Dr. Mark Humayun featured in Nature Outlook for groundbreaking work to treat blindness

By Alexandra Demetriou

Dr. Mark Humayun from the USC Dr. Allen and Charlotte Ginsburg Institute for Biomedical Therapeutics was recently featured in Nature Outlook for his outstanding contributions to advance the treatment of blindness. The article highlighted a handful of the world’s top researchers tackling the problem of retinal degeneration, which is the leading cause of blindness in developed countries.

Image: Nature Outlook
Image: Nature Outlook

Dr. Humayun’s Argus series implants were showcased amongst the most cutting-edge approaches to restoring eyesight for patients with some functional retinal cells still intact. The Argus II “bionic eye” consists of an electrode array that is implanted on the surface of the retina. The patient wears glasses equipped with a small video camera that transmits signals wirelessly to the implant. The electrodes stimulate the retina, which then communicates those signals to the brain. Over 300 patients have received the Argus II prosthesis and have regained their perception of light patterns, movement and basic shapes.

For patients who have completely lost functionality of the retina, Humayun and his colleagues at Second Sight have a different approach: sending signals from a camera directly to the brain.

The researchers have developed a chip, called Orion, which is surgically implanted on the outer surface of the very back of one’s brain. This region of the brain, called the visual cortex, is responsible for processing and interpreting information from the eyes. Like Argus II, Orion receives signals from a camera mounted on the patient’s glasses, and the brain can then convert those signals into visual information. So far, the chip has been successfully implanted in five patients with limited or no light perception. The trial is still its early stages, but the preliminary results look promising and Humayun hopes the chip will receive FDA approval in a few years.

To read the entire Nature Outlook article, click here.

Researchers at the USC Ginsburg Institute for Biomedical Therapeutics develop augmented reality glasses to help low-vision patients navigate their environments

By Alexandra Demetriou

A team of researchers at the USC Dr. Allen and Charlotte Ginsburg Institute for Biomedical Therapeutics recently developed a pair of augmented reality (AR) glasses to help visually impaired patients navigate their surroundings and perceive depth more clearly.

The glasses were designed to help patients with a degenerative eye disease called retinitis pigmentosa (RP). The condition causes progressive vision loss, particularly on the periphery of one’s vision, and makes it difficult to see in low-light conditions. Patients with RP often experience tunnel vision and have trouble perceiving their 3D environment. Specifically, they struggle to grasp objects and avoid obstacles in their path, and these issues are worse at night.

The AR glasses help solve this problem by allowing patients to see a color-coded mesh on top of the objects in their surroundings. The colors correspond to depth, with objects closest to the wearer appearing white, followed by green, blue and eventually red for objects that are furthest away.

The augmented reality glasses allow patients to perceive a color-coded mesh on top of the objects in their surroundings, which helps wearers perceive depth. (Image: Anastasios Nikolas Angelopoulos)

The device, customized by Anastasios Nikolas Angelopoulos and Dr. Mark Humayun, was configured with the user’s experience in mind. Rather than using virtual reality, which completely replaces the wearer’s field of view with an image on a screen, the augmented reality color mesh enhances the wearer’s depth perception while still allowing the patient to see the true color and texture of an object through gaps in the mesh. This is important for patients, because it allows them to interact with the world around them as normally as possible without having to sacrifice any of the perception they still have.

With the help of their colleagues, Drs. Hossein Ameri and Debbie Mitra, the researchers tested the visual aid in subjects with retinitis pigmentosa. The team asked patients to both navigate a simple obstacle course and grasp objects in front of them while they had the glasses on. When using the glasses, RP patients were able to navigate the maze and avoid obstacles 50% better than they could without the visual aid. The grasping task required patients to grab the furthest of four pegs placed in front of them, without hitting any of the closer ones. The glasses improved the patients’ abilities to grasp the furthest peg by 70%, meaning that much of their depth perception was restored thanks to the AR color mesh.

Currently, many patients with RP avoid going out at night and may experience anxiety or fear of losing their independence due to their vision problems. Although the device is still in development, the researchers hope these glasses will eventually help improve quality of life by allowing patients to return to their day-to-day activities safely and with more confidence and independence.

The team published their work in Scientific Reports, an online, open access journal from the publishers of Nature, and the article has been accessed close to 2,000 times. Their publication ranks in the 98th percentile of all similarly aged papers tracked by the data science company Altmetric across all journals, and it ranks 1st of 12 tracked articles of a similar age in Scientific Reports. The researchers’ work was additionally featured in news outlets such as ScienceDaily, and the full list of media coverage is available here.