A 20-year-old woman with redness and drainage in the right eye for two days wears contact lenses. VA is intact and fluorescein examination is negative. What is the most appropriate first-line ophthalmic therapy?

• A. Ciprofloxacin
• B. Erythromycin ointment
• C. Tobramycin
• D. Gentamicin

Answer: (A)

When a contact lens wearer presents with acute conjunctivitis, the priority is to cover potential bacterial pathogens that can affect the cornea, especially Pseudomonas, while ruling out corneal involvement. Since fluorescein is negative and vision is intact, this is conjunctivitis without a corneal ulcer—so the first-line therapy should provide broad anti-pseudomonal coverage with good ocular penetration. A topical fluoroquinolone like ciprofloxacin fits perfectly here: it covers Pseudomonas and other common Gram-negative and Gram-positive organisms, penetrates the ocular surface well, and is well tolerated with convenient dosing.

Erythromycin ointment, while safe, lacks robust anti-pseudomonal activity and is less ideal for this presentation. Aminoglycosides such as tobramycin or gentamicin do have anti-pseudomonal activity but are less favored due to safety considerations and dosing practicality in simple conjunctivitis cases. Instruct the patient to stop wearing contact lenses until cleared and to return if symptoms worsen, worsen rapidly, or if there are changes in vision.