New Concepts Regarding Anterior Drainage of the Eye

Abstract

The aqueous veins apparently join the jugular vein. Compression of the latter causes the retrograde appearance of blood in the former and in Schlemm''s canal. Sometimes visible pulsation can be seen in a normal aqueous vein, representing a transmission to the vein of the undulations of intra-ocular tension, synchronous with the cardiac cycle. The venous plexus of Kiss is an additional anterior drainage system. It lies adjacent to ciliary muscle and from the plexus thin T-shaped veins and a few thick acutely angled emissary veins branch off towards the episclera. In hydrophthalmos Schlemm''s canal is replaced by hyperplastic tissue and the aqueous veins are absent, yet there is often some stabilization of intra-ocular tension. This suggests the presence of an additional drainage system apart from Schlemm''s canal.