AOA Ocular Pharmacology 2

Question 1

Which class of drugs is specifically contraindicated with topical pilocarpine due to risk of cholinergic toxicity?

Accepted Answer

Systemic cholinesterase inhibitors (e.g., echothiophate iodide)

Answer

Echothiophate (an irreversible cholinesterase inhibitor) combined with pilocarpine produces additive muscarinic stimulation; echothiophate also prolongs succinylcholine-induced apnea in surgery.

Question 2

Brimonidine (alpha-2 agonist) lowers IOP through which dual mechanism?

Accepted Answer

Decreasing aqueous production AND increasing uveoscleral outflow

Answer

Brimonidine stimulates alpha-2 adrenergic receptors to both decrease aqueous production (reduced cAMP) and increase uveoscleral outflow, achieving a 20–25% IOP reduction.

Question 3

Topical corticosteroids used for ocular inflammation can cause which serious ocular complication with prolonged use?

Accepted Answer

Posterior subcapsular cataracts and elevated IOP (steroid-induced glaucoma)

Answer

Long-term topical steroid use induces posterior subcapsular cataracts and increases IOP in susceptible 'steroid responders' by reducing trabecular outflow facility.

Question 4

Which mydriatic agent is preferred for fundus examination in pediatric patients due to its shorter duration?

Accepted Answer

Tropicamide 0.5–1%

Answer

Tropicamide has a short duration (4–8 hours) making it practical for routine dilation, while atropine's 7–14 day effect is reserved for cycloplegic refraction when needed.

Question 5

Systemic side effects of topical phenylephrine 10% include:

Accepted Answer

Hypertension and tachycardia due to systemic absorption

Answer

Phenylephrine 10% can be absorbed systemically via nasolacrimal drainage, stimulating alpha-1 receptors to cause hypertension, sometimes severe, especially in elderly patients.

AOA - American Optometric Association Practice Test

AOA - American Optometric Association Practice Test

AOA Ocular Pharmacology 2