BACKGROUND: Rapid evaluation and management of intracranial pressure (ICP) can help to early detection of increased ICP and improve postoperative outcomes in neurocritically-ill patients. Sonographic measurement of optic nerve sheath diameter (ONSD) is a non-invasive method of evaluating increased intracranial pressure at the bedside. In the present study, we hypothesized that sonographic ONSD, as a surrogate of ICP change, can be dynamically changed in response to carbon dioxide change using short-term hyperventilation. METHODS: Fourteen patients were enrolled. During general anesthesia, end-tidal carbon dioxide concentration (ETCO2) was decreased from 40 mmHg to 30 mmHg within 10 minutes. ONSD, which was monitored continuously in the single sonographic plane, was repeatedly measured at 1 and 5 minutes with ETCO2 40 mmHg (time-point 1 and 2) and measured again at 1 and 5 minutes with ETCO2 30 mmHg (time-point 3 and 4). RESULTS: The mean +/- standard deviation of ONSD sequentially measured at four time-points were 5.0 +/- 0.5, 5.0 +/- 0.4, 3.8 +/- 0.6, and 4.0 +/- 0.4 mm, respectively. ONSD was significantly decreased at time-point 3 and 4, compared with 1 and 2 (P < 0.001). CONCLUSIONS: The ONSD was rapidly changed in response to ETCO2. This finding may support that ONSD may be beneficial to close ICP monitoring in response to CO2 change.
Anesthesia, General* ; Carbon Dioxide ; Humans ; Hyperventilation* ; Intracranial Pressure ; Optic Nerve* ; Ultrasonography

BACKGROUND: Rapid evaluation and management of intracranial pressure (ICP) can help to early detection of increased ICP and improve postoperative outcomes in neurocritically-ill patients. Sonographic measurement of optic nerve sheath diameter (ONSD) is a non-invasive method of evaluating increased intracranial pressure at the bedside. In the present study, we hypothesized that sonographic ONSD, as a surrogate of ICP change, can be dynamically changed in response to carbon dioxide change using short-term hyperventilation. METHODS: Fourteen patients were enrolled. During general anesthesia, end-tidal carbon dioxide concentration (ETCO2) was decreased from 40 mmHg to 30 mmHg within 10 minutes. ONSD, which was monitored continuously in the single sonographic plane, was repeatedly measured at 1 and 5 minutes with ETCO2 40 mmHg (time-point 1 and 2) and measured again at 1 and 5 minutes with ETCO2 30 mmHg (time-point 3 and 4). RESULTS: The mean +/- standard deviation of ONSD sequentially measured at four time-points were 5.0 +/- 0.5, 5.0 +/- 0.4, 3.8 +/- 0.6, and 4.0 +/- 0.4 mm, respectively. ONSD was significantly decreased at time-point 3 and 4, compared with 1 and 2 (P < 0.001). CONCLUSIONS: The ONSD was rapidly changed in response to ETCO2. This finding may support that ONSD may be beneficial to close ICP monitoring in response to CO2 change.
Anesthesia, General* ; Carbon Dioxide ; Humans ; Hyperventilation* ; Intracranial Pressure ; Optic Nerve* ; Ultrasonography

OBJECTIVE: While the optic nerve sheath diameter (ONSD) is measured by computed tomography and ultrasonography as an indicator of an elevation in the intracranial pressure (ICP), it is unclear which ONSD measurement is useful for predicting an increased ICP. This study examined the comparability between the ONSD measured by computed tomography and ultrasonography. METHODS: A prospective study of 150 patients in the emergency center was performed. The ONSD was measured 3 mm behind the globe of all patients by computed tomography and ultrasonography. The receiver operator characteristic (ROC) curve was analyzed to determine the diagnostic utility of detecting ICP through ONSD. RESULTS: A total of 150 patients were enrolled. Thirty-three patients (22.0%) were found to have an increased ICP. The ONSD in patients with increased ICP was significantly higher than that of normal ICP patients measured by computed tomography and ultrasonography. Moreover, computed tomography and ultrasonography revealed an area under the ROC curve value of 0.886 and 0.933, respectively. The ONSD measurement by computed tomography and ultrasonography produced similar results (P=0.256). CONCLUSION: The ONSD measured by computed tomography and ultrasonography is a valuable indicator of an ICP elevation. Therefore, either of the two diagnostic methods for monitoring the ICP can be used in patients with a critical care and resource-limited setup.
Critical Care ; Emergencies ; Humans ; Intracranial Pressure ; Optic Nerve ; Prospective Studies ; ROC Curve ; Ultrasonography

OBJECTIVE: To evaluate the prognostic value of ultrasonographic measurement of optic nerve sheath diameter (ONSD) and ONSD/eyeball transverse diameter (ETD) ratio in stroke patients during hospitalization. METHODS: Adult patients with stroke (ischemic stroke or hemorrhagic stroke) admitted to department of critical care medicine of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine from November 2017 to November 2018 were enrolled. On the day of admission, ONSD and ETD (retina-retina at 3 mm behind the globe along) were detected by ultrasound, the ONSD/ETD ratio was calculated, and the baseline data and outcomes were recorded. Patients were divided into survival group and death group according to their survival status. Locally weighted scatterplot smoothing (LOWESS) and the receiver operating characteristic (ROC) curve were used to calculate the thresholds of ONSD and ONSD/ETD. The correlation between ONSD, ONSD/ETD and prognosis were assessed. RESULTS: Thirty-eight of 83 patients (45.8%) survived and were discharged from the hospital, while 45 patients died (54.2%). There were significant differences in Glasgow coma score (GCS), shifting of the middle structure, ONSD and ONSD/ETD between the death group and the survival group [GCS: 4.7±2.8 vs. 11.0±3.2, shifting of the middle structure (mm): 5.8±5.9 vs. 1.3±2.6, ONSD (mm): 5.5±0.4 vs. 4.4±0.5, ONSD/ETD: 0.25±0.02 vs. 0.20±0.02, all P < 0.05]. LOWESS and ROC curve analysis suggested thresholds of ONSD and ONSD/ETD for predicting adverse prognosis of stroke patients were 5.0 mm and 0.25, respectively. By adjusting the influence of confounding factors on prognosis, a prediction model based on ONSD was established, and the ROC curve was drawn. The area under the curve (AUC) was 0.978, the optimal predictive point of the model was 0.870, the sensitivity was 89%, and the specificity was 100%. The ONSD/ETD prediction model was also obtained, and the AUC was 0.988, the optimal prediction threshold of the model was 0.768, and the sensitivity for predicting adverse clinical prognosis was 94%, and the specificity was 97%. The stability of ONSD/ETD was better than that of ONSD. ONSD coefficient of variation was 0.14, and ONSD/ETD coefficient of variation was 0.13. CONCLUSIONS ONSD and ONSD/ETD were significantly correlated with the prognosis of critical patients with stroke. The mortality increased significantly in patients with an ONSD greater than 5.0 mm and ONSD/ETD greater than 0.25. ONSD and ONSD/ETD may be promising tools for early assessment of clinical outcomes in these patients.
Adult ; China ; Hospitalization ; Humans ; Intracranial Pressure ; Optic Nerve ; Prognosis ; ROC Curve ; Stroke ; Ultrasonography

PURPOSE: To evaluate orbital blood flow velocities and optic nerve diameter with Doppler and gray-scale sonography in patients with acute unilateral optic neuritis (ON). METHODS: Orbital Doppler and gray-scale sonography was performed in 46 eyes of 23 patients aged 19- to 47-years with acute unilateral ON. ON was diagnosed by an ophthalmologist on the basis of clinical presentation, presence of decreased visual acuity and assessment of visual evoked potentials. The peak systolic velocity (PSV) and end-diastolic velocity (EDV), as well as the resistance index (RI) and pulsatile index (PI) of the ophthalmic artery (OA), central retinal artery (CRA), posterior ciliary arteries (PCAs) and optic nerve diameter were measured in both eyes. We compared results from affected and unaffected eyes using the paired t-test. The area under the receiver operating characteristic (ROC) curves was used to assess the diagnosis of ON based on measured blood flow parameters of the OA, CRA and PCAs and optic nerve diameter. RESULTS: The mean (standard deviation) optic nerve diameter in eyes with ON was 4.1 (0.8) mm, which was significantly larger than the 3.0 (0.4) mm diameter measured in unaffected control eyes (p < 0.001). There were no differences in average PSV, EDV, RI, or PI of the OA and CRA between affected and unaffected eyes (p > 0.05). The mean RI in the PCAs was slightly lower in the eyes with ON than in the contralateral eyes (0.60 vs. 0.64, p < 0.05). The area under the ROC curves indicated that optic nerve diameter was the best parameter for the diagnosis of ON. CONCLUSIONS: Optic nerve diameter was related to ON, but orbital blood flow parameters were not.
Adult ; Humans ; Middle Aged ; Ophthalmic Artery/*physiology/*ultrasonography ; Optic Nerve/*blood supply/*ultrasonography ; Optic Neuritis/*physiopathology/*ultrasonography ; Orbit/blood supply/ultrasonography ; Pulsatile Flow/physiology ; Regional Blood Flow/physiology ; Ultrasonography, Doppler, Color ; Vascular Resistance/physiology ; Young Adult

PURPOSE: A rapid, portable, and noninvasive means of detecting increased intracranial pressure (IICP) is desirable when conventional imaging methods are unavailable. The purpose of this study was to show that ultrasonographic measurement of the optic nerve sheath diameter (ONSD) can accurately predict the presence of IICP. METHODS: We performed a prospective study of emergency department patients suspected of having IICP due to possible focal intracranial pathology. The ONSD was measured 3 mm behind the globe using a linear probe on the closed eyelids of supine patients. For each patient, the mean of the two ONSD measurements was calculated, and the brain computed tomography (CT) was evaluated for signs of IICP. RESULTS: One hundred patients were enrolled; 31 had CT results consistent with IICP, and their mean ONSD was 6.30 mm; the mean ONSD of patients who didn't show signs of IICP on CT was 4.50 mm. The sensitivity and the specificity for the ONSD, when compared with CT results, were 100% and 98.6%, respectively. CONCLUSIONS: The evaluation of the ONSD is a simple noninvasive procedure, and is a potentially useful tool in assessing and monitoring patients suspected of having IICP.
Brain ; Emergencies* ; Emergency Service, Hospital ; Eyelids ; Humans ; Intracranial Pressure* ; Optic Nerve* ; Pathology ; Prospective Studies ; Sensitivity and Specificity ; Ultrasonography*

Optical coherence tomography is a new imaging technique analogous to ultrasound B scan that can provide cross sectional images of retina with approximately 10micrometer resolution. This study was designed to evaluate the quantification of nerve fiber layer [NFL] thickness in normal eyes using OCT. We studied 66 eyes of 66 subjects by conventional ophthalmoscopic physical examination, Humphrey central 30-2 visual fields, stereoscopic optic nerve head photography, retinal nerve fiber layer photography, HRT and OCT. Imaging with OCT was performed circumferentially around the optic nerve head with a circle diameter of 2.3mm & 3.4mm using an internal fixation technique. At a scan diameter of 2.3mm and 3.4mm, average, superior, inferior, nasal and temporal NFL thicknesses were 125.45 +/-19.05 micrometer, 150.33 +/-25.53micrometer, 154.55 +/-25.72 micrometer, 102.89 +/-29.13micrometer, and 92.65 +/-27.04micrometer and 109.02 +/-15.68 micrometer,135.53 +/-22.65 micrometer, 132.98 +/-20.19micrometer, 73.11 +/-26.85 micrometer and 89.70 +/-14.65 micrometer each. The NFL was thickest in the superior and inferior quadrants,thinnest in the nasal quadrant at a scan diameter of 2.3mm, and thinnest in the temporal quadrant at a scan diameter of 3.4 mm. In general the thickness for the 2.3 mm scans was greater than that for the 3.4mm scans.NFL thickness decreased significantly with age in the temporal quadrants [P<0.05]. At a scan diameter of 3.4 mm, NRA decreased significantly with decreased average NFL thickness and average NFL thickness decreased significantly with decreased disc area [P<0.05]. By direct investigation of the NFL with OCT, earlier diagnosis of glaucoma and earlier detection of glaucomatous progression can be made, before conventional signs such as visual field loss, cupping of the optic nerve head, and NFL defects are evident, thus allowing earlier treatment and reducing the damage.
Diagnosis ; Glaucoma ; Nerve Fibers* ; Optic Disk ; Photography ; Physical Examination ; Retina ; Retinaldehyde* ; Tomography, Optical Coherence* ; Ultrasonography ; Visual Fields

PURPOSE: Many reports have shown that the optic nerve sheath diameter (ONSD) can be measured easily by ultrasonography, and that it becomes wider when the intra-cranial pressure (ICP) is increased. However, there have been no reports comparing the two ONSDs following proper treatment. We measured the 2nd ONSDs of patients who were diagnosed with intra-cranial hemorrhage and increased ICP and who were admitted to an intensive care unit following management of their conditions, and analyzed the changes of the ONSDs and their relationship to the outcomes. METHODS: During the 10 months beginning December 1, 2004, we recruited 29 patients who were suspected to have increased ICP as indicated by computed tomography at the emergency center. Meeting any one of the following criteria was defined as elevated ICP: mid-line shifting of 3 mm or greater due to mass effect; a collapsed 3rd ventricle; hydrocephalus; effacement of sulci with significant edema; abnormal mesencephalic cisterns. We determined initial ONSDs by ultraonography and the Glasgow Coma Scale (GCS). At the 7th hospital day, GCS and ONSDs were re-evaluated and compared against the previous data. RESULTS: 29 patients (21 male, 8 female, average age 55.55 years) were enrolled. Mean GCS at the admission was 7.86+/-3.60. 18 patients had spontaneous hemorrhage (62%) and 11 patients had traumatic hemorrhage (38%). 22 patients received emergency surgery, 18 patients (62%) showed improved neurological outcomes and 11 (38%) failed to achieve any good outcomes. The initial mean ONSD was 5.41+/-0.70 mm. The average ONSD for traumatic hemorrhage (5.51+/-0.45 mm) was not statistically different from the ONSD for non-traumatic hemorrhage (5.35+/-0.84 mm) (p=0.55). The mean ONSD after 7 days of admission was 4.41+/-0.53 mm, which represented a significant decrease compared with the initial measurements (p<0.05). The mean GCS and ONSD showed significant differences between the improved group and the nonimproved group (GCS: 13.44+/-2.15, 3.82+/-3.82 respectively; and ONSD: 4.13+/-0.40 mm, 4.86+/-0.37 mm respectively; p<0.05). CONCLUSION : Among the patients with increased ICP, the ONSDs who progressed to good neurological outcomes after treatment had a significantly smaller diameter than those of the others. Through measurement of the ONSDs using ultrasonography, we could not only predict increased ICP but also determine the correlation between a patient's ICP and clinical course.
Edema ; Emergencies ; Female ; Glasgow Coma Scale ; Hemorrhage ; Humans ; Hydrocephalus ; Intensive Care Units ; Intracranial Pressure ; Male ; Optic Nerve* ; Ultrasonography

PURPOSE: Many reports have shown that the optic nerve sheath diameter (ONSD) can be measured easily by ultrasonography, and that it becomes wider when the intra-cranial pressure (ICP) is increased. However, there have been no reports comparing the two ONSDs following proper treatment. We measured the 2nd ONSDs of patients who were diagnosed with intra-cranial hemorrhage and increased ICP and who were admitted to an intensive care unit following management of their conditions, and analyzed the changes of the ONSDs and their relationship to the outcomes. METHODS: During the 10 months beginning December 1, 2004, we recruited 29 patients who were suspected to have increased ICP as indicated by computed tomography at the emergency center. Meeting any one of the following criteria was defined as elevated ICP: mid-line shifting of 3 mm or greater due to mass effect; a collapsed 3rd ventricle; hydrocephalus; effacement of sulci with significant edema; abnormal mesencephalic cisterns. We determined initial ONSDs by ultraonography and the Glasgow Coma Scale (GCS). At the 7th hospital day, GCS and ONSDs were re-evaluated and compared against the previous data. RESULTS: 29 patients (21 male, 8 female, average age 55.55 years) were enrolled. Mean GCS at the admission was 7.86+/-3.60. 18 patients had spontaneous hemorrhage (62%) and 11 patients had traumatic hemorrhage (38%). 22 patients received emergency surgery, 18 patients (62%) showed improved neurological outcomes and 11 (38%) failed to achieve any good outcomes. The initial mean ONSD was 5.41+/-0.70 mm. The average ONSD for traumatic hemorrhage (5.51+/-0.45 mm) was not statistically different from the ONSD for non-traumatic hemorrhage (5.35+/-0.84 mm) (p=0.55). The mean ONSD after 7 days of admission was 4.41+/-0.53 mm, which represented a significant decrease compared with the initial measurements (p<0.05). The mean GCS and ONSD showed significant differences between the improved group and the nonimproved group (GCS: 13.44+/-2.15, 3.82+/-3.82 respectively; and ONSD: 4.13+/-0.40 mm, 4.86+/-0.37 mm respectively; p<0.05). CONCLUSION : Among the patients with increased ICP, the ONSDs who progressed to good neurological outcomes after treatment had a significantly smaller diameter than those of the others. Through measurement of the ONSDs using ultrasonography, we could not only predict increased ICP but also determine the correlation between a patient's ICP and clinical course.
Edema ; Emergencies ; Female ; Glasgow Coma Scale ; Hemorrhage ; Humans ; Hydrocephalus ; Intensive Care Units ; Intracranial Pressure ; Male ; Optic Nerve* ; Ultrasonography

In ultrasound/computed tomography (CT) fusion images, ultrasound allows visualization of the target in real time. CT provides a navigation for ultrasound scanning and improves the overview in areas of limited visualization with ultrasound. This study was performed to investigate the feasibility of ultrasound/CT fusion based on an electromagnetic tracking technique using external fiducial markers for canine ocular and periocular regions. In 7 Beagle dogs, contrast-enhanced CT images of the head were obtained with placing external fiducial markers over the frontal region and both sides of the forepaws of the dog. Ultrasonography was performed under a magnetic field by installing a position sensor in the linear probe, without changing the dog's position. The positions of the external fiducial markers were adjusted and matched, based on the CT images. The execution time of co-registration and the distance between the regions of interest and the co-registration points, the frontal bone, cornea, retina, and optic nerve, were estimated. Approximately 60% of external fiducial markers were properly recognized in all dogs. After adjustment, all external fiducial markers were precisely matched. The co-registration execution time was less than 1 min. The distances between the regions of interest and co-registration points were less than 3 mm in all dogs. The electromagnetic tracking technique using external fiducial markers was a simple and applicable method for fusion imaging of a canine head using real-time ultrasonography and CT. This technique can be useful for interventional procedures of retrobulbar and periorbital lesions.
Animals ; Cornea ; Dogs ; Fiducial Markers ; Frontal Bone ; Head ; Magnetic Fields ; Magnets ; Methods ; Optic Nerve ; Retina ; Tomography, X-Ray Computed ; Ultrasonography