Glaucoma Meds

Question 1

What causes the pupil to constrict?

Answer 1

iris circular muscle

M3 receptor

Question 2

What causes the pupil to dilate?

Answer 2

iris radial muscle

alpha 1

Question 3

What causes accommodation of the eye to near vision and decreases intraocular pressure (improves outflow of aqueous humor)?

Answer 3

ciliary muscle

M3

Question 4

What produces aqueous humor?

Answer 4

ciliary epithelium

Question 5

What activation increases humor production?

Answer 5

beta adrenergic

Question 6

What receptor activation decreases humor production?

Answer 6

alpha 2

Question 7

What does carbonic anhydrase do to aqueous humor?

Answer 7

transports sodium and bicarb from ciliary body into humor

increases osmotic pressure, enhances water transport to humor–>increases volume

Question 8

What improves outflow of aqueous humor?

Answer 8

contraction of ciliary muscle

contraction of iris circular muscle (constriction of pupil)

both M3

Question 9

What improves unconventional aqueous humor outflow?

Answer 9

prostaglandin F2a

Question 10

What does sympathetic nervous system do to eye?

Answer 10

dilates pupil via contraction of iris radial muscle (decrease outflow)
–> alpha 1

relax ciliary muscle (increase uveoscleral outflow)
–> alpha 2

Question 11

Define glaucoma

Answer 11

ocular disorders–> optic neuropathy a/w loss of visual sensitivity and field

Question 12

What types of glaucoma are there?

Answer 12

primary (genetic, congenital)

• -> open angle glaucoma most common: progressive disease without mechanical blockage to humor outflow
• -> closed angle glaucoma: acute intermittent partial or complete blockage of outflow (emergency to avoid vision loss)

secondary (disease, trauma, surgery, drug-induced)

Question 13

What is the most common form of glaucoma?

Answer 13

open-angle (no known outflow blockage)

Question 14

What is one factor that can cause open angle glaucoma?

Answer 14

increased IOP–> optic neuropathy (damage to optic nerve)

Question 15

Generally, what drugs reduce the amount of aqueous humor produced?

Answer 15

beta blockers (olol)

alpha 2 agonists (idine)

carbonic anhydrase inhibitors (amide)

Question 16

Generally, what drugs increase aqueous humor outflow?

Answer 16

prostaglandin analog (oprost)

alpha 2 agonist (idine)

direct cholinergic agonist

inhibitors of cholinesterase

Question 17

Why is Timolol favored in glaucoma?

Answer 17

lacks local anesthetic effects

generic

full antagonist

Question 18

Why are beta blockers used?

Answer 18

convenience of dosing

general lack of local adverse effects

Question 19

Beta blocker MOA

Answer 19

reduce production of humor by ciliary body

Question 20

Local adverse effects of beta blockers

Answer 20

little, usually well tolerated

ocular irritation
dry eyes

Question 21

Systemic adverse effects of beta blockers

Answer 21

bradycardia

bronchospasm

hyperlipidemia

hypoglycemia

interact with calcium blockers

careful with use in cardiac patients

Question 22

What is the main alpha 2 agonist used in glaucoma?

Answer 22

brimonidine

Question 23

Alpha 2 agonist MOA

Answer 23

decrease humor production

increase uveoscleral outflow (unconventional) via relaxing ciliary muscle

Question 24

Side effects of alpha 2 agonists

Answer 24

systemic: headache, fatigue, dry mouth
local: eyelid edema, itching, hyperemia (allergic rxn)

Question 25

MOA of carbonic anhydrase inhibitors

Answer 25

-lamide

decrease osmotic pressure of humor

Question 26

Side effects of carbonic anhydrase inhibitors

Answer 26

local–> ocular irritation and redness

systemic: N, diarrhea, altered taste, weight loss, paresthesia, renal stones, decreased libido

intolerable with long-term use

Question 27

MOA of prostaglandin analogs

Answer 27

-oprost

reduce IOP via increased uveoscleral and conventional outflow of humor

Question 28

Why give prostaglandin analogs for glaucoma?

Answer 28

once at nighttime

more efficiently reduce IOP c/t beta blockers

Question 29

Adverse effects of prostaglandin analogs

Answer 29

systemic not significant

local: corneal erosions, hyperemia, iris hyperpigmentation (irreversible with months of use), hypertrichosis of eye lashes that is reversible with d/c

Question 30

What are direct-acting cholinergic agonists?

Answer 30

pilocarpine

carbachol

Question 31

What are indirect-acting cholinergic agonists (AKA inhibit cholinesterase)?

Answer 31

echothiophate

Question 32

MOA of cholinergic agonists

Answer 32

activate M3 directly or indirectly (inhibit cholinesterase)–> elevate Ach levels

increases conventional humor outflow

Question 33

Adverse effects of cholinergic agonists

Answer 33

systemic rare

local: ha, periorbital pain, constriction of pupil with diminished night vision, eyelid twitching, myopia, cataracts with long-term use, iris-lens adhesions with long-term use

Question 34

How to treat glaucoma

Answer 34

beta blocker or prostaglandin first

if intolerant: use class alternative

if contraindications to both: brimonidine or topical carbonic anhydrase inhibitor

combo therapy

laser or surgical procedure

Question 35

Describe pupillary block closed angle glaucoma

Answer 35

tight contact between iris and lens–> flow of humor into anterior chamber blocked–> iris moves forward and blocks outflow

Question 36

Describe closed angle glaucoma without pupillary block

Answer 36

ciliary processes located in such a way that they push the iris forward–> blocks outflow, especially when pupil is dilated

Question 37

Goals for treatment of closed angle glaucoma

Answer 37

medical emergency to keep vision

• -> reduce IOP with oral glycerin or IV mannitol to prep for surgery
• -> pilocarpine before surgery induces constriction of pupil
• -> reduce humor production via beta blocker, alpha 2 agonist or carbonic anhydrase inhibitor

Question 38

What drugs promote elevation of IOP?

Answer 38

open angle glaucoma patients: glucocorticoids, topical antimuscarinic drugs

closed angle glaucoma patients, cause dilation of pupil: alpha 1, antimuscarinic drugs