3 Nov 2010

Scientists help blind man see again

In a major breakthrough for the blind, scientists have restored a man’s sight with a “bionic eye” for the first time ever, reports Science Correspondent Julian Rush.

Scientists help blind man see again (Retina Implant AG)

Miikka Tertho, from Finland, inherited the disease retinitis pigmentosa, a common degenerative disorder that affects some 200,000 people around the world. At 24, he started to lose his sight. Now 46, he is registered blind.

For three months, Miikka was one of eleven patients testing the retinal implant built by Prof. Dr. Eberhart Zrenner of Tuebingen University in Germany. The 1500 pixel chip, similar to that found in a digital camera, was implanted behind the retina of his left eye where it effectively replaced the light receptors lost as a result of the degenerative disease.

Electrodes on the back of the tiny 3x3mm2 chip passed pulsed signals to his optic nerve that varied according to the amount of light falling on the chip. Previous experiments to restore sight in this way have used a bulky external camera; this is the first time an implanted “bionic eye” has been shown to work successfully.

What the chip looks like outside the eye (Retina Implant AG)

When the time came to switch on his new bionic eye, Miikka was nervous.

“They told me that I should see dots in my eye, like light bulbs when they pressed the button on the computer,” Miikka said. “I was a bit shaky, but when they hit the button and I could see the dots, I shouted out ‘yes!’ at the top of my voice.”

Miikka quickly learned to “see” with his bionic eye. He went from being able to identify vertical and horizontal lines on a computer screen, to form letters into words, even in one extraordinary moment, correcting the spelling of his name.

In video that dramatically captures the delight of both Miikka and the scientists, the team break into spontaneous applause as Miikka recognises foreign objects such as a banana and distinguishes between a fork, knife and spoon.

Graphic showing how the implant works (Retina Implant AG)

Video provided by University of Tuebingen/Retina Implant AG

Writing in the journal “Proceedings of the Royal Society B“, where the results of the pilot study have been published, Professor Zrenner says the results surpassed his expectations.

“The results of this pilot study provide strong evidence that the visual functions of patients blinded by a hereditary retinal dystrophy can, in principle, be restored to a degree sufficient for use in daily life,” he said.

The first trials on UK patients are expected to start in London and Oxford in 2011.