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Preeclampsia is recognized as the most frequent medical complication related to pregnancy whose pathogenesis varies with different risk factors. Doppler velocimetry of the ophthalmic artery (DVOA) is an innovative study that evaluated in conjunction with the uterine arteries in the second trimester has proven to be a predictive test of high reproducibility. In order to determine the Doppler ultrasonography features of ophthalmic and uterine arteries in pregnant women with risk factors for preeclampsia, a descriptive cross-sectional investigation was carried out in 20 women between 18 and 24 weeks of pregnancy who attended the prenatal consultation of the Gynecology and Obstetrics Department of the Hospital Central Universitario Dr. Antonio Maria Pineda. Past history of prior preeclampsia is a risk factor for the development of subsequent preeclampsia observed in 50% of patients. 55% of pregnant women were overweight and 30% had obesity type I. Diastolic arterial pressure was high in 75% of patients. 65% ​​of patients had high uterine artery mean pulsatility index and presence of Notch. The diastolic hump in ophthalmic artery was observed in 60% of the patients. It is concluded that DVOA may indicate intracranial maternal hemodynamic changes even when patients do not exhibit the classic features of preeclampsia., La preeclampsia es reconocida como la complicación médica más frecuente relacionada al embarazo cuya patogénesis varía con distintos factores de riesgo. La velocimetría Doppler de arteria oftálmica (VDAO) es un estudio innovador que, al evaluarse conjuntamente con las arterias uterinas en el segundo trimestre de embarazo, ha demostrado ser un test predictor de alta reproducibilidad. Con el objetivo de determinar la caracterización ultrasonográfica Doppler de la arteria oftálmica y uterina en gestantes con factores de riesgo para preeclampsia, se realizó una investigación descriptiva transversal en 20 mujeres entre las 18 y 24 semanas de gestación que acudieron a la consulta prenatal del Servicio de Ginecología y Obstetricia del Hospital Central Universitario Dr. Antonio María Pineda. El antecedente personal de preeclampsia previa como factor de riesgo para el desarrollo de preeclampsia subsiguiente fue observado en 50% de las pacientes. 55% de las gestantes presentó sobrepeso y 30% obesidad I. La presión arterial diastólica se encontró elevada en 75% de las pacientes. El 65% de las pacientes presentó un índice de pulsatilidad medio de arteria uterina alto y presencia de Notch; la joroba diastólica de la arteria oftálmica fue observada en 60% de las pacientes. Se concluye que la VDAO puede indicar cambios hemodinámicos maternos intracraneales inclusive cuando las pacientes no exhiben las características clásicas de preeclampsia.

This paper presented the assessment of feature extraction methods used in automated diagnosis of arterial diseases. Since classification is more accurate when the pattern is simplified through representation by important features, feature extraction and selection play an important role in classifying systems such as neural networks. Different feature extraction methods were used to obtain feature vectors from ophthalmic and internal carotid arterial Doppler signals. In addition to this, the problem of selecting relevant features among the features available for the purpose of classification of Doppler signals was dealt with. Multilayer perceptron neural networks (MLPNNs) with different inputs (feature vectors) were used for diagnosis of ophthalmic and internal carotid arterial diseases. The assessment of feature extraction methods was performed by taking into consideration of performances of the MLPNNs. The performances of the MLPNNs were evaluated by the convergence rates (number of training epochs) and the total classification accuracies. Finally, some conclusions were drawn concerning the efficiency of discrete wavelet transform as a feature extraction method used for the diagnosis of ophthalmic and internal carotid arterial diseases. (c) 2004 Elsevier Ltd. All rights reserved.

In this paper, we introduced fuzzy similarity index for analysis of the Doppler ultrasound signals. Doppler ultrasonography is a reliable technique, which demonstrates the flow characteristics and resistance of arteries in various arterial diseases. The analyzed ophthalmic arterial (OA) Doppler signals were recorded from healthy subjects and subjects suffering from ophthalmic artery stenosis, ocular Behcet disease and uveitis disease. The OA Doppler signals were decomposed into time-frequency representations using discrete wavelet transforrn and wavelet coefficients were calculated to represent the signals. The aim of the study is discriminating the OA Doppler signals by the combination of wavelet coefficients and fuzzy similarity index. Toward achieving this aim, fuzzy sets were obtained from the feature sets (wavelet coefficients) of the signals under study. Our results demonstrated that the similarity between the fuzzy sets of the studied signals indicated the variabilities in the OA Doppler signals. Thus, the fuzzy similarity index could discriminate the healthy CIA Doppler signals and the other three disease states (stenosis, ocular Behcet disease and uveitis). (c) 2005 Elsevier Ltd. All rights reserved.

Objectives The purpose of this study was to assess the effect of carotid artery stenting on ophthalmic artery blood flow using transorbital color and spectral Doppler sonography and review the changes in relation to cerebral hemodynamics. Methods Twenty-eight consecutive patients with severe internal carotid artery stenosis (>= 70%) who were scheduled for carotid stenting were included. Ophthalmic artery Doppler sonography was performed bilaterally before and after stenting. The flow direction, peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI), and resistive index in the ophthalmic artery were recorded. Results Twenty male and 8 female patients with 10 right-sided and 18 left-sided stenoses were studied. The mean overall carotid stenosis ratio +/- SD was 87.3% +/- 9.9%. After stenting in the ophthalmic artery ipsilateral to the stenosis, significant increases in the PSV (-3.87 +/- 48.81 to 46.70 +/- 25.33 cm/s; P .001), and EDV (-3.02 +/- 16.31 to 11.24 +/- 7.37 cm/s; P .001) were detected, and the increase in the PI approached significance (1.40 +/- 0.59 to 1.62 +/- 0.52; P =.055). A change in the flow direction from retrograde to antegrade was noted in 11 patients (39%) after stenting, and in 1 patient with no detectable flow, reconstitution of flow was observed. Increases in the PSV and EDV (P =.03 for Delta EDV) were more pronounced in symptomatic patients than asymptomatic patients after stenting. Conclusions Substantially decreased ophthalmic artery velocity and retrograde flow are suggestive of high-grade carotid artery stenosis (greater than or similar to 90%). Stenting improves ophthalmic artery perfusion and positively changes cerebral hemodynamics in high-grade carotid artery stenosis, especially in symptomatic patients, which can be monitored with ophthalmic artery Doppler sonography.

In this paper, we present the probabilistic neural networks (PNNs) for the Doppler ultrasound blood flow signals. The ophthalmic arterial (OA) and internal carotid arterial (ICA) Doppler signals were decomposed into time-frequency representations using discrete wavelet transform (DWT) and statistical features were calculated to depict their distribution. Decision making was performed in two stages: feature extraction by computing the wavelet coefficients and classification using the classifier trained on the extracted features. The purpose was to determine an optimum classification scheme for this problem and also to infer clues about the extracted features. Our research demonstrated that the wavelet coefficients are the features which well represent the Doppler signals and the PNNs trained on these features achieved high classification accuracies. (c) 2006 Elsevier Ltd. All rights reserved.

The aim of this study is to evaluate the diagnostic accuracy of the recurrent neural networks (RNNs) trained with Levenberg-Marquardt algorithm on the Doppler ultrasound blood flow signals. The ophthalmic arterial (OA) and internal carotid arterial (ICA) Doppler signals were decomposed into time-frequency representations using discrete wavelet transform and statistical features were calculated to depict their distribution. The RNNs were implemented for diagnosis of OA and ICA diseases using the statistical features as inputs. We explored the ability of designed and trained Elman RNNs, combined with wavelet preprocessing, to discriminate the Doppler signals recorded from different healthy subjects and subjects suffering from OA and ICA diseases. The classification results demonstrated that the proposed combined wavelet/RNN approach can be useful in analyzing long-term Doppler signals for early recognition of arterial diseases. (c) 2006 Elsevier B.V. All rights reserved.

Doppler ultrasound is known as a reliable technique, which demonstrates the flow characteristics and resistance of ophthalmic arteries. In this study, ophthalmic arterial Doppler signals were obtained from 95 subjects - that 45 of them had suffered from Uveitis disease and the rest of them had been healthy subjects. Multilayer perceptron neural network (MLPNN) employing quick propagation training algorithm was used to detect the presence of Uveitis disease. Spectral analysis of ophthalmic arterial Doppler signals was performed by autoregressive moving average (ARMA) method for determining the MLPNN inputs. The MLPNN was trained with training set, cross validated with cross validation set and tested with testing set. All these data sets were obtained from ophthalmic arteries of healthy subjects and subjects suffering from Uveitis disease. Performance indicators and statistical measures were used for evaluating the MLPNN. The correct classification rate was 95.83% for healthy subjects and 91.30% for subjects suffering from Uveitis disease. Based on the accuracy of the MLPNN detections, it can be mentioned that the classification of ophthalmic arterial Doppler signals with Uveitis disease is feasible by the MLPNN employing quick propagation training algorithm.

For diagnostic systems, features are extracted from signals by the usage of autoregressive (AR) and autoregressive moving average (ARMA) methods and power level-frequency distributions of the signals are demonstrated by statistical features. In the present study, spectral analysis of ophthalmic arterial Doppler signals obtained from different subjects was performed using the AR and ARMA methods and Doppler power spectral density values which contain a significant amount of information about the signal were considered as feature vectors representing the signal. In order to reduce the dimensionality of the extracted feature vectors, statistical processes were performed over the Doppler power spectral density values and input feature vectors of multilayer perceptron neural networks used in classification were selected. Performances of the AR and ARMA methods in the analysis of Doppler signals were determined by examining performances of multilayer perceptron neural networks trained by different algorithms. Total classification accuracies of the constructed networks were demonstrated that multilayer perceptron neural network trained by Levenberg-Marquardt algorithm which used ARMA Doppler power spectral density values as inputs could be used in classification of ophthalmic arterial Doppler signals.

This paper presented the assessment of feature extraction methods used in automated diagnosis of arterial diseases. Since classification is more accurate when the pattern is simplified through representation by important features, feature extraction and selection play an important role in classifying systems such as neural networks. Different feature extraction methods were used to obtain feature vectors from ophthalmic and internal carotid arterial Doppler signals. In addition to this, the problem of selecting relevant features among the features available for the purpose of classification of Doppler signals was dealt with. Multilayer perceptron neural networks (MLPNNs) with different inputs (feature vectors) were used for diagnosis of ophthalmic and internal carotid arterial diseases. The assessment of feature extraction methods was performed by taking into consideration of performances of the MLPNNs. The performances of the MLPNNs were evaluated by the convergence rates (number of training epochs) and the total classification accuracies. Finally, some conclusions were drawn concerning the efficiency of discrete wavelet transform as a feature extraction method used for the diagnosis of ophthalmic and internal carotid arterial diseases. (c) 2004 Elsevier Ltd. All rights reserved.

In this paper, we introduced fuzzy similarity index for analysis of the Doppler ultrasound signals. Doppler ultrasonography is a reliable technique, which demonstrates the flow characteristics and resistance of arteries in various arterial diseases. The analyzed ophthalmic arterial (OA) Doppler signals were recorded from healthy subjects and subjects suffering from ophthalmic artery stenosis, ocular Behcet disease and uveitis disease. The OA Doppler signals were decomposed into time-frequency representations using discrete wavelet transforrn and wavelet coefficients were calculated to represent the signals. The aim of the study is discriminating the OA Doppler signals by the combination of wavelet coefficients and fuzzy similarity index. Toward achieving this aim, fuzzy sets were obtained from the feature sets (wavelet coefficients) of the signals under study. Our results demonstrated that the similarity between the fuzzy sets of the studied signals indicated the variabilities in the OA Doppler signals. Thus, the fuzzy similarity index could discriminate the healthy CIA Doppler signals and the other three disease states (stenosis, ocular Behcet disease and uveitis). (c) 2005 Elsevier Ltd. All rights reserved.

Objectives The purpose of this study was to assess the effect of carotid artery stenting on ophthalmic artery blood flow using transorbital color and spectral Doppler sonography and review the changes in relation to cerebral hemodynamics. Methods Twenty-eight consecutive patients with severe internal carotid artery stenosis (>= 70%) who were scheduled for carotid stenting were included. Ophthalmic artery Doppler sonography was performed bilaterally before and after stenting. The flow direction, peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI), and resistive index in the ophthalmic artery were recorded. Results Twenty male and 8 female patients with 10 right-sided and 18 left-sided stenoses were studied. The mean overall carotid stenosis ratio +/- SD was 87.3% +/- 9.9%. After stenting in the ophthalmic artery ipsilateral to the stenosis, significant increases in the PSV (-3.87 +/- 48.81 to 46.70 +/- 25.33 cm/s; P .001), and EDV (-3.02 +/- 16.31 to 11.24 +/- 7.37 cm/s; P .001) were detected, and the increase in the PI approached significance (1.40 +/- 0.59 to 1.62 +/- 0.52; P =.055). A change in the flow direction from retrograde to antegrade was noted in 11 patients (39%) after stenting, and in 1 patient with no detectable flow, reconstitution of flow was observed. Increases in the PSV and EDV (P =.03 for Delta EDV) were more pronounced in symptomatic patients than asymptomatic patients after stenting. Conclusions Substantially decreased ophthalmic artery velocity and retrograde flow are suggestive of high-grade carotid artery stenosis (greater than or similar to 90%). Stenting improves ophthalmic artery perfusion and positively changes cerebral hemodynamics in high-grade carotid artery stenosis, especially in symptomatic patients, which can be monitored with ophthalmic artery Doppler sonography.

The aim of this study is to evaluate the diagnostic accuracy of the recurrent neural networks (RNNs) trained with Levenberg-Marquardt algorithm on the Doppler ultrasound blood flow signals. The ophthalmic arterial (OA) and internal carotid arterial (ICA) Doppler signals were decomposed into time-frequency representations using discrete wavelet transform and statistical features were calculated to depict their distribution. The RNNs were implemented for diagnosis of OA and ICA diseases using the statistical features as inputs. We explored the ability of designed and trained Elman RNNs, combined with wavelet preprocessing, to discriminate the Doppler signals recorded from different healthy subjects and subjects suffering from OA and ICA diseases. The classification results demonstrated that the proposed combined wavelet/RNN approach can be useful in analyzing long-term Doppler signals for early recognition of arterial diseases. (c) 2006 Elsevier B.V. All rights reserved.

In this paper, we present the probabilistic neural networks (PNNs) for the Doppler ultrasound blood flow signals. The ophthalmic arterial (OA) and internal carotid arterial (ICA) Doppler signals were decomposed into time-frequency representations using discrete wavelet transform (DWT) and statistical features were calculated to depict their distribution. Decision making was performed in two stages: feature extraction by computing the wavelet coefficients and classification using the classifier trained on the extracted features. The purpose was to determine an optimum classification scheme for this problem and also to infer clues about the extracted features. Our research demonstrated that the wavelet coefficients are the features which well represent the Doppler signals and the PNNs trained on these features achieved high classification accuracies. (c) 2006 Elsevier Ltd. All rights reserved.

Doppler ultrasound is known as a reliable technique, which demonstrates the flow characteristics and resistance of ophthalmic arteries. In this study, ophthalmic arterial Doppler signals were obtained from 95 subjects - that 45 of them had suffered from Uveitis disease and the rest of them had been healthy subjects. Multilayer perceptron neural network (MLPNN) employing quick propagation training algorithm was used to detect the presence of Uveitis disease. Spectral analysis of ophthalmic arterial Doppler signals was performed by autoregressive moving average (ARMA) method for determining the MLPNN inputs. The MLPNN was trained with training set, cross validated with cross validation set and tested with testing set. All these data sets were obtained from ophthalmic arteries of healthy subjects and subjects suffering from Uveitis disease. Performance indicators and statistical measures were used for evaluating the MLPNN. The correct classification rate was 95.83% for healthy subjects and 91.30% for subjects suffering from Uveitis disease. Based on the accuracy of the MLPNN detections, it can be mentioned that the classification of ophthalmic arterial Doppler signals with Uveitis disease is feasible by the MLPNN employing quick propagation training algorithm.

For diagnostic systems, features are extracted from signals by the usage of autoregressive (AR) and autoregressive moving average (ARMA) methods and power level-frequency distributions of the signals are demonstrated by statistical features. In the present study, spectral analysis of ophthalmic arterial Doppler signals obtained from different subjects was performed using the AR and ARMA methods and Doppler power spectral density values which contain a significant amount of information about the signal were considered as feature vectors representing the signal. In order to reduce the dimensionality of the extracted feature vectors, statistical processes were performed over the Doppler power spectral density values and input feature vectors of multilayer perceptron neural networks used in classification were selected. Performances of the AR and ARMA methods in the analysis of Doppler signals were determined by examining performances of multilayer perceptron neural networks trained by different algorithms. Total classification accuracies of the constructed networks were demonstrated that multilayer perceptron neural network trained by Levenberg-Marquardt algorithm which used ARMA Doppler power spectral density values as inputs could be used in classification of ophthalmic arterial Doppler signals.

Purpose: To examine feasibility of phase-contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls. Methods: Sixteen patients with treated NTG and 16 age- and sex-matched healthy controls underwent PCMRI using a 3-Tesla scanner and ophthalmological examinations. OA blood flow rate was measured using a 2D PCMRI sequence with a spatial resolution of 0.35 mm(2). Results: The blood flow rate in the NTG group was 9.6 +/- 3.9 ml/min [mean +/- SD] compared with 11.9 +/- 4.8 ml/min in the control group. Resistance Index (RI) and Pulsatility Index (PI) were 0.73 +/- 0.08 and 1.36 +/- 0.29, respectively, in the NTG group and 0.68 +/- 0.13 and 1.22 +/- 0.40, respectively, in the healthy group. The mean visual field index (VFI) was 46% +/- 25 for the worse NTG eyes. The measured differences observed between the NTG group and the control group in blood flow rate (p = 0.12), RI (p = 0.18) and PI (p = 0.27) were non-significant. Conclusions: This case-control study, using PCMRI, showed a slight, but non-significant, reduction in OA blood flow rate in the NTG patients compared with the healthy controls. These results indicate that blood flow may be of importance in the pathogenesis of NTG. Considering that only a limited portion of the total OA blood flow supplies the ocular system and the large inter-individual differences, a larger study or more advanced PCMRI technique might give the answer.

Purpose: To examine feasibility of phase-contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls. Methods: Sixteen patients with treated NTG and 16 age- and sex-matched healthy controls underwent PCMRI using a 3-Tesla scanner and ophthalmological examinations. OA blood flow rate was measured using a 2D PCMRI sequence with a spatial resolution of 0.35 mm(2). Results: The blood flow rate in the NTG group was 9.6 +/- 3.9 ml/min [mean +/- SD] compared with 11.9 +/- 4.8 ml/min in the control group. Resistance Index (RI) and Pulsatility Index (PI) were 0.73 +/- 0.08 and 1.36 +/- 0.29, respectively, in the NTG group and 0.68 +/- 0.13 and 1.22 +/- 0.40, respectively, in the healthy group. The mean visual field index (VFI) was 46% +/- 25 for the worse NTG eyes. The measured differences observed between the NTG group and the control group in blood flow rate (p = 0.12), RI (p = 0.18) and PI (p = 0.27) were non-significant. Conclusions: This case-control study, using PCMRI, showed a slight, but non-significant, reduction in OA blood flow rate in the NTG patients compared with the healthy controls. These results indicate that blood flow may be of importance in the pathogenesis of NTG. Considering that only a limited portion of the total OA blood flow supplies the ocular system and the large inter-individual differences, a larger study or more advanced PCMRI technique might give the answer.

PURPOSE: To investigate if decrease of IOP affects the volumetric blood flow rate in the ophthalmic artery (OA) in patients with previously untreated ocular hypertension. METHODS: Subjects with untreated ocular hypertension (n = 30; mean age 67 +/- 8 years; 14 females) underwent ophthalmologic examination and a 3-Tesla magnetic resonance imaging investigation. The magnetic resonance imaging included three-dimensional high-resolution phase-contrast magnetic resonance imaging to measure the OA blood flow rate. The subjects received latanoprost once daily in the eye with higher pressure, the untreated eye served as control. The same measurements were repeated approximately 1 week later. RESULTS: The mean OA blood flow rate before and after treatment was 12.4 +/- 4.4 and 12.4 +/- 4.6 mL/min in the treated eye (mean +/- SD; P = 0.92) and 13.5 +/- 5.2 and 13.4 +/- 4.1 mL/min in the control eye (P = 0.92). There was no significant difference between the treated and control eye regarding blood flow rate before (P = 0.13) or after treatment (P = 0.18), or change in blood flow rate after treatment (0.1 +/- 3.1 vs.-0.1 +/- 4.0 mL/min, P = 0.84). Latanoprost decreased the IOP by 7.2 +/- 3.1 mm Hg in the treated eye (P < 0.01). CONCLUSIONS: The results indicate that a significant lowering of IOP does not affect the blood flow rate of the OA in ocular hypertension subjects. The ability to maintain blood supply to the eye independent of the IOP could be a protective mechanism in preserving vision in subjects with ocular hypertension.

Purpose: To examine feasibility of phase-contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls. Methods: Sixteen patients with treated NTG and 16 age- and sex-matched healthy controls underwent PCMRI using a 3-Tesla scanner and ophthalmological examinations. OA blood flow rate was measured using a 2D PCMRI sequence with a spatial resolution of 0.35 mm(2). Results: The blood flow rate in the NTG group was 9.6 +/- 3.9 ml/min [mean +/- SD] compared with 11.9 +/- 4.8 ml/min in the control group. Resistance Index (RI) and Pulsatility Index (PI) were 0.73 +/- 0.08 and 1.36 +/- 0.29, respectively, in the NTG group and 0.68 +/- 0.13 and 1.22 +/- 0.40, respectively, in the healthy group. The mean visual field index (VFI) was 46% +/- 25 for the worse NTG eyes. The measured differences observed between the NTG group and the control group in blood flow rate (p = 0.12), RI (p = 0.18) and PI (p = 0.27) were non-significant. Conclusions: This case-control study, using PCMRI, showed a slight, but non-significant, reduction in OA blood flow rate in the NTG patients compared with the healthy controls. These results indicate that blood flow may be of importance in the pathogenesis of NTG. Considering that only a limited portion of the total OA blood flow supplies the ocular system and the large inter-individual differences, a larger study or more advanced PCMRI technique might give the answer.

PURPOSE: To investigate if decrease of IOP affects the volumetric blood flow rate in the ophthalmic artery (OA) in patients with previously untreated ocular hypertension. METHODS: Subjects with untreated ocular hypertension (n = 30; mean age 67 +/- 8 years; 14 females) underwent ophthalmologic examination and a 3-Tesla magnetic resonance imaging investigation. The magnetic resonance imaging included three-dimensional high-resolution phase-contrast magnetic resonance imaging to measure the OA blood flow rate. The subjects received latanoprost once daily in the eye with higher pressure, the untreated eye served as control. The same measurements were repeated approximately 1 week later. RESULTS: The mean OA blood flow rate before and after treatment was 12.4 +/- 4.4 and 12.4 +/- 4.6 mL/min in the treated eye (mean +/- SD; P = 0.92) and 13.5 +/- 5.2 and 13.4 +/- 4.1 mL/min in the control eye (P = 0.92). There was no significant difference between the treated and control eye regarding blood flow rate before (P = 0.13) or after treatment (P = 0.18), or change in blood flow rate after treatment (0.1 +/- 3.1 vs.-0.1 +/- 4.0 mL/min, P = 0.84). Latanoprost decreased the IOP by 7.2 +/- 3.1 mm Hg in the treated eye (P < 0.01). CONCLUSIONS: The results indicate that a significant lowering of IOP does not affect the blood flow rate of the OA in ocular hypertension subjects. The ability to maintain blood supply to the eye independent of the IOP could be a protective mechanism in preserving vision in subjects with ocular hypertension.

Purpose: To examine feasibility of phase-contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls. Methods: Sixteen patients with treated NTG and 16 age- and sex-matched healthy controls underwent PCMRI using a 3-Tesla scanner and ophthalmological examinations. OA blood flow rate was measured using a 2D PCMRI sequence with a spatial resolution of 0.35 mm(2). Results: The blood flow rate in the NTG group was 9.6 +/- 3.9 ml/min [mean +/- SD] compared with 11.9 +/- 4.8 ml/min in the control group. Resistance Index (RI) and Pulsatility Index (PI) were 0.73 +/- 0.08 and 1.36 +/- 0.29, respectively, in the NTG group and 0.68 +/- 0.13 and 1.22 +/- 0.40, respectively, in the healthy group. The mean visual field index (VFI) was 46% +/- 25 for the worse NTG eyes. The measured differences observed between the NTG group and the control group in blood flow rate (p = 0.12), RI (p = 0.18) and PI (p = 0.27) were non-significant. Conclusions: This case-control study, using PCMRI, showed a slight, but non-significant, reduction in OA blood flow rate in the NTG patients compared with the healthy controls. These results indicate that blood flow may be of importance in the pathogenesis of NTG. Considering that only a limited portion of the total OA blood flow supplies the ocular system and the large inter-individual differences, a larger study or more advanced PCMRI technique might give the answer.

PURPOSE: To investigate if decrease of IOP affects the volumetric blood flow rate in the ophthalmic artery (OA) in patients with previously untreated ocular hypertension. METHODS: Subjects with untreated ocular hypertension (n = 30; mean age 67 +/- 8 years; 14 females) underwent ophthalmologic examination and a 3-Tesla magnetic resonance imaging investigation. The magnetic resonance imaging included three-dimensional high-resolution phase-contrast magnetic resonance imaging to measure the OA blood flow rate. The subjects received latanoprost once daily in the eye with higher pressure, the untreated eye served as control. The same measurements were repeated approximately 1 week later. RESULTS: The mean OA blood flow rate before and after treatment was 12.4 +/- 4.4 and 12.4 +/- 4.6 mL/min in the treated eye (mean +/- SD; P = 0.92) and 13.5 +/- 5.2 and 13.4 +/- 4.1 mL/min in the control eye (P = 0.92). There was no significant difference between the treated and control eye regarding blood flow rate before (P = 0.13) or after treatment (P = 0.18), or change in blood flow rate after treatment (0.1 +/- 3.1 vs.-0.1 +/- 4.0 mL/min, P = 0.84). Latanoprost decreased the IOP by 7.2 +/- 3.1 mm Hg in the treated eye (P < 0.01). CONCLUSIONS: The results indicate that a significant lowering of IOP does not affect the blood flow rate of the OA in ocular hypertension subjects. The ability to maintain blood supply to the eye independent of the IOP could be a protective mechanism in preserving vision in subjects with ocular hypertension.

Purpose: To examine feasibility of phase-contrast magnetic resonance imaging (PCMRI) and to assess blood flow rate in the ophthalmic artery (OA) in patients with normal tension glaucoma (NTG) compared with healthy controls. Methods: Sixteen patients with treated NTG and 16 age- and sex-matched healthy controls underwent PCMRI using a 3-Tesla scanner and ophthalmological examinations. OA blood flow rate was measured using a 2D PCMRI sequence with a spatial resolution of 0.35 mm(2). Results: The blood flow rate in the NTG group was 9.6 +/- 3.9 ml/min [mean +/- SD] compared with 11.9 +/- 4.8 ml/min in the control group. Resistance Index (RI) and Pulsatility Index (PI) were 0.73 +/- 0.08 and 1.36 +/- 0.29, respectively, in the NTG group and 0.68 +/- 0.13 and 1.22 +/- 0.40, respectively, in the healthy group. The mean visual field index (VFI) was 46% +/- 25 for the worse NTG eyes. The measured differences observed between the NTG group and the control group in blood flow rate (p = 0.12), RI (p = 0.18) and PI (p = 0.27) were non-significant. Conclusions: This case-control study, using PCMRI, showed a slight, but non-significant, reduction in OA blood flow rate in the NTG patients compared with the healthy controls. These results indicate that blood flow may be of importance in the pathogenesis of NTG. Considering that only a limited portion of the total OA blood flow supplies the ocular system and the large inter-individual differences, a larger study or more advanced PCMRI technique might give the answer.

PURPOSE: To investigate if decrease of IOP affects the volumetric blood flow rate in the ophthalmic artery (OA) in patients with previously untreated ocular hypertension. METHODS: Subjects with untreated ocular hypertension (n = 30; mean age 67 +/- 8 years; 14 females) underwent ophthalmologic examination and a 3-Tesla magnetic resonance imaging investigation. The magnetic resonance imaging included three-dimensional high-resolution phase-contrast magnetic resonance imaging to measure the OA blood flow rate. The subjects received latanoprost once daily in the eye with higher pressure, the untreated eye served as control. The same measurements were repeated approximately 1 week later. RESULTS: The mean OA blood flow rate before and after treatment was 12.4 +/- 4.4 and 12.4 +/- 4.6 mL/min in the treated eye (mean +/- SD; P = 0.92) and 13.5 +/- 5.2 and 13.4 +/- 4.1 mL/min in the control eye (P = 0.92). There was no significant difference between the treated and control eye regarding blood flow rate before (P = 0.13) or after treatment (P = 0.18), or change in blood flow rate after treatment (0.1 +/- 3.1 vs.-0.1 +/- 4.0 mL/min, P = 0.84). Latanoprost decreased the IOP by 7.2 +/- 3.1 mm Hg in the treated eye (P < 0.01). CONCLUSIONS: The results indicate that a significant lowering of IOP does not affect the blood flow rate of the OA in ocular hypertension subjects. The ability to maintain blood supply to the eye independent of the IOP could be a protective mechanism in preserving vision in subjects with ocular hypertension.

PURPOSE: To investigate if decrease of IOP affects the volumetric blood flow rate in the ophthalmic artery (OA) in patients with previously untreated ocular hypertension. METHODS: Subjects with untreated ocular hypertension (n = 30; mean age 67 +/- 8 years; 14 females) underwent ophthalmologic examination and a 3-Tesla magnetic resonance imaging investigation. The magnetic resonance imaging included three-dimensional high-resolution phase-contrast magnetic resonance imaging to measure the OA blood flow rate. The subjects received latanoprost once daily in the eye with higher pressure, the untreated eye served as control. The same measurements were repeated approximately 1 week later. RESULTS: The mean OA blood flow rate before and after treatment was 12.4 +/- 4.4 and 12.4 +/- 4.6 mL/min in the treated eye (mean +/- SD; P = 0.92) and 13.5 +/- 5.2 and 13.4 +/- 4.1 mL/min in the control eye (P = 0.92). There was no significant difference between the treated and control eye regarding blood flow rate before (P = 0.13) or after treatment (P = 0.18), or change in blood flow rate after treatment (0.1 +/- 3.1 vs.-0.1 +/- 4.0 mL/min, P = 0.84). Latanoprost decreased the IOP by 7.2 +/- 3.1 mm Hg in the treated eye (P < 0.01). CONCLUSIONS: The results indicate that a significant lowering of IOP does not affect the blood flow rate of the OA in ocular hypertension subjects. The ability to maintain blood supply to the eye independent of the IOP could be a protective mechanism in preserving vision in subjects with ocular hypertension.

Measurement of intracranial pressure (ICP) is necessary in many neurological and neurosurgical diseases. To avoid lumbar puncture or intracranial ICP probes, non-invasive ICP techniques are becoming popular. A recently developed technology uses two-depth Doppler to compare arterial pulsations in the intra- and extra-cranial segments of the ophthalmic artery for non-invasive estimation of ICP. The aim of this study was to investigate how well non-invasively-measured ICP and invasively-measured cerebrospinal fluid (CSF) pressure correlate. We performed multiple measurements over a wide ICP span in eighteen elderly patients with communicating hydrocephalus. As a reference, an automatic CSF infusion apparatus was connected to the lumbar space. Ringer's solution was used to create elevation to pre-defined ICP levels. Bench tests of the infusion apparatus showed a random error (95 % CI) of less than ±0.9 mmHg and a systematic error of less than ±0.5 mmHg. Reliable Doppler signals were obtained in 13 (72 %) patients. An infusion test could not be performed in one patient. Thus, twelve patients and a total of 61 paired data points were studied. The correlation between invasive and non-invasive ICP measurements was good (R = 0.74), and the 95 % limits of agreements were -1.4 ± 8.8 mmHg. The within-patient correlation varied between 0.47 and 1.00. This non-invasive technique is promising, and these results encourage further development and evaluation before the method can be recommended for use in clinical practice.

English: The human orbit contains various important structures that may show variations relating to their anatomy. This study focused on the intraorbital part of the ophthalmic artery in a South African cadaver sample in the Free State (UFS) and Western Cape provinces (UCT). Meyer pioneered the study of the ophthalmic artery as far back as 1887, with a main focus on its branches and their variations. Very limited investigation has been carried out in this field and available literature has little information on this. Currently no published data exists on the South African population with regard to intraorbital variations within the ophthalmic artery and its branches. Original research was conducted to address the problem of the lack of data. Dissections of the eyes were done to investigate and document the possible variations of the intraorbital part of the ophthalmic artery and its branches. The aim of the study was to determine the prevalence of anatomical variations in the intraorbital part of the ophthalmic artery and its branches in a cadaver sample. The results of the study will be of value to surgical interventionists treating patients with vascular diseases within the orbital region and also to the ophthalmology students studying the orbital vascular anatomy. A total number of 59 cadavers were utilised, and 118 eyes were dissected under the lighted magnifier and observed for variations. The sample consisted of 23 cadavers (46 eyes) from the Department of Basic Medical Sciences of the University of the Free State, and 36 cadavers (72 eyes) from the Department of Human Biology of the University of Cape Town. Sixteen types of variations were observed and documented. The ophthalmic artery crossed below the optic nerve in the left eye in 7.63% of cadavers at both institutions. No ophthalmic artery crossed below the optic nerve in the right eye in the UCT group, whereas 17.39% in the UFS group crossed below the optic nerve. Statistical analyses determined the freq, Afrikaans: Die menslike oog bevat verskeie belangrike strukture wat moontlik variasies kan toon wat verband hou met hul anatomie. Hierdie studie fokus op die intraorbitale deel van die oftalmiese arterie in ʼn Suid-Afrikaanse kadawersteekproef in die Vrystaat (UV) en die Wes- Kaapse (UCT) provinsies. Meyer was alreeds in 1887 die voorloper van studies van die oftalmiese arterie en het veral gefokus op die vertakkings en hul variasies. Slegs beperkte ondersoeke op hierdie terrein is gedoen en beskikbare literatuur bevat min inligting oor die onderwerp. Tans is daar geen gepubliseerde data beskikbaar oor die Suid-Afrikaanse bevolking met betrekking tot intraorbitale variasies binne die oftalmiese arterie en sy vertakkings nie. Oorspronklike navorsing is gedoen om die probleem van die gebrek aan data aan te spreek. Disseksies van die oog is uitgevoer om die moontlike variasies van die intraorbitale deel van die oftalmiese arterie en sy vertakkings te ondersoek en te dokumenteer. Die doel van die studie was om die voorkoms van anatomiese variasies in die intraorbitale deel van die oftalmiese arterie en sy vertakkings in ’n kadawersteekproef te bepaal. Die resultate van die studie sal waardevol wees vir chirurge wat intervensies doen op pasiënte met vaskulêre siektetoestande binne die orbit en ook vir oftalmologiestudente wat die anatomie van die orbit bestudeer. In totaal is 59 kadawers bestudeer en 118 oë is gedissekteer onder ’n verligte vergrootglas, en die variasies is waargeneem. Die steekproef het bestaan uit 23 kadawers (46 oë) van die Departement Basiese Mediese Wetenskappe van die Universiteit van die Vrystaat (UV) en 36 kadawers (72 oë) van die Departement van Mensbiologie van die Universiteit van Kaapstad (UCT). Sestien tipes variasies is waargeneem en gedokumenteer. Die oftalmiese arterie van die linkeroog het in 7.63% van kadawers van beide instansies die optiese senuwee onder gekruis. Geen oftalmiese arterie het onder die optiese senuwee in die regteroog ge, UFS (M) Research Bursary 2016, DHET through nGAP, National Research Foundation (NRF), UFS Health Sciences Bursary 2016

The ophthalmic artery has an anomalous origin in 2–3 % of cases and rarely arises from the anterior cerebral artery. Herein, we provide the first anatomical, radiological, and histological description of such an anomalous origin, together with a literature review. During the anatomical dissection of an 81-year-old Caucasian male, the absence of the right ophthalmic artery in its usual location was evident from an endonasal transsphenoidal perspective. The specimen was then studied in detail, through multiple dissections, corrosion casting, high-resolution CT, and histological analysis. The English literature on anomalous origins of the ophthalmic artery was reviewed, together with reported associated pathologies. Anatomo-radiological analysis documented that the right ophthalmic artery arose from the inferior surface of A1 tract of the anterior cerebral artery (A1) and passed over the optic nerve in its subarachnoid tract. A meningo-ophthalmic artery was evident on the same side and reached the orbit through the superior orbital fissure. Histological examination of both internal carotid artery (ICA) walls documented a significantly decreased thickness of the tunica media and adventitia on the side of the anomalous ophthalmic artery, with a significantly different content of collagen types I and III. The literature review documented an association of aneurysms and anomalous ophthalmic arteries. To the best of our knowledge, this is the first anatomical report that includes a radiological and arterial wall analysis of a persistent ventral ophthalmic artery. The latter provides histological data that support the clinical evidence of a higher association of aneurysms with anomalous origins of the ophthalmic artery.

A 39-year-old woman presented with left visual disturbance and diplopia. Magnetic resonance imaging revealed a well-enhanced tumor in the left tentorium, cavernous sinus, and suprasellar region. Angiography demonstrated an abnormal origin of the ophthalmic artery from the anterior cerebral artery. The tumor was partially removed by left frontotemporal craniotomy with orbitozygomatic osteotomy. Intraoperatively, the anomalous origin of the ophthalmic artery was confirmed. This anatomical variation is extremely rare.

A 12-month-old boy with a history of bilateral retinoblastoma refractory to systemic chemotherapy, laser therapy and cryotherapy, with excellent response to previous intra-arterial melphalan infusion, presents with active tumour deposits in the right eye. Repeat intra-arterial chemotherapy was recommended. Previous bilateral melphalan infusion was uneventful using flow-guided catheterisation technique. Direct catheterisation of the right ophthalmic artery was unsuccessful despite employment of several flow-guided and over-the-wire catheters. Superselective catheterisation of the ipsilateral middle meningeal artery was unable to identify an anastomotic connection to the ophthalmic artery; however, angiography of the anterior deep temporal artery identified an alternate route for chemotherapy infusion. The anterior deep temporal artery was successfully and safely catheterised to infuse chemotherapy into the ophthalmic artery. The anterior deep temporal artery is an important potential anastomotic connection to the ophthalmic artery that can be used safely and effectively for central retinal artery chemotherapy infusion for retinoblastoma treatment.

PURPOSE: Recent development of magnetic resonance imaging (MRI) offers new possibilities to assess ocular blood flow. This prospective study evaluates the feasibility of phase-contrast MRI (PCMRI) to measure flow rate in the ophthalmic artery (OA) and establish reference values in healthy young (HY) and elderly (HE) subjects. METHODS: Fifty HY subjects (28 females, 21-30 years of age) and 44 HE (23 females, 64-80 years of age) were scanned on a 3-Tesla MR system. The PCMRI sequence had a spatial resolution of 0.35 mm per pixel, with the measurement plan placed perpendicularly to the OA. Mean flow rate (Qmean), resistive index (RI), and arterial volume pulsatility of OA (ΔVmax) were measured from the flow rate curve. Accuracy of PCMRI measures was investigated using a vessel-phantom mimicking the diameter and the flow rate range of the human OA. RESULTS: Flow rate could be assessed in 97% of the OAs. Phantom investigations showed good agreement between the reference and PCMRI measurements with an error of <7%. No statistical difference was found in Qmean between HY and HE individuals (HY: mean ± SD = 10.37 ± 4.45 mL/min; HE: 10.81 ± 5.15 mL/min, P = 0.655). The mean of ΔVmax (HY: 18.70 ± 7.24 μL; HE: 26.27 ± 12.59 μL, P < 0.001) and RI (HY: 0.62 ± 0.08; HE: 0.67 ± 0.1, P = 0.012) were significantly different between HY and HE. CONCLUSIONS: This study demonstrated that the flow rate of OA can be quantified using PCMRI. There was an age difference in the pulsatility parameters; however, the mean flow rate appeared independent of age. The primary difference in flow curves between HE and HY was in the relaxation phase of the systolic peak.

IntroductionStudies have reported a correlation between blood flow dynamics in the cardiac cycle and vascular diseases, but research to analyze the dynamic changes of flow in cerebral aneurysms is limited. This quantitative study investigates the temporal changes in flow during a cardiac cycle (flow waveform) in different regions of aneurysms and their association with aneurysm rupture.MethodsTwelve ruptured and 29 unruptured aneurysms from the internal carotid artery-ophthalmic artery segment were studied. Patient-specific aneurysm data were implemented to simulate blood flow. The temporal flow changes at different regions of the aneurysm were recorded to compare the flow waveforms.ResultsIn more than 60 % of the cases, peak flow in the aneurysm sac occurred after peak flow in the artery. Flow rate varied among cases and no correlation with rupture, aneurysm flow rate, and aneurysm size was found. Higher pulsatility within aneurysm sacs was found when comparing with the parent artery (P < 0.001). Pulsatility was high throughout ruptured aneurysms, but increased from neck to dome in unruptured ones (P = 0.021). Significant changes between inflow and outflow flow profile were found in unruptured aneurysms (P = 0.023), but not in ruptured aneurysms.ConclusionQuantitative analysis which considers temporal blood flow changes appears to provide additional information which is not apparent from aneurysmal flow at a single time point (i.e., peak of systole). By considering the flow waveform throughout the cardiac cycle, statistically significant differences were found between ruptured and unruptured cases - for flow profile, pulsatility and timing of peak flow.

IntroductionStudies have reported a correlation between blood flow dynamics in the cardiac cycle and vascular diseases, but research to analyze the dynamic changes of flow in cerebral aneurysms is limited. This quantitative study investigates the temporal changes in flow during a cardiac cycle (flow waveform) in different regions of aneurysms and their association with aneurysm rupture.MethodsTwelve ruptured and 29 unruptured aneurysms from the internal carotid artery-ophthalmic artery segment were studied. Patient-specific aneurysm data were implemented to simulate blood flow. The temporal flow changes at different regions of the aneurysm were recorded to compare the flow waveforms.ResultsIn more than 60 % of the cases, peak flow in the aneurysm sac occurred after peak flow in the artery. Flow rate varied among cases and no correlation with rupture, aneurysm flow rate, and aneurysm size was found. Higher pulsatility within aneurysm sacs was found when comparing with the parent artery (P < 0.001). Pulsatility was high throughout ruptured aneurysms, but increased from neck to dome in unruptured ones (P = 0.021). Significant changes between inflow and outflow flow profile were found in unruptured aneurysms (P = 0.023), but not in ruptured aneurysms.ConclusionQuantitative analysis which considers temporal blood flow changes appears to provide additional information which is not apparent from aneurysmal flow at a single time point (i.e., peak of systole). By considering the flow waveform throughout the cardiac cycle, statistically significant differences were found between ruptured and unruptured cases - for flow profile, pulsatility and timing of peak flow.

Pseudomonas aeruginosa meningitis is an uncommon complication of neurosurgical procedures or head trauma. Here, a case of infectious mid basilar artery aneurysm from Pseudomonas meningitis, and its angiographic remission from timely antibiotic therapy, is reported.

The present report describes a case of variation of the ophthalmic artery observed in a 90-year-old Japanese female at dissection in 1988. It was found that on one side, the ophthalmic artery originated as two branches of unequal size, the smaller arising from the internal carotid artery and the larger from the middle meningeal artery, with the latter entering the orbit through a special incisure.

The present report describes a case of variation of the ophthalmic artery observed in a 90-year-old Japanese female at dissection in 1988. It was found that on one side, the ophthalmic artery originated as two branches of unequal size, the smaller arising from the internal carotid artery and the larger from the middle meningeal artery, with the latter entering the orbit through a special incisure.

Pseudomonas aeruginosa meningitis is an uncommon complication of neurosurgical procedures or head trauma. Here, a case of infectious mid basilar artery aneurysm from Pseudomonas meningitis, and its angiographic remission from timely antibiotic therapy, is reported.

The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia.

The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia.

脳血管障害に対する超音波診断には,主に頚部血管超音波検査法,経眼窩超音波検査法,経頭蓋超音波検査法がある。頚部血管超音波検査では,Bモード断層法,カラードプラ法,ドプラ血流速度計測法があり,1.頚動脈内膜一中膜肥厚,2.プラークの存在及び性状,3.狭窄度,4.血流情報を評価する。経眼窩超音波検査では,眼動脈,網膜中心動脈,上眼静脈などが観察可能だが,閉塞性内頚動脈病変での眼動脈血流の血流方向,血流波形,収縮期最大流速を主に評価する。経頭蓋超音波検査法では頭蓋内のWillis輪周辺の構造,血流の観察が可能である。脳血管障害における超音波検査は非侵襲的に繰り返し,簡便に行えるので,頚動脈閉塞性病変の高精度なスクリーニング検査法としても優れているだけでなく,外科的治療や保存的治療例 での治療経過の観察にも有用な検査法である。

In four large, 15-25 mm, internal carotid artery aneurysms (3 intracavernous and 1 carotid ophthalmic), treatment by common carotid ligation was preferred. Pre- and postoperative MRI were obtained, at a delay between 5 to 9 years. Recovery of the ocular and visual symptomatology was a function of the role played by mechanical and/or ischaemic factors. No early or late consequences, ascribable to the common carotid ligation, were observed. Aneurysmal thrombosis occurred in the first postoperative week, but retraction of the thrombosed aneurysms was only obvious and maximal after several months. For this reason, rapid clinical recovery could be due, in the first instance, to the loss of aneurysmal pulsatility. Complete disappearance of the aneurysm was observed in two cases. In the other two, a small remnant of the initial lesion, without any unfavourable consequences, was revealed, respectively 6 and 9 years after the intervention, by current, modern-days, MRA.

To obtain standard values of blood flow velocity in the ophthalmic artery and central retinal artery in the neonatal period and to compare blood flow velocity of orbital vessels with that of the anterior cerebral artery and middle cerebral artery.