Optic nerve sheath diameter
In a study of Agrawal et al. optic nerve sheath diameter demonstrated a modest, statistically significant correlation with intracranial pressure, a predetermined level of diagnostic accuracy to justify routine clinical use as a screening test was not achieved. Measurement of optic disc elevation appears promising for the detection of elevated intracranial pressure, however, verification from larger studies is necessary 4).
Optic nerve sheath diameter ultrasonography
1) Hansen HC, Helmke K. Validation of the optic nerve sheath response to changing cerebrospinal fluid pressure: Ultrasound findings during intrathecal infusion tests. J Neurosurg. 1997;87:34–40.2) Helmke K, Hansen HC. Fundamentals of transorbital sonographic evaluation of optic nerve sheath expansion under intracranial hypertension. I. Experimental study. Pediatr Radiol. 1966;26:701–5.3) Liu M, Yang ZK, Yan YF, Shen X, Yao HB, Fei L, Wang ES. Optic nerve sheath measurements by computed tomography to predict intracranial pressure and guide surgery in patients with traumatic brain injury. World Neurosurg. 2019 Oct 17. pii: S1878-8750(19)32683-X. doi: 10.1016/j.wneu.2019.10.065. [Epub ahead of print] PubMed PMID: 31629929.4) Agrawal D, Raghavendran K, Zhao L, Rajajee V. A Prospective Study of Optic Nerve Ultrasound for the Detection of Elevated Intracranial Pressure in Severe Traumatic Brain Injury. Crit Care Med. 2020 Oct 13. doi: 10.1097/CCM.0000000000004689. Epub ahead of print. PMID: 33048902.