High-resolution adaptive optics (AO) imaging of retinal neurons in living eyes holds promise for improved diagnosis and better assessment of treatment outcomes for retinal diseases. By integrating different imaging modalities, such as scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT), AO has enabled microscopic views of different retinal neurons, including recently reported retinal ganglion cells. In this study, we present a novel design of a multimodal adaptive optics imaging system to investigate the microscopic structure of living human retina. The optical system was designed using Zemax ray tracing software. The system performance was evaluated in terms of image quality and beam displacement. Optical performance was predicted to achieve diffraction limited image quality at the retinal plane and beam displacement was predicted to be >7× smaller than the pitch of Shack-Hartmann lenslet at the pupil planes for scan angles over 3.6°×3.6° field of view. The initial human subject images are presented. High quality photoreceptor images were acquired in both AO-SLO channel and AO-OCT channel simultaneously at 3° temporal from the fovea. Individual cones are delineated in AO-SLO image, the corresponding AO-OCT image showed four main reflections from outer retina, namely external limiting membrane, cone inner segment/outer segment junction, cone outer segment tip, and retinal pigment epithelium. The system allows flexibly alternating between AO-SLO and AO-OCT modes, which provides complementary views of retinal cells, and the potential to improve disease diagnosis and treatment.
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