Retinal implant brings bionic vision to blind patients

Scientists have successfully implanted microchips in the retinas of three blind volunteers, allowing them to see shapes and letters within days of surgery.

Retinitis pigmentosa and macular degeneration are diseases that affect the light receptors in the retina, one of the eyeball's outer layers.

Whether hereditary or age-related, they cause vision loss and lead to the eventual blindness of over 15 million people around the world.

In a Proceedings of the Royal Society B study, Eberhart Zrenner from the University of Tuebingen in Germany and colleagues describe their device as a subretinal electronic chip that can be surgically implanted underneath the retina, in effect replacing the light receptors that were lost.

The chip is about three millimeters wide with 1,500 pixel-generating elements, each with its own electrode. Each electrode, in turn, provides an electrical stimulus to nearby neurons, reflecting the visual signal that would normally be received by the degenerated photoreceptor.

The three volunteers in this study used to possess good vision, but had all been blind for at least five years.

After surgery, all three patients were able to visually locate bright objects that were placed on a dark tabletop in front of them. One patient, Miikka, was able to name and describe a variety of everyday objects, geometric patterns, different fruits, and clock faces. He was even able to discern varying shades of gray and approach people in a room using his newly restored visual abilities.

Miikka also noticed when his named was misspelled in giant white letters.

Here's a look:

(Interested in more? You can watch more videos about the feat on the Royal Society's website.)

The results of this pilot study, according to the authors, “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."

While this study presents proof-of-concept that such devices can restore useful vision in blind human subjects, Zrenner says, the ultimate goal of broad clinical application will take time to develop.

The device is developed by Retinal Implant AG together with the Institute for Ophthalmic Research at the University of Tuebingen.

This post was originally published on Smartplanet.com