Optical Coherence Tomography Angiography Evaluation of Ocular Changes in Patients With Carotid Artery Stenosis

Study Overview
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Brief Summary
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This study aims to evaluate ocular changes in patients with carotid artery stenosis by optical coherence tomography angiography before and after carotid artery revascularization procedure.

Detailed Description
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A growing body of research indicates that abnormal ocular microvascular features may serve as a novel biomarker reflecting the severity of underlying cardiovascular, neurodegenerative, and microvascular disease. Since blood flow to the retina is predominantly supplied by the internal carotid artery (ICA), we hypothesized that ocular microvasculature and structure changes may reflect the disease status or therapeutic effects in patients with carotid artery stenosis. Optical coherence tomography angiography (OCTA) is a novel, non-invasive imaging modality that can be a reliable tool for the qualitative and quantitative assessments of ocular vessels during various ocular pathological or physiological changes. Recent studies have also demonstrated the ability of OCTA to quantify retinal microvascular changes in monitoring cardiovascular risk. This study aims to evaluate ocular changes in patients with carotid artery stenosis by optical coherence tomography angiography before and after carotid artery revascularization procedure.In this study, the patients with carotid artery stenosis and control group will receive a series of cerebral and ocular examinations including the most important cerebral CT perfusion (CTP) and OCTA. After that, the cerebral and ocular data between the two groups will be compared. Also, the preoperative and postoperative data acquired will be compared.

Official Title
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Optical Coherence Tomography Angiography Evaluation of Ocular Changes in Patients With Carotid Artery Stenosis

Conditions
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Carotid Stenosis

Intervention / Treatment
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* Procedure: Carotid artery revascularization procedure
* Device: Optical coherence tomography angiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis of carotid artery stenosis Age-gender-race-matched controls Exclusion Criteria: age <18 years intraocular pressure (IOP) >21 mmHg VA >logMAR 1.0 spherical equivalent (SE) between >1.00 or < -6.00 D other serious eye diseases which may affect OCTA results including diabetic retinopathy, hypertensive retinopathy, retinal vascular occlusion, age-related macular degeneration, and uveitis major intraocular surgery performed in the past 6 months or a history of laser photocoagulation or intravitreal injection glaucoma or first-degree relatives with a history of glaucoma; and any disease that might cause poor scan quality (image quality <6).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 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 |
| --- | --- |
| Carotid artery stenosis<br>Patients with carotid artery stenosis. Procedure: Carotid artery revascularization procedure | Procedure: Carotid artery revascularization procedure<br>* The patients with carotid artery stenosis will be examined before and after finishing the carotid artery revascularization procedure.<br>Device: Optical coherence tomography angiography<br>* Examination will be performed using optical coherence tomography angiography. This device allows quantitative analysis, since it provides numerical data about flow area and flow density maps.<br>|
| Control<br>Patients without carotid artery stenosis | Device: Optical coherence tomography angiography<br>* Examination will be performed using optical coherence tomography angiography. This device allows quantitative analysis, since it provides numerical data about flow area and flow density maps.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Radical Peripapillary Capillaries Vessel Density | Radical peripapillary capillaries vessel density of Optical Coherence Tomography Angiography（OCTA） | Difference of vessel density in each group at baseline | 
| Superficial Vascular Complexes Vessel Density | superficial vascular complexes vessel density of Optical Coherence Tomography Angiography | Difference of vessel density in each group at baseline | 
| Deep Vascular Complexes Vessel Density | deep vascular complexes vessel density of Optical Coherence Tomography Angiography | Difference of vessel density in each group at baseline | 
| Choriocapillaris Vessel Density | choriocapillaris vessel density of Optical Coherence Tomography Angiography | Difference of vessel density in each group at baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Difference of Mean Transit Time(dMTT) | Change of dMTT is the dMTT value at 4 days after carotid artery procedure minus the value at baseline. dMTT is that the value of the lesion side minus value of contralateral side. Mean transit time (MTT) corresponds to the average time, in seconds, that red blood cells spend within a determinate volume of capillary circulation. | baseline and 4 days after carotid artery procedure | 
| Change of the Ratio of Cerebral Blood Flow(rCBF) | Change of rCBF is the rCBF value at 4 days after carotid artery procedure minus the value at baseline. rCBF is that the CBF value of the lesion side divided by the value of contralateral side. CBF refers to the flow of blood through a certain cross-sectional area of cerebrovascular per unit time. | baseline and 4 days after carotid artery procedure | 
| Changes of Retinal Nerve Fiber Layer | changes of retinal nerve fiber layer of Optical Coherence Tomography Angiography | baseline and 4 days after carotid artery procedure | 
| Changes of Deep Vascular Complexes Vessel Density | changes of deep vascular complexes vessel density of Optical Coherence Tomography Angiography | baseline and 4 days after carotid artery procedure | 
| Changes of Radical Peripapillary Capillaries Vessel Density | changes of radical peripapillary capillaries vessel density of Optical Coherence Tomography Angiography | baseline and 4 days after carotid artery procedure | 
| Changes of Superficial Vascular Complexes Vessel Density | changes of superficial vascular complexes vessel density of Optical Coherence Tomography Angiography | baseline and 4 days after carotid artery procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Carotid Stenosis, OCTA