Dr. Kristina Narfstrom is fine-tuning the technique with Abyssinian and Persian cats affected with the hereditary retinal blinding disease similar to retinitis pigmentosa, an incurable genetic disease in humans that usually leads to blindness.
"About one in 3,500 people worldwide is affected with a hereditary disease, retinitis pigmentosa, that causes the death of retinal cells and, eventually, blindness," Narfstrom said.
"Our current study is aimed at determining safety issues in regard to the implants and to further develop surgical techniques. We also are examining the protection the implants might provide to the retinal cells that are dying due to disease progression with the hope that natural sight can be maintained much longer than would be possible in an untreated patient."
Retinitis pigmentosa affects the eye's photoreceptor cells that process light and color.
The chip experiment with Narfstrom's cats will aid researchers to perfect its performance and instruct physicians on the needed surgical techniques for the devices.
Manufactured by Optobionics Corp., the 2-millimeter-wide chips are surgically placed in the back of eye. Each chip is covered with 5,000 microphotodiodes that process light and sends electric signals in the eye's optic nerve to the brain.
Director of research development for the Foundation Fighting Blindness, Tim Schoen, said technology that allows prosthetic sight is encouraging.
"This offers great hope to individuals who have completely lost vision," said Schoen. "We can treat these patients with gene therapy, but once the photoreceptors die, we have to replace them with stem cells or one of these artificial methods."
