Carrasco-Zevallos Oscar, Nankivil Derek, Keller Brenton, Viehland Christian, Lujan Brandon J, Izatt Joseph A
Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Box 90281, Durham, NC 27708, USA.
Department of Vision Science, School of Optometry, University of California, Berkeley, CA 94701, USA ; West Coast Retina Medical Group, San Francisco, CA 94109, USA.
Biomed Opt Express. 2015 Aug 17;6(9):3405-19. doi: 10.1364/BOE.6.003405. eCollection 2015 Sep 1.
To maximize the collection efficiency of back-scattered light, and to minimize aberrations and vignetting, the lateral position of the scan pivot of an optical coherence tomography (OCT) retinal scanner should be imaged to the center of the ocular pupil. Additionally, several retinal structures including Henle's Fiber Layer (HFL) exhibit reflectivities that depend on illumination angle, which can be controlled by varying the pupil entry position of the OCT beam. In this work, we describe an automated method for controlling the lateral pupil entry position in retinal OCT by utilizing pupil tracking in conjunction with a 2D fast steering mirror placed conjugate to the retinal plane. We demonstrate that pupil tracking prevents lateral motion artifacts from impeding desired pupil entry locations, and enables precise pupil entry positioning and therefore control of the illumination angle of incidence at the retinal plane. We use our prototype pupil tracking OCT system to directly visualize the obliquely oriented HFL.
为了最大化背向散射光的采集效率，并最小化像差和渐晕，光学相干断层扫描（OCT）视网膜扫描仪的扫描枢轴的横向位置应成像于眼瞳中心。此外，包括亨利纤维层（HFL）在内的几种视网膜结构的反射率取决于照明角度，这可以通过改变OCT光束的瞳孔入射位置来控制。在这项工作中，我们描述了一种通过结合瞳孔跟踪与放置在与视网膜平面共轭位置的二维快速转向镜来控制视网膜OCT中瞳孔横向入射位置的自动化方法。我们证明，瞳孔跟踪可防止横向运动伪影妨碍所需的瞳孔入射位置，并实现精确的瞳孔入射定位，从而控制视网膜平面的照明入射角。我们使用我们的原型瞳孔跟踪OCT系统直接可视化倾斜取向的HFL。
