The purpose of this study was to measure optic nerve sheath diameter (ONSD) in paediatric patients without pathology using brain CT performed for various reasons and to provide normal tomographic reference values. This was a retrospective study of CT scans of children aged 1–16 years. There was no intracranial pathology, no asymmetric head positioning and no artefacts on scans. Four age groups were defined for 361 children: (1) 78 aged 1–2 years, (2) 117 aged 3–6 years, (3) 85 aged 7–10 years, and (4) 81 aged 11–16 years. There were 60.1% males and 39.9% females with mean age of 6.97 ±4.55 years. Three ONSD measurements were made on axial images: (1) posterior right to left to sclera, (2) 3mm, and (3) 10mm distance from posterior margin of the globe. Group 2 and Group 3 values from left to right showed significant differences between age groups with values increasing with age, with positive correlation. These normative values should prove useful as a reference in detecting optic nerve abnormalities. However, further capture of such measurements is needed in future studies across more ages in children, from different ethnicities and from different imaging slices, to further build reference values.
Normative reference values for optic nerve sheath diameter in children
Reviewed by Fiona Rowe
Measurement of optic nerve sheath diameter by computed tomography in the pediatric population: normal values.
CONTRIBUTOR
Fiona Rowe (Prof)
Institute of Population Health, University of Liverpool, UK.
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