Laslandes Marie, Salas Matthias, Hitzenberger Christoph K, Pircher Michael
Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
Biomed Opt Express. 2017 Oct 3;8(11):4811-4826. doi: 10.1364/BOE.8.004811. eCollection 2017 Nov 1.
An adaptive optics scanning laser ophthalmoscope (AO-SLO) set-up with two deformable mirrors (DM) is presented. It allows high resolution imaging of the retina on a 4°×4° field of view (FoV), considering a 7 mm pupil diameter at the entrance of the eye. Imaging on such a FoV, which is larger compared to classical AO-SLO instruments, is allowed by the use of the two DMs. The first DM is located in a plane that is conjugated to the pupil of the eye and corrects for aberrations that are constant in the FoV. The second DM is conjugated to a plane that is located ∼0.7 mm anterior to the retina. This DM corrects for anisoplanatism effects within the FoV. The control of the DMs is performed by combining the classical AO technique, using a Shack-Hartmann wave-front sensor, and sensorless AO, which uses a criterion characterizing the image quality. The retinas of four healthy volunteers were imaged in-vivo with the developed instrument. In order to assess the performance of the set-up and to demonstrate the benefits of the 2 DM configuration, the acquired images were compared with images taken in conventional conditions, on a smaller FoV and with only one DM. Moreover, an image of a larger patch of the retina was obtained by stitching of 9 images acquired with a 4°×4° FoV, resulting in a total FoV of 10°×10°. Finally, different retinal layers were imaged by shifting the focal plane.
本文介绍了一种配备两个可变形镜(DM)的自适应光学扫描激光检眼镜(AO-SLO)装置。考虑到眼睛入口处7毫米的瞳孔直径,它能够在4°×4°的视野(FoV)上对视网膜进行高分辨率成像。与传统的AO-SLO仪器相比,该装置使用两个DM实现了更大视野的成像。第一个DM位于与眼睛瞳孔共轭的平面上,用于校正视野中恒定的像差。第二个DM与位于视网膜前方约0.7毫米处的平面共轭,用于校正视野内的非等晕效应。通过结合使用夏克-哈特曼波前传感器的经典AO技术和使用图像质量特征判据的无传感器AO技术来控制DM。使用该研发仪器对四名健康志愿者的视网膜进行了活体成像。为了评估该装置的性能并展示双DM配置的优势,将采集到的图像与在传统条件下、较小视野且仅使用一个DM拍摄的图像进行了比较。此外,通过拼接9张4°×4°视野采集的图像,获得了更大视网膜区域的图像,总视野达到10°×10°。最后,通过移动焦平面成像不同的视网膜层。