title: Phase-stabilized optical frequency domain imaging at 1-µm for the measurement of blood flow in the human choroid.
abstract: In optical frequency domain imaging (OFDI) the measurement of interference fringes is not exactly reproducible due to small instabilities in the swept-source laser, the interferometer and the data-acquisition hardware. The resulting variation in wavenumber sampling makes phase-resolved detection and the removal of fixed-pattern noise challenging in OFDI. In this paper this problem is solved by a new post-processing method in which interference fringes are resampled to the exact same wavenumber space using a simultaneously recorded calibration signal. This method is implemented in a high-speed (100 kHz) high-resolution (6.5 µm) OFDI system at 1-µm and is used for the removal of fixed-pattern noise artifacts and for phase-resolved blood flow measurements in the human choroid. The system performed close to the shot-noise limit (<1dB) with a sensitivity of 99.1 dB for a 1.7 mW sample arm power. Suppression of fixed-pattern noise artifacts is shown up to 39.0 dB which effectively removes all artifacts from the OFDI-images. The clinical potential of the system is shown by the detection of choroidal blood flow in a healthy volunteer and the detection of tissue reperfusion in a patient after a retinal pigment epithelium and choroid transplantation.
authors: Rotterdam Ophthalmic Institute, Schiedamse Vest 160, 3011 BH Rotterdam, The Netherlands. b.braaf@eyehospital.nl
authors: Boy
authors: B
authors: Braaf
authors: Koenraad A
authors: KA
authors: Vermeer
authors: Victor Arni D P
authors: VA
authors: Sicam
authors: Elsbeth
authors: E
authors: van Zeeburg
authors: Jan C
authors: JC
authors: van Meurs
authors: Johannes F
authors: JF
authors: de Boer
mesh_terms: D000465:Algorithms; D016477:Artifacts; D002138:Calibration; D002829:Choroid / Q000098:blood supply*; D003952:Diagnostic Imaging / Q000379:methods; D004867:Equipment Design; D005583:Fourier Analysis; D006801:Humans; D007368:Interferometry / Q000379:methods; D007834:Lasers; D008027:Light; D009038:Motion; D009885:Ophthalmology / Q000379:methods; D055095:Optics and Photonics / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods