Doppler Holography Of Blood Flow In The Anterior Segment Of The Eye
Published 2023 - 41st Congress of the ESCRS
Reference: PO0231 | Type: Free paper | DOI: 10.82333/m7cq-g910
Authors: Roxane Flamant* 1 , Benjamin Stern 1 , Olivier Martinache 2 , Yohan Blazy 3 , Zofia Bratasz 3 , Julia Sverdlin 3 , Josselin Gautier 2 , Ethan Rossi 4 , Jay Chhablani 4 , José-Alain Sahel 5 , Tristan Aubert 2 , Christophe Baudouin 2 , Vincent Borderie 2 , Michel Paques 2 , Vivien Vasseur 1 , Sophie Bonnin 1 , Damien Gatinel 1 , Michael Atlan 1
1Hôpital Fondation Ophtalmologique Adolphe de Rothschild,Paris,France, 2Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts,Paris,France, 3Institut Langevin. Centre National de la Recherche Scientifique (CNRS). Paris Sciences & Lettres (PSL University). Ecole Supérieure de Physique et de Chimie Industrielles (ESPCI),Paris,France, 4Department of Ophtalmology, University of Pittsburgh School of Medicine,Pittsburgh,United States, 5Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts,Paris,France;Department of Ophtalmology, University of Pittsburgh School of Medicine,Pittsburgh,United States
Purpose
Exploration of anterior segment blood vessels is currently limited to a few advanced acquisition techniques. Fluorescent dye injection angiography carries a risk of allergy and can be difficult to perform and quantify. OCT angiography has a long acquisition time with low resolution imaging and gives no information about blood flow fluctuations. In this study, we present a new anterior segment angiography technique with real-time Doppler holography to explore its potential clinical uses.
Setting
The experimental study of a new anterior segment angiography technique was carried out with a device developed at the Rothschild Ophthalmologic Foundation, the Center Hospitalier National d'Ophtalmologie des Quinze-Vingts and the Institut Langevin in Paris, France, as well as only at the Department of Ophthalmology of the University of Pittsburgh, USA.
Methods
We used a modified holographic retinal blood flow imaging instrument that relies on diffuse laser light illumination. The anterior segment of the eye was imaged with different lateral resolutions, from 10 pixel pitch to 3 microns. The real time calculation of Doppler images was performed from a stream of 1024 x 768 pixel interferograms recorded at 4000 frames per second by an Ametek Phantom S710 streaming camera. The image rendering was carried out by Fresnel transformation of each interference frame. Doppler optical fluctuations of blood flow were revealed by local principal component analysis of batches of 32 consecutive images. All numerical calculations were performed by the holovibes digital holography software.
Results
Conjunctival, episcleral, and arterial and venous iris blood flow have been successfully imaged in control patients with a variety of ocular pigmentations, which result in iris colors ranging from very light blue to dark brown. We were able to visualize arterial pulse waves and venous flow in vessels of different sizes, depending on the selected principal component range and lateral field of view. Finally, several anatomical landmarks, such as the long ciliary arteries, have been identified.
Conclusions
The ability of near-infrared Doppler holography to image retinal and choroidal blood flow can be successfully transposed to real-time anterior segment angiography. In this respect, it could complement the contribution of the reference techniques for anterior segment angiography, namely OCT-A and dye angiography.
All the authors declare that they have no financial interests to disclose. The device was designed in our institutions.