Which antibiotic is commonly used topically to cover Pseudomonas in ocular infections?

• A. Ciprofloxacin
• B. Erythromycin
• C. Tobramycin
• D. Doxycycline

Answer: (C)

Covering Pseudomonas in the eye requires a topical antibiotic with strong anti-Pseudomonal activity. Tobramycin fits this need because it is an aminoglycoside formulated for eye drops that reliably targets Pseudomonas aeruginosa and penetrates the cornea well, which is crucial in severe keratitis or contact lens–related infections. Erythromycin is more focused on gram-positive organisms and has limited Pseudomonas coverage, doxycycline isn’t used topically for ocular Pseudomonas and lacks potent activity in the eye, and while ciprofloxacin can treat Pseudomonas and is used topically, tobramycin is the agent most specifically associated with direct anti-Pseudomonal coverage in ocular infections.