Opthalmology Midterm Flashcards by Tricia Spooner

What is the main site of resistance to drug penetration in the eye?

corneal epithelium

How well did you know this?

Not at all

Perfectly

What is the maximum volume of subconjuctival injections into the eye for small and large animals?

cat and dog = 0.25 ml

LA = up to 1 ml

How well did you know this?

Not at all

Perfectly

Which parts of the eye require systemic administration for treatment?

retina, optic nerve, vitreous

How well did you know this?

Not at all

Perfectly

What are the 3 types of miotic agents and what are examples of each?

parasympathomimetic - pilocarpine
anticholinesterase - demecarium bromide
PGF2a analog - latanoprost, travoprost

How well did you know this?

Not at all

Perfectly

Which mydriatic agent is cycloplegic and should not be used in glaucoma patients?

atropine

How well did you know this?

Not at all

Perfectly

What are the two groups of mydriatic drugs and examples of each?

parasympatholytic - atropine, tropicamide

sympathomimetic - epinephrine, phenylephrine, dipivefrin

How well did you know this?

Not at all

Perfectly

What is the MOA of atropine in the eye?

cycloplegic - paralyzes ciliary musculature to decrease intraocular pain

How well did you know this?

Not at all

Perfectly

Which ocular drugs can help differentiate scleral injection?

phenylephrine and epinephrine

How well did you know this?

Not at all

Perfectly

What is the MOA of adrenergic beta blockers in the eye?

reduce aqueous humor

How well did you know this?

Not at all

Perfectly

What is the number one antibiotic that causes conjuctival irritation?

neomycin

How well did you know this?

Not at all

Perfectly

What is the drug of choice for mycoplasma and chlamydia conjuctivis in cats?

oral doxycycline

How well did you know this?

Not at all

Perfectly

What can doxycycline help with the eye besides being an antibiotic?

stabalizes corneal collegenases - helps with corneal ulcer

How well did you know this?

Not at all

Perfectly

What drug can cause retinal degeneration in cats?

enrofloxacin

How well did you know this?

Not at all

Perfectly

What is the only approved topical treatment for fungus in the eye?

natamycin

How well did you know this?

Not at all

Perfectly

What is the drug of choice for use as a subpalpebral lavage treatment?

voriconazole

How well did you know this?

Not at all

Perfectly

What 2 antiviral drugs are NOT used in feline herpes treatment?

acyclovir and vacyclovir

How well did you know this?

Not at all

Perfectly

What drug can be used to treat the rare condition, neurogenic KCS?

pilocarpine

How well did you know this?

Not at all

Perfectly

What are the 2 drugs of choice to treat KCS?

Cyclosporine A and tacrolimus

How well did you know this?

Not at all

Perfectly

What muscles open the eyelid and what are their innervation?

levator palpebrae superioris(CN 3)
Mullers muscle (sympathetic)

How well did you know this?

Not at all

Perfectly

What muscle closes the eyelid and what innervates it?

orbicularis oculi - CN 7

How well did you know this?

Not at all

Perfectly

Term for turning in of the eyelid

entropion

How well did you know this?

Not at all

Perfectly

Term for turning out of the eylid

ectropian

How well did you know this?

Not at all

Perfectly

Term for distortion of normally positioned lashes so they irritate eye

trichiasis

How well did you know this?

Not at all

Perfectly

Term for hair emerging from one or more meibomian gland openigns

distichiasis

How well did you know this?

Not at all

Perfectly

Term for hair growing from meibomian gland through plapebral conjuctiva

atypical distichia, ectopic cilia

What is the treatment of choice for distichiasis?

cryotherapy

How is ectopic cilia treated?

partial thickness excision and/or cryoablation

What dog breeds are predisposed to entropion?

shar pei, chow, bulldog, st bernard, golden retreiver

What is the treatment for entropion in puppies less than 5 months of age?

temporary eyelid tacking

What breeds are predisposed to ectropion?

st bernards, spaniels, hounds

What species have T-shaped third eyelids?

ruminants and dogs

Which species has a muscle to the third eyelid?

cat (sympathetic innervation to retract)

What kind of neoplasms occur in the third eyelid?

lymphosarcoma and adenocarcinoma

What breed gets plasma cell infiltration of the third eyelid?

german shepherds

What is the indication for a full thickness eyelid resection in neoplastic eyelid diseases?

when lesion involves less than 1/4 to 1/3 of eyelid margin

What is the best treatment for canine eyelid neoplasms?

cryotherapy

Term for absolute enlargement of globe secondary to chronic glaucoma

buphthalmos

Term for rostral displacement of the globe

exophthalmos

Term for retraction of the globe into the orbit

enophthalmos

Resistance to opening the mouth can indicate what eye disease?

retrobulbar abscess

What are common causes of exopthalmos?

abscess, cellulitis, neoplasia

What are common causes of enophthalmos?

congenital (dolio), phthisis bulbi, microphthalmia

What are common causes of strabismus?

neoplasia, proptosis, congenital (brachy)

What percentage of fibers cross over in the optic chiasm in cats, dogs, horses, sheep, pigs, cows, fish, birds and reptiles?

Cats : 65% Dogs: 75% Cows, horses, sheep, pigs: 90% Fish, birds, reptiles: 100%

What is the afferent nerve for the PLR reflex?

CN 2

Which cranial nerve is motor to the superior oblique muscle?

CN 4

Which CN is motor to lateral rectus and retractor oculi muscles?

CN 6 (abducens)

What CN supplies adrenergic innervation to the cats third eyelid?

CN 6 (abducens)

What Cn is motor to orbicularis oculi muscle and gives parasympathetic innervation to lacrimal gland?

CN 7

What CNs are tested in the palpebral reflex?

5, 6, and brainstem

What CNs are tested in the corneal reflex?

CN 5, 6, and 7

What CNs are tested in the dazzle reflex?

CN 2 and 7 and visual pathway up to before visual cortex

What are Ddx for unilateral miosis?

drugs, horners syndrome, uveitis, posterior synechiae, iris hypoplasia

What are ddx for bilateral miosis?

drugs, uveitis, organophosphate toxicity

What are ddx for unilateral mydriasis?

drugs, CN 3 lesion, iris atrophy, ciliary ganglion lesion, posterior synechiae, optic neuritis, glaucoma, retina problems

What are ddx for bilateral mydriasis?

drugs, fear, death, total retinal atrophy, optic nerve atrophy, retinal detachment

What are the CS of horners syndrome in all species?

miosis, ptosis, elevation of nictating membrane

What are the special CS of horners syndrome in cows and horses?

horses - unilateral sweating | cow - reduced sweating, pinna heat

How can you differentiate between feline herpes conjuctivitis and chlamydia?

herpes - can cause keratitis | chlam - more chemosis

What are the 3 layers of the tear film and what produces them?

lipid - meibomian glands aqueous - lacrimal gland, third eyelid gland mucus - goblet cells

What is the medical treatment for KCS?

cyclosporine A, tacrolimus

What is the main cause of KCS?

immune mediated, T cell infiltration of lacrimal tissue

What is the most common cause of horners syndrome in dogs?

lesions of third neuron, postganglionic lesion, idiopathic

What is the surgery treatment for KCS?

medial canthoplasty (brachy breeds)

What layer of the cornea is hydrophobic and lipophilic?

epithelium - barrier to drugs and fluorescin

What is the cornea stroma made of?

75% water, 25% collagen

What nerve innervates the cornea?

CN V (trigeminal)

What is reflex uveitis?

any stimulation of corneal nerves = reflex of CN V to anterior uveal tract (happens with keratitis and corneal ulcers - muscle spasms)

Term for stromal loss but some healing occured and there is still a hole covered with epithelium.

facet

What is the rate of growth of corneal blood vessels and epithelial cells in the cornea?

1 mm/day

What is the rate of WBC migrating in the cornea?

8.6 mm/day

What part of the cornea is hydrophobic?

descemets membrane

What is seidel's test?

if fluorescein in diluted in a deep ulcer --> aqueous humor leaking out

What is an indolent ulcer?

superficial corneal erosion with epithelial "lips" -fluorescin seeps under the lip

What is the treatment for of canine indolent ulcers?

debridement followed by grid keratotomy or diamond burr debridement

When should grid keratotomys not be done?

complicated ulcers or cats or horses

What is the most common cause of corneal ulcers in cats? Whats the most classic sign?

feline herpesvirus 1 | dendritic ulcers

What is the treatment for feline herpesvirus ulcers?

cidofovir (antiviral)

What antiviral is fatal to cats?

acyclovir

What are the different diseases associated with white corneas?

corneal dystrophy, degeneration, fibrosis, descemets striae, keratic precipitates

What disease is descemet's striae associated with? What does it look like?

glaucoma - membrane breaks leaving linear white scars

What white corneal disease is pathognomic for anterior uveitis?

keratic precipitates - can become brown over time

What is the only blue corneal opacity?

edema

What part of the cornea is a barrier to edema and an active pump?

endothelial layer

What are diffuse corneal edemas a result of?

endothelial dysfunction - glaucoma, uveitis, immune mediated endothelitis, blue eye (CAV 1)

What happens when there is damage to the endothelium of the cornea?

does not undergo mitosis - hypertrophies instead

What is the treatment for corneal edema?

5% saline, 30 mins apart from other meds thermokeratoplasty - make dots on cornea keratoleptynnsis - conjuctiva graft

Opthalmology Midterm Flashcards

(87 cards)