Color Doppler imaging of the ocular ischemic syndrome.

PURPOSE: This study describes hemodynamic characteristics of the ophthalmic, central retinal, and posterior ciliary arteries in 16 eyes of 11 patients with the ocular ischemic syndrome. Understanding the hemodynamic characteristics of the retrobulbar circulation may elucidate the natural history and pathophysiology of the ocular ischemic syndrome and perhaps form the basis for rational treatment of this condition. METHODS: Color Doppler imaging, a procedure that permits rapid noninvasive imaging of the ophthalmic, central retinal, and posterior ciliary arteries, was used to quantitate peak systolic blood flow velocities and vascular resistance (pulsatility index) within these vessels in study group eyes and in an age-matched control population. RESULTS: We demonstrated markedly reduced ocular ischemic syndrome central retinal and posterior ciliary artery peak systolic velocities compared with control group eyes. Central retinal and posterior ciliary artery vascular resistance (pulsatility index) was greater in ocular ischemic eyes versus control group eyes. Reversal of ophthalmic artery blood flow was detected in 12 of 16 ocular ischemic syndrome eyes. Study group eyes with poor vision had no detectable posterior ciliary arterial blood flow. CONCLUSION: Color Doppler imaging quantitates hemodynamic characteristics of the retrobulbar circulation in the ocular ischemic syndrome. There is markedly reduced peak systolic velocity and increased vascular resistance in ocular end arteries such as the central retinal and posterior ciliary arteries. Ophthalmic artery reversal of flow seems to represent collateral blood flow to lower resistance vascular beds. Posterior ciliary artery hypoperfusion may correlate with poor vision in the ocular ischemic syndrome.     

Color Doppler imaging of the retrobulbar circulation in non-exudative and exudative age-related macular degeneration

PURPOSE: To study ocular perfusion in the ophthalmic artery, central retinal artery, nasal and temporal posterior ciliary : arteries in non-exudative and exudative age-related macular degeneration. MATERIAL AND METHODS: Twenty five subjects with non-exudative age-related macular degeneration were compared to twenty five subjects with exudative age-related macular degeneration and to twenty five age-matched control subjects. Color Doppler imaging measured peak systolic velocity (PSV) and end diastolic velocity (EDV) in the ophthalmic artery, central retinal artery, nasal and temporal posterior ciliary arteries of one eye. The resistivity index (RI) and the pulsatility index (PI) were calculated. RESULTS: There were statistically significant differences between: subjects with non-exudative age-related macular degeneration and subjects with exudative age-related macular degeneration in EDV, RI and PI in the ophthalmic artery and PSV in the temporal posterior ciliary artery, subjects with non-exudative age-related macular degeneration and control subjects in RI in central retinal artery, subjects with non-exudative age-related macular degeneration and control subjects in RI and PI in nasal posterior ciliary artery, subjects with exudative age-related macular degeneration and control subjects in PI in nasal posterior ciliary artery. CONCLUSIONS: The study results showed reduced ocular blood flow in patients with non-exudative age-related macular degeneration compared to patients with exudative age-related macular degeneration and to control subjects. The higher RI in central retinal artery in non-exudative age-related macular degeneration compared to control subjects, suggest there may be a more generalized perfusion abnormality beyond the choroid.     

Ocular blood flow in healthy and primary open-angle glaucomatous eyes

PURPOSE: To evaluate blood flow parameters in the ophthalmic artery, in the posterior ciliary arteries and in the central retinal artery in eyes with primary open-angle glaucoma. METHODS: Hemodynamic parameters were evaluated by color Doppler imaging in 48 patients with primary open-angle glaucoma and 42 age-matched normal control subjects. Peak systolic velocity (Pv), end-diastolic velocity (Ev), and resistive index (RI) were calculated in the central retinal artery, short posterior ciliary arteries and the ophthalmic artery. RESULTS: The analysis of the ocular blood flow velocities in the central retinal artery, short posterior ciliary arteries and the ophthalmic artery revealed a significant reduction in peak systolic velocity and end-diastolic velocity with an increase in resistive index in primary open-angle glaucoma compared with controls (p < 0.05). CONCLUSION: Our data indicate primary open-angle glaucoma to be associated with a decreased flow velocity and increased resistive index in the ocular vasculature.     

Application of Color Doppler ultrasonography in the evaluation of the blood flow in the ocular vessels in patients with anterior ischemic optic neuropathy--the preliminary report

PURPOSE: Anterior ischemic optic neuropathy (AION) is one of the most common causes of acute loss vision in the middle-aged and elderly persons. It occurs due to hypoperfusion in the short posterior ciliary arteries supplying the optic nerve head. The aim of our study was evaluation of the usefulness of colour Doppler ultrasonography in diagnostics of AION. MATERIAL AND METHODS: Color Doppler imaging of the ophthalmic artery, central retinal artery and posterior ciliary arteries were performed in 10 patients with clinically evident AION. The peak-systolic velocity (PSV), end-systolic velocity (EDV) and resistance index (RI) were measured. RESULTS: No significant differences in the mean values of PSV, EDV and RI of ophthalmic arteries and posterior ciliary arteries between the affected and non-affected eyes were found. Reduction of mean flow velocities as well as significantly increased resistance index were observed in the central retinal artery in eyes with AION. CONCLUSIONS: The Color Doppler findings in the ciliary arteries do not reflect the ischemic changes in patients with AION. It is probably due to anatomical limitation of this method in evaluation of the blood flow in posterior ciliary arteries supplying the optic nerve head. Abnormal blood flow parameters in the central retinal artery are secondary changes due to optic disc oedema.     

Assessment of blood flow in the ocular circulation in type 2 diabetes patients with Color Doppler imaging

PURPOSE: Color Doppler assessment of blood flow in ocular circulation in type 2 diabetes patients. MATERIAL AND METHODS: Total of 56 patients were included in the study and divided into 3 groups: group I--control group, group II--type 2 diabetes patients without diabetic retinopathy, group III--type 2 diabetes patients with nonproliferative diabetic retinopathy. USG Color Doppler method was used in all patients to assess peak systolic blood velocity (PSV), end-diastolic blood velocity (ESV) and resistivity index (RI) in the following arteries: ophthalmic artery (OA), central retinal artery (CRA), short posterior ciliary artery (SPCA). In addition several clinical parameters including age, diabetes duration, blood pressure, body mass index (BMI) and blood glucose level with empty stomach were statistically analyzed. RESULTS: Peak systolic blood velocity (PSV) and end-diastolic blood velocity (ESV) in ophthalmic artery (OA) in diabetic patients were significantly lower in comparison to the control group. Peak systolic blood velocity (PSV) and end-diastolic blood velocity (ESV) in central retinal artery (CRA) were significantly lower only in patients with diabetic retinopathy. In short posterior ciliary arteries (SPCA) only peak systolic blood velocity (PSV) was decreased in patients with diabetic retinopathy. Average age of patients was significantly higher in the group with diabetic retinopathy. Diabetes duration was significantly longer in group III in comparison to group II. CONCLUSIONS: Color Doppler imaging method is useful for assessing blood flow in ocular circulation. Blood flow in ophthalmic artery is decreased in patients with diabetes. Reduction of blood flow in central retinal artery and short posterior ciliary arteries can be significant in the development of diabetic retinopathy.     

Blood flow parameters in ocular vessels of patients with glaucoma

PURPOSE: To determine Doppler flow parameters in ocular vessels of glaucomatous patients. MATERIAL AND METHODS: 38 glaucomatous patients, aged 64 +/- 16, and 57 healthy volunteers were examined with 7.5 MHz linear-array probe. Consistently identified arterial structures included ophthalmic artery, central retinal artery and short posterior ciliary arteries. The peak systolic, end-diastolic and mean velocities were measured from Doppler spectra. Resistance and pulsatility indices were also determined. RESULTS: End-diastolic and mean velocities in central retinal artery of glaucomatous eyes were: 1.5 +/- 1.9 cm/s, 4.0 +/- 2.0 cm/s, whereas in healthy eyes they were significantly higher: 3.5 +/- 1.0 cm/s, 5.4 +/- 1.5 cm/s, respectively. These velocities in short posterior ciliary arteries in glaucomatous patients were significantly lower: 2.4 +/- 2.3 cm/s, 5.6 +/- 2.2 cm/s, comparing to healthy subjects: 4.8 +/- 1.7 cm/s, 7.3 +/- 2.2 cm/s. Resistance and pulsatility indices in central retinal artery and short posterior ciliary arteries were significantly higher in the group of patients: RI = 0.85 +/- 0.18, PI = 2.11 +/- 0.92--in central retinal artery and RI = 0.81 +/- 0.18, PI = 1.96 +/- 0.91--in short posterior ciliary arteries, comparing to healthy subjects: RI = 0.61 +/- 0.08, PI = 1.20 +/- 0.17--in central retinal artery, RI = 0.61 +/- 0.09, PI = 1.13 +/- 0.18--in short posterior ciliary arteries. Impedance indices were increasing progressively with intraocular pressure elevation. There were no significant differences of Doppler blood flow parameters in ophthalmic artery between patients and control group. CONCLUSIONS: Blood flow velocities in central retinal and short posterior ciliary arteries are lower, and resistance and pulsatility indices are higher in glaucomatous eyes in comparison to healthy subjects, whereas in ophthalmic artery doppler parameters are similar in both groups.     

Color Doppler imaging in evaluation of optic nerve blood supply in normal and glaucomatous subjects

The authors evaluate by means of Color Doppler Imaging (CDI) the blood flow in ophthalmic artery, posterior ciliary arteries and central retinal artery in a group of glaucomatous patients. The data obtained in this study show a statistically significant reduction of the mean systolic peak flow velocity in ophthalmic artery in glaucomas in comparison with controls. In Glaucomatous patients with uncontrolled IOP there was a reduction of end-diastolic flow velocities and a rise of resistivity index in ciliary arteries and central retinal artery.     

Estimation of Doppler qualitative blood flow parameters in the eyeball arteries in early pregnancy

PURPOSE: The study was aimed to evaluate changes in Doppler blood flow indices in the eyeball arteries in women in the early stage of pregnancy compared with non pregnant woman. MATERIAL AND METHODS: Color Doppler imaging (CDI) of ophthalmic artery, central retinal artery and posterior ciliary arteries was performed in 15 health pregnant women between 6 and 9 weeks of gestation and in 13 non pregnant women. RESULTS: S/D values were statistically significantly higher in women in early pregnancy, compared with non pregnant woman. In the eyeball arteries, of both pregnant and non pregnant woman, blood flow indices were the highest in the ophthalmic artery, and decline subsequently in the central retinal artery and ciliary posterior arteries. CONCLUSIONS: Women in early pregnancy had higher values of all blood flow parameters but only values of systolic-diastolic index was statistically significant.     

Value of color doppler imaging in the diagnosis of occlusive retinal venous lesions

A hundred and twenty-five patients aged 47 to 72 years who had retinal venous occlusions were examined. Occlusion of the central retinal vein (CRV) was observed in 82 (65.6%) patients and that of CRV branches was seen in 43 (34.4%) patients. In all the patients, color Doppler imaging (CDI) was performed to study blood flow in the ophthalmic artery, central retinal artery (CRA), CRV, and short posterior ciliary arteries. The study indicated a marked reduction in diastolic velocity, no diastolic component of the Doppler blood flow spectrum, and a significant increase in the CRA resistance index (from 0.9 to 1.0), and a pronounced decrease in the maximum systolic velocity in the CRV, as well as a considerable reduction in blood flow velocity parameters, and a rise in the resistance index in the ophthalmic artery and short posterior ciliary arteries. CDI is a highly informative, non-invasive technique that makes it possible to study the blood flow in the CRA and CRV for the evaluation the severity of disease and the efficiency of therapy for occlusive retinal venous lesions.     

Comparison of colour Doppler imaging of orbital vessels in elderly compared with young adult patients.

PURPOSE: Colour Doppler imaging provides an estimate of the velocity of blood flow in vessels supplying the eye. METHODS: To assess changes in orbital blood flow with age, we used a method to study peak systolic velocity in 20 young normal patients, mean age 25.2+/-2.4 years and 30 elderly normal patients, mean age 69.5+/-7.9 years. RESULTS: Peak systolic velocity was significantly higher in the central retinal artery and the temporal division of the posterior ciliary artery in elderly patients. There was greater variation in the peak systolic velocity readings in the distal part of the ophthalmic artery in the elderly than in the younger group. There was greater variation in the pulsatility index in the central retinal artery in young subjects. CONCLUSIONS: Though not large, these differences suggest changes in the orbital blood vessels with age which could affect the development of disease processes in elderly patients. These changes should be taken into account when assessing blood flow in elderly patients.     

Reduced ocular blood flow in asymmetric glaucoma: cause or effect?

Carotid Doppler measures blood flow velocity and vascular resistance index in the central retinal arteries and short posterior ciliary arteries. The blood flow profile of the optic nerve in chronic angle-closure glaucoma (CACG), however, has not been well documented. We report a 48-year-old female patient who presented with grossly asymmetric CACG and was evaluated by carotid Doppler. The patient had coexistent reduced blood flow in the ophthalmic artery of the more afflicted eye. Color Doppler imaging clarifies hemodynamic alterations in the glaucomatous optic nerve and helps to identify vascular aspects of the disease and its treatment.     

Ocular blood flow parameters after pars plana vitrectomy in patients with diabetic retinopathy.

BACKGROUND: Whereas the anatomic result of vitrectomy in patients with vitreoretinal complications due to diabetes is usually satisfying, the functional outcome is sometimes poor. The authors investigated whether this may be related in part to effects of vitrectomy on ocular perfusion. METHODS: Ocular hemodynamics were measured before vitrectomy and 1 and 4 weeks postoperatively in 13 consecutive diabetic patients. Pulsatile choroidal blood flow was assessed with laser interferometric measurement of fundus pulsation amplitude. In addition, mean blood flow velocity and resistive index in the ophthalmic artery, the central retinal artery, and the posterior ciliary arteries were measured with color Doppler imaging. RESULTS: Fundus pulsation amplitude was significantly reduced after surgery as compared to baseline (baseline: 3.7 +/- 1.0 microm; 4 weeks: 3.1 +/- 0.8; P < 0.001). Postoperatively, mean blood flow velocity in the central retinal artery (P = 0.009) and the posterior ciliary arteries (P = 0.0006) was significantly reduced, whereas resistive index was increased in the central retinal artery (P = 0.028) but not in the posterior ciliary arteries. CONCLUSIONS: The current data suggest that vitrectomy induces significant reductions in ocular blood flow in patients with diabetic retinopathy. Whether this may affect the visual outcome after vitrectomy or whether this reflects improved retinal oxygenation after vitrectomy remains to be established.     

Ocular and orbital vascular blood flow in patients with endocrine ophthalmopathy

Twenty patients with endocrine ophthalmopathy (EOP) (40 eyes) were examined, of them 11, 14, and 15 eyes were in a state of compensation, subcompensation, and decompensation, respectively. Color Doppler imaging was made in all the patients in order to study blood flow in the ophthalmic artery, retinal central artery, retinal central vein, posterior short ciliary arteries, posterior long ciliary arteries, and superior ophthalmic vein. There was a significant reduction in end diastolic blood flow velocity and a pronounced increase in the orbital arteries, which is typical of the ocular ischemic syndrome. The patients in a stage of EOP decompensation were found to have lowest values of the maximum systolic blood flow velocity in the retinal central vein and superior ophthalmic vein. The higher values of the maximum blood flow velocity in the orbital arteries in patients with decompensated EOP resulted from orbital pathological processes that may be largely determined by congestive processes rather than orbital inflammation.     

急性眼压改变对兔眼球后动脉血流动力学的影响

目的应用超声彩色多普勒诊断仪对短期内不同眼压条件下兔眼球后动脉的血流动力学参数进行对比研究。为临床上选择降眼压、改善眼球后动脉血流药物的筛选提供理论依据。方法进行兔左眼球后动脉的自身对照研究：制作兔眼的高眼压模型。测量正常眼压、高眼压及高眼压后人为再恢复至正常眼压这三种条件下眼球后动脉血流动力学参数。结果兔眼动脉、视网膜中央动脉、睫状动脉主干及睫状后短动脉均为低阻力血管,当眼压迅速增高时,以上各动脉的血流阻力指数增高,流速降低,当使眼压短期内恢复正常后,大部分血流参数不能恢复至正常水平。结论眼压短期内的变化影响眼球后动脉血流动力学的变化。彩色多普勒超声测量技术是对这种改变进行监测的较好方法。     

Color Doppler imaging of the orbital vessels in Behçet's disease

OBJECTIVE: To investigate blood flow velocity changes, pulsatility and resistivity index values of orbital vessels in Beh?et's disease with or without ocular involvement (groups I and II) and healthy volunteers (group III). METHODS: Twenty-five eyes in the first group, 24 eyes in the second group and 24 eyes in the third group were examined by using color Doppler imaging. Peak systolic and end-diastolic blood flow velocity measurements, pulsatility and resistivity index values were measured in ophthalmic, central retinal, nasal and temporal ciliary arteries and the central retinal vein. RESULTS: The end-diastolic blood flow velocity measurements in all arteries were significantly higher in groups II and III than in group I, but resistivity and pulsatility indexes of all arteries were higher in group I than the other two groups. There was no significant difference in blood flow velocity of the central retinal vein in the three groups. CONCLUSION: Detection of increased vascular resistance of orbital vessels may predict the diagnosis of ocular involvement in Beh?et's disease.     

Color Doppler imaging of choroidal circulation in patients with asymmetric age-related macular degeneration

We aimed at evaluating the possible role of choroidal perfusion abnormalities in the development of choroidal neovascularisation (CNV) in patients with age-related macular degeneration (AMD). Twenty-six patients who had non-exudative AMD in the first eye and CNV secondary to AMD in the fellow eye were enrolled. Blood flow velocities, vessel pulsatilities and resistivities were measured from ophthalmic artery, nasal and temporal posterior ciliary arteries using colour Doppler imaging. Systolic and diastolic velocities were lower in eyes with CNV for all vessels, except for the systolic velocity of the nasal posterior ciliary artery (p >0.05). Pulsatility and resistivity indices were higher in eyes with CNV for all vessels. This difference was statistically significant for the resistivity index of the nasal and temporal posterior ciliary arteries (p = 0.032 and p = 0.021, respectively) and the pulsatility index of the nasal posterior ciliary artery (p = 0.035). We have shown that in patients with AMD choroidal blood flow is more impaired in the eyes with CNV than in the fellow eyes.     

Relationship between the effect of carbon dioxide inhalation or nilvadipine on orbital blood flow in normal-tension glaucoma

PURPOSE: To investigate the relationship between the effect of carbon dioxide (CO2) inhalation or oral nilvadipine, a calcium-channel blocker, on orbital blood flow in patients with normal-tension glaucoma, as determined by color Doppler imaging. PATIENTS AND METHODS: Sixteen patients with normal-tension glaucoma (mean age, 55.6+/-9.8 years; male:female ratio, 3:13) underwent color Doppler imaging to measure the resistance index, and peak systolic and end-diastolic blood flow velocities of the ophthalmic artery, central retinal artery, and nasal and temporal short posterior ciliary arteries. Measurements were taken before and during CO2 supplementation sufficient to increase the end-tidal CO2 partial pressure by 10%. The color Doppler imaging measurements were repeated after 2 to 4 weeks of treatment with 2 mg oral nilvadipine, and comparisons were made between the effects of the two treatments. RESULTS: Both CO2 inhalation and nilvadipine treatment significantly reduced the resistance index in the central retinal artery, nasal short posterior ciliary artery, and temporal short posterior ciliary artery. There was a significant correlation between the effects of the two treatments on the difference in the resistance indexes of the ophthalmic artery and central retinal artery, but not on those of the nasal or temporal short posterior ciliary artery. CONCLUSIONS: Both CO2 inhalation and oral nilvadipine significantly reduce the resistance index measured by color Doppler imaging in orbital vessels. The effect of oral nilvadipine might be predicted by CO2 inhalation in patients with normal-tension glaucoma.     

Relationship between blood flow velocities in retrobulbar vessels and laser Doppler flowmetry at the optic disk in glaucoma patients

The relationship between blood flow velocities in retrobulbar vessels and blood flow at the optic nerve in glaucoma patients was assessed in a prospective study. The Heidelberg retina flowmeter (HRF) was used to assess optic nerve head blood flow in 13 open-angle glaucoma patients. In the same patients, color Doppler imaging (CDI) measurements were obtained from the ophthalmic artery, the central retinal artery and the posterior ciliary arteries. Using data for one randomly selected eye per subject, correlations between HRF recordings and CDI measurements were evaluated by means of Spearman's rank correlation factor. All three HRF parameters correlated with CDI measurements obtained from retrobulbar vessels. The most marked correlations were those of the HRF parameter 'volume' with the end-diastolic velocity in the ophthalmic artery and the medial posterior ciliary artery (R = 0.79, p = 0.0012 and R = 0.81, p = 0.0007, respectively), and the peak systolic velocity in the lateral posterior ciliary artery (R = 0.82, p = 0.0006). The present study suggests that glaucoma patients with altered blood flow in retrobulbar vessels are likely to show an alteration in optic nerve blood flow as measured with the HRF.     

Color Doppler imaging discloses reduced ocular blood flow velocities in nonexudative age-related macular degeneration.

PURPOSE: To study ocular perfusion defects in age-related macular degeneration. METHODS: Twenty-five subjects with nonexudative age-related macular degeneration were compared with 25 age-matched control subjects in studies of flow velocities in several retrobulbar vessels. Color Doppler imaging, which was performed by an examiner who was masked to the subjects' assignment to the control or age-related macular degeneration group, measured peak systolic and end diastolic velocity in the ophthalmic, central retinal, and nasal and temporal posterior ciliary arteries of one eye. A resistive index was calculated from the peak systolic and end diastolic velocity. RESULTS: Subjects with nonexudative age-related macular degeneration showed a consistent trend toward lower peak systolic and end-diastolic velocities in the posterior ciliary arteries. For example, in the nasal posterior ciliary artery, the mean end diastolic velocity measured 1.45 +/- 0.34 cm per sec in the age-related macular degeneration group compared with 1.96 +/- 0.66 cm per sec in the control group, yielding a 26% decrease in the age-related macular degeneration group, which represented the largest difference and was highly statistically significant (P = .0012). The resistive index was not significantly altered in the nasal or temporal posterior ciliary artery. Subjects with nonexudative age-related macular degeneration did not differ from control subjects in peak systolic velocity, end diastolic velocity, or resistive index in the ophthalmic artery. In the central retinal artery, the end diastolic velocity was lower (1.37 +/- 1.95 cm per sec vs 1.95 +/- 0.66 cm per sec), whereas the resistive index was higher (0.83 +/- 0.05 vs 0.76 +/- 0.06 cm per sec), in the age-related macular degeneration group; these results were highly statistically significant (P = .0007 and P < .0001, respectively). CONCLUSIONS: Retrobulbar vascular changes in nonexudative age-related macular degeneration subjects include reduced flow velocities in the nasal and temporal posterior ciliary arteries. The reduced peak systolic velocity, combined with the reduced end diastolic velocity at a constant resistive index, seen in nonexudative age-related macular degeneration, is consistent with reduced bulk flow in these vessels, suggesting that choroidal perfusion is abnormal in this form of age-related macular degeneration. The changes in the central retinal artery suggest there may be a more generalized perfusion abnormality beyond the choroid in patients with age-related macular degeneration or that the central retinal artery exhibits a secondary autoregulatory response to a primary change elsewhere.     

Early postcontusion eyeball circulation as evidenced by color Doppler mapping

Early postcontusion hemodynamic disorders were studied, by analyzing the results of color Doppler mapping. The study included patients aged 10 to 45 years with moderate and severe postcontusion retinal changes and a visual acuity of 0.8 to 0.01. Color Doppler mapping was used to visualize blood flow in the ophthalmic artery, central retinal artery, and posterior short ciliary arteries. Preliminary studies revealed circulatory changes in the ophthalmic arterial system in the early postcontusion period. In severe macular and optic nerve lesions, a significant reduction in blood flow was detectable in all the vessels under study, but there was its more pronounced reduction in the central retinal artery and posterior short ciliary arteries, which directly corrected with the found retinal changes since these arteries are the only source of retinal circulation.