Neurocritical Care

, Volume 32, Issue 1, pp 327–332 | Cite as

A Proposal for a New Protocol for Sonographic Assessment of the Optic Nerve Sheath Diameter: The CLOSED Protocol

  • Raffaele AspideEmail author
  • Giacomo Bertolini
  • Luca Albini Riccioli
  • Diego Mazzatenta
  • Giorgio Palandri
  • Daniele Guerino Biasucci


Measuring and monitoring of intracranial pressure is considered standard of care in patients with suspected intracranial hypertension. Sonographic assessment of the optic nerve sheath diameter (ONSD) has been promising and potentially useful for noninvasive intracranial hypertension screening. ONSD measurements are easy to perform, repeatable at bedside, fast, low cost, and radiation-free. However, they are still burdened by inter-rater variability, lack of ultrasound (US) setting standardization (e.g., US frequency, focus depth, etc.), and possible artifacts. To overcome this problem, we propose the CLOSED protocol associated with equipment specifications, as a guide to minimize the occurrence of such artifacts enabling a more reliable and accurate measurement. We suggest that color Doppler could be used as a new standard evaluation for the ONSD.


CLOSED protocol Optic nerve sheath diameter Ultrasound color Doppler Central retinal artery Point-of-care ultrasound 



As low as reasonably achievable


Central retinal artery


Central retinal vein


Intracranial pressure


Intensive care unit


Idiopathic intracranial hypertension


Idiopathic normal pressure hydrocephalus


Spatial-peak temporal-average intensity


Mechanical index




Optic nerve


Optic nerve sheath diameter


Pulse repetition frequency


Subarachnoid hemorrhage


Thermal index


Thermal index cranium


Soft tissue thermal index at surface





We thank Dr. Monica Ferri for color Doppler learning skills, Dr. Veronica Salvatore for assistance with US settings support, and Dr. Franziska Lohmeyer for the revision of our manuscript.

Authors contribution

Aspide, Bertolini was involved in conception and design. Aspide, Bertolini, Albini was involved in acquisition of data. Aspide, Bertolini, Biasucci contributed in drafting the article. All authors critically revised the article and reviewed the submitted version of manuscript. Albini was also involved in Technical/material support. Mazzatenta, Palandri, and Biasucci contributed in study supervision.

Source of support

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Conflicts of Interest

The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Ethical approval

The local Institutional Review Board approved the present study. CLOSED protocol adhered to ethical standards and Helsinki Declaration.


  1. 1.
    Rossi S, Buzzi F, Paparella A, Mainini P, Stocchetti N. Complications and safety associated with ICP monitoring: a study of 542 patients. In: Marmarou A, et al., editors. Intracranial pressure and neuromonitoring in brain injury., Acta neurochirurgica supplementsVienna: Springer; 1998.Google Scholar
  2. 2.
    Rebuck JA, Murry KR, Rhoney DH, Michael DB, Coplin WM. Infection related to intracranial pressure monitors in adults: analysis of risk factors and antibiotic prophylaxis. J Neurol Neurosurg Psychiatry. 2000;69:381–4.CrossRefGoogle Scholar
  3. 3.
    Ma R, Rowland D, Judge A, Calisto A, Jayamohan J, Johnson D, et al. Complications following intracranial pressure monitoring in children: a 6-year single-center experience. J Neurosurg Pediatr. 2018;21:278–83.CrossRefGoogle Scholar
  4. 4.
    Robba C, Cardim D, Tajsic T, Pietersen J, Bulman M, Donnelly J, et al. Ultrasound non-invasive measurement of intracranial pressure in neurointensive care: a prospective observational study. PLoS Med. 2017;14:e1002356.CrossRefGoogle Scholar
  5. 5.
    Robba C, Santori G, Czosnyka M, Corradi F, Bragazzi N, Padayachy L, et al. Optic nerve sheath diameter measured sonographically as non-invasive estimator of intracranial pressure: a systematic review and meta-analysis. Intensive Care Med. 2018;44:1284–94.CrossRefGoogle Scholar
  6. 6.
    Moretti R, Pizzi B, Cassini F, Vivaldi N. Reliability of optic nerve ultrasound for the evaluation of patients with spontaneous intracranial hemorrhage. Neurocrit Care. 2009;11:406.CrossRefGoogle Scholar
  7. 7.
    Lochner P, Coppo L, Cantello R, Nardone R, Naldi A, Leone MA, et al. Intra- and interobserver reliability of transorbital sonographic assessment of the optic nerve sheath diameter and optic nerve diameter in healthy adults. J Ultrasound. 2016;11:406.Google Scholar
  8. 8.
    Popovic D, Khoo M, Lee S. Noninvasive monitoring of intracranial pressure. Recent Patents Biomed Eng. 2009;2:165–79.CrossRefGoogle Scholar
  9. 9.
    Zeiler FA, Ziesmann MT, Goeres P, Unger B, Park J, Karakitsos D, et al. A unique method for estimating the reliability learning curve of optic nerve sheath diameter ultrasound measurement. Crit Ultrasound J. 2016;8:9.CrossRefGoogle Scholar
  10. 10.
    Helmke K, Hansen HC. Fundamentals of transorbital sonographic: evaluation of optic nerve sheath expansion under intracranial hypertension. II. Patient study. Pediatr Radiol. 1996;26:701–10.CrossRefGoogle Scholar
  11. 11.
    Helmke K, Hansen HC. Fundamentals of transorbital sonographic evaluation of optic nerve sheath expansion under intracranial hypertension. I. Experimental study. Pediatr Radiol. 1996;26:701–5.CrossRefGoogle Scholar
  12. 12.
    Hansen H-C, 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.CrossRefGoogle Scholar
  13. 13.
    Tsutsumi S, Rhoton AL. Microsurgical anatomy of the central retinal artery. Neurosurgery. 2006;59:870–9.CrossRefGoogle Scholar
  14. 14.
    Ertl M, Barinka F, Torka E, Altmann M, Pfister K, Helbig H, et al. Ocular color-coded sonography—a promising tool for neurologists and intensive care physicians. Ultraschall Med. 2014;35:422–31.CrossRefGoogle Scholar
  15. 15.
    Pribojszki M, Komáromi K, Csomor A, Vörös ES. Tortuous optic nerve-ECR 2017/C-2914. 2017.Google Scholar
  16. 16.
    Feldman MK, Katyal S, Blackwood MS. US artifacts. RadioGraphics. 2009;24:1179–89.CrossRefGoogle Scholar
  17. 17.
    Baad M, Lu ZF, Reiser I, Paushter D. Clinical significance of US artifacts. RadioGraphics. 2017;37:1408–23.CrossRefGoogle Scholar
  18. 18.
    Food and Drug Administration. Marketing clearance of diagnostic ultrasound systems and transducers—draft guidance for industry and Food and Drug Administration Staff. 2019. Accessed 30 Aug 2019.
  19. 19.
    Hewick SA, Fairhead AC, Culy JC, Atta HR. A comparison of 10 MHz and 20 MHz ultrasound probes in imaging the eye and orbit. Br J Ophthalmol. 2004;88:551–5.CrossRefGoogle Scholar
  20. 20.
    Coleman DJ, Silverman RH, Chabi A, Rondeau MJ, Shung KK, Cannata J, et al. High-resolution ultrasonic imaging of the posterior segment. Ophthalmology. 2004;111:1344–51.CrossRefGoogle Scholar
  21. 21.
    Toms DA. The mechanical index, ultrasound practices, and the ALARA principle. J Ultrasound Med. 2006;25:560–1.CrossRefGoogle Scholar
  22. 22.
    Shah S, Kimberly H, Marill K, Noble V. Ultrasound techniques to measure the optic nerve sheath: is a specialized probe necessary? Med Sci Monit. 2009;15:63–8.Google Scholar
  23. 23.
    Nelson TR, Fowlkes JB, Abramowicz JS, Church CC. Ultrasound biosafety considerations for the practicing sonographer and sonologist. J Ultrasound Med. 2009;28:139–50.CrossRefGoogle Scholar
  24. 24.
    Safety Group of the British Medical Ultrasound Society. Guidelines for the safe use of diagnostic ultrasound equipment. Ultrasound. 2010;18:52–9.CrossRefGoogle Scholar
  25. 25.
    Romagnuolo L, Tayal V, Tomaszewski C, Saunders T, Norton HJ. Optic nerve sheath diameter does not change with patient position. Am J Emerg Med. 2005;23:686–8.CrossRefGoogle Scholar
  26. 26.
    Roque PJ, Hatch N, Barr L, Wu TS. Bedside ocular ultrasound. Crit Care Clin. 2014;30:227–41.CrossRefGoogle Scholar
  27. 27.
    Rubens DJ, Bhatt S, Nedelka S, Cullinan J. Doppler artifacts and pitfalls. Radiol Clin N Am. 2006;44:805–35.CrossRefGoogle Scholar
  28. 28.
    Shankar H, Pagel PS. Potential adverse ultrasound-related biological effects: a critical review. Anesthesiology. 2011;115:1109–24.CrossRefGoogle Scholar
  29. 29.
    Ertl M, Gamulescu M-A, Schlachetzki F. Application of orbital sonography in neurology. In: Thoirs K, editor. sonography. Rijeka: InTech; 2012.Google Scholar
  30. 30.
    Rasulo FBR. Transcranial Doppler and optic nerve sonography. J Cardiothorac Vasc Anesth. 2019;33:S38–52.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature and Neurocritical Care Society 2019

Authors and Affiliations

  1. 1.Anesthesia and Neurointensive Care UnitIRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
  2. 2.Department of Biomedical and Neuromotor SciencesUniversity of BolognaBolognaItaly
  3. 3.Neuroradiology UnitIRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
  4. 4.Department of NeurosurgeryIRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
  5. 5.Neurointensive Care Unit, Department of Emergency, Anesthesiology and Intensive Care MedicineFondazione Policlinico Universitario A. Gemelli IRCCSRomeItaly

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