Which of the following is an antibiotic used in ophthalmology?

• A. Ofloxacin
• B. Diclofenac
• C. Prednisolone
• D. Ketorolac

Answer: (A)

Ofloxacin is an antibiotic formulated for topical use in the eye. It belongs to the fluoroquinolone class and works by inhibiting bacterial DNA gyrase and topoisomerase IV, enzymes essential for bacterial DNA replication, which leads to bacterial death. This makes it effective against many common ocular bacterial infections such as conjunctivitis and keratitis.

The other drugs listed are not antibiotics: diclofenac and ketorolac are nonsteroidal anti-inflammatory drugs used to reduce pain and inflammation, while prednisolone is a corticosteroid used to suppress inflammation. Using a steroid or an NSAID alone does not treat bacterial infections and can be inappropriate if an infection is present. Therefore, ofloxacin is the correct choice as the antibiotic in ophthalmology.