Non-invasive intraocular pressure monitor

#This invention relates to non-invasive wearable devices for monitoring and measuring intraocular pressure.

#Intraocular pressure (IOP) is a critical factor that is used to monitor the health of the eyes. High intraocular pressure (IOP) is associated with glaucoma, a leading cause of blindness. Lowering IOP is currently the only evidence-based treatment for preventing the development of glaucoma or reducing the rate of its progression.

#An individual's IOP may vary significantly throughout the day. There are considerable data showing that the IOP peaks of many glaucoma patients occur outside daytime hours when IOP is usually measured. As peak IOP is related to glaucoma progression, this suggests that IOP measurements outside office hours should be taken into account when clinicians plan and prescribe glaucoma treatment. However, IOP measurements are typically conducted by professionals during eye examinations during regular business hours and only at relatively infrequent intervals, leading to a need for more accessible IOP measurement technology that provides frequently repeated IOP measurements.

#For a greater understanding of the invention, and to show more clearly how it may be carried into effect, embodiments will be described, by way of example, with reference to the accompanying drawings, wherein:

#FIGS. 1A and 1B are diagrams of an IOP measuring device according to one embodiment, wherein FIG. 1A shows a lens with a microchannel, and FIG. 1B is a cross-sectional view showing the device installed on an eye.

#FIGS. 1C-1H are diagrams of IOP measuring devices according to various embodiments.

#Embodiments described herein address the drawbacks of prior IOP measuring approaches by providing non-invasive and low cost devices that are easily and conveniently interfaced with readily available equipment. Furthermore, the embodiments also address the need to obtain IOP data more frequently, and outside of regular office hours, since the embodiments allow subjects to obtain measurement data themselves using readily available equipment such as a smartphone or tablet computer.

#In general, embodiments are non-invasive and are based on a contact lens or cosmetic lens, in and/or on which is disposed a microstructure. The microstructure has at least one feature that exhibits a change in shape and/or geometry and/or position on the lens in response to a change in IOP. The change in shape and/or geometry and/or position of the one or more feature may be recorded by images captured by a camera. Analysis of the images provides a correlation of the change in shape and/or geometry to a change in IOP, and/or a measurement of IOP. The images may be taken using a digital camera of a mobile device such as a smart phone, tablet, or laptop computer, etc., and therefore, the image may be easily taken by the subject without the need for specialized equipment and at any time of the day or night, without a professional's intervention. Further, an application running on the mobile device or remotely may include an algorithm that provides the image analysis, and may provide substantially instant feedback about the subject's IOP.

#As used herein, the term “lens” refers to any type of lens that may be fitted to and worn on the eye, such as, for example, a contact lens or a cosmetic lens. A lens may fit substantially only on the cornea, or a lens may fit on the cornea and extend outwardly from the cornea to also fit over a portion of the conjunctiva and sclera. Embodiments may be constructed using a flexible polymer material suitable for lens applications such as silicone (e.g., polydimethyl siloxane (PDMS)). Other materials such as polymethyl methacrylate (PMMA) may be used in some embodiments, although such material is less flexible. In some embodiments a readily available (i.e., off-the-shelf) lens is used, which is machined or modified to obtain the desired microstructure. Embodiments may be constructed by one or more of: molding a lens including a microstructure; machining a microstructure into a lens; and applying a microstructure to a lens. Molding may include preparing a 3D mold with the microstructure features (e.g., a microchamber, microchannel, or motion amplifier) using a high-speed micromilling machine. A microstructure that is applied to a lens may be an off-the-shelf structure, or it may be prepared with a micromachining process or with 3D printing technology using a material such as, but not limited to, Nylon™ or a thermoplastic polymer such as acrylonitrile butadiene (ABS).