Simulations signal early success

New research on retinal implants

Simulations signal early success for fractal-based retinal implants

University of Oregon researchers seeking to build devices using nature’s geometry report that their approach uses less voltage and reaches more neurons than current technologies

by: UNIVERSITY OF OREGON

EUGENE, Ore. – Computer simulations of electrical charges sent to retinal implants based on fractal geometry have University of Oregon researchers moving forward with their eyes focused on biological testing.

That is potential down-the-road good news for people facing vision loss from retinal diseases, such as macular degeneration that, alone, incurs costs exceeding $340 billion globally, according to the Brightfocus Foundation.

“What we’ve demonstrated is that using a fractal implant should allow us, in principle, to deliver 20/80 vision,” said physics professor Richard P. Taylor, head of the UO’s Materials Science Institute.

People with acuity of 20/80 are able to see objects at 20 feet away that those with normal or 20/20 vision can see from a distance of 80 feet. According to the Social Security Act in the United States, any person with a corrected vision of 20/200 or less is considered blind.

In their simulations, the UO researchers studied the performance of their bio-inspired implant, which would be inserted behind the eye’s retina. The implant features an array of fractal electrodes designed to stimulate retinal neurons. The results were published in the journal Scientific Reports.

Fractal objects have repeating patterns at many scales and are seen in nature in such things as tree branches, rivers, snowflakes, blood vessels and neurons.

The idea behind Taylor’s implant is to exploit electrodes that have the same fractal shape as the neurons with which they will interact. Currently used retinal implants feature electrode shapes based on traditional Euclidean geometry such as squares.

In human clinical trials with Euclidean-based devices, visual acuity has only achieved 20/1260 for implants placed in front of the retina. Only one patient achieved 20/546 with a device placed behind the retina; 86 percent of cases resulted in no restored acuity, the researchers noted in their paper….

Read more: https://www.eurekalert.org/pub_releases/2017-07/uoo-sse072717.php

Source: Eurek Alert

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