Electronic device promises partial eradication of blindness

Kathy-BlakeAlmost 100,000 people in United States are suffering from blindness due disease like retinitis pigmentosa. It is a hereditary disease that disable the photoreceptor cells- rods and cones, these cells helps to adjust in dim and bright light.

Researchers observed that though the diseased cells are not in a position to react at light but the neurons beneath the inactive cells are capable of sending electronic signals to the brain through optic nerve. On the basis of this observation researchers(Second Sight Medical Product) have created an electronic implant called Argus II Retinal Prosthesis System, which was a decade old brain child of Dr. Mark Humayun, now a professor of ophthalmology, biomedical engineering and cell and neural biology at the University of Southern California.

Patients using the Argus II system can identify a cup, knife and plate faster; 63 percent can reliably find a door 20 feet away; and 40 percent can follow a line on the floor for 20 feet.

The Argus II system has 60 electrodes, which provide more detail, and works like a tiny video camera mounted in a pair of glasses takes pictures of what's in front of a patient and transmits each image to a processor worn on the hip.

The processor turns the image into a pattern of electronic impulses that are sent to an antenna on the side of the glasses. The impulses are directed to a receiver implanted on the side of the eye. The receiver relays these impulses to the electrodes in the retina.

The impulses travel along the retinal neurons through the optic nerve and to the brain. The patient sees flashes of light, which the brain uses to make the equivalent of low-resolution images.

The National Eye Institute has provided nearly $25 million in grants. The Department of Energy says it spent about $15 million on Argus II and expects to spend $55 million on the Argus III.

Electrodes are essentially pixels, and the idea is to provide more  for clearer picture.
The Argus III will have more than 200. The ultimate goal, the fourth one would have more than 1,000 so that patients can recognize faces and read fairly reasonable size of fonts.

Researchers eager to implants a high resolution system that would eliminate the blindness of 30 million people worldwide who are legally blind due to macular degeneration but still have their peripheral vision.

57 years old Kathy Blake who lost her visions 18 years ago due to retinitis pigmentosa, is one of the 17 people worldwide to receive an experimental implant that helps her detect outlines. After the implantation she can actually look and scan the sky and see a flash and point to the moon. She is highly optimistic about her future as well as the device's.

Source:The Columbus Dispatch


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