Two-Dimensional Plasmonic Grating for Intraocular Pressure Sensing

Glaucoma is a group of characteristic optic neuropathies that collectively are the leading cause of irreversible blindness globally. Elevated intraocular pressure (IOP) is the major causal risk factor. While the fundamental mechanisms of the IOP elevation and consequent optic neuropathy are not well understood, recent studies have indicated that there may be pressure spikes directed at the optic nerve head during accommodation and that IOP may not be homogeneous throughout the eye. To facilitate the in situ and in vivo measurement of IOP in various locations within the vitreous and facilitate measurement of accommodative IOP spikes at the ONH, here, we report the development of an implantable, biocompatible, and miniaturized IOP sensor using 2-D plasmonic grating that generates structural color. The change of the grating period with pressure between 0 and 50 mmHg results in a change in the visible color, allowing us to observe small changes in pressure without additional electronics.