Properties of human photoreceptors measured using a scanning laser ophthalmoscope to illuminate and image the retina

视觉始于眼睛内侧视网膜内的视杆和视锥感光器对光线的探测。虽然关于光的探测和信号处理的方式已经知道了很多，但仍有很多东西需要学习。一些悬而未决的问题可以通过对一种名为扫描激光眼底镜(SLO)的相对较新的仪器的改进来回答，该仪器提供眼睛内部的图像。这个项目的目的是开发一种改进的SLO，它能够测量活着的眼睛中视觉色素(视紫红质)的水平，并且能够将视觉刺激传递到眼睛，并最终扩展到使用自适应光学技术，以便它可以成像和刺激单个视锥感光器。使用这个装置，我们将能够测量在强光下暴露后视觉色素的再生，以帮助解释强光后视觉灵敏度恢复缓慢的原因。我们还将能够测量局部视网膜区域的视网膜电信号(ERG)，以研究整个视网膜光感受器细胞的特性如何变化。最后，我们将不仅能够可视化单个微小的锥体光感受器，而且能够选择性地刺激它们，以便我们可以确定活着的人眼中不同类别的锥体(红色、绿色和蓝色敏感的锥体)的反应。

Vision begins with the detection of light by the rod and cone photoreceptors in the retina lining the interior of the eye. Although much is already known about the way that light is detected and the signals are processed, a great deal remains to be learned. Some of the outstanding questions could be answered using modifications to a relatively new instrument called a scanning laser ophthalmoscope (SLO) which provides images of the interior of the eye. The aims of this project are to develop a modified SLO, which is able to measure the levels of visual pigment (rhodopsin) in the living eye, which is also able to deliver visual stimuli to the eye, and which finally is extended to use adaptive optics so that it can image and excite individual cone photoreceptors. Using this device, we will be able to measure the regeneration of visual pigment following exposures to intense illumination, to help explain the slow recovery of visual sensitivity after intense light. We will also be able to measure the electroretinogram (ERG) from localized retinal areas, to investigate how the properties of the photoreceptor cells vary across the retina. And finally we will be able not only to visualize the individual tiny cone photoreceptors, but also to stimulate them selectively, so that we can determine the responses of the different classes of cone (red-, green-, and blue-sensitive cones) in the living human eye.