Healthy
Conditions
Keywords
Regional Blood Flow, Color Doppler Optical Coherence Tomography, CDOCT, Retinal Blood Flow, Hyperoxia, Vasoconstriction, Laser Doppler Velocimetry, Retinal Vessel Analyzer
Brief summary
Noninvasive monitoring of blood flow in retinal circulation may elucidate the progression and treatment of ocular disorders, including diabetic retinopathy, age-related macular degeneration and glaucoma. Laser Doppler velocimetry (LDV), a noninvasive optical method combined with vessel size determination has been used extensively as a valuable research tool to examine blood flow dynamics in the human retina. However, no information on the velocity profile within the vessel is available. Ophthalmic color Doppler optical coherence tomography (CDOCT) provides laser Doppler information in addition to conventional optical coherence tomography, allowing the observation of blood flow dynamics simultaneously to imaging retinal structure. We have recently demonstrated the feasibility of Fourier domain CDOCT to assess velocity profiles in human retinal vessels in vivo. In the present study the validity of Fourier domain CDOCT for retinal blood flow measurements will be tested at baseline and during hyperoxia-induced vasoconstriction in humans by comparison with retinal blood flow measurements using a commercially available LDV system and the Zeiss retinal vessel analyzer (RVA)
Interventions
OTHER100% Oxygen
100% Oxygen- breathing over 30 minutes
Sponsors
Medical University of Vienna
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
19 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Men aged between 19 and 35 years, nonsmokers * Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant * Normal ophthalmic findings, ametropia \< 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 * Ametropia equal or over 3 dpt
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Retinal blood flow (LDV, RVA) | 15 minutes |
Secondary
| Measure | Time frame |
|---|---|
| Retinal venous diameters (Zeiss retinal vessel analyzer) | 5 minutes |
| Retinal blood velocity (laser Doppler velocimetry) | 10 minutes |
Countries
Austria
Outcome results
None listed