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

This study has been completed.
Sponsor:
Collaborator:
Anesthesia Patient Safety Foundation
Information provided by:
Rutgers, The State University of New Jersey
ClinicalTrials.gov Identifier:
NCT00875043
First received: April 1, 2009
Last updated: April 2, 2009
Last verified: April 2009
  Purpose

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
Blindness

Study Type: Observational
Study Design: 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

Further study details as provided by Rutgers, The State University of New Jersey:

Enrollment: 10
Study Start Date: March 2008
Study Completion Date: July 2008
Primary Completion Date: June 2008 (Final data collection date for primary outcome measure)
Groups/Cohorts
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.

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.

  Eligibility

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Healthy volunteers

Criteria

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
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00875043

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

No publications provided

Responsible Party: Geordie P. Grant, MD, UMDNJ
ClinicalTrials.gov Identifier: NCT00875043     History of Changes
Other Study ID Numbers: 0120070324
Study First Received: April 1, 2009
Last Updated: April 2, 2009
Health Authority: United States: Institutional Review Board

Keywords provided by Rutgers, The State University of New Jersey:
ischemic optic neuropathy
cortical blindness

Additional relevant MeSH terms:
Hyperemia
Blindness
Vascular Diseases
Cardiovascular Diseases
Vision Disorders
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Eye Diseases
Signs and Symptoms

ClinicalTrials.gov processed this record on July 24, 2014