Methods and apparatus for measurement of IOP following glaucoma surgery comprise an implant device having a pressure sensitive capacitor and coil sized for placement along the tissue drainage path, to monitor the success of the surgery and measure IOP directly. The implantable sensor device may comprise a MEMS based capacitive pressure sensor and coil. A complaint material is disposed over the pressure sensitive capacitor and coil to conform with tissue to further decrease invasiveness and such that the implant can measure pressure from at least a first side and a second side when positioned along the drainage path. The implant can work well with trabeculectomies and trabeculotomies, and can be positioned on the sclera at a location corresponding to the bleb, such that the effectiveness of the surgery and medication can be determined postoperatively to detect pressure changes and elevations.