Outcomes of Combination Systemic and Intravitreal Antiviral Therapy for Acute Retinal Necrosis

Purpose Determine the efficacy of combination intravitreal and systemic antiviral therapy for the treatment of acute retinal necrosis (ARN) and risk factors impacting visual acuity (VA) and retinal detachment (RD) outcomes. Design Single-center retrospective case series. Participants Patients with an ARN diagnosis based on clinical features and polymerase chain reaction confirmation who were treated at a tertiary referral, university-based academic practice. Methods Patient records were reviewed for demographic information including age and gender. Snellen VA, disease findings including RD outcomes, optic nerve involvement, and treatments were recorded. Incidence rates of major VA and RD outcomes were calculated based on the number of events and exposure times. Cox proportional hazards regression modeling and survival analyses were used to identify factors related to VA and RD outcomes over time. Main Outcome Measures Logarithm of the minimal angle of resolution VA, 2-line or more VA gain, severe vision loss (SVL) of 20/200 or worse, RD development, and fellow eye involvement. Results Twenty-three eyes of 21 patients (11 male, 10 female) were reviewed. Thirteen patients (62%) had herpes simplex virus and 8 patients (38%) had varicella zoster virus. The event rate for 2-line or more VA gain was 0.49 events/eye-year (95% confidence interval [CI], 0.26–0.86 events/eye-year), whereas the rate of SVL was 0.61 events/eye-year (95% CI, 0.34–1.02 events/eye-year). Retinal detachment development was observed at a rate of 0.59 events/eye-year (95% CI, 0.33–1.00 events/eye-year). Thirteen of 23 eyes (57%) demonstrated RD with a mean time of 120 days after ARN diagnosis. With each additional quadrant of retina involved, a greater risk of RD development over time was observed (hazard ratio, 2.21; 95% CI, 1.12–4.35). Nine percent of eyes progressed with additional quadrantic involvement, despite combination systemic and intravitreal antiviral therapy; however, none of the 19 patients demonstrating unilateral ARN showed fellow-eye involvement after initiation of therapy. Conclusions Combination intravitreal and systemic antiviral therapy for ARN can be effective in improving VA and limiting retinitis progression. Each additional quadrant of retina involved was associated with a 2.2-fold greater risk of RD, which may impact monitoring, timing of intervention, and patient counseling.