Waveform analysis of human retinal and choroidal blood flow with laser Doppler holography

TL;DR

This study uses laser Doppler holography to analyze blood flow waveforms in the human retina and choroid, revealing distinct behaviors and potential for diagnosing ocular conditions.

Contribution

It introduces methods to separate flow contributions, map resistivity indices, and identify vessels based on flow waveforms in the eye.

Findings

Retinal arteries and veins show distinct flow waveforms.

Full-field resistivity index mapping is demonstrated.

Choroidal and retinal arterial waveforms are synchronous with different pulsatility.

Abstract

Laser Doppler holography was introduced as a full-field imaging technique to measure blood flow in the retina and choroid with an as yet unrivaled temporal resolution. We here investigate separating the different contributions to the power Doppler signal in order to isolate the flow waveforms of vessels in the posterior pole of the human eye. Distinct flow behaviors are found in retinal arteries and veins with seemingly interrelated waveforms. We demonstrate a full field mapping of the local resistivity index, and the possibility to perform unambiguous identification of retinal arteries and veins on the basis of their systolodiastolic variations. Finally we investigate the arterial flow waveforms in the retina and choroid and find synchronous and similar waveforms, although with a lower pulsatility in choroidal vessels. This work demonstrates the potential held by laser Doppler holography to study ocular hemodynamics in healthy and diseased eyes.