Point-of-care ultrasound of optic nerve sheath diameter to detect elevated intracranial pressure: Ultrasound in the eye of the beholder?

Raised intracranial pressure (ICP) is a frequent complication in neurocritically-ill patients. Current diagnostic methods are invasive and have ample drawbacks. Ultrasound of ONSD can be an alternative modality to diagnose and monitor a raised ICP. A thorough search in PubMed/EMBASE was applied to find relevant articles. Two reviewers independently evaluated the relevant articles and extracted the data. The optimal cut-off value of ONSD to detect a raised ICP ranged from 4.7 – 5.7 mm with corresponding sensitivity and specificity rates ranging from 70% - 100% and 31.9% - 100%, respectively. Measurements of ultrasound ONSD showed to be less accurate in presence of fluctuations of ICP values. Ultrasound of ONSD is an accurate, safe, sensitive and specific method to detect a raised ICP. For now, ultrasound of ONSD has its limitations and must not be used as a primary modality to diagnose an elevated ICP and further research is needed.