Which two fluoroquinolones are commonly used in ophthalmology for keratitis and conjunctivitis?

• A. Moxifloxacin and levofloxacin (ciprofloxacin is also used)
• B. Ciprofloxacin and ofloxacin
• C. Norfloxacin and moxifloxacin
• D. Levofloxacin and gatifloxacin

Answer: (A)

Topical fluoroquinolones with strong corneal penetration and broad coverage against common ocular pathogens are preferred for keratitis and conjunctivitis. Moxifloxacin and levofloxacin fit this well: they cover the usual culprits such as Staphylococcus, Streptococcus, Moraxella, and Haemophilus, and they achieve good drug levels in the cornea when used as eye drops. Moxifloxacin, a fourth-generation agent, offers particularly robust Gram-positive activity and excellent penetration, while levofloxacin provides reliable broad-spectrum activity with convenient dosing. Ciprofloxacin is indeed used in ophthalmology, but the combination of moxifloxacin and levofloxacin is the one most commonly emphasized as a first-choice pairing in contemporary practice.

Norfloxacin has weaker Gram-positive coverage and less favorable corneal penetration for typical keratitis pathogens, making it less favored as a first-line option. Gatifloxacin is another effective fluoroquinolone but is not the standard pair described here. Ofloxacin and ciprofloxacin are older generations with narrower Gram-positive coverage compared with newer agents, so they’re less commonly touted as the two main ocular choices today.