Resistive Index Of Ophthalmic Artery Research Articles

Investigation of alterations in retrobulbar hemodynamics and their correlation with choroidal thickness after strabismus surgery.

To evaluate the changes in retrobulbar circulation after strabismus surgery and to assess the relationship of these changes with choroidal thickness (CT). This prospective study included 26 eyes of 26 patients who underwent strabismus surgery and 15 eyes of 15 healthy individuals as control group. The patients who had single horizontal muscle surgery were included in Group 1 (n = 14); and those who had surgery on both horizontal muscles were included in Group 2 (n = 12). Peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) of ophthalmic artery (OA), posterior ciliary artery (PCA), and central retinal artery (CRA) were measured using Color Doppler Ultrasonography. Subfoveal CT was measured via Optical Coherence Tomography. All measurements were obtained preoperatively, at 1st week and 1st month after surgery. There were no differences regarding preoperative blood flow velocity parameters among the groups. OA RI increased significantly at 1st week and 1st month after surgery in Group 1 and 2 (P = 0.029 and P = 0.045, respectively). There was a significant increase in PCA PSV at 1st week in Group 1 (P = 0.002). There was no difference between the mean preoperative and postoperative CT among the 3 groups. A negative correlation between the percentage changes of CT and CRA EDV was found in Group 2 (P = 0.011). Single and double horizontal rectus muscle surgery have a measurable effect on retrobulbar hemodynamics but these changes do not correlate with CT.

Quantitative evaluation of ocular vascularity and correlation analysis in patients with diabetic retinopathy by SMI and OCTA

AimsTo find potential relation between retrobulbar vessels and fundus microvessels and to detect sensitive and effective clinical indicators in predicting the progress of diabetic retinopathy (DR), ocular hemodynamics were measured using superb microvascular imaging (SMI) and ultrawide-field optical coherence tomography angiography (UWF-OCTA).MethodsObservational, cross-sectional study evaluating ocular hemodynamics in patients with DR by SMI (Aplio i900, Canon Medical) and UWF-OCTA (BM-400 K BMizar, Tupai Medical Technology). The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) of the central retinal artery (CRA), posterior ciliary artery (PCA), and ophthalmic artery (OA) were measured by SMI. UWF-OCTA evaluated the fundus vascular parameters. A correlation analysis was used to determine the correlation between SMI and UWF-OCTA parameters.ResultsOne hundred thirty-nine eyes of 139 diabetic patients were included: 29 without DR (NDR), 36 with mild to moderate nonproliferative DR (M-NPDR), 37 with severe NPDR (S-NPDR), and 37 with proliferative DR (PDR). PSV and EDV of retrobulbar vessels decreased from NDR to S-NPDR while increasing PDR. RI of OA showed a decreasing trend in the progression of DR, but other vessels didn’t show the same trend. ROC curve analysis showed that CRAPSV, CRAEDV, PCAEDV, OAPSV, and OAEDV had diagnostic value distinguishing M-NPDR and S-NPDR. The correlation analysis observed a significant association between the SMI parameters of CRA and PCA and UWF-OCTA parameters. CRA hemodynamics were more associated with fundus vascular parameters, especially the retina, in the NDR group than in the M-NPDR group. In contrast, PCA consistently correlated with fundus vascular parameters, especially in the choroid, from the NDR to the M-NPDR group. However, OA showed a poor correlation with OCTA parameters.ConclusionThe velocity of retrobulbar vessels, mainly the CRA, may serve as a valuable predictor for assessing the progress of DR. The use of SMI in diabetic patients may help identify patients at risk of developing retinopathy.

Ocular blood flow in normal tension glaucoma and primary open angle glaucoma

Objectives: The purpose of the study was to study the ocular blood flow (OBF) in primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG) by color Doppler imaging (CDI) in the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery (PCA) and to correlate this with structural and functional damage in glaucoma. Materials and Methods: This was a cross-sectional and observational study. This was a cross-sectional study, in which 30 eyes of each group and controls were studied, CDI was done by a single observer for all cases. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) were calculated for OA, CRA, and PCA. Visual fields and retinal nerve fiber layer (RNFL) analysis were done. Results: PSVs and EDVs were lower and RIs were higher for CRA and PCA of NTG and POAG compared to those of controls. The severity of glaucoma (visual field defect) increased when RI of OA was increased in NTG. No such relationship was established between RNFL thinning and OBF. Conclusion: Reduction in PSV and EDV leads to increased RI which is one of the contributory factors in the functional damage in NTG.

Orbital blood vessels changes on color duplex imaging in diabetics with and without diabetic retinopathy

To compare changes in ophthalmic artery (OA) and its branches in diabetics with and without diabetic retinopathy (DR) using color duplex imaging (CDI), and to correlate these changes with the disease variables. 60 eyes of 60 diabetic patients were enrolled, divided into 3 groups: without DR (Group A), with Non-Proliferative DR (Group B) and with Proliferative DR (PDR) (Group C). Laboratory testing including HbA1c was done. Patients underwent CDI, by which OA, Central Retinal Artery (CRA) and Ciliary Arteries were identified; for each of them we measured Peak systolic velocity (PSV), End Diastolic velocity (EDV) and Resistivity Index (RI). Results were compared to clinical, laboratory and fundus examination. OA EDV was significantly lower and OA RI was found to be significantly higher in Group C (p = 0.027 and 0.025 respectively). CRA PSV and EDV were significantly lower in Group C (p = 0.017 and 0.001 respectively). PCA RI was significantly higher in Group C (p = 0.008). HbA1c was negatively correlated with CRA PSV (p = 0.041), also it was negatively correlated with CRA EDV (p = 0.0001), as well as with PCA EDV (p = 0.002). There was direct significant correlation between HbA1c and PCA RI (p = 0.012). Duration since diagnosis was negatively correlated with CRA EDV (p = 0.004). Multivariate linear regression showed that DR is an independent predictor for low OA EDV, high OA RI, low CRA EDV and high PCA RI. DR is an independent risk factor for orbital and ocular vessels flow alteration, thus can be used as a prognostic tool in diabetic patients. CDI can be reliably used in diabetics to predict early changes or progression of DR.

NCX 470 Exerts Retinal Cell Protection and Enhances Ophthalmic Artery Blood Flow After Ischemia/Reperfusion Injury of Optic Nerve Head and Retina.

The purpose of this study was to assess the retinal protective activity and ocular hemodynamics after NCX 470 (0.1%) compared to bimatoprost administered as the US Food and Drug Administration (FDA)-approved drug (Lumigan - 0.01% ophthalmic solution, LUM) and at an equimolar dose (0.072%, BIM) to that released by NCX 470. Endothelin-1 (ET-1) induced ischemia/reperfusion injury model in rabbits was used. ET-1 was injected nearby the optic nerve head (ONH) twice/week for 6 weeks. Starting on week 3, the animals received vehicle (VEH), NCX 470, LUM, or BIM (30 µL/eye, twice daily, 6days/week) until the end of ET-1 treatment. Intraocular pressure (IOP), ophthalmic artery resistive index (OA-RI), and electroretinogram (ERG) data were collected prior to dosing and at different time points postdosing. Reduced glutathione, 8-Hydroxy 2-deoxyguanosine, and Caspase-3 were determined in the retina of treated eyes. DNA fragmentation was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining. ET-1 increased IOP (VEHIOP_Baseline = 20.5 ± 0.8 and VEHIOP_Week6 = 24.8 ± 0.3mmHg) and OA-RI (VEHOA-RI_Baseline = 0.36 ± 0.02 and VEHOA-RI_Week6 = 0.55 ± 0.01) and reduced rod/cone responses over time. Oxidative stress, inflammation, and apoptotic markers increased in ET-1-treated eyes. NCX 470 prevented IOP (NCX 470IOP_Week6 = 18.1 ± 0.6mmHg) and OA-RI changes (NCX 470OA-RI_Week6 = 0.33 ± 0.01) and restored ERG amplitude leaving unaltered the respective latency; these effects were only partially demonstrated by LUM or BIM. Additionally, NCX 470 reduced oxidative stress, inflammation, and apoptosis in the retinas of treated eyes. BIM and LUM were numerically less effective on these parameters. NCX 470 repeated ocular dosing ameliorates ocular hemodynamics and retinal cell dysfunction caused by ischemia/reperfusion via nitric oxide- and bimatoprost-mediated mechanisms. If confirmed in clinical setting our data may open new therapeutic opportunities to reduce visual field loss in glaucoma.

The ophthalmic artery resistive index as a predictor of choriocapillaris ischemia in multivariate logistic models

The ophthalmic artery resistive index as a predictor of choriocapillaris ischemia in multivariate logistic models

Diagnostic and predictive value of resistive / pulsatility indices of ophthalmic artery and common carotid artery for the development of diabetic retinopathy.

Ophthalmic artery resistive index (OA RI) was a controversial parameter to show hemodynamic changes due to diabetic retinopathy (DRP). To investigate the diagnostic and predictive value of resistive and pulsatility index (RI and PI, respectively) of OA and common carotid artery (CCA) for the development of DRP. A total of 60 patients with diabetes mellitus (DM) type 2 (study group) and 30 healthy participants (control group) were evaluated between January and June 2021 by Doppler ultrasonography (DUS). RI and PI values were compared between groups with a Student's t-test. Cutoff value, sensitivity, and specificity were calculated for the significant variables with receiver operating characteristic (ROC) analysis. In total, there were 20 (22.2%) patients with DM without DRP (DMwoRP), 20 (22.2%) patients in the non-proliferative diabetic retinopathy group (NPDRP), and 20 (22.2%) patients in the proliferative diabetic retinopathy group (PDRP). The mean of CCA RI and OA RI in the PDRP group was significantly higher than in the other three groups (P < 0.001). The mean of CCA RI and OA RI was significantly higher in the PDRP group than in the NPDRP group, and in the NPDRP group compared to the DMwoRP group. CCA RI and OA RI showed a significantly high correlation (r = 0.849; P < 0.001). Sensitivity was 95% and specificity was 100% for the diagnosis of PDRP for the 0.82 cutoff value of OA RI (AUR = 0.999, 95% confidence interval for AUC = 0.997-0.1000; P < 0.001). The OA RI accurately reflects DRP-induced orbital blood flow changes and is a predictive index for DRP prognosis.

Newly imaging biomarker of hypertension-related vascular and kidney damage: The ophthalmic artery index

Background and Aims : Ophthalmic artery resistive index (RI-OA) is associated with atherosclerotic diseases. The aim of this study was to evaluate the association of RI-OA and hypertension-related vascular and kidney damage.

NCX 470 Restores Ocular Hemodynamics and Retinal Cell Physiology After ET-1-Induced Ischemia/Reperfusion Injury of Optic Nerve and Retina in Rabbits.

Purpose: Determine whether NCX 470, a nitric oxide (NO)-donating bimatoprost with clinically demonstrated intraocular pressure (IOP)-lowering effects, improves ocular hemodynamics and retinal physiology. Methods: Endothelin-1 (ET-1)-induced ischemia/reperfusion model in New Zealand white rabbits was used. ET-1 was injected next to the optic nerve twice/week (Monday and Thursday) for 6 weeks. Starting on week 3, animals received NCX 470 (0.1% bid, 6 days/week Monday-Saturday) or vehicle until the end of ET-1 treatment. IOP, ophthalmic artery resistive index (OA-RI) and retina physiology (electroretinogram, ERG) were determined before dosing and at different times post-dosing. All measurements were taken on Mondays before the AM daily dosing (36 h treatment-free). Finally, oxidative stress markers were determined in dissected retina and iris/ciliary body of treated eyes. Results: Injection of ET-1 progressively increased IOP (20.7 ± 0.6, 24.9 ± 1.2, and 27.0 ± 0.6 mmHg at baseline, week 2 and 6, respectively) and OA-RI (0.30 ± 0.02, 0.39 ± 0.02, and 0.42 ± 0.03 at baseline, week 2 and 6, respectively) and reduced rods and/or cones response as indicated by changes in ERG amplitudes under different stimulating conditions. NCX 470 re-established baseline IOP (21.8 ± 1.0 mmHg), OA-RI (0.33 ± 0.02), and ERG amplitude by week 6 (mostly rod response, 0.01Dark_AVeh_6week = 32.2 ± 3.0 μV and 0.01Dark_ANCX470_6week 44.3 ± 4.5 μV; mostly cone response, 3.0Dark_AVeh_6week = 87.6 ± 10.1 μV and 3.0Dark_ANCX470_6week = 122.8 ± 11.4 μV; combined rod/cone response, 3.0Light_AVeh_6week = 49.8 ± 6.5 μV and 3.0Light_ANCX470_6week = 64.2 ± 6.8 μV). NCX 470 also reversed ET-1-induced changes in glutathione and manganese superoxide dismutase (oxidative stress markers) in retina and iris/ciliary body. Conclusions: Repeated ocular topical dosing with NCX 470 reverses ET-1-induced changes in IOP, OA-RI, and ERG suggesting improved ocular hemodynamics and retinal physiology likely independently from its demonstrated IOP-lowering effect.

Ocular blood flow and retinal, choroidal, and retinal nerve fiber layer thickness in children with familial Mediterranean fever with at least five attacks.

This study aimed to evaluate ocular blood flow and, retinal, choroidal and retinal nerve fiber layer thickness in children with familial Mediterranean fever (FMF) with patients who had at least five attacks. Fifty-six patients with FMF and 56 healthy subjects were enrolled in the study. Each participant's choroidal thickness (CT) and retinal thickness (RT) measurements were performed in the foveola and at horizontal nasal and temporal quadrants within 500-μm intervals up to 1.500μm from the foveola using spectral-domain optical coherence tomography as well as the retinal nerve fiber layer thickness (RNFLT). Disc boundaries were determined manually by identifying seven points on the inner edge of the scleral ring. Following complete ophthalmological evaluation, peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) values in the central retinal artery (CRA), ophthalmic artery (OA), and nasal posterior ciliary artery (NPCA) were measured using color Doppler ultrasonography (CDU) in the left eyes of the patients diagnosed with FMF and the controls. The results were subsequently compared. No statistically significant differences were observed between the groups in terms of all RNFLT quadrant and RT measurements. All CT measurements were thinner in patients with FMF than in the controls (For Central and Temporal_1500 p = 0.01; For Temporal_500, Nasal 500 and Nasal_1000 p < 0.001; Temporal_1000 p = 0.002) except than the Nasal_1500 point. For nasal_1500 p = 0.121). The PSV and EDV values in the OA, CRA, and NPCA were significantly lower in patients with FMF compared to healthy controls (p < 0.001 for all). In contrast, the RI values of all arteries were significantly higher than in the control group (Regarding OA, CRA and NPCA RI, p = 0.003, p = 0.039, and p = 0.039, respectively). The results of this study support the idea that chronic inflammation and frequent attacks in FMF may have an effect on decreased ocular blood flow and choroidal thinning.

Evaluation of Hemodynamic Changes in Retrobulbar Blood Vessels Using Color Doppler Imaging in Diabetic Patients.

Background—Diabetic retinopathy is a common complication of long-standing hyperglycemia. Microangiopathy-induced retinal changes are well-visualized on ophthalmoscopic examination. However, certain hemodynamic alterations have also been documented in the diabetic population, which have not been completely understood. Aim—To study the hemodynamic changes in retrobulbar circulation in diabetic patients with and without retinopathy, and to compare these changes with non-diabetic controls. Materials and Methods—This hospital-based prospective study included 50 diabetic and 50 non-diabetic patients. The diabetic groups consisted of 25 patients without retinopathy and 25 patients with retinopathy, and were labeled as Groups I and II, respectively. All subjects underwent orbital color Doppler ultrasonography using a linear high-frequency probe. The color Doppler parameters (peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI)) were measured and recorded using the spectral waveform of the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCA). Comparison of obtained values was carried out using appropriate tests of significance. Results—The resistive indices of the ophthalmic, central retinal, and short posterior ciliary arteries were significantly higher in diabetic patients compared to controls (p < 0.001). The difference was also significant between Group I and Group II. Comparison of PSV and EDV of CRA and SPCAs among three groups using one-way ANOVA revealed a significant difference, with the highest blood flow velocities in the control group and the lowest in diabetics with retinopathy. The ophthalmic artery showed no significant change in blood flow velocity. Analysis using the Pearson correlation coefficient provided a positive correlation between the RI values of OA, CRA, and SPCA and the presence of diabetic retinopathy (OA = r 0.417, p < 0.001; CRA = r 0.466, p < 0.001; SPCA = r 0.438; p < 0.001). Conclusions—The resistive index of OA, CRA, and SPCA is a reliable indicator to assess diabetic-associated hemodynamic changes. The use of orbital color Doppler ultrasonography in diabetic patients can help in the identification of patients who are at risk of developing retinopathy.

Correlation of Measurements From Doppler Ultrasound and Optical Coherence Tomography in Glaucoma.

To relate the changes in ocular structure and hemodynamic response in primary open-angle glaucoma (POAG). Patients with POAG (n=46) and control subjects (n=53) were recruited. Retinal nerve fiber layer and ganglion cell complex were evaluated using optical coherence tomography (OCT). Blood flow was characterized in ophthalmic artery (OA) and central retinal artery (CRA) using color Doppler ultrasonography (CDU), and resistivity index (RI) was calculated. Measurements from CDU and OCT were statistically correlated and the degree of the association was examined. Receiver operating characteristics was produced based on RI and optimal threshold was determined. In POAG patients, OCT revealed neuronal damage and CDU indicated increased resistance to arterial flow. Flow dynamics correlated negatively with the ocular tissue dimensions, sufficiently establishing an association between the ocular structure and its hemodynamic response. Based on the possibility of indirect POAG diagnosis with CDU, threshold 0.7 for RI of OA yielded 73.9% sensitivity and 77.4% specificity in distinguishing the cases of POAG from the controls. Threshold of 0.66 for RI of CRA, had higher specificity of 83%, but lower sensitivity of 52.1%. Ocular flow exhibits different characteristics in individuals with POAG than normal. The changes associated with the underlying neuronal structure, suggesting the possibility of a potential new diagnostic biomarker for POAG. This justifies further studies with a larger cohort, examining the ocular flow with CDU in POAG and comparing it against OCT findings for establishing the power of CDU in differential diagnosis or glaucoma progression.

Resistive index of ophthalmic artery as animaging biomarker of hypertension-related vascular and kidney damage.

Aim: Resistive index of ophthalmic artery (RI-OA) is associated with atherosclerotic diseases. The aim of this study was to evaluate the association of RI-OA and hypertension-related vascular and kidney damage. Materials and methods: Two-hundred and eighty hypertensive patients underwent evaluation of RI-OA, carotid atherosclerosis and level of 24h albuminuria. Results: Albuminuria and carotid atherosclerosis were positively associated with RI-OA independently of other cardiovascular risk factors. Receiver-operating characteristic curve analysis allowed us to calculate a cut-off value of RI-OA >0.625, which would be suspicious about the existence of atherosclerotic disease. Conclusion: The ophthalmic vascular circulation allows to study connections between macro-and microcirculation in vivo. RI-OA could be a useful marker for a better stratification of the risk of developing kidney and cardiovascular disease.

Comparison of the Doppler Indices in the Ophthalmic Artery and Central Retinal Artery in Diabetic and Nondiabetic Individuals

Objective: Diabetes can lead to diabetic retinopathy, which damages the retina due to blood flow remodeling of occular vessels. Early stages of diabetic retinopathy may not present with patient symptoms. Doppler indices, of the ophthalmic arteries, could help in determining the effect of diabetic vascular remodeling. This research was designed to compare the Doppler indices, in the ophthalmic artery and central retinal artery, in both diabetic and nondiabetic patients. Materials and Methods: This was a cross-sectional observational study of 72 total patients. Sonography was performed on the ophthalmic arteries of 36 diabetics and 36 nondiabetics, to compare Doppler indices. All patients were voluntarily consented to this research that was approved by the university’s Institutional Review Board (IRB). Doppler parameters recorded were peak systolic velocity, end dystopic velocity, resistive index, and pulsatility index, which were taken in both patient groups and compared. Results: A significant difference was noted in the ophthalmic artery peak systolic velocity, end-diastolic velocity, pulsatility index, and resistive index for diabetic and nondiabetic individuals, with a statistically significant set at .01. Conclusions: There was a significant difference between diabetic and nondiabetic ophthalmic Doppler indices in this cohort of patients. This cohort demonstrated vascular remodeling of the ophthalmic arteries, caused by diabetes; therefore, blood flow resistance was increased due to diabetes.

Ocular blood flow study using color doppler imaging: Normative value and its relevance in glaucoma

Aim: The aim was to study the normative pattern of ocular blood flow (OBF) using color Doppler imaging. Materials and Methods: It was a prospective study including healthy volunteers without any ocular pathology. Results: We analyzed ocular blood flow for 25 eyes of consecutive normal patients. Our study had 14 males and 11 females. The standard deviation of the resistive index of Ophthalmic artery, Central retinal artery and short posterior ciliary artery were 0.07, 0.08 and 0.12 respectively. Discussion: Ischemia to the optic nerve and dysfunctional vascular regulation are likely responsible for glaucomatous damage. Ocular hemodynamics, though complex, can be assessed to an extent by many ways. The quantification of blood flow in these vessels can give great lengths of information with regard to the pathological processes behind retinal and optic nerve head diseases such as glaucoma. Lower ocular perfusion pressure, vascular dysregulation, and lower OBF can worsen glaucoma. Conclusion: To our knowledge, there are no South Indian studies showing the normative data.

Ocular Echobiometry and Resistivity Index of External Ophthalmic Artery in Agoutis (Dasyprocta prymnolopha)

Background: Veterinary Ophthalmology provides complementary information for the diagnosis of ocular pathologies. Studies in wild species are essential. Among the diagnostic techniques in ophthalmology, two-dimensional ultrasonography stands out. The agouti is a rodent belonging to the Dasyproctidae family that has been widely used as an experimental model. For these animals, sight is one of the crucial senses for their survival. The aim of this study was to evaluate the effectiveness of the two-dimensional ocular ultrasound technique to obtain anatomical measurements and the external ophthalmic artery resistivity index, presumably normal in the species Dasyprocta prymnolopha.Materials, Methods &amp; Results: Forty eye bulbs of 20 adult rodents of the species were evaluated by ultrasonography. In these animals, B-mode echobiometry was performed using the transpalpebral approach and the hemodynamic study of the external ophthalmic artery using the color Doppler technique. All examinations were initiated by the left eye bulb and all measurements were performed by only one examiner. The collected data related to echobiometry were analyzed using Bioest 5.0 for Windows. Initially, normality was tested using the Shapiro-Wilk test for each parameter, then the paired t-test was performed, comparing right and left eyes, and a significance level of 5% (P &lt; 0.05) was adopted. Based on the methodology used, the following values were obtained for the right and left eyeballs, respectively: anterior chamber thickness - mean of 1.28 ± 0.3 mm and 1.22 ± 0.1 mm; lens thickness - 8.27 ± 0.9 mm and 8.11 ± 0.9 mm; vitreous chamber thickness - 5.35 ± 0.48 mm and 5.30 ± 0.47 mm and axial length - 12.7 ± 0.9 mm and 13 ± 0.68 mm. The mean external ophthalmic artery resistivity values were 0.4305 ± 0.0390 and 0.4258 ± 0.0387 (right and left eye, respectively), characterizing a low resistance. There was no statistical difference between the right and left eyeballs in any of the studied parameters.Discussion: The use of the convex transducer was feasible, promoting adequate contact with the ocular surface and images of satisfactory quality for obtaining measurements, similar to what was observed in studies evaluating the ocular biometry of primates and dogs. The anterior chamber thickness values in this experiment did not differ statistically between the antimers, as well as observed for dogs. The data obtained for lens thickness did not differ statistically for antimers, like those obtained for other rodent species evaluated with the same methodology. The mean values of vitreous chamber thickness were like those observed in chinchillas but correspond to about half of that obtained for capybaras. In this study, the external ophthalmic artery was characterized in all animals, but obtaining the spectral tracing was difficult due to its fine caliber. In wild animals, and especially in wild rodents, there are few data reporting the resistivity of the ophthalmic artery, and there is a lack of studies, which can be explained by the behavioral characteristics of defense and by the high susceptibility to stress in capture, since the performing the technique requires, as in other procedures, the use of chemical containment.Keywords: Doppler flow, ultrasound, eye, agouti.

Assessment of Doppler flow parameters of the retrobulbar arteries and internal carotid artery in patients with glaucoma: the significance of ophthalmic artery peak ratio and the intima-media thickness of the internal carotid artery.

The objective of this study was to analyze flow parameters of the central retinal artery (CRA), ophthalmic artery (OA), and internal carotid artery (ICA) assessed by color Doppler ultrasound. Thirty-five patients with primary open-angle glaucoma (PAAG), 65 patients with normal-tension glaucoma (NTG), and 45 healthy controls, a total of 145 patients were included in this study and study participants were divided into three groups. All study participants underwent color Doppler ultrasound to assess blood flow parameters of CRA, OA and ICA. Comparisons among three groups revealed that pulsatility index and resistive index of the OA were significantly higher and peak ratio and end-systolic volume were significantly lower in patients with NTG or PAAG compared to healthy controls (p < 0.001 for all). As with OA, resistive index of the CRA was statistically significantly higher in patients with glaucoma (PAAG and NTG) compared to healthy controls (p < 0.001). The peak systolic volume and intima-media thickness of the ICA were statistically significantly higher in patients with PAAG compared to the other two groups (p < 0.001). ROC curve analysis of the CRA resistive index, OA resistive index and OA peak ratio in patients with glaucoma (PAAG and NTG) revealed that the sensitivity and specificity were 89% and 88%; 86% and 84%; 84% and 82%, respectively, at cutoff values of 0.64, 0.78 and 0.59, respectively. Ophthalmic artery peak ratio and ICA intima-media thickness may be useful parameters in the diagnosis of patients with glaucoma.

The Relationship between Ocular Vascular Changes and the Levels of Malondialdehyde and Vascular Endothelial Growth Factor in Patients with Inflammatory Bowel Disease

ABSTRACT Background: We evaluated ocular hemodynamic changes, malondialdehyde(MDA) and vascular endothelial growth factor (VEGF) levels in patients with IBD. Methods: We used ocular color Doppler ultrasonography to analyze 56 eyes with Crohn’s disease (CD), 62 eyes with ulcerative colitis (UC), 68 eyes of healthy volunteers. We measured peak systolic velocity (PSV),end-diastolic velocity (EDV),and the resistivity index (RI) of ophthalmic artery (OA) and central retinal artery (CRA). MDA and VEGF levels were measured in the plasma samples. Results: MDA levels were significantly higher in both UC and CD patients, whereas VEGF levels were only higher in the CD group (p = .003,p < .001,p = .01).The PSV and EDV of the OA were significantly lower in CD patients (p = .017,p = .001). The EDV of the CRA was significantly lower in CD patients than UC patients and controls (p = .014,p < .001). Conclusions: CD patients exhibited decreased blood flow in both the OA and CRA. Ocular vascular flow was only affected in CD patients. We found that ocular ischemia may occur in CD patients even in the absence of any clinical finding.

Abnormal retrobulbar blood flow variables in central serous chorioretinopathy.

To evaluate if the retrobulbar blood flow variables were deteriorated in central serous chorioretinopathy (CSC) patients. We included 25 CSC patients and 25 healthy subjects. We used color Doppler ultrasonography to assess the ophthalmic artery (OA), the central retinal artery (CRA), and the posterior ciliary arteries (PCA) for peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI). Mean ages of the patients and controls were 42.3 ± 8.5 and 41.3 ± 9.4 years, respectively (P = .853). There were no significant differences between the two groups with regard to the values of PSV, EDV, and RI of CRA (P = .406, P = .627, P = .227) and PCA (P = .785, P = .403, P = .935, respectively). The PSV and EDV of OA were lower in the CSC patients (P = .005, P = .024, respectively). Whereas the RI of OA was not significantly different (P = .729). Submacular choroidal thickness (SCT) was greater in CSC patients (P < .001). There was a negative correlation between SCT and PSV of PCA (P = .022, r = -0.457) and between SCT and EDV of PCA (P = .004, r = -0.560) in CSC patients. Hemodynamic changes in OA and a negative correlation between PCA values and SCT suggest ocular circulatory dysfunction in patients with CSC.

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.