Time profile of viral DNA in aqueous humor of patients treated for VZV acute retinal necrosis using quantitative real‐time PCR

Abstract

AbstractPurpose To evaluate the kinetics of varicella zoster virus (VZV) load using quantitative PCR (qPCR) in patients treated for acute retinal necrosis (ARN). Design: Cohort study, evaluation of diagnostic test or technology.Methods Six patients (52±13 years) with ARN syndrome were consecutively studied. Aqueous humor (AH) was sampled from all eyes for qPCR evaluation. The patients were treated with intravenous aciclovir and intravitreal injections of antiviral drugs. The mean follow‐up was 17.6±16.4 months.Results Two main portions of the viral load curves were observed for each patient: a plateau phase (27.8±24.9 days) followed by a decrease in the number of viral genome copies. The mean baseline viral load was 3.4×107±4.45×107copies/ml (6×106 to 1.2×108). The viral load decreased following a logarithmic model, with a 50% reduction obtained in 3±0.7 days. There was a significant viral load (> 102 copies/ml) at 50 days after the onset of treatment, despite antiviral drugs.Conclusion qPCR use demonstrated reproducible VZV DNA kinetics with a two‐phase evolution: plateau followed by logarithmic decrease. These data suggest that high‐dosage antiviral therapy during the conventional 10 days duration is insufficient in most patients. This patient's series responded with a similar decrease in viral load once initiated, this may be used to predict the progression of future patients. The correlation of the viral load threshold with clinical improvement needs to be more clearly defined.