Scientists develop device that stimulates tears to treat 'dry eyes'

Washington: Scientists have developed a tiny device to electronically stimulate tear production, which could help sufferers of dry eye syndrome, one of the most common eye diseases in the world.

The device, 16mm long, 3-4mm wide and 1-2mm thick, was implanted beneath the inferior lacrimal gland in rabbit eyes. It was activated wirelessly, and shown to increasing the generation of tears by nearly 57 per cent.

'Dry eye' - deficiency of the tear film on the surface of the cornea leading to inflammation of the cornea and conjunctiva - is one of the most common eye disease, affecting 5-6 per cent of the population. Currently it does not have an effective treatment. The researchers also discovered that the afferent neural pathway - the neural pathway from sensory neurons to the brain which activates the reflex tearing - offered an even more efficient way to enhance tear production.

"Initially we only planned to stimulate the lacrimal gland. The biggest surprise for us was discovering that stimulating the afferent neural pathway provided a more potent and long-lasting tear response," said Daniel Palanker, a professor at the Stanford University in US.

The next phase of the research will be to evaluate the 'quality' of the tears produced, as in addition to volume, protein and lipid content are important. The device is currently undertaking clinical trials.

"I hope to see it on the market in the next year. Meanwhile, we're continuing research into the mechanisms of the tearing response, its enhancement and quality of the tears produced by neural stimulation," said Mr Palanker. The study was published in the Journal of Neural Engineering.