Provided is a glaucoma valve, a casing for containing a glaucoma valve and a glaucoma drainage device including the glaucoma valve and/or the casing. The valve includes a flow channel having an inlet and an outlet and a valve member connected to the outlet of the flow channel. The valve member may be formed from a degradable polymer or a combination of degradable polymer and non-degradable polymer. The valve may have a first flow channel, the interior of which may be coated with a degradable polymer, such that in use, the polymer degrades to allow a greater flow of fluid through the flow channel. The valve may include a second flow channel, which may be arranged in parallel to the first flow channel. The casing may be formed from a degradable polymer, such as a biodegradable polymer.