HealthyNCT00912665
Regulation of Optic Nerve Head Blood Flow During Combined Changes in Intraocular Pressure and Arterial Blood Pressure
A study testing Laser Doppler Flowmetry, Goldmann applanation tonometer and squatting in people with Healthy, run by Medical University of Vienna at 1 site in Austria.
Trial summary
Autoregulation is defined as the ability of a vascular bed to adapt its vascular resistance to changes in perfusion pressure. In the eye, several studies have reported that retinal blood flow is autoregulated over a wide range of ocular perfusion pressures. In the optic nerve head only few data are available. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Laser Doppler Flowmetry, Goldmann applanation tonometer and squatting
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteAustria
- Study dates
- Jul 2009to Dec 2010
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and women aged between 18 and 35 years, nonsmokers
- Men and women will be included in equal parts
- Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
- Normal findings in the laboratory testings unless the investigator considers an abnormality to be clinically irrelevant
- Normal ophthalmic findings, ametropia less than 1 diopter
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
Austria1 site
Department of Clinical Pharmacology, Medical University of Vienna
Vienna, State of Vienna, 1090
About this study
Autoregulation is defined as the ability of a vascular bed to adapt its vascular resistance to changes in perfusion pressure. In the eye, several studies have reported that retinal blood flow is autoregulated over a wide range of ocular perfusion pressures. In the optic nerve head only few data are available. Large scale studies have shown that reduced ocular perfusion pressure is an important risk factor for the prevalence, the incidence and the progression of primary open angle glaucoma.
Former studies that investigated ocular blood flow autoregulation only measured choroidal blood flow. For the optic nerve head only few data are available, although it seems likely that it underlies similar autoregulatory mechanisms.
Read more
The primary goal of the present study is to gain more insight into these phenomena in humans.
The present study aims to investigate the pressure/flow relationship as a measure for optic nerve head autoregulation during combined changes of intraocular pressure and arterial pressure. Intraocular pressure will be increased by the use of a suction cup technique, mean arterial pressure will be increased by squatting. During the whole procedure, optic nerve head blood flow will be measured continuously.
- Conditions
- Healthy
- Being tested
- Laser Doppler Flowmetry, Goldmann applanation tonometer, squatting, Suction cup
- Keywords
- Optic Nerve Head Blood Flow, Intraocular Pressure, Regional Blood Flow, Ocular Physiology, Optic Disk
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Laser Doppler FlowmetryDevice
blood flow measurements at the temporal neuroretinal rim to assess optic nerve head blood flow
Goldmann applanation tonometerDevice
intraocular pressure measurements
squattingOther
Subjects will perform squatting for 6 minutes while either blood flow or intraocular pressure measurements
Suction cupDevice
Experimental stepwise increase of intraocular pressure while either optic nerve head blood flow or intraocular pressure measurements
| Study group | Role | What they receive |
|---|---|---|
| Healthy Volunteer | Experimental | Not described Receives: Device: Laser Doppler Flowmetry; Device: Goldmann applanation tonometer; Other: squatting; Device: Suction cup |
What is being measured
The primary outcome is the main question the study is designed to answer.
Optic nerve head pressure-flow relationship
Measured: in total 3x on 2 study days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jun 2009 (estimated)
- Study startJul 2009
- Primary completionDec 2010
- Study completionDec 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by Medical University of ViennaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medical University of Vienna
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Gerhard Garhofer, Medical University of Vienna
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00912665
- Sponsor's protocol ID
- OPHT-150808
- Status last verified
- Aug 2012
- First submitted
- 1 Jun 2009
- Last updated
- 10 Aug 2012
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 10 Aug 2012. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Regulation of Optic Nerve Head Blood Flow During Combined Changes in Intraocular Pressure and Arterial Blood Pressure
- ClinicalTrials.gov ID
- NCT00912665
- Acronym / sponsor ID
- OPHT-150808
- Conditions
- Healthy
- Keywords
- Optic Nerve Head Blood Flow, Intraocular Pressure, Regional Blood Flow, Ocular Physiology, Optic Disk
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Medical University of ViennaUniversity, hospital or other
- Study start
- Jul 2009
- Primary completion
- Dec 2010 (actual)
- Study completion
- Dec 2010 (actual)
- First posted
- 3 Jun 2009 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Autoregulation is defined as the ability of a vascular bed to adapt its vascular resistance to changes in perfusion pressure. In the eye, several studies have reported that retinal blood flow is autoregulated over a wide range of ocular perfusion pressures. In the optic nerve head only few data are available. Large scale studies have shown that reduced ocular perfusion pressure is an important risk factor for the prevalence, the incidence and the progression of primary open angle glaucoma.
Former studies that investigated ocular blood flow autoregulation only measured choroidal blood flow. For the optic nerve head only few data are available, although it seems likely that it underlies similar autoregulatory mechanisms.
The primary goal of the present study is to gain more insight into these phenomena in humans.
The present study aims to investigate the pressure/flow relationship as a measure for optic nerve head autoregulation during combined changes of intraocular pressure and arterial pressure. Intraocular pressure will be increased by the use of a suction cup technique, mean arterial pressure will be increased by squatting. During the whole procedure, optic nerve head blood flow will be measured continuously.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Healthy Volunteer | Experimental | Device: Laser Doppler Flowmetry, Device: Goldmann applanation tonometer, Other: squatting, Device: Suction cup |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Men and women aged between 18 and 35 years, nonsmokers
- Men and women will be included in equal parts
- Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
- Normal findings in the laboratory testings unless the investigator considers an abnormality to be clinically irrelevant
- Normal ophthalmic findings, ametropia less than 1 diopter
Key exclusion criteria (4 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Laser Doppler Flowmetryblood flow measurements at the temporal neuroretinal rim to assess optic nerve head blood flow | Device | Healthy Volunteer |
| Goldmann applanation tonometerintraocular pressure measurements | Device | Healthy Volunteer |
| squattingSubjects will perform squatting for 6 minutes while either blood flow or intraocular pressure measurements | Other | Healthy Volunteer |
| Suction cupExperimental stepwise increase of intraocular pressure while either optic nerve head blood flow or intraocular pressure measurements | Device | Healthy Volunteer |
Primary outcome
Optic nerve head pressure-flow relationship
Time frame: in total 3x on 2 study days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Aug 2012.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Laser Doppler Flowmetry, Goldmann applanation tonometer and squatting in people with Healthy, run by Medical University of Vienna at 1 site in Austria.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 10 Aug 2012. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Optic nerve head pressure-flow relationship (time frame: in total 3x on 2 study days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Aug 2012.