Optical Coherence Tomography Angiography Evaluation of Ocular Changes in Patients With Carotid Artery Stenosis
Conditions: Carotid Stenosis
Sponsor: First Affiliated Hospital of Harbin Medical University

Optical Coherence Tomography
Angiography Evaluation of Ocular
Changes in Patients With Carotid
Artery Stenosis
NCT04326842
2020.6.5

Optical Coherence Tomography Angiography
Evaluation of Ocular Changes in Patients With
Carotid Artery Stenosis
Relevant background and objective
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.
Study design and methods
This was an observational retrospective and propensity score-matched
analysis study. It was approved by the Ethics Committee of our hospital.
We searched for a clinical database of patients with carotid artery
stenosis in our hospital between November 2019 and February 2020. The
patients were examined by digital subtraction angiography (DSA), and the
degree of carotid artery stenosis was measured by the North American
Symptomatic Carotid Endarterectomy Trial(NASCET). The degree of
carotid artery stenosis was graded as mild(50-70%) and severe(≥70%).
Besides, healthy individuals were selected from Physical Examination
Centers in our hospital; these individuals were confirmed to have no carotid
artery stenosis by bilateral carotid doppler ultrasound examination.

Information
collected
including
visual
acuity
(VA),
diopter
measurement
using
automated
optometry,
intraocular
pressure
(IOP)
measurement using a noncontact tonometer, slit-lamp biomicroscopy fundus
examination, OCTA, and CTP(patients only). Each subject’s medical history
and family history were also recorded.
Interventional procedure
The patients in the experimental group were treated with carotid
endarterectomy (CEA) or carotid artery stenting (CAS). Their surgical
indications, surgical procedures and surgical norms all follow the AHA
guidelines12 and "Rutherford's Vascular Surgery13"
Follow-up assessments
All patients were asked to repeat OCTA and CTP examination on the
4th day after the operation before discharge. We also collected this
information.
Statistical analysis
Categorical
variables
are
presented
as
percentages,
continuous
variables are presented as mean ± SD and skewed variables are presented as
median
(boundaries
of
interquartile
range,
IQR).
A
propensity
score-matched(PSM) analysis was done using a multivariable logistic
regression model based on age, gender, tobacco, alcohol, diabetes mellitus.
Pairs of participants were derived using 1:1 greedy nearest neighbor
matching. This strategy resulted in 31 matched pairs in each group.
Clinical characteristics between groups were compared using
test
for categorical variables, paired t-test for normally distributed continuous
variables, and Wilcoxon rank-sum tests for non-normally distributed
continuous variables. Paired sample t-tests were used to assess preoperative
to postoperative changes in OCTA variables.
Fisher exact probability method was used to verify p-value when 25%
theoretical frequency was less than 5; all tests were bilateral tests, and there
was statistical significance when p<0.05. All statistical analyses were
performed using SPSS Statistics software (v25, IBM, Armonk, NY, USA),
whereas graphs were generated using Prism 7 (v7.02, GraphPad, La Jolla,
CA, USA).