NEI funded research shows promise for healing damage from dry eye, surgery, and toxin exposure

New research supported by the National Eye Institute shows a promising new technique that may help the cornea heal itself in people with long-lasting symptoms due to surgery, injury or dry eye. The findings are published in the Journal of Neuroscience Research.

The cornea - the clear, dome-shaped outer layer of the eye - contains more nerves per surface area than any other tissue in the human body. Its nerve density is 300-600 times that of the skin. These nerves are vital for preserving eye health, sending pain signals to let you know if your eye is at risk from damage from bright light or a foreign object, and reminding you to continuously blink to prevent your eyes from drying out.

This part of the eye is also known for being remarkably quick to heal. It's why laser eye surgery patients can typically return to their daily activities within a day or two, with minimal discomfort.

Still, a small percentage of people experience lasting adverse effects from eye surgery, including chronic dry eye and pain or deficits in pain sensation. Other people experience these symptoms even without having had surgery, as part of the complex condition known as "dry eye." And still others have more serious eye injuries inflicted by exposure to toxic chemicals, whether household cleaning solvents or chemical weapons deployed in a military context.

Five years ago, Royce Mohan, Ph.D, professor of neuroscience at the University of Connecticut had the idea to look closely at Schwann cells in the cornea. These cells wrap themselves around nerve cells, forming a protective sheath and helping signals travel along the nerves. The researchers hypothesized that these cells played a key role in healing the cornea and restoring its sensory function.

"The Schwann cell had never actually been explored for what it's made up of," Mohan explains. "And since the cornea is clear, and there are no blood vessels, we reasoned that the Schwann cells in the cornea would be different from those in the vascularized skin."

Mohan's lab set to work isolating these corneal Schwann cells, using a technique called single-cell RNA sequencing analysis to determine what genes they expressed. In the process, they found a gene called DKK1 (Dickkopf WNT signaling pathway inhibitor 1), which researchers had never seen Schwann cells express before.

Excited by this finding, they developed a DKK1 inhibitor that could be topically applied to the eye. They found that this inhibitor helped repair damage from both physical injury (a small incision similar to the one made by a laser eye surgeon) and chemical injury (exposure to nitrogen mustard) in mouse models. These DKK1 inhibitor treated mice regained corneal sensation as the DKK1 inhibitor promoted Schwann cell and axon regeneration in both injury models.

To continue reading, visit University of Connecticut's news center.

Reference:

Li, M., C. A. Tallo, M. K. Eddy, et al. 2026. "DKK1 Targeting in Corneal Schwann Cells Rescues Axonal Regeneration and Mechanosensory Function After Corneal Injury." Journal of Neuroscience Research104, no. 6: e70142. doi.org/10.1002/jnr.70142.