Ophthalmology & Visual Sciences at the Eye Institute

Medical College of Wisconsin Eye Institute Named NAC Attack AOSLO Reading Center and Clinical Trial Site

The Medical College of Wisconsin Eye Institute will serve as the adaptive optics scanning laser ophthalmoscopy (AOSLO) Reading Center for a new clinical trial, “NAC Attack: a phase III study of the efficacy and safety of oral N-Acetylcysteine (NAC) in patients with Retinitis Pigmentosa (RP).” The AOSLO Reading Center will be led by Dr. Jacque Duncan at the University of California San Francisco and Dr. Joe Carroll at the Medical College of Wisconsin.

RP is an inherited retinal genetic disease resulting from one or more genetic mutations that make the photoreceptors in the eye break down over time, causing vision loss. NAC is a drug that helps reduce oxidative stress that researchers hope will provide protection for the photoreceptors in the eye. In an earlier short-term clinical trial, NAC appeared to be well tolerated and may improve sub-optimally functioning cone photoreceptors. The current phase III trial aims to determine the long-term safety of NAC and determine whether oral NAC can slow photoreceptor loss and thus delay visual function loss in patients with RP.

“This is one of a growing number of clinical trials using adaptive optics imaging (AOSLO) as an exploratory outcome,” says Dr. Carroll. “AOSLO allows us to visualize the living retina with single-cell resolution, meaning we can detect changes in photoreceptors before such changes impact more global clinical measures of retinal structure or function.”

“The Dennis P. Han, MD Advanced Ocular Imaging Program (AOIP) has allowed us to create a unique infrastructure to support these important clinical trials.”

The Eye Institute will also serve as a site for the clinical trial being coordinated by Johns Hopkins University, and Dr. Thomas Connor will serve as local Principal Investigator at MCW.

The five-year project will be funded by the National Institutes of Health.

In an earlier study that surveyed patients’ attitudes toward a study over four years to test an oral medication to slow or stop vision loss caused by RP, crowdsourcing showed that enthusiasm was high for participating in a clinical trial that may find an effective treatment for RP.

“We are honored and excited to have been chosen as a clinical trial site for this landmark study, the largest of its kind for RP. It is a potential game changer. And we are thrilled to partner with our colleagues at the MCW AOIP to offer AOSLO cutting edge imaging to the participants in this trial,” says Dr. Thomas Connor.

“Despite many previously suggested treatments, there is no actual effective therapy for RP. If the clinical trial is successful, NAC would be the first drug treatment for RP, a disease with no known cure.”