EpoR mRNA expression in the posterior normal (A-C) and diabetic (D-F) retina. A, Phase contrast micrograph of a normal human retina. B, Anti-sense RNA probes for EpoR in normal retina. C, Control sense RNA probes for EpoR in normal retina demonstrates expression in the retinal ganglion cell layer. D, Phase contrast micrograph of a diabetic human retina with an artifactual detachment. E, Anti-sense sense RNA probes for EpoR in diabetic retina. F, Control sense RNA probes for EpoR shows decreased expression in the RGC layer and an increase in the photoreceptor segments. Abbreviations: RGC, retinal ganglion cell layer; INL, inner nuclear layer; ONL outer nuclear layer; RPE, retinal pigment epithelium layer; PS, photoreceptor segments.