Which topical antiviral agent for ocular herpes is a common alternative to trifluridine?

• A. Idoxuridine
• B. Acyclovir
• C. Ganciclovir
• D. Fomivirsen

Answer: (C)

Topical antivirals for ocular herpes rely on nucleoside analogs that halt HSV DNA synthesis. Trifluridine is a common first-line option, but another widely used topical choice is ganciclovir. Ganciclovir ophthalmic gel works by being taken up into infected cells and converted to its active triphosphate form, where it inhibits viral DNA polymerase and stops HSV replication in corneal epithelial cells. It provides similar antiviral activity to trifluridine but generally causes less irritation and surface toxicity, making it a convenient alternative for longer or more comfortable courses of therapy.

Older or less suitable choices in this context include idoxuridine, which is more toxic to the ocular surface; acyclovir is less favored topically due to limited corneal penetration and practical dosing considerations; and fomivirsen is an intravitreally delivered antisense therapy used for CMV, not topical HSV infections.