Impact of Carotid Endarterectomy on Choroidal Thickness and Volume in Enhanced Depth Optical Coherence Tomography Imaging

Influence of Carotid Artery Stenting on the Retina and Choroid

Purpose

The effect of carotid artery stenting in patients with unilateral carotid artery stenosis on the retina and choroid was evaluated using swept-source optical coherence tomography angiography (SS-OCTA).

Methods

SS-OCTA examination was conducted before stenting and 4 days and 3 months after stenting. The retinal nerve fiber layer, ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer, superficial vascular complex (SVC), deep vascular complex (DVC), choroidal vascular volume (CVV), and choroidal vascular index were measured. Repeated-measures analysis of variance was performed to assess the impact of carotid artery stenting on optical coherence tomography angiography (OCTA) metrics.

Results

At baseline, 303 eyes from 160 patients (61.82 ± 9.98 years; 85.29% males) were enrolled. SVC and DVC densities and CVV were lower in ipsilateral eyes (stenosed side) compared to contralateral eyes (all P < 0.05). Four days after stenting, a significant increase was seen in SVC density in ipsilateral eyes (P < 0.05) while a significant increase was seen in CVV in ipsilateral eyes and contralateral eyes (both P < 0.05). Three months after stenting (63 patients with 114 eyes), a significant decrease was seen in the GCIPL thickness of ipsilateral and contralateral eyes (all P < 0.001).

Conclusions

Short term after carotid artery stenting, ipsilateral eyes showed a rapid and significant increase in SVC density and CVV.

Translational Relevance

Optical coherence tomography (OCT)/OCTA measurements may have the potential to detect retinal and choroidal changes after stenting. Future research on the long-term effect of stenting on the retina and choroid will be guided by these findings.

Internal Carotid Artery Stenosis and Ipsilateral Subretinal Drusenoid Deposits

Purpose

Subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) are strongly associated with vasculopathies such as myocardial infarction and ischemic stroke. This study evaluates ischemic stroke subjects for SDDs to determine whether ocular hypoperfusion from internal carotid artery (ICA) stenosis is associated with ipsilateral SDDs.

Methods

A cross-sectional study at Mount Sinai Hospital recruited 39 subjects with ischemic stroke (aged 52-90; 18 women, 21 men); 28 completed all study procedures. Computed tomography (CT) of the head and neck evaluated 54/56 ICAs for stenosis criteria: none (n = 33), mild (n = 12), moderate (n = 3), severe (n = 3), and complete (n = 3). Spectral-domain optical coherence tomography (SD-OCT) scans were read to consensus by two masked graders for soft drusen, SDDs and choroidal thickness (CTh; choroidal thinning = CTh < 250 µm). Univariate testing was done with Fisher's exact test. Multivariate logistic regression models tested age, gender, and ICA stenosis as covariates.

Results

Moderate or more ICA stenosis (≥50%-69%) was significantly associated with ipsilateral choroidal thinning (P = 0.021) and ipsilateral SDDs (P = 0.005); the latter were present distal to six of nine stenosed ICAs versus five of 33 normal ICAs. Mild ICA stenosis (≥1%-49%) was not significantly associated with ipsilateral SDDs. Multivariate regression found that older age (P = 0.015) and moderate or more ICA stenosis (P = 0.011) remained significant independent risks for ipsilateral SDDs.

Conclusions

At least moderate ICA stenosis (≥50%-69%) is strongly associated with ipsilateral SDDs and choroidal thinning, supporting downstream ophthalmic artery and choroidal hypoperfusion from ICA stenosis as the mechanism for SDD formation. SDDs may thus serve as sensitive biomarkers for ischemic stroke and other vascular diseases.

Influence of Carotid Endarterectomy on Choroidal Perfusion: The INFLATE Study

PURPOSE

Patients with clinically significant carotid artery stenosis (CAS) undergoing carotid artery endarterectomy (CEA) were imaged with swept-source OCT angiography (SS-OCTA) imaging protocol to determine if there were changes in choroidal blood flow after surgery.

DESIGN

Prospective observational study.

PARTICIPANTS

Patients with clinically significant CAS undergoing unilateral CEA.

METHODS

All participants underwent SS-OCTA imaging using a 6 × 6-mm scan pattern on both eyes before CEA and within 1 week after CEA. Previously validated automated algorithms were used to measure the mean choroidal thickness (MCT) and choroidal vascular index (CVI) within 2.5-mm and 5-mm circles centered on the fovea. Multivariable regression analysis was conducted to evaluate the impact of various baseline factors including age, mean arterial blood pressure, and degree of stenosis, on both baseline of MCT and CVI, and the changes in MCT and CVI.

MAIN OUTCOME MEASURES

Changes in MCT and CVI.

RESULTS

One hundred sixteen eyes from 60 patients with a mean age of 71.57 ± 7.37 years were involved in the study. At baseline, MCT in both the 2.5-mm and 5-mm circles was significantly thinner on the surgical side compared with the nonsurgical side (P = 0.03), while no significant differences were seen in the CVI at baseline between the 2 sides (2.5-mm circle: P = 0.24; 5-mm circle: P = 0.09). Within 1 week after CEA, there were significant increases in the MCT on the surgical side, as compared with the nonsurgical side, in both the 2.5-mm (P < 0.001) and the 5-mm (P < 0.001) circles. No significant change in mean CVI was noted before and after CEA on the surgical side versus the nonsurgical side (2.5-mm circle: P = 0.30; 5-mm circle: P = 0.97). Multivariable regression analysis revealed that baseline MCT before CEA significantly decreased with age on both the surgical (P < 0.001) and nonsurgical sides (P = 0.003) while the changes in MCT and CVI after CEA were not associated with age, mean arterial blood pressure, or degree of stenosis.

CONCLUSION

A rapid and significant increase in MCT was observed on the ipsilateral side of CEA, suggesting an improvement in choroidal perfusion within 1 week after surgery.

FINANCIAL DISCLOSURE(S)

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

Impaired cerebrovascular reactivity correlates with reduced retinal vessel density in patients with carotid artery stenosis: Cross-sectional, single center study

BACKGROUND

The cerebral and retinal circulation systems are developmentally, anatomically, and physiologically interconnected. Thus, we hypothesized that hypoperfusion due to atherosclerotic stenosis of the internal carotid artery (ICA) can result in disturbances of both cerebral and retinal microcirculations. We aimed to characterize parameters indicating cerebrovascular reactivity (CVR) and retinal microvascular density in patients with ICA stenosis, and assess if there is correlation between them.

METHODS

In this cross-sectional study the middle cerebral artery (MCA) blood flow velocity was measured by transcranial Doppler (TCD) and, simultaneously, continuous non-invasive arterial blood pressure measurement was performed on the radial artery by applanation tonometry. CVR was assessed based on the response to the common carotid artery compression (CCC) test. The transient hyperemic response ratio (THRR) and cerebral arterial resistance transient hyperemic response ratio (CAR-THRR) were calculated. Optical coherence tomography angiography (OCTA) was used to determine vessel density (VD) on the papilla whole image for all (VDP-WIall) and for small vessels (VDP-WIsmall). The same was done in the peripapillary region: all (VDPPall), and small (VDPPsmall) vessels. The VD of superficial (VDMspf) and deep (VDMdeep) macula was also determined. Significance was accepted when p<0.05.

RESULTS

Twenty-four ICA stenotic patients were evaluated. Both CVR and retinal VD were characterized. There was a significant, negative correlation between CAR-THRR (median = -0.40) and VDPPsmall vessels (median = 52%), as well as between VDPPall vessels (median = 58%), and similar correlation between CAR-THRR and VDP-WIsmall (median = 49.5%) and between VDP-WIall (median = 55%).

CONCLUSION

The significant correlation between impaired cerebrovascular reactivity and retinal vessel density in patients with ICA stenosis suggests a common mechanism of action. We propose that the combined use of these diagnostic tools (TCD and OCTA) helps to better identify patients with increased ischemic or other cerebrovascular risks.

Does the Presence of the Cilioretinal Artery Affect the Incidence, Clinical Picture and Progression of Age-Related Macular Degeneration?

The aims of this study were to analyze the relationship between the presence of the cilioretinal artery (CRA) and the incidence, severity and progression of age-related macular degeneration (AMD) and to estimate the influence of the CRA on choroidal and retinal parameters. A total of 287 patients with AMD and 110 healthy controls were enrolled in the study. CRA occurrence was determined using color fundus images. AMD progression was assessed after 3 years. There was no difference in the incidence of CRA between the AMD and control groups (23.34% vs. 24.55%; p = 0.8). Lower-stage AMD was more frequently observed in eyes with the CRA than in eyes without the artery (p = 0.016). The CRA did not influence disease progression (p = 0.79). The CRA did not influence retinal and choroidal thickness and volume parameters or the retinal vessel caliber and functionality in either the AMD or control groups. There was no relationship between CRA presence and CFH Y402H and ARMS2 A69S risk variants. The results did not show a protective effect of the CRA on the incidence and progression of AMD. The CRA may affect the severity of AMD; however, the mechanism of this phenomenon is unclear.

Subretinal drusenoid deposits are strongly associated with coexistent high-risk vascular diseases

Background/aims

Demonstrate that subretinal drusenoid deposits (SDDs) in age-related macular degeneration (AMD) are linked to coexistent high-risk vascular diseases (HRVDs).

Methods

Cross-sectional study. Two hundred AMD subjects (aged 51–100 years; 121 women, 79 men) were recruited. Spectral domain optical coherence tomography, autofluorescence and near-infrared reflectance imaging, and lipid profiles were obtained. Subjects were assigned by health history questionnaires into those with or without HRVDs, defined as: cardiac valve defect (eg, aortic stenosis), myocardial defect (eg, myocardial infarction) and stroke/transient ischaemic attack. Masked readers assigned subjects into two groups: SDD (with or without drusen) and drusen (only). Univariate testing was performed by χ2test. We built multivariate regression models to test relationships of coexistent HRVD to SDD status, lipid levels and other covariates.

Results

The prevalence of HRVD was 41.2% (40/97) and 6.8% (7/103) in the SDD and non-SDD groups, respectively (correlation of SDD with HRVD, p=9×10−9, OR 9.62, 95% CI 4.04 to 22.91). Multivariate regressions: only SDDs and high-density lipoprotein (HDL) in the first two HDL quartiles remained significant for HRVD (p=9.8×10−5, 0.021, respectively). Multivariate regression model: SDDs and an HDL in Q1 or Q2 identified the presence of HRVD with the accuracy of 78.5%, 95% CI 72.2% to 84.0%.

Conclusions

High-risk cardiovascular and neurovascular diseases were accurately identified in an AMD cohort from SDDs and HDL levels. The SDDs may be related to inadequate ocular perfusion resulting from the systemic vasculopathies. Further research with this paradigm is warranted and might reduce mortality and morbidity from vascular disease.

Subfoveal choroidal thickness in ipsi- and contralateral eyes of patients with carotid stenosis before and after carotid endarterectomy: a prospective study

PURPOSE

To compare subfoveal choroidal thickness (SFCT) and associated clinical variables in patients with carotid stenosis (CS) before and 6 months after carotid endarterectomy (CEA).

METHODS

The prospective non-randomized Helsinki Carotid Endarterectomy Study - Brain and Eye Sub-sTudy included seventy patients (81% male, mean age 69 years) and 40 control subjects (77% male, 68 years), from March 2015 to December 2018. Ophthalmological examination included SFCT measured with enhanced-depth imaging-optical coherence tomography. Carotid stenosis (CS) was more severe (≥70% stenosis in 92%) ipsilateral to the CEA than contralaterally (<50% stenosis in 74%; p < 0.001).

RESULTS

At baseline, patients had thinner mean SFCT than control subjects in both eyes (ipsilateral, 222 versus 257 μm and contralateral, 217 versus 258 μm, p ≤ 0.005). At follow-up, SFCT did not change in ipsi- and contralateral eyes compared to baseline in patients (p = 0.68 and p = 0.77), or in control subjects (p = 0.59 and p = 0.79). Patients with coronary artery disease had thinner mean SFCT versus those without it in ipsilateral eyes before CEA (200 versus 233 μm, p = 0.027). In ipsilateral eyes of patients before CEA, thinner SFCT and ocular signs of CS, plaque and hypoperfusion related findings combined, were associated (p = 0.036), and the best-corrected visual acuity, measured in logMAR, increased with increasing SFCT (r = -0.25; p = 0.046).

CONCLUSIONS

Subfoveal choroidal thickness (SFCT) is thinner in patients with CS without association between SFCT and the grade of CS. Unchanged SFCT after CEA suggests, that choroidal vessels in severe CS are unable to react to increased blood flow. Bilaterally thin SFCT could be considered as yet another sign of CS.

The impact of vascular risk factors on the thickness and volume of the choroid in AMD patients

Disturbances in choroidal microcirculation may lead to the onset and progression of age-related macular degeneration (AMD). We aimed to assess changes in the choroidal volume and thickness in the macular region in AMD eyes and to investigate whether coexisting vascular risk factors alter choroidal status. We enrolled 354 AMD patients (175 dry, 179 wet AMD) and 121 healthy controls. All participants underwent a complete ophthalmologic examination and assessment of choroidal thickness and volume. A multivariate analysis adjusted for age, sex, and smoking status revealed that wet AMD was an independent factor associated with higher average thickness of the central ring area (ATC) and average volume of the central ring area (AVC) and lower choroidal vascularity index (CVI) compared to controls (β =  + 0.18, p = 0.0007, β =  + 0.18, p = 0.0008, respectively) and to dry AMD (β =  + 0.17, p = 0.00003 for both ATC and AVC and β =  - 0.30 p < 0.0001 for CVI). ATC, AVC and average volume (AV) were lower in AMD patients with hypertension and ischaemic heart disease (IHD). The duration of hypertension was inversely correlated with ATC, AVC and AV (Rs =  - 0.13, p < 0.05; Rs =  - 0.12; p < 0.05, Rs =  - 0.12; p < 0.05, respectively) while IHD duration negatively correlated with AV (Rs =  - 0.15, p < 0.05). No such associations were observed in the control group. Our findings show that the choroidal vascular system in eyes with AMD is much more susceptible to damage in the presence than in the absence of systemic vascular disease.