Clinical trial NCT00431730: Is There a Difference in Flicker Induced Vasodilatation Between Smokers and Non-Smokers?
Official title: Is There a Difference in Flicker Induced Vasodilatation Between Smokers and Non-Smokers?
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Ocular Physiology
Retina
Blood Flow Velocity
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
First posted: 2007-02-06
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL

Brief summary: 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.


Eligibility criteria: 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

Primary outcomes:
measure: Flicker response (Retinal vessel analyzer, Laser Doppler Velocimetry)
Secondary outcomes:
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Department of Clinical Pharmacology
Study officials:
affiliation: Department of CLinical Pharmacology, Medical University of Vienna
name: Gabriele Fuchsjaeger-Mayrl, MD
role: PRINCIPAL_INVESTIGATOR
References: