Measurement of the Eye's Blood Vessels Using the Dynamic Vessel Analyzer (DVA)

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: NCT00783029
Recruitment Status : Completed
First Posted : October 31, 2008
Last Update Posted : February 7, 2012
Information provided by (Responsible Party):
Kerstin Bettermann, Penn State University

October 30, 2008
October 31, 2008
February 7, 2012
October 2008
December 2011   (Final data collection date for primary outcome measure)
To characterize changes in the diameter of retinal blood vessels to a light-induced flicker stimulus in healthy subjects on two separate visits. [ Time Frame: 1 Year ]
Same as current
Complete list of historical versions of study NCT00783029 on Archive Site
To compare retinal vasodilator responses to brachial reactive hyperemic responses. [ Time Frame: 1 Year ]
Same as current
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Measurement of the Eye's Blood Vessels Using the Dynamic Vessel Analyzer (DVA)
Reproducibility of Dynamic Vessel Analyzer Measurements and Establishment of Standards
The purpose of this research study is examine the response of the blood vessels in the eye to a light flicker stimulus using the Dynamic Vessel Analyzer (DVA) on two separate days in healthy individuals. The DVA uses an instrument which is used during routine eye examinations. The hypothesis of the study is that the changes in eye's blood vessel will be similar between the two visits; thus establishing reproducibility of the measurements for future comparisons to individuals with stroke or heart disease. In addition, this study will compare the eye's blood vessel responses to responses of the blood vessels in the arm using Doppler ultrasound.
Retinal blood vessels have been suggested to be an index of the cerebral and coronary microvasculature function. Since the retinal vessels are not under direct sympathetic control, this vascular bed is an ideal location to examine local mechanisms of vascular regulation(i.e. metabolite/endothelial and myogenic). Based on previously published data on animal and human responses, the central purpose for the proposed research is to compare the retinal and brachial vasodilatation responses in healthy subjects using the Dynamic Vessel Analyzer (DVA). Our rationale for this proposal is to better understand retinal blood flow in healthy individuals, gain insight into vascular reactivity in different vascular beds, and lastly to establish standards and reproducibility of DVA Measurements.
Observational Model: Case-Only
Time Perspective: Prospective
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Non-Probability Sample
Healthy Subjects
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Healthy Subjects
Healthy participants between the ages of 21 and 65 years old.
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*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
December 2011
December 2011   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Healthy Individuals
  • Age: 21 to 65 years
  • Non-smokers
  • Non-obese

Exclusion Criteria:

  • History of cardiovascular, pulmonary, peripheral vascular disease, renal, prostate, and urinary retention disease; Hypertension; Narrow angle Glaucoma or Age Related Macular Degeneration.
  • Pregnancy
  • Inability to fixate using eye device
  • Does not wish to participate
Sexes Eligible for Study: All
21 Years to 65 Years   (Adult)
Contact information is only displayed when the study is recruiting subjects
United States
IRB # 29113
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Kerstin Bettermann, Penn State University
Penn State University
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Principal Investigator: Kerstin Bettermann, MD, PhD Penn State College of Medicine
Penn State University
February 2012