The human choriocapillaris in organ culture

4 x 4 mm pieces of human eye walls consisting of the sclera, the choroid and the pigment epithelium were kept in organ culture for 1 month and studied with light and transmission electron microscopy comparing the findings with normal tissue. After 1 month the choriocapillaris still had open vessel lumina lined with flattened endothelial cells containing organelles and vesicles on both inner and outer cell membranes. The endothelial cells lost their fenestrations and polarity in regard to the location of cell nuclei. Otherwise the ultrastructure was similar to that of the choriocapillaris in vitro. This study has shown that choriocapillaris can survive in organ culture for 1 month, and it permits further studies on the behaviour of the choroid under controlled conditions, and on the long-term effects of different types of trauma to the choroid in vitro.