Laser Doppler holography of the anterior segment for blood flow imaging, eye tracking, and transparency assessment

TL;DR

This paper demonstrates the use of Laser Doppler holography (LDH) for high-resolution blood flow imaging, eye tracking, and transparency assessment in the anterior eye segment without hardware modifications.

Contribution

It introduces a method to perform anterior segment imaging with LDH, enabling simultaneous blood flow visualization, eye movement tracking, and transparency evaluation.

Findings

Effective imaging of blood flow in conjunctiva and cornea.

High temporal resolution tracking of retina and pupil movements.

Use of retinal backscattering for transparency assessment.

Abstract

Laser Doppler holography (LDH) is a full-field blood flow imaging technique able to reveal human retinal and choroidal blood flow with high temporal resolution. We here report on using LDH in the anterior segment of the eye without making changes to the instrument. Blood flow in the bulbar conjunctiva and episclera as well as in corneal neovascularization can be effectively imaged. We additionally demonstrate simultaneous holographic imaging of the anterior and posterior segments by simply adapting the numerical propagation distance to the plane of interest. We used this feature to track the movements of the retina and pupil with high temporal resolution. Finally, we show that the light backscattered by the retina can be used for retro-illumination of the anterior segment. Hence digital holography can reveal opacities caused by absorption or diffusion in the cornea and eye lens.