The Risk of Ischemic Stroke in Patients With Nonarteritic Anterior Ischemic Optic Neuropathy: A Big Data Study.

Background: This study explored ischemic stroke occurrence in patients with nonarteritic anterior ischemic optic neuropathy (NAION) and assess the link between NAION and carotid artery stenosis (CAS) as an ischemic stroke risk factor.

Methods: A retrospective (2009-2019) nationwide, population-based study was conducted using a cohort database from Clalit, the largest healthcare network in Israel. Among 1,200,000 insured individuals, 605 NAION patients without prior ischemic stroke diagnosis were included, matched with a 10-fold larger comparison group by age, sex, and cardiovascular risk factors.

Results: Results indicated a higher incidence of large-vessel ischemic stroke (18.7% vs 14.7% in the comparison group) and small-vessel ischemic stroke (4.8% vs 3.1% in the comparison group) in patients with NAION. CAS prevalence was elevated in patients with NAION both during the study and during follow-up. Multivariable analysis showed hazard ratios of 1.5 (P = 0.002) for large-vessel ischemic strokes and 1.56 (P = 0.031) for small-vessel ischemic strokes in patients with NAION. The cumulative probability of ischemic strokes for patients with NAION without risk factors was higher than for the comparison group without risk factors (log rank test, P = 0.017).

Conclusions: These population-based study results revealed a higher incidence of ischemic stroke after a NAION episode compared with the comparison group. This association was valid regardless of any additional vascular risk factors. There is a need to consider specific management for patients with NAION diagnosed with carotid artery stenosis because of the potential for a triadic relationship among the 3 conditions.