Doppler ultrasonography of the central retinal artery in patients with diabetes and vascular disease treated with topical timolol

[Effect on ocular blood flow of Combigan® versus placebo in patients with ocular hypertension]

PURPOSE

This study was undertaken to compare the ocular haemodynamic effects of Combigan(®) versus placebo in patients with ocular hypertension (OHT).

METHODS

Thirty patients with OHT were included in a controlled, randomised, double blind study in two parallel groups; 15 were randomised to receive Combigan(®) and 15 to receive placebo for a period of 3 months. At baseline and at 3 months retrobulbar blood flowmeasurements of the ophthalmic artery (OA) and central retinal artery (CRA) were taken using colour Doppler imaging(CDI) ultrasound, concurrently with intraocular pressure (IOP).

RESULTS

Combigan(®) significantly reduced IOP after 3 months of treatment (P = 0.001), whereas placebo showed no significant change in IOP. The baseline haemodynamic parameters were similar between treatment and placebo groups. Patients treated with Combigan® showed a statistically significant decrease in CRA resistive index (P = 0.007).

CONCLUSIONS

Patients treated for 3 months with Combigan(®) showed a significant decrease of CRA resistive index that could be explained by the decrease in IOP.

Orbital blood flow velocities in patients with rheumatoid arthritis

PURPOSE

To assess orbital blood flow changes in patients with rheumatoid arthritis using Doppler sonography.

PATIENTS AND METHODS

The study comprised 35 patients who were diagnosed with RA and were treated at the Department of Physical Therapy and Rehabilitation at Duzce Medical School. A control group consisted of 35 healthy volunteers. Color Doppler imaging was used to measure peak systolic velocity (PSV) and end diastolic velocity (EDV), from which the resistance index (RI) was calculated in the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary arteries (PCAs).

RESULTS

In the OA, PSV, EDV, and RI were, respectively, 36.7 +/- 0.6 cm/sec, 9.7 +/- 0.2 cm/sec, and 0.73 in the control group versus 34.7 +/- 3.0 cm/sec, 9.1 +/- 1.1 cm/sec, and 0.74 in the patient group. In the CRA, they were, respectively, 11.8 +/- 1.7 cm/sec, 3.6 +/- 0.7 cm/sec, and 0.66 in the control group versus 11.1 +/- 1.7 cm/sec, 3.4 +/- 0.7 cm/sec, and 0.68 in the patient group. In the PCAs, they were, respectively, 13.2 +/- 1.2 cm/sec, 4.7 +/- 0.6 cm/sec, and 0.65 in the control group versus 12.4 +/- 1.2 cm/sec, 4.2 +/- 0.6 cm/sec, and 0.66 in the PCAs. PSV, EDV, and RI of the PCAs and OA and RI of the CRA were significantly different between patients and controls, whereas there was no difference in the serum levels of glucose, triglyceride, low-density lipoprotein cholesterol, and total cholesterol. In the patient group, there was a significant correlation between orbital blood flow and duration of disease.

CONCLUSION

Ocular blood flow appears to be slightly lower in RA patients than in healthy controls, suggesting that RA is a systemic inflammatory disease that may also involve ocular vessels.

High serum homocysteine levels correlate with a decrease in the blood flow velocity of the ophthalmic artery in highway toll collectors

Highway workers, such as policemen, automotive service companies, and toll collectors, are placed at risk of the accelerated atherosclerotic process, since recent studies have suggested that exposure to exhaust particles and ambient air pollution increases carotid intima-media thickness and reduces ocular blood flow velocity. Therefore, we assessed the relationship between serum homocysteine, a potential parameter for atherosclerosis, and the ocular blood flow velocity and the resistivity index in highway toll collectors. The peak systolic and end diastolic flow velocities and the resistivity index were measured in 22 toll collectors and 24 control subjects by color Doppler ultrasonography. The resistivity index, which is an indirect measure of the atherosclerotic process, was calculated: resistivity index = (peak systolic velocity - end diastolic velocity)/peak systolic velocity. Serum homocysteine levels were determined by fluorometric high-performance liquid chromatography. In the highway toll collectors, the serum homocysteine level (14.4 +/- 4.8 micromol/l; p < 0.005) and the resistivity index of the ophthalmic artery (0.741 +/- 0.015; p < 0.05) were higher and the ophthalmic blood flow velocity (33.0 +/- 3.0 cm/s; p < 0.001) was lower than those in the controls (10.6 +/- 3.1 micromol/l; 0.728 +/- 0.023; 36.8 +/- 2.2 cm/s; respectively). There were significant correlations between the serum homocysteine level and ophthalmic artery resistivity index in both highway toll collectors (p < 0.001) and controls (p < 0.005). Exposure to exhaust particles might increase the serum homocysteine level, which in turn could lead to the decreased ocular blood flow and the increased resistivity index.

Ocular and orbital blood flow velocity in patients with peripheral vascular disease and diabetes treated with intravenous prostaglandin E1

The purpose of this study was to evaluate the effect of intravenous prostaglandin E1 (PGE1) on the flow velocity of the ophthalmic artery and the central retinal artery in patients with peripheral vascular disease manifested by intermittent claudication. The flow velocity of these vessels is frequently decreased in vascular patients. Since these patients were already being treated with PGE1 for their intermittent claudication, the authors wanted to evaluate the effect on the flow velocity of the ocular vessels as well. A randomized 21-week study of two groups of vascular patients was performed. The first group had intermittent claudication. The second group had intermittent claudication and were also diabetics. Both groups were treated with intravenous PGE1 for their intermittent claudication. Using the color Doppler, the flow velocities of the ophthalmic artery and central retinal artery were measured before and after the intravenous treatment. Before treatment, the flow velocity of the ophthalmic artery and the central retinal artery was decreased when compared to that in the normals. After treatment, there was a significant increase in the systolic and diastolic phases of the flow velocity in both arteries. The systolic flow velocity increased by as much as 40%, and the diastolic flow velocity increased by as much as 80%. The flow velocities of the ophthalmic artery and the central retinal artery are frequently decreased in certain ocular diseases, and this decreased flow may contribute to the ocular pathology. If intravenous PGE1 is able to increase the flow velocity of these vessels in patients with peripheral vascular disease, it is possible that it is also able to increase the flow velocity of these vessels in patients with ocular disease as well. Intravenous PGE1 may prove to be a useful adjunct therapy in eyes when ischemia is part of the pathology.

Ocular and retrobulbar blood flow in ocular hypertensives treated with topical timolol, betaxolol and carteolol

The purpose of this study was to evaluate the effect of topical timolol 0.5%, betaxolol 0.5% and carteolol 2% on the blood flow velocity of the central retinal artery (CRA), the posterior ciliary artery (PCA) and the ophthalmic artery (OA) in patients with ocular hypertension. A group of 14 patients with ocular hypertension and a group of 11 normals were studied. The color Doppler was used to measure the peak systolic flow velocity (PSFV) and the end diastolic flow velocity (EDFV) of the CRA, the PCA and the OA in the normals and in the patients. The normals were under no treatment, while the patients were studied before and after treatment with topical timolol 0.5%, betaxolol 0.5% and carteolol 2%. In the systolic phase, there was a significant increase in the flow velocity of the CRA with all three drugs. In the diastolic phase of the CRA, the increase was significant for timolol 0.5% and carteolol 2% but not for betaxolol 0.5%. The flow velocity of the PCA and OA remained unchanged. In this study of 14 patients with ocular hypertension, topical timolol 0.5%, betaxolol 0.5% and carteolol 2% led to a significant increase in the flow velocity of the CRA without creating a steal or decrease in the flow velocity of the PCA.

Pressure and microcirculatory effects of treatment with lercanidipine in hypertensive patients and in vascular patients with hypertension

The aim of this study was to evaluate the macrocirculatory and microcirculatory effects of treatment with lercanidipine, a new antihypertensive agent acting both on blood pressure and microcirculation in patients with moderate essential hypertension and without vascular disease and in patient with hypertension and vascular disease. In hypertensive subjects target-organ damage associated with high blood pressure may now be objectively documented by noninvasive tests. These alterations constitute a model to evaluate not only the pressure effects of antihypertensive treatment but also the normalization of the peripheral microcirculatory network. With color duplex scanning, flow velocity in the central retinal artery and retinal flow velocity can be measured and with use of laser-Doppler-flowmetry, it is also possible to evaluate microcirculation alterations in hypertensive subjects. These evaluation methods are completely noninvasive and may be used to assess the microcirculatory effects of antihypertensive drugs.