When it comes to managing diabetes, there have been a lot of advances. But one thing that's remained a constant- those frequent, and often painful, finger pricks to measure blood sugar levels.
Diabetics know the drill. They do it again and again- sometimes 10 times a day. Each prick tells them if their blood sugar levels are too high or too low.
Right now it's the only way to find out, and it can be inconvenient and painful. But now researchers are working on a way around that, using a patient's tears instead.
Dr. Jeffrey Thomas Labelle from Arizona State University knows the frustration firsthand- his dad had Type 2 diabetes.
"I asked him all the time, 'how many times a day are you finger-pricking?'" said Labelle. "And he'd be like, 'oh you know, four to six.'"
Labelle and his colleagues at the Mayo Clinic have been working on a way that could one day make blood-sugar monitoring easier for patients by using fluid from the eye.
"It's really amazing," said Labelle. "It's another extension of the blood system."
They've created a device that can extract and measure tear fluid. The idea is patients put it on the white part of the eye, called the conjunctiva.
"And basically you can get a small volume, about 5 micro-liters or less, in a few seconds," said Labelle.
The fluid then travels to another region where a sensor reads blood sugar levels. Studies show if it's done correctly, the tear fluid reading is just as accurate as a blood sugar reading.
But Labelle says there are some challenges. The test has to be performed quickly and efficiently without letting the tear sample evaporate.
"So it's a little bit easier to get samples from your eye, but it's a lot harder to measure them," he said.
Doctors hope to solve these issues and have the device on the market in the next three to five years. It's a big advance that could make life easier for millions. And experts don't think this device will cost more than the current equipment needed to perform finger pricks.
Eventually doctors may one day implant the device, either through a person's contact lenses or directly in the tear duct itself, to measure the tear fluid as it comes out of the eye.