Measurement of the Eye's Blood Vessels Using the Dynamic Vessel Analyzer (DVA)
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.
|Study Design:||Observational Model: Case-Only
Time Perspective: Prospective
|Official Title:||Reproducibility of Dynamic Vessel Analyzer Measurements and Establishment of Standards|
- 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 ] [ Designated as safety issue: No ]
- To compare retinal vasodilator responses to brachial reactive hyperemic responses. [ Time Frame: 1 Year ] [ Designated as safety issue: No ]
|Study Start Date:||October 2008|
|Study Completion Date:||December 2011|
|Primary Completion Date:||December 2011 (Final data collection date for primary outcome measure)|
Healthy participants between the ages of 21 and 65 years old.
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.
|United States, Pennsylvania|
|Penn State Milton S. Hershey Medical Center|
|Hershey, Pennsylvania, United States, 17033|
|Principal Investigator:||Kerstin Bettermann, MD, PhD||Penn State College of Medicine|