optic nerve diameter

Increases in intracranial pressure (ICP) may damage the brain by compression of its structures or restriction of its blood flow, and medical providers my encounter elevated ICP in conventional and non-conventional medical settings. Early identification of elevated ICP is critical to ensuring timely and appropriate management. However, few diagnostic methods are available for detecting increased ICP in an acutely ill patient, which can be performed quickly and noninvasively at the bedside. The optic nerve sheath is a continuation of the dura mater of the central nervous system and can be viewed by ocular ultrasound...

OBJECTIVE: To determine if ultrasound guided measurement of the optic nerve sheath diameter accurately predicted elevated intracranial pressure (ICP) as demonstrated by cranial computed tomography (CT) in at-risk emergency department patients. METHODS: Optic nerve sheath diameters were measured on a convenience sample of adult patients presenting with suspected elevated ICP to the emergency department of a large teaching hospital over a 6-month period. A cut off for optic nerve sheath diameter of 5 mm was considered positive for elevated ICP...

BACKGROUND: Quantification of the optic nerve sheath diameter (ONSD) by transbulbar sonography is a promising non-invasive technique for the detection of altered intracranial pressure. In order to establish this method as follow-up tool in diseases with intracranial hyper- or hypotension scan-rescan reproducibility and accuracy need to be systematically investigated. METHODS: The right ONSD of 15 healthy volunteers (mean age 24.5 ± 0.8 years) were measured by both transbulbar sonography (9 - 3 MHz) and 3 Tesla MRI (half-Fourier acquisition single-shot turbo spin-echo sequences, HASTE) 3 and 5 mm behind papilla...

PURPOSE: Increased intracranial pressure (ICP) is associated with worse outcomes following traumatic brain injury (TBI). Studies have confirmed that ICP is correlated with optic nerve sheath diameter (ONSD) on ultrasound. The aim of our study was to assess the independent relationship between ONSD measured using CT and mortality in a population of patients admitted with severe TBI. METHODS: We conducted a retrospective cohort study of patients with a TBI requiring ICP monitoring admitted to the ICU between April 2006 and May 2012 to two neurotrauma centers...

BACKGROUND: Traditionally, intracranial pressure is measured by direct ventriculostomy, which is invasive. Noninvasive measures such as bedside ultrasound and magnetic resonance imaging have been advocated and utilized recently to assess the intracranial pressure. The role of this study is to determine the degree of agreement between measurements of the optic nerve sheath diameter by computed tomography (CT) and magnetic resonance imaging (MRI). MATERIALS AND METHODS: Retrospective chart review of 100 consecutive patients who had both MRI and CT scan of the head from January 1, 2011, until March 31, 2013, at our center was performed...

The use of point-of-care ultrasound in the emergency department has expanded considerably in recent years, allowing enhanced evaluation of the patient with an emergent eye or vision complaint. The technique is simple and quick to perform, and can yield clinical information that may not be readily obtainable through physical or slit-lamp exams. Ocular bedside sonography can aid in the diagnosis of retinal and vitreous hemorrhage, retinal and vitreous detachments, ocular infections, foreign bodies, retrobulbar hematoma, or ocular vascular pathology...

OBJECTIVE: Increased intracranial pressure (ICP) may contribute to acute mountain sickness (AMS). Measuring optic nerve sheath diameter (ONSD) by ultrasound (US) is a noninvasive technique to detect elevated ICP, and increased ONSD has been associated with AMS. We hypothesized that ONSD would increase with acute, rapid ascent to 4300 m and that increased ONSD would be associated with symptoms of AMS. We further hypothesized that treatment with oxygen at 4300 m would reduce symptoms and ONSD...

BACKGROUND: Ultrasonic assessment of optic nerve sheath diameter (ONSD) as a non-invasive measure of intracranial pressure (ICP) has been evaluated in the literature as a potential valid technique for rapid ICP estimation in the absence of invasive intracranial monitoring. The technique can be challenging to perform and little literature exists surrounding intra-operator variability. OBJECTIVES: In this study we describe the creation of a novel model of ONSD to be utilized in ultrasound training of this technique...

BACKGROUND: In some cases of severe preeclampsia/eclampsia, brain imaging displays signs compatible with raised intracranial pressure. We aimed to estimate the incidence of raised intracranial pressure in preeclampsia using ocular ultrasonography. METHODS: Optic nerve sheath diameter (ONSD) measurements were compared in 26 preeclamptic and 25 healthy pregnant women. For each optic nerve, two measurements were made (transverse plane and sagittal plane) using a 7...

BACKGROUND: Ultrasound measurement of the optic nerve sheath diameter (ONSD) has been shown to correlate with intracranial pressure (ICP). This study looked at intra-observer and inter-observer reliability among three emergency physicians (EPs) using three different imaging protocols. MATERIAL/METHODS: Ocular ultrasound was performed in 20 healthy volunteers. Each physician obtained 3 measurements of the right eye ONSD with both the 10-5 MHz and 13-6 MHz probes using the axial imaging technique (experiment 1)...

BACKGROUND: Measurements of the optic nerve sheath diameter (ONSD) using bedside ultrasound (US) have been shown to correlate with clinical and radiologic signs and symptoms of increased intracranial pressure (ICP). OBJECTIVES: Previous literature has identified 5 mm as the ONSD measurement above which patients exhibit either clinical or radiologic signs of elevated ICP. The goals of this study were to evaluate the association between ONSD and ICP and to validate the commonly used ONSD threshold of 5 mm using direct measurements of ICP as measured by ventriculostomy...

OBJECTIVE: To assess at admission to the ICU the relationship between optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) and to investigate whether increased ONSD at patient admission is associated with raised ICP in the first 48[Symbol: see text]h after trauma. DESIGN AND SETTING: Prospective, blind, observational study in a surgical critical care unit, level 1 trauma center. PATIENTS AND PARTICIPANTS: 31 adult patients with severe traumatic brain injury (TBI; Glasgow coma scale <or=8) requiring sedation and ICP monitoring, and 31 control patients without brain injury requiring sedation...

UNLABELLED: Patients with altered level of consciousness may be suffering from elevated intracranial pressure (EICP) from a variety of causes. A rapid, portable, and noninvasive means of detecting EICP is desirable when conventional imaging methods are unavailable. OBJECTIVES: The hypothesis of this study was that ultrasound (US) measurement of the optic nerve sheath diameter (ONSD) could accurately predict the presence of EICP. METHODS: The authors performed a prospective, blinded observational study on emergency department (ED) patients with a suspicion of EICP due to possible focal intracranial pathology...