Genetic PolymorphismNCT00708929
Does Complement Factor H Gene Polymorphism Play a Role in the Regulation of Vascular Tone in the Choroid?
A study testing Squatting in people with Genetic Polymorphism and Macular Degeneration, run by Medical University of Vienna at 1 site in Austria.
Trial summary
Age related macular degeneration (AMD) is a multifactorial disease with a strong genetic component. Most importantly a genetic polymorphism in the gene encoding for the complement factor H (CFH) has been recently identified which is highly associated with an increased risk of developing AMD. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Genetic Polymorphism, Macular Degeneration, Regional Blood Flow
- What is being tested?
- Squatting
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteAustria
- Study dates
- Jun 2009to Dec 2011
- 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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and women aged between 18 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, ametropy less than 3 diopters
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
- 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
About this study
Age related macular degeneration (AMD) is a multifactorial disease with a strong genetic component. Most importantly a genetic polymorphism in the gene encoding for the complement factor H (CFH) has been recently identified which is highly associated with an increased risk of developing AMD. This Tyr402His polymorphism located on chromosome 1q31 has been implicated to play a role in the development of the disease.
Given that it is known that impaired regulation of choroidal vascular tone is present in patients with AMD, the current study seeks to investigate whether the Tyr402His polymorphism is associated with altered choroidal autoregulation in healthy subjects. For this purpose a total of 100 healthy volunteers will be included in order to test the hypothesis that an impaired regulation of choroidal blood flow is present in subjects with homozygous Tyr402His variant.
- Being tested
- Squatting
- Keywords
- Age-related macular degeneration, Complement factor H, Choroidal blood flow
- Medical subject headings
- Macular Degeneration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SquattingProcedure or surgery
Squatting for 6 minutes
| Study group | Role | What they receive |
|---|---|---|
| 1 | Other | 14 subjects homozygous HH for the Tyr402His single nucleotide polymorphism Receives: Procedure: Squatting |
| 2 | Other | 14 subjects homozygous TT for the Tyr402His single nucleotide polymorphism Receives: Procedure: Squatting |
What is being measured
The primary outcome is the main question the study is designed to answer.
Choroidal blood flow during isometric exercise
Measured: 10 minutes
Tyr402His genotyping
Measured: screening
Secondary outcomes (4)
Mean arterial pressure
Measured: 20 minutes
Intraocular pressure
Measured: before and after blood flow measurements
Systolic/diastolic blood pressure
Measured: 20 minutes
Pulse rate
Measured: 20 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jul 2008 (estimated)
- Study startJun 2009
- Primary completionDec 2011
- Study completionDec 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Genetic PolymorphismStudies 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
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 100 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
- Investigators
- Gerhard Garhöfer, MD, Principal investigator, Department of Clinical Pharmacology, Medical University of Vienna
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00708929
- Sponsor's protocol ID
- OPHT-040607
- Status last verified
- Mar 2013
- First submitted
- 1 Jul 2008
- Last updated
- 19 Mar 2013
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 19 Mar 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Does Complement Factor H Gene Polymorphism Play a Role in the Regulation of Vascular Tone in the Choroid?
- ClinicalTrials.gov ID
- NCT00708929
- Acronym / sponsor ID
- OPHT-040607
- Keywords
- Age-related macular degeneration, Complement factor H, Choroidal blood flow
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 100 participants (actual)
- Lead sponsor
- Medical University of ViennaUniversity, hospital or other
- Study start
- Jun 2009
- Primary completion
- Dec 2011 (actual)
- Study completion
- Dec 2011 (actual)
- First posted
- 3 Jul 2008 (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.
Age related macular degeneration (AMD) is a multifactorial disease with a strong genetic component. Most importantly a genetic polymorphism in the gene encoding for the complement factor H (CFH) has been recently identified which is highly associated with an increased risk of developing AMD. This Tyr402His polymorphism located on chromosome 1q31 has been implicated to play a role in the development of the disease.
Given that it is known that impaired regulation of choroidal vascular tone is present in patients with AMD, the current study seeks to investigate whether the Tyr402His polymorphism is associated with altered choroidal autoregulation in healthy subjects. For this purpose a total of 100 healthy volunteers will be included in order to test the hypothesis that an impaired regulation of choroidal blood flow is present in subjects with homozygous Tyr402His variant.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1 | Other | Procedure: Squatting14 subjects homozygous HH for the Tyr402His single nucleotide polymorphism |
| 2 | Other | Procedure: Squatting14 subjects homozygous TT for the Tyr402His single nucleotide polymorphism |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Men and women aged between 18 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, ametropy less than 3 diopters
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
- 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 |
|---|---|---|
| SquattingSquatting for 6 minutes | Procedure or surgery | 1, 2 |
Primary outcome
Choroidal blood flow during isometric exercise
Time frame: 10 minutes
Tyr402His genotyping
Time frame: screening
4 secondary outcomes
Mean arterial pressure
Time frame: 20 minutes
Intraocular pressure
Time frame: before and after blood flow measurements
Systolic/diastolic blood pressure
Time frame: 20 minutes
Pulse rate
Time frame: 20 minutes
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 19 Mar 2013.
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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.
Gerhard Garhöfer, MD principal investigator
Department of Clinical Pharmacology, Medical University of Vienna
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Squatting in people with Genetic Polymorphism and Macular Degeneration, 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 4 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 19 Mar 2013. 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?
Choroidal blood flow during isometric exercise (time frame: 10 minutes). The study lists 2 primary outcomes in all. 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 19 Mar 2013.