COT Ophthalmic Pharmacology 4 — Questions and Answers
Question 1: Which topical ophthalmic antibiotic is a fluoroquinolone commonly used to treat bacterial conjunctivitis and corneal ulcers?
- Erythromycin
- Bacitracin
- Ciprofloxacin (Correct answer)
- Neomycin
Correct answer: Ciprofloxacin
Ciprofloxacin is a broad-spectrum fluoroquinolone antibiotic that inhibits bacterial DNA gyrase and is effective against both gram-positive and gram-negative organisms causing ocular infections.
Question 2: Sodium hyaluronate (viscoelastic) used during cataract surgery serves which primary intraoperative purpose?
- Providing antibiotic prophylaxis
- Maintaining anterior chamber depth and protecting the corneal endothelium (Correct answer)
- Inducing miosis to facilitate IOL placement
- Dissolving the lens nucleus
Correct answer: Maintaining anterior chamber depth and protecting the corneal endothelium
Viscoelastic agents like sodium hyaluronate maintain space in the anterior chamber and coat the corneal endothelium to protect it from surgical trauma during intraocular procedures.
Question 3: A patient with herpes simplex keratitis should avoid which class of ophthalmic medication, as it can worsen the infection and cause stromal melting?
- Topical antivirals
- Topical corticosteroids used alone without antivirals (Correct answer)
- Artificial tears
- Topical antibiotics
Correct answer: Topical corticosteroids used alone without antivirals
Topical corticosteroids used without concurrent antiviral coverage can suppress local immune response, allowing HSV replication and potentially causing progressive stromal ulceration.
Question 4: Mast cell stabilizers such as cromolyn sodium are used in allergic conjunctivitis primarily to:
- Provide immediate relief of itching by blocking histamine receptors
- Prevent degranulation of mast cells before allergen exposure (Correct answer)
- Constrict blood vessels to reduce redness acutely
- Kill bacteria secondarily infecting the conjunctiva
Correct answer: Prevent degranulation of mast cells before allergen exposure
Mast cell stabilizers prevent the release of histamine and other mediators from mast cells when used prophylactically before allergen exposure, reducing allergic response.
Question 5: Which anti-VEGF agent administered by intravitreal injection is FDA-approved specifically for neovascular (wet) age-related macular degeneration?
- Triamcinolone acetonide
- Ranibizumab (Lucentis) (Correct answer)
- Bevacizumab (Avastin)
- Ozurdex (dexamethasone implant)
Correct answer: Ranibizumab (Lucentis)
Ranibizumab is a VEGF inhibitor fragment specifically FDA-approved for treating neovascular AMD by blocking pathological new vessel growth in the retina.
Question 6: Dipivefrin is a prodrug converted to which active compound after penetrating the cornea?
- Pilocarpine
- Timolol
- Epinephrine (Correct answer)
- Brimonidine
Correct answer: Epinephrine
Dipivefrin is a prodrug of epinephrine that is converted by corneal esterases after penetration, lowering IOP with fewer systemic side effects than direct epinephrine use.
Question 7: A patient on long-term topical corticosteroid therapy should be routinely monitored for which two ocular complications?
- Corneal neovascularization and retinal detachment
- Posterior subcapsular cataract and elevated intraocular pressure (Correct answer)
- Macular degeneration and optic neuritis
- Conjunctival scarring and iris atrophy
Correct answer: Posterior subcapsular cataract and elevated intraocular pressure
Chronic topical steroid use is associated with posterior subcapsular cataract formation and steroid-induced ocular hypertension (glaucoma), both of which require regular monitoring.
COT Ophthalmic Pharmacology 4
Which topical ophthalmic antibiotic is a fluoroquinolone commonly used to treat bacterial conjunctivitis and corneal ulcers?