PURPOSE: To provide a population-based estimate of the incidence of herpes zoster ophthalmicus (HZO) with comparisons across racial, sex, and age groups, as well as to estimate the frequency of postherpetic neuralgia (PHN).
DESIGN: Retrospective, population-based cohort study.
PARTICIPANTS: All patients enrolled in the Kaiser Permanente Hawaii health plan during the study period (N = 217 061).
METHODS: All patient encounters between January 1, 2006, and December 31, 2007, in the electronic medical record of Kaiser Permanente Hawaii were queried for International Classification of Diseases, 9th edition (ICD-9) codes corresponding to HZO. Charts were reviewed to confirm a diagnosis of HZO and to collect information about specific ocular manifestations. Demographic data and information on PHN were collected electronically. Incidence rates were calculated per 100 000 person-years for the entire population and for age-, sex-, and race-specific subgroups.
MAIN OUTCOME MEASURES: Clinical diagnosis of HZO during the study period.
RESULTS: A total of 134 cases of HZO were identified in this population of 217 061 people. The overall incidence was 30.9 per 100 000 person-years (95% confidence interval [CI], 25.9-36.6). The incidence rate for the population aged ≥65 years was 104.6 per 100 000 person-years (95% CI, 79.0-135.9), approximately 5 times the remainder of the population (P < 0.001). The most common manifestation of HZO was dermatitis, followed by keratitis and conjunctivitis. The incidence of HZO for Pacific Islanders was 19.0 per 100 000 person-years (95% CI, 12.4-28.3), which was significantly lower than the rate for non-Pacific Islanders (P = 0.007). Twenty-one percent of patients with HZO developed PHN. Older age and HZO with keratitis, conjunctivitis, or uveitis were found to be risk factors for PHN.
CONCLUSIONS: This study provides a population-based estimate of HZO and highlights differences across various age and racial groups. It also suggests that demographic characteristics may be useful in determining the risk of developing HZO.
