Can bionic eyes help the blind see?

Scientists are developing and testing an amazing new generation of bionic eyes that are returning some vision to the blind — enabling some of them to see invisible parts of the electromagnetic spectrum, including ultraviolet and infrared, by wearing a visor that works much like the one worn on “Star Trek: The Next Generation” by Geordi La Forge. 

“I like the idea of a blind person who has always been the challenged person to be the bionic person who can see things we can’t,” says Sheila Nirenberg, inventor of an artificial retina and a professor in neurology and neuroscience at Weill Cornell Medical College.

There are a number of promising artificial retina technologies being developed now to help millions of people who suffer from blindness due to degenerative retinal disease such as retinitis pigmentosa, for which there is no cure. 

Worldwide, some 36 million are blind and 217 million have low vision (severe or moderate visual impairment), according to the International Agency for the Prevention of Blindness. 

But that may not always be the case.

How do we see?

Here’s how vision works: Light enters the eye and falls on light-sensitive protein cells on the surface of the retina. These cells convert the light into a series of coded electrical signals or neural pulses and then pass them along the optic nerve at the back of the eye to the brain. 

In a degenerative retinal disease most, if not all, of these light-sensitive protein cells on the retina are no longer functional. 

Several companies hope to counter this using optogenetics — the use of light to control genetically modified cells that express light-sensitive proteins. 

Nirenberg uses optogenetics to create an artificial retina by injecting the eye with an engineered virus carrying a gene from algae, which instructs cells to make the light-sensitive proteins. However, these new proteins can’t convert light into a neural code the brain can read as images.

Nirenberg’s big claim to fame is cracking the brain’s code for vision. And to get the code to the brain, her company, Bionic Sight, has developed a Geordi La Forge-like visor equipped with a camera and a light-emitting microprocessor powered by proprietary software. The camera takes in the images and the processor converts those images into coded light pulses the new proteins can “see” and pass up the line to the brain. 

Blind mice can suddenly see. 

“It happens almost instantly,” says Nirenberg in an interview. 

However, while the blind mice can follow movement they don’t see particularly well. The hope is that by boosting the number of light-seeing proteins, the resolution will improve. 

Additionally, tweaking the system could allow users to see the UV and infrared parts of the spectrum. 

It’s a relatively simple procedure that one day could be done in a doctor’s office, she said. However, the treatment won’t be available any time soon. 

Human clinical trials are expected to begin in the next few months and will take several years to complete. 

Other efforts

Allergan, a big pharma company, hopes to have its first phase of human trials concluded next year. It uses a similar injection technique, but without the code or a visor. Instead, they are relying on natural light to activate the new light-seeing proteins. 

A French company, GenSight Biologics, uses goggles with a camera, a microprocessor and a digital micromirror to beam bright pulses of red light into the eye to stimulate the modified cells. U.S. clinical trials began last year.

The other main approach to helping the blind see is with electrodes directly implanted into the optic nerve of the eye. 

The Argus II Retinal Prosthesis System from Second Sight Medical Products has been in use for 10 years. About 350 people have had electrodes implanted and wear a visor or glasses equipped with a camera and a microprocessor. The images are converted into electrical impulses that are transmitted wirelessly to electrodes, even if the eyes are closed. This method allows users to see shapes but not depth or much detail. 

A new version of the Argus II called the Orion Visual Cortical Prosthesis System involves planting the electrodes directly in the brain. This requires a small craniotomy in the back of the patient’s head to place the electrode array against the visual cortex in the brain’s occipital lobe. Five patients are part of the first human trial and have had the Orion system in place for more than a year. Four of five have been able to see better, the company has reported. 

“A 35-year-old father of three, blinded by pediatric glaucoma at the age of 9, describes his joy at seeing his wife and three daughters for the first time with our device,” says Will McGuire, Second Sight’s CEO. 

Since Orion bypasses the eye entirely, it can help those with detached retinas and missing or badly damaged eyes. Final results of the trial are not expected until 2023.

McGuire says the company has a prototype stereo system to enable depth perception with two cameras and software with advanced obstacle detection capabilities. By the end of this year, McGuire says, “We also aim to develop prototype systems for eye tracking and thermal imaging.” 

Human testing of these prototypes could begin in the first few months of 2020, he said in a call with investors.

Unfortunately for the visually impaired, it will be some years before these technologies are fully developed. That said, this should happen long before the 24th century, when Geordi La Forge and his visor were traveling through space in the starship Enterprise.

How to keep your eyes healthy

The National Eye Institute suggests a number of simple steps to keep your eyes healthy:

• Don’t smoke. Smoking is associated with increased risks of developing cataracts, optic nerve damage and age-related macular degeneration.

• Maintain a healthy weight and eat a balanced diet.

• Clean your hands and contact lenses properly to reduce the risk of eye infection.

• Know your family’s eye health history.  Serious eye disorders such as retinitis pigmentosa are hereditary and knowing your risk can improve the level of treatment available.

• Have a comprehensive eye exam. The only way to be completely sure of the health of the eyes is to visit an eye care professional.

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