Researchers from Northumbria University in the UK and Boğaziçi University in Turkey have collaborated to develop contact lenses with embedded sensors that can measure the pressure inside the eye. The information collected by these sensors is then sent to an ophthalmologist for evaluation. The main objective of this innovation 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 fluid build-up in the front part of the eye. Unfortunately, glaucoma is often referred to as the “silent thief of sight” because it develops slowly over time, causing irreparable harm before any vision loss occurs. By the time glaucoma is detected during routine eye tests, significant damage may have already been done.
However, the development of these contact lenses, known as GlakoLens, could change the game. The lenses are made of a disposable soft material called polydimethylsiloxane (PDMS) and contain an electrically passive sensor. 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 advantages of using GlakoLens is that it allows for easier and more accurate IOP measurements compared to conventional eye exams. Traditional methods involve visiting a clinic for a single measurement, 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 process includes numbing the eye with drops and using a small cone to touch the cornea and measure pressure. In contrast, GlakoLens allows patients to go about their day normally while their IOP measurements are continuously recorded and sent to a doctor for analysis once the 24-hour testing period is complete.
The researchers conducted a trial of the contact lenses on six healthy volunteers. These participants were asked to drink water and lie flat to intentionally increase their IOP. The findings showed that the contact lens sensors accurately responded to the effects of water loading, with measurements from the lens-less right eye matching those taken by the device.
Further experiments using larger groups of healthy individuals will be conducted to investigate the accuracy and reliability of the sensors. The researchers also plan to optimize the comfort and non-invasiveness of the 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 IOP-reducing medication into the eye as needed. However, their lenses were only tested on rabbits. Additionally, a California-based startup trialed miLens, a ring placed in the eye that physically measured IOP on glaucoma patients. The readings provided by miLens were found to be just 2 mmHg different from GAT readings.
The researchers behind GlakoLens emphasize that previous contact lenses used an electrically active silicon chip, resulting in a thicker, less comfortable lens that restricted vision. In contrast, GlakoLens’ electrically passive sensor and soft contact lens ensure wearers’ comfort.
Apart from diagnosing glaucoma, the researchers believe that their lenses could also be used to detect other health conditions by measuring glucose, lactic acid, and other molecules present in the eye.
The study detailing this innovation was published in the journal Contact Lens and Anterior Eye, and the lenses are expected to be commercially available through the spin-off company GlakoLens.
Source: Northumbria University