A glaucoma drainage device has an active valve (750) configured to be located between an anterior chamber of an eye (710) and a drainage location (1030), a power source coupled to the active valve, and a controller coupled to the power source. A first pressure sensor (P1) is located in fluid communication with the anterior chamber, a second pressure sensor (P2) is located in the drainage location, and a third pressure sensor located remotely from the first and second pressure sensors. The controller reads the first, second, and third pressure sensors once during a period of time and adjusts the active valve to control intraocular pressure.
