Specialist Contact Lenses: Smart contact lenses help predict glaucoma progression

Smart contact lenses that measure a day’s worth of changes in intraocular pressure (IOP) may soon allow optometrists to identify patients most at risk of disease progression, based on results from a new study.

Lead author and Columbia University associate professor, Dr Carlos Gustavo De Moraes, said – compared to the “snapshot” given by a one-off pressure measurement – the 24-hour picture from the lenses gave invaluable IOP data.

The 40 glaucoma patients monitored in the research had significantly different patterns in their IOP overnight.

Dr Gustavo De Moraes said: “What we see in these measurements is a signature that indicates which glaucoma patients will get worse and which are relatively stable.”He explained: “We have identified a wide range of curves, as expected, but progressing patients had up to five or six long peaks [in IOP] while stable patients had only one or none. The same is true for the mean peak ratio – progressing patients had mean peak-ratios up to two-fold what was seen in stable eyes.”

Dr Gustavo De Moraes said the 24-hour use of the sensing lenses was comfortable and practical, compared to asking a patient to visit multiple times or enter a sleep clinic for IOP measurements. The smart lenses might one day replace these methods and stress tests, he said, adding: “Our study and many others have shown [the lenses’] usefulness in clinical practice. Becoming a standard for glaucoma patients is still questionable and warrants more research.

“One reason, among others, is the fact that we do not yet know how to interpret its results the same way we interpret IOP measurements from applanation tonometry,” he concluded.The study used the Sensimed Triggerfish contact lens system, which is currently approved for use in Europe, though not the US.