FDA Grant Expands Foundation-Funded Study of Retinal Imaging Technology

September 26, 2012

One of the biggest challenges in moving a potential treatment for an inherited retinal degeneration through a clinical trial is determining in a relatively short amount of time, perhaps a year or two, if it works to preserve vision. That’s because diseases like retinitis pigmentosa (RP) often progress slowly enough that it can take several years for measurable changes in vision to occur.

A four-year, $1-million-dollar grant from the Food and Drug Administration (FDA) to Drs. Jacque Duncan and Austin Roorda, two researchers funded by the Foundation, may help solve that problem. The University of California-based researchers are developing the Adaptive Optics Scanning Laser Ophthalmoscope (AOSLO), which captures images of individual cones, the retinal cells that provide central vision and the ability to perceive color and detail.

With help from AOSLO, Drs. Duncan and Roorda have shown evidence that one treatment’s positive effects on the number and health of cones happen sooner than vision changes. This makes AOSLO a potentially valuable tool, because it can measure outcomes in clinical trials for emerging therapies more quickly than other available technologies can.

Video: Cones, captured live, on a video shot via the Adaptive Optics Scanning Laser Ophthalmoscope.

The treatment in question is Neurotech’s encapsulated cell technology (ECT) — an implantable device that provides sustained delivery of a protein called ciliary neurotrophic factor (CNTF). It was designed to slow vision loss in people with RP, Usher syndrome and other retinal degenerations, such as choroidermia. Researchers were unable to detect preservation of visual acuity or peripheral vision in earlier Phase II/III clinical trials of the ECT for people with those conditions.

However, using AOSLO in a three-person follow-up study, Drs. Duncan and Roorda determined that eyes with the ECT showed no significant cone loss over a two- to three-year period. Inspired by the results from their study, the researchers applied for and received funding from the Foundation Fighting Blindness for a 10-person AOSLO investigation of the ECT. The new FDA award enables the investigators to include 20 more participants in their project.

The researchers’ ultimate goal is to get the FDA to validate AOSLO as an endpoint in future clinical trials for retinal degeneration treatments.

“We are very excited about the potential for AOSLO as an outcome measure in clinical trials,” says the Foundation’s chief research officer, Dr. Stephen Rose. “Measuring changes in vision over time in human studies has always been a struggle. But by being able to look at individual photoreceptors, we have a much more sensitive, granular view of what a treatment is doing and can more quickly determine its long-term potential for saving sight.”

Neurotech continues to evaluate the ECT in human studies for achromatopsia and macular telangiectasia.

The ECT did stabilize vision in an earlier Phase II clinical trial for people with dry age-related macular degeneration.

Video, above, courtesy of Dr. Jacque Duncan, University of California, San Francisco, and Dr. Austin Roorda, University of California, Berkeley.