Retrobulbar Hemodynamics Research Articles

Evaluación mediante ecografía doppler color del efecto de la combinación fija bimatoprost/timolol sobre el flujo sanguíneo ocular en pacientes con hipertensión ocular. Estudio preliminar

Purpose To investigate the effects of topical bimatoprost (0.3 mg/ml)/timolol maleate (5 mg/ml) fixed combination on retrobulbar blood flow in patients with ocular hypertension (OHT). Patients and methods Twenty consecutive patients with OHT were prospectively randomised to either bimatoprost/timolol or placebo during a 12 weeks double masked treatment trial. Examinations were performed at baseline and after 12 weeks of treatment. Visual acuity, intraocular pressure (IOP), slit-lamp examination, automated static perimetry, systemic blood pressure and heart rate were all recorded. Retrobulbar blood flow measurements of the ophthalmic artery (AO) and central retinal artery (CRA) were measured by colour Doppler imaging. Results IOP was significantly decreased by bimatoprost/timolol fixed combination (p < 0.0001). Bimatoprost/timolol fixed combination therapy resulted in a significant increase in end diastolic velocity (EDV) of the CRA (p = 0.03). In patients treated with bimatoprost/timolol a statistically significant correlation between IOP and EDV was observed after 12 weeks of treatment (r = −0.511, p = 0.045). The systolic (p = 0.54) and diastolic (p = 0.67) blood pressures and heart rate (p = 0.10) did not show statistically significant differences during the study period. Conclusions Topical bimatoprost/timolol fixed combination significantly reduced IOP in patients with OHT. However, the only significant change observed in retrobulbar haemodynamics was an increase in EDV of the CRA, probably associated with a reduction in IOP.

Evaluation of the effect of bimatoprost/timolol fixed combination on ocular blood flow in patients with ocular hypertension using colour Doppler imaging. Preliminary study

PurposeTo investigate the effects of topical bimatoprost (0.3mg/ml)/timolol maleate (5mg/ml) fixed combination on retrobulbar blood flow in patients with ocular hypertension (OHT). Patients and methodsTwenty consecutive patients with OHT were prospectively randomised to either bimatoprost/timolol or placebo during a 12 weeks double masked treatment trial. Examinations were performed at baseline and after 12 weeks of treatment. Visual acuity, intraocular pressure (IOP), slit-lamp examination, automated static perimetry, systemic blood pressure and heart rate were all recorded. Retrobulbar blood flow measurements of the ophthalmic artery (AO) and central retinal artery (CRA) were measured by colour Doppler imaging. ResultsIOP was significantly decreased by bimatoprost/timolol fixed combination (p<0.0001). Bimatoprost/timolol fixed combination therapy resulted in a significant increase in end diastolic velocity (EDV) of the CRA (p=0.03). In patients treated with bimatoprost/timolol a statistically significant correlation between IOP and EDV was observed after 12 weeks of treatment (r=−0.511, p=0.045). The systolic (p=0.54) and diastolic (p=0.67) blood pressures and heart rate (p=0.10) did not show statistically significant differences during the study period. ConclusionsTopical bimatoprost/timolol fixed combination significantly reduced IOP in patients with OHT. However, the only significant change observed in retrobulbar haemodynamics was an increase in EDV of the CRA, probably associated with a reduction in IOP.

A Comparison of the Long-Term Effects of Dorzolamide 2% and Brinzolamide 1%, Each Added to Timolol 0.5%, on Retrobulbar Hemodynamics and Intraocular Pressure in Open-Angle Glaucoma Patients

To compare the effect on the retrobulbar hemodynamics and intraocular pressure (IOP) of dorzolamide 2% and brinzolamide 1%, each added to timolol 0.5% in patients with primary open-angle glaucoma (POAG). 146 POAG patients were prospectively randomized to receive either dorzolamide 2% or brinzolamide 1% BID, each added to timolol 0.5%, during a 60-month evaluator-masked study. At baseline and every 6 months for 60 months, we measured the retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCA) using color Doppler imaging (CDI), intraocular pressure (IOP), and blood pressure measurements. Dorzolamide significantly increased the end-diastolic velocity (EDV) in the OA in 1.22 cm/s, 95% confidence interval (95% CI) 0.90-1.56 cm/s, P < 0.001 and reduced the resistivity index (RI) in the OA in 0.04 units, 95% CI 0.03-0.05, P < 0.001. None of the retrobulbar parameters changed significantly on therapy with brinzolamide when the results were analyzed at month 60. Both dorzolamide and brinzolamide significantly decreased IOP (-4.3, 95% CI -4.5 to -4.2 mmHg and -4.3, 95% CI -4.4 to -4.2 mmHg, respectively). Dorzolamide significantly reduced the RI in the OA from 0.74 (0.02) to 0.70 (0.02), CRA from 0.66 (0.02) to 0.62 (0.02), and SPCA from 0.66 (0.02) to 0.62 (0.02), P < 0.001, respectively. Our results suggest augmented retrobulbar blood flow after 5 years of treatment with dorzolamide but not with brinzolamide, each added to timolol, in POAG patients.

Colour Doppler imaging evaluation of blood flow parameters in the ophthalmic artery in acute and chronic phases of optic neuritis in multiple sclerosis

Optic neuritis (ON) is a common manifestation of multiple sclerosis (MS). It is caused by the immune-mediated inflammation of the optic nerve. Some vascular factors that may influence blood flow in the ophthalmic artery (OA) have also been suggested as factors in the pathogenesis of ON. The purpose of our study was to evaluate blood flow velocities and resistance (RI) and pulsatile (PI) indices in the OA in both orbits in patients in the acute and chronic phases of unilateral ON and to compare these with equivalent findings in healthy control subjects. Orbital colour Doppler imaging (CDI) was performed in 40 consecutive MS patients during acute unilateral ON prior to corticosteroid treatment. Optic neuritis was diagnosed on the basis of clinical presentation and facultative assessment of visual evoked potentials (VEPs). The peak systolic (PSV) and end-diastolic (EDV) velocities and RI and PI were measured in the OA in both eyes. We compared results from affected and unaffected orbits using the paired t-test. The same measurements were performed in 114 MS patients with a history of acute unilateral ON that occurred > 1 year prior to ultrasound examination. We also measured the same parameters in the middle cerebral arteries (MCAs) on both sides in all subjects in both groups. The same measurements were obtained in healthy controls. The PSV (p < 0.0001), RI (p < 0.0001) and PI (p < 0.0001) in the OA in the eye affected with acute ON were significantly higher than in the unaffected eye. There was no difference in EDV in the OA between affected and unaffected eyes (p > 0.05) in the group with acute ON. We did not observe any significant differences between eyes in either blood flow velocities or the RI or PI (p > 0.05) in the group in the chronic phase of ON or in the control group. All the parameters in the MCAs on both sides were normal in both the acute and chronic groups, as well as in the control group. Pathophysiological changes during acute unilateral ON influence orbital haemodynamics, as is indicated by increased PSV, RI and PI in the OA in eyes affected with ON. However, these changes do not persist over longer periods.

Retrobulbar haemodynamics and carotid wall thickness in patients with non-arteritic anterior ischaemic optic neuropathy

Aim:To compare retrobulbar haemodynamics and ipsilateral carotid wall thickness of patients with unilateral non-arteritic anterior ischaemic optic neuropathy (NAION) with their contralateral side.Methods:Seventeen patients with unilateral NAION participated in this...

Diagnostic compatibility of structural and haemodynamic parameters in open‐angle glaucoma patients

Current evidence indicates that alteration in ocular blood flow may be relevant in open-angle glaucoma (OAG) patients independent of intraocular pressure (IOP). Presently, the lack of an adequate methodology capable of assessing all vascular beds limits the clinical role of blood flow parameters in glaucoma management. We aimed to compare differences in retinal nerve fibre layer (RNFL) thickness and retrobulbar haemodynamics between OAG patients and healthy age-matched control subjects. Sixty eyes of 30 OAG patients and 30 healthy age-matched controls were enrolled into the prospective, randomized study. Retinal nerve fibre layer thickness was analysed by scanning laser polarimetry (SLP). Standard SLP parameters were determined, including: average temporal, superior, nasal, inferior thickness (TSNIT); superior and inferior averages; TSNIT standard deviation (TSNIT-SD), and nerve fibre indicator (NFI). Retrobulbar haemodynamics were assessed using colour Doppler imaging (CDI). Peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistivity index (RI) in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary artery (SPCA) were evaluated. The RNFL in OAG patients was statistically significantly thinner compared with that in age-matched controls: the NFI was 24.9 +/- 10.24 in OAG patients and 16.13 +/- 7.95 in healthy controls (p < 0.05). Statistically significant differences were observed: CRA PSV was 20.54 +/- 7.84 cm/second in OAG subjects and 16.5 +/- 6.19 cm/second in healthy controls (p = 0.0038); OA EDV was 8.99 +/- 4.71 cm/second in OAG subjects and 5.93 +/- 3.23 cm/second in healthy controls (p = 0.0048). Correlation analysis of NFI was in positive association with CRA EDV (r = 0.395; p < 0.05) and CRA PI (r = 0.403; p < 0.05) in OAG subjects, but no statistically significant association was seen in healthy controls. Statistically significant thinning of the RNFL in association with reduced retrobulbar blood flow velocities was observed in OAG patients. Combining ocular structural alterations with ocular circulation assessment may increase our ability to elucidate potential IOP-independent glaucomatous risk factors.

Retrobulbar hemodynamic parameters in pseudoexfoliation syndrome and pseudoexfoliative glaucoma

To compare the hemodynamic parameters in the retrobulbar vessels in pseudoexfoliative syndrome (PXS), pseudoexfoliative glaucoma (PXG), and age-matched healthy subjects by using color Doppler imaging (CDI). 72 eyes from 72 patients with PXS, 70 eyes from 70 patients with PXG, and 66 eyes from 66 age-matched healthy subjects who met the inclusion/exclusion criteria were included in this prospective cross-sectional study. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and Pourcelot resistance index (RI) were assessed in the ophthalmic artery (OA), central retinal artery (CRA), and temporal short-posterior ciliary arteries (SPCA). Visual function was assessed using the 24-2 Swedish Interactive Threshold Algorithm (SITA). The main outcomes of the study were PSV, EDV and RI in the OA, SPCA, and CRA. The EDV in the OA, SPCA and the CRA was decreased significantly (p < 0.001, <0.001, and 0.003 respectively) in the eyes of PXG patients compared with controls and PSX respectively. The RI in the OA, SPCA, and the CRA was significantly higher (p = 0.022, 0.005, and 0.007 respectively) in the eyes of PXG patients compared with healthy controls and PSX patients respectively. The mean difference in mean EDV in the OA between the control group and the PXS was 0.18 cm/s, 95% confidence interval (CI) -0.60 to 0.95, p = 0.661. The mean difference in mean EDV in the SPCA between the control healthy subjects and the pseudoexfoliative subjects was -0.18 cm/s, 95% CI -0.45 to 0.08, p = 0.176. Multivariate regression analysis showed that in the PXG patients the PSV and EDV in the CRA were significantly positively correlated with the mean defect (p = 0.006 and 0.002 respectively). The RI in the CRA was significantly negatively correlated with the mean defect in PXG patients, p = 0.009. The results of this study showed that the retrobulbar hemodynamics might be disturbed in patients with PXG, especially in the central retinal artery. Our results have found no significant differences in the retrobulbar hemodynamic parameters between pseudoexfoliative syndrome patients and age-matched healthy subjects.

The effects of raloxifene hydrochloride on ocular hemodynamics and visual function

To assess the comprehensive effects of raloxifene hydrochloride on retinal, choroidal and retrobulbar hemodynamics and on visual function in post-menopausal women. Twenty-four post-menopausal women (age 55 +/- 3.8 years) were recruited for this cross-sectional study: 12 received placebo and 12 received raloxifene hydrochloride 60 mg once a day for 3 months. Baseline measurements of both groups included heart rate (HR), blood pressure (BP), visual acuity, contrast sensitivity and intraocular pressure (IOP) for both eyes. A comprehensive ocular blood flow (OBF) assessment was obtained for each patient in a randomly chosen study eye. Retinal blood flow data was obtained using confocal scanning laser Doppler flowmetry [Heidelberg Retinal Flowmeter (HRF)]. Color Doppler imaging (CDI) was used to assess retrobulbar hemodynamics in the ophthalmic, central retinal, short nasal and temporal posterior ciliary arteries. Baseline vision and hemodynamics in post-menopausal subjects were compared using paired Student's t tests, and the percentage change in baseline versus 3-month parameters was analyzed. There were no statistically significant differences between 3 months of raloxifene therapy and placebo in terms of age, HR, arterial or mean BP, visual acuity, contrast sensitivity, IOP or retinal or retrobulbar blood flow. Raloxifene therapy at 60 mg/day had no clinically significant impact on BP, IOP or OBF in post-menopausal women.

The Effect of Caffeine on Retrobulbar Hemodynamics

Background: To investigate the acute effect of caffeine on intraocular pressure and retrobulbar blood flow velocity. Methods: In this randomized, double-masked, placebo-controlled, prospective study, we examined the effects of single 300-mg oral administration of caffeine on retrobulbar arteries' hemodynamics by using color Doppler ultrasonography imaging in healthy human volunteers. The subjects were divided into two groups; group 1 received a 300-mg caffeine tablet and group 2 received placebo. Measurements were obtained in two eyes at baseline, and 1 hr after acute ingestion of caffeine. Blood pressure, pulse rate, and intraocular pressure were monitored. Results: When compared with placebo, no significant change in mean blood pressure or intraocular pressure was observed after administration of caffeine. No significant differences were detected in the peak systolic and end diastolic velocities of retrobulbar arteries, compared with baseline values. Resistive index of ophthalmic, central retinal, and short posterior nasal ciliary artery were significantly increased after oral application of caffeine in group 1 (p < 0.05). Conclusion: The vascular resistance of the retrobulbar vessels appears to be altered by caffeine consumption. Further studies are needed to investigate the effects of caffeine on hemodynamics in patients with glaucoma.

Ocular perfusion pressure and retrobulbar haemodynamics in pseudoexfoliative glaucoma

Previous investigations have shown that vascular factors are involved in pseudoexfoliative glaucoma (XFG). The present study aims at comparing ocular perfusion pressure (OPP), diastolic ocular perfusion pressure (dOPP), and retrobulbar haemodynamics in pseudoexfoliative glaucoma and primary open-angle glaucoma (POAG). Forty-seven XFGs, 41 POAGs, and 38 healthy controls were evaluated. OPP and dOPP were calculated. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) were recorded in ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs) by color Doppler imaging (CDI). Correlations between OPP and CDI parameters and between dOPP and CDI parameters were determined. OPP and dOPP were significantly lower in XFGs than in POAGs and controls (p < 0.001). CDI investigation revealed decreased EDV of OA, SPCAs, and CRA (p < 0.001) and increased RI of all the three considered vessels in XFGs compared with POAGs and controls (p < 0.001). A negative correlation between OPP and RI of OA and between dOPP and RI of OA was found in XFGs (p = 0.022 and p = 0.015 respectively). Ocular perfusion pressure is decreased and retrobulbar haemodynamics are worse in pseudoexfoliative glaucoma patients than in primary open-angle glaucoma patients and healthy controls. An impaired ocular vascular regulation is suggested in pseudoexfoliative glaucoma.

Retrobulbar hemodynamics and corneal surface temperature in glaucoma surgery

The purpose of this study was to investigate the effects of glaucoma surgery on retrobulbar hemodynamics and corneal surface temperature (CST). A total of 22 primary open-angle glaucoma eyes underwent deep sclerectomy, and 19 trabeculectomy. The follow-up was of 3 months. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) were evaluated in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs) by color Doppler imaging (CDI). CST was measured using infrared thermography. At 3 months, EDV was increased in OA (P<0.001 in deep sclerectomy, P=0.005 in trabeculectomy), CRA (P=0.044 and P<0.001), and SPCAs (P=0.011 and P=0.003), and RI decreased in OA, CRA, and SPCAs (P<0.001 in both groups). CST values were augmented (P<0.001 in both groups). A negative correlation between the postoperative changes in RI-OA and CST was found (P=0.023 and P=0.032, respectively). Deep sclerectomy and trabeculectomy seem to be equally effective in improving retrobulbar hemodynamics. Color Doppler imaging and infrared thermography might be useful to evaluate the vascular outcome of glaucoma surgery.

Determination of the effect of a single hemodialysis session on retrobulbar blood hemodynamics by color Doppler ultrasonography

Retrobulbar hemodynamic alterations can occur during hemodialysis sessions, and patients with chronic renal failure may experience visual problems. To evaluate the effect of single-session hemodialysis on retrobulbar vessel hemodynamics by color Doppler ultrasonography. Thirty-five patients were included in the study. Retrobulbar blood flows were examined before and after dialysis sessions. Doppler spectral patterns of retrobulbar blood flow were evaluated. The t test for paired samples and the Wilcoxon matched-pairs signed-rank test were used for comparing the flow values before and after dialysis. Systolic and diastolic blood flow velocities of the ophthalmic artery, central retinal artery, central retinal vein, nasal posterior ciliary artery, and temporal posterior ciliary artery were found to be decreased bilaterally after hemodialysis sessions. No significant change was observed in resistivity index values after hemodialysis sessions. Our findings reveal that retrobulbar circulation was disturbed after a single hemodialysis session.

The effect of strabismus surgery on retrobulbar hemodynamics

To investigate the potential alterations of ocular hemodynamics after strabismus surgery using color Doppler ultrasonography. Twenty eyes of 18 patients and the left eyes of 20 healthy age- and sex-matched volunteers were evaluated. Patients were divided into two groups according to the number of operated muscles. Group 1 included seven patients with surgery on one rectus muscle; group 2 included 13 patients with surgery on two rectus muscles. Nine patients underwent adjustable suture eye muscle surgery. The ophthalmic artery, central retinal artery, short posterior ciliary artery, long posterior ciliary artery, and central retinal veins of both groups were examined. With spectral analysis, peak systolic velocity, end-diastolic velocity, resistivity, and pulsatility indices were calculated. There was no difference in the Doppler ultrasonography parameters between the group with surgery on one-horizontal rectus muscle and the group with surgery on two-horizontal rectus muscles. The adjustable suture procedure did not affect retrobulbar hemodynamics. There was no difference between the preoperative and postoperative Doppler examinations. In contrast with some recent studies, our results suggest that the strabismus surgery involving one- or two-horizontal rectus muscles does not have a measurable effect on retrobulbar blood flow.

Altered Retrobulbar Hemodynamics in Patients Who Have Transient Monocular Blindness Without Carotid Stenosis

This study was to evaluate the retrobulbar hemodynamics in patients who have transient monocular blindness (TMB) without carotid stenosis. Fifty-nine patients who have TMB without carotid stenosis were studied along with 59 age- and sex-matched controls. Color Doppler-imaging was used to study the retrobulbar hemodynamic by measuring the flow velocities (peak-systolic velocity, and end-diastolic velocity), vascular resistance indices (pulsatility index, and resistance index) in central retinal arteries, short posterior ciliary arteries, and ophthalmic arteries. The patients were divided into 2 groups according to the attack frequency: group 1 (occasional TMB, 2 or fewer attacks, 26 patients) and group 2 (frequent TMB, 3 or more attacks, 33 patients). The risk factors for atherosclerosis were similar between the cases and controls. The means of end-diastolic velocity were significantly lower in central retinal arteries and ophthalmic arteries, and the pulsatility index and resistance index were significantly higher in all the 3 retrobulbar vessels in TMB patients than for the controls. The differences between patients and controls were greater for the group-2 patients. Patients who have TMB without carotid stenosis had altered retrobulbar hemodynamics with a generalized increase in vascular resistance in the retrobulbar arteries. The role of venous hypertension as an etiology needs further study.

The Relationship Between Retrobulbar and Choroidal Hemodynamics in Non-Neovascular Age-Related Macular Degeneration

To evaluate the relationship between retrobulbar and choroidal hemodynamics in non-neovascular age-related macular degeneration. Thirteen patients with age-related macular degeneration were assessed by both color Doppler imaging and scanning laser ophthalmoscope indocyanine green (ICG) angiography. Color Doppler imaging was used to measure peak systolic and end diastolic velocity (from which the resistance index, a measure of the resistance to flow downstream, was calculated) in the retrobulbar vessels. Scanning laser ophthalmoscope ICG angiograms were analyzed by area dilution analysis for quantitative choroidal fluorescence intensity assessment. Color Doppler imaging parameters were correlated with scanning laser ophthalmoscope ICG area dilution analysis parameters. A good correlation was found between the posterior ciliary arteries resistance index and scanning laser ophthalmoscope ICG area dilution analysis fluorescence duration. Scanning laser ophthalmoscope ICG area dilution analysis "duration" may serve as an alternative to color Doppler imaging in assessing the resistance to blood flow in the posterior ciliary arteries.

A Comparative Analysis of the Effects of the Fixed Combination of Timolol and Dorzolamide Versus Latanoprost Plus Timolol on Ocular Hemodynamics and Visual Function in Patients with Primary Open-Angle Glaucoma

The aim of this study was to assess the effects of fixed combination of timolol and dorzolamide and latanoprost plus timolol on retinal, choroidal, and retrobulbar hemodynamics and visual function in primary open-angle glaucoma (OAG) subjects. Sixteen (16) OAG patients (age, 63.5 +/- 10.8 years; 9 male) were evaluated in a randomized, crossover, double-blind study design after 4 weeks of treatment of latanoprost with timolol and fixed combination of timolol and dorzolamide. After randomization, 9 right eyes and 7 left eyes were included in the hemodynamic portion of the study. Measurements included: adverse events check, visual acuity, contrast sensitivity, blood pressure, heart rate, intraocular pressure (IOP), and fundus examination. Ocular blood flow was assessed using confocal scanning laser Doppler flowmetry, color Doppler imaging, and scanning laser ophthalmoscopy. Both therapies were effective at lowering IOP, whereas there was no statistically significant difference between latanoprost plus timolol and the fixed combination of timolol and dorzolamide (13.9% and 12.2% reduction, respectively; P = 0.5533). Fixed combination of timolol and dorzolamide significantly increased central retinal artery end diastolic blood flow velocity (P = 0.0168) and lowered resistance to flow (P = 0.0279). Temporal posterior ciliary artery peak systolic and end diastolic velocities were significantly increased with the fixed combination of timolol and dorzolamide (P = 0.0125 and 0.0238, respectively). Latanoprost plus timolol had no significant effects on ocular blood flow during 4 weeks of treatment. There were no statistically significant differences in adverse events, blood pressure, heart rate, visual acuity, contrast sensitivity scanning laser ophthalmoscopy, or Heidelberg Retinal Flowmeter for any treatment period. Fixed combination of timolol and dorzolamide therapy might increase blood flow in OAG patients while attaining a similar IOP reduction compared to latanoprost plus timolol. Visual function, however, was not different in this short-term comparison between the two treatments.

Retrobulbar haemodynamics and contrast sensitivity improvements after CO2 breathing

Effects of gas mixtures have been widely studied. Carbon dioxide (CO(2)) is known to act as a vasodilator, whereas oxygen (O(2)) acts as a vasoconstrictor. Therefore, the interpretation of results is difficult. In this study, only the effect of an elevated CO(2) level on retrobulbar hemodynamics and contrast sensitivity was investigated. Thirty adults (age 31 +/- 7) were examined under normocapnic and hypercapnic conditions. Colour Doppler imaging was used to measure the velocity in the ophthalmic and central retinal artery. Moreover, contrast sensitivity using the CSV-1000 was investigated. Blood pressure, heart rate and intraocular pressure (IOP) were measured and ocular perfusion was calculated. Under hypercapnia, mean end tidal CO(2) increased from 36.4 mmHg to 42.5 mmHg and blood oxygen saturation increased from 98.3% to 98.6% (p < 0.0001). Hypercapnia significantly reduced IOP by 0.94 mmHg (p < 0.0008). In the central retinal artery, the mean PSV increased by 18% (p < 0.0001) and the mean EDV by 21% (p = 0.0054). In the ophthalmic artery, the mean PSV increased by 13% (p < 0.0001) and the mean EDV by 26% (p = 0.0002). Furthermore, there was a significant increase of contrast sensitivity (spatial frequency: 3cpd: p = 0.0016; 6cpd: p = 0.005; 12cpd: p = 0.0012). Systolic blood pressure (p = 0.0225), mean arterial blood pressure (p = 0.0097) and ocular perfusion pressure (p = 0.0013) increased significantly. This setting was able to detect an increase in blood flow velocity in normal subjects under hypercapnia. Furthermore, hypercapnia results in a functional improvement in contrast sensitivity, possible due to the increased blood flow or the increase in blood oxygen levels.

Changes in cerebral and ocular hemodynamics in Behçet's disease assessed by color-coded duplex sonography

Aim To quantify the cerebral and retrobulbar hemodynamics in Behçet's disease with and without ocular involvement and compared with that of healthy controls. Materials and methods Of 51 people studied, 17 had Behçet's disease with ocular involvement, 17 had Behçet's disease without ocular involvement, and 17 were healthy controls. A single eye was examined in each patient. Peak systolic velocity (PSV), end-diastolic velocity (EDV), time-averaged maximum velocity (Tamax), and resistance index (RI) were evaluated in the ophthalmic (OA), posterior ciliary (PCA), central retinal (CRA) and middle cerebral artery (MCA). Additionally, the average blood flow velocities in the central retinal vein (CRV), and acceleration time (AT) and pulsatility index (PI) in the MCA were calculated. Results The mean EDV in the PCA was 25% lower and RI was higher in patients with ocular involvement of BD than in patients without involvement ( p = 0.006 and p = 0.005, respectively) and in healthy controls ( p = 0.003 and p = 0.004, respectively). Differences were smaller in comparisons of the CRA and absent on comparisons of the OA and MCA. The acceleration time of the MCA was significantly higher in patients with Behçet's disease than in healthy controls ( p = 0.03). Conclusion This study suggests that the flow hemodynamics in retrobulbar circulation has more altered Behçet's disease with ocular involvement than without ocular involvement and healthy control. Additionally, the cerebral hemodynamic might be affected in patients with Behçet's disease compared with healthy controls.

Asymmetric visual field loss and retrobulbar haemodynamics in primary open-angle glaucoma

To investigate interocular differences in retrobulbar flow velocities in patients with asymmetric glaucomatous visual field loss. Twenty-five patients with primary open-angle glaucoma (POAG) and asymmetric visual field loss were included in this study. Asymmetric visual field loss was defined as a difference of the global index mean deviation (MD) >6 dB between the two eyes. Flow velocities (peak systolic velocity PSV and end-diastolic velocity EDV) and resistive indices (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and nasal and temporal posterior ciliary arteries were measured by means of colour Doppler imaging. MD of eyes with more severe glaucomatous visual field loss was -18.3+/-7.8 dB vs -6.8+/-5.5 dB (p<0.0001) in the less affected eyes. The PSV and the EDV of the CRA and the PSV of the OA were significantly decreased in eyes with more severe glaucomatous visual field loss (CRA PSV: 7.6+/-2.0 cm/s vs 8.3+/-1.7 cm/s, p=0.04; CRA EDV: 2.24+/-0.5 cm/s vs 2.55+/-0.6 cm/s, p<0.007; OA PSV: 29.7+/-9.9 cm/s vs 32.7+/-11.5 cm/s, p<0.02). None of the other differences in velocity or resistive index were significant. Patients with asymmetric glaucomatous visual field loss exhibit asymmetric flow velocities of the CRA and OA. Patients with more severe damage display reduced flow velocities in retrobulbar vessels in POAG.

Effect of Oxymetazoline Nasal Spray on Intraocular Pressure and Retrobulbar Hemodynamics

To determine the effect of oxymetazoline nasal spray on intraocular pressure and retrobulbar hemodynamics in patients with open-angle glaucoma and to compare the results with those measured in healthy control participants. Controlled, prospective clinical trial. University hospital. Thirty patients with open-angle glaucoma and 30 healthy volunteers as controls were topically self-administered oxymetazoline nasal spray three times a day (one spray in each nostril of 0.05% concentration) for 5 days continuously. Intraocular pressure and retrobulbar hemodynamics were measured in glaucomatous and normal eyes at baseline and at the end of oxymetazoline application . Oxymetazoline nasal spray lowered intraocular pressure significantly in both the glaucoma group (p = .02) and the control group (p = .001) after 5 days of treatment. The systemic parameters in the glaucoma and control groups (systolic blood pressure, p = .14 and p = .17; diastolic blood pressure, p = .18 and p = .49; and pulse rate, p = .06 and p = .50, respectively) did not show statistically significant differences during the study period. Additionally, except with a significant decrease in the resistivity index of the central retinal artery in the glaucoma patients (p = .001), oxymetazoline nasal spray did not result in any significant changes in the retrobulbar hemodynamics in both the glaucoma and control groups. This study showed that a 5-day treatment with oxymetazoline nasal spray reduced intraocular pressure in both healthy controls and patients with glaucoma under treatment. In addition, it had no significant adverse effects on the retrobulbar hemodynamics.