Invention: Eyeball stiffener - Reproduced with kind permission of Jeremy Webb (Editor) New Scientist
* 16:39 21 October 2008
* NewScientistnews service
* Justin Mullins
The blinding disease keratoconus affects as many as one person in 435, striking between the ages of 10 and 20.
It involves a progressive thinning of the cornea which then bulges into a cone shape, causing severe visual impairment that can only sometimes be corrected with contact lenses.
But now David Paik and colleagues at Department of Ophthalmology at Columbia University, New York, say a solution containing sodium nitrite ions could provide a simple treatment.
Daily application causes collagen fibres in the cornea to bond together, creating a supporting scaffold within the outer layers of the eye. Once diagnosed and treated, the stiffer cornea would prevent the condition progressing, they say.
Eyeball stiffening has previously been shown to work by German researchers. But that method involves scraping the top layer of cells from the cornea before applying a solution that must be fixed using strong UV light.
Neither the scraping nor the UV light do the eye any good, preventing that approach from receiving FDA approval, says the Columbia team.
But the friendlier sodium nitrite solution is able to soak through to the collagen-rich layer and can be applied by patients at home, they say.
It could also be also used to stabilise the eyesight of patients with severe myopia, or short-sightedness, caused by other conditions in which the cornea changes shape, such as some types of glaucoma.
Title: METHOD OF STABILIZING HUMAN EYE TISSUE BY REACTION WITH NITRITE AND RELATED AGENTS SUCH AS NITRO COMPOUNDS
A method for stabilizing collagenous eye tissues by nitrite ion treatment. The topical stiffening agent contains sodium nitrite in a buffered balanced salt solution and can be applied to the surface of the eye on a daily basis for a prolonged period. The pH of the sodium nitrite solution can be lowered to speed the effect. Application of the solution results in progressive stabilization of the corneal and scleral tissues through non-enzymatic cross-linking of collagen fibers. The nitrite can penetrate into the corneal stroma without the need to remove the corneal epithelium. In addition, ultraviolet light is not needed to activate the cross-linking process. The resulting stabilization of corneal and scleral tissues can prevent future alterations in corneal curvature and has utility in diseases such as keratoconus, keratectasia, progressive myopia, and glaucoma.