Retinal Blood Flow in Response to an Intravitreal Injection of Ranibizumab for Central Retinal Vein Occlusion (CRVO)
Recruitment status was Not yet recruiting
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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 |
|---|
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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 |
- 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
- 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 |
|---|
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Anti-VEGF group
Patients who are clinically indicated for the intravitreal injection of ranibizumab
|
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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 |
Patients with central retinal vein occlusion will be recruited from the Retina Clinics of Toronto Western Hospital
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| 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 |
| 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 | |
| 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 May 23, 2013