The nationwide frequency of herpes zoster ophthalmicus (HZO) has more than doubled between 2004 and 2016, according to a new study. Researchers from the University of Michigan analyzed health claims data for 21 million patients enrolled in a large nationwide managed care plan to evaluate HZO incidence. They presented their results earlier this month at ARVO 2019 in Vancouver.

Incidence rates of HZO increased 2.4-fold from 2004 to 2016, increasing from 8.10 cases per 100,000 person-years in 2004 to 19.5 per 100,000 person-years in 2016. The study also found that HZO incidence increased with age, with the lowest incidence among patients younger than age 15 (3.5 per 100,000 person-years) and highest incidence among patients 75 or older (72.9 per 100,000 person-years). Females had a higher incidence of HZO than males (42.2 per 100,000 person-years vs. 37.2 per 100,000 person-years), and incidence rates per 100,000 person-years were highest among Caucasians (39.1) and lower among blacks (31.1), Asians (27.3) and Latinos (19.2).

Researchers speculate that because far fewer children and adults are being exposed to chickenpox virus than before, they are at greater risk of HZO. Periodic re-exposure to chickenpox virus from the community boosts patients’ immune systems and reduces risk of developing HZO. The researchers also wonder if the immune systems of female and Caucasian patients uniquely put them at greater risk. Nevertheless, they note that it is now important more than ever for older patients to get their shingles vaccination. 

Shekhawat N, Talwar N, Stein JD. Demographic and temporal variation in incidence of herpes zoster ophthalmicus in the United States population. ARVO 2019. Abstract 4257.