Due to the complexity of the human eye, it is difficult to replicate and model and scientists have to use eye test cells in a petri dish or animal models. Now, a team from University of Pennsylvania has engineered an artificial human eye on a chip to help ease the way eyes are studied.
According to CNET, the new eye replica is built on a transparent, octagon-shaped, dime-sized chip. There is a contact-lens shaped scaffold placed in the center that contains cells from the front eye layer (cornea) and cells from the conjunctiva, which together forms the eye surface.
The ‘eyelid’ of the model eye is a rectangle of gelatin that slides over the scaffold to imitate the blinking and small channels above this eye provides a way to produce tears.
“From an engineering standpoint, we found it interesting to think about the possibility of mimicking the dynamic environment of a blinking human eye,” said Dan Huh, lead author of the study published in Nature Medicine.
Imitating the blinking also allowed the team to induce a condition called dry-eye disease that leads to itching and inflammation due to dehydration. For this, the researchers slowed down the artificial blinking down from 12 times per minute to six, which also reduced tear volume. They then also tested an investigational drug and found that it reduced some of the inflammation seen with the disease.
However, there are certain limitation like the model does not contain all cells in the human eye, such as lack of blood vessels, nerves, and immune cells. Also, it an unable to precisely mimic tear production and how the eye would interact with physiological systems present in a human being.
“I hope our eye-on-a-chip platform is further advanced and used for a variety of applications besides drug screening, such as testing of contact lenses and eye surgeries in the future,” said co-author Jeongyun Seo.