Retrobulbar Hemodynamics 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.

Measurement of Retrobulbar Blood Flow and Vascular Reactivity—Relevance for Ocular and Cardiovascular Diseases

Abnormal retrobulbar hemodynamics have been linked to the development of various ocular diseases, including glaucoma, age-related macular degeneration, and diabetic retinopathy. Additionally, altered retrobulbar blood flow has been observed in patients with severe cardiovascular diseases, including carotid artery occlusion, stroke, heart failure, and acute coronary syndrome. Due to the complex and intricate anatomy of retrobulbar blood vessels and their location behind the eyeball, measurement of retrobulbar blood flow and vascular reactivity, as well as the interpretation of the findings, are challenging. Various methods, such as color Doppler imaging, computed tomography angiography or magnetic resonance imaging, have been employed to assess retrobulbar blood flow velocities in vivo. Color Doppler imaging represents a fast and non-invasive method to measure retrobulbar blood flow velocities in vivo. While no information about vessel diameter can be gained performing this method, computed tomography angiography and magnetic resonance imaging provide information about vessel diameter and detailed information on the anatomical course. Additionally, ex vivo studies, such as myography, utilizing genetically modified animal models may provide high optical resolution for functional vascular investigations in these small vessels. To our best knowledge, this is the first review, presenting a detailed overview of methods aiming to evaluate retrobulbar blood flow and vascular reactivity in both humans and laboratory animals. Furthermore, we will summarize the disturbances observed in retrobulbar blood flow in retinal, optic nerve, and cardiovascular diseases.

Evaluation of the impact of childhood obesity on retrobulbar hemodynamics and retinal microvasculature.

To evaluate changes in retrobulbar ocular blood flow parameters by using Colour Doppler Imaging (CDI) and changes in foveal microvasculature by using Optical Coherence Tomography Angiography (OCTA) in pediatric obese patients and to compare them with a group of healthy children. Children diagnosed with obesity without hypertension and diabetes (39 subjects, obese group) and age-matched healthy controls (26 subjects, control group) underwent CDI and OCTA imaging. Peak systolic velocity, end-diastolic velocity and resistivity index from ophthalmic, central retinal and posterior ciliary arteries on CDI; superficial and deep capillary plexus vascular density and foveal avascular zone area on OCTA imaging were obtained in each group. Central foveal and subfoveal choroidal thicknesses were also measured. CDI and OCTA parameters were compared between two groups. Peak systolic and end-diastolic velocities were found to be significantly lower in obese children than in controls in all three examined arteries (p < 0.05). Resistivity index values were similar between the groups. OCTA imaging did not reveal significant changes in superficial and deep capillary plexus vascular densities and foveal avascular zone area across analysed retinal regions between the groups. Subfoveal choroid was thicker in obese group than in control group (325.89 ± 52.77 µm vs. 304.52 ± 21.76 µm, p = 0.04). An apparent decrease was present in retrobulbar hemodynamics in obese children. This arises the possibility of early ocular macrovascular compromise rather than retinal microvascular impairment in childhood obesity.

Comparison of ocular blood flow by doppler evaluation in middle aged type 2 diabetes patients with and without diabetic macular edema

Introduction: The World Health Organization (WHO) has estimated that the number of people diagnosed with Diabetes is 347 million worldwide. Diabetic macular edema (DME) and Diabetic Retinopathy are the main causes of vision loss in Diabetes mellitus. Objective: To compare altered ocular blood flow by Doppler evaluation in middle aged type 2 diabetic patients with and without diabetic macular edema. Materials and Methods: An analytical cross–sectional study was conducted in the out-patient and in-patient department of ophthalmology and the department of radiodiagnosis in a tertiary care hospital including 36 patients in each group (A-with DME & B-without DME). Color doppler was done to evaluate ocular blood flow velocities in internal carotid, ophthalmic and central retinal arteries and central retinal vein. Results: The majority of diabetes patients in developing countries are middle aged (45–64 years of age). Vascular changes and subsequent ocular hemodynamic changes are critical events in the pathogenesis of diabetic retinopathy. Mean Resistivity Index (RI) and Mean Pulsatility Index (PI) in the ophthalmic artery were found to be significantly high in the DME group. Mean end diastolic velocity (EDV) in the common carotid artery was found to be significantly high in the NO DME group than the DME group. In our study, the mean values of Low Density Lipoprotein (LDL) (mg/dl) , Total cholesterol (mg/dl) , Serum urea (mg/dl), Serum creatinine (mg/dl) was found to be higher (Statistically significant) in the DME group as compared to NO DME group. Conclusion: Our findings may indicate disturbances of retinal and choroidal circulation in patients with DME. Further studies with larger groups of patients are needed to understand better the role of retrobulbar hemodynamics in the pathogenesis of Diabetic macular edema. Keywords: Diabetic macular edema, Doppler evaluation, Ocular blood flow

Blood flow disturbances in the central retinal artery in patients with bilateral optic disc drusen

To evaluate retrobulbar hemodynamics in patients with optic disc drusen (ODD) by color Doppler imaging. A prospective study included 52 patients with bilateral ODD and 50 age-matched controls. Blood flow in the central retinal artery (CRA) in both eyes was evaluated. Peak-systolic velocity (PSV), end-diastolic velocity (EDV), and the resistivity index (RI) were measured. Mean values of the blood flow Doppler parameters were compared between the patients with ODD and the controls. Both PSV and EDV in the CRA were significantly lower in patients with ODD than in the controls (p < 0.001). The RI in the CRA of ODD patients was significantly higher than in the controls (p < 0.001). Women with ODD presented with significantly lower values of PSV and EDV than men (p = 0.05 and p = 0.03, respectively). Arterial hypertension, cigarette smoking and location of ODD in the left or right eye did not exert a significant effect on the blood flow in the CRA. Blood flow in the CRA is considerably disturbed in patients with ODD. This disturbance might result from mechanical stenosis of the vascular wall caused by the drusen. Color Doppler ultrasound is a useful method in the assessment of retrobulbar hemodynamics in ODD.

A Color Doppler Imaging Study of Ocular Haemodynamic Parameters in Primary Open Angle Glaucoma (POAG)

Aims: To study retrobulbar haemodynamics in primary open angle glaucoma (POAG) patients. Methods: It was a hospital based cross-sectional study carried out in Medical College Out Patient Department (OPD). A total of 26 patients with newly diagnosed POAG and 23 controls were randomly selected for the study. The haemodynamic parameters i.e. Peak systolic velocity (PSV), End diastolic velocity (EDV) and resistivity index (RI) were studied in ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) measured using Color Doppler imaging (CDI). Mean, standard deviation (SD) and Independent t- test was applied to compare the results between the two group. Results: The mean intraocular pressure (IOP) for the POAG group and control group was 26.31±4.51 mmHg and 17.04±1.26 mmHg, respectively (P < 0.001). The mean PSV for both OA and CRA, the mean EDV for all OA, CRA and SPCA were significantly lower whereas the mean RI in the CRA and SPCA were significantly higher in POAG than controls. Conclusions: Retrobulbar blood flow was significantly lower in POAG as compared to controls, thereby suggesting the importance of measuring the retrobulbar blood flow in POAG patients.

Longitudinal follow-up study of the retrobulbar and intrarenal hemodynamics in patients with T2DM.

Objective:The primary aim of this study is to examine the hemodynamics of retrobulbar and intrarenal in the changes of early stage of type 2 diabetes mellitus (T2DM) patients from 2000 to 2015 and to assess incidence associated with diabetic kidney disease (DKD) and diabetic retinopathy (DR).Method:Our study contained 60 subjects newly diagnosed of T2DM were divided into 2 groups base on the mean resistive index (RI) (≤0.7 and >0.7) of hemodynamic and to compare between-group differences of the early changes in hemodynamics of retrobulbar and intrarenal and also to conclude the incidences of diabetic kidney disease (DKD) and diabetic retinopathy (DR)subsequently with a long follow-up duration(2000–2015). First, to compare the mean RI of central retinal artery (CRA) between 2 groups. Second, to compare the mean RI of intrarenal hemodynamics in the bilateral interlobular renal arteries, renal function parameters (blood urea nitrogen (BUN), creatinine (Cr), blood glucose parameters (glycosylated hemoglobinA1c (HbA1c), fasting plasma glucose (FBG), and 2-hour postprandial blood glucose (2hPBG)), glomerular filtration rate (GFR), albumin excretion rate (AER), and urine albumin-to-creatinine ratio (UACR) between 2 groups.Results:First part of our follow-up studies was to compare hemodynamic RI index of retrobulbar in years of 2000 and 2015, both renal function and blood glucose parameters were fund significantly enhanced in subject group RIs ≤0.7. Incidence of DKD and DR was notably lower in group RIs ≤0.7 than group RIs > 0.7, difference was statistically significant (P < .05). Incidence of HbA1c ≤7% was higher in group RIs ≤0.7 than group RIs >0.7, but difference was not statistically significant (P > .05). Incidence of proliferative diabetic retinopathy (PDR) was notably lower in group RIs ≤0.7 than group RIs >0.7, but the difference was not statistically significant (P > .05). Second part of our follow-up studies was to compare hemodynamic RI index of interlobular renal in years of 2000 and 2015, both renal function and blood glucose parameters were fund significantly enhanced in subject group RIs ≤0.7. Compared data of various incidences from first part of study were coherent with second part. (Incidence of DKD and DR was notably lower in group RIs ≤0.7 than group RIs >0.7, difference was statistically significant (P < .05). Incidence of HbA1c ≤7% was higher in group RIs ≤0.7 than group RIs >0.7, but difference was not statistically significant (P > .05). Incidence of PDR was notably lower in group RIs ≤0.7 than group RIs >0.7, but the difference was not statistically significant (P > .05).Conclusions:RIs of retrobulbar and interlobular renal which would serve as a good predictors for the hemodynamics changes in retrobulbar and intrarenal would assess incidence of DKD and DR during the preclinical stage in long-term range excluding renal function and HbA1c in T2DM patients.

Assessment of the optic nerve and its arterial supply by ultrasound imaging in multiple sclerosis patients

BackgroundTransorbital sonography (TOS) has emerged as a promising assessment tool of the optic nerve and orbital arterial supply in multiple sclerosis (MS) patients.ObjectiveTo evaluate optic nerve diameter (OND), optic nerve sheath diameter (ONSD), and orbital hemodynamics using TOS in MS patients.MethodsForty MS patients and 28 matched healthy controls were included. Thirty-three eyes with previous optic neuritis (ON) and 47 eyes without previous ON of MS patients were examined. All subjects were submitted to assessment of OND, ONSD, and parameters of orbital hemodynamics using orbital ultrasound.ResultsOND and ONSD were smaller in MS eyes with previous ON than in controls. MS eyes with and without previous ON had statistically significant higher peak systolic and mean velocity of posterior ciliary arteries than the control eyes. Orbital blood flow velocities were negatively correlated with the duration of disease and Expanded Disability Status Scale (EDSS). A statistically significant decrease in blood flow velocities of the central retinal artery was detected in secondary progressive MS (SPMS) patients than in relapsing-remitting MS patients (RRMS).ConclusionTOS can be used as a feasible tool to detect optic atrophy in MS patients. MS patients may have abnormal retrobulbar hemodynamics compared to healthy controls.

Evaluating the Effect of Intravitreal Ranibizumab on Retrobulbar Hemodynamics by Color Doppler Ultrasonography in Neovascular AMD.

To evaluate changes in retrobulbar blood flow by using color Doppler ultrasonography (CDUS) after intravitreal ranibizumab injection in patients with neovascular age-related macular degeneration (AMD). Eighteen patients who had undergone intravitreal ranibizumab (0.05 mg/0.05 mL) injection due to choroidal neovascular membrane (CNVM) were included in the study. Contralateral eyes of the patients were also analyzed. Peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistivity index (RI) were measured from the ophthalmic artery (OA), central retinal artery (CRA), lateral posterior ciliary artery (LPCA), and medial posterior ciliary artery (MPCA) for all patients pre-injection, and at 1 day, 1 week, and 1 month after ranibizumab injection. The mean age of the 18 patients included in the study was 66.94 years (± 8.3 years). Of these 18 patients, eight were female and 10 were male. After Bonferroni's correction for multiple comparisons was carried out, there were significant differences only in some values of LPCA; these included the decrease in EDV and an increase in PI values of LPCA between the pre-injection and post-injection of the first month measurements in uninjected eyes (P = .002, P = .002), and a decrease in PI value of LPCA between post-injection first day and first week measurements in injected eyes (P = .004). There were no statistically significant differences in other parameters. Ocular blood flow velocities may change after intravitreal ranibizumab injection in patients with CNVM. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:437-443.].

The impact of intravitreal dexamethasone implant (Ozurdex®) on retrobulbar hemodynamics in patients with diabetic macular edema and retinal vein occlusions

Objective: To evaluate the effect of single intravitreal dexamethasone implant (Ozurdex®) on ocular blood flow velocities in patients with diabetic macular oedema (DME) and retinal vein occlusions (RVO).Methods: This prospective non-randomized interventional study included injected and fellow eyes of 12 patients with DME and of 16 patients with RVO treated with intravitreal Ozurdex®. Colour Doppler Ultrasonography (CDU) measures of the central retinal artery (CRA), posterior ciliary artery (PCA), ophthalmic artery (OA) those are peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) were performed in both injected and uninjected eyes before injection, at one week, one month after injection, and prior to re-injection.Results: Inter-eye comparison of all the measured CDU data (baseline, first week, first month, reinjection) showed no statistically significant difference in both DME and RVO group. PSV and EDV values of the CRA, OA, and PCA showed a decreasing trend in the first week and first-month visits and then increased at reinjection time. RI and PI measures of the CRA, OA, and PCA measures showed minimal alterations in the follow-up. But all these differences were not statistically significant. Significant visual gain and anatomic recovery were obtained by the intravitreal dex-implant both in the DME and RVO group.Conclusions: Single intravitreal dex-implant did not alter ocular blood flow in the treatment of macular oedema due to RVO and diabetes.

Research on retrobulbar hemodynamics in senile patients with ischemic ophthalmopathy measured by color Doppler ultrasound

Objective To investigate the retrobulbar hemodynamic changes in elderly patients with ischemic ophthalmopathy(IOP). Methods Three groups of 35 elderly unilateral IOP(n=35 patients), 32 elderly normal eye(n=32 volunteers)and 30 non-elderly normal eye(n=30 volunteers)were recruited in our hospital for the IOP or not, for elderly(aged≥60)or not(aged <60). The peak systolic velocity(PSV), end-diastolic velocity(EDV), resistance index(RI), color Doppler blood stream spectrum form and arm-retinal circulation time(A-RCT)in both ophthalmic artery(OA)and central retinal artery(CRA)were measured on three groups by color Doppler flow imaging(CDFI)and fundus fluorescein angiography(FFA). Results Compared with elderly normal eye group, or with non-elderly normal eye group, the elderly unilateral IOP group showed that PSV and EDV of both OA and CRA were decreased, RI was increased, CD blood stream spectrum form was changed and A-RCT was prolonged(all P 0.05), while CD blood stream spectrum form was changed(P<0.05). Conclusions In the elderly unilateral IOP patients, PSV and EDV of both OA and CRA are decreased, RI is increased, blood stream spectrum form is changed, and A-RCT is prolonged.The color Doppler ultrasound-detected hemodynamic changes are displayed clearly so that CDFI can provide a reliable evidence for clinical diagnosis of IOP. Key words: Senile ischemic ophthalmopathy; Ultrasonography; Hemodynamics

Retrobulbar hemodynamics and aqueous humor levels of endothelin-1 in exfoliation syndrome and exfoliation glaucoma.

BackgroundEndothelin-1 (ET-1) is the most potent vasoconstrictor in the body. There are reports in the literature correlating plasma levels of ET-1 and its impact on retrobulbar hemodynamics. This study evaluates aqueous humor levels of ET-1 and retrobulbar hemodynamics in patients with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG).Patients and methodsPatients scheduled for cataract surgery were included. Patients were allocated to non-exfoliation non-glaucoma group (controls), XFG and XFS groups. Peak systolic velocity (PSV), end diastolic velocity, and resistivity index of the ophthalmic artery (OA), short posterior ciliary arteries, and central retinal artery (CRA) were determined preoperatively using color Doppler imaging. Aqueous humor samples obtained at the beginning of cataract surgery were analyzed with enzyme-linked immunosorbent assay.ResultsSixty-nine participants of similar age were included (controls: n=24, XFG: n=22, XFS: n=23). Multiple regression analysis showed that ET-1, OA-PSV, OA-resistivity index, CRA-PSV, and CRA-end diastolic velocity were influenced by group but not by sex or age. ET-1 for the XFG group (15.93±2.8 pg/mL) was significantly higher than for the XFS (8.92±2.7 pg/mL) and control (8.44±2.6 pg/mL) groups. The difference in ET-1 titers between the control and XFS groups was not statistically significant. All four hemodynamic parameters affected by group status significantly correlated with ET-1 levels in eyes with XFS. In eyes with XFG, two of the four hemodynamic parameters significantly correlated with ET-1 levels. In control eyes, no correlation between ET-1 and hemodynamic parameters affected by group status was detected.ConclusionET-1 aqueous levels in eyes with XFG were significantly higher than those of age-matched controls. Reduced blood flow and increased vascular resistivity were detected in the OA and the CRA in eyes with XFG/XFS. ET-1 levels in eyes with XFG/XFS exhibit a significant correlation with hemodynamic parameters that indicate reduced perfusion.

Effect of intravitreal aflibercept (Eylea®) on retrobulbar hemodynamics in patients with neovascular age-related macular degeneration.

To investigate the short-term effect of single intravitreal aflibercept injection on retrobulbar blood flow in patients with neovascular age-related macular degeneration (nAMD). Twenty eyes of 20 patients with nAMD scheduled for single intravitreal aflibercept (Eylea®) injection and 20 fellow eyes (uninjected) were enrolled in this prospective interventional study. The hemodynamic parameters of the ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary artery (PCA) comprising peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) were measured by using color Doppler ultrasonography (CDU) in both injected and uninjected fellow eyes at baseline and 1week after the injection. The measured first-week values of PSV and EDV in the CRA, OA and PCA showed a statistically significant reduction when comparing baseline values in both injected and uninjected fellow eyes (p=0.0001). Also, it was found a significant increase in the post-injection RI values of all the CRA, OA, PCA in injected eye and OA in the uninjected eye (p=0.0001). There was any significant difference between pre- and post-injection RI values of the CRA and PCA in the fellow eyes (p=0.137, p=0.736, respectively). Single intravitreal administration of aflibercept alters retrobulbar blood flow velocities (BFVs) in both injected and uninjected fellow eyes in the short-term period.

Oral Administration of Cilostazol Increases Ocular Blood Flow in Patients with Diabetic Retinopathy

PurposeTo investigate the effect of cilostazol on ocular hemodynamics and to determine whether the administration of cilostazol increases the ocular blood flow in patients with diabetic retinopathy.MethodsThis prospective observational study investigated the effect of orally administered cilostazol on diabetic retinopathy. Before and after administration for 1 week, pulsatile ocular blood flow (POBF) and retrobulbar hemodynamics were measured using a POBF analyzer and transcranial Doppler imaging, respectively. Visual acuity, intraocular pressure, and blood pressure were also evaluated before and after treatment.ResultsTwenty-five eyes of 25 patients were included in this study. POBF increased significantly (16.8 ± 4.6 µL/sec vs. 19.6 ± 6.2 µL/sec, p < 0.001) after administration of cilostazol, while no significant change was identified in visual acuity, intraocular pressure, and blood pressure. Mean flow velocity in the ophthalmic artery as measured with transcranial Doppler imaging also increased significantly after medication (23.5 ± 5.6 cm/sec vs. 26.0 ± 6.9 cm/sec, p = 0.001). The change in POBF directly correlated with the change in mean flow velocity (r = 0.419, p = 0.007).ConclusionsCilostazol was effective in increasing ocular blood flow in patients with diabetic retinopathy, possibly by modulating retrobulbar circulation.

Ocular perfusion pressure and color Doppler imaging of the external ophthalmic artery of rabbits treated with sildenafil citrate.

BackgroundIt has been proposed that sildenafil citrate can increase ocular blood flow, and that this property can be used to treat ocular disorders that involve reflex vasoconstriction. This study therefore proposes to ascertain the vasodilator effect of the drug on retrobulbar circulation in healthy rabbits. For this matter rabbits treated with sildenafil citrate or saline solution had their intraocular pressure (IOP), mean arterial pressure (MAP), ocular perfusion pressure (OPP) and color Doppler imaging of the external ophthalmic artery measured prior to treatment and on days one (moment M1), seven (when M2), fourteen (moment M3), twenty-one (moment M4), and thirty (moment M5) of treatment.ResultsThe MAP and OPP values of treated group were lower than those of control group at all times, and the mean values differed statistically at moments M1 (S = 71.52 mmHg, C = 84.76 mmHg, p = 0.0356) and M5 (S = 71.38 mmHg, C = 85.52 mmHg, p = 0.0252). The IOP and color Doppler values of the external ophthalmic artery did not differ between tested groups.ConclusionsThe dose of 10 mg of sildenafil citrate administered to healthy rabbits causes systemic vasodilation and consequently lower values of MAP and OPP. However, it does not induce changes in IOP and retrobulbar hemodynamics identifiable by color Doppler assessment of the external ophthalmic artery.

Effects of dorzolamide/timolol fixed combination on retrobulbar hemodynamics in pseudoexfoliative glaucoma

In our study we aimed to evaluate the short-term effects of dorzolamide/timolol on ocular perfusion pressure and retrobulbar blood flow in patients with pseudoexfoliative glaucoma (PXG). This prospective observational cross-sectional study enrolled 22 eyes of 22 newly-diagnosed patients with PXG in a single center. All of the patients received a fixed combination of dorzolamide/timolol. Besides routine ophthalmologic examination, the retrobulbar hemodynamic parameters in the ophthalmic artery, central retinal artery, and short posterior ciliary arteries were measured in all participants at baseline and the 3rd month using color Doppler imaging. The mean intraocular pressure (IOP) was 22.3 ± 2.1 mmHg at baseline and reduced to 17.4 ± 2.3 mmHg at the 3rd month (p < 0.05). None of the retrobulbar parameters, except peak systolic velocity and resistive index in temporal short posterior ciliary arteries, changed significantly on therapy with dorzolamide/timolol fixed combination when the results were analyzed at Month 3. The drug significantly decreased the peak systolic velocity (p = 0.044) and reduced the resistive index in 0.04 units, 95% confidence interval 0.03–0.05, (p < 0.001) in the temporal short posterior ciliary arteries. This study reports that the retrobulbar hemodynamics might be affected less than expected by dorzolamide/timolol fixed combination in patients with PXG although the reduction of IOP was statistically significant.

Coats' disease and retrobulbar haemodynamics.

To study the retrobulbar haemodynamics in patients with Coats' disease. The clinical study included 43 patients with Coats' disease. Using colour Doppler imaging, we measured the blood flow velocity in the ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary arteries (PCA), and recorded the peak systolic velocity (PSV), end diastolic velocity (EDV), time averaged maximum velocity (TAMX), pulsatility index (PI) and resistance indexes (RI). The unaffected contralateral eyes served as control group. The disease was graded into four stages. Compared to the contralateral eyes, the Coats' disease affected eyes showed for the CRA a significant decrease in PSV (7.08±1.38cm/s versus 8.64±1.45cm/s; p<0.001), EDV (2.03±0.41cm/s versus 2.52±0.62cm/s; p<0.001) and TAMX (3.67±0.96cm/s versus 4.40±1.22cm/s; p=0.003) and for the PCA a significant decrease in PSV (9.15±1.87cm/s versus 10.14±1.61cm/s; p=0.01). Subgroup analysis revealed that the decrease in haemodynamic parameters existed mainly in patients with stage 3A2 and stage 3B of Coats' disease. As measured by colour Doppler imaging, the retrobulbar blood vessels showed decreased haemodynamic parameters in patients with Coats' disease on the affected side as compared to the contralateral unaffected side, in particular in advanced stages of the disease. Future studies may address the causes and effects of these haemodynamic changes.

Change of retrobulbar artery hemodynamics and bulbar conjunctival microcirculation indexes of patients with optic atrophy

Change of retrobulbar artery hemodynamics and bulbar conjunctival microcirculation indexes of patients with optic atrophy

The role of lipid dysregulation and vascular risk factors in glaucomatous retrobulbar circulation.

The aim of this study was to evaluate selected lipid-related and vascular factors and their effect on retrobulbar hemodynamics in glaucoma. Fifty-six patients with primary open angle glaucoma (POAG) [POAG group; mean age 68.32 years (SD±0.21)] and 54 patients in control group [CG, mean age 68.1 years (SD±5.34)] were examined. Peak systolic velocity, end-diastolic velocity, mean velocity, pulsatility index, and resistive index of the ophthalmic artery, the central retinal artery and the posterior ciliary arteries were measured by Color Doppler Imaging. Selected lipid-related, systemic and local vascular parameters were evaluated. Statistical methods included Shapiro-Wilk, Student-t and Mann-Whitney U tests, and Spearman rank correlations. In POAG group systolic arterial blood pressure, diastolic arterial blood pressure, total cholesterol, low density lipoprotein cholesterol (LDL-ch), and intraocular pressure were significantly higher; while ocular perfusion pressure, high density lipoprotein cholesterol (HDL-ch) and diastolic ocular perfusion pressure were significantly lower (p≤0.05). Color Doppler Imaging confirmed blood flow abnormalities in all investigated arteries. In addition, significant correlations of HDL-ch, LDL-ch and triglycerides (TG) with peak systolic velocity, end-diastolic velocity and mean velocity were found in individual arteries (p≤0.05). Also, significant associations of systolic arterial blood pressure, ocular perfusion pressure, systolic oclular perfusion pressure and diastolic ocular perfusion pressure with peak systolic velocity, end-diastolic velocity, mean velocity and resistive index were revealed in the posterior ciliary arteries (p≤0.05). Dysregulation of lipid-related and vascular factors, as well as statistical correlation between the above and retrobulbar blood flow indices, might imply their role in vasoconstrictive processes during glaucomatous endotheliopathy.

Retrobulbar Hemodynamics and Visual Field Progression in Normal Tension Glaucoma: A Long-Term Follow-Up Study.

Purpose. Vascular risk factors are important factors in the pathogenesis of glaucoma. The purpose of this research was to investigate retrobulbar hemodynamics and visual field progression in patients with normal tension glaucoma (NTG). Patients and Methods. 31 eyes of 16 patients with NTG were included in a retrospective long-term follow-up study. Colour Doppler imaging was performed at baseline to determine various CDI parameters in the different retrobulbar vessels. The rate of visual field progression was determined using the Visual Field Index (VFI) progression rate per year (in %). To be included in the analysis, patients had at least 4 visual field examinations with a follow-up of at least 2 years. Results. Mean follow-up was 7.6 ± 4.1 years with an average of 10 ± 5 visual field tests. The mean MD (mean defect) at baseline was −7.61 ± 7.49 dB. The overall VFI progression was −1.14 ± 1.40% per year. A statistical significant correlation between VFI progression and the RI of the NPCA and PSV of the CRA was found. Conclusion. Long-term visual field progression may be linked to impaired retrobulbar hemodynamics in patients with NTG only to a limited degree. Interpretation of the data for an individual patient seems to be limited due to the variability of parameters.