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Updated: Aug 19, 2026
Optic Nerve Sheath Point of Care Ultrasound: Image Acquisition
Published on: August 18, 2023
[Sonography of the optical nerve -- experience in 483 children]
1Kinderradiologie, Justus-Liebig-Universität Giessen. Friederike.Koerber@uk-koeln.de
Insights
Ultrasound effectively detects increased intracranial pressure (IICP) in children by measuring optic nerve diameter. A diameter over 4.5 mm strongly indicates IICP, aiding in diagnosis.
Area of Science:
- Pediatric Neurology
- Medical Imaging
- Ophthalmology
Background:
- Increased intracranial pressure (IICP) can cause optic nerve (ON) sheath widening, detectable via ultrasound.
- Establishing normative and pathological sonographic values for the ON diameter in children is crucial for diagnosis.
Purpose of the Study:
- To assess the utility of optic nerve ultrasound in diagnosing IICP in pediatric patients.
- To determine mean ON diameter values in children without IICP and pathological values in those with confirmed IICP.
Main Methods:
- Retrospective ultrasound analysis of the optic nerve diameter and morphology in 483 children presenting with IICP symptoms.
- Evaluation included nerve sheath and papilla characteristics, with clinical data for confirmation.
Main Results:
- In children without IICP (n=466), the mean ON diameter was 3.4 mm ± 0.7 mm, with clear nerve sheath demarcation.
- Children with confirmed IICP (n=17) showed an increased mean ON diameter of 5.6 mm ± 0.9 mm, often with an indistinguishable nerve sheath.
Conclusions:
- Optic nerve ultrasound, particularly ON diameter and nerve sheath appearance, demonstrates high sensitivity for detecting IICP in children.
- An ON diameter exceeding 4.5 mm is a significant indicator of IICP requiring further investigation; papilla prominence is less reliable.
Introduction:
In case of increased intracranial pressure (IICP), the inflow of cerebrospinal fluid widens the space between the optic nerve (ON) itself and the surrounding dura mater leading to the sonographic appearance of increased diameter of the ON. The purpose of the study was to gain clinical experience in children and to determine (a) the mean values for patients without proven IICP and (b) pathologic values of those with proven IICP.
Materials And Methods:
Ultrasound of the optic nerve was performed in 483 children with symptoms consistent with IICP, comprising 287 males and 196 females at an age ranging from 4 days to 24 years with a mean age of 7.5 + 5.1 years. The measured diameter of the ON of both eyes and the morphologic criteria concerning nerve sheath and papilla were evaluated retrospectively.
Results:
Most of the investigated patients (n = 466) had no IICP as confirmed by neurological examination, EEG, sometimes CCT and/or MRI and clinical follow-up. The typical morphological findings in patients with normal intracranial pressure (ICP) were a clear and longitudinally extended demarcation of the ON with a well-delimited nerve sheath and without prominent papilla. The mean diameter of the ON in patients with normal ICP was 3.4 mm + 0.7 mm. In 17 patients with proven IICP, the mean diameter of the ON increased to 5.6 mm + 0.9 mm. Typically, the nerve sheath was indistinguishable from the hypoechoic ON, often but not invariably associated with a prominent papilla. In patients with IICP, the diameter of the ON alone matches the diameter of the ON plus nerve sheath in patients with normal ICP.
Conclusion:
IICP was detected with a high sensitivity by ultrasound using the diameter and the morphological criteria of an indistinguishable nerve sheath. A diameter of more than 4.5 mm is definitely pathologic and requires further investigation. Prominence of the papilla is an unreliable criterion for acute IICP.
