Ultrasonographic evaluation of optic nerve sheath diameter in severe traumatic brain injury patients: a comparison with intraparenchymal pressure monitoring

doi:10.21203/rs.3.rs-4909463/v1

Objective: Increased intracranial pressure (ICP) can worsen the clinical condition of traumatic brain injury (TBI) patients. One non-invasive and bedside-performed technique to estimate ICP is ultrasonographic measurement of optic nerve sheath diameter (ONSD). This study aimed to analyze ONSD and correlate it with ICP values obtained by intraparenchymal monitoring to establish the ONSD threshold value for elevated ICP and reference range of ONSD in severe TBI patients.

Methods: Forty severe TBI patients were included. Ultrasonographic measurement of ONSD was performed and compared with intraparenchymal ICP monitoring to assess their association and determine the ONSD threshold value. Exclusion criteria included individuals under eighteen years old, penetrating TBI, or direct ocular trauma.

Results: Fifty-three ONSD measurements were conducted in all patients. The mean ONSD value in the group with intracranial pressure < 20 mmHg was 5.4 mm ± 1.0, while in the group with intracranial pressure ≥ 20 mmHg, it was 6.4 mm ± 0.7 (p = 0.0026). A positive and statistically significant correlation, albeit weak (r = 0.33), was observed between ultrasonographic measurement of ONSD and intraparenchymal ICP monitoring. The statistical analysis of the ROC curve identified the best cut-off as 6.18 mm, with 77.8% sensitivity and 81.8% specificity.

Conclusion: Our results reveal a positive, albeit weak, correlation between ultrasonographic measurement of ONSD and intraparenchymal ICP monitoring, with an ONSD threshold value of 6.18 mm. Achieving only 77.8% sensitivity and considering the substantial variability between ONSD measurements (standard deviation at 1.0) might limit the reliability of ICP assessment based solely on ONSD measurements.

Traumatic Brain Injury

Increased Intracranial Pressure

Optic Nerve Sheath Diameter

Ultrasonographic Measurement

Intracranial Pressure Monitoring

Increased intracranial pressure (ICP) significantly impacts the clinical outcome and prognosis of patients with acute neurological injuries, especially those with traumatic brain injury (TBI). Early identification and timely intervention are essential to reduce morbidity and mortality in this population[1].

Various techniques exist for estimating ICP, ranging from clinical examinations involving direct ophthalmoscopy to non-invasive imaging tests such as computed tomography (CT) scans and magnetic resonance imaging (MRI). Invasive methods include intraparenchymal catheter implantation and ventriculostomy, with the latter considered the gold standard procedure. However, severely ill patients may not be suitable candidates for repeated CT or MRI scans. Moreover, certain institutions may lack specialized staff and equipment for invasive ICP estimation, and there are also non-negligible risks of intracranial bleeding and infection associated with invasive techniques[2]. A relatively recent modality involves ultrasonographic evaluation of the optic nerve sheath diameter (ONSD), a non-invasive method feasible at the bedside[3–7].

The optic nerve is enveloped by a meningeal sheath directly connected to the cerebrospinal fluid (CSF) space. During acute neurological events leading to elevated ICP, such as TBI or hemorrhagic stroke, there is a displacement of CSF into the subarachnoid space, resulting in distention of the optic nerve sheath. Increased ONSD can be identified through transocular or transpalpebral ultrasonographic measurements[3–8].

The primary objective of this study was to analyze ultrasonographic measurements of ONSD and correlate them with ICP values obtained through intraparenchymal monitoring. The aim is to establish an ONSD threshold value indicative of raised ICP and to define a reference range for ONSD in severe TBI patients.

Study Population

Patients with severe TBI, defined by a Glasgow Coma Scale (GCS) score of ≤ 8, and requiring mechanical ventilation with intraparenchymal ICP monitoring (Camino® Cam 02), were included in the study. Patient enrollment occurred between December 2017 and August 2019 at a single-center in Brazil. Exclusion criteria encompassed individuals under 18 years old, those with penetrating head trauma, individuals with prior eye disorders or direct eye injuries that could potentially interfere with ultrasonographic measurements of ONSD, and subjects whose legal representatives did not provide consent for participation in the clinical research study. Adhering to the prospective and observational nature of the study, standard protocols for TBI at the participating institution were followed. The study design received approval from the local research and ethics committee. Notably, this study was not registered in a trial registry before the commencement of enrollment, and informed consent from family members or legal representatives of the participants was deemed mandatory.

Data Collection

After enrollment, baseline demographic characteristics were extracted from the medical records. Admission CT scans were reviewed and categorized according to Marshall's Classification[9]. The decision to implement an ICP monitoring device was at the discretion of the neurosurgeon, following hospital protocols. These protocols specified criteria such as severe TBI and CT scan categories Marshall II and III, or Marshall I plus two of the following criteria: hypotension, age ≥ 40 years, or decerebrate/decorticate posturing[1–10]. Patients in CT scan category Marshall IV underwent decompressive craniectomy along with ICP monitoring on the opposite side of the surgery. The ICP monitoring device (Camino® Cam 02) was positioned at Kocher's point in the frontal lobe, at a depth of two centimeters. Subsequently, patients were transferred to the intensive care unit, and the ICP monitoring device was retained for a minimum of 48 hours.

The collected variables included age, mechanism of trauma, tomographic Marshall’s category, ICP values, time (in hours) between ultrasonographic measurement of the ONSD and ICP monitoring placement, and measurements of the ONSD for both eyes.

Ultrasonographic Measurement of the Optic Nerve Sheath Diameter

The ultrasound examination of the eye was conducted by the principal author (F.M.F.), who was trained in ocular sonography. The SonoSite M-Turbo® with a 10 MHz probe in B-mode was utilized for this purpose. The measurement technique adhered to established guidelines in the literature[3–5,11–13], employing a transpalpebral approach with measurements of the optic nerve dural-dural diameter taken 3.0 mm posterior to the surface of the optic disc (Fig. 1). Three measurements were taken for each optic nerve, and their arithmetic mean was calculated. Subsequently, the arithmetic mean of measurements between the two nerves was determined.

The ultrasound examination occurred simultaneously with the invasive ICP monitoring reading, performed by a second investigator. This approach was adopted to prevent the principal author from being aware of ICP values before conducting the ultrasonographic measurement of the ONSD. Each patient was expected to undergo at least one ultrasonographic measurement of the ONSD daily, contingent upon the availability of the author, starting from device insertion until discontinuation of invasive ICP monitoring.

Analysis Criteria

The data were analyzed using the STATA 14.0 program (Stata Corp LP, College Station, TX, USA). Descriptive analysis utilized frequency tables. To assess the normal distribution of continuous variables, the Shapiro-Wilk test was employed. Between-group comparisons of these variables were conducted using the Wilcoxon test. Fisher's exact test was employed to evaluate associations between categorical variables. Spearman's correlation test was utilized to assess correlations between continuous variables.

For the analysis of the receiver operating characteristic curve (ROC curve), key parameters such as the area under the curve (AUC), optimal cutoff, and sensitivity and specificity of the ultrasonographic measurement of the ONSD in the detection of ICP ≥ 20 mmHg were obtained. A significance level of p ≤ 0.05 was considered for all tests to determine statistical significance.

A total of 40 patients were included in this study, with 8 (20%) diagnosed with raised ICP through invasive intraparenchymal monitoring. Among the participants, 36 were male (90%) and 4 were female (10%), with a mean age of 46 years (range: 18–85). Mechanisms of trauma included 11 traffic accidents (27.5%), 11 falls (27.5%), 9 pedestrians struck by vehicles (22.5%), 5 physical assaults (12.5%), and 4 cases with unknown causes (10.0%). In this population, 53 ultrasonographic measurements of the ONSD were conducted. A single measurement was performed in 28 patients (70%), 2 measurements were performed on separate days in 11 patients (27.5%), and a single patient had 3 measurements on separate days. Regarding tomographic Marshall categories, there were 25 cases of Marshall II (62.5%), 2 cases of Marshall III (5.0%), and 13 cases of Marshall IV (32.5%).

The mean ONSD of the right eye was 5.58 mm ± 1.0, and the mean ONSD of the left eye was 5.57 mm ± 1.0. Comparison using the Wilcoxon test showed no statistically significant difference between them (p = 0.4228). Consequently, the subsequent analysis considered the average between the measurements of the two eyes.

Out of the 53 ultrasonographic measurements, 44 (83%) were associated with invasive ICP values < 20 mmHg, and 9 (17%) were associated with invasive ICP values ≥ 20 mmHg. The mean ONSD in the group without raised ICP was 5.4 mm ± 1.0, whereas in the group with raised ICP, it was 6.4 mm ± 0.7. This difference was statistically significant according to the Wilcoxon test (p = 0.0026) (Table 1).

Table 1

Mean ONSD in association with or without raised ICP
ICP value	Measurements, n	ONSD, mean (SD), mm	Range of ONSD, mm
ICP ≤ 20 mmHg	44	5.4 ± 1.0	3.2–6.9
ICP ≥ 20 mmHg	9	6.4 ± 0.7	4.9–7.4
Total sample	53	5.6 ± 1.0	3.2–7.4
ONSD: optic nerve sheath diameter ICP: intracranial pressure SD: standard deviation

The correlation between ONSD and invasive ICP measurements was assessed using Spearman's correlation test, revealing a positive but weak correlation (r = 0.3310) that was statistically significant (p = 0.0155), as depicted in Graph 1.

Results obtained from the analysis of the ROC curve (Graph 2) indicated an AUC of 0.8207 (95% CI: 0.6444–0.9972). The best cut-off point was 6.18 mm, corresponding to 77.8% sensitivity and 81.8% specificity for the ultrasonographic measurement of the ONSD in detecting ICP ≥ 20 mmHg.

There was no statistically significant difference between the averages of the ultrasonographic measurement of the ONSD of the right and left eyes, allowing for the use of the mean measurement of both eyes for the final analysis, as recommended by current literature[3–5,10–12].

Due to an uneven distribution among Marshall categories, the final analysis considered the set of ONSD measurements for all patients. A more extensive study with a more homogenous distribution and a higher number of patients could analyze each Marshall category separately, providing a more robust statistical power analysis.

The current study demonstrated a weak positive correlation between the increase in ICP and the ultrasonographic measurement of the ONSD. The identified best cutoff point, indicative of an ICP ≥ 20 mmHg, was 6.18 mm, with 77.8% sensitivity and 81.8% specificity.

Several articles[14–19] have been published with the objective of determining the ideal cutoff point for ONSD to predict increased ICP (Table 2). While some publications involved a substantial number of individuals, it is important to note that many authors did not use objective measures of ICP as a comparison parameter, often relying on factors such as CT scans analysis and physical exam findings.

Table 2

Overview of the ultrasonographic ONSD studies without invasive monitoring as reference for determining ICP
Study	Number of participants, n	Mean age, years ± SD	Cutoff, mm	Sensibility, %	Specificity, %	Limitations
Amini et al., 2013[15]	222	42.2 ± 19.5	4.85	96.4	95.3	IICP based on CT scan and non-simultaneous measurement
Chen et al., 2015[19]	519	46.1 ± 14.2	5.9	-	-	Without comparison
Komut et al., 2016[16]	100	-	5.3	70	74	IICP based on CT scan and non-simultaneous measurement
Lee et al., 2016[17]	134	-	5.5	98.77	85.19	IICP based on CT scan and non-simultaneous measurement
Wang et al., 2015[18]	279	41.3 ± 15.1	4.1	95	92	IICP based on lumbar puncture and non-simultaneous measurement
ONSD: optic nerve sheath diameter ICP: intracranial pressure IICP: increased intracranial pressure
CT: computerized tomography SD: standard deviation

Three different studies[20–22] established comparisons between ultrasonographic measurements of the ONSD and findings suggestive of raised ICP on CT scans in severe TBI patients or those with spontaneous intracranial hemorrhage. Using a pre-established cutoff point for determining raised ICP (ONSD of 5.0 mm), these authors obtained sensitivity and specificity values of 100% and 95%[20], 100% and 63%[21], and 98.3% and 62.5%[22], respectively. However, these studies did not analyze the correlation with adequate invasive ICP measurements specific to their study population. While a previous study has established radiologic findings on head CT scans suggestive of raised ICP[23], these are not precise quantitative measurements and may be influenced by factors such as age, specific brain injuries, and cerebral atrophy.

When analyzing data from publications where ultrasonographic measurement of ONSD was compared to invasive intracranial monitoring techniques, a more relevant comparison can be established with the results of the present study due to methodological proximity.

Moreti et al.[24], in a study involving 63 sedated and mechanically ventilated patients diagnosed with spontaneous intracranial hemorrhage, found a mean ONSD value of 5.0 mm ± 0.49 in patients with ICP < 20 mmHg and 6.16 mm ± 0.57 in patients with ICP ≥ 20 mmHg. The cutoff point was 5.2 mm, with 93.10% sensitivity and 73.85% specificity.

Another study[25] with 31 severe TBI patients demonstrated an ONSD mean value of 5.1 mm ± 0.7 in patients with ICP < 20 mmHg and 6.2 mm ± 0.4 in those with ICP ≥ 20 mmHg (p < 0.0001). The cutoff point was 5.9 mm, with 87% sensitivity and 94% specificity. The objective of this study was to determine, at the time of admission, an ONSD measurement predictive of increased ICP for the next 48 hours. Notably, the ultrasonographic measurement of the ONSD was performed within one hour after obtaining invasive ICP readings, potentially introducing a bias. In contrast, in the present study, measurements were performed simultaneously with invasive ICP monitoring.

Robba et al.[26] published a study with 64 patients, including 45 TBI patients, 15 patients with subarachnoid hemorrhage, and 4 patients with intraparenchymal hemorrhage. Invasive ICP reading was monitored by ventriculostomy or intraparenchymal catheter. Ultrasonographic measurement of the ONSD showed a mean value of 4.9 mm (4.2–6.0), with a defined cutoff point of 5.85 mm, 86.6% sensitivity, and 82.6% specificity. Positive and statistically significant correlations were found between invasive ICP measures and the ONSD, as well as between invasive ICP measures and the speed of systolic flow through the straight sinus.

From the comparative analysis in Table 3, the cutoff point identified in our study showed a higher value compared to other populations but was closer to those with severe TBI patients only. It is noteworthy that this work is the first to evaluate the correlation of ultrasonographic measurements of the ONSD in a Brazilian population. Differences in ONSD measurements across populations of different ethnicities have been noted[12,18–19,31–34].

Table 3

Overview of the ultrasonographic ONSD main studies that set invasive monitoring as reference for determining ICP
Study	Number of participants, n	Diagnosis	Cutoff, mm	Sensibility, %	Specificity, %
Geeraerts et al., 2007[25]	31	Severe TBI	5.9	87	94
Geeraerts et al., 2008[13]	37	Miscellaneous	5.86	95	79
Kimberly et al., 2008[34]	15	Miscellaneous	5.0	88	93
Soldatos et al., 2008[31]	32	Severe TBI	5.7	74.1	100
Moreti et al., 2009[24]	63	Intracranial hemorrhage	5.2	93.1	73.8
Rajajee et al., 2011[33]	65	Miscellaneous	4.8	96	94
Jeon et al., 2017[35]	62	Miscellaneous	4.8	96	94
Robba et al., 2017[26]	64	Miscellaneous	5.85	86.6	82.6
Wang et al., 2019[36]	75	Severe TBI + healthy control adults	5.83	94.4	81
Present study (Ferreira, 2024)	40	Severe TBI	6.18	77.8	81.8
ONSD: optic nerve sheath diameter ICP: intracranial pressure TBI: traumatic brain injury

Rajajee et al.[29], in a 2011 study, presented a sample of 65 patients subjected to both invasive and noninvasive measurements of ICP. They identified a cutoff point of 4.8 mm, the smallest one found until then. The authors emphasized that their more precise measurements contributed to this result, as they took utmost care to avoid hypoechoic artifacts located posterior to the eyeball, which could lead to inaccurate ONSD determinations.

The discrepancy in cutoff points cannot be solely explained by this detail, as the current study shared the same concern during the acquisition of ONSD values. Rajajee et al.[29] further stratified patients into groups submitted or not to mechanical ventilation, finding that the group subjected to mechanical ventilation presented higher ONSD mean values with a statistically significant difference. Since all patients in the present study were mechanically ventilated, this factor could also contribute to the observed higher cutoff point (6.18 mm) compared to other studies. To achieve a sensitivity of 100% in the present study's sample, a cutoff point of 4.5 mm could be employed. However, it is crucial to note that the specificity value would be extremely low, approximately 20.5%.

Robba et al.[35], in 2019, conducted a prospective observational study involving 100 adult patients with severe TBI, measuring ONSD at admission to the neurocritical care unit and calculating predicted ICP using a formula with ONSD as a variable. As a secondary outcome, they found a significant correlation between ONSD and invasive ICP measurements (r = 0.85, p < 0.0001). They also observed a positive correlation between admission ONSD and mean ICP during the intensive care stay (r = 0.45, p < 0.0001). The results suggest that measuring ONSD at admission can provide important information about patients at risk of developing intracranial hypertension and impaired autoregulation. Additionally, admission ONSD was significantly correlated with intensive care mortality. However, the predicted ICP using ONSD ranged widely (± 7.66 mm), making it difficult to base clinical decisions solely on this measurement as a substitute for invasive ICP.

Wang et al.[36] conducted a study to assess the association of ONSD with ICP in severe TBI patients after decompressive craniotomy (DC). In this study, ONSDs were measured by ocular ultrasonography in 40 healthy control adults and 35 TBI patients at 6 and 24 hours post-DC operation. Patients were categorized into three groups based on ICP levels: normal (ICP ≤ 13 mm Hg), mildly elevated (ICP = 14–22 mm Hg), and severely elevated (ICP > 22 mm Hg). They found significant linear correlations between ONSD and ICP (r = 0.771, p < 0.0001). The mean ONSDs were 4.09 ± 0.38 mm in the control group and 4.92 ± 0.37 mm, 5.77 ± 0.41 mm, and 6.52 ± 0.44 mm in the normal, mildly elevated, and severely elevated ICP groups, respectively (p < 0.001). With an ONSD cutoff of 5.48 mm for ICP > 13 mm Hg, sensitivity and specificity were 91.1% and 88.0%, respectively. For an ICP > 22 mm Hg, a cutoff of 5.83 mm yielded sensitivity and specificity of 94.4% and 81.0%, respectively.

Xu et al.[37] conducted a systematic review and meta-analysis on the use of ONSD sonography for diagnosing intracranial hypertension in TBI patients. They included 10 studies with a total of 512 patients. The meta-analysis revealed a pooled sensitivity of 0.85 (95% CI: 0.79–0.89) and a specificity of 0.88 (95% CI: 0.80–0.93), indicating that ONSD sonography can be a valuable method for predicting elevated ICP in adult TBI patients.

Martínez-Palacios[38] et al. conducted a comprehensive review focusing exclusively on TBI patients, examining the use of ONSD for ICP monitoring. The review included 16 studies and highlighted that ONSD demonstrates high test accuracy and a strong, almost linear correlation with invasive methods. Specifically, all studies used a 7.5 MHz linear probe and measured ONSD 3 mm behind the globe. The findings underscore that ONSD can reliably estimate ICP, with several studies also exploring additional parameters like the ONSD/eyeball transverse diameter ratio and optic disc elevation, which showed high sensitivity and reliability. The authors concluded that ONSD should be considered one of the most effective non-invasive techniques for ICP estimation in TBI patients, especially given its correlation with invasive ICP measurements and potential utility in bedside applications.

The ultrasonographic measurement of the ONSD does not aim to replace highly accurate invasive techniques, which are considered the gold standard for determining ICP. However, based on the analysis of the results from the present study and existing literature, it can be inferred that ultrasonographic measurement of the ONSD could serve as a possible, although with limitations, complementary technique in the management of TBI, particularly in cases where invasive intracranial monitoring is not feasible.

This method could be particularly valuable in trauma and emergency services where immediate access to neurosurgical teams or CT scanners may be limited. Given its lower financial cost compared to invasive monitoring devices and CT scans, ultrasound can be employed by clinicians, general surgeons, and emergency physicians for screening trauma and neurological patients. This approach enables the provision of timely treatment and facilitates the referral of patients to specialized neurosurgical services. Additionally, ultrasound can be beneficial for monitoring clinically unstable patients, especially in intensive care units, where factors such as severe thoracic and abdominal trauma or hemodynamic instability may complicate patient transportation.

Study Limitations

- Measurement variability: a primary limitation of our study is the high variability in ONSD measurements. The wide range of values for ICP < 20 mmHg (3.2–6.9 mm) and ICP ≥ 20 mmHg (4.9–7.4 mm) results in a high standard deviation (1.0 mm). This variability limits the accuracy of the technique in distinguishing between patients with elevated and normal ICP. As demonstrated in Fig. 1, this variability makes it challenging to reliably assess ICP based solely on ONSD measurements.

- Sensitivity and specificity: while we identified a cutoff point of 6.18 mm for ONSD with 77.8% sensitivity and 81.8% specificity, these values are not high enough to reliably guide clinical decisions. In clinical settings, especially for screening, methods with high specificity and predictive values are necessary. Therefore, the clinical applicability of ONSD measurement as an independent method for ICP assessment is limited.

- Operator variability: all measurements were performed by a single experienced operator, which may not reflect the inter-observer variability that can occur in real clinical settings. Future studies should investigate the consistency of measurements between different operators to assess the reproducibility and reliability of this technique.

- Discontinuity of measurements: ONSD measurements were intended to be performed once daily, but this was not always possible, representing a significant limitation for continuous ICP monitoring. This limitation is further compounded by the fact that the author was not physically present at the institution every day to perform the analysis. As such, the technique does not replace continuous invasive monitoring, which is essential for patients requiring rigorous monitoring of cerebral physiology after severe injuries. This aspect should be emphasized, highlighting the need for future studies to explore the feasibility of more frequent or continuous ONSD measurements by a larger team of trained operators.

This project represents the first study to measure the ultrasonographic ONSD in the Brazilian population, correlating it with ICP readings obtained through an intraparenchymal monitor. The study demonstrates a positive, albeit weak, correlation between the ultrasonographic measurement of the ONSD and the ICP values obtained through invasive monitoring. Based on this correlation, a cutoff point of 6.18 mm for the ONSD was established to predict an increased ICP ≥ 20 mmHg, achieving a sensitivity of 77.8% and specificity of 81.8%.

However, the substantial variability between ONSD measurements (standard deviation of 1.0) and the relatively moderate sensitivity achieved might limit the reliability of ICP assessment based solely on ONSD measurements. These findings suggest that while ultrasonographic ONSD measurement can provide valuable insights and serve as a useful complementary non-invasive method for assessing intracranial pressure in specific clinical scenarios, it should not be relied upon as the sole method for ICP estimation. Further studies with larger sample sizes and multiple operators are necessary to enhance the accuracy, reproducibility, and clinical applicability of this technique.

Funding

The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Competing Interests

The authors have no relevant financial or non-financial interests to disclose.

Ethics approval

This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of the João XXIII Hospital (Date November 2017/No 78743317.8.0000.5119)

Consent to participate

Written informed consent was obtained from family members or legal representatives of the participants.

Author Contribution

All authors made substantial contributions to the conception and design of the work. B.L. assisted the author F.F. in training for ocular ultrasound. The analysis and interpretation of the data were conducted by the author F.F. In the end, all authors contributed to the revision and preparation of the final text submitted for publication.

Data Availability

The data supporting the findings of this study are contained within an Excel spreadsheet, which is available upon request. Due to privacy restrictions, the data are not publicly accessible. Interested researchers can obtain access to the dataset by contacting the author at [email protected] . All data sources cited in the article are included in the reference list, following the recommended guidelines.

Carney N, Totten AM, O’Reilly C, Ullman JS, Hawryluk GW, Bell MJ, Bratton SL, Chesnut R, Harris OA, Kissoon N, Rubiano AM, Shutter L, Tasker RC, Vavilala MS, Wilberger J, Wright DW, Ghajar J. Guidelines for the management of severe traumatic brain injury, forth edition. 2017;80(1): 6-15.
Tavakoli S, Peitz G, Ares W, Hafeez S, Grandhi R. Complications of invasive intracranial pressure monitoring devices in neurocritical care. Neurosurg Focus. 2017;43(5):E6.
Helmke K, Hansen H. Fundamentals of transorbital sonographic evaluation of optic nerve sheath expansion under intracranial hypertension. Pediatr Radiol. 1996;26(10):706-10.
Helmke K, Hansen H. Validation of the optic nerve sheath response to changing cerebrospinal fluid pressure: ultrasound findings during intrathecal infusion tests. J Neurosurg. 1997;87(1):34-40.
Lochner P, Czosnyka M, Naldi A, Lyros E, Pelosi P, Mathur S, Fassbender K, Robba C. Optic nerve sheath diameter: present and future perspectives for neurologists and critical care physicians. Neurol Sci. 2019;40(12):2447-2457.
Mundt GH, Hughes WS. Ultrasonics in ocular diagnosis. Am J Opthalmol. 1956;41:488-98.
Schroeder W, Guthoff R. Modellversuche zur Messung des Sehnerven. In: Gernet H, ed. Proceedings, SIDUO VLL. Munster: Remy, 1979:3.
Bron AJ, Tripathi RC, Tripathi BJ. Wolff’s anatomy of the eye and orbit. London: Arnold, 2001.
Marshall LF, Marshall SB, Klauber MR, Clark MB, Eisenberg HM, Jane JA, Luerssen TG, Marmarou A, Foulkes MA. A new classification of head injury based on computerized tomography. J Neurosurg. 1991;75:14-20.
Jull N, Morris GF, Marshall SB, Marshall LF. Intracranial hypertension and cerebral perfusion pressure: influence on neurological deterioration and outcome in severe head injury. The Executive Committee of the International Selfotel Trial. J Neurosurg. 2000;92(1):1-6.
Amini A, Kariman H, Dolatabadi A, Hatamabadi H, Derakhshanfar H, Mansouri B, Safari S, Eqtesadi R. Use of the sonographic diameter of optic nerve sheath to estimate intracranial pressure. Am J Emerg Med. 2013;31(1):236-9.
Bauerle J, Lochner P, Kaps M, Nedelmann M. Intra and interobserver reliability of sonographic assessment of the optic nerve sheath diameter in healthy adults. J Neuroimaging. 2012;22(1):42-5.
Geeraerts T, Merceron S, Benhamou D, Vigué B, Duranteau J. Non-invasive assessment of intracranial pressure using ocular sonography in neurocritical care patients. Intensive Care Med. 2008;34(11):2062-7.
Goeres P, Zeiler FA, Unger B, Karakitsos D, Gilman LM. Ultrasound assessment of optic nerve sheath diameter in healthy volunteers. Journal of Crit Care. 2016;31(1):168-71.
Amini A, Eghtesadi R, Feizi AM, Mansouri B, Kariman H, Dolatabadi AA, Hatamabadi H, Kabir A. Sonographic optic nerve sheath diameter as a screening tool for detection of elevated intracranial pressure. Emerg (Tehran). 2013;1(1):15-9.
Komut E, Kozaci N, Sonmez BM, Yilmaz F, Komut S, Yildirim ZN, Beydilli I, Yel C. Bedside sonographic measurement of optic nerve sheath diameter as a predictor of intracranial pressure in ED. AM J Emerg Med. 2016;34(6):963-7.
Lee S, Jeon J, Lee H, Han J, Seo M, Byoun H, Cho W, Ryu H, Kang H, Kim J, Kim H, Jang K. Optic nerve sheath diameter threshold by ocular ultrasonography for detection of increased intracranial pressure in Korean adult patients with brain lesions. Medicine (Baltimore). 2016;95(41):1-5.
Wang L, Feng L, Yao Y, Wang Y, Chen Y, Feng J, Xing Y. Optimal optic nerve sheath diameter threshold for the identification of elevated opening pressure on lumbar puncture in a Chinese population. PLoS One. 2015;10(2):1-10.
Chen H, Ding GS, Zhao YC, Yu RG, Zhou JX. Ultrasound measurement of optic nerve diameter and optic nerve sheath diameter in healthy Chinese adults. BMC Neurol. 2015;15(106):1-6.
Blaivas M, Theodoro D, Sierzenski PR. Elevated intracranial pressure detected by bedside emergency ultrasonography of the optic nerve sheath. Acad Emerg Med. 2003;10(4):376-81.
Tayal VS, Neulander M, Norton HJ, Foster T, Saunders T, Blaivas M. Emergency department sonographic measurement of optic nerve sheath diameter to detect findings of increased intracranial pressure in adult head injury patients. Ann Emerg Med. 2007;49(4):508-14.
Goel RS, Goyal NK, Dharap SB, Kumar M, Gore MA. Utility of optic nerve ultrasonography in head injury. Injury. 2008;39(5):519-24.
Eisenberg HM, Gary Jr HE, Aldrich EF, Saydjari C, Turner B, Foulkes MA, Jane JA, Marmarou A, Marshall LF, Young HF. Initial CT findings in 753 patients with severe head injury. A report from the NIH traumatic coma databank. J Neurosurg. 1990;73(5):688-98.
Moreti 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(3):406-10.
Geeraerts T, Launey Y, Martin L, Pottecher J, Vigué B, Duranteau J, Benhamou D. Ultrasonography of the optic nerve sheath may be useful for detecting raised intracranial pressure after severe brain injury. Intensive Care Med. 2007;33(10):1704-11.
Robba C, Cardim D, Tajsic T, Pietersen J, Bulman M, Donnelly J, Lavinio A, Gupta A, Menon DK, Hutchinson PJA, Czosnyka M. Ultrasound non-invasive measurement of intracranial pressure in neurointensive care: a prospective observational study. PLoS Med. 2017;14(7):e1002356.
Kimberly HH, Shah S, Marill K, Noble V. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Acad Emerg Med. 2008;15(2):201-4.
Soldatos T, Karakitsos D, Chatzimichael K, Papathanasiou M, Gouliamos A, Karabinis A. Optic nerve sonography in the diagnostic evaluation of adult brain injury. Crit Care. 2008;12(3):1-7.
Rajajee V, Vanaman M, Fletcher J, Jacobs TL. Optic nerve ultrasound for the detection of raised intracranial pressure. Neurocrit Care. 2011;15(3):506-15.
Jeon JP, Lee SU, Kim SE, Kang SH, Yang JS, Choi HJ, Cho YJ, Ban SP, Byoun HS, Kim YS. Correlation of optic nerve sheath diameter with directly measured intracranial pressure in Korean adults using bedside ultrasonography. PLoS One. 2017;12(9):e0183170.
Lee JS, Lim DW, Lee SH, Oum BS, Kim HJ, Lee HJ. Normative measurements of Korean orbital structures revealed by computerized tomography. Acta Ophtalmol Scandinavica. 2001;79(2):197-200.
Saucedo PS, Redondo OG, Mateu-Mateu A, Arroyo RH, Ruiz RG, Paniagua EB. Sonographic assessment of the optic nerve sheath diameter in the diagnosis of idiopathic intracranial hypertension. J Neurol Sci. 2016;361:122-7.
Ko SB. Optic nerve sheath diameter on brain magnetic resonance imaging: a single center study. J Neurocrit Care. 2015;8:16-24.
Ozgen A, Ariyurek M. Normative measurements of orbital structures using CT. Am J Roentgenol. 1998;170:1093-6.
Robba C, Donelly J, Cardim D, Tajsic T, Cabeleira M, Citerio G, Pelosi P, Smielewski P, Hutchinson P, Menon DK, Czosnyka M. Optic nerve sheath diameter ultrasonography at admission as a predictor of intracranial hypertension in traumatic brain injured patients: a prospective observational study. J Neurosurg. Published online March 8, 2019.
Wang J, Li K, LI H, Ji C, Wu Z, Chen H, Chen B. Ultrasonographic optic nerve sheath diameter correlation with ICP and accuracy as a tool for noninvasive surrogate ICP measurement in patients with decompressive craniotomy. J Neurosurg. 2019; 19:1-7.
Xu J, Song Y, Nayaz BMS, Shi W, Zhao Y, Liu Y, Wu S, Li Z, Sun Y, Zhao Y, Yu W, Wang X. Optic nerve sheath diameter sonography for the diagnosis of intracranial hypertension in traumatic brain injury: a systematic review and meta-analysis. World Neurosurg. 2024: 182:136-143.
Mart;inez-Palacios K, Vásquez-García S, Fariyike OA, Robba C, Rubiano AM, noninvasive ICP monitoring international consensus group. Using optic nerve sheath diameter for intracranial pressure (ICP) monitoring in traumatic brain injury: a scoping review. Neurocrit Care. 2023

Graphs 1 and 2 are available in the Supplementary Files section.

No competing interests reported.

Graph1.png
Graph 1 - Correlation between invasive intracranial pressure (ICP) readings and ultrasonographic measurement of the optic nerve sheath diameter (ONSD).
Graph2.png
Graph 2 - ROC Curve for ICP and mean ONSD in patients with raised ICP. The Area Under the Curve (AUC) is 0.8207 (95% CI: 0.6444 - 0.9972), with the best cutoff point at 6.18 mm, achieving 77.8% sensitivity and 81.8% specificity.

Ultrasonographic evaluation of optic nerve sheath diameter in severe traumatic brain injury patients: a comparison with intraparenchymal pressure monitoring

Status:

Version 1

Abstract

Figures

Introduction

Materials and Methods

Study Population

Data Collection

Ultrasonographic Measurement of the Optic Nerve Sheath Diameter

Analysis Criteria

Results

Discussion

Conclusions

Declarations

Author Contribution

Data Availability

References

Graphs

Additional Declarations

Supplementary Files

Status:

Version 1