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Determine the Effect of Intraocular Pressure (IOP), Optic Nerve Imaging, Venous Congestion in Volunteers Prone Position 5 Hours

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00875043
Recruitment Status : Completed
First Posted : April 3, 2009
Last Update Posted : October 14, 2016
Anesthesia Patient Safety Foundation
Information provided by (Responsible Party):
Rutgers, The State University of New Jersey

Brief Summary:
The purpose of this study is to provide data that would give the investigators a better understanding of the physiologic changes that occur and may contribute to post operative blindness. An improved understanding may lead to the development of protocols or devices that reduce the chance of catastrophic visual loss.

Condition or disease

Detailed Description:
Post operative vision loss resulting from nonocular surgery is a devastating, poorly understood and potentially preventable complication. Ischemic optic neuropathy, affecting both the anterior or posterioir portions of the optic nerve, is the most common cause of postoperative vision loss(POVL). Other, less common causes include retinal artery occlusion, retinal vein occlusion, retinal embolism, and cortical blindness. The estimated incidence of POVL in patients undergoing general anesthesia is 1/60,000. The incidence dramatically increases in cardiopulmonary bypass and prone spine surgery with estimates at 1/1600 and 1/1100, respectively. The etiology is unknown but it is thought to be multifactorial, and several potential risk factors have been identified, including degree of hypotension, preoperative hematocrit, external compression of the eye, blood loss and prone position. The investigators are proposing eight volunteers in two different sessions of 5.5 hours each. The first session the volunteer will lie prone of the flat Jackson table and the second session the volunteer will spend 5 hours prone on the Jackson table with a table elevation of 6 inches. The following measurements will be done: Intraocular Pressure (IOP) with a device called the Tonopen-XL, the Nidex NM 200 to visualize the retinal optic nerve imaging, refractometry, ultrasound, corneal thickness pachymetry, measurement of proptosis, measurement of pupillary reflex, The volunteers do not receive anesthetic medications or intravenous fluids and will provide a baseline for comparision with patients enrolled in the prospective study.

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Study Type : Observational
Actual Enrollment : 10 participants
Observational Model: Case-Crossover
Time Perspective: Prospective
Official Title: A Pilot Study to Determine the Effect on Intraocular Pressure, Optic Nerve Imaging and Other Markers of Venous Congestion of Volunteer Subjects in the Prone Position for a Period of Five Hours
Study Start Date : March 2008
Actual Primary Completion Date : June 2008
Actual Study Completion Date : July 2008

Resource links provided by the National Library of Medicine

1. flat Jackson table
All measurements previously described will be done with the patient in the prone postion and Jackson table flat.
2. Elevated Jackson tablet
All measurements previously described will be performed with subjects placed prone on the elevated Jackson table.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Healthy volunteers

Inclusion Criteria:

  • subjects willing to consent

Exclusion Criteria:

  • individuals unable to tolerate prone position for 5 hours
  • individuals unable to tolerate contact lens placement
  • females who are pregnant
  • individuals with a sensitivity to proparacaine hcl 0.5% or tropicamide 1%
  • individuals who are unable to have repeated mesaurements of intaocular pressure

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00875043

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United States, New Jersey
UMDNJ/University Hospital
Newark, New Jersey, United States, 07101
Sponsors and Collaborators
Rutgers, The State University of New Jersey
Anesthesia Patient Safety Foundation
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Principal Investigator: Geordie P. Grant, MD University of Medicine & Dentistry of New Jersey

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Responsible Party: Rutgers, The State University of New Jersey Identifier: NCT00875043    
Other Study ID Numbers: 0120070324
First Posted: April 3, 2009    Key Record Dates
Last Update Posted: October 14, 2016
Last Verified: April 2009
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Rutgers, The State University of New Jersey:
ischemic optic neuropathy
cortical blindness
Additional relevant MeSH terms:
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Vision Disorders
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Eye Diseases
Signs and Symptoms
Vascular Diseases
Cardiovascular Diseases