CONFOCAL LASERSCANNING FLUORESCENCE ANGIOGRAPHY: A NEW METHOD FOR THREE-DIMENSIONAL FUNCTIONAL IMAGING OF VASCULAR STRUCTURES
R. Birngruber1, U. Schmidt-Erfurth2, N. Koop1, J. Noack1
Principle: Three-dimensional topography of perfused vascular structures is possible via confocal laserscanning of intravascular fluorescence. The lateral resolution is given by the spot-size of the scanning laserbeam (typically 10 µm at the retina). The axial resolution, however, depends on the acuracy to detect the surface of the fluorescent structure which ist typical one order of magnitude better (30pm at the retina) than the confocal resolution.
Method: The vascular structure is stained with an appropriate fluorescence dye prior to the investigation using standard systemic dye-injection. Confocal scanning of the fluorescence in planes of different depth within the vascular structure under investigation leads to a three-dimensional dataset of fluorescence radiance. Signal processing includes passive eye tracking, lateral averaging and axial determination of the surface of the fluorescent structure.
Testing: The potential of this new technique is demonstrated by showing the topography of anatomical vessel structures as well as of selected vascular diseases such as Stargarts disease, AMD or post retinal lasercoagulation.
Conclusion: Confocal Laser AngioScopic Topography (CLAST) measures the three-dimensional surface structure of functional (perfused) vasulature and surrounding leakages. CLAST may help to diagnose and quantify status and time course of vascular diseases.
1Medical Laser Center Lübeck, Peter-Monnik-Weg 4, D-23562 Lübeck
2University Eye Clinic Lübeck, Ratzeburger Allee 160, D-23538 Lübeck