Topical interferon alpha-2a treatment of herpes simplex keratitis resistant to multiple antiviral medications in an immunosuppressed patient.

The treatment of herpes simplex keratitis has ranged from simple debridement to the use of prototypic antiviral agents specific to the herpes family, such as acyclovir. The various treatment modalities for dendritic keratitis, for the most part, have been effective. However, in recent years numerous reports of antiviral-resistant strains of herpes simplex have appeared, particularly in immunocompromised patients receiving chronic acyclovir. Interferon has been proposed as a possible treatment adjunct in these cases. We report the case of a 46-year-old man on chronic immunosuppressive and acyclovir therapy after a renal transplant who developed ulcerative keratitis due to a strain of herpes simplex virus that was resistant to multiple antiviral agents both in vivo and in vitro. After 7 weeks without improvement on multiple treatment regimens, including trifluridine, vidarabine, debridement, and topical and systemic acyclovir, interferon alpha-2a was added to topical acyclovir therapy, and the keratitis quickly resolved. Topical interferon alpha-2a appears to be an effective treatment adjunct for refractory herpes simplex keratitis in patients with cell-mediated immune dysfunction and subsequent lack of endogenous interferon. Its value in nonimmunocompromised patients remains to be determined.