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Diabetes PRP and OCT (PRP)

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ClinicalTrials.gov Identifier: NCT01928550
Recruitment Status : Completed
First Posted : August 26, 2013
Last Update Posted : April 9, 2018
Sponsor:
Collaborator:
Oregon Clinical and Translational Research Institute
Information provided by (Responsible Party):
David Huang, Oregon Health and Science University

Brief Summary:
The purpose of this study is to evaluate the effectiveness of investigational Doppler Optical Coherence Tomography (OCT) and OCT angiography in the management of proliferative diabetic retinopathy (PDR - a leading cause of blindness in diabetic patients) before and after treatment. Angiography is the mapping of the blood vessels, and Doppler detects blood flow. PDR is due to poor oxygen circulation in smaller blood vessels in the back of the eye (retina), and is observed in 80% of people who have had diabetes for more than 10 years. This study will look at how blood flow to the eye is affected before and after treatment.

Condition or disease
Proliferative Diabetic Retinopathy

Detailed Description:

Diabetic retinopathy (DR) refers to changes in the blood vessels of the retina associated with long-term diabetes mellitus. These changes can be found in patients both with Type I and II diabetes. DR is a leading cause of blindness in the United States. It is categorized as either non-proliferative (NPDR) or proliferative (PDR). In the PDR progress, the lack of oxygen in the retina causes fragile, new blood vessels to grow along the retina and in the clear, gel-like vitreous humour. Without timely treatment, the new vessels can bleed, cloud vision, and destroy the retina. So, the PDR is classified as either the existence of retinal neovascularization or vitreous or pre-retinal hemorrhage. PDR is typically treated with a laser, known as panretinal photocoagulation (PRP), which will create 1,600-2,000 burns in the retina to reduce the retinal oxygen demand, and then reduce the possibility of ischemia, or with an injection of an anti-vascular endothelial growth factor (anti-VEGF) drug into the vitreous, which always needs multiple injections. In cases of severe bleeding, a vitrectomy may be performed under local anesthesia. However, an eye patch and medicated eye drops are always needed after the operation to protect against infection and the outcomes are not always as good as expected.

PDR is currently diagnosed by a comprehensive eye exam including a visual acuity test, ophthalmoscopy or fundus photography, fluorescein angiography (FA) and optical coherence tomography (OCT). If the PDR is thought to require treatment, the subsequent assessment of disease severity and treatment planning utilizes FA. FA requires the injection of sodium fluorescein into the systemic circulation. However, 1 in 3 people have adverse reactions to sodium fluorescein, which can include nausea, vomiting, hives, and acute hypotension. Severe reactions such as anaphylaxis and related anaphylactoid reactions, causing cardiac arrest and sudden death due to anaphylactic shock, have also been reported. Finally, because the risks of sodium fluorescein to a developing fetus are unknown, its use in pregnant women is contraindicated. Replacing FA with a less invasive and better tolerated method would reduce the risk in the patient population. One option is OCT angiography.

Optical coherence tomography is an imaging technology that can perform non-contact cross-sectional imaging of tissue structure in real time. It has a number of features that make it attractive as a diagnostic imaging modality: 1) It has micron-level resolution, which is not possible with any other non-contact technique; 2) No potentially allergenic dyes or contrast agents are required; 3) OCT images are generated in electronic form, which facilitates the use of digital image processing techniques to extract quantitative parameters regarding the imaged tissue anatomy. For these reasons, structural OCT is already routinely used to assess the early stage of DR (NPDR) by imaging the areas of macular edema and response to treatment. Novel functional OCT including Doppler OCT and OCT angiography may allow an assessment of retinal blood flow and alleviate the need for the more invasive FA test. Thus, if the diagnostic data provided by functional OCT are at least equivalent or superior to those achieved by FA, patients and healthcare providers could realize a substantial benefit in utilizing this technology in the management of PDR and the evaluation of PRP.

Therefore, we propose a pilot study to evaluate the feasibility of Doppler OCT to measure total retinal blood flow to assess global retinal ischemia after PRP treatment and OCT angiography of the retina to assess proliferative changes in the management of PDR subjects in comparison to standard FA. Functional OCT data (Doppler OCT and OCT angiography) are acquired using the Swept Source-OCT (SS-OCT) with a depth resolution of 5 microns and an ultrafast scan rate of 100 kHz which allows us to obtain detailed 3D OCT images. OCT angiography performs noninvasive microcirculation measurement and visualization which are not options on commercially available OCT systems. Though not FDA-approved, the SS-OCT prototype satisfies the American national standards for laser safety (ANSI) safety requirement. The power level is low enough to be classified as a non-significant risk device.

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Study Type : Observational
Actual Enrollment : 8 participants
Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Pilot Study OCT of Retinal Blood Flow in Proliferative Diabetic Retinopathy Before and After Panretinal Photocoagulation
Study Start Date : August 2013
Actual Primary Completion Date : May 25, 2016
Actual Study Completion Date : May 25, 2016

Resource links provided by the National Library of Medicine


Group/Cohort
PDR patients
Patients suspected to have Proliferative Diabetic Retinopathy or PDR



Primary Outcome Measures :
  1. Total retinal blood flow & visual acuity [ Time Frame: 1 year ]

    1) Total retinal blood flow, as measured by Doppler OCT, will be correlated with visual acuity and the severity of PDR. This will be performed by the following analysis:

    1. Pearson's correlation test of total retinal blood flow with logMAR (Logarithm of the Minimal Angle of Resolution) visual acuity before and after PRP;
    2. Pearson's correlation test of total retinal blood flow with area of capillary drop-out on FA before and after PRP;
    3. Pearson's correlation test of total retinal blood flow with areas of leakage on FA before and after PRP;
    4. Pearson's correlation test of total retinal blood flow with areas of thickening on OCT before and after PRP.
    5. Paired t test of total retinal blood flow on OCT before and after PRP.


Secondary Outcome Measures :
  1. Macular ischemic areas and microaneurysms, as identified by FA vs. OCT [ Time Frame: 1 year ]

    2) Macular ischemia and retinal neovascularization, as measured by OCT angiography, will be correlated with visual acuity and macular ischemia as evaluated by fluorescein angiography. This will be performed by the following analysis:

    1. Pearson's correlation test of retinal neovascularization identified by OCT angiograms with that identified by FA.
    2. Pearson's correlation test of macular ischemic area with area of capillary drop-out on FA before and after PRP.
    3. Pearson's correlation test of retinal parafoveal flow index and size of retinal neovascularization with logMAR visual acuity before and after PRP;
    4. Paired t test of retinal parafoveal flow index before and after PRP.



Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 100 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Individuals 18 years of age and older presenting to the Retina Service within the Department of Ophthalmology at the Casey Eye Institute of Oregon Health & Science University with signs and symptoms of PDR will be considered and evaluated for enrollment into this study. This pilot study has a planned enrollment target sample size of 28 subjects needing PRP. However, up to 40 subjects will be recruited as it is possible that after subjects sign the consent form they may not meet all eligibility criteria.
Criteria

Inclusion Criteria:

a. Diagnosis of diabetes mellitus (type 1 or type 2).

Exclusion Criteria:

  1. Inability to give informed consent.
  2. Inability to maintain stable fixation for OCT imaging.
  3. Significant renal disease, defined as a history of chronic renal failure requiring dialysis or kidney transplant.
  4. A condition that, in the opinion of the investigator, would preclude participation in the study (e.g., unstable medical status including blood pressure, cardiovascular disease, and glycemic control).
  5. Blood pressure > 180/110 (systolic above 180 OR diastolic above 110). If blood pressure is brought below 180/110 by anti-hypertensive treatment, subject can become eligible.
  6. Systemic anti-VEGF or pro-VEGF treatment within 4 months prior to treatment
  7. Women who are pregnant or lactating or intending to become pregnant within the next 12 months due to unknown safety of fluorescein angiography
  8. Subject is expecting to move out of the area of the clinical center to an area and not willing to return for follow-up visits during the 6 months of the study.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01928550


Locations
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United States, Oregon
Oregon Health & Science University
Portland, Oregon, United States, 97239
Sponsors and Collaborators
Oregon Health and Science University
Oregon Clinical and Translational Research Institute
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Responsible Party: David Huang, Christina Flaxel, MD, Oregon Health and Science University
ClinicalTrials.gov Identifier: NCT01928550    
Other Study ID Numbers: IRB00009572
8UL1TR000128-07 ( U.S. NIH Grant/Contract )
First Posted: August 26, 2013    Key Record Dates
Last Update Posted: April 9, 2018
Last Verified: April 2018
Keywords provided by David Huang, Oregon Health and Science University:
Diabetes
OCT
PDR
Additional relevant MeSH terms:
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Retinal Diseases
Diabetic Retinopathy
Eye Diseases
Diabetic Angiopathies
Vascular Diseases
Cardiovascular Diseases
Diabetes Complications
Diabetes Mellitus
Endocrine System Diseases