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.

Project Report

Elevated intraocular pressure (IOP) is universally accepted as one of the most important risk factors contributing to the development of glaucoma and the subsequent progression to blindness. Adults over the age of 40 develop this disease and are sometimes unknowingly going blind. In the US alone, more than 8.7 million office visits are made each year for the diagnosis or treatment of glaucoma. The current treatment is based on attempts to reduce the intraocular pressure and slow down the progression of the disease. Therefore, the diagnosis and treatment of glaucoma relies on accurate and frequent measurements of the intraocular pressure. Currently, the most commonly used method, Goldmann applanation tonometery, has to be performed at a hospital due to the required anesthesia and sterilization. The natural diurnal variation is affected by certain activities, food or beverage intake, or medications. Therefore, a single office visit to the physician does not represent the complete picture of IOP fluctuations, which can create difficulties in making a proper diagnosis or a timely determination if the selected treatment is producing the desired results. The frequent measurement of the IOP throughout the day would allow for significant improvement in the treatment outcome and early diagnosis of glaucoma. This project is aimed at the development of a new method for non-invasive eye pressure measurement though the eye lid, which can be performed at home. The approach uses multiple force sensors combined with advanced signal processing techniques to extract the eye pressure. Intellectual Merit: One of the main challenges of developing through-the-eye lid tonometer is the need for person-specific calibration. Through this project, we have developed a novel calibration method, which allows tonometer calibration using as few as 1-2 measurements. The method relies on a machine learning algorithm processing data from multiple force sensors applied at once. Broader Impact: The project is likely to reduce the need for office visits for diagnosis and treatment of glaucoma and is likely to result in lower patient costs and improved public health. Through participation in the NSF I-Crops program, the research team also established that the commercial impact of the technology in approximately $1B in US alone. Similar market opportunities exist in the rest of the developed world.

Agency
National Science Foundation (NSF)
Institute
Division of Industrial Innovation and Partnerships (IIP)
Type
Standard Grant (Standard)
Application #
1157898
Program Officer
Rathindra DasGupta
Project Start
Project End
Budget Start
2011-10-01
Budget End
2013-03-31
Support Year
Fiscal Year
2011
Total Cost
$50,000
Indirect Cost
Name
University of Arizona
Department
Type
DUNS #
City
Tucson
State
AZ
Country
United States
Zip Code
85719