Pseudopodia of choriocapillary endothelium.

The electron microscopic observation of Bruch's membrane of the macular area was performed in 12 human eyes, from newborn to 77-year-old subjects. In all the eyes examined the choriocapillary endothelial cells were observed to project pseudopodia through defects in the endothelial basement membrane. The frequency of pseudopodia oriented to the retinal pigment epithelial cell side was significantly larger than those projected from the lateral side of the choriocapillaris or oriented to the choroidal side. Deposits in Bruch's membrane increased along with age, and, even in young eyes, deposits of vesicular and tube-like structures were observed in the outer collagenous zone of Bruch's membrane. Choriocapillary endothelial pseudopodia might be related to the deposit formation in Bruch's membrane, especially the vesicular or tube-like deposit structures.