Biomedical subjects

B E Walman

Publications and source records attributed to B E Walman.

6 recordsLinked to original sources

PubMed1996

A comparative study of the effects of timolol and latanoprost on blood flow velocity of the retrobulbar vessels.

PURPOSE: To examine the effects of topical timolol and latanoprost on retrobulbar vessel blood velocity in patients with glaucoma or ocular hypertension. METHODS: Nine patients with primary open-angle glaucoma and six patients with ocular hypertension were enrolled for this study. All patients were treated topically with 0.5% timolol or 0.005% latanoprost, using a double-masked crossover design with a 3-week washout before administration of each drug. Each patient had a baseline color Doppler imaging ultrasound of the central retinal artery, short posterior ciliary arteries, and ophthalmic artery and two other ultrasound examinations during the 1-week treatment with each drug, performed 12 hours after the first dose of the drug and 12 hours after the last dose, 7 days later. RESULTS: Both topical timolol and topical latanoprost significantly reduced the intraocular pressure. The only significant change observed in the retrobulbar blood velocity with timolol was a reduction of end diastolic velocity in the ophthalmic artery 12 hours after the first dose, accompanied by a trend toward a decrease in the peak systolic velocity and an increase in the resistance index in the same vessel. No change in blood velocity was observed with latanoprost. CONCLUSION: Topical timolol and latanoprost significantly reduced the intraocular pressure in ocular hypertensive and glaucoma patients without creating substantial hemodynamic changes in the retrobulbar vessels.

Administration, Topical↗

PubMed1996

Color Doppler imaging in patients with asymmetric glaucoma and unilateral visual field loss.

PURPOSE: To determine whether lower blood velocities and high resistive index in the retrobulbar arteries are primary or secondary to glaucomatous damage in patients with open-angle glaucoma. METHODS: Color Doppler imaging was performed in 32 glaucomatous patients with unilateral visual field loss and in 31 control subjects. Peak systolic velocity and end diastolic velocity were measured, and resistive index was calculated in the central retinal artery and short posterior ciliary arteries. RESULTS: In patients with glaucoma, both the more affected and the contralateral eyes with normal visual fields had significantly lower peak systolic velocity and end diastolic velocity in their central retinal artery and short posterior ciliary arteries than did the control subjects of similar age (P < or = .03). The resistive index of the central retinal artery of both eyes of patients with glaucoma was also significantly higher than in the control subjects (P = .001). When considering the 16 patients who had the greatest visual field asymmetry, the more affected eyes had lower peak systolic velocity and end diastolic velocity in the central retinal artery than the contralateral eyes did (P = .02). CONCLUSIONS: Even eyes with normal visual fields in patients with asymmetric disease had decreased blood velocities in their retrobulbar vessels, suggesting that these circulatory changes probably precede detectable damage. Furthermore, the finding of lower central retinal artery blood velocities in the more affected eye of asymmetric patients suggests that low blood velocities may be one of the lateralizing factors in those patients and that they have a possible role in the pathogenesis of the disease.

Aged↗

PubMed1996

Various glaucomatous optic nerve appearances. A color Doppler imaging study of retrobulbar circulation.

PURPOSE: The purpose of this study was to observe the blood flow velocity in the retrobulbar vessels of patients with glaucoma with different appearances of optic discs. METHODS: Patients with four different disc appearances (focal ischemic discs, myopic glaucomatous discs, senile sclerotic discs, and discs with a generalized enlargement of the cup) were selected from a pool of optic disc photographs. No clinical information from the patients was available during the selection. Color Doppler imaging (CDI) was performed in those patients whose discs clearly belonged to one of the disc patterns. The peak systolic and end diastolic velocity were measured and the resistance index calculated from the central retinal artery, short posterior ciliary arteries and ophthalmic artery. RESULTS: Color Doppler imaging was performed in 24 patients with focal ischemic discs, 26 patients with myopic glaucomatous discs, 16 patients with senile sclerotic discs, and 16 patients with generalized enlargements of the cup. The patients with senile sclerotic discs had statistically significantly lower diastolic velocity and a higher resistance index in their ophthalmic, central retinal and the mean of the short posterior ciliary arteries sampled. These statistical differences persisted for the ophthalmic artery even after correcting the values for the age differences between the groups. CONCLUSIONS: Patients with senile sclerotic discs seem to have greater circulatory abnormalities in their retrobulbar vessels studied with color Doppler imaging that are compatible with a higher downstream resistance in these vessels. These circulatory abnormalities could be related to the pathogenesis of the glaucoma in these patients.

Aged↗

PubMed1996

Visual field correlations with color Doppler studies in open angle glaucoma.

PURPOSE: This study was designed to assess the correlation between flow velocity, the resistive index and visual field defects in patients with chronic open angle glaucoma in comparison with a nonglaucomatous control population. METHODS: Color Doppler imaging was used to study flow velocity in the central retinal artery and short posterior ciliary arteries of 76 patients with chronic open angle glaucoma and 28 normal subjects. Velocity and resistive index were correlated with visual field abnormalities. RESULTS: The chronic open angle glaucoma patients showed a statistically significant lowering of the end diastolic velocity and a raised resistive index in all vessels studied. The end diastolic velocity of the central retinal arteries of glaucoma patients were significantly correlated with the Mean Deviation of the visual field (right eye, p = 0.0041; left eye, p = 0.0167). The glaucoma patients showed a statistically significant lowering of the end diastolic velocity and a raised resistive index in all vessels supplying those parts of the optic disc that corresponded to visual hemifield defects. CONCLUSION: Open angle glaucoma is associated with changes in central retinal and ciliary artery flow velocity and resistive index which suggest a compromised circulation in this region.

Adult↗

PubMed1996

Ocular hypertension and primary open-angle glaucoma: a comparative study of their retrobulbar blood flow velocity.

PURPOSE: To compare the orbital blood flow velocities of patients with long-standing ocular hypertension and patients with primary open-angle glaucoma. METHODS: Twenty patients with ocular hypertension were recruited from our clinic and underwent color Doppler imaging evaluation of their retrobulbar vessels. The blood flow velocities and resistance index of their central retinal artery, temporal short posterior ciliary artery, and ophthalmic artery were compared with those of 20 glaucoma patients individually matched for age and level of the highest untreated intraocular pressure ever recorded. RESULTS: Glaucoma patients had significantly lower peak systolic velocity and end-diastolic velocity than did patients with ocular hypertension in their central retinal artery (p < 0.001). No significant difference between the groups was observed in the other vessels studied. CONCLUSIONS: Glaucoma patients had lower blood flow velocity in the central retinal artery compared with that of ocular hypertension patients of similar age and level of untreated intraocular pressure. This might be important in the development of glaucomatous damage in those patients.

Blood Flow Velocity↗

PubMed1995

Color Doppler imaging and spectral analysis of the optic nerve vasculature in glaucoma.

PURPOSE: We used color Doppler imaging to study blood flow velocity in the central retinal artery and the short posterior ciliary arteries in patients with glaucoma. METHOD: Fifty-two patients with chronic open-angle glaucoma, 24 patients with normal-tension glaucoma, and 28 normal subjects were studied. The mean of the peak systolic velocity, the end diastolic velocity, and the resistive index were compared in the three groups. RESULTS: Compared with the normal subjects, the patients with chronic open-angle glaucoma showed a statistically significant (P < .05) decrease in the mean end diastolic velocity and an increase in the mean resistive index in all vessels studied. The patients with normal-tension glaucoma showed similar changes, achieving significance most prominently in the central retinal arteries, compared with normal subjects (P < .05). There were no statistically significant differences between the patients with chronic open-angle glaucoma and those with normal-tension glaucoma. CONCLUSIONS: Open-angle glaucoma appears to be associated with a decreased mean flow velocity and an increased mean resistive index in the ocular vasculature. These changes are in keeping with possibly compromised circulation in this region.

Adult↗