Fig 2: Histology and immunohistochemistry. Scale bar = 31 µm. Reaction color: brown. (A,B) Hematoxylin and eosin (HE) staining. In RVO complicated by ischemia, increased thickness was observed in the nerve fiber layer (NFL), the ganglion cell layer (GCL), the inner plexiform layer (IPL), and the outer plexiform layer (OPL). (C,D) In RVO, rhodopsin was downregulated in the outer nuclear layer (ONL), the photoreceptor inner segments (IS), and outer segments (OS). (E,F) Immunohistochemistry confirmed a general upregulation of IL-18 in ischemic RVO. (G,H) S100A12 was abundant in retinal ganglion cells in RVO. (I,J) ANXA1 was abundant in the inner retinal layers in RVO.