title: An adaptive optics imaging system designed for clinical use.
abstract: Here we demonstrate a new imaging system that addresses several major problems limiting the clinical utility of conventional adaptive optics scanning light ophthalmoscopy (AOSLO), including its small field of view (FOV), reliance on patient fixation for targeting imaging, and substantial post-processing time. We previously showed an efficient image based eye tracking method for real-time optical stabilization and image registration in AOSLO. However, in patients with poor fixation, eye motion causes the FOV to drift substantially, causing this approach to fail. We solve that problem here by tracking eye motion at multiple spatial scales simultaneously by optically and electronically integrating a wide FOV SLO (WFSLO) with an AOSLO. This multi-scale approach, implemented with fast tip/tilt mirrors, has a large stabilization range of ± 5.6°. Our method consists of three stages implemented in parallel: 1) coarse optical stabilization driven by a WFSLO image, 2) fine optical stabilization driven by an AOSLO image, and 3) sub-pixel digital registration of the AOSLO image. We evaluated system performance in normal eyes and diseased eyes with poor fixation. Residual image motion with incremental compensation after each stage was: 1) ~2-3 arc minutes, (arcmin) 2) ~0.5-0.8 arcmin and, 3) ~0.05-0.07 arcmin, for normal eyes. Performance in eyes with poor fixation was: 1) ~3-5 arcmin, 2) ~0.7-1.1 arcmin and 3) ~0.07-0.14 arcmin. We demonstrate that this system is capable of reducing image motion by a factor of ~400, on average. This new optical design provides additional benefits for clinical imaging, including a steering subsystem for AOSLO that can be guided by the WFSLO to target specific regions of interest such as retinal pathology and real-time averaging of registered images to eliminate image post-processing.
authors.affiliation: Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA ; Equal contribution first authors.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA ; Equal contribution first authors.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Healthcare Solutions Division, Business Imaging Solution Group, Canon U.S.A. Inc., Melville, NY, 11747, USA.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Saito
authors.affiliation: Healthcare Solutions Division, Business Imaging Solution Group, Canon U.S.A. Inc., Melville, NY, 11747, USA.
authors.forename: Koji
authors.initials: K
authors.lastname: Nozato
authors.affiliation: Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA ; The Institute of Optics, University of Rochester, Rochester, NY, 14642, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Williams
authors.affiliation: Center for Visual Science, University of Rochester, Rochester, NY, 14642, USA.
authors.forename: Ethan A
authors.initials: EA
authors.lastname: Rossi
keywords: (110.1080) Active or adaptive optics; (120.3890) Medical optics instrumentation; (170.3880) Medical and biological imaging; (170.4470) Ophthalmology; (330.2210) Vision - eye movements