Which of the following is NOT a major topical use for fluoroquinolones in ophthalmology?

• A. Bacterial conjunctivitis
• B. Ocular toxoplasmosis
• C. Corneal ulcers related to contact lenses
• D. Corneal abrasions

Answer: (B)

Fluoroquinolones are used topically in ophthalmology because they are bactericidal agents that inhibit bacterial DNA gyrase and topoisomerase IV, giving broad coverage against common ocular pathogens. Their good penetration into the cornea makes them a mainstay for treating bacterial conjunctivitis and bacterial keratitis, including corneal ulcers and infections associated with contact lens wear. Ocular toxoplasmosis, however, is caused by a parasite (toxoplasma) and requires antiparasitic therapy, not a fluoroquinolone. So while the other listed conditions are typical bacterial eye infections treated with topical fluoroquinolones, ocular toxoplasmosis is not, which is why it’s not a major topical use.