Researchers from Northumbria University in the UK and Boğaziçi University in Turkey have developed contact lenses with embedded sensors that can measure the pressure inside the eye. The information gathered by these sensors is then sent to an ophthalmologist for evaluation. The aim of this innovative technology is to enable early diagnosis of glaucoma, a condition that can lead to irreversible vision loss if left untreated.
Glaucoma occurs when the optic nerve, which connects the eye to the brain, is damaged due to increased intraocular pressure (IOP). This pressure is usually caused by a buildup of fluid in the front part of the eye. Unfortunately, glaucoma develops slowly over time, often causing irreparable harm before any vision loss is noticed. By the time it is detected during routine eye tests, significant damage may have already occurred.
However, the collaboration between researchers from Northumbria University and Boğaziçi University may change this. They have successfully developed contact lenses that can detect fluctuations in IOP and use this information to diagnose glaucoma. These lenses have been trialed on individuals, marking a significant step forward in the field.
The contact lenses, known as GlakoLens, contain an electrically passive sensor embedded in a disposable soft lens made of polydimethylsiloxane (PDMS). The data collected by the sensors is wirelessly transmitted to a wearable electronic readout system, which then processes and stores the information. Finally, the processed data is given to an ophthalmologist for evaluation.
One of the major advantages of using GlakoLens is that it allows for easier and more accurate IOP measurements compared to conventional eye exams. Traditional methods involve a single measurement taken at a clinic, which can be misleading due to natural variations in IOP. If a variation is detected, further investigation is required, often involving hospitalization for repeated measurements using a technique called Goldmann applanation tonometry (GAT). This technique requires numbing the eye with drops and using a small cone to touch the cornea and measure pressure. In contrast, GlakoLens allows for continuous monitoring of IOP over a 24-hour period, providing a more comprehensive understanding of the patient’s eye health.
Hamdi Torun, the corresponding author of the study, explains, “Intraocular pressure, or IOP, can vary greatly over a 24-hour period, so it is important to monitor the patient either at intervals or ideally continuously for a whole day to get the best insight into the health of their eyes.” He further adds, “The benefit of the contact lenses we have developed is that once placed in the eye, the patient can then go about their day as normal while their IOP measurements are recorded and sent to a doctor for analysis once the 24-hour period of testing is complete.”
The researchers conducted trials on six healthy volunteers who were asked to drink water and lay flat to intentionally increase their IOP. The contact lenses were worn in the left eye, while the right eye served as a comparison without lenses. The findings showed that the contact lens sensors accurately responded to the effects of water loading, with measurements from the right eye aligning with those taken by the device.
Further experiments will involve larger cohorts of healthy individuals to assess the accuracy and reliability of these sensors. The researchers also plan to enhance the comfort and non-invasiveness of their contact lenses in future iterations.
It’s worth noting that GlakoLens is not the first glaucoma-detecting contact lens to be developed. In February 2023, researchers from South Korea’s Pohang University of Science and Technology tested a contact lens that monitored glaucoma and released medication to reduce IOP when necessary. However, their trials were limited to rabbits. Additionally, a California-based startup recently trialed miLens, a ring placed in the eye to physically measure IOP in glaucoma patients. The readings provided by miLens were found to be only 2 mmHg different from GAT readings.
The researchers highlight that previous contact lenses used an electrically active silicon chip, resulting in a thicker and less comfortable lens that restricted vision. In contrast, GlakoLens utilizes an electrically passive sensor and a soft contact lens, ensuring greater comfort for wearers.
In addition to diagnosing glaucoma, the researchers believe that their lenses could be used to detect other health conditions by measuring glucose, lactic acid, and other molecules present in the eye. They see immense potential in this technology, as it could not only save the sight of patients in the early stages of glaucoma but also enable early diagnosis of other diseases in the future.
The study detailing the development of these contact lenses was published in the journal Contact Lens and Anterior Eye. The lenses are expected to be commercially available through the spin-off company GlakoLens.
Source: Northumbria University