Herpesvirus-Associated Visual Impairment: Clinical Features, Etiological Spectrum, and Treatment Outcomes in Consecutive Patients from a Tertiary Neurological Clinic.

[Background] Herpesvirus infections can induce diverse visual impairments with permanent sequelae, yet systematic data on their clinical spectrum and outcomes remain scarce. [Methods] We conducted a single-center retrospective cohort study at the Department of Neurology, Beijing Tongren Hospital, Capital Medical University. Thirteen consecutive patients (19 affected eyes) with herpesvirus-related visual impairment admitted between January 2016 and January 2025 were enrolled. Demographic data, clinical manifestations, etiological tests (polymerase chain reaction [PCR], metagenomic next-generation sequencing [mNGS], serology), neuroimaging, treatment regimens, and visual outcomes were analyzed. [Results] The cohort had a mean age of 50.4 years (range 31-66), with male predominance (84.6%, 11/13). Varicella zoster virus (VZV) was the leading pathogen (76.9%, 10/13), followed by herpes simplex virus type 1 (HSV-1), Epstein-Barr virus (EBV), and pseudorabies virus (PRV). Eight patients (61.5%) developed optic neuritis (ON) secondary to VZV infection, and five patients (38.5%) suffered from acute retinal necrosis (ARN), which was caused by VZV (n = 2), HSV-1 (n = 2), and PRV (n = 1). Bilateral involvement occurred in 46.2% (6/13) of patients. ARN was associated with the most severe visual loss. At the disease nadir, 46.2% of patients (6/13) presented with no light perception (NLP). Notably, five of these six NLP cases were diagnosed with ARN. Etiological confirmation was achieved in only 38.5% (5/13) of cases. mNGS of cerebrospinal and vitreous fluid, alongside aqueous humor PCR, are pivotal for diagnosing HSV-1/EBV mixed infections and rare PRV infection. All patients received antiviral therapy, 11 of whom (84.6%) were treated with intravenous antiviral agents. Glucocorticoids were administered as combination therapy to all patients. However, only one of eight VZV-ON eyes showed genuine visual improvement. In VZV-ARN, the initially involved eyes stayed NLP at final follow-up, while the fellow eyes recovered vision. Still, all non-VZV ARN patients had persistent bilateral NLP during follow-up. [Conclusions] Herpesvirus-associated visual impairment is dominated by VZV, manifests as ON or ARN, and carries a high risk of severe permanent vision loss-particularly in ARN. The emergence of zoonotic PRV underscores the need for heightened clinical vigilance. Diagnostic delays and insufficient interdisciplinary collaboration contribute substantially to poor outcomes.