Fig. 3.

RPE alterations. A Normal aged RPE. Characteristic ultrastructural features: sparsely distributed mitochondria in the cytoplasm, which contains numerous small vacuoles features of the lysosome (Ly) and electrodense LDs of various sizes (LDs); mitochondrial cristae and matrix mostly with normal appearance, one of them forms a contact site with small peroxisome (white arrow); two of them show mitochondrial fission (black arrows); some small round-form mitochondria with confluent electron-dense cristae characteristic for iron overload seen in ferroptosis (fp); basal lamina (BL) of RPE shows normal appearance. Eighty-one years; female; ×22,000;1 μm. B Early AMD. Characteristic ultrastructural features: a few sparsely distributed mitochondria in the cytoplasm which contains numerous (Ly); focal loss of mitochondrial cristae and matrix, one of them forms a MCSs with LDs and lysosome (black arrows) and one contact site between a small LDs and lysosome (white arrow); some small round-form mitochondria with confluent electron-dense cristae suggesting seen in ferroptosis (fp); LDs in the cytoplasm (LDs) one in the upper right angel, some smaller in the basal cytoplasm of RPE; BLD with some round-form electron-translucent areas characteristic to non-membrane-bound cholesterol. n: nucleus. Seventy-two years; male; ×22,000; bar: 1 μm