hyerpemia?
redness of the eyes
What is chemosis?
swelling of the eyes
What are the different causes of conjunctivitis in cats?
Feline herpes virus 1
accomplany other ocular disease
What are the different causes of conjunctivitis in dogs?
canine distemper virus
immune mediated, atopy, pannus
accompany other ocular disease
What are the clinical signs of conjunctivitis?
ocular discharge - serous or mucopurulent
swelling of conjunctival lymph follicals (cobblestone)
What is epiphora?
overflow of tears
How do you diagnose conjuncitivis?
complete physical exam
thorough visual exam of conjunctiva
conjunctival scraping, cytology, culture and sensitivity
Schirmer tear test
check lid for entropion, ectropion, trichiasis, distichiasis, ectopic cilia, foreign body
check behind the third eyelid
cornea - keratitis, ulcer
What is entropion?
eyelids rolled inward toward cornea
What is ectropion?
eyelids rolled outwards away from cornea
What is trichiasis?
normal hairs that touch the cornea or conjunctiva
What is distichiasis?
hairs from the meibomian glands on the inner lid surface
What is ectopic cilia?
hair growing from an abnormal place
How do we treat conjuncitivits?
treat underlying systemic disease if any
treat primary ocular disease
topical antibiotic ointments
What are some different topical antibiotic ointments we can use?
may contain corticsone for follicular or atopic conjunctivitis
nonsteroidals - Ketorolac, Lodoxamide
How do we treat viral conjunctivitis in cats?
adenine arabinoside (Vir-A)
lysine PO - arginine inhibitor - slows replication of herpes virus
keep eyes clear of discharge
What kind of client education do we need to provide about conjuncitivis?
do not allow your dog to ride with his head out the car window
remove excess hair that may trap discharge
vaccinate kittens for upper respiratory disease
do not touch ointment tip to the eye
ointments provide longer contact time than solutions
need to be applied frequently to be effective
demonstrate proper technique of applying medications
What is epiphora?
overflow of tears
What causes epiphora?
overproduction o ftears due to ocular pain or ocular irritation
faulty drainage - lacrimal system
What causes faulty drainage in the eye?
blockage of ducts by swelling or inflammation
imperforate puncta, trauma
Why do brachycephalics have a problem with epiphora?
large globes, shallow orbits
little room for accumulation of tears - tears spill out on face
accumulation in hair or face folds may wick the tears onto face
What are the clinical signs of epiphora?
watering of the eye, acute or chronic
wet facial hair in medial canthus
secondary bacterial infection of periocular skin
discoloration of periocular skin and hair
How do we diagnose epiphora?
eye exam - look for causes of pain
fluorescein stain - look for stain to exit through the nares
How do we treat epiphora?
treat primary cause of pain or irritation
flush nasolacrimal ducts to remove obstructions
surgically open imperforate puncta
surgical correction of lids
keep facial hair trimmed away from eyes to prevent contact with cornea
What is keratoconjunctivitis sicca (KCS)?
deficiency of aqueous tear production
What are the purpose of tears?
aid in healing
What are the three tear layers?
What is the the aqueous layer?
produced by lacrimal gland
bulk of tear volume
immunoglobulins, enzymes, glucose, proteins, ions, salt
What is the lipid layer?
secreted by the meibomian glands
aids in tear distribution
waxy - helps hold watery tears in the orbit
What is the mucus layer?
secreted by conjunctival goblet cells
aids in tear adherence to the corneal surface
How many lacrimal glands do dogs and cats have? What are they?
What does the lateral orbit lacrimal gland do?
produces 70% of tear volume
What does the nictitans gland do?
produces 30% of tear volume
What does the loss of both lacrimal glands produce?
What are the clinical signs of KCS?
recurrent conjunctivitis, corneal ulcers, and keratitis
cornea and conjunctiva appear dry, dull, and irregular
tenacious mucoid ocular discharge (mucopurulent)
discharge sticks to cornea and lid margins, conjunctival sacs
usually bilateral, may be unilateral
How do we diagnose KCS?
schirmer tear test (STT)
base diagnosis on clinical signs and STT together
What is the Schirmer Tear Test?
commercially available test strips
use same brand each time animal is rechecked
remove excess corneal discharge
How do you do the Schirmer Tear Test?
bend test strip at notch
place bent area into the conjunctival sac
close lids and leave in for one minute
measure tears on the strips in mm
Should we use other medications and eye drops before doing the STT?
How do we treat KCS?
topical antibiotic ointment
parotid duct transposition
How do we do tear stimulation?
cyclosporines in corn oil - can get compounded at most pharmacies
oral pilocarpine in food (salivation, vomiting, diarrhea, and bradycardia)
What kind of client education do we need to provide for KCS?
prognosis for resolution is guarded
usually life long treatment
15 - 20% may go into remission
failure to treat will result in blindness
What is entropion?
eyelids roll in towards cornea
Which animal is entropion the most common in?
common in dogs
less common in cats
What are the different types of entropion?
How does acquired non-spastic entropion occur?
usually due to trauma or surgery
scarring of the lid with contraction
lid turns inward towards globe
How does acquired spastic entropion occur?
usually secondary to painful corneal lesions or conjunctival inflammaion
What are the clinical signs of entropion?
range from absent to severe
hair rubbing on cornea
corneal pigmentation, vasculatization, ulceration
chemosis, pain, photophobia
rolling in of eyelid margins
How do we treat entropioin?
: treat causes of spastic entropion, treat corneal ulceration
surgical: temporary tacking, permanent
What kind of client education do we need to provide about entropion?
avoid purchasing breeds known to have this defect
carefully examine puppies
dogs do not usually outgrow this condition
What is ectropion?
eyelid margins rolled away from eye
Which eyelid does ectropion affect the most?
What are the clinical signs of ectropion?
may be asymptomatic
vary with extent of the entropion
debris accumulation (purulent)
keratitis if severe (exposure)
How do we treat ectropion?
medical: clean accumulated discharge daily, topical lubricant
surgical: wedge resection lateral canthus, technique to shorten lower lid
What is another name for a prolapsed third eyelid?
What is the third eyelid and what is its purpose?
is a protective structure
assists in spreading tears
covers the eye to protect it from injury
How does a patient get a cherry eye?
Gland embedded in the third eyelid
gland slips forward but remains underneath the conjunctiva
exposure results in swelling and inflammation of the gland
Which animals typically get a cherry eye?
Young dogs less than 2years old
Describe what a cherry eye looks like.
Round, reddened soft mass in the media, canthus
possible mucous discharge
unilateral or bilateral
may be irritated
usually not painful
How do we treat cherry eyes?
Surgical restoration of normal gland pposition surgical removal is a last resort-cancer
What are the two surgical restoration techniques for fixing cherry eyes?
orbital rim tracking
What are the different problems with the structure of the globe?
What is another name for a corneal ulcer?
What are the 5 ayers of the cornea?
What is a superficial corneal ulcer?
Loss of epithelium only
What is a stomal ulcer?
Loss of epithelium and some stoma
What is a desmetocele?
Stroma lost down to descemets membrane
What is perforation in descemets membrane?
Loss of aqueous humor, may have iris prolapse
What are the different causes of corneal ulcers?
Trauma, chemicals, foreign bodies, KCS
bacterial, fungal, viral
distichia, trichiasis, ectopic cilia
What are the clinical signs of corneal ulcers?
Pain, blepharospasm, epiphora
ocular discharge (purulent)
fluid leakage from wound
upper respiratory infection in cats
How do we diagnose corneal ulcers?
fluorescein stain-detects corneal ulcers and abrasions
descemet's membrane will not stain
How do we treat corneal ulcers?
NSAIDs for uveitis
contact lense protection
oral lysine for cats
surgery -grid keratectomy, third eye lid flaps, eyelid flaps, conjunctival flaps
What does topical atropine do?
dilates pupil to prevent adhesions of iris to cornea
Does the corneal epithelium heal fast or slow?
How long does it take for superficial ulcers heal?
Do infected ulcers heal fast or slow?
How long does it take for indolent ulcers to heal?
Fail to heal after weeks of therapy
Should we use products containing cortisone for corneal ulcers? Why or why not?
No because cortisone delays wound healing and can make ulcers worse
How often should a patient with corneal ul era get rechecked?
What is glaucoma?
Increased intraocular pressure (IOP) beyond what is compatible with the health of the eye
What can glaucoma result in?
What is primary glaucoma?
What is secondary glaucoma?
Due to another disease affecting the drainage of the eye (uveitis, lens luxation, neoplasia, trauma)
What are the acute clinical signs of glaucoma?
Ocular pain -rubbing eyes, hiding, personality changes
dilated pupil -slow to absent pupillary light reflex
What are the chronic clinical signs of glaucoma?
Any acute sign
buphthalmos -abnormal enlargement of the eye
linear streaks in the cornea
How do we diagnose glaucoma?
measure both eyes for comparison
What are the two devices for tonometry?
What is gonioscopy?
checks filtration angle
How do we treat glaucoma?
Reduction of IOP
may be able to preserve vision
no known cure
a true emergency
mannitol - hyperosmotic
How do medications treat glaucoma?
decrease aqueous humor production
increase aqueous outflow
What are the different types of surgery for glaucoma?
What are gonioimplants?
What is cyclophotocoagulation?
Laser ablation of ciliary bodies
What is cyclocryotherapy?
Cold applied to the globe over the area of the ciliary body- partial destruction
What is salvage surgery?
Evisceration with implant
intravitreal gentamicin injection - only on blind eyes - toxic to structures in the vitreous and the ciliary body
What are cataracts?
Opacity of the lens
What is the most common disease involving the lens?
What color does the lens change to with cataracts?
From clear to white or blue
What is the frequent cause of blindness in dogs?
What could cataracts be secondary to?
What is senile nuclear (lenticular) sclerosis?
Normal change in aging animals
lens may appear gray or opaque
vision is maintained
can visualize fundus
begins at around 7 years old
What are the clinical signs of cataracts?
Progressive vision loss
opaque pupil opening
other systemic disease
How do we diagnose cataracts?
assess vision loss - obstacle course, lack of menace reflex, failure to track
PLR - pupillary light reflex - normal
serum profile for primary disease
How do we treat cataracts?
Stabilize primary cause if any
surgical removal if necessary
treat uveitis or other inflammation in the eye
if surgery is not an option, monitor yearly
What is phacoemulsification?
Ultrasound - breaks up lens
aspirate lens out with needle
preferred technique for removing most cataracts
can replace lens with intraocular lens prosthesis
success rate about 95%
usually a unilateral surgery
What do we need to educate clients on about cataracts?
Cataracts are usually progressive
most cataracts are inherited - do not use animal for breeding
quality of life can be maintained
do not move furniture around if animal is blind
What is anterior uveitis?
Inflammation of the iris, ciliary body, or choroid
What causes anterior uveitis?
Bacterial, viral, mycotic, parasites, immune mediated
lens induced - lens proteins
trauma, systemic disease, rickettsial
cats - FeLV, FIP, herpes
What are the clinical signs of anterior uveitis?
corneal edema (gray, white)
chemosis, scleral injection
change in color of iris
How do we diagnose anterior uveitis?
blood work for systemic disease
immunology screening panel (FeLV, FIP, FIV, mycosis panels)
ultrasound of the eye
tonometry - eye is usually soft
How do we treat anterior uveitis?
treat underlying disease
How do we control inflammation with anterior uvetitis?
Banamine or aspirin
topical opthalmic steroids and NSAIDs
atropine - for pain and to prevent adhesions
What is PRA?
progressive retinal atrophy
What is the retina?
where the visual pathway begins
What does the retina consist of?
photoreceptor cells - rods and cones
arteries and veins which connect to the optic disc
the optic disc connects to the optic nerve which connects to the brain
What are photoreceptors cells?
: black/white, low light
: color, bright light
Does the retina have to be functioning normally for vision to occur?
What does PRA result in?
loss of vision
When do we start to see signs of PRA?
as early as 6 months of age
usually starts at middle age
What type of vision is lost first with PRA?
loss of night/low light vision
progresses to affecting day vision
What are the clinical signs of PRA?
most cases - complete blindness
cataracts often develop
Is there a cure for PRA?
Is there a treatment for PRA?
How do we diagnose PRA?
electroretinogram is abnormal
DNA testing in some breeds
How do we treat PRA?
instruct owners on ow to care for a blind pet
do not breed animals with PRA
What are CERF exams?
Canine Eye Registration Foundation
certifies dog free of heritable eye disease
board certified veterinary ophthalmologist
exam done yearly