Purchase this article with an account.
Peng XIAO, Pedro Mecê, Viacheslav Mazlin, Mathias Fink, Claude Boccara, Jin Yuan; In vivo Wavefront-correctionless Full-field OCT Human Retinal Imaging. Invest. Ophthalmol. Vis. Sci. 2019;60(9):1274.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We have previously presented the very first full-filed OCT (FFOCT) images of in vivo human retina (Xiao et al, ARVO 2018). As the lateral resolution of FFOCT is insensitive to eye aberrations with spatially incoherent light source, in this study, we demonstrate in vivo cellular resolution en face FFOCT human retinal imaging on dilated eye without any hardware or computational wavefront correction.
A customized FFOCT system was developed and combined with a spectral-domain OCT (SDOCT) system. FFOCT retinal imaging on various locations was achieved on a healthy subject with the SDOCT cross-sectional images providing the depth information of FFOCT en face images. In order to freeze eye motion during image acquisition, FFOCT images were acquired at 200Hz with a high-speed camera. Image stacks acquired within 200ms were cross-correlated and averaged to improve signal to noise ratio (SNR). By dilating the subject's eye pupil, foveal retinal imaging was also performed with 4.5mm, 6.5mm and 8mm pupil diameter for comparison without applying adaptive optics (AO).
The FFOCT images of the retinal nerve fiber layer (RNFL) and the photoreceptor inner/outer segment (IS/OS) junction layer at retinal near periphery clearly revealed structural information such as nerve fiber orientation, blood vessel distribution, and the photoreceptor mosaic. Images of the foveal IS/OS layer with different pupil diameters also showed strong signals from cone photoreceptors. Although bigger pupil size induced higher aberration level, damping the FFOCT SNR which results in the FFOCT image intensity anisoplanatism, the captured foveal cones showed reduced size with increased numerical aperture since aberrations do not affect the lateral resolution.
We have successfully demonstrated in vivo FFOCT human retinal imaging without wavefront correction. Cellular retinal structures like never fiber bundles and the photoreceptor mosaic are resolved in en face FFOCT images. By imaging the foveal cones with dilated pupils, we have confirmed the spatial resolution of FFOCT is not defeated by the increased eye aberrations. This opens the way for a straightforward implementation of a compact FFOCT system with transmissive adaptive lens for low order aberration correction to increase SNR for high resolution en face retinal imaging in clinical studies.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
High-Resolution in vivo FFOCT human retinal images
This PDF is available to Subscribers Only