Changes in Ocular Subfoveal Choroidal Thickness After Carotid Endarterectomy Using Enhanced Depth Imaging Optical Coherence Tomography: A Pilot Study

Changes in retinal vascular density measured by optical coherence tomography angiography in patients with carotid artery stenosis after carotid artery stenting and angioplasty

PURPOSE

The aim of this study was to compare the effect of carotid artery stenting and angioplasty (CASA) on retinal vascular density (VD) in patients with severe carotid stenosis with a healthy control group and to evaluate using optical coherence tomography angiography (OCTA).

METHODS

For this prospective study, eyes on the operated side constituted the ipsilateral eye group, and the other eye constituted the contralateral eye group. 40 eyes of 40 patients with ipsilateral eye of carotisid artery stenosis (CAS), 34 eyes on contralateral side, and 30 healthy eyes (control group) were included in this study. We performed quantitative OCTA analyses of retinal VD changes, before and after CASA. The main outcome measures were the quantitative changes of VD of superficial capillary plexus (SCP) and deep capillary plexus (DCP).

RESULTS

We evaluated the VD of ipsilateral eyes and contralateral eyes separately before and after the procedure. All patients did not have visual symptoms. There was no significant difference in the VD of SCP in all groups before the procedure. No significant change was observed in all groups when the VD of the SCP was compared before and after the procedure. The VD of the DCP in the ipsilateral and contralateral group improved significantly after CASA.

CONCLUSION

OCTA could noninvasively detect retinal VD improvements after CASA in CAS patients. Quantitative changes in VD evaluated using OCTA are thought to be early indicators in the diagnosis of CAS and in the follow-up of treatment success.

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.

The Impact of Carotid Endarterectomy on Choriocapillaris Perfusion

Purpose

The impact of carotid endarterectomy (CEA) on choriocapillaris (CC) perfusion was investigated using swept-source optical coherence tomography angiography (SS-OCTA) imaging before and after surgery in patients with clinically significant carotid artery stenosis (CAS).

Methods

In this prospective observational study, patients with clinically significant CAS undergoing unilateral CEA had SS-OCTA imaging performed in both eyes before and within 1 week after surgery. The percent CC flow deficits (CC FD%) and CC thickness were assessed using previously validated algorithms. Multivariable regression analysis was conducted to evaluate the impact of variables on the change in CC measurements.

Results

A total of 112 eyes from 56 patients with an average age of 72.6 ± 6.9 years were enrolled. At baseline, significantly higher CC FD% and thinner CC thickness were observed on the surgical side (eyes ipsilateral to the side of CEA) versus the nonsurgical side (eyes contralateral to the side of CEA) (P = 0.001 and P = 0.03, respectively). Following CEA, a significant reduction in CC FD% and a significant increase in CC thickness were detected on the surgical as compared with the nonsurgical side (P = 0.008 and P = 0.01, respectively). Smoking status positively affected CC FD% change (coefficient of variation [CV] = 0.84, P = 0.01) on the surgical side and negatively affected CC thickness change on both the surgical side (CV = -0.382, P = 0.009) and the nonsurgical side (CV = -0.321, P = 0.04). The degree of stenosis demonstrated a positive influence on CC FD% change (CV = 0.040, P = 0.02) on the surgical side.

Conclusions

Unilateral CEA on the side of clinically significant CAS increases carotid blood flow, which further results in improved CC perfusion.

Quantitative Assessment of Retinal and Choroidal Microvasculature in Asymptomatic Patients with Carotid Artery Stenosis

SIGNIFICANCE

Carotid disease contributes to 15 to 20% of all ischemic strokes, one of the leading causes of permanent disabilities and mortality globally. With its growing prevalence and the inflicted disability rates, screening for anomalies that precede the onset of its serious complications is of crucial global significance.

PURPOSE

This study aimed to assess the relationship between retinal and choroidal perfusion changes with the degree of stenosis using quantitative swept-source optical coherence tomography angiography in patients with internal carotid artery stenosis.

METHODS

A retrospective cohort study was conducted in 72 eyes with carotid stenosis. According to the degree of stenosis, the participants were divided into a healthy group (group 1: 34 eyes), a mild-moderate stenosis group (group 2: 22 eyes), and a severe stenosis group (group 3: 16 eyes). Swept-source optical coherence tomography angiography was performed to scan macular fovea. Capillary density values in the different retinal and choroidal layers were the major measurements for our study.

RESULTS

Mean vessel density in the midchoroid layer was significantly higher in groups 2 and 3 compared with group 1. Deep choroid disclosed significantly superior vascular density values in group 3 compared with groups 2 and 1. Superficial and deep capillary plexus showed decreased vascular density values when comparing group 3 with groups 1 and 2, although they were not significant.

CONCLUSIONS

Our report provides the first evidence that choroidal microvascular changes were correlated with severity of carotid artery stenosis. Optical coherence tomography angiography can sensitively detect subtle, early changes in the ocular blood in carotid disease representing a useful, noninvasive, and objective approach to the retinal microvasculature.

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.

Retinal microvasculature and cerebral hemodynamics in patients with internal carotid artery stenosis

Purpose

To investigate the relationship between retinal microvasculature and cerebral hemodynamics in patients with internal carotid artery (ICA) stenosis.

Methods

Patients with unilateral moderate or severe ICA stenosis(≥50%) from West China hospital, Sichuan university were consecutively and prospectively recruited enrolled in the current study. En face angiograms of the superficial vascular complex (SVC), deep vascular complex (DVC), superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were generated by automatic segmentation using swept-source optical coherence tomography angiography (SS-OCTA) to assess the retinal microvascular perfusion. The cerebral blood flow perfusion on bilateral middle cerebral artery territories measured at the basal ganglia level was assessed by brain computed tomography perfusion (CTP). CTP data were postprocessed to generate maps of different perfusion parameters including cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT) and permeability surface(PS). Relative perfusion parameters (rPS, rCBF, etc.) were calculated as the ratio of the value on the contralateral side to that on the ipsilateral side.

Results

In the final analysis, 31 patients were included, of whom 11 patients had a moderate ICA stenosis (50–69%) and 20 with a severe ICA stenosis(≥70%). A total of 55 eyes were analyzed in the study, 27 eyes from the ipsilateral side (ie, side with stenosis) and 28 eyes from the contralateral side. In the patients with ICA stenosis, there was a strong correlation between the retinal microvascular perfusion of SVC with rCBV(B = 0.45, p = 0.03), rCBF(B = 0.26, p = 0.02) and rPS(B = 0.45, p < 0.001) after adjustment for age, sex and vascular risk factors. Similar correlations were also found between microvasculature in SVP and cerebral perfusion changes. There were no any significant associations of microvascular perfusion in both DVC and DCP with CTP parameters(all p > 0.05).

Conclusions

Retinal perfusion changes in superficial vascular layer (SVC and SVP) were correlated with brain hemodynamic compromise in patients with unilateral moderate or severe ICA stenosis(≥50%). Given the limited size of our study, future studies with larger sample size are needed to confirm our findings.

Choroidal changes in carotid stenosis patients after stenting detected by swept-source optical coherence tomography angiography

BACKGROUND

Carotid artery stenosis (CAS) patients show reduced blood flow in the ophthalmic artery. This study aimed to assess the changes in the choriocapillaris and choroidal thickness in patients with unilateral carotid artery stenosis after carotid stenting using swept-source optical coherence tomography (SS-OCT)/swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

Fifty-three mild to moderate CAS patients and 40 controls were enrolled in this study. All participants underwent digital subtraction angiography (DSA) and SS-OCT/SS-OCTAA imaging before and 4 days after carotid artery stenting. SS-OCTA was used to image and measure the perfusion of the choriocapillaris (mm2) while SS-OCT was used to image and measure the choroidal thickness (µm). The stenosed side was described as the ipsilateral eye while the other side was the contralateral eye.

RESULTS

Choroidal thickness was significantly thinner (P = 0.024) in CAS when compared with controls. Ipsilateral eyes of CAS patients showed significantly thinner (P = 0.008) choroidal thickness when compared with contralateral eyes. Ipsilateral eyes of CAS patients showed thicker (P = 0.027) choroidal thickness after carotid artery stenting while contralateral eyes showed thinner choroidal thickness (P = 0.039).

CONCLUSIONS

Our report suggests that in vivo quantification of the choroid with the SS-OCT/SS-OCTA may allow monitoring of CAS and enable the assessment of purported treatments.

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.

Optical Coherence Tomography Angiography as a Noninvasive Assessment of Cerebral Microcirculatory Disorders Caused by Carotid Artery Stenosis

Purpose

Using retinal optical coherence tomography angiography (OCTA), we aimed to investigate the changes in important indicators of cerebral microcirculatory disorders, such as the properties of the radial peripapillary capillaries, vascular complexes, and the retinal nerve fiber layer, caused by carotid stenosis and postoperative reperfusion.

Methods

In this prospective longitudinal cohort study, we recruited 40 carotid stenosis patients and 89 healthy volunteers in the First Affiliated Hospital of Harbin Medical University (Harbin, China). Eyes with ipsilateral carotid stenosis constituted the experimental group, while the fellow eyes constituted the contralateral eye group. Digital subtraction angiography, CT perfusion imaging (CTP), and OCTA examinations were performed in all subjects. The vessel density of the radial peripapillary capillaries (RPC), superficial retinal vascular complexes (SVC), deep vascular complexes (DVC), choriocapillaris (CC), and the thickness of the retinal nerve fiber layer (RNFL) were assessed. Propensity-matched analysis was undertaken to adjust for covariate imbalances. Intergroup comparative analysis was conducted, and the paired sample t-test was used to evaluate the preoperative and postoperative changes in OCTA variables.

Results

The ocular vessel density in the experimental group was significantly lower than that in the control group (RPC: 55.95 vs. 57.24, P = 0.0161; SVC: 48.65 vs. 52.22, P = 0.0006; DVC: 49.65 vs. 57.50, P < 0.0001). Participants with severe carotid stenosis have reduced contralateral ocular vessel density (RPC 54.30; SVC 48.50; DVC 50.80). Unilateral stenosis removal resulted in an increase in vessel density on both sides, which was detected by OCTA on the 4^th day (RPC, P < 0.0001; SVC, P = 0.0104; DVC, P = 0.0104). Moreover, the ocular perfusion was consistent with that established by CTP.

Conclusion

OCTA can be used for sensitive detection and accurate evaluation of decreased ocular perfusion caused by carotid stenosis and may thus have the potential for application in noninvasive detection of cerebral microcirculation disorders. This trial is registered with NCT04326842.

Carotid Disease and Retinal Optical Coherence Tomography Angiography Parameters in Type 2 Diabetes: The Fremantle Diabetes Study Phase II

OBJECTIVE

To use optical coherence tomography angiography (OCTA) to determine whether retinal microvascular parameters are associated with carotid arterial disease in people with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Participants (community-based) underwent detailed assessments including carotid ultrasonography and OCTA. Ultrasound images were assessed for mean intima-media thickness (IMT) and the presence of stenosis. OCTA image analysis provided measures of vessel density, foveal avascular zone (FAZ) area, blood flow areas, and retinal thickness. For each OCTA variable, the most parsimonious model was generated using generalized estimating equations, then ipsilateral and contralateral carotid disease-related variables were added to determine their significance.

RESULTS

A total of 474 eyes from 261 participants (mean ± SD age 72.0 ± 9.3 years, 57.1% males, median diabetes duration 15.4 years [interquartile range 11.1-22.4]) were analyzed. When carotid variables were added to the most parsimonious models, the ipsilateral natural logarithm of common carotid artery IMT (coefficient -2.56 [95% CI -4.76, -0.35], P = 0.023) and presence of any ipsilateral stenosis (-0.82 [-1.48, -0.17], P = 0.014) were statistically significantly associated with a lower parafoveal density in the deep capillary plexus. A mean bifurcation IMT ≥1 mm was associated with a decreased vessel density in the 300-μm ring surrounding the FAZ (coefficient -0.79 [-1.50, -0.08], P = 0.030)). Contralateral carotid disease-related variables were also significantly associated with retinal microvascular parameters.

CONCLUSIONS

This is the first study to show that carotid disease is an independent associate of retinal microvascular disease assessed by OCTA in type 2 diabetes. Appropriately intensive management of carotid disease may improve the retinal microcirculation.

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

Purpose

Carotid endarterectomy (CEA) is considered an effective therapeutic method for improving ocular circulation. The choroid is a predominantly vascular tissue; thus, systemic and local vascular alterations may influence its morphology and function. The aim of the current study was to analyse changes in choroidal thickness and volume in patients with significant internal carotid artery stenosis (ICAS) before and after unilateral CEA.

Methods

The 42 eyes of the 21 asymptomatic patients included in the study were divided into two groups: those ipsilateral (EIE) and those contralateral (ECE) to CEA. All participants underwent a complete ophthalmologic examination, including enhanced depth imaging-optical coherence tomography (EDI-OCT). A comparative analysis of subfoveal thickness (CT) and choroidal volume (CV) measured in nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields at baseline, on the 2nd day after CEA, and in the 3rd month after CEA was performed.

Results

In the EIE and ECE groups, no significant differences in either CT or CV values before and on the 2nd day after the CEA were observed. In the EIE group, a significant increase in CT and CV in the 3rd month after CEA compared to baseline was noted in the specific ETDRS region. Changes in CT and CV after surgery were positively correlated with the participants' physical activity status and diastolic blood pressure and negatively correlated with the participants' age and smoking status. Additionally, the analysis of changes in CV after CEA showed a positive correlation between the EIE and ECE groups.

Conclusions

CT and CV fluctuations in the central and perifoveal areas visualized with EDI-OCT enabled the observation of the processes of tissue adaptation to variable blood flow conditions.

Choroidal thickness in patients with cardiovascular disease: A review

The choroid is a vascular network that supplies the bulk of the retina's oxygen and nutrient supply. Prior studies have associated changes in the thickness of the choroid with the presence of various cardiovascular diseases. This is the first review that summarizes current knowledge on the relationship between choroidal thickness and cardiovascular diseases while highlighting important findings. Acute hypertension increases choroidal thickness. Chronic hypertension and heart failure may decrease choroidal thickness, but controversy exists. Both coronary artery disease and carotid artery stenosis result in decreased choroidal thickness and blood flow. Carotid endarterectomy may reverse these changes. Choroidal thickening in early stages of carotid stenosis may arise from mechanisms compensating for ischemia. Hyperlipidemia is linked to choroidal thickening, while caffeine intake is linked to choroidal thinning. The effects of smoking and exercise are mixed. Changes in choroidal thickness have been linked to cardiovascular disease. Clarity regarding these changes could lead to the use of choroidal thickness changes as a noninvasive screening or prognostic test for pathological cardiovascular changes. Future studies should also investigate the effect of cardiovascular disease treatments on the choroid.

Structural Analysis of the Retina and Choroid before and after Carotid Artery Surgery

Purpose: To evaluate retinal and choroidal changes in patients with internal carotid artery stenosis who had undergone carotid artery stenting or endarterectomy.Methods: The study included 43 patients with internal carotid artery (ICA) stenosis that required stenting or endarterectomy and 40 healthy controls. Patients were divided into two groups according to the degree of stenosis evaluated by magnetic resonance angiography. Group 1 consisted of patients having ICA stenosis of 50 to 70%, and Group 2 has more than 70%. Enhanced depth imaging optical coherence tomography (EDI-OCT) was used to measure the retinal thickness (RT) and choroidal thickness (CT) in all subjects before surgery and at 1, 3, and 6 months after surgery.Results: Subfoveal and parafoveal CT were significantly lower in patients with ICA stenosis than the control group (p < .05, respectively). Patients with 50-70% stenosis had a significant increase in the CT at 1, 3, and 6 months after ICA stenting or endarterectomy (p < .05). Patients with >%70 stenosis did not have a significant increase in the CT at any time after ICA stenting or endarterectomy. Retinal thickness was not statistically different between the patients with ICA stenosis and the control subjects, and RT showed no significant change in patients with ICA stenosis before and after the surgery.Conclusion: Choroidal thickness was significantly thinner in patients with internal carotid artery stenosis. ICA stenting provided a recovery in the choroidal thickness in patients with moderate to advanced stenosis.

Visual Outcome of Carotid Endarterectomy in Patients with Carotid Artery Stenosis

BACKGROUND

Carotid endarterectomy (CEA) is deemed to restore the blood flow of the carotid and ophthalmic arteries in patients with carotid artery stenosis. However, specific changes in visual function before and after CEA are not well understood; hence, this observational study aimed to investigate the functional and structural changes in vision after CEA in those patients.

METHODS

Patients with severe carotid artery stenosis (>70% with standard carotid duplex scanning or arteriography) scheduled to undergo CEA were consecutively recruited for the study between September 2015 and July 2016. All patients underwent a standardized ophthalmic examination, including intraocular pressure (IOP) measurement, slit-lamp examination, and fundus examination. Visual acuity, best corrected visual acuity (BCVA), and kinetic and static visual fields (VFs) were tested to evaluate subjective visual function. Flash and pattern visual evoked potentials (VEPs) and an electroretinogram (ERG) were measured for objective visual function. Retinal nerve fiber layer (RNFL) thickness was scanned using optical coherence tomography for structural evaluation.

RESULTS

The study involved 15 patients (11 male and 4 female, corresponding to 30 eyes; mean age 62.8 ± 5.0 years). After CEA, both uncorrected visual acuity and BCVA improved, and IOP significantly decreased from 17.41 ± 2.59 to 15.95 ± 2.50 mm Hg (P = 0.0022). Kinetic VF range increased significantly (P = 0.0126) as did mean sensitivity from 18.8 ± 5.5 to 20.6 ± 4.3 dB (P = 0.0208), whereas mean defect decreased from 8.2 ± 5.3 to 6.5 ± 4.2 dB (P = 0.025). RNFL thickness was not significantly altered. Latency of the P2 wave on flash VEP reduced significantly after CEA (P = 0.0151), whereas the oscillatory potential amplitude of waveform 3 in the ERG significantly increased after CEA.

CONCLUSIONS

Our results demonstrate that an improvement in carotid artery and ophthalmic artery blood flow after CEA does indeed enhance subjective and objective assessments of visual function in patients with carotid artery stenosis, including visual acuity, kinetic and static VF, P2 latency, and ocular pressure amplitude; however, it did not affect RNFL thickness.

Carotid Artery Endarterectomy Effect on Choroidal Thickness: One-Year Follow-Up

Purpose

To evaluate the change in choroidal thickness after carotid artery endarterectomy (CEA) in patients without retinal pathology.

Methods

A prospective series of patients who underwent CEA at the Tel Aviv Medical Center. Spectral domain optical coherence tomography (SD-OCT) was performed one day before the CEA and at least 6 months after. Data included medical history, smoking history, percentage of carotid stenosis before and after CEA, best-corrected visual acuity (BCVA), central macular thickness (CMT), and choroidal thickness (subfoveal, 500 µm, 1000 µm, and 1500 µm nasal and temporal).

Results

Eight patients (seven male and one female) with a mean age of 70.5 ± 6.1 years were included in the study. The mean internal carotid artery (ICA) stenosis was 89.8% ± 5.1 in the operated side, 33.7% ± 10.9 in the nonoperated side (p < 0.0001), and 0% after CEA (p < 0.0001). Operated side BCVA was 0.35 ± 0.66 compared to 0.61 ± 0.83 in the nonoperated side (p=0.51). The mean subfoveal choroidal thickness (SFChT) of the operated side was 277 ± 67 µm compared to 268 ± 71 µm in the nonoperated side (p=0.81). SFChT and CMT after CEA were 275 ± 64 µm (p=0.96) and 268 ± 29 µm (p=0.98), respectively.

Conclusions

SFChT and CMT in patients without retinal or choroidal pathology and significant ICA stenosis can be normal and may not change after successful ipsilateral CEA.

Changes in retinal flow density measured by optical coherence tomography angiography in patients with carotid artery stenosis after carotid endarterectomy

The aim of the study presented here was to evaluate retinal and optic nerve head (ONH) perfusion in patients with severe asymptomatic carotid artery stenosis (CAS) compared with healthy controls and to analyze the impact of carotid endarterectomy using optical coherence tomography angiography (OCT-A). 25 eyes of 25 patients with CAS (study group) and 25 eyes of 25 healthy controls (control group) were prospectively included in this study. OCT-A was performed using RTVue XR Avanti (Optovue, Inc, Fremont, California, USA). The flow density data in the superficial and deep retinal OCT-angiogram of the macula and in the radial peripapillary capillary network (RPC) of the ONH were extracted and analyzed. The flow density in the superficial retinal OCT angiogram of the macula and in the ONH were significantly lower in the study group compared with the control group (macula: p = 0.003) (ONH: p = 0.013). The flow density in the ONH improved significantly after carotid endarterectomy (p = 0.004). A reduced flow density was observed in patients with CAS when compared with healthy controls. The flow density also improved after carotid endarterectomy. Quantitative changes in the microvascular density, as measured using OCT-A, could well be useful in the diagnosis of CAS and the evaluation of therapy success.