[Ultrastructural studies of the lamina suprachoroidea in the human eye]

Abstract

The lamina suprachoroidea of the human choroid was examined by electron microscopy using both thin sections and freeze fracture replicas. The lamina suprachoroidea was composed of 5-10 layers of pigmented cells interspersed with multiple layers of flattened fibroblastic cells. Tight junctions, gap junctions and intermediate junctions were seen between the fibroblastic cells. Tight junctions did not reveal zonula occludens but predominantly isolated types were revealed, as well as several pore-like fenestrations in the attenuated cell processes of the fibroblasts. The characteristic morphological appearance of the lamina suprachoroidea might suggest that the aqueous humour may be able to leak into the extraocular tissues through it. However, the numerous cellular layers and also the junctional complexes between the fibroblasts of the lamina suprachoroidea are likely to produce more resistance to uveoscleral drainage. As the multi-layered arrangement of fibroblastic cells and pigmented cells in the lamina suprachoroidea did not show the cellular barrier, it may be possible that the extraocular substances are able to flow into the eye through it.