"Each quadrant of the retina is drained by multiple minor retinal veins which coalesce to form a main retinal vein. The confluence of the superotemporal and superonasal main retinal veins forms the superior papillary vein, whilst the confluence of the two inferior main retinal veins forms the inferior papillary vein. The superior and inferior papillary veins converge creating the central vein of the retina. This union of the papillary veins sometimes occurs in the optic nerve itself 2."
"Each quadrant of the retina is drained by multiple minor retinal veins which coalesce to form a main retinal vein. The confluence of the superotemporal and superonasal main retinal veins forms the superior papillary vein, whilst the confluence of the two inferior main retinal veins forms the inferior papillary vein. The superior and inferior papillary veins converge creating the central vein of the retina. This union of the papillary veins sometimes occurs in the optic nerve itself 2."