Functional imaging of retinal photoreceptors

项目摘要：这是R01的更新版本，用于开发功能性本征光学信号(IOS)成像 视网膜光感受器的生理评估。视网膜光感受器是已知的主要目标 老年性黄斑变性(AMD)和视网膜色素变性(RP)。及早发现眼部疾病 对治疗结果的客观评估是预防视力丧失和失明的重要步骤。 仅有结构上的生物标志物不能为评价视网膜的生理状态提供足够的信息 光感受器和联合功能测试常被用于疾病的检测和治疗 评估。然而，将结构和功能分开进行既费时又费钱，效率低下 测量。功能性iOS成像，也称为视网膜术(ORG)或视生理学，基于 视网膜中刺激诱发的生理活动的近红外(NIR)光图。因为iOS映像 基于对视网膜图像的动态处理，它可以自然地提供 传统的眼底照相术。在第一次授予期间，我们展示了刺激引发的IO 视网膜光感受器外段的反应。快速光感受器-iOS在 视网膜刺激的开始，与视网膜内部延迟的IOS变化不同。这个 快速光感受器-iOS为光感受器生理的客观ORG提供了一个独特的标记，没有信号 光感受器后层的污染。我们建议在这里描述FAST的生物物理机制 光感受器-IOS(Aim 1)；并验证感光器目标ORG的快速光感受器-IOS成像 人体功能(目标2)。第一个目标是使用动物模型来验证FAST与 光感受器-IOS进入光转导的活化期。一种定制设计的混合共焦-OCT 眼底镜将用于在体表征WT和RD10小鼠的快速光感受器-IOS。离体 时间推移光学显微镜将被用来表征个体的瞬时外段反应 光感受器。将对暗适应和光适应的视网膜组织进行比较电子显微镜检查 以验证子光盘级别的光驱动外段收缩。第二个目标是验证 快速光感受器-iOS成像在活体人光感受器ORG中的临床翻译。我们有 最近展示了基于虚拟结构检测(VSD)的单个棒和 清醒的人类体内的锥体。在这个项目中，基于VSD的超分辨率眼底镜将改进为 实现微米级空间分辨率和毫秒级时间分辨率，快速成像光感受器-iOS变化 在人类的光感受器中。这项研究的成功将为寻求临床应用铺平道路 目的视网膜光感受器的ORG，使疾病的早期诊断和及时的治疗评估成为可能 AMD、RP和其他可能导致光感受器功能障碍的眼睛问题。

Project summary: This is a R01 renewal to develop functional intrinsic optical signal (IOS) imaging for physiological assessment of retinal photoreceptors. Retinal photoreceptors are known as the primary target of both age-related macular degeneration (AMD) and retinitis pigmentosa (RP). Early detection of eye diseases and objective assessment of therapeutic outcomes are essential steps to prevent vision loss and blindness. Structural only biomarkers cannot provide enough information for evaluating physiological condition of retinal photoreceptors, and combined functional test is frequently required for disease detection and treatment assessment. However, it is time-consuming and costly inefficient to conduct separate structural and functional measurements. Functional IOS imaging, also termed as optoretinography (ORG) or optophysiology, is based on near infrared (NIR) light mapping of stimulus-evoked physiological activities in the retina. Because IOS imaging is based on dynamic processing of retinal images, it can naturally provide structural information offered in traditional fundus photography. During the first grant period, we have demonstrated stimulus evoked IOS response at the outer segment of retinal photoreceptors. The fast photoreceptor-IOS occurs immediately after the onset of the retinal stimulation, differentiating itself from timely delayed IOS changes at the inner retina. The fast photoreceptor-IOS provides a unique marker for objective ORG of photoreceptor physiology, without signal contamination of post-photoreceptor layers. We propose here to characterize biophysical mechanism of the fast photoreceptor-IOS (aim 1); and validate fast photoreceptor-IOS imaging for objective ORG of photoreceptor function in human subjects (aim 2). The first aim is to use animal models to verify the correlation of the fast photoreceptor-IOS to the activation phase of phototransduction. A custom-designed hybrid confocal-OCT ophthalmoscope will be used for in vivo characterization of fast photoreceptor-IOS in WT and rd10 mice. In vitro time-lapse light microscopy will be conducted to characterize transient outer segment response in individual photoreceptors. Comparative electron microscopy of dark- and light-adapted retinal tissues will be implemented to verify light-driven outer segment shrinkage at sub-disc level. The second aim is to verify the feasibility of clinical translation of using fast photoreceptor-IOS imaging for in vivo ORG of human photoreceptors. We have recently demonstrated virtually structured detection (VSD) based super-resolution imaging of individual rods and cones in awake human. During this project, the VSD based super-resolution ophthalmoscopy will be refined to achieve µm level spatial-resolution and ms level temporal-resolution for imaging fast photoreceptor-IOS changes in human photoreceptors. Success of this study will pave the way towards pursuing clinical application of objective ORG of retinal photoreceptors, enabling early disease diagnosis and prompt treatment assessment of AMD, RP and other eye problems which can cause photoreceptor dysfunctions.