Retinal Blood Flow in Response to an Intravitreal Injection of Ranibizumab for Central Retinal Vein Occlusion (CRVO)

The recruitment status of this study is unknown because the information has not been verified recently.
Verified February 2011 by University of Toronto.
Recruitment status was  Not yet recruiting
Sponsor:
Information provided by:
University of Toronto
ClinicalTrials.gov Identifier:
NCT01303276
First received: February 15, 2011
Last updated: February 22, 2011
Last verified: February 2011
  Purpose

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.


Condition
Central Retinal Vein Occlusion

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Retinal Blood Flow in Response to an Intravitreal Injection of Ranibizumab for Central Retinal Vein Occlusion

Resource links provided by NLM:


Further study details as provided by University of Toronto:

Primary Outcome Measures:
  • Quantitative change in retinal blood flow [ Time Frame: Baseline, 7, 30 days ] [ Designated as safety issue: No ]
    Retinal blood flow will be measured using Canon Laser Blood Flowmeter


Secondary Outcome Measures:
  • Best Corrected Visual Acuity (LogMAR, EDTRS) [ Time Frame: Baseline, 7, 30 days ] [ Designated as safety issue: No ]
    Best Corrected Visual Acuity will be examined using 96% and 10 % contrast EDTRS letter charts


Estimated Enrollment: 30
Study Start Date: June 2011
Groups/Cohorts
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

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.

  Eligibility

Ages Eligible for Study:   50 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Patients with central retinal vein occlusion will be recruited from the Retina Clinics of Toronto Western Hospital

Criteria

Inclusion Criteria:

  • Age > 50 years
  • central retinal vein occlusion scheduled for first intravitreal injection of ranibizumab as part of their clinical care

Exclusion Criteria:

  • 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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01303276

Contacts
Contact: Edmund Tsui, BSc (416)603-5694 ext 5694 tsui.edmund@gmail.com
Contact: Tien Wong, BSc (416)603-5694 ext 5694 twong@uhnresearch.ca

Locations
Canada, Ontario
Toronto Western Hospital Not yet recruiting
Toronto, Ontario, Canada, M5T 2S8
Contact: Edmund Tsui, BSc    (416)603-5694 ext 5694    tsui.edmund@gmail.com   
Contact: Tien Wong, BSc    (416)603-5694 ext 5694    twong@uhnresearch.ca   
Principal Investigator: Christopher Hudson, PhD         
Sub-Investigator: Michael Brent, MD         
Sub-Investigator: Wai-Ching Lam, MD         
Sub-Investigator: Robert G Devenyi, MD         
Sub-Investigator: Mark Mandelcorn, MD         
Sponsors and Collaborators
University of Toronto
Investigators
Principal Investigator: Christopher Hudson, PhD University of Toronto
  More Information

No publications provided

Responsible Party: Christopher Hudson, University of Toronto
ClinicalTrials.gov Identifier: NCT01303276     History of Changes
Other Study ID Numbers: CRVO-blood flow study
Study First Received: February 15, 2011
Last Updated: February 22, 2011
Health Authority: Canada: Ethics Review Committee
Canada: Health Canada

Keywords provided by University of Toronto:
retinal vein occlusion
anti-VEGF
blood flow

Additional relevant MeSH terms:
Retinal Vein Occlusion
Retinal Diseases
Eye Diseases
Venous Thrombosis
Thrombosis
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases

ClinicalTrials.gov processed this record on September 18, 2014