Comparison of Retinal Morphology of Wild-Type RIR, Untreated GUCY1*B, and Treated GUCY1*B Chickens

<div><p>(A) The morphology of the retinas of treated animals was examined to determine if the viral treatment had affected the course of retinal degeneration. Regions were analyzed along the vertical meridian of the right eyes of experimental and control animals; representative micrographs from the locus superior to the optic nerve (SUP ON) are shown from one wild-type, one untreated GUCY1*B, and three treated retinas (animals 1, 5, and 6). GCL, ganglion cell layer; INL, inner nuclear layer; IPL, inner plexiform layer; IS, inner segments; ONL, outer nuclear layer; OS, outer segments; RPE, retinal pigment epithelium.</p> <p>(B) Relative percent change in retinal thickness of treated animals. Retinal width (in micrometers) from the outer limiting membrane to the ganglion cell layer was measured at six loci (100 μm apart) within the regions examined. These widths were expressed as percent change relative to average widths of the untreated GUCY1*B retinas in these regions, which were set to zero for graphing purposes. A simple one-sample <i>t</i>-test (null hypothesis that treatment groups are not different from untreated GUCY1*B) was used to analyze the results. The results of this test showed that retinal thicknesses of the treated animals in the SUP ON (SON) and INF ON (ION) regions were greater than those of untreated animals ( <i>p</i> < 0.05). Four of six treated animals also showed evidence of slowing of degeneration in the SUP region, but this was not statistically significant. The key for animal number is shown in the upper left of the graph. </p>