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In the new approach, microparticles with neuroprotective effects are injected into the vitreous jelly of the eye where they slowly dissolve, preserving the retina in the face of damaging conditions or cellular degeneration. "This strategy does not rebuild the retina the way stem cells hopefully will, but it is aimed at slowing or halting disease progression," says DEF-funded researcher Dr. Henry Klassen, assistant professor and director of the Stem Cell and Retinal Regeneration Program in the Department of Ophthalmology at UC Irvine.

Intercontinental approach

Klassen has been working with researchers at the University of Copenhagen on the drug-delivery system to combat optic-nerve degeneration in animal models. They found the new method not only preserved the nerve cells that make up the optic nerve, but that those preserved cells remained functional. The results inspired the group to consider trying the new method in humans.

Researchers at the Vision Institute of the Federal University of São Paulo, led by Prof. Rubens Belfort Jr., have been working with similar delivery systems for different retinal diseases, primarily involving inflammation. Using the technology developed by Klassen and his collaborators, the Brazilian team began a Phase 1 safety trial on patients with retinitis pigmentosa (a type of inherited photoreceptor degeneration). According to Klassen, the trial patients were chosen for two main reasons: 1) they were already severely affected by eye disease, which is prudent from a safety standpoint, and 2) there was evidence in animals that the new technology would work for either the optic-nerve cells (retinal ganglion cells) or the photoreceptors.

The trial is set to finish in mid 2009. "Early indications suggest a modest but welcome regenerative influence," Klassen says.

Novelty and the future

Previous methods had shown some limited ability to preserve the retina, but the current method has been developed to allow prolonged delivery of the medicine.

The real novelty, according to Klassen, is to get this technology working in a patient. "People have thought about doing something like this for decades, but few efforts have gone very far," he says. "It is challenging to bring it all together: the right agent and the right formulation and the right type of patient."

If all goes well in the Brazil trial, Klassen says, "We'll be considering larger trials that will tell us more about efficacy, and we'll be considering expanding to other retinal conditions - not only photoreceptor degeneration, but optic-nerve diseases, as well."

Researchers hope to bring results to the United States as soon as possible, but like everyone else, they are worried about funding in the current economic climate.

"The expansion of this promising work will depend, in part, on finding funding," Klassen says. "Here it is we've got something good going, and it's right when the bottom is dropping out of the economy. It's a concern."

It's a concern of which DEF is well aware. "At the Discovery Eye Foundation, we are proud of our role in supporting translational research by leading scientists such as Dr. Klassen," says Dr. Anthony Nesburn, medical director of DEF. "They are finding new ways to help patients with sight-robbing diseases such as macular degeneration, retinitis pigmentosa and glaucoma." -Lauren Hauptman