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

February 15, 2011
February 22, 2011
June 2011
Not Provided
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
Same as current
Complete list of historical versions of study NCT01303276 on ClinicalTrials.gov Archive Site
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
Same as current
Not Provided
Not Provided
 
Retinal Blood Flow in Response to an Intravitreal Injection of Ranibizumab for Central Retinal Vein Occlusion (CRVO)
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.

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.

Observational
Observational Model: Cohort
Time Perspective: Prospective
Not Provided
Not Provided
Non-Probability Sample

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

Central Retinal Vein Occlusion
Not Provided
  • 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
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Not yet recruiting
30
Not Provided
Not Provided

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
Both
50 Years and older
Yes
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
 
NCT01303276
CRVO-blood flow study
No
Christopher Hudson, University of Toronto
University of Toronto
Not Provided
Principal Investigator: Christopher Hudson, PhD University of Toronto
University of Toronto
February 2011

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP