Measuring choriocapillaris blood flow with laser Doppler optical coherence tomography

TL;DR

This paper introduces a method using laser Doppler processing of Fourier-domain OCT data to measure pulsatile blood flow in the choriocapillaris, capturing heartbeat variations and flow direction with high sensitivity.

Contribution

The study presents a novel approach to assess choriocapillaris blood flow and flow direction using Fourier transform analysis of OCT data, enabling high temporal resolution and flow orientation detection.

Findings

Derived a flow velocity index in physical units.

Captured heartbeat-induced flow variations.

Determined flow direction with high sensitivity.

Abstract

We report on using a laser Doppler processing of Fourier-domain optical coherence tomography (OCT) data for the assessment of pulsatile blood flow in the choriocapillaris. Signal fluctuations in B-scans recorded at 2 kHz were analyzed by Fourier transform to extract blood flow information. The spectral broadening of light backscattered by the choriocapillaris was used to derive a choriocapillaris flow velocity index in physical units, with sufficient temporal resolution to capture heartbeat-induced variations. Furthermore, the asymmetry in the spectral broadening enabled us to determine the axial direction of blood flow with high sensitivity, allowing for the detection of flow orientation in retinal capillaries. This approach is promising as it can be directly implemented on widely available fast-scanning Fourier-domain OCT instruments.