The Eyes Have It: Scientists 3-D Print Human Corneas

Eye
The cornea is the transparent layer on the front of the eye that covers the iris, pupil, and anterior chamber. 3-D printing of human corneas may end wait times for people on transplant waiting lists. (WIKIMEDIA/PFRANKOZ/CC BY-SA 3.0)

3-D printing is a manufacturing process that creates a physical object from a digital design. The technology has evolved rapidly and 3-D printers are being used to make everything from prosthetic hands to bottle openers.

Now, according to a paper published online on May 30, 2018 in the journal Experimental Eye Research, scientists are using 3-D printers to make human corneas — an advancement that could dramatically ease the shortage of corneas from donors.

Before now, people who needed a cornea transplant to improve their vision were put on ever-growing wait lists to receive a cornea from an organ donor. Researchers estimate there is only one donor cornea for every 70 needed worldwide. However, this promising 3-D printing technique may help people see better without the prolonged wait.

Corneas are comprised of clear layers of cells that work together to protect the eye’s inner workings and focus light to provide clear vision. If the cornea is damaged, and doesn’t heal or can’t be repaired, it can be replaced with a healthy cornea from a human donor. That’s where this new 3-D printing technique comes into play.

Using a “bio-ink” made of cornea stem cells, collagen and alginate (an organic polymer derived from seaweed stems), researchers at the University of Newcastle in England 3-D printed concentric circles in the shape of a cornea. The alginate helped the cornea keep its shape, while the collagen kept the stem cells alive until they’d grown into a full-fledged cornea.

Potentially, the 3-D printed corneas could be used in a surgical procedure, known as keratoplasty, to replace part or all of a person’s damaged cornea with corneal tissue. Researchers are now working to ensure the corneas work properly and that the human body won’t attack and reject them once implanted. It’s a process that could take several years, but that could one day change the way many people see the world.