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 main aim of these lenses 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 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, the damage may already be done.
However, this new collaboration between researchers from Northumbria University and Boğaziçi University brings hope for early detection of glaucoma. The contact lenses they have developed can detect fluctuations in IOP and use this information to diagnose glaucoma. These lenses have been successfully trialed in individuals.
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 collects, stores, and processes the information. The processed data is then evaluated by an ophthalmologist.
One of the advantages of using GlakoLens is that it allows for easier and more accurate IOP measurements compared to traditional eye exams. IOP can vary greatly over a 24-hour period, so continuous monitoring is crucial for a better understanding of eye health. Traditional methods involve single measurements at clinics, which can be misleading due to natural variations in IOP. Further investigation often requires hospitalization for a whole day, during which repeated measurements are taken using a technique called Goldmann applanation tonometry (GAT). This method involves numbing the eye with drops and using a small cone to touch the cornea and measure pressure. GlakoLens offers a less invasive alternative.
Once the GlakoLens is placed in the eye, patients can go about their day as usual while their IOP measurements are recorded. The data is then sent to a doctor for analysis after the 24-hour testing period is complete. This convenience and comfortability make GlakoLens a promising solution for glaucoma diagnosis.
The researchers conducted tests on six healthy volunteers who intentionally increased their IOP by drinking water and lying flat. All participants wore the lens on their left eye, while the right eye served as a comparison without the lens. The results showed that the contact lens sensors responded to the effects of water loading, and the measurements from the right eye matched those taken by the device.
Further experiments will be conducted with larger groups of healthy individuals to assess 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 this is not the first attempt at developing glaucoma-detecting contact lenses. In February 2023, researchers from South Korea’s Pohang University of Science and Technology tested contact lenses that monitored glaucoma and released IOP-reducing medication into the eye when needed. However, their tests were only conducted on rabbits. In May, 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 and less comfortable lens that restricted vision. In contrast, GlakoLens utilizes an electrically passive sensor and a soft contact lens, ensuring wearers’ comfort.
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 great potential in this technology for saving patients’ sight in the early stages of glaucoma and providing early diagnosis for 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