Resistive Index Of Ophthalmic Artery Research Articles

Color Doppler imaging in thyroid eye disease and its correlation to disease activity

ABSTRACTPurpose: To evaluate alterations in orbital color Doppler imaging (CDI) parameters and their correlation to disease activity and severity in patients with thyroid eye disease (TED).Methods: Seventy-six orbits of 45 TED patients and 40 orbits of 40 normal controls were enrolled in this cross-sectional study. According to clinical activity score (CAS), patients were categorized to active (CAS ≥ 3) or inactive disease (CAS < 3). Patients were also classified as having mild, moderate or severe disease. Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) in ophthalmic artery and central retinal artery, and maximum and minimum velocity in superior ophthalmic vein and central retinal vein were determined in all subjects.Results: There was a significant difference in maximum velocity of superior ophthalmic vein and EDV and RI of ophthalmic artery between patients with TED and normal subjects. Superior ophthalmic vein maximum and minimum velocity and ophthalmic artery RI were significantly higher in patients with active disease than inactive cases. Disease severity did not affect the blood flow parameters independently. A cutoff point of 3.99 cm/s in superior ophthalmic vein maximum velocity yielded a sensitivity of 91.2% and specificity of 81.2% in detecting active disease.Conclusion: Retrobulbar blood flow is altered in TED and is related to disease activity. Superior ophthalmic vein maximum velocity could be helpful in differentiation of active and inactive cases.

Ocular findings and blood flow in patients with Takayasu arteritis: a cross-sectional study

Background/aimsTakayasu arteritis (TAK) is a chronic granulomatous vasculitis that can lead to ischaemic ocular complications. We aimed to document ocular complications, ocular blood flow and the association of them with...

Resistive index of ophthalmic artery correlates with retinal pigment epithelial alterations on spectral domain optical coherence tomography in diabetic retinopathy

BackgroundRetinal pigment epithelium (RPE) plays a significant role in maintenance of integrity of retinal photoreceptors and choriocapillaries. RPE derives its blood supply through ophthalmic artery (OA) via choriocapillaries. RPE topographic alterations have been observed to be associated with severity of retinopathy. The present study was undertaken to assess the correlation between resistive index (RI) of the OA with RPE topographic alterations on Spectral-Domain optical coherence tomography (SD-OCT), to our knowledge, it is for the first time.MethodsA tertiary care center based cross-sectional study was undertaken after informed consent. Sample size was calculated using 95% confidence interval. Seventy five consecutive cases of type 2 diabetes mellitus between the ages of 40 and 70 years were included. The cases were divided into three groups according to Early Treatment Diabetic Retinopathy Study classification: diabetes mellitus with no retinopathy (No DR) (n = 24); non-proliferative diabetic retinopathy (n = 27); and proliferative diabetic retinopathy (n = 24). Healthy control subjects of similar age group were included (n = 24). RI in OA was studied using Color Doppler imaging. Grades of RPE topographic alterations and retinal photoreceptor ellipsoid zone (EZ) disruption were studied using SD-OCT. Data was analysed using Chi square (χ2) test, analysis of variance (ANOVA), Pearson correlation analysis and Neuman–Keuls test.ResultsLogMAR best corrected visual acuity was found to increase significantly with the severity of DR (F = 105.74, p < 0.001). ANOVA revealed a significant increase in RI of OA (F = 14.23, p < 0.001) with severity of diabetic retinopathy. χ2 test revealed significant increase in grades of RPE alterations (χ2 = 71.83, p < 0.001) and EZ disruption (χ2 = 60.59, p < 0.001) with the severity of diabetic retinopathy. Pearson correlation analyses revealed a significant positive correlation between RI of OA with grades of RPE alterations (r = 0.48, p < 0.001) and also between grades of RPE alterations and EZ disruption (r = 0.82, p < 0.001).ConclusionsDecrease in ocular blood flow resulting from an increase in RI of OA correlates with severity of DR and grades of topographic alterations in RPE. Integrity of EZ was observed to be dependent on RPE.

The relation between retrobulbar blood flow and posterior ocular changes measured using spectral-domain optical coherence tomography in patients with obstructive sleep apnea syndrome.

To investigate the effect of posterior ocular hemodynamics on the retinal nerve fiber layer (RNFL), choroid thickness (CT) and central macular thickness (CMT) in patients with obstructive sleep apnea syndrome (OSAS) and to reveal the association with glaucomatous optic neuropathy. The research was planned as a prospective, randomized study. The ophthalmic, retinal and posterior ciliary artery pulsatile index (PI) and resistive index (RI) were measured by colored Doppler sonography. RNFL thickness, CMT and CT were then measured by spectral-domain optical coherence tomography. Sixty subjects were divided into four groups-mild, moderate and severe OSAS and a control group. There were 16 subjects in the control group, 14 in the mild OSAS group, 15 in the moderate OSAS group and 15 in the severe OSAS group. Ophthalmic artery and central retinal artery PI and RI values of the OSAS patients did not show statistically significant difference than those of the control group, but posterior ciliary artery (PCA) PI and RI values were significantly higher. In addition, mean, superior and inferior RNFL thickness values were significantly lower than those in the control group. Moreover, the glaucoma prevalence of the OSAS patients in this study was 6.8% and all of these patients were in the severe OSAS group. PI and RI values of the PCA, which supplies the optic nerve, show a linear increase as the apnea hypoxia index values in OSAS. As the grade of OSAS improves, this situation leads to a more serious ischemic optic neuropathy. Furthermore, the prevalence of glaucoma in this study is found to be higher in the severe OSAS group.

Advanced vascular exams improve the accuracy of conventional parameters in distinguishing normal tension from primary open angle glaucoma

PurposeThe role vascular factors play in glaucoma is still not fully understood. We aim to understand if advanced vascular exams can improve our ability to distinguish primary open angle glaucoma (POAG) from normal tension glaucoma (NTG) patients.MethodsWe applied multivariate logistic regression on the Leuven Eye Study data (182 NTG and 202 POAG patients), and created three prediction models. One with conventional parameters, one with parameters from advanced vascular exams [colour Doppler imaging (CDI), retinal oximetry, ocular pulse amplitude and choroidal thickness] and one where both kinds of parameters were allowed in (mixed). The area under the curve (AUC) was calculated and compared between them. Intra‐ocular pressure (IOP) and IOP‐related variables were excluded.ResultsThe conventional model included Raynaud phenomenon, mean arterial pressure (MAP), central corneal thickness, migraine, visual field mean deviation (VF MD), cup‐disc (C/D) ratio, visual acuity and mean retinal nerve fiber layer (mRNFL) thickness (in decreasing order of importance). The advanced vascular model included parameters from CDI and retinal oximetry. The mixed model included Raynaud phenomenon, MAP, arterio‐venous retinal oxygen saturation difference, acceleration (acc) of central retinal artery (CRA), end‐diastolic velocity of CRA, resistive index of ophthalmic artery, VF MD, C/D ratio, mRNFL thickness, acc of temporal posterior ciliary artery and migraine (in decreasing order of importance). The AUCs were 0.687, 0.677 and 0.743, respectively. The mixed model was able to significantly increase the prediction ability of the conventional model (p = 0.049).ConclusionsAdding advanced vascular exams increased the accuracy of the conventional model to distinguish between groups. These results show how important vascular factors can be in the pathogenesis of glaucoma.

Resistive Index of Ophthalmic Artery as a Bioimaging Biomarker for the Severity of Diabetic Retinopathy

Objective: To assess the resistive index (RI) of ophthalmic artery (OA) and central retinal artery (CRA) as a bioimaging biomarker for the severity of diabetic retinopathy, for the first time. Design: Tertiary care center based cross sectional study. Setting: RI in OA and CRA was studied using color Doppler and gray scale sonography. Central Subfield Thickness (CST), Cube Average Thickness (CAT), retinal photoreceptor ellipsoid zone (EZ) disruption, and Retinal Nerve Fiber Layer (RNFL) thickness were studied using SD-OCT. Participants: Sample size was calculated using 95% confidence interval. 69 consecutive cases of type 2 diabetes mellitus between the ages of 40 and 70 years were included after informed consent. According to Early Treatment Diabetic Retinopathy Study (ETDRS) classification cases were grouped as: diabetes mellitus with no retinopathy (No DR) (n=22); non-proliferative diabetic retinopathy (NPDR) (n=25); and Proliferative Diabetic Retinopathy (PDR) (n=22). Healthy control subjects of similar age were included (n=22). Main outcome measures: RI in OA and CRA. Results: A significant increase in RI of OA and CRA was observed with increased severity of DR. A significant positive correlation of RI of OA and CRA with CST, CAT and grades of EZ disruption and a negative correlation with RNFL thickness was observed. RI of OA was found to be a significant independent predictor of severity of DR [multivariate analysis OR=0.00, p<0.001; area under receiver operating characteristic curve analysis=0.941-1.000, p<0.001]. Conclusions: Resistive index of OA is a bio imaging biomarker for the severity of DR.

Ocular blood flow and cerebrospinal fluid pressure in glaucoma.

Disease mechanism underlying glaucoma remains unclear. Extensive research on this pathology has highlighted changes in vascular parameters and in circulation of the cerebrospinal fluid (CSF). Here, we review the most recent research on alterations in ocular blood flow and/or CSF flow in glaucoma. Ultrasound Doppler imaging studies have shown an increased resistive index in ophthalmic artery’s in glaucoma. Furthermore, changes in optic nerve CSF circulation, which can be assessed with magnetic resonance imaging, may lead to a greater translaminar pressure difference, mechanical stress, and poor clearance of toxic substances. This constitutes a new approach for understanding blood–CSF interactions involved in glaucoma.

Ophthalmic Artery Blood Flow Parameters in Pseudoexfoliation Glaucoma

To investigate orbital flow parameters of ophthalmic artery (OA) in patients with pseudoexfoliation glaucoma (XFG) by ultrasonography. This case-control study included 38 patients with XFG and 32 healthy control subjects. Color Doppler imaging was performed to evaluate orbital flow parameters of OA. Receiver operating characteristic analyses were performed to define the best cutoff value. In the XFG group, decreased peak systolic velocity (p = 0.114), end diastolic velocity (p = 0.002), and increased resistivity index (RI) (p&lt;0.001) at OA compared to healthy controls were observed. A cutoff value 0.72 for OA RI was found to have a sensitivity of 66% and specificity of 94%. The results support the findings of increased vascular resistance in OA XFG. High sensitivity and specificity obtained for OA RI may be useful in evaluation of future therapeutic vascular agents.

Retrobulbar blood flow and carotid intima–media thickness alteration may relate to subclinic atherosclerosis in patients with chronic inflammatory diseases

Objective: AA amyloidosis occurs in the setting of longstanding inflammation. An increased incidence of coronary artery disease (CAD) was noted in patients with chronic inflammatory disease (CID). Retrobulbar blood flow predicts future macrovascular events including CAD. Increase in carotid artery intima–media thickness is regarded as a marker for early atherosclerosis. The relationship between chronic inflammation and atherosclerosis is well known; however, the connection between amyloidosis-advanced CIDs and retrobulbar microvascular function and carotid intima–media thickness (CIMT) is unidentified. We aimed to investigate whether retrobulbar microcirculation and CIMT were impaired or not in amyloidosis-advanced CID patients compared to normal subjects. Methods: Fourteen patients with renal AA amyloidosis and a group of healthy volunteers were included in the study. Measurement of CIMT and retrobulbar blood flow velocities was performed with ultrasound scanner and color Doppler ultrasonography. Results: The CIMT of patients with renal amyloidosis was significantly thicker than that of the normal population (p < 0.001). The resistivity index of the ophthalmic artery (OA) of patients with renal amyloidosis was significantly higher than the study group (p < 0.001). Conclusion: This study demonstrates that accelerated atherosclerosis which can be shown by increased OA resistivity index and CIMT are found in amyloidal-related CID patients.

Doppler flowmetry of ophthalmic arteries for prediction of pre-eclampsia.

central nervous system (CNS) hyperperfusion is one of the events that constitute the pathophysiological basis for the clinical manifestations and complications of pre-eclampsia (PE). Detecting the increased flow in the CNS through Doppler flowmetry of the ophthalmic artery might precede the clinical onset of PE and could be used as a marker for subsequent development of PE. to evaluate the ophthalmic artery resistive index (OARI) values in the second trimester of pregnancy for prediction of the clinical manifestations of PE. to evaluate the ophthalmic artery resistive index (OARI) values in the second trimester of pregnancy for prediction of the clinical manifestations of PE. a total of 73 patients with risk factors for the development of PE were selected from the prenatal service at the HC-UFMG. They were submitted to ophthalmic artery Doppler flowmetry between 24 and 28 weeks of pregnancy and monitored until the end of the pregnancy to verify the occurrence of PE. ROC curves were created to determine the predictive characteristics of the OARI. fourteen of the patients selected developed PE and 59 remained normotensive until the postpartum period. Patients with subsequent development of PE presented OARI values lower than patients that remained normotensive (0.682 ± 0.028 X 0.700 ± 0.029, p = 0.044). Considering the development of PE as an outcome, the area under the OARI curve was 0.694 (CI 0.543 to 0.845), with no points obtaining good values of sensitivity or specificity. Doppler flowmetry of ophthalmic arteries between 24 and 28 weeks of pregnancy did not present itself as a good exam for predicting PE.

Color Doppler Imaging Analysis of Retrobulbar Blood Flow Velocities in Diabetic Patients Without or With Retinopathy: A Meta-analysis.

To analyze hemodynamic changes in retrobulbar blood vessels using color Doppler imaging in diabetic patients without or with retinopathy. Pertinent publications were retrieved from 3 databases. Changes in peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) of the ophthalmic artery, central retinal artery, and short posterior ciliary artery of diabetic eyes without or with retinopathy and healthy controls were evaluated by color Doppler imaging. Comparisons were conducted in 3 groups: group 1, no retinopathy versus control; group 2, retinopathy versus control; and group 3, no retinopathy versus retinopathy. In group 1, eyes without retinopathy had a significant increase in ophthalmic artery PSV (P = .002), with no heterogeneity (Pheterogeneity = 0.09; inconsistency index [I(2)] = 46%); however, significant reductions in central renal artery PSV and EDV were shown (P = .002; P = .007, respectively), with significant heterogeneity (Pheterogeneity < .00001; I(2) = 85%; Pheterogeneity = .008, I(2) = 68%). A significant increase in ophthalmic artery RI (P = .02) was found in eyes without retinopathy, with heterogeneity (Pheterogeneity = .0009; I(2) = 74%). In group 2, central retinal artery PSV and EDV in eyes with retinopathy decreased significantly (P < 0.00001). Similar results were found for ophthalmic and short posterior ciliary artery EDVs (P= .0003; P< .00001). Ophthalmic artery RI was significantly higher in eyes with retinopathy than controls (P = .0008), with heterogeneity (Pheterogeneity < .00001; I(2) = 84%). In group 3, ophthalmic artery PSV was lower in eyes with retinopathy (P= .04) than eyes without, and central retinal artery PSV and EDV decreased significantly (P = .004; P < .00001) in eyes with retinopathy compared to eyes without. Differences in ophthalmic and central retinal artery RIs were also found in eyes with retinopathy (P = .05; P < .00001). Significant changes in retrobulbar blood flow were found in eyes without and with diabetic retinopathy, especially those with retinopathy.

Effect of lowering intraocular pressure treatment on ocular hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy

Objective To observe the effect of lowering intraocular pressure(IOP) treatment on ocular hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION).Methods A total of 68 patients with NAION (68 eyes) were enrolled in this study.The patients were randomly divided into treatment group (38 eyes of 38 patients) and control group (30 eyes of 30 patients).All the patients were received methylprednisolone pulse therapy (200 mg,three days),vasodilator therapy with intravenous infusion of Xueshuantong solution (300 mg),optic nerve nutritional therapy with mouse nerve growth factor (30 μg) and acupoint injection in temporal with compound anisodine (2 ml).The total course was 10 days.The patients of treatment group received IOP lowering treatment to reduce the IOP to ≥ 8 mm Hg (1 mm Hg=0.133 kPa) or in a 30％ reduction.The patients of control group received no IOP lowering treatment.The peak systolic velocity (PSV),pulsatility index (PI) and resistance index (RI) of ophthalmic artery (OA),central retinal artery (CRA) and short posterior ciliary arteries (PCA) before and after treatment were comparatively analyzed by color doppler flow imaging.Results The differences of PSV (t=1.023,1.145,0.569),PI (t=0.679,0.956,1.634) and RI (t=0.816,1.657,0.998) of OA,CRA and PCA before treatment in treatment group and control group were not statistically significant (P＞ 0.05).Compared with before treatment,PSV (t=3.150,7.650,3.520) and PI (t=2.420,5.430,7.650) of OA,CRA and PCA increased obviously (P＜0.05),RI of OA,CRA and PCA decreased obviously (t=5.320,9.640,18.360; P＜0.05) after treatment in treatment group.In control group,the differences of PSV (t=2.090,-2.550,-2.100) and PI (t=-2.310,-2.230,-4.490) of OA,CRA and PCA between before and after treatment were not statistically significant (P＞0.05) ; but the differences of RI of OA,CRA and PCA between before and after treatment was statistically significant (t=2.970,2.160,2.690μ P＜0.05).Compared with control group,PSV (t=2.632,2.135,5.364) and PI (t=3.251,2.432,4.243) of OA,CRA and PCA increased obviously (P＜0.05),RI of OA,CRA and PCA decreased obviously (t=3.664,2.938,4.324; P＜0.05) after treatment in treatment group.Conclusion Lowering intraocular pressure treatment can improve the ocular hemodynamics in NAION patients. Key words: Optic neuropathy, ischemic/therapy; Ocular hypertension/drug therapy; Hemodynamics; Ultrasonography,doppler,color

The effect of anisometropic amblyopia on retrobulbar blood flow parameters

To look for a correlation between or the effect of anisometropia amblyopia on retrobulbar blood flow parameters. Peak systolic velocity (PSV) and end-diastolic velocity (EDV) of the ophthalmic artery (OA), central retinal artery (CRA), and temporal posterior ciliary artery (tPCA) were measured with color Doppler imaging, and systolic/diastolic ratio, resistivity index (RI), and pulsatility index (PI) were computed in 42 patients with anisometropic amblyopia. The mean PSV of OA, CRA, and tPCA in amblyopic and fellow eyes were 62.69 ± 24.04, 62.64 ± 20.18; 9.28 ± 3.71, 10.27 ± 4.18; 10.81 ± 4.59, 11.28 ± 4.91, respectively. The mean EDV of OA, CRA, and tPCA in amblyopic and fellow eyes were 15.87 ± 11.31, 14.52 ± 6.54; 2.48 ± 1.17, 2.62 ± 2.06; 3.04 ± 2.34, 3.14 ± 2.18, respectively. The mean RI of OA, CRA, and tPCA in amblyopic and fellow eyes were 0.76 ± 0.08, 0.76 ± 0.08; 0.72 ± 0.08, 0.74 ± 0.95; 0.72 ± 0.09, 0.72 ± 0.08, respectively. The mean PI of OA, CRA, and tPCA in amblyopic and fellow eyes were 1.77 ± 0.42, 1.81 ± 0.46; 01.58 ± 0.42, 1.59 ± 0.43; 1.54 ± 0.43, 1.58 ± 0.49, respectively. There was no statistically significant difference in any of the measured parameters between the amblyopic and fellow eyes. Anisometropic amblyopia did not cause any change in retrobulbar blood flow in amblyopic eyes.

Evaluation of Resistive Index by Color Doppler Imaging of Orbital Arteries in Type II Diabetes Mellitus Patients with Microalbuminuria

Objective: Resistive index (RI) is an indirect measurement of blood flow resistance that can be used to evaluate vascular damage in ophthalmologic diseases. The purpose of this study was to evaluate the association between RI values of orbital arteries by using the color Doppler imaging (CDI) in type II diabetes mellitus (DM) patients with microalbuminuria. Patients and methods: We evaluated 91 type II DM patients with microalbuminuria and 27 healthy subjects. The DM patients with microalbuminuria were grouped into two: group 1 consisted of patients with retinopathy (n = 51) and group 2 consisted of patients without retinopathy (n = 40). Healthy subjects constituted group 3 (n = 27). The mean RI values of ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery (PCA) were measured using CDI. Results: Compared to diabetic group 2, group 1 had significantly higher mean RIs of OA, CRA, PCA, and HbA1c levels (p < 0.001 for all). Besides, there were no statistical differences in mean RIs of OA, CRA, and PCA between the control group and group 2 (p = 1.0; p = 0.44; p = 0.67, respectively). Mean RIs of OA and PCA were significantly correlated with age in group 1 (r = 0.549, p < 0.001; r = 0.407, p = 0.003, respectively). Mean RI of CRA was significantly correlated with the duration of diabetes and age in group 1 (r = 0.296, p = 0.035; r = 0.486, p < 0.001, respectively). Conclusion: Our study indicates that RI might be a useful marker for early diagnosis and follow-up of diabetic retinopathy, and orbital RI assessment would be beneficial for diabetic patients with retinopathy.

Early Orbital Blood Flow Changes in Multiple Sclerosis Patients with Unilateral Acute Optic Neuritis

The aim of this study was to evaluate orbital blood flow by using colour Doppler imaging before corticosteroid administration in multiple sclerosis patients with unilateral acute optic neuritis. Thirty multiple sclerosis patients with unilateral acute optic neuritis and 30 healthy subjects were included as the study and the control groups. The diagnosis of multiple sclerosis optic neuritis was based on clinical presentation, visually evoked potential, and magnetic resonance imaging findings. Data obtained from affected and unaffected eyes were compared with each other and the control group. Ophthalmic artery peak systolic velocity, end-diastolic velocity, resistivity index, and pulsatile index were measured in all patients before administration of systemic corticosteroid treatment and in control subjects. All parameters of blood flow obtained from affected eyes of patients who developed acute optic neuritis were significantly higher than those of the clinically uninvolved eyes of the affected patients (p < 0.001) and those of control eyes (p < 0.001). In addition, statistically significant increases were found in ophthalmic artery peak systolic velocity, end-diastolic velocity, and resistivity index of the clinically uninvolved eye of the affected patients compared with the control group (p = 0.002, p = 0.012, p = 0.013, respectively). No significant differences were found in blood flow data between left and right eyes of the control group (p > 0.05).

Disturbed correlation between arterial resistance and pulsatility in glaucoma patients

(i) To investigate whether pulsatility index (PI) and mean flow velocities (MFV) are altered in glaucoma patients. (ii) To evaluate the significance of PI in retrobulbar autoregulation capacity. Patients with primary open-angle glaucoma (POAG; n = 49), normal tension glaucoma (NTG; n = 62) and healthy controls (n = 48) underwent colour Doppler imaging measurements of the retrobulbar vasculature. Kruskal-Wallis test was used to compare variables between the three diagnostic groups. Restricted cubic splines were used to determine nonlinearities between the resistive index (RI) and PI correlations. Mean flow velocities (MFV) were lower in both short posterior ciliary arteries (SCPA) and central retinal arteries (CRA) from the two glaucoma groups (p < 0.04 versus healthy controls). No differences were detected in RI or PI in any arteries of the three diagnostic groups (p > 0.08). In healthy individuals, correlations between RI and PI were linear in all arteries. In both POAG and NTG patients, CRA presented a nonlinear curve with a cutpoint at RI 0.77 (p < 0.001) and 0.61 (p = 0.03), respectively, above which the slope increased nearly five- and tenfold (POAG: 1.96 to 10.06; NTG: -0.46-4.06), respectively. A nonlinear correlation in the ophthalmic artery was only observed in NTG patients, with a cutpoint at RI 0.82 (p < 0.001), above which the slope increased from 3.47 to 14.03. Glaucoma patients do not present the linear relationships between RI and PI observed in healthy individuals. Their nonlinear relations may be indicative of an altered autoregulation and suggest a possible threshold RI could be determined above which autoregulatory disturbances become more relevant.

The nitric oxide donating triamcinolone acetonide NCX 434 does not increase intraocular pressure and reduces endothelin-1 induced biochemical and functional changes in the rabbit eye

BackgroundNCX 434 is a nitric oxide (NO)-donating triamcinolone acetonide (TA), shown to enhance optic nerve head (ONH) oxygen saturation in non-human primate eyes. Here, the effects of a single intravitreal...

The Validity of Reliability Measure in Threshold Perimetry

Purpose: To evaluate the color Doppler imaging (CDI) and pattern visual evoked potential (P-VEP) examinations in primary open angle glaucoma (POAG) patients and investigate the relation between flow velocities measured by CDI and P-VEP examination in POAG patients. Methods: Sixty five POAG patients and 45 control subjects underwent CDI evaluation of the ophthalmic artery (OA), short posterior ciliary artery (SPCA) and central retinal arteries (CRA). The peak systolic velocities (PSV) and end-diastolic velocities (EDV) and resistive index (RI) of all retrobulbar vessels were measured. The latency and amplitude of P100 in P-VEP were recorded. The differences of CDI and P-VEP parameters among POAG and control groups were compared. The correlations between CDI parameters, visual field indices and P-VEP in POAG patients were evaluated by Pearson's correlation analysis. Results: POAG patients had the lower EDV and higher RI in the OA, CRA and SPCA comparing with that of control subjects. Also, POAG patients had lower PSV in OA and CRA comparing with that of control subjects. The latency of P100 in VEP delayed and the amplitude of P100 decreased in the POAG patients comparing with that of the control group. The RI of OA and SPCA were negatively correlated with the mean deviation (MD) values in the POAG patients. The RI of OA was positively correlated with the PSD value in POAG patients. The MD values in POAG patients were negatively correlated with the latency time of P100. The RI of OA was positively correlated with the latency time of P100 and negatively correlated with the amplitude of P100 in the POAG patients. Conclusions: The combination of the CDI and pattern VEP techniques provides further interpretation of ocular circulatory changes in POAG patients. Further studies are needed for assessment the relationship between circulatory and neural changes.

Diagnostic Value of Color Doppler Imaging and Pattern Visual Evoked Potential in Primary Open-Angle Glaucoma

Purpose: To evaluate the color Doppler imaging (CDI) and pattern visual evoked potential (P-VEP) examinations in primary open angle glaucoma (POAG) patients investigate the relation between flow velocities measured by CDI and P-VEP examination in POAG patients. Methods: Sixty five POAG patients and 45 control subjects underwent CDI evaluation of the ophthalmic artery (OA), short posterior ciliary artery (SPCA) and central retinal arteries (CRA). The peak systolic velocities (PSV) and end-diastolic velocities (EDV) and resistive index (RI) of all retrobulbar vessels were measured. The latency and amplitude of P100 in P-VEP were recorded. The differences of CDI and P-VEP parameters among POAG and control groups were compared. The correlations between CDI parameters, visual field indices and P-VEP in POAG patients were evaluated by Pearson’s correlation analysis. Results: POAG patients had the lower EDV and higher RI in the OA, CRA and SPCA comparing with that of control subjects. Also, POAG patients had lower PSV in OA and CRA comparing with that of control subjects. The latency of P100 in VEP delayed and the amplitude of P100 decreased in the POAG patients comparing with that of the control group. The RI of OA and SPCA were negatively correlated with the mean deviation (MD) values in the POAG patients. The RI of OA was positively correlated with the PSD value in POAG patients. The MD values in POAG patients were negatively correlated with the latency time of P100. The RI of OA was positively correlated with the latency time of P100 and negatively correlated with the amplitude of P100 in the POAG patients. Conclusions: The combination of the CDI and pattern VEP techniques provides further interpretation of ocular circulatory changes in POAG patients. Further studies are needed for assessment the relationship between circulatory and neural changes.

Ophthalmic Artery-Resistive Index and Evidence of Overperfusion-Related Encephalopathy in Severe Preeclampsia

Neurological findings in preeclampsia fulfill diagnostic criteria of posterior reversible encephalopathy syndrome (PRES), which is related to cerebral autoregulation impairment associated with high blood pressure. In preeclampsia, PRES may occur without a significant increase in blood pressure. Our aim was to investigate the association between ophthalmic artery resistive index (OARI) and clinical evidence of PRES, defined as the presence of headache and blurred vision, in patients with severe preeclampsia. OARI and main clinical and laboratory parameters were obtained in 112 patients with severe preeclampsia. Differences in these parameters were analyzed in the function of clinical evidence of PRES with a 2-sample t test. The area under receiver operating characteristic curve for each of these parameters in the function of clinical evidence of PRES was obtained. Logistic regression models were established with parameters categorized by cutoff points obtained in receiver operating characteristic curves. Among 112 patients with severe preeclampsia, 46 (41%) presented clinical evidence of PRES. These patients presented lower OARI (P<0.0001), higher mean blood pressure at admission (P<0.0001), higher mean blood pressure elevation after the first trimester (P<0.0001), and higher lactate dehydrogenase (P<0.0001) than those without clinical evidence of PRES. OARI presented an area under receiver operating characteristic curve of 0.810+/-0.039 (95% CI: 0.742 to 0.895; P<0.0001). OARI <0.56 was associated with clinical evidence of PRES, with an odds ratio of 12.67 (95% CI: 4.08 to 39.39; P<0.0001). Data suggest that OARI is a relevant biomarker of PRES in severe preeclampsia.