Abstract
Presentation Description :
Phase-sensitive optical coherence tomography (OCT) measures functional changes in the human retina by detecting temporal variations in the phase of the backscattered waves. By parallelizing both lateral and axial data acquisition, full-field swept-source OCT (FF-SS-OCT) provides particularly robust phase stability of retinal images. Using this FF-SS-OCT to detect functional phase changes thus allows the detection of minute morphological changes in the single-digit nanometer range.
Due to the tomographic nature of the imaging method, the changes can be assigned to lateral and axial structures of the retina with micrometer accuracy. Thus, it is possible to detect the functional changes of different cell layers simultaneously and to investigate their functional connectivity.
Using FF-SS-OCT, it was possible to measure reproducible results in the photoreceptors and the inner plexiform layer (IPL), allowing us to investigate the connection between the photoreceptors and the ganglion cells. In addition, the functional contributions of phase changes from different sub-layers of the IPL were also separated, enabling us to differentiate the functional contribution of different bipolar/ganglion cell types. For example, a clear sensitivity to flicker stimulation is observed in the central sub-layer of the IPL, whereas the other sub-layers show no change for flickering lights. The high lateral resolution also allows the observation of signal processing steps of the retinal neurons, for example, the center-surround processing of the receptive fields.
So far, we investigated these functional signals in a small group of healthy volunteers aged 26 to 60 years and showed high quantitative reproducibility for each subject and qualitative reproducibility between subjects.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.