News / Health

Gene Therapy a Step Closer to Restoring Eyesight to Some Blind Patients

Researchers have moved a step closer toward fully restoring the eyesight of people with a rare genetic disorder.  A new study shows the treatment is safe and effective, and could pave the way for helping cure more common causes of blindness.

Leber's congenital amaurosis is an extremely rare condition that causes blindness in approximately 4,000 people in the United States.  

Approximately five to seven babies are born each year with the progressive inherited disorder, according to Jean Bennett, a professor of ophthalmology at the University of Pennsylvania in Philadelphia. "It's probably one of the most severe forms of retinal degeneration, most severe because it affects infants, and it's usually the parents who first notice that their children aren't seeing the way most normal children do at approximately six weeks of age," Bennett said.

LCA is caused by a single defective gene. This defect prevents normal function of the retina, the light-sensitive layer of cells at the back of the eye. This results in severely impaired vision from a very young age and there are currently no effective treatments available.

A recent study done on animals has shown that tests on both eyes are safe and effective and improve vision. This clears the hurdle for trials in humans to receive treatments in both eyes.

In a groundbreaking clinical trial last year, researchers repaired the gene and injected it into the retinas of the single eye of 12 people, where it started to produce healthy cells.  Bennett says the patients experienced a dramatic improvement in their eyesight in the single eye, particularly among younger patients whose vision had not deteriorated to near blindness. "It now allows them to be able to read books and sit in the front of a classroom and see what a teacher is writing on a blackboard and to riding their bike around the neighborhood by themselves, whereas before they enrolled in the study, they were learning braille. They sat in the back of a classroom looking at computer monitors which magnified the teacher's image and they were dependent upon canes or holding on to people to walk around," Bennett said.

Bennett, one of the researchers, says the study participants have been clamoring to have their other eye treated with the gene therapy.  But before researchers did that, they wanted to make sure the treatment was safe.

Now researchers are waiting for the green light to treat the second eye of Leber's congenital amaurosis patients, to significantly restore their sight in both eyes.

Bennett says a similar strategy could someday be used to treat age-related macular degeneration, which is responsible for vision loss in more than 14 million older adults worldwide each year.  The disease is the result of damage to the macula, a part of the retina in the eye,  which results in central vision loss.

Scientists have identified several gene candidates involved in the disease.

Although there are currently no gene therapy trials under way to treat macular degeneration, Bennett says her study shows that using a virus to repair defective genes involved in the disease is safe. "If a strategy is developed to deliver a corrective gene to the eyes of patients with AMD, it may be possible to correct the defect in the second eye of the person at a later time point," she said.

An article on gene therapy by the University of Pennsylvania's Jean Bennett and colleagues is published this week in the journal Science Translational Medicine.

You May Like

Myanmar Fighting Poses Dilemma for China

To gain some insight into conflict, VOA’s Steve Herman spoke with Min Zaw Oo, director of ceasefire negotiation and implementation at Myanmar Peace Center More

Australia Concerned Over Islamic State 'Brides'

Canberra believes there are between 30 and 40 Australian women who have taken part in terror attacks or are supporting the Islamic State terror network More

Recreational Marijuana Use Now Legal in Washington, DC

Law allows adults 21 and over to privately possess and smoke 0.05 kilogram of pot, and to grow small amounts of the plant More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
US Supreme Court Hears Hijab Discrimination Casei
X
Katherine Gypson
February 25, 2015 11:30 PM
The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video US Supreme Court Hears Hijab Discrimination Case

The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video Falling Gas Prices Hurt Nascent Illinois Hydraulic Fracturing Industry

Falling oil prices are helping consumers purchase cheaper petroleum at the pump. But that’s made hydraulic fracturing or “fracking” less economically viable for the companies in the United States invested in the process. VOA’s Kane Farabaugh reports on one Midwestern town that was hoping to change its fortunes by cashing in on the next big U.S. oil boom.
Video

Video Fighting in Sudan's South Kordofan Fuels Mass Displacement

Heavy fighting in Sudan's South Kordofan state is causing hundreds of thousands to flee into uncertain conditions. Local aid organizations estimate as many as 400,000 civilians have been internally displaced since the conflict began more than three years ago, while another 250,000 have fled across the border to refugee camps in South Sudan. VOA's Adam Bailes reports.
Video

Video Lao Dam Project Runs Into Opposition

A Lao dam project on a section of the Mekong River is drawing opposition from local fishermen, international environmental groups and neighboring countries. VOA's Say Mony visited the region to investigate the concerns. Colin Lovett narrates.
Video

Video A Filmmaker Discovers Her Biracial Identity in "Little White Lie

Lacey Schwartz grew up in an upper middle-class Jewish family, in a town in upstate New York where almost everyone she knew was white. She assumed that she was, as well. Her recent documentary, Little White Lie, tells the story of how she uncovered the secret of her true racial background. VOA’s Carolyn Weaver has more on the film.
Video

Video Deep Under Antarctic Ice Sheet, Life!

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.
Video

Video US-Cuba Normalization Talks Resume Friday

Negotiations aimed at normalizing diplomatic relations between the U.S. and Cuba resume Friday. On the table: lifting a half-century trade embargo and easing banking and travel restrictions. There's opposition in Congress, but some analysts say there may be sufficient political and economic incentives in both nations for a potential breakthrough this year. VOA's Mil Arcega reports.
Video

Video Pakistan's Deadline For SIM Registration Has Cellphone Users Scrambling

Pakistani cell phone users have until midnight Thursday to register their SIM cards, or their service will be cut off. While some privacy experts worry about government intrusion, many Pakistanis are just worried about keeping their phone lines open. VOA Deewa reporter Arshad Muhmand has more from Peshawar.
Video

Video Myanmar Warns Factory Workers to End Strikes

Outside Myanmar's main city Yangon, thousands of workers walked off their jobs earlier this month demanding a doubling of their wages, pay raises after a year and input from labor unions on industrial regulations. Since Friday, the standoff has grown more tense as police moved in to disrupt the sit-ins, resulting in clashes that injured people from both sides. VOA correspondent Steve Herman visited industrial zones which have become a focus of Myanmar's fledgling workers rights movement.
Video

Video Oscar Winners Do More Than Thank the Academy

The Academy Awards presentation is Hollywood’s night to reward the best movies from the previous year. It’s typically a lot of glitter, a lot of thank you’s, a lot of speeches. But many of this year’s speeches carried messages beyond the thank you's. VOA’s Carolyn Presutti takes a look.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More