Scientists Discover New Layer in Human Cornea: Eye Diseases May Receive Better Treatment

The human eye is a bit more complicated than we first thought. Scientists have discovered a previously undetected layer in the cornea, the clear window at the front of the eye. The findings could dramatically improve surgeries that involve corneal grafts and transplants.

Named the Dua Layer after the professor who discovered it, this new layer is located at the back of the cornea between the corneal stroma and Descemet's membrane. Although it's just 15 microns thick, it's incredibly tough and strong enough to withstand one and a half to two bars of pressure.

Before this latest finding, researchers believed that the cornea was made up of only five layers. This clear protective lens is located on the front of the eye and is the site where light enters the organ. The fact that there are actually six layers to this piece of the eye means that researchers may be able to associate certain diseases with the new layer.

"From a clinical perspective, there are many diseases that affect the back of the cornea which clinicians across the world are already beginning to relate to the presence, absence or tear in this layer," said Harminder Dua, the researcher who discovered the layer, in a news release.

Actually finding this layer was no easy task, though. The scientists simulated human corneal transplants and grafts on eyes donated for research purposes. During the surgery, they injected tiny bubbles of air into the cornea in order to separate the different layers. They then subjected the different layers to electron microscopy. This allowed the scientists to study the layers at many thousand times their actual size.

"This is a major discovery that will mean that ophthalmology textbooks will literally need to be rewritten," said Dua in a news release. "Having identified this new and distinct layer deep in the tissue of the cornea, we can now exploit its presence to make operations much safer and simpler for patients."

The new layer will have a major impact on advancing understanding of a number of diseases in the cornea. These include acute hydrops, Descematocele and pre-Descemet's dystrophies. The findings could also allow researchers to develop better treatments for patients with these diseases.

The findings are published in the journal Ophthalmology.