Artikel
Retinal circulation and local application of Phenylephrin
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
Text
Objective
Phenylephrin (Neosinephrin-POS 5%) is an alpha1-agonist that is used regulary to widen the pupil. Application of Neosynephrin 10% eye drops decreased of the diameter of the vessels in the retina (Lanzl. Ith With Vilser W. Kotliar K.E. Berlin 99.DOG 2001). Purpose: Measurement of the retinal microcirculation by Scanning Doppler Flowmetry after local application of Neosinephrin-POS® 5% (Phenylephrin).
Methods
The capillar perfusion of the retina was measured by HRF (Retina Heidelberg Flowmetry). The analyses were carried out with AFFPIA. We evaluated: DC, flow entire, flow average, flow in big vessels, capillaries, capillar+intercapillar area. The number of the measurement points per picture was measured additional and the offset correction parameters a and b were analysed. Persons: 10 healthy persons in the age of year 46±13. Study design: We examined the retinal microcirculation before and after local application of Neosinephrin POS 5%. The images of the capillar circulation were made in the same areas of the retina before and 20 minutes after application of one drop Neosynephrin POS® 5% (Phenylephrin) into the right-eye. In 5 subjects we measured the retinal microzirculation after local application of phenylephrin every 10 minutes up to 40 minutes. The contralateral, undropped eye, was regarded as control.
Results
The DC-value, the number of the measurement points and the noise component showed no change within 20 minutes after local application of Phenylephrin. The retinal circulation decreased significantly about -36±12% (p=0.005), flow average about -31±16% (p=0.005), flow in the capillar+intercapillar area about -31±16% (p= 0.005). We observed the strongest effect 20 to 30 minutes after local application of Phenylephrin. After 40 minutes we have observed no normalisation of the retinal circulation.
Conclusions
Locally applied Neosynephrin POS® 5% decreases the capillar circulation in the retina ca. -30%.