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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.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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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

Other trials in Canada

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.

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 groups in NCT01303276
Study groupRoleWhat they receive
Anti-VEGF groupPatients who are clinically indicated for the intravitreal injection of ranibizumab
Age-matched controlsGroup 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.

  1. 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)
  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.

  1. First posted24 Feb 2011 (estimated)
  2. Study startJun 2011

Resources

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)
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

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.

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