Ultrasound for the Anesthesiologists: Present and Future
Figure 5
Optic nerve sheath: (a) normal diameter and (b) large diameter that represents increase intracranial pressure. ONSD: optic nerve sheath diameter. It is usually measured 3 mm behind the retina. Ultrasound pupillary light reflex: (c) diameter of the pupil before shining light to the contralateral eye and (d) the pupil constricted after shining the light.
