Non-invasive intraocular pressure monitoring with a contact lens engineered with a nanostructured polymeric sensing film

A new prototype of contact lens sensor (CLS) for monitoring the intraocular pressure (IOP) variations in a non-invasive way has been developed. The CLS has as a key element a thin film, comprised of a new all-organic flexible highly piezo-resistive sensor, that is glued to the central hole of a doughnut-shaped hard contact lens. A few CLSs were fabricated and tested with an eye phantom and with enucleated pig eyes by means of applying pressure with a low pressure transducer and recording the electrical changes in the sensor with a portable recorder. The developed CLSs are biocompatible permitting to transmit the changes in cornea curvature induced by the IOP variations, directly to the flexible conducting polymeric sensor embedded in the CL. The electrical response of the CLS to pressure changes reveals a high linearity as well as a good reproducibility having the proper sensitivity to perform continuous monitoring of IOP.