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

Sydney Hostage-taker Failed to Manipulate Social Media

Gunman forced captives to use personal Facebook, YouTube accounts to issue his demands; online community helped flag messages, urged others not to share them More

UN Seeks $8.4 Billion to Help War-Hit Syrians

Effort aimed at helping Syrians displaced within their own country and those who've fled to neighboring ones More

Who Are the Pakistani Taliban?

It's an umbrella group of militant organizations whose objective is enforcement of Sharia in Pakistan 'whether through peace or war' 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.
Putin: Russian Economy to Rebound in 2 Yearsi
X
December 18, 2014 5:13 PM
Russian President Vladimir Putin held his annual end-of-the-year news conference Thursday, tackling questions on the Russian economy, the crisis in Ukraine and Russian relations with the west. VOA's Jeff Custer reports.
Video

Video Putin: Russian Economy to Rebound in 2 Years

Russian President Vladimir Putin held his annual end-of-the-year news conference Thursday, tackling questions on the Russian economy, the crisis in Ukraine and Russian relations with the west. VOA's Jeff Custer reports.
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 Detained Turkish Journalists Follow Teachings of US-Based Preacher

The Turkish government’s jailing of critical journalists has sparked international condemnation and is being seen as an effort to undermine the followers of an ailing Turkish preacher based in the United States. VOA religion reporter Jerome Socolovsky has more.
Video

Video Will Pakistan School Shooting Galvanize Pakistan Against Extremism?

The attack on a military school in Pakistan’s northwest city of Peshawar left 141 dead, including 132 children. Strong statements of condemnation poured in from across the world. The country announced three days of mourning, and the leadership, both political and military, promised retribution. VOA's Ayesha Tanzeem looks at how likely the Pakistani government is to clamp down on all extremist groups.
Video

Video ‘Anti-Islamization’ Marches Increase Tensions In Germany

Anti-immigrant rallies in Germany have been building in recent weeks, peaking Monday night in the city of Dresden where tens of thousands of people turned out to demonstrate against what they call the ‘Islamization’ of the West. Germany has offered asylum to more Syrian refugees than any other country, and this appears to have set off the protests. Henry Ridgwell reports from London.
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.
Video

Video Refugees Living in Kenya Long for Peace in the Home Countries

Kenya is host to numerous refugees seeking safe haven from conflict. Immigrants from Somalia face challenges in their new lives in Kenya. Ahead of International Migrants Day (December 18) Lenny Ruvaga has more for VOA News from the Kenyan capital.
Video

Video Turkey's Authoritarianism Dismays Western Allies

The Turkish government has been defiant in the face of criticism at home and abroad for its raids targeting opposition media. The European Union on Monday expressed dismay after President Recep Tayyip Erdogan lashed out at Brussels for criticizing his government's action. Turkey's bid to be considered for EU membership has been on hold while critics accuse the NATO ally of increasingly authoritarian rule. Zlatica Hoke reports.

All About America

AppleAndroid