Variable Inductor Passive Contact Lens-Based IOP Sensor

preventing glaucoma with cost-effective monitoring

Over 3 million Americans and 80 million people worldwide over the age of 40 have glaucoma, but only 50% know it due to the insidious nature of the disease. Monitoring and managing intraocular pressure (IOP), the fluid pressure inside the eye, is the standard method for preventing glaucoma. However, IOP monitoring typically requires periodic doctor visits that may not detect acute or nocturnal fluctuations in IOP, imposes time and financial burdens on the patient, and results in low patient compliance with respect to monitoring and treatment of the disease.

A team from Michigan State University, led by Dr. Arthur J. Weber, Ph.D., and Dr. Wen Li, Ph.D., is developing a cost-effective, easy-to-use, non-surgical, contact lens-based device that continuously monitors a patient’s IOP to better manage or prevent glaucoma from developing.

“At its core, this device is about prevention,” explains Weber. “Once a patient is diagnosed with glaucoma, they face many challenges, including increased financial burden, loss of self-esteem and social status, depression, and increased risk of accidents. This contact lens-based device will provide patients with a continuous, cost-effective, and non-invasive option for monitoring intraocular pressure, and thus a better means for preventing or managing the disease.”

The device is based on a standard HEMA-based soft contact lens to incorporate the IOP sensor. Similar to a person’s typical contact prescription, the lens will be custom-made and calibrated for each patient. The main cost to the patient will be for the simple contact lens sensor, while the external electronics can be leased during the monitoring period and returned to the clinician for reuse when finished.

The collected data will be transmitted via Bluetooth to the patient’s smartphone or handheld device for conversion to IOP, display, and storage. From there, the data can be transmitted to the patient’s eye care specialist. Additionally, the sampling frequency can be adjusted from a few seconds to several minute intervals.

Significant Need

Current methods for monitoring intraocular pressure are insufficient for detecting acute or nocturnal fluctuations in IOP. They also can be inefficient, not cost-effective, and result in low patient compliance with respect to monitoring and treatment of the disease. Other at-home monitoring systems currently on the market do not meet the growing needs of patients due to low resolution, limited number of daily measurements, requirement of professional assistance, and high upfront costs.

Compelling Science

The system comprises a non-invasive, passive sensor configured as a variable inductor. It consists of a closed-loop of stretchable serpentine wire that serves as a strain sensor responsive to pressure-induced corneal stretching and a wireless sensor antenna. The sensor is incorporated into a customized, donut-shaped contact, permitting optimal sensitivity while preserving the patient’s field of view.

Competitive Advantage

By encircling the cornea, the device is sensitive to change over the entire circumference of the cornea and provides physicians with instantaneous and continuous monitoring so further intervention can be applied in a matter of hours or days rather than weeks or months. Other devices do not provide continuous IOP measurement, limit the number of measurements per day, are more complex, and may impact the patient’s central vision.

Overall Commercialization

  • Intellectual Property: A U.S. utility patent application has been filed as well as a European patent. First office action has been received and a response is in preparation. PCT opinion accepted several claims as novel with inventive step.
  • Commercialization Strategy: Licensing as well as potential startup company.
  • Regulatory Pathway: This technology is covered under 21CFR886.1925 and would be considered a Class II Diagnostic Device by the FDA. The entire Class II regulatory research package will be performed by a Michigan-based Contract Research Organizations (CROs).
  • Engage Investors & Product Launch Strategy: To scale the current model, the project team is in discussions with a commercial manufacturer with extensive experience integrating various electrical components into soft contact lenses. A similar, in-state, commercial relationship will also be investigated for mass production of the external reader system.


Aim 1:

  • Finalize reader electronics
  • Miniaturize the packaging of the reader electronics
  • Optimize the overall sensor system

Aim 2:

  • Finalize preclinical model and protocol for the use of goggles, reader, and external electronics

Aim 3:

  • Establish preclinical model of glaucoma
  • Validate and characterize preclinical model of glaucoma versus control animals

Aim 4:

  • Develop and standardize the manufacturing protocols for contact lens prototype
  • Initial safety assessment; Irritancy
February 4, 2022