Background : The optic nerve sheath diameter (ONSD) can predict intracranial pressure and outcomes in patients with neurological disease. The utility of measuring the ONSD via computed tomography (CT) according to slice thickness in acute ischemic stroke (AIS) patients is unknown.
Methods : We measured the ONSD and ONSD/eyeball transverse diameter (ETD) ratio on routine-slice and thin-slice brain CT images from initial brain CT scans of AIS patients. ONSD-related variables, National Institutes of Health Stroke Scale (NIHSS) scores at baseline and age were compared between patients with good (modified Rankin Scale [mRS] score <2) and poor (mRS score >3) outcomes at hospital discharge.
Results : Of the 155 patients analyzed, 38 had a poor outcome. In contrast to other ONSD-related variables, routine-slice ONSD did not differ between outcome groups. The area under the curve (AUC) values of the ONSD and ONSD/ETDs were 0.58 (95% CI, 0.49–0.66) and 0.58 (95% CI, 0.50–0.66), respectively, on routine-slice CT images and 0.60 (95% CI, 0.52–0.68) and 0.62 (95% CI, 0.54–0.69), respectively, on thin-slice CT images. All ONSD-related variables, especially thin-slice ONSD/ETD ratio, were positively correlated with initial NIHSS scores (r=0.225, p=0.005). However, after adjusting for NIHSS scores and age, ONSD-related variables were not independent predictors of outcomes at discharge.
Conclusion : ONSD-related variables measured on thin-slice brain CTs appear to offer better prognostic performance than those measured on routine-slice brain CTs in these patients. However, combining these variables with the clinical variables model did not improve performance in determining poor functional outcomes.