Measurement of Retinal Blood Flow, Retinal Oxygenation and Retinal Oxygen Extraction in Healthy Subjects During Normoxia and Systemic Hyperoxia
Overview
- Phase
- Not Applicable
- Intervention
- Oxygen
- Conditions
- Healthy
- Sponsor
- Medical University of Vienna
- Enrollment
- 48
- Locations
- 1
- Primary Endpoint
- Retinal blood velocity Retinal vessel diameters Oxygen saturation of retinal vessels Oxygen extraction as calculated from these parameters
- Status
- Completed
- Last Updated
- 9 years ago
Overview
Brief Summary
The inner retina is crucially dependent on an adequate retinal blood supply. When the retina becomes ischemic and hypoxic this results in severe vision loss due to retinal neovascularization. Measurement of retinal blood flow and retinal oxygenation is, however, still a difficult task. Information on retinal oxygenation is almost unavailable from human studies. In the present protocol the investigators propose a procedure allowing for the measurement of retinal blood flow, retinal oxygenation and retinal oxygen extraction by combining a number of innovative techniques. Specifically, retinal vessel diameters will be measured with a Retinal Vessel Analyzer, retinal blood velocities with bi-directional laser Doppler velocimetry and retinal oxygenation with spectroscopic evaluation of retinal fundus images. This will allow for the calculation of retinal oxygen extraction, a fundamental parameter of retinal function. Up to now, no data for retinal oxygen extraction are available in the literature.
Investigators
Gerhard Garhofer
Assoc. Prof. Priv.-Doz. Dr
Medical University of Vienna
Eligibility Criteria
Inclusion Criteria
- •Men and women aged between 18 and 35 years
- •Nonsmokers
- •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, 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 except oral contraceptives
- •Symptoms of a clinically relevant illness in the 3 weeks before the first study day
- •Blood donation during the previous 3 weeks
- •Pregnancy
Arms & Interventions
Healthy subjects
Intervention: Oxygen
Outcomes
Primary Outcomes
Retinal blood velocity Retinal vessel diameters Oxygen saturation of retinal vessels Oxygen extraction as calculated from these parameters
Time Frame: 20 min ocular blood flow measurement on 1 study day