Angioarchitecture of the ciliary artery circulation of the posterior pole

Morphologic findings on scanning electron microscopy of vascular cast of the posterior pole in primates are presented. The prelaminar region of the optic disc received the majority of its blood supply from the short posterior ciliary arteries, mainly from direct branches arising from peripapillary arterioles surrounding the optic nerve but also from indirect branches from the peripapillary choroid. The capillaries from this prelaminar region drained directly into the central retinal vein. The peripapillary choriocapillaris was a single layer of anastomosing capillaries supplied by precapillary choroidal arterioles. The peripapillary choriocapillaris was not seen to contribute to the vascular supply of the optic disc. Our results are in general agreement with those of previous scanning electron microscopy studies of the vascular supply of the distal part of the optic nerve.