Ocular Pharm

Question 1

Very generally, how do the SNS agonists work as compared to the PNS agonists in ocular pharmacology?

Answer 1

Both reduce IOP

• SNS does so by decreasing aqueous humor synthesis
• PNS does so by increasing outflow

Question 2

What muscarinic agonists can be used for cataract surgery or treatment of glaucoma (there are 4)?

Answer 2

• acetylcholine
• carbachol
• methacholine
• pilocarpine

Question 3

What muscarinic antagonists can be used for cycloplegia or iriditis (there are 5)? Which is shortest acting?

Answer 3

• atropine
• scopolamine
• homatropine
• cyclopentolate
• tropicamide

Question 4

What are contraindications for using sympathetic agents to decrease intraocular pressure?

Answer 4

• can exacerbate CHF or asthma

Question 5

What are the 6 direct sympathetic agonists and what receptors do they work on?

Answer 5

• phenylephrine (alpha)
• L-epinephrine (alpha, beta)
• dipivalyl epinephrine (alpha, beta)
• bromondine tartrate (alpha 2)
• apraclonidine (like clonidine, but doesn’t cross BBB)
• clonidine (alpha)

Question 6

What are the 2 indirect sympathetic agonists and how do they work?

Answer 6

cocaine - prevents reuptake of NE

hydroxyamphetamine - release NE

Question 7

What are the 6 sympathetic antagonists and what receptors do they block?

Answer 7

• depiprazole (alpha)
• timolol (beta 1/2)
• betaxolol (beta 1)
• carteolol (beta 1/2)
• levobunolol (beta 2)
• metipranolol (beta 1/2)

Question 8

What are the 3 oral carbonic anhydrase inhibitors and how do they work?

Answer 8

• acetazolamide, ethoxzolamide, and methazolamide

- work by interfering with the active transport of Na through Na-K-ATPase pump (decrease aqueous production)

Question 9

What are the 2 topical carbonic anhydrase inhibitors?

Answer 9

dorzolamide hydrochloride and brinzolamide

Question 10

What are prostaglandin analogs used for and how do they work?

Answer 10

• main therapy for treating glaucoma

- increase uveoscleral outflow

Question 11

What are the four prostaglandin eye drops available?

Answer 11

• latanoprost
• bimatroprost
• travoprost
• unoprostone isopryl

Question 12

Patient presents with miosis, ptosis, and anhidrosis. Everything in you is screaming HORNER’S!!! but what test can you do to confirm?

Answer 12

apply cocaine! If it is truly Horner’s, pupillary dilation will not occur

Question 13

You’ve confirmed Horner’s in a patient and are now trying to determine which order neuron the lesion is in. What can you do to figure this out?

Answer 13

• Apply hydroxyamphetamine (paredrine), and if dilation occurs, lesion is at 1st or 2nd order neuron (BAD)
• If pupil does not dilate, lesion is in 3rd order neuron and process is probably more benign

Question 14

You see a patient on the neuro floor and notice in your exam that there is a light-near dissociation (pupil does not constrict to light but does to convergence). What is on your differential?

Answer 14

• Adie’s syndrome
• Parinaud’s syndrome
• Argyll-Robertson - syphilis
• Aberrant CNIII regeneration
• Diabetes (rarely)

Question 15

You’re in the ED and a patient comes in with a blown pupil and the worse headache of her life. You swear she looks familiar but can’t be sure… Did she serve you coffee last week? Was she drug seeking last month? What simple test can you do to test the validity of her eye dilation?

Answer 15

• administer pilocarpine 1%
• if pupil constricts, the process is organic
• if pupil remains dilated, there is a pharmacologic block already in place and she’s schooling you

Question 16

You’re in the ED and a 15 yo female comes in with one large pupil. Her parents are worried about intracranial hemorrhaging! Based on her demographic and absent patellar reflex, what condition do you suspect she has and how can you test this?

Answer 16

• Adie’s syndrome, a dysfunction in PNS due to ciliary ganglion damage
• administer 1/8% pilocarpine, and if pupil constricts, this is diagnostic due to denervation hypersensitivity