Ocular Surgery

Question 1

what muscle closes eyelids and what is it innervated by?

Answer 1

obicularis oculi muscle

auriculopalpebral branch of fascial n.

Question 2

uses for transpalpebral US (3)

Answer 2

• lens
• retrobulbar masses
• ocular chamber

Question 3

tyndall effect looks at..

Answer 3

anterior chamber clarity

+ = uveitis

Question 4

what part of LA eye exam is unique to LAs?

Answer 4

• digital palpation of palpebral fissure

- digital palpation of dorsal and ventral fornix of conjunctival sac

Question 5

what disinfectant is safe on eyes?

Answer 5

diluted povidone iodine NOT chlorhexidine

Question 6

block used for ocular akinesia in horses

Answer 6

-auriculopalpebral block

Question 7

block used for ocular anesthesia in horses

Answer 7

-supraorbital n. block (branch of frontal n, which is branch of trigeminal)

Question 8

block used for ocular akinesia in bovine

Answer 8

auriculopalpebral block (branch of fascial; targets obicularis oculi)

Question 9

block used for ocular anesthesia in bovine

Answer 9

line block (often too hard to palpate in order to do supraorbital)

Question 10

blocks used for BOTH ocular anesthesia and akinesia

Answer 10

retrobulbar blocks

• peterson block
• 4 point block

Question 11

evaluating retrobulbar blocks (peterson, 4 point)

4

Answer 11

• proptosis (protrusion of eyeball)
• lack of eye movement when head is turned
• ipsilateral pupil dilation
• lack of corneal sensation

Question 12

options for covering the cornea (3)

Answer 12

• third eyelid flap (mostly ruminants)
• temporary tarsorrhaphy
• reversible split lid tarsorrhaphy (RSLT)

Question 13

surgical treatment for dermoids

Answer 13

lamellar superficial keratectomy

Question 14

main causes of corneal ulcers in equine

Answer 14

• EHV-2

- pseudomonas

Question 15

never use _____ on corneal ulcers

Answer 15

steroids

Question 16

surgical treatment for corneal ulcers

Answer 16

conjunctival flap/graft

Question 17

ideal suture placement for conjunctival flap/graft

Answer 17

80% thickness of cornea!!!

Question 18

ideal sutures to place when doing a conjunctival flap/graft

Answer 18

simple interrupted using a semicircular needle inserted at 90 degrees using circular motion

Question 19

equipment needed for conjunctival flap/graft

Answer 19

• bishop-harmon forceps
• stevens tenotomy scissors
• castroviejo needle drivers

Question 20

surgical treatment for entropion

Answer 20

short term:

• skin mattress sutures
• skin staples
• Michael wound clips

permanent:
-Hotz Celsus

Question 21

hotz celsus is used to treat

Answer 21

entropion (usually only severe cases like cicatricial entropion)

Question 22

causes of entropion in LAs (5)

Answer 22

• congenital
• dehydration in newborns
• microphthalmus (BVD)
• spastic (secondary to pain)
• cicatricial entropion (secondary to scarring)

Question 23

cicatricial entropion

Answer 23

secondary to scarring

Question 24

enucleation

Answer 24

removal of glove ONLY

Question 25

removal of globe ONLY

Answer 25

enucleation

Question 26

eviseration

Answer 26

removal of intraocular contents ONLY

Question 27

removal of intraocular contents only

Answer 27

eviseration

Question 28

when is eviseration commonly used?

Answer 28

for cosmetic reasons in horses

involves removing intraocular contents ONLY

Question 29

exenteration

Answer 29

removal of globe AND oribital soft tissues

mainly used in cattle

Question 30

main complications of exenteration

Answer 30

hemorrhage

entering maxillary sinus-> no longer sterile

Question 31

orbital fractures are considered open if…

Answer 31

they enter maxillary sinus

Question 32

gonioimplant

Answer 32

used to treat glaucoma. increases drainage of aqueous fluid

Question 33

treatment for chronic glaucoma (2)

Answer 33

evisceration (intraocular contents only) or enucleation (globe only)

Question 34

surgical treatment for cataracts

Answer 34

phacoemulsification

Question 35

phacoemulsification

Answer 35

used to treat cataracts

Question 36

ERU often leads to _____ synechia

Answer 36

posterior (lens sticks to iris

Question 37

anterior vs. posterior synechia

Answer 37

anterior: lens sticks to cornea
posterior: lens sticks to iris

Question 38

surgical treatment options for ERU

Answer 38

• intravitreal injections
• suprachoroidal cyclosporine implants
• pars plana vitrectomy (PPV): risk for retinal detachment!!

Question 39

pars plana virtectomy

Answer 39

surgical treatment for ERU

risk for retinal detachment!

Question 40

suprachorodial cyclosporine implants

Answer 40

treatment option for ERU

Question 41

how to collect samples for testing in ERU cases (rarely done)

Answer 41

paracentesis