Which antiviral medication specifically inhibits DNA polymerase for the treatment of HSV keratitis?

Trifluridine is an antiviral medication that is specifically designed to inhibit viral DNA polymerase, making it highly effective in treating infections caused by the herpes simplex virus (HSV), such as HSV keratitis. It works by incorporating itself into viral DNA, thereby disrupting DNA synthesis and halting viral replication.

Trifluridine is particularly beneficial for ocular infections because it can be administered topically in the form of eye drops, allowing for direct application to the affected area. This targeted delivery helps to minimize systemic side effects while maximizing the therapeutic effect on the ocular surface.

Other antiviral medications listed, such as valacyclovir, famciclovir, and ganciclovir, may also be effective against HSV but they do not primarily function by inhibiting HSV DNA polymerase in the same way that trifluridine does. Valacyclovir and famciclovir are prodrugs that get converted to acyclovir, which inhibits viral DNA synthesis but does not directly target DNA polymerase. Ganciclovir is used mainly for cytomegalovirus (CMV) infections, and while it has some utility against HSV, its primary use is not for treating HSV keratitis specifically.

Thus, trifluridine