A drainage device for implantation in an eye of a patient to treat an ocular condition includes a first tube configured to extend into an anterior chamber of the eye and convey aqueous humor from the anterior chamber. An exit portion is in fluid communication with the distal end portion. A passage extends between the distal portion of the first tube and the exit portion, with a liquid disposed in the passage. The implant may include a first seal associated with the distal end portion and a second seal associated with the exit portion to prevent drainage of the liquid through the exit portion. The implant may include an implant body disposed between the distal end portion and the exit portion, the passage extending through the implant body. The implant body may comprise a fluid-sensitive component in fluid communication with the passage that may be formed of a flexible membrane.
