The association of stroke with herpes zoster ophthalmicus.

BACKGROUND/OBJECTIVES: Studies have reported an association between herpes zoster ophthalmicus (HZO) and stroke. We sought to validate this association with rigorous controls for both medical comorbidities and social factors using a nationwide U.S. administrative medical claims database. SUBJECTS/METHODS: A two-step approach was taken: first a retrospective case-control study was performed, followed by a self-controlled case series (SCCS). For the case control study, cox proportional hazard regression with inverse proportional treatment weighting assessed the hazard for stroke. In the SCCS, incidence of stroke was compared prior to and after the diagnosis of HZO. RESULTS: For the case-control study, 25,720 cases and 75,924 controls met our eligibility criteria. 1712 (6.7%) and 4544 (6.0%) strokes occurred in the case and control groups respectively, conferring an 18% increased risk of stroke in the observed 1-year post-HZO period (HR = 1.18, 95% CI: 1.12-1.25, p < 0.001). SCCS analysis showed the risk for stroke was highest in the month immediately after HZO episode compared to any other time range (1-30 days after, relative risk 1.58, p < 0.001) and even higher when assessing time more distal time points prior to the HZO diagnosis (days 1-30 after HZO diagnosis had RR = 1.69 (95% CI: 1.38-2.07) and RR = 1.93 (95% CI: 1.55-2.39) compared with days -120 to -91 and -150 to -121 prior to index, respectively (p < 0.001). CONCLUSIONS: After accounting for stroke risk factors, our analysis confirms the association between HZO and stroke, with highest risk in the immediate month after an episode.