Video fluorescein angiography: Method and clinical application

Abstract

Video fluorescein angiography, combined with a picture analyzing system, is a clinically applicable, objective method of evaluating the retinal blood-flow parameters. Optical density measurements were performed on videorecordings of fluorescence angiograms by means of a picture-analyzing system in order to determine the circulation parameters of the retina. These included: the arm-retina time (ART), the arteriovenous passage time (AVP), and the mean arterial dye-bolus velocity (MDV). Normal values for these parameters were derived from measurements in 75 healthy volunteers. The mean arm-retina time (ART) was 11.2 +/- 3.3 s, the mean arteriovenous passage time (AVP) 1.45 +/- 0.4 s and the mean arterial dye-bolus velocity (MDV) 6.39 +/- 1.7 mm/s. No significant correlation could be shown between pulse or blood pressure and one of the retinal circulation parameters. A group of ten healthy volunteers was examined twice in order to obtain the intraindividual variation for the measuring parameters. The coefficient of variation for the ART was 18%, 10% for the AVP, and 26% for the MDV.

Effects of oxygen and carbon dioxide on human retinal circulation: an investigation using blue field simulation and scanning laser ophthalmoscopy

“…Arteriovenous passage time is the difference in time between the first appearance of fluorescein in the artery close to the disc and its appearance in the nearby vein (Wolf et al 1989); it demonstrates the shortest passage time through a vascular segment. The time when the fluorescein concentration reached 10% of its maximum was used to define the first appearance of dye in the vessels in order to determine AVP (Tomic et al 2001;Bja¨rnhall et al 2002).…”

A comparison between laser interferometric measurement of fundus pulsation and pneumotonometric measurement of pulsatile ocular blood flow 1. Baseline considerations

“…Definition of the sites of fundus pulsation measurements in the optic disc. Points [1][2][3][4] were located at the neuroretinal rim, points [5][6][7][8] were located at the cup.…”

Retinal Blood Flow Evaluation

“…Using scanning laser ophthalmoscopy, additional parameters from the fluorescence intensity time course have been determined, such as the mean velocity of the dye in a retinal artery, which has been calculated from the appearance time of the dye front at two sites along a vessel and the distance between the sites, and the AVP, which is the time difference between a reference point at the temporal retinal artery and the first appearance in a vein adjacent to the artery [25]. In contrast to MCT , AVP favors strongly the measurement of passage times of the dye through the shortest segment between an artery and a vein close to the papilla [24].…”