Fluorescein fundus angiographies performed with the Cannon wide-angle fundus camera enable a good vascular definition, which improves our knowledge of the choroidal circulation. Owing to the better quality of filters, the choroidal arteriolar network can be seen more precisely. Our recent studies have enabled us to confirm the existence of a special avascular area in the central part of the submacular choroid, surrounded by a perimacular choriocapillaris ring.
In the macular area, the choriocapillaris corresponds to a thin layer which is most probably supplied by several arterioles from the short posterior ciliary arteries near their site of entry into the eyeball. As stated by Hayreh, there may be a central area where the capillary pressure, while being well balanced, is very low.
embryology anatomy choriodal vascularization angiography of the choroid