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 collected by these lenses is then sent to an ophthalmologist for evaluation. The goal 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 typically caused by a buildup of fluid in the front part of the eye. Unfortunately, glaucoma often develops slowly over time, causing irreversible harm before any vision loss is noticed. By the time it is detected during routine eye tests, significant damage may have already occurred.
The collaboration between researchers from Northumbria University and Boğaziçi University has resulted in the development of contact lenses capable of detecting fluctuations in IOP. These lenses, known as GlakoLens, contain an electrically passive sensor embedded in a disposable soft contact lens made of polydimethylsiloxane (PDMS). The data collected by the lenses 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 often involve single measurements taken at a clinic, which can be misleading due to natural variations in IOP. Further investigation usually 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. 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 their contact lenses on six healthy volunteers. These participants were asked to drink water and lie flat to intentionally increase their IOP. The findings demonstrated that the contact lens sensors accurately responded to the effects of water loading, with measurements from the right eye (without the lens) matching those taken by the device.
The next step for the researchers is to conduct further experiments using larger groups of healthy individuals to investigate the accuracy and reliability of the sensors. They also plan to optimize the comfort and non-invasiveness of the contact lenses in future iterations.
While GlakoLens is not the first glaucoma-detecting contact lens, it offers unique advantages over previous versions. Other lenses have used electrically active silicon chips, resulting in thicker, less comfortable lenses that restrict vision. In contrast, GlakoLens uses 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 have the potential to detect other health conditions by measuring glucose, lactic acid, and other molecules present in the eye.
The study detailing this innovative technology 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