The overall frequency of herpes zoster ophthalmicus (HZO) from 2004 to 2021 was 4.2% and has increased annually since 2012, according to findings published in the Canadian Journal of Ophthalmology. Researchers conducted a retrospective cohort study to determine the frequency of HZO and evaluate risk factors for developing uncommon ocular manifestations of laboratory-verified HZO.
The researchers calculated the frequency of HZO out of all herpes zoster cases using International Classification of Diseases codes for patients seen at the University of Pittsburgh Medical Center from 2004 to 2021. Demographic and clinical data was collected for patients with HZO identified by polymerase chain reaction (PCR) detection of varicella zoster virus from 2011 to 2020.
The study found that, in all ages, the frequency of HZO from 2004 to 2021 was 4.2% and ranged from 2.7% to 6.7% annually, with a consistent increase of 2.9% from 2012 to 2021. The frequency of HZO decreased by 5.1% from 2008 to 2012 in patients aged 60 and older after the live zoster vaccine became available in 2008. Among 50 cases of PCR-verified HZO, 62% represented clinically-common ocular manifestations, mostly comprised of 13 cases of keratitis and 10 cases of anterior uveitis. The majority of uncommon HZO manifestations (38%) were represented by 15 cases of acute retinal necrosis (ARN). These manifestations were significantly more likely to occur in immunosuppressed patients (95% CI 1.29-13.83).
The researchers explained that obtaining a vaccination against HZO is important, especially for immunosuppressed patients who are more prone to developing uncommon manifestations such as ARN with poor visual outcomes.
“Vaccination with live zoster vaccine or recombinant zoster vaccine is critical for limiting the increasing burden of HZO,” according to the researchers. “Involvement of ocular structures has been shown in 30%-78% of HZO cases, with common manifestations including keratitis, granulomatous anterior uveitis, and conjunctivitis.”
Study limitations include its retrospective design and the inability to assess the incidence of HZO or any specific manifestations using International Classification of Diseases codes from the research database.
Dmitriev AA, Odden J, Mora-Boellstorff D, et al. Herpes zoster ophthalmicus: frequency and risk factors for developing uncommon ocular manifestations. Can J Ophthalmol. Published online May 13, 2023. doi:10.1016/j.jcjo.2023.04.011