Background: Diagnosis and management of Acute Retinal Necrosis (ARN) inchildren that does not respond to systemic acyclovir treatment can be challenging. We report two casesof ARN secondary to herpes simplex virus (HSV) type 2 that was resistant to acyclovir but was treatedsuccessfully with intravenous foscarnet. Case Report: Two children diagnosed with ARN failed to showclinical response to systemic acyclovir treatment. Both cases had histories of previous HSV infectionsand vitreous taps positive for HSV-2. Both were converted to systemic foscarnet treatment with successfulcontrol of the retinitis and satisfactory visual outcomes. Conclusions: Systemic foscarnet can be effectivein the management of pediatric acute retinal necrosis caused by HSV-2 when there is an atypical responseto conventional acyclovir treatment.

Keywords: Acyclovir - therapeutic use, Adolescent, Antiviral Agents - therapeutic use, Child, Drug Resistance, Viral, Foscarnet - therapeutic use, Herpes Simplex - virology, Herpesvirus 2, Human - drug effects, Injections, Intravenous, Retinal Necrosis Syndrome, Acute - virology