Categories: ConditionsResearch

USC Roski Eye Institute Improves Image Sharpness in Retinal Implants

FDA Approved Retinal Prosthesis, Argus IIRetinitis pigmentosa (RP) is an inherited eye disease that causes gradual degeneration of the light sensitive photoreceptors in the retina, which eventually leads to total blindness. Roughly one in 4,000 people suffer from the debilitating disease; however, according to a recent study by researchers from the USC Roski Eye Institute and the USC Viterbi School of Engineering, patients who have regained some vision with the help of revolutionary retinal implants may gain even better, sharper vision.

The Argus II retinal implant, also called the bionic eye, was developed by ophthalmologists and engineers at USC to help people once again perceive light through a pair of eyeglasses that feature a video camera mount and a video processing unit. The implant transforms images via the camera into electronic signals that are wirelessly transmitted to implanted electrodes in the eye in order to stimulate visual neurons.

While retinal implants have been able to provide blind individuals with some degree of vision, such as the ability to find large objects or detect motion, the devices also inadvertently triggered axons in the retina, resulting in reduced vision quality. When the axons are triggered, patients would see large, unusual shapes of light that interfere with the patients’ overall vision.

The USC researchers determined that by using various durations of stimulus pulses, it was possible to create more precise stimulus that would not interfere with the axons in the retina nearly as much as with shorter pulses. For example, electrical pulses of only eight milliseconds or shorter would stimulate the axons and obscure the patients’ vision, whereas pulses of at least 25 ms did not produce any signs of axonal stimulation, providing a clearer focal spot of light.

“Our findings further support that it is possible for patients with RP to see forms using artificial vision,” said James Weiland, PhD, professor of ophthalmology and biomedical engineering. “This makes a strong case for developing high-resolution retinal implants.”

What is Retinitis Pigmentosa?

RP occurs when the light sensitive cells (rods and cones) of the retina on the back of the eye begin to degenerate and die. The condition causes a gradual loss of vision as more and more of the retina cells stop working. The progression of RP will depend on which rods and cones are affected first. Some patients experience night blindness initially, while others may notice a decrease in central vision and color. The rate of progression will also depend largely on each patient.

Contact Our Expert Ophthalmologists Today

To protect your vision and ensure the highest quality of care, schedule an annual eye exam with the professional ophthalmologists at USC Roski Eye Institute. Regular screenings and exams will help accurately catch potential issues that may develop into serious eye conditions, such as retinitis pigmentosa. Take preventative action early. Make an appointment with a skilled ophthalmologist today.

Help support the USC Roski Eye Institute by making a tax-deductible gift! Contact Rebecca Melville, senior director of development, at 323.442.5396 or via email at Rebecca.Melville@med.usc.edu today!

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