Characterization of Retinal Microvascular and FAZ Changes in Ischemic Stroke and Its Different Types

Study Overview
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Brief Summary
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The study aimed to access the microvascular changes in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in patients with ischemic stroke and its different types using optical coherence tomography angiography.

Detailed Description
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Investigators used OCTA to quantitatively access the retinal microvasculature of SCP and DCP, aiming to detect the geometry changes of retinal microvasculature and FAZ in ischemic stroke patients and its different types.

Official Title
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Characterization of Retinal Microvascular and FAZ Changes in Ischemic Stroke and Its Different Types

Conditions
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Ischemic Stroke

Intervention / Treatment
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* Device: Optical Coherence Tomography Angiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who were diagnosed with ischemic stroke by MRI were scheduled for an OCTA examination. The diagnosis of ischemic stroke was obtained from previous diagnostic reports or electronic medical records, according to the diagnostic criteria from the Trial of Org 10172 in Acute Stroke Treatment (TOAST). Exclusion Criteria: 1) Retinal diseases or diseases affecting vessel structure in fundus photography, including age-related maculopathy; diabetic retinopathy, central serous chorioretinopathy, retinal pigment epithelial detachment and glaucoma); poor cooperation in ophthalmic examinations; high refractive error (>+6.00 D or <-6.00 D Spherical Equivalent); low-quality OCTA images (signal strength index < 6/10). Inclusion criteria for healthy controls were no history of ischemic stroke or other neurological and ocular diseases.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Ischemic Stroke<br>The diagnosis of ischemic stroke was obtained from previous diagnostic reports or electronic medical records, according to the diagnostic criteria from the Trial of Org 10172 in Acute Stroke Treatment (TOAST). | Device: Optical Coherence Tomography Angiography<br>* Optical coherence tomography angiography (OCTA) is a novel non-invasive, non-dye and high-resolution imaging technique, allowing real-time quantitative evaluation of retinal vasculature and the structure of foveal avascular zone (FAZ).<br>|
| Control<br>Inclusion criteria for healthy controls were no history of ischemic stroke or other neurological and ocular diseases. | Device: Optical Coherence Tomography Angiography<br>* Optical coherence tomography angiography (OCTA) is a novel non-invasive, non-dye and high-resolution imaging technique, allowing real-time quantitative evaluation of retinal vasculature and the structure of foveal avascular zone (FAZ).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vascular Area Density(VAD) | The total length in millimeters of perfused retinal microvasculature per unit area in square millimeters in the annular region of analyzed area | immediately after meeting the inclusion and exclusion criteria | 
| Vascular Fractal Dimension(VFD) | A well-known parameter which indicates the degree of geometric complexity of vasculature | immediately after meeting the inclusion and exclusion criteria | 
| Vascular Orientation Distribution(VOD) | The direction of each vascular pixel to indicate the trend of the blood flow | immediately after meeting the inclusion and exclusion criteria | 
| FAZ Area(FA) | The total numbers of pixels in the FAZ region | immediately after meeting the inclusion and exclusion criteria | 
| FAZ Axis Ratio(FAR) | The ratio between the major and minor axes of the fitted ellipse from the FAZ boundary. The axis ratio of a perfect circular FAZ is equal to 1 | immediately after meeting the inclusion and exclusion criteria | 
| FAZ Circularity(FC) | The ratio of the perimeter of the FAZ to the parameter of a circle with equal area, reflecting the degree of roundness of the FAZ | After meeting the inclusion and exclusion criteria | 
| FAZ Roundness(FR) | Similar to FC, but is less sensitive to irregular borders along the parameter of FAZ | immediately after meeting the inclusion and exclusion criteria | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ischemic Stroke, Optical Coherence Tomography Angiography, Retina