Revolutionary gene replacement surgery restores vision in patients with retinal degeneration

More than a year after becoming one of the first medical institutions nationally to complete a revolutionary gene replacement surgery to restore vision in patients with retinal degeneration, surgeons at the of The Vision Center at Children's Hospital Los Angeles (CHLA) have successfully completed the procedure on an additional 13 patients.

The outcomes of two of those patients, San Diego residents Monroe Le, 6, and Heather Hodlin, 25, were chronicled on the recent ABC News Nightline episode, "Miracle of Sight."

Photos of Monroe and Heather are available upon request at [email protected]

We have found that using gene therapy to treat this condition can be life-changing for children under the age of 10. While they are not going to have normal vision, we can improve it to a degree that they can do activities they couldn't do before, like playing outside at night. They gain greater visual clarity of edges on objects, so they can draw and enjoy picture books, and play with toys like puzzles and Legos."

CHLA surgeon Aaron Nagiel, MD, PhD

The breakthrough one-time treatment replaces a defective gene called RPE65 located in the retina, the membrane at the back of the eye that detects light and color, with a healthy copy made from artificial DNA, the equivalent of human DNA. RPE65 is responsible for producing a protein that makes light receptors work in the eye.

Of the seven hospitals nationwide originally approved to deliver this therapy to patients, CHLA was the only program with two full-time, dedicated pediatric retinal surgeons on site -; Nagiel, and Thomas C. Lee, MD, director of The Vision Center at CHLA and associate professor of ophthalmology at the USC Roski Eye Institute. CHLA also is home to the Center for Personalized Medicine, where a laboratory certified by the Clinical Laboratory Improvement Amendments (CLIA) can do the necessary genetic testing for potential patients to determine if they have the defective RPE65 gene.

"We are pleased to be able to offer this therapy that can truly impact a patient's quality of life and, potentially, help them see their future through 'new eyes'," said Lee.

CHLA has performed the procedure on nine children, as young as age three, and a handful of adults. While results have been less dramatic with adult patients – the inherited disease manifests itself early in childhood and gets worse over time, leading to total blindness – eyesight improvement is largely contingent on how far the condition has advanced. "For adults the clock has been ticking and cells have been dying over time," explains Nagiel, an assistant professor of Ophthalmology at Keck School of Medicine of USC. "We want to save what they have but the treatment is allowing them to see and experience things they haven't done before."