Ultrasound of Optic Nerve Sheath Diameter and Stroke Outcomes

We aimed at utilizing ocular ultrasound to determine its utility in predicting outcomes among stroke patients. DESIGN Single-center prospective observational study. SETTING Emergency department and ICUs. PATIENTS Patients suspected of stroke. INTERVENTIONS None. MEASURES AND MAIN RESULTS Bilateral optic nerve sheath diameter was measured on arrival and within the first 2 days of admission. Outcomes were inpatient survival, Cerebral Performance Category, and modified Rankin Scale at 3 and 6 months. Analysis was conducted using descriptive statistics, paired t test, chi-square test. Eighty-six patients were enrolled with ischemic or hemorrhagic stroke. Mean age was 67.2 years (± 15 yr), and 54.7% of patients were male. There was no difference between left and right eye measurements (p = 0.467 and p = 0.903, respectively) or between longitudinal and transverse measurements (transverse p = 0.163 and longitudinal p = 0.270). Mean optic nerve sheath diameter differed in patients who survived versus died prior to discharge in both ischemic (0.53 vs 0.58 cm; p = 0.009) or hemorrhagic stroke (0.57 vs 0.62 cm; p = 0.019). For every 0.1 cm increase in optic nerve sheath diameter, odds ratio for death were 4.2 among ischemic stroke (95% CI, 1.32-13.64; p = 0.015), and odds ratio 6.2 among ischemic or hemorrhagic patients (95% CI, 1.160-33.382; p = 0.033). Increased optic nerve sheath diameter correlated (r = 0.44; p < 0.0001) with poor functional outcomes measured as modified Rankin Scale scores of 3-6 at 6 months. CONCLUSIONS Elevations in optic nerve sheath diameter were associated with increased inhospital mortality and poor functional outcome at 6 months. Optic nerve sheath diameter may serve as a noninvasive marker of inhospital mortality and functional outcome. Further multicenter prospective trials for evaluating and treating optic nerve sheath diameter in ischemic and hemorrhagic strokes are warranted.