Changes of viral DNA load in the early stages of antiviral treatment in varicella zoster virus-induced acute retinal necrosis / 中华眼底病杂志

ABSTRACT

Objective:To observe the changes of varicella zoster virus (VZV)-DNA load in aqueous humour samples in VZV-induced acute retinal necrosis (ARN) in the early stages of antiviral treatment.Methods:A retrospective observational clinical study. From April 2016 to April 2018, 24 patients with 24 eyes of VZV-induced ARN who were diagnosed by Department of Ophthalmology, Eye and ENT Hospital of Fudan University and received complete aqueous humor sampling were included in the study. Among them, there were 13 males with 13 eyes, 11 females with 11 eyes; 12 left eyes and 12 right eyes; the age was 52.0±9.5 years old (39-71 years old). The time from the onset of ocular symptoms to the diagnosis of ARN was 16.6±6.1 days (7-30 days). Best-corrected visual acuity (BCVA) and ultra-wide-field fundus imaging were performed in all affected eyes. The BCVA examination was carried out using the Snellen visual acuity chart, which was converted into the logarithm of the minimum angle of resolution (logMAR) visual acuity. All patients were given intravitreal injection of 40 mg/ml ganciclovir 0.1 ml (including 4 mg of ganciclovir), 2 times a week, until the active necrotizing retinal lesions subsided, at most after the diagnosis 4 weeks, with a maximum of 9 injections. The follow-up period was 12.8±5.6 months. The aqueous humor samples were collected at presentation and 4, 7, 14, 21, 28 days after the initiation of antiviral therapy, and the VZV-DNA load was detected by real-time quantitative polymerase chain reaction. A plateau phase and a logarithmic reduction phase of the DNA load changes were observed after antiviral treatment began. Wilcoxon rank sum test was used to compare and analyze the differences in BCVA between the eyes at baseline and last follow-up.Results:The mean viral load at presentation was 8.6×10 7±1.3×10 8 copies/ml. The initial plateau phase last for an average of 7.4±2.4 days. In the following logarithmic reduction phase, the mean slope of the decline in viral load was -0.13±0.04 log/day, and the expected time for half reduction of the initial viral load was 2.5±0.7 days. After 28 days antiviral treatment, the viral load decreased to 1.7×10 5±1.8×10 5 copies/ml. In the course of the disease, rhegmatogenous retinal detachment occurred in 16 eyes. Before treatment and at the last follow-up, the logMAR BCVA of the affected eye was 1.1±0.6 and 0.8±0.7, respectively. The results of correlation analysis showed that the logMAR BCVA at the last follow-up was correlated with the initial VZV-DNA load ( r=0.467, P=0.033). Conclusion:The VZV-DNA load in the aqueous humor of eyes with VZV-induced ARN is significantly decreased after antiviral treatment, which is closely related to the clinical process of ARN.