Functional imaging of retinal photoreceptors

描述（由申请人提供）：许多眼部疾病，例如年龄相关性黄斑变性（AMD）、糖尿病性视网膜病变（DR）和青光眼，涉及视网膜光感受器和/或视网膜内层神经元的病理变化。众所周知，不同的疾病可以针对不同的细胞类型。原则上，生理改变必须发生在病变细胞中， 在视网膜形态异常之前。因此，视网膜生理功能评估对于早期疾病检测和可靠的治疗管理是重要的。在伯明翰的亚拉巴马大学（UAB），我们已经开发了几种光学方法，包括功能性光学相干断层扫描（OCT）和线扫描共聚焦显微镜，利用与视网膜刺激相关的瞬态内在光信号（IOS）变化来进行生理活动的光生理监测。我们建议在这里，以高分辨率（< 50米）的感光生理功能IOS映射验证。该项目的成功可以导致更好地研究和诊断与眼部疾病相关的光感受器功能障碍，包括AMD，这是严重视力丧失和法律的失明的主要原因。我们的初步研究揭示了IOS异常的一个小鼠模型与遗传性感光细胞变性，并在体内共焦IOS观察个别青蛙光感受器已被证明。快速共焦IOS成像承诺一个高分辨率的感光生理功能检查的方法，同时提供视网膜形态的信息。然而，在功能性IOS成像的临床部署之前，存在几个障碍：1）视网膜中的IOS机制尚不清楚; 2）杆和锥系统的IOS成像方案尚未开发; 3）IOS修饰与视网膜疾病之间的临床相关性尚未建立。这些问题将在本项目的三个具体目标中得到解决。第一个目的是调查IOS的生理来源。将采用混合共焦OCT显微镜以亚细胞分辨率解剖感光细胞和视网膜内细胞中的IOS。将使用正常和酒石酸盐处理的视网膜的比较测量来测试IOS的生理途径。第二个目标是开发用于视网膜光感受器的功能IOS映射的刺激方案。我们预计，局部（例如，50 m）的视杆细胞和视锥细胞的功能可以通过视网膜适应和刺激的定量控制来实现，而不需要分辨单个光感受器。第三个目的是建立功能IOS成像的临床潜力。一种遗传性光感受器变性模型rd 10，即，C57 BL/6 J-Pde 6 brd 10将用于比较IOS、电生理和组织学研究。本研究的成功标准是证明IOS成像允许在不晚于视网膜中可检测到的结构变化的时间点早期检测光感受器功能障碍。年底 在该项目中，最终的成像模式（即，共焦或OCT）进行临床应用， 基于共聚焦和OCT-10 S图像的定量比较来识别。

DESCRIPTION (provided by applicant): Many eye diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR) and glaucoma, involve pathological changes in retinal photoreceptors and/or inner retinal neurons. It is well known that different diseases can target different cell types. In principle, physiological modification must occur in diseased cells, before detectable abnormality of retinal morphology. Therefore, functional evaluation of retinal physiology is important for early disease detection and reliable treatment management. At University of Alabama at Birmingham (UAB), we have developed several optical approaches, including functional optical coherence tomography (OCT) and line-scan confocal microscopy, to pursue optophysiological monitoring of physiological activities using transient intrinsic optical signal (IOS) changes correlated with retinal stimulation. We propose here to validate functional IOS mapping of photoreceptor physiology at high resolution (< 50 m). Success of this project can lead to better study and diagnosis of photoreceptor dysfunction associated with eye diseases, including AMD which is the leading cause of severe vision loss and legal blindness. Our preliminary study has revealed IOS abnormalities in one mouse model with inherited photoreceptor degeneration, and in vivo confocal-IOS observation of individual frog photoreceptors have been demonstrated. Fast confocal-IOS imaging promises a high-resolution method for functional examination of photoreceptor physiology, while simultaneously providing information of retinal morphology. However, before clinical deployments of the functional IOS imaging, there are several obstacles: 1) IOS mechanism in the retina is not clear; 2) IOS imaging protocol of rod and cone systems is not developed; 3) clinical relevance between IOS modification and retinal disease is not established. These problems will be tackled in our three specific aims of this project. The first aim is to investigate physiological sources of the IOS. A hybrid confocal-OCT microscope will be employed to dissect the IOS in the photoreceptor and inner retinal cells at sub-cellular resolution. Comparative measurement of normal and aspartate-treated retinas will be used to test physiological pathways of the IOS. The second aim is to develop stimulation protocol for functional IOS mapping of retinal photoreceptors. We anticipate that selective mapping of localized (e.g., 50 m) rod and cone functions can be achieved through quantitative controls of retinal adaptation and stimulation, without the requirement of resolving individual photoreceptors. The third aim is to establish clinical potential of functional IOS imaging. One inherited photoreceptor degeneration model rd10, i.e., C57BL/6J-Pde6brd10, will be used for comparative IOS, electrophysiological, and histological study. Success criterion of this study is to demonstrate that the IOS imaging allows early detection of photoreceptor dysfunction at the time point no later than detectable structural changes in the retina. By the end of this project, ultimate imaging modality (i.e., confocal or OCT) for clinical application will be identified based on quantitative comparison of confocal- and OCT-IOS images.