The architecture of the choriocapillaris at the posterior pole.

The afferent and efferent vessels as well as the choriocapillaris in the human posterior pole, studied in flat preparations, paraffin sections, and Epon sections, formed relatively discrete units of organization which we called lobules. A lobule is a segment of the choriocapillaris supplied centrally by a precapillary arteriole and demarcated peripherally by a ring of postcapillary venules. Observations on the choroidal phase of fundus fluorescein angiography indicated that blood entering a lobule did not intermingle with blood from adjoining lobules. The choriocapillaris in the posterior pole of the human eye, with its supplying and draining vessels, appeared as a mosaic of adjoining lobules that function independently.