Figure 6.

Representative in vivo IOS imaging. A 10-ms flash stimulus was used for retinal stimulation of the frog eye. Raw OCT images were collected with a frame rate of 100 Hz. Stimulus onset is indicated by time “0”. OCT B-scan images are presented with a linear scale, as opposed to logarithmic scale in conventional OCT systems. (a1–a3) OCT B-scan images and spatial IOS image sequences of one control and two experimental groups. All the images were averaged over 10 frames (100 ms interval). Images consisted of 140 pixels (lateral) × 200 pixels (axial), corresponding to 200 mm (lateral) × 360 mm (axial). (b) Temporal curves of the number of activated (positive and negative) pixels corresponding to (a1–a3). (c) Temporal curves of positive and negative IOSs averaged from six recording trials. (d) To better visualize the signal onset time, an enlarged profile of the early 80 ms period from (c) is illustrated. (e) IOS distribution map superimposed on the OCT B-scan image. Red and green dots in (e) present areas with positive signals (increasing reflectance) and negative signals (decreasing reflectance), respectively. Signal magnitude is not indicated in the image. (f) Comparative OCT-IOS and histological images of the outer retina. In the histological image, cone photoreceptors are highlighted in green or red to show cell sizes and locations. Cone photoreceptor outer segments (OSs) highlighted with red circles are located at the level of the rod inner segment ellipsoid (ISe). Scale bars indicate 50 µm. Reprinted with permission from Zhang et al.²⁴ (A color version of this figure is available in the online journal.)