High-speed automated focus tracking using complex focus metrics for point-of-care ophthalmic OCT

Focus adjustments to compensate for refractive power differences between patients are critical for high-quality OCT/A in point-of-care retinal imaging. Optimal focus is typically identified by maximizing OCT brightness metrics; however, these metrics are susceptible to source power fluctuations as well as pupil clipping and hand motion that occur during point-of-care imaging. We present closed-loop automated focus tracking using novel phase-based focus metrics to address these challenges and demonstrate integrated tracking with our handheld spectrally encoded coherence tomography and reflectometry (HH-SECTR) probe. We predict phase-based automated focus tracking will improve clinical ergonomics for more efficient point-of-care retinal OCT/A imaging.