Dendritic keratitis caused by an acyclovir-resistant herpes simplex virus with frameshift mutation.

Purpose: To report a case of acyclovir-resistant herpes simplex virus (HSV) keratitis after long-term, inconsistent use of topical acyclovir and fluorometholone.

Methods: A 70-year-old man with dendritic keratitis caused by an acyclovir-resistant HSV strain was examined. The 50% inhibitory concentration of different antiviral agents against the isolated virus and the DNA sequence of viral thymidine kinase were determined.