Artificial eyes

A new vision

Normally, when light rays or images are focused by the lens of the eye on the retina, light-sensing cells called 'rod cells' and 'cone cells' convert this light into electrical impulses. into the brain and expressed into images of the world around us. 'The retina actually does some image processing functions and then sends this information to the brain, and we see it ' - That's Mark's explanation.

Retina chips are implanted in the eye

Mark Humayun (left) & Eugene de Juan, Professor of Ophthalmology at Keck School of Medicine
(Photo: usc.edu)

Humayun, Professor of Ophthalmology at Keck School of Medicine and Doheny Retina Research Director. Currently, Humayun is developing an artificial retina that he hopes can restore some vision to people who are blind due to retinal cell degeneration.'Once vision is lost and the patient cannot see it then it is very difficult to treat, and people have nothing to restore their eyesight' - Humayun said - 'And the recovery of the condition vision loss is aimed at this retinal transplant '.

Researchers have focused on blindness caused by degeneration of the retina due to retinitis pigmentosa disease (RP) and age-related rash degeneration (AMD). RP is the name given to a group of genetic eye diseases that damage cells around the retina. Gradually led to what is called the 'tubular market'. AMD also causes cells at the center of the eye to fail, creating a black spot in the middle of a person's vision whose vision is blurred and wavy, or completely blind, and this condition develops. bigger and bigger. Therefore, implantation of the retina or chip will provide peripheral vision for people with RP, and a central look for people with AMD.

Small electrodes propagate to the retinal implant

By the time the retinal implant project started nearly 17 years ago, scientists had begun studying similar cochlear implants. Instead of turning sound into electrical impulses, Humayun and his colleagues recorded images and converted them into very small electrical impulses so they could excite the retina.'The idea behind this retinal implant is that when light-sensitive cells are destroyed, you can use a camera and turn the image into tiny electrical impulses to then stimulate - stimulate the cells. cells remain in the retina ' and make people visible - he said.

Currently, their "model 1" implant, developed by California-based Second Sight Medical Products Company, implanted for 6 patients. With the 4x5mm size, this electronic retina excitation chip consists of a piece of silicon and platinum attached to 16 electrodes, implanted in the back of the eye above the retina. The images are recorded by a tiny, lightweight video camera attached to eyeglasses, which is sent wirelessly in the form of tiny electronic pulses to a receiver hidden behind the patient's ear. "When these electrodes stimulate the retina, that information is sent to the brain and allowed the patient to see it," Humayun said.