Bionic Eye may Restore Sight to the Blind

Stevie Wonder- world-renowned singer and composer is just one of many blind people around the world who would like to hear more about this invention.

Scientists working for the Doheny Eye Institute at the University of Southern California have improved upon a previous invention released in 2002; a prototype artificial retina. They plan to start clinical studies for the development of its successor, the Argus II Retinal Prosthesis System.

According to them, the improved version is smaller and much more efficient.

The ‘miracle’ implant is designed to restore a certain degree of sight to those suffering from loss of sight caused by ailments like age-related macular degeneration and retinitis pigmentosa.

It does not offer a cure for blindness caused by damage of the optic nerve.

With the previous electronic implant, six blind patients had their sight partially restored. The device proved so successful that its developers led by Dr. Mark Humayun, applied for FDA approval to begin clinical trials of the technology in around 50 to 75 subjects, with blindness.

They hope to release the improved version in 2 years.

The bionic eye works by converting images from a tiny camera mounted on a pair of glasses into a grid of 16 electrical signals that transmit directly to the nerve endings in the retina.

The camera in the glasses sends a wireless signal to a pea-sized pocket device, which processes the images in real time into a four by four grid of electrical signals. This grid is then transmitted wirelessly to the eye implant, which converts these into signals sent directly to nerve endings in the retina.

The previous six patients were able to tell the difference between objects such as a cup, a plate and a knife. They could also tell which direction objects were moving in front of them.

In the current device, the receiver for the signal is implanted under the skin behind the ear with a wire connection to the eye implant, but the improved version will fit under the skin around the eye.

More significantly, it now has 60 pixels instead of 16 and because it is smaller the operation to implant it is much less traumatic, taking just 90 minutes instead of eight hours. Eyesight will also be increased correspondingly, say the scientists.

Humayun predicts that it will cost around $30,000, which he says is just about the cost of a cochlear transplant and he believes that his implants will be most successful in patients who were once fully sighted, rather than people who were blind from birth.

However he wants to try the device out in those people too.

Speaking in San Francisco at the annual meeting of the American Association for the Advancement of Science, Humayun was quoted: "Our work to date with our retinal prosthesis has exceeded all expectations we had, and we are very excited and look forward to the results from our 60-channel implant."

The technology is being targeted at both young and elderly patients blinded by either retinitis pigmentosa or macular degeneration.

Approximately 25 million people, six million in the United States alone, have lost most or all of their vision to such diseases, a figure Humayun said researchers expect will double by 2020.

Source-Medindia
ANN