I-Corps: Hand-Held Tonometer for Transpalpebral Intraocular Pressure Measurement

University Of Arizona, Tucson AZ

Investigators

Abstract

Elevated IOP is the leading cause of Glaucoma, a disease leading to damage of the optic nerve and subsequently, to blindness. Currently IOP is measured via the Goldman's applanation tonometer, a mechanical device that measures the force required to flatten the cornea to a prescribed contact area. Palpation (digital) tonometry measures the intraocular pressure through the eyelid and therefore, does not require anesthesia and instrument sterilization. Palpation of the IOP is performed by lightly pressing the fingertips of both index fingers onto the upper part of the eye through the eyelid. Typically, the two fingers press in alternating sequence allowing the examiner to "feel" the flexibility of the sclera and gauge its tension. The objective of this innovation proposal is to demonstrate a commercially-viable tactile tonometer that can be used for frequent IOP measurements at home. Specifically, the team proposes to develop an integrated tactile sensor and alignment platform that will allow self-administered digital palpation of the IOP through the eyelid. To date, measurement of the intraocular pressure is only possible under local anesthesia, using the cornea of the eye. Less direct measurements have had limited accuracy and, therefore, had limited diagnostic value. The proposed effort is aimed at the development of a novel self-administered tactile tonometry system, which will extract intraocular pressure and other tissue response parameters via simultaneous measurement from multiple force micro-sensors. The proposed system will also be able to predict the facility of outflow of intraocular fluid (aqueous humor), which is a key indicator of the ability of the eye tocontrol its pressure. Given that there is no such instrument available today; the proposed effort is likely to give new diagnostic tool to ophthalmologists and their patients. Over 4M people in the US alone are diagnosed with glaucoma and require regular eye pressure measurements. Similar incidence levels exist in the rest of the developed countries. If successful, this effort will result in novel tactile tonometry system that can be utilized for continuous monitoring of the intraocular pressure and thus allow of better diagnosis and treatment of Glaucoma. We anticipate a significant economic benefit due to the reduced need for hospital visits as well as better management of episodes of elevated IOP. The proposed technology can also be applied to prostate and breast cancer screening with appropriate modifications. We anticipate that when established, the tactile tonometry system could result in 200M in annual sales in US and similar levels in Europe. The project will also produce online curriculum on innovation and translational research that is likely to assist other investigators in transforming basic research into commercially viable products and services.