GlaucomaNCT00152932
Ocular Blood Flow in Early Glaucoma Patients Before and After Treatment With Dorzolamide
A study testing Dorzolamide 2% drops and HRF and CLBF in people with Glaucoma, run by University Health Network, Toronto at 1 site in Canada.
Trial summary
Impaired ocular blood flow is an important risk factor in the pathogenesis of primary open angle glaucoma (POAG). A few studies suggest that topical dorzolamide 2% may increase optic nerve perfusion. Read more about this study
- Who is it for?
- Ages 20 to 80 years
- Conditions the study is for
- Glaucoma
- What is being tested?
- Dorzolamide 2% drops and HRF and CLBF
- Type of treatment
- Medical device
- How many people
- 17 participants
- Where
- 1 siteCanada
- Study dates
- May 2005to Jun 2006
- 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 20 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Males or females 20-80 years of age.
- Presence of typical early glaucomatous optic disc changes (cup/disc ratio ≤ 0.75) and/or early glaucomatous visual field defects (mean deviation less than 5dB and outside of 10° from fixation) in the study eye at the baseline visit.
- Best corrected visual acuity of at least 20/40.
- Signed informed consent from the subject
- The subject should be able to understand the instructions and perform the HRF and CLBF tests as well as be willing and able to comply with the study schedule and treatment.
Who cannot join
- Pregnant women or nursing mothers.
- Any other active ocular disease (ocular infections, Uveitis, etc.)
- Known allergy or sensitivity to the study medications.
- Functionally significant visual field loss (mean deviation greater than 5dB) or cup/disc ratio greater than 0.75 or evidence of progressive visual field loss within the last 6 months.
- Required chronic use of other ocular or systemic hypotensive medications during the study, other than the study medication (e.g. beta-blockers, Ca-channel blockers)
- Vascular occlusive disease affecting the ocular circulation such as: diabetic retinopathy, central retinal vein occlusion, central retinal artery occlusion, or non-arteritic ischemic optic neuropathy.
- Previous intraocular surgery or ocular traumas.
- Any past history of serious systemic condition affecting cerebral circulation including: hypertension, diabetes, cerebral vascular accident (CVA), or coronary artery bypass graft (CABG).
Trial locations and contacts
1 site in 1 country.
Canada1 site, 1 recruiting
- Recruiting
Department of Ophthalmology and Visual Sciences; Toronto Western Hospital
Toronto, Ontario
Rony Rachmiel, MD, 416-603-5317, rachmiel_r@hotmail.com
Graham E Trope, MB PhD, FRCSC, 416-603-5317, Graham.Trope@uhn.on.ca
About this study
Official title: Ocular Blood Flow Measured by HRF and CLBF in Newly Diagnosed and Early Glaucoma Patients Before and After Instillation of Dorzolamide 2%
Impaired ocular blood flow is an important risk factor in the pathogenesis of primary open angle glaucoma (POAG). A few studies suggest that topical dorzolamide 2% may increase optic nerve perfusion. The objectives of this study are to learn the effects of dorzolamide on the retinal and optic nerve blood flow of glaucoma patients.
The present study is a prospective, randomized, double-masked, crossover design study of newly diagnosed or already treated patients with early glaucoma.
Read more
The investigators will check ocular blood flow parameters using the Canon Laser Blood Flowmeter (CLBF), used to evaluate retinal arteriole blood flow, and the Heidelberg retinal flowmeter (HRF), which measures blood flow through capillary beds in the retina and optic nerve head.
Any demonstrated improvements to retinal and optic nerve blood flow with dorzolamide, will mean that the drug may protect against ischaemic nerve and retinal damage. Any documented improvement in flow could lead to a major change in the management of glaucoma patients as well as other retinal ischemic diseases such as diabetic retinopathy and central retinal vein occlusion.
Read the detailed description
High intraocular pressure (IOP) is the major risk factor for glaucoma. Lowering intraocular pressure is still the only accepted form of treatment for glaucoma.
Over the past decade, epidemiological and experimental evidence suggested that impaired ocular blood flow is an important risk factor with an important role in the pathogenesis of primary open angle glaucoma (POAG). Several studies suggest that ischemia-promoting vascular factors may contribute to glaucomatous damage including vasospasm, impaired ocular perfusion pressure and general vascular disorders such as low blood pressure, especially dips in blood pressure at night.
Different techniques are employed to assess vascular dysfunction in the eye. As the methodology of ocular blood flow assessment is complex and differs in various aspects (e.g. target tissue and physiological parameters), comparative studies are required in order to enhance the interpretation of these measurements.
Our laboratory has state of the art equipment to assess ocular blood flow. One study done by us suggested that one drop of Dorzolamide 2% does not improve retinal blood flow in normal eyes. In the present study we plan to extend this study to 2 weeks of treatment in patients with POAG.
Dorzolamide hydrochloride 2% is a topical carbonic anhydrase inhibitor which reduces intraocular pressure (IOP) by decreasing the production of aqueous humour. Pharmacological studies on volunteers and glaucoma patients, using Color Doppler Imaging (measuring the retrobulbar blood flow) and Scanning laser Ophthalmoscopy (measuring arteriovenous passage time), indicate that topically applied Dorzolamide may increase perfusion of the optic nerve and peripapillary retina.
- Conditions
- Glaucoma
- Being tested
- Dorzolamide 2% drops, HRF and CLBF
- Keywords
- Glaucoma, Intraocular pressure, Ocular blood flow, Laser-Doppler Flowmetry
- Medical subject headings
- Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dorzolamide 2% dropsDrug
HRF and CLBFDevice
What is being measured
The primary outcome is the main question the study is designed to answer.
Ocular blood flow measurements
Secondary outcomes (1)
Intraocular pressure reduction
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Sep 2005 (estimated)
- Study startMay 2005
- Study completionJun 2006
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 University Health Network, TorontoThe 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
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Enrolment
- 17 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Health Network, Toronto
- Sponsor type
- University, hospital or other
- Collaborators
- Merck Frosst Canada Ltd.
- Investigators
- Graham E Trope, MB, FRCSC, Principal investigator, University of Toronto, Department of OphthalmologyChris Hudson, PhD, Study chair, Department of Ophthalmology, Toronto Western Hospital, TorontoJohn Flanagan, PhD, Study chair, Department of Ophthalmology, Toronto Western Hospital, TorontoYvonne M Buys, MD, FRCSC, Study chair, University of Toronto, Department of Ophthalmology, Toronto Western Hospital, Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00152932
- Sponsor's protocol ID
- 04-0645-A
- Status last verified
- Sep 2005
- First submitted
- 8 Sep 2005
- Last updated
- 25 Jul 2007
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Jul 2007. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ocular Blood Flow Measured by HRF and CLBF in Newly Diagnosed and Early Glaucoma Patients Before and After Instillation of Dorzolamide 2%
- ClinicalTrials.gov ID
- NCT00152932
- Acronym / sponsor ID
- 04-0645-A
- Conditions
- Glaucoma
- Keywords
- Glaucoma, Intraocular pressure, Ocular blood flow, Laser-Doppler Flowmetry
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 17 participants (estimated)
- Lead sponsor
- University Health Network, TorontoUniversity, hospital or other
- Collaborators
- Merck Frosst Canada Ltd.
- Study start
- May 2005
- Study completion
- Jun 2006
- First posted
- 9 Sep 2005 (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.
Impaired ocular blood flow is an important risk factor in the pathogenesis of primary open angle glaucoma (POAG). A few studies suggest that topical dorzolamide 2% may increase optic nerve perfusion. The objectives of this study are to learn the effects of dorzolamide on the retinal and optic nerve blood flow of glaucoma patients.
The present study is a prospective, randomized, double-masked, crossover design study of newly diagnosed or already treated patients with early glaucoma.
The investigators will check ocular blood flow parameters using the Canon Laser Blood Flowmeter (CLBF), used to evaluate retinal arteriole blood flow, and the Heidelberg retinal flowmeter (HRF), which measures blood flow through capillary beds in the retina and optic nerve head.
Any demonstrated improvements to retinal and optic nerve blood flow with dorzolamide, will mean that the drug may protect against ischaemic nerve and retinal damage. Any documented improvement in flow could lead to a major change in the management of glaucoma patients as well as other retinal ischemic diseases such as diabetic retinopathy and central retinal vein occlusion.
Detailed description
High intraocular pressure (IOP) is the major risk factor for glaucoma. Lowering intraocular pressure is still the only accepted form of treatment for glaucoma.
Over the past decade, epidemiological and experimental evidence suggested that impaired ocular blood flow is an important risk factor with an important role in the pathogenesis of primary open angle glaucoma (POAG). Several studies suggest that ischemia-promoting vascular factors may contribute to glaucomatous damage including vasospasm, impaired ocular perfusion pressure and general vascular disorders such as low blood pressure, especially dips in blood pressure at night.
Different techniques are employed to assess vascular dysfunction in the eye. As the methodology of ocular blood flow assessment is complex and differs in various aspects (e.g. target tissue and physiological parameters), comparative studies are required in order to enhance the interpretation of these measurements.
Our laboratory has state of the art equipment to assess ocular blood flow. One study done by us suggested that one drop of Dorzolamide 2% does not improve retinal blood flow in normal eyes. In the present study we plan to extend this study to 2 weeks of treatment in patients with POAG.
Dorzolamide hydrochloride 2% is a topical carbonic anhydrase inhibitor which reduces intraocular pressure (IOP) by decreasing the production of aqueous humour. Pharmacological studies on volunteers and glaucoma patients, using Color Doppler Imaging (measuring the retrobulbar blood flow) and Scanning laser Ophthalmoscopy (measuring arteriovenous passage time), indicate that topically applied Dorzolamide may increase perfusion of the optic nerve and peripapillary retina.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
Who may qualify
- Ages
- 20 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Males or females 20-80 years of age.
- Presence of typical early glaucomatous optic disc changes (cup/disc ratio ≤ 0.75) and/or early glaucomatous visual field defects (mean deviation less than 5dB and outside of 10° from fixation) in the study eye at the baseline visit.
- Best corrected visual acuity of at least 20/40.
- Signed informed consent from the subject
- The subject should be able to understand the instructions and perform the HRF and CLBF tests as well as be willing and able to comply with the study schedule and treatment.
Key exclusion criteria (8 listed)
- Pregnant women or nursing mothers.
- Any other active ocular disease (ocular infections, Uveitis, etc.)
- Known allergy or sensitivity to the study medications.
- Functionally significant visual field loss (mean deviation greater than 5dB) or cup/disc ratio greater than 0.75 or evidence of progressive visual field loss within the last 6 months.
- Required chronic use of other ocular or systemic hypotensive medications during the study, other than the study medication (e.g. beta-blockers, Ca-channel blockers)
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 |
|---|---|---|
| Dorzolamide 2% drops | Drug | – |
| HRF and CLBF | Device | – |
Primary outcome
Ocular blood flow measurements
1 secondary outcome
Intraocular pressure reduction
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Jul 2007.
Related trials for Glaucoma
Recruiting
Implementing AI-based Glaucoma Screening Within Federally Qualified Health Centers
Glaucoma, Ocular Hypertension
Not yet recruiting
AI-Assisted vs Conventional Teleglaucoma Referral
Glaucoma
Recruiting
Brain Stimulation Effects on Orientation and Mobility Skills in Adults With Vision Impairment
Retinitis Pigmentosa (RP), Rod Cone Dystrophy
Recruiting
Automated Applanation Tonometry - Updated
Glaucoma, Glaucoma, Suspect
RecruitingPhase 2
A Phase 2a Study Comparing the Efficacy, Safety and Tolerability of Pregabalin Eye Drops Comparing With Timolol Eye Drops in Adults With Glaucoma or High Eye Pressure.
Primary Open - Angle Glaucoma (POAG), Ocular Hypertension (OHT)
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.
Graham E Trope, MB, FRCSC principal investigator
University of Toronto, Department of Ophthalmology
Chris Hudson, PhD study chair
Department of Ophthalmology, Toronto Western Hospital, Toronto
John Flanagan, PhD study chair
Department of Ophthalmology, Toronto Western Hospital, Toronto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Dorzolamide 2% drops and HRF and CLBF in people with Glaucoma, run by University Health Network, Toronto at 1 site in Canada.
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 8 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: status not confirmed, as of the sponsor's last update on 25 Jul 2007. 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 Canada. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Rony Rachmiel, MD (416-603-5317, rachmiel_r@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Ocular blood flow measurements. 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 25 Jul 2007.