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 data collected by these lenses is then sent to an ophthalmologist for evaluation, with the hope that it will lead to early diagnosis of glaucoma, a condition that can cause 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 often develops slowly over time, causing irreparable harm before any vision loss is noticed. 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 developed contact lenses that can detect fluctuations in IOP and use this information to diagnose glaucoma. These lenses have been trialed in people and have shown promising results.
The contact lenses contain an electrically passive sensor embedded in a disposable soft lens made of polydimethylsiloxane (PDMS). The data collected by the lenses is wirelessly transmitted to a wearable electronic readout system, which then processes the information. The processed data is then given to an ophthalmologist for evaluation.
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 involve single measurements taken at a clinic, which can be misleading due to natural variations in IOP. If a variation is detected, further investigation is needed, requiring hospitalization for repeated measurements using a technique called Goldmann applanation tonometry (GAT).
The GlakoLens contact lenses offer a less invasive experience. Once placed in the eye, the patient can go about their day as normal 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 a trial with 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, with measurements from the lens-less right eye matching 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 optimize 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 into the eye. Another California-based startup trialed miLens, a ring placed in the eye that physically measured IOP on glaucoma patients. However, the GlakoLens contact lenses offer greater comfort and flexibility due to their electrically passive sensor and soft lens material.
In addition to diagnosing glaucoma, the researchers believe that their lenses could be used to detect other health conditions by measuring molecules such as glucose and lactic acid present in the eye.
The study has been 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