Comparing Treatment of Acute Retinal Necrosis With Either Oral Valacyclovir or Intravenous Acyclovir

Abstract

To compare the visual outcomes of patients with acute retinal necrosis (ARN) treated initially with intravenous acyclovir vs oral valacyclovir therapy. Retrospective, comparative, interventional case series. Sixty-two patients (68 eyes) with ARN, treated at Moorfields Eye Hospital (United Kingdom) between 1992 and 2016, were identified through the hospital's electronic database. Exclusion criteria included insufficient patient records or follow-up (<150days). Fifty-six patients had unilateral ARN, while 6 had bilateral ARN. Patients who received intravenous acyclovir on diagnosis (n= 33) were compared with patients treated with oral valacyclovir (n= 29) across outcomes including best-corrected visual acuity, retinal detachment, severe vision loss, and other complications. The impact of adjunctive intravitreal antiviral and prophylactic barrier laser treatment was also assessed. Change in best-corrected visual acuity was not significantly different for eyes treated initially with intravenous therapy vs oral therapy over 5 years of follow-up data (P= .16). There was no difference in the rates of severe vision loss between the 2 groups (46% and 59%, respectively, P= .18), or of those eyes retaining good vision (28% vs 31%, respectively, P=.80). Retinal detachment occurred in 63% of cases and did not differ across treatment groups (62% vs 66%, respectively, P= .67). Barrier laser and intravitreal therapy had no effect on retinal detachment rate in either group. Oral valacyclovir is clinically equivalent to intravenous therapy in the management of ARN. Oral valacyclovir as an outpatient therapy-with or without intravitreal foscarnet-can therefore be considered as an acceptable alternative to inpatient therapy required for intravenous treatment.