Histologic ocular changes observed in (LEW × BN) F1 rats 35 days after S Ag immunization. (A) In the control rat injected only with S Ag, there is destruction of the photoreceptor cell layer and most of the bipolar cell layer with the presence of inflammatory cells. (B) In a rat treated with IVIgM, there is complete integrity of the retinal structure (Hematoxylin eosin, original magnification × 270).