GlaucomaNCT00275756
Effects of Common Topical Glaucoma Therapy on Optic Nerve Head Blood Flow Autoregulation During Increased Arterial Blood Pressure and Artificially Elevated Intraocular Pressure in Healthy Humans
A study testing Timolol (drug), dorzolamide (drug) and brimonidine (drug) in people with Glaucoma, run by Medical University of Vienna at 1 site in Austria.
Trial summary
Background Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. The existence of an effective autoregulation in the optic nerve circulation has been shown in animals and humans. The exact mechanism behind this autoregulation is still unknown. Read more about this study
- Who is it for?
- Ages 19 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Glaucoma
- What is being tested?
- Timolol (drug), dorzolamide (drug) and brimonidine (drug)
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 0 participants
- Where
- 1 siteAustria
- Study dates
- Sep 2008to Nov 2014
- 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 19 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men aged between 19 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 ophthalmic findings, ametropia < 1 Dpt.
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
- Presence of intraocular pathology: ocular hypertension, glaucoma, retinal vasculopathy or other retinal diseases
Trial locations and contacts
1 site in 1 country.
About this study
Background
Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. The existence of an effective autoregulation in the optic nerve circulation has been shown in animals and humans. The exact mechanism behind this autoregulation is still unknown. The motive for the investigation of optic nerve head (ONH) blood flow autoregulation is to enhance the understanding of pathologic eye conditions associated with ocular vascular disorders. To clarify the regulatory mechanisms of ONH microcirculation is of critical importance to understand the pathophysiology of glaucoma, because there is evidence that glaucoma is associated with optic nerve head ischemia. Several studies indicate that a disturbed autoregulation might contribute to glaucomatous optic neuropathy. Currently, five classes of intraocular pressure (IOP) reducing drugs are available for topical therapy in patients with glaucoma or elevated intraocular pressure. These drugs have also vasoactive properties, which may influence both the resting ocular circulation and the autoregulatory mechanisms of blood flow during changes in ocular perfusion pressure.
Read more
Study objective
To investigate the influence of common topical glaucoma therapy on ONH blood flow regulation during changes in IOP and systemic arterial blood pressure.
- Conditions
- Glaucoma
- Being tested
- Timolol (drug), dorzolamide (drug), brimonidine (drug), Laser Doppler flowmetry, Goldmann applanation tonometer
- Keywords
- Ocular Physiology, Brimonidine, Timoptic, Dorzolamide, ocular blood flow, Regional Blood Flow
- Medical subject headings
- Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Timolol (drug)Drug
Timolol (0.5%, non-selective beta-blocker, Timoptic®, Merck Sharp \& Dohme, Haarlem, Netherlands), dose 1 drop in one eye twice daily for two weeks
dorzolamide (drug)Drug
Dorzolamide (2%, carbonic anhydrase inhibitor, Trusopt®, Laboratoires Merck Sharp \& Dohme - Chibret, France), dose: 1 drop in one eye twice daily for two weeks
brimonidine (drug)Drug
Brimonidine (0.2%. alpha-2 adrenergic agonist, Alphagan®, Allergan Pharmaceuticals, Westport, Ireland), dose: 1 drop in one eye twice daily for two weeks
Laser Doppler flowmetryDevice
blood flow measurements at the temporal neuroretinal rim of the optic nerve head, in total 4x 9 minutes on 2 study days
Goldmann applanation tonometerDevice
intraocular pressure measurements, in total 2x 5 measurements on two study days
Suction cup methodProcedure or surgery
The IOP will be raised by an 11 mm diameter, standardized suction cup placed on the temporal sclera with the anterior edge at least 1 mm from the limbus; 4x 8 minutes on 2 study days
| Study group | Role | What they receive |
|---|---|---|
| 1 | Experimental | Not described Receives: Drug: Timolol (drug); Device: Laser Doppler flowmetry; Device: Goldmann applanation tonometer; Procedure: Suction cup method |
| 2 | Experimental | Not described Receives: Drug: dorzolamide (drug); Device: Laser Doppler flowmetry; Device: Goldmann applanation tonometer; Procedure: Suction cup method |
| 3 | Experimental | Not described Receives: Drug: brimonidine (drug); Device: Laser Doppler flowmetry; Device: Goldmann applanation tonometer; Procedure: Suction cup method |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ocular perfusion pressure - ONH blood flow relationship
Measured: on 2 study days
Secondary outcomes (1)
Composite measure: Blood pressure, heart rate
Measured: 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 posted12 Jan 2006 (estimated)
- Study startSep 2008
- Primary completionNov 2014
- Study completionNov 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for GlaucomaStudies 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
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medical University of Vienna
- Sponsor type
- University, hospital or other
- Investigators
- Gabriele Fuchsjaeger-Mayrl, MD, Principal investigator, Department of Clinical Pharmacology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00275756
- Sponsor's protocol ID
- OPHT-040106
- Status last verified
- Nov 2014
- First submitted
- 11 Jan 2006
- Last updated
- 21 Nov 2014
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 21 Nov 2014. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Common Topical Glaucoma Therapy on Optic Nerve Head Blood Flow Autoregulation During Increased Arterial Blood Pressure and Artificially Elevated Intraocular Pressure in Healthy Humans
- ClinicalTrials.gov ID
- NCT00275756
- Acronym / sponsor ID
- OPHT-040106
- Conditions
- Glaucoma
- Keywords
- Ocular Physiology, Brimonidine, Timoptic, Dorzolamide, ocular blood flow, Regional Blood Flow
- Study type
- Interventional
- Recruitment status
- Withdrawn
- Enrolment
- 0 participants (actual)
- Lead sponsor
- Medical University of ViennaUniversity, hospital or other
- Study start
- Sep 2008
- Primary completion
- Nov 2014 (actual)
- Study completion
- Nov 2014 (actual)
- First posted
- 12 Jan 2006 (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.
Background
Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. The existence of an effective autoregulation in the optic nerve circulation has been shown in animals and humans. The exact mechanism behind this autoregulation is still unknown. The motive for the investigation of optic nerve head (ONH) blood flow autoregulation is to enhance the understanding of pathologic eye conditions associated with ocular vascular disorders. To clarify the regulatory mechanisms of ONH microcirculation is of critical importance to understand the pathophysiology of glaucoma, because there is evidence that glaucoma is associated with optic nerve head ischemia. Several studies indicate that a disturbed autoregulation might contribute to glaucomatous optic neuropathy. Currently, five classes of intraocular pressure (IOP) reducing drugs are available for topical therapy in patients with glaucoma or elevated intraocular pressure. These drugs have also vasoactive properties, which may influence both the resting ocular circulation and the autoregulatory mechanisms of blood flow during changes in ocular perfusion pressure.
Study objective
To investigate the influence of common topical glaucoma therapy on ONH blood flow regulation during changes in IOP and systemic arterial blood pressure.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| 1 | Experimental | Drug: Timolol (drug), Device: Laser Doppler flowmetry, Device: Goldmann applanation tonometer, Procedure: Suction cup method |
| 2 | Experimental | Drug: dorzolamide (drug), Device: Laser Doppler flowmetry, Device: Goldmann applanation tonometer, Procedure: Suction cup method |
| 3 | Experimental | Drug: brimonidine (drug), Device: Laser Doppler flowmetry, Device: Goldmann applanation tonometer, Procedure: Suction cup method |
Who may qualify
- Ages
- 19 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Men aged between 19 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 ophthalmic findings, ametropia < 1 Dpt.
Key exclusion criteria (5 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
- Presence of intraocular pathology: ocular hypertension, glaucoma, retinal vasculopathy or other retinal diseases
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 |
|---|---|---|
| Timolol (drug)Timolol (0.5%, non-selective beta-blocker, Timoptic®, Merck Sharp \& Dohme, Haarlem, Netherlands), dose 1 drop in one eye twice daily for two weeks | Drug | 1 |
| dorzolamide (drug)Dorzolamide (2%, carbonic anhydrase inhibitor, Trusopt®, Laboratoires Merck Sharp \& Dohme - Chibret, France), dose: 1 drop in one eye twice daily for two weeks | Drug | 2 |
| brimonidine (drug)Brimonidine (0.2%. alpha-2 adrenergic agonist, Alphagan®, Allergan Pharmaceuticals, Westport, Ireland), dose: 1 drop in one eye twice daily for two weeks | Drug | 3 |
| Laser Doppler flowmetryblood flow measurements at the temporal neuroretinal rim of the optic nerve head, in total 4x 9 minutes on 2 study days | Device | 1, 2, 3 |
| Goldmann applanation tonometerintraocular pressure measurements, in total 2x 5 measurements on two study days | Device | 1, 2, 3 |
| Suction cup methodThe IOP will be raised by an 11 mm diameter, standardized suction cup placed on the temporal sclera with the anterior edge at least 1 mm from the limbus; 4x 8 minutes on 2 study days | Procedure or surgery | 1, 2, 3 |
Primary outcome
Ocular perfusion pressure - ONH blood flow relationship
Time frame: on 2 study days
1 secondary outcome
Composite measure: Blood pressure, heart rate
Time frame: on 2 study days
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Nov 2014.
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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.
Gabriele Fuchsjaeger-Mayrl, MD principal investigator
Department of Clinical Pharmacology
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Timolol (drug), dorzolamide (drug) and brimonidine (drug) in people with Glaucoma, 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 5 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: withdrawn, as of the sponsor's last update on 21 Nov 2014. 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 was withdrawn before enrolling participants, so there are no results.
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?
Ocular perfusion pressure - ONH blood flow relationship (time frame: 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 21 Nov 2014.