Abstract

With an ageing population showing an increasing prevalence of glaucoma, there is a pressing demand for continuous intraocular pressure (IOP) measurements which could surpass clinic based measurements such as routine applanation tonometry. Glaucoma patients experience fluctuations in IOP, and it has been proposed that these fluctuations are relevant to glaucoma progression. In addition, inter–individual and intra-individual variation in corneal thickness and rigidity can lead to significant and poorly quantitated errors in applanation-based methods of estimating IOP. Micro Electrical Mechanical Systems (MEMS) & Complementary metal oxide semiconductor (CMOS) based technology has enabled the development of smart miniaturised devices by augmenting the computational ability of microelectronics with capabilities of micro-sensors and micro-actuators. This review addresses various sensor technologies and both invasive and non-invasive approaches to measure IOP. Advances in wireless communication (telemetry) between the implanted sensors and external readout device are reviewed. In addition, biocompatibility of implantable sensors is discussed.