BACKGROUND AND OBJECTIVE: Acute retinal necrosis (ARN) may lead to severe visual loss because of its rapid progression and high likelihood of retinal detachment (RD). This study investigates whether combination systemic and intravitreal antiviral therapy is superior to systemic antiviral therapy alone. PATIENTS AND METHODS: Single-center, interventional, comparative case series of patients with ARN treated with combination systemic antiviral and intravitreal foscarnet injection therapy or systemic antiviral therapy alone. Survival analysis and incidence rates of visual acuity (VA) gain of two lines or greater, severe visual loss of 20/200 or worse, and RD were assessed. RESULTS: Twelve patients received combination therapy and 12 received systemic therapy alone. Patients receiving combination therapy were more likely to gain two or more lines of VA and showed decreased incidences of severe visual loss and RD. CONCLUSION: Combination oral and intravitreal antiviral therapy may improve the likelihood for VA gain and decrease the risk of RD in patients with ARN. Clinicians should consider administering combination systemic and intravitreal antiviral therapy for patients with the ARN syndrome.