Cornea Layer Discovery could Make Eye Surgeries Safer, Researchers Say

Researchers have now discovered a new corneal layer in the human eye. The discovery could help thousands of people who suffer from diseases that affect the cornea.

The cornea is a clear dome-shaped structure and is the outermost layer of the eye. A clear cornea helps direct light to the eye. Until now, it was believed that the cornea had five basic layers: epithelium, Bowman's layer, the corneal stroma, Descemet's membrane and the corneal endothelium.

The discovery was made by researchers from the University of Nottingham and is expected to help patients undergoing corneal transplants and grafts. Every year, about 40,000 people in the U.S. undergo a corneal transplant.

The newly-discovered corneal layer is called the Dua's Layer, after Professor Harminder Dua who discovered it.

"This is a major discovery that will mean that ophthalmology textbooks will literally need to be re-written. 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," said Dua, Professor of Ophthalmology and Visual Sciences.

"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," he added in a news release.

The entire cornea is about 550 microns or 5mm in thickness. The new layer is about 15 microns thick and is present between the corneal stroma and Descemet's membrane. The layer is incredibly tough and can withstand pressure of one and a half to two bars of pressure.

Researchers now think that a condition known as corneal hydrops, where the cornea bulges due to fluid buildup, is caused by a tear in the Dua layer.

The researchers discovered its presence on a simulated corneal graft surgery. During the procedure, tiny bubbles of air were injected in the cornea to separate the layers. Each layer was then studied using an electron microscope.

Insights into the Dua's layer could help make corneal surgeries safer. Injecting an air bubble next to this layer could prevent corneal tearing during surgeries.

The study is published in the journal Ophthalmology.