Glaucoma

Question 1

what is glaucoma

Answer 1

increased IOP and vision loss from damage to the optic nerve and retina

Question 2

aqueous humor pathway

Answer 2

ciliary body→ posterior chamber → pupil → anterior chambler → iridocorneal angle → venous drainage

Question 3

what enzyme is responsible for active secretion of aqueous humor

Answer 3

carbonic anhydrase

Question 4

the majority of aqueous humor is drained via______

Answer 4

iridocorneal angle

Question 5

T/F glaucoma is almost always due to over production of aqeuous humor

Answer 5

False

glaucoma is almost always due to impaired outflow

Question 6

common clinical signs

Answer 6

red eye (DDx keratoconjunctivitis, uveitis)

painful eye (blepharospasm)

cloudy eye (corneal edema)

mydriasis (dialted pupil)

impared vision

Question 7

chronic clinical signs

Answer 7

optic disc cupping

retinal degeneration

blindness

bupthalmos (enlarged eye)

phthisis bulbi

Question 8

T/F a bupthalmic eye is blind

Answer 8

TRUE!

Question 9

what is normal IOP

Answer 9

10-20 mmHg

Question 10

in IOP of ____ along with clinical signs is sufficient for diagnosis of glaucoma

Answer 10

25 mmHg

Question 11

You use a tonopen to assess the IOP of a dog with red eye. Your results are as follows: 25mmHg, 13mmHg, and 17mmHg. Which of these readings is the most accurate?

Answer 11

13mmHg

the lowest IOP is always the most acurate - pressure on the neck, head possition, squinting, and pressure on the globe from improper lid retraction can all falsly increase, but nothing we are doing will decrease the pressure

Question 12

what is goniodysgenesis

Answer 12

primary angle closure glaucoma

much more common - cocker spaniels (poster child), basset hounds, Labs

Question 13

T/F primary glauma will present bilaterally

Answer 13

False

• primary glaucoma is bilateral, but the onset is typically asymmetric*
• without prophylactic therapy, glaucoma develops in the fellow eye 6-12 months later*

Question 14

common causes of secondary glaucoma

Answer 14

uveitis (most common-especially with complete hyphema)

neoplasia

lens luxation

Question 15

what 2 outcomes should be considered with treatment

Answer 15

vision

comfort

we almost always eventually fail to preserve vision and are often considering comfort

Question 16

emergency therapy

Answer 16

latanoprost - increases uveoscleral outflow

Question 17

when is latanoprost (protaglandin) cantraindicated

Answer 17

anterior lens luxation

secondary glaucoma due to uveitis

Question 18

what is the second most effective therapy

Answer 18

dorzolamide - decreases aqeuous production, carbonic anhydrase inhibitor

Question 19

what should be used if topical latanoprost and dorzolamide are ineffective

Answer 19

intravenous mannitol 20%

Question 20

what are the vision preserving surgical therapies

Answer 20

gonioimplants

ciliary body ablation

Question 21

prophylactic therapy in the contralateral eye can extend the onset of blindness by _____

Answer 21

~ 3 years (on average)

Question 22

prophylactic therapy

Answer 22

dorzolamide - 1 drop BID

latanoprost - available for owner in event of blindness, give one drop the call clinic to start agressive tx to preserve vision)

Question 23

T/F pressures in the contralateral eye tend to creep up

Answer 23

False

IOP spikes suddenly, typically recheck stables eyes q 3 months

Question 24

3 options for treating end stage glaucoma

Answer 24

enucleation

evisceration and prothesis

ciliary body ablation

Question 25

feline glaucoma is usually due to ______

Answer 25

uveitis