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Is There a Difference in Flicker Induced Vasodilatation Between Smokers and Non-Smokers?

This study has been completed.
Information provided by:
Medical University of Vienna Identifier:
First received: February 5, 2007
Last updated: July 1, 2008
Last verified: June 2008

Habitual smoking is associated with an increased risk of coronary artery disease, cerebral and peripheral vascular disease, including ocular diseases like age-related macular degeneration or diabetic retinopathy. Data of a recent study performed in the investigators lab revealed abnormal choroidal blood flow regulation in chronic smokers as compared to age-matched non-smoking subjects during isometric exercise. However, no information is yet available about the regulation of retinal vascular tone in habitual smokers.

Thus, in the current study, the investigators set out to investigate whether the regulation of retinal vessels diameters is affected in habitual smokers. It has been shown in several reports that stimulation with diffuse luminance flicker, increases retinal arterial and venous diameters, indicating for the ability of the retina to adapt to changing metabolic demands. In the current study we use this effect as a tool to investigate whether the flicker induced vasodilatation is affected in habitual smokers. This would indicate for an impaired vascular regulation process in smokers.

Condition Intervention
Ocular Physiology
Blood Flow Velocity
Procedure: flicker light stimulation

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Official Title: Is There a Difference in Flicker Induced Vasodilatation Between Smokers and Non-Smokers?

Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:
  • Flicker response (Retinal vessel analyzer, Laser Doppler Velocimetry)

Study Start Date: December 2006
Study Completion Date: September 2007
Primary Completion Date: September 2007 (Final data collection date for primary outcome measure)

Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • 24 subjects aged between 18 and 35 years, nonsmokers (since at least 2 years)
  • 24 subjects aged between 18 and 35 years, smokers (at least 10 cigarettes/day since 2 years)
  • Body mass index between 15th and 85th percentile
  • Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
  • Normal laboratory values unless the investigator considers an abnormality to be clinically irrelevant
  • Normal ophthalmic findings, ametropy < 3 dpt.

Exclusion Criteria:

  • Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
  • Treatment in the previous 3 weeks with any drug
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with distribution, metabolism or excretion of study drugs
  • Blood donation during the previous 3 weeks
  • Ametropy >= 3 dpt
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Please refer to this study by its identifier: NCT00431730

Department of Clinical Pharmacology
Vienna, Austria, 1090
Sponsors and Collaborators
Medical University of Vienna
Principal Investigator: Gabriele Fuchsjaeger-Mayrl, MD Department of CLinical Pharmacology, Medical University of Vienna
  More Information

Responsible Party: Gabriele Fuchsjäeger-Mayrl, Department of Clinical Pharmacology, Medical University of Vienna Identifier: NCT00431730     History of Changes
Other Study ID Numbers: OPHT-121203
Study First Received: February 5, 2007
Last Updated: July 1, 2008 processed this record on April 28, 2017