Abstract
Purpose :
A retinal imaging system was implemented for high-speed full-field (FF) swept-source (SS) optical coherence tomography (OCT), incorporating an adaptive optics (AO) subsystem. It has been previously reported that digital aberration correction (DAC) permits visualization of cones with FF-SS-OCT, but only in the parafovea and periphery. By combining AO with FF-SS-OCT this system will be able to resolve all cones and measure functional responses previously reported only in the periphery. With the reference arm blocked, the system is a high speed (kHz) AO fundus camera capable of measuring light-evoked responses through common path interference.
Methods :
The setup is a Mach-Zehnder interferometer with tuneable source (Superlum BS-840-2-HP) illuminating the retina. The backscattered light is imaged at a CMOS sensor (Photron NOVA S12 Fastcam). In parallel, a deformable mirror (ALPAO DM-97-15) is operated by custom software in closed-loop with a Hartmann-Shack wavefront sensor for real-time aberration correction. Two normal subjects were imaged at locations between the foveal center and 3o.
Results :
OCT sensitivity and lateral resolution were measured to be 53 dB and 3 μm, respectively. With closed-loop AO correction, diffraction-limited areal images of the cone mosaic and OCT images of the retina were successfully collected at rates of 1 kHz and 200 Hz, respectively. Cones were laterally resolved in the areal images and resolved in 3D in the OCT images.
Conclusions :
The system was demonstrated to be capable of producing multimodal images of the foveal cone mosaic. Future plans include incorporation of a DMD-based visible stimulus channel and modification of the AO system to permit higher speed and dynamic range.
Funding: R00-EY-026068 (RSJ); R01-EY-026556 (RJZ).
This is a 2020 ARVO Annual Meeting abstract.