New eye layer may help treat blindness

An Indian-origin scientist in the UK has discovered an ultra-thin layer hidden deep in the eye that may help cure blindness caused by glaucoma.
The new layer in the human cornea, discovered by Professor Harminder Dua, of Nottingham University, plays a vital role in the structure of the tissue that controls the flow of fluid from the eye, research has shown.
The findings could shed new light on glaucoma, a devastating disease caused by defective drainage of fluid from the eye and the world's second leading cause of blindness, researchers said.
The latest research shows that the new layer, dubbed Dua's Layer, makes an important contribution to the sieve-like meshwork, 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'.

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, researchers said.

Around 1 to 2 per cent of the world's population yearly have chronic glaucoma and globally around 45 million people have open angle glaucoma which can permanently damage the optic nerve - 10 per cent of whom are blind, researchers said.
The latest research sheds new light on the basic anatomy of Dua's Layer, which is just 15 microns thick but incredibly tough. Comprised of thin plates of collagen, it sits at the back of the cornea between the corneal stroma and Descemet's membrane.
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.

It is hoped the discovery will offer new clues on why the drainage system malfunctions in the eyes of some people, leading to high pressure.
The research was published in the British Journal of Ophthalmology.