Fig. 4

a Right submacular surgical specimen consists of collagen with many capillary channels (arrows), some of which have erythrocytes in their lumens (crossed arrows). Scattered pigment granules are observed, with a concentration of pigment epithelial cells (PE) toward the bottom left (Toluidine blue, ×200). b A nonfunctioning capillary exhibits attenuation and fragmentation of the endothelial (EN) cell layer in the absence of pericytes. Note the persistence of erythrocytes (ER) within the lumen, which is filled with microfilaments (F). H histiocyte, PE retinal pigment epithelial cell process, MA extracellular fibrocollagenous matrix (EM ×2,600). c A viable neovascular unit displays endothelium (E) with focal fenestrations (f) and elongated lumen (L). Both the endothelial cells and surrounding pericytes (P) are clothed by a basement membrane. The matrix (MA) is looser in this region and contains a macrophage (M) with complex phagolysosomes (V) and surface villi (vi). (EM ×5,800). d Multilaminar membrane (M) from the left eye has formed above Bruch’s membrane (BM) and contains small neovascular units (arrows). The adherent choriocapillaris (Cc) is patent. Within the choroid (CH) is a small collection of lymphocytes (LY). Inset: erythrocytes in a neovascular lumen (arrow). (Toluidine blue, ×200)