Blood supply to the retina in the laboratory shrew (Suncus murinus)

The blood supply to both retinae was studied light microscopically and by scanning electron microscopy in 48 adult laboratory shrews (Suncus murinus) of both sexes. Thirty-eight of the animals were injected into the left ventricle with Neoprene latex (Du Pont. 601A) or with Mercox (Dai Nippon Ink Ltd., CL-2R) to elucidate the blood supply to the retina from the ophthalmic artery. The remaining animals were kept for histological study of the retina. The central retinal artery, originating from the ophthalmic artery in the muscular part of the orbit, enters the optic nerve, passes through the optic disk together with the central retinal vein and penetrates the vitreous space (cavity of the eye) between the lens and the inner limiting membrane of the retina, where it divides into the dorsal, ventral, and caudal branches. Each branch, moreover, bifurcates into nasal and temporal arterioles and is distributed throughout the retina on the inner limiting membrane as far as the ciliary body and the lens. On the way they obliquely send small vessels through the inner limiting membrane into the outer plexiform layer of the retina. Their vascularization appears to correspond to the membrana vasculosa retinae found in teleosts, amphibia and reptiles.