Multi-scale and -mode sensorless adaptive optics OCT for in vivo human retinal imaging (Conference Presentation)

In this study we describe our novel Multi-Scale and multi-Mode Sensorless Adaptive Optics OCT system (MSM-SAO-OCT). Our system expands upon our previously reported work by introducing a zoomable collimator, phase calibration interferometer, and polarization diversity detection module. By using a zoomable collimator into the system setup, we allow an adjustable probing beam diameter without the need to change the optical setup, permitting imaging with both low and high lateral resolution (18 µm – 6 µm) at various Fields of View (FOV) within diffraction limited resolution. By employing SAO optimization algorithm, different morphological structures and microvasculature in a retina were clearly visualized after wavefront aberration correction with dual deformable optical elements – Variable Focus Lens (VFL) for defocus and a Multi-Actuator Adaptive Lens (MAL) for two astigmatisms. For retinal vasculature imaging, MSM-SAO-OCT system generates flow-specific contrast as measuring amplitude of complex variance from the multiple OCT B-scans from the same transverse location after stabilizing OCT signals in a phase using a static interference signal from phase calibration interferometer. In addition, the use of polarization diversity detection allows to create Degree Of Polarization Uniformity (DOPU) contrast using for visualization of the Retinal Pigment Epithelium (RPE) with its inherent tissue characteristic (polarization scrambling). In order to demonstrate functionality and clinical utility of the MSM-SAO-OCT system, in vivo human retinal imaging was performed on research subjects, and imaging results are presented and discussed.