Reversed Ophthalmic Artery Flow Research Articles

The Prognostic Value of Reversed Ophthalmic Artery Flow Direction in Acute Stroke Patients with Ipsilateral Extra Cranial Carotid Artery Stenosis

Abstract Background According to the World Health Organization, about 15 million people suffer a stroke each year with roughly one-third resulting in death and another one-third sustaining severe permanent disability. Even in developed nations, stroke is the third leading cause of death. It also costs billions of dollars through lost productivity, premature mortality and care for stroke survivors. The evaluation of hemodynamics, autoregulation and collaterals is cardinal for clinical outcomes. The Use of Transcranial Doppler (TCD) in detecting reversal of blood flow direction especially in anterior communicating and ophthalmic arteries, and flow diversion between anterior and posterior circulation provide critical information on ipsilateral collateral status. The impact of collateral status has been correlated with clinical symptoms, reperfusion success and functional outcome at discharge. A rationale now exists for imaging assessment to guide physicians in the precision medicine of stroke care. Aim of the work This study is performed for evaluation of hemodynamics in ophthalmic artery as a collateral and its value as a prognostic factor in patients with carotid artery extra cranial stenosis in acute cerebrovascular stroke. Patients and Methods 30 patients with acute cerebrovascular stroke were recruited in this cross-sectional study admitted in stroke unit at the department of neurology of Ain Shams University hospitals. Results There was a statistically significant difference between the Modified Rankin Scale on discharge and follow up after 3 months in patients suffering from acute cerebrovascular stroke with ipsilateral severe extra cranial carotid artery stenosis and reversed ophthalmic artery flow direction (p value =0.042), compared to the group with direct ophthalmic artery flow direction where the (p = 0.086). Conclusion Transcranial Duplex is a diagnostic tool that provides a non-invasive, real time, safe technique information data on intracerebral hemodynamics. It was used in this study to detect that there is a significant difference in functional outcome between patients with forward and reversed ophthalmic artery flow direction with acute cerebrovascular stroke and ipsilateral extracranial carotid artery stenosis.

Reversed ophthalmic artery flow following ischemic stroke: a possible predictor of outcomes following carotid artery stenting

ABSTRACTStroke is the leading cause of death worldwide and stenosis of the carotid artery accounts for more than half of all cases. Carotid duplex is an effective non-invasive ultrasound test which identifies stroke patients with moderate to severe carotid stenosis who are candidates for preventative intervention to reduce the risk of recurrence.In patients with moderate to severe carotid stenosis, reversed ophthalmic artery flow (ROAF) is often observed at the time of the carotid duplex scan. In this study, we investigated whether ROAF, denoting exhaustion of cerebral collateral flow in ischemic stroke patients affected mid-term functional outcomes following carotid artery stenting (CAS) procedures.In total, 144 consecutive patients with a first episode of ischemic stroke and subsequent CAS procedure conducted between January 2010 and November 2014 at Changhua Christian Hospital, Taiwan were included. Clinical data were obtained by medical record review. Disability was assessed at two time points by utilising the Barthel Index (BI) and modified Rankin Scale (mRS) before CAS and 12 months post-CAS.Among 85 patients presenting without ROAF, 48/85 (56.4%) had improved mRS scores following stenting. The condition remained unchanged (stationary) in 36/85 (43.5%) patients after stenting and one patient exhibited deteriorated condition 1/85(1.1%).In contrast, among the 59 patients presenting with ROAF, 24/59 (40.6%) had improved mRS score following stenting. The condition remained unchanged (stationary) in the remaining 35/59 (59.3%) patients after stenting, and no patient exhibited deteriorated condition 0/59 (0 %).This study provides evidence that CAS is a valid and effective treatment option regardless of whether patients exhibited ROAF or not. Patients without ROAF were significantly more likely to have improved mid-term functional outcomes compared to those with ROAF. In the group without ROAF admission, CRP may play a role in predicting subsequent functional outcomes, whereas admission Barthel Index was a predictor of outcome in the ROAF group.

Ophthalmic Artery Flow and Cognitive Performance in Patients with Carotid Artery Stenosis

The circle of Willis is regarded as the primary collaterals in patients with severe carotid artery stenosis (CAS), while the secondary collaterals from the reversed ophthalmic artery (OA) flow would be recruited when the primary collaterals are inadequate to maintain cerebral perfusion. Even though some reports suggest patients with reversed OA flow are more vulnerable to cerebral ischemic injury, whether reversed OA flow is adequate to maintain cognitive function or can be employed as a surrogate marker of cognitive impairment remains elusive. The purpose of this article is to review the dynamic behavior of collateral flow and to assess the relationship between OA hemodynamics, cerebral perfusion and cognitive performance in patients with CAS. There is evidence that the OA flow patterns behave dynamically according to the hemodynamic, metabolic, and neural demands. Patients with reversed OA flow have compensatory increased cerebral blood volume and timerelated perfusion parameters, while cerebral blood flow usually remains unchanged. Despite of the evidence having been scarce, the associations between hemodynamics of OA flow and cognitive performance have been observed in several recent studies. Furthermore, our previous study demonstrated a tendency for specific cognitive impairment observed in patients with reversed OA flow, depending on the side of reversed OA flow. However, the impacts of the OA flow patterns on cognition may be modified when the other pathogenic factors of stroke are taken into account. Concurrent application of multimodality neuroimaging findings about perfusion status and neural activities will greatly enhance our understanding of the relationships between the hemodynamics of OA flow and cognition.

Reversal of Ophthalmic Artery Flow and Stroke Outcomes in Asian Patients with Acute Ischemic Stroke and Unilateral Severe Cervical Carotid Stenosis

BackgroundThe aim of this study was to assess the clinical implications of reversed ophthalmic artery flow (ROAF) for stroke risk and outcomes in subjects with unilateral severe cervical carotid stenosis/occlusion.MethodsWe investigated 128 subjects (101 with acute stroke and 27 without), selected from a large hospital patients base (n = 14,701), identified with unilateral high-grade cervical carotid stenosis/occlusion by using duplex ultrasonography and brain magnetic resonance imaging. All clinical characteristics were compared for stroke risk between acute stroke and nonstroke groups. Patients with acute stroke were divided into 4 subgroups according to ophthalmic artery flow direction and intracranial stenosis severity, and stroke outcomes were evaluated.ResultsThe acute stroke group had significantly higher percentages of ROAF (52.5%, p = 0.003), carotid occlusion (33.7%, p = 0.046), and severe intracranial stenosis (74.3%, p<0.001). However, multivariate analysis demonstrated that intracranial stenosis was the only significant risk factor (odds ratio = 10.38; 95% confidence interval = 3.64–29.65; p<0.001). Analysis of functional outcomes among the 4 subgroups of patients with stroke showed significant trends (p = 0.018 to 0.001) for better stroke outcomes from ROAF and mild or no intracranial stenosis. ROAF improved 10–20% stroke outcomes, as compared to forward ophthalmic artery flow, among the patients with stroke and the same degree of severities of intracranial stenosis.ConclusionsPatients with acute stroke and severe unilateral cervical carotid stenosis/occlusion significantly have high incidence of intracranial stenosis and ROAF. Intracranial stenosis is a major stroke risk indicator as well as a predictor for worse stroke outcomes, and ROAF may provide partial compensation for improving stroke outcomes.

Relationships between ophthalmic artery flow direction and cognitive performance in patients with unilateral carotid artery stenosis

BackgroundCerebral hypoperfusion is responsible for cognitive impairment in patients with severe carotid artery stenosis (CAS). The manifestation of reversed ophthalmic artery flow (ROAF) is not uncommon in patients with CAS, suggesting a state of intensified cerebral hypoperfusion. This study aimed to examine whether the presence of ROAF can exacerbate cognitive impairment in patients with severe unilateral CAS. MethodsOne-hundred-and-two patients with CAS and 37 age-matched volunteers participated in this case–control study. Depending on the side of CAS and occurrences of ROAF, the patients were allocated to four groups: left CAS groups with ROAF (n=28) or without ROAF (n=22), and right CAS groups with ROAF (n=26) or without ROAF (n=26). All subjects underwent a battery of neuropsychological tests. ResultsAll patients performed worse than the control group on most tests. No significant differences were observed between patient groups (ps>0.05), except for inferior performance on psychomotor speed and visuospatial tests in the right ROAF group (ps<0.03). Hierarchical regression analyses indicated strong contributions of estimated premorbid intelligence to performance on most tests (ps<0.05). The severity of left and right CAS was distinctively associated with different functions. To a lesser extent, the severity of infarcts was also associated with impairment of psychomotor speed and some executive functions (ps<0.05). The contributions of ROAF to performance on most tests were negligible. ConclusionPatients with unilateral CAS may present with specific cognitive impairment relevant to the ipsilateral hemispheric functions. However, the manifestation of ROAF does not necessarily imply more extensive or severe cognitive impairment.

Reversal of ophthalmic artery flow as a predictor of intracranial hemodynamic compromise: implication for prognosis of severe carotid stenosis

High-grade cervical carotid stenosis (70-99%) or occlusion often accompanies reversed ophthalmic artery flow (ROAF), but its potential clinical significances remain poor understood. This study assessed ROAF and the related variables caused by carotid hemodynamic compromise in patients with unilateral severe cervical carotid stenosis. The study consisted of 200 patients diagnosed as unilateral high-grade cervical carotid stenosis/occlusion using ultrasonography. The hemodynamic parameters of 152 patients, excluding 48 with cervical carotid occlusion, were compared based on the presence of ROAF. Out of 200 patients, 159 underwent brain magnetic resonance imaging and were analysed for risk factors impacting functional outcomes including ROAF. The patients (n = 48) with internal carotid artery occlusion had significantly higher incidence (62.5%) of ROAF compared with that of 25.0% in those patients (n = 152) with unilateral high-grade carotid stenosis (P < 0.001). In ROAF patients (n = 38) with the unilateral high-grade stenosis, a significant retrobulbar arteries hemodynamic difference was observed between the stenotic and non-stenotic vessels. The patients (n = 159) with history of stroke (P = 0.035), ROAF (P = 0.023) and intracranial stenosis (P < 0.001) exhibited significantly higher incidence of poor functional outcome compared with the corresponding control groups. In the same patients (n = 159), those with both cervical and intracranial stenosis showed sevenfold higher risk (OR, 7.60; 95% CI, 3.44-16.81) for ROAF than those with only cervical stenosis. ROAF may result from intracranial hemodynamic compromise. Patients with unilateral high-grade cervical carotid stenosis/occlusion in combination with intracranial stenosis appear to be a significant risk factor for poor functional outcome and increased incidence of ROAF.

Bedside Emergency Transcranial Doppler Diagnosis of Severe Carotid Disease Using Orbital Window Examination

Identifying internal carotid artery (ICA) stenosis in the acute stroke setting can provide clinically useful information. Transcranial Doppler (TCD) through the orbital window is an easy test to perform and to track and identify different vessels. Previous TCD studies have suggested that a reversed ophthalmic artery (OA) flow is a useful collateral pattern to predict ICA disease. The authors sought to evaluate the TCD orbital window for predicting cervical ICA (cICA) stenosis in the setting of acute stroke and TIA. Power M-mode/TCD was performed in acute stroke and transient ischemic attack patients at 2 institutions. Each orbital window depth was detected on M-mode and evaluated for the direction of flow and resistance pattern. Gold standard for comparison was carotid evaluation using carotid duplex, computed tomography angiogram, or conventional angiography. The assessment of cICA disease was categorized by degree of stenosis or occlusion. A total of 216 transorbital exams were performed in 117 patients. Twenty-five cICA occlusions and 8 critical cICA stenoses (>or=95%) were identified by gold standard imaging. Reversed OA flow at 50 to 60 mm depth revealed high specificity (100%; confidence interval [CI], 97.6%-100.0%) and good sensitivity (75%; CI, 53.3%-90.2%) for identifying cICA occlusion or critical stenosis (>or=95%). Low pulsatility index (<1.2) and mean flow velocity (<15 cm/s) discriminated critical severe ICA stenosis or occlusion when OA flow was anterograde with good sensitivity (87.2%) and specificity (95.2%). The reversed OA sign at 50 to 60 mm depth is very specific for identifying cICA occlusion or critical stenosis. When OA flow is anterograde, a low mean flow velocity or pulsatility index is also useful to identify cICA critical stenosis or occlusion.

Bedside Emergency Transcranial Doppler Diagnosis of Severe Carotid Disease Using Orbital Window Examination

BACKGROUND: Identifying internal carotid artery (ICA) stenosis in the acute stroke setting can provide clinically useful information. Transcranial Doppler (TCD) through the orbital window is an easy test to perform and to track and identify different vessels. Previous TCD studies have suggested that a reversed ophthalmic artery (OA) flow is a useful collateral pattern to predict ICA disease. The authors sought to evaluate the TCD orbital window for predicting cervical ICA (cICA) stenosis in the setting of acute stroke and TIA. METHOD: Power M-mode/TCD was performed in acute stroke and transient ischemic attack patients at 2 institutions. Each orbital window depth was detected on M-mode and evaluated for the direction of flow and resistance pattern. Gold standard for comparison was carotid evaluation using carotid duplex, computed tomography angiogram, or conventional angiography. The assessment of cICA disease was categorized by degree of stenosis or occlusion. RESULTS: A total of 216 transorbital exams were performed in 117 patients. Twenty-five cICA occlusions and 8 critical cICA stenoses (>or=95%) were identified by gold standard imaging. Reversed OA flow at 50 to 60 mm depth revealed high specificity (100%; confidence interval [CI], 97.6%-100.0%) and good sensitivity (75%; CI, 53.3%-90.2%) for identifying cICA occlusion or critical stenosis (>or=95%). Low pulsatility index (<1.2) and mean flow velocity (<15 cm/s) discriminated critical severe ICA stenosis or occlusion when OA flow was anterograde with good sensitivity (87.2%) and specificity (95.2%). CONCLUSION: The reversed OA sign at 50 to 60 mm depth is very specific for identifying cICA occlusion or critical stenosis. When OA flow is anterograde, a low mean flow velocity or pulsatility index is also useful to identify cICA critical stenosis or occlusion.

内頚動脈閉塞症における側副血行路としての眼動脈血流―血行力学的脳虚血との関係―

We attempted to evaluate the function of ophthalmic artery (OA) flow as the collateral pathway in cases of internal carotid artery occlusion (ICAO). Methods. We examined 18 patients having symptomatic ICAO who underwent OA color Doppler flow imaging (CDFI) and quantitative SPECT regional cerebral blood flow (rCBF)study. Results. (1) The OA CDFI findings were reversed OA flow in 10 patients and antegrade flow in 8. (2) The mean resting rCBF was 25.2ml/100 g/min in the patients with reversed OA flow, and 26.7 ml/100 g/min in the patients with antegrade OA flow. The mean cerebral blood flow reserve capacity with acetazolamide was 8.68% in the former and 28.3% in the latter. This difference was statistically significant (p<0.05). (3) In eight patients with severe hemodynamic compromise with a cerebral blood flow reserve capacity of less than 10% and a resting rCBF of less than 80%, the reversed OA flow was visualized significantly frequently (p<0.05). Conclusion. In ICAO patients, OA CDFI findings are well correlated with the hemodynamic stage and development of other collateral pathways. Reversed OA flow indicates severe intracranial hemodynamic compromise.

Ophthalmic artery flow direction on color flow duplex imaging is highly specific for severe carotid stenosis.

Collateral flow patterns are important risk factors for brain ischemia in the presence of internal carotid artery (ICA) stenosis or occlusion. Ophthalmic artery (OA) flow reversal, routinely studied by transcranial Doppler sonography, is an important marker for high-grade ICA stenosis or occlusion. The authors sought to define the value of assessing OA flow direction with color flow duplex ultrasonography (CDUS) in the setting of significant ICA disease. Of all patients having routine carotid ultrasound in the neurosonology laboratory between July 1995 and November 2000, 152 had both carotid and orbital (OA flow direction by reduced power orbital CDUS) examinations as well as angiographic confirmation of stenosis to which North American Symptomatic Carotid Endarterectomy Trial criteria could be applied. Degree of angiographic stenosis in these 152 patients (304 arteries) was correlated with OA flow direction. Of 304 arteries, 101 had greater than 80% stenosis by angiogram. In 56 of these 101 arteries with high-grade stenosis or occlusion, the ipsilateral OA was reversed; however, OA flow direction was never reversed ipsilateral to arteries with less than 80% stenosis (sensitivity 55%, specificity 100%, negative predictive value 82%, and positive predictive value 100% for OA flow reversal as a marker of high-grade carotid lesions). OA flow direction is easily studied with CDUS. Reversed OA flow direction is highly specific (100%) for severe ipsilateral ICA stenosis or occlusion, with excellent positive predictive value, moderate negative predictive value, and limited sensitivity. OA flow reversal is not only quite specific for severe ICA disease, which may be helpful if the carotid CDUS is difficult or inadequate, but may also provide additional hemodynamic insights (i.e., the inadequacy of other collateral channels such as the anterior communicating artery). OA evaluation can provide important hemodynamic information and should be included as part of carotid CDUS if there is any evidence of ICA stenosis or occlusion.

A Case of Reversed Ophthalmic Artery Flow without Occlusion of the Internal Carotid Artery

Background: We report a case of reversed ophthalmic artery (OA) flow showing neither occlusion of the internal carotid artery (ICA) nor ophthalmic symptoms. Case: An 82-year-old man had transient blindness in both eyes. After left carotid endarterectomy, ophthalmic symptoms improved in the right and left eyes. Afterwards, he had a relapse in the left eye. Results: There was no unusual impression in the ophthalmic examinations, but color Doppler imaging showed reduced flow in the left OA, reversal of flow direction in the right OA. The central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were not detected in the left eye but were detected in the right eye. Digital subtraction angiography demonstrated that the right OA was not contrasted with the right ICA, despite there being no stenosis or occlusion of the right ICA. Conclusions: We suggest that carotid surgery may affect the ocular circulation of the opposite side, and reversed OA flow as a collateral pathway from the external carotid artery may occur in the absence of carotid artery stenosis. Good circulation of the CRA and SPCA may preclude manifestation of ophthalmic symptoms even if the OA flow is reversed.

Assessment of ocular perfusion after carotid endarterectomy with color-flow duplex scanning

Purpose: The purpose of this study was to assess the effect of carotid endarterectomy (CEA) on ocular perfusion with the measurement of the ophthalmic artery (OA) and the central retinal artery (CRA) flow velocities with color-flow ocular duplex scanning (ODS). Ocular hemodynamics also were examined in a subset of patients with visual symptoms in an attempt to characterize the origin of the ocular symptoms and their response to surgery. Methods: Twenty-five patients with internal carotid artery stenoses (≥70%) underwent 29 CEAs. All the patients underwent ODS for the measurement of the peak systolic velocity (PSV) in the OA and the CRA of the ipsilateral eye before and after CEA. The preoperative and postoperative flow velocities were compared in all the patients and in the patients with and without visual symptoms. Results: The preoperative PSV in the OA was 21.6 ± 2.2 cm/s and in the CRA was 7.7 ± 0.7 cm/s. These values were reduced as compared with normative values (OA, 37.8 cm/s; CRA, 10.7 cm/s). After CEA, the PSV increased significantly in both vessels (postoperative OA, 38.6 ± 2.5 cm/s, P < .0001; postoperative CRA, 12.1 ± 0.9 cm/s, P = .0008). Fifteen of the 29 CEAs were performed for visual symptoms. The patients with ocular symptoms had significantly lower preoperative PSVs in the CRA as compared with those patients without visual symptoms (CRA with ocular symptoms, 6.5 ± 0.8 cm/s; CRA with no ocular symptoms, 9.4 ± 0.9 cm/s; P = .02). The PSV in the OA was not significantly lower in the patients with ocular symptoms. Eight patients (28%) were found to have reversed OA flow before surgery, but only three patients had ocular symptoms. All eight patients had normal antegrade flow in the OA after surgery. Conclusion: Severe carotid stenosis may be associated with reduced ocular perfusion, which can be quantitatively evaluated with ODS. Reduced OA and CRA flow velocities are corrected with successful CEA. The patients with ocular symptoms were observed to have significant reductions in CRA flow velocities. Reversed flow in the OA was not a marker for ocular symptoms in this study. ODS can identify global ocular ischemia and may be helpful in the evaluation of patients with atypical visual symptoms or with amaurosis fugax and no evidence of retinal emboli. (J Vasc Surg 1999;29:665-71.)

Collateral blood supply through the ophthalmic artery: A steal phenomenon analyzed by color Doppler imaging

Objective This study aimed to evaluate the retrobulbar circulatory effects of reversed ophthalmic artery flow (ROAF) on the ophthalmic artery branches by means of color Doppler imaging. Design The design was a case-controlled study. Participants Among 56 consecutive patients with severe (>70% stenosis) occlusive carotid artery disease, 15 patients (26.8%) with ROAF were identified. The control group consisted of 15 patients with similar degrees of carotid artery stenosis and forward ophthalmic artery flow. Intervention Arteriography and measurement of the retrobulbar hemodynamic parameters with color Doppler imaging were performed. Main outcome measures Blood flow velocities and resistive index in the ophthalmic, central retinal, and temporal short posterior ciliary arteries were measured. Results Arteriography confirmed the diagnosis of ROAF in all 15 patients. There was no patient with ROAF diagnosed by arteriography and not diagnosed by color Doppler imaging. The frequency of bilateral severe occlusive carotid artery disease was significantly higher in the ROAF group (40%) compared to the control group (6.6%) ( P = 0.04). Patients with ROAF showed significantly reduced vascular resistance in the ophthalmic artery ( P = 0.03), higher vascular resistance, and lower blood flow velocities in the central retinal and temporal short posterior ciliary arteries ( P < 0.05). Conclusion This study suggests that patients with ROAF show a steal phenomenon, characterized by a shunt to the low-resistance intracranial circuit and reduction of retrobulbar blood flow.