Ocular Pharmacology Flashcards Preview

PNS/Cardiology > Ocular Pharmacology > Flashcards

Flashcards in Ocular Pharmacology Deck (27):
1

Is pupillary dilation (mydriasis) controlled by parasympathetic or sympathetic pathway?

Sympathetic

2

Is pupillary constriction (miosis) controlled by parasympathetic or sympathetic pathway?

Parasympathetic

3

What are the two things necessary to achieve pharmacologic pupil dilation?

Stimulate dilation of pupil
Prevent constriction of pupil

4

What type of agonist is used to directly stimulate pupil dilation?

Adrenergic agonist

5

Which adrenergic agonist is most commonly used for pupil dilation?

Phenylephrine (alpha-1 agonist)

6

What type of antagonist is used to prevent constriction of the pupil?

Muscarinic antagonist

7

Which muscarinic antagonist is most commonly used to prevent constriction of pupil?

Tropicamide

8

What can be used to reverse pharmacologic mydriasis?

Alpha blocker called Dapiprazole (no longer available in US)

9

What are the 5 agents used for pharmacologic mydriasis and what is their mechanism of action?

Atropine
Cyclopentolate
Homatropine
Scopalomine
Tropicamide

All non-selective muscarinic antagonists (prevent constriction of pupil)

10

Which pharmacologic mydriasis agents are long-acting?

Atropine
Cyclopentolate

11

What are systemic side effects that can occur from use of the muscarinic antagonists (parasympatholytics)?

"Mad as a hatter, dry as a bone"
Blocks DUMBBeLSS, causing:
Reduced GI motility
Urinary retention
Mydriasis
Bronchodilation
Tachycardia
Decreased lacrimation (dry eye)
Decreased sweat (dry skin)
Decreased salivation (dry mouth)

12

What are the two major types of glaucoma?

Open angle glaucoma
Closed angle glaucoma

13

How can you recognize acute angle closure glaucoma?

Red painful eye
Nausea, vomiting
Blurred vision
Fixed mid-dilated pupil (pressure is increased and pupil can't work at higher pressure)
Hazy cornea

14

What is the only treatable risk factor of glaucoma?

Intraocular pressure

15

How is acute angle closure glaucoma treated?

Iridotomy (make a hole in iris)

16

What categories of drugs can be used in treatment of glaucoma (i.e. lower IOP)?

Beta antagonists
Alpha-2 agonists
Muscarinic agonists

17

How do beta antagonists lower IOP?

Decrease production of aqueous humor in ciliary body

18

What are the beta antagonists commonly used to lower IOP?

Timolol

19

How do alpha-2 agonists lower IOP?

Decrease production of aqueous humor in ciliary body
Also increase outflow (by preventing pupil dilation)

20

What are the alpha-2 agonists commonly used to lower IOP?

Brimonidine
Apraclonidine

21

How do muscarinic agonists lower IOP?

Cause miosis, which opens iridocorneal angle to improve drainage of aqueous humor

22

What are the muscarinic agonists commonly used to lower IOP?

Pilocarpine
Carbamycholine

23

What are the 3 major characteristics of Horner syndrome?

Ptosis
Miosis
Anhydrosis

24

What two drugs are necessary to test for Horner's syndrome?

Cocaine
Amphetamine

25

What is the purpose of cocaine in diagnosis of Horner's syndrome?

Cocaine blocks reuptake of NE, so should have increased NE and therefore dilation of pupil

No dilation of pupil upon cocaine administration = no NE being released by postganglionic neuron = defect somewhere in oculosympathetic pathway (could be pre or post ganglionic)

26

What is the purpose of amphetamine in diagnosis of Horner's syndrome?

Amphetamine is an adrenergic agonist and stimulates release of NE, so should cause release of NE from postganglionic neuron and dilation of pupil

No dilation of pupil upon amphetamine administration = defect is at postganglionic neuron

Dilation of pupil with amphetamine but no dilation with cocaine = defect is further up the oculosympathetic pathway

27

What is a possible cause of Horner's syndrome that can be diagnosed by chest xray?

Pancoast tumor in the apical lung