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. These sensors send the information to an ophthalmologist for evaluation, with the hope of enabling early diagnosis of glaucoma. Glaucoma is 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 build-up of fluid in the front part of the eye. Unfortunately, glaucoma develops slowly over time and can cause irreparable harm before any vision loss occurs. By the time it is detected during routine eye tests, the damage may already be done.
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 diagnose glaucoma. These lenses have been trialed on individuals.
The contact lenses contain an electrically passive sensor embedded in a disposable soft contact 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. The processed data is later evaluated by an ophthalmologist.
One of the advantages of using these contact lenses, known as GlakoLens, is that they allow for easier and more accurate IOP measurements compared to conventional eye exams. Traditional methods usually involve a single measurement at a clinic, which can be misleading due to natural variations in IOP. If variations are detected, further investigation is required, often involving hospitalization and repeated measurements using a technique called Goldmann applanation tonometry (GAT).
The GlakoLens contact lenses offer a less invasive experience for patients. Once placed in the eye, patients can go about their day as usual while their IOP measurements are recorded. After a 24-hour period of testing, the data is sent to a doctor for analysis.
The researchers conducted tests on six healthy volunteers who intentionally increased their IOP by drinking water and lying flat. The contact lenses accurately responded to the effects of water loading, and the measurements from the lens-less right eye were consistent with those taken by the device.
Further experiments will be conducted using larger groups of healthy individuals to assess the accuracy and reliability of the sensors. The researchers also plan to improve the comfort and non-invasiveness of the contact lenses in future iterations.
It’s worth noting that these contact lenses are not the first of their kind. 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. However, their tests were only conducted on rabbits. Another 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 similar to those obtained through GAT.
The researchers behind GlakoLens 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 these lenses could be used to detect other health conditions by measuring various molecules present in the eye, such as glucose and lactic acid.
The study detailing the development of GlakoLens 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