Eye filtration prostheses

An eye filtration prosthesis for relieving intraocular pressure from within an eye, the eye having an interior portion and a periphery thereabout, said device comprising:

• conduit means for receiving fluid from within the interior portion of the eye and draining fluid away from the eye;
• said conduit means including a drainage tube and a drainage plate attached thereto;
• drainage port means for draining fluid received by said conduit means out of said prosthesis at a location exterior of the eye;
• said drainage port means being located about the periphery of said drainage plate;
• a low pressure gradient unidirectional valve within said conduit means, said valve including means for allowing fluid to pass away from the eye under low pressure gradient conditions and preventing retrograde flow back into the eye;
• and
• flow restrictor means for restricting fluid from flowing within said conduit means away from the eye;
• and
• wherein said prosthesis, when implanted, is operable in a flow restricted state in which said flow restrictor means restricts fluid from flowing within said conduit means away from the eye and out of said prosthesis;
• and a free flow state in which said flow restrictor means has been deactivated to allow fluid to freely flow there past, with said valve allowing fluid to flow though said conduit means under low pressure gradient conditions while preventing retrograde flow back into the eye.