Dr Walter-G Wrobel, president and CEO, Retina Implant, says the focus is now to get regulatory approvals in the US and Europe for the microchip. "Our current focus is on the second clinical trial. We are concentrating on expanding the second human clinical trial in more locations around the world. We are also focussing on pursuing the CE mark in Europe and FDA approval in the US for our microchip."

The trial by Retina Implant is the first to implant patients with such a large number of electrodes and this study also presents the first proof-of-concept that such devices can restore reasonable and useful vision in blind human patients. Scientists at Massachusetts Institute of Technology in the US are also conducting trials with their own version of a subretinal implant. However, they do not anticipate implanting the chip in humans until 2013. Dr Wrobel, says, "To date, between our first and second human clinical trials, 26 patients have been implanted with our technology."

Explaining the superiority of the subretinal implant, Dr Wrobel says an epiretinal implant involves placing the chip on the retina and requires several parts to work: a camera and transmitter mounted on the eyeglasses of the patient, an implanted receiver, electrodes secured to the retina with a tack to keep the device in place and a battery pack worn on the patient's belt. "The camera captures images that are processed by the transmitter and receiver and turned into electrical pulses. The desired result is for the retina to respond to the pulses by perceiving them as patterns of light and dark spots which patients learn to interpret as meaningful images," he says, adding that clinical trial results have yielded some success.

Unlike the epiretinal approach, the subretinal approach leverages the natural movement of the eye. "Therefore, it does not require additional equipment to function. Our microchip also contains significantly more electrodes than the epiretinal option (1500 against 64). The increased number of electrodes allows for the light and dark images to appear more vibrant, making them easier to see," adds Dr Wrobel.

According to the company, the market volume for the microchip is about 30,000 units per annum worldwide, which roughly translates into sales of $2.2 billion (1.8 billion euros). The cost of surgery for Retina Implant's microchip is between $7,500 and $10,000 (6,000-8,000 euros).