by Stuart Tomlinson, KATU News

Even before her first birthday, Kristin Kelly Bretanas parents noticed a fluttering in her eyes. As she grew, Bretana said she was accident-prone and had trouble seeing colors.

I have difficulty seeing far away, and I have difficulty with a lot of light saturation and Im almost completely color blind, Bretena said. And I say almost because there are certain situations where I can see a color if the saturations high enough.

Eventually her doctors gave her the news: She had achromatopsia, a rare genetic disease that results when you have a mutation in a gene that codes for a protein thats very important for the function of the cones.

To see, our retinas use rods and cones. Rods we use at nighttime and in dim light, cones are what we use during the daytime and for our color vision, says Dr. Mark Pennesi, OHSU Associate Professor of Ophthalmology whos now treating Bretana for the disease with gene therapy.

With achromatopsia the rods are actually ok, but the cones have no function at all," Pennesi said. "These patients have severe vision loss, theyre legally blind and they have no color vision at all. When they go outside they can barely see. They have to wear very dark sunglasses, but in dim light they actually see very well.

Pennesi said by taking a modified virus and stripping out all the things that make you sick, doctors then inject a normal copy of the missing or diseased gene back into the eye. The modified gene can then perhaps either stop the progression of the disease, or even restore function.

We actually go inside of the eye with a very, very fine needle and create a little pocket of fluid underneath the retina and inject that modified virus, Pennesi said. The virus then attaches to the retinal cells and inserts that DNA into the cells so they can start making the protein again.

Bretana said she has come to accept her limitations.

Its something I am not allowed to forget whether it be crossing the street and realizing that I am putting my life into a persons hands who is driving down the road because I cannot see inside the cab of a car, she said. It doesnt bother me nearly as much as it used to when I was a child and struggling with issues like self-identity and self-efficacy and what-not.

Pennesi said the therapy can be used for other diseases of the eye. OHSU currently has 7 gene therapy studies underway.

Its actually a very exciting time because many of these patients for decades have been told theres nothing that can be done, Pennesi said.

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OHSU gene therapy studies offer hope - and vision - to patients with eye disease - KATU