Measurement of Retinal Blood Flow, Retinal Oxygenation and Retinal Oxygen Extraction in Healthy Subjects During Normoxia and Systemic Hyperoxia

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00914407

Enrollment

Registered

2009-06-05

Start date

2010-04-30

Completion date

2017-03-01

Last updated

2017-03-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy, Normoxia, Systemic Hypoxia

Keywords

Ocular physiology

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.

Interventions

DRUGOxygen

100% Oxygen inhalation for 30 minutes

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 35 Years

Healthy volunteers

Yes

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

Design outcomes

Primary

Measure	Time frame
Retinal blood velocity Retinal vessel diameters Oxygen saturation of retinal vessels Oxygen extraction as calculated from these parameters	20 min ocular blood flow measurement on 1 study day

Countries

Austria

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 1, 2026