COT Ophthalmic Pharmacology 5 — Questions and Answers
Question 1: Which diagnostic dye is used to evaluate lacrimal drainage patency during the Jones dye tests?
- Rose bengal
- Lissamine green
- Fluorescein sodium (Correct answer)
- Indocyanine green
Correct answer: Fluorescein sodium
Fluorescein sodium is instilled in the conjunctival sac for Jones I and II dye tests to assess whether dye passes through the nasolacrimal drainage system into the nasal cavity.
Question 2: Apraclonidine (Iopidine) is most commonly used in the ophthalmic setting to:
- Prevent post-laser IOP spikes after anterior segment laser procedures (Correct answer)
- Treat bacterial endophthalmitis
- Reverse pupillary dilation after examination
- Provide long-term glaucoma management as monotherapy
Correct answer: Prevent post-laser IOP spikes after anterior segment laser procedures
Apraclonidine is an alpha-2 agonist most commonly used perioperatively around laser treatments to blunt the acute IOP spike that can follow procedures such as laser iridotomy or trabeculoplasty.
Question 3: Which antiviral medication is the first-line topical treatment for herpes simplex epithelial keratitis?
- Acyclovir ointment or trifluridine drops (Correct answer)
- Tobramycin drops
- Natamycin suspension
- Voriconazole drops
Correct answer: Acyclovir ointment or trifluridine drops
Trifluridine 1% ophthalmic solution and acyclovir ointment are first-line topical antivirals used to treat active HSV epithelial (dendritic) keratitis.
Question 4: Natamycin ophthalmic suspension 5% is the drug of choice for treating which type of corneal infection?
- Bacterial corneal ulcer caused by Pseudomonas
- Fungal (filamentous) keratitis caused by Fusarium or Aspergillus (Correct answer)
- Acanthamoeba keratitis
- Viral keratitis caused by adenovirus
Correct answer: Fungal (filamentous) keratitis caused by Fusarium or Aspergillus
Natamycin is a polyene antifungal that disrupts fungal cell membrane integrity and is the FDA-approved first-line topical treatment for filamentous fungal keratitis.
Question 5: The mechanism by which latanoprost lowers intraocular pressure is primarily by:
- Decreasing aqueous humor production by the ciliary body
- Increasing uveoscleral outflow via prostaglandin FP receptor activation (Correct answer)
- Constricting the pupil to open the trabecular meshwork
- Inhibiting carbonic anhydrase in the ciliary epithelium
Correct answer: Increasing uveoscleral outflow via prostaglandin FP receptor activation
Latanoprost is a prostaglandin F2α analog that binds FP receptors in the ciliary muscle, increasing uveoscleral (unconventional) outflow to reduce IOP.
Question 6: A patient using phenylephrine 10% drops experiences an acute hypertensive episode. This is most likely due to:
- Cholinergic stimulation of the heart
- Systemic absorption of the sympathomimetic through conjunctival vessels (Correct answer)
- Inhibition of carbonic anhydrase systemically
- Prostaglandin-mediated vasodilation followed by rebound
Correct answer: Systemic absorption of the sympathomimetic through conjunctival vessels
Phenylephrine 10% can be absorbed through the conjunctival vasculature into the systemic circulation, stimulating alpha-1 adrenergic receptors in blood vessels and causing acute hypertension.
Question 7: Which ophthalmic medication is classified as a rho kinase (ROCK) inhibitor and represents a newer mechanism for lowering IOP in open-angle glaucoma?
- Latanoprostene bunod
- Netarsudil (Rhopressa) (Correct answer)
- Tafluprost
- Brinzolamide
Correct answer: Netarsudil (Rhopressa)
Netarsudil inhibits rho kinase (ROCK), which increases conventional trabecular outflow and decreases episcleral venous pressure to lower IOP through a novel mechanism.
COT Ophthalmic Pharmacology 5
Which diagnostic dye is used to evaluate lacrimal drainage patency during the Jones dye tests?