Abstract
Purpose :
Fourier-domain full-field optical coherence tomography is one of the fastest methods to image human eye. However, crosstalk noise is limiting its performance. Here we use phase randomization to remove crosstalk in images of retina and cornea.
Methods :
We have developed a Fourier-domain full-field optical coherence tomography (FD-FF-OCT) system with phase randomization that allowed to remove crosstalk in images. The system primarily consisted of a fast-tunable laser source, a fast deformable membrane, a Linnik interferometer and a fast camera. The deformable membrane DM was used to destroy spatial coherence of the laser through phase randomization. In addition, a supplementary optical focusing system was used in retinal imaging, which allowed to dynamically go through the retinal layers, and thus, compensate for the defocus aberrations. The combination of fast imaging and computational correction of various image properties makes it a very powerful technique in eye imaging. It could acquire a single 3D volume in 8 msec.
Results :
The system was able to show that 3D volumes, acquired in 258 ms, had a significantly improved image contrast when the spatial coherence of the laser was destroyed with the deformable membrane. Specifically, we were able to see a more detailed choroid structure, which was otherwise buried behind the crosstalk noise when imaged with the conventional FD-FF-OCT. It also enabled better delineation of the retinal layers. After computational processing we were able to revealed photoreceptor mosaic or epithelial corneal cells.
Conclusions :
In conclusion, we have shown that crosstalk-free in vivo retinal imaging is possible in FD-FF-OCT system by means of spatial coherence destruction with a fast deformable membrane that projects random phase patterns at a megahertz rate. Crosstalk-free images of retina obtained with the FD-FF-OCT revealed the choroidal structure and demonstrated contrast improvement in most of the retinal layers.
This is a 2020 ARVO Annual Meeting abstract.