Abstract
Purpose :
Previously, we presented an Adaptive-glasses Full-Field OCT (FFOCT) retinal imaging system [2], which allowed for high-resolution across a wide field-of-view within a compact system suitable for clinical applications. However, the clinical imaging over a large population was still challenging, because patients large ocular aberrations could not be well compensated by the small stroke capacity of the used Adaptive Lens. To address this limitation, we present a Woofer-Tweeter Adaptive-glasses approach, enabling to compensate separately for defocus from high order aberration, improving SNR and resolution over a wide FOV (5° x 5°).
Methods :
We used our retinal imager combining a time-domain FFOCT and an SDOCT, and presenting a footprint of 30cm × 30cm. To correct for ocular aberrations, we used a Woofer-Tweeter approach consisted of placing a Optotune Variable Focal Lens (VFL, Woofer), followed by a Phaseform Deformable Phase Plate (DPP, Tweeter, up to 7th Zernike radial order replication) just in front of the eye, for a plug n’ play AO approach. Defocus correction was done by manually optimizing the SD-OCT signal via VFL, while the DPP was used to compensate up to 4th radial order of Zernike modes using a Phaseform’s AO sensorless wavefront estimation algorithm. Retinal imaging was performed on dilated subjects and images were acquired at 500Hz for the FFOCT at IS/OS layer at 4° N.
Results :
Figure 1 shows images before and after correction through the Woofer-Tweeter approach in a healthy subject that undergone LASIK surgery, thus presenting strong high-order aberrations. FFOCT’s SNR was enhanced by a factor of two, while photoreceptors became visible. Comparison of the Fourier transforms of the acquired images shows that the spatial frequency content of the photoreceptor mosaic (the so-called Yellot's ring) is only visible after AO correction.
Conclusions :
We presented high resolution retinal images generated with compact, clinical-adapted FFOCT. This was made possible thanks to the replacement of the former AL by a Woofer-Tweeter approach, combining a VFL for defocus correction, and the Phaseform’s DPP for high-order aberrations correction, enabling to improve both SNR and lateral resolution when imaging subjects with high order aberrations. We plan to test the new Woofer-Tweeter Adaptive-glasses approach on a large population of patients for further validation.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.