Which antibiotic combination is recommended for sight-threatening corneal ulcers?

• A. Tobramycin plus dexamethasone
• B. Fortified Cefazolin alone
• C. Tobramycin plus Cefazolin
• D. Tobra/Gent plus Fortified Cefazolin

Answer: (D)

For sight-threatening corneal ulcers, you need rapid, broad-spectrum coverage that targets both gram-positive cocci and gram-negative bacteria, including Pseudomonas. An aminoglycoside such as tobramycin or gentamicin provides strong activity against many gram-negatives, while fortified cefazolin covers gram-positive cocci well. Using both together at fortified concentrations achieves higher drug levels in the cornea than standard-strength drops, which is crucial when the infection is severe and threatening vision. This combination offers comprehensive empiric coverage and helps prevent progression while cultures are being processed. In the acute infectious phase, steroids are avoided because they can hinder the host response and worsen infection. A regimen with only one antibiotic or with a steroid-containing preparation would not provide the necessary spectrum or tissue penetration for a sight-threatening ulcer.