Blockage of the cilioretinal artery. The central retinal artery supplies the inner retina and the surface of the optic nerve. In some individuals, the cilioretinal artery, a branch of the ciliary circulation, may supply a portion of the retina including the macula. In cilioretinal artery occlusion, vision loss results from cell death in the inner retinal layers (mainly ganglion cells) despite relative sparing of the outer layers. [from
HPO]