Bionic retina gives partial sight to six

CHICAGO: Thanks to an artificial silicon retina, the six patients, many of whom were virtually blind, are rediscovering simple gifts of the sighted: the flight of a flock of geese, the pattern on a well-worn tablecloth, the face of a loved one.

The patients are part of a pilot study of a solar-powered microchip created by Optobionics, a private company based in Illinois.

The microchips, surgically implanted behind the retina, are smaller than the head of a pin and about half the thickness of a sheet of paper. They work by converting light into electrical impulses.

“What we are doing is trying to replace the function of photoreceptors, said Alan Chow, a pediatric ophthalmologist and chief operating officer of Optobionics. He developed the chip with his brother Vincent Chow, an electrical engineer.

Loss of light-sensing photoreceptor cells occurs in retinitis pigmentosa and macular degeneration, the two most common causes of untreatable blindness in developed countries, affecting at least 20 million people worldwide.

What Chow found is that the chips also seem to be stimulating remaining healthy cells. He said the device is having a “rescue effect” on the retina, restoring cells located near the implant site.

Chow is presenting his results later on Wednesday at the Association for Research in Vision and Ophthalmology annual meeting in Florida. The trial includes three patients implanted with the chips for nine months and three implanted for 21 months. Patients range in age from 45 to 76. All had lost their vision to retinitis pigmentosa, a hereditary condition in which the retina gradually degenerates.

Source: The Times of India
Dated 9th May, 2002