Closed-loop optical stabilization and digital image registration in adaptive optics scanning light ophthalmoscopy.

Eye motion is a major impediment to the efficient acquisition of high resolution retinal images with the adaptive optics (AO) scanning light ophthalmoscope (AOSLO). Here we demonstrate a solution to this problem by implementing both optical stabilization and digital image registration in an AOSLO. We replaced the slow scanning mirror with a two-axis tip/tilt mirror for the dual functions of slow scanning and optical stabilization. Closed-loop optical stabilization reduced the amplitude of eye-movement related-image motion by a factor of 10-15. The residual RMS error after optical stabilization alone was on the order of the size of foveal cones: ~1.66-2.56 μm or ~0.34-0.53 arcmin with typical fixational eye motion for normal observers. The full implementation, with real-time digital image registration, corrected the residual eye motion after optical stabilization with an accuracy of ~0.20-0.25 μm or ~0.04-0.05 arcmin RMS, which to our knowledge is more accurate than any method previously reported.

[1]  Jeffrey B. Mulligan,et al.  Recovery of motion parameters from distortions in scanned images , 1997 .

[2]  Lawrence C. Sincich,et al.  Resolving Single Cone Inputs to Visual Receptive Fields , 2009, Nature Neuroscience.

[3]  Austin Roorda,et al.  High-speed, image-based eye tracking with a scanning laser ophthalmoscope , 2012, Biomedical optics express.

[4]  L A Riggs,et al.  Accuracy of retinal image stabilization achieved with a plane mirror on a tightly fitting contact lens. , 1968, Vision Research.

[5]  Scott B Stevenson,et al.  How the unstable eye sees a stable and moving world. , 2013, Journal of vision.

[6]  Austin Roorda,et al.  Real-time eye motion compensation for OCT imaging with tracking SLO , 2012, Biomedical optics express.

[7]  David R. Williams,et al.  Visual Function and Cortical Organization in Carriers of Blue Cone Monochromacy , 2010, PloS one.

[8]  Austin Roorda,et al.  Retinal motion estimation in adaptive optics scanning laser ophthalmoscopy. , 2006, Optics express.

[9]  Austin Roorda,et al.  Real-time eye motion correction in phase-resolved OCT angiography with tracking SLO , 2012, Biomedical optics express.

[10]  Jennifer J. Hunter,et al.  Imaging retinal mosaics in the living eye , 2011, Eye.

[11]  J NACHMIAS,et al.  Two-dimensional motion of the retinal image during monocular fixation. , 1959, Journal of the Optical Society of America.

[12]  M Lades,et al.  Measurement of eye rotations in three dimensions and the retinal stimulus projection using scanning laser ophthalmoscopy , 1990, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[13]  R. D. Ferguson,et al.  Adaptive optics scanning laser ophthalmoscope for stabilized retinal imaging. , 2006, Optics express.

[14]  Alfredo Dubra,et al.  Registration of 2D Images from Fast Scanning Ophthalmic Instruments , 2010, WBIR.

[15]  D Ott,et al.  Ocular torsion measured by TV- and scanning laser ophthalmoscopy during horizontal pursuit in humans and monkeys. , 1989, Investigative ophthalmology & visual science.

[16]  D H Brainard,et al.  The Psychophysics Toolbox. , 1997, Spatial vision.

[17]  Michele Rucci,et al.  EyeRIS: A general-purpose system for eye-movement-contingent display control , 2007, Behavior research methods.

[18]  J B Mulligan,et al.  Image processing for improved eye-tracking accuracy , 1997, Behavior research methods, instruments, & computers : a journal of the Psychonomic Society, Inc.

[19]  H D Crane,et al.  Accurate two-dimensional eye tracker using first and fourth Purkinje images. , 1973, Journal of the Optical Society of America.

[20]  L. Riggs,et al.  The disappearance of steadily fixated visual test objects. , 1953, Journal of the Optical Society of America.

[21]  Daniel X Hammer,et al.  Large-field-of-view, modular, stabilized, adaptive-optics-based scanning laser ophthalmoscope. , 2007, Journal of the Optical Society of America. A, Optics, image science, and vision.

[22]  D R Williams,et al.  Supernormal vision and high-resolution retinal imaging through adaptive optics. , 1997, Journal of the Optical Society of America. A, Optics, image science, and vision.

[23]  David R Williams,et al.  In vivo imaging of retinal pigment epithelium cells in age related macular degeneration. , 2013, Biomedical optics express.

[24]  H D Crane,et al.  Generation-V dual-Purkinje-image eyetracker. , 1985, Applied optics.

[25]  Daniel X Hammer,et al.  Adaptive optics scanning laser ophthalmoscope with integrated wide-field retinal imaging and tracking. , 2010, Journal of the Optical Society of America. A, Optics, image science, and vision.

[26]  Austin Roorda,et al.  Design of an integrated hardware interface for AOSLO image capture and cone-targeted stimulus delivery , 2010, Optics express.

[27]  David Williams.  Imaging single cells in the living retina , 2011, Vision Research.

[28]  M. Rolfs.  Microsaccades: Small steps on a long way , 2009, Vision Research.

[29]  THE ANGLE VELOCITY OF EYE MOVEMENTS , 2004 .

[30]  D. Troxler.  Ueber das Verschwinden gegebener Gegenstande innerhalb unseres Gesichtskreises , 1804 .

[31]  Austin Roorda,et al.  Retinally stabilized cone-targeted stimulus delivery. , 2007, Optics express.

[32]  Denis G. Pelli,et al.  ECVP '07 Abstracts , 2007, Perception.

[33]  T. Hebert,et al.  Adaptive optics scanning laser ophthalmoscopy. , 2002, Optics express.

[34]  R. Dodge,et al.  The angular velocity of eye movements , 1901 .

[35]  G. Timberlake,et al.  A Novel Method for Measuring Saccade Profiles Using the Scanning Laser Ophthalmoscope , 1996, Vision Research.

[36]  D. Hubel,et al.  The role of fixational eye movements in visual perception , 2004, Nature Reviews Neuroscience.

[37]  Fabrice Manns,et al.  Correcting for Miniature Eye Movements in High Resolution Scanning Laser Ophthalmoscopy , 2005 .

[38]  Austin Roorda,et al.  Mapping the Perceptual Grain of the Human Retina , 2014, The Journal of Neuroscience.

[39]  D G Pelli,et al.  The VideoToolbox software for visual psychophysics: transforming numbers into movies. , 1997, Spatial vision.

[40]  L A RIGGS,et al.  Motions of the retinal image during fixation. , 1954, Journal of the Optical Society of America.

[41]  Manuel Guizar-Sicairos,et al.  Efficient subpixel image registration algorithms. , 2008, Optics letters.

[42]  A. Dubra,et al.  Reflective afocal broadband adaptive optics scanning ophthalmoscope , 2011, Biomedical optics express.

[43]  W. J. Daunicht,et al.  Eye movement measurement with the scanning laser ophthalmoscope , 1992 .

[44]  Robert Michael Jones,et al.  Accuracy of image stabilization by an optical-electronic feedback system , 1975, Vision Research.