The Johns Hopkins Gazette: November 26, 2001
November 26, 2001
VOL. 31, NO. 12


APL Licenses International Rights to Retinal Treatment Method

Johns Hopkins Gazette Online Edition

The Applied Physics Laboratory has licensed the international rights to a patented method for diagnosing and treating age-related macular degeneration--a leading cause of vision loss--to Novadaq Technologies Inc.

The multiyear licensing agreement enables Toronto-based Novadaq to develop a process and technology known as dye-enhanced photocoagulation, which was invented by a former APL researcher, and sell the resulting product in markets outside the United States. The agreement, negotiated by APL's Office of Technology Transfer, also forges a strategic alliance in which Novadaq can work with APL's Institute for Advanced Science and Technology in Medicine to develop innovative medical technologies.

"This alliance and agreement with Novadaq presents a tremendous opportunity for the Applied Physics Laboratory to extend its capabilities to additional critical areas of biomedical research, starting with this technology addressing a very serious retinal disease," says Steve Yanek, interim director of the Institute for Advanced Science and Technology in Medicine.

Age-related macular degeneration, which affects about 15 million people in the United States alone, is the leading cause of vision loss in people over age 60. Dye-enhanced photocoagulation addresses the "wet" form of AMD, which occurs when tiny blood vessels begin to grow under the central part of the retina, called the fovea. These new, abnormal vessels can leak fluid and distort a person's central vision.

Currently, doctors can treat a small number of early wet AMD cases with laser surgery called photocoagulation. After using a special dye and optical camera to find the leaking vessels, a doctor blasts the area with a high-energy laser. But since the procedure also damages the tissue around the target vessels, doctors can treat only leaks that develop away from the central part of the macula. Another drawback is that the laser targets only the capillaries closest to the retina's surface, not the "source" vessels, so there's a good chance the capillaries could grow back.

APL's dye-enhanced photocoagulation aims to do what today's technology can't, by combining diagnostic and treatment equipment in one device designed to help doctors find and permanently seal off these abnormal vessels. For this procedure, a doctor injects a small amount of fluorescent indocyanine green dye into the patient's arm. A laser scans the back of the eye beneath the retina, causing the circulating dye to fluoresce and allowing the doctor to identify on a high-resolution computer screen the source of the blood feeding the leaking vessels. The doctor then focuses a second laser directly on the feeder vessel and gives the patient a second injection of concentrated dye. The treatment laser is fired at the precise moment the dye passes through the feeder vessel, destroying it without harming the overlying retinal area.

Rick Mangat, president of Novadaq Technologies, says, "This technology is similar to our current product being developed for coronary artery imaging in that it makes use of the unique properties of indocyanine green, so it greatly complements and strengthens our core competencies. Also, the expertise we can now tap into at APL will significantly enhance our research and development capabilities."

Novadaq Technologies, founded in April 2000, is a privately held company that was spun off from the Canadian National Research Council's Institute for Biodiagnostics.

APL formed the Institute for Advanced Science and Technology in Medicine in 1995 to establish the Laboratory as a center of excellence in biomedical and health care systems research, development and education.