Figure 5: Ultrastructure of nontapetal (a) and tapetal retina (b) from the same dog shown in Figure 4. Note the severely disorganized outer and inner retinal cell layers and structures. The RPE cell layer appears preserved, however. In (b) there is relative sparing of the retina with some minor remnants of photoreceptor nuclei with inner segments (arrow) and an abundance of RPE apical microvilli. RPE: retinal pigment epithelial cells, T: tapetal cells. Bar depicts magnification which is the same for (a) and (b).