Multiple studies have compared ONSD directly to ventriculostomy and have demonstrated that there is a significant increase in ONSD above a certain threshold of ICP (≥ 20 mmHg) in neurocritically ill patients (ref). However, there still remains uncertainty regarding the degree or significance of ONSD changes below this threshold (ref). In addition, although it has been illustrated that distention of the ONSD occurs rapidly in response to elevated ICP5, there continues to be debate on the reversibility of the ONSD ranging from complete reversibility with CSF pressure changes6 to a delayed5 and even incomplete recovery when pressures have exceeded 40-45 mmHg7. Therefore, the relationship between ONSD and response to acute fluctuations and reversibility remains to be further
Multiple studies have compared ONSD directly to ventriculostomy and have demonstrated that there is a significant increase in ONSD above a certain threshold of ICP (≥ 20 mmHg) in neurocritically ill patients (ref). However, there still remains uncertainty regarding the degree or significance of ONSD changes below this threshold (ref). In addition, although it has been illustrated that distention of the ONSD occurs rapidly in response to elevated ICP5, there continues to be debate on the reversibility of the ONSD ranging from complete reversibility with CSF pressure changes6 to a delayed5 and even incomplete recovery when pressures have exceeded 40-45 mmHg7. Therefore, the relationship between ONSD and response to acute fluctuations and reversibility remains to be further