Central Retinal Vein OcclusionNCT01303276
Retinal Blood Flow in Response to an Intravitreal Injection of Ranibizumab for Central Retinal Vein Occlusion (CRVO)
An observational study of Central Retinal Vein Occlusion, run by University of Toronto at 1 site in Canada.
Trial summary
Ranibizumab (Lucentis, Genentech) is an off-label drug used for the clinical treatment of central retinal vein occlusion, which is one of the most common retinal vascular disorders. Read more about this study
- Who is it for?
- Ages 50 years and olderHealthy volunteers can take part
- Conditions the study is for
- Central Retinal Vein Occlusion
- Type of treatment
- Injection or infusion
- How many people
- 30 participants
- Where
- 1 siteCanada
- Study dates
- Jun 2011to not given
- Phase
- Observational
- 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 50 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients with central retinal vein occlusion will be recruited from the Retina Clinics of Toronto Western Hospital
Who may be able to join
- Age > 50 years
- central retinal vein occlusion scheduled for first intravitreal injection of ranibizumab as part of their clinical care
Who cannot join
- previous history of intravitreal therapy,
- history of thromboembolic events,
- glaucoma or an intraocular pressure >21 mmHg
- diabetes mellitus or altered blood viscosity syndromes
- blood donation in the previous 2 weeks
- refractive error of +/- 6.00 DS and/or 2.00 DC
Trial locations and contacts
1 site in 1 country.
Canada1 site
Toronto Western Hospital
Toronto, Ontario, M5T 2S8
Edmund Tsui, BSc, (416)603-5694 ext. 5694, tsui.edmund@gmail.com
Tien Wong, BSc, (416)603-5694 ext. 5694, twong@uhnresearch.ca
About this study
Official title: Retinal Blood Flow in Response to an Intravitreal Injection of Ranibizumab for Central Retinal Vein Occlusion
Ranibizumab (Lucentis, Genentech) is an off-label drug used for the clinical treatment of central retinal vein occlusion, which is one of the most common retinal vascular disorders. Despite its clinical effectiveness, concerns remain regarding the systemic effects of the drug and previous studies have noted retinal arteriolar vasoconstriction following a ranibizumab injection. We aim to provide a physiological basis to these observations by assessing retinal blood flow before and after the ranibizumab injections. Specifically, we will assess the blood flow parameters (i.e. retinal vessel diameter, velocity \& flow) immediately before the first injection and post-injection over a follow-up continued treatment period.
Read the detailed description
Ranibizumab is an antibody fragment designed to inhibit the activity of Vascular Endothelial Growth Factor (VEGF), which is responsible for the neovascularization and retinal edema responsible for interference of normal vision in central retinal vein occlusion. However, VEGF has a role in the vasculature as a vasodilator where it alters the expression of tight junction proteins and upregulates the release of the vasodilator nitric oxide. Consequently, intravitreal ranibizumab injections could result in systemic inhibition of VEGF, leading to long-term retinal arteriolar vasoconstriction and potentially adverse cerebrovascular and myocardial accidents. Therefore, evaluating retinal blood flow would provide a physiological foundation to this concern and provide physicians with valuable information regarding the risks of continued ranibizumab therapy.
Given the role of VEGF as a vasodilator in the vasculature where it works to alter the expression of tight junction proteins and the production of vasoactive substances especially nitric oxide, inhibiting this molecule with ranibizumab could result in vasoconstriction in these vessels. We hypothesize that vasoconstriction and decreased retinal blood flow will be observed after an intravitreal injection of ranibizumab for treatment of central retinal vein occlusion.
- Conditions
- Central Retinal Vein Occlusion
- Keywords
- retinal vein occlusion, anti-VEGF, blood flow
- Medical subject headings
- Retinal Vein Occlusion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Anti-VEGF group | Patients who are clinically indicated for the intravitreal injection of ranibizumab | |
| Age-matched controls | Group of healthy participants who will be age and gender matched |
What is being measured
The primary outcome is the main question the study is designed to answer.
Quantitative change in retinal blood flow
Retinal blood flow will be measured using Canon Laser Blood Flowmeter
Measured: Baseline, 7, 30 days
Secondary outcomes (1)
Best Corrected Visual Acuity (LogMAR, EDTRS)
Best Corrected Visual Acuity will be examined using 96% and 10 % contrast EDTRS letter charts
Measured: Baseline, 7, 30 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Feb 2011 (estimated)
- Study startJun 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Central Retinal Vein OcclusionStudies of the same condition, open and under way.
- More trials run by University of 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Toronto
- Sponsor type
- University, hospital or other
- Investigators
- Christopher Hudson, PhD, Principal investigator, University of Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01303276
- Sponsor's protocol ID
- CRVO-blood flow study
- Status last verified
- Feb 2011
- First submitted
- 15 Feb 2011
- Last updated
- 24 Feb 2011
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Feb 2011. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Retinal Blood Flow in Response to an Intravitreal Injection of Ranibizumab for Central Retinal Vein Occlusion
- ClinicalTrials.gov ID
- NCT01303276
- Acronym / sponsor ID
- CRVO-blood flow study
- Conditions
- Central Retinal Vein Occlusion
- Keywords
- retinal vein occlusion, anti-VEGF, blood flow
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- University of TorontoUniversity, hospital or other
- Study start
- Jun 2011
- First posted
- 24 Feb 2011 (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.
Ranibizumab (Lucentis, Genentech) is an off-label drug used for the clinical treatment of central retinal vein occlusion, which is one of the most common retinal vascular disorders. Despite its clinical effectiveness, concerns remain regarding the systemic effects of the drug and previous studies have noted retinal arteriolar vasoconstriction following a ranibizumab injection. We aim to provide a physiological basis to these observations by assessing retinal blood flow before and after the ranibizumab injections. Specifically, we will assess the blood flow parameters (i.e. retinal vessel diameter, velocity \& flow) immediately before the first injection and post-injection over a follow-up continued treatment period.
Detailed description
Ranibizumab is an antibody fragment designed to inhibit the activity of Vascular Endothelial Growth Factor (VEGF), which is responsible for the neovascularization and retinal edema responsible for interference of normal vision in central retinal vein occlusion. However, VEGF has a role in the vasculature as a vasodilator where it alters the expression of tight junction proteins and upregulates the release of the vasodilator nitric oxide. Consequently, intravitreal ranibizumab injections could result in systemic inhibition of VEGF, leading to long-term retinal arteriolar vasoconstriction and potentially adverse cerebrovascular and myocardial accidents. Therefore, evaluating retinal blood flow would provide a physiological foundation to this concern and provide physicians with valuable information regarding the risks of continued ranibizumab therapy.
Given the role of VEGF as a vasodilator in the vasculature where it works to alter the expression of tight junction proteins and the production of vasoactive substances especially nitric oxide, inhibiting this molecule with ranibizumab could result in vasoconstriction in these vessels. We hypothesize that vasoconstriction and decreased retinal blood flow will be observed after an intravitreal injection of ranibizumab for treatment of central retinal vein occlusion.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Anti-VEGF group | – | –Patients who are clinically indicated for the intravitreal injection of ranibizumab |
| Age-matched controls | – | –Group of healthy participants who will be age and gender matched |
Who may qualify
- Ages
- 50 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with central retinal vein occlusion will be recruited from the Retina Clinics of Toronto Western Hospital
Key inclusion criteria (2 listed)
- Age > 50 years
- central retinal vein occlusion scheduled for first intravitreal injection of ranibizumab as part of their clinical care
Key exclusion criteria (6 listed)
- previous history of intravitreal therapy,
- history of thromboembolic events,
- glaucoma or an intraocular pressure >21 mmHg
- diabetes mellitus or altered blood viscosity syndromes
- blood donation in the previous 2 weeks
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Quantitative change in retinal blood flow
Time frame: Baseline, 7, 30 days
Retinal blood flow will be measured using Canon Laser Blood Flowmeter
1 secondary outcome
Best Corrected Visual Acuity (LogMAR, EDTRS)
Time frame: Baseline, 7, 30 days
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Feb 2011.
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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.
Christopher Hudson, PhD principal investigator
University of Toronto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Central Retinal Vein Occlusion, run by University of 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 2 inclusion and 6 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 24 Feb 2011. 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 Edmund Tsui, BSc ((416)603-5694 ext. 5694, tsui.edmund@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Quantitative change in retinal blood flow (time frame: Baseline, 7, 30 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 24 Feb 2011; AzTrials last refreshed its copy on 7 Nov 2026.