Correlation of optic nerve and optic nerve sheath diameter with intracranial pressure in pigs.

Mija, R.; Zubak, I.; Schuetz, A.; Glas, M.; Fung, C.; Jakob, S. M.; Beck, J.; Z'Graggen, W. J.; Bloch, Andreas (2020). Correlation of optic nerve and optic nerve sheath diameter with intracranial pressure in pigs. PLoS ONE, 15(2), e0228242. Public Library of Science 10.1371/journal.pone.0228242

2020 - Mija - PloS One - PMID 32017786 .pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (1MB) | Preview


Several studies have shown an association between intracranial pressure and the diameter of the optic nerve sheath measured by transbulbar ultrasonography. To understand the pathophysiology of this phenomenon, we aimed to measure the changes of the optic nerve, optic nerve sheath and perineural space separately with increasing intracranial pressure in a porcine model.


An external ventricular drain was placed into the third ventricle through a right paramedian burrhole in eight anesthesized pigs. The diameters of the optic nerve and the optic nerve sheath were measured while the intracranial pressure (ICP) was increased in steps of 10mmHg from baseline up to 60 mmHg.


The median diameters of the optic nerve (ON) increased from 0.36 cm (baseline- 95% confidence interval (CI) 0.33 cm to 0.45 cm) to 0.68 cm (95% CI 0.57 cm to 0.82 cm) at ICP of 60 mmHg (p<0.0001) and optic nerve sheath (ONS) from 0.88 cm (95% CI 0.79 cm to 0.98 cm) to 1.24 cm (95% CI 1.02 cm to 1.38 cm) (p< 0.002) while the median diameter of the perineural space (PNS) (baseline diameter 95% CI 0.40 cm to 0.59 cm to diameters at ICP 60 95% CI 0.38 cm to 0.62 cm) did not change significantly (p = 0.399). Multiple comparisons allowed differentiation between baseline and values ≥40 mmHg for ON (p = 0.017) and between baseline and values ≥ 50mmHg for ONS (p = 0.006). A linear correlation between ON (R2 = 0.513, p<0.0001) and ONS (R2 = 0.364, p<0.0001) with ICP was found. The median coefficient of variation for intra- and inter-investigator variability was 8% respectively 2.3%.


Unexpectedly, the increase in ONS diameter with increasing ICP is exclusively related to the increase of the diameter of the ON. Further studies should explore the reasons for this behaviour.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Department of Intensive Care, Emergency Medicine and Anaesthesiology (DINA) > Clinic of Intensive Care
04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Neurosurgery

UniBE Contributor:

Glas, Michael; Z'Graggen, Werner Josef and Bloch, Andreas


600 Technology > 610 Medicine & health




Public Library of Science




Mirella Aeberhard

Date Deposited:

13 Feb 2020 16:48

Last Modified:

13 Feb 2020 16:48

Publisher DOI:


PubMed ID:





Actions (login required)

Edit item Edit item
Provide Feedback