AUSTIN, Texas — This new test system gives new meaning to the phrase “making eyes.”
For the first time, researchers used human cells to build a blinking model of the surface of the eye. To achieve that blinking, the system contains a fake eyelid. Researchers hope to use such an artificial organ to study eye tissues and test medical treatments.
Dan Huh described the new system February 16 at a news conference. It took place here at the annual meeting of the American Association for the Advancement of Science.
Huh is a bioengineer at the University of Pennsylvania in Philadelphia. Conjunctival (Kon-junk-TY-vul) cells form a thin tissue that covers the white part of the eye. Huh was part of a team that grew a ring of such cells around a circle of cells that ordinarily make up the human cornea. That’s the clear tissue in the front of the eye.
The researchers grew the cells together on a contact lens‒shaped platform. Because these cells need plenty of moisture, the system delivers fake tears. A synthetic “eyelid” spreads that liquid over the cells. Huh’s team fashioned that eyelid out of a thin water-based film. It’s known as a hydrogel. A mechanical system pulls the eyelid open and closed to move the fluid over the living cells. That motion keeps those thirsty cells properly hydrated.
This artificial eye is not anatomically correct. It has no retina, for instance, to capture light and images. It also has no nerve cells to relay such sensory information to the brain. But it does give scientists a more realistic surface to study such conditions as dry-eye disease. This disorder affects some 16 million adults in the United States alone. Affected people cannot produce enough tears — or don’t make tears with the proper chemical recipe — to slake their eye cells’ thirst.
By making the eyelid blink less, Huh’s team could give their test bed the symptoms of dry eye. The device also could be used to test the safety and effectiveness of new eye drops to treat this or other conditions. Huh said this type of artificial organ should even be able to help study eye injuries. These might include open sores on the eye surface known as corneal ulcers.