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

Obama: I Will Do 'Everything I Can' to Close Guantanamo

US president says prison continues 'to inspire jihadists and extremists around the world' More

Sierra Leone Educates on Safe Ebola Burials

Also, country is improving at rapid response to isolated outbreaks, but health workers need to be even faster, officials say More

Christmas Gains Popularity in Vietnam

Increasingly wealthy Vietnamese embrace holiday due to its non-religious glamor, commercial appeal 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 Decision on Cuba Underscores Divisions Among Miami Cubansi
X
Sharon Behn
December 19, 2014 9:34 PM
For decades, older, more conservative Cubans have been gathering at Café Versailles on the corner of Calle Ocho to eat Cuban food and talk politics. After hearing of President Barack Obama’s decision, a number of them gathered in front of the café with posters to protest. VOA's Sharon Behn reports on the situation.
Video

Video US Decision on Cuba Underscores Divisions Among Miami Cubans

For decades, older, more conservative Cubans have been gathering at Café Versailles on the corner of Calle Ocho to eat Cuban food and talk politics. After hearing of President Barack Obama’s decision, a number of them gathered in front of the café with posters to protest. VOA's Sharon Behn reports on the situation.
Video

Video Three Cities Bid for Future Obama Presidential Library

President Barack Obama still has two years left in his term in office, but the effort to establish his post-presidential library is already underway. The bid for the Obama Presidential Library is down to four locations in three states -- New York, Hawaii, and Illinois. As VOA’s Kane Farabaugh reports, each of them played an important part in the president’s life before he reached the White House.
Video

Video Cuba Deal is Major Victory for Pope’s Diplomatic Initiatives

Pope Francis played a key role in brokering the US-Cuba deal that was made public earlier this week. It is the most stunning success so far in a series of peacemaking efforts by the pontiff. VOA religion reporter Jerome Socolovsky has more.
Video

Video Fears of More Political Gridlock in 2015

2014 proved to be a difficult year politically for President Barack Obama and a very good year for the U.S. Republican Party. Republican gains in the November midterm elections gave them control of the Senate and House of Representatives for the next two years -- setting the stage for more confrontation and gridlock in the final two years of the Obama presidency. VOA National Correspondent Jim Malone has a preview from Washington.
Video

Video Sudan School Becomes Target of Aerial Attacks

The school dropout rate is at an all-time high in Sudan's South Kordofan state because many schools have been destroyed during the three-year civil war between the government and SPLA-N rebel forces. Adam Bailes visited Sudan's Nuba Mountains' region and reports many children are simply too scared to go to school
Video

Video VOA Reporter Tours Devastated Peshawar School

Islamist militants wearing military uniforms and strapped with explosives attacked a military run school Tuesday in the northwestern Pakistani city of Peshawar. At least 141 people were killed in the horrific attack, most of them young students. VOA reporter Ayaz Gul visited the devastated school and attended the funeral of the principal who courageously tried to save her students from the deadly attack.
Video

Video Nigerians Fleeing Boko Haram Languish in Camp Near Capital

In its five-year effort to impose Islamic law in northeastern Nigeria, the Boko Haram extremist group has killed thousands of people and forced hundreds of thousands to flee. Some of those who ran for their lives now live in squalor on the edges of the capital, Abuja. Chris Stein reports for VOA.
Video

Video Aceh Rebuilt Decade After Tsunami, But Scars Remain

On December 26, 2004 there was an earthquake in the Indian Ocean so powerful it caused the Earth’s axis to wobble a few centimeters. Onshore on the island of Sumatra, the resulting tsunami was devastating. A decade later, VOA Correspondent Steve Herman reports from Banda Aceh, Indonesia, where although there is little remaining evidence of the physical devastation, the psychological scars among survivors remain.

All About America

AppleAndroid