Quantitative assessment of retinal vessel density and thickness changes in internal carotid artery stenosis patients using optical coherence tomography angiography

Investigation of retinal microcirculation alterations following carotid artery angioplasty and stenting using optical coherence tomography angiography

Background

Carotid artery stenosis (CAS) is a common vascular condition that can impair retinal and optic nerve blood supply, leading to ocular ischemic damage. Optical coherence tomography angiography (OCTA) provides a non-invasive method to evaluate retinal microcirculation and detect vascular changes in CAS patients.

Methods

This study utilized OCTA to evaluate changes in retinal microcirculation in CAS patients before and after carotid artery angioplasty and stenting. A 6 × 6 mm OCTA scan was performed to analyze deep retinal vascular complex (DVC) blood flow density, foveal avascular zone area (FAZA), foveal density within a 300 μm-wide ring surrounding the FAZ (FD-300), and radial peripapillary capillary vessel density (RPC-VD). Additionally, ultra-wide-field OCTA imaging (24 × 20 mm) was employed to comprehensively assess perfusion in both the posterior pole and peripheral retina.

Results

Following carotid artery angioplasty and stenting, significant improvements were observed in the ipsilateral eye, including increased macular blood flow density (p = 0.004), FD-300 (p = 0.031), RPC-VD (p = 0.028) and decreased FAZA (p = 0.018) in the deep retinal vascular layer, indicating enhanced retinal microcirculation. No statistically significant changes were found in the contralateral eye. In some cases, ultra-wide-field OCTA revealed a reduction in macular non-perfusion areas in the ipsilateral eye, alongside an increase in non-perfusion areas near the vascular arcades.

Conclusion

Carotid artery angioplasty and stenting effectively improves retinal microcirculation in CAS patients, as evidenced by increased blood flow density and reduced non-perfusion areas in the ipsilateral eye. OCTA is a valuable non-invasive tool for assessing retinal circulation dynamics, identifying microvascular abnormalities, and monitoring treatment efficacy in CAS patients.

Decreased Choriocapillaris Vessel Density in the Ipsilateral Eye after Carotid Artery Revascularization Detected by Widefield Swept-Source OCT Angiography

Objective

To investigate the short-term blood flow changes and image features of the retina and choroid in patients who underwent carotid artery revascularization (CAR) for severe carotid artery stenosis using widefield swept-source OCT angiography (OCTA).

Design

Prospective study.

Participants

This prospective study included 112 eyes (56 eyes on the ipsilateral side and 56 eyes on the contralateral side) of 56 participants with severe carotid artery stenosis.

Methods

Participants were examined using widefield swept-source OCTA covering an area of 16 × 16 mm centered on the fovea before and after CAR. Retinal parameters including central macular thickness, vessel density of the retinal superficial vascular complex (VDRSVC), vessel density of the retinal deep vascular complex, and vessel density of the retina (VDR) and choroidal parameters, including central choroidal thickness (CCT), vessel density of the choriocapillaris (VDCC), vessel density of the medium and large choroidal vessels, choroidal vessel volume ratio (CVV/a), and 3-dimensional choroidal vascularity index (3D-CVI) were measured. Besides, preoperative and postoperative OCTA images were screened and compared.

Main Outcome Measures

Retinal and choroidal parameters obtained from swept-source OCTA.

Results

In the ipsilateral eye (56 eyes), an increase in VDRSVC, VDR, CVV/a, CCT, and 3D-CVI and a decrease in VDCC was found after CAR. Thirteen patients were identified with postoperative ipsilateral choriocapillaris flow voids (PICCFVs) with OCTA images, and the presence of PICCFVs was associated with greater postoperative VDCC decrease. In the contralateral eye (56 eyes), we found an increase in VDRSVC, vessel density of the retinal deep vascular complex, and VDR, whereas no difference in choroidal parameters after CAR and no findings of PICCFVs were found.

Conclusions

The findings of this study suggest that ocular microvascular perfusion is improved after CAR in the ipsilateral eye and the contralateral eye within a wide field of the fundus. The VDCC is decreased in the ipsilateral eye, which may indicate infarctions of choriocapillaris or ischemia-reperfusion injury of the choriocapillaris after CAR.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Detection of macular and peripheral ocular microvascular changes after carotid artery revascularization using widefield SS-OCTA

Purpose

This study aims to investigate microvascular changes in the macular and peripheral regions, as well as alterations in the foveal avascular zone (FAZ) of the ipsilateral eye using widefield swept-source optical coherence tomography angiography (SS-OCTA) in patients with severe carotid artery stenosis (SCAS) after carotid artery revascularization (CAR).

Design

This study employed a prospective study design.

Methods

SCAS patients were examined using widefield SS-OCTA, which covered an area of 16 × 16 mm centered on the fovea. These examinations were conducted both before and after CAR to assess changes in retinal and choroidal blood flow in the macular and peripheral regions, as well as alterations in the characteristics of the FAZ.

Results

A total of 56 patients and their corresponding 56 ipsilateral eyes were included in this study. In the macular area, a significant increase in the vessel density of the retinal superficial vascular complex (VDRSVC) was found, while a significant decrease was noted in the vessel density of the retinal deep vascular complex (VDRDVC) after CAR. Additionally, both the area and circumference of the FAZ decreased significantly after CAR. In the peripheral regions, significant increases were detected in both VDRSVC and the three-dimensional choroidal vascularity index (3D-CVI) post-CAR.

Conclusion

The findings of this study demonstrated that CAR can improve perfusion in both the macular and peripheral fundus and lead to a decreased area and circumference of the FAZ in the ipsilateral eye. The observed decrease in the VDRDVC after CAR may be attributed to microvascular embolization and ischemia within the deep capillary plexus (DCP).

The Use of Retinal Imaging Including Fundoscopy, OCT, and OCTA for Cardiovascular Risk Stratification and the Detection of Subclinical Atherosclerosis

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is a leading cause of preventable morbidity and mortality globally, and retinal imaging modalities (old and new) are being explored as noninvasive tools to predict latent atherosclerosis and cardiovascular disease. This review focuses on the emerging promise of fundoscopy, optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA) in CVD prognostication.

RECENT FINDINGS

High-quality studies have established the utility of vessel-based parameters and discrete conditions diagnosable via fundoscopy in subclinical atherosclerosis detection or CVD prediction. Recent research shows OCT measurements of different retinal layers and specific imaging findings (such as retinal ischemic perivascular lesions) are widely accessible and objective biomarkers for incipient CVD and ensuing risk. Myriad OCTA metrics appear to reliably inform on current CVD burden and cardiovascular risk. Fundoscopy, OCT, and OCTA all have a growing body of literature supporting their utility as adjuncts in CVD prediction and risk stratification.

Metrics of retinal vasculature detected on OCTA in carotid artery stenosis: A systematic review and meta-analysis

BACKGROUND

Carotid artery stenosis (CAS) is a major cause of cerebral microcirculation dysfunction, contributing to 15-20% of ischemic strokes. Retinal vessel changes is associated with several systemic diseases, including CAS. This systematic review investigates retinal microvascular alterations measured using optical coherence tomography angiography (OCTA) in patients with CAS.

METHODS

We comprehensively searched the electronic databases, namely PubMed, Cochrane Library, Embase, and Web of Science. Macular and optic nerve head vascular density (VD) in patients with CAS were compared to controls. Pooled data for each outcome were calculated as standardized mean difference (SMD) and 95% confidence interval. OCTA parameters were analyzed using Review Manager Version 5.4.1 software.

RESULTS

Seven articles were included in this meta-analysis. Whole macular enface superficial and deep VD were significantly lower in patients with CAS than in controls (SMD = -0.97, P = 0.002; SMD = -1.05, P = 0.006, respectively). Additionally, the parafoveal superficial VD was significantly lower in the CAS group than in the healthy group (SMD = -0.71, P= 0.001). Radial peripapillary capillary (RPC) whole-image VD (SMD = -0.90, P< 0.0001), RPC inside disc VD (SMD = -0.49, P = 0.02), and RPC peripapillary VD (SMD = -0.64, P = 0.0003) were also significantly lower in patients with CAS compared to healthy individuals.

CONCLUSION

These findings suggest that patients with CAS are prone to decreased VD in the macular and optic nerve head areas. Hence, OCTA shows potential as a promising tool for the early detection of cerebral microcirculation disorders due to CAS.

Comparison of optical coherence tomography angiography results in patients with internal carotid artery stenosis who underwent carotid artery stenting and carotid endarterectomy

It is important to examine the ocular hemodynamic changes after carotid artery stenting (CAS) and carotid endarterectomy (CEA) in patients with internal carotid artery stenosis (ICAS). We aimed to compare the differences in retinal and optic nerve head blood flow after 2 surgical methods. The ipsilateral eyes of 34 patients who had over 50% ICAS with no ocular findings and 30 healthy controls were included in the study. Foveal avascular zone vessel density in the superficial retinal capillary plexus, deep retinal capillary plexus (DCP), and radial peripapillary capillary plexus (RPCP) were measured with an optical coherence tomography angiography device. These measurements were repeated 1 month after CAS or CEA in patients with ICAS. The preoperative and postoperative values of the patients were compared both within themselves and with the control group. When patients with ICAS were compared with the control group, lower vessel density values were found in the DCP parafovea, RPCP whole image, and peripapillary regions both before and after the procedure. There was no significant difference in terms of other parameters. Furthermore, there was no significant difference in any parameter examined between the pre- and postprocedural values of the patients who underwent CAS and CEA. DCP and RPCP are mostly affected in patients with ICAS. We observed that after application of the CAS and CEA methods, the effects on ocular blood flow were similar.

Changes in the retina and choroid in patients with internal carotid artery stenosis: a systematic review and meta-analysis

Background

Internal carotid artery stenosis (ICAS) is a prevalent vascular condition associated with ischemic cerebrovascular disease. The ophthalmic artery is the first branch of the internal carotid artery stenosis (ICA). Given the crucial role of the ICA in ocular perfusion, we aimed to assess the thickness and vessel density of the retina and choroid in individuals with ICAS.

Methods

The PubMed and Embase databases were searched from inception to 10 January 2023 for studies evaluating retinal and choroidal changes between ICAS patients and healthy controls using optical coherence tomography (OCT) or optical coherence tomography angiography (OCTA). Data of interest were extracted and analyzed using Stata software version 16.

Results

Thirteen studies involving 419 ICAS eyes and 398 healthy eyes were included. The pooled results demonstrated that the average thickness of peripapillary retinal nerve fiber layer (pRNFL) (WMD = -0.26, 95% CI: -0.45 to -0.08, P = 0.005), ganglion cell complex (GCC) (WMD = -0.36, 95% CI: -0.65 to -0.06, P = 0.017), and choroid (WMD = -1.06, 95% CI: -1.59 to -0.52, P = 0.000), were significantly thinner in patients with ICAS than in healthy controls. The overall vessel density of the radial peripapillary capillaries (RPC) in whole-image scans was lower in ICAS patients than in healthy control subjects (WMD = -0.94, 95% CI: -1.49 to -0.39, P = 0.001). No differences were detected in the vessel density of the superficial capillary plexus (SCP) (WMD = -0.84, 95% CI: -1.15 to -0.53, P = 0.092), the deep capillary plexus (DCP) (WMD = -0.27, 95% CI: -0.56 to 0.03, P = 0.074), or the choriocapillaris (CC) (WMD = -0.39, 95% CI: -1.12 to 0.35, P = 0.300).

Conclusion

This systematic review and meta-analysis demonstrated that ICAS can reduce the vessel density of the RPC and the thickness of the retina and choroid. The retinal and choroidal microvasculature is a potential biomarker of the initial signal of ICAS.

Systematic review registration

https://inplasy.com/, identifier NPLASY202410038.

Insight into the Brain: Application of the Retinal Microvasculature as a Biomarker for Cerebrovascular Diseases through Optical Coherence Tomography Angiography

Purpose of review

The present article serves as a comprehensive review of the published research literature surrounding the retinal microvasculature, characterized through the optical coherence tomography angiography (OCTA) and its potential clinical value for understanding and detecting cerebrovascular diseases.

Recent findings

Studies from the past 3 years (2020-2023) have identified a degeneration of the retinal microvasculature, commonly defined through the loss of vascular density, in ischemic stroke, dementia, carotid artery stenosis, cerebral small vessel disease, and a series of rare, potentially inherited cerebrovascular disorders. These retinal microvascular changes often correlate with structure and functional changes in the brain and sometimes occur prior to debilitating neurodegeneration.

Summary

While further investigations with longitudinal data and larger sample sizes are necessary, OCTA shows promising results for characterizing the retinal microvasculature as a potential imaging biomarker in reflecting the changes in the cerebral microvasculature for early detection, prevention, and treatment of cerebrovascular diseases.

Optical Coherence Tomography Angiography: Revolutionizing Clinical Diagnostics and Treatment in Central Nervous System Disease

Optical coherence tomography angiography (OCTA), as a new generation of non-invasive and efficient fundus imaging technology, can provide non-invasive assessment of vascular lesions in the retina and choroid. In terms of anatomy and development, the retina is referred to as an extension of the central nervous system (CNS). CNS diseases are closely related to changes in fundus structure and blood vessels, and direct visualization of fundus structure and blood vessels provides an effective "window" for CNS research. This has important practical significance for identifying the characteristic changes of various CNS diseases on OCTA in the future, and plays a key role in promoting early screening, diagnosis, and monitoring of disease progression in CNS diseases. This article reviews relevant fundus studies by comparing and summarizing the unique advantages and existing limitations of OCTA in various CNS disease patients, in order to demonstrate the clinical significance of OCTA in the diagnosis and treatment of CNS diseases.

Retinal Findings and Cardiovascular Risk: Prognostic Conditions, Novel Biomarkers, and Emerging Image Analysis Techniques

Many retinal diseases and imaging findings have pathophysiologic underpinnings in the function of the cardiovascular system. Myriad retinal conditions, new imaging biomarkers, and novel image analysis techniques have been investigated for their association with future cardiovascular risk or utility in cardiovascular risk prognostication. An intensive literature search was performed to identify relevant articles indexed in PubMed, Scopus, and Google Scholar for a targeted narrative review. This review investigates the literature on specific retinal disease states, such as retinal arterial and venous occlusions and cotton wool spots, that portend significantly increased risk of future cardiovascular events, such as stroke or myocardial infarction, and the implications for personalized patient counseling. Furthermore, conditions diagnosed primarily through retinal bioimaging, such as paracentral acute middle maculopathy and the newly discovered entity known as a retinal ischemic perivascular lesion, may be associated with future incident cardiovascular morbidity and are also discussed. As ever-more-sophisticated imaging biomarkers and analysis techniques are developed, the review concludes with a focused analysis of optical coherence tomography and optical coherence tomography angiography biomarkers under investigation for potential value in prognostication and personalized therapy in cardiovascular disease.

Retinal Microvascular Changes in Internal Carotid Artery Stenosis

Purpose: We aimed to analyze retinal microvascular parameters, measured by optical coherence tomography angiography in patients with internal carotid artery stenosis compared to healthy individuals. Materials and Methods: A total of 41 eyes from 30 patients who had varying degrees of carotid stenosis, and 42 eyes from 42 healthy controls, were enrolled in this study. Depending on the degree of stenosis evaluated by Doppler ultrasonographic imaging, the patient group was further subclassified into mild, moderate, and severe carotid artery stenosis. Superficial and deep capillary plexus vessel densities, radial peripapillary capillary vessel density, foveal avascular zone, and flow densities in the choriocapillaris and outer retina were evaluated by optical coherence tomography angiography. Results: The superficial and deep capillary plexus vessel densities were significantly reduced among the groups, only sparing the foveal region. The mean superficial plexus vessel density was 45.67 ± 4.65 and 50.09 ± 4.05 for the patient and control group, respectively (p = 0.000). The mean deep capillary plexus density was 46.33% ± 7.31% and 53.27% ± 6.31% for the patient and control group, respectively (p = 0.000). The mean superficial and deep capillary vessel densities in the foveal region did not show any statistical difference between the patient and control groups (p = 0.333 for the superficial and p = 0.195 for the deep plexus vessel density). Radial peripapillary capillary vessel density was decreased in the patient group (p = 0.004). The foveal avascular zone area was wider in the patient group but this difference did not show a significant difference (p = 0.385). Conclusions: Retinal microvascular changes are a prominent outcome of internal carotid disease, and even mild stenosis can lead to alterations in the retinal microvascular bed which could be detected by OCTA. By early detection of microvascular changes in the retina in this patient group, we might speculate the overall vascular condition.