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

Reproducibility of Dynamic Vessel Analyzer Measurements and Establishment of Standards

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT00783029

Enrollment

Registered

2008-10-31

Start date

2008-10-31

Completion date

2011-12-31

Last updated

2012-02-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

Vasodilation, Vessel Reactivity, Dynamic Vessel Analyzer, Retina

Brief summary

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.

Detailed description

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.

Interventions

None listed

Study design

Observational model

CASE_ONLY

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

21 Years to 65 Years

Healthy volunteers

Yes

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

Design outcomes

Primary

Measure	Time frame
To characterize changes in the diameter of retinal blood vessels to a light-induced flicker stimulus in healthy subjects on two separate visits.	1 Year

Secondary

Measure	Time frame
To compare retinal vasodilator responses to brachial reactive hyperemic responses.	1 Year

Countries

United States

Outcome results