Lecture 10: Equine ophthalmology II

Question 1

What wrong

Answer 1

Iris cyst

Question 2

what wrong

Answer 2

glaucoma

Question 3

What wrong

Answer 3

cataract

Question 4

what wrong

Answer 4

Synechiae

Question 5

what is a common cause of blindness in horses

Answer 5

equine recurrent uveitis: aka moon blindness

Question 6

what breeds are predisposed to equine recurrent uveitis

Answer 6

appaloosas and European warm bloods

Question 7

what is the cause of equine recurrent uveitis

Answer 7

immune mediated with multiple etiologies: lepto, toxoplas,a, brucella, streptococcus, E. Coli, R. Equi, visceral larval migrans, viral infections

Question 8

what genetic mutation is seen in appaloosas with recurrent uveitis

Answer 8

TRMP1 gene on ECA1
MCH ELA on ECA 20

Question 9

what are the goals of equine recurrent uveitis care

Answer 9

preserve vision, decrease pain, minimize recurrence

Question 10

what is the tx for equine recurrent uveitis

Answer 10

1. Corticosteroids (neopolydex)
2. NSAIDS
3. Cyclosporine
4. Atropine
5. Vitrectomy
6. Intravitreal gentocin injection

Question 11

t or f: hydrocortisone is good drug to tx equine recurrent uveitis

Answer 11

false- does not penetrate cornea

Question 12

how does a vitrectomy work to tx equine recurrent uveitis

Answer 12

removes all fibrin, inflammatory cells, and debris trapped in vitreous to improve vision and delay progression

Question 13

what are some complications from intravitreal gentocin injection

Answer 13

hemorrhage, cataracts, retinal degeneration

Question 14

what are cataracts

Answer 14

lens opacities associated with various degrees of blindness

Question 15

t or f: the rate of progression and development of blindness from cataract can be predicted

Answer 15

false!

Question 16

what is nuclear or lenticular sclerosis

Answer 16

cloudiness of the lens nuclear starting at 7-8yrs old but shouldn’t interfere with vision

Question 17

what are the tx for cataracts

Answer 17

1. Extracapsular cataract sx- lens is removed
2. Phacoemulsification cataract sx- lens emulsified and aspirated (quickest return to fx and comfort)

Question 18

what is glaucoma

Answer 18

group of diseases that result in alterations of aqueous humor dynamics that cause increase in OP resulting in damage to retinal ganglion cells and optic nerves

Question 19

what are some signs of glaucoma

Answer 19

1. Bupthalmos
2. Haabs stria
3. Corneal edema
4. Loss of vision

Question 20

what is indicated by black arrow and what is that a sign of

Answer 20

Haab’s stria- sign of glaucoma

Question 20

what is the tx for glaucoma

Answer 20

1. Dorzolamide: Topical carbonic anhydrase inhibitor:
2. Pilocarpine: topical Miotic
3. Timolol- topical beta blocker
4. Anti-inflammatory ens

Question 21

what is exophthalmos

Answer 21

normal sized globe that is being pushed forward by space occupying lesion in orbit

Question 22

what most commonly causes exophthalmos

Answer 22

retrobulbar abscess/cellulitis or neoplasia

Question 23

what wrong

Answer 23

exophthalmos

Question 24

exophthalmos or buphthalmos: unilateral or bilateral

Answer 24

buphthalmos

Question 25

buphthalmos vs exophthalmos: eye is pushed forward, excessive conjunctiva visible

Answer 25

exophthalmos

Question 26

buphthalmos vs exophthalmos: third eyelid elevated

Answer 26

exophthalmos

Question 27

bupthalmos vs exophthalmos: diameter of cornea enlarged

Answer 27

bupthalmos

Question 28

bupthalmos vs exophthalmos: normal IOP

Answer 28

exothalmos

Question 29

what is coloboma

Answer 29

full thickness holes in iris

Question 30

what wrong

Answer 30

coloboma

Question 31

iridial cysts are hallmarks of hereditary ___ of __horse

Answer 31

anterior segment abnormalities or Rocky Mountain horse

Question 32

what wrong

Answer 32

chorioretinitis

Question 33

what are some causes of chorioretinitis

Answer 33

infectious agents, immune mediated uveitis, trauma, vitamin E deficiency, vascular disease

Question 34

what are some lesions associated with chorioretinitis

Answer 34

1. Focal bullet hole 2. Black lightening 3. Butterfly lesions of optic nerve

Question 35

what is tx for chorioretinitis

Answer 35

1. Systemic NSAIDS

Question 36

what mutations/coloration is associated with congenital stationary night blindness

Answer 36

two copies of specific white spotting pattern mutation known as leopard complex spotting- symmetrical whiter pattern centered over rump

Question 37

what are some signs of congenital stationary night blindness

Answer 37

visual impairment in dim light with normal vision during daylight

Question 38

mutation in what gene causes congenital stationary night blindness

Answer 38

calcium ion channel gene known as TRPM1 gene

Question 39

what is tx for congenital stationary night blindness

Answer 39

no tx

Question 40

what is dacryocystitis

Answer 40

inflammation of nasolacrimal duct and gland

Question 41

what are some signs of dacryocystitis

Answer 41

ocular discharge

Question 42

what is tx for dacryocystitis

Answer 42

flush with saline +/- lidocaine +/- steroids

Question 43

if fail to flush dacryocystitis what do you do

Answer 43

perform dacryocystorhinogram with radiopaquew solution

Question 44

how do you sx tx dacryocystitis

Answer 44

nasolacrimal punctua or duct agenesis- create fistula between lacrimal lake and nasal cavity