Branch Retinal Artery OcclusionNCT01348633
Retinal Oxygen Saturation, Blood Flow, Vascular Function and High Resolution Morphometric Imaging in the Living Human Eye
An observational study of Branch Retinal Artery Occlusion and Central Retinal Artery Occlusion, run by University of Toronto at 1 site in Canada.
Trial summary
Canadians fear loss of vision more than any other disability. Vision loss has an enormous impact on quality-of-life and is extremely costly from a societal and economic perspective. In 2001, more than 600,000 Canadians were estimated to have severe vision loss, accounting for 17% of total disability in Canada. Read more about this study
- Who is it for?
- Ages 20 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Branch Retinal Artery Occlusion, Central Retinal Artery Occlusion, Branch Retinal Vein Occlusion
- How many people
- 275 participants
- Where
- 1 siteCanada
- Study dates
- Mar 2012to Aug 2015
- 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 20 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Flyers advertising the study will be posted on noticeboards within Toronto Western Hospital. The cohorts will be selected from the respondents to the flyer. Clincians in the Ophthalomology department in the Toronto Western Hopital will also offer the study to patients whom they consider to be potential participants.
Who may be able to join
- 20 to 80 years of age
- good vision in at least one eye (equivalent to 20/40 or better when wearing up-to-date spectacles)
- normal intraocular pressure (i.e. < 22 mm Hg)
- spectacle refraction between +/- 6.00 DS \& / or +/- 2.50 DC
Who cannot join
- any ocular disease apart from retinal vein / artery occlusion (for stub study #3, patients with retinal vessel occlusion will be recruited)
- history of stroke, chronic lung disease (i.e. does not include seasonal asthma)
- taking medications with known effects on the blood vessels, other than medications to control blood glucose, blood pressure or cholesterol levels
Trial locations and contacts
1 site in 1 country.
Canada1 site, 1 recruiting
- Recruiting
Department of Ophthalmology and Vision Science, Toronto Western Research Institute, University Health Network, Toronto Western Hospital
Toronto, Ontario, M5T 2S8
Chris Hudson, Ph.D, 416 603 5694, chudson@uwaterloo.ca
About this study
Official title: Phase 1. Validation and Calibration Phase: Retinal Oxygen Saturation, Blood Flow, Vascular Function and High Resolution Morphometric Imaging in the Living Human Eye
Canadians fear loss of vision more than any other disability. Vision loss has an enormous impact on quality-of-life and is extremely costly from a societal and economic perspective. In 2001, more than 600,000 Canadians were estimated to have severe vision loss, accounting for 17% of total disability in Canada. One in 9 individuals experience severe vision loss by 65 years of age; however, this increases to 1 in 4 individuals by 75 years. The financial cost of vision loss in Canada is $15.8 billion per year. There is a general perception that vision loss is "normal with aging" but 75% of vision loss is estimated to be preventable. The major causes of severe vision loss are age-related macular degeneration (ARMD), glaucoma, particularly primary open-angle glaucoma (POAG), and diabetic retinopathy (DR). Canada is headed for an epidemic of age-related eye disease and, unless something is done to prepare for this, severe vision loss will have significant consequences in terms of societal and economic costs. Through this proposed Research Program, and in conjunction with our international academic and private sector partners, we will build and develop unique quantitative imaging technologies to permit non-invasive assessment of visual changes, structural changes in the thickness of the retina at the back of the eye and also changes in the amount of blood flowing through the blood vessels that feed the retina with oxygen. This research will add to our basic knowledge in predicting the development of sight-threatening change in patients with the three diseases, and facilitate earlier detection of the problem to help us discover earlier treatments for people with these conditions. The reliability of each imaging technology will be assessed by determining its ability to differentiate between diseased and healthy eyes. Cross-sectional analyses at yearly intervals, as well as change over time analyses, will be undertaken.
Read the detailed description
There are a number of major steps that are required prior to the utilisation of these technologies in a clinical setting. This phase of the Proposal will aim to validate and calibrate the new technologies, explore the signal-to-noise ratio of RBF and oxygen saturation parameters, generate values to define the impact of absorption, morphological fundus variation and pre-retinal autofluorescence on oxygen saturation imaging and will establish a database of healthy control imaging values for both new technologies and the reproducibility of those measurements. Note: Sample size calculations have been conducted for all aspects of this phase of the protocol, based upon our extensive retinal vascular reactivity work. We will build and develop unique quantitative imaging technologies to that will permit us to explore the physiology of retinal and choroidal perfusion and vascular regulation, and retinal oxygenation.
Having completed the Validation and Calibration phase, this research will ultimately add to our basic knowledge in predicting the development of sight-threatening change in patients with the ARMD, diabetic retinopathy and primary open glaucoma, and facilitate earlier detection of the problem to help us discover earlier treatments for people with these conditions. The reliability of each imaging technology will be assessed by determining its ability to differentiate between diseased and healthy eyes. Through this proposed Research Program, we will build and develop unique quantitative imaging technologies to: Comprehensively assess the blood supply to, and vascular regulation characteristics of the posterior segment of the eye, a diagnostic capability that is currently severely limited. Assess oxygen saturation disturbances in the retina and ON that occur prior to clinically detectable changes, diagnostic capability that currently does not exist. Using the retinal blood supply and oxygen saturation parameters, we will derive net oxygen delivery to the retina and optic nerve head (ONH), a diagnostic capability that does not exist
- Conditions
- Branch Retinal Artery Occlusion, Central Retinal Artery Occlusion, Branch Retinal Vein Occlusion, Central Retinal Vein Occlusion
- Keywords
- Doppler SD-OCT Blood Flow Technology, Retinal and choroidal blood flow, Canon Laser Blood Flowmeter
- Medical subject headings
- Retinal Artery Occlusion, 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 |
|---|---|---|
| Sub-study 1 | The Quantitative, Doppler SD-OCT Blood Flow Technology will be validated and calibrated by manipulating end-tidal blood gases using the computer-controlled gas sequencer (Slessarev et al, 2005) in 15 healthy controls. Homeostatic inner retina blood flow values and the magnitude of vascular reactivity will be compared between Doppler SD-OCT blood flow technology and the Canon Laser Blood Flowmeter, an established standard, at specific locations within the retinal vascular tree. | |
| Sub-study 2 | The Quantitative, Hyper-Spectral Imaging Derived Oxygen Saturation Maps of the major retinal vessels and capillary beds will be validated and calibrated in human volunteers using our novel and exact technique that allows the precise control of the partial pressure of oxygen (PO2) to induce controlled and safe levels of hypoxia. Oxygen saturation values will be compared to measured PO2 values (i.e. recognized standard) for various levels of hypoxia and will be used to provide in-sight into the properties of the data output e.g. effective operating range, linearity of response. At the end of the study, subjects will be returned to normoxic conditions to assess reproducibility of oxygen saturation maps. | |
| Sub-study 3 | Subjects with symptoms of branch and central retinal artery and vein occlusion within the past 2 months will be used to validate the Doppler SD-OCT blood flow technology and the hyperspectral imaging derived oxygen saturation maps. In cases of central retinal vein and artery occlusion, imaging values (i.e. inner retinal and choroidal blood flow, oxygen saturation values of the major retinal vessels and the capillary beds of the retina and ONH) will be compared between the affected and unaffected eyes. In cases of branch occlusion, imaging values will be compared between the affected and unaffected quadrants of the affected eye and between the affected and unaffected eyes. The difference in inner retinal and choroidal blood flow for each eye will be calculated and compared between eyes. | |
| Sub-study 4 | Calibration for retinal melanin, crystalline lens absorption, macular pigment, morphological variation and pre-retinal autofluorescence in healthy subjects (n=20 per decade, range 40 to 80yrs). Established reflectometric techniques to derive absorption values and autofluorescence techniques will be used to calculate correction values for each parameter that influences the hyper-spectral retinal and ON oxygen saturation imaging data (Keilhauer and Delori, 2006; Delori et al, 2007). | |
| Sub-study 5 | Establishment of a database of healthy control imaging values (n=20 per decade, range 40 to 80yrs). A database of healthy control values will be established for each technology taking into account extraneous factors such as age (range 40 to 70 years) and gender. The healthy control database will be compared to the results of each individual patient in the prospective study phase of this proposed Research Program (see Prospective Study Phase, 3, Control group). Statistical confidence limits for abnormality at each time point, and for progression overtime, will be established. Measurements will be repeated at separate visits to establish repeatability. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Validation and calibration of the Quantitative, Doppler SD-OCT Blood Flow Technology
Validation and calibration of the Doppler SD-OCT technology for their optimal utilisation in a clinical setting is required. We aim to explore the signal-to-noise ratio of retinal blood flow and oxygen saturation parameters, generate values to define the impact of absorption, morphological fundus variation and pre-retinal autofluorescence on oxygen saturation imaging and will establish a database of healthy control imaging values for both new technologies and the reproducibility of those measurements.
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 May 2011 (estimated)
- Study startMar 2012
- Primary completionAug 2015 (estimated)
- Study completionAug 2015 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Branch Retinal Artery OcclusionStudies of the same condition, open and under way.
- 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
- 275 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Toronto
- Sponsor type
- University, hospital or other
- Collaborators
- Ontario Research Fund
- Responsible party
- Principal investigator, Chris Hudson, University of Toronto
- Investigators
- Chris Hudson, OD, PhD, Principal investigator, University of Toronto, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, University of Waterloo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01348633
- Sponsor's protocol ID
- ORF1
- Status last verified
- Jan 2013
- First submitted
- 4 May 2011
- Last updated
- 17 Jan 2013
- Results posted
- No
- Data monitoring committee
- No
Publications
Tayyari F, Venkataraman ST, Gilmore ED, Wong T, Fisher J, Hudson C. The relationship between retinal vascular reactivity and arteriolar diameter in response to metabolic provocation. Invest Ophthalmol Vis Sci. 2009 Oct;50(10):4814-21. doi: 10.1167/iovs.09-3373. Epub 2009 Apr 1.
PubMed 19339742Keilhauer CN, Delori FC. Near-infrared autofluorescence imaging of the fundus: visualization of ocular melanin. Invest Ophthalmol Vis Sci. 2006 Aug;47(8):3556-64. doi: 10.1167/iovs.06-0122.
PubMed 16877429Slessarev M, Fisher JA, Volgyesi G, Prisman E, Mikulis D, Hudson C, Ansel C (2005). PATENT: A new method and apparatus to attain and maintain target end tidal gas concentrations (WO/2007/012170). International Application #: PCT/CA2005/001166. Filing Date: 28 / 07 / 2005. Pub Date: 01 / 02 / 2007.
Study at a glance
From the registry record, last updated by the sponsor on 17 Jan 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase 1. Validation and Calibration Phase: Retinal Oxygen Saturation, Blood Flow, Vascular Function and High Resolution Morphometric Imaging in the Living Human Eye
- ClinicalTrials.gov ID
- NCT01348633
- Acronym / sponsor ID
- ORF1
- Conditions
- Branch Retinal Artery Occlusion, Central Retinal Artery Occlusion, Branch Retinal Vein Occlusion, Central Retinal Vein Occlusion
- Keywords
- Doppler SD-OCT Blood Flow Technology, Retinal and choroidal blood flow, Canon Laser Blood Flowmeter
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 275 participants (estimated)
- Lead sponsor
- University of TorontoUniversity, hospital or other
- Collaborators
- Ontario Research Fund
- Study start
- Mar 2012
- Primary completion
- Aug 2015 (estimated)
- Study completion
- Aug 2015 (estimated)
- First posted
- 5 May 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.
Canadians fear loss of vision more than any other disability. Vision loss has an enormous impact on quality-of-life and is extremely costly from a societal and economic perspective. In 2001, more than 600,000 Canadians were estimated to have severe vision loss, accounting for 17% of total disability in Canada. One in 9 individuals experience severe vision loss by 65 years of age; however, this increases to 1 in 4 individuals by 75 years. The financial cost of vision loss in Canada is $15.8 billion per year. There is a general perception that vision loss is "normal with aging" but 75% of vision loss is estimated to be preventable. The major causes of severe vision loss are age-related macular degeneration (ARMD), glaucoma, particularly primary open-angle glaucoma (POAG), and diabetic retinopathy (DR). Canada is headed for an epidemic of age-related eye disease and, unless something is done to prepare for this, severe vision loss will have significant consequences in terms of societal and economic costs. Through this proposed Research Program, and in conjunction with our international academic and private sector partners, we will build and develop unique quantitative imaging technologies to permit non-invasive assessment of visual changes, structural changes in the thickness of the retina at the back of the eye and also changes in the amount of blood flowing through the blood vessels that feed the retina with oxygen. This research will add to our basic knowledge in predicting the development of sight-threatening change in patients with the three diseases, and facilitate earlier detection of the problem to help us discover earlier treatments for people with these conditions. The reliability of each imaging technology will be assessed by determining its ability to differentiate between diseased and healthy eyes. Cross-sectional analyses at yearly intervals, as well as change over time analyses, will be undertaken.
Detailed description
There are a number of major steps that are required prior to the utilisation of these technologies in a clinical setting. This phase of the Proposal will aim to validate and calibrate the new technologies, explore the signal-to-noise ratio of RBF and oxygen saturation parameters, generate values to define the impact of absorption, morphological fundus variation and pre-retinal autofluorescence on oxygen saturation imaging and will establish a database of healthy control imaging values for both new technologies and the reproducibility of those measurements. Note: Sample size calculations have been conducted for all aspects of this phase of the protocol, based upon our extensive retinal vascular reactivity work. We will build and develop unique quantitative imaging technologies to that will permit us to explore the physiology of retinal and choroidal perfusion and vascular regulation, and retinal oxygenation.
Having completed the Validation and Calibration phase, this research will ultimately add to our basic knowledge in predicting the development of sight-threatening change in patients with the ARMD, diabetic retinopathy and primary open glaucoma, and facilitate earlier detection of the problem to help us discover earlier treatments for people with these conditions. The reliability of each imaging technology will be assessed by determining its ability to differentiate between diseased and healthy eyes. Through this proposed Research Program, we will build and develop unique quantitative imaging technologies to: Comprehensively assess the blood supply to, and vascular regulation characteristics of the posterior segment of the eye, a diagnostic capability that is currently severely limited. Assess oxygen saturation disturbances in the retina and ON that occur prior to clinically detectable changes, diagnostic capability that currently does not exist. Using the retinal blood supply and oxygen saturation parameters, we will derive net oxygen delivery to the retina and optic nerve head (ONH), a diagnostic capability that does not exist
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Sub-study 1 | – | –The Quantitative, Doppler SD-OCT Blood Flow Technology will be validated and calibrated by manipulating end-tidal blood gases using the computer-controlled gas sequencer (Slessarev et al, 2005) in 15 healthy controls. Homeostatic inner retina blood flow values and the magnitude of vascular reactivity will be compared between Doppler SD-OCT blood flow technology and the Canon Laser Blood Flowmeter, an established standard, at specific locations within the retinal vascular tree. |
| Sub-study 2 | – | –The Quantitative, Hyper-Spectral Imaging Derived Oxygen Saturation Maps of the major retinal vessels and capillary beds will be validated and calibrated in human volunteers using our novel and exact technique that allows the precise control of the partial pressure of oxygen (PO2) to induce controlled and safe levels of hypoxia. Oxygen saturation values will be compared to measured PO2 values (i.e. recognized standard) for various levels of hypoxia and will be used to provide in-sight into the properties of the data output e.g. effective operating range, linearity of response. At the end of the study, subjects will be returned to normoxic conditions to assess reproducibility of oxygen saturation maps. |
| Sub-study 3 | – | –Subjects with symptoms of branch and central retinal artery and vein occlusion within the past 2 months will be used to validate the Doppler SD-OCT blood flow technology and the hyperspectral imaging derived oxygen saturation maps. In cases of central retinal vein and artery occlusion, imaging values (i.e. inner retinal and choroidal blood flow, oxygen saturation values of the major retinal vessels and the capillary beds of the retina and ONH) will be compared between the affected and unaffected eyes. In cases of branch occlusion, imaging values will be compared between the affected and unaffected quadrants of the affected eye and between the affected and unaffected eyes. The difference in inner retinal and choroidal blood flow for each eye will be calculated and compared between eyes. |
| Sub-study 4 | – | –Calibration for retinal melanin, crystalline lens absorption, macular pigment, morphological variation and pre-retinal autofluorescence in healthy subjects (n=20 per decade, range 40 to 80yrs). Established reflectometric techniques to derive absorption values and autofluorescence techniques will be used to calculate correction values for each parameter that influences the hyper-spectral retinal and ON oxygen saturation imaging data (Keilhauer and Delori, 2006; Delori et al, 2007). |
| Sub-study 5 | – | –Establishment of a database of healthy control imaging values (n=20 per decade, range 40 to 80yrs). A database of healthy control values will be established for each technology taking into account extraneous factors such as age (range 40 to 70 years) and gender. The healthy control database will be compared to the results of each individual patient in the prospective study phase of this proposed Research Program (see Prospective Study Phase, 3, Control group). Statistical confidence limits for abnormality at each time point, and for progression overtime, will be established. Measurements will be repeated at separate visits to establish repeatability. |
Who may qualify
- Ages
- 20 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Flyers advertising the study will be posted on noticeboards within Toronto Western Hospital. The cohorts will be selected from the respondents to the flyer. Clincians in the Ophthalomology department in the Toronto Western Hopital will also offer the study to patients whom they consider to be potential participants.
Key inclusion criteria (4 listed)
- 20 to 80 years of age
- good vision in at least one eye (equivalent to 20/40 or better when wearing up-to-date spectacles)
- normal intraocular pressure (i.e. < 22 mm Hg)
- spectacle refraction between +/- 6.00 DS \& / or +/- 2.50 DC
Key exclusion criteria (3 listed)
- any ocular disease apart from retinal vein / artery occlusion (for stub study #3, patients with retinal vessel occlusion will be recruited)
- history of stroke, chronic lung disease (i.e. does not include seasonal asthma)
- taking medications with known effects on the blood vessels, other than medications to control blood glucose, blood pressure or cholesterol levels
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
Validation and calibration of the Quantitative, Doppler SD-OCT Blood Flow Technology
Time frame: 1 year
Validation and calibration of the Doppler SD-OCT technology for their optimal utilisation in a clinical setting is required. We aim to explore the signal-to-noise ratio of retinal blood flow and oxygen saturation parameters, generate values to define the impact of absorption, morphological fundus variation and pre-retinal autofluorescence on oxygen saturation imaging and will establish a database of healthy control imaging values for both new technologies and the reproducibility of those measurements.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Jan 2013.
- Background: PubMed 19339742Tayyari F, Venkataraman ST, Gilmore ED, Wong T, Fisher J, Hudson C. The relationship between retinal vascular reactivity and arteriolar diameter in response to metabolic provocation. Invest Ophthalmol Vis Sci. 2009 Oct;50(10):4814-21. doi: 10.1167/iovs.09-3373. Epub 2009 Apr 1.
- Background: PubMed 16877429Keilhauer CN, Delori FC. Near-infrared autofluorescence imaging of the fundus: visualization of ocular melanin. Invest Ophthalmol Vis Sci. 2006 Aug;47(8):3556-64. doi: 10.1167/iovs.06-0122.
- Results publicationSlessarev M, Fisher JA, Volgyesi G, Prisman E, Mikulis D, Hudson C, Ansel C (2005). PATENT: A new method and apparatus to attain and maintain target end tidal gas concentrations (WO/2007/012170). International Application #: PCT/CA2005/001166. Filing Date: 28 / 07 / 2005. Pub Date: 01 / 02 / 2007.
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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.
Chris Hudson, OD, PhD principal investigator
University of Toronto, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, University of Waterloo
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 Branch Retinal Artery Occlusion and Central Retinal Artery 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 4 inclusion and 3 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 17 Jan 2013. 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 Chris Hudson, Ph.D (416 603 5694, chudson@uwaterloo.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Validation and calibration of the Quantitative, Doppler SD-OCT Blood Flow Technology (time frame: 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01348633, which also lists 3 linked publications.
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 17 Jan 2013; AzTrials last refreshed its copy on 26 Oct 2026.