title: Measurement of retinal blood flow in the rat by combining Doppler Fourier-domain optical coherence tomography with fundus imaging.
abstract: A wide variety of ocular diseases are associated with abnormalities in ocular circulation. As such, there is considerable interest in techniques for quantifying retinal blood flow, among which Doppler optical coherence tomography (OCT) may be the most promising. We present an approach to measure retinal blood flow in the rat using a new optical system that combines the measurement of blood flow velocities via Doppler Fourier-domain optical coherence tomography and the measurement of vessel diameters using a fundus camera-based technique. Relying on fundus images for extraction of retinal vessel diameters instead of OCT images improves the reliability of the technique. The system was operated with an 841-nm superluminescent diode and a charge-coupled device camera that could be operated at a line rate of 20 kHz. We show that the system is capable of quantifying the response of 100% oxygen breathing on the retinal blood flow. In six rats, we observed a decrease in retinal vessel diameters of 13.2% and a decrease in retinal blood velocity of 42.6%, leading to a decrease in retinal blood flow of 56.7%. Furthermore, in four rats, the response of retinal blood flow during stimulation with diffuse flicker light was assessed. Retinal vessel diameter and blood velocity increased by 3.4% and 28.1%, respectively, leading to a relative increase in blood flow of 36.2%. The presented technique shows much promise to quantify early changes in retinal blood flow during provocation with various stimuli in rodent models of ocular diseases in rats.
authors.affiliation: Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: René M
authors.initials: RM
authors.lastname: Werkmeister
authors.affiliation: Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, AustriabVienna University of Technology, Institute of Applied Physics, Wiedner Hauptstrasse 8-10/134, 1040 Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Vietauer
authors.affiliation: Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Corinna
authors.initials: C
authors.lastname: Knopf
authors.affiliation: Medical University of Vienna, Department of Internal Medicine II, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Fürnsinn
authors.affiliation: Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Rainer A
authors.initials: RA
authors.lastname: Leitgeb
authors.affiliation: Paracelsus University, Department of Ophthalmology, Müllner Hauptstraße 48, 5020 Salzburg, Austria.
authors.forename: Herbert
authors.initials: H
authors.lastname: Reitsamer
authors.affiliation: Vienna University of Technology, Institute of Applied Physics, Wiedner Hauptstrasse 8-10/134, 1040 Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Gröschl
authors.affiliation: Medical University of Vienna, Department of Clinical Pharmacology, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Garhöfer
authors.affiliation: Imedos Systems UG, Am Nasstal 4, 07751 Jena, Germany.
authors.forename: Walthard
authors.initials: W
authors.lastname: Vilser
authors.affiliation: Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20, 1090 Vienna, AustriaeMedical University of Vienna, Department of Clinical Pharmacology, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Leopold
authors.initials: L
authors.lastname: Schmetterer
mesh_terms: D000818:Animals; D005654:Fundus Oculi; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000502:physiology*; D012171:Retinal Vessels / Q000502:physiology*; D041623:Tomography, Optical Coherence / Q000379:methods*