Non-invasive intraocular pressure monitor
The invention provides devices and methods for non-invasive monitoring and measuring of intraocular pressure (IOP) of a subject. Embodiments include a lens that is adapted to fit on the subject's eye, a microstructure disposed in or on the lens, the microstructure having 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 curvature of the lens. When the curvature of the lens changes in response to a change in IOP, a corresponding change in shape and/or geometry and/or position of the feature may be used to determine the change in IOP. The change in the feature is detectable in digital images of the lens taken with a mobile electronic device such as a smartphone.
1. A device for monitoring intraocular pressure (IOP) of a subject, comprising:
a non-invasive lens that is adapted to fit on the subject's eye;
a strain-amplifying microstructure disposed in or on the lens, including a sealed chamber and connected microchannel, and an indicator solution that fills a length of the connected microchannel;
wherein the strain-amplifying microstructure exhibits a change in shape and/or geometry and/or position on the lens in response to a change in curvature of the lens;
wherein the lens is adapted to change curvature in response to a change in IOP;
wherein the length of the microchannel filled with the indicator solution changes according to the change in curvature to the lens;
wherein the change in length of the microchannel that is filled with the indicator solution is detectable in digital images of the lens, or of a part of the lens, and indicates a change in IOP.
2. The device of claim 1 , further comprising a reference structure:
wherein the reference structure has a selected size and/or position and/or shape that is substantially constant irrespective of a change in curvature of the lens in response to a change in IOP.
3. The device of claim 1 , wherein the digital images are captured using a digital camera of a personal electronic device.
4. The device of claim 3 , wherein the personal electronic device is a smartphone.
5. A method for monitoring intraocular pressure (IOP) of a subject, comprising:
disposing a strain-amplifying microstructure in or on a lens that is adapted to fit on the subject's eye, the strain-amplifying microstructure including a sealed chamber and connected microchannel, and an indicator solution that fills a length of the connected microchannel, wherein the strain-amplifying microstructure exhibits a change in shape and/or geometry and/or position on the lens in response to a change in curvature of the lens,
wherein the curvature of the lens changes in response to a change in IOP;
obtaining two or more digital images of the lens, or a part of the lens, at two or more instants in time;
detecting a change in the length of the microchannel filled with the indicator solution in the digital images; and
correlating the change in the length of the microchannel filled with the indicator solution with a change in IOP.
6. The method of claim 5 , further comprising quantifying a change in the length of the microchannel filled with the indicator solution in the digital images using a reference structure:
wherein the reference structure is embedded or integrated in the lens and has a selected size and/or position and/or shape that is substantially constant irrespective of a change in curvature of the lens in response to a change in IOP.
7. The method of claim 5 , wherein the digital images are captured using a digital camera of a personal electronic device.
8. The method of claim 7 , wherein the personal electronic device is a smartphone.