OPKO Ultrasound system does the job
on Mount Everest.
Published in the British Journal of Sports Medicine, Dr. Sutherland and his team reported a research study named Optic nerve sheath diameter, intracranial pressure and acute mountain sickness on Mount Everest: a longitudinal cohort study.
(Copyright © 2008 BMJ Publishing Group Ltd & British Association of Sport and Exercise Medicine) http://bjsm.bmj.com/cgi/content/full/42/3/183
OPKO’s OTI-Scan 3D ultrasound was used in the study. The study investigated the association of optic nerve sheath diameter (ONSD), as a correlate of intracranial pressure (ICP), with acute mountain sickness (AMS). The longitudinal cohort study of mountaineers is conducted from sea level to 6400 m (20,997 feet) on the North side of Mount Everest.
Despite the fact that acute mountain sickness (AMS) has been recognized as a specific condition since the early 20th century, the mechanisms underlying its development remain unclear. This study set out to explore the association between ICP and AMS at increasing altitudes in humans, using a new, non-invasive ultrasound method to measure optic nerve sheath diameter (ONSD). This technique has been described recently as a safe and reliable method to assess ICP. The optic nerve sheath is continuous with the dura mater, and cerebrospinal fluid (CSF) usually communicates freely between the intracranial space and the optic nerve. Using B-scan ultrasound of the eye, it is possible to determine the ONSD, which has been shown to have a linear correlation with ICP. This technique has been used successfully to identify raised ICP in children with hydrocephalus, and in patients with head injuries in the emergency room and the intensive care unit. The measure has been shown to have good inter-observer and intra-observer repeatability, and portable equipment is available that allows measurements to be taken in remote settings, including at high altitude.
In the study, ONSD was measured ultrasonically, 3 mm behind the globe using B scans recorded with an OTI-Scan 3D scanner from Ophthalmic Technologies Inc, Canada, acquired by OPKO Health Inc. in 2007. Serial binocular scans were recorded at sea level, and 2000, 3700, 5200 and 6400 m. All ONSDs were measured by a blinded observer. The aim of this study was to measure ONSD at different altitudes above sea level, as a correlate of ICP, in a cohort of mountaineers attempting to climb Mount Everest.
It concluded ONSD increases at high altitude, and this increase is associated with more severe symptoms of AMS. Given the linkage between ONSD and ICP, these results strongly suggest that intracranial pressure plays an important role in the pathophysiology of AMS.
To read the full research article, please visit:
http://bjsm.bmj.com/cgi/content/full/42/3/183
Published Online First: 8 January 2008. doi:10.1136/bjsm.2007.045286
British Journal of Sports Medicine 2008;42:183-188
Copyright © 2008 BMJ Publishing Group Ltd & British Association of Sport and Exercise Medicine.
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