Wireless smart contact lenses: Revolutionizing patient care with continuous IOP monitoring and enhanced treatment compliance
Managing and monitoring intraocular pressure (IOP) is crucial for preventing vision loss in glaucoma patients. Traditional methods, such as the air puff test, have limitations, prompting a quest for better solutions. Enter the ‘smart’ contact lens—a promising technology that could revolutionize how we detect and manage glaucoma.
According to Dr. Carmen Abesamis-Dichoso, an optometrist and orthokeratology practitioner in the Philippines, IOP is the single most important modifiable risk factor in the development and progression of glaucoma.1 If there is increased variability in IOP, there is increased ganglion cell complex, which is an objective measure of macular structural damage.2
Current methods, such as the air puff test, have notable drawbacks, including higher IOP readings, which compromise the accuracy of the readings.3
“The air puff test has been found to yield higher IOP results than other methods. It can also induce corneal deformation or irregularity,” Dr. Abesamis-Dichoso said.
The potential of smart contact lenses
Smart contact lenses, specifically wireless measuring contact lenses (WMCL), offer a non-invasive way to continuously monitor IOP. These lenses could provide significant benefits, including convenience and diurnal measurements, according to Dr. Abesamis-Dichoso. “Continuous monitoring of IOP using smart contact lenses is helpful in the management of glaucoma patients due to the convenience they offer for patients and clinicians, especially in taking diurnal measurements. They enable at-home monitoring without disrupting daily routines or sleep,” she explained.
Dr. Abesamis-Dichoso noted, however, that despite these advantages, current sensors in smart lenses do not have a clear, universally accepted mmHg equivalence, highlighting the need for further refinement and standardization.4,5
Studies have shown that atmospheric pressure and temperature can influence IOP fluctuations. She mentioned that individuals in warmer climates tend to have lower IOP compared to those in colder environments.6 This variability underscores the importance of a monitoring device that can adapt to different environmental conditions.
Dual LCR technology in smart contact lenses
A recent development may just solve the issue. Dengbao Xiao, along with colleagues from the Institute of Advanced Structure Technology at Beijing Institute of Technology, China, had succeeded in creating an intelligent WMCL that incorporates a dual inductor-capacitor-resistor (LCR) resonant system, enabling temperature self-compensation for quantitative IOP monitoring in various application environments.7
Xiao and his team developed the smart contact lens by designing two miniature spiral circuits with unique vibration patterns that change with the eye’s pressure and diameter. These circuits were embedded between layers of polydimethylsiloxane, a common contact lens material. The lens’ vibrations were wirelessly read using a coil connected to a computer, with signals unaffected by simulated eye movements, moisture, and wear.
In laboratory tests on pig eyes, the lenses monitored and transmitted pressure data across a range of temperatures (50 to 122 degrees F). Single-circuit readings deviated up to 87% from true values, but dualcircuit readings differed by only 7%, eliminating temperature-related errors. This dual-circuit design shows promise for accurate early detection and monitoring of glaucoma across various temperatures.8
“The dual inductor capacitor-resistor (LCR) resonant system achieves temperature self-compensation for quantitative IOP monitoring in different application environments. This means it can monitor IOP in any temperature situation that enables early diagnosis and better management of glaucoma regardless of temperature or environmental factors,” Dr. Abesamis-Dichoso said, commenting on this innovation.
Challenges in clinical adoption
However, she highlighted challenges in integrating this technology into everyday clinical practice, citing concerns over maintenance costs, hygiene, and corneal safety. Factors such as corneal base curve and thickness are critical in ensuring accurate fitting, centration, and comfort of the contact lens device on the eye.
“Also, anything novel takes time for the consumer or public to accept, resulting in a ‘waiting time’ for people to see if it is effective,” shared Dr. Abesamis-Dichoso. “Another drawback is the hygienic maintenance required to keep the cornea healthy while wearing the device. While we understand the sophistication of the material and design, as well as the biocompatibility of this device with the eye, it is still a foreign body that needs to be closely monitored to ensure it can effectively monitor the IOP,” she remarked.
In addition, she suggested that the device should be tested in a larger number of individuals living in countries with warm and cold temperatures to make it more wearable. The device should also be designed with simpler parameters for clinicians to choose from, including base curve, diameter, and, if possible, incorporating power.
Nevertheless, if the WMCL does take off, it will be a game-changer in glaucoma management. “Patient compliance in the timely administration of IOP-lowering drops has been a challenge for both clinicians and patients,” said Dr. Abesamis-Dichoso. “If the IOP can be continuously monitored, it would be similar to blood sugar and blood pressure monitoring devices, where patients are alerted to peaks or spikes in their levels, reminding them to take their medication or see their doctor immediately. The same is true for glaucoma patients. Since the condition is potentially blinding, consistent monitoring of IOP would be very helpful in delaying its progression,” she continued.
Emerging frontiers in glaucoma care
In addition to smart contact lenses, Dr. Abesamis-Dichoso mentioned three areas of research that are currently being investigated to improve glaucoma diagnosis, treatment, and management: Gene therapy, neuroprotective agents, and artificial intelligence (AI) in diagnostics.
“Gene therapy aims to identify genetic factors that contribute to the development of the condition. By targeting specific genes, treatments can be implemented that can potentially prevent or reverse the damage caused by glaucoma. Neuroprotective agents aim to protect the optic nerve from damage to slow down or halt the progression of the disease,” she shared. “Last but not least, AI algorithms can now analyze complex datasets and assist eye care professionals in early detection and personalized treatment plans. AI can also provide patients with valuable advice on how to better comply with the regimen prescribed, offering a good foundation to both clinician and patients in glaucoma care,” Dr. Abesamis-Dichoso concluded.
Editor’s Note: A version of this article was first published in COOKIE magazine Issue 16.
References
- Van de Veire S, Germonpre P, Renier C, et al. Influences of atmospheric pressure and temperature on intraocular pressure. Invest Ophthalmol Vis Sci. 2008;49(12):5392- 5396.
- Mahmoudinezhad G, Moghimi S, Nishida T, et al. Association of long-term intraocular pressure variability and rate of ganglion complex thinning in patients with glaucoma. Am J Ophthlamol. 2024:264:104-119.
- Piffaretti F, Barrettino D, Orsatti P. Rollable and implantable intraocular pressure sensor for the continuous adaptive management of glaucoma. Annu Int Conf Proc IEEE Eng Med Biol Soc. 2013;2013:3198-3201.
- Bhartiya S, Gangwani M, Kalra RB, et al. 24- hour Intraocular pressure monitoring: the way ahead. Rom J Ophthalmol. 2019;63(4):315- 320.
- Downs JC, Burgoyne CF, Seigfreid WP. 24-Hour IOP telemetry in the nonhuman primate: implant system performance and initial characterization of IOP at multiple timescales. Invest Ophthalmol Vis Sci. 2011;52:7365– 7375.
- Hartmann A, Grabitz SD, Hoffmann EM, et al. Intraocular Pressure and Its Relation to Climate Parameters-Results From the Gutenberg Health Study. Invest Ophthalmol Vis Sci. 2023;64(7):15.
- Li X, Chen W, Xiao D, et al. Temperature SelfCompensating Intelligent Wireless Measuring Contact Lens for Quantitative Intraocular Pressure Monitoring. ACS Appl Mater Interfaces. 2024;16(17):22522-22531.
- American Chemical Society. ‘Smart’ contact lenses could someday enable wireless glaucoma detection. Discover Chemistry PressPacs. Available at https://www.acs.org. Published on May 9, 2024. Accessed July 5, 2024.
