Fig. 18 Basal surface of the retinal pigment epithelium of the macula of a 69-year-old woman. The basement membrane (BM) has been penetrated by lipid vesicles (LV) emanating from the epithelium. Deposition of material with 100-nm periodicity (arrows) increases the distance between the epithelium and its normal basement membrane. The focal adhesion (FA) exists between the epithelium and this newly deposited material (El, elastic lamina of Bruch's membrane; ×24,500).