Imaging pulse wave propagation in human retinal vessels using full-field swept-source optical coherence tomography.

We demonstrate a new noninvasive method to assess biomechanical properties of the retinal vascular system. Phase-sensitive full-field swept-source optical coherence tomography (PhS-FF-SS-OCT) is used to investigate retinal vascular dynamics at unprecedented temporal resolution. The motion of retinal tissue that is induced by expansion of the vessels therein is measured with an accuracy of about 10 nm. The pulse shapes of arterial and venous pulsations, their temporal delays, as well as the frequency-dependent pulse propagation through the capillary bed, are determined. For the first time, imaging speed and motion sensitivity are sufficient for a direct measurement of pulse waves propagating with more than 600 mm/s in retinal vessels of a healthy young subject.