Glaucoma

Question 1

Define: Glaucoma

Answer 1

damage of the eye’s optic nerve, usually associated with increased intraocular pressure = vision loss and blindness

Question 2

What are the risk factors for glaucoma?

Answer 2

-age = >40 years old
-family history
-angle closure glaucoma= women

Question 3

How can glaucoma be diagnosed?

Answer 3

-exam of the optic nerve
-exam of the visual field
-intraocular pressure (>21 mmHg)

Question 4

What is the iris smooth muscle responsible for?

Answer 4

pupil size
-sympathetic= mydriasis (dilation)
-parasympathetic= miosis (constriction)

Question 5

What is the ciliary body responsible for?

Answer 5

vision focus/lens shape
-sympathetic= relaxed (less convex), far vision
-parasympathetic= contracted (more convex), near vision

Question 6

Describe: Aqueous Humor

Answer 6

produced in the ciliary epithelium and flows around the iris through the trabecular meshwork and out the canal of Schlemm into the bloodstream, responsible for intraocular pressure

Question 7

Describe: Open Angle Glaucoma

Answer 7

most common type, drainage angle is open, but the fluid passes too slowly through the meshwork

Question 8

Describe: Closed Angle Glaucoma

Answer 8

obstruction of outflow of aqueous humor, medical emergency!

Question 9

What is the treatment goal of glaucoma?

Answer 9

to decrease pressure inside the eye either by increasing outflow of aqueous humor or decreasing production of aqueous humor

Question 10

What adrenergic receptors are found in the eye?

Answer 10

alpha1= contraction of the dilator muscle that results in pupil dilation, beta= increased secretion of fluid, alpha2= decreased secretion of fluid

Question 11

What cholinergic receptors are found in the eye?

Answer 11

M3= causes contraction of the ciliary muscle which allows increased outflow of aqueous humor AND causes contraction of sphincter muscle that results in pupil constriction

Question 12

What classes of drugs would increase the outflow of aqueous humor?

Answer 12

mAChR agonists, AChE inhibitors

Question 13

What classes of drugs would decrease secretion of aqueous humor?

Answer 13

beta blockers, alpha2 agonists, nonselective agonists

Question 14

What beta blockers are used to treat glaucoma?

Answer 14

-timolol (non-selective)
-betaxolol (beta1 selective)

Question 15

MOA: Adrenergic drugs for treatment of Glaucoma

Answer 15

reduce aqueous humor production

Question 16

What alpha2 agonists are used to treat glaucoma?

Answer 16

-apraclonidine
-brimonidine

Question 17

What non-selective adrenergic agonists are used to treat glaucoma?

Answer 17

-epinephrine
-dipivefrin (prodrug -> epinephrine)

Question 18

MOA: Cholinergic drugs for the treatment of Glaucoma

Answer 18

increase outflow of aqueous humor by contracting the ciliary muscle which widens the trabecular mesh to allow outflow through the canal of Schlemm

Question 19

What mAchR agonists are used to treat glaucoma?

Answer 19

-pilocarpine
-carbachol

Question 20

What AChE inhibitors are used to treat glaucoma?

Answer 20

-physostigmine
-echothiophate

Question 21

Side effects: Cholinergic drugs

Answer 21

the are cholinomimetics that may induce visual problems, eyelid muscle twitching when used locally. occasionally, systemic parasympathetic effects occur, such as: diarrhea and urinary incontinence

Question 22

MOA: Prostaglandins analogs for the treatment of glaucoma

Answer 22

stimulates prostaglandin F receptor, which enhances outflow of aqueous humor through the uveoscleral tract

Question 23

What prostaglandin analogs are used to treat glaucoma?

Answer 23

-latanoprost
-travoprost
-bimatoprost

Question 24

MOA: Nitric Oxide

Answer 24

promotes outflow of aqueous humor via trabecular meshwork through canal of Schlemm

Question 25

MOA: Carbonic Anhydrase inhibitors

Answer 25

diminishes the production of aqueous humor

Question 26

MOA: Netarsudil (Rhopressa)

Answer 26

main mechanism= reduces cell contraction and stiffness in the trabecular meshwork to increase outflow through the canal of Schlemm, minor mechanism= inhibitor of the norepinephrine transporter which decreases aqueous humor production

Question 27

What is the treatment of closed-angle glaucoma?

Answer 27

-initially a combination of a direct muscarinic agonist and a cholinesterase inhibitor -IV mannitol to rapidly reduce intraocular pressure -once pressure is controlled, patient is prepared for a corrective surgery (iridectomy or iridotomy)