Therapies for Glaucoma - Fitzpatrick

Question 1

Purpose of anti-glaucoma drugs

Answer 1

Decrease intraocular pressure by

(1) limiting aqueous humor production by the ciliary body
(2) enhancing aqueous outflow through trabecular meshwork or uveoscleral pathways

Question 2

Describe normal aqueous humor flow

Answer 2

Posterior chamber –> over Iris –> through Schlemm’s canal in the sclera –> into the trabecular meshwork OR uveoscleral outflow

Question 3

Describe aqueous humor flow in open-angle glaucoma

Answer 3

Prevention of flow into trabecular meshwork, causing rise in IOP in the ANTERIOR CHAMBER

Question 4

Describe aqueous humor flow in closed-angle glaucoma

Answer 4

Prevention of flow around the iris, causing rise in IOP in the POSTERIOR CHAMBER

Question 5

Describe route of topical glaucoma meds into body

Benefit of this?

Answer 5

Punctum lacrimale –> nasolacrimal duct –> nasal cavity –> systemic circulation

SKIP 1st pass effect in the liver

Question 6

Timolol

Answer 6

Non-selective beta-blocker

Decreases IOP by inhibiting ciliary body

Question 7

Pilocarpine

Answer 7

ACh (parasympathetic) agonist

Promote increased trabecular flow by contracting ciliary muscle of the eye

Question 8

Apraclonidine

Answer 8

Alpha-2 agonist
Management of IOP increase after ocular surgery
Improves uveoscleral drainage and inhibits ciliary body

Question 9

Latanoprost

Answer 9

Prostaglandin analog (PRODRUG)
Improves uveoscleral drainage
Does same effect WITHOUT side effects
Lasts longer due to metabolism into drug over time