Delayed reversal of ONS distension- initial scan. ONUS performed in a 66-year-old patient who became acutely unresponsive two days after removal of an EVD. Scan performed prior to placement of new EVD. The ocular globe is the hypoechoic structure in the upper part of the images and the ONS the linear hypoechoic structure behind the globe. Caliper A identifies a point 3 mm behind the retina while Caliper B measures the ONSD. ONSD is 0.55 cm, suggestive of raised ICP. Opening pressure was >50 mmHg.