Fig. 18. Posterior pars plana. A. Nonpigmented epithelial (NPE) cells appear tilted and compressed with dense cytoplasm. The extensive cystic dilatation of the intercellular spaces (IS) around these cells is characteristic of this region. Only the nucleus (N) and the many hydropic mitochondria are visible in the cytoplasm. The basement membrane under the pigment epithelium (PE) is multilaminarand thick. (X 5700) B. Higher magnification of asterisked region in A shows that the cytoplasm is full of branching and curved profiles of smooth endoplasmic reticulum (arrow), which is also typical of this region. M, mitochondrion. (X 22,000)