Gao Y, et al. - In this prospective observational study, the physicians investigated the utility of the optic nerve sheath diameter (ONSD) in cases after a hemicraniectomy. The ONSD was evaluated in the Glasgow Outcome Score (GOS), according to the intracranial pressure (ICP) and neurological outcome. The receiver operator characteristic (ROC) curve report showed that Glasgow coma score (GCS), Helsinki computed tomography (CT) score, pupil reaction, and the opposite side (ONSDcon) measured after the craniectomy were significantly linked with a poor outcome. It was also observed that after hemicraniectomy, the ONSD measured on ultrasound was not found reliable to estimate ICP but revealed potential prognostic value for a poor neurological outcome.