Correlation of Clinical Outcomes with Quantitative Polymerase Chain Reaction DNA Copy Number in Patients with Acute Retinal Necrosis

Purpose: To correlate visual acuity outcomes and clinical features with quantitative PCR DNA copy number in patients with acute retinal necrosis (ARN). Methods: Retrospective, consecutive case series. Results: In total, 14 eyes of 13 patients were diagnosed with ARN, based on the American Uveitis Society criteria, and were followed for a mean of 324.5 days (median 250.5 days, SD ± 214 days). Anterior chamber fluid analyzed by quantitative PCR identified viral DNA in 11 of 14 eyes (78.5%). Varicella zoster virus (VZV) was identified in seven eyes (50%) and herpes simplex virus (HSV) in four eyes (28.5%). Mean DNA copy number was 7.9 × 10⁶/mL (median 2.10 × 10⁶/mL, range: 0–5.60 × 10⁷/mL). Eyes with quantitative PCR DNA copy number of ≥5.0 × 10⁶/mL (n = 6 eyes) had worse baseline visual acuity (logMAR 1.48 ± 0.71 vs 0.94 ± 0.76, p = 0.196) and final visual acuity (logMAR 2.10 ± 0.60 vs 0.82 ± 0.81, p = 0.007) compared with patients with a DNA copy number <5.0 × 10⁶/mL (n = 8 eyes). Patients with a DNA copy number of ≥5.0 × 10⁶/mL were more likely to have at least 5 clock hours of retinitis on funduscopic exam (p = 0.03) and developed retinal detachment more frequently (p = 0.08). Conclusions: Quantitative DNA copy number of ≥5.0 × 10⁶/mL is associated with more extensive retinitis, worse visual acuity, and development of retinal detachment in patients with acute retinal necrosis.