Glaucoma

Question 1

what does the aqueous humor do?

Answer 1

provides glucose and other substances to avascular lens and posterior cornea
removes metabolites and toxins

Question 2

how can you alter the uveoscleral pathway?

Answer 2

pharmacologically

Question 3

what structures of the eye can elevated intra-ocular pressure damage?

Answer 3

lamina cribosa/optic nerve
retina
corneal epithelium
iris vasculature/nerves

Question 4

what are key examination findings with glaucoma?

Answer 4

scleral injection
corneal edema
dilated pupil

Question 5

what are some signs of chronicity?

Answer 5

buphthalmia
haab’s striae
optic nerve changes

Question 6

is primary or secondary glaucoma more common?

Answer 6

secondary

Question 7

which animals should you suspect secondary glaucoma in?

Answer 7

cat
very young or old dog
wrong breed

Question 8

what causes secondary glaucoma?

Answer 8

something blocks the drainage angle or trabecular network
something blocks the pupil

Question 9

how do carbonic anhydrase inhibitors work?

Answer 9

decreasing aqueous production

Question 10

how do beta blockers work?

Answer 10

by decreasing aqueous humor production

Question 11

when should you not use mannitol?

Answer 11

significant heart disease
kidney disease

Question 12

what is a surgical procedure that enhances outflow?

Answer 12

shunt or valve with flexible tubing into anterior chamber

Question 13

what is the proper definition of glaucoma?

Answer 13

a group of diseases that lead to ganglion cell death and axon loss

Question 14

what produces aqueous humor?

Answer 14

nonpigmented ciliary epithelium

Question 15

what is the conventional outflow pathway of aqueous humor?

Answer 15

through pupil to iridocorneal angle
pectinate ligaments, trabecular network
aqueous collector channels
episcleral veins

Question 16

what can you use to measure intra-ocular pressure?

Answer 16

tonopen
tonovet

Question 17

what difference in IOP between eyes may be significant?

Answer 17

> 5-6 mmHg

Question 18

what in the eye should you look at for signs of underlying disease?

Answer 18

flare
position and clarity of lens

Question 19

what is primary glaucoma?

Answer 19

no overt underlying ocular disease

Question 20

what is primary glaucoma usually from?

Answer 20

breed-related in dogs
uncommon in cats and other species

Question 21

what type of glaucoma is most common in dogs?

Answer 21

angle closure glaucoma

Question 22

will most dogs with glaucoma get it in both eyes?

Answer 22

yes, not at same time

Question 23

what dog breeds are commonly affected by primary glaucoma?

Answer 23

cocker
basset
husky
samoyed
beagle
chow chow
shar pei
shih tzu
shiba inu

Question 24

how can cataracts cause secondary glaucoma?

Answer 24

lens-induced uveitis
phacomorphic glaucoma: swollen lens
following cataract surgery

Question 25

what do you need to distinguish with lens luxation/instability secondary glaucoma?

Answer 25

lens subluxation due to buphthalmia

Question 26

how can neoplasia cause secondary glaucoma?

Answer 26

infiltration or compression of angle hemorrhage from tumor uveitis

Question 27

what are globe/vision-sparing surgical management options for glaucoma?

Answer 27

shunt/valve placement laser ablations

Question 28

what are some carbonic anhydrase inhibitors?

Answer 28

dorzolamide/truspot brinzolamide/azopt oral: methazolamide

Question 29

when should you use an oral carbonic anhydrase inhibitor?

Answer 29

cannot medicate any other way can cause systemic disturbances

Question 30

what are the most potent option in dogs for glaucoma?

Answer 30

prostaglandin analogues

Question 31

how do prostaglandin analogues work?

Answer 31

increasing unconventional (uveoscleral) outflow

Question 32

why should you be sure that you know the lens is not anteriorly luxated in dogs you prescribe prostaglandin analogues?

Answer 32

cause marked miosis in dogs

Question 33

what is a prostaglandin analogue?

Answer 33

latanoprost/xalatan

Question 34

do beta blockers work well in dogs with glaucoma?

Answer 34

not really

Question 35

what is there potential for with beta blockers?

Answer 35

significant systemic absorption brady cardia, bronchoconstriction

Question 36

when might you use osmotics for glaucoma?

Answer 36

emergent treatment of acute glaucoma

Question 37

what is the dose of mannitol?

Answer 37

0.5-2 grams per kg

Question 38

what should you do for the good eye?

Answer 38

dorzolamide q12h as prophylaxis check IOP q2-3months

Question 39

what surgery is performed to decrease aqueous production?

Answer 39

diode or other pigment-targeting laser used to ablate ciliary epithelium