An Indian doctor in Britain has discovered a new layer in the human cornea that could help cure blindness due to glaucoma.
Harminder Dua from the University of Nottingham discovered that the layer -15 microns thick but incredibly tough— plays a vital role in the structure of the tissue that controls the flow of fluid from the eye.
The findings could shed new light on glaucoma, the devastating disease caused by defective drainage of fluid from the eye and the world’s second leading cause of blindness.
The new layer dubbed Dua’s Layer comprises of thin plates of collagen and sits at the back of the cornea between the corneal stroma and descemet’s membrane. Scientists hope that the discovery will offer new clues on why the drainage system malfunctions in the eyes of some people leading to high pressure.
The latest research shows that the new layer makes an important contribution to the sieve-like meshwork called the Trabecular Meshwork (TM) in the periphery of the cornea.
The TM is a wedge-shaped band of tissue that extends along the circumference of the angle of the anterior chamber of the eye. It is made of beams of collagen wrapped in a basement membrane to which trabecular cells and endothelial cells attach. The beams branch out randomly to form a ‘meshwork’.
Scientists had 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.
Pressure within the eye is maintained by the balance of aqueous fluid production by eye tissue called the ciliary body and drainage principally through the TM to the canal of Schlemm, a circular channel in the angle of the eye.
Defective drainage through the TM is an important cause of glaucoma, a condition that leads to raised pressure in the eye that can permanently affect sight.
By examining human donor eyes using electron microscopy, the researchers were able to look at Dua’s Layer beyond the central part of the cornea to shed more light on its features at the extreme periphery of the cornea. They discovered that the collagen fibres of Dua’s Layer also branch out to form a meshwork and that the core of TM is in fact an extension of Dua’s Layer.
Source : Times of India