Impact of the COVID-19 Pandemic on Outpatient Visit-Based Frequency Trends of Herpes Zoster Ophthalmicus.

Herpes zoster ophthalmicus (HZO) is a vision-threatening disease, yet the long-term impact of the COVID-19 pandemic on its relative frequency and ocular complication profile remains insufficiently understood. This retrospective observational study aimed to quantitatively evaluate the pandemic's influence on the long-term relative frequency trends of HZO and its ocular complications. We analyzed 15 years of clinical data from January 2011 to June 2025 at a single institution in Japan. Interrupted time series analysis was employed to distinguish immediate level changes from long-term trend changes in disease relative frequency following the pandemic's onset in early 2020. Comparing the pre-pandemic and post-pandemic cohorts, the mean age of patients with HZO increased significantly by approximately eight years, and the proportion of cases complicated by uveitis increased from 22.7% to 41.6%. While the time series analysis indicated no immediate surge in the relative frequency of HZO at the pandemic's start, it revealed a highly significant acceleration in the long-term increasing trend of HZO cases. Furthermore, the frequency trend of herpetic uveitis exhibited a similar and statistically significant upward shift during the post-pandemic period. These findings suggest that the pandemic period was associated with a transient fluctuation in healthcare utilization, but it was also associated with a sustained acceleration in the relative frequency of HZO and a notably higher frequency of HZO-associated uveitis. The pronounced increase in cases among older adults underscores the critical importance of proactive herpes zoster vaccination and enhanced ophthalmic triage to prevent permanent vision loss in the post-pandemic era.