Problems with the layer could also explain many eye diseases that until now were elusive in origin.
The new layer has been dubbed the Dua’s layer, after Professor Harminder Dua who discovered it, reports journal
.Professor Dua said: “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.
Professor Harminder Dua at the University of Nottingham discovered the previously undetected 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.’
Scientists previously believed the cornea to be comprised of five layers, from front to back, the corneal epithelium, Bowman’s layer, the corneal stroma, Descemet’s membrane and the corneal endothelium.
The new layer that has been discovered is located at the back of the cornea between the corneal stroma and Descemet’s membrane.
Although it is just 15 microns thick – the entire cornea is around 550 microns thick or 0.5mm – it is incredibly tough and is strong enough to be able to withstand one and a half to two bars of pressure.
Researchers proved the layer existed by simulating human corneal transplants and grafts on eyes donated for research.
During these experiments, tiny bubbles of air were injected into the cornea to separate the different layers.
The scientists then subjected the separated layers to electron microscopy, allowing them to study them at many thousand times their actual size and revealing Dua’s layer.
The authors say that the discovery will have an impact on advancing understanding of a number of diseases of the cornea, including acute hydrops, Descematocele and pre-Descemet’s dystrophies
The scientists now believe that corneal hydrops, a bulging of the cornea caused by fluid build up that occurs in patients with keratoconus (conical deformity of the cornea), is caused by a tear in the Dua layer, through which water from inside the eye rushes in and causes waterlogging.