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

Ocular Physiology Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00431730
• Other study ID #: OPHT-121203
• Status: Completed
• Phase: N/A
• First received: February 5, 2007
• Last updated: July 1, 2008
• Start date: December 2006
• Est. completion date: September 2007

Study information

• Verified date: June 2008
• Source: Medical University of Vienna
• Contact: n/a
• Is FDA regulated: No
• Health authority: Austria: Agency for Health and Food Safety
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 0
• Est. completion date: September 2007
• Est. primary completion date: September 2007
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 35 Years

Eligibility

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

Study Design

Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label

Related Conditions & MeSH terms

• Blood Flow Velocity
• Ocular Physiology
• Retina

Intervention

Procedure:
• flicker light stimulation

Locations

Country	Name	City	State
Austria	Department of Clinical Pharmacology	Vienna

Sponsors (1)

Lead Sponsor	Collaborator
Medical University of Vienna

Country where clinical trial is conducted

Austria, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Flicker response (Retinal vessel analyzer, Laser Doppler Velocimetry)