Vasculature: Choroid.

The choroid is the highly vascularized connective tissue compartment exterior to the outer blood retinal barrier, which resides between the RPE and the sclera and is the main vascular supply for the retinal pigment epithelium and photoreceptor cells. This review summarizes the structure, innervation, vascular supply, and cell types of the human choroid in both healthy and disease eyes. Special attention is paid to the choriocapillaris and its biochemical and molecular changes in aging and atrophic macular degeneration.