Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) benefit clinical diagnostic imaging in
ophthalmology by enabling in vivo noninvasive en face and volumetric visualization of retinal structures, respectively.
Spectrally encoding methods enable confocal imaging through fiber optics and reduces system complexity. Previous
applications in ophthalmic imaging include spectrally encoded confocal scanning laser ophthalmoscopy (SECSLO) and
a combined SECSLO-OCT system for image guidance, tracking, and registration. However, spectrally encoded imaging
suffers from speckle noise because each spectrally encoded channel is effectively monochromatic. Here, we demonstrate
in vivo human retinal imaging using a swept source spectrally encoded scanning laser ophthalmoscope and OCT (SSSESLO-
OCT) at 1060 nm. SS-SESLO-OCT uses a shared 100 kHz Axsun swept source, shared scanner and imaging
optics, and are detected simultaneously on a shared, dual channel high-speed digitizer. SESLO illumination and
detection was performed using the single mode core and multimode inner cladding of a double clad fiber coupler,
respectively, to preserve lateral resolution while improving collection efficiency and reducing speckle contrast at the
expense of confocality. Concurrent en face SESLO and cross-sectional OCT images were acquired with 1376 x 500
pixels at 200 frames-per-second. Our system design is compact and uses a shared light source, imaging optics, and
digitizer, which reduces overall system complexity and ensures inherent co-registration between SESLO and OCT
FOVs. En face SESLO images acquired concurrent with OCT cross-sections enables lateral motion tracking and three-dimensional
volume registration with broad applications in multivolume OCT averaging, image mosaicking, and
intraoperative instrument tracking.
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