ABO Ocular Pharmacology and Therapeutics 2

Question 1

Which systemic condition is a contraindication to topical timolol?

Accepted Answer

Bronchial asthma

Answer

Nonselective beta-blockers like timolol can cause bronchospasm through beta-2 blockade, so they are contraindicated in asthma.

Question 2

Brimonidine is contraindicated in infants and children under 2 years mainly because of which risk?

Accepted Answer

CNS depression and apnea

Answer

Brimonidine readily crosses the blood-brain barrier in infants, which can cause somnolence, hypotonia, bradycardia, and apnea.

Question 3

Long-term oral acetazolamide therapy is most closely associated with which adverse effect?

Accepted Answer

Calcium phosphate nephrolithiasis

Answer

Carbonic anhydrase inhibition causes metabolic acidosis, reduced urinary citrate, and alkaline urine, which favor calcium phosphate stones.

Question 4

What is the main mechanism by which latanoprost lowers intraocular pressure?

Accepted Answer

It increases uveoscleral outflow

Answer

Prostaglandin F2-alpha analogs remodel the ciliary muscle extracellular matrix through matrix metalloproteinases, which increases uveoscleral outflow.

Question 5

Why is pilocarpine often ineffective early in acute angle-closure with IOP above 50 mm Hg?

Accepted Answer

Pressure-induced ischemia of the iris sphincter

Answer

Very high IOP causes ischemic paralysis of the iris sphincter, so it cannot respond to miotics until pressure is lowered by other means.

ABO - American Board of Ophthalmology Practice Test

ABO - American Board of Ophthalmology Practice Test

ABO Ocular Pharmacology and Therapeutics 2