Currently, people with glaucoma must have their internal optic pressure (the pressure within their eye) regularly checked by a specialist. If that IOP gets too high, then steps need to be taken to lower it, before vision damage can occur. The problem is, the pressure can change quickly, potentially rising to dangerous levels between those checks. A new implant, however, could make it possible for patients to check their own IOP as often as they like, using their smartphone.

The implant was designed in a collaboration between Stanford University’s Prof. Stephen Quake, and ophthalmologist Yossi Mandel of Bar-Ilan University in Israel.

It incorporates a small transparent tube (known as a sensing channel) which is open at one end, and capped with a gas-filled bulb at the other. As the patient’s IOP rises, intraocular fluid is pushed into the tube. The gas pushes back against the fluid, though, creating a gas/fluid barrier within the tube, that can be seen from the outside.

A close-up of the sensing channel, and a view of the whole implant (Photos: Stanford/Quake Lab)

Using a smartphone camera and an app, it should be possible to determine the IOP level based on where within the sensing channel that barrier is located. Should it be dangerously high, patients could get in touch with their specialist to take steps to lower it.

In its current form, the device is designed to go inside a standard intraocular lens prosthetic, which many glaucoma patients end up getting as a result of cataract surgery. Test have shown that it does not obstruct the user’s vision.

That said, Quake and Mandel are working on turning it into a stand-alone implant. They’re hoping that clinical trials could begin within a few years. A team at the University of Washington has also created a prototype IOP-monitoring implant, although it incorporates onboard electronics such as an RF chip and antenna.

A paper on the Stanford/Bar-Ilan research was recently published in the journal Nature Medicine.

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