Which of the following describes the initial management of bacterial keratitis with standard risk?

• A. Moxifloxacin 0.5% and Polymyxin B - Trimethoprim q2h
• B. Fortified tobramycin and cefazolin q1h
• C. Cycloplegic therapy alone
• D. Observation without antibiotics

Answer: (A)

Start with immediate, broad-spectrum topical antibiotics to rapidly control the infection. A fourth-generation fluoroquinolone like moxifloxacin 0.5% provides strong activity against common keratitis pathogens and has good corneal penetration, making it a solid first-line choice for standard-risk cases. Adding polymyxin B-trimethoprim expands coverage to additional Gram-negative organisms, giving broader initial protection without resorting to fortified regimens. High-frequency dosing, such as every 2 hours, helps achieve and maintain therapeutic drug levels at the ulcer site during the critical early phase. Cycloplegic therapy alone or observation without antibiotics would not treat the infection and could allow progression, while fortified antibiotic regimens are typically reserved for more severe or high-risk presentations.