Cooper Robert F, Dubis Adam M, Pavaskar Ashavini, Rha Jungtae, Dubra Alfredo, Carroll Joseph
Biomed Opt Express. 2011 Sep 1;2(9):2577-89. doi: 10.1364/BOE.2.002577. Epub 2011 Aug 11.
Using adaptive optics imaging tools to image the living retina, numerous investigators have reported temporal fluctuation in the reflectivity of individual cone photoreceptors. In addition, there is cone-to-cone (spatial) variation in reflectivity. As it has only recently become possible to image the complete rod photoreceptor mosaic in the living human retina, we sought to characterize the reflectivity of individual rods and compare their behavior to that of foveal/parafoveal cones. Across two subjects, we were able to successfully track the reflectance behavior of 1,690 rods and 1,980 cones over 12 hours. Rod and cone photoreceptors showed similar regional and temporal variability in their reflectance profiles, suggesting the presence of a common governing physiological process. Within the rod and cone mosaics, there was no sign of spatial clumping of reflectance profile behavior; that is, the arrangement of cells of a given archetypal reflectance profile within the mosaic was indistinguishable from random. These data demonstrate the ability to track the behavior of rod reflectivity over time. Finally, as these and other reflectance changes may be an indicator of photoreceptor function, a future extension of this method will be to analyze this behavior in patients with rod photoreceptor dysfunction (e.g., retinitis pigmentosa, Usher's syndrome, and congenital stationary night blindness).
使用自适应光学成像工具对活体视网膜进行成像时，众多研究人员报告了单个视锥光感受器反射率的时间波动。此外，视锥之间（空间上）的反射率也存在差异。由于直到最近才能够对活体人类视网膜中的完整视杆光感受器镶嵌结构进行成像，我们试图表征单个视杆的反射率，并将它们的行为与中央凹/中央凹旁视锥的行为进行比较。在两名受试者中，我们成功地在12小时内追踪了1690个视杆和1980个视锥的反射率行为。视杆和视锥光感受器在其反射率分布上表现出相似的区域和时间变异性，这表明存在一个共同的主导生理过程。在视杆和视锥镶嵌结构中，没有反射率分布行为的空间聚集迹象；也就是说，镶嵌结构中具有给定原型反射率分布的细胞排列与随机排列没有区别。这些数据证明了随时间追踪视杆反射率行为的能力。最后，由于这些和其他反射率变化可能是光感受器功能的一个指标，该方法未来的扩展将是分析视杆光感受器功能障碍患者（如视网膜色素变性、乌谢尔综合征和先天性静止性夜盲症）的这种行为。
