Glaucoma Flashcards Preview

RUSVM SAM 2 > Glaucoma > Flashcards

Flashcards in Glaucoma Deck (25):
1

What is glaucoma?

Increased intraocular pressure (IOP)

2

How does the aqueous humor flow though the eye?

Ciliary body —> posterior chamber —> pupil —> anterior chamber —> iridoconreal angle —> venous drainage

3

What enzyme is responsible for active secretion of aqueous humor?

Carbonic anhydrase

4

T/F: glaucoma is almost always due to impaired outflow

True

— iridocorneal angle
— uveoscleral

5

Acute clinical signs of glaucoma?

Red eye — episceral injection
Blepharospasm
Corneal edema
Mydriasis
Impaired vision

6

Chronic clinical signs of glaucoma?

Optic disc cupping

Retinal degeneration

Irreversible blindness

Buphthalmos

Lens changes — Haabs striae (cracks in desmenths membrane)
Lens luxation

Phthisis bulbi — shrunken eye, end strange

7

What factors do you base your prognosis for vision on in a case of glaucoma?

Acute vs chronic — duration of signs over a day decreases prognosis

Buphthalmic —bind
Bupthalmia vs exophthalmia
—> check IOP
—> check corneal diameter (larger with buphthalmia)
—> lens luxation (secondary with bupthamia)

8

At what IOP can you confirm glaucoma?

>20mmHg or >20% difference between eyes is suspicious for glaucoma

>25-27mmHg with clinical signs is sufficient for diagnosis of glaucoma

9

What are the primary causes of glaucoma?

Primary angle closure glaucoma — goniodysgenesis (most common)

Primary open angle glaucoma

10

Breeds predisposed to primary angle closure glaucoma?

Cocker spaniels, basset hounds

Females > males

Middle aged to older

11

Breed predisposed to primary open angle glaucoma

Beagle

12

What are causes of secondary glaucoma?

Associated with other ocular or systemic abnormalities

Uveitis
Neoplasia
Lens luxation

13

How do you diagnose a primary glaucoma?

Lack of uveitis
Lack of intraocular tumors
Lack of lens luxation
Appropriate signalment

Goinosocpy — examin iridocorneal angle (referral procedure)

14

T/F: Primary angle glaucoma attacks are associated with stress, excitement, and dim light

True

15

T/F: primary angle glaucoma is usually unilateral disease

False

Initially unilateral but becomes bilateral

16

What is the most effective therapy for primary glaucoma in canines?

Lantanoprost

— topical prostaglandin derivative

Increases uveoscleral outflow
Potent miotic increases drainage angle

17

Side effects to lantanoprost?

Topical irritation, uveitis

18

When is lantanoprost contraindicated?

Secondary glaucoma due to uveitis
Lens luxation


Not effective in most forms of feline glaucoma

19

What is the most effective therapy for glaucoma in cats and horses?

Dorzolamide

Carbonic anhydrase inhibitor
— decrease aqueous production

20

How do you treat pressure induced ischemia and inflammation in a glaucoma case?

Neo/poly/Dex

Prednisolone acetate

21

If both lantanoprost and dorzolamide are ineffective at reducing glaucoma, what can you use?

mannitol IV

Hyperosmoic

22

What surgical therapies can treat glaucoma?

If eye is visual
- increase aqueous outflow (gonioimpant) which drains from anterior chamber into SQ

-decrease aqueous production (ciliary body ablation) — trans-scleral or endolaser

23

What prophylactic therapy can you use in the contralateral eye to prevent onset of glaucoma

Betaxolol
- increased chance of KCS

Demarcarium bromide
- can cause uveitis
- use in combo with topical steroid

Timolol

24

What are the treatment options for end-stage glaucoma ? And when is it indicated?

Enucleation
Evisceration and prosthesis
Ciliary body ablation

Blind and painful eyes

25

What is usually the primary presenting sign in feline glaucoma?

Mydriasis

Almost always due to uveitis