Okuläre Hämodynamik beim Normaldruckglaukom: Effekte von Bimatoprost

Zusammenfassung

Hintergrund: Störungen der Hämodynamik spielen in der Pathophysiologie des Normaldruckglaukoms eine bedeutende Rolle. Prostaglandinartige Wirkstoffe sind sehr effektiv bezüglich der Senkung des intraokularen Drucks. Kürzlich konnte in vitro gezeigt werden, dass Bimatoprost, ein relativ neues, lokal anzuwendendes antiglaukomatöses Medikament, den Tonus der Ziliararterien beeinflusst. In dieser Studie soll untersucht werden, ob dieser Effekt in vivo nachvollziehbar ist. Patienten und Methoden: Bei n = 9 Augen von 9 Patienten mit gesichertem Normaldruckglaukom wurde vor und unter einer 3- bis 5-wöchigen Therapie mit Bimatoprost-Augentropfen die okuläre Durchblutungssituation mittels Farbdopplersonographie (CDI) prospektiv untersucht. Ergebnisse: Bimatoprost führte zu einer Senkung des intraokularen Drucks von 14,0 ± 0,4 auf 11,0 ± 0,5 mmHg (n = 9; p < 0,001). Die systolischen und diastolischen Flussgeschwindigkeiten, gemessen mit der CDI, sowie die abgeleiteten Indizes für Gefäßwiderstand (RI) und Pulsatilität (PI) wurden durch Bimatoprost nicht beeinflusst. Diskussion: Bimatoprost beeinflusst die retrobulbären Blutflussgeschwindigkeiten nicht. Die in vitro gezeigte Beeinflussung des Gefäßtonus der Ziliararterien scheint hämodynamisch nicht wirksam zu sein.

Abstract

Background: Altered ocular perfusion plays a role in the pathophysiology of normal tension glaucoma. Prostaglandin-like substances are very effective in lowering intraocular pressure. Less data are available regarding the influence of these compounds on ocular perfusion. In the present study the effects of bimatoprost, which has recently been shown to increase the vascular tone of ciliary arteries in vitro, on the blood flow velocity are investigated. Patients and Methods: n = 9 eyes from 9 normal tension glaucoma patients were subjected to color Doppler imaging (CDI) before and during a 3 - 5 week therapy with bimatoprost. Results: Bimatoprost reduces intraocular pressure from 14.0 ± 0.4 to 11.0 ± 0.5 mmHg (n = 9; P < 0.001). Systolic as well as diastolic blood flow velocities, resistive index (RI) and pulsatility index (PI), measured by CDI, were unaltered in the presence of bimatoprost. Discussion: Bimatoprost does not influence blood flow velocities in the retrobulbar vessels. The in vitro observation of increased vascular tone in the presence of bimatoprost seems not to be relevant for ocular hemodynamics.

Schlüsselwörter

Aderhautperfusion - Farbdopplersonographie der retrobulbären Gefäße - Glaukom - Antiglaukomatosa - Prostaglandine

Key words

Choroid perfusion - color Doppler imaging - glaucoma - glaucoma therapy - prostaglandins

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