Purpose:
To test the feasibility of new instrumentation that acquires simultaneous optical coherence tomography and scanning laser ophthalmoscope images, both corrected for ocular aberrations with adaptive optics (AO) for clinical retinal imaging.
Methods:
An ultra-high-resolution AO - Fourier-domain optical coherence tomography (AO-OCT) system was combined with an adaptive optics scanning laser ophthalmoscope (AO-SLO). Both systems share a common AO sub-system and vertical scanner to permit simultaneous acquisition of retinal images from both AO-OCT and AO-SLO. Image acquisition is based on two different wavelengths, 840 nm (110 nm bandwidth) for OCT and 680 nm (10 nm bandwidth) for SLO. Additionally, the OCT light source serves as the beacon for wavefront sensing in the AO sub-system. Monochromatic aberration correction is based on a Shack-Hartmann wavefront sensor and two deformable mirrors in tandem. A custom achromatizing lens is used to correct longitudinal chromatic aberration in the OCT beam.
Results:
For each AO-SLO en-face frame, an AO-OCT vertical B-scan is acquired. The AO-UHR OCT subsystem allows real-time imaging with high volumetric resolution (~ 3.5 µm in all three dimensions). The AO-SLO system has the same lateral resolution with ~50 µm axial resolution.
Conclusions:
Several commercial clinical instruments combine an SLO view finder with OCT, and AO-OCT has been combined with AO-SLO using transversal scanning time domain OCT. This is the first report of a combined AO-Fourier-domain-OCT and AO-SLO instrument. One of the benefits of combining AO-Fd-OCT with AO-SLO includes automatic co-registration between the two modalities and potential for correcting lateral and transversal eye motion resulting in motion artifact-free volumetric retinal imaging. Feasibility for clinical application will be discussed as well as potential further improvements of the current system and image processing methods.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: non-clinical • imaging/image analysis: clinical